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The present invention relates to a recording medium and a recording and reproducing system for the recording medium.
Heretofore, there is known the DVD (digital versatile disc),the DVD-R (DVD WRITE ONCE) and the DVD-RW (DVD-Re-Writable) as the rewritable disc.
As shown in the Japanese Patent Laid-Open Publication No. 9-17029, the DVD-R or DVD-RW (hereinafter called DVD) has a spiral or co-axial groove for recording information, a land between the grooves and a plurality of land prepits formed between the grooves. The land prepit is provided with various sets of information such as the address.
In such a disc, it is possible to read the information recorded on the groove and the information recorded on the land prepit at the same time.
However, there is a problem that signals reproduced from the information recorded on land prepits affect the RF signal reproduced from the information recorded on the groove as offset. | {
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Stroke is the third most common cause of death in the United States and the most disabling neurologic disorder. Approximately 700,000 patients suffer from stroke annually. Stroke is a syndrome characterized by the acute onset of a neurological deficit that persists for at least 24 hours, reflecting focal involvement of the central nervous system, and is the result of a disturbance of the cerebral circulation. When a patient presents with neurological symptoms and signs which resolve completely within 1 hour, the term transient ischemic attack (TIA) is used. Etiologically, TIA and stroke share the same pathophysiologic mechanisms and thus represent a continuum based on persistence of symptoms and extent of ischemic insult.
Outcome following stroke is influenced by a number of factors, the most important being the nature and severity of the resulting neurologic deficit. Overall, less than 80% of patients with stroke survive for at least 1 month, and approximately 35% have been cited for the 10-year survival rates. Of patients who survive the acute period, up to 75% regain independent function, while approximately 15% require institutional care.
Hemorrhagic stroke accounts for 20% of the annual stroke population. Hemorrhagic stroke often occurs due to rupture of an aneurysm or arteriovenous malformation bleeding into the brain tissue, resulting in cerebral infarction. The remaining 80% of the stroke population are hemispheric ischemic strokes and are caused by occluded vessels that deprive the brain of oxygen-carrying blood. Ischemic strokes are often caused by emboli or pieces of thrombotic tissue that have dislodged from other body sites or from the cerebral vessels themselves to occlude in the narrow cerebral arteries more distally. The internal carotid artery, commonly affected by atherosclerosis causing symptomatic occlusion in the arterial lumen, is often responsible for hemispheric ischemic stroke and generating thromboembolic material downstream to the distal cerebral vessels. Treatment of the occluded carotid artery in patients with stroke and TIA or for stroke prevention in patients with asymptomatic flow limiting carotid stenosis undergoing major cardiothoracic surgeries includes performing angioplasty, stent placement, or atherectomy on the occluded carotid artery. Unfortunately, placing instrumentation within a diseased carotid artery is associated with increased risk of ischemic stroke, since manipulation of an atheromatous plaque in the arterial wall often causes emboli to dislodge distally in the narrow cerebral arteries.
Current methods of preventing distal embolization from carotid instrumentation include insertion of a blood filter distal to the occlusion and suctioning embolic debris during the procedures. Disadvantages associated with the conventional methods are that (1) inserting the filter through the atheromatous lesion is associated with increased risk of distal embolization, (2) using suction to reverse the flow in the internal carotid artery may increase a patient's blood loss if the suctioned blood is discarded, and (3) systemic anticoagulation and pumping may be required to recycle the suctioned blood back into the arterial or venous system, and such anticoagulation is associated with increased risk of hemorrhage.
New devices and methods are thus needed in patients undergoing carotid procedures for definitive or prophylactic treatment of carotid plaque, which minimize the risk of distal embolization and prevent ischemic stroke. | {
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1. Field of the Invention:
The invention relates to CATV systems, and more particularly to a method and apparatus for selectively jamming selected channels to selected subscribers in a CATV system.
2. Description of Related Art:
CATV systems commonly provide a multiple of channels to their subscribers; such systems are well known in the art and have been for many years. Many CATV systems, however, do not require each of their subscribers to subscribe to every one of the channels they offer. The result is that an effective method, and apparatus to carry out that method, is needed to allow a CATV system to provide different numbers of channels to different subscribers, and at the same time retain the ability to provide up to all of their channels to up to all of their subscribers. It is even more desirable for a CATV system to be able to easily change the number of channels it is providing to any, of its subscribers, at any time, and from time to time. That is generally desirable because most CATV systems charge different amounts to their various subscribers, depending on how many of the supplied channels the particular subscriber wants to receive, and those features allow a subscriber to easily change the number of channels he receives. The result is that with those features a CATV system can easily sell additional channels to its subscribers, or stop sending channels to subscribers who do not want them or are not paying for them.
Scrambling and de-scrambling systems have been developed and are used by some CATV systems to control which channels a particular subscriber receives. Certain channels are scrambled prior to transmission from the supplier's head end, and subsequently de-scrambled at the home ends of those subscribers who have paid for those scrambled channels. A device commonly referred to as a de-scrambler is installed in the paying subscribers homes, which restores the scrambled television signal. Those systems require access to the subscriber's home, and man power to do the installation, or to remove the de-scrambler in the event the subscriber no longer wants it, or has stopped paying the fee. Those systems also run the risk of channels being pirated by subscribers who have built, or purchased, their own illegal de-scrambler.
Another known means of controlling subscriber access to the total channels in a CATV system is to selectively jam the channels to be denied to the subscribers who have not paid for them. The jamming of channels is usually accomplished by sending a separate jamming signal for each of the channels to be jammed, together with the television signals, to the subscriber(s) for whom those channels are to be jammed. Each jamming signal can be a signal having a repetition rate close to the repetition rate of the vertical synchronization signal of the channel to be jammed, and of a greater amplitude. The television will pick up the jamming signal as the synchronization signal and will therefore produce a vertically unstable picture. Similarily, the jamming signal can be a signal having a repetition rate close to the repetition rate of the horizontal synchronization signal of the channel to be jammed, and of a greater amplitude. The television will then pick up the jamming signal as the horizontal synchronization signal and will therefore produce a horizontally unstable picture.
A device is required that will not only produce the required jamming signals, but also, will only combine the jamming signals with the television channel signals going to the subscriber(s) who have not paid for those channel.
Some of the earlier prior art has used one separate line per subscriber, and one RF switch per subscriber, per channel that might be jammed. The separate subscriber lines are each coupled to a different RF switch for each channel that might be jammed, thereby creating a switch and subscriber line matrix in which each subscriber line has a unique RF switch for each channel that might be jammed, controlling that subscriber's access to said channel, and in which all RF switches controlling subscriber access to a particular channel are connected to each other. For example only, if the situation is that channel "C" is to be jammed to subscribers "101", "222", and "223", each of the channel "C" RF switches that couple the jamming signal to those subscriber lines must be closed. Accordingly, if there are 2500 subscribers and 4 channels to be jammed, 2500 separate subscriber lines are needed, and (4.times.2500)=10,000 RF switches are required. Accordingly, a large number of RF switches are required. In such a system it would be difficult to add further subscriber lines and switches to the switch and subscriber line matrix.
Some of the more recent prior art use apparatuses that are capable of generating up to a fixed number of different jamming signals, (for example the maximum might be 6) sometimes continuously, and sometimes on a time divisional basis. In some of the more sophisticated present art systems the jamming signals are added on a time shared bases to the subscribers lines who are not permitted to view the particular channel being jammed. In many of the more sophisticated prior art systems that add jamming signals to subscriber lines on a time divisional basis the maximum number of jamming signals that can be generated is eight or less. Therefore, the maximum number of channels that can be jammed is eight or less. That is obviously a problem for a CATV system that wants to offer nine or more alternative channels.
A number of difficulties have to be overcome when jamming signals are not continuously added to the appropriate subscriber lines. However, the benefits of adding jamming signals to the appropriate subscriber lines on a time divisional basis are great. Therefore it is worth the effort of trying to overcome the difficulties involved in time divisional jamming. A major benefit to time divisional jamming is that only one line can be used to carry all of the different jamming signals to one subscriber. Only one line has to be used, because when the jamming signal being transmitted is to jam a channel the subscriber is not entitled to receive, then the RF switch to that subscriber's single jamming signal line is closed, hence the subscriber receives the jamming signal, and that channel is jammed on the subscriber's television set. However, when the jamming signal being transmitted is to jam a channel the subscriber is entitled to receive, then the RF switch to that subscriber's single jamming signal line is left open, hence the subscriber does not receives the jamming signal, and that channel is not jammed on the subscriber's television set. The result is that the channel is jammed during the time its jamming signal is being transmitted, but not during the time it's jamming signal is not being transmitted. Therefore, if the time between transmissions of the same jamming signal is too great, the channel will only be jammed sometimes, hence it would be partly viewable. It should therefore be a goal of time divisional jamming systems to reduce the time between transmissions of the same jamming signal so that the channel is humanly unviewable.
It is more desirable to produce a horizontally unstable picture than a vertically unstable picture, as the former is more difficult to watch. To produce a horizontally unstable picture the jamming signal must be sent to each subscriber who is to be jammed by it many thousands of times per second, thereby effectively always jamming the television signal. To accomplish transmitting different jamming signals on the same line many thousands of times per second, rapid switching is required; rapid or continuous generation of the jamming signals is also required, and finally, the rapid switching and the jamming signals must be combined correctly to the appropriate subscribers. Those skilled in the art will perceive many problems in rapidly switching between frequencies and maintaining accuracy of frequency within a small range.
Some of the more sophisticated prior art systems have used fixed inductive circuits which are alternately coupled with an oscillator to generate different frequencies through that oscillator. Some of the other more sophisticated prior art systems have used a voltage controlled oscillator to generate the different jamming frequencies on a time divisional basis. The goals in the prior art have generally been to effectively jam the largest number of channels with the least amount of expensive components, while at the same time allowing for control of what channels are jammed to which subscribers, from the head end, with a minimum of equipment malfunction. The goals of the present invention are the same as the stated generally accepted goals in the prior art. The present invention accomplishes those goals in a new and effective way not contemplated by the prior art, and for a greater number of channels than the prior art inventions of which the Inventors of the present invention are aware. | {
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In order to explain the prior art and the present invention, an equivalent logic circuit according to an example register comprised of latches will first be described with reference to FIG. 5. As shown, the register 1 comprises two latches 1a and 1b, a selector 1c for selecting an input, and OR gates 1d and 1e for respectively feeding two kinds of clocks to the latches 1a and 1b, and further has a data input terminal 1f, a scan input terminal 1g, a mode change input terminal 1h for changing the mode between normal mode and scan mode, clock input terminals 1i and 1j, scan clock input terminals 1k and 1l, a data output terminal 1m and a scan output terminal 1n which may also serve to output data. When the latch 1b is exclusively used for scanning purposes, the OR gate 1e and the clock input terminal 1j will be unnecessary.
FIG. 6 is a block diagram showing an arrangement of a scan path used in the conventional data processing unit. As shown, reference numeral 8 indicates an LSI, or printed circuit board, or a combination thereof which may constitute the data processing unit. The system 8 has a plurality of registers 1 as described above, reference numeral 2 denoting a scan input terminal, 3 a scan output terminal, 4 an input terminal for changing the mode between normal mode and scan mode, 5 a scan A clock input terminal, and 6 a scan B clock input terminal. Registers 1 are each connected to each of the input and output terminals as shown while the scan output terminal 1n of a preceding stage register 1 is sequentially connected to the scan input terminal 1g of the next stage register 1 to form a scan path.
The operation of the above-described system is described hereinafter by referring to FIGS. 5 and 6. The operation is split into normal and scan modes. These modes are switched in accordance with the value applied to the mode change input terminal 4 which may be controlled by a service processor.
In normal mode, each clock applied to the scan A clock input terminal 5 and the scan B clock input terminal 6 are set to be turned off. Data are set into the latch 1a from the data input terminal 1f of each register via the selector 1c by the clock from the clock input terminal 1i. If the OR gate 1e and the clock input terminal 1j are present and a clock has been fed to this clock input terminal 1j, the value in the latch 1a is transferred to the latch 1b.
In scan mode, A clock and B clock which alternately into a significant state are applied to the scan A clock input terminal 5 and the scan B clock input terminal 6 respectively, and accordingly the scan clock input terminals 1k and 1l of each register 1 are alternately switched into a significant state. As the same time, scan data is applied thereto from the scan input terminal 2 and is passed through the scan input terminal 1g, and the latches 1a and 1b of the first stage register 1 are sequentially set to the latches 1a and 1b through the scan input terminals 1g of the next stage register etc. At the same time, the value of each register 1 is transmitted through the scan output terminals 1n and 3 to be taken out to the exterior. During the scan, the clocks set to off-state.
Meanwhile, a reset operation is conducted as follows. The clocks applied to the clock input terminals 1i and 1j of each register 1 are previously set to off-state, the mode change input terminal 4 is set to the scan mode and the scan input terminal 2 is set to "0". Next, the clocks applied to the scan A clock input terminal 5 and the scan B clock input terminal 6 are both set to on-state. Since the data directly passes through the latch when the clocks are turned on, "0"input from the scan input terminal 2 will be sequentially transmitted through the registers 1. Since the propagation speed is only retarded by the gate delay, the reset operation can be processed at a speed 100 to 1000 times as high as in the above-described scan mode operation where the clocks are alternately applied. After the value of "0" has been propagated to all of the registers 1, the clocks applied to the scan A clock input terminal 5 and the scan B clock input terminal 6 are turned off, and all of the registers 1 are set to "0" and the reset action is completed.
Since the conventional reset system has the arrangement described above, resetting all registers to "0" can be done at high-speed, but it has been necessary when resetting to a pattern including "1" to resort to an operation of applying the clocks alternately, as described-above, which has made it difficult to achieve a fast reset action. In general, if odd parity is used as a parity bit, the need arises to reset to a pattern including "1". | {
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Three-dimensional graphics processing pipelines accept commands from a host (such as a central processing unit of a computing system) and process those commands to generate pixels for display on a display device. Graphics processing pipelines include a number of stages that perform individual tasks, such as transforming vertex positions and attributes, calculating pixel colors, and the like. Graphics processing pipelines are constantly being developed and improved. | {
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High speed links employ sophisticated analog circuits and logic in order to achieve performance targets and in many cases utilize a plurality of calibrated local clocks in order to transfer data while maximizing data transmit and capture margins. Phase rotator circuits are commonly used to produce the plurality of local clocks. Phase rotators act as clock phase mixers and provide a mechanism of creating, manipulating, and calibrating tightly timed clock edges from a much smaller set of high accuracy root phases. For example, a phase rotator may be designed to provide 128 output phases using just 16 selectable input phases. Further, the compact nature of the phase rotator structure allows for a plurality of phase rotators to be placed within the high speed link. For example, a DDR data link may be implemented with separate Rx (read) and Tx (write) clock phase rotators for each data bit/lane, and provided with additional phase rotators for digital synchronization and calibration.
Manufacturing defects have the potential to totally disable a phase rotator and, as such, it is common to test for such defects. However, it can be very difficult to ensure no manufacturing defects exist in a phase rotator design. A manufacturing tester normally does not have fine enough resolution to discern whether a phase rotator is properly operating at its functional speed since the manufacturing tester typically operates at a slower speed than the phase rotator operates. Also, some manufacturing testers do not have fine enough granularity to discern the individual step increments of a phase rotator. As a result, the quality of the manufacturing test is reduced to match the quality of the manufacturing tester or test-only logic is inserted into the design. This is counterproductive since reducing the quality of the manufacturing test may lead to defective parts being released from the manufacturer, and inserting test-only logic onto the design increases area and power demands. | {
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The present invention relates to a Francis-type runner, and, more particularly, to the contour of a runner blade at the runner entrance.
In general, a Francis-type runner comprises a crown ring, a shroud ring and a plurality of runner blades interconnected therebetween. Pump-turbines having conventional Francis-type runners have dual characteristics of operation in which two efficiencies correspond with a given rotational speed of the runner within a predetermined range during the operation of the turbine when the opening of the runner blade remains constant.
The reason for the dual characteristics of operation is that flowing water is separated from the runner blades on the side of the crown ring at the runner entrance. That is, if consideration is given to the case where the rotational speed of the runner and the angle of the absolute velocity of water entering the runner are maintained constant and the head of water is reduced, the direction of the relative velocity of water flow at the runner entrance forms a large negative angle relative to the working surface of the runner blade because the flow rate of the entering water is decreased. Consequently, flowing water does not flow smoothly at the working surface of the runner blade and is separated therefrom.
As described above, when the phenomenon of the separation of flowing water occurs, the flow rate of flowing water or the work done on the working surface of the runner blade is changed, thereby increasing or decreasing the efficiency of the pump-turbine. | {
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1. Field of the Invention
The present invention relates to a Low Drop-Out (LDO) voltage regulator with efficient frequency compensation, and more particularly, to a LDO voltage regulator that adjusts output capacitance to fix frequency of a pole according to current variation of a back-end load.
2. Description of the Prior Art
A linear voltage regulator has ability to provide a stable output voltage. A Low Drop-Out (LDO) linear voltage regulator is further able to generate an output voltage very close to an input voltage, so as to save power consumption of power transistors and increase battery life. Thus, the LDO voltage regulator is widely used in various portable electronic products, such as music players, digital cameras, mobile phones, notebook computers, and so on.
Please refer to FIG. 1, which shows a schematic diagram of a conventional LDO voltage regulator 10. The LDO voltage regulator 10 includes an error amplifier 110, a transmission element 120 and an output capacitor Cout, and mainly operates by utilizing a voltage divider 130 to generate a feedback voltage VFB for the error amplifier 110 to control the transmission element 120 according to difference between the feedback voltage VFB and a reference voltage VREF, so as to generate stable output voltages. Additionally, the output capacitor Cout is utilized for providing current temporarily required by a back-end load to improve transient response of the output voltage when load current Iload of the back-end load is changed suddenly.
Generally, loop stability is an important issue in the design of the LDO voltage regulator. In a traditional circuit structure, the load current and the output capacitor are two major factors affecting the loop stability. By establishing a small signal circuit model of the above LDO voltage regulator, it can be found that the circuit loop mainly has two poles, which relate closely to the design of the loop stability. A dominant pole is generated by a parasitic capacitor formed between the error amplifier and the transmission element and output impedance of the error amplifier, and can be expressed as:
fp 1 ≈ 1 2 π × Roe × Cpar ,in which Roe and Cpar represent the output impedance of the error amplifier and the parasitic capacitor between the error amplifier and the transmission element, respectively. A second pole is generated by the output capacitor and output impedance of the LDO voltage regulator, and can be expressed as:
fp 2 ≈ 1 2 π × Ro × Cout ≈ λ × I load 2 π × Cout ,in which Ro and λ represent the output impedance of the transmission element 120 and a channel length modulation coefficient, respectively.
As can be seen in the above, when the load current Iload varies, frequency of the second pole will drift while the other pole remains unchanged. However, since the frequency drift may significantly change frequency response of the LDO voltage regulator, loop instability may occur due to insufficient phase margin in some situations.
In short, the LDO voltage regulator may suffer problems of loop instability when the load current varies. | {
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This invention relates to the addition of trace amounts of metal to a melt.
It is particularly concerned with the addition of a metal from Group 1A of the Periodic Table to a melt of another metal, e.g. aluminium or zinc. Thus the Group 1A metal may be, for example sodium or lithium.
The invention is most preferably concerned with the addition of sodium to molten aluminium or an aluminium alloy and, although it will be appreciated that it is not intended to be limited thereto, it will be described for convenience below with specific reference to those metals.
The addition of trace amounts of sodium, e.g. amounts less than about 200 ppm, to an aluminium melt is well known. It can result in improved quality of castings and the castings can be more easily removable from the mould and subject to a reduction in shrinkage.
Conventionally, sodium has been added to the aluminium melt in metallic form as sticks or in aluminium cans or in the form of tablets of a sodium compound and while these methods have the advantage of simplicity they are very inefficient. Owing to the violence of the reaction that occurs much of the added sodium is lost by oxidation and considerable smoke generation is caused. Frequent additions are, therefore, necessary and the method is very wasteful, environmentally unfriendly and cannot provide a controlled amount of effective addition.
A method of overcoming these disadvantages is disclosed in EP-A-0688881. This teaches a method of adding sodium to a melt of aluminium or aluminium alloy in which an electrode comprising molten sodium or a molten sodium compound is immersed in the aluminium melt and is separated from the melt by a solid-state electrolyte which conducts sodium ions. A direct voltage is provided between that electrode and the melt by the provision of a second electrode in the melt. While providing a number of advantages in principle, this technique can lead to problems in the melt, e.g. if there is any failure of the solid-state electrolyte container.
It is an object of the present invention to provide a further improved means of metal addition.
Accordingly, the invention provides a method of adding a metal to a melt of a material in a vessel, in which a molten compound of the metal or a solution of a compound of the metal is provided in a container, the container being positioned outside the vessel, the compound is electrolytically decomposed and ions of the metal are caused to pass through a wall of a solid-state electrolyte which is a conductor therefor, from a first side of the wall to an opposite second side thereof, and to combine with electrons at the second side of the wall and then to flow as molten metal from the container into the melt.
In another aspect the invention provides an apparatus for adding a metal to a melt of a material in a vessel, the apparatus comprising a container for a molten compound of the metal or a solution of the compound of the metal, the container being positioned outside the vessel, means to electrolytically decompose the molten or dissolved compound, a wall positioned inside the container and formed of a solid-state electrolyte which is a conductor for ions of the metal, whereby the metal ions formed can pass through the wall from a first side to an opposite second side thereof, a source of electrons at the second side of the wall to combine with the metal ions, and means to pass the molten metal so formed from the second side of the wall into the melt.
For embodiments of the invention in which the container is for a molten compound of the metal, the apparatus preferably includes means to heat the compound of the metal to molten form.
For embodiments of the invention in which a solution of a compound of the metal is used, the solvent is preferably an organic solvent, for example acetamide or glycerol. When a solvent is used, the invention preferably includes means for preventing substantial loss of the solvent through evaporation or boiling.
As indicated above, the melt in the vessel will normally be a metal melt, e.g. of zinc or, preferably, aluminium but it will be appreciated that the invention is applicable in principle to non-metallic melts.
Also as indicated above, the metal to be added to the melt will normally be a metal of Group 1A of the Periodic Table and the invention is particularly useful for the addition of sodium.
The metal compound is preferably an ionic compound but the invention is equally applicable to the use of non-conducting metal compounds. A mixture of a plurality of metal compounds (ionic or non-ionic) may be used.
Where the or each metal compound is ionic, current may be passed between a first electrode positioned in the molten compound and a second electrode positioned beyond or at the second side of the wall of the solid-state electrolyte, whereas if one or more non-conducting metal compounds is/are used, the first electrode should be porous and be positioned to lie on the first side of the wall.
Thus electrolytic decomposition of the metal compound is effected, molten metal being discharged at the second electrode and anionic species being discharged at the first electrode. The metal compound is preferably a metal salt, for example a metal hydroxide, carbonate or oxalate salt. The anionic species preferably discharge to form one or more gases, e.g. where sodium hydroxide is used as the metal compound, water vapour and oxygen are produced, and where sodium carbonate is used as the metal compound, carbon dioxide and oxygen are produced. (It will be appreciated that where water vapour is produced, it should normally be ducted away to prevent any possible contact with the melt in the vessel.)
At the start up of the process, priming may be needed at the second side of the wall of the solid-state electrolyte. This may be achieved by contact between the second side and the second electrode or by the provision of an amount of the molten metal.
The wall of solid-state electrolyte may conveniently form a container. In one embodiment this container also provides the container in which the metal compound is held. Thus the first electrode for the required passage of current extends into the metal compound in the container or lies on the interior (first side) of the wall. The metal ions, therefore, pass through the container wall to the outside, are discharged and liquid metal then passes from the outside of the wall via a passage to the melt in the vessel. In a second embodiment the container formed of solid-state electrolyte is positioned inside another container. This outer container may conveniently act as one of the electrodes for the required passage of current.
In this second embodiment the metal compound may either be contained in the inner solid-state electrolyte container or outside that container but inside the outer container. The metal ions then either flow through the wall of the inner container from the inside to the outside or vice versa and the electrical circuitry is arranged accordingly as desired. Liquid metal is, therefore, provided with a passageway from inside or outside the inner container, as appropriate, to the melt in the vessel.
The electrodes may be formed of any suitable electrically conducting materials. Thus the first electrode may be formed, for example, of nickel, stainless steel or graphite and the second electrode may be formed, for example, of nickel, iron or steel depending on the metal compound used.
Where the metal to be added to the melt is sodium, the sodium compound to provide the source of sodium ions may be, for example, as indicated above, sodium hydroxide or sodium carbonate. Whatever compound is used, it should preferably be compatible with the solid-state electrolyte, should preferably be non-toxic and should preferably produce harmless by-products.
Where it is desired to use sodium carbonate, it may be preferable to mix it with a proportion of sodium chloride to reduce the melting temperature of pure sodium carbonate from 858xc2x0 C. to, say, about 635xc2x0 C. for the mixture. (It will be appreciated that in these circumstances the chloride ions will not be discharged.) Similarly, where it is desired to use sodium hydroxide, it may be preferable to mix it with a proportion of sodium carbonate to reduce the melting temperature of pure sodium hydroxide from 322xc2x0 C. to about 285xc2x0 C. for the mixture.
Where the device is operated at an elevated temperature, care may need to be taken during the addition of metal compound to replenish that used up in the process, because thermal shock could, for example, damage the solid electrolyte. The fresh compound may, for example, be added at a steady slow rate, or the solid electrolyte may be constructed to withstand thermal shock. This may, for example, be achieved by ensuring that the electrolyte has a radius of curvature, preferably a small radius of curvature, in all areas in at least 2 directions. For instance, in the case of tubular shaped electrolytes, the diameter would be reduced to the smallest practical value. Also, solid electrolytes such as beta alumina may be toughened by including about 12% zirconia in its structure. However, the preferred method in the invention is to use a separate compartment where the fresh metal compound is heated to a temperature close to that of the liquid surrounding the solid electrolyte. In one embodiment of the invention solid sodium hydroxide is melted in a separate container and the molten salt from this container is fed to the electrolysis section to keep the molten salt level there at a reasonably constant level. In a second embodiment, an aqueous solution of sodium hydroxide is dropped into a container of molten sodium hydroxide. Rapid drying and melting of the solution results. Again, the drying compartment is preferably sufficiently separated from the electrolysis compartment to prevent the solid electrolyte being damaged by thermal shock or chemical attack by water.
The power supply for the electrolysis process frequently constitutes a major part of the total cost, so attention is preferably given to minimizing its power and size. The voltage requirement may be minimized by using an easily decomposed salt, and by ensuring that all current carrying parts are as short as possible and have the highest cross-sectional area that is practical. The current requirement can be reduced by eliminating intermittent operation of the device. Since metal is often required to be introduced into the vessel in an intermittent mode, the invention preferably includes means for storing a small amount of metal within the device until it is needed. A means is then also included to feed the stored and produced metal when required. However, metallic sodium and other group 1A metals present a safety problem, therefore the apparatus preferably includes means to ensure that the minimum amount of metal is present at any given stage of the addition process. For this reason pressurized inert gas is the favoured method for pumping the molten metal from the electrolysis compartment into the vessel. Where a secondary pumping system is used to move metal from the apparatus to the vessel, it is desirable to include a sensor for the flow of metal so that the flow can be set at an optimum rate. Such a sensor may also aid in the detection of blockages in the metal feed pipe, for example. In the case where gas pressure is used, one or more gas pressure gauges are preferably used.
The solid-state electrolyte for sodium addition is preferably of sodium beta alumina. Sodium beta alumina has a sodium ion conductivity similar to that of molten salts with a negligible electronic conductivity over a wide temperature range but any other suitable sodium ion conducting electrolyte may be used. The solid-state electrolyte for lithium addition is preferably lithium beta alumina although, again, any other suitable lithium ion conducting electrolyte may be used.
Thus it is possible by means of the present invention to control the addition of metal to a melt by controlling the charge across the solid-state electrolyte. The amount of material that is pumped through the solid-state electrolyte is determined by Faraday""s law. For 26.8 ampere hours one mole of monovalent ionised metal is pumped through the solid-state electrolyte.
A sensor for the added metal, e.g. for sodium, can be inserted into the melt and the addition of the metal monitored and controlled up to a predetermined, desired level.
It can then be maintained at that level without need to add excess, thereby significantly reducing waste and fume and dross production and these advantages are achieved without any risk of failure of a container within the melt.
A substantial amount of gas may be given off during the method, so that the arrangement of the first electrode should preferably be such as to minimise the effect of the gas on the electrolytic process. For example, gas produced by the electrolysis may have difficulty escaping between the anode and the electrolyte. The distance between the anode and the electrolyte may need to be a compromise between being sufficiently small to provide efficient electrolysis and sufficiently large to enable gas produced at the anode to escape. In one embodiment, use is made of the fact that gas produced at the anode will decrease the overall density of the source material (i.e. molten metal compound or metal compound solution) into which it discharges. This density difference is used to create a flow of source material between the anode and the source material in a direction which aids the removal of gas from this region. Additionally or alternatively, a pump can be used to circulate the source material and thus aid the removal of the gas. Advantageously, the anode may be gas permeable, for example porous. The first electrode may, for example, comprise a gas permeable electrically conductive layer on the solid-state electrolyte.
The arrangement of the second electrode relative to the container can be such as to minimise the inventory of molten metal. Alternatively, the molten metal can be produced electrolytically on a continuous basis and maintained in a reservoir between the container and the vessel and pumped through as and when required. The rate of electrolysis can thereby be boosted.
The first electrode may, for example, be generally in the form of a cylinder, preferably a hollow cylinder. Advantageously, the first electrode and the solid-state electrolyte may be shaped such that they are separated by an approximately constant minimum distance over substantially their entire opposing surfaces. This may substantially prevent the formation of a concentration of current at a particular point in the solid-state electrolyte, which could cause its premature failure. This is particularly important when the electrolyte is formed from beta alumina.
The apparatus of the invention preferably includes a control means, for example a timer and/or a monitoring means, which causes the molten metal compound or metal compound solution to be replaced periodically; the method of the invention preferably includes a step of replacing the molten metal compound or metal compound solution periodically. This periodic replacement (or xe2x80x9cflushing-outxe2x80x9d) of the molten metal compound or metal compound solution preferably substantially prevents the build-up of precipitates which may, for example, be formed from impurities or from reaction of the metal compound with air. For example, if sodium hydroxide is used as the source material for the metal (in this case, sodium), it may react with carbon dioxide in the air to form carbonate which will normally electrolytically decompose more slowly than the sodium hydroxide and may therefore build up with time and form a precipitate which could form a blockage. Alternatively, the production of carbonate may increase the melting point of the source material above the operating temperature, causing solidification which may prevent the source material contacting the first electrode.
As the container in the apparatus of the invention is positioned outside the vessel containing the melt, a wider range of operating temperatures of the container can be employed enabling a wider range of metal compounds to be used. In particular, the operating temperature of the apparatus may be minimized (compared to that of the melt vessel) thereby normally enabling the use of more economical materials and a simpler construction. Sealing of the system, if required, is also generally more easily implemented.
Moreover, the design of the apparatus of the invention avoids the thermal shock problems associated with the prior art designs where the container has to be immersed in the melt in the vessel and, particularly for aluminium melts, overcomes the problem that solid-state electrolytes are unstable in molten aluminium.
The apparatus preferably includes a conduit, for example a feeding tube, to transport the molten metal to the melt. The conduit may be fully enclosed so that the metal is isolated from the external environment, for example it may be submerged in the melt. This is particularly important for the addition of sodium, for example. The conduit may be a simple tube or the like, but it is preferably a rotor, for example as illustrated schematically in FIG. 5. The conduit may be formed from a refractory material, e.g. a ceramic material (alumina is one possibility), or it may be formed from a metal which has a higher melting point than the temperature of the melt, e.g. it may be formed from steel.
Alternatively, the apparatus may include means, preferably a pump, which conveys the melt material out of the vessel for addition of the metal to the melt material in a location exterior to the vessel. Preferably, the melt material is conveyed into, or adjacent to, the apparatus for addition of the metal to the melt material in, or adjacent to, the apparatus.
The apparatus will normally include an outer housing enclosing the other components, for example for thermal insulation (to protect the operators) and also to aid its positioning and mounting with respect to the melt vessel. | {
"pile_set_name": "USPTO Backgrounds"
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The demand for higher operating speeds and increased functionality of semiconductor integrated circuit devices have driven designs to extreme integration densities and extremely small minimum feature sixes near the limits of lithographic mask image resolution, principally due to diffraction distortion effects, and the capability of lithographic processes to produce structures with adequate shape fidelity to the lithographic resist exposure to avoid significant chip-to-chip variation in electrical characteristics or reliability. Smaller electronic element (e.g. transistors) size and increased proximity allows higher circuit density and often requires operation at reduced voltages and currents which reduces power consumption and allows more devices to be fabricated on a single chip of given dimensions and lithographic process costs while increased proximity of electrical elements reduces signal propagation time and reduces susceptibility to noise.
This same demand has necessitated the development of numerous sophisticated lithographic exposure processes in order to extend the limits of lithographic resolution and shape fidelity of lithographic processes. For example, lithographic resists have been developed which can be exposed by energy of very short wavelengths such as ultraviolet light, X-rays and electron beam exposures in order to increase resolution. So-called phase shift masks have also been developed to provide a degree of control over diffraction distortion effects. Masks having “pre-corrected” shapes have also been developed to more accuracy produce intended shapes at sizes where diffraction distortion effects occur and are referred to as optical proximity correction (OPC) masks. Additionally, several techniques have been developed for multiple exposures of one or more resists, sometimes in conjunction with a so-called hard mask, that have achieved some degree of success in improving lithographic exposure resolution and/or fidelity but which do so at the expense or increased process/complexity and cost; significantly for the design and preparation of multiple masks for the respective exposures. Further* each of the multiple exposures is subject to registration or “overlay” errors which can compromise manufacturing yield.
Image reversal resists are also Known and provide some degree of improvement in image fidelity. Essentially, image reversal resists: cause initially exposed areas soluble and subject to development in the manner of a normal positive resist. However, if the exposed resist is then balked instead of being developed, the initially exposed areas become substantially inert due to cross-linking that occurs during the baking process while leaving unexposed areas unaffected. If the resist is exposed again with an unpatterned, so-called “flood” exposure, the initially-unexposed areas become soluble and can be developed and removed in the normal manner with a suitable developer; leaving the initially exposed areas of the resist, which have been rendered inert by the baking process, in place; a result similar to the use of a negative resist but with improved properties of resistance to many lithographic processes and thus capable of producing improved shape fidelity of the structures formed by those lithographic processes. Known commercially available image reversal resists include AZ 5214E, TI 35E, TI 35ES, Ti Plating, TI xLift, TI Spray and AZ nLof 2070, all of which are available from Clariant AZ Electronic Materials Corp. | {
"pile_set_name": "USPTO Backgrounds"
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Receivers in a global navigation satellite system (GNSS), such as the Global Positioning System (GPS), use range measurements that are based on line-of-sight navigation signals broadcast from satellites. A receiver measures a time-of-arrival of one or more broadcast signals. This time-of-arrival measurement includes a time measurement based upon a coarse acquisition (C/A) coded portion of a signal, called pseudo-range, and a phase measurement.
The navigation signals from satellites in a GNSS are broadcast on carrier signal frequencies and use one or more pseudo-random codes. Navigation information, such as the pseudo-range and/or the phase measurement, in the navigation signals may be recovered in a receiver using correlation in a code tracking loop. Correlation may de-spread an energy of the navigation signals and thereby may de-modulate signals encoded with one or more pseudo-random codes. The correlation operation in effect mixes a received navigation signal from a satellite with a replica of the signal generated in the receiver. Generation of the replica of the signal in the receiver includes generating a corresponding pseudo-random code. If a phase, carrier signal frequency and timing of the replica signal substantially duplicate the received navigation signal from the satellite, an output power is maximized. If there are timing errors in the replica signal, the output power is reduced if the timing of the pseudo-random code is in error by less than one pseudo-random code bit, or is zero if the timing error is greater than or equal to the pseudo-random code bit.
There are, however, many different pseudo-random codes corresponding to navigation signals from different satellites in a GNSS (for those GNSSs that utilize code diversity multiple access methods to mitigate inter-satellite interference) as well as different GNSSs. In order to recover a wide variety of navigation signals, the receiver often will have circuitry for generating many different pseudo-random codes. This circuitry adds complexity and cost to the receiver. As a consequence, there is a need for improved generation of pseudo-random codes in GNSS receivers. | {
"pile_set_name": "USPTO Backgrounds"
} |
1. Field of the Invention
This invention relates to a semiconductor article and a method for producing the same, particularly to a semiconductor article having a plurality of semiconductor single crystal regions comprising a semiconductor single crystal region of one electroconductive type and a semiconductor single crystal region of the opposite electroconductive type.
2. Related Background Art
In the prior art, in most cases when semiconductor elements are to be formed on the same substrate, electrical separation has been effected by providing a PN junction portion, an insulating layer, etc. to a semiconductor single crystal substrate of one electroconductive type.
In the following, description is made about one example of such isolation techniques of semiconductor elements formed on a semiconductor single crystal substrate.
FIG. 14 is a schematic illustration of PN junction isolation structure and FIG. 15 a schematic illustration of insulator isolation structure.
As shown in FIG. 14, the PN junction isolation structure separates each element region 10 from the semiconductor single crystal substrate 11 through a PN junction portion 12. Also, as shown in FIG. 15, the insulator isolation structure separates the side face portion of each element region 10 from an adjacent region 10 through an insulating region 13, while it separates each bottom portion from the semiconductor single crystal substrate 11 through a PN junction portion 12.
The above isolation structure does not affect complete electrical insulation, whereby there is the influence from junction capacitance or parasitic effect. Further, the above isolation structure is used primarily in the case when the respective element regions are of the same electroconductive type. When different electroconductive type element regions are formed on a semiconductor single crystal substrate, that is, when one electroconductive type semiconductor single crystal region and the opposite electroconductive type semiconductor single crystal region are formed on the same substrate to form semiconductor elements in the respective regions (for example, CMOS transistor), the respective regions are opposed through PN junction portions, whereby there is the problem that parasitic effect, etc. appears marketedly. | {
"pile_set_name": "USPTO Backgrounds"
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1. Field of the Invention
The present invention relates to the fabrication of multilayer combined rigid and flex printed circuits having flexible printed circuits extending from the rigid board. In particular, the present invention relates to an improved process for the fabrication of multilayer combined rigid and flex printed circuits, wherein two circuit boards having rigid and flexible sections can be prepared from a novel basestock composite.
2. Background of the Invention
Techniques for making multilayer rigid flex printed circuit boards are well known in the art. One early example of the prior art is disclosed in U.S. Pat. No. 3,409,732, assigned to the Assignee of the present application and whose teachings are incorporated by reference. Typically a rigid flex stacked printed circuit board includes flexible printed circuit cables extending from the periphery of the rigid section or sections. The rigid portions of the flex cables are typically used as sites for electronic components or mechanical hardware. It is important to note that the copper conductor in each plane or layer is fabricated from one continuous sheet of copper foil.
With improvements in electronic technology, there has been a constant need for advances in electronic packaging. This need has led to more complex multilayer rigid flex printed circuit boards with many boards now using up to twenty-five, or even more, layers of circuitry. However, severe problems developed when the rigid circuit portions included many layers of conductors and holes plated through with copper to provide conductor barrels connecting the conductor layers.
One particular problem, reported on and discussed in U.S. Pat. No. 4,800,461, assigned to the assignee of the present Application, and whose teachings are incorporated by reference, described the fact that in multilayer rigid flex boards which included insulator materials such as acrylic adhesive and Kapton (Kapton is a trademark of E.I. duPont de Nemours and Company Inc. for polyimide film), the insulating materials placed a "Z-axis" stress on plated through holes. The coefficient of thermal expansion, it was reported, of the acrylic adhesive (Z-axis expansion) was the dominate influence. It was observed that because of the amount of acrylic required in many multilayer rigid flex applications, all plated through holes are stressed, with many cracking, making the boards unusable.
To overcome this problem, the '461 patent reported on a novel process to provide a rigid section incorporating insulator materials which, when subjected to elevated temperatures, did not expand in the Z direction to cause difficulties, including delamination and cracking of plated copper barrels. Stated another way, in the '461 patent, the materials causing undesirable expansion in the Z direction in the multilayer rigid section of the board, and the materials absorbing excessive amounts of moisture, such as acrylic adhesives and Kapton, were eliminated from the boards rigid section.
However, although the '461 patent was extremely successful in addressing the various problems recited therein, and in particular, the problem of thermal stresses described above, the process for fabrication of the rigid flex printed circuits has remained limited to the fabrication of a multilayer combined rigid and flex printed circuit board wherein two circuit boards are always prepared from a basestock composition, and remain attached to one another via the prepreg. In other words, the process of fabrication according to the teachings of the prior art begin with the step of laminating two conductor layers (i.e. copper layers) to a single insulator layer (prepreg) followed by imaging and etching. Accordingly if one of the two bonded conductor layers was somehow improperly imaged, it was necessary to discard the entire lamination.
