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https://en.wikipedia.org/wiki/Dyck%20language | In the theory of formal languages of computer science, mathematics, and linguistics, a Dyck word is a balanced string of brackets.
The set of Dyck words forms a Dyck language. The simplest, D1, use just two matching brackets, e.g. ( and ).
Dyck words and language are named after the mathematician Walther von Dyck. They have applications in the parsing of expressions that must have a correctly nested sequence of brackets, such as arithmetic or algebraic expressions.
Formal definition
Let be the alphabet consisting of the symbols [ and ]. Let denote its Kleene closure.
The Dyck language is defined as:
Context-free grammar
It may be helpful to define the Dyck language via a context-free grammar in some situations.
The Dyck language is generated by the context-free grammar with a single non-terminal , and the production:
That is, S is either the empty string () or is "[", an element of the Dyck language, the matching "]", and an element of the Dyck language.
An alternative context-free grammar for the Dyck language is given by the production:
That is, S is zero or more occurrences of the combination of "[", an element of the Dyck language, and a matching "]", where multiple elements of the Dyck language on the right side of the production are free to differ from each other.
Alternative definition
In yet other contexts it may instead be helpful to define the Dyck language by splitting into equivalence classes, as follows.
For any element of length , we define partial functions and by
is with "" inserted into the th position
is with "" deleted from the th position
with the understanding that is undefined for and is undefined if . We define an equivalence relation on as follows: for elements we have if and only if there exists a sequence of zero or more applications of the and functions starting with and ending with . That the sequence of zero operations is allowed accounts for the reflexivity of . Symmetry follows from the observation |
https://en.wikipedia.org/wiki/Reynolds%20stress | In fluid dynamics, the Reynolds stress is the component of the total stress tensor in a fluid obtained from the averaging operation over the Navier–Stokes equations to account for turbulent fluctuations in fluid momentum.
Definition
The velocity field of a flow can be split into a mean part and a fluctuating part using Reynolds decomposition. We write
with being the flow velocity vector having components in the coordinate direction (with denoting the components of the coordinate vector ). The mean velocities are determined by either time averaging, spatial averaging or ensemble averaging, depending on the flow under study. Further denotes the fluctuating (turbulence) part of the velocity.
We consider a homogeneous fluid, whose density ρ is taken to be a constant. For such a fluid, the components τ'''ij of the Reynolds stress tensor are defined as:
Another – often used – definition, for constant density, of the Reynolds stress components is:
which has the dimensions of velocity squared, instead of stress.
Averaging and the Reynolds stress
To illustrate, Cartesian vector index notation is used. For simplicity, consider an incompressible fluid:
Given the fluid velocity as a function of position and time, write the average fluid velocity as , and the velocity fluctuation is . Then .
The conventional ensemble rules of averaging are that
One splits the Euler equations (fluid dynamics) or the Navier-Stokes equations into an average and a fluctuating part. One finds that upon averaging the fluid equations, a stress on the right hand side appears of the form . This is the Reynolds stress, conventionally written :
The divergence of this stress is the force density on the fluid due to the turbulent fluctuations.
Reynolds averaging of the Navier–Stokes equations
For instance, for an incompressible, viscous, Newtonian fluid, the continuity and momentum equations—the incompressible Navier–Stokes equations—can be written (in a non-conservative form) as
and
wh |
https://en.wikipedia.org/wiki/Linear%20probing | Linear probing is a scheme in computer programming for resolving collisions in hash tables, data structures for maintaining a collection of key–value pairs and looking up the value associated with a given key. It was invented in 1954 by Gene Amdahl, Elaine M. McGraw, and Arthur Samuel and first analyzed in 1963 by Donald Knuth.
Along with quadratic probing and double hashing, linear probing is a form of open addressing. In these schemes, each cell of a hash table stores a single key–value pair. When the hash function causes a collision by mapping a new key to a cell of the hash table that is already occupied by another key, linear probing searches the table for the closest following free location and inserts the new key there. Lookups are performed in the same way, by searching the table sequentially starting at the position given by the hash function, until finding a cell with a matching key or an empty cell.
As write, "Hash tables are the most commonly used nontrivial data structures, and the most popular implementation on standard hardware uses linear probing, which is both fast and simple."
Linear probing can provide high performance because of its good locality of reference, but is more sensitive to the quality of its hash function than some other collision resolution schemes. It takes constant expected time per search, insertion, or deletion when implemented using a random hash function, a 5-independent hash function, or tabulation hashing. Good results can also be achieved in practice with other hash functions such as MurmurHash.
Operations
Linear probing is a component of open addressing schemes for using a hash table to solve the dictionary problem. In the dictionary problem, a data structure should maintain a collection of key–value pairs subject to operations that insert or delete pairs from the collection or that search for the value associated with a given key.
In open addressing solutions to this problem, the data structure is an array (the hash |
https://en.wikipedia.org/wiki/Quadratic%20probing | Quadratic probing is an open addressing scheme in computer programming for resolving hash collisions in hash tables. Quadratic probing operates by taking the original hash index and adding successive values of an arbitrary quadratic polynomial until an open slot is found.
An example sequence using quadratic probing is:
Quadratic probing can be a more efficient algorithm in an open addressing table, since it better avoids the clustering problem that can occur with linear probing, although it is not immune. It also provides good memory caching because it preserves some locality of reference; however, linear probing has greater locality and, thus, better cache performance.
Quadratic function
Let h(k) be a hash function that maps an element k to an integer in [0, m−1], where m is the size of the table. Let the ith probe position for a value k be given by the function
where c2 ≠ 0 (If c2 = 0, then h(k,i) degrades to a linear probe). For a given hash table, the values of c1 and c2 remain constant.
Examples:
If , then the probe sequence will be
For m = 2n, a good choice for the constants are c1 = c2 = 1/2, as the values of h(k,i) for i in [0, m−1] are all distinct (in fact, it is a permutation on [0, m−1]). This leads to a probe sequence of (the triangular numbers) where the values increase by 1, 2, 3, ...
For prime m > 2, most choices of c1 and c2 will make h(k,i) distinct for i in [0, (m−1)/2]. Such choices include c1 = c2 = 1/2, c1 = c2 = 1, and c1 = 0, c2 = 1. However, there are only m/2 distinct probes for a given element, requiring other techniques to guarantee that insertions will succeed when the load factor exceeds 1/2.
For , where m, n, and p are integer greater or equal 2 (degrades to linear probe when p = 1), then gives cycle of all distinct probes. It can be computed in loop as: , and
For any m, full cycle with quadratic probing can be achieved by rounding up m to closest power of 2, compute probe index: , and skip iteration when . There is maxim |
https://en.wikipedia.org/wiki/Marangoni%20effect | The Marangoni effect (also called the Gibbs–Marangoni effect) is the mass transfer along an interface between two phases due to a gradient of the surface tension. In the case of temperature dependence, this phenomenon may be called thermo-capillary convection (or Bénard–Marangoni convection).
History
This phenomenon was first identified in the so-called "tears of wine" by physicist James Thomson (Lord Kelvin's brother) in 1855. The general effect is named after Italian physicist Carlo Marangoni, who studied it for his doctoral dissertation at the University of Pavia and published his results in 1865. A complete theoretical treatment of the subject was given by J. Willard Gibbs in his work On the Equilibrium of Heterogeneous Substances (1875-8).
Mechanism
Since a liquid with a high surface tension pulls more strongly on the surrounding liquid than one with a low surface tension, the presence of a gradient in surface tension will naturally cause the liquid to flow away from regions of low surface tension. The surface tension gradient can be caused by concentration gradient or by a temperature gradient (surface tension is a function of temperature).
In simple cases, the speed of the flow , where is the difference in surface tension and is the viscosity of the liquid. Water has a surface tension of around 0.07 N/m, and a viscosity of approximately 10−3 Pa s, at room temperature. So even variations of a few percent in the surface tension of water can generate Marangoni flows of almost 1 m/s. Thus Marangoni flows are common and easily observed.
For the case of a small drop of surfactant dropped onto the surface of water, Roché and coworkers performed quantitative experiments and developed a simple model that was in approximate agreement with the experiments. This described the expansion in the radius of a patch of the surface covered in surfactant, due to an outward Marangoni flow at a speed . They found that speed of expansion of the surfactant-covered patch of t |
https://en.wikipedia.org/wiki/LightScribe | LightScribe is an optical disc recording technology that was created by the Hewlett-Packard Company. It uses specially coated recordable CD and DVD media to produce laser-etched labels with text or graphics, as opposed to stick-on labels and printable discs. Although HP is no longer developing the technology, it is still maintained and supported by a number of independent enthusiasts.
The LightScribe method uses the laser in a way similar to when plain data are written to the disc; a greyscale image of the label is etched (physically burned) onto the upper side of the disc using a laser. In the beginning, the discs were available only in a sepia color but later became available in many monochromatic colors.
The purpose of LightScribe is to allow users to create direct-to-disc labels (as opposed to stick-on labels), using their optical disc writer. Special discs and a compatible disc writer are required. Before or after burning data to the read-side of the disc, the user turns the disc over and inserts it with the label side down. The drive's laser then burns the label side in such a way that an image is produced. (see Thermal printing; LightScribe uses a laser instead of a thermal printing head)
History
LightScribe was conceived by Hewlett-Packard engineer Daryl Anderson, and the coating's chemistry was developed by Dr. Makarand Gore, and brought to market through the joint design efforts of HP's imaging and optical storage divisions, where it was first introduced in January 2004 at the 2004 Consumer Electronics Show.
It was the first direct to disc labeling technology that allowed users to laser etch images to the label side of a disc. DiscT@2 technology had been on the market since 2002, but DiscT@2 allows users to burn only to the unused portion of the data side of the disc. In 2005, LabelFlash became the main competitor for LightScribe.
Various brands manufacture the required media. Dual Layer DVD+Rs are the highest-capacity disc to support the technology. |
https://en.wikipedia.org/wiki/Adventure%20Island%20%28video%20game%29 | Hudson's Adventure Island, known as in Japan and also known as Adventure Island, is a side-scrolling platform game produced by Hudson Soft that was released in Japan for the Famicom and MSX on September 12, 1986. Adventure Island was released in North America for the Nintendo Entertainment System in 1988 and in the PAL region in 1992.
Adventure Island is an adaptation of the arcade game Wonder Boy, developed by Escape for Sega. Adventure Island was followed by a series of sequels with no connection to the Wonder Boy series.
Plot
The player controls Master Higgins (known as Master Wigins in the United Kingdom and as Takahashi Meijin in Japanese versions), a young man who ventured to Adventure Island in the South Pacific after hearing that the Evil Witch Doctor kidnapped Princess Tina. To rescue her, Higgins must survive a series of 32 stages. There are eight worlds called "areas", which are divided into four stages or "rounds" each, which are further divided into four checkpoints. When the player reaches the fourth round of each area, he must confront a boss at the end to continue to the next area. The game is completed when the player saves the girl after defeating the eighth and final form of the evil lord.
Gameplay
Master Higgins (the player character) loses a life whenever he touches an enemy, an enemy's attack, a fire roast, or when he falls into a pitfall or a body of water. The player also has a health gauge that starts out with 11 points, which gradually depletes over time or whenever Higgins trips on a rock in his path. When Higgins' health gauge reaches zero, he will lose a life. If Higgins still has extra lives, he will revive at the last checkpoint he passed through. The game ends when all of Higgins' lives run out. To replenish his health, Higgins can pick up fruit or a milk bottle and has a maximum health of up to 16 points. When the player's score reaches 50,000 points, 100,000 points, and 200,000 points, Higgins will receive an extra life. Findin |
https://en.wikipedia.org/wiki/Complementary%20currency | A complementary currency is a currency or medium of exchange that is not necessarily a national currency, but that is thought of as supplementing or complementing national currencies. Complementary currencies are usually not legal tender and their use is based on agreement between the parties exchanging the currency. According to Jérôme Blanc of Laboratoire d'Économie de la Firme et des Institutions, complementary currencies aim to protect, stimulate or orientate the economy. They may also be used to advance particular social, environmental, or political goals.
When speaking about complementary currencies, a number of overlapping and often interchangeable terms are in use: local or community currencies are complementary currencies used within a locality or other form of community (such as business-based or online communities); regional currencies are similar to local currencies, but are used within a larger geographical region; and sectoral currencies are complementary currencies used within a single economic sector, such as education or health care. Many private currencies are complementary currencies issued by private businesses or organizations. Other terms include alternative currency, auxiliary currency, and microcurrency. Mutual credit is a form of alternative currency, and thus any form of lending that does not go through the banking system can be considered a form of alternative currency. Barters are another type of alternative currency. These are actually exchange systems, which trade only items, without the use of any currency whatsoever. Finally, LETS is a special form of barter that trades points for items. One point stands for one worker-hour of work, and is thus a time-based currency.
Purposes
Current complementary currencies have often been designed intentionally to address specific issues, for example to increase financial stability. Most complementary currencies have multiple purposes and/or are intended to address multiple issues. They can be u |
https://en.wikipedia.org/wiki/Winner-take-all%20%28computing%29 | Winner-take-all is a computational principle applied in computational models of neural networks by which neurons compete with each other for activation. In the classical form, only the neuron with the highest activation stays active while all other neurons shut down; however, other variations allow more than one neuron to be active, for example the soft winner take-all, by which a power function is applied to the neurons.
Neural networks
In the theory of artificial neural networks, winner-take-all networks are a case of competitive learning in recurrent neural networks. Output nodes in the network mutually inhibit each other, while simultaneously activating themselves through reflexive connections. After some time, only one node in the output layer will be active, namely the one corresponding to the strongest input. Thus the network uses nonlinear inhibition to pick out the largest of a set of inputs. Winner-take-all is a general computational primitive that can be implemented using different types of neural network models, including both continuous-time and spiking networks.
Winner-take-all networks are commonly used in computational models of the brain, particularly for distributed decision-making or action selection in the cortex. Important examples include hierarchical models of vision, and models of selective attention and recognition. They are also common in artificial neural networks and neuromorphic analog VLSI circuits. It has been formally proven that the winner-take-all operation is computationally powerful compared to other nonlinear operations, such as thresholding.
In many practical cases, there is not only one single neuron which becomes active but there are exactly k neurons which become active for a fixed number k. This principle is referred to as k-winners-take-all.
Circuit example
A simple, but popular CMOS winner-take-all circuit is shown on the right. This circuit was originally proposed by Lazzaro et al. (1989) using MOS transistors biased |
https://en.wikipedia.org/wiki/Floor%20area%20ratio | Floor area ratio (FAR) is the ratio of a building's total floor area (gross floor area) to the size of the piece of land upon which it is built. It is often used as one of the regulations in city planning along with the building-to-land ratio. The terms can also refer to limits imposed on such a ratio through zoning. FAR includes all floor areas but is indifferent to their spatial distribution on the lot whereas the building coverage ratio (or lot coverage) measures building footprint on the lot but is indifferent to building height.
Written as a formula, FAR = .
Lower maximum-allowed floor area ratios are linked to lower land values and lower housing density.
Terminology
Floor Area ratio is sometimes called floor space ratio (FSR), floor space index (FSI), site ratio or plot ratio.
The difference between FAR and FSI is that the first is a ratio, while the latter is an index.
Index numbers are values expressed as a percentage of a single base figure. Thus an FAR of 1.5 is translated as an FSI of 150%.
Regional variation
The terms most commonly used for this measurement vary from one country or region to the next.
In Australia floor space ratio (FSR) is used in New South Wales and plot ratio in Western Australia.
In France coefficient d'occupation des sols (COS) is used.
In India floor space index (FSI) and floor area ratio (FAR) are both used.
In the United Kingdom and Hong Kong both plot ratio and site ratio are used.
In Singapore the terms plot ratio and gross plot ratio (GPR) are more commonly used.
In the United States and Canada, floor space ratio (FSR) and floor area ratio (FAR) are both used.
Use ratios are used as a measure of the density of the site being developed. High FAR indicates a dense construction. The ratio is generated by dividing the building area by the parcel area, using the same units.
History
One of the purposes of the 1916 zoning ordinance of New York City was to prevent tall buildings from obstructing too much light and air. |
https://en.wikipedia.org/wiki/Computational%20epistemology | Computational epistemology is a subdiscipline of formal epistemology that studies the intrinsic complexity of inductive problems for ideal and computationally bounded agents. In short, computational epistemology is to induction what recursion theory is to deduction. It has been applied to problems in philosophy of science.
Themes
Some of the themes of computational epistemology include:
the essential likeness of induction and deduction (as illustrated by systematic analogies between their respective complexity classes)
the treatment of discovery, prediction and assessment methods as effective procedures (algorithms) as originates in algorithmic learning theory.
the characterization of inductive inference problems as consisting of:
a set of relevant possibilities (possible worlds), each of which specifies some potentially infinite sequence of inputs to scientific method,
a question whose potential answers partition the relevant possibilities (in the set theoretic sense),
a convergent success criterion and
a set of admissible methods
the notion of logical reliability for inductive problems
Quotations
Computational epistemology definition:
"Computational epistemology is an interdisciplinary field that concerns itself with the relationships and constraints between reality, measure, data, information, knowledge, and wisdom" (Rugai, 2013)
On making inductive problems easier to solve:
"Eliminating relevant possibilities, weakening the convergence criterion, coarsening the question, or augmenting the collection of potential strategies all tend to make a problem easier to solve" (Kelly, 2000a)
On the divergence of computational epistemology from Bayesian confirmation theory and the like:
"Whenever you are inclined to explain a feature of science in terms of probability and confirmation, take a moment to see how the issue would look in terms of complexity and success"(Kelly, 2000a)
Computational epistemology in a nutshell:
Formal learning theory is very simple in outli |
https://en.wikipedia.org/wiki/Hydraulic%20conductivity | In science and engineering, hydraulic conductivity (, in SI units of meters per second), is a property of porous materials, soils and rocks,< that describes the ease with which a fluid (usually water) can move through the pore space, or fractures network. It depends on the intrinsic permeability (, unit: m) of the material, the degree of saturation, and on the density and viscosity of the fluid. Saturated hydraulic conductivity, , describes water movement through saturated media.
By definition, hydraulic conductivity is the ratio of volume flux to hydraulic gradient yielding a quantitative measure of a saturated soil's ability to transmit water when subjected to a hydraulic gradient.
Methods of determination
There are two broad categories of determining hydraulic conductivity:
Empirical approach by which the hydraulic conductivity is correlated to soil properties like pore size and particle size (grain size) distributions, and soil texture
Experimental approach by which the hydraulic conductivity is determined from hydraulic experiments using Darcy's law
The experimental approach is broadly classified into:
Laboratory tests using soil samples subjected to hydraulic experiments
Field tests (on site, in situ) that are differentiated into:
small scale field tests, using observations of the water level in cavities in the soil
large scale field tests, like pump tests in wells or by observing the functioning of existing horizontal drainage systems.
The small scale field tests are further subdivided into:
infiltration tests in cavities above the water table
slug tests in cavities below the water table
The methods of determination of hydraulic conductivity and other related issues are investigated by several researchers and include more empirical approaches.