It is therefore an object of this invention to provide a process for the fabrication of a multilayer combined rigid and flex printed circuits, wherein two circuit boards having rigid and flex sections can be prepared and imaged from a novel basestock composite, followed by separation into two individual single sided basestock laminates.
It is also an object of this invention to provide a novel basestock composition of sufficient planarity and rigidity to permit adequate handling and further processing thereof, and which can be separated into two individual layers each comprising an imaged copper layer laminated to a fiberglass sheet which is impregnated with adhesives such as an epoxy. | {
"pile_set_name": "USPTO Backgrounds"
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This invention relates generally to microwave, electromagnetic radiation and more particularly to a method and apparatus for producing controlled, coherent microwave radiation from a warm, uniform plasma at approximately twice the electron plasma frequency.
As was pointed out in our U.S. Pat. No. 3,944,946 issued on 16 Mar. 1976, and an article in THE PHYSICS OF FLUIDS Vol. 19, No. 3, of March 1976 pages 464-478 by Balram Prasad, an electron beam propagating through a plasma generates quasi-stable longitudinal electrostatic (plasma) waves peaked at electron plasma frequency via the two-stream instability mechanism. These plasma waves are scattered by both mass (ion density) and charge (electron density) inhomogeneities or fluctuations (at ion and electron plasma frequencies, respectively) which are always present in a warm plasma.
Scattering by mass density fluctuations of the incident or "pump" electrostatic waves builds up a coherent background field of scattered plasma waves via the Rayleigh scattering process. Consequently, the charge density fluctuations are coherently enhanced.
Scattering of pump waves by the coherently enhanced charge density fluctuations (Raman scattering) results in the conversion of both the electrostatic pump waves and the charge density fluctuations into coherent transverse electromagnetic waves. The frequency of this transverse radiation is the sum of the frequencies of the pump waves and the Rayleigh scattered background waves, i.e., approximately twice the electron plasma frequency.
In general, the pump waves propagate in the direction of the electron beam which produces them, much as the wake behind a speeding boat in water. The Rayleigh scattered electrostatic waves have a spatial distribution which is an asymmetric dipole elongated in the direction of the beam. That is, the spatial distribution has two asymmetric lobes, a small backwardly directed lobe and a large elongated forwardly lobe. The maxima of these lobes lie along the direction in which the pump waves are propagating. Since only near "head-on" collisions between pump waves and Rayleigh scattered waves result in Raman emission, it is the interaction of pump waves with the small backwardly directed lobe of the coherent background of Rayleigh scattered waves that is responsible for the Raman emission of transverse electromagnetic waves in a single electron beam-plasma system. The much stronger forwardly directed lobe makes little or no contribution to the Raman emission process.
It is herein proposed to launch two oppositely directed electron beams into a warm plasma such that the transverse electromagnetic power output will be 10 to 100 times the amount obtainable using a single electron beam-plasma system.
With two oppositely directed electron beams, there will be two counter-streaming sets of pump waves and two sets of coherent background charge density fluctuations. Thus, if one set of pump waves is right-directed and the other is left-directed, not only do the right-directed pump waves interact with the right-directed coherent background wave field but also with the left-directed coherent background wave field. The same occurs for the left-directed pump waves which also interact with both sets of coherent background wave fields. It follows, therefore, that there are four distinct interaction processes leading to the Raman emission of transverse electromagnetic waves in a two opposing beam-plasma, whereas there is only one for a single beam-plasma system. Although the input power is doubled (i.e., two beams instead of one), the output power (transverse electromagnetic waves) is at least 10 times greater. Hence, the efficiency of the two opposing beam-plasma system is at least 5 times that of a single beam-plasma system. Moreover, since the forwardly directed lobe of the Rayleigh scattered wave field becomes increasingly stronger than the backward scattered lobe as the phase velocity of the electrostatic waves decrease, their contribution to the Raman process becomes far greater than that of the backwardly directed lobe. | {
"pile_set_name": "USPTO Backgrounds"
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In mobile communication, various frequency efficiency enhancing technologies have been used in order to support more users and achieve a higher transmission rate. One among them is a multi-input multi-output technology that increases a channel capacity by using multiple transmitters and receivers. It is known that the multi-input multi-output technology shows an excellent performance in a rich scattering environment, but the performance of the multi-input multi-output technology deteriorates under a line-of-sight environment. However, a wider bandwidth has been required according to a demand for high-speed communication, and as a result, there is a trend that a transmitting frequency increases up to a millimeter wave band. Due to a characteristic of the millimeter wave, since the millimeter wave is primarily used in a line-of-sight environment having strong linearity, it is not easy to apply the multi-input multi-output technology thereto. However, by recent researches, when transmitting and receiving antennas are appropriately separated from each other, it is demonstrated that orthogonality can be maintained among channels and various performance verification using the demonstration is made.
FIG. 1 is a diagram for describing a general line-of-sight 2×2 multi-input multi-output system.
As illustrated in FIG. 1, when the 2×2 system is assumed, a distance Da/Db between one-side antenna and one-side antenna is proportional to a link distance R and a wavelength λ. An example of the distance Da/Db between one-side antenna and one-side antenna in which a signal phase difference between the antennas becomes 90° according to the link distance Rat 18.7 GHz is shown in [Table 1]. For example, in the link distance R of 1 Km, as the distance Da/Db between one-side antenna and one-side antenna, 2.828 m is required.
TABLE 1Distance between one-side antenna and one-side antenna requiredaccording to link distanceDistance90° 5 m20cm31.25 m 50cm125 m1m500 m2m1000 m 2.828m
In general, it can be seen that an 18.7-GHz fixed wireless communication system may have a lot of problems in actual installation on reality in which a link distance of several kms is required. In addition, when a radio link is configured by using the same product, there is a problem in that a distance between the antennas according to the distance needs to be continuously controlled. | {
"pile_set_name": "USPTO Backgrounds"
} |
1. Field of the Invention
This invention relates to optical systems. More specifically, this invention relates to optical systems utilized in automatic inspection equipment.
While the present invention is described herein with reference to an illustrative embodiment for a particular application, it is understood that the invention is not limited thereto. Those having ordinary skill in the art and access to the teachings provided herein will recognize additional modifications, applications and embodiments within the scope of the present invention.
2. Description of the Related Art
For many applications, the speed and efficiency associated with optical, and other noncontact, measurement and inspection systems has afforded substantial reductions in manufacturing costs. In printed circuit board fabrication, for example, optical systems, such as the Opti III made by Hughes Aircraft Company, verify the dimensions between metal and substrate with heretofore acceptable resolution.
These conventional systems typically scan a spot beam across a board under test. Where the spot illuminates metal, e.g. copper, the reflected light is detected at one amplitude and where the spot illuminates the board, a second amplitude is detected. The detected signals are compared to a threshold to make the desired measurement. The tolerance of the measurement is the diameter of the spot. That is, the measurement is often inaccurate when the spot straddles both copper and board.
Accordingly, efforts to improve the performance of these systems have focused on reducing the diameter of the spot. However, this approach has been found to be problematic. One reason results from the higher costs associated with generating smaller spots. That is, smaller spots require larger, more expensive lenses and associated optical equipment.
A more significant limitation derives from the added processing requirements. To utilize a spot having a diameter 1/n times smaller than that of a conventional spot, where n is a number, necessitates an increase in the load on the processor by a factor of n.sup.2. This is due to the need to process n times as many spots in the inscan direction and n times as many spots in the crossscan direction. Thus, with this approach, a doubling in resolution requires a four fold increase in processing speed and power. There are also comparable associated increases in other key components and parameters such as memory, bandwidth, power, number of detectors, and system noise.
There is therefore a need in the art for a an improved inspection system or a technique by which the performance of conventional measuring systems may be improved without forcing added burdens on tee associated optical and processing systems. | {
"pile_set_name": "USPTO Backgrounds"
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Lyocell fibers are typically used in textiles or filter media. See, for example, U.S. Patent Application Publication No. 2003/0177909, now U.S. Pat. No. 6,872,311, and No. 2003/0168401, now U.S. Pat. No. 6,835,311, both to Koslow, as well as U.S. Pat. No. 6,511,746 to Collier et al. On the other hand, high efficiency wipers for cleaning glass and other substrates are typically made from thermoplastic fibers.
U.S. Pat. No. 6,890,649 to Hobbs et al. (3M) discloses polyester microfibers for use in a wiper product. According to the '649 patent, the microfibers have an average effective diameter less than 20 microns and, generally, from 0.01 microns to 10 microns. See column 2, lines 38 to 40. These microfibers are prepared by fibrillating a film surface and then harvesting the fibers.
U.S. Pat. No. 6,849,329 to Perez et al. discloses microfibers for use in cleaning wipes. These fibers are similar to those described in the '649 patent discussed above. U.S. Pat. No. 6,645,618 also to Hobbs et al. also discloses microfibers in fibrous mats such as those used for removal of oil from water or their use as wipers.
U.S. Patent Application Publication No. 2005/0148264 (application Ser. No. 10/748,648) of Varona et al. discloses a wiper with a bimodal pore size distribution. The wiper is made from melt blown fibers as well as coarser fibers and papermaking fibers. See page 2, paragraph 16.
U.S. Patent Application Publication No. 2004/0203306 (application Ser. No. 10/833,229) of Grafe et al. discloses a flexible wipe including a non-woven layer and at least one adhered nanofiber layer. The nanofiber layer is illustrated in numerous photographs. It is noted on page 1, paragraph [0009], that the microfibers have a fiber diameter of from about 0.05 microns to about 2 microns. In this publication, the nanofiber webs were evaluated for cleaning automotive dashboards, automotive windows, and so forth. For example, see page 8, paragraphs [0055] and [0056].
U.S. Pat. No. 4,931,201 to Julemont discloses a non-woven wiper incorporating melt-blown fiber. U.S. Pat. No. 4,906,513 to Kebbell et al. also discloses a wiper having melt-blown fiber. Here, polypropylene microfibers are used and the wipers are reported to provide streak-free wiping properties. This patent is of general interest as is U.S. Pat. No. 4,436,780 to Hotchkiss et al., which discloses a wiper having a layer of melt-blown polypropylene fibers and, on either side, a spun bonded polypropylene filament layer. U.S. Pat. No. 4,426,417 to Meitner et al. also discloses a non-woven wiper having a matrix of non-woven fibers including a microfiber and a staple fiber. U.S. Pat. No. 4,307,143 to Meitner discloses a low cost wiper for industrial applications, which includes thermoplastic, melt-blown fibers.
U.S. Pat. No. 4,100,324 to Anderson et al. discloses a non-woven fabric useful as a wiper, which incorporates wood pulp fibers.
U.S. Patent Application Publication No. 2006/0141881 (application Ser. No. 11/361,875), now U.S. Pat. No. 7,691,760, of Bergsten et al., discloses a wipe with melt-blown fibers. This publication also describes a drag test at pages 7 and 9. Note, for example, page 7, paragraph [0059]. According to the test results on page 9, microfiber increases the drag of the wipe on a surface.
U.S. Patent Application Publication No. 2003/0200991 (application Ser. No. 10/135,903) of Keck et al. discloses a dual texture absorbent web. Note pages 12 and 13 that describe cleaning tests and a Gardner wet abrasion scrub test.
U.S. Pat. No. 6,573,204 to Philipp et al. discloses a cleaning cloth having a non-woven structure made from micro staple fibers of at least two different polymers and secondary staple fibers bound into the micro staple fibers. The split fiber is reported to have a titer of 0.17 to 3.0 dtex prior to being split. See column 2, lines 7 through 9. Note also, U.S. Pat. No. 6,624,100 to Pike, which discloses splittable fiber for use in microfiber webs.
While there have been advances in the art as to high efficiency wipers, existing products tend to be relatively difficult and expensive to produce, and are not readily re-pulped or recycled. Wipers of this invention are economically produced on conventional equipment, such as a conventional wet press (CWP) papermachine and may be re-pulped and recycled with other paper products. Moreover, the wipers of the invention are capable of removing micro-particles and substantially all of the residue from a surface, reducing the need for biocides and cleaning solutions in typical cleaning or sanitizing operations. | {
"pile_set_name": "USPTO Backgrounds"
} |
1. Field of the Invention
This invention relates to the field of latches, and more particularly to a draw latch.
2. Brief Description of the Prior Art
A variety of draw latches are known for providing a latching action which is achieved by drawing a clamping member against, or over, another member. Generally, a keeper member is mounted to one panel surface and a clamping member of the latch, which is mounted on a second panel surface, engages the keeper and draws the panels together when the clamping member is drawn toward or over the latch body. Draw latches essentially are comprised of a handle assembly and a keeper. The handle assembly generally includes the components of the base, a lever and a catch, with the base and lever being pivotally connected to each other, and with the catch and lever being pivotally connected to each other. In operation, the handle assembly is adapted to be mounted onto a first panel member and the keeper is adapted to be mounted on a second panel member and is designed to receive the catch for latching. Generally, when the catch engages the keeper, a downward force is applied to the lever which causes the catch to pull the panels together and into a fastened position. In essence, the latching action is achieved by rotating the lever about a pivot axis.
In the art of over-center draw latches, it is known to provide a draw latch having a base member a lever and a catch. The base and lever are pivotally connected to each other with the catch and lever being pivotally connected to each other. The pivotal connections are generally at the locations of the shafts. Prior art latches of this type, although effective for securing one or more members or panels together, have an undesirable effect of freely movable members. In order to enable the components of this type of latch to be retained in open positions, a technique used includes applying a plastic resistance member between the pivot shaft pivotally connecting the lever and base, and the pivot shaft that connects the lever and the catch. This plastic member provides a sufficient frictional resistance between these pivot shafts, that it will maintain the basic three components in various positions, relative to each other. However, such a plastic member comprises essentially a fourth component which can increase cost and the work associated with assembly of the latch. Generally, the additional plastic member has been replaced, and dimples or detents used to provide a resistance to keep the members of the latch assembly in a variety of given positions. For example, an over-center draw latch having a base and lever pivotally connected to each other, with a catch being pivotally connected to the lever is shown in U.S. Pat. No. 4,890,869 "Over-Center Draw Latch", the complete disclosure of which is herein incorporated by reference.
In the operation of draw latches, the handle assembly is adapted to be mounted onto a first panel member and the keeper is adapted to be mounted on a second panel member. The keeper is further designed to receive the catch for latching. When the catch engages the keeper, a downward force is applied to the lever which causes the catch to pull the panels together into a fastened position. In such a latch, the latching action is achieved by rotating the lever to shift the pivotal connection of the catch and the lever in relation to a line extending between the keeper and the point of pivotal connection of the lever and base. Generally, there are two distinct latching actions for such latches, namely, over-center and under-center. An over-center action provides the pivot connection of the lever and the catch below the centerline between the base and the keeper when in the fastened position. With respect to an under-center action, the pivot of the lever and the catch is positioned above the centerline of the base and the keeper when fastened. For unlatching, an upward force is applied to the lever in order to provide rotation of the lever in the direction opposite that for latching. A disadvantage with conventional draw latches however is that following rotation of the lever for unlatching; the catch must manually be raised in order to be disengaged from the keeper. In one type of draw latch known, a spring which automatically raises or provides "kick-out" of the catch from the keeper when unlatched is utilized. However, in this type of draw latch, the catch movement generally cannot be controlled. For example, when unlatched, the spring operates to force the catch from the keeper in all instances, even in those situations where it is desirable to have the catch remain in other positions. An example of a draw latch which addresses and overcomes such drawbacks is disclosed in U.S. Pat. No. 5,478,125, "Draw Latch With Catch Having Kick-Out Action" wherein controlled kick-out action of the latching member is featured, the complete disclosure of which is herein incorporated by reference.
Another example of a draw latch assembly includes a base and a handle and an underlying pawl. The handle is rotated to secure the latch in a latching position by moving the underlying pawl member therewith. In this type of latch assembly, the handle does not itself secure to a keeper. The latching is accomplished by the pawl securing to a keeper member.
Other prior known draw latches are provided for use in panels wherein a gasketing member is provided on the panel to supply a biasing force.
A need exists for a latch which can provide the benefits of a draw latch with improved locking and securing capabilities. | {
"pile_set_name": "USPTO Backgrounds"
} |
The endo-1,3-.beta.-glucanase gene family encodes isozymes that catalyze the hydrolysis of 1,3-.beta.-D-glycosidic bonds in cell wall polymers of plants and fungi. The substrates for these glucanases include 1,3-.beta.-glucans and 1,3;1,6-.beta.-glucans. An N-terminal signal peptide directs all glucanase isozymes into the endoplasmic reticulum. Most glucanase isozymes are then secreted into the apoplast, but C-terminal peptides direct certain glucanase isozymes into the vacuole (Simmons, 1994).
This diversity of functions is matched by a multiplicity of 1,3-.beta.-glucanase genes and isozymes. In the more exhaustively studied plant species, the number of genes or isozymes ranges from 5 to 14 (Simmons, 1994). The first .beta.-glucanase gene characterized in rice was Gns1;1, which was predicted to encode a 1,3;1,4-.beta.-glucanase based on homology to the EI gene of barley (Simmons, et al., 1992). Akiyama, et al. have recently characterized a glucanase isozyme from rice which has 1,3;1,4-.beta.-glucanase activity and an acidic pI (Akiyama, et al., 1996a, 1996b); this isozyme may be encoded by the Gns1;1 gene. Akiyama, et al. have also recently characterized two 1,3-.beta.-glucanase isozymes from rice (Akiyama, et al., 1996a, 1996b; Akiyama, et al., 1997).
Eight genes which encode novel rice .beta.-glucanase isozymes Gns2-9 are discosed herein. The genes, the gene promoters, and nucleic acids encoding signal peptides, full-length proteins, and mature proteins, are useful in a variety of transgenic monocot plants, for example, in achieving increased plant resistance to fungal infection, improved growth characteristics, and high levels of expression of heterologous proteins in various tissues obtained from the plants. | {
"pile_set_name": "USPTO Backgrounds"
} |
1. Field of the Invention
This invention is related to a power system which converts DC output from a DC power source such as a solar cell and a fuel cell to AC output by an inverter and supplies to a load, and is intended for an efficient operation of the inverter.
2. Description of Prior Art
A solar power generating system which uses solar cells becomes popular as a clean power system.
FIG. 5 is a schematic view illustrating a conventional solar power generating system for domestic use. DC sources 101 comprising of a plurality of solar cells are placed on a house roof. DC output from the plurality of DC sources is accumulated and flowed into a connection box 102. The DC output from the connection box 102 is converted to AC output by an inverter 103, and is supplied to a load 105 as home electric appliance through a panelboard 104. Electricity can be also supplied to the loads 105 from a commercial power supply 106. When electricity runs short, for example at night, electric power is supplied from the commercial power supply 106.
In the meanwhile, efficiency of an inverter dips sharply at a time of low output. To solve the problem, Patent Abstracts of Japan, publication number 06165513, for example, provides a method for operating a plurality of inverters in parallel and determining how many inverters should be operated by judging a total output current of inverters. | {
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1. Field of the Invention
The present invention relates to methods for preparing and using energetic fills containing crystalline high explosive materials.
2. Related Art
The basic standard methods for loading energetic or explosive materials into munitions are press-loading, and cast loading (whether using melt-cast or cast-cure techniques). With the relatively recent emergence of the production of smart weapon systems that are lighter and smaller and have greater lethality and survivability, the need exists for smaller, reliable Safe and Arm (S&A) devices for activating the explosive train of the explosive device. The challenges in producing Micro-Energetic Initiators (MEI) for Micro Electro-mechanical Mechanisms (MEMS) as safe and arm devices, involve the need to introduce the energetic materials into extremely small volumes and to have the energetic materials function properly after such introduction. MEIs for safe and arm devices will necessarily be smaller in size and weight than traditional fuzing devices, and will permit a larger loading of the energetic fill of the end item, thereby resulting in increased lethality. The standard loading methods mentioned above cannot be used to load the very small (microliter) volumes contained in these devices.
Considering the latter point in more detail, as indicated previously, the standard methods for loading an energetic fill into a munition are press-loading and cast-loading. With respect to the former, delivering the material to the fixture, followed by consolidation thereof by pressing, presents difficulties because of the very small required volume of the solids. Further, because of the delicateness of the materials of construction of the critical fixture, press loading of the energetic fill into the fixture is not a viable option. One potential approach would be to prepare a pellet of the energetic material externally of the fixture, and then load the pellet into the fixture. To complete the process, in order to maintain the pellet in place, some kind of adhesive would have to be applied to the pellet, e.g., on the side thereof, or to the wall of the fixture. It will be appreciated that such a process would be cumbersome and relatively costly.
As was also mentioned previously, casting of an energetic fill into a fixture can be done either by melt casting and cast curing. Melt casting basically entails heating a substance to a temperature above its melting point, adding any needed ancillary materials to the melt, pouring the mixture into the volume to be filled, and allowing the fill to solidify in place. Among other problems with this approach, because of the very small delivery volumes involved in producing MEIs for safe and arm devices, heat loss to the ambient environment would be a problem and, in this regard, could cause the energetic material to solidify before being emplaced.
Cast curing basically entails mixing the substance to be cast in a liquid polymer mixed with a cross-linking reagent. The resultant cast mixture has a finite “pot life” after which the viscosity of the mixture increases because of the chemical crosslinking process. This change in rheological properties may cause difficulty in the delivery into the fixture of energetic material prepared in this way.
There are, of course, a number of state-of-the-art delivery devices for the delivery of small volumes of materials including ink jet printing. The latter is a mature technology that can be used to accurately deliver small volumes of material. However, the present technology is unsuitable for delivering energetic materials for two reasons. First, most inks used for ink jet printing are dye-based, i.e., the colorant dye is dissolved in the fluid medium, and although there are pigment-based ink jet inks available wherein the colorant is an undissolved crystalline material, the undissolved solids are of a sub-micron particle size. Important secondary high explosives such as CL-20 (epsilon HNIW) are not presently available in a sub-micron particle size. Further, in an ink jet printer, the ink is typically delivered from the print head by a piezoelectric discharge that ejects droplets of ink at elevated pressure and temperature onto the printing substrate; the combination of an electric discharge and high temperature/pressure may be a safety hazard when attempting to deliver energetic materials using ink jet printing. | {
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A conventional controller of an A.C. generator for vehicles controlled a duty ratio of a switching element for intermittently controlling a field current of a generator to thereby limit the field current so as for the field current not to exceed a predetermined limitation value. Note that, the predetermined limitation value is selected so as to become a value equal to or larger than a value of a field current which is to be caused to flow in order to obtain a predetermined output from the generator when a temperature of a generator has risen up to a predetermined value (refer to JP 6-38720 B (page 2 and FIG. 1)).
In accordance with such a conventional controller for an A.C. generator for vehicles, there are shown generator output characteristics in which a power transistor is usually held in a conduction state as long as a generated voltage is lower than a predetermined value after a maximum vehicle electrical load has been put on a generator, and hence an output is also increased in accordance with an increase in rotational speed of the generator. That is to say, there was encountered a problem such that temperatures of an armature coil and a rectifier rose along with an increase in output of the generator to become difficult to be suppressed within an allowable temperature, which resulted in reduction of quality. In addition, there was encountered a problem that a large cooling fan was required as means for enhancing a cooling property in order to suppress rise of a temperature, which resulted in that a generator could not be miniaturized. | {
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The invention relates to a crane lattice boom comprising two boom sections and a crane, in particular a mobile crane, having such a crane lattice boom.
In cranes, the maximum working load with long booms is limited by the lateral stiffness of the boom system. This applies in a particular degree with lattice-shaped booms and when the lattice is used in a steep position. This instability is further amplified e.g. with an inclined crane installation, unfavorable wind conditions or different temperature influences at the sides of the booms. | {
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(Not Applicable).
(Not Applicable).
(Not Applicable).
(1) Field of the Invention
This invention relates to projection lithography systems for imaging on curved substrates, and more particularly relates to a large-area lithography system featuring a curved mask that is identical in size and shape to the curved substrate, for the purpose of achieving a constant optical path length for conjugate image points in order to maintain the substrate surface within the depth-of-focus of the projection optics, thereby providing an effective depth-of-focus significantly greater than the depth-of-focus of the projection optics. Additionally, the system has provisions for compensating for magnification errors that arise as a result of imaging a curved mask onto a curved substrate. The system performs patterning on curved surfaces by means of small-field seamless scanning techniques to achieve high resolution over an entire large-area curved substrate. This invention also relates to a technique for fabricating the appropriate curved projection masks, using a planar contact printing technique to replicate a planar pattern onto a flexible film which is stretched over a curved mask blank and secured by a frame, with the option of using the system itself to replicate the original mask onto an indeterminate number of curved fused-silica mask blanks, by projection printing.
(2) Description of Related Art
Although microlithographic patterning has traditionally been performed on planar substrates, primarily for the fabrication of computer chips and microcircuits, there exist many applications which are based on microcircuits or circuit-like elements fabricated on curved surfaces. For example, CCD (charge coupled device) arrays constructed on spherical silicon substrates, rather than flat substrates, could significantly enhance the performance of digital imaging systems. As with any conventional lens system, an increased collection efficiency and larger fields-of-view could be achieved by utilizing a curved image plane, in this case a curved CCD array, matched to the inherent curvature of focus of the optical system (the Petzval curvature). Although the individual pixels for CCD arrays are typically xcx9c25 xcexcm in size, the electrical interconnects are of the order of 1 xcexcm in width. We note that microcircuits having features 1 xcexcm and below generally are fabricated using projection lithography, and thus projection techniques would be useful for patterning curved CCD""s. Another area of potential widespread application is in the fabrication of frequency selective surfaces (FSS), which are used as electromagnetic windows usually in the millimeter-wave and microwave portions of the electromagnetic spectrum. FSS consist of a repeating array of identical elements, typically on a flexible dielectric material such as Kapton. The individual elements are often in a tripole or quadrupole configuration, with the sizes of the elements of the same scale as the wavelength of selectivity. In order to optimize the bandwidth and polarization responses of FSS arrays, and to improve the uniformity of the responses with respect to angle of incidence, the FSS elements often are fabricated as closed contours with the contour linewidth measuring a fraction of the design wavelength, of the order of tens or hundreds of microns. Active FSS, which have electronic devices, such as diodes, integrated into their periodic structures, are based on semiconductor device technology and are therefore fabricated using traditional semiconductor-processing materials and techniques. The active elements must be printed with high resolution, of the order of microns in scale. Thus the fabrication of both passive and active FSS requires the use of high-resolution patterning technology, with resolution down to the micron scale for active FSS.
Many techniques have been investigated for patterning high-resolution features on curved surfaces, with a number of methods based on new materials-based processes and applications. For example, there exist a variety of imprinting techniques based on soft-lithography methods, using stamps or molds to replicate patterns on curved surfaces. (Y. Xia and G. Whitesides, Angew Chem. Int. Ed., 37, 550-575, (1998)). A somewhat different fabrication method utilizes conventional photolithography processes, by which a flat substrate is first patterned using planar fabrication techniques; the planar substrate is subsequently mechanically deformed into the desired curved shape, so that after deformation the features reside on a surface having the desired curvature (see, for example, Z. Suo, Appl. Phy. Lett, 74, 1177-1179 (1999)). Several variations of the deformation approach have been utilized for FSS fabrication on curved dielectric substrates. For example, planar substrates may be patterned and subsequently deformed into the desired FSS shape either by heat-forming or by assembling patterned strips directly onto the curved substrate. (T. Wu, Frequency Selective Surface and Grid Array, John Wiley and Sons, 1995) Contact printing directly onto FSS substrates has also been investigated, using a mask that conforms to the curved substrate. See, for example, U.S. Pat. No. 5,395,718, Jensen et al., CONFORMAL PHOTOLITHOGRAPHIC METHOD AND MASK FOR MANUFACTURING PARTS WITH PATTERNED CURVED SURFACES, Mar. 7, 1995. See also, U.S. Pat. No. 5,552,249, Jensen et al., METHOD FOR MAKING A MASK USEFUL IN THE CONFORMAL PHOTOLITHOGRAPHIC MANUFACTURE OF PATTERNED CURVED SURFACES, Sep. 3, 1996.
As described by Jensen, et al., the curved masks used in this process have been fabricated by laser direct-writing, utilizing a three-axis stage to control the position of the mask during the writing process. Masks fabricated in this manner have been successfully used to pattern images on curved substrates by contact printing. However, as with planar contact printing methods, throughput is limited by the vacuum pulldown time, and cost efficiency is reduced by the need to replace masks, as they are subject to degradation resulting from their intimate contact with the curved substrates.
Other methods for patterning onto curved surfaces, such as direct-writing, could be successfully used, having the substrate situated on an x, y, z-stage, with z-adjustments for maintaining the substrate in the focus of the writing beam. However, direct-writing is slow and would therefore be unsuitable for high-throughput fabrication. For example, for patterning on planar substrates, projection lithography is the preferred method because of the much higher throughputs that can be achieved, compared to direct writing. Although traditional projection lithography techniques using planar masks can be used for very high throughput lithography on planar substrates, there are currently no very high throughput techniques described in the literature for projection imaging onto curved surfaces, even for relatively large features, tens or hundreds of microns in size. This is primarily due to the limited depth-of-focus (DOF) of projection imaging systems. For example, for conventional steppers and scanners achieving a resolution of the order of a micron, the DOF is of the order of 10 microns, which is far too small for imaging a planar mask onto curved CCD or FSS substrates having height variations of typically several centimeters and several tens or hundreds of centimeters, respectively. Even for projection systems having a resolution of only 100 microns, which would be sufficient for certain passive FSS, the DOF would be of the order of only several millimeters, which is not sufficient for imaging a planar mask onto typical FSS structures, which have height variations significantly greater than several millimeters. We note that it would be possible to perform projection imaging onto curved substrates, using planar masks, by modifying conventional steppers or scanning systems such that the z-position of the substrate could be adjusted during patterning to maintain the substrate within the DOF of the imaging system. However, to operate in this mode, it would be necessary to restrict the size of the image field such that the height of the substrate does not vary by more than the DOF of the imaging system, over any substrate region equal in size to the image field. For practical curved-substrate imaging applications, such as CCD fabrication, the maximum-allowable image field would consequently not be much larger than many microns. Using such a technique, throughputs would be higher than for contact printing but significantly lower than for projection printing onto planar substrates. Thus the use of conventional projection lithography systems operating with planar masks would not be suitable for very high throughput lithographic patterning onto curved surfaces such as CCD arrays and FSS. However, it should be noted that a method for achieving improved throughputs by projection printing using planar masks has been described in copending U.S. patent application Ser. No. 09/176,920 now U.S. Pat. No. 6,304,316, MICROLITHOGRAPHY SYSTEM FOR HIGH-RESOLUTION, LARGE-AREA PATTERNING OF CURVED SURFACES, Jain, Farmiga and Dunn, filed Oct. 22, 1998. See also U.S. Pat. No. 5,285,236, LARGE-AREA, HIGH-THROUGHPUT, HIGH-RESOLUTION PROJECTION IMAGING SYSTEM, Jain, Feb. 8, 1994. The copending Jain et al. application describes the Anvik system for seamless hexagonal complementary projection scanning using planar masks, for projection printing onto curved substrates using a deformable mirror in the imaging system to enhance the DOF, and z-actuators to maintain the substrate within the enhanced DOF region. The Anvik system is effective, but its wide range of capability does not always provide the optimum economics in mass production, and there may be limits to the degree of enhanced performance that can be achieved by using the deformable mirror. There remains a need for a more effective, economical system for mass-production projection imaging of microelectronics features on curved substrates.
There are a number of existing techniques for imaging onto a curved surface, in addition to Jensen""s method, which was noted earlier. See, for example, U.S. Pat. No. 3,694,080, Malsky, METHOD AND APPARATUS FOR PHOTOPRINTING CONDUCTOR PATTERNS ON THE CURVED SURFACES OF TRANSDUCERS, Sep. 26, 1972, which describes a technique using a cylindrical substrate with the cylinder revolving past a small scanning station for projection patterning via a curved mask, keeping the focus effectively unchanged at the scanning station while the cylinder revolves. Malsky is limited to rotational presentation of the substrate in a step and repeat imaging system.
Another technique, a contact method which permits the curved surface to be a compound curve such as a radome for an aircraft, uses a contact photo mask which is adhered to a metallic layer on the inside of the radome. After exposure, an etching step leaves a pattern in the metallic lawyer. See, for example, U.S. Pat. No. 4,388,388, Kornbau et al, METHOD OF FORMING METALLIC PATTERNS ON CURVED SURFACES, Jun. 14, 1983. See also U.S. Pat. No. 5,344,729, Akins et al, CONFORMAL PHOTOMASK FOR THREE-DIMENSIONAL PRINTED CIRCUIT BOARD TECHNOLOGY, Sep. 6, 1994.
The prior art suffers from the problems of contact printing, including wear and damage due to contact, or does not have the resolution required for present-day needs. There is a continuing need for high-resolution non-contact projection imaging for patterning intricate details on curved surfaces.
This invention provides to a large-area lithography system the capability of patterning onto a curved substrate, using a curved mask in order to achieve a fixed track length for conjugate object and image points, thereby maintaining the curved substrate surface within the depth-of-focus (DOF) of the projection optics; this invention also provides the capability for controlling magnification errors arising as a result of the curved patterning technique. This invention provides these capabilities while retaining the option of small-field seamless scanning techniques to achieve high resolution over the entire large-area curved substrate.
The object of the invention is to make possible a high-resolution projection imaging operation on a curved substrate with height variations significantly greater than the depth-of-focus of the imaging optics.
Another object of the invention is to permit scanning projection imaging, by minimizing and compensating for destructive magnification error.
A feature of the invention is a curved mask having a curvature that is identical to, i.e., having the same size and shape, as the curved substrate.
Another feature of the invention is the inverted orientation of the curved substrate with respect to the curved mask when the mask and substrate are mounted on a common scanning platform, thus keeping the track length constant for conjugate image points, with motion provided to the projection lens to compensate for magnification error.
An advantage of the invention is that it makes it possible to perform high-resolution projection imaging on curved surfaces having topography variations greater than the depth-of-focus of the imaging system.
Other objects, features and advantages of the invention will be apparent to those skilled in the art, in view of the drawings and written description. | {
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1. Field of the Invention
The present invention relates to integrated circuit designs; and, in particular, the present invention relates to integrated circuit designs for image processing.
2. Discussion of the Related Art
The Motion Picture Experts Group (MPEG) is an international committee charged with providing a standard (hereinbelow "MPEG standard") for achieving compatibility between image compression and decompression equipment. This standard specifies both the coded digital representation of video signal for the storage media, and the method for decoding. The representation supports normal speed playback, as well as other playback modes of color motion pictures, and reproduction of still pictures. The MPEG standard covers the common 525- and 625-line television, personal computer and workstation display formats. The MPEG standard is intended for equipment supporting continuous transfer rate of up to 1.5 Mbits per second, such as compact disks, digital audio tapes, or magnetic hard disks. The MPEG standard is intended to support picture frames of approximately 288.times.352 pixels each at a rate between 24 Hz and 30 Hz. A publication by MPEG entitled "Coding for Moving Pictures and Associated Audio for digital storage medium at 1.5 Mbit/s," included herein as Appendix A, provides in draft form the proposed MPEG standard, which is hereby incorporated by reference in its entirety to provide detailed information about the MPEG standard.
Under the MPEG standard, the picture is divided into a matrix of "Macroblock slices" (MBS), each MBS containing a number of picture areas (called "macroblocks") each covering an area of 16.times.16 pixels. Each of these picture areas is further represented by one or more 8.times.8 matrices which elements are the spatial luminance and chrominance values. In one representation (4:2:2) of the macroblock, a luminance value (Y type) is provided for every pixel in the 16.times.16-pixel picture area (i.e. in four 8.times.8 "Y" matrices), and chrominance values of the U and V (i.e., blue and red chrominance) types, each covering the same 16.times.16 picture area, are respectively provided in two 8.times.8 "U" and two 8.times.8 "V" matrices. That is, each 8.times.8 U or V matrix has a lower resolution than its luminance counterpart and covers an area of 8.times.16 pixels. In another representation (4:2:0), a luminance value is provided for every pixel in the 16.times.16 pixels picture area, and one 8.times.8 matrix for each of the U and V types is provided to represent the chrominance values of the 16.times.16-pixel picture area. A group of four contiguous pixels in a 2.times.2 configuration is called a "quad pixel"; hence, the macroblock can also be thought of as comprising 64 quad pixels in an 8.times.8 configuration.
The MPEG standard adopts a model of compression and decompression based on lossy compression of both interframe and intraframe information. To compress interframe information, each frame is encoded in one of the following formats: "intra", "predicted", or "interpolated". Intra encoded frames are least frequently provided, the predicted frames are provided more frequently than the intra frames, and all the remaining frames are interpolated frames. In a prediction frame ("P-picture"), only the incremental changes in pixel values from the last I-picture or P-picture are coded. In an interpolation frame ("B-picture"), the pixel values are encoded with respect to both an earlier frame and a later frame. By encoding frames incrementally, using predicted and interpolated frames, the redundancy between frames can be eliminated, resulting in a high efficiency in data storage. Under the MPEG, the motion of an object moving from one screen position to another screen position can be represented by motion vectors. A motion vector provides a shorthand for encoding a spatial translation of a group of pixels, typically a macroblock.
The next steps in compression under the MPEG standard provide lossy compression of intraframe information. In the first step, a 2-dimensional discrete cosine transform (DCT) is performed on each of the 8.times.8 pixel matrices to map the spatial luminance or chrominance values into the frequency domain.
Next, a process called "quantization" weights each element of the 8.times.8 transformed matrix, consisting of 1 "DC" value and sixty-three "AC" values, according to whether the pixel matrix is of the chrominance or the luminance type, and the frequency represented by each element of the transformed matrix. In an I-picture, the quantization weights are intended to reduce to zero many high frequency components to which the human eye is not sensitive. In P- and B-pictures, which contain mostly higher frequency components, the weights are not related to visual perception. Having created many zero elements in the 8.times.8 transformed matrix, each matrix can be represented without further information loss as an ordered list consisting of the "DC" value, and alternating pairs of a non-zero "AC" value and a length of zero elements following the non-zero value. The values on the list are ordered such that the elements of the matrix are presented as if the matrix is read in a zig.sub.-- zag manner (i.e., the elements of a matrix A are read in the order A00, A01, A10, A02, A11, A20 etc.). This representation is space efficient because zero elements are not represented individually.
Finally, an entropy encoding scheme is used to further compress, using variable-length codes, the representations of the DC coefficient and the AC value-run length pairs. Under the entropy encoding scheme, the more frequently occurring symbols are represented by shorter codes. Further efficiency in storage is thereby achieved.
The steps involved in compression under the MPEG standard are computationally intensive. For such a compression scheme to be practical and widely accepted, however, a high speed processor at an economical cost is desired. Such processor is preferably provided in an integrated circuit.
Other standards for image processing exist. These standards include JPEG ("Joint Photographic Expert Group") and CCITT H.261 (also known as "P.times.64"). These standards are available from the respective committees, which are international bodies well-known to those skilled in the art. | {
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Mobile devices, including for example laptop computers and mobile phones (so-called “smart” phones), provide remote access to more than computer files and email. For example, users may access security systems, lighting control systems, television recording devices, and even peripheral devices (e.g., printers) for home or office computers, from just about anywhere a network connection is available, including the Internet and mobile communications networks. By way of illustration, a user at a coffee shop can print a coupon on a mobile website being viewed on their smart phone to a printer at their home or office computer. The user can then pick up the printed coupon the next time they are at home. In another illustration, a user at the airport can print a presentation from their laptop computer at the office printer, and then call a coworker at the office to retrieve the printed presentation from the printer. Of course, there are many other uses in addition to these illustrations.
Printers and other devices may be enabled for remote access by assigning a network address to the printer, such as a uniform resource locator (URL) or email address. The user can then access the printer from any network using this identification in much the same way that the user would access the printer on the local network using the printer's local area network (LAN) ID.
Unfortunately, even long and randomly assigned device IDs can be determined by unauthorized users (so-called “hackers”). The hackers can then send unauthorized communications (so-called “spam”) to the printer. Not only is this unauthorized communication a nuisance for the user, it also wastes paper, ink, and other resources (e.g., electricity), and causes unnecessary wear and tear on the device. | {
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1. Field of the Invention
The present invention relates to an endoscope apparatus configured to use illuminating light of a plurality of wavelength bands to pick up an image.
2. Description of the Related Art
In recent years, endoscopes configured to inspect inside of subjects are widely used in a medical field and the like. Illumination light of narrow bands of a plurality of wavelength bands is used to pick up an image of a traveling state or the like of blood vessels near a surface layer of a biological tissue to perform endoscopy (or diagnosis) in some cases.
To generate an image by picking up an image of blood vessels near a surface layer of a biological tissue, light of a plurality of wavelength bands, such as light with a wavelength of 600 nm easily absorbed by deep blood vessels near the surface layer and light with a wavelength of 630 nm that is reference light not easily absorbed by the deep blood vessels compared to the light of the wavelength of 600 nm, is used to generate an image emphasizing the deep blood vessels.
In generating such an image, it is difficult to acquire a sufficiently bright image when the reference light is from a visible long wavelength to a near infrared region, because a transmittance of a lens and a sensitivity of image pickup are reduced. Furthermore, balance of light of each wavelength needs to be adjusted to appropriately set color balance, but this is not clearly defined so far.
For example, Japanese Patent Application Laid-Open Publication No. 2009-135907 as a first conventional example is disclosed to provide an image pickup device capable of providing a desirable image with fine color components according to a penetration depth of light in an object, the image pickup device including a light emitting section configured to emit light of first to third wavelength regions (650 nm, 450 nm, and 540 nm) and first to third light receiving elements with sensitivity for the first to third wavelength regions, wherein spectral sensitivities of the respective light receiving elements, a spectral reflectance of the object, and a spectral intensity of light emitted to the object by a light emitting portion are multiplied to obtain values, the values are integrated throughout the wavelength regions to calculate relative light receiving intensities of the respective light receiving elements, and the light receiving elements are arranged on the image pickup device so that the number of first light receiving elements:the number of second light receiving elements:the number of third light receiving elements are 2:2:1 because the relative light receiving intensities are 2:1:1 in the first light receiving elements:the second light receiving elements:the third light receiving elements.
Japanese Patent No. 5404968 as a second conventional example is disclosed to provide an endoscope apparatus capable of clearly displaying blood vessels of a deep part of mucosa at an appropriate brightness without performing cumbersome work of administration of a medicine, wherein narrow band light near the wavelength of 600 nm and narrow band light near the wavelength of 630 nm are emitted, each narrow band signal is multiplied by a light adjustment control parameter, and a largest weight 0.6 is provided to a narrow band signal near the wavelength of 600 nm. | {
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A perennial problem in data analysis is the increasing dataset sizes. This trend dictates the need not only for more efficient compression schemes, but also for analytic operations that work directly on the compressed data. Efficient compression schemes can be designed based on exploiting inherent patterns and structures in the data. Data periodicity is one such characteristic that can significantly boost compression.
Periodic behavior is omnipresent, many types of collected measurements exhibit periodic patterns, including weblog data [1, 2, 3], network measurements [4], environmental and natural processes [5, 6], medical and physiological measurements. The aforementioned are only a few of the numerous scientific and industrial fields that handle periodic data.
When data contain inherent structure, efficient compression can be performed with minimal loss in data quality. This is achievable by encoding the data using only few high-energy coefficients in a complete orthonormal basis representation, e.g., Fourier, Wavelets, Principal Component Analysis (PCA).
In the data-mining community, searching on time-series data under the Euclidean metric has been studied extensively, as e.g., described in [8]. However, such studies have typically considered compression using only the first Fourier or wavelets. The use of diverse sets of coefficients has been studied as described in [1].
The majority of data compression techniques for sequential data use the same set of low-energy coefficients whether using Fourier [7, 8], Wavelets [9, 10] or Chebyshev polynomials [11] as the orthogonal basis for representation and compression. Using the same set of orthogonal coefficients has several advantages: First, it is immediate to compare the respective coefficients. Second, space-partitioning indexing structures, such as R-trees, may be directly used on the compressed data. Third, there is no need to store also the indices of the basis functions that the stored coefficients correspond to. The disadvantage may be that both object reconstruction and distance estimation may be far from optimal for a given fixed compression ratio.
Side-information may also be recorded, such as the energy of the discarded coefficients, to better approximate the distance between compressed sequences by exploiting the Cauchy-Schwartz inequality [13].
In US 2009/0204574 A1 (see [25]), the distance estimation between one compressed and one uncompressed data vector is examined. | {
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1. Field of the Invention
This invention relates to a hand-held dispenser and more particularly to a hand-held dispenser which is convenient to use and which is capable of controlling the flow rate of water therethrough for mixing with a liquid chemical into the water passing through the dispenser. Further, this invention relates to a hand-held dispenser which is capable of mixing precise amounts of liquid chemical into the water flowing through the dispenser. Even further, this invention relates to a hand-held dispenser including means for blocking the flow of liquid chemical into the water so that a water-only rinse spray is obtained.
2. Description of the Related Art
Many types of dispensers have been previously provided which may be connected to the end of a water hose or the like wherein the device introduces chemicals into the water flow so that a lawn or the like may be sprayed. The devices of the prior art are also able to inject liquid chemicals into a water stream so that a mop bucket, etc., may be filled with water, detergent or other chemicals.
In Applicant's earlier U.S. Pat. Nos. 7,237,728 and 7,296,761, hand-held dispensers are disclosed which are able to conveniently and economically precisely control the rate of water flow through the dispenser and to precisely control the metering of liquid chemicals in the precisely controlled flow of water.
Although the dispensers of Applicant's earlier patents have met with considerable success, Applicant has developed an improved hand-held dispenser which is convenient to use which precisely controls the water flow therethrough and which precisely controls the injection of liquid chemicals thereinto. | {
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Not applicable.
Not applicable.
The invention relates to an apparatus for vibration-isolating bearing of loads including at least one first vibration-isolating device, arranged between a load and a standing surface, for at least partially decoupling the static and dynamic forces acting between the load and the standing surface, the first vibration-isolating device comprising a passively isolating coupling element for mechanically decoupling the static and dynamic forces including a natural frequency, at least one second vibration-isolating device, assigned to the load, for imparting control forces to the load for actively damping the substantially decoupled dynamic forces, said second vibration-isolating device comprising a coupling element for dynamically coupling the second vibration-isolating device to the load and the first isolating device, said coupling element including a natural frequency; means for tuning the control forces of the second vibration-isolating device and the natural frequencies, wherein the control forces of the second vibration-isolating device and the natural frequencies are determined by means of characteristic curves describing the functional dependency of the control forces to the natural frequencies of the passively isolating coupling element and the ratio of the natural frequencies. The invention also relates to a method for isolating vibrations of loads, comprising the following steps:
providing at least one first vibration-isolating device for at least partial decoupling of the static and dynamic forces acting between the load and a standing surface with a passively isolating coupling element including a natural frequency,
providing a second vibration-isolating device for imparting control forces to the load, comprising a coupling element for coupling the second vibration-isolating device to the load, the coupling element including a natural frequency,
tuning the control forces of the second vibration-isolating device and the natural frequencies, wherein the control forces of the second vibration-isolating device and the natural frequencies are determined by means of characteristic curves describing the functional dependency of the control forces to the natural frequencies of the passively isolating coupling element and the ratio of the natural frequencies,
providing the control force of the second vibration-isolating device and the natural frequencies of the coupling elements
imparting the tuned control force to the load for actively damping the at least partially decoupled dynamic forces.
Undesired vibrations and shocks are to be found in a multiplicity of technical applications. Such disturbing vibrations have a negative effect, in particular, in the case of highly sensitive, or else very heavy technical units. A computer tomograph weighing several tons may be named by example. An attempt is made to prevent the transmission of vibrations to such machines by what is termed isolation of vibrations. In this case, a purely passive isolation, for example, by the use of a spring, is frequently employed. However, such systems are no longer adequate for particularly heavy loads and for sensitive units, in particular. Consequently, there is an increased shift to the use of what are termed as active systems. The use of active systems for isolating vibrations is highly limited according to the prior art by the very restricted availability of suitable actuators. Specifically, the prior concepts have proceeded from the fact that the actuator or actuators used would have to act directly on the loads for the purpose of isolating vibrations, and so, as a result, they must always bear the entire weight of the installation in order to obtain an adequate isolation of vibrations. As a consequence of this prevailing view, it has been impossible to date to use a multiplicity of actuators that would be suitable in principle for isolating vibrations because of their technical and physical properties within the scope of the prior vibration isolating systems. In particular, these are here what are termed piezoelectric translators or ceramic solid-state actuators that can convert electric energy directly into mechanical energy and vice versa. Piezoelectric actuators can be used only in a very restrictive fashion, if at all, in the existing systems. The reason for this is that piezoelectric actuators for large static loads are, on the one hand, virtually unavailable industrially and, on the other hand, provide only a slight stroke and static loadability.
It is therefore the object of the invention to provide an apparatus for active isolation of vibrations that can be used flexibly for isolating vibrations of loads of different weight and, in particular, permits the use of actuators for isolating vibrations that it has not yet so far been possible to use under the conditions of the prior art.
This object is achieved in the most surprising way by an active system for isolating vibrations having at least one first vibration-isolating device, arranged between a load and a standing surface, for at least partially decoupling the static and dynamic forces acting between the load and the standing surface, the first vibration-isolating device comprising a passively isolating coupling element for mechanically decoupling the static and dynamic forces including a natural frequency, at least one second vibration-isolating device, assigned to the load, for imparting control forces to the load for actively damping the substantially decoupled dynamic forces, the second vibration-isolating device comprising a coupling element for dynamically coupling the second vibration-isolating device to the load and the first isolating device, the coupling element including a natural frequency, means for tuning the control forces of the second vibration-isolating device and the natural frequencies, wherein the control forces of the second vibration-isolating device and the natural frequencies are determined by means of characteristic curves describing the functional dependency of the control forces to the natural frequencies of the passively isolating coupling element and the ratio of the natural frequencies.
The method is carried out according to the invention, which includes
providing at least one first vibration-isolating device for at least partial decoupling of the static and dynamic forces acting between the load and a standing surface with a passively isolating coupling element including a natural frequency;
providing a second vibration-isolating device for imparting control forces to the load, comprising a coupling element for coupling the second vibration-isolating device to the load, the coupling element including a natural frequency;
tuning the control forces of the second vibration-isolating device and the natural frequencies, wherein the control forces of the second vibration-isolating device and the natural frequencies are determined by means of characteristic curves describing the functional dependency of the control forces to the natural frequencies of the passively isolating coupling element and the ratio of the natural frequencies;
providing the control force of the second vibration-isolating device and the natural frequencies of the coupling elements;
imparting the tuned control force to the load for actively damping the at least partially decoupled dynamic forces.
By virtue of the fact that the invention provides an apparatus that comprises at least one first vibration-isolating device, arranged between a load and a standing surface, for at least partially decoupling the static and dynamic forces acting between the load and the standing surface, and includes at least one second vibration-isolating device assigned to the first one and/or the load, for absorbing the substantially decoupled dynamic forces, the possibility arises for the first time that the dynamic forces acting on the apparatus and/or originating from the apparatus can be decoupled substantially from the static forces in a fashion actively isolating vibrations.
In this context, the apparatus according to the invention comprises at least one dynamic coupling element for the purpose of mechanical decoupling of the vibration-isolating devices. Within the purpose of the invention, the coupling element has a property that it can vibrate both in the vertical and horizontal directions, and thereby ensures, inter alia, passive isolation of vibrations.
In a development of the invention, this can be implemented, in particular, by a rubber spring. In a particularly advantageous development of the subject matter of the invention, the rubber spring can comprise a rubber combination or a plurality of interconnected rubber springs.
In a further development of the subject matter of the invention, the vibration-isolating devices according to the invention are arranged and/or tuned with reference to one another and with reference to the load such that the coupling elements assigned to the vibration-isolating devices alternately effect a dynamic coupling between the vibration-isolating devices and the load.
If, to this extent, a passive isolation of vibrations is set up for the first vibration-isolating device, the first device advantageously substantially bears the complete static load. Furthermore, through its physical properties, the passive isolation substantially defines the vibrational dynamics of the apparatus according to the invention. In this case, it is particularly the degree of damping of the coupling element, or in the case of the use of rubber, the stiffness thereof that are to be considered as parameters. Also important, in addition, are, of course, the weight bearing on the passive isolation and, in some circumstances, also the bearing surface of a coupling element on the floor.
It also holds in this context that, according to the invention, the second vibration-isolating device likewise very advantageously comprises a coupling element in such a way that, with reference to the load, stresses that can occur in particular between the second vibration-isolating device and the load can be reduced or even eliminated.
In a positive development of the subject matter of the invention, the coupling element according to the invention can, of course, be fitted not only with rubber springs. In this connection, of course, it would also be possible to use coupling elements in the form, for example, of metal springs, air cushions and/or magnetic levitation devices.
It has proved to be particularly advantageous within the scope of the invention that the dynamic coupling can very positively be set via the physical and/or technical parameters of the coupling elements, and that, in particular, dynamic transmission of force can very advantageously be set, in particular, to the second vibration-isolating device via the setability of the coupling. There is the particularly positive possibility in this way, above all, of setting the force that can be transmitted by the second vibration-isolating device, in particular to the load. In this case, it is possible, above all, in this way also to set the force that can be transmitted by the second vibration-isolating device, in particular to the load. Moreover, however, there is also the possibility in this case to exert a positive influence on the vibration amplitude of the dynamic vibration produced by the dynamic transmission of force such that said dynamic vibration can be set.
In particular, within the scope of the invention, the above-described measures permit the specific adaptation of, for example, building vibration or floor vibration to the isolation of vibration that is to be provided with reference to the technical and physical parameters of the actuators to be used for the purpose of active isolation of vibrations.
In the case of the use of a plurality of rubber springs for the vibration-isolating devices according to the invention, it has proved that in addition, above all, to the stiffness of the rubber in the coupling element of the second vibration-isolating device, the ratio of the rubber stiffness of the individual springs, in particular, can also be a very good measure of the transmission of force. In this case, the stifffiess can be expressed, in particular, by the natural frequencies of the coupling elements or by the natural frequencies of the rubber.
It was possible in the case of the invention also to show that the dynamic transmission of force can be determined in a very simple way from one or more characteristics that reproduce the functional relationship between the natural frequency of the coupling element of the first vibration-isolating device and the ratio of the natural frequency of the coupling element of the first vibration-isolating device to the natural frequency of the coupling element of the second vibration-isolating device. Within the scope of the invention, it is particularly easy in this way, for example given the knowledge of the potential transmission of force, to use the characteristic or characteristics to define and/or select the suitable coupling elements and/or the suitable actuators. Conversely, when the natural frequencies of the coupling elements are given it is also possible, of course, to use the characteristics to determine the possible transmission of force.
The invention renders it possible for the first time, on the basis of the settability and/or determinability of the dynamic transmission of force or of the dynamic vibration with reference to the load to be borne, to make use, for the purpose of active isolation of vibrations, of actuators that have so far not yet been capable of use for vibration isolating systems because of their technical parameters. For this purpose, standard piezoelectric modules and/or piezoelectric actuators are used according to the invention for the purpose of active isolation of vibrations in a development of the subject matter of the invention. The point is that it is possible according to the invention to compensate the properties of piezoelectric actuators previously regarded as disadvantageous: low loadability with respect to static forces, and small stroke. In this case, the piezoelectric modules in the apparatus can be arranged very advantageously such that they exert an active vibration-isolating effect in all directions in space.
In a further development of the subject-matter of the invention, the latter comprises an additional load-bearing means that is assigned, in particular, to the first vibration-isolating device for bearing the load. The load-bearing means according to the invention offers the advantage that the weight of a load lying on it can be distributed uniformly over a plurality of vibration-isolating devices according to the invention. Moreover, such a load-bearing means offers the possibility of producing a local mechanical coupling between the first vibration-isolating device and the second vibration-isolating device.
Furthermore, it lies within the scope of the invention to provide a system that not only has only actuator properties, but also has tensile properties. It is therefore provided according to the invention also to fit the apparatus with a vibration-sensing unit. According to the invention, the latter transmits the exciting movement to the load to be isolated, and also the vibrations that are caused by disturbing forces that act on the load. For the purpose of active isolation of vibrations, within the scope of the invention, the excitations of vibration are fed back to the second vibration-isolating device via a feedback control and/or forward control, in order thus to compensate and/or damp the undesired vibrations.
To this extent, in addition to an active system or apparatus in the case of which the actuator is addressed in terms of regulation and/or control for the purpose of damping vibrations, the present invention also comprises what is termed an adaptive system or adaptive apparatus with sensor and actuator properties that can simultaneously also take over bearing functions and whose multifunctionality also relies on the fact that on the basis of the possibility of using the most varied actuators it permits very flexible and cost effective individual solutions to the active isolation of vibrations of arbitrary loads.
The scope of the invention also includes, of course, a method for isolating vibrations of loads, particular of heavy loads. In this case, the static and dynamic forces originating from a load or acting on the latter are at least partially decoupled, and the dynamic forces thus decoupled are subsequently separately damped. The decoupling of the forces is performed in the course of the passive isolation of the load. The vibrations occurring during the passive isolation are coupled to at least one actuator. This coupling is advantageously performed to the actuator via a spring. It is particularly positive in this context that according to the invention the transmission of force for the actuator can be determined from one characteristic of dependence of the natural frequency of vibration of the passive isolation on the ratio between the natural frequency of the spring with reference to the actuator and the natural frequency of the passive isolation. | {
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Various systems allow users to post and share photos that were taken at different geographic locations. These photos may depict objects (such as streets, buildings and people) present at the locations when the photos were captured. In many situations, these photos may capture an image of other people. For example, a photo taken at a location may capture images of various people in a background scene of the photo. Further, some of those photos may be publicly shared by the person who took the photo. Some people may want to see any images publicly shared online, which include a view of themselves. However, locating these images of a particular person can be difficult, particularly where the person is only partially depicted or is included in the background of an image. | {
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There are a considerable number of vibration testing apparatus that are well-known in the prior art. Such apparatus is used to mechanically shake an item for the purpose of diagnostically testing responses to certain driving forces. The item is physically attached to a moving portion of the apparatus and when the apparatus is activated, the item is subjected to a variety of test conditions. The moving portion of the vibration testing apparatus is typically driven by a force which may be continuous, cyclical or impulsed. One class of such apparatus employs the use of an electromagnetic field between field and armature windings. Various driving signals are impressed across the armature winding to control the movement of the armature. For convenience, the movable member of the vibration testing apparatus may be referred to from time to time hereinafter simply as the armature.
In many of the prior art vibration testing apparatus springs or static air pressure systems were relied upon to center the armature between its axial displacement limits. However, such systems are proving inadequate to meet the present demands for heavier pay loads, increased armature displacement, and unsymmetrical shock and random wave forms. | {
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1. Field of the Invention
This invention relates to a system for pleasurable use by people of all ages with youthful minds in operating remotely controlled vehicles simultaneously in a somewhat confined area. In the system of this invention, the vehicles can be remotely controlled to perform competitive or cooperative tasks. The system includes control pads for operation by the users, vehicles remotely controlled in accordance with the operation of the control pads and a central control station for coordinating the operation of the control pads and the vehicles. In addition to the inventive aspects of the system, each of the control pads, the central control station and the vehicles includes features of an inventive nature. The system of this invention also includes stationary plants (e.g. power plants and elevators) which are controlled by the operation of the control pads. The invention additionally relates to methods including methods for controlling the operation of the vehicles on a remotely controlled basis.
More specifically, this invention relates to remotely controlled vehicles having inventive features such as toy self-loading dump trucks, trailers, forklifts and bulldozers that can be operated to mimic the operation of similar full-size vehicles by employing highly-maneuverable skid steering, having automatic tow hitch actuation mechanisms and having motorized accessories for scooping up transportable elements, transferring the transportable elements to a hopper, automatically activating the hopper to dump the transportable elements, and for gripping, lifting and translating transportable elements.
2. Description of the Related Art
Various types of toy systems exist, and have existed for some time, in which vehicles are moved on a remotely controlled basis. Examples of a vehicle in such a system are an automobile, airplane, truck or construction vehicle. In most such systems, however, the functions and activities that the vehicle is capable of are limited to merely maneuvering a vehicle about on the ground, in the air or in the water. Other types of toy systems involve the use of blocks for building structures. These blocks often include structure for providing an interlocking relationship between abutting blocks. In this way, elaborate structures can be created by users with creative minds. However, such structures are generally built by hand manipulation of the blocks or hand manipulation of a mechanism of toy vehicle for handling the blocks.
Experience has proven that there is a desirability, and even a need, for play systems in which vehicles are remotely operated to perform functions other than merely being steered or maneuvered through a path of travel. For example, there exists a desire for a play system in which the remotely controlled vehicles have the capability of transporting elements such as building blocks maneuverable into position to build a toy or other structure. It is desirable that such systems employ a plurality of vehicles remotely controlled by switches in hand-held control pads so they can compete against one another in performing various tasks such as moving building blocks into place to build a miniature building.
Co-pending application Ser. No. 08/580,753 filed by John J. Crane on Dec. 29, 1995, for a "Remote Control System for Operating Toys" and assigned of record to the assignee of record of this application discloses and claims a play system for use by people of all ages with youthful minds. It provides for a simultaneous control by each player of an individual one of a plurality of remotely controlled vehicles. This control is provided by the operation by each such player of switches in a hand-held unit or pad, the operation of each switch in such hand-held unit or pad providing a control of a different function in the individual one of the remotely controlled vehicles. Each of the remotely controlled vehicles in the system disclosed an claimed in application Ser. No. 08/580,753 can be operated in a competitive relationship with others of the remotely controlled vehicles or in a co-operative relationship with others of the remotely controlled vehicles. The vehicles can be constructed to pick up and transport elements such as blocks or marbles and to deposit such elements at displaced positions.
When manually closed in one embodiment of the system disclosed and claimed in application Ser. No. 08/580,753, switches in pads control the selection of toy vehicles and the operation of motors for moving the vehicles forwardly, rearwardly, to the left and to the right and moving upwardly and downwardly (and rightwardly and leftwardly) a receptacle for holding transportable elements (e.g. marbles) or blocks.
When sequentially and cyclically interrogated by a central station, each pad in the system disclosed and claimed in application Ser. No. 08/580,753 sends through wires to the central station signals indicating the switch closures in such pad. Such station produces first binary signals addressing the vehicle selected by such pad and second binary signals identifying the control operations in such vehicle. Thereafter the switches identifying in such pad the control operations in such selected vehicle can be closed without closing the switches identifying such vehicle.
The first and second signals for each vehicle in the system disclosed and claimed in application Ser. No. 08/580,753 are transmitted by wireless by the central station to all of the vehicles at a common carrier frequency modulated by the first and second binary signals. The vehicle identified by the transmitted address demodulates the modulating signal and operates its motors in accordance with such demodulation. When the station fails to receive signals from a pad for a particular period of time, the vehicle selected by such pad becomes available for selection by another pad and such pad can select that vehicle or another vehicle.
A cable may couple two (2) central stations (one as a master and the other as a slave) in the system disclosed and claimed in application Ser. No. 08/580,753 so as to increase the number of pads controlling the vehicles. Stationary accessories (e.g. elevator) connected by wires to the central station become operative when selected by the pads.
Co-pending application Ser. No. 08/763,678 filed by William M. Barton, Jr., Peter C. DeAngelis and Paul Eichen on Dec. 11, 1996 for a "System For And Method Of Selectively Providing The Operation Of Toy Vehicles" and assigned of record to the assignee of record of this application discloses and claims a system wherein a key in a vehicle socket closes contacts to reset a vehicle microcontroller to a neutral state. Ribs disposed in a particular pattern in the key operate switches in a particular pattern in the vehicle to provide an address for the vehicle with the vehicle inactive but powered. When the vehicle receives such individual address from an individual one of the pads in a plurality within a first particular time period thereafter, the vehicle is operated by commands from such pad. Such individual pad operates such vehicle as long as such vehicle receives commands from such individual pad within the first particular period after the previous command from such individual pad. During this period, the vehicle has a first illumination to indicate that it is being operated.
When the individual pad of the system disclosed and claimed in application Ser. No. 08/763,678 fails to provide commands to such vehicle within such first particular time period, the vehicle becomes inactive but powered and provides a second illumination. While inactive but powered, the vehicle can be addressed and subsequently commanded by any pad including the individual pad, which thereafter commands the vehicle. The vehicle becomes de-activated and not illuminated if (a) the vehicle is not selected by any of the pads during a second particular time period after becoming inactivated but powered or, alternatively, (b) all of the vehicles become inactivated but powered and none is selected during the second particular period. The vehicle becomes de-activated and not illuminated. The key can thereafter be actuated to operate the vehicle to the inactive but powered state.
Co-pending application Ser. No. 08/696,263, filed by Peter C. DeAngelis on Aug. 13, 1996 for a "System And Method Of Controlling The Operation Of Toys" and assigned of record to the assignee of record of this application discloses and claims a system wherein individual ones of pads remotely control the operation of selective ones of vehicles. In each pad, (a) at least a first control provides for the selection of one of the vehicles, (b) second controls provide for the movement of the selected vehicle and (c) third controls provide for the operation of working members (e.g. pivotable bins) in the selected vehicle. Each pad provides a carrier signal, preferably common with the carrier signals from the other pads. Each pad modulates the carrier signal in accordance with the operation of the pad controls. The first control in each pad provides an address distinctive to the selected one of the vehicles and modulates the carrier signal in accordance with such address.
Each pad of the system disclosed and claimed in application 08/696,263 sends the modulated carrier signals to the vehicles in a pseudo random pattern, different for each pad, with respect to time. Each vehicle demodulates the carrier signals to recover the address distinctive to such vehicle. Each vehicle then provides a movement of such vehicle and an operation of the working members in such vehicle in accordance with the modulations provided in the carrier signal by the operation of the second and third controls in the pads selecting such vehicle. Each vehicle is controlled by an individual one of the pads for the time period that such pad sends control signals to such vehicle within a particular period of time from the last transmission of such control signals to such vehicle. Thereafter such vehicle can be selected by such pad or by another pad.
What has been needed, and heretofore unavailable, is a toy system including vehicles remotely operated to accomplish tasks such as lifting, scooping, dumping, leveling, and hauling suitably sized materials and towing of trailers carrying such material, or other vehicles, in combination to create a miniature community or industrial environment, thus providing a person having a youthful mind with the opportunity to employ a remotely-controlled system of vehicles and mechanisms to accomplish these tasks and others within a reduced-scale, industrial environment in cooperation or competition with other individuals in a pleasurable manner. | {
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Consumers often indicate that obtaining an insurance product can be a time consuming and tedious process, requiring the consumer to provide detailed information that often is not readily remembered by or available to the consumer. The consumer must research information requested by an insurance agent in order to obtain a reliable indication of how much the consumer's insurance premium might be. As a result, consumers can be hesitant to research insurance rates because of the time believed to be involved with obtaining an insurance quote.
A previous approach involved obtaining in-depth information about the consumer in order to develop a price estimate. Because insurance, e.g., auto insurance, is tailored to the individual applying for insurance and/or the property being insured, the individual would provide his or her driver's license number, home address, VIN number for the vehicle(s) and other specific personal information. Based on this specific personal information, the agent or insurance company would use sophisticated quoting tools and charts to develop a quote. The extent of this personal information creates a barrier to marketing and lead generation because it is time-consuming for the customer to provide. Additionally, as consumers' sensitivity to providing personal information has increased, consumers increasingly do not want to provide such extensive information in order to shop for insurance.
As an alternative to providing detailed information to obtain a quote, consumers often request a less precise estimate of what his or her insurance premium might be. However, given the large number of factors that must be taken into account in determining an insurance quote, providing even an estimate can be a difficult task. The basic tension in providing a meaningful estimated insurance quote to a member of the public, who is not an existing customer of an insurance company, is accuracy versus speed. Both elements of this equation are largely dependent upon the amount of information provided—the information which forms the basis for an estimated quote. If the person submits a great deal of information to the process then the estimate will likely be much more accurate, but the process will also be very time consuming and cumbersome to the person. At the other end of the spectrum, if the person submits very little information to the quoting process then the process is much more “user friendly” and quicker; however, the estimate may not be very accurate.
Inaccurate estimates result in lower chances of closing on a new policy with the consumer as well as decreased customer satisfaction. When the consumer subsequently provides more detailed information and the policy for that individual is developed, the price might not meet the expectations of the consumer because his or her expectations were premised on the estimate that turned out to be inaccurate. | {
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A new model for purchasing a computer system has emerged in the computer industry, referred to as capacity-on-demand billing. According to this model, the customer agrees to purchase a computer system with a fixed baseline performance capability level based on a quantity of computer resources installed on the computer system (i.e., the number of Central Processing Units (CPUs), memory units, and/or Input/Output (I/O) modules, available in the computer system). In return, the manufacturer of the computer system agrees to install extra computer resources on the computer system at no upfront expense to the customer, and the customer is entitled to use the extra computer resources, but on a pay-per-use basis. Automated usage metering technology employed with the computer system detects when the customer's resource usage exceeds a threshold level, i.e., the fixed baseline performance capability level, and the customer is charged a usage fee for excessive usage over the threshold. Typically, the usage metering technology operates in the background recording computer resource utilization data and transmitting the data to a billing site for invoicing.
An advantage of the capacity-on-demand billing model is that it allows the customer to purchase a computer system with reserve capacity, but at no additional upfront costs. This means a customer may have additional resources instantly available during periods of high computing demand, but without the penalty of having to purchase extra computer resources that lay dormant during slower demand periods.
Ensuring the customer is accurately charged for using computer resources above an agreed threshold is a challenge with the capacity-on-demand billing model. For instance, some usage metering technologies rely on averaging methods that tend to record the resource utilization of a computer system over relatively long periods and often fail to account for the moment-by-moment operation of a typical computer system performing real-world tasks. For example, suppose a customer purchased a computer system with an agreed to maximum threshold of four CPUs, but in actuality, resident with the computer system are 16 CPUs. Now suppose that for three hours out of the day the customer uses 12 CPUs worth of processing power and for the remaining 21 hours the customer uses only two CPUs worth of processing power. If the usage metering technology uses an averaging method, it would appear that the customer only used 3.2 CPUs worth of CPU resources, which is well within the customer's baseline threshold of four CPUs. In reality, for three hours out of the day during peak usage, 12 CPUs were used and the customer should have been charged for using eight additional CPUs over their four base CPUs. In other words, but for the ability to use the additional CPU resources during peak usage times, the customer's work would not have been completed in a timely fashion, and the customer ought to have been charged for using extra resources, but was not in this scenario. Thus, a drawback with sampling usage data on an averaging basis is the likelihood that the metering usage tool may fail to capture short-lived events, and may produce results with a lower computer resource utilization level than actually occurring in a computer system.
To compensate for averaging problems, some usage metering tools attempt to collect system resource data metrics, such as CPU and I/O performance data, at high frequencies to accurately reflect system resource utilization. A drawback, however, of sampling performance data at high frequencies is a tendency to consume a substantial amount of system resources, which skews computer resource consumption measurements, is expensive, and burdensome. | {
"pile_set_name": "USPTO Backgrounds"
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In packet-switched networks, a router is a network device or, in some cases, software in a computer, that determines the next network point to which a packet should be forwarded toward its destination. The router is connected to at least two networks and decides which way to send each information packet based on its current understanding of the state of the networks it is connected to. A router is located at any gateway where one network meets another and is often included as part of a network switch.
Typically, packets are transported through a router by hardware and software operating in a data plane which is in turn controlled by hardware and software operating in a control plane. In general, the control plane includes the hardware and software that handles non-wire speed functions and data that are required to operate a network device or network. These functions include connection, setup, and tear down, operations, administration, and management. In general, the data plane includes the hardware and software that handles the classification, modification, scheduling, and transmission of wire-speed application data. The control and data planes maybe combined into a single processing plane.
To improve availability, a router may be equipped with redundant or two control, data, or processing planes. A first control plane, for example, is designated as the active control plane and a second control plane is designated as the inactive control plane. In the event that a device in the active control plane fails, the inactive control plane takes over to reduce down time and hence maintain availability of the router. In such a case, activity is said to switch from the active control plane to the inactive control plane, that is, the two planes exchange roles. Routers and other network devices having redundant systems (i.e., control or data plane devices) are often referred to as “high availability” systems. Thus, a typical high availability router may have two main processing cards that run the same software and perform the same operation. If one card fails in the field, the other card takes over in order to keep the router up and running. Such a router is highly available as the card redundancy ensures that the router is almost always operable or available.
Thus, in a redundant or high availability system, two redundant control planes or cards typically run the same software as mentioned above. Even if both control plane cards are running, the system is still one system and therefore only one control card can configure and operate the system. This one card is the active card. The other card remains in a standby mode monitoring what is going on within the system. It is the inactive card. If the active card fails, then the inactive card takes over and becomes the active card. This is an activity switch. An activity switch can occur due to a failure of the active card, but it is also possible to trigger an activity switch by removing the active card from the system to perform an upgrade, for example. An activity switch may also be generated by entering a software command but this is typically done only for internal debugging purposes. An activity switch may also be generated by entering a software command.
In addition to control and data plane cards, the router also includes various-external modules or “off-card” assemblies or cards that may be plugged into (or unplugged from) the system. They are physically separated from the control planes but connect to them once they are inserted into the system. Typically, an off-card assembly terminates the control path and the data path.
One problem with current control plane management schemes is that they cannot typically detect and respond quickly enough to changes on multiple off-card assemblies, particularly when an activity switch is required in a high availability system in order to maintain stringent customer service level agreements. This problem causes the following: loss of bandwidth resulting from control plane traffic timing out when the status from an off-card assembly changes (or has been removed) and cannot be responded to efficiently; and, loss of reliability resulting from unauthorized write accesses to the off-card assembly from the inactive control plane. In addition, off-card assemblies cannot quickly detect and react to an activity switch in order to optimize performance of the active control plane and hence maintain bandwidth.
Another problem with current control plane management schemes relates to reset mechanisms. Control plane cards and off-card assemblies are typically provided with reset mechanisms which may be based, for example, on the power provided to the card. Until a card is properly powered-up and its alimentation (i.e., support and maintenance) is stable, a reset line or pin is kept low hence keeping the card in a reset state. The use of such reset mechanisms in high availability systems can be problematic. First, in general, existing reset mechanisms cannot target resets to a subset of the logic on a control plane or on an off-card assembly. This prevents the core logic from staying in-service during an activity switch or a failure and can result in increased recovery time (which is contrary to the objective of a high availability system). Second, existing reset mechanisms cannot detect and respond to changes in conditions in a timely fashion, which is important for high availability systems (i.e., to maintain customer service level agreements). Third, existing reset mechanisms cannot properly handle independent reset instructions from redundant control planes, thereby preventing resolution of conflicts and leading to false resets. Fourth, existing reset mechanisms use many signals to distribute reset instructions to multiple off-card assemblies. This increases package pin count, which leads to increased system cost.
A need therefore exists for an improved method and system for control plane signaling in high availability network devices such as routers. Accordingly, a solution that addresses, at least in part, the above and other shortcomings is desired. | {
"pile_set_name": "USPTO Backgrounds"
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The present invention relates to noise dissipation panels, and more particularly to acoustic liners and arrangements of liners in aircraft engines and surrounding surfaces.
Aircraft engine noise is a significant problem in high population areas and other noise controlled environments. Attempts currently focus on lining the aircraft engine nacelle and surrounding engine areas with acoustic liners to reduce the amount of noise radiating to the community.
As background information regarding general engine acoustic theory, there exists a linearized wave equation that describes the acoustic pressure distributions present in an airflow duct. This wave equation has a general solution given by a superposition (i.e., discrete summation) of eigenfunctions. Eigenfunctions vary with the boundary conditions at the duct wall, i.e., the wall""s impedance. There are an infinite number of such eigenfunctions, each with an associated eigenvalue, that are referred to as the xe2x80x9cmodes of propagationxe2x80x9d, or xe2x80x9cmodesxe2x80x9d for short. In general, low order modes have eigenvalues that are low in absolute value. High order modes have eigenvalues that are high in absolute value. Typical low mode order values for aircraft engine noise are 0 to 5, though the range will change depending on frequency, duct size, etc. Typical high mode order values for aircraft engine noise are 8 to 15, though, these will also vary.
As used in the discussions below, the term xe2x80x9clow mode order noisexe2x80x9d is meant to describe noise waves that are represented mathematically by relatively low absolute value eigenvalues with respect to the range of noise modes present in a given application. When viewed physically, the order of mode corresponds generally to the angle of wave propagation in the duct relative to the duct walls. As shown in FIG. 1, engine noise wavefronts 12 propagate along the duct 13 at various angles xcex8 relative to the duct walls 14. If the angle is zero, the wave is said to be a fundamental wave 15, i.e., xcex8=xcex8f=0. Fundamental waves have wavefronts that travel in the axial direction of the duct and have a uniform pressure distribution at any particular duct cross-section.
In addition to fundamental waves, there are non-fundamental noise wavefronts which reflect back and forth between the duct walls as the wavefronts travel along the duct. These non-fundamental wavefronts create a non-uniform pressure distribution across the duct cross-section. The non-fundamental waves are generally classified according to their angular directions relative to the duct walls. Low order modes of noise propagation have wavefronts 16 oriented at small angles as measured relative to the duct walls, i.e., xcex8=xcex8lxe2x89xa6approximately 30 degrees. High order modes of noise propagation have wavefronts 17 oriented at relatively larger angles as measured from the duct walls, i.e., xcex8=xcex8hxe2x89xa7approximately 60 degrees. A wide range of noise frequencies exists for each mode order, low or high. For further discussion of theoretical considerations, see Aeroacoustics of Flight Vehicles, by Harvey H. Hubbard, published for the Acoustical Society of America through the American Institute of Physics, 1995. See also, Theoretical Acoustics, by Philip M. Morse et al., McGraw-Hill Book Company, dated 1968.
In a given aircraft application, an engine will generate both high and low mode order noise. Current design practice focuses on reducing this noise through the use of absorptive acoustic liners. Absorptive liners are known in various configurations, including the use of a honeycomb core sandwiched between an imperforate sheet and a perforate sheet having a small amount of open surface area. This particular combination is sometimes referred to as a single degree of freedom absorptive acoustic liner.
Absorptive liners are successful because pressure waves cause air to pass into and out of the openings of the perforate sheet and to experience a sufficient amount of friction, or resistance, which is dissipated as heat energy. The overall impedance of an acoustic liner is a complex number, given by a real part, the resistance, and an imaginary part, the reactance. Resistance relates to the liner""s ability to dissipate noise energy as heat. Reactance relates to the liner""s tendency to react noise energy back onto itself Absorptive liners provide moderate resistance and low reactance for high mode order noise waves.
FIG. 2 illustrates the theoretical effect of using absorptive liners for a hypothetical case. A given total noise energy 18 is initially comprised of a combination of one low and one high mode order noise 19, 21, each having equal energy. Starting at the beginning of the duct at position 0, the total noise energy 18 encounters an absorptive liner that quickly reduces the high mode order noise 21 and more slowly reduces the low mode order noise 19. Since high mode order noise attenuates quickly in the duct, only a relatively short duct length is needed to dissipate most of the high mode order noise present. In FIGS. 2 and 3, the vertical axis is logarithmic. A change of about xe2x88x923 dB, for example, refers to a reduction in noise energy of about half The horizontal axis is normalized to be dimensionless. The exact values of the information shown in FIGS. 2 and 3 will vary according to the characteristics of a particular application, and in general there will be energy in more than two modes.
As is evident by FIG. 2, absorptive liners are very effective for absorbing high mode order noise 21, but are inefficient for reducing low mode order noise 19, i.e., those noise wavefronts traveling along the duct at a low angular displacement relative to the duct walls. Propagating at low angles, these low order modes strike the absorptive liners fewer times in a given length of duct. Therefore, to reduce all of the low mode order noise requires a greater length of acoustic lining than is typically possible in the space-limited regions of aircraft engines. Noise reduction from use of absorptive liners is thus practically limited to higher mode order noise.
Thus, a need exists for an acoustic liner, or arrangement of liners, that effectively reduces both high and low mode order noise. The present invention is directed to fulfilling this need.
The present invention provides a new type of acoustic liner and arrangement of liners specifically for use in dissipating low mode order noise. This new liner is termed a low resistance acoustic liner and includes a middle layer, or core layer, having partitioned cavities. The cavities aid in scattering a large amount of low mode order noise into higher mode order noise. An imperforate sheet is attached to one side of the middle layer. A perforate sheet having a large open surface area is optionally attached to the middle layer, opposite the imperforate sheet, so that the partitioned cavities of the middle layer are substantially sandwiched between the imperforate and the perforate sheets. The perforate sheet stops the whistling effect caused by high speed air flowing into the cavities and minimizes airflow drag as may be required for some applications, e.g., in aircraft engines. The preferred middle layer material for high-speed commercial aircraft engines is honeycomb core having cavities with axes preferably oriented perpendicular to the central plane of the core.
In accordance with further aspects of the invention, the preferred middle layer cavity depth is approximately one quarter the noise wavelength sought to be reduced. The middle layer cavities may also be comprised of cavities having varying depths. The preferred average diameter of each middle layer cavity is equal to or less than approximately one tenth the noise wavelength. For noise having wavelengths from 3 to 12 inches, the cavity depth is between roughly 0.75 and 3 inches, and the cavity average diameter is between roughly 0.3 to 1.2 inches.
In accordance with other aspects of the invention, the perforate sheet includes uniformly distributed openings. The percent open area of the perforate sheet is preferably in an amount of at least 15% the entire perforate sheet surface area. These openings are preferably holes that have diameters less than the average cavity diameter. The low resistance acoustic liner has an absorption coefficient of about 0 to 0.5, the preferred value being less than 0.5. The low resistance acoustic liner has a resistance coefficient of about 0 xcfx81c to 0.5 xcfx81c, the preferred value being 0.3 xcfx81c.