Estimation by empirical approach
Estimation from grain size
Allen Hazen derived an empirical formula for approximating hydraulic conductivity from grain size analyses:
where
Hazen's empirical coefficient, whic |
https://en.wikipedia.org/wiki/Donkey%20Kong%20Jr.%20Math | is an edutainment platform video game developed and published by Nintendo for the Nintendo Entertainment System. It is a spin-off of the 1982 arcade game Donkey Kong Jr. In the game, players control Donkey Kong Jr. as he solves math problems set up by his father Donkey Kong. It was released in Japan in 1983 for the Family Computer, and in North America and the PAL region in 1986.
It is the only game in the Education Series of NES games in North America, owing to the game's lack of success. It was made available in various forms, including in the 2002 GameCube video game Animal Crossing and on the Virtual Console services for Wii and Wii U in 2007 and 2014 respectively. Donkey Kong Jr. Math was a critical and commercial failure. It has received criticism from several publications including IGN staff, who called it one of the worst Virtual Console games.
Gameplay
The game features two modes, one single-player and the allowing for one to two players. Its mechanics are similar to its predecessor, Donkey Kong Jr. The Calculate mode has Donkey Kong hold up a number, which players must attempt to reach by collecting a combination of digits and arithmetic symbols to eventually reach that number. Players must climb vines to reach these figures. The +−×÷ Exercise requires players to solve fixed math puzzles by climbing chains to reach the correct numbers and arithmetic symbols to do so.
Development
Donkey Kong Jr. Math was developed by Nintendo Research & Development 2 and designed by Toshihiko Nakago. It was published by Nintendo for the Nintendo Entertainment System (NES) and Family Computer (Famicom). It reuses its engine, assets, and gameplay from Donkey Kong Jr. It was a part of the Educational Series on the NES, a series that was originally supposed to have three entries, including a Donkey Kong music game. However, it was the only one released under that line. A lack of success by the game was attributed by a Nintendo spokesman to be the reason Nintendo did not m |
https://en.wikipedia.org/wiki/Rainout%20%28radioactivity%29 | A rainout is the process of precipitation causing the removal of radioactive particles from the atmosphere onto the ground, creating nuclear fallout by rain. The rainclouds of the rainout are often formed by the particles of a nuclear explosion itself and because of this, the decontamination of rainout is more difficult than a "dry" fallout.
In atmospheric science, rainout also refers to the removal of soluble species—not necessarily radioactive—from the atmosphere by precipitation.
Factors affecting rainout
A rainout could occur in the vicinity of ground zero or the contamination could be carried aloft before deposition depending on the current atmospheric conditions and how the explosion occurred. The explosion, or burst, can be air, surface, subsurface, or seawater. An air burst will produce less fallout than a comparable explosion near the ground due to less particulate being contaminated. Detonations at the surface will tend to produce more fallout material. In case of water surface bursts, the particles tend to be rather lighter and smaller, producing less local fallout but extending over a greater area. The particles contain mostly sea salts with some water; these can have a cloud seeding effect causing local rainout and areas of high local fallout. Fallout from a seawater burst is difficult to remove once it has soaked into porous surfaces because the fission products are present as metallic ions which become chemically bonded to many surfaces. For subsurface bursts, there is an additional phenomenon present called "base surge". The base surge is a cloud that rolls outward from the bottom of the subsiding column, which is caused by an excessive density of dust or water droplets in the air. This surge is made up of small solid particles, but it still behaves like a fluid. A soil earth medium favors base surge formation in an underground burst. Although the base surge typically contains only about 10% of the total bomb debris in a subsurface burst, it can cr |
https://en.wikipedia.org/wiki/Yamaha%20YMF7xx | There have been various families of Yamaha audio controllers labelled as YMF7xx.
OPL3-SA families
YMF701 (OPL3-SA): Incorporates OPL3 and OPL3-L features, 16-bit stereo CODEC, MPU-401-compatible MIDI interface, game port, Plug and Play ISA interface, Windows Sound System (CS4231) and Sound Blaster Pro compatibility.
YMF711 (OPL3-SA2): Based on OPL3-SA, it adds Plug and Play ISA compatibility, 10-pin interface supports 16-bit port address decode (top 4 bits), EEPROM interface, Zoomed video port, CPU and DAC interface for OPL4-ML, modem interface, or IDE CD-ROM interface.
YMF715 (OPL3-SA3): Based on OPL3-SA2, the OPL3-SA3 family adds 3D audio support via DirectSound3D and QSound.
DS-XG family
The last model number for controller chips used on ISA bus cards is 719; chips used on PCI cards start at 720 and higher. Chips for PCI bus standalone adapters are marked YMF7x4, while on-board or embedded systems are marked YMF7x0. The DS-XG series features hardware-assisted XG MIDI synthesis with either 32- or 64-note polyphony, full-duplex playback and recording at any samplerate (internally upsampled to 48 kHz), external game controller and MIDI interface, and a legacy block for DOS application support.
The DS-XG family processors were used in many inexpensive (sub-$50) soundcards. Relative performance was good despite the typical low cost. The cards were usually equipped with good quality 18-bit Digital-to-Analogue Converters, providing similar low noise and harmonic distortion levels to those found in semi-professional hardware.
The XG synthesizer on the DS-XG series features not only basic XG System Level 1, but also some of the MU-50 additions, and can reproduce most musical data previously programmed for the popular DB50XG daughterboard. YMF7x4 cards shipped with a 2 MB bank of 8-bit samples by default, which must be loaded into system RAM during booting. Neither the resolution nor content of the sample bank are hardware limitations. A user can load their own banks |
https://en.wikipedia.org/wiki/Lu%C3%ADs%20Cruls | Luíz Cruls or Luís Cruls or Louis Ferdinand Cruls (21 January 1848 – 21 June 1908) was a Belgian-Brazilian astronomer and geodesist. He was Director of the Brazilian National Observatory from 1881 to 1908, led the commission charged with the survey and selection of a future site for the capital of Brazil in the Central Plateau, and was co-discoverer of the Great Comet of 1882. Cruls was also an active proponent of efforts to accurately measure solar parallax and towards that end led a Brazilian team in their observations of 1882 Transit of Venus in Punta Arenas, Chile.
Early life
Cruls was born in 1848 in Diest, Belgium, the son of Philippe Augustin Guillaume Cruls (a civil engineer) and Anne Elizabeth Jordens. From 1863 to 1868, Cruls studied civil engineering at the University of Ghent. In 1869 he undertook training as a military engineer and officer, graduating as a 2nd Lieutenant. Cruls served in the Belgian army, attaining the rank of 1st Lieutenant, until 1873 or 1874 (sources disagree).
Likely inspired by Brazilian friends at University (including Caetano de Almeida Furquim, a fellow engineer), Cruls resigned his commission and set out for Brazil on 5 September 1874. During the trans-Atlantic crossing on the steamer Orénoque, Cruls met and became friends with Joaquim Nabuco, a journalist and abolitionist, and also the son of Jose Thomas Nabuco, an influential Brazilian politician. Nabuco's connections were to provide Cruls with access to the highest levels of Brazilian society.
Brazil, Belgium, and back again
Within weeks after Cruls' arrival in Brazil, Joaquim Nabuco and his father arranged for him to be presented to Dom Pedro II, Emperor of Brazil, and more importantly, to meet Buarque de Macedo, the Director General of the Ministry of Public Works. This latter meeting led to Cruls being hired as an engineer by the Commission of the Empire General Charter (Comissão da Carta Geral do Império) in the Geodesy section.
In January 1875 Cruls was forced to |
https://en.wikipedia.org/wiki/Ecosystem%20service | Ecosystem services are the many and varied benefits to humans provided by the natural environment and healthy ecosystems. Such ecosystems include, for example, agroecosystems, forest ecosystem, grassland ecosystems, and aquatic ecosystems. These ecosystems, functioning in healthy relationships, offer such things as natural pollination of crops, clean air, extreme weather mitigation, and human mental and physical well-being. Collectively, these benefits are becoming known as ecosystem services, and are often integral to the provision of food, the provisioning of clean drinking water, the decomposition of wastes, and the resilience and productivity of food ecosystems.
While scientists and environmentalists have discussed ecosystem services implicitly for decades, the Millennium Ecosystem Assessment (MA) in the early 2000s popularized this concept. There, ecosystem services are grouped into four broad categories: provisioning, such as the production of food and water; regulating, such as the control of climate and disease; supporting, such as nutrient cycles and oxygen production; and cultural, such as spiritual and recreational benefits. To help inform decision-makers, many ecosystem services are being evaluated to draw equivalent comparisons to human-engineered infrastructure and services.
Estuarine and coastal ecosystems are marine ecosystems that perform the four categories of ecosystem services in a variety of ways. For example, their regulating services include climate regulation and buffer zones. Furthermore, their provisioning services include marine products and genetic resources. Their cultural services include recreation and tourism. Finally, their supporting services include nutrient cycling and primary production.
Definition
Ecosystem services or eco-services are defined as the goods and services provided by ecosystems to humans. Per the 2006 Millennium Ecosystem Assessment (MA), ecosystem services are "the benefits people obtain from ecosystems". The |
https://en.wikipedia.org/wiki/Electronic%20Signatures%20in%20Global%20and%20National%20Commerce%20Act | The Electronic Signatures in Global and National Commerce Act (ESIGN, , ) is a United States federal law passed by the U.S. Congress to facilitate the use of electronic records and electronic signatures in interstate and foreign commerce by ensuring the validity and legal effect of contracts entered into electronically.
Although every state has at least one law pertaining to electronic signatures, it is the federal law that lays out the guidelines for interstate commerce. The general intent of the ESIGN Act is spelled out in the first section (101.a), that a contract or signature “may not be denied legal effect, validity, or enforceability solely because it is in electronic form”. This simple statement provides that electronic signatures and records are just as good as their paper equivalents, and therefore subject to the same legal scrutiny of authenticity that applies to paper documents.
Sections from the ESIGN Act
Definitions
Sec 106 of the ESIGN Act defines:
General intent
Consumer disclosure
Section 101 of the ESIGN Act, sub-section (b), preserves the rights of individuals to NOT USE electronic signatures. Here the law provides that individuals reserve the right to use a paper signature. Sub-section (c) is in direct support of (b) by requiring a "Consumer Disclosure" that the signatory has consented to use an electronic format.
Section 101(c)(1)(C) states that the consumer also "consent electronically, in a manner that reasonably demonstrates that the consumer can access information in the electronic form that will be used to provide the information that is the subject of the consent".
The consumer must provide affirmative consent, meaning that it cannot be assumed that a consumer has given consent simply because he/she has not chosen the option to deny consent, or has not responded to an option to grant consent.
The first public implementation of Section 106 of the ESIGN Act came nine months prior to its approval, when in October 1999, Save Daily found |
https://en.wikipedia.org/wiki/Volume%20form | In mathematics, a volume form or top-dimensional form is a differential form of degree equal to the differentiable manifold dimension. Thus on a manifold of dimension , a volume form is an -form. It is an element of the space of sections of the line bundle , denoted as . A manifold admits a nowhere-vanishing volume form if and only if it is orientable. An orientable manifold has infinitely many volume forms, since multiplying a volume form by a nowhere-vanishing real valued function yields another volume form. On non-orientable manifolds, one may instead define the weaker notion of a density.
A volume form provides a means to define the integral of a function on a differentiable manifold. In other words, a volume form gives rise to a measure with respect to which functions can be integrated by the appropriate Lebesgue integral. The absolute value of a volume form is a volume element, which is also known variously as a twisted volume form or pseudo-volume form. It also defines a measure, but exists on any differentiable manifold, orientable or not.
Kähler manifolds, being complex manifolds, are naturally oriented, and so possess a volume form. More generally, the th exterior power of the symplectic form on a symplectic manifold is a volume form. Many classes of manifolds have canonical volume forms: they have extra structure which allows the choice of a preferred volume form. Oriented pseudo-Riemannian manifolds have an associated canonical volume form.
Orientation
The following will only be about orientability of differentiable manifolds (it's a more general notion defined on any topological manifold).
A manifold is orientable if it has a coordinate atlas all of whose transition functions have positive Jacobian determinants. A selection of a maximal such atlas is an orientation on A volume form on gives rise to an orientation in a natural way as the atlas of coordinate charts on that send to a positive multiple of the Euclidean volume form
A vol |
https://en.wikipedia.org/wiki/Tautological%20one-form | In mathematics, the tautological one-form is a special 1-form defined on the cotangent bundle of a manifold In physics, it is used to create a correspondence between the velocity of a point in a mechanical system and its momentum, thus providing a bridge between Lagrangian mechanics and Hamiltonian mechanics (on the manifold ).
The exterior derivative of this form defines a symplectic form giving the structure of a symplectic manifold. The tautological one-form plays an important role in relating the formalism of Hamiltonian mechanics and Lagrangian mechanics. The tautological one-form is sometimes also called the Liouville one-form, the Poincaré one-form, the canonical one-form, or the symplectic potential. A similar object is the canonical vector field on the tangent bundle.
To define the tautological one-form, select a coordinate chart on and a canonical coordinate system on Pick an arbitrary point By definition of cotangent bundle, where and The tautological one-form is given by
with and being the coordinate representation of
Any coordinates on that preserve this definition, up to a total differential (exact form), may be called canonical coordinates; transformations between different canonical coordinate systems are known as canonical transformations.
The canonical symplectic form, also known as the Poincaré two-form, is given by
The extension of this concept to general fibre bundles is known as the solder form. By convention, one uses the phrase "canonical form" whenever the form has a unique, canonical definition, and one uses the term "solder form", whenever an arbitrary choice has to be made. In algebraic geometry and complex geometry the term "canonical" is discouraged, due to confusion with the canonical class, and the term "tautological" is preferred, as in tautological bundle.
Coordinate-free definition
The tautological 1-form can also be defined rather abstractly as a form on phase space. Let be a manifold and be the cotangen |
https://en.wikipedia.org/wiki/Z/Architecture | z/Architecture, initially and briefly called ESA Modal Extensions (ESAME), is IBM's 64-bit complex instruction set computer (CISC) instruction set architecture, implemented by its mainframe computers. IBM introduced its first z/Architecture-based system, the z900, in late 2000. Later z/Architecture systems include the IBM z800, z990, z890, System z9, System z10, zEnterprise 196, zEnterprise 114, zEC12, zBC12, z13, z14, z15 and z16.
z/Architecture retains backward compatibility with previous 32-bit-data/31-bit-addressing architecture ESA/390 and its predecessors all the way back to the 32-bit-data/24-bit-addressing System/360. The IBM z13 is the last z Systems server to support running an operating system in ESA/390 architecture mode. However, all 24-bit and 31-bit problem-state application programs originally written to run on the ESA/390 architecture will be unaffected by this change.
Operating system support
IBM's operating systems z/OS, z/VSE, z/TPF, and z/VM are versions of MVS, VSE, Transaction Processing Facility (TPF), and VM that support z/Architecture. Older versions of z/OS, z/VSE, and z/VM continued to support 32-bit systems; z/OS version 1.6 and later, z/VSE Version 4 and later, and z/VM Version 5 and later require z/Architecture.
Linux also supports z/Architecture with Linux on IBM Z.
z/Architecture supports running multiple concurrent operating systems and applications even if they use different address sizes. This allows software developers to choose the address size that is most advantageous for their applications and data structures.
On July 7, 2009, IBM on occasion of announcing a new version of one of its operating systems implicitly stated that Architecture Level Set 4 (ALS 4) exists, and is implemented on the System z10 and subsequent machines. The ALS 4 is also specified in LOADxx as ARCHLVL 3, whereas the earlier z900, z800, z990, z890, System z9 specified ARCHLVL 2. Earlier announcements of System z10 simply specified that it implements |
https://en.wikipedia.org/wiki/WXSP-CD | WXSP-CD (channel 15) is a low-power, Class A television station licensed to Grand Rapids, Michigan, United States, serving West Michigan as an affiliate of MyNetworkTV. It is owned by Nexstar Media Group alongside Grand Rapids–licensed NBC affiliate WOOD-TV (channel 8) and Battle Creek–licensed ABC affiliate WOTV (channel 41). The stations share studios on College Avenue Southeast in the Heritage Hill section of Grand Rapids, while WXSP-CD's transmitter is located in Walker (along I-96). Another repeater station licensed to Grand Rapids, WOLP-CD (channel 35), utilizes and is co-located with WOOD-TV's transmitter southwest of Middleville.
History
The station signed on the air on July 23, 1986, as W29AD, broadcasting on UHF channel 29. It moved to UHF channel 15 and acquired the W15AM calls on January 12, 1988. In the station's early days, it was a translator for World Harvest Television from WHME-TV in South Bend, Indiana, which is owned by LeSEA Broadcasting (now Family Broadcasting Corporation). The station was then purchased by LIN TV, the owner of WOOD-TV, and converted to the station's Local Weather Station (LWS) format with the call sign WOWD-LP (variation on WOOD-TV). WOWD and its low-power network of repeaters aired 24-hour weather information direct from WOOD-TV's weather center, including current conditions and severe weather coverage. This was in an early pre-digital format comparable to the now defunct NBC Weather Plus.
The weather programming aired from the mid-1990s until it switched to a general entertainment programming format a few years later. It featured graphic displays of various current conditions and forecasts as well as periodic forecast segments from WOOD-TV's meteorologists. Short commercial breaks would feature promotional advertising for WOOD-TV's news and entertainment programming, as well as LWS' station identification. A format change took place when it became a UPN affiliate on August 31, 1999 (displacing that network from secondary |
https://en.wikipedia.org/wiki/Symlink%20race | A symlink race is a kind of software security vulnerability that results from a program creating files in an insecure manner. A malicious user can create a symbolic link to a file not otherwise accessible to them. When the privileged program creates a file of the same name as the symbolic link, it actually creates the linked-to file instead, possibly inserting content desired by the malicious user (see example below), or even provided by the malicious user (as input to the program).
It is called a "race" because in its typical manifestation, the program checks to see if a file by that name already exists; if it does not exist, the program then creates the file. An attacker must create the link in the interval between the check and when the file is created.
A symlink race can happen with antivirus products that decide they will quarantine or delete a suspicious file, and then go ahead and do that. During the interval between decision and action, malicious software can replace the suspicious file with a system or antivirus file that the malicious software wants overwritten.
Example
In this naive example, the Unix program foo is setuid. Its function is to retrieve information for the accounts specified by the user. For "efficiency", it sorts the requested accounts into a temporary file (/tmp/foo naturally) before making the queries.
The directory /tmp is world-writable. Malicious user Mallory creates a symbolic link to the file /root/.rhosts named /tmp/foo. Then, Mallory invokes foo with user as the requested account. The program creates the (temporary) file /tmp/foo (really creating /root/.rhosts) and puts information about the requested account (e.g. user password) in it. It removes the temporary file (merely removing the symbolic link).
Now the /root/.rhosts contains password information, which (if it even happens to be in the proper format) is the incantation necessary to allow anyone to use rlogin to log into the computer as the superuser.
Also in some Unix- |
https://en.wikipedia.org/wiki/Devocalization | Devocalization (also known as ventriculocordectomy or vocal cordectomy; when performed on a dog debarking or bark softening; when performed on a cat demeowing or meow softening) is a surgical procedure where tissue is removed from the vocal cords.
Indications and contraindications
Devocalization is usually performed at the request of an animal owner (where the procedure is legally permitted). The procedure may be forcefully requested as a result of a court order. Owners or breeders generally request the procedure because of excessive animal vocalizations, complaining neighbors, or as an alternative to euthanasia due to a court order.