In accordance with yet further aspects of the invention, a preferred method of manufacturing a low resistance acoustic liner having cavities of constant depth includes attaching the imperforate sheet to one side of the middle layer using an adhesive. The perforate sheet is attached to the opposite side of the middle layer also using an adhesive.
In accordance with yet other aspects of the invention, a preferred method of manufacture for creating cavities of varying depth includes providing a support layer of hardened wax-like material, placing an uncured imperforate septum on top of the support layer, placing a middle layer formed of a partitioned cavity material (e.g., honeycomb core) on top of the uncured imperforate septum, and using a uniform force to press the middle layer through the septum and the support layer until the septum is located at a desired cavity position. The septum is cured to form the imperforate sheet. After curing, the support layer is removed, such as by melting, and a perforate sheet is optionally attached to the side of the core opposite the cured septum.
In accordance with still further aspects of the invention, the desired imperforate septum material is a thermoplastic, resin, rubber, or rubber-like film material with which the middle layer can be used to xe2x80x9ccookie-cutxe2x80x9d during pressing and that which can be later cured to form a seal within each cavity. The preferred support layer material is wax. The support layer is of varying cross-sectional thickness in order to cause the imperforate sheet to be located at different heights within the middle layer cavities. A mating layer may be optionally used to aid in supporting the middle layer as it is forced through the uncured imperforate septum and support layer. The mating layer is placed between the uncured imperforate septum and the middle layer prior to pressing. The surface shapes of the mating layer and the support layer are matched. The method of making a low resistance acoustic liner may optionally include the step of warming the support layer prior to pressing so that the support layer may be more easily cut by the middle layer.
In accordance with still other aspects of the invention, a first embodiment of acoustic liners includes inner and outer linings formed of alternating low resistance liners with absorptive liners. The liners are positioned side-by-side and extend within an airflow duct for a length as necessary or as space allows. It is preferable that an absorptive liner initially precede the first low resistance liner. The liners may be formed to replace duct walls or may be attached directly to the existing duct walls. All liners are placed with their imperforate sheets located farthest from the airflow. The low resistance acoustic liner surface area adjacent the airflow is sized approximately 5% to 25% the size of the absorptive liners. For circular engine locations such as in the bypass duct surrounding an turbofan engine core, the liners are formed as annuluses.
In accordance with yet additional aspects of the invention, a second embodiment of acoustic liners includes inner and outer linings with a splitter positioned generally mid-way between the linings. The splitter may be formed entirely of low resistance acoustic liner or may formed as a combination of both low resistance liner and absorptive liner. For circular engine locations, it is preferable to use annular liners attached to surrounding engine structures using conventional attachment methods. | {
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A wide variety of different forms of saws and similar cutting devices are generally known and used. Conventional manual saws, as used for cutting both wood and metal, have saw teeth inclined in one direction. In use, the saw moves reciprocally; movement in one direction constitutes a cutting stroke whereas movement in the opposite direction merely returns the saw blade to the beginning of another cutting stroke.
Saw teeth are often bent outwardly of the plane of the saw blade, alternately left and right, to produce a cut wider than the saw blade, so that the blade can slide through the cut easily without jamming. For carpentry and metal work, the saw usually has a single handle and is operated by one person; for felling trees larger two-handled saws are employed, worked by two people. In the latter, some of the teeth may be inclined in one direction and the balance inclined in the other so that a partial cutting action is achieved in each stroke of the saw.
Mechanically driven saws of various types operate on the same basic principles. Thus, the teeth of circular saws, including planing and smoothing saws, are usually all inclined in a single direction and the saw is consistently rotated in one direction. The same characteristics apply to chain saws, in which the saw teeth are mounted on an endless chain driven either by an electric motor or an internal combustion engine. For bench work, an endless band is often employed as the carrier of the saw teeth, with a unidirectional drive. It is also known to provide gang saws consisting of several parallel blades held in a single frame, with the blades actuated in a reciprocating movement to cut the material simultaneously in several locations. The variety of mechanically driven saws is almost endless, including saber saws, jig saws, and many other examples.
In any of these known saws and similar cutting devices, the saw teeth are subject to substantial wear. This is true even with respect to saws employed in cutting relatively soft woods, since the wood is at least somewhat abrasive and continuously erodes the saw teeth. In metal saws, harder metals are employed for the saw teeth, but the problem of wear is nevertheless present.
In virtually any conventional saw that is used regularly, the wear on the teeth necessitates periodic sharpening in order to maintain an efficient cutting operation. Saw sharpening requires specialized machinery and trained personnel; precision alignment and shaping of the teeth is essential to effective operation. Moreover, care must be exercised in grinding the saw teeth, in a sharpening operation, to avoid overheating of the teeth with consequent possible annealing and softening of the cutting elements of the saw.
One particular application in which the necessity for regular re-sharpening of a saw is highly disadvantageous is in the felling, cutting, and shaping of trees for railroad ties. This is particularly true in tropical and subtropical locations, where work conditions are quite difficult and skilled personnel are frequently unavailable. In applications of this kind, and especially where the trees are of hardwood varieties, the cost of saw maintenance may be an appreciable element of the overall cost of operation, and may be so high as to preclude economical use of available resources. Most conventional saws are inadequate and uneconomical, particularly for the cutting and shaping of tropical hardwoods, because the useful life of the saw is quite short and frequent re-sharpening and setting is necessary.
Another disadvantage of conventional saws is that the saw teeth have no point of support other than the actual cutting edges. This is particularly true with respect to planing saws, which often exhibit excessive vibration caused by the lack of support for the saw teeth, other than the cutting edges.
One saw construction in which these difficulties are partially alleviated is described in Topolinski U.S. Pat. No. 2,795,247, issued June 11, 1975. In the construction shown in the Topolinski patent, the saw teeth are inclined alternately in opposite directions, and alternate pairs of the saw teeth are bent outwardly of opposite sides of the saw blade. With this construction, the trailing teeth of each pair are partly self-sharpened as they ride through the cut made by the other teeth of the pair, and the saw can be reversed in direction to afford an extended period between re-sharpening operations. However, the use of the conventional laterally bent construction for the teeth to widen the saw cut limits the effectiveness of the self-sharpening operation and allows for undesirable vibration. Moreover, the individual teeth still have no support other than the actual cutting edge of the tooth itself. | {
"pile_set_name": "USPTO Backgrounds"
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1. Field of the Invention
The present invention relates to a vibration damping device to be used, for example, for engine mounts and the like on motor vehicles.
2. Description of the Related Art
Conventionally, there has been known a vibration damping device interposed between members constituting a vibration transmission system to link or support the members each other in a vibration damping manner, which has been considered for application to engine mounts and the like on motor vehicles. This vibration damping device, as shown in Japanese Unexamined Patent Publication No. JP-A-11-311291 and others, has a structure where a first mounting member and a cylindrical second mounting member are elastically connected by a main rubber elastic body.
By the way, in the vibration damping device described in JP-A-11-311291, the first mounting member is arranged on the upper side of the second mounting member to be attached to the vibration source such as a power unit, while the second mounting member is attached to the member to be vibration-damped such as a vehicular body. In contrast, Japanese Patent No. JP-B-4755147 proposes an inverted vibration damping device, wherein the first mounting member is arranged on the lower side of the second mounting member to be attached to the member to be vibration-damped, while the second mounting member is attached to the vibration source.
However, since a massive bracket is fixed by press-fitting to the second mounting member constituting the upper portion of the vibration damping device in the vibration damping device shown in JP-B-4755147, the center of gravity thereof is positioned in the upper portion, which posed a risk of developing problems such as lack of rigidity of the vibration damping device in the falling direction.
In addition, in the structure of JP-B-4755147, since an axis-perpendicular stopper member that restricts relative displacement between the first mounting member and the second mounting member in the axis-perpendicular direction (front-back direction of the vehicle) is provided on the upper portion of the vibration damping device, there were some problems such as further deviation upward of the center of gravity position and a risk of adverse effects on the load bearing performance or ride comfort caused by a stopper load of the axis-perpendicular stopper member acting on the upper portion of the vibration damping device during acceleration and deceleration of the motor vehicle. | {
"pile_set_name": "USPTO Backgrounds"
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The present invention relates to fastening devices and relates more particularly to a fastening device for fastening a key chain to one'waist belt or clothes.
Key chain is a device commonly used holding a bunch of keys. When in use, people tend to attach a key chain to one's waist belt or clothes by a clip or clamp. FIG. 1 illustrates a known structure of key chain clip for fastening a key chain to one's waist belt or clothes. This structure is not satisfactory in use because the teeth of the clip may damage one's waist belt or clothes easily when it is in use. FIG. 1--1 illustrates a known structure of R-shaped clamp for fastening a key chain to one'waist belt or clothes. This structure is still not satisfactory in use due to weak clamping force. | {
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1. Field of the Invention
The invention relates to an attachment which is mounted on a rotary lawn mower for cleaning the underside of the mower and, more particularly to a quick disconnect attachment which is combatable with garden hose connections.
2. Description of the Prior Art
There is a problem in the prior art in obtaining a suitable means for cleaning the underside of lawn mowers.
In reviewing the prior art patents in this area, it is seen that U.S. Pat. No. 2,936,563 discloses a rotary lawn mower having a water conduit connected through the mower housing. The conduit portion external to the housing is connectable to a hose and the tubular pipe section conduit internal to the housing extends within the housing some distance above the blade. The problems with this attachment are that the tubular pipe conduit internal of the housing extends internally such a distance that it tends to catch grass a debris and itself has to be cleaned, and also is in such close proximity to the blade that there is always the possibility of being hit by the rotating blade which could result in extensive damage. A further problem is that the conduit pipe portion external to the housing requires a complicated system of attaching the hose which requires time and effort.
U.S. Pat. Nos. 3,214,893 and 3,040,990 are also directed to washer attachments for rotary lawn mowers but also have problems associated with complicated attachment elements.
A point of particular interest in this situation is in general use today are quick disconnect attachments for water hoses and other water supply equipment. These devices are popular because of their simplicity of connection and disconnection and their efficiency of use. However, the devices are not compatible with present day lawn mower cleaning attachments because of the lack of a quick connect receiver to connect the same to lawn mowers. It would be a significant improvement in the field if such quick disconnect attachments could be used with a lawn mower cleaning device.
Thus a need exists for an attachment for rotary lawn mowers which efficiently cleans the interior surface of the mower, is inexpensive, is easy to install, is easily attachable to, and easily disconnectable from, hose quick disconnect attachments, does not create an internal cleaning problem because of grass or debris being caught therein, is durable and rust resistant, and is not located in such close proximity so as to come in contact with the blade of the mower. | {
"pile_set_name": "USPTO Backgrounds"
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1. Field of Invention
The present invention relates generally to methods and apparatus for improving the performance of software applications. More particularly, the present invention relates to methods and apparatus for reducing the number of edges in an interference graph.
2. Description of the Related Art
In an effort to increase the efficiency associated with the execution of computer programs, many computer programs are xe2x80x9coptimized.xe2x80x9d Optimizing a computer program generally serves to eliminate portions of computer code which are essentially unused. In addition, optimizing a computer program may restructure computational operations to allow overall computations to be performed more efficiently, thereby consuming fewer computer resources.
An optimizer is arranged to effectively transform or a computer program, e.g., a computer program written in a programming language such as C++, FORTRAN or Java bytecodes, into a faster program. The faster, or optimized, program generally includes substantially all the same, observable behaviors as the original, or pre-converted, computer program. Specifically, the optimized program includes the same mathematical behavior has its associated original program. However, the optimized program generally recreates the same mathematical behavior with fewer computations.
As will be appreciated by those skilled in the art, an optimizer generally includes a register allocator that is arranged to control the use of registers within an optimized or otherwise compiled, internal representation of a program. A register allocator allocates register space in which data associated with a program may be stored. A register is a location associated with a processor of a computer that may be accessed relatively quickly, as compared to the speed associated with accessing xe2x80x9cregularxe2x80x9d memory space, e.g., stack or heap space, associated with a computer.
Often, in order to allocate registers and stack slots, interference graphs are used to facilitate the allocation process. Interference graphs generally include a representation of a live range for each variable or value associated with a particular portion of code. A live range is generally a range in a portion of code over which a particular variable or value must remain accessible and available for use. A coloring process may be used on an interference graph to represent relationships between live ranges of variables represented in the interference graph, as will be appreciated by those skilled in the art.
Interference graphs are typically generated by a compiler during a process of compiling source code. FIG. 1 is a diagrammatic representation of a compiler with a register allocator. Source code 102 is provided as input to a compiler 106 which includes a register allocator 110. Compiler 106 may be an optimizing compiler, and is generally arranged to produce an internal representation 120 of source code 102. As shown, a live range 132 for a variable stored in xe2x80x9cCXxe2x80x9d overlaps a live range 134 for a variable stored in xe2x80x9cDX.xe2x80x9d Accordingly, when register allocator 110 assigns registers to live ranges 132, 134, the registers must be assigned to prevent interference between the registers.
Source code 102 includes a call 140 to a subroutine. In general, calls are relatively common in source code, especially source code created in a computing language such as the C++ programming language or the Java(trademark) programming language, developed by Sun Microsystems, Inc. of Palo Alto, Calif. Call 140 includes variables xe2x80x9cCXxe2x80x9d and xe2x80x9cDXxe2x80x9d as arguments. Specifically, call 140 is made with the contents ofxe2x80x9cCXxe2x80x9d and xe2x80x9cDXxe2x80x9d as arguments. Typically, during register allocation, at least some of the variables associated with call 140 are bound to specific registers. In other words, no other variables may use the registers to which arguments associated with call 140 are bound. As will be appreciated by those skilled in the art, incoming parameters used by some methods may also be bound to specific registers.
The information provided in internal representation 120 may be used to create an interference graph of source code 102. With reference to FIG. 2, an interference graph created as a representation of source code 102 of FIG. 1 will be described. An interference graph 204 is created to represent live ranges and conflicts between live ranges with respect to register allocation. All variables associated with source code 102 of FIG. 1 are represented in interference graph 204. Nodes 208 represent live ranges for variables. By way of example, node 208d is arranged to indicate a live range for xe2x80x9cCX,xe2x80x9d while node 208e is arranged to indicate a live range for xe2x80x9cDX.xe2x80x9d It should be appreciated that a representation of the live range for a variable associated with xe2x80x9cDX,xe2x80x9d which is bound to a specific real register, is included in interference graph 204.
Edges 212 drawn between two nodes 208 indicate that the two nodes 208 interfere. That is, edges 212 that are present between two nodes 208 are arranged to show that the variables associated with the two nodes 208 may not be stored in the same register, as they must be live simultaneously. For example, edge 212d between node 208d and node 208e indicates that contents of xe2x80x9cCXxe2x80x9d and contents of xe2x80x9cDXxe2x80x9d must be alive simultaneously and, as a result, interfere with each other, e.g., conflict with each other.
Building and manipulating, e.g., coloring, an interference graph in the course of performing a register allocation is intended to allow registers to be assigned to variables without conflicts. In general, the process of assigning registers to variables without interference, using an interference graph or other approach, is relatively complex. Interference graphs are often relatively large, and may require more than approximately 12 megabytes of memory space for a bit-set implementation when approximately 10,000 nodes are involved. Typically, for a bit-set implementation, each edge requires eight bytes. As source code that is provided to a compiler may often include thousands of variables, an interference graph which includes approximately 10,000 nodes may occur fairly frequently.
Interference graphs which occupy a relatively large amount of memory space tend to occupy memory space which would otherwise be available for other purposes. In addition, as creating and modifying an interference graph is a substantial part of an overall compilation process or, more specifically, a register allocation process, reducing the complexity associated with creating and modifying an interference graph may significantly affect the speed at which the overall compilation process may occur. Therefore, what is desired is a method and an apparatus for increasing the efficiency with which an interference graph. may be created and modified. That is, what is needed is a method and an apparatus for reducing the number of edges included in an interference graph without compromising the accuracy of a register allocation process.
The present invention relates to reducing the number of edges in an interference graph that is created for a register allocation process. According to one aspect of the present invention, a computer-implemented method for allocating registers in an object-based computing system includes obtaining source code that includes a code segment associated with a first variable and a code segment associated with a second variable. The method also includes obtaining a live range for the first variable and binding the first variable to a specific register, and obtaining a live range for the second variable. The representation of the second variable is then modified to exclude the specific register bound to the first variable form its potential allocation choices. Once the live range for the second variable is obtained and modified, a register allocation is performed. Performing the register allocation includes creating an interference graph that includes a representation of the second variable and does not to include a representation of the first variable. The representation of the second variable may be a representation of the live range for the second variable.
In one embodiment, obtaining source code that includes the code segment associated with the first variable includes obtaining a call to a subroutine which includes the first variable as an argument in the call. In another embodiment, obtaining the source code further includes obtaining a code segment associated with a third variable, in addition to obtaining a second live range that is associated with the third variable, and modifying that live range to exclude the specific register which was bound to the first variable from the choices available to the third variable. In such an embodiment, the interference graph includes a representation of the third variable, and performing the register allocation involves determining whether the first live range and the second live range overlap. When it is determined that the live ranges overlap, a coloring process is performed using the interference graph. Such a coloring process adds an indication, e.g., an edge, to the interference graph that indicates that the first live range and the second live range overlap.
By eliminating a representation of a variable that is bound to a register from an interference graph, the number of edges associated with the interference graph may be reduced. Reducing the number of edges increases the speed at which register allocation may occur. Since building and manipulating an interference graph is typically one of the most time-intensive part of an overall register allocation process, by reducing the number of edges in the interference graph, e.g., by keeping the interference graph sparse, the efficiency of the overall register allocation process may be improved.
These and other advantages of the present invention will become apparent upon reading the following detailed descriptions and studying the various figures of the drawings. | {
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There is described in U.S. Pat. No. 4,063,642, dated Dec. 20, 1977, apparatus comprising a machine frame with a conveying device mounted thereon and being in the form of a conveying brush. In front of the conveying brush is a storage area for a disordered quantity of individual parts and following the storage area is a linear conveying device, in the form of a vibratory conveyor for aligning and/or sorting the individual parts. Although such apparatus have proved to be successful in aligning, sorting and separating individual parts, additional devices need to be provided in order to enable rapid changes in the type of the individual parts to be processed by means of the apparatus.
The present invention is intended to avoid this disadvantage. | {
"pile_set_name": "USPTO Backgrounds"
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The invention relates to the concept of interleaving, which is used to help signal receivers overcome errors in acquired signals. For example, interleaving is applied to signals that are sent through the air interface in wireless telecommunications networks that comply with the Third Generation Partnership Program (3GPP) standards.
Generally speaking, interleaving, as performed by an interleaver, is the deliberate and reversible disordering of a sequence of information symbols. If a receiver acquires an interleaved signal in which an error affects a contiguous group of symbols, the error can be dispersed by reversing the interleaving, so-called “deinterleaving”.
The ability to disperse an error is important when a transmitted information symbol sequence is prepared using forward error correction (FEC) coding that enables the resolution of an error in an acquired sequence provided that the error does not extend over too great a contiguous part of the acquired sequence. Turbo encoding is an example of FEC that is used within the 3GPP standards.
In a turbo encoder, a symbol sequence is supplied in parallel to both a first convolutional encoder and an interleaver. The interleaver produces an interleaved version of the sequence, which is then input to a second convolutional encoder. The outputs of the convolutional encoders are combined with the original sequence to provide the output of the turbo encoder. In a turbo decoder, a received turbo encoded sequence is used to prime a pair of constituent decoders. The output of a first one of the constituent decoders is interleaved and sent to the second constituent decoder for a further decoding iteration and the output of the second constituent decoder is deinterleaved and sent to the first constituent decoder for a further decoding iteration. The outputs of the first and second constituent decoders are exchanged several times prior to the emergence of a finally decoded sequence. Thus, where turbo coding is employed, considerable processing effort is devoted to interleaving, particularly in turbo decoding.
Several classes of interleaving algorithm exist. For example, a rectangular interleaver loads a symbol sequence into a memory block in a column-wise fashion and reads the symbols out in a row-wise fashion. Another type of interleaving is quadratic permutation polynomial (QPP) interleaving, which will be discussed after a brief reminder regarding some mathematical operations that feature in the remainder of this document: the operation A mod B returns the remainder part of A divided by B. the operation └C┘ returns the largest integer value that is less than C.
A definition of QPP interleaving will now be provided.
Given a data sequence of length K symbols (where K has an integer value) and two parameters a and b that are dependent on K, the relationship between the position x of a symbol in the interleaved sequence and its position f(x) in the original sequence is:f(x)=(ax+bx2)mod K Equation 1where x=0, 1, 2, 3, 4, . . . , K-1.
It has been shown in “A Decoder Architecture for High-Speed Free-Space Laser Communications” (M. Cheng, M. Nakashima, J. Hamkins, B. Moision, and M. Barsoum, Proceedings of SPIE, vol. 5712, pp. 174-185, April 2005) that if we define:g(x)=(a+b+2bx)mod K then:f(x+1)=(f(x)+g(x))mod K andg(x+1)=(g(x)+2b)mod K
The function g(x) is an auxiliary function whose purpose is to permit a recursive definition for f(x). | {
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1. Field of the Invention
The invention relates to a guard section length detection method and system.
2. Description of the Related Art
Orthogonal Frequency Division Multiple Access (OFDMA) is a multi-user version of the popular OFDM digital modulation scheme. Multiple accesses are achieved in OFDMA by assigning subsets of subcarriers to individual users. Compared with the conventional single carrier communication system, the OFDM communication system allocates data in several subcarriers, thus, the data transmission speed can be increased. Because the OFDM system is increasingly being used in wireless communication systems, a guard section is used to reduce inter-symbol interference (ISI). Inter-symbol interference (ISI) is a form of signal distortion that causes previously transmitted symbols to have an effect on the currently received symbol. Adding the guard section reduces ISI, but, also reduces transmission efficiency because the guard section does not carry information. If the OFDM symbol length is NFFT points and the guard section length is NGI points, for example, the transmission rate after adding the guard section is
N FFT N FFT + N GI of the transmission rate without an added guard section. Generally speaking, ISI can be avoided when the guard section is longer than the channel length and a longer guard section length decreases the transmission rate and cannot increase the OFDM system performance.
As selection of the length of the guard interval depends on the channel condition, the length of the guard interval will dynamically change. For example, the IEEE 802.16 standard defines a guard section having a length of ¼, ⅛, 1/16 or 1/32 (hereinafter, called a ¼ mode, ⅛ mode, 1/16 mode and 1/32 mode) of an actual OFDM symbol length, and the base station selects a proper guard section length based on the channel length and the environment. Thus, a method for synchronizing the guard section parameter between the transmitter and the receivers is desirable. | {
"pile_set_name": "USPTO Backgrounds"
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1. Field of the Invention
The present invention relates to television displays and the control thereof. More particularly, it relates to television displays with progressive rather than interlaced scan.
2. Description of the Prior Art
As is well known, television pictures are generally generated by interlaced scanning; i.e., for each pair of fields constituting a frame, each line of the second field is positioned in space between successive lines of the first field. This is illustrated in FIG. 1A. In this figure, as in FIGS. 1B and 1C, an edge view of the scanning lines shown, the arrows depicting light intensity. It will be noted that the interlace pattern illustrated in FIG. 1A results in interline flicker which becomes increasingly annoying as the size of the display is increased. On the other hand, in FIG. 1B a progressive scan utilizing and adjacent line averaging algorithm is illustrated. In a progressive scan, a line is interpolated between two successive scan lines within each field and horizontal scanning takes place at double the interlace scan frequency. The problem of interline flicker has been alleviated, but, as will be noted in particular where the light intensity changes from maximum to minimum, namely at the top and bottom of the lines displayed in FIG. 1B, there is smear in the vertical direction, i.e. sharp contours are destroyed. Finally, FIG. 1C illustrates a progressive scanning algorithm in which the interpolated lines are simply repeats of the previous line. It will be noted that the pattern is stretched in the vertical direction, while interline flicker is still present.
In addition, more complex and expensive methods of processing the interlace signal to create the progressive scan display are known. These require motion detection means if an acceptable picture is to result. | {
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Device management involves the administration of various computing devices, such as smartphones, tablet computers, laptops, and other computing devices, using a set of defined organizational and control policies. Device management can be implemented using certain administration services that have management features for computing devices of various manufacturers.
Companies and other organizations can control certain operating aspects of computing devices provided to their employees and members using management services. Management services focus on containerization, data segregation, policy enforcement, application distribution and management, security for email, documents, and other on-device data, and other aspects of device management. Management services can be applied to both company-owned and employee-owned (e.g., “bring your own device” (BYOD)) devices and can be provided through on-premises, cloud-based, or on-premises and cloud-based (i.e., hybrid) implementations. | {
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This invention relates to fasteners of the type utilized to secure coverings to cementitious substrates. More particularly, this invention concerns fasteners or "nails" of the type used to anchor built-up waterproofing membranes to cementitious roof decks, which fasteners improve the wind uplift resistance of the built-up roofing membrane.
Conventional "flat" roofs or roof decks often utilize a layer of hydratable cementitious material such as Portland cement type concrete to impart structural strength and rigidity and/or thermal insulating properties in the case of lightweight aggregate-containing concretes which hydrate into relatively low-density masses. Typically a waterproof covering layer is applied to the uppermost surface of the cementitious layer and such covering layer must be secured in some fashion. Most commonly the waterproof covering is in the form of several plies of sheet material bonded together by hot asphalt, each ply being applied or "built-up" on the job site and adhered together by intermittent moppings of hot fluid asphalt. The first ply, termed the "base ply", is either adhered over its entire surface to the surface of the cementitious layer using e.g. hot asphalt, or is secured only at spaced intervals using "spot" applications of hot asphalt or mechanical fasteners forced through the base ply and into the soft concrete before it has fully hydrated into a hard rigid mass. The remaining plies of the built-up roofing are then secured to the base ply over their entire surfaces by hot moppings of fluid asphalts.
The mechanical fasteners or "nails" used to secure the base ply in various "spots" generally have a penetrating shank designed to resist withdrawal from the concrete layer, and a flat head which is wider in diameter than the shank thereby acting as a washer to hold the built-up roofing. The shank is typically made resistant to withdrawal from the concrete by causing the shank to expand in diameter near its penetrating end either as it enters the soft concrete or soon thereafter. In the fasteners for example of U.S. Pat. Nos. 3,466,967; 3,710,672 and 4,031,802 to Hallock, the shank portion of the fastener comprises a slit cone or a pair of hinged legs and is caused to expand as the fastener is inserted into the soft cementitious mass. The shank portions of these fasteners moreover define a hollow space which receives a portion of the soft cement mixture as the fastener is driven thereby increasing the resistance of the fastener to withdrawal particularly after the cement has hardened.
The nail in particular of the type shown in U.S. Pats. No. 3,710,672 and 4,031,802 to Hallock has proven in practice to be especially effective for locking built-up roofing to lightweight low density expanded vermiculite or perlite containing concretes. This nail has a flat, disc-shaped head approximately 1.19 inches (3.02 cms.) in diameter and a pair of channel-shaped, overlapping legs approximately 1.63 inches (4.13 cms.) in length hinged to the head and defining the aforementioned hollow space. The nail is economically formed as a one piece integral product from sheet metal stock and has a high resistance to withdrawal from the concrete layer. Difficulty has been experienced however in passing certain stringent wind uplift resistance requirements with built-up roofings fastened to concrete layers using nails of this type. A need exists therefore for a practical manner of enhancing the wind uplift resistance of roofings secured with this and other similar types of "base ply" fasteners. | {
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Benign prostatic hyperplasia (BPH) is a common disorder in middle-aged and older men, with prevalence increasing with age. At age 50, more than one-half of men have symptomatic BPH, and by age 70, nearly 90% of men have microscopic evidence of an enlarged prostate. The severity of symptoms also increase with age with 27% of patients in the 60-70 age bracket having moderate-to-severe symptoms, and 37% of patients in their 70's suffering from moderate-to-severe symptoms.
The prostate early in life is the size and shape of a walnut and prior to the enlargement resulting from BPH, weighs about 20 grams. Prostate enlargement appears to be a normal process. With age, the prostate gradually increases in size to twice or more its normal size. The fibromuscular tissue of the outer prostatic capsule restricts expansion after the gland reaches a certain size. Because of such restriction on expansion, the intracapsular tissue will compress against and constrict the prostatic urethra, thus causing resistance to urine flow.
FIG. 1 is a sectional schematic view the male urogenital anatomy, with the walnut-sized prostate gland 100 located below the bladder 105 and bladder neck indicated at 106. The walls 108 of bladder 105 can expand and contract to cause urine flow through the urethra 110, which extends from the bladder 105, through the prostate 100 and penis 112. The portion of urethra 110 that is surrounded by the prostate gland 100 is referred to as the prostatic urethra 120. The prostate 100 also surrounds the ejaculatory ducts 122 which have an open termination in the prostatic urethra 120. During sexual arousal, sperm is transported from the testes 124 by the ductus deferens 126 to the prostate 100 which provides fluids that combine with sperm to form semen during ejaculation. On each side of the prostate, the ductus deferens 126 and seminal vesicles 128 join to form a single tube called an ejaculatory duct 122. Thus, each ejaculatory duct 122 carries the seminal vesicle secretions and sperm into the prostatic urethra 120.
Referring to FIGS. 2A-2C, the prostate glandular structure can be classified into three zones: the peripheral zone, transition zone, and central zone. The peripheral zone PZ, which is the region forming the postero-inferior aspect of the gland, contains 70% of the prostate glandular elements in a normal prostate (FIGS. 2A-2C). A majority of prostate cancers (up to 80%) arise in the peripheral zone PZ. The central zone CZ surrounds the ejaculatory ducts 122 and contains about 20-25% of the prostate volume. The central zone is often the site of inflammatory processes. The transition zone TZ is the site in which benign prostatic hyperplasia develops, and contains about 5-10% of the volume of glandular elements in a normal prostate (FIG. 2C), but can constitute up to 80% of such volume in cases of BPH. The transition zone TZ consists of two lateral prostate lobes and the periurethral gland region indicated at 130. As can be understood from FIGS. 2A-2C, there are natural barriers around the transition zone TZ, i.e., the prostatic urethra 120, the anterior fibromuscular stroma FS, and a fibrous plane FP between the transition zone TZ and peripheral zone PZ. In FIGS. 2A-2C, the anterior fibromuscular stroma FS or fibromuscular zone can be seen and is predominantly fibromuscular tissue.
BPH is typically diagnosed when the patient seeks medical treatment complaining of bothersome urinary difficulties. The predominant symptoms of BPH are an increase in frequency and urgency of urination, and a significant decrease in the rate of flow during urination. BPH can also cause urinary retention in the bladder which in turn can lead to lower urinary tract infection (LUTI). In many cases, the LUTI then can ascend into the kidneys and cause chronic pyelonephritis, and can eventually lead to renal insufficiency. BPH also may lead to sexual dysfunction related to sleep disturbance or psychological anxiety caused by severe urinary difficulties. Thus, BPH can significantly alter the quality of life with aging of the male population.
BPH is the result of an imbalance between the continuous production and natural death (apoptosis) of the glandular cells of the prostate. The overproduction of such cells leads to increased prostate size, most significantly in the transition zone which traverses the prostatic urethra.
In early stage cases of BPH, pharmacological treatments can alleviate some of the symptoms. For example, alpha-blockers treat BPH by relaxing smooth muscle tissue found in the prostate and the bladder neck, which may allow urine to flow out of the bladder more easily. Such drugs can prove effective until the glandular elements cause overwhelming cell growth in the prostate.
More advanced stages of BPH, however, can only be treated by surgical or less-invasive thermal ablation device interventions. A number of methods have been developed using electrosurgical or mechanical extraction of tissue, and thermal ablation or cryoablation of intracapsular prostatic tissue. In many cases, such interventions provide only transient relief, and these treatments often cause significant peri-operative discomfort and morbidity.
In a prior art thermal ablation method, RF energy is delivered to prostate tissue as schematically depicted in FIGS. 3A-3B. FIG. 3A depicts the elongated prior art RF needle being penetrated into a plurality of locations in a prostate lobe. In a first aspect of the prior art method, the elongated RF needle typically is about 20 mm in length, together with an insulator that penetrates into the lobe. The resulting RF treatment thus ablates tissue away from the prostatic urethra 120 and does not target tissue close to, and parallel to, the prostatic urethra 120. In another aspect of the prior art RF thermal ablation method, the application of RF energy typically extends for 1 to 3 minutes or longer which allows thermal diffusion of the RF energy to ablate tissue out to the capsule periphery. Such prior art RF energy delivery methods may not create a durable effect, since smooth muscle tissue and alpha adrenergic receptors are not uniformly ablated around the prostatic urethra or within the transition zone. As a result, tissue in the prostate lobes can continue to grow and impinge on the urethra thus limiting long-term effectiveness of the treatment. | {
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The present invention relates generally to portable electric power tools designed for use with extension cords, and specifically to a system for securely retaining the extension cord to the tool in a way which reduces stress on the cord, and which prevents cord pullout.
Conventional portable electric power tools, including but not limited to drills, hammer drills, sanders, grinders, circular saws, reciprocating saws, routers, power fastener drivers, garden weed trimmers, leaf blowers and the like are typically provided with a power cord which, depending on the manufacturer and model, varies in length from about six inches to about 12 feet. Regardless of the length of the standard equipment cord or tool cord, users often need to employ extension cords to reach remote work sites. For example, on construction sites, long extension cords are often connected to portable generators. In such cases, if the extension cord is merely plugged into the tool cord, pulling on the tool, which often occurs during use, may cause the extension cord to become detached from the tool cord, which disrupts work and is frustrating to the operator. Also, the junction of the tool cord and the extension cord often becomes caught on workplace obstructions, causing the tool to become disconnected from the extension cord.
To address this problem, operators often tie adjacent ends of the extension and tool cords together in a knot. While making a more secure junction, the knot has a tendency to become caught on workpiece edges or on other surfaces, requiring the operator to interrupt work and free the caught knot. Another disadvantage of the knot is that it requires tight bends to be made in both the tool cord and the extension cord. Repetitive sharp bending stresses of this type cause stresses on the internal wiring of the cords and may result in fraying of the cords and/or short circuits.
One attempted solution to this problem is to provide a tool which lacks a tool cord, but instead has an electric receptacle for directly receiving an extension cord. While this solution removes the problems associated with the extension cord-tool cord knot, a new problem is introduced in that pulling on the tool during work or movement causes the extension cord to become detached from the tool. The plug is vulnerable because it is only held in place by the friction between the receptacle and the plug, which can vary depending on the plug manufacturer and by the amount of wear. As the plug wears, its ability to grip the male receptacle blades decreases resulting in degradation of fit, increasing the ease by which the plug can become disconnected. Further, as the plug loosens, power to the tool may become intermittent or be completely lost. When this occurs, work is interrupted, which is often frustrating to the operator. Also, tool vibration may cause loosening of otherwise securely held extension cord plugs.
To address the problem of retention of the extension cord on the tool, tools have been provided with cord retention and plug retention systems. Such systems are typically configured with formations such as hooks and/or loops which bend the extension cord in a serpentine manner near the tool receptacle and thus isolate the cord plug from a pulling action on the cord. In this manner, pulling on the tool while attached to the cord will not cause the extension cord to become unplugged from the tool.
However, such conventional systems are often unsatisfactory because they cause excessive and/or sharp bends in the cord, which shorten the life of the extension cord and may cause short circuits. Such stresses occur when the cord is forced into sharp bends around hooks or other projections. One related and important design criteria of such systems is that construction workers working on ladders or on second stories of buildings often raise and/or lower the tool by the cord. Especially with heavier tools, this places a significant load on the cord. When the cord has sharp bends, particularly where the cord leaves the retention system, there is excessive and potentially damaging stress placed on the cord. This problem is especially severe where the retention system creates a right angle bend in the cord as it exits the system. In instances where the tool has a tool cord, the stresses are severe enough to cause the tool cord to be pulled out of the tool.
Another disadvantage of conventional cord retention systems is that the cord is not sufficiently secured in the system or at other locations on the holder. One problem resulting from this disadvantage is that when a tool is moved backward, as in a sawing motion, a slack condition in the extension cord may cause the cord to become disengaged from portions of conventional systems. Another problem is that when operating in heavy vegetation or crowded work environments, the many cord loops created by conventional systems are prone to becoming caught on branches or other environmental obstructions, which may cause the cord to become detached from the retention system.
Still another disadvantage of conventional extension cord retention systems relates to the fact that extension cords are provided in a variety of gauges or thicknesses. Conventional cord retention systems are incapable of accommodating a wide range of cord gauges.
Accordingly, there is a need for an improved cord retention system for a power tool which reduces stress on the cord, especially when the cord is used to raise and/or lower the tool.
Another need is for an improved cord retention system for a power tool which positively secures the cord to the tool.
Still another need is for an improved cord retention system for a power tool which accommodates a range of extension cord gauges.
A further need is for an improved plug retention system for a power tool which positively secures the plug to the tool.
Yet another need is to provide an improved plug retention system which accommodates a variety of types of extension cords.
A still further need is to provide an improved cord retention and plug retention system which positively secures the cord and the plug to the tool. | {
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1. Field of the Invention
This invention relates to monitoring the cleaning and drying processes during the manufacture of ICs, MEMS and other micro devices and more specifically to a micro sensor for high aspect ratio micro channels in dielectric films oriented parallel to the fluid-solid interface to emulate either “vertical” or “horizontal” micro features.
2. Description of the Related Art
A major challenge in manufacturing of the micro and nano devices is the cleaning and drying of very small void features (“micro features”), particularly those with large aspect ratios. These micro features are fabricated in various processing steps and can be very small voids such as gaps, holes, vias or trenches that are intentionally etched. The micro features can also be pores (voids) in a deposited dielectric material. Cleaning and drying occur repeatedly during the processing chain and are responsible for a significant part of the total processing time and for the consumption of much of the water, chemicals and energy.
In semiconductor manufacturing, trenches and vias are fabricated both in the device level and in the interconnect level. Most of these features have high aspect ratios with submicron openings and are therefore very difficult to clean and dry. In Integrated Circuits, MEMS and other micro device manufacturing, well controlled cleaning and drying are essential to avoid deformation of layers and improper adhesion of moving parts. Improper cleaning and drying would have a significant effect on manufacturing yield and device performance and reliability in both semiconductor and MEMS fabrication. Over-cleaning, over-rinsing or over-drying results in excessive use of chemicals, water and energy and also increases cycle time and potentially causes yield loss. Therefore, there is a strong economic and environmental incentive to use a process that is “just good enough”.
The fine structures left behind after processes such as etching, deposition, and patterning, need to be cleaned and the reaction by-products need to be removed often down to trace levels. This usually involves three steps: 1) application of a cleaning solution; 2) rinsing and/or purging using ultra pure water or other rinsing solutions; and 3) drying by removing and purging the traces of any solvents used during rinsing. Due to the undesirable surface tension associated with aqueous chemicals and non-wetting nature of most future dielectrics, industry is pursing the development of processes based on supercritical fluids such as supercritical carbon dioxide for cleaning and pattern development. Measurement of cleanliness under these processing conditions is very critical.
Cleaning, rinsing, and subsequent drying processes are often performed and controlled almost “blindly” and based on trial and error or past experience. The way these processes are monitored and controlled presently is based on ex-situ testing of wafer, chips, or structures. Within the process tool, fixed recipes are provided by tools and process suppliers. Run-by-run adjustments or control are based on external and delayed information on product performance or product yields. The key reason for this inefficient and costly approach is that no sensors or techniques are available to measure the cleanliness and monitor the removal of impurities from micro features—to measure cleanliness where it actually counts. The sensors that are currently available are used in the fabs to monitor the conditions of fluid inside the process vessels and tanks, but far away from the inside of micro features (that is what needs to be monitored; it is also the bottleneck of cleaning and drying). The present monitoring techniques and devices do not provide realistic and accurate information on the cleanliness and condition of micro features.
Industry currently works around this problem while waiting for a solution; the process condition and cleaning and drying are often set with very large factors of safety (over-cleaning and over-rinsing). Large quantities of water and other chemicals are used (much more than what is really needed). This results in wasted chemicals, increased process time, lowered throughput, increased cost, and it causes reliability issues because of lack of process control.
K. Romero et al “In-situ analysis of wafer surface and deep trench rinse,” Cleaning Technology in Semiconductor Device Manufacturing VI, The Electrochemical Society, 2000 propose a trench device for monitoring the process in-situ. As shown in FIG. 1, a trench device 10 comprises a pair of conducting electrodes (Poly-Si) 12 and 13 sandwiched between dielectric (SiO2) layers 16 and 17 on opposite sides of a trench 14 on a substrate 18. Trench 14 is oriented perpendicular to the fluid-solid interface 19 of the device. An impedance analyzer 20 applies a measurement voltage 21 to the electrodes, which carry the measurement signal (voltage and current) to the trench. The impedance analyzer measures the impedance between its two terminals (ratio of voltage and current and the phase difference between the voltage and current).
Standard fabrication techniques limit the ability to form very deep trenches that are also very narrow, hence the aspect ratio of the trench. Furthermore, these deep etch techniques are not particularly well controlled so the actual aspect ratio of a particular trench may deviate significantly from the aspect ratio of the micro feature it is intended to emulate. In addition, the trench device can only emulate “vertical” micro features, which are common in microelectronics processing. However, MEMS and microfluidic devices often include “horizontal” micro features. Thus the trench device limits the type and aspect ratio of micro features that can be monitored and the accuracy of the monitoring. The trench device includes a single sensor (pair of electrodes) that measures the impedance at a single depth in the trench. Multiple electrodes at different depths in the trench device would require extra manufacturing steps and therefore substantially increase its cost.
Furthermore, for the sensor to be useful as a monitor of the fluid in the micro feature, the total parasitic capacitance between the electrodes and the substrate and/or fluid must be sufficiently small to allow an electrical measurement of the total impedance between the electrodes to resolve the solution resistance Rsol'n and/or the interface double layer capacitance Cdl. If the parasitic capacitance dominates the total electrical response, then the circuit will not have a good signal to noise ratio and the sensor will not be very sensitive. In the paper by Romero et al., the parasitic capacitance was found to dominate the solution resistance. At the parasitic capacitance measured (88 pF), the equivalent circuit calculation predicts no discernable impedance variation between highest and lowest trench resistances. The full ionic concentration range was not experimentally resolvable in comparison to electronic noise. | {
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A variety of applications require precise cutting of flat articles; two such applications are framing and quilting. In framing applications, flat mats are used to suspend articles such as pictures, drawings, and photographs within the frame, as well as to provide an aesthetically pleasing border between the item being framed and the frame itself In most applications, the mid-section of the mat is cut out to form an opening having an outline corresponding to, but slightly smaller than, the periphery of the object to be mounted. In other applications in which the picture is cropped, the opening has an outline substantially smaller than the periphery of the picture, and can also have a shape varying from the periphery of the picture. The edges of the opening in the mat are preferably beveled to provide a more pleasing transition between the article being framed and the mat. As shown in U.S. Pat. No. 4,038,751, devices currently exist for accurately cutting framing mat, but these devices usually require abutting an edge of the mat against an alignment guide and then making a cut parallel to the alignment guide. In the absence of supporting hardware, these devices are usually limited to making apertures in the mat in which the edges of the aperture are parallel to the edges of the mat. Also, these devices are limited to cutting framing mat because the item being cut must be rigid enough that its edge can be abutted against the alignment guide of the cutter, meaning that non-rigid articles, such as fabric, cannot be cut using this type of device.
Quilting involves sewing together many pieces of fabric to form one big item or sewing many small pieces of fabric onto a larger piece to form a specific pattern thereon. The fabric pieces are usually strips or blocks cut to a particular shape and size. Because a large number of fabric pieces go into a quilt, each piece must be cut accurately; otherwise, errors in the size of the fabric pieces will accumulate as they are sewn together resulting in a finished article that may not have the correct shape, size, or pattern. In addition, inaccurately cut fabric pieces result in a needless waste of fabric. Blocks and strips of fabric for quilting are currently cut by placing the fabric upon a flexible pad, manually holding a straightedge upon the fabric along a line to be cut, and drawing a cutter along the straightedge. This method does not provide high accuracy cuts, because it is difficult to get a precise alignment manually, and because the straightedge can easily slip from the user's hand during cutting. This method is unsuitable for cutting framing mat because of the difficulty in obtaining a precise alignment, and the difficulty in holding a blade at the precise bevel angle necessary while running it along the straightedge.
Some devices exist that are capable of cutting a variety of flat articles, including both framing mat and fabric. Examples are U.S. Pat. No. 4,685,366 and U.S. Pat. No. 4,470,201. One device, shown in U.S. Pat. No. 4,685,366, employs a straight bar that functions as both a straightedge and a means of clamping the flat article to a base. The article is usually aligned so that the edge of the straight bar runs along the line to be cut, and securely clamped using the bar. After clamping, a cutter is run along the edge of the bar to obtain the cut in the article. Although these devices are able to cut a larger variety of items, they are not well suited for accurate cutting because the bar used to clamp and cut the item does not provide an accurate means of aligning the item; instead, the item must be placed and aligned by hand, leading to errors. Furthermore, because the same bar is used for both clamping and cutting, the bar must be unclamped and re-clamped for each separate cut; it follows that the flat item being cut must be realigned for every cut to be made on it, resulting in further errors. Finally, these devices do not provide an accurate means of cutting at an arbitrary angle; if an angled cut is desired, the article must be un-clamped, manually aligned to the desired orientation, and re-clamped. This leads to both linear and angular cutting errors. | {
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1. Field of Invention
The present invention relates generally to data communication networks and devices, and relates more particularly to multi-chassis link aggregation groups.
2. Description of the Related Art
As the value and use of information continues to increase, individuals and businesses seek additional ways to process and store information. One option available to users is information handling systems. An information handling system generally processes, compiles, stores, and/or communicates information or data for business, personal, or other purposes thereby allowing users to take advantage of the value of the information. Because technology and information handling needs and requirements vary between different users or applications, information handling systems may also vary regarding what information is handled, how the information is handled, how much information is processed, stored, or communicated, and how quickly and efficiently the information may be processed, stored, or communicated. The variations in information handling systems allow for information handling systems to be general or configured for a specific user or specific use such as financial transaction processing, airline reservations, enterprise data storage, or global communications. In addition, information handling systems may include a variety of hardware and software components that may be configured to process, store, and communicate information and may include one or more computer systems, data storage systems, and networking systems.
As information handling systems provide increasingly more central and critical operations in modern society, it is important that the networks are reliable. One method used to improve reliability is to provide redundant links between network devices. By employing redundant links, network traffic between two network devices that would normally be interrupted can be re-routed to the back-up link in the event that the primary link fails.
Although having redundant links is helpful for failover situations, it creates network loops, which can be fatal to networks. To remove the loops, a protocol named Spanning Tree Protocol (STP) is often employed. STP is a Layer-2 protocol that runs on network devices, such as bridges and switches, to ensure that loops are not created when there are redundant paths in the network. The result of the STP is that some links are inactive unless a primary link fails. Thus, networks using redundant links with STP have links that are underutilized.
FIG. 1 depicts an example of a networking system 100 that employs Spanning Tree Protocol. Depicted in FIG. 1 is a set of networking devices 105A-105D that are connected to other networks devices 110A and 110B (which may be access switches), which are in turn connected to other network devices 115A and 115B (which may be core switches or routers). The network devices are connected with redundant links. Due to STP, some of the links are active 120 and some of the links are placed into an inactive state 125 to avoid network loops. Because many of the links are placed into an inactive state by the STP, the network capacity is underutilized. To address the limitations of STP, a protocol called the multiple spanning tree protocol (MSTP) was developed by IEEE 802.1 [IEEE 802.1s]. While this protocol allows for more links to be used for forwarding, it still suffers from the limitation of having a loop-free active topology for any given VLAN.
However, ever increasing demands for data have required communication networks to provide more throughput. Not only must networks be reliable, but they must also provide adequate bandwidth. Thus, a key area in which communication networks strive to improve is in increasing capacity (data throughput or bandwidth).
One way to increase capacity through recapturing unused network capacity involves the use of link aggregation. Link aggregation refers to various methods of aggregating network connections to increase data throughput while still supporting fault tolerance in case of failures. Generally, link aggregation involves grouping two or more physical data network links between two network devices into one logical link in which the two or more physical network links may be treated as a single logical link. By using certain link aggregation implementations, the need for STP can be eliminated by increasing the intelligence of network forwarding devices, providing a non-blocking high performance network.
Initial implementation of link aggregation required that the aggregated links terminate on a single switch. However, additional implementation developed that allowed the links to terminate on two switches. An example of a mechanism used to support LAG networking across more than one device is multi-chassis link aggregation (“MLAG”) and distributed resilient network interconnect (DRNI) [IEEE P802.1AX-REV].
MLAG is a LAG implementation in which a LAG terminates on two separate chassis or devices. A MLAG is configured such that one or more links comprising one LAG terminate at ports on a first device and one or more links comprising the same LAG terminate on a second device. The first and second devices are configured so that they appear to the surrounding network to be one logical device. At least one standard for link aggregation has been promulgated by the Institute of Electrical and Electronic Engineers, which is contained in the IEEE 802.1AX-2008 standard, which is incorporated by reference herein. However, a number of different vendors have implemented their own versions. For example, Cisco markets EtherChannel and Port Aggregation Protocol (along with its related Virtual Switching System (VSS), virtual PortChannel (vPC), Multichassis EtherChannel (MEC), and Multichassis Link Aggregation (MLAG)). Avaya markets Multi-Link Trunking (MLT), Split Multi-Link Trunking (SMLT), Routed Split Multi-Link Trunking (RSMLT), and Distributed Split Multi-Link Trunking (DSMLT). ZTE markets “Smartgroup” and Huawei markets “EtherTrunks”. Other vendors provide similar offerings. A standard for this technology is under development in the IEEE 802.1 standards committee; the project is called distributed resilient network interconnect (DRNI).
FIG. 2 depicts an example implementation of a networking system, which is similar to the system in FIG. 1 but which employs link aggregation. Depicted in FIG. 2 is a set of networking devices 205A-205D that are connected to other networks devices 210A and 210B (which may be access switches). In the depicted example, the network devices 205A-205D are connects such that each device 205x has a link aggregation group (LAG) to the switches 210A and 210B. For example, network device 205A has two port connections 220A and 220B that together form link aggregation group 220, as shown in the physical view 200A of FIG. 2. To the network devices 205x having such a link aggregation configuration to the switches, the two switches 210A and 210B may be configured to appear as a single logical switch, as shown in the logical view 200B of FIG. 2.
As noted above, the two switches may optionally be configured to appear as a single logical switch. Multi-chassis link aggregation implementation provide special links (e.g., links 205 between switch 210A and switch 210B) that can be used to connect two separate switches together to form an aggregation switch that in some ways acts like a single larger chassis. With two chassis aggregated in this manner, when a packet arrives at one of the switches that must egress on the other switch, the first switch forwards the packet to a port associated with the special link interconnect where it is transmitted to the other device for transmission over the network.
It must be noted, however, that the current various implementations of link aggregation have serious limitations. First, the current implementations support only two switches configurations connected in a point-to-point fashion. Extending beyond two switches significantly adds complexity in connections, configuration, and operation. For example, it is relatively simple to synchronize data between two devices, but it becomes significantly more complex to synchronize between multiple devices.
Second, at any point in time, within a given aggregation switch only one switch typically operates in a primary switch role, while the remaining switch operates in a secondary role. In the primary role, the primary switch assumes control over at least some of the aggregation switch functionality. Among other things, this can involve the primary switch being responsible for running some Layer-2 network protocols (such as Spanning Tree Protocol (STP)) that assist in the operation of the switch in the network environment. The network information learned by the primary switch can be distributed as needed to the secondary switches in order to synchronize at least some of the states between the primary switch and secondary switch. While running in such as primary-secondary configuration is easy to manage, it does not efficiently utilize network resources.
Third, limiting the number of switches that form the logical switch group does not provide a readily scalable solution. Clients desiring to add infrastructure incrementally need to add pairs of devices rather than simply being able to add any number of switches. Also, clients wanting to extend their current link aggregation system cannot do so because new each switch or pair of switches forms a new domain rather than simply extending an existing domain. Thus, increasing the system involves adding separate link aggregation switch groups that must be separately managed, configured, and operated—needlessly adding complexity and administrative overhead.
Fourth, when pairing switches, vendors generally require that the devices be the same. Having mirrored devices makes it easier for vendors because it limits possible combinations; a vendor therefore does not have to make sure different products interoperate. Also, having homogeneous devices tend to force symmetry in the configuration, for which it is also simpler for vendors to develop and support. However, requiring like switches is rarely the best for clients. As data centers and networks grow, a client would prefer to purchase a single new model device rather than being forced to choose between buying an older model to pair with its current older model or to buy two new models and shelve it current older, but still operational, model. Thus, current multi-chassis link systems inhibit cost effective equipment migration plans.
Accordingly, what is needed are systems and methods that can address the deficiencies and limitations of the current multi-chassis link aggregation approaches. | {
"pile_set_name": "USPTO Backgrounds"
} |
1. Field of the Invention
Preparations of sulfur-and-selenium-containing fulvalenes are well known. Of particular interest herein is a one-step method for synthesis of substituted sulfur-and-selenium-containing fulvalenes from reactions of an acetylenic compound with sulfide-and-selenide starting materials under high pressure conditions.
2. State of the Art
Recent findings of the unusual electronic properties of complexes of certain sulfur-and-selenium-containing fulvalenes have generated increased interest in new synthetic routes for preparation of these fulvalene compounds. Certain fulvalene compounds having sulfur and selenium atoms in the fulvalene rings can be used to prepare crystalline charge-transfer salts. For example, in IBM German Offen. No 2,739,584 (1978), there is described a charge-transfer salt comprised of dithiadiselenafulvalene and tetracyano-p-quino-dimethane. Such salt, in which the fulvalene compound is characterized as the electron-donor cation, exhibits metallic properties over a wide temperature range and reportedly has electrical conductivity among the highest of known organic materials.
The superior electrical properties of these salts, so-called "organic metals", make the salts particularly likely candidates for many solid-state or physical-electronics applications. In such applications, materials of very high purity are usually required. Known preparations of sulfur-and-selenium fulvalenes and substituted sulfur-and-selenium fulvalene compounds involve complicated multi-step synthetic routes which typically produce these fulvalene compounds in low yields or in relatively impure form.
One lengthy method for making fulvalene compounds containing sulfur and selenium in the five-membered ring system is described in U.S. Pat. No. 3,941,809 to Kaplan et al. These fulvalene compounds are prepared by a multi-step method involving firstly reduction of a sulfur-and-selenium-containing five-member ring organic halide to its partially-hydrogenated derivative, which derivative is reacted with anhydrous fluoboric acid to provide a fluoborate, which fluoborate is then deprotonated in the presence of an alkyl tertiary amine to yield a fulvalene compound containing two sulfur and two selenium atoms.
In U.S. Pat. No. 4,028,346 to Engler et al, a two-step synthesis is described for preparation of sulfur-selenium fulvalenes. This method involves reacting sodium acetylide with carbon diselenide in the presence of sulfur to provide 1,3-thiaselenole-2-selone. A subsequent coupling reaction of this selone compound in the presence of trimethylphosphite produces dithiadiselenafulvalene in an unreported yield. In a later publication, however, Lakshmikantham and Cava [J. Org. Chem., 45, 2632 (1980)] report that the Engler type two-step synthesis provides an overall yield of dithiadiselenafulvalene of less than one percent. This later publication then describes an improved route for synthesis of dithiadiselenafulvalene by first converting 1,2,3-selenadiazole to 1,3-thiaselenole-2-thione, which thione is then converted by conventional methods to 1,3-thiaselenole-2-selone and then by coupling reaction to dithiadiselenafulvalene. Overall yield of this fulvalene is only about 24 percent, however. | {
"pile_set_name": "USPTO Backgrounds"
} |
1. Field of the Invention
The present invention relates to a piezoelectric actuator and an apparatus for driving a lens applied to an optical device using the piezoelectric actuator, and more particularly, to a piezoelectric actuator which is simplified in a driving mechanism to achieve a smaller size, minimized in loss of a driving force for driving a lens and ensures more accurate and stable transport of the lens.
2. Description of the Related Art
In general, an optical apparatus includes a lens driving device for driving a lens. This lens driving device employs an actuator such as an electromagnetic motor or a piezoelectric actuator to generate a driving force, and a cam or a screw to transmit the driving force generated from the actuator.
Therefore, the lens driving device drives the lens in an optical axis direction using the driving force generated from the actuator. At this time, the lens driving device changes a relative distance between a lens and an adjacent lens thereof to perform zooming or focusing.
Meanwhile, recently, a piezoelectric actuator utilizing a piezoelectric body has been highlighted as a new motor to substitute an electromagnetic motor.
This piezoelectric actuator generates high frequency vibration of minute amplitudes in a piezoelectric vibrator and transfers these minute vibrations by contact friction between a friction member and a slider (rotor) attached to the piezoelectric vibrator, thereby enabling the slider (rotor) to perform minute motion. This piezoelectric actuator is smaller in size, higher in driving resolution and less noise-causing than the conventional electromagnetic motor.
FIG. 1 is a schematic view illustrating a structure of a conventional piezoelectric actuator. The piezoelectric actuator includes a piezoelectric body 10, and a friction member 30 attached to one side thereof.
The piezoelectric body 10 is structured such that a plurality of piezoelectric ceramic sheets formed of a plurality of ceramics are stacked, and each of the piezoelectric ceramic sheets has an internal electrode formed thereon to define the piezoelectric body into a plurality of vibrators.
These internal electrodes can be configured variously on a surface of the piezoelectric sheet considering type and direction of vibration generated from the piezoelectric body 10, and number and location of the friction member 30.
Also, wires or the external electrodes 21 and 22 are formed on the piezoelectric body 10 to connect the internal electrodes together so as to supply alternating currents of an identical phase to the two vibrators 11 and 14, and 12 and 13 located diagonally. Also, the friction member 30 is disposed on the one side surface of the piezoelectric body 10 to transfer vibration generated from the piezoelectric body 10 to the outside. The friction member 30 is made of a ceramic material or a hard metal.
Accordingly, the alternating voltages of an identical phase are applied to the two rotators 11 and 14, and 12 and 13 located diagonally through the wires or external electrodes 21 and 22 of the piezoelectric body 10 which is divided into the vibrators 11, 12, 13 and 14. Then, the piezoelectric body 10 generates vibrations of two modes.
That is, the piezoelectric body 10 generates a dilation mode of vibration for enabling dilation along a longitudinal direction and a bending mode of vibration for enabling bending in a thickness direction thereof.
With simultaneous occurrence of the vibrations of these two modes, the friction member performs elliptical motion and this elliptical motion of the friction member 30 is transferred to the slider or rotor to enable linear motion for the slider and rotational movement for the rotor.
However, the conventional piezoelectric actuator entails a complicated process of forming the external electrodes connected to the internal electrode, thus requiring high precision. This hinders simplification of a manufacturing process for saving manufacturing costs and reduction of the bulk of the piezoelectric actuator.
U.S. Pat. No. 5,768,038 discloses a device for moving a lens including a lens frame, a signal generator, a piezoelectric vibrator, a supporter, a pressure surface and a pressure member. The guiding member guides a lens frame. The signal generator generates an electrical signal. The piezoelectric vibrator moves the lens frame along the guiding member by vibration according to the electrical signal. The supporter supports the piezoelectric vibrator. The pressure surface is in pressure contact with the piezoelectric vibrator. The pressure member brings the piezoelectric vibrator into pressure contact with the pressure surface.
However, this conventional device requires the guiding member to be additionally assembled so that the lens frame is moved along an optical axis direction. This complicates an assembling structure and a process, and hinders miniaturization of the product.
Moreover, U.S. Pat. No. 6,215,605 discloses a driving device. In the driving device, piezoelectric devices are fixed to a base block and a driving force is transferred to driving rods. Then, a lens is moved by a pressure generated from a slide part, an inertial force of a lens frame and acceleration effects. The lens frame is transferred along with the driving rods according to a waveform of an input voltage or performs slidable relative motion, thereby enabling the driving device to reciprocally move the lens.
However, in this conventional device, the driving rods are fixed so that a length of barrel cannot be changed. This accordingly is an impediment to reduction in size. Also, a driving signal of the device is an asymmetrical wave signal, not a sine wave signal, thereby complicating a driving circuit.
Therefore, there is a need for a lens driving device which can be mounted in a small volume, controlled precisely due to high driving resolution, while operating with a small driving power and achieving a sufficient driving distance. | {
"pile_set_name": "USPTO Backgrounds"
} |
This application claims the benefit of U.S. Provisional Application No. 60/307,197 filed Jul. 20, 2001.
1. Field of the Invention
The present invention relates to a composition and method for marking non-porous objects with fluorescent identification that is non-toxic, water soluble, clear-drying, and will not damage surfaces.
2. Description of the Related Art
A safe marking system is needed by e-commerce auction sellers to prevent fraud. Sellers are sometimes defrauded when an item that is returned by a buyer is not the same item shipped by a seller, but an inferior item. This practice is called “upgrading” and is used by unscrupulous collectors who claim that an item is defective then return a different item and demand their money back.
A safe marking system is needed such that a seller may mark an item so that if it is returned, a seller can confirm that the returned item is the item shipped by the seller. Currently the ability to mark glassware, china, porcelain, pottery, jewelry, toys, tools, painted items, and plastics, i.e., any item that can safely be cleaned with a damp cloth, is limited by the destructiveness, permanence, or unsightliness of the marking agent. Diamond pens, permanent markers, oil-based paints, etc. can permanently damage expensive items and reduce their value. Permanence is an important characteristic of any marking system. Any identification mark must be permanent until such identification is deliberately removed. Marks made on labels or tape, subsequently attached to a non-porous object, are frequently lost when the adhesive fails.
A need also exists for a safe marking system for collectors and homeowners for inventory and insurance purposes. A common method of marking is to place an identifying number on a piece of tape or on a small paper label affixed to the bottom of items. Such tapes and labels are easily dislodged by routine handling of objects. Another method used to identify non-porous items is to engrave an identifying number onto the item. Such an engraving may permanently mar or deface an object and may cause subsequent reduction in value. Further, both methods of identification are readily visible upon inspection and may be removed by someone other than the owner.
A need therefore exists for a composition and method for marking non-porous objects that will allow an e-commerce auction seller to positively identify items that are subsequently returned and further allow owners to mark items for inventory and insurance purposes. | {
"pile_set_name": "USPTO Backgrounds"
} |
Recently, digital cameras and digital video cameras that store and save a subject image as a digital image signal in a storage medium have been spread. In a case where images are shot using such camera, it is necessary to set shooting parameters of the camera appropriately according to a surrounding environment and situation. For example, Patent Literature 1 below proposes an operating lever enabling complex operations to be performed intuitively so as to comfortably switch the configuration of various shooting parameters.
However, it is difficult for general users to manually set appropriate shooting parameters. Accordingly, in general, digital cameras and the like have an auto function by which shooting parameters corresponding to environments are automatically set. For example, the following Patent Literatures 2 through 4 propose imaging devices that automatically set appropriate shooting parameters corresponding to subjects.
In addition, the following Patent Literature 5 proposes a technology of presenting shooting parameters corresponding to a specified subject, and the following Patent Literatures 6 and 7 propose technologies of easily setting shooting conditions corresponding to a preference of a user. | {
"pile_set_name": "USPTO Backgrounds"
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The present invention relates to plastic containers adapted to contain food and beverages whose taste and/or odor may be affected by the materials of which the containers are made as well as by contaminants generated in the course of their manufacture and use of the containers. In particular, the invention relates to containers produced from polymers subject to degradation in the course of their conversion into containers, with the products of such degradation remaining entrapped within their walls and capable of diffusing into the contents, thereby affecting the taste and odor thereof.
Similarly, the polymers may contain oligomers i.e., molecular fractions that have insufficiently polymerized, as well as unreacted monomers, both of which may diffuse into the contents of the containers, with the same affect, as above. These conditions are encountered particularly in polymers obtained by condensation reactions, such as polycarbonate, nylon, and also polyethylene terephthalate (PET), the polymer predominantly used for beverage bottles and food jars.
To be suitable for use in food and beverage containers, PET must provide protection of the contents against deterioration such as, in the case of soft drinks, loss of carbonation or chemical reactions due to exposure to ambient conditions. Further, depending on their intended use, containers may be subject to considerable internal pressure and forces due to handling and storage. Therefore, the grades of PET to be used must be able to impart physical properties for withstanding these forces.
As is known, PET is a polymer that may be obtained in stepwise condensation of terephthalic acid and ethylene glycol. Polymerization is more complete the longer it is carried out at the appropriate temperature, and it may be repeatedly interrupted. Up to a certain stage of condensation, the reaction is carried out in the "molten" phase i.e., low-viscosity state, and is therefore termed a melt phase reaction, with the product designated as melt-phase PET. As this phase of the reaction progresses, the viscosity of the heated reacting mass increases to a degree, beyond which continuing manufacture is impractical. The polymer obtained at that stage, and even before, has many uses, notably for the production of textile fibers and film. However, melt-phase PET has insufficient physical properties and permeation resistance for use in large beverage bottles and certain other important packaging containers. Even more important, melt-phase PET entrains acetaldehyde (AA), a noxious product of thermal degradation, and also some oligomers, down to as yet unreacted monomer constituents, notably ethylene glycol. AA, which abbreviation stands for acetaldehyde, CH.sub.3 CHO, is a liquid of pungent-fruity odor that desorbs readily out of the walls of a container that is made from PET, in which the AA is entrained, into the contents to spoil the odor and taste thereof, even in very small concentrations. Thus, typical specifications for soft-drink bottles call for an AA limit of 1 ppm, and even less for drinking water. Likewise, unreacted monomers and oligomers may enter the content of the container and may, apart from interference with taste, constitute a health hazard as determined by prevailing laws regulating the same.
Accordingly, since AA is present in melt phase PET, the use of melt phase PET is not accepted for many forms of packaging, including some of the most important ones, i.e. beverage bottles. For the same reason melt-phase PET cannot be used even when its physical properties suffice, as in the case of small bottles that are subject to lesser stresses than large ones, since these stresses rise in proportion with size.
In order to obtain PET without the drawbacks associated with melt-phase PET, polymerization/condensation has to be continued. Since it is impractical to continue in the molten state, additional, expensive processes are added, wherein the melt-phase product is cooled, comminuted to a particle size suitable to be suspended and heated in and by a stream of hot air. The product is heated in a solid-state post-condensation reaction, preceded by crystallizing the melt-phase PET. Naturally, the cost of the finished PET increases substantially by these steps.
The cost of polymerizing the feedstock into the bottle-grade PET nearly doubles, compared with limiting the process to melt-phase polymerization. Particularly when the physical properties of containers made of melt-phase PET would otherwise suffice, as for small bottles, the increase in cost is accepted solely to eliminate excessive amounts of AA and other contaminants. In view of the fact that some 40% or more of the total manufacturing cost of a PET bottle is represented by the cost of the PET, it is readily seen that the use of melt-phase resin would represent great economic benefits.
There exists, therefore, a need for a container and process for manufacturing the container wherein melt-phase or scrap PET can be used in the container having unrestricted application to food and beverage by not contaminating the same. | {
"pile_set_name": "USPTO Backgrounds"
} |
Straight through flow filter elements have been used in systems for cleaning fluid passing therethrough. Straight through flow filter elements typically will have an inlet face and an oppositely disposed outlet face. In this manner, fluid flows in one certain direction upon entering the filter element at the inlet face and will have the same direction of flow as it exits the outlet face. Typically, straight through flow filter elements will be installed in a duct or housing of some type. After a period of use, the filter element will require servicing, either cleaning or a complete replacement. If it is difficult or inconvenient to service the filter element, the user may delay the proper servicing, which can cause damage to whatever system is being filtered.
Improvements to straight through flow filter elements are desirable. | {
"pile_set_name": "USPTO Backgrounds"
} |
1. Field of the Invention
This invention generally relates to the field of drug delivery. More particularly, this invention is directed to inhaled medications (for example medications delivered through pressurized metered dose inhalers (“pMDIs”) or other inhalers) and the delivery of medications to conducting airways and alveoli in a respiratory system.
2. Background of the Invention
Inhaled medications are commonly used to target drugs to the lungs in the treatment and prevention of various medical conditions. A. Steimer, E. Haltner, & C. M. Lehr, Cell Culture Models of the Respiratory Tract Relevant to Pulmonary Drug Delivery, 18 J. Aerosol Med. 137 (2005); R. Dalby & J. Suman, Inhalation Therapy: Technological Milestones in Asthma, 55 Adv. Drug. Del. Rev. 779 (2003). Drugs administered through the pulmonary route either act locally in the lungs or enter the systemic circulation following dissolution and absorption. Numerous particle and device engineering approaches have been attempted to incorporate drugs into small particles or make small pure drug particles for delivery to the most desirable lung locations. Such approaches include modifications to nebulizers, pressurized metered dose inhalers (pMDIs), active or passive dry powder inhalers (DPIs), or changes to the nature of the particles themselves. The ultimate objectives of particle and device engineering are to generate small slow moving particles with favorable aerodynamic properties. S. J. Farr, S. J. Warren, P. Lloyd, J. K. Okikawa, J. A. Schuster, A. M. Rowe, R. M. Rubsamen & G. Taylor, Comparison of in Vitro and in Vivo Efficiencies of a Novel Unit-Dose Liquid Aerosol Generator and a Pressurized Metered Dose Inhaler, 198 Int. J. Pharm. 63 (2000); VIII R. W. Niven, Respiratory Drug Delivery, Powders and Processing: Deagglomerating of a Dose of Patents and Publications 257-266 (R. N. Dalby, P. Byron, J. Peart, & S. Farr eds., DHI, Rayleigh 2002); K. R. Chapman, L. Love, & H. Brubaker, A Comparison of Breath-Actuated and Conventional Metered-Dose Inhaler Inhalation Techniques in Elderly Subjects, 104 Chest. 1332 (1993).
The fraction of drug delivered to the bronchial tree may be cleared by mucociliary transport and absorption through the airway epithelium into the systemic circulation. Thus, after initial deposition, drug particles do not migrate deeper into the lung. The opposite occurs: once particles encounter the fluid lining of the lung; they are either absorbed or transported to the larger airways of the lung by lung clearance mechanisms. Drug reaching the target region (which may be conducting airways or alveoli) of the lung following pulmonary inhalation (expressed as bioavailability or a deposition fraction) is often estimated at less than 10%. VIII M. Sakagami, Respiratory Drug Delivery, Pulmonary Insulin: a Critical Review of Its Biopharmaceutics 69-78 (R. N. Dalby, P. Byron, J. Peart, & S. Farr eds., DHI, Rayleigh 2002).
Following premature births, structurally immature and surfactant-deficient lungs containing reduced levels of pulmonary phospholipids are sometimes treated with natural and synthetic exogenous surfactants (treatment of Respiratory Distress Syndrome RDS). G. K. Suresh & R. F. Soll, Lung Surfactants for Neonatal Respiratory Syndrome: Animal Derived or Synthetic Agents, 4 Pediatr. Drugs. 485 (2002). These exogenous surfactants are complex colloidal dispersions composed primarily of phospholipids. They may contain additional components such as fatty acids, triglycerides and spreading agents. The dose of surfactant is relatively high and is administered to premature infants affected with RDS via endotracheal or intratracheal instillation wherein the surfactant is dripped directly into the bronchioles.
After instillation, the surfactant is distributed throughout the airways and the bolus advances distally while coating the airway walls with a thin layer of surfactant. F. F. Espinosa & R. D. Kamm, Bolus Dispersal Through Lungs in Surfactant Replacement Therapy, 86 J. Appl. Physiol. 391 (1999). The thickness of the coat of surfactant is dependent on surfactant concentration, viscosity and surface tension. In addition, a “reservoir” of surfactant remains in the larger airways as the surfactant expands into the lungs. Surface tension gradients draw exogenous surfactant distally to high surface tension locations thereby allowing surfactant to reach the alveoli.
FDA approval and continuous commercial availability of exogenous surfactants and their use in critically ill neonatal patients confirms the safety of phospholipid administration to the human respiratory tract. Their mode of administration (tracheal instillation) and site of action (alveolar spaces) confirms that the active components of these surfactant mixtures successfully spread from the trachea to the alveoli to exert their beneficial effect. R. J. Rodriguez, Management of Respiratory Distress Syndrome: An Update, 48 Respir. Care. 279 (2003). | {
"pile_set_name": "USPTO Backgrounds"
} |
Spark ignition engines typically have a gas pedal that is connected to an air throttle that meters air into engine. Stepping on the gas pedal typically opens the air throttle, which allows more air into the engine. In some cases, a fuel injector controller adjusts the fuel that is provided to the engine to maintain a desired air/fuel ratio (AFR). The AFR is typically held close to a stoichiometric ratio to produce stoichiometric combustion, which helps minimizes engine emissions and allows three-way catalysts to simultaneously remove hydrocarbons, carbon monoxide, and oxides of nitrogen (NOX).
Compression ignition engines (e.g. diesel engines) typically do not operate at stoichiometric ratios, and thus greater emissions and different emission components often result. Because diesel engines are now making real headway into the car and light truck markets, federal regulations have been passed requiring more stringent emission levels for diesel engines.
Unlike spark ignition engines, the pedal of a diesel engine is typically not directly connected to an air throttle that meters air into engine. Instead, in diesel engines with electronic fuel injection (EFI), the pedal position is sensed by a pedal position sensor, and the sensed pedal position is used to control the fuel rate provided to the engine, which allows more or less fuel per fuel pump shot. In many modern diesel engines, the air to the engine is typically controlled by a turbocharger, often a Variable Nozzle Turbocharger (VNT) or waste-gate turbocharger.
In many diesel engines, there is a time delay, or “turbo-lag”, between when the operator moves the pedal—injecting more fuel—and when the turbocharger spins-up to provide the additional air required to produce the desired air-fuel ratio. This “turbo-lag” can reduce the responsiveness and performance of the engine, and can increase emissions from the engine.
There are typically no sensors in the exhaust stream of a diesel engine that are analogous to those emissions sensors found in spark ignition engines. One reason for this is that diesel engines typically operate at about twice as lean as spark ignition engines. As such, the oxygen level in the exhaust of a diesel engine can be at a level where standard emission sensors do not provide useful information. At the same time, diesel engines typically burn too lean for conventional three-way catalysts. As such, control over combustion in a diesel engine is often performed in an “open-loop” manner, often relying on engine maps or the like to generate set points for the intake manifold parameters that are believed to be favorable for acceptable exhaust emissions.
In any event, after-treatment is often required to help clean up exhaust emissions in a diesel engine. In many cases, after-treatment includes a “flow through oxidation” catalyst system, which typically does not have any controls. Hydrocarbons, carbon monoxide and most significantly those hydrocarbons that are adsorbed on particulates can sometimes be cleaned up when the conditions are right. Some after-treatment systems include particulate filters. These particulate filters, however, must typically be periodically cleaned often by burning off the soot particulate which has been collected on the filter to “Regenerate” the filter surface. Increasing the exhaust gas temperature is the primary way to initiate Regeneration, and injecting additional fuel in-cylinder or into an exhaust burner is one method. The control of this type of after-treatment may be based on a pressure sensor or on distance traveled, often in an open loop manner. | {
"pile_set_name": "USPTO Backgrounds"
} |
Some electronic module sub-assemblies need to be inserted into a chassis and then be connected and fully mated with a chassis-mounted connector. Examples of such sub-assemblies are power supplies, RAID disks, peripheral devices, fan assemblies, and processors, all of which require a power connection of some sort. When these sub-assemblies have a power connection there is a requirement for sufficient surface contact (barrel contact) to insure adequate performance. Sufficient surface contact is only accomplished and assured with a fully mated or almost fully mated connector.
Providing for full connector insertion of power connectors (pre-loading) is of vital importance when preventing power failures as is maintaining the fully loaded connection during service. If a power connector loosens or begins to back out and there is less and less surface contact, the power connection and the connector itself may eventually fail. Consequently, yield (longevity and service life of the connector and thus any product) is compromised by a non-fully inserted power connector.
For purposes of quality and safety, and especially with high voltage, one typically uses an injector tool when inserting a sub-assembly into a chassis, usually then securing the sub-assembly with a lock of some kind and a mounting screw or two.
Previous solutions include securing screws, locking inserter/ejector levers, and simple locking mechanisms (like a door handle).
Securing screws can be used to provide enough pre-load to ensure fully mated connectors. The problem is they are often numerous in number and are subject to stripping or cross threading due to alignment problems. There are also tolerance problems in getting the threads started. The screw stripping, screw binding, and screw damage sometimes leaves metal particles and slivers that can short electronics near the failure. Furthermore, since the screws are not initially attached to the chassis or sub-assembly, they can be easily lost or misplaced. Sometimes when this happens, a sub-assembly is secured with less than the full number of required screws, and the connection is either not as complete as it needs to be initially or is prone to earlier failure.
Inserter/ejector levers themselves are adequate to fully engage a connector pair at time of insertion. The problem is that they generally cannot provide enough pre-loading to overcome extended field shock and vibration, especially in the telecom environment. Furthermore, they generally cannot maintain full engagement during fragility operations such as transportation and shipping because there is no pre-loading spring action.
Simple locking mechanisms do not provide any pre-load, and thus are inadequate for powered sub-assemblies, especially when the service environment includes shocks and vibrations. | {
"pile_set_name": "USPTO Backgrounds"
} |
1. Field of the Invention
The present invention relates to the problem of resonance due to plating stubs on circuit boards.
2. Background of the Related Art
An integrated circuit (IC), also commonly referred to as a “microchip” or “chip,” is an electronic circuit comprising miniaturized semiconductor devices formed in a semiconductor substrate. Many copies of an integrated circuit may be formed on a large semiconductor wafer, which is then cut into individual pieces referred to as a “die chips” or “dies,” each containing a copy of the integrated circuit. Semiconductor materials such as silicon are typically brittle, so a fragile die chip is commonly packaged on a carrier, referred to as a “chip package” or simply “package.” The substrate of the chip package functions as an interposer for interfacing the chip with a printed circuit board (PCB). For example the processor for a computer may be carried on a chip package that is mounted to a motherboard.
The die chip may be electrically connected to a package substrate by wirebonding. Wirebonding is a process known in the art by which a very fine wire is connected from a bond pad on the chip to corresponding signal pathways (“traces”) on the package substrate. Bond wires are typically formed of a highly conductive material, such as platinum or other precious metal. A package in which a die chip is connected to the substrate by wirebonding may be referred to as a “wirebond package.” The traces on the substrate extend from the location of bonding with the wirebond to signal interconnects elsewhere on the substrate. The signal interconnects on one layer of the substrate may be electrically connected to signal interconnects on another layer of the substrate using through-connections known as “vias.” Thus, for example, the signal connects on the face to which the chip is mounted may be connected to corresponding pins of a pin grid array (PGA) or to corresponding balls of a ball grid array (BGA) on the opposing face of the substrate. The PGA or BGA may then be placed in contact with a corresponding pattern of electrical contacts on the PCB to which the chip package is subsequently secured.
Signal traces are typically formed of commonly available materials, such as copper, that are relatively affordable and have sufficient electrical conductivity. Materials having improved electrical conductivity, including precious metals such as platinum and gold, are then selectively applied to the substrate at locations where the expense of such materials is warranted. For example, to facilitate wire bonding, platinum may be applied at locations along the signal traces where wire bonds are formed. Gold is often applied to signal interconnects. These materials are usually applied by electroplating. However, most electroplating processes result in open plating stubs extending from the signal interconnects. The electroplating voltage is applied at or near the periphery of the package substrate, which results in the plating stubs extending to or near the periphery of the substrate.
Plating stubs may hinder signal performance of the package if left intact. An open-ended plating stub can cause signal reflections. Signal performance is greatly impacted by reflections from these open stubs, particularly at higher frequencies wherein the wavelength of the signal is comparable to or less than the length of the plating stub. A quarter-wave length resonance is particularly detrimental in high speed data transmissions. One solution to avoid signal degradation caused by plating stubs is to remove the plating stubs by additional etching. However, such measures increase manufacturing costs and decrease product yield. | {
"pile_set_name": "USPTO Backgrounds"
} |
1. Field of the Invention
The invention relates to a collapsible liquid container, particularly for storing and transporting helicopter fuel, which can be easily transported by a helicopter.
2. Prior Art
A helicopter is severly limited in its range of operations by the volume of fuel consumed. Small helicopters can rarely carry sufficient fuel on board for normal work, and commonly the helicopter is required to carry external fuel, e.g. to sling steel fuel drums from the cargo hook, for transporting fuel to the work area. Commonly, at a work site where there has been extensive use of helicopters, many empty fuel drums accumulate and become a hazard due to residual fuel which is difficult to empty completely, and furthermore require considerable storage space. Because returning empty fuel drums back to base is time consuming, they are commonly left behind and it is estimated that there are millions of empty fuel drums scattered across the northern portions of Canada and Alaska.
Flexible, pillow bladder tanks have been used to store fuel but such tanks are prone to a rupture by rough handling and thus require extra protection. Such tanks are also difficult to empty completely of fuel as the discharge opening is not always at a lowermost point. If the bladder tanks are merely fitted in a conventional net sling beneath the helicopter, the tanks are commonly damaged when the helicopter lands, due to puncturing by sharp objects on the ground. To avoid this problem, the pillow tanks have been transported on pallets suspended from cables, but this arrangement can exhibit poor aerodynamic characteristics requiring the helicopter to fly at lower cruise speeds. Also, when the helicopter is returning to base with empty pillow tanks, the pillow tanks are bulky and do not fold easily, and thus are returned as an external load. If the empty pillow tanks are strapped to the pallet, they also exhibit poor aerodynamic characteristics requiring a relatively slow cruise speed. | {
"pile_set_name": "USPTO Backgrounds"
} |
Semiconductor memory has become increasingly popular for use in various electronic devices. For example, non-volatile semiconductor memory is used in cellular telephones, digital cameras, personal digital assistants, mobile computing devices, non-mobile computing devices and other devices. Electrically Erasable Programmable Read Only Memory (EEPROM) and flash memory are among the most popular non-volatile semiconductor memories. With flash memory, also a type of EEPROM, the contents of the whole memory array, or of a portion of the memory, can be erased in one step, in contrast to the traditional, full-featured EEPROM.