Contraindications include negative reaction to anesthesia, infection, bleeding, and pain. There is also the possibility that the removed tissue will grow back, or of scar tissue blocking the throatboth cases requiring further surgeriesthough with the incisional technique the risk of fibrosis is virtually eliminated.
Effectiveness
The devocalization procedure does not take away a dog's ability to bark. Dogs will normally bark just as much as before the procedure. After the procedure, the sound will be softer, typically about half as loud as before, or less, and it is not as sharp or piercing.
Most devocalized dogs have a subdued "husky" bark, audible up to 20 metres.
Procedure
The surgery may be performed via the animal's mouth, with a portion of the vocal folds removed using a biopsy punch, cautery tool, scissor, or laser. The procedure may also be performed via an incision in the throat and through the larynx, which is a more invasive technique. All devocalization procedures require general anesthesia.
Reasons for excessive vocalization
Chronic, excessive vocalization may be due to improper socialization or training, stress, boredom, fear, or frustration. Up to 35% of dog owners report problems with barking, which can cause disputes and legal problems. The behavior is more common among some breeds of dog, such as the Shetland She |
https://en.wikipedia.org/wiki/Grease%20gun | A grease gun is a common workshop and garage tool used for lubrication. The purpose of the grease gun is to apply lubricant through an aperture to a specific point, usually from a grease cartridge to a grease fitting or 'nipple'. The channels behind the grease nipple lead to where the lubrication is needed. The aperture may be of a type that fits closely with a receiving aperture on any number of mechanical devices. The close fitting of the apertures ensures that lubricant is applied only where needed. There are four types of grease gun:
Hand-powered, where the grease is forced from the aperture by back-pressure built up by hand-cranking the trigger mechanism of the gun, which applies pressure to a spring mechanism behind the lubricant, thus forcing grease through the aperture.
Hand-powered, where there is no trigger mechanism, and the grease is forced through the aperture by the back-pressure built up by pushing on the butt of the grease gun, which slides a piston through the body of the tool, pumping grease out of the aperture.
Air-powered (pneumatic), where compressed air is directed to the gun by hoses, the air pressure serving to force the grease through the aperture. Russell Gray, inventor of the air-powered grease gun, founded Graco based on this invention.
Electric, where an electric motor drives a high pressure grease pump. These are often battery-powered for portability.
The grease gun is charged or loaded with any of the various types of lubricants, but usually a thicker heavier type of grease is used.
It was a close resemblance to contemporary hand-powered grease guns that gave the nickname to the World War II-era M3 submachine gun.
See also
Grease gun injury
Drum pump |
https://en.wikipedia.org/wiki/Musikalisches%20W%C3%BCrfelspiel | A (German for "musical dice game") was a system for using dice to randomly generate music from precomposed options. These games were quite popular throughout Western Europe in the 18th century. Several different games were devised, some that did not require dice, but merely choosing a random number.
The earliest example is Johann Kirnberger's (German for "The Ever-Ready Minuet and Polonaise Composer") (1757 [1st edition; revised 2nd 1783]). Examples by well known composers include C. P. E. Bach's (German for "A method for making six bars of double counterpoint at the octave without knowing the rules") (1758) and Maximilian Stadler's (French for "A table for composing minuets and trios to infinity, by playing with two dice") (1780).
In the early 20th century the Kaleidacousticon System, using arbitrarily combinable playing cards, was unsuccessfully marketed in the Boston area as a parlour game.
Aesthetics
According to Lawrence Zbikowski, "In truth, chance played little part in the success of the music produced by such games. Instead, what was required of the compilers...[was] a little knowledge about how to put the game together and an understanding of the formal design of waltzes, etc."
According to Stephen Hedges, "The 'galant' middle class in Europe was playing with mathematics. In this atmosphere of investigation and cataloguing, a systematic device that would seem to make it possible for anyone to write music was practically guaranteed popularity.<ref>Hedges, Stephen A. (1978). "Dice Music in the Eighteenth Century", pp. 184–185, Music & Letters, vol. 59, pp. 180–187. Quoted in Berkowitz (2010), p. 65n60.</ref>
According to Leonard Meyer, "Eighteenth-century composers constructed musical dice games while nineteenth century composers did not. ... [W]hat constrained the choice of figures [in seventeenth- and eighteenth-century music] were the claims of taste, coherent expression and propriety, given the genre of work being composed, rather than the inner |
https://en.wikipedia.org/wiki/Polly%20and%20Molly | Polly and Molly (born 1997), two ewes, were the first mammals to have been successfully cloned from an adult somatic cell and to be transgenic animals at the same time. This is not to be confused with Dolly the Sheep, the first animal to be successfully cloned from an adult somatic cell where there wasn’t modification carried out on the adult donor nucleus. Polly and Molly, like Dolly the Sheep, were cloned at the Roslin Institute in Edinburgh, Scotland.
The creation of Polly and Molly built on the somatic nuclear transfer experiments that led to the cloning of Dolly the Sheep. The crucial difference was that in creating Polly and Molly, scientists used cells into which a new gene had been inserted. The gene chosen was a therapeutic protein to demonstrate the potential of such recombinant DNA technology combined with animal cloning. This could hopefully be used to produce pharmacological and therapeutic proteins to treat human diseases. The protein in question was the human blood clotting factor IX. Another difference from Dolly the Sheep was the source cell type of the nucleus that was transferred. Although Polly and Molly were nuclear clones, they had different mtDNA that was different from the nuclear cells where they received their DNA.
Prior to the production of Polly and Molly, the only demonstrated way to make a transgenic animal was by microinjection of DNA into the pronuclei of fertilized oocytes (eggs). However, only a small proportion of the animals will integrate the injected DNA into their genome. In the rare cases that they do integrate this new genetic information, the pattern of expression of the injected transgene's protein due to the random integration is very variable. As the aim of such research is to produce an animal that expresses a particular protein in high levels in, for example, its milk, microinjection is a very costly procedure that does not usually produce the desired animal.
In mice, there is an additional option for genetic transfe |
https://en.wikipedia.org/wiki/Scientific%20drilling | Scientific drilling into the Earth is a way for scientists to probe the Earth's sediments, crust, and upper mantle. In addition to rock samples, drilling technology can unearth samples of connate fluids and of the subsurface biosphere, mostly microbial life, preserved in drilled samples. Scientific drilling is carried out on land by the International Continental Scientific Drilling Program (ICDP) and at sea by the Integrated Ocean Drilling Program (IODP). Scientific drilling on the continents includes drilling down into solid ground as well as drilling from small boats on lakes. Sampling thick glaciers and ice sheets to obtain ice cores is related but will not be described further here.
Like probes sent into outer space, scientific drilling is a technology used to obtain samples from places that people cannot reach. Human beings have descended as deep as 2,212 m (7,257 ft) in Veryovkina Cave, the world's deepest known cave, located in the Caucasus mountains of the country of Georgia. Gold miners in South Africa regularly go deeper than 3,400 m, but no human has ever descended to greater depths than this below the Earth's solid surface. As depth increases into the Earth, temperature and pressure rise. Temperatures in the crust increase about 15 °C per kilometer, making it impossible for humans to exist at depths greater than several kilometers, even if it was somehow possible to keep shafts open in spite of the tremendous pressure.
Scientific drilling is interdisciplinary and international in scope. Individual scientists cannot generally undertake scientific drilling projects alone. Teamwork between scientists, engineers, and administrators is often required for success in planning and in carrying out a drilling project, analyzing the samples, and interpreting and publishing the results in scientific journals.
Purposes
Scientific drilling is used to address a wide range of problems, which cannot be addressed using rocks exposed on the surface or the seafloor. T |
https://en.wikipedia.org/wiki/Real-time%20clock%20alarm | A real time clock alarm is a feature that can be used to allow a computer to 'wake up' after shut down to execute tasks every day or on a certain day. It can sometimes be found in the 'Power Management' section of a motherboard's BIOS/UEFI setup. Wake On LAN, Wake on ring, and IPMI functions could also be used to start a computer after it is turned off.
In Linux, the real time clock alarm can be set or retrieved using /proc/acpi/alarm or /sys/class/rtc/rtc0/wakealarm. Alternatively the rtcwake utility may be used which prevents problems when using local time instead of UTC by automatically processing the /etc/adjtime file. systemd can be used to wake a system and run a task at a specific time.
In Microsoft Windows there are different programs which could be used to 'wake up' a computer from standby or hibernation. Task Scheduler settings for power management can be used to 'Wake the computer to run this task'. |
https://en.wikipedia.org/wiki/Sentences%20of%20Sextus | The Sentences of Sextus, also called the Sayings of Sextus, is a Hellenistic Pythagorean collection of maxims which was popular among Christians and translated into several languages. The identity of the Sextus who originated the collection is unknown.
Transmission
The Sentences was probably compiled in the second century AD. The original collection was pagan. It was later modified to reflect a Christian viewpoint, although there are no explicit references to Jesus.
The earliest mention of the Sentences is by Origen in the mid third century. Origen quotes Sextus on self-castration, a widespread habit among ascetic early Christians, which Origen deplores, and mentions in passing that the work is one "that many considered to be tested by time."
A Latin translation was made from the original Greek by Rufinus of Aquileia under the title Anulus around 400. A partial Coptic translation was discovered in one of the books of the New Testament apocrypha recovered from the Nag Hammadi library in 1945. A Syriac translation is also known, its title translates Dicta Selecta Sancti Xysti Episcopi Romani ('select sayings of Saint Xystus, Roman bishop').
Authorship
The identity of Sextus has been disputed for a long time. The identification with Pope Xystus II (), current by the time of the Latin and Syriac translations, is denied by Jerome, who calls the author Sextus Pythagoreus. Such attributions to important figures, which happened frequently, were usually attempts to give the works more authority.
One possible author of the Sentences is Quintus Sextius, a Roman philosopher who combined Stoicism with Pythagoreanism, and who lived in the 1st century BC.
Contents
The work is similar to the sayings gospels called the Gospel of Phillip and the Gospel of Thomas in that it is purely a collection of sayings, with no bridging framework. Unlike the Christian sayings gospels, the wisdom comes from a man named Sextus rather than Jesus. Sextus appears to have been a Pythagorean. Ther |
https://en.wikipedia.org/wiki/Advanced%20Microcontroller%20Bus%20Architecture | The Arm Advanced Microcontroller Bus Architecture (AMBA) is an open-standard, on-chip interconnect specification for the connection and management of functional blocks in system-on-a-chip (SoC) designs. It facilitates development of multi-processor designs with large numbers of controllers and components with a bus architecture. Since its inception, the scope of AMBA has, despite its name, gone far beyond microcontroller devices. Today, AMBA is widely used on a range of ASIC and SoC parts including applications processors used in modern portable mobile devices like smartphones. AMBA is a registered trademark of Arm Ltd.
AMBA was introduced by Arm in 1996. The first AMBA buses were the Advanced System Bus (ASB) and the Advanced Peripheral Bus (APB). In its second version, AMBA 2 in 1999, Arm added AMBA High-performance Bus (AHB) that is a single clock-edge protocol. In 2003, Arm introduced the third generation, AMBA 3, including Advanced eXtensible Interface (AXI) to reach even higher performance interconnect and the Advanced Trace Bus (ATB) as part of the CoreSight on-chip debug and trace solution. In 2010 the AMBA 4 specifications were introduced starting with AMBA 4 AXI4, then in 2011 extending system-wide coherency with AMBA 4 AXI Coherency Extensions (ACE). In 2013 the AMBA 5 Coherent Hub Interface (CHI) specification was introduced, with a re-designed high-speed transport layer and features designed to reduce congestion. These protocols are today the de facto standard for embedded processor bus architectures because they are well documented and can be used without royalties.
Design principles
An important aspect of an SoC is not only which components or blocks it houses, but also how they interconnect. AMBA is a solution for the blocks to interface with each other.
The objective of the AMBA specification is to:
facilitate right-first-time development of embedded microcontroller products with one or more CPUs, GPUs or signal processors,
be technology inde |
https://en.wikipedia.org/wiki/ARexx | ARexx is an implementation of the Rexx language for the Amiga, written in 1987 by William S. Hawes, with a number of Amiga-specific features beyond standard REXX facilities. Like most REXX implementations, ARexx is an interpreted language. Programs written for ARexx are called "scripts", or "macros"; several programs offer the ability to run ARexx scripts in their main interface as macros.
ARexx can easily communicate with third-party software that implements an "ARexx port". Any Amiga application or script can define a set of commands and functions for ARexx to address, thus making the capabilities of the software available to the scripts written in ARexx.
ARexx can direct commands and functions to several applications from the same script, thus offering the opportunity to mix and match functions from the different programs. For example, an ARexx script could extract data from a database, insert the data into a spreadsheet to perform calculations on it, then insert tables and charts based on the results into a word processor document.
History
ARexx was first created in 1987, developed for the Amiga by William S. Hawes. It is based on the REXX language described by Mike Cowlishaw in the book The REXX Language: A Practical Approach to Programming. ARexx was included by Commodore with AmigaOS 2.0 in 1990, and has been included with all subsequent AmigaOS releases. This later version of ARexx follows the official REXX language closely; Hawes was later involved in drafting the ANSI standard for REXX.
ARexx is written in 68000 Assembly, and cannot therefore function at full speed with new PPC CPUs, a version of ARexx has not been rewritten for them and is still missing from MorphOS 3.0. William Hawes is no longer involved in development of Amiga programs and no other Amiga-related firm is financing new versions of ARexx. Notwithstanding this fact, the existing version of ARexx continues to be used, although it is not distributed with MorphOS.
From the ARexx manual |
https://en.wikipedia.org/wiki/Vascular%20endothelial%20growth%20factor | Vascular endothelial growth factor (VEGF, ), originally known as vascular permeability factor (VPF), is a signal protein produced by many cells that stimulates the formation of blood vessels. To be specific, VEGF is a sub-family of growth factors, the platelet-derived growth factor family of cystine-knot growth factors. They are important signaling proteins involved in both vasculogenesis (the de novo formation of the embryonic circulatory system) and angiogenesis (the growth of blood vessels from pre-existing vasculature).
It is part of the system that restores the oxygen supply to tissues when blood circulation is inadequate such as in hypoxic conditions. Serum concentration of VEGF is high in bronchial asthma and diabetes mellitus.
VEGF's normal function is to create new blood vessels during embryonic development, new blood vessels after injury, muscle following exercise, and new vessels (collateral circulation) to bypass blocked vessels.
It can contribute to disease. Solid cancers cannot grow beyond a limited size without an adequate blood supply; cancers that can express VEGF are able to grow and metastasize. Overexpression of VEGF can cause vascular disease in the retina of the eye and other parts of the body. Drugs such as aflibercept, bevacizumab, ranibizumab, and pegaptanib can inhibit VEGF and control or slow those diseases.
History
In 1970, Judah Folkman et al. described a factor secreted by tumors causing angiogenesis and called it tumor angiogenesis factor. In 1983 Senger et al. identified a vascular permeability factor secreted by tumors in guinea pigs and hamsters. In 1989 Ferrara and Henzel described an identical factor in bovine pituitary follicular cells which they purified, cloned and named VEGF. A similar VEGF alternative splicing was discovered by Tischer et al. in 1991. Between 1996 and 1997, Christinger and De Vos obtained the crystal structure of VEGF, first at 2.5 Å resolution and later at 1.9 Å.
Fms-like tyrosine kinase-1 (flt-1) was sh |
https://en.wikipedia.org/wiki/Ecohydrology | Ecohydrology (from Greek , oikos, "house(hold)"; , hydōr, "water"; and , -logia) is an interdisciplinary scientific field studying the interactions between water and ecological systems. It is considered a sub discipline of hydrology, with an ecological focus. These interactions may take place within water bodies, such as rivers and lakes, or on land, in forests, deserts, and other terrestrial ecosystems. Areas of research in ecohydrology include transpiration and plant water use, adaption of organisms to their water environment, influence of vegetation and benthic plants on stream flow and function, and feedbacks between ecological processes, the soil carbon sponge and the hydrological cycle.
Key concepts
The hydrologic cycle describes the continuous movement of water on, above, and below the surface on the earth. This flow is altered by ecosystems at numerous points. Transpiration from plants provides the majority of flow of water to the atmosphere. Water is influenced by vegetative cover as it flows over the land surface, while river channels can be shaped by the vegetation within them. Ecohydrology was developed under the International Hydrological Program of UNESCO.
Ecohydrologists study both terrestrial and aquatic systems. In terrestrial ecosystems (such as forests, deserts, and savannas), the interactions among vegetation, the land surface, the vadose zone, and the groundwater are the main focus. In aquatic ecosystems (such as rivers, streams, lakes, and wetlands), emphasis is placed on how water chemistry, geomorphology, and hydrology affect their structure and function.
Principles
The general assumptions of ecological hydrology is to decrease ecosystem degradation using concepts that integrate terrestrial and aquatic processes across scales. The principles of Ecohydrology are expressed in three sequential components:
Hydrological (Framework): The quantification of the hydrological cycle of a basin, should be a template for functional integration of h |
https://en.wikipedia.org/wiki/Frederick%20John%20Jackson | Sir Frederick John Jackson, (17 February 1860 – 3 February 1929) was an English administrator, explorer and ornithologist.
Early years
Jackson was born at Oran Hall, near Catterick, North Yorkshire in 1860. He attended Shrewsbury School and then Jesus College, Cambridge.
In 1884 he went to Africa on a shooting trip, joining J. G. Haggard, the British consul at Lamu. On this trip he explored the coast of what is now Kenya, the Tana River and Mount Kilimanjaro. As well as shooting big game, he collected birds and butterflies. Soon after the 1886 treaty was signed to delimit the German and British spheres of influence in East Africa he joined the Imperial British East Africa Company (IBEAC).
Administrator
In 1889 Jackson led an IBEAC expedition that included his friend and fellow explorer Arthur Neumann in the party designed to open up the regions between Mombasa and Lake Victoria, which was largely unknown to Europeans at that time, and if possible to obtain news of Emin Pasha. At Kavirondo he received a letter from King Mwanga II of Buganda in Uganda describing a state of great confusion there owing to rivalry between different Christian factions. He went north, exploring the country beyond Mount Elgon. On his return to Kavirondo he found that the German Karl Peters had passed him and raised the German flag, which he pulled down. He went on to Uganda where he found the Baganda uncertain about whether to accept an IBEAC administration. The decision was made for them by the Heligoland treaty of 1900 in which Britain was given Uganda.
The British government took over the administration of British East Africa from IBEAC in 1894, and Jackson became an official. He was Lieutenant-Governor of the East African Protectorate (1907–1911) and Governor of Uganda (1911–1917).
He was appointed a Companion of the Order of the Bath (CB) for services during the mutiny of Sudanese troops in Uganda in 1898. For his administrative work he was appointed a Companion of the Order of |
https://en.wikipedia.org/wiki/PUREX | PUREX (plutonium uranium reduction extraction) is a chemical method used to purify fuel for nuclear reactors or nuclear weapons. PUREX is the de facto standard aqueous nuclear reprocessing method for the recovery of uranium and plutonium from used nuclear fuel (spent nuclear fuel, or irradiated nuclear fuel). It is based on liquid–liquid extraction ion-exchange.
PUREX is applied to spent nuclear fuel, which consists primarily of very high atomic-weight (actinoid or "actinide") elements (e.g. uranium, plutonium, americium) along with smaller amounts of material composed of lighter atoms, notably the fission products produced by reactor operation.