Both the traditional EEPROM and the flash memory utilize a floating gate that is positioned above and insulated from a channel region in a semiconductor substrate. The floating gate is positioned between the source and drain regions. A control gate is provided over and insulated from the floating gate. The threshold voltage (VTH) of the transistor thus formed is controlled by the amount of charge that is retained on the floating gate. That is, the minimum amount of voltage that must be applied to the control gate before the transistor is turned on to permit conduction between its source and drain is controlled by the level of charge on the floating gate.
Some EEPROM and flash memory devices have a floating gate that is used to store two ranges of charges and, therefore, the memory element can be programmed/erased between two states, e.g., an erased state and a programmed state. Such a flash memory device is sometimes referred to as a binary flash memory device because each memory element can store one bit of data.
A multi-state (also called multi-level) flash memory device is implemented by identifying multiple distinct allowed/valid programmed threshold voltage ranges. Each distinct threshold voltage range corresponds to a predetermined value for the set of data bits encoded in the memory device. For example, each memory element can store two bits of data when the element can be placed in one of four discrete charge bands corresponding to four distinct threshold voltage ranges.
Typically, a program voltage VPGM applied to the control gate during a program operation is applied as a series of pulses that increase in magnitude over time. In one possible approach, the magnitude of the pulses is increased with each successive pulse by a predetermined step size, e.g., 0.2-0.4 V VPGM can be applied to the control gates of flash memory elements. In the periods between the program pulses, verify operations are carried out. That is, the programming level of each element of a group of elements being programmed in parallel is read between successive programming pulses to determine whether it is equal to or greater than a verify level to which the element is being programmed. For arrays of multi-state flash memory elements, a verification step may be performed for each state of an element to determine whether the element has reached its data-associated verify level. For example, a multi-state memory element capable of storing data in four states may need to perform verify operations for three compare points.
Moreover, when programming an EEPROM or flash memory device, such as a NAND flash memory device in a NAND string, typically VPGM is applied to the control gate and the bit line is grounded, causing electrons from the channel of a cell or memory element, e.g., storage element, to be injected into the floating gate. When electrons accumulate in the floating gate, the floating gate becomes negatively charged and the threshold voltage of the memory element is raised so that the memory element is considered to be in a programmed state. More information about such programming can be found in U.S. Pat. No. 6,859,397, titled “Source Side Self Boosting Technique For Non-Volatile Memory,” and in U.S. Pat. No. 6,917,542, titled “Detecting Over Programmed Memory,” issued Jul. 12, 2005; both of which are incorporated herein by reference in their entirety. | {
"pile_set_name": "USPTO Backgrounds"
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Web services and other network-based applications may be employed to store and retrieve data on behalf of numerous users. In some cases, use of the service may be exchanged for a fee. In other cases, a customer may contract with a third party to host a service on behalf of the customer's users. However, the architecture of these services may be complex, and accordingly the cost of providing the service might be difficult to calculate. The problem may be more difficult when multiple services are hosted within a single computing environment.
A related issue involves the complexity of diagnosing database performance problems. Web services and similar applications may employ one or more databases to store and retrieve data. When a web service interface is invoked, the invocation may result in a number of additional nested calls to various computing resources. Each of these may, in turn, send a request to one or more databases. When one of these queries causes a performance problem, it may be difficult to trace the query to its original source. | {
"pile_set_name": "USPTO Backgrounds"
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SiAlON materials have a number of uses such as, for example, cutting inserts for various metal cutting application and wear parts for various wear applications (e.g., plunger rods for pumps, plunger ball blanks, down hole pump check valve blanks, bushings, blast nozzles, and other wear and impact applications).
Ceramic materials have also been used in high temperature wear applications in structures like, for example, microturbines. In the microturbine applications, the ceramic materials may comprise the stator (i.e., the stationary blades), the rotor (including the rotor blades), the fuel injector nozzle, and the shroud. These components of the microturbine require adequate high temperature creep resistance and adequate high temperature deformation resistance.
Exemplary patents that disclose SiAlON materials are U.S. Pat. No. 4,563,433 and U.S. Pat. No. 4,711,644. One article that discusses SiAlON materials is Izhevskiy et al., “Progress in SiAlON ceramics, Journal of the European Ceramic Society 20 (2000) pages 2275–2295.
SiAlON materials may contain an alpha prime (or alpha′) phase and a beta prime (or beta′) phase and one or more other phases such as, for example, a glassy phase and/or a crystalline phase. The alpha prime SiAlON phase may be of the formula MxSi12−(m+n)Alm+nOnN16−n where M is Li, Ca, Y or other lanthanides and where the theoretical maximum of x is 2, the value of n ranges between greater than 0 and less than or equal to 2.0, and the value of m ranges between greater than or equal to 0.9 and less than or equal to 3.5. The beta prime SiAlON phase may be of the formula Si6−zAlzOzN8−z where 0<z≦4.2. In the case where M is yttrium, the crystalline phases may include YAG (yttrium aluminum garnet) which is a cubic phase of the formula Y3Al5O12); YAM which is a monoclinic phase of the formula Y4Al2O9; N—YAM which is a monoclinic phase of the formula Y4Si2O7N2; and Y—N-α-Wollastonite which is a monoclinic phase of the formula YSiO2N.
SiAlON materials may comprise an alpha prime SiAlON phase and a beta prime SiAlON phase, as well as further contain silicon carbide particles dispersed throughout the SiAlON matrix. Such a SiAlON material is disclosed in U.S. Pat. No. 4,826,791 to Mehrotra et al.
Other ceramic materials include an alpha prime SiAlON phase, a beta SiAlON phase and an intergranular phase wherein the ceramic optionally contains refractory phases. The ceramic material has an alloyed surface with a higher oxygen and aluminum content. U.S. Pat. No. 4,880,755 to Mehrotra et al. discloses such a ceramic material.
U.S. Pat. No. 5,370,716 to Mehrotra et al. discloses a high Z-SiAlON material comprising beta prime SiAlON phase. The beta prime SiAlON phase has a formula Si6−zAlzOzN8−z where 1<z<3.
U.S. Pat. No. 5,908,798 to Chen et al. discloses a SiAlON material wherein the focus is on the reinforcement of alpha prime SiAlON with elongated grains of alpha prime SiAlON. The examples that include ytterbium produce a material with only alpha prime SiAlON phase that does not contain any beta prime SiAlON phase.
U.S. Pat. No. 6,124,225 to Tien et al. focuses upon the use of gadolinium (Gd) in a SiAlON material to produce an alpha prime SiAlON material that is reinforced by elongated grains of alpha prime SiAlON.
Although current SiAlON cutting inserts exhibit acceptable properties (e.g., hardness, toughness, thermal shock resistance) it would be desirable to provide for an improved SiAlON material that has application as a cutting insert that exhibits improved metal cutting performance properties including hardness, Young's modulus, toughness, thermal conductivity, and thermal shock resistance. The same is true for SiAlON wear parts in that although current SiAlON wear parts have acceptable properties (e.g., hardness, Young's modulus, toughness, thermal conductivity, and thermal shock resistance), it would be desirable to provide an improved SiAlON material that has application as a wear part that exhibits improved properties. | {
"pile_set_name": "USPTO Backgrounds"
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1. Technical Field
This disclosure relates in general to network computer systems, and more particularly to a method, apparatus and program storage device for providing mutual failover and load-balancing between interfaces in a network.
2. Description of the Prior Art
Computer systems linked to each other in a network are commonly used in businesses and other organizations. Computer system networks (“networks”) provide a number of benefits for the user, such as increased productivity, flexibility, and convenience as well as resource sharing and allocation.
Networks are configured in different ways depending on implementation-specific details such as the hardware used and the physical location of the equipment, and also depending on the particular objectives of the network. In general, networks include one or more server computer systems, each communicatively coupled to numerous client computer systems.
As the use of networked computer systems increases, the need has arisen to provide additional bandwidth to handle the electronic traffic on the network. For example, inadequate bandwidth can result in data stalling in the pipeline between a client and a server. This stalling can significantly limit network performance.
Network interface cards (NIC) are used to connect a server or any computing device to a network. Such NICs include, for example, Ethernet cards or Token Ring cards that plug into a desktop computer or server. The NIC implements the physical layer signaling and the Media Access Control (MAC) for a computer attached to a network. Multiple NICs effectively attach a computer to a network multiple times. This increases the potential bandwidth into the network proportionally. Multiple NICs also provide resiliency and redundancy if one of the NICs fails. In the case of a failure of a NIC, one of the other NICs is used to handle the traffic previously handled by the failed NIC, thereby increasing overall system reliability. Accordingly, it is necessary to be able to detect when a NIC fails and, when a failed NIC is detected, to switch to a functioning NIC (this is referred to as fault tolerance and fail over support). NICs are typically represented in the host operating system through kernel objects referred to as “network interfaces.” Herein, the network interfaces that are directly used by the Internet Protocol (IP) will be referred to as “IP interfaces.” Furthermore, interfaces directly corresponding to the NICs will be referred to as the physical interfaces. Interfaces derived from physical interfaces, as described herein will be variously referred to as logical or virtual interfaces.
Load balancing is a technique used to reduce data bottlenecks caused by an overloaded communications network. In load balancing, the traffic between a server and a network is shared over multiple NICs. Such load balancing typically requires special software. Load balancing also provides fault tolerance, which maintains data communication between the server and the network in the event of a disruption in a data link. When a link fails, the load is failed over to a backup or secondary link such that signal continuity is maintained.
A well-known technique is to group multiple physical links together so that they appear as a single network interface to the Internet Protocol (IP) layer of the TCP/IP stack. The load balancing and failover are then implemented among the links without the IP layer being aware of it. Examples of such techniques are the ‘bonding’ driver in Linux, Etherchannel or IEEE 802.3ad link aggregation standard.
However, these techniques suffer from several disadvantages. For example, since the system considers the multiple physical links as a single NIC the load balancing is implemented below the IP layer. In other words, the multitude of NICs is presented as a single interface to the IP protocol. Therefore the network layer information, e.g. the routing table, cannot be used to load balance the data traffic. Generic tools that work at the network layer do not apply as well. These disadvantages also apply to the failover mode.
The link aggregation techniques described above further require specialized switches that can consider multiple switch ports as one; in the case of directly connected peer systems, both ends must be configured to support the standard. Furthermore, the failure of the switch causes all the links to loose connectivity. In an alternative mode, which supports failover only but not load balancing, the links may be connected to different switches, however in such a configuration, only one link can be active at a given time.
Load-balancing can also be provided at the IP layer wherein the load is balanced across multiple IP interfaces. The data is load balanced in accordance to the routing table entries, which point to a particular IP interface for a given route. On failure of a NIC an alternative method for failover must be implemented and the routing table updated which can take time. The link level fail over described earlier occurs within a short (millisecond) interval whereas route propagation can take much longer. In addition the IP address needs to be associated with the backup interface and failover MAC address informed to the peers. Therefore, a method is required that allows for load balancing at the IP layer while providing a fast failover.
It can be seen then that there is a need for a method, apparatus and program storage device for providing mutual failover and load balancing between interfaces at the IP layer in a network. | {
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The present invention relates to a mask that may be used for selectively growing a solid over a substrate during the manufacture of a semiconductor device. The mask defines a region in which the solid is to be grown. The present invention also relates to a manufacturing method of such a mask, and a method for selectively growing a solid using the mask.
Selective growth of a solid is a common technology required during the manufacture of a semiconductor device, in which silicon (Si) or gallium arsenide (GaAs) is selectively grown on a defined region of a semiconductor substrate. Currently, a semiconductor such as Si or GaAs, a metal such as tungsten (W) or aluminum (Al); and a silicide compound have been used as a material for a thin film, which is capable of being grown selectively.
During a selective growth process, the surface of the substrate is covered with a mask so as to suppress the growth of a solid on an undefined region covered by the mask. The material for the mask is determined by taking into consideration the types of substrate and solid material to be grown. Typical materials for a mask includes silicon dioxide which is obtained through the thermal oxidation of silicon or a vapor deposition method, and silicon nitride, which is formed by the vapor deposition method. In general, the thickness of a mask is several tens of nanometers (nm) or more. Also, the region in which a solid is to be selectively grown is defined by depositing a photoresist over the mask and then patterning the mask by photolithography.
However, as semiconductor devices become smaller, a technology for reducing the size of the selective growth region from units of submicrons into units of nanometers is required together with an ultra thin mask for use in this process, having a thickness of several nanometers or less, e.g., below 10 nm. Also, as the thickness of the mask is reduced, a mask material with both reaction selectivity and stability is required. However, such thin film cannot be formed of a single chemical composition.
The above problem will be explained using a thin mask formed of silicon dioxide by way of example. Firstly, if the mask is thin, the mask will be susceptible to defects such as fine voids or holes, so that the selectivity will be deteriorated. Therefore, it is favorable to form such an ultra thin mask at a lower temperature than a conventional method so as to precisely control the thickness of the thin mask. However, these low-temperature conditions can easily cause other defects in the mask. In order to reduce the density of defects in the mask, a high-temperature annealing is favorable. However, a silicon dioxide film with a thickness of several nanometers or less, e.g., below 10 nm, is thermally unstable on the silicon substrate. As a result, the silicon dioxide film decomposes and desorbs during any annealing step performed at approximately 800.degree. C. or more. Thus, it is not possible to anneal the silicon dioxide film at a high temperature.
A second problem occurs when the mask is used as an insulating layer in a final device. By using the phenomenon of a desorption of oxygen by irradiating electron beams onto the silicon dioxide film, a fine pattern having a thickness of several nanometers, e.g., below 10 nm, can be formed directly by irradiating electron beams onto the mask without using a resist. However, it is necessary to limit the desorption of oxygen from the mask within the surface layer, which is caused by the irradiation of electron beams, so as to use the mask as an insulating layer later. However, the general electron beams, which have an energy of 10 keV, because of their long free path of 10 nm or more within the solid, pass over the entire silicon dioxide with a thickness of several nanometers. In other words, the mask layer formed of only silicon dioxide cannot be used as an insulating layer if oxygen is desorbed from it by irradiating the electron beams. | {
"pile_set_name": "USPTO Backgrounds"
} |
1. Field of the Invention
This invention relates to a fuel evaporation control or vapor recovery system including a charcoal canister, and, more particularly, to a system of the type described, which allows the supply of gasoline vapor to pass to the engine during engine deceleration, thereby improving the efficiency of the charcoal canister.
2. Description of the Prior Art
A fuel evaporation control or vapor recovery system, which prevents the emission of gasoline vapor from the fuel tank into the atmosphere, having a charcoal canister having activated charcoal housed therein, is known. In the prior art fuel evaporation control system, gasoline vapor, which is accumulated or adsorbed within the charcoal canister, is supplied to an internal combustion engine under the following conditions: when the engine is loaded over a given load level; while the supply of gasoline vapor is interrupted; and when the engine is loaded below a given load level.
Recently, government regulations for controlling fuel evaportion from fuel tanks have become more strict, and hence it is desirable to improve the efficiency of charcoal canisters. According to the prior art, it is an easy task to provide systems, which may increase the amount of gasoline vapor to be supplied to an engine by increasing the size of the charcoal canister. However, the amount of oxygen in an exhaust system is limited in high load conditions, so that an increase in amount of gasoline vapor would lead to an increase in amount of harmful emission from an engine. An increase in size of the charcoal canister to offset this is not desirable from a design viewpoint.
Meanwhile, it has become common practice to use a secondary air supply means for an exhaust system for treating harmful constituents of exhaust gases (for instance, hydrocarbons and carbon monoxide). The secondary air is supplied to an exhaust system from an air pump or through a reed valve means, which operates in response to a variable vacuum in the exhaust manifold. Meanwhile, the concentration of oxygen contained in exhaust gases is relatively high, during engine deceleration or in a negative output condition of the engine. This discovery has been overlooked in solving the aforesaid problem. | {
"pile_set_name": "USPTO Backgrounds"
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The invention relates generally to an automatic lubrication system for an impact tool or the like, and more particularly to a system which includes a pump component for delivering lubricant from a lubricant storage container to a location on the tool where the lubricant is to be applied, the lubricant being transported either by its own flow characteristics and/or by means of pressure to the delivery chamber of the pump component, and means for producing a pump stroke of the pump component with each actuation of the impact tool to deliver lubricant to the point of lubrication.
EP-A-0 430 024 describes an automatic lubricating system for the tool of a hydraulic impact mechanism. The system comprises a delivery unit connected to a lubricant storage container for delivering lubricant to the chisel guide supporting the chisel of the impact mechanism. In that case, the lubricant storage container, filled with lubricating grease, features a movable separating component which acts under the bias of a compression spring to force lubricant grease to the delivery chamber of the delivery unit. Here, the delivery pressure of the delivery unit is generated by the same hydraulic operating pressure that drives the impact mechanism, so that each time operating pressure is applied to the impact mechanism, the delivery unit produces a predetermined delivery stroke of adjustable magnitude. Such a lubricating system requires expensive hydraulic and/or pneumatic connecting lines as well as the pertinent control and command installations.
is an object of the present invention to create a simpler and more reliable lubricating system of the type mentioned at the outset.
This task is achieved by an oscillatory mass to which is transferred the impact motion of the tool, and by means which converts the oscillating motion of this mass into a pump pressure for driving the pump component.
In a first embodiment of the invention, the oscillatory mass for actuating the pumping component is either slidably supported on a fixed rod element or is affixed to a movable rod element supported in an axially sliding fashion, so that on each actuation (vibration) of the impact tool the oscillatory mass is deflected from its rest position. In this embodiment, the rod element is preferably aligned with the direction of impact. At least one slide bearing is provided for the oscillating mass. This bearing may consist of a bearing housing in which the mass oscillates back and forth. In the case where the oscillating mass is slidable on a fixed rod element, the slide bearing may comprise the walls of the bearing housing; where the mass is affixed to a movable rod element, the slide bearing for the rod element may comprise the lids of the bearing housing.
To ensure that the oscillating mass returns to its starting point or home position after each oscillation, the mass may be supported on opposite sides by compression springs. The compression springs in turn may react against the end walls or lids of the bearing housing.
A further defining feature of the invention consists of the fact that the rod element comprises, at least in part, a gear rack which is engageable with a gear to drive the pump component. In this embodiment, the gear rack drivingly engages the toothed rim of the gear as the rod element moves through a forward stroke; during a reverse stroke the gear rack slides, ratchet-fashion, over the appropriately inclined teeth of the gear rack. This ensures that the gear that actuates the delivery piston of the pump component moves only in one direction. In this embodiment, the gear rack is preferably attached to one end of the rod element for pivotal movement relative to the axis of rotation of the gear. The rack pivots away from the axis during a reverse stroke of the rod element and is urged by a spring toward the axis during a forward stroke to ensure that the gear rack drivingly engages the gear to drive the pump component.
According to a further aspect of this invention, a cam is used to transfer the motion of the gear to the delivery piston of the pump. The cam has a cam surface which engages the piston to drive it through a forward pumping stroke. A spring is used to move the piston back through a return stroke.
In another aspect of this invention, the range of movement of the oscillating mass, and thus the stroke of the delivery piston, can be varied by an adjustable stop. This stop permits adjustment of the amount of lubricant to be delivered to the lubrication site with each impact.
In another embodiment of this invention, the oscillatory mass is supported on a shaft element by first and second one-way clutches. In this case the axis of the shaft element is preferably oriented crosswise relative to the impact direction of the impact mechanism. Movement of the oscillating mass in one direction causes the first one-way clutch to engage the shaft to rotate it and thus drive the piston of the pump through a forward pumping strike. The second one-way clutch is disengaged from the shaft during this rotation. As the oscillating mass moves in the opposite direction, the first one-way clutch disengages the shaft and the second one-way clutch engages the shaft to prevent reverse rotation of the shaft. In this fashion the impact (vibrating) motion of the tool is converted into a directional rotating movement of the shaft element.
The rotary movement of the shaft is transferred to the piston of the delivery pump by means of a cam having a cam surface which is engageable with the delivery piston of the pump component. Rotation of the eccentric drives the piston through a forward stroke to deliver lubricant to the point of lubrication. The piston is moved through a reverse stroke by a return spring.
In this embodiment, an adjustable stop is provided at the bearing housing to vary the stroke of the delivery piston. This enables the amount of lubricant delivered to be adjusted.
In general, a lubrication system for a vibratory apparatus of the present invention comprises a lubricant pump for pumping lubricant from a supply thereof to one or more points of lubrication of the apparatus. A drive for the pump is powered in response to the vibration of the apparatus.
In another aspect, a lubrication system of the present invention is for a hydraulic striking device, the device being vibratory in operation. The system comprises a base for attachment to the device for vibration therewith and a lubricant pump for pumping lubricant from a supply to one or more points of lubrication of the device. The pump comprises a cylinder and a plunger reciprocable in the cylinder through a stroke between a retracted position for intake of lubricant into the cylinder and a forward position for delivery of the intake from the cylinder. A weight is mounted on the base for oscillation in response to the vibration of the device when the base is attached to the device, oscillation of the weight effecting reciprocation of the plunger through a stroke.
Additional objectives, features and application possibilities of the present invention are found in the description of examples of embodiment, below, based on the drawing. In so doing the defining features, described and/or illustrated in figures, constitute, per se or in any desired combination, the object of this invention, independently of their summarization into individual claims or their back-references. | {
"pile_set_name": "USPTO Backgrounds"
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1. Field of the Invention
The present invention relates to a method of manufacturing a semiconductor package, and a molding apparatus used in the method, and more particularly, to a method of manufacturing a wafer-level chip-size package, and a molding apparatus used in the method.
2. Description of the Related Art
In keeping with the trend toward miniaturization in the development of electronic devices, i.e., the trend toward making ever smaller and ever thinner packages, wafer-level chip-size packages. Such packages, which are about the same size as the incorporated semiconductor chips and which are substantially complete before being separated from the wafer, have been the subject of increasing interest. During the manufacture of a wafer-level chip-size package, typically both a rewiring process and an encapsulating process are performed while the chips remain in a wafer state, after which the individual chip packages are separated from the wafer using a dicing process.
If a thin wafer is used for making a wafer-level chip-size package, the wafer tends to have insufficient strength and is more susceptible to deformation such as bending and/or warping. Both the likelihood and seriousness of such wafer warping formation tends to increase as the diameter of the wafer increases. Similar problems are associated with larger semiconductor chip geometries which may experience or be susceptible to chip warping. Both wafer warping and/or chip warping are detrimental to the fabrication process and tend to decrease the overall process yield and may degrade the quality and reliability of the wafer-level chip-size packages that are produced.
In particular, conventional wafer-level chip-size packages are susceptible to wafer warping because only the front surface of the wafer is molded using an encapsulant. Further, when a wafer is molded only on its front surface, the edges of chips of the wafer may be more susceptible to cracking or chipping during the subsequent dicing processing and associated handling. Moreover, conventional wafer-level chip-size packages having and encapsulant layer provided only on the front surface tend to be more susceptible to semiconductor chip cracking resulting from impacts associated with the handling during subsequent wafer level testing, board mounting processes and package test processes. | {
"pile_set_name": "USPTO Backgrounds"
} |
1. Field of the Invention
The present invention relates to a hardness tester.
2. Description of Related Art
Conventionally, hardness testing methods of a pressing type are well known, such as the Vickers hardness test and the Knoop hardness test, in which an indenter having a planar polygonal shape is pressed against a surface of a sample, then a degree of hardness of the sample is measured from a length of a diagonal line in a resulting polygonal indentation in the sample surface. Such hardness testing methods are widely used in evaluating mechanical characteristics of metallic materials.
As is commonly known, the Vickers hardness test employs a quadrangular pyramid diamond indenter and indicates the degree of hardness by a relationship between an average value for the length of the two diagonal lines of the quadrangular pyramid indentation formed in the surface of the sample and a pressing load of the indenter on the sample. The Knoop hardness test employs a rhomboid pyramid diamond indenter and indicates the degree of hardness by a relationship between the length of the longer of the diagonal lines of the rhomboid pyramid indentation formed in the surface of the sample and the pressing load of the indenter on the sample.
Typically, when conducting a hardness test with the Vickers hardness test or the Knoop hardness test, the sample is observed with a field lens to set a test position. A turret is then rotated to replace the field lens with the indenter, and an indentation operation is performed. Then, the turret is switched back to the field lens once again to observe the indentation formed in the surface of the sample. At this point, in order to correctly form the indentation in the set test position, a center position of the indenter that will form the indentation and the center position of the field lens that will conduct the observation must be positioned correctly. In a conventional hardness tester, a centering mechanism is used to automatically adjust the field lens to match the center position of the indenter when the indenter is disposed, or positioned, in a predetermined position opposite the sample.
However, because the indenter is disposable (i.e., can be thrown away) the indenter must be changed when worn out. When the indenter is changed, the center position of the indenter and the center position of the field lens may become offset, thus creating a need to center the field lens. In order to center the field lens, indentation is performed with a reference indenter, then the turret is rotated to switch to the field lens to be centered. Next, while observing the indentation, the field lens is centered such that the center position of the indentation matches the center position on a screen. Finally, the turret switches to the indenter and performs another indentation, then switches to the centered field lens and confirms whether the center position of the indentation matches the center position on the screen.
Existing hardness testers are mounted with a large number of field lenses. Therefore, the above-described centering procedure must be performed for the number of field lenses installed. In addition, some of the existing hardness testers are mounted with two indenters, and thus a second indenter must be centered to match the center position of a first indenter serving as the reference. A user is burdened in performing the above-described sequence of centering work.
To address this, a hardness tester is disclosed that is capable of performing an accurate hardness test even when the center position of the indenter is offset from the center position of the field lens (see, e.g., Japanese Patent Laid-open Publication No. 2004-286541). Specifically, the invention described in Japanese Patent Laid-open Publication No. 2004-286541 calculates a coordinate differential between a center coordinate of a display screen (a field lens) and the center coordinate of an indentation displayed on the display screen. Then, the offset between the center position of the indenter and the center position of the field lens is corrected by displacing a sample stage in a horizontal direction such that the coordinate differential is approximately zero.
However, the invention described in Japanese Patent Laid-open Publication No. 2004-286541 is a correction process performed during hardness calculation after the indentation is formed and cannot correct the offset between the center position of the indenter and the center position of the field lens during formation of the indentation. Therefore, the user may be unable to form the indentation in a desired test position. | {
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1. Field
Example embodiments of the inventive concepts described herein relate to a storage system and/or a write method thereof.
2. Related Art
A storage system consists of a host and a storage device and is connected through a variety of interface standards such as UFS (Universal Flash Storage), SATA (Serial ATA), SCSI (Small Computer Small Interface), SAS (Serial Attached SCSI), eMMC (embedded MultiMediaCard), etc.
A common problem associated with data storing is corruption of a part of a file system at a storage medium. Data corruption causes interruption of a data writing operation of a storage device. Data corruption, for example, is generated as a consequence of power loss. An approach of evading the data corruption includes utilizing a journaling file system that logs a change on a storage medium (e.g., a hard disk drive) before the change is executed.
Therefore, when the power loss arises, a journaled change is replayed or executed such that an actual data structure conforms to the journaled change. It may be difficult to replay journaled actions that are incomplete due to the power loss. | {
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The present invention generally relates to semiconductor devices and more particularly to a high-dielectric capacitor, a semiconductor having such a high-dielectric capacitor, and a fabrication process thereof.
With the advancement in the art of device miniaturization, the integration density of semiconductor integrated circuits, in which a number of semiconductor devices are integrated on a common substrate, is increasing every year. With this, device miniaturization is going on also for the individual semiconductor devices and the operational speed of the semiconductor devices is increasing also. In the case of memory semiconductor devices having a capacitor such as a DRAM, the device miniaturization also brings forth an increase of the amount of information stored in the memory semiconductor device.
On the other hand, in the semiconductor memory device such as a DRAM which store information in a memory cell capacitor in the form of electric charges, it should be noted that excessive device miniaturization causes a decrease in the electric charges held in the memory cell capacitor due to the decrease of the memory cell capacitance. Thereby, stable retention of information tends to become difficult. While it is possible to compensate for such a decrease of the capacitance to some extent by reducing the thickness of the capacitor insulation film, it is necessary to reduce the thickness of the capacitor insulation film to the order of several nanometers or less in the DRAMs of sub-micron or sub-quarter micron size, as long as a conventional SiO.sub.2 film or an SiN film is used for the capacitor insulation film. As will be easily understood, formation of such an extremely thin capacitor insulation film is difficult, as it is required in a capacitor that the capacitor insulation film is perfectly free from defects such as pin holes. Further, the use of such a thin capacitor insulation film tends to cause the problem of increased tunneling leakage current.
Meanwhile, it has been proposed to use a Ta.sub.2 O.sub.5 film for the capacitor insulation film of a DRAM memory cell capacitor.
FIGS. 1A-1D show the fabrication process of a MIS capacitor that uses a conventional Ta.sub.2 O.sub.5 capacitor insulation film.
Referring to FIG. 1A, a capacitor region is defined on a Si substrate 11 by a field oxide film 12, and a polysilicon pattern 13 and an SiN pattern 14 are formed on the foregoing capacitor region in the step of FIG. 1B by depositing a polysilicon film and an SiN film consecutively and further by applying a patterning process, wherein the polysilicon pattern 13 forms a lower electrode of the capacitor. Typically, the SiN pattern 14 is formed with a thickness of 2 nm.
Next, in the step of FIG. 1C, a Ta.sub.2 O.sub.5 film is deposited on the structure of FIG. 1B typically with a thickness of about 8 nm, followed by a patterning process to form a Ta.sub.2 O.sub.5 capacitor insulation film 15. Further, the step FIG. 1D is conducted in which an upper electrode pattern 16 of Pt, and the like, is formed on the capacitor insulation film 15.
Because Ta.sub.2 O.sub.5 is a simple oxide, it is possible to form the Ta.sub.2 O.sub.5 capacitor insulation film 15 stably and with reliability in the step of FIG. 1C by a sputtering process or a CVD process. On the other hand, it is known that the bulk crystal of Ta.sub.2 O.sub.5 has a dielectric constant of 30-40, and this value of dielectric constant is obtained also in the case of a Ta.sub.2 O.sub.5 film. It should be noted that the foregoing dielectric constant is, while larger than the dielectric constant of SiO.sub.2 or SiN, distinctly smaller than that of a perovskite complex oxide such as PZT (Pb(Zr,Ti)O.sub.3) or STO (SrTiO.sub.3) by a factor of 10.
Thus, if a method is found to realize a large dielectric constant in a Ta.sub.2 O.sub.5 film, which is a simple oxide film, with a magnitude of the dielectric constant comparable to the dielectric constant of a perovskite complex oxide, the fabrication process of a large-capacitance memory cell capacitor would become substantially simplified and the cost of the semiconductor memory device using such a memory cell capacitor would be reduced. | {
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There presently exist numerous devices that may be used to grip tubular members while torque is being applied to the tubular member. Such devices include by way of illustration “power tongs,” “backups,” and “chrome tools” and various other devices for gripping tubular members. Examples of power tongs are disclosed in U.S. Pat. Nos. 4,649,777 and 5,291,808 to David Buck. Typically power tongs will have a set of jaws which are the actual components of the power tongs which grip the tubular member. One example of these jaws is set forth in U.S. Pat. No. 4,576,067 to David Buck. The jaws disclosed in U.S. Pat. No. 4,576,067 include a die member which is the sub-component of the jaw that actually contacts the tubular member. In U.S. Pat. No. 4,576,067, the face of the die that contacts the tubular member has ridges or teeth cut therein. Typically, the teeth are sized such that 5 to 8 teeth per linear inch are formed across the gripping surface of the die. When the jaws close upon the tubular member, these teeth firmly bite into the tubular member and prevent slippage between the tubular member and jaws when large torque loads are applied to the power tongs or the tubular member.
Another class of devices to which the invention pertains grips the tubular in order to hold the tubular against vertical movement. Typically, the tubular is part of a tubing, casing or drill string formed from a long series of tubulars and the drill string is suspended above and/or in the well bore. This class of devices includes conventional slips, elevators and safety clamps. Slips and safety clamps utilize the weight of the tubular and/or drill string, and, in some cases, an external preload, to force the gripping surfaces into contact with the tubular being gripped. By way of example, the gripping member of the slip will have a gripping surface or gripping die on one face and an inclined plane on an opposite face. A slip bowl or similar device having a second and supplementary inclined surface will be positioned around the tubular with sufficient space between the tubular and slip bowl for the gripping member to be partially inserted between the slip bowl and tubular. As described in more detail below, the movement of the gripping member's inclined surface along the slip bowl's inclined surface causes the gripping surface to move toward and engage the tubular. The die or gripping surface of prior art slips is similar to the above described power tong jaw dies in that the gripping surface generally comprises a series of steel teeth which bite into the tubular to grip it.
While the above described methods for gripping pipe has been successful in many applications, there are certain disadvantages. One disadvantage is that after gripping tubular members, the teeth from the die will leave deep indentations or gouges in the surface of the tubular member. These “bite marks” left by the teeth may effect the structural integrity of the tubular member by causing a weak point in the metal which may render the tubular member unsuitable for further use or may lead to premature failure of the tubular at a future date.
A second disadvantage is encountered when using the dies with corrosion resistant alloy (CRA) tubular members. Exotic Stainless Steel with large percentages of Chromium, Nickle, etc., are typical CRA materials used in the oil and gas drilling industry. Oil and gas production frequently occurs in high temperature, corrosive environments. Because the above described die teeth are normally constructed of standard carbon steel, the bite mark made by the die teeth tend to introduce iron onto the surface of the CRA tubular. In such environments, the iron in the bite mark can act as a catalyst, causing a premature, rapid corrosion failure in the CRA tubular.
A further problem is encounter in that many CRA materials such as stainless steel are work hardened materials. This means that the malleability of the material decreases after the material is mechanically stressed. In the case of stainless steel tubulars, the bite marks or indentations caused by the prior art die teeth produce localized “cold working.” The points at which the teeth marks have been made are then less malleable than the other sections of the tubular and therefore may create inherent weak points in the tubular's structural integrity. Additionally, prior art steel teeth are formed in a uniform pattern. A series of uniformly sharp teeth bite marks may manifest themselves as a major stress riser with an adverse impact significantly more detrimental than a few individual random marks of similar depth. Thus, an uniform pattern of indentations or bite marks will create more damaging internal stresses in the tubular than a non-uniform pattern of bite marks.
As an alternative to using dies with teeth on CRA tubulars, the industry has employed dies which have smooth aluminum surfaces engaging the tubular. However, because these smooth faced aluminum dies rely purely on a frictional grip of the tubular, these dies must employ significantly greater clamping forces than dies with steel teeth. This greater clamping force in turn increases the risk that the clamping forces themselves will cause damage to the tubular. Furthermore, even with high clamping forces, the aluminum surfaces often do not have a sufficiently high coefficient of friction to prevent slippage between the dies and the tubular at high torque loads or high vertical loads.
To overcome the problem of slippage between the aluminum surfaced dies and a CRA tubular, the industry has developed a method of using a silicon carbide coated fabric or screen in combination with the aluminum surfaced dies. This method consists of placing the silicon carbide screen between the tubular and the dies before the dies close upon the tubular. The dies are then closed on the tubular with the silicon carbide screen positioned in between. The silicon carbide screen thereby allows a substantially higher coefficient of friction to be developed between the dies and the tubular. However, this method also has serious disadvantages. First, the silicon carbide screen must be re-position between the tubular and die surface each time the dies grip and then release a tubular. Thus for example, when a drilling crew is making up or breaking down a long string of drill pipe, several pieces (typically 5 to 6) of the silicon carbide screen must be placed in position for each successive section of pipe being made up or broken out. This repeated operation can be extremely inefficient and costly in terms of lost time. Secondly, this process requires a member of the drilling crew to repeatedly place his hands in a position where they could possible be crushed or amputated. Thirdly, while providing greater resistance to torque than a smooth surfaced aluminum die, there may nevertheless be situations where such high torque forces are being applied to the tubular that the silicon carbide screen method does not prevent slippage between the die and the tubular. | {
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The present invention generally concerns compositions and methods for fabricating semiconducting devices; and more particularly, in various representative and exemplary embodiments, to deposition of BST on low-loss, insulating substrates for frequency agile applications.
An ordered and stable silicon (Si) surface is most desirable for subsequent epitaxial growth of single crystal thin films on silicon for numerous device applications, e.g., ferroelectrics or high dielectric constant oxides for non-volatile high density memory and logic devices. It is pivotal to establish an ordered transition layer on the Si surface, especially for subsequent growth of single crystal oxides, e.g., perovskites.
Some reported growth of these oxides, such as BaO and BaTiO3 on Si(100) was based on a BaSi2 (cubic) template by depositing one fourth monolayer of Ba on Si(100) using reactive epitaxy at temperatures greater than 850xc2x0 C. See, for example: R. McKee et al., Appl. Phys. Lett. 59(7), pp 782-784 (Aug. 12, 1991); R. McKee et al., Appl. Phys. Lett. 63(20), pp. 2818-2820 (Nov. 15, 1993); R. McKee et al., Mat. Res. Soc. Symp. Proc., Vol. 21, pp. 131-135 (1991); U.S. Pat. No. 5,225,031, issued Jul. 6, 1993, entitled xe2x80x9cProcess for Depositing an Oxide Epitaxially onto a Silicon Substrate and Structures Prepared with the Processxe2x80x9d; and U.S. Pat. No. 5,482,003, issued Jan. 9, 1996, entitled xe2x80x9cProcess for Depositing Epitaxial Alkaline Earth Oxide onto a Substrate and Structures Prepared with the Processxe2x80x9d. However, atomic level simulation of this proposed structure indicates that it likely is not stable at elevated temperatures.
Growth of SrTiO3 on silicon (100) using an SrO buffer layer has been accomplished. T. Tambo et al., Jpn. J. Appl. Phys., Vol. 37 (1998), pp. 4454-4459. However, the SrO buffer layer was thick (100 xc3x85), thereby limiting application for transistor films, and crystallinity was not maintained throughout the growth.
Furthermore, SrTiO3 has been grown on silicon using thick metal oxide buffer layers (60-120 xc3x85) of Sr or Ti (B. K. Moon et al., Jpn. J Appl. Phys., Vol. 33 (1994), pp. 1472-1477); however such thick buffer layers would considerably limit applications to transistors. In the case of BST, use of amorphous buffer layers between substrates and crystalline BST films has been investigated (see, for example: Chang et al., JAP vol. 92, 1528); however, these approaches generally do not address thermal expansion problems nor loss problems associated with amorphous BST turning crystalline upon annealing. Accordingly, a composition and method for fabricating relatively thin, stable amorphous interfaces with BST for low-loss, frequency agile applications is desired.
In various representative aspects, the present invention provides a microwave regime frequency-agile device. An exemplary method for fabricating such a device is disclosed as comprising the steps of inter alia: providing an insulating substrate; providing a layer of silicon on the surface of the substrate; providing a layer of alkaline earth metal over the silicon layer; and heating the structure in the presence of oxygen to transform the crystalline silicon layer into amorphous silicon dioxide. Fabrication is relatively simple and straightforward. Additional advantages of the present invention will be set forth in the Detailed Description which follows and may be obvious from the Detailed Description or may be learned by practice of exemplary embodiments of the invention. Still other advantages of the invention may be realized by means of any of the instrumentalities, methods or combinations particularly pointed out in the claims. | {
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The present invention relates to a new and distinctive corn inbred line, designated N61060. There are numerous steps in the development of any novel, desirable plant germplasm. Plant breeding begins with the analysis and definition of problems and weaknesses of the current germplasm, the establishment of program goals, and the definition of specific breeding objectives. The next step is selection of germplasm that possess the traits to meet the program goals. The goal is to combine in a single variety or hybrid an improved combination of desirable traits from the parental germplasm. These important traits may include higher yield, resistance to diseases and insects, better stalks and roots, tolerance to drought and heat, and better agronomic quality.
Choice of breeding or selection methods depends on the mode of plant reproduction, the heritability of the trait(s) being improved, and the type of cultivar used commercially (e.g., F1 hybrid cultivar, pureline cultivar, etc.). For highly heritable traits, a choice of superior individual plants evaluated at a single location will be effective, whereas for traits with low heritability, selection should be based on mean values obtained from replicated evaluations of families of related plants. Popular selection methods commonly include pedigree selection, modified pedigree selection, mass selection, and recurrent selection.
The complexity of inheritance influences choice of the breeding method. Backcross breeding is used to transfer one or a few favorable genes for a highly heritable trait into a desirable cultivar. This approach has been used extensively for breeding disease-resistant cultivars. Various recurrent selection techniques are used to improve quantitatively inherited traits controlled by numerous genes. The use of recurrent selection in self-pollinating crops depends on the ease of pollination, the frequency of successful hybrids from each pollination, and the number of hybrid offspring from each successful cross.
Each breeding program should include a periodic, objective evaluation of the efficiency of the breeding procedure. Evaluation criteria vary depending on the goal and objectives, but should include gain from selection per year based on comparisons to an appropriate standard, overall value of the advanced breeding lines, and number of successful cultivars produced per unit of input (e.g., per year, per dollar expended, etc.).
Promising advanced breeding lines are thoroughly tested and compared to appropriate standards in environments representative of the commercial target area(s) for three years at least. The best lines are candidates for new commercial cultivars; those still deficient in a few traits are used as parents to produce new populations for further selection.
These processes, which lead to the final step of marketing and distribution, usually take from eight to 12 years from the time the first cross is made. Therefore, development of new cultivars is a time-consuming process that requires precise forward planning, efficient use of resources, and a minimum of changes in direction.
A most difficult task is the identification of individuals that are genetically superior, because for most traits the true genotypic value is masked by other confounding plant traits or environmental factors. One method of identifying a superior plant is to observe its performance relative to other experimental plants and to a widely grown standard cultivar. If a single observation is inconclusive, replicated observations provide a better estimate of its genetic worth.
The goal of plant breeding is to develop new, unique and superior corn inbred lines and hybrids. The breeder initially selects and crosses two or more parental lines, followed by repeated selfing and selection, producing many new genetic combinations. The breeder can theoretically generate billions of different genetic combinations via crossing, selfing and mutations. The breeder has no direct control at the cellular level. Therefore, two breeders will never develop the same line, or even very similar lines, having the same corn traits.
Each year, the plant breeder selects the germplasm to advance to the next generation. This germplasm is grown under unique and different geographical, climatic and soil conditions, and further selections are then made, during and at the end of the growing season. The inbred lines which are developed are unpredictable. This unpredictability is because the breeder's selection occurs in unique environments, with no control at the DNA level (using conventional breeding procedures), and with millions of different possible genetic combinations being generated. A breeder of ordinary skill in the art cannot predict the final resulting lines he develops, except possibly in a very gross and general fashion. The same breeder cannot produce the same line twice by using the exact same original parents and the same selection techniques. This unpredictability results in the expenditure of large research monies to develop a superior new corn inbred line.
The development of commercial corn hybrids requires the development of homozygous inbred lines, the crossing of these lines, and the evaluation of the crosses. Pedigree breeding and recurrent selection breeding methods are used to develop inbred lines from breeding populations. Breeding programs combine desirable traits from two or more inbred lines or various broad-based sources into breeding pools from which inbred lines are developed by selfing and selection of desired phenotypes. The new inbreds are crossed with other inbred lines and the hybrids from these crosses are evaluated to determine which have commercial potential.
Pedigree breeding is used commonly for the improvement of self-pollinating crops or inbred lines of cross-pollinating crops. Two parents which possess favorable, complementary traits are crossed to produce an F1. An F2 population is produced by selfing one or several F1's or by intercrossing two F1's (sib mating). Selection of the best individuals is usually begun in the F2 population; then, beginning in the F3, the best individuals in the best families are selected. Replicated testing of families, or hybrid combinations involving individuals of these families, often follows in the F4 generation to improve the effectiveness of selection for traits with low heritability. At an advanced stage of inbreeding (i.e., F6 and F7), the best lines or mixtures of phenotypically similar lines are tested for potential release as new cultivars.
Mass and recurrent selections can be used to improve populations of either self- or cross-pollinating crops. A genetically variable population of heterozygous individuals is either identified or created by intercrossing several different parents. The best plants are selected based on individual superiority, outstanding progeny, or excellent combining ability. The selected plants are intercrossed to produce a new population in which further cycles of selection are continued.
Backcross breeding has been used to transfer genes for a simply inherited, highly heritable trait into a desirable homozygous cultivar or inbred line which is the recurrent parent. The source of the trait to be transferred is called the donor parent. The resulting plant is expected to have the attributes of the recurrent parent (e.g., cultivar) and the desirable trait transferred from the donor parent. After the initial cross, individuals possessing the phenotype of the donor parent are selected and repeatedly crossed (backcrossed) to the recurrent parent. The resulting plant is expected to have the attributes of the recurrent parent (e.g., cultivar) and the desirable trait transferred from the donor parent.
Descriptions of other breeding methods that are commonly used for different traits and crops can be found in one of several reference books (e.g., Allard, 1960; Simmonds, 1979; Sneep et al., 1979; Fehr, 1987).
Proper testing should detect any major faults and establish the level of superiority or improvement over current cultivars. In addition to showing superior performance, there must be a demand for a new cultivar that is compatible with industry standards or which creates a new market. The introduction of a new cultivar will incur additional costs to the seed producer, the grower, processor and consumer; for special advertising and marketing, altered seed and commercial production practices, and new product utilization. The testing preceding release of a new cultivar should take into consideration research and development costs as well as technical superiority of the final cultivar. For seed-propagated cultivars, it must be feasible to produce seed easily and economically.
Once the inbreds that give the best hybrid performance have been identified, the hybrid seed can be reproduced indefinitely as long as the homogeneity of the inbred parent is maintained. A single-cross hybrid is produced when two inbred lines are crossed to produce the F1 progeny. A double-cross hybrid is produced from four inbred lines crossed in pairs (A×B and C×D) and then the two F1 hybrids are crossed again (A×B)×(C×D). Much of the hybrid vigor exhibited by F1 hybrids is lost in the next generation (F2). Consequently, seed from hybrid varieties is not used for planting stock.
Hybrid corn seed is typically produced by a male sterility system incorporating manual or mechanical detasseling. Alternate strips of two corn inbreds are planted in a field, and the pollen-bearing tassels are removed from one of the inbreds (female). Providing that there is sufficient isolation from sources of foreign corn pollen, the ears of the detasseled inbred will be fertilized only from the other inbred (male), and the resulting seed is therefore hybrid and will form hybrid plants.
The laborious, and occasionally unreliable, detasseling process can be avoided by using cytoplasmic male-sterile (CMS) inbreds. Plants of a CMS inbred are male sterile as a result of factors resulting from the cytoplasmic, as opposed to the nuclear, genome. Thus, this characteristic is inherited exclusively through the female parent in corn plants, since only the female provides cytoplasm to the fertilized seed. CMS plants are fertilized with pollen from another inbred that is not male-sterile. Pollen from the second inbred may or may not contribute genes that make the hybrid plants male-fertile. Seed from detasseled fertile corn and CMS produced seed of the same hybrid can be blended to insure that adequate pollen loads are available for fertilization when the hybrid plants are grown.
There are several methods of conferring genetic male sterility available, such as multiple mutant genes at separate locations within the genome that confer male sterility, as disclosed in U.S. Pat. Nos. 4,654,465 and 4,727,219 to Brar et al. and chromosomal translocations as described by Patterson in U.S. Pat. Nos. 3,861,709 and 3,710,511. These and all patents referred to are incorporated by reference. In addition to these methods, Albertsen et al., U.S. Pat. No. 5,432,068 have developed a system of nuclear male sterility which includes: identifying a gene which is critical to male fertility, silencing this native gene which is critical to male fertility; removing the native promoter from the essential male fertility gene and replacing it with an inducible promoter; inserting this genetically engineered gene back into the plant; and thus creating a plant that is male sterile because the inducible promoter is not “on” resulting in the male fertility gene not being transcribed. Fertility is restored by inducing, or turning “on”, the promoter, which in turn allows the gene that confers male fertility to be transcribed.
There are many other methods of conferring genetic male sterility in the art, each with its own benefits and drawbacks. These methods use a variety of approaches such as delivering into the plant a gene encoding a cytotoxic substance associated with a male tissue specific promoter or an anti-sense system in which a gene critical to fertility is identified and an antisense to that gene is inserted in the plant (see, Fabinjanski, et al. EPO 89/3010153.8 publication no. 329, 308 and PCT application PCT/CA90/00037 published as WO 90/08828).
Another version useful in controlling male sterility makes use of gametocides. Gametocides are not a genetic system, but rather a topical application of chemicals. These chemicals affect cells that are critical to male fertility. The application of these chemicals affects fertility in the plants only for the growing season in which the gametocide is applied (see Carlson, G. R., U.S. Pat. No. 4,936,904). Application of the gametocide, timing of the application and genotype specifically often limit the usefulness of the approach.
Corn is an important and valuable field crop. Thus, a continuing goal of plant breeders is to develop stable, high yielding corn hybrids that are agronomically sound. The reasons for this goal are obviously to maximize the amount of grain produced on the land used and to supply food for both animals and humans. To accomplish this goal, the corn breeder must select and develop corn plants that have the traits that result in superior parental lines for producing hybrids. | {
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1. Field of the Invention
This invention relates to the field of thermal mechanical processes for the alpha/beta titanium alloys and the articles produced thereby.
2. Description of the Prior Art
The alpha/beta titanium alloys are well known in the art, and are described in the Metals Handbook, Vol. 1 (1961) at pp 1147-1156. These alloys, and various proceses applicable thereto are the subject of U.S. Pats. Nos. 2,801,167; 2,974,076; 3,007,824; 3,147,115; 3,405,016 and 3,645,803. In particular, U.S. Pat. No. 3,007,824 discloses a surface hardening process applicable to a specific alpha/beta alloy which involves heating the article at a temperature within the beta phase field and then quenching. No deformation is required. U.S. Pat. No. 3,405,016 discusses a heat treatment, for maximizing the formability of alpha/beta alloys, involving quenching from the beta phase field followed by deformation in the alpha/beta phase field.
The beta forging of the alpha/beta alloys is described in the Metals Handbook, Vol. 5 (1970) pp 143-144 wherein it is noted that beta forging as conventionally employed incorporates deformation both in the beta phase field and the alpha/beta phase field. The subject of beta forging is also discussed in Metals Engineering Quarterly, Vol. 8, Aug. 1968, at pp 10-15 and 15-18. These references imply that beta forging may have an adverse effect upon fatigue properties. | {
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Electronic devices such as central processing units (CPUs) and digital signal processors (DSPs) are comprised of various electronic components including active elements such as transistors and passive elements such as capacitors. Part of electric energy for driving the electronic components is converted into thermal energy and dissipated. Since the performance of electronic components normally depends on temperature, dissipated heat affects the electronic components and, in turn, the performance of the electronic device. Thus, technology for cooling an electronic device is extremely important to control an electronic device properly.
An example of technology for cooling an electronic device is air-cooling using an electric fan. In this method, an electric fan is provided to face the surface of an electronic device. Air taken in from an air inlet is blown to the surface of the electronic device by the electric fan. Air heated as a result of absorbing heat generated from the surface of the electronic device is discharged from an air outlet. Thus, the electronic device is cooled by removing the heat generated from the surface of the electronic device by using the electronic fan.
A device called a heat sink for dissipating heat is also used commonly. A heat sink is usually designed to have a large heat dissipation surface in order to transfer heat from a heat source such as an electronic device to a cool fluid or air that surrounds the electronic device. Heat generated from an electronic device is conducted to a heat sink and dissipated through an extensive heat dissipation surface of the heat sink.
A cooling method using an electric fan and a heat sink in combination is generally used to cool a semiconductor chip.
Time response of an electric fan or a heat sink to temperature variation is generally slow compared to variation in the amount of heat generated in an electronic device. In other words, the related-art cooling method cannot efficiently cool an electronic device in the face of minute-by-minute variation in the amount of heat generated in an electronic device. This necessitates holding extra cooling capacity in reserve in order to maintain the reliability of an electronic device. One drawback of this approach consists in large power consumption and noise of an electric fan. Another drawback is that the volume 6f an electric fan has to be larger than is necessary. | {
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It should be noted that a considerable amount of the pertinent prior art in respect of this technology is disclosed in various patent applications filed designating the present applicant as inventor. These include PCT WO2010/072830 entitled to “A dual fuel boiler” and European patent specification number EP 2 187 122 entitled “A granular fuel-fired boiler brazier”.
One of the major problems with such granular fuel burning boilers is the removal of ash contents from the boiler. Much of the granular fuel is normally pelleted wood. Unfortunately, such pelleted wood contains impurities and what is effectively sand which is ingested through the bark of the tree as it grows. When it burns, the ash content is made up of relatively soft combustion products, almost pure carbon dust and what is a vitrified clinker, very similar to glass. It should be appreciated that the ash usually weighs somewhat of the order of 0.5% of the weight of the fuel and the vitrified clinker is somewhat of the order of 1 to 2% by weight of the ash. Thus, it is a relatively small proportion of the combustion products. However, because of its effect, it is found to be a not insignificant component of the ash contents. What happens is that this vitrified clinker forms a skin over the base of the brazier and prevents air being delivered up into the burning fuel from underneath. The way in which the combustion products are removed from the brazier is to move the base of the brazier away from it's side walls to allow the combustion products to fall out of the brazier. There are considerable problems with this as the vitrified clinker does not fall through the brazier but bridges the brazier retaining the softer ash. A particularly useful means of breaking up this vitrified clinker on discharging the brazier is described in the co-pending British Patent Application Number 0821060.1, filed by my company However, even with this extremely efficient invention, we have found some slight, albeit minor, problems with the operation of this fragmentation means and the present application is directed towards attending to this. With many other solid granular fuels, this problem is exacerbated. It is hard to over emphasise the difficulties that such vitrified ash causes.
A further problem with these boilers for burning granular fuel is that they are usually arranged so that there is a hood over the brazier, which hood is essential to retain the burning products to ensure that they burn correctly before being dissipated out of the boiler. A typical example of such a hood is described in GB Patent Specification Number 22 274 162 A (Jonathon Greenall). Even with such hoods, there is a problem in that the amount of carbon monoxide (CO) in the boiler flue, on discharge, is relatively large, at best being somewhat of the order of 100 ppm and, at worst, 1000 ppm or even more. Clearly, if this could be improved on, it would be advantageous. Ideally, the amount of carbon monoxide should not exceed 100 ppm. A further problem with these hoods is that they disintegrate fairly rapidly in use and require constant replacement. The problem is that to be effective, the hood must trap hot combustion gases to ensure adequate combustion before delivery out of the brazier enclosure. Since the hood will be directly above the brazier and the gases will naturally rise to impinge against the hood, the hood is under severe stress. A typical solution to this problem is to provide a hollow hood such as described in the aforementioned GB Patent Specification Number 22 274 162. However, there are still considerable problems in producing an efficient construction of such a hood which will ensure minimal amounts of carbon monoxide.
Another problem with these boilers for burning granular fuels such as wood pellets is the necessity to make sure that the granular fuel is delivered onto the burning fuel bed as gently as possible so as not to disturb the burning fuel already there. The problem is that if the burning fuel within the brazier is disturbed, then the lighter ash will be prematurely delivered out of the brazier into the boiler itself or more usually into the ash pan, rather than being retained for subsequent delivery to an ash pan on complete combustion taking place. Any incompletely combusted fuel which is light can also be delivered out of the boiler enclosure into the ash pan where it will smoulder producing carbon monoxide. Any ash delivered into the boiler itself will almost certainly form a thin layer on the inside of the boiler reducing the heat transfer properties. Accordingly, the less disturbance of the burning fuel the better. Accordingly, disturbing the burning fuel also reduces the efficiency of the burning operation and generates more carbon monoxide.
Another problem with these boilers is to ensure that there is adequate air available for combustion. It has been found, for example, that with these constructions of braziers, air escaping out of the brazier is a major problem. Further, the escaping air almost certainly is mixed with incomplete combustion gases, further reducing the efficiency of the boiler. Additionally, it has been found essential to ensure that adequate air is provided into the centre of the brazier and also into the hot combustion gases as they rise out of the brazier. The efficient control of the air is an essential requirement for optimum burning conditions and thus optimum operation of the boiler.
Another problem that has been identified is the need to provide boilers of different heat outputs which causes difficulties in that braziers of different sizes have to be provided.
A problem with present constructions of such boilers is that they are often not cleaned adequately or indeed, more importantly, at the right time intervals. If the boiler is relatively inefficiently operated, then very quickly a skin of ash builds up on the boiler walls, reducing the heat transfer capacity of the boiler. A further problem is that very often the brazier is not emptied frequently enough. This is particularly a problem when the boiler is operating somewhat close to maximum capacity.
An additional problem that has been noted with these boilers is the amount of carbon monoxide and other incomplete combustion gases which are delivered out of the boiler flue into the atmosphere during start-up. This is particularly a problem when the boiler is working at well under normal capacity as it is starting up and shutting down a considerable number of times in any period of operation. Again something needs to be done to improve the efficiency of combustion during start-up.
What has to be emphasised about most of these problems is that they are not of themselves when taken singularly seen as being of major importance however it is the cumulative effect of these problems that has led to a less than satisfactory performance in the market place.
Heretofore, while granular fuel fired boilers such as wood pellet boilers have been welcomed and installed on quite a large scale in many countries, they have not, by any means, been successful. This unfortunately has led to a very bad reputation for such granular fuel burning boilers and indeed their abandonment by many of their original champions.
The initial problem related to the indifferent quality of granular fuel and particularly wood pellets. Most of the problems encountered with the fuels and their storage have been generally resolved. It was felt by many that when these problems were solved the granular fuel burning boilers would operate satisfactorily. Unfortunately, that was not the case. It just merely highlighted the remaining problems which have now come to prominence. Indeed, we believe that many of these problems were not fully appreciated by those in the industry heretofore. Many were aware that, for example, there was too much ash build up within the boiler, relatively large percentages of carbon monoxide in the exhaust flue and so on, without appreciating the reason for these. These often apparently minor problems were largely centred round the handling of the combustion products and the fuel. The boilers must operate at required efficiency without requiring constant attention and maintenance by the householder. Until these problems are solved, the clear advantages of using a granular fuel burning boiler will not be appreciated by the consumer. | {
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This invention relates to a support mechanism for supporting dental instruments, and more particularly, to a dental instrument support mechanism for establishing stable support for dental instruments such as a dental cutting tool, a drill, a fiber scope and a diamond bar within an oral cavity in desired positions therein to perform a dental treatment or test.
In performing a dental treatment such as dental test or dental operation, a dentist and his/her assistant must use various types of dental instruments. Such dental instruments include grinding tools such as a diamond bar for grinding a tooth, and cutting tools such as a dental reamer or a dental file for forming a root canal. Further, for an implant such as an artificial root of tooth, a hole must be created on a bone in the jaw, which requires a special drill.
Further, in the dental treatment, since the object in the oral cavity is not easily visible, a special tool such as a fiber scope has to be used in the location near the object to observe the object through the monitor. Moreover, a drain pipe may also be used to remove the fluid such as saliva and or debris in the oral cavity.
Ordinarily, such dental instruments, i.e., a diamond bar, reamer, and file for drilling and cutting, a fiber scope for monitoring, and a drain pipe for cleaning the oral cavity, have to be supported by the hands of the dentist and/or dentist""s assistant. Thus, in a typical example of dental treatment, the fiber scope and the drain pipe are held by, for example, the assistant while the diamond bar and/or reamer are operated by the dentist.
However, this process of performing the dental treatment while holding the dental instruments in the hands requires a high level of skill and experience by both the dentist and the assistant. Because the oral cavity is small, it is difficult to hold the various instruments in the right positions in the oral cavity. Further, since the small movement of the fiber scope is magnified in the microscope monitor, the manual handling of the fiber scope needs special talents and experience.
This invention has been made to solve the problems involved in the dental treatment and operation in the conventional technology. It is, therefore, an object of the present invention to provide a dental instrument support mechanism which can stably support dental instruments with a relatively simple structure.
It is another object of the present invention to provide a dental instrument support mechanism which can stably support dental instruments while maintaining the positional relationship with the object.
It is a further object of the present invention to provide a dental instrument support mechanism which is able to adjust the positions and directions of the dental instrument held at the end of the support mechanism.
In the present invention, the dental instruments support mechanism is comprised of a base portion, and a support arm connected to the base portion at one end for holding a dental instrument at another end. The dental instrument held by the support arm is fixedly maintained a positional relationship with dental object in an oral cavity of a patient. The dental instrument support mechanism is attached to one or more of a head, face, jaw, tooth of the patient or a treatment bed.
Each component of the dental instrument support mechanism is provided with sufficient stiffness to endure loads received during movements of dental instrument or dental treatment using the dental instrument wherein a distance and an angle of the dental instrument relative to the dental object in the oral cavity is adjustable.
Preferably, the dental instrument on the support arm is moveable along a predetermine route in the oral cavity. A plurality of dental instruments can be supported by the dental instrument support mechanism. Alternatively, two or more dental instrument support mechanisms support one dental instrument in the oral cavity of the patient.
Preferably, the support arm has a column connected to the base portion and an arm connected to the column at one end for mounting the dental instrument at another end, wherein the arm is moveable along the column. To achieve this, a combination of a pinion gear and a rack gear are incorporated in the support arm.
According to the present invention, the dental instrument support mechanism has the base portion and the support arm attached to the base portion at one end to support the dental instrument at the other end. The dental instrument supported by the support arm can be fixedly maintained in the oral cavity with a constant positional relationship with the intended object. Therefore, the dental instruments can be fixed in the desired positions and orientation in the oral cavity without requiring any experience of skill by the user, thereby enabling the dental treatment with high efficiency and accuracy. | {
"pile_set_name": "USPTO Backgrounds"
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This invention relates to digital communication networks having a network management system (NMS) for managing data traffic between user endpoints through intermediate core switches in the network and more particularly to the establishment of soft permanent virtual circuits (SPVC) across the network provisioned with means to identify any SPVC crossing a randomly selected core switch.
Digital communications networks, such as frame relay (FR) and asynchronous transfer mode (ATM), conventionally employ virtual circuits for the routing of data traffic across the integrated switching fabric of the network. When a virtual circuit is provisioned externally to provide a user with a quasi-dedicated route through the network it is known as a permanent virtual circuit (PVC). In digital networks a soft permanent virtual circuit is a communications medium which is permanently provisioned at the endpoints, but switched in the middle. The provisioning is controlled by the Communications Network Management Systems (NMSs) which also allow the creation, configuration, and display of the soft permanent virtual circuits (SPVCs) across the network. SPVCs traverse one or more core switches in order to allow two or more system end users to communicate. When an NMS establishes a SPVC, it requests a single switch at one of the desired endpoints of the SPVC to perform the necessary cross connections to reach the other endpoint of the SPVC. The endpoint switch uses routing software to establish the route for the SPVC, sets up a single cross connection on itself, then uses signaling software to request other switches to establish the rest of the cross connections. The signaling software sends only the minimum amount of information necessary to establish and maintain the cross connections such as; calling address, called address, bandwidth, traffic management characteristics, etc. The other switches signal back to the endpoint switch when they have completed the cross connections, and the endpoint switch then reports to the NMS that the SPVC has been established.
In a network in which many SPVCs exist, a user of the NMS can commonly select any switch in the network, and discover whether SPVC cross connections exist on that switch. Having discovered the existence of a cross connection, the user of the NMS should then be able to determine to which SPVC the cross connection belongs.
Identifying SPVCs in this way is useful, for example, for gauging the efficiency of the SPVC routing software, or for determining which edge switches, edge interfaces or SPVC end users are utilizing particular resources in the core of the network.
One solution to the problem of identifying SPVCs from randomly-selected cross connections in the middle of the network is not entirely satisfactory. It is possible for the NMS to identify the parent SPVC from a randomly selected point in the network without collecting and storing information on every SPVC cross connection in the network, but only storing information on the two endpoints of each cross connection, by a process of following cross connections and links forward or backward from the selected point, thus xe2x80x9cwalkingxe2x80x9d through the network until a known SPVC endpoint is reached. Each node within the network that is traversed by the SPVC connection must be queried by the NMS in order to trace the entire path of that connection.
Applying this solution to the example presented in FIG. 1, if the user selects the point B.2, the NMS first queries switch B and finds out that it is cross connected to point B.1. If it is known that point B.1 is physically or logically connected to point A.2, then the NMS can query switch A to determine what A.2 is cross connected to. When it learns that A.2 is cross connected to A.1, it compares A.1 to its list of SPVC endpoints and thus determines the identity of the SPVC (8 in this example) that crosses point B.2.
The shortcoming of this approach is that it is costly in terms of (a) the user""s time, (b) NMS processing resources, (c) NMS-to-switch bandwidth resources, and (d) switch processing resources. The larger the network (and therefore the more cross connections that are required for an SPVC to cross the network), the higher the cost of using this algorithm.
Accordingly, a solution which makes more efficient use of the systems resources, is required.
Therefore, in accordance with a first aspect of the present invention there is provided in a digital communications network for routing data between endpoint switches through a plurality of core switches, the network having a network management system (NMS). for provisioning a selected one of the endpoint switches to establish a switched virtual connection in the form of a switched virtual channel (SVC) or a soft permanent virtual circuit (SPVC) through the network, the SPVC or SVC being created by the core switches configuring cross connections therebetween, a method of identifying the SPVC at a selected core switch comprising: providing a database in said NMS for storing routing information; providing means at each of said core switches for collecting routing information; providing means in said NMS to collect said routing information from said core switches; and providing means in said NMS for identifying route information respecting said selected core switch.
In accordance with a second aspect of the invention there is provided in a digital communications network for routing data between endpoint switches through a plurality of core switches, said network having a network management system (NMS) for provisioning a selected one of said endpoint switches to establish a switched virtual connection in the form of a switched virtual channel (SVC) or a soft permanent virtual circuit (SPVC) through said network, said SVC or SPVC being created by said core switches configuring cross connections therebetween, a method of identifying said SPVC at a selected core switch comprising: providing an identifying tag to said SVC or SPVC upon initial establishment thereof; providing storage means in each of said core switches for storing relevant information; transporting said identifying tag through said core switches together with the cross connection configuration instructions and retaining said identifying tag in each of the storage means crossed; providing means in said NMS for accessing said storage means; and accessing said storage means in a selected core switch in response to a request to identify said SPVC or SVC thereat. | {
"pile_set_name": "USPTO Backgrounds"
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1. Field of the Invention
The present invention relates to an intelligent peripheral system and a call processing method thereof, and in particular to an improved IP(Intelligent Peripheral) system and a call processing method thereof which are capable of directly being connected with another IP system and implementing an easier expandability of a resource channel by separately connecting an apparatus processing a protocol matching function between a user and an IP network and an apparatus processing a call processing function.
2. Description of the Conventional Art
The IP(Intelligent Peripheral) system is directed to an independent intelligent network system which is capable of providing a user who requests an advanced intelligent network service through a SSP(Service Switching Point) with a special resource such as a guide broadcasting, a DTMF(Dual Tone Multi-Frequency) gathering, an audio recording, an audio mixing, an audio recognition, a FAX transmission/receiving function, etc. In particular, an IP(Intelligent Peripheral) system which is connected with another advanced intelligent network element through a NO. 7 signaling network in the IP system is called as a network IP(Network Intelligent Peripheral) system.
FIG. 1 is a view illustrating an advanced intelligent network including the above-described IP. In the advanced intelligent network, a SCP(Service Control Point) 10, a SSP(Service Switching Point) 20 and an IP system 30 are connected with a common line signal network 50 through a plurality of STPs(Signaling Transfer Point) 51. At this time, the IP 30 connects a bearer channel 40 and a SSP 20 based on an E1 trunk and communicates a signal message with the SCP 10 and the SSP 20 through a signaling link 60 connected with the STP 51.
The IP 30 is formed of a resource sub-system which performs a call processing operation by allocating a resource to a bearer channel using an ISUP(ISDN user Part) and an INAP(Intelligent Network Application Protocol) which are connected in a common line signal network platform.
FIG. 2 illustrates a procedure that an advanced intelligent network system provides a user with an intelligent network service. As shown therein, when a user transmits a request message for an intelligent network service in Step S201, the SCP 10 recognizes the intelligent network service request and allows the SSP 20 to connect the bearer channel with the IP 30 for providing a user with a special resource in accordance with a service logic in Step S202. The SSP 20 transmits an IAM(Initial Address Message) which set a called party address as an address of the IP 30 for connecting the bearer channel. At this time, the IAM is transferred through a signaling route of the common line signal network. The IP 30 which receives the IAM transmits an ACM(Address Complete Message) to the SSP 20 in accordance with an ISUP call processing procedure in Step 204 and requests a special resource to the SCP 10 for the user.
The SCP 10 received the request from the IP 30 drives the special resource in the IP 30 in accordance with the service logic, and the IP 30 transmits an AM(Answer Message) in accordance with an ISUP call processing procedure in Step S207 and drives the special resource for therein implementing an interface with the user based on the special resource in Step S208. In addition, a result of the special resource is informed to the SCP 10. At this time, the SCP 10 may continuously instructs a special resource driving and releases a bearer channel between the SSP 20 and the IP 30. If the bearer channel between the SSP 20 and the IP 30 is released, it is performed based on the ISUP call processing procedure.
Namely, when a channel release request signal is transmitted from the SCP 10 to the SSP 20 in Step S210, the SSP 20 received the signal transmits a REL(Release) message to the IP 30 for releasing the bearer channel, and the IP 30 transmits a RLC(Release Complete) message in Step S212.
When the IP is formed of an independent network, the call processing is performed based on the ISUP and INAP signal processing method. In the conventional exchange, the call is processed based on the R2 or ISUP signal method. An output repeater bearer channel is obtained by interpreting the called number of the input repeater bearer channel and IAM based on a number interpretation function of the exchange for thereby switching the bearer channel.
In the case of the conventional IP system formed of the resource sub-systems, if it is needed to expand the channel capacity of the special resource, the capacity of the resource sub-system should be expanded. In this case, since there is a limit in the capacity of the system for expanding the resource sub-system, other IP systems formed of the resource system should be added to the common line signal network. Therefore, the common line signal network platform is build for every IP system which is to be build for thereby increasing the fabrication cost of the system.
Accordingly, it is an object of the present invention to provide an intelligent peripheral system and a call processing method thereof which overcome the aforementioned problems encountered in the conventional art.
It is another object of the present invention to provide an intelligent peripheral system and a call processing method thereof which are capable of directly being connected with another IP system and implementing an easier expandability of a resource channel by separately connecting an apparatus processing a protocol matching function between a user and an IP network and an apparatus processing a call processing function.
In order to achieve the above objects, there is provided an intelligent peripheral system which includes an apparatus storing and maintaining a special resource information for providing an intelligent network system to a user in accordance with a request of the user, and an apparatus performing a protocol matching function and a call processing function between a service switching point(SSP) and a service control point(SCP) of the advanced intelligent network system, wherein said both apparatuses are separately installed for thereby implementing a direct connection to another intelligent network system through a common line signal network and easily expanding a resource channel.
In order to achieve the above objects, there is provided a call processing method of an intelligent peripheral system which includes the steps of a first step in which the SSP receives a request message for an intelligent network service from a user and transmits an initial address message(IAM) to the resource exchange sub-system for a bearer channel connection between the SSP and the IP providing system, a second step in which the resource exchange sub-system which received the IAM checks the capacity of the resource sub-system to provide a user with a special resource, a third step for transmitting an address receiving completed message(ACM) to the SSP and then requesting a special resource to the SCP when the resource sub-system is available as a result of the check of the second step, a fourth step for selecting an available special channel among the special resource channels connected between the resource exchange sub-system and the resource sub-system in accordance with a special resource requested, requesting a connection to the time switch of the resource exchange sub-system for connecting the selected special resource channel and the bearer channel and transmitting an answer message(ANM) to the SSP, a fifth step in which the resource exchange sub-system drives the special resource of the resource sub-system connected by the special channel for receiving a special resource from the resource sub-system and transmits a result of the special resource providing operation to the SCP, and a sixth step for maintaining a communication state so that a special resource is transmitted to the user through a special channel set between the resource sub-system and the resource exchange sub-system and a bearer channel set between the resource exchange sub-system and the service exchange.
Additional advantages, objects and other features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objects and advantages of the invention may be realized and attained as particularly leveled out in the appended claims as a result of the experiment compared to the conventional arts. | {
"pile_set_name": "USPTO Backgrounds"
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This invention relates to polyorganosiloxane traction fluids. The polyorganosiloxane traction fluids of this invention are particularly well suited for use in traction drive systems and transmissions subject to wide operating temperature conditions.
A traction drive is a device by which torque can be transmitted from one smooth rolling element to another wherein the rolling elements are in nominal point or line contact. One such simple traction drive might consist of two parallel cylindrical elements in nominal line contact where one element is the input member and the other is the output member. As is well known in the art, both fixed speed and variable speed traction drives can be made by proper selection of the number, size, shape, and geometrical configuration of the roller elements. The continuously variable speed traction drive is attracting current interest for automotive applications because it has been estimated that use of such a traction drive could result in increased fuel efficiencies of 30-50% without sacrificing vehicle performance. Another advantage of traction drives over conventional transmissions is the smooth and quiet operation of the traction drive.
The limited lifetime and load carrying capabilities of traction drives have substantially prevented their wide-spread use except for light-duty applications. Recently, however, the development of better lubricants, called traction fluids, have allowed the development of traction drive transmissions which are suitable for heavy-duty applications. Indeed, the properties of the traction fluid, which also acts as a lubricant and coolant in the traction drive, determines to a large degree the performance, capacity, and lifetime of the traction drive. Of critical importance are the properties of the traction fluid under the high pressure and high shear conditions found in the area of contact between the roller elements. Although the roller elements are usually spoken of as being in contact, it is generally accepted that the roller elements are separated by a thin film of the tractive fluid. It is through the traction fluid's resistance to shear that the torque transmitting ability of a given fluid arises. The torque transmitting ability of a fluid, and thus its suitability as a traction fluid, is measured by and is directly related to its traction coefficient.
Hammann, et al. disclosed in U.S. Pat. No. 3,440,894 (Apr. 29, 1969) that certain classes of fluids characterized by high traction coefficient and molecular structure were superior traction fluids. Wygant in U.S. Pat. No. 3,994,816 (Nov. 30, 1976) discloses that certain hydrogenated dimers of alpha-methylstyrene (e.g. 2,4-dicyclohexyl-2-methyl pentane) are suitable as traction fluids. U.S. Pat. No. 3,994,816 is further discussed in an article entitled "Base Fluids" in Functional Fluids for Industry, Transportation and Aerospace, M. W. Ranney (Ed), Noyes Data Corporation, Park Ridge, N.J. (1980). Among the disclosed traction fluids were the cycloaliphatic hydrocarbon species. Preferred cycloaliphatic hydrocarbons are now offered as traction fluids by Monsanto Company under the tradename Santotrac. Although the Santotrac fluids offer high traction coefficients they have one major disadvantage which has prevented the more wide-spread utilization of traction drives. At sub-zero temperatures the viscosity of the Santotrac fluid increases dramatically. For example, one Santotrac fluid has a viscosity of 31,600 centistokes at -20.degree. F. and an estimated viscosity of 200,000 centistokes at -40.degree. F. Clearly such fluids could not be successfully used in applications subjected to low temperature extremes. One such application, for example, in which a Santotrac fluid traction drive might not be successfully employed would be vehicles exposed to sub-zero temperatures.
Several attempts have been made to develop fluids with reasonable low temperature viscosity and high traction coefficients. Wygant in U.S. Pat. No. 3,652,418 (Mar. 28, 1972) discloses that a low temperature traction fluid can be prepared by blending 30-60% by weight hydrogenated dicumyl, 30-60% by weight tercyclohexyl, and at least 5% by weight dicyclohexyl or certain alkyl dicyclohexyl. The disclosed blends of Wygant gave acceptable traction coefficients and improved low temperature viscosities as compared to U.S. Pat. No. 3,440,894 traction fluids. However, Wygant admits that his blended traction fluids gave only "operable viscosity ranges over temperatures of 0.degree. to 210.degree. F."
Kulik and Smith in U.S. Pat. No. 4,190,546 (Feb. 26, 1980) disclosed that a traction fluid with acceptable low temperature properties and traction coefficients could be obtained by blending a Santotrac fluid with a silicone fluid containing from 15 to 25 methyl groups per phenyl group if, and only if, about 2 to 10% by weight of an aromatic hydrocarbon or aromatic ether co-solvent is added. The co-solvent is required to ensure complete miscibility of the siloxane and Santotrac fluids.
Siloxanes have been evaluated for use as traction fluids. F. G. Rounds ("Effect of Lubricant Composition on Friction as Measured With Thrust Ball Bearings," J. Chem. Engn. Data, 5, 499-507 (1960)) found that several different siloxanes had traction coefficients approximately equal to that found for mineral oils. The mineral oils have traction coefficients much lower than that of cycloaliphatic hydrocarbons such as Santotrac. One siloxane, a chlorophenyl silicone, was reported by Green and Langenfeld ("Lubricants for Traction Drives," Mach. Design, 46, 108,113 (1974)), to have a traction coefficient approaching that found for the cycloaliphatic hydrocarbons. However, this chlorophenyl silicone was not suitable as a traction fluid because of its poor resistance to oxidation and moisture and the resulting tendency to gel.
More recently, certain siloxanes suitable for use as traction fluids were described in Groenhof, U.S. patent application Ser. No. 304,726, filed Sept. 23, 1981 which is hereby incorporated by reference. The siloxanes of Ser. No. 304,726 could be used as traction fluids either alone or in combination with cycloaliphatic hydrocarbons. The disclosed siloxane fluids contained [(CH.sub.3).sub.3 SiO.sub.1/2 ] units, [(CH.sub.3)R'SiO] units, and, optionally, [(CH.sub.3).sub.2 SiO] units where R' is a phenyl radical or a cyclohexyl radical and where there are about 1.6 to 14 methyl radicals for each R' radical. The disclosed siloxane fluids may also contain a limited amount of [RSiO.sub.3/2 ] units where R is methyl, phenyl, or cyclohexyl radicals. The [RSiO.sub.3/2 ] content of the siloxanes of Ser. No. 304,726 should be kept below 5 percent by weight and preferably below 1 percent by weight. The most preferred siloxanes of Ser. No. 304,726 do not contain any [RSiO.sub.3/2 ] units.
It has now been found that siloxane fluids containing significant amount of [RSiO.sub.3/2 ] units make excellent traction fluids. It is, therefore, one object of this present invention to provide polyorganosiloxanes which contain significant amounts of [RSiO.sub.3/2 ] units and which are useful as traction fluids. Another object is to provide polyorganosiloxane traction fluids suitable for use at low temperatures. Another object is to provide polyorganosiloxane traction fluids which contain only methyl radicals as the organic groups attached to silicon. Still another object of this invention is to provide improved traction drive systems particularly well suited for operating under widely varying temperature environments. | {
"pile_set_name": "USPTO Backgrounds"
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Although the present invention is potentially useful in a variety of environments, it was developed primarily for use in a medical facility. In moving patients from one treatment area to another, the practice prior to development of the present invention was to use personnel to guide an IV-pole along with the gurney or wheelchair. Such a procedure frequently required three people: two to handle the gurney and one to control the IV. For background, an IV (intravenous fluid) set-up includes the fluid bottle and the delivery line which delivers fluids/medications from the bottle to a needle in the patient's vein. The bottle is suspended from an upright IV-pole which may be permanently attached to the patient bed, or which is more frequently a separate unit comprised of a vertical pole mounted on rollers. The detached, mobile unit is the one most frequently used when moving patients. Therefore, because there has been no adequate and safe means for attaching IVs to gurneys and wheelchairs, extra personnel has been required for accomplishing transport. At the time of filing, other attempts at solving the problem were unknown to applicant. The present invention is thus a truly unique device for attaching an IV-pole to a gurney or wheelchair for towing purposes.
One reason that other known towing devices are unsuitable is because they are generally designed for use with automobiles, or in other environments where the relative motion between the towing vehicle and the object being towed is not as critical. In movement of patients it is highly important that the IV set-up be fully controlled at all times. Loss of control of an IV set-up is a potentially dangerous situation for a number of rather obvious reasons. Known towing devices allow considerable motion of the towed vehicle or object. With IV set-ups, there should be no movement of the IV set-up relative to the gurney or wheelchair. It is important that the two vehicles be moved substantially as one unit. However, it is also important that the connecting or towing device be easily attached to or detached from the gurney and the IV-pole. The attachment/detachment must be easily made by various levels of personnel and should be accomplished in seconds, with as few moving parts as possible. It is also recognized that the present invention is applicable in other environments where there are relatively small wheeled carts, tables, or other such devices which occasionally need to be moved in tandem.
The present inventor has attempted to overcome the disadvantages in moving patients with IVs and to provide a device that would meet the above objectives in medical or other environments. The present invention is a device that can be used for connecting or coupling two objects together for moving them in tandem. The device is comprised substantively of an elongated body portion having a hooking or connecting member on each end thereof. A spring-biased locking means is associated with each hooking member to lock the hook securely to a portion of the frame of the gurney and of the IV-pole respectively.
The device is of relatively small size, is simple in construction and thus economical to produce and maintain. There are a minimum of moving, interrelated parts, keeping the likelihood of failure, and cost of maintenance, to a minimum. | {
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Many consumer products are applied to the skin or hair, and/or involve the sensory experience of touching. Consumer preferences are influenced by a multitude of factors, including product effectiveness, the feel of the product, fragrance, durability, ease of rinsing, etc. One way to determine consumer preferences is by conducting consumer marketing tests, in which a representative group of consumers, or panelists, provide feedback after using a product. Consumer marketing tests have several drawbacks, however. Because panelists must be appropriately selected and compensated for their time, such tests are expensive and time consuming. Human feedback is inherently subjective, and may raise concerns about reliability. Products must be safe for human testing, and the analyses that can be performed after application also are limited.