The actinoid elements in this case consist primarily of the unconsumed remains of the original fuel (typically U-235, U-238, and/or Pu-239).
Chemical process
The fuel is first dissolved in nitric acid at a concentration around 7 M. Solids are removed by filtration to avoid the formation of emulsions, referred to as third phases in the solvent extraction community.
The organic solvent consists of 30% tributyl phosphate (TBP) in a hydrocarbon such as kerosene. Uranyl(VI) ions are extracted in the organic phase as UO2(NO3)2·2TBP complexes; plutonium is extracted as similar complexes. The heavier actinides, primarily americium and curium, and the fission products remain in the aqueous phase. The nature of uranyl nitrate complexes with trialkyl phosphates has been characterized.
Plutonium is separated from uranium by treating the TBP-kerosene solution with reducing agents to convert the plutonium to its +3 oxidation state, which will pass into the aqueous phase. Typical reducing agents include N,N-diethyl-hydroxylamine, ferrous sulphamate, and hydrazine. Uranium is then stripped from the kerosene solution by back-extraction into nitric acid at a concentration around 0.2 M.
PUREX raffinate
The term PUREX raffinate describes the mixture of metals in nitric acid which are left behind when the uranium and plutonium have bee |
https://en.wikipedia.org/wiki/The%20Tao%20of%20Programming | The Tao of Programming is a book written in 1987 by Geoffrey James. Written in a tongue-in-cheek style spoof of classic Taoist texts such as the Tao Te Ching and Zhuangzi which belies its serious message, it consists of a series of short anecdotes divided into nine "books":
The Silent Void
The Ancient Masters
Design
Coding
Maintenance
Management
Corporate Wisdom
Hardware and Software
Epilogue
Geoffrey James wrote two other books on this theme, The Zen of Programming (978-0931137099) in 1988 and Computer Parables: Enlightenment in the Information Age (978-0931137136) in 1989.
See also
Hacker koan |
https://en.wikipedia.org/wiki/Lothar%20Collatz | Lothar Collatz (; July 6, 1910 – September 26, 1990) was a German mathematician, born in Arnsberg, Westphalia.
The "3x + 1" problem is also known as the Collatz conjecture, named after him and still unsolved. The Collatz–Wielandt formula for the Perron–Frobenius eigenvalue of a positive square matrix was also named after him.
Collatz's 1957 paper with Ulrich Sinogowitz, who had been killed in the bombing of Darmstadt in World War II, founded the field of spectral graph theory.
Biography
Collatz studied at universities in Germany including the University of Greifswald and the University of Berlin, where he was supervised by Alfred Klose, receiving his doctorate in 1935 for a dissertation entitled Das Differenzenverfahren mit höherer Approximation für lineare Differentialgleichungen (The finite difference method with higher approximation for linear differential equations). He then worked as an assistant at the University of Berlin, before moving to the Technical University of Karlsruhe in 1935 where he remained through 1937. From 1938 to 1943, he worked as a Privatdozent in Karlsruhe. In the war years he worked with Alwin Walther at the Institute for Practical Mathematics of the Technische Hochschule Darmstadt.
From 1943 to 1952, Collatz held a chair at the Technical University of Hannover. From 1952 until his retirement in 1978, Collatz worked at the University of Hamburg, where he founded the Institute of Applied Mathematics in 1953. After retirement as professor emeritus, he continued to be very active at mathematical conferences.
For his many contributions to the field, Collatz had many honors bestowed upon him in his lifetime, including:
election to the Academy of Sciences Leopoldina, the Academy of Sciences of the Institute of Bologna, and the Academy at Modena in Italy
honorary member of the Hamburg Mathematical Society
honorary degrees from the University of São Paulo, the Technical University of Vienna, the University of Dundee in Scotland, Brunel Un |
https://en.wikipedia.org/wiki/Parsons%20code | The Parsons code, formally named the Parsons code for melodic contours, is a simple notation used to identify a piece of music through melodic motion – movements of the pitch up and down. Denys Parsons developed this system for his 1975 book The Directory of Tunes and Musical Themes. Representing a melody in this manner makes it easier to index or search for pieces, particularly when the notes' values are unknown. Parsons covered around 15,000 classical, popular and folk pieces in his dictionary. In the process he found out that *UU is the most popular opening contour, used in 23% of all the themes, something that applies to all the genres.
The book was also published in Germany in 2002 and reissued by Piatkus in 2008 as the Directory of Classical Themes.
An earlier method of classifying and indexing melody was devised by Harold Barlow and Sam Morgenstern in A Dictionary of Musical Themes (1950).
The code
The first note of a melody is denoted with an asterisk (*), although some Parsons code users omit the first note. All succeeding notes are denoted with one of three letters to indicate the relationship of its pitch to the previous note:
* = first tone as reference,
u = "up", for when the note is higher than the previous note,
d = "down", for when the note is lower than the previous note,
r = "repeat", for when the note has the same pitch as the previous note.
Some examples
"Twinkle Twinkle Little Star": *
"Silent Night": *
"Aura Lea" ("Love Me Tender"): *
"White Christmas": *
First verse in Madonna's "Like a Virgin": *
See also
List of music software |
https://en.wikipedia.org/wiki/Bioindicator | A bioindicator is any species (an indicator species) or group of species whose function, population, or status can reveal the qualitative status of the environment. The most common indicator species are animals. For example, copepods and other small water crustaceans that are present in many water bodies can be monitored for changes (biochemical, physiological, or behavioural) that may indicate a problem within their ecosystem. Bioindicators can tell us about the cumulative effects of different pollutants in the ecosystem and about how long a problem may have been present, which physical and chemical testing cannot.
A biological monitor or biomonitor is an organism that provides quantitative information on the quality of the environment around it. Therefore, a good biomonitor will indicate the presence of the pollutant and can also be used in an attempt to provide additional information about the amount and intensity of the exposure.
A biological indicator is also the name given to a process for assessing the sterility of an environment through the use of resistant microorganism strains (e.g. Bacillus or Geobacillus). Biological indicators can be described as the introduction of a highly resistant microorganisms to a given environment before sterilization, tests are conducted to measure the effectiveness of the sterilization processes. As biological indicators use highly resistant microorganisms, any sterilization process that renders them inactive will have also killed off more common, weaker pathogens.
Overview
A bioindicator is an organism or biological response that reveals the presence of pollutants by the occurrence of typical symptoms or measurable responses and is, therefore, more qualitative.
These organisms (or communities of organisms) can be used to deliver information on alterations in the environment or the quantity of environmental pollutants by changing in one of the following ways: physiologically, chemically or behaviourally.
The information ca |
https://en.wikipedia.org/wiki/Lock-in%20amplifier | A lock-in amplifier is a type of amplifier that can extract a signal with a known carrier wave from an extremely noisy environment. Depending on the dynamic reserve of the instrument, signals up to a million times smaller than noise components, potentially fairly close by in frequency, can still be reliably detected. It is essentially a homodyne detector followed by low-pass filter that is often adjustable in cut-off frequency and filter order.
The device is often used to measure phase shift, even when the signals are large, have a high signal-to-noise ratio and do not need further improvement.
Recovering signals at low signal-to-noise ratios requires a strong, clean reference signal with the same frequency as the received signal. This is not the case in many experiments, so the instrument can recover signals buried in the noise only in a limited set of circumstances.
The lock-in amplifier is commonly believed to have been invented by Princeton University physicist Robert H. Dicke who founded the company Princeton Applied Research (PAR) to market the product. However, in an interview with Martin Harwit, Dicke claims that even though he is often credited with the invention of the device, he believes that he read about it in a review of scientific equipment written by Walter C. Michels, a professor at Bryn Mawr College. This could have been a 1941 article by Michels and Curtis, which in turn cites a 1934 article by C. R. Cosens, while another timeless article was written by C. A. Stutt in 1949.
Whereas traditional lock-in amplifiers use analog frequency mixers and RC filters for the demodulation, state-of-the-art instruments have both steps implemented by fast digital signal processing, for example, on an FPGA. Usually sine and cosine demodulation is performed simultaneously, which is sometimes also referred to as dual-phase demodulation. This allows the extraction of the in-phase and the quadrature component that can then be transferred into polar coordinates, i. |
https://en.wikipedia.org/wiki/Atomic%20coherence | Atomic coherence is the induced coherence between levels of a multi-level atomic system.
Examples
Rabi Flopping
If an electron in a two level atomic system is excited by narrow line width coherent electro-magnetic radiation, like a laser, that is on resonance with the two level transition, the electron will Rabi flop. During Rabi flopping the electron oscillates between the ground and excited states and can be described by a continuous rotation around the Bloch sphere.
For a perfectly isolated system the Rabi oscillation will continue indefinitely and will undergo no phase change, making it a "coherent state". In physical systems interactions between the system and the environment introduce an unknown phase in the Rabi oscillation between the two levels with respect to the Rabi oscillation in the perfectly isolated system causing "decoherence".
If instead of a single two-level system an ensemble of identical two level systems (such as a chain of identical atoms in an ion trap) is prepared and continuously addressed with a laser, all the atoms may begin to simultaneously Rabi flop. At the beginning all two level systems will have a defined relative phase relation (they will all be in phase) and the system will be coherent.
As atoms begin to undergo random spontaneous emission their Rabi oscillations will accumulate a random relative phase with respect to each other and become decoherent. In actual experiments ambient magnetic field noise and thermal heating from collisions between atoms cause decoherence faster than random spontaneous emission and are the dominant uncertainties when running atomic clocks or trapped ion quantum computers. Atomic coherence can also apply to multi-level systems which require more than a single laser.
Atomic coherence is essential in research on several effects, such as electromagnetically induced transparency (EIT), lasing without inversion (LWI),Stimulated raman adiabatic passage (STIRAP) and nonlinear optical interaction wit |
https://en.wikipedia.org/wiki/Vibrio%20parahaemolyticus | Vibrio parahaemolyticus (V. parahaemolyticus) is a curved, rod-shaped, Gram-negative bacterial species found in the sea and in estuaries which, when ingested, may cause gastrointestinal illness in humans. V. parahaemolyticus is oxidase positive, facultatively aerobic, and does not form spores. Like other members of the genus Vibrio, this species is motile, with a single, polar flagellum.
Pathogenesis
While infection can occur by the fecal-oral route, ingestion of bacteria in raw or undercooked seafood, usually oysters, is the predominant cause of the acute gastroenteritis caused by V. parahaemolyticus. Wound infections also occur, but are less common than seafood-borne disease. The disease mechanism of V. parahaemolyticus infections has not been fully elucidated.
Clinical isolates usually possess a pathogenicity island (PAI) on the second chromosome. The PAI can be acquired by horizontal gene transfer and contains genes for several virulence factors. Two fully sequenced variants exist of the V. parahaemolyticus PAI with distinctly different lineages. Each PAI variant contains a genetically distinct Type III Secretion System (T3SS), which is capable of injecting virulence proteins into host cells to disrupt host cell functions or cause cell death by apoptosis. The two known T3SS variants on V. parahaemolyticus chromosome 2 are known as T3SS2α and T3SS2β. These variants correspond to the two known PAI variants.
Aside from the T3SS, two genes encoding well-characterized virulence proteins are typically found on the PAI, the thermostable direct hemolysin gene (tdh) and/or the tdh-related hemolysin gene (trh). Strains possessing one or both of these hemolysins exhibit beta-hemolysis on blood agar plates. A distinct correlation seems to exist between presence of tdh, trh, and the two known T3SS variants: observations have shown T3SS2α correlating with tdh+/trh- strains, while T3SS2β correlates with tdh-/trh+ strains.
Signs and symptoms
The incubation period of about |
https://en.wikipedia.org/wiki/Toxoid | A toxoid is an inactivated toxin (usually an exotoxin) whose toxicity has been suppressed either by chemical (formalin) or heat treatment, while other properties, typically immunogenicity, are maintained. Toxins are secreted by bacteria, whereas toxoids are altered form of toxins; toxoids are not secreted by bacteria. Thus, when used during vaccination, an immune response is mounted and immunological memory is formed against the molecular markers of the toxoid without resulting in toxin-induced illness. Such a preparation is also known as an anatoxin. There are toxoids for prevention of diphtheria, tetanus and botulism.
Toxoids are used as vaccines because they induce an immune response to the original toxin or increase the response to another antigen since the toxoid markers and toxin markers are preserved. For example, the tetanus toxoid is derived from the tetanospasmin produced by Clostridium tetani. The latter causes tetanus and is vaccinated against by the DTaP vaccine. While patients may sometimes complain of side effects after a vaccine, these are associated with the process of mounting an immune response and clearing the toxoid, not the direct effects of the toxoid. The toxoid does not have virulence as the toxin did before inactivation.
Toxoids are also useful in the production of human antitoxins. Multiple doses of tetanus toxoid are used by many plasma centers in the United States for the development of highly immune persons for the production of human anti-tetanus immune globulin (tetanus immune globulin (TIG), HyperTet (c)), which has replaced horse serum-type tetanus antitoxin in most of the developed world.
Toxoids are also used in the production of conjugate vaccines. The highly antigenic toxoids help draw attention to weaker antigens such as polysaccharides found in the bacterial capsule.
List of toxoids |
https://en.wikipedia.org/wiki/TMPGEnc | TMPGEnc or TSUNAMI MPEG Encoder is a video transcoder software application primarily for encoding video files to VCD and SVCD-compliant MPEG video formats and was developed by Hiroyuki Hori and Pegasys Inc. TMPGEnc can also refer to the family of software video encoders created after the success of the original TMPGEnc encoder. These include: TMPGEnc Plus, TMPGEnc Free Version, TMPGenc Video Mastering Works, TMPGEnc Authoring Works, TMPGEnc MovieStyle and TMPGEnc MPEG Editor. TMPGEnc products run on Microsoft Windows.
The free trial version of TMPGEnc Video Mastering works has a 14-day time limit. The TMPGEnc Free Version has 30-day time limit for MPEG-2 encoding, MPEG-1 encoding is without limit, but it can be used only for non-commercial, personal or demonstration purposes.
History
The first beta versions of the TMPGEnc encoder were freely available in 2000 and 2001 and were known as Tsunami MPEG Encoder. The first "stable" version was TMPGEnc 2.00, released on 2001-11-01. In December 2001, sales of "TMPGEnc Plus" started in Japan. In January 2002, the "TMPGEnc Plus - English version" was released. In August 2002, TMPGEnc DVD Source Creator was released and bundled with Sony "Vaio" PC in Japan. In April 2003, "TMPGEnc DVD Author - English version" was released. In March 2005, Tsunami MPEG Video Encoder XPress was released. In August 2005, "TSUNAMI" and "TMPGEnc" were combined into one brand.
TMPGEnc Plus/TMPGEnc Free Version was often rated as one of the best-quality MPEG-1/MPEG-2 encoders, alongside Canopus ProCoder and Cinema Craft Encoder. The popularity of TMPGEnc encoders has spawned various other products and "TMPGEnc" is now used as a general brand name for products such TMPGEnc Authoring Works (a consumer-grade Blu-ray Disc, DVD, and DivX authoring tool), TMPGEnc MovieStyle (a video converter primarily for portable and set-top devices), and TMPGEnc MPEG Editor (an MPEG editing program). TMPGEnc Plus is currently still sold by Pegasys Inc., alongside T |
https://en.wikipedia.org/wiki/Feedback%20vertex%20set | In the mathematical discipline of graph theory, a feedback vertex set (FVS) of a graph is a set of vertices whose removal leaves a graph without cycles ("removal" means deleting the vertex and all edges adjacent to it). Equivalently, each FVS contains at least one vertex of any cycle in the graph. The feedback vertex set number of a graph is the size of a smallest feedback vertex set. The minimum feedback vertex set problem is an NP-complete problem; it was among the first problems shown to be NP-complete. It has wide applications in operating systems, database systems, and VLSI chip design.
Definition
The FVS decision problem is as follows:
INSTANCE: An (undirected or directed) graph and a positive integer .
QUESTION: Is there a subset with such that, when all vertices of and their adjacent edges are deleted from , the remainder is cycle-free?
The graph that remains after removing from is an induced forest (resp. an induced directed acyclic graph in the case of directed graphs). Thus, finding a minimum FVS in a graph is equivalent to finding a maximum induced forest (resp. maximum induced directed acyclic graph in the case of directed graphs).
NP-hardness
showed that the minimum FVS problem for directed graphs is NP-complete. The problem remains NP-complete on directed graphs with maximum in-degree and out-degree two, and on directed planar graphs with maximum in-degree and out-degree three.
Karp's reduction also implies the NP-completeness of the FVS problem on undirected graphs, where the problem stays NP-hard on graphs of maximum degree four. The FVS problem can be solved in polynomial time on graphs of maximum degree at most three.
Exact algorithms
The corresponding NP optimization problem of finding the size of a minimum feedback vertex set can be solved in time O(1.7347n), where n is the number of vertices in the graph. This algorithm actually computes a maximum induced forest, and when such a forest is obtained, its complement is a minimum |
https://en.wikipedia.org/wiki/Feedback%20arc%20set | In graph theory and graph algorithms, a feedback arc set or feedback edge set in a directed graph is a subset of the edges of the graph that contains at least one edge out of every cycle in the graph. Removing these edges from the graph breaks all of the cycles, producing a directed acyclic graph, an acyclic subgraph of the given graph. The feedback arc set with the fewest possible edges is the minimum feedback arc set and its removal leaves the maximum acyclic subgraph; weighted versions of these optimization problems are also used. If a feedback arc set is minimal, meaning that removing any edge from it produces a subset that is not a feedback arc set, then it has an additional property: reversing all of its edges, rather than removing them, produces a directed acyclic graph.
Feedback arc sets have applications in circuit analysis, chemical engineering, deadlock resolution, ranked voting, ranking competitors in sporting events, mathematical psychology, ethology, and graph drawing. Finding minimum feedback arc sets and maximum acyclic subgraphs is NP-hard; it can be solved exactly in exponential time, or in fixed-parameter tractable time. In polynomial time, the minimum feedback arc set can be approximated to within a polylogarithmic approximation ratio, and maximum acyclic subgraphs can be approximated to within a constant factor. Both are hard to approximate closer than some constant factor, an inapproximability result that can be strengthened under the unique games conjecture. For tournament graphs, the minimum feedback arc set can be approximated more accurately, and for planar graphs both problems can be solved exactly in polynomial time.
A closely related problem, the feedback vertex set, is a set of vertices containing at least one vertex from every cycle in a directed or undirected graph. In undirected graphs, the spanning trees are the largest acyclic subgraphs, and the number of edges removed in forming a spanning tree is the circuit rank.
Applications |
https://en.wikipedia.org/wiki/Clifton%20Fadiman | Clifton Paul "Kip" Fadiman (May 15, 1904 – June 20, 1999) was an American intellectual, author, editor, and radio and television personality. He began his work in radio, and switched to television later in his career.
Background
Born in Brooklyn, New York, Fadiman was a nephew of the emigree Ukrainian psychologist Boris Sidis and a first cousin of the child prodigy William James Sidis.
Fadiman grew up in Brooklyn. His mother worked as a nurse; his father, Isadore, immigrated from Russian empire in 1892 and worked as a druggist.