Some product testing can be performed using model systems. Artificial substrates are available that, to some extent, imitate human skin. For example, theatrical performers often transform their appearance by using molded body parts that can be made to look remarkably like human skin. Alternatively, keratinous tissue from animals or human cadavers may be used. Whereas these and other available models may be suitable for some types of product testing, all have significant limitations. Cadaver tissue is costly, and neither cadaver nor animal tissue can truly mimic living, human tissue. Artificial substrates are poorly suited to assess characteristics such as product adsorption, rinseability, elasticity and compressibility. Many substrates absorb water and/or decompose, and thus cannot be effectively cleaned or reused. Currently available models also fail to reflect differences in skin on various parts of the body, in different environments, and between different individuals, which may be critical in developing certain personal care products. Characteristics of skin on, for example, one's face, fingertips, palms of the hand, heels, and underarms tend to differ dramatically. The skin of babies and young children differs from the skin of adults, and skin having hair differs from non-haired skin. In summary, to date no suitable substrate is available that can reproduce complex properties of various types of keratinous tissue that are relevant to a wide range of products.
There exists a need, therefore, to provide a more suitable model of a range of types of mammalian keratinous tissue for testing consumer products, which is capable of reproducing a wide range of properties most relevant to a given product, and which can reduce the need for testing with human subjects. | {
"pile_set_name": "USPTO Backgrounds"
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1. Field of the Invention
The present invention relates to an electronic control unit and method using a microcomputer, specifically to an electronic control unit and method in which a control program and control data used for the microcomputer performing a control process can be rewritten on board.
2. Related Art
As an electronic control unit to control, for example, a vehicle engine, there has been proposed the on-board rewritable type, which contains a microcomputer including a rewritable nonvolatile memory such as an EEPROM or a flash EEPROM storage contents of which can electrically be rewritten (specifically, erased and newly written), and enables a control program and control data stored in the rewritable nonvolatile memory to be rewritten in a state that the concerned unit is completely assembled.
In Japanese Patent Publication JP-A-9-44216 U.S. Pat. No. 5,828,977), an electronic control unit is designed to be connected to a memory rewrite unit not only through a communication line, but also through a mode determining control signal line. Immediately after a microcomputer of the electronic control unit starts its operation at the reset state, the microcomputer executes a starting program (boot program) in a non-rewrite-object nonvolatile memory, and thereby checks the state of a signal inputted from the memory rewrite unit through the mode determining control signal line. In accordance with the state of the signal, the microcomputer switches the self operation mode into either one of the normal mode that executes the control program in the rewritable nonvolatile memory and the rewrite mode that executes the rewrite process.
Therefore, after the electronic control unit is powered, if it is arranged to operate the microcomputer from the reset state, and to output a signal indicating the rewrite mode to the mode determining control signal line from the memory rewrite unit, the microcomputer will execute the rewrite process without relation to the control program in the rewritable nonvolatile memory. Accordingly, even when the control program is not yet written into the rewritable nonvolatile memory, or when the control program stored in the rewritable nonvolatile memory becomes abnormal by any cause, the data write (that is, a new data write, or rewrite) into the rewritable nonvolatile memory can be executed.
However, if the mode determining control signal line is provided between the electronic control unit and the memory rewrite unit, the following problems will occur.
{circle around (1)} It is necessary to add a dedicated terminal for the mode determining control signal line to the connector that connects the electronic control unit and the memory rewrite unit. Although the mode determining control signal line is rarely used in practice, a new connector terminal has to be provided additionally.
{circle around (2)} Maintenance shops of vehicles and the like have been using a trouble diagnostic service tool whereby self-diagnostics data stored in the electronic control unit can be read through the communication line. Accordingly, there arises a request from them such that the function of the memory rewrite unit is incorporated into the foregoing service tool, and thereby the control program and control data can be written by using the communication line only.
However, if the mode determining control signal line is provided, the foregoing request will not be satisfied, which lacks in flexibility. That is, a special one will be needed as the memory rewrite unit. In addition, the wire harness for connecting the memory rewrite unit and the wire harness for connecting the other service tools cannot be integrated into one.
{circle around (3)} In general, the connection of the electronic control unit and the memory rewrite unit of this type is made such that the connector provided on the end of the wire harness extended from the electronic control unit side is engaged in the connector of the memory rewrite unit side. However, if the mode determining control signal line inside the wire harness extended from the electronic control unit side is short-circuited to a part of the voltage level indicating the rewrite mode in a vehicle, the normal control program will not be executed.
Here, when writing the control program and the control data, for example, if the operator takes a procedure to open the cover of the electronic control unit, and to directly apply a mode determining signal to the input terminal (input port) of the microcomputer, it will be possible to dispense with the mode determining control signal line. However, from the workability and the reliability of the electronic control unit, this is not practicable.
The present invention has an object to provide an electronic control unit and method that can execute a data write into a rewritable nonvolatile memory without a signal line for determining the mode furnished between an external unit and the electronic control unit, even when a control program is not written into the rewritable nonvolatile memory, or when the control program stored in the rewritable nonvolatile memory becomes abnormal.
According to the present invention, a microcomputer is programmed to execute a control program composed of data stored in a rewritable nonvolatile memory, and executes a control process for controlling a control object. A monitor circuit monitors whether an execution state of the control program by the microcomputer is normal or not.
In this electronic control unit, specially, when the monitor circuit determines that the execution state of the control program is abnormal, the microcomputer executes a rewrite process for updating to write a rewrite data transmitted from an external unit into the rewritable nonvolatile memory.
Thus, in case the control program is not yet written into the rewritable nonvolatile memory, or in case the control program stored in the rewritable nonvolatile memory becomes abnormal by any cause, the microcomputer is not able to execute the control program normally. Therefore, in both of the foregoing cases, the monitor circuit determines the execution state by the microcomputer to be abnormal, and the microcomputer shifts the mode to the rewrite mode to execute the rewrite process.
Accordingly, although a signal line for determining the mode is not furnished between the external unit and the electronic control unit, it is possible to write a new control program and new control data into the rewritable nonvolatile memory from a state that the control program is not written into the rewritable nonvolatile memory. When the control program stored in the rewritable nonvolatile memory is brought into an abnormal state, it is possible to rewrite the concerned control program into a program of normal contents.
Here, as the rewritable nonvolatile memory, an EEPROM or flash EEPROM is generally used, however other rewritable ROMs may also be used. | {
"pile_set_name": "USPTO Backgrounds"
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1. Field of the Invention
This present invention relates generally to the field of electronic circuitry and, more specifically, to techniques for fabricating integrated circuits implementing small wavelength photolithography technology.
2. Description of the Related Art
This section is intended to introduce the reader to various aspects of art that may be related to various aspects of the present invention, which are described and/or claimed below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present invention. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art.
Microprocessor-controlled circuits are used in a wide variety of applications throughout the world. Such applications include personal computers, control systems, telephone networks, and a host of other consumer products. A personal computer or control system is made up of various different components that handle different functions for the overall system. By combining these different components, various consumer products and systems are able to meet the specific needs of an end user. As is well known, microprocessors are essentially generic devices that perform specific functions under the control of software programs. These software programs are generally stored in one or more memory devices that are coupled to the microprocessor and/or other peripherals.
The memory devices generally include many different types of integrated circuits that are typically fabricated from one or more semiconductor materials. The integrated circuits work together to enable the memory device to carry out and control various functions within an electronic device. With the current trend in decreasing the “footprint” or overall size of the electronic devices, the different components of the electronic devices, such as the memory devices, may be reduced to accommodate these requirements. Accordingly, the integrated circuits that make up the memory device may be designed to consume less space. The reduction in size of these integrated circuits is a key component to the technological development of many devices containing electrical components. Accordingly, the fabrication processes that are used to form these integrated circuits have experienced dramatic changes.
Integrated circuits, such as memory devices, are typically fabricated on a wafer surface through any number of manufacturing processes, such as layering, doping, and patterning. Layering generally refers to adding material to the surface of the wafer by a growth process, such as oxidation, or through a deposition process, such as chemical vapor deposition (CVD) or physical vapor deposition (PVD). Doping generally refers to the process of implanting dopants into the wafer surface or overlying layer and may be used to increase the current carrying capacity of a region of the wafer or overlying layer of material. The doping process may be implemented before a layer is formed, between layers, or even after the layer are formed. Generally, the doping process may be accomplished through an ion implantation process, using boron or other similar dopants, or through thermal diffusion, for example.
Patterning refers to a series of steps that result in the removal of selected portions of layers or underlying wafer material. After removal of the selected portions of the layer(s), via a wet or dry etch process, a pattern of the layer is left on the wafer surface. The removal of material allows the structure of the device to be formed by providing holes or windows between layers or by removing unwanted layers. Patterning sets the critical dimensions of the integrated circuit structures being fabricated. Disadvantageously, errors in the patterning and removal process may result in changes and failures in the electrical characteristics in the device.
One commonly used patterning technique is photolithography. In using photolithography, a pattern may be formed by using a photomask to expose certain regions of a radiation sensitive material, such as a photoresist or resist, to a certain wavelength of light. Typically, the radiation source provides UV light to pattern the resist. However, certain resists may also be implemented using other energy types, such as X-rays. Exposure to the radiation changes the structure of the resist. If the resist is a negative resist, then the resist become polymerized where it is exposed. If the resist is a positive resist, the exposed region of resist becomes divided or softened. After the exposure to the radiation, the unpolymerized regions may be dissolved by applying an appropriate solvent.
To fabricate an appropriately sized structure, a bottom anti-reflectant coating (BARC) layer may be implemented underneath the resist to enhance the photolithography process. The BARC layer is used to absorb the radiation generated by the source, thereby reducing development of the photoresist caused by reflections from underlying layers. By providing an underlying layer for absorbing the radiation, the patterned structure is typically more defined with fewer defects than the methods wherein a BARC layer is not included. Once the resist has been patterned, the resist layer may be removed to allow the underlying structure to be developed. While it may be desirable to retain the BARC layer, it is typically desirable to remove the BARC layer through an etching process.
After patterning of the photoresist layer, various etchants may be selected to implement the removal of selected portions of material from the surface of the structure. Selectivity relates to the preservation of the surface underlying the etched material layer. The selectivity is generally expressed as a ratio of the etch rate of the material layer to the etch rate of the underlying surface. Further, selectivity may be used to refer to the removal rate of the photoresist with respect to the underlying material layer. As can be appreciated, as the material layer is being etched through the openings patterned in the photoresist, some of the photoresist may also be removed. The selectivity should be high enough to ensure that the photoresist layer is not removed before the etched patterns in the material layer.
One of the objectives in photolithography is to transfer a well-defined pattern with minimal ambiguities or anomalies. One technique that may be used to develop the respective gates, devices, or desired structures is to implement a multi-layer resist scheme. The multi-layer resist scheme employs multiple layers of resist for each gate or structure. This process employs different photoresists and etchants to ensure that the gate or structure is formed correctly. However, with the multi-layer resist process, the resulting gate or structure is more expensive because the various layers of resist may increase the number of steps in the process, which increases the time required to fabricate the device. This increase in processing time has a further negative effect of decreasing the quantity of devices that may be produced over a period of time, such as a week or month. Furthermore, the additional fabrication process steps increase the likelihood of potential errors by complicating the method of making the device.
To meet the ever-increasing demand for smaller integrated circuit structures, smaller wavelength photolithography techniques have been developed. One such technique implements 193 nm technology. That is to say that the photoresist used to pattern the underlying materials is developed by exposure to a radiation source having a wavelength of 193 nm. While 193 nm technology allows the resist to be patterned with smaller structures, the resist does not generally retain a crisp pattern throughout the entire etch process. Instead, the 193 nm resist tends to wrinkle, shred, and bend during the etch process. To mitigate some of these effects, an etchant to which the 193 nm photoresist has a higher selectivity could be implemented. However, in the 193 nm process, increased resist selectivity produces large striations through the resist. Regardless of whether the defects include wrinkles, striations, or other anomalies, defects in the photoresist are undesirable, since the defects may be transferred to the underlying layers. Disadvantageously, defects in the underlying layers may result in failures of the structure or integrated circuit device being fabricated. | {
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1. Field of the Invention
The present invention relates to an imaging apparatus, and, more particularly, to an imaging apparatus having a print media dam in association with an automatic sheet feeder mechanism.
2. Description of the Related Art
An imaging apparatus typically includes an automatic sheet feeder (ASF) including a media tray and a sheet picking mechanism. The automatic sheet feeder automatically supplies a sheet of print media from a stack of print media positioned in the media tray to the print engine. During the loading of the media tray of the automatic sheet feeder, however, some of the print media may be pushed down into the automatic sheet feeder too far, resulting in simultaneous multiple sheet feeds, and may ultimately result in a media jam.
What is needed in the art is an imaging apparatus that reduces the occurrence of multiple media picks due to faulty loading of the automatic sheet feeder mechanism. | {
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Modern military engagements require detecting and monitoring the movement of people and resources, both military and civilian, in real time over a wide area with little direct human supervision. This problem poses a number of challenges to conventional sensing and data processing technologies. In the context of such behavior, it has become increasingly difficult to automatically detect such movements, since the relevant patterns may exist on many disparate levels. In some situations, combinations of geographical movement of personnel, vehicles and objects may need to be analyzed simultaneously. Currently this is a very human-intensive operation, typically requiring numerous individuals.
Active monitoring of human and non-human movement involves the detection and classification of spatio-temporal patterns across a large number of real-time data streams. Approaches that analyze data in a central computing facility tend to be overwhelmed with the amount of data that needs to be transferred and processed in a timely fashion. Also, centralized processing raises proprietary and privacy concerns that may make many data sources inaccessible.
The detection and classification of subtle changes in an activity requires the integration of a wide variety of non-specific real-time data sources into the operation of the tracking system. Furthermore, to guarantee the early detection of a suspicious or critical movement, the system must operate on real-time data that is continuously updated. As a result, there is an immense amount of data that needs to be processed in a timely fashion.
Our co-pending U.S. patent application Ser. No. 10/352,288, entitled “Swarming Agents For Distributed Pattern Detection and Classification,” incorporated herein by reference, describes a swarming agent architecture for the distributed detection and classification of spatio-temporal patterns in a heterogeneous real-time data stream. The invention is not limited to geographic structures or patterns in Euclidean space, and is more generically applicable to non-Euclidean patterns such as topological relations in abstract graph structures. According to this disclosure, large populations of simple mobile agents are deployed in a physically distributed network of processing nodes. At each such node, a service agent enables the agents to share information indirectly through a shared, application-independent runtime environment. The indirect information sharing permits the agents to coordinate their activities across entire populations. The architecture may be adapted to the detection of various spatio-temporal patterns and new classification schemes may be introduced at any time through new agent populations. The system is scalable in space and complexity due to the consequent localization of processing and interactions. The system and method inherently protect potentially proprietary or private data through simple provable local processes that execute at or near the actual source of the data. The fine-grained agents, which swarm in a large-scale physically distributed network of processing nodes, may be designed to perform three major tasks: 1) they may use local sensors to acquire data and guide its transmission; 2) they may fuse, interpolate, and interpret data from heterogeneous sources, and 3) they may make or influence command and control decisions. In contrast to previous approaches involved with command and control, or data acquisition and transmission, such an approach facilitates a swarming agent architecture for distributed pattern-detection and classification. | {
"pile_set_name": "USPTO Backgrounds"
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Field of the Invention
The disclosure relates to a signal processing method and signal processing apparatus and, more particularly, to a technique for extracting a feature amount suited to pattern identification from multi-dimensional data such as image data.
Description of the Related Art
As a feature amount effective for pattern identification such as face recognition, an LGBP (Local Gabor Binary Pattern) described in W. Zhang, S. Shan, W. Gao, X. Chen, H. Zhang, “Local Gabor Binary Pattern Histogram Sequence (LGBPHS): A Novel Non-Statistical Model for Face Representation and Recognition”, Proc. IEEE International Conference on Computer Vision, pp. 768-791, 2005. has been proposed. The LGBP is a feature amount obtained by applying several ten Gabor Wavelet filters to input image data, and extracting, from image data after the filtering, an LBP (Local Binary Pattern) described in T. Ojala, M. Pietikainen, D. Harwood, “A Comparative Study of Texture Measures with Classification Based on Featured Distributions”, Pattern Recognition, Vol. 29, 51-59, 1996.
FIG. 14 shows overview of processing required to extract an LBP. The LBP is an 8-bit feature amount calculated based on a pixel of interest (x, y) and eight pixels (to be referred to as reference pixels (x+xn, y+yn) hereinafter) which neighbor the pixel of interest, as given by:
LBP ( x , y ) = ∑ n = 0 7 s ( i ( x + x n , y + y n ) - i ( x , y ) ) · 2 n ( 1 ) where i(x, y): an input pixel value at coordinates (x, y),
LBP (x, y): an LBP at the coordinates (x, y), and
(xn, yn): relative positions of the reference pixels with respect to the pixel of interest,
and
s ( u ) = { 1 if u ≥ th 0 if u < th ( 2 )
Note that in the example of FIG. 14, a threshold th=0. Also, assuming that a pixel immediately above the pixel of interest is set to be (x0, y0)=(0, 1), the relative positions (xn, yn) are set to be (x1, y1)=(1, 1), (x2, y2)=(1, 0), . . . , (x7, y7)=(−1, 1) so as to surround the pixel of interest clockwise.
As described above, the LGBP is popularly used in face recognition and the like as a feature amount effective for pattern identification, but several ten Gabor Wavelet filters are required to be used so as to obtain high identification accuracy. For example, when 40 Gabor Wavelet filters are used, a data amount of the LGBP generated as a result of the processing is “output data size×40×8 bits”. For example, upon calculating the data amount to have an output data size=64×64, the data amount of the LGBP is about 1.3 Mbits. That is, in case of the LGBP, especially when pattern identification is implemented as hardware, a cost of the overall apparatus increases. | {
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Conventional vehicles have a multiplicity of safety functions which are dependent on ambient data of the vehicle. This has the effect of sensing, for example, bends, other vehicles etc. and correspondingly reacting. This usually requires a multiplicity of sensors, and depending on the sensor, also emitters for outputting radiation. Usually an ultrasonic system or a radar system is used for distance measurement. An ultrasonic system is used, for example, for a parking aid in which only one distance measurement takes place. Radar systems serve as distance control systems but also as a parking aid. Said systems can be provided as distance control systems for autonomous or partially autonomous driving. Such systems usually require additional installation space and give rise to additional costs. | {
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Contemporary cleaning appliances, such as dishwashers or clothes washers, are a common convenience in many homes. A user simply loads the cleaning appliance with laundry to be treated into a treating chamber, along with an optional supply of a treating chemistry, such as detergents, bleach, enzymes, and anti-spotting agents and selects and initiates a cleaning cycle that may be subsequently automatically carried out by the cleaning appliance. An example of a typical cleaning cycle includes the steps of washing the laundry with heated liquid and optional treating chemistry and rinsing the laundry with heated liquid.
Cleaning appliances may be provided with a dispenser for automatically dispensing one or more treating chemistries during a cleaning cycle. There are generally two types of treating chemistry dispensing systems found in the cleaning appliances: single use dispensing systems and bulk dispensing systems. The single use dispensing system is by far the most common type and typically has one or more dispensing cups that may be filled with only enough treating chemistry, i.e. a “charge” or “dose”, for a single cleaning cycle. Water is then flushed through the cup to dispense the treating chemistry. A user must fill these single use dispensing systems with treating chemistry prior to each cleaning cycle of the cleaning appliance, which may be a tedious task that many users would prefer not to perform. Users have also been known to forget to fill the cup, fill the cup with the wrong treating chemistry, or to fill the cup with the wrong amount of treating chemistry.
The bulk dispensing systems, while known, are not very common. The bulk dispensing systems hold multiple charges of treating chemistries. Some systems are capable of controlling and varying the amount of treating chemistry. These systems are more convenient to the user in the sense that the user only has to remember to fill them once over several cycles of operation. However, they are less convenient in that if the user has a non-standard wash load that requires a special treating chemistry, the bulk dispensing system may be loaded with the wrong treating chemistry.
Only a few cleaning appliances have both single use and bulk dispensing systems. The two systems are functionally redundant and add cost to the cleaning appliance. Further, each system tends to have water supply systems that are incompatible because of the different manner in which the systems dispense the treating chemistry. | {
"pile_set_name": "USPTO Backgrounds"
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A framing system may be a structural (i.e., load bearing) system, or a non-structural (i.e., a non-load bearing) system. A non-structural framing system is not intended for use in load bearing applications. Non-structural framing systems have practical applications including, for example, building mock-ups or light-weight structures, prototyping, product development, shop work, fencing, tent frames, awnings, theater/stage structures, artistic structures, and the like.
In typical frames made with metal tubing, the joints have to be coped (i.e., cut to fit, e.g., beveled) and then joined, or joints are formed with fittings or with metal strapping and screws. Both of these techniques are time consuming, and therefore, they are not used for this type of framing.
Accordingly, there is a need for a framing system and method for making same that is easily assembled of readily available components. The framing system may be a non-structural framing system. | {
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Medical imaging techniques for organs and tissues in a human or animal body have changed considerably over the last 20 years, in good measure because of adoption of nuclear magnetic resonance imaging for medical imaging. Damadian(Science 171(1971) 1151-1153), Weisman(Science 178 (1972) 1288-1290), Lauterbur(Nature 242(1973) 190-191), Eggleston et al(Cancer Research 33 (1973) 2156-2160) and Damadian et al (Proc. Nat. Acad. Sci. 71 (1974) 1471-1473; Science 194 (1976) 1430-1431) were among the first to recognize the value of, and to apply the techniques of, NMR to distinguish between normal and abnormal developments in human and animal bodies.
Nuclear magnetic resonance ("NMR") is a relatively young research area and was first discussed and experimentally investigated by Bloch and his co-workers in 1946 (Phys. Rev. 70 (1946) 460-474 and 474-485). The Bloch articles are incorporated herein by reference. In NMR, an approximately constant magnetic field B.sub.0 =B.sub.0Hi.sub.z is applied in a fixed direction, which defines the z-axis of the associated coordinate system, to the target(organ, tissue, etc.), and a time-varying field B.sub.1 =B.sub.1 (i.sub.x cos .omega.t+i.sub.y sin .omega.t) is applied in a plane perpendicular to the z-direction, where the amplitude B.sub.1 is also approximately constant. The magnetic polarization vector M satisfies the magnetization torque equation EQU dM/dt=.gamma.(M.times.B)+(M.sub.0 /T1)i.sub.z -.OMEGA..multidot.M (1)
where .gamma. is the gyromagnetic ratio, B=B.sub.0 +B.sub.1 is the total impressed magnetic field, M.sub.0 is an equilibrium magnetization established by the polarization field, T1 is a characteristic time interval for return to equilibrium of the transverse component of magnetization, T2 is a characteristic time interval describing de-phasing of the magnetization, and .OMEGA. is a diagonal second rank tensor or dyadic that phenomenologically accounts for relaxation of the three magnetization components that is of the form ##EQU1## For protons, the ratio .epsilon. is 42.57 MHz per Tesla. The spin-lattice relaxation time T1 and the spin-spin relaxation time T2 are often of the order of 600-1,000 msec and 20-100 msec, respectively. The observable quantities are M.sub.x and M.sub.y.
These equations can be solved under various driving and receiving field conditions to obtain the magnetization components for the system. When the system is excited by a radiofrequency ("RF") magnetic field intensity B.sub.1 at or near the resonant frequency f.sub.0 =.omega..sub.0 /2.pi.=.gamma.B.sub.0, the spin system will draw energy from the RF exciting field. Conversely, if the spin system is near resonance, energy can be returned to a structure positioned to receive this RF energy. Analysis of the system of equations is Eq. (1) is discussed by A. Abragam, The Principles of Nuclear Magnetism, Oxford University Clarendon Press, 1961, pp. 37-75, and is incorporated herein by reference. Medical imaging is concerned generally with receipt and interpretation of the fields produced by this given-back energy.
In subsequent discussions, it will be assumed that the frame of reference is one that rotates with the RF rotating magnetic field B.sub.1 at the resonant frequency f.sub.0. The magnetization components M.sub.x' and M.sub.y' are of particular interest here. In a frame rotating with the field, the magnetic field directed along the x'-axis in the rotating frame produces a magnetization only along the y'-axis. In this frame, the broadband RF pulse and various gradient magnetic fields (discussed below) that perturb the spin system are easily visualized and analyzed.
One problem that faces any approach to excitation, selective or otherwise, of a tissue, organ or other biological component of a human or animal body (herein referred to simply as "tissue" for convenience), or parts thereof, is that the "noise", which arises from tissue not within the desired volume element, is often substantial because of the relatively large surrounding tissue volume that produces such noise. A time-varying magnetic field B.sub.1 in the tissue produces a corresponding electric field E.sub.1 by Maxwell's equations, and because the tissue has non-zero conductivity, this produces a corresponding non-zero current vector J. The volume integral of the scalar product of J and E gives rise to power dissipation in the entire tissue volume element, and this produces noise at the signal sensing apparatus unless the field of view of the tissue volume element can be somehow limited. This process can be represented by a "body noise" resistor whose contribution is proportional to tissue conductivity. Noise sets a lower limit on the resolution, expressed as the smallest volume of tissue that can be sensed by the receiver, and sets a lower limit on the length of the time interval over which signal acquisition is possible. Noise is produced by uncontrolled electronic action in the receiver circuits ("Johnson noise"), by the "body noise" resistor noise source, and by thermally induced magnetization in the tissue being imaged.
Three volume elements, of quite different sizes, are involved here: (1) tissue volume, which can be a few hundred to a few hundred thousand cm.sup.3 in size; (2) RF signal interrogation volume from which the receiver receives the sensed response signals; and (3) magnetic resonance excitation volume or "voxel volume" within the tissue, which can be much less than 1 mm.sup.3 in size. The interrogation volume is defined by the volume surrounded by the coil, applicator or other transmitter used to generate the RF magnetic field and by the extend of the unwanted electric field generated in the body itself. In conventional approaches, this interrogation volume can be 50,000-100,000 cm.sup.3, which is much larger than the tissue volume for cardiac monitoring. Preferably, the interrogation volume should be about the same size as the tissue volume, or smaller.
According to one well known relation in magnetic resonance physics, the signal-to-noise ratio (SNR) is proportional to the product of B.sub.0 and a volume ratio: EQU SNR.varies.B.sub.0 [voxel volume/interrogation volume][.DELTA.t].sup.1/2,
where .DELTA.t is the data acquisition time and B.sub.0 is the primary magnetic field strength. Increase of B.sub.0 causes a proportional increase in the system's resonant frequency. Increase of .DELTA.t is often constrained by throughput requirements. Increase of B.sub.0 and/or reduction of the interrogation volume is thus a primary concern, if the signal-to-noise ratio is to be increased.
What is needed here is an approach that (1) minimizes or suppresses the body noise per unit acquisition time that issues from the tissue volume, and (2) increases the available signal per unit acquisition time. | {
"pile_set_name": "USPTO Backgrounds"
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1. Field of the Invention
The present invention relates to a wind-power generation system and a control method for the same.
2. Description of Related Art
In recent years, when the grid frequency has become higher than the rated frequency, an output-power limiting operation for limiting the output power of wind turbines is sometimes performed irrespective of the wind speed to decrease the frequency. During the output-power limiting operation, the output power is reduced, and the rotational speed becomes higher than that in a normal operation. This causes overspeeding if a gust of wind occurs during the output-power limiting operation, thus increasing the possibility of disconnection. | {
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The invention pertains to a process for treating a mineral oil having a substantially large nitrogen content during which process at least some hydrocarbon molecules of the mineral oil are chemically altered to form a mineral oil having different properties. More particularly, the invention pertains to a process for hydrocracking hydrocarbon feedstocks containing a large amount of organic nitrogen compounds, which process employs two catalysts.
It is well known that a hydrocracking process may employ a catalyst containing a zeolitic molecular sieve component. In U.S. Pat. No. 3,159,564, Kelley, et al., disclose a hydrofining-hydrocracking process wherein the catalyst employed in the hydrocracking step of the process can contain partially dehydrated, zeolitic, crystalline molecular sieves, e.g., of the "X" or "Y" crystal types. In U.S. Pat. Nos. 3,894,930 and 4,054,539, Hensley discloses a hydrocracking process employing a catalyst comprising a hydrogenation component comprising a Group VI metal, preferably molybdenum, and a Group VIII metal, preferably cobalt, on a co-catalytic acidic cracking component comprising an ultrastable, large-pore crystalline aluminosilicate material and a silica-alumina cracking catalyst.
In U.S. Pat. No. 3,536,605, Kittrell discloses a hydrofining-hydrocracking process which comprises contacting a hydrocarbon feed containing substantial amounts of organic nitrogen with a catalyst comprising a gel matrix comprising silica and alumina and nickel and/or cobalt and molybdenum and/or tungsten and a crystalline zeolitic molecular sieve having a silica-to-alumina ratio above about 2.15, a unit cell size below about 24.65 Angstroms (A), and a sodium content below about 3 wt.%. Kittrell also discloses that the effluent from the reaction zone of the process may be hydrocracked in a second reaction zone in the presence of hydrogen and a hydrocracking catalyst at hydrocracking conditions.
In U.S. Pat. No. 3,558,471, Kittrell discloses a two-catalyt process wherein the hydrocarbon feedstock is first hydrotreated in the presence of a catalyst comprising a silica-alumina gel matrix containing nickel or cobalt, or both, and molybdenum or tungsten, or both, and a crystalline zeolitic molecular sieve substantially in the ammonia or hydrogen form, substantially free of any catalytic loading metal or metals, the sieve further having a silica-to-alumina ratio above about 2.15, a unit cell size below about 24.65 A, and a sodium content below about 3 wt.%, calculated as Na.sub.2 O, to produce a first effluent and contacting the first effluent in a second reaction zone in the presence of a hydrocracking catalyst. The catalyst in the second reaction zone may be the same catalyst as is used in the first reaction zone or it may be a conventional hydrocracking catalyst.
Buchmann, et al., in U.S. Pat. No. 3,788,974, disclose a two-catalyst hydrocracking process wherein a hydrocarbon oil feedstock containing from about 0.01 to 0.5 wt.% nitrogen compounds is contacted in a first hydrocracking zone with a crystalline aluminosilicate zeolite catalyst having hydrogen cations in at least a portion of its exchangeable cationic sites, the zeolite having uniform pore diameters, a crystal structure of faujasite, and a silica-to-alumina mole ratio greater than 3, and containing less than 2 wt.% sodium, the catalyst having associated therewith a hydrogenation component comprising nickel and tungsten, to provide an effluent which is contacted in a second separate hydrocracking zone with a hydrocracking catalyst. The catalyst in the first zone may have a silica-alumina binder, a content of 20% binder being shown in one of the examples, and the second hydrocracking catalyst can be the same as the first catalyst. The catalyst that is employed in the second stage can consist of any desired combination of a refractory cracking base with a suitable hydrogenation component. Suitable cracking bases include, for example, mixtures of two or more difficultly reducible oxides, such as silica-alumina, silica-magnesia, silica-zirconia, acid-treated clays, and the like. The preferred cracking bases comprise partially dehydrated zeolitic X- or Y- type crystalline molecular sieves.
Jaffe, in U.S. Pat. No. 3,536,604, discloses a hydrofining-hydrocracking process wherein a feed containing 300 to 10,000 ppm organic nitrogen is contacted with a hydrofining catalyst at a liquid hourly space velocity (LHSV) of 0.1 to 5 to reduce the organic nitrogen content to a level of 10 ppm to 200 ppm and a substantial portion of the resulting hydrofined hydrocarbon stream is contacted subsequently with a second catalyst comprising a gel matrix comprising at least 15 wt.% silica, alumina, nickel and/or cobalt, molybdenum and/or tungsten, and a crystalline zeolitic molecular sieve substantially in the ammonia or hydrogen form, substantially free of any loading metal, the second catalyst having an average pore diameter that is less than 100 A and a surface area that is greater than 200 m.sup.2 /gm. The hydrofining catalyst comprises a Group VI metal, a Group VIII metal, and a support selected from alumina and silica-alumina.
In U.S. Pat. No. 3,535,225, Jaffe discloses a two-catalyst hydrocracking process in which the hydrocarbon feedstock is contacted with a first catalyst comprising a hydrogenating component selected from the group consisting of Group VI metals and compounds thereof and Group VIII metals and compounds thereof and a component selected from the group consisting of alumina and silica-alumina and subsequently with a second catalyst, which second catalyst consists essentially of a gel matrix consisting essentially of a gel selected from silica-alumina, silica-alumina-titania, and silica-alumina-zirconia, at least one hydrogenating component selected from Group VIII metals and compounds thereof, and a crystalline zeolitic molecular sieve substantially in the ammonia or hydrogen form and substantially free of any loading metal or metals.
None of the above patents discloses a two-catalyst hydrocracking process which employs specifically as a first catalyst a catalyst comprising a specific hydrogenation component comprising nickel and molybdenum or tungsten and as the second catalyst a catalyst comprising a specific hydrogenation component comprising cobalt and molybdenum, each of the catalysts also comprising a co-catalytic acidic cracking component comprising an ultrastable, large-pore crystalline aluminosilicate material dispersed in and suspended throughout a silica-alumina matrix. Such a two-catalyst hydrocracking process is disclosed hereinafter. | {
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This invention relates to polypeptides found in vertebrate species, which polypeptides are mitogenic growth factors for glial cells, including Schwann cells. The invention is also concerned with processes capable of producing such factors, and the therapeutic application of such factors.
The glial cells of vertebrates constitute the specialized connective tissue of the central and peripheral nervous systems. Important glial cells include Schwann cells which provide metabolic support for neurons and which provide myelin sheathing around the axons of certain peripheral neurons, thereby forming individual nerve fibers. Schwann cells support neurons and provide a sheath effect by forming concentric layers of membrane around adjacent neural axons, twisting as they develop around the axons. These myelin sheaths are a susceptible element of many nerve fibers, and damage to Schwann cells, or failure in growth and development, can be associated with significant demyelination or nerve degeneration characteristic of a number of peripheral nervous system diseases and disorders. In the development of the nervous system, it has become apparent that cells require various factors to regulate their division and growth, and various such factors have been identified in recent years, including some found to have an effect on Schwann cell division or development.
Thus, Brockes et al., inter alia, in J. Neuroscience, 4 (1984) 75–83 describe a protein growth factor present in extracts from bovine brain and pituitary tissue, which was named Glial Growth Factor (GGF). This factor stimulated cultured rat Schwann cells to divide against a background medium containing ten percent fetal calf serum. The factor was also described as having a molecular weight of 31,000 Daltons and as readily dimerizing. In Meth. Enz., 147 (1987), 217–225, Brockes describes a Schwann cell-based assay for GGF.
Brockes et al., supra, also describes a method of purification of GGF to apparent homogeneity. In brief, one large-scale purification method described involves extraction of the lyophilized bovine anterior lobes and chromatography of material obtained thereby using NaCl gradient elution from CM cellulose. Gel filtration is then carried out with an Ultrogel column, followed by elution from a phosphocellulose column, and finally, small-scale SDS gel electrophoresis. Alternatively, the CM-cellulose material was applied directly to a phosphocellulose column, fractions from the column were pooled and purified by preparative native gel electrophoresis, followed by a final SDS gel electrophoresis.
Brockes et al. observe that in previously reported gel filtration experiments (Brockes et al., J. Biol. Chem. 255 (1980) 8374–8377), the major peak of growth factor activity was observed to migrate with a molecular weight of 56,000 Daltons, whereas in the first of the above-described procedures activity was predominantly observed at molecular weight 31,000. It is reported that the GGF dimer is largely removed as a result of the gradient elution from CM-cellulose in this procedure.
Benveniste et al. (PNAS, 82 (1985), 3930–3934) describe a T lymphocyte-derived glial growth promoting factor. This factor, under reducing conditions, exhibits a change in apparent molecular weight on SDS gels.
Kimura et al. (Nature, 348 (1990), 257–260) describe a factor they term Schwannoma-derived growth factor (SDGF) which is obtained from a sciatic nerve sheath tumor. The authors state that SDGF does not stimulate the incorporation of tritium-labelled TdR into cultured Schwann cells under conditions where, in contrast, partially purified pituitary fraction containing GGF is active. SDGF has an apparent molecular weight of between 31,000 and 35,000.
Davis and Stroobant (J. Cell. Biol., 110 (1990), 1353–1360) describe the screening of a number of candidate mitogens. Rat Schwann cells were used, the chosen candidate substances being examined for their ability to stimulate DNA synthesis in the Schwann cells in the presence of 10% FCS (fetal calf serum), with and without forskolin. One of the factors tested was GGF-carboxymethyl cellulose fraction (GGF-CM), which was mitogenic in the presence of FCS, with and without forskolin. The work revealed that in the presence of forskolin, inter alia, platelet derived growth factor (PDGF) was a potent mitogen for Schwann cells, PDGF having previously been thought to have no effect on Schwann cells.
Holmes et al. Science (1992) 256: 1205 and Wen et al. Cell (1992) 69: 559 demonstrate that DNA sequences which encode proteins binding to a receptor (p185erbB2) are associated with several human tumors.
The p185erbB2 protein is a 185 kilodalton membrane spanning protein with tyrosine kinase activity. The protein is encoded by the erbB2 proto-oncogene (Yarden and Ullrich Ann. Rev. Biochem. 57: 443 (1988)). The erbB2 gene, also referred to as HER-2 (in human cells) and neu (in rat cells), is closely related to the receptor for epidermal growth factor (EGF). Recent evidence indicates that proteins which interact with (and activate the kinase of) p185erbB2 induce proliferation in the cells bearing p185erbB2 (Holmes et al. Science 256: 1205 (1992); Dobashi et al. Proc. Natl. Acad. Sci. 89: 8582 (1991); Lupu et al. Proc. Natl. Acad. Sci. 89: 2287 (1992)). Furthermore, it is evident that the gene encoding p185erbB2 binding proteins produces a number of variably-sized, differentially-spliced RNA transcripts that give rise to a series of proteins, which are of different lengths and contain some common peptide sequences and some unique peptide sequences. This is supported by the differentially-spliced RNA transcripts recoverable from human breast cancer (MDA-MB-231) (Holmes et al. Science 256: 1205 (1992)). Further support derives from the wide size range of proteins which act as (as disclosed herein) ligands for the p185erbB2 receptor (see below). | {
"pile_set_name": "USPTO Backgrounds"
} |
1. Field of the Invention
The present invention relates generally to shock absorbers which create an anti-roll system for a vehicle. More particularly, the present invention relates to shock absorbers having a passive damping system for providing variable damping in response to lateral forces placed upon the vehicle.
2. Description of the Related Art
Various types of shock absorbers are used in connection with motor vehicle suspension systems to absorb unwanted vibrations which occur during various driving conditions. To dampen the unwanted vibrations, shock absorbers are generally connected between the sprung portion (i.e., the vehicle body) and the unsprung (i.e., the suspension) of the vehicle. A piston assembly is located within the working chamber of the shock absorber and is connected to the body of the motor vehicle through a piston rod. Generally, the piston assembly includes a primary valving arrangement that is able to limit the flow of damping fluid within the working chamber when the shock absorber is compressed or extended. As such, the shock absorber is able to generate a damping force which "smooths" or "dampens" the vibrations transmitted from the suspension to the vehicle body. Typically, these vibrations occur from forces generated in a vertical direction between the vehicle body and the driving surface.
The greater the degree to which the flow of damping fluid within the working chamber is restricted across the piston assembly, the greater the damping forces which are generated by the shock absorber. It is also possible to implement a primary valving arrangement which produces one magnitude of damping on the compression stroke, and a second magnitude of damping on the rebound stroke. However, these different damping rates are typically constant because they are produced by varying the sizes of the compression and rebound bypass orifices.
While these shock absorbers produce ride comfort levels ranging from "soft" to "firm," few, if any, of the known shock absorbers produce varying degrees of damping in a passive manner. The shock absorber systems known within the art which are capable of producing varying degrees of damping force, typically achieve this through the use of active control systems. However, these systems generally react to the vertically generated forces placed upon the vehicle suspension.
Accordingly, it is desirable to provide a shock absorber which includes a primary damping mechanism for counteracting the vertical forces placed upon the vehicle, and a secondary damping mechanism which is capable of providing varying damping in response to horizontal and lateral forces which are placed upon the vehicle suspension. Further, it is desirable that this secondary and variable damping be provided in proportion to the lateral force encountered by a passive control or valving arrangement. Such a system could be used to implement a passive anti-roll system for enhancing the control to the vehicle provided by the vehicle suspension. Such a passive damping system also eliminates the need for complicated and expensive control systems which actively provide the varying degrees of damping.
An example of the lateral forces placed upon the vehicle suspension are the lateral forces generated during high-speed cornering. As these lateral forces are counteracted by the vehicle's suspension and tires, a rolling action on the vehicle body is produced. When these rolling forces exceed the limit for the vehicle, a rollover condition may be created where the vehicle is literally flipped over on its side. Accordingly, it is desirable to provide a shock absorber which provides increased damping in response to these lateral and horizontal forces for counteracting or at least minimizing these rolling forces. | {
"pile_set_name": "USPTO Backgrounds"
} |
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