He attended Columbia College at Columbia University. One of his teachers was lifelong friend Mark Van Doren; his undergraduate contemporaries included Jacques Barzun, Mortimer Adler, Lionel Trilling, Herbert Solow, Arthur F. Burns, Frank S. Hogan, Louis Zukofsky and Whittaker Chambers. Though he entered with the Class of 1924, his graduation was delayed until 1925 because of financial constraints. Chambers clearly includes Fadiman in a group of ernste Menschen ["serious people"], whose ability to attend Columbia he attributes to "a struggle with a warping poverty impossible for those who have not glimpsed it to imagine it." He graduated Phi Beta Kappa.
Fadiman had ambitions to become a scholar, but at graduation, the chairman of the English Department told him, "We have room for only one Jew, and we have chosen Mr. Trilling."
Career
After graduation from Columbia, Fadiman taught English at the Ethical Culture High School (now known as the "Fieldston School") in the Bronx from 1925 to 1927.
Literature
Fadiman worked ten years for Simon & Schuster, ending as its chief editor. At his interview with Max Schuster (a fellow alumnus of Columbia), Fadiman pulled out a folder with a hundred ideas for books. Among Fadiman's original one hundred was to turn Robert Ripley's newspaper cartoon, Believe it or Not! into book form. The series has gone on to sell over 30 million copies.
While at Simon & Schuster, he started the translation career of W |
https://en.wikipedia.org/wiki/Wire%20drawing | Wire drawing is a metalworking process used to reduce the cross-section of a wire by pulling the wire through a single, or series of, drawing die(s). There are many applications for wire drawing, including electrical wiring, cables, tension-loaded structural components, springs, paper clips, spokes for wheels, and stringed musical instruments. Although similar in process, drawing is different from extrusion, because in drawing the wire is pulled, rather than pushed, through the die. Drawing is usually performed at room temperature, thus classified as a cold working process, but it may be performed at elevated temperatures for large wires to reduce forces.
Of the elemental metals, copper, silver, gold, and platinum are the most ductile and immune from many of the problems associated with cold working.
Process
The wire drawing process is quite simple in concept. The wire is prepared by shrinking the beginning of it, by hammering, filing, rolling or swaging, so that it will fit through the die; the wire is then pulled through the die. As the wire is pulled through the die, its volume remains the same, so as the diameter decreases, the length increases. Usually the wire will require more than one draw, through successively smaller dies, to reach the desired size. The American wire gauge scale is based on this. This can be done on a small scale with a draw plate, or on a large commercial scale using automated machinery. The process of wire drawing changes material properties due to cold working.
The area reduction in small wires is generally 15–25% and in larger wires is 20–45%. The exact die sequence for a particular job is a function of area reduction, input wire size and output wire size. As the area reduction changes, so does the die sequence.
Very fine wires are usually drawn in bundles. In a bundle, the wires are separated by a metal with similar properties, but with lower chemical resistance so that it can be removed after drawing. If the reduction in are |
https://en.wikipedia.org/wiki/Solomon%20W.%20Golomb | Solomon Wolf Golomb (; May 30, 1932 – May 1, 2016) was an American mathematician, engineer, and professor of electrical engineering at the University of Southern California, best known for his works on mathematical games. Most notably, he invented Cheskers (a hybrid between chess and checkers) in 1948. He also fully described polyominoes and pentominoes in 1953. He specialized in problems of combinatorial analysis, number theory, coding theory, and communications. Pentomino boardgames, based on his work, would go on to inspire Tetris.
Achievements
Golomb, a graduate of the Baltimore City College high school, received his bachelor's degree from Johns Hopkins University and master's and doctorate degree in mathematics from Harvard University in 1957 with a dissertation on "Problems in the Distribution of the Prime Numbers".
While working at the Glenn L. Martin Company he became interested in communications theory and began his work on shift register sequences. He spent his Fulbright year at the University of Oslo and then joined the Jet Propulsion Laboratory at Caltech, where he researched military and space communications. He joined the faculty of USC in 1963 and was awarded full tenure two years later.
Golomb pioneered the identification of the characteristics and merits of maximum length shift register sequences, also known as pseudorandom or pseudonoise sequences, which have extensive military, industrial and consumer applications. Today, millions of cordless and cellular phones employ pseudorandom direct-sequence spread spectrum implemented with shift register sequences. His efforts made USC a center for communications research.
Golomb was the inventor of Golomb coding, a form of entropy encoding. Golomb rulers, used in astronomy and in data encryption, are also named for him, as is one of the main generation techniques of Costas arrays, the Lempel-Golomb generation method.
He was a regular columnist, writing Golomb's Puzzle Column in the IEEE Information |
https://en.wikipedia.org/wiki/Phytosterol | Phytosterols are phytosteroids, similar to cholesterol, that serve as structural components of biological membranes of plants. They encompass plant sterols and stanols. More than 250 sterols and related compounds have been identified. Free phytosterols extracted from oils are insoluble in water, relatively insoluble in oil, and soluble in alcohols.
Phytosterol-enriched foods and dietary supplements have been marketed for decades. Despite well-documented LDL cholesterol-lowering effects from long-term consumption of phytosterols, there is insufficient evidence for an effect on cardiovascular diseases, fasting blood sugar, glycated hemoglobin, or overall mortality rate.
Structure
They have a fused polycyclic structure and vary in carbon side chains and / or presence or absence of a double bond (saturation). They are divided into 4,4-dimethyl phytosterols, 4-monomethyl phytosterols, and 4-desmethyl phytosterols based on the location of methyl groups at the carbon-4 position. Stanols are saturated sterols, having no double bonds in the sterol ring structure.
The molecule in the article lead is β-sitosterol. The nomenclature is shown on the right.
By removing carbon 242, campesterol is obtained.
By removing carbons 241 and 242, cholesterol is obtained.
Removing a hydrogen from carbons 22 and 23 yields stigmasterol (stigmasta-5,22-dien-3β-ol).
By hydrogenating the double bond between carbons 5 and 6, β-sitostanol (Stigmastanol) is obtained.
By hydrogenating the double bond between carbons 5 and 6 and removing carbon 242, campestanol is obtained.
Removing carbon 242 and hydrogens from carbons 22 and 23, and inverting the stereochemistry at C-24 yields brassicasterol (ergosta-5,22-dien-3β-ol).
Further removal of hydrogens from carbons 7 and 8 from brassicasterol yields ergosterol (ergosta-5,7,22-trien-3β-ol). Important: Ergosterol is not a plant sterol. Ergosterol is a component of fungal cell membranes, serving the same function in fungi that cholesterol serves in ani |
https://en.wikipedia.org/wiki/SQR | SQR (Hyperion SQR Production Reporting, Part of OBIEE) is a programming language designed for generating reports from database management systems. The name is an abbreviation of Structured Query Reporter, which suggests its relationship to SQL (Structured Query Language). Any SQL statement can be embedded in an SQR program.
History
In the early 80's SQR was a 'free' add-on to Gupta's SQLBase. At the time SQLBase was the only relational database that ran on IBM PCs (x86) machines. SQR was written by Israel Stern in Cleveland, Ohio, probably around 1984 or 1985.
SQ Software created SQR in the mid 1980s. It had a marketing agreement with D & N Systems, which changed its name to SQL Solutions and was later acquired by Sybase Inc in the early 1990s. To avoid competing directly with Oracle Corporation, Sybase had a marketing and development agreement with MITI for the Oracle database compatible versions of SQR. MITI acquired the full rights to SQR in the mid-1990s. MITI changed its name to SQRiBE Technologies in 1997. Brio Technology acquired SQRiBE in August, 1999. Brio Technology later changed its name to Brio Software. Brio licensed its source code to PeopleSoft Inc. sometime around 2000. Hyperion Solutions Corporation acquired Brio Software in October, 2003. Oracle Corporation acquired PeopleSoft in December, 2004. In March 2007, Oracle Corporation acquired Hyperion Solutions.
SQR-Related Products
ORACLE: Hyperion SQR Production Reporting - System 9 (Release 9.3.1, 2008);
ORACLE: Hyperion SQR Production Reporting - System 11 (Release 11.1.2, 2010);
ORACLE: PeopleSoft Enterprise Tools & Technology (PeopleTools, Release 8.52, 2011)
General Components
SQR Server
SQR Viewer
SQR Print
SQR Execute
SQR Workbench for Windows; SQR Developer
Features
SQR is notable for its database and printing functions. It can embed any SQL statement almost anywhere in a program. One configuration of SQR can access multidimensional databases such as Essbase. It can comb |
https://en.wikipedia.org/wiki/Digital%20paper | Digital paper, also known as interactive paper, is patterned paper used in conjunction with a digital pen to create handwritten digital documents. The printed dot pattern uniquely identifies the position coordinates on the paper. The digital pen uses this pattern to store handwriting and upload it to a computer.
The paper
The dot pattern is a two-dimensional barcode; the most common is the proprietary Anoto dot pattern. In the Anoto dot pattern, the paper is divided into a grid with a spacing of about 0.3 mm, a dot is printed near each intersection offset slightly in one of four directions, a camera in the pen typically records a 6 x 6 groups of dots. The full pattern is claimed to consist of 669,845,157,115,773,458,169 dots, and to encompass an area exceeding 4.6 million km² (this corresponds to 73 trillion unique sheets of letter-size paper).
The complete pattern space is divided into various domains. These domains can be used to define paper types, or to indicate the paper's purpose (for example, memo formatting, personal planners, notebook paper, Post-it notes, et cetera).
The Anoto dot pattern can be printed onto almost any paper, using a standard printing process of at least 600 dpi resolution (some claim a required resolution of 1,000 dpi),
and carbon-based black ink. The paper can be any shape or size greater than 2 mm to a side. The ink absorbs infrared light transmitted from the digital pen; the pen contains a receiver that interprets the pattern of light reflected from the paper. Other colors of ink, including non-carbon-based black, can be used to print information that will be visible to the user, and invisible to the pen.
Standard black and white laser printers or color laser printers with a resolution of 600 dpi can be used to print the Anoto dot pattern.
With a typical CMYK color laser printer, it's possible use full-color text and graphics that cover the entire page by avoiding using black (i.e., under color removal is turned off) and instead u |
https://en.wikipedia.org/wiki/Ambipolar%20diffusion | Ambipolar diffusion (ambipolar: relating to or consisting of both electrons and positive ions moving in opposite directions) is diffusion of positive and negative species with opposite electrical charge due to their interaction via an electric field. In the case of ionic crystals, the fluxes of the diffusing species are coupled, while in a plasma the various species diffuse at the same rate.
Diffusion in plasmas
In plasma physics, ambipolar diffusion is closely related to the concept of quasineutrality. In most plasmas, the forces acting on the ions are different from those acting on the electrons, so naively one would expect one species to be transported faster than the other, whether by diffusion or convection or some other process. If such differential transport has a divergence, then it results in a change of the charge density. The latter will in turn create an electric field that can alter the transport of one or both species in such a way that they become equal.
The simplest example is a plasma localized in an unmagnetized vacuum. (See Inertial confinement fusion.) Both electrons and ions will stream outward with their respective thermal velocity. If the ions are relatively cold, their thermal velocity will be small. The thermal velocity of the electrons will be fast due to their high temperature and low mass: . As the electrons leave the initial volume, they will leave behind a positive charge density of ions, which will result in an outwardly-directed electric field. This field will act on the electrons to slow them down and on the ions to speed them up. The net result is that both ions and electrons stream outward at the speed of sound, , which is much smaller than the electron thermal velocity, but usually much larger than the ion thermal velocity.
In astrophysics, "ambipolar diffusion" refers specifically to the decoupling of neutral particles from plasma, for example in the initial stage of star formation. The neutral particles in this case are mo |
https://en.wikipedia.org/wiki/Dynamic%20Data%20Exchange | In computing, Dynamic Data Exchange (DDE) is a technology for interprocess communication used in early versions of Microsoft Windows and OS/2. DDE allows programs to manipulate objects provided by other programs, and respond to user actions affecting those objects. DDE was partially superseded by Object Linking and Embedding (OLE), and is currently maintained in Windows systems only for the sake of backward compatibility.
History and architecture
Dynamic Data Exchange was first introduced in 1987 with the release of Windows 2.0 as a method of interprocess communication so that one program could communicate with or control another program, somewhat like Sun's RPC (Remote Procedure Call). At the time, the only method for communication between the operating system and client applications was the "Windows Messaging Layer." DDE extended this protocol to allow peer-to-peer communication among client applications, via message broadcasts.
Because DDE runs via message broadcasts, it is vulnerable to any window-management code that does not pump messages. This problem was not considered during the design of DDE, because DDE predates pre-emptive multitasking.
Moreover, any code managing a window handle can respond to a DDE broadcast; the initiator of DDE must distinguish between expected and unexpected responses. DDE interlocutors usually express what information they seek in terms of hierarchical string keys. For example, a cell in Microsoft Excel was known to DDE by its "application" name. Each application could further organize information by groups known as "topic" and each topic could serve up individual pieces of data as an "item". For example, if a user wanted to pull a value from Microsoft Excel which was contained in a spreadsheet called "Book1.xls" in the cell in the first row and first column, the application would be "Excel", the topic "Book1.xls" and the item "r1c1". Internal changes in the cell due to Excel actions would then be signaled (in reverse |
https://en.wikipedia.org/wiki/BLIS/COBOL | BLIS/COBOL is a discontinued operating system that was written in COBOL. It is the only such system to gain reasonably wide acceptance. It was optimised to compile business applications written in COBOL. BLIS was available on a range of Data General Nova and Data General Eclipse 16-bit minicomputers. It was marketed by Information Processing, Inc. (IPI), who regularly exhibited the product at the National Computer Conference in the 1970s and 80s. It was priced between US$830 and $10,000 depending on the number of supported users and features. In 1977, IPI boasted over 100 operational installations of the system worldwide.
By 1985, a version for the IBM PC existed called PC-BLIS.
Originally, most operating systems were written in assembly language for a particular processor or family of processors. Non-assembler operating systems were comparatively slow, but were easier for revision and repair. One of the reasons for the C programming language's low-level features, which resemble assembly language in some ways, is an early intent to use it for writing operating systems. Similar goals led to IBM's development of PL/S. The high-level nature of COBOL, which created some problems for operating system development, was partially addressed in BLIS, since it was deliberately optimized for COBOL. |
https://en.wikipedia.org/wiki/Open%20Grid%20Services%20Infrastructure | The Open Grid Services Infrastructure (OGSI) was published by the Global Grid Forum (GGF) as a proposed recommendation in June 2003. It was intended to provide an infrastructure layer for the Open Grid Services Architecture (OGSA). OGSI takes the statelessness issues (along with others) into account by essentially extending Web services to accommodate grid computing resources that are both transient and stateful.
Obsolescence
Web services groups started to integrate their own approaches to capturing state into the Web Services Resource Framework (WSRF). With the release of GT4, the open source tool kit is migrating back to a pure Web services implementation (rather than OGSI), via integration of the WSRF.
"OGSI, which was the former set of extensions to Web services to provide stateful interactions -- I would say at this point is obsolete," Jay Unger said. "That was the model that was used in the Globus Toolkit 3.0, but it's been replaced by WSRF, WS-Security, and the broader set of Web services standards. But OGSA, which focuses on specific service definition in the areas of execution components, execution modeling, grid data components, and information virtualization, still has an important role to play in the evolution of standards and open source tool kits like Globus."
Implementations
Globus Toolkit version 3 contains an implementation of OGSI. |
https://en.wikipedia.org/wiki/MonetDB | MonetDB is an open-source column-oriented relational database management system (RDBMS) originally developed at the Centrum Wiskunde & Informatica (CWI) in the Netherlands.
It is designed to provide high performance on complex queries against large databases, such as combining tables with hundreds of columns and millions of rows.
MonetDB has been applied in high-performance applications for online analytical processing, data mining, geographic information system (GIS), Resource Description Framework (RDF), text retrieval and sequence alignment processing.
History
Data mining projects in the 1990s required improved analytical database support. This resulted in a CWI spin-off called Data Distilleries, which used early MonetDB implementations in its analytical suite. Data Distilleries eventually became a subsidiary of SPSS in 2003, which in turn was acquired by IBM in 2009.
MonetDB in its current form was first created in 2002 by doctoral student Peter Boncz and professor Martin L. Kersten as part of the 1990s' MAGNUM research project at University of Amsterdam. It was initially called simply Monet, after the French impressionist painter Claude Monet. The first version under an open-source software license (a modified version of the Mozilla Public License) was released on September 30, 2004. When MonetDB version 4 was released into the open-source domain, many extensions to the code base were added by the MonetDB/CWI team, including a new SQL front end, supporting the SQL:2003 standard.
MonetDB introduced innovations in all layers of the DBMS: a storage model based on vertical fragmentation, a modern CPU-tuned query execution architecture that often gave MonetDB a speed advantage over the same algorithm over a typical interpreter-based RDBMS. It was one of the first database systems to tune query optimization for CPU caches. MonetDB includes automatic and self-tuning indexes, run-time query optimization, and a modular software architecture.
By 2008, a follow-on p |
https://en.wikipedia.org/wiki/Data%20mapping | In computing and data management, data mapping is the process of creating data element mappings between two distinct data models. Data mapping is used as a first step for a wide variety of data integration tasks, including:
Data transformation or data mediation between a data source and a destination
Identification of data relationships as part of data lineage analysis
Discovery of hidden sensitive data such as the last four digits of a social security number hidden in another user id as part of a data masking or de-identification project
Consolidation of multiple databases into a single database and identifying redundant columns of data for consolidation or elimination
For example, a company that would like to transmit and receive purchases and invoices with other companies might use data mapping to create data maps from a company's data to standardized ANSI ASC X12 messages for items such as purchase orders and invoices.
Standards
X12 standards are generic Electronic Data Interchange (EDI) standards designed to allow a company to exchange data with any other company, regardless of industry. The standards are maintained by the Accredited Standards Committee X12 (ASC X12), with the American National Standards Institute (ANSI) accredited to set standards for EDI. The X12 standards are often called ANSI ASC X12 standards.
The W3C introduced R2RML as a standard for mapping data in a relational database to data expressed in terms of the Resource Description Framework (RDF).
In the future, tools based on semantic web languages such as RDF, the Web Ontology Language (OWL) and standardized metadata registry will make data mapping a more automatic process. This process will be accelerated if each application performed metadata publishing. Full automated data mapping is a very difficult problem (see semantic translation).
Hand-coded, graphical manual
Data mappings can be done in a variety of ways using procedural code, creating XSLT transforms or by using graphi |
https://en.wikipedia.org/wiki/GAFOR | GAFOR ("General Aviation Forecast") is a format for reporting weather information for aviation purposes. The GAFOR is used in many European countries. In order to easy transmit and understand GAFOR forecasts, the original (local) names are systematically replaced by a code number. There are two kinds of application:
In France and Germany for example the GAFOR - Code refers to regions.
In Switzerland, Austria, Croatia and Slovenia the code refers to often used or simply usable and therefore predefined routes for crossing the country. This is a special need for the alpine or other mountainous regions, where VFR routing between mountains higher than the physical performance of pilots (oxygen) or the aircraft are common.
GAFOR codes
The GAFOR gives information on weather conditions (VIS/ceiling) prevailing along the main VFR Routes in Switzerland, Austria, Croatia and Slovenia. VIS and ceiling conditions considered, four weather categories are distinguished:
X: closed
M: marginal
D: difficult
O: open
Other weather phenomena dangerous for aviation, such as icing and turbulence are forecasted in GAMET or flight forecast. For this reason they are not taken into account in GAFOR.
Transmission of Swiss GAFOR
The GAFOR is spoken on magnetic disk or tape at Zurich and Genève. The forecast enumerates weather categories in chronological order, first for groups of routes REF: 4.4.2 then for single routes REF: 4.4.3, using the ICAO spelling alphabet:
O = OSCAR
D = DELTA
M = MIKE
X = X-RAY
GAFOR Routes (groups) in Switzerland
Each group is or can be divided into several distinct routes, e.g. for choosing one of different possible passes through the Alps.
Groups of routes:
00 Basel-Schaffhausen-Altenrhein
10 Genève-Grenchen-Zürich-Altenrhein
20 Montreux-Bern-Zürich
30 Spiez-Meiringen-Brünig-Goldau
40 Genève-Simplonpass-Lugano
50 Basel-Gemmipass-Sion
70 Zürich-Gotthardpass-Lugano
80 Zürich-Lukmanierpass-Biasca
90 Altenrhein-Julierpass-Malojapass-Lugano
|
https://en.wikipedia.org/wiki/PhysX | PhysX is an open-source realtime physics engine middleware SDK developed by Nvidia as a part of Nvidia GameWorks software suite.
Initially, video games supporting PhysX were meant to be accelerated by PhysX PPU (expansion cards designed by Ageia). However, after Ageia's acquisition by Nvidia, dedicated PhysX cards have been discontinued in favor of the API being run on CUDA-enabled GeForce GPUs. In both cases, hardware acceleration allowed for the offloading of physics calculations from the CPU, allowing it to perform other tasks instead.
PhysX and other middleware physics engines are used in many video games today because they free game developers from having to write their own code that implements classical mechanics (Newtonian physics) to do, for example, soft body dynamics.
History
What is known today as PhysX originated as a physics simulation engine called NovodeX. The engine was developed by Swiss company NovodeX AG, an ETH Zurich spin-off. In 2004, Ageia acquired NovodeX AG and began developing a hardware technology that could accelerate physics calculations, aiding the CPU. Ageia called the technology PhysX, the SDK was renamed from NovodeX to PhysX, and the accelerator cards were dubbed PPUs (Physics Processing Units).
In its implementation, the first video game to use PhysX technology is The Stalin Subway, released in Russia-only game stores in September 2005.
In 2008, Ageia was itself acquired by graphics technology manufacturer Nvidia. Nvidia started enabling PhysX hardware acceleration on its line of GeForce graphics cards and eventually dropped support for Ageia PPUs.
PhysX SDK 3.0 was released in May 2011 and represented a significant rewrite of the SDK, bringing improvements such as more efficient multithreading and a unified code base for all supported platforms.
At GDC 2015, Nvidia made the source code for PhysX available on GitHub, but required registration at developer.nvidia.com. The proprietary SDK was provided to developers for free f |
https://en.wikipedia.org/wiki/Inosinic%20acid | Inosinic acid or inosine monophosphate (IMP) is a nucleotide (that is, a nucleoside monophosphate). Widely used as a flavor enhancer, it is typically obtained from chicken byproducts or other meat industry waste. Inosinic acid is important in metabolism. It is the ribonucleotide of hypoxanthine and the first nucleotide formed during the synthesis of purine nucleotides. It can also be formed by the deamination of adenosine monophosphate by AMP deaminase. It can be hydrolysed to inosine.
The enzyme deoxyribonucleoside triphosphate pyrophosphohydrolase, encoded by YJR069C in Saccharomyces cerevisiae and containing (d)ITPase and (d)XTPase activities, hydrolyzes inosine triphosphate (ITP) releasing pyrophosphate and IMP.
Important derivatives of inosinic acid include the purine nucleotides found in nucleic acids and adenosine triphosphate, which is used to store chemical energy in muscle and other tissues.
In the food industry, inosinic acid and its salts such as disodium inosinate are used as flavor enhancers. It is known as E number reference E630.
Inosinate synthesis
The inosinate synthesis is complex, beginning with a 5-phosphoribosyl-1-pyrophosphate (PRPP). Enzymes taking part in IMP synthesis constitute a multienzyme complex in the cell. Evidence demonstrates that there are multifunctional enzymes, and some of them catalyze non-sequential steps in the pathway.
Synthesis of other purine nucleotides
Within a few steps inosinate becomes AMP or GMP. Both compounds are RNA nucleotides. AMP differs from inosinate by the replacement of IMP's carbon-6 carbonyl with an amino group. The interconversion of AMP and IMP occurs as part of the purine nucleotide cycle. GMP is formed by the inosinate oxidation to xanthylate (XMP), and afterwards adds an amino group on carbon 2. Hydrogen acceptor on inosinate oxidation is NAD+. Finally, carbon 2 gains the amino group by spending an ATP molecule (which becomes AMP+2Pi). While AMP synthesis requires GTP, GMP synthesis uses ATP. |
https://en.wikipedia.org/wiki/ROFOR | ROFOR is a format for reporting weather information. ROFOR is an abbreviation for "Route Forecast". As the name suggests is the weather forecast of the route of any aircraft which will be flying through the route. ROFOR contains various information regarding date and time of forecast, direction and speed of the wind, aerodrome ICAO code for which the forecast is made, cloud levels and freezing (icing) levels, turbulence and vertical wind shear information.
Example
Example of ROFOR report:
ROFOR 060300Z 0606/0612 KT VIDP 12580 2AC120 4CI300 7///180 403028 27010 405020 28015 407015 30020 410010 33025 523306 631209 11111 12775 40120 22222 38150 27115=
Interpretation of report: |
https://en.wikipedia.org/wiki/Geocomputation | Geocomputation (sometimes GeoComputation) is a field of study at the intersection of geography and computation.
See also
Geoinformatics
Geomathematics
Geographic information system
Bibliography
Openshaw, S., and R. J. Abrahart. (1996). “Geocomputation.” In Proceedings of the 1st International Conference on GeoComputation, 665–6, edited by R. J. Abrahart. Leeds, U.K.: University of Leeds
Longley, P. A., S. M. Brooks, R. McDonnell, and W. D. Macmillan. (1998). Geocomputation: A Primer. Chichester, U.K.: John Wiley & Sons
Gahegan, M. (1999). “Guest Editorial: What is Geocomputation?” Transactions in GIS 3(3), 203–6.
Brunsdon, C., and A. D. Singleton. (2015). Geocomputation: A Practical Primer. London: Sage
Harris, R., D. O’Sullivan, M. Gahegan, M. Charlton, L. Comber, P. Longley, C. Brunsdon, N. Malleson, A. Heppenstall, A. Singleton, D. Arribas-Bel, and A. Evans. (2017). “More Bark than Bytes? Reflections on 21+ Years of Geocomputation.” Environment and Planning B 44(4), 598–617.
Geographic data and information fields of study
Computational fields of study |
https://en.wikipedia.org/wiki/Specific%20storage | In the field of hydrogeology, storage properties are physical properties that characterize the capacity of an aquifer to release groundwater. These properties are storativity (S), specific storage (Ss) and specific yield (Sy). According to Groundwater, by Freeze and Cherry (1979), specific storage, [m−1], of a saturated aquifer is defined as the volume of water that a unit volume of the aquifer releases from storage under a unit decline in hydraulic head.
They are often determined using some combination of field tests (e.g., aquifer tests) and laboratory tests on aquifer material samples. Recently, these properties have been also determined using remote sensing data derived from Interferometric synthetic-aperture radar.
Storativity
Storativity or the storage coefficient is the volume of water released from storage per unit decline in hydraulic head in the aquifer, per unit area of the aquifer. Storativity is a dimensionless quantity, and is always greater than 0.
is the volume of water released from storage ([L3]);
is the hydraulic head ([L])
is the specific storage
is the specific yield
is the thickness of aquifer
is the area ([L2])
Confined
For a confined aquifer or aquitard, storativity is the vertically integrated specific storage value. Specific storage is the volume of water released from one unit volume of the aquifer under one unit decline in head. This is related to both the compressibility of the aquifer and the compressibility of the water itself. Assuming the aquifer or aquitard is homogeneous:
Unconfined
For an unconfined aquifer, storativity is approximately equal to the specific yield () since the release from specific storage () is typically orders of magnitude less ().
The specific storage is the amount of water that a portion of an aquifer releases from storage, per unit mass or volume of the aquifer, per unit change in hydraulic head, while remaining fully saturated.
Mass specific storage is the mass of water that an aquife |
https://en.wikipedia.org/wiki/John%20Moffat%20%28physicist%29 | John W. Moffat (born 24 May 1932) is a Canadian physicist. He is currently professor emeritus of physics at the University of Toronto and is also an adjunct professor of physics at the University of Waterloo and a resident affiliate member of the Perimeter Institute for Theoretical Physics.
Moffat is best known for his work on gravity and cosmology, culminating in his nonsymmetric gravitational theory and scalar–tensor–vector gravity (now called MOG), and summarized in his 2008 book for general readers, Reinventing Gravity. His theory explains galactic rotation curves without invoking dark matter. He proposes a variable speed of light approach to cosmological problems. The speed of light c may have been more than 15 orders of magnitude higher during the early moments of the Big Bang. His recent work on inhomogeneous cosmological models purports to explain certain anomalous effects in the CMB data, and to account for the recently discovered acceleration of the expansion of the universe.
Moffat has proposed a new nonlocal variant of quantum field theory, that is finite at all orders and hence dispenses with renormalization. It also generates mass without a Higgs mechanism.
Early life and education
Moffat was born in Copenhagen, Denmark, the son of a Scottish father, George Moffat, and Danish mother, Esther (née Winther). His father, a musician from Glasgow, was performing in a night club in Copenhagen when he met Esther, a dancer. They married three weeks later.
In 1938, on the eve of the Second World War, John's father moved the family to London, correctly predicting that Denmark would be invaded by Germany. In later 1939, during the Blitz, the 7-year-old John was evacuated to Glasgow to live with his grandparents. But he failed to thrive in Glasgow, struggling academically, so after a year he returned to his parents, and all three moved to Bristol, where his father got a job searching ships for German spies.
In Bristol, they lived close to the factory that man |
https://en.wikipedia.org/wiki/Groundwater%20flow%20equation | Used in hydrogeology, the groundwater flow equation is the mathematical relationship which is used to describe the flow of groundwater through an aquifer. The transient flow of groundwater is described by a form of the diffusion equation, similar to that used in heat transfer to describe the flow of heat in a solid (heat conduction). The steady-state flow of groundwater is described by a form of the Laplace equation, which is a form of potential flow and has analogs in numerous fields.
The groundwater flow equation is often derived for a small representative elemental volume (REV), where the properties of the medium are assumed to be effectively constant. A mass balance is done on the water flowing in and out of this small volume, the flux terms in the relationship being expressed in terms of head by using the constitutive equation called Darcy's law, which requires that the flow is laminar. Other approaches are based on Agent Based Models to incorporate the effect of complex aquifers such as karstic or fractured rocks (i.e. volcanic)
Mass balance
A mass balance must be performed, and used along with Darcy's law, to arrive at the transient groundwater flow equation. This balance is analogous to the energy balance used in heat transfer to arrive at the heat equation. It is simply a statement of accounting, that for a given control volume, aside from sources or sinks, mass cannot be created or destroyed. The conservation of mass states that, for a given increment of time (Δt), the difference between the mass flowing in across the boundaries, the mass flowing out across the boundaries, and the sources within the volume, is the change in storage.
Diffusion equation (transient flow)
Mass can be represented as density times volume, and under most conditions, water can be considered incompressible (density does not depend on pressure). The mass fluxes across the boundaries then become volume fluxes (as are found in Darcy's law). Using Taylor series to represent the in |
https://en.wikipedia.org/wiki/Negative-calorie%20food | A negative-calorie food is food that supposedly requires more food energy to be digested than the food provides. Its thermic effect or specific dynamic action—the caloric "cost" of digesting the food—would be greater than its food energy content. Despite its recurring popularity in dieting guides, there is no evidence supporting the idea that any food is calorically negative. While some chilled beverages are calorically negative, the effect is minimal and requires drinking very large amounts of water, which can be dangerous, as it can cause water intoxication.
Controversy
There is no evidence to show that any of these foods have a negative calorific impact. Foods claimed to be negative in calories are mostly low-calorie fruits and vegetables such as celery, grapefruit, orange, lemon, lime, apple, lettuce, broccoli, and cabbage. However, celery has a thermic effect of around 8%, much less than the 100% or more required for a food to have "negative calories".
Diets based on negative-calorie food do not work as advertised but can lead to weight loss because they satisfy hunger by filling the stomach with food that is not calorically dense. A 2005 study based on a low-fat plant-based diet found that the average participant lost over fourteen weeks, and attributed the weight loss to the reduced energy density of the foods resulting from their low fat content and high fiber content, and the increased thermic effect. Nevertheless, these diets are not "negative-calorie" since they bear energy. Another study demonstrated that negative-calorie diets (NCDs) have the same efficacy to low-calorie diets (LCDs) in inducing weight loss when both of these diets are combined with exercise.
Chewing gum was once speculated as "negative-calorie food"; however, a study on chewing gum reported mastication burns roughly per hour. Therefore, one stick of gum which contains around 10 kcal would require being chewed for one or more hours to reach "negative-calorie".
See also
Diet
Die |
https://en.wikipedia.org/wiki/Monochromatic%20triangle | In graph theory and theoretical computer science, the monochromatic triangle problem is an algorithmic problem on graphs,
in which the goal is to partition the edges of a given graph into two triangle-free subgraphs. It is NP-complete but fixed-parameter tractable on graphs of bounded treewidth.
Problem statement
The monochromatic triangle problem takes as input an n-node undirected graph G(V,E) with node set V and edge set E.
The output is a Boolean value, true if the edge set E of G can be partitioned into two disjoint sets E1 and E2, such that both of the two subgraphs G1(V,E1) and G2(V,E2) are triangle-free graphs, and false otherwise. This decision problem is NP-complete.
Generalization to multiple colors
The problem may be generalized to triangle-free edge coloring, finding an assignment of colors to the edges of a graph so that no triangle has all three edges given the same color. The monochromatic triangle problem is the special case of triangle-free edge-coloring when there are exactly two colors available. If there exists a two-color triangle-free edge coloring, then the edges of each color form the two sets E1 and E2 of the monochromatic triangle problem. Conversely, if the monochromatic triangle problem has a solution, we can use one color for E1 and a second color for E2 to obtain a triangle-free edge coloring.
Connection to Ramsey's theorem
By Ramsey's theorem, for any finite number k of colors, there exists a number n such that complete graphs of n or more vertices do not have triangle-free edge colorings with k colors. For k = 2, the corresponding value of n is 6. That is, the answer to the monochromatic triangle problem on the complete graph K6 is no.
Parameterized complexity
It is straightforward to express the monochromatic triangle problem in the monadic second-order logic of graphs (MSO2), by a logical formula that asserts the existence of a partition of the edges into two subsets such that there do not exist three mutually adjacent vertices |
https://en.wikipedia.org/wiki/Chocolate%20agar | Chocolate agar (CHOC) or chocolate blood agar (CBA), is a nonselective, enriched growth medium used for isolation of pathogenic bacteria. It is a variant of the blood agar plate, containing red blood cells that have been lysed by slowly heating to 80°C. Chocolate agar is used for growing fastidious respiratory bacteria, such as Haemophilus influenzae and Neisseria meningitidis. In addition, some of these bacteria, most notably H. influenzae, need growth factors such as nicotinamide adenine dinucleotide (factor V or NAD) and hemin (factor X), which are inside red blood cells; thus, a prerequisite to growth for these bacteria is the presence of red blood cell lysates. The heat also inactivates enzymes which could otherwise degrade NAD. The agar is named for its color and contains no chocolate products.
Variants
Chocolate agar with the addition of bacitracin becomes selective for the genus Haemophilus. Another variant of chocolate agar called Thayer–Martin agar contains an assortment of antibiotics which select for Neisseria species.
Composition of Chocolate Agar Medium
The composition of chocolate agar includes the following components:
The exact concentrations of these ingredients may vary slightly depending on the specific formulation used in different laboratories or by different manufacturers. |
https://en.wikipedia.org/wiki/Water%20content | Water content or moisture content is the quantity of water contained in a material, such as soil (called soil moisture), rock, ceramics, crops, or wood. Water content is used in a wide range of scientific and technical areas, and is expressed as a ratio, which can range from 0 (completely dry) to the value of the materials' porosity at saturation. It can be given on a volumetric or mass (gravimetric) basis.
Definitions
Volumetric water content, θ, is defined mathematically as:
where is the volume of water and is equal to the total volume of the wet material, i.e. of the sum of the volume of solid host material (e.g., soil particles, vegetation tissue) , of water , and of air .
Gravimetric water content is expressed by mass (weight) as follows:
where is the mass of water and is the mass of the solids.
For materials that change in volume with water content, such as coal, the gravimetric water content, u, is expressed in terms of the mass of water per unit mass of the moist specimen (before drying):
However, woodworking, geotechnics and soil science require the gravimetric moisture content to be expressed with respect to the sample's dry weight:
And in food science, both and are used and called respectively moisture content wet basis (MC) and moisture content dry basis (MC).
Values are often expressed as a percentage, i.e. u×100%.
To convert gravimetric water content to volumetric water content, multiply the gravimetric water content by the bulk specific gravity of the material:
.
Derived quantities
In soil mechanics and petroleum engineering the water saturation or degree of saturation, , is defined as
where is the porosity, in terms of the volume of void or pore space and the total volume of the substance . Values of Sw can range from 0 (dry) to 1 (saturated). In reality, Sw never reaches 0 or 1 - these are idealizations for engineering use.
The normalized water content, , (also called effective saturation or ) is a dimensionless value defined |
https://en.wikipedia.org/wiki/Enumerator%20polynomial | In coding theory, the weight enumerator polynomial of a binary linear code specifies the number of words of each possible Hamming weight.
Let be a binary linear code length . The weight distribution is the sequence of numbers
giving the number of codewords c in C having weight t as t ranges from 0 to n. The weight enumerator is the bivariate polynomial
Basic properties
MacWilliams identity
Denote the dual code of by
(where denotes the vector dot product and which is taken over ).
The MacWilliams identity states that
The identity is named after Jessie MacWilliams.
Distance enumerator
The distance distribution or inner distribution of a code C of size M and length n is the sequence of numbers
where i ranges from 0 to n. The distance enumerator polynomial is
and when C is linear this is equal to the weight enumerator.
The outer distribution of C is the 2n-by-n+1 matrix B with rows indexed by elements of GF(2)n and columns indexed by integers 0...n, and entries
The sum of the rows of B is M times the inner distribution vector (A0,...,An).
A code C is regular if the rows of B corresponding to the codewords of C are all equal. |
https://en.wikipedia.org/wiki/Dual%20code | In coding theory, the dual code of a linear code
is the linear code defined by
where
is a scalar product. In linear algebra terms, the dual code is the annihilator of C with respect to the bilinear form . The dimension of C and its dual always add up to the length n:
A generator matrix for the dual code is the parity-check matrix for the original code and vice versa. The dual of the dual code is always the original code.
Self-dual codes
A self-dual code is one which is its own dual. This implies that n is even and dim C = n/2. If a self-dual code is such that each codeword's weight is a multiple of some constant , then it is of one of the following four types:
Type I codes are binary self-dual codes which are not doubly even. Type I codes are always even (every codeword has even Hamming weight).
Type II codes are binary self-dual codes which are doubly even.
Type III codes are ternary self-dual codes. Every codeword in a Type III code has Hamming weight divisible by 3.
Type IV codes are self-dual codes over F4. These are again even.
Codes of types I, II, III, or IV exist only if the length n is a multiple of 2, 8, 4, or 2 respectively.
If a self-dual code has a generator matrix of the form , then the dual code has generator matrix , where is the identity matrix and . |
https://en.wikipedia.org/wiki/IL%20%28network%20protocol%29 | The Internet Link protocol or IL is a connection-based transport-layer protocol designed at Bell Labs originally as part of the Plan 9 operating system and is used to carry 9P. It is assigned the Internet Protocol number of 40. It is similar to TCP but much simpler.
Its main features are:
Reliable datagram service
In-sequence delivery
Internetworking using IP
Low complexity, high performance
Adaptive timeouts
As of the Fourth Edition of Plan 9, 2003, IL is deprecated in favor of TCP/IP because it doesn't handle long-distance connections well.
See also
Fast Local Internet Protocol |
https://en.wikipedia.org/wiki/Lyutika | Lyutika (, ) is a traditional vegetable mixture — salad or chunky relish, popular in the northern part of Bulgaria. It is consumed in the summer. Basic lyutika is made from roasted peppers, tomatoes, garlic, onions, and vegetable oil usually crushed with a pestle in a mortar. Often chopped parsley is added. Lyutika is served cold. The name comes from the pungent taste (lyut, meaning hot, pungent).
There are varieties of lyutika that include yogurt, sirene (white cheese), hardboiled eggs, or chunks of cooked chicken breasts.
See also
List of salads
Bulgarian cuisine
Salads
Condiments |
https://en.wikipedia.org/wiki/Cosmology | Cosmology () is a branch of physics and metaphysics dealing with the nature of the universe. The term cosmology was first used in English in 1656 in Thomas Blount's Glossographia, and in 1731 taken up in Latin by German philosopher Christian Wolff, in Cosmologia Generalis. Religious or mythological cosmology is a body of beliefs based on mythological, religious, and esoteric literature and traditions of creation myths and eschatology. In the science of astronomy, cosmology is concerned with the study of the chronology of the universe.
Physical cosmology is the study of the observable universe's origin, its large-scale structures and dynamics, and the ultimate fate of the universe, including the laws of science that govern these areas. It is investigated by scientists, including astronomers and physicists, as well as philosophers, such as metaphysicians, philosophers of physics, and philosophers of space and time. Because of this shared scope with philosophy, theories in physical cosmology may include both scientific and non-scientific propositions and may depend upon assumptions that cannot be tested. Physical cosmology is a sub-branch of astronomy that is concerned with the universe as a whole. Modern physical cosmology is dominated by the Big Bang Theory which attempts to bring together observational astronomy and particle physics; more specifically, a standard parameterization of the Big Bang with dark matter and dark energy, known as the Lambda-CDM model.
Theoretical astrophysicist David N. Spergel has described cosmology as a "historical science" because "when we look out in space, we look back in time" due to the finite nature of the speed of light.
Disciplines
Physics and Astrophysics have played central roles in shaping our understanding of the universe through scientific observation and experiment. Physical cosmology was shaped through both mathematics and observation in an analysis of the whole universe. The universe is generally understood to have beg |
https://en.wikipedia.org/wiki/Hans%20Rademacher | Hans Adolph Rademacher (; 3 April 1892 – 7 February 1969) was a German-born American mathematician, known for work in mathematical analysis and number theory.
Biography
Rademacher received his Ph.D. in 1916 from Georg-August-Universität Göttingen; Constantin Carathéodory supervised his dissertation. In 1919, he became privatdozent under Constantin Carathéodory at University of Berlin. In 1922, he became an assistant professor at the University of Hamburg, where he supervised budding mathematicians like Theodor Estermann. He was dismissed from his position at the University of Breslau by the Nazis in 1933 due to his public support of the Weimar Republic, and emigrated from Europe in 1934.
After leaving Germany, he moved to Philadelphia and worked at the University of Pennsylvania until his retirement in 1962; he held the Thomas A. Scott Professorship of Mathematics at Pennsylvania from 1956 to 1962. Rademacher had a number of well-known students, including George Andrews, Paul T. Bateman, Theodor Estermann and Emil Grosswald.
Research
Rademacher performed research in analytic number theory, mathematical genetics, the theory of functions of a real variable, and quantum theory. Most notably, he developed the theory of Dedekind sums. In 1937 Rademacher discovered an exact convergent series for the partition function P(n), the number of integer partitions of a number, improving upon Ramanujan's asymptotic non-convergent series and validating Ramanujan's supposition that an exact series representation existed.
Awards and honors
With his retirement from the University of Pennsylvania, a group of mathematicians provided the seed funding for The Hans A. Rademacher Instructorships, and honored him with an honorary degree as Doctor of Science.
Rademacher is the co-author (with Otto Toeplitz) of the popular mathematics book The Enjoyment of Mathematics, published in German in 1930 and still in print.
Works
with Otto Toeplitz: Von Zahlen und Figuren. 1930. 2nd edn. 1933. |
https://en.wikipedia.org/wiki/Old%20vine | Old vine (, ), a common description on wine labels, indicates that a wine is the product of grape vines that are notably old. There is a general belief that older vines, when properly handled, will give a better wine. There is no legal or generally agreed definition for old.
Usage
Grape vines can grow for over 120 years. After about 20 years vines start to produce smaller crops, and average yields decrease, leading to more concentrated, intense wines. Diseases such as "dead arm" can also afflict old vines, in some cases further concentrating the juice. "Old vines" might apply to an entire estate, or it might mean only a certain parcel planted before others. In the U.S., the most common use is on Zinfandel, because in California vineyards up to 125 years old are still bearing small amounts of prized Zinfandel fruit.
In a place where wine production is longstanding, it often means a wine whose vines are thirty to forty years old. Some wine makers insist the vines should be older than this. In newly established wine regions, twenty years might be old. The definition is further complicated by the fact that certain varieties simply do not have economically viable yields when they get truly ancient.
Old vines around the globe
The oldest known grape-producing vine is a Žametovka vine growing in Maribor in Slovenia, which is known to have been alive in the 17th century; it produces only about of grapes each year, which is fermented and put into about 100 miniature bottles.
In the South Tyrol wine region of northeast Italy, a more than 350-year-old vine of Versoaln planted at Castel Katzenzungen is being used to produce wine with the fruit of the old vine blended with the fruit of younger plantings to produce approximately 500 bottles a year.
The oldest vine with a fully authenticated minimum age, and thought to be the largest in the world, is known as the Great Vine at Hampton Court Palace in England. It was transplanted under the direction of Lancelot Capability Bro |
https://en.wikipedia.org/wiki/Lesser%20bandicoot%20rat | The lesser bandicoot rat, Sindhi rice rat, bengal rat or Indian mole-rat (Bandicota bengalensis) is a giant rat of Southern Asia, not related to the true bandicoots which are marsupials. They can be up to 40 cm long (including the tail), are considered a pest in the cereal crops and gardens of India and Sri Lanka, and emit piglike grunts when attacking. The name bandicoot is derived from the Telugu language word pandikokku, which translates loosely to "pig-rat". Like the better known rats in the genus Rattus, bandicoot rats are members of the family Muridae. Their fur is dark or (rarely) pale brown dorsally, occasionally blackish, and light to dark grey ventrally. The head-body length is around 250 mm, and the uniformly dark tail is shorter than the head-body length.
Distribution and habitat
These rats are also known to inhabit houses in villages and are particularly aggressive when threatened. The controls are done by mechanical (mouse trap etc.), rodenticides and biological control (by introducing rodent diseases etc.)
Behaviour and ecology
Commonly, it lives in cultivated plains and gardens and is one of the most destructive pests to crops and cultivation. It digs burrows with characteristic pile of earth around the entrance, hence its name. The burrow system is extensive and elaborate, consisting of numerous chambers (sleeping, storing, etc.), galleries and exits or 'bolt-holes', which are covered with loose earth, facilitating an easy escape during emergencies. The storage chambers are stocked with large amounts of grain, specially during harvest time. Usually, one mole-rat is found in one burrow, except when a mother is with young. It has a habit of erecting its long guard hairs scattered over the back and emitting harsh grunts when disturbed.
Reproduction
The lesser bandicoot and two other species are nocturnal or most active at twilight. They construct burrows to nest and bear their litters. The number of bandicoot babies can range from two to 18. Their s |
https://en.wikipedia.org/wiki/Fumagillin | Fumagillin is a complex biomolecule and used as an antimicrobial agent. It was isolated in 1949 from the microbial organism Aspergillus fumigatus.
Uses
In animals
It was originally used against microsporidian parasites Nosema apis infections in honey bees.
Some studies found it to be effective against some myxozoan parasites, including Myxobolus cerebralis, an important parasite of fish; however, in the more rigorous tests required for U.S. Food and Drug Administration approval, it was ineffective.
There are reports that fumagillin controls Nosema ceranae, which has recently been hypothesized as a possible cause of colony collapse disorder.
The latest report, however, has shown it to be ineffective against N. ceranae.
Fumagillin is also investigated as an inhibitor of malaria parasite growth.
In humans
Fumagillin has been used in the treatment of microsporidiosis. It is also an amebicide.
Fumagillin can block blood vessel formation by binding to an enzyme methionine aminopeptidase 2 and for this reason, the compound, together with semisynthetic derivatives, are investigated as an angiogenesis inhibitor in the treatment of cancer.
The company Zafgen conducted clinical trials using the fumagillin analog beloranib for weight loss, but they were unsuccessful.
Fumagillin is toxic to erythrocytes in vitro at concentrations greater than 10 μM.
Total synthesis
Fumagillin and the related fumagillol (the hydrolysis product) have been a target in total synthesis, with several reported successful strategies, racemic, asymmetric, and formal. |
https://en.wikipedia.org/wiki/Nobunaga%27s%20Ambition | is a series of turn-based grand strategy role-playing simulation video games. The original game was one of the first in its genre, being released in March 1983 by the Japanese video game developer Koei. Nobunaga's Ambition takes place during the Sengoku period of feudal Japan. The player is tasked with achieving the ultimate goal of warlord Oda Nobunaga: the conquest and unification of Japan. Selecting Oda Nobunaga is optional, however, as the player is also able to choose from a variety of other regional daimyōs of the time.
Games in the franchise have been released for the Nintendo Entertainment System, Game Boy, Sega Genesis, 3DO, Super Nintendo, PlayStation, Sega Saturn, PlayStation 2, PlayStation 3, Xbox 360, Wii, PlayStation Portable, PlayStation Vita, PlayStation 4 and Nintendo Switch. The title was also released for Macintosh as well as MSX, Amiga, and MS-DOS. As of March 2018, the series has shipped more than 10 million copies worldwide.
Gameplay
The player may choose from four campaign scenarios, including "Battle for the East" (beginning in 1560), "Daimyo Power Struggles" (1560), "Ambition Untamed" (1571), and "Road Towards Unification" (1582). In each scenario, the player must allocate resources to raise a capable military force, provide a productive economy to support both military and civilian expansion, and support the peasants in order to sustain their respect and loyalty. Gameplay is taken in turns, with each turn in the map view corresponding to a season, and each turn during battle corresponding to a day. The player may achieve victory through numerous means, among which are forcing the enemy to retreat, destroying the enemy command unit, outlasting an invading force, or prolonging battle until the opposing force has exhausted its supplies.
The player can make many choices during the campaign. According to Evan Brooks of Computer Gaming World: "One may transfer soldiers between fiefs, go to war, increase taxes (which causes a decrease in peasan |
https://en.wikipedia.org/wiki/BitTorrent%20tracker | A BitTorrent tracker is a special type of server that assists in the communication between peers using the BitTorrent protocol.
In peer-to-peer file sharing, a software client on an end-user PC requests a file, and portions of the requested file residing on peer machines are sent to the client, and then reassembled into a full copy of the requested file. The "tracker" server keeps track of where file copies reside on peer machines, which ones are available at time of the client request, and helps coordinate efficient transmission and reassembly of the copied file. Clients that have already begun downloading a file communicate with the tracker periodically to negotiate faster file transfer with new peers, and provide network performance statistics; however, after the initial peer-to-peer file download is started, peer-to-peer communication can continue without the connection to a tracker.
Modern BitTorrent clients may implement a distributed hash table and the peer exchange protocol to discover peers without trackers; however, trackers are still often included with torrents to improve the speed of peer discovery.
Public vs private trackers
Public trackers
Public or open trackers can be used by anyone by adding the tracker address to an existing torrent, or they can be used by any newly created torrent, like OpenBitTorrent. The Pirate Bay operated one of the most popular public trackers until disabling it in 2009 due to legal trouble, and thereafter offered only magnet links.
Private trackers
A private tracker is a BitTorrent tracker that restricts use by requiring users to register with the site. The method for controlling registration used among many private trackers is an invitation system, in which active and contributing members are given the ability to grant a new user permission to register at the site, or a new user goes through an interview process.
Legal issues
Legal uses
There are several circumstances under which it is legal to distribute copyri |
https://en.wikipedia.org/wiki/Signalling%20%28economics%29 | In contract theory, signalling (or signaling; see spelling differences) is the idea that one party (the agent) credibly conveys some information about itself to another party (the principal).
Although signalling theory was initially developed by Michael Spence based on observed knowledge gaps between organisations and prospective employees, its intuitive nature led it to be adapted to many other domains, such as Human Resource Management, business, and financial markets.
In Spence's job-market signaling model, (potential) employees send a signal about their ability level to the employer by acquiring education credentials. The informational value of the credential comes from the fact that the employer believes the credential is positively correlated with having the greater ability and difficulty for low-ability employees to obtain. Thus the credential enables the employer to reliably distinguish low-ability workers from high-ability workers. The concept of signaling is also applicable in competitive altruistic interaction, where the capacity of the receiving party is limited.
Introductory questions
Signalling started with the idea of asymmetric information (a deviation from perfect information), which relates to the fact that, in some economic transactions, inequalities exist in the normal market for the exchange of goods and services. In his seminal 1973 article, Michael Spence proposed that two parties could get around the problem of asymmetric information by having one party send a signal that would reveal some piece of relevant information to the other party. That party would then interpret the signal and adjust their purchasing behaviour accordingly—usually by offering a higher price than if they had not received the signal.
There are, of course, many problems that these parties would immediately run into.
Effort: How much time, energy, or money should the sender (agent) spend on sending the signal?
Reliability: How can the receiver (the principal, who is u |
https://en.wikipedia.org/wiki/Meet-me%20room | A meet-me room (MMR) is a place within a colocation center (or carrier hotel) where telecommunications companies can physically connect to one another and exchange data without incurring local loop fees. Services provided across connections in an MMR may be voice circuits, data circuits, or Internet Protocol traffic.
An MMR provides a safe production environment where the carrier handover point equipment can be expected to run on a 24/7 basis with minimal risk of interruption. It is typically located within the data center.
To interconnect, companies order a patch from their cage or suite to the MMR and then arrange for the organization running the facility to connect them together. These physical connections may be an optical fiber cable, coaxial cable, twisted pair, or any other networking medium.
Typically, a meet-me room will discourage or disallow customers from installing large amounts of equipment. However, multiplexing equipment is often welcome in the meet-me room, so that a customer can have a single connection between the room and the rest of their equipment in the building, and the multiplexing equipment can then break that out to allow for direct, private connections to several other organizations present in the meet-me room.
An Internet exchange point can also be present in a meet-me room to allow many organizations in the meet-me room to interchange traffic without having to make physical interconnections between every possible pair of organizations.
Examples
One Wilshire: Los Angeles, California
Westin Building: Seattle, Washington
MAE-West (located in Market Post Tower): Downtown San Jose, California
60 Hudson St, New York
111 Eighth Ave, New York
Infomart: Dallas, Texas
350 E. Cermak Rd: Chicago
165 Halsey Street, Newark, New Jersey
399 Chai Wan Road, Hong Kong |
https://en.wikipedia.org/wiki/Environmentalism | Environmentalism or environmental rights is a broad philosophy, ideology, and social movement about supporting life, habitats, and surroundings. While environmentalism focuses more on the environmental and nature-related aspects of green ideology and politics, ecologism combines the ideology of social ecology and environmentalism. Ecologism is more commonly used in continental European languages, while environmentalism is more commonly used in English but the words have slightly different connotations.
Environmentalism advocates the preservation, restoration and improvement of the natural environment and critical earth system elements or processes such as the climate, and may be referred to as a movement to control pollution or protect plant and animal diversity. For this reason, concepts such as a land ethics, environmental ethics, biodiversity, ecology, and the biophilia hypothesis figure predominantly.
At its crux, environmentalism is an attempt to balance relations between humans and the various natural systems on which they depend in such a way that all the components are accorded a proper degree of sustainability. The exact measures and outcomes of this balance is controversial and there are many different ways for environmental concerns to be expressed in practice. Environmentalism and environmental concerns are often represented by the colour green, but this association has been appropriated by the marketing industries for the tactic known as greenwashing.
Environmentalism is opposed by anti-environmentalism, which says that the Earth is less fragile than some environmentalists maintain, and portrays environmentalism as overreacting to the human contribution to climate change or opposing human advancement.
Definitions
Environmentalism denotes a social movement that seeks to influence the political process by lobbying, activism, and education in order to protect natural resources and ecosystems.
An environmentalist is a person who may speak out about our |
https://en.wikipedia.org/wiki/Dark%20Sector | Dark Sector, stylized as darkSector is a third-person shooter video game developed by Digital Extremes for the Xbox 360, PlayStation 3 and Microsoft Windows.
The game is set in the fictional Eastern Bloc country of Lasria, and centers on protagonist Hayden Tenno (voiced by Michael Rosenbaum), a morally ambivalent CIA "clean-up man". While trying to intercept rogue agent named Robert Mezner, Hayden's right arm is infected with the fictional Technocyte virus, which gives him the ability to grow a three-pronged "Glaive" at will.
Dark Sector received mixed reviews for its visual design, originality of action and weapon-based gameplay. Many critics have compared the game to Resident Evil 4 and Gears of War, for their similar style of play and story.
Gameplay
Gameplay of Dark Sector revolves around the use of the Glaive, a tri-blade throwing weapon similar to a boomerang which returns to Hayden after each throw. The Glaive can be used for long-distance combat, solving environmental puzzles, and picking up in-game items. When in close proximity to an enemy, context-sensitive actions may appear, allowing the player to execute enemies with "finishers". Enemies hold onto Hayden while attacking, and the player must rapidly press a randomly prompted button to break free.
Environmental puzzles in the game usually focus upon capturing various elements (fire, electricity, or ice) with the Glaive. For example, a web blocking Hayden's path can be bypassed by capturing fire with the Glaive, and then launching it at the web to burn it down. The Glaive can also be dual-wielded with a gun, which allows the player to perform weapon combos which are more effective against shielded enemies. As the game progresses, Hayden and the Glaive are given several new abilities; it can be guided through the air, being able to kill multiple enemies; a charged-up throw for deadlier attacks; and the ability to make Hayden invisible for a short time and provide a temporary shield.
The camera is pos |
https://en.wikipedia.org/wiki/Electronic%20filter | Electronic filters are a type of signal processing filter in the form of electrical circuits. This article covers those filters consisting of lumped electronic components, as opposed to distributed-element filters. That is, using components and interconnections that, in analysis, can be considered to exist at a single point. These components can be in discrete packages or part of an integrated circuit.
Electronic filters remove unwanted frequency components from the applied signal, enhance wanted ones, or both. They can be:
passive or active
analog or digital
high-pass, low-pass, band-pass, band-stop (band-rejection; notch), or all-pass.
discrete-time (sampled) or continuous-time
linear or non-linear
infinite impulse response (IIR type) or finite impulse response (FIR type)
The most common types of electronic filters are linear filters, regardless of other aspects of their design. See the article on linear filters for details on their design and analysis.
History
The oldest forms of electronic filters are passive analog linear filters, constructed using only resistors and capacitors or resistors and inductors. These are known as RC and RL single-pole filters respectively. However, these simple filters have very limited uses. Multipole LC filters provide greater control of response form, bandwidth and transition bands. The first of these filters was the constant k filter, invented by George Campbell in 1910. Campbell's filter was a ladder network based on transmission line theory. Together with improved filters by Otto Zobel and others, these filters are known as image parameter filters. A major step forward was taken by Wilhelm Cauer who founded the field of network synthesis around the time of World War II. Cauer's theory allowed filters to be constructed that precisely followed some prescribed frequency function.
Classification by technology
Passive filters
Passive implementations of linear filters are based on combinations of resistors (R), induc |
https://en.wikipedia.org/wiki/Open%20Cluster%20Framework | Open Cluster Framework (OCF) is a set of standards for computer clustering.
The project started as a working group of the Free Standards Group, now part of the Linux Foundation. Original supporters included several computing companies and groups, including Compaq, Conectiva, IBM, Linux-HA, MSC Software, the Open Source Development Lab, OSCAR, Red Hat, SGI and SUSE.
OCF Resource agents are currently supported by Linux-HA Heartbeat, the high-availability cluster software. |
https://en.wikipedia.org/wiki/Slope%20field | A slope field (also called a direction field) is a graphical representation of the solutions to a first-order differential equation of a scalar function. Solutions to a slope field are functions drawn as solid curves. A slope field shows the slope of a differential equation at certain vertical and horizontal intervals on the x-y plane, and can be used to determine the approximate tangent slope at a point on a curve, where the curve is some solution to the differential equation.
Definition
Standard case
The slope field can be defined for the following type of differential equations
which can be interpreted geometrically as giving the slope of the tangent to the graph of the differential equation's solution (integral curve) at each point (x, y) as a function of the point coordinates.
It can be viewed as a creative way to plot a real-valued function of two real variables as a planar picture. Specifically, for a given pair , a vector with the components is drawn at the point on the -plane. Sometimes, the vector is normalized to make the plot better looking for a human eye. A set of pairs making a rectangular grid is typically used for the drawing.
An isocline (a series of lines with the same slope) is often used to supplement the slope field. In an equation of the form , the isocline is a line in the -plane obtained by setting equal to a constant.
General case of a system of differential equations
Given a system of differential equations,
the slope field is an array of slope marks in the phase space (in any number of dimensions depending on the number of relevant variables; for example, two in the case of a first-order linear ODE, as seen to the right). Each slope mark is centered at a point and is parallel to the vector
The number, position, and length of the slope marks can be arbitrary. The positions are usually chosen such that the points make a uniform grid. The standard case, described above, represents . The general case of the slope field for |
https://en.wikipedia.org/wiki/Linear%20code | In coding theory, a linear code is an error-correcting code for which any linear combination of codewords is also a codeword. Linear codes are traditionally partitioned into block codes and convolutional codes, although turbo codes can be seen as a hybrid of these two types. Linear codes allow for more efficient encoding and decoding algorithms than other codes (cf. syndrome decoding).
Linear codes are used in forward error correction and are applied in methods for transmitting symbols (e.g., bits) on a communications channel so that, if errors occur in the communication, some errors can be corrected or detected by the recipient of a message block. The codewords in a linear block code are blocks of symbols that are encoded using more symbols than the original value to be sent. A linear code of length n transmits blocks containing n symbols. For example, the [7,4,3] Hamming code is a linear binary code which represents 4-bit messages using 7-bit codewords. Two distinct codewords differ in at least three bits. As a consequence, up to two errors per codeword can be detected while a single error can be corrected. This code contains 24=16 codewords.
Definition and parameters
A linear code of length n and dimension k is a linear subspace C with dimension k of the vector space where is the finite field with q elements. Such a code is called a q-ary code. If q = 2 or q = 3, the code is described as a binary code, or a ternary code respectively. The vectors in C are called codewords. The size of a code is the number of codewords and equals qk.
The weight of a codeword is the number of its elements that are nonzero and the distance between two codewords is the Hamming distance between them, that is, the number of elements in which they differ. The distance d of the linear code is the minimum weight of its nonzero codewords, or equivalently, the minimum distance between distinct codewords. A linear code of length n, dimension k, and distance d is called an [n, |
https://en.wikipedia.org/wiki/Nonlinear%20filter | In signal processing, a nonlinear (or non-linear) filter is a filter whose output is not a linear function of its input. That is, if the filter outputs signals R and S for two input signals r and s separately, but does not always output αR + βS when the input is a linear combination αr + βs.
Both continuous-domain and discrete-domain filters may be nonlinear. A simple example of the former would be an electrical device whose output voltage R(t) at any moment is the square of the input voltage r(t); or which is the input clipped to a fixed range [a,b], namely R(t) = max(a, min(b, r(t))). An important example of the latter is the running-median filter, such that every output sample Ri is the median of the last three input samples ri, ri−1, ri−2. Like linear filters, nonlinear filters may be shift invariant or not.
Non-linear filters have many applications, especially in the removal of certain types of noise that are not additive. For example, the median filter is widely used to remove spike noise — that affects only a small percentage of the samples, possibly by very large amounts. Indeed, all radio receivers use non-linear filters to convert kilo- to gigahertz signals to the audio frequency range; and all digital signal processing depends on non-linear filters (analog-to-digital converters) to transform analog signals to binary numbers.
However, nonlinear filters are considerably harder to use and design than linear ones, because the most powerful mathematical tools of signal analysis (such as the impulse response and the frequency response) cannot be used on them. Thus, for example, linear filters are often used to remove noise and distortion that was created by nonlinear processes, simply because the proper non-linear filter would be too hard to design and construct.
From the foregoing, we can know that the nonlinear filters have quite different behavior compared to linear filters. The most important characteristic is that, for nonlinear filters, the filte |
https://en.wikipedia.org/wiki/Canonical%20ring | In mathematics, the pluricanonical ring of an algebraic variety V (which is nonsingular), or of a complex manifold, is the graded ring
of sections of powers of the canonical bundle K. Its nth graded component (for ) is:
that is, the space of sections of the n-th tensor product Kn of the canonical bundle K.
The 0th graded component is sections of the trivial bundle, and is one-dimensional as V is projective. The projective variety defined by this graded ring is called the canonical model of V, and the dimension of the canonical model is called the Kodaira dimension of V.
One can define an analogous ring for any line bundle L over V; the analogous dimension is called the Iitaka dimension. A line bundle is called big if the Iitaka dimension equals the dimension of the variety.
Properties
Birational invariance
The canonical ring and therefore likewise the Kodaira dimension is a birational invariant: Any birational map between smooth compact complex manifolds induces an isomorphism between the respective canonical rings. As a consequence one can define the Kodaira dimension of a singular space as the Kodaira dimension of a desingularization. Due to the birational invariance this is well defined, i.e., independent of the choice of the desingularization.
Fundamental conjecture of birational geometry
A basic conjecture is that the pluricanonical ring is finitely generated. This is considered a major step in the Mori program.
proved this conjecture.
The plurigenera
The dimension
is the classically defined n-th plurigenus of V. The pluricanonical divisor , via the corresponding linear system of divisors, gives a map to projective space , called the n-canonical map.
The size of R is a basic invariant of V, and is called the Kodaira dimension.
Notes |
https://en.wikipedia.org/wiki/Kodaira%20dimension | In algebraic geometry, the Kodaira dimension κ(X) measures the size of the canonical model of a projective variety X.
Igor Shafarevich in a seminar introduced an important numerical invariant of surfaces with the notation κ. Shigeru Iitaka extended it and defined the Kodaira dimension for higher dimensional varieties (under the name of canonical dimension), and later named it after Kunihiko Kodaira.
The plurigenera
The canonical bundle of a smooth algebraic variety X of dimension n over a field is the line bundle of n-forms,
which is the nth exterior power of the cotangent bundle of X.
For an integer d, the dth tensor power of KX is again a line bundle.
For d ≥ 0, the vector space of global sections H0(X,KXd) has the remarkable property that it is a birational invariant of smooth projective varieties X. That is, this vector space is canonically identified with the corresponding space for any smooth projective variety which is isomorphic to X outside lower-dimensional subsets.
For d ≥ 0, the
dth plurigenus of X is defined as the dimension of the vector space
of global sections of KXd:
The plurigenera are important birational invariants of an algebraic variety. In particular, the simplest way to prove that a variety is not rational (that is, not birational to projective space) is to show that some plurigenus Pd with d > 0
is not zero. If the space of sections of KXd is nonzero, then there is a natural rational map from X to the projective space
called the d-canonical map. The canonical ring R(KX) of a variety X is the graded ring
Also see geometric genus and arithmetic genus.
The Kodaira dimension of X is defined to be if the plurigenera Pd are zero for all d > 0; otherwise, it is the minimum κ such that Pd/dκ is bounded. The Kodaira dimension of an n-dimensional variety is either or an integer in the range from 0 to n.
Interpretations of the Kodaira dimension
The following integers are equal if they are non-negative. A good reference is , Theorem 2.1.33.
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https://en.wikipedia.org/wiki/Puffed%20grain | Puffed grains are grains that have been expanded ("puffed") through processing. They have been made for centuries with the simplest methods like popping popcorn. Modern puffed grains are often created using high temperature, pressure, or extrusion.
People eat puffed grains in many ways, but it can be as simple as puffed grain alone and with sugar or salt for taste. Commercial products such as corn flakes and Corn Pops mix many ingredients into a homogeneous batter. The batter is then formed into shapes then toasted and/or extruded. This causes them to rise, but not puff or pop. Puffed grains can be healthful if plain, but when other ingredients are mixed with them they may lose some of their health benefits.
Puffed grains are popular as breakfast cereals and in the form of rice cakes. While it is easy to recognize that cereals came from whole grains, the expansion factor for rice cakes is even greater, and the final product is somewhat more homogeneous.
History
The oldest puffed grain was found in west-central New Mexico in 1948 and 1950. Ears of popcorn were found that were up to 4,000 years old. These pieces of puffed grain were smaller than a penny to two inches in size and can be made in a similar way to popping popcorn.
Rice has been puffed since ancient times using a technique called hot salt frying in which parboiled rice (e.g. steamed and then dried) is puffed by preheated salt.
The modern process of making puffed grains was invented by Dr. Alexander P. Anderson in 1901 in Red Wing, Minnesota. He was doing an experiment dealing with the effect of heat and pressure on corn starch granules where he put them in six glass tubes, sealed them, and put them in an oven until they changed color. When Dr. Anderson took them out and cracked them open an explosion happened; he had made the corn starch turn into a puffed, white mass.
Dr. Anderson's invention of puffed grain was first introduced at the World's Fair in St. Louis in 1904. The puffed grain was shot fro |
https://en.wikipedia.org/wiki/Canopy%20research | Canopy research is the field of scientific research based upon data collected in the canopy of trees.
Objects
Description of plant and animal species residing in the tree-summits. Mainly ancient forests and tropical forests are studied.
Study of forest ecosystem dynamics, change drivers and other factors that shape forest systems.
Collection of meteorological data. Meteorological studies can help researchers measure the efficacy of forest canopies in offsetting global climate change. Researchers at the Agricultural Research Service have calibrated a model for forest canopies that measures and estimates the amount of carbon a forest canopy absorbs/releases due to photosynthesis/respiration. The research found that the forest canopy shifted from a carbon “sink” (of net carbon absorption due to photosynthesis) to a carbon “source” (of net carbon respiration) following the defoliation of the canopy due to the gypsy moth. This research helps scientists determine the role of trees in offsetting carbon released into the atmosphere, which contributes to global warming, and the biological influences that impact it.
Chief discoveries
90% of animal and 50% of plant species in tropical rainforests live in the upper levels of the large trees. As many as 1000 different insects have been collected from one tree.
Tropical forests require a minimum area to develop their crucial micro climate and to provide habitats for larger mammals.
While grown forests continue to store carbon dioxide, young forests store up ten times more.
Canopy research is a relatively new scientific field which was hampered for a long time by lack of means of access to the tree canopies and lack of appropriate means of housing researchers.
Climbing gear, tree houses, canopy walkways, cranes, airships and inflatable platforms resting on the treetops have lately overcome these barriers.
Cranes have proven to offer the best three-dimensional access. The effort to set them up is worthwhile, as m |
https://en.wikipedia.org/wiki/Joule%20expansion | The Joule expansion (also called free expansion) is an irreversible process in thermodynamics in which a volume of gas is kept in one side of a thermally isolated container (via a small partition), with the other side of the container being evacuated. The partition between the two parts of the container is then opened, and the gas fills the whole container.
The Joule expansion, treated as a thought experiment involving ideal gases, is a useful exercise in classical thermodynamics. It provides a convenient example for calculating changes in thermodynamic quantities, including the resulting increase in entropy of the universe (entropy production) that results from this inherently irreversible process. An actual Joule expansion experiment necessarily involves real gases; the temperature change in such a process provides a measure of intermolecular forces.
This type of expansion is named after James Prescott Joule who used this expansion, in 1845, in his study for the mechanical equivalent of heat, but this expansion was known long before Joule e.g. by John Leslie, in the beginning of the 19th century, and studied by Joseph-Louis Gay-Lussac in 1807 with similar results as obtained by Joule.
The Joule expansion should not be confused with the Joule–Thomson expansion or throttling process which refers to the steady flow of a gas from a region of higher pressure to one of lower pressure via a valve or porous plug.
Description
The process begins with gas under some pressure, , at temperature , confined to one half of a thermally isolated container (see the top part of the drawing at the beginning of this article). The gas occupies an initial volume , mechanically separated from the other part of the container, which has a volume , and is under near zero pressure. The tap (solid line) between the two halves of the container is then suddenly opened, and the gas expands to fill the entire container, which has a total volume of (see the bottom part of the drawing). A therm |
https://en.wikipedia.org/wiki/Quantum%20sort | A quantum sort is any sorting algorithm that runs on a quantum computer. Any comparison-based quantum sorting algorithm would take at least steps, which is already achievable by classical algorithms. Thus, for this task, quantum computers are no better than classical ones, and should be disregarded when it comes to time complexity. However, in space-bounded sorts, quantum algorithms outperform their classical counterparts. |
https://en.wikipedia.org/wiki/Binary%20quadratic%20form | In mathematics, a binary quadratic form is a quadratic homogeneous polynomial in two variables
where a, b, c are the coefficients. When the coefficients can be arbitrary complex numbers, most results are not specific to the case of two variables, so they are described in quadratic form. A quadratic form with integer coefficients is called an integral binary quadratic form, often abbreviated to binary quadratic form.
This article is entirely devoted to integral binary quadratic forms. This choice is motivated by their status as the driving force behind the development of algebraic number theory. Since the late nineteenth century, binary quadratic forms have given up their preeminence in algebraic number theory to quadratic and more general number fields, but advances specific to binary quadratic forms still occur on occasion.
Pierre Fermat stated that if p is an odd prime then the equation has a solution iff , and he made similar statement about the equations , , and .
and so on are quadratic forms, and the theory of quadratic forms gives a unified way of looking at and proving these theorems.
Another instance of quadratic forms is Pell's equation .
Binary quadratic forms are closely related to ideals in quadratic fields, this allows the class number of a quadratic field to be calculated by counting the number of reduced binary quadratic forms of a given discriminant.
The classical theta function of 2 variables is , if is a positive definite quadratic form then is a theta function.
Equivalence
Two forms f and g are called equivalent if there exist integers such that the following conditions hold:
For example, with and , , , and , we find that f is equivalent to , which simplifies to .
The above equivalence conditions define an equivalence relation on the set of integral quadratic forms. It follows that the quadratic forms are partitioned into equivalence classes, called classes of quadratic forms. A class invariant can mean either a funct |
https://en.wikipedia.org/wiki/Cross-browser%20compatibility | Cross-browser compatibility is the ability of a website or web application to function across different browsers and degrade gracefully when browser features are absent or lacking.
History
Background
The history of cross-browser is involved with the history of the "browser wars" in the late 1990s between Netscape Navigator and Microsoft Internet Explorer as well as with that of JavaScript and JScript, the first scripting languages to be implemented in the web browsers. Netscape Navigator was the most widely used web browser at that time and Microsoft had licensed Mosaic to create Internet Explorer 1.0. New versions of Netscape Navigator and Internet Explorer were released at a rapid pace over the following few years. Due to the intense competition in the web browser market, the development of these browsers was fast-paced and new features were added without any coordination between vendors. The introduction of new features often took priority over bug fixes, resulting in unstable browsers, fickle web standards compliance, frequent crashes and many security holes.
Creation of W3C and Web standardization
The World Wide Web Consortium (W3C), founded in 1994 to promote open standards for the World Wide Web, pulled Netscape and Microsoft together with other companies to develop a standard for browser scripting languages called ECMAScript. The first version of the standard was published in 1997. Subsequent releases of JavaScript and JScript would implement the ECMAScript standard for greater cross-browser compatibility. After the standardization of ECMAScript, W3C began work on the standardization of Document Object Model (DOM), which is a way of representing and interacting with objects in HTML, XHTML and XML documents. DOM Level 0 and DOM Level 1 were introduced in 1996 and 1997. Only limited supports of these were implemented by the browsers, as a result, non-conformant browsers such as Internet Explorer 4.x and Netscape 4.x were still widely used as late as 2000 |
https://en.wikipedia.org/wiki/MicroEmpix | MicroEmpix is the microkernel (much nearer to an exokernel) version of Empix, an operating system (OS) developed at the Computing Systems Laboratory (CSLab) of the Electrical & Computer Engineering department at the National Technical University of Athens.
Empix began in the late 1980's as the laboratory's effort to write a small Unix-like modern multitasking OS, intended for educational use. Borrowing most of its basic characteristics (file system, binary format, shell) from other popular OSes of the time (Xinu, Minix, DOS). Empix is quite small (about 10,000 lines of code) and supports Intel x86 processors, in the IBM Personal Computers (PC) XT (8088), and AT (80286) architectures, floppy disks and hard disk drives (with the File Allocation Table (FAT) 16 limits), and Enhanced Graphics Adapter (EGA) graphics (80x25 color terminal) and the serial ports. It has a shell with some basic commands, and the ability to execute multiple processes.
MicroEmpix is far different. It's about 1,600 lines of code (over which about 1,000 devoted to serial port control), and it's a microkernel, meaning that it creates and runs processes in kernel-space, with no distinction between process-space and kernel space. What the kernel sees, the process sees and vice versa. No system calls occur to require a system call dispatcher or a similar mechanism. Kernel functions are inherent to the processes created, and there is but one user. |
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