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https://en.wikipedia.org/wiki/Mathematics%20and%20the%20Imagination | Mathematics and the Imagination is a book published in New York by Simon & Schuster in 1940. The authors are Edward Kasner and James R. Newman. The illustrator Rufus Isaacs provided 169 figures. It rapidly became a best-seller and received several glowing reviews. Special publicity has been awarded it since it introduced the term googol for 10100, and googolplex for 10googol. The book includes nine chapters, an annotated bibliography of 45 titles, and an index in its 380 pages.
Reviews
According to I. Bernard Cohen, "it is the best account of modern mathematics that we have", and is "written in a graceful style, combining clarity of exposition with good humor".
According to T. A. Ryan's review, the book "is not as superficial as one might expect a book at the popular level to be. For instance, the description of the invention of the term googol ... is a very serious attempt to show how misused is the term infinite when applied to large and finite numbers."
By 1941 G. Waldo Dunnington could note the book had become a best-seller. "Apparently it has succeeded in communicating to the layman something of the pleasure experienced by the creative mathematician in difficult problem solving."
Contents
The introduction notes (p xiii) "Science, particularly mathematics, ... appears to be building the one permanent and stable edifice in an age where all others are either crumbling or being blown to bits."
The authors affirm (p xiv) "It has been our aim, ... to show by its very diversity something of the character of mathematics, of its bold, untrammelled spirit, of how, both as an art and science, it has continued to lead the creative faculties beyond even imagination and intuition."
In chapter one, "New names for old", they explain why mathematics is the science that uses easy words for hard ideas. They note (p 5) "many amusing ambiguities arise. For instance, the word function probably expresses the most important idea in the whole history of mathematics. Also, the theory |
https://en.wikipedia.org/wiki/SMART-1 | SMART-1 was a Swedish-designed European Space Agency satellite that orbited the Moon. It was launched on 27 September 2003 at 23:14 UTC from the Guiana Space Centre in Kourou, French Guiana. "SMART-1" stands for Small Missions for Advanced Research in Technology-1. On 3 September 2006 (05:42 UTC), SMART-1 was deliberately crashed into the Moon's surface, ending its mission.
Spacecraft design
SMART-1 was about one meter across (3.3 ft), and lightweight in comparison to other probes. Its launch mass was 367 kg or 809 pounds, of which 287 kg (633 lb) was non-propellant.
It was propelled by a solar-powered Hall effect thruster (Snecma PPS-1350-G) using 82 Kg of xenon gas contained in a 50 litres tank at a pressure of 150 bar at launch. The ion engine thruster used an electrostatic field to ionize the xenon and accelerate the ions achieving a specific impulse of 16.1 kN·s/kg (1,640 seconds), more than three times the maximum for chemical rockets. One kg of propellant (1/350 to 1/300 of the total mass of the spacecraft) produced a delta-v of about 45 m/s. The electric propulsion subsystem weighted 29 kg with a peak power consumption of 1,200 watts. SMART-1 was the first in the program of ESA's Small Missions for Advanced Research and Technology.
The solar arrays made capable of 1850W at the beginning of the mission, were able to provide the maximum set of 1,190 W to the thruster, giving a nominal thrust of 68 mN, hence an acceleration of 0.2 mm/s2 or 0.7 m/s per hour (i.e., just under 0.00002 g of acceleration). As with all ion-engine powered craft, orbital maneuvers were not carried out in short bursts but very gradually. The particular trajectory taken by SMART-1 to the Moon required thrusting for about one third to one half of every orbit. When spiraling away from the Earth thrusting was done on the perigee part of the orbit. At the end of the mission, the thruster had demonstrated the following capability:
Thruster operating time: 5000 h
Xenon throughput: 82 kg |
https://en.wikipedia.org/wiki/Jim%20Hugunin | Jim Hugunin is a software programmer who created the Python programming language extension Numeric (ancestor to NumPy), and later created Python implementations for the Java Platform (Jython) and for Microsoft .NET platform (IronPython); he has also co-designed the AspectJ extension for the Java programming language. He worked for Microsoft from 2004 to 2010, mainly on IronPython and Dynamic Language Runtime.
In October 2010, after Microsoft abandoned the IronPython project, Hugunin left Microsoft to work for Google.
On his personal website, he described Microsoft's decision regarding IronPython as "a catalyst but not the cause of my leaving the company", and said that having "a healthy relationship with Open Source code and communities" at Microsoft was "possible" but "felt like trying to fit a square peg into a round hole". According to LinkedIn, Jim left Google in May 2013.
In December 2017, Jim launched a beta version of a cloth simulator called Artful Physics. |
https://en.wikipedia.org/wiki/Weil%E2%80%93Brezin%20Map | In mathematics, the Weil–Brezin map, named after André Weil and Jonathan Brezin, is a unitary transformation that maps a Schwartz function on the real line to a smooth function on the Heisenberg manifold. The Weil–Brezin map gives a geometric interpretation of the Fourier transform, the Plancherel theorem and the Poisson summation formula. The image of Gaussian functions under the Weil–Brezin map are nil-theta functions, which are related to theta functions. The Weil–Brezin map is sometimes referred to as the Zak transform, which is widely applied in the field of physics and signal processing; however, the Weil–Brezin Map is defined via Heisenberg group geometrically, whereas there is no direct geometric or group theoretic interpretation from the Zak transform.
Heisenberg manifold
The (continuous) Heisenberg group is the 3-dimensional Lie group that can be represented by triples of real numbers with multiplication rule
The discrete Heisenberg group is the discrete subgroup of whose elements are represented by the triples of integers. Considering acts on on the left, the quotient manifold is called the Heisenberg manifold.
The Heisenberg group acts on the Heisenberg manifold on the right. The Haar measure on the Heisenberg group induces a right-translation-invariant measure on the Heisenberg manifold. The space of complex-valued square-integrable functions on the Heisenberg manifold has a right-translation-invariant orthogonal decomposition:
where
.
Definition
The Weil–Brezin map is the unitary transformation given by
for every Schwartz function , where convergence is pointwise.
The inverse of the Weil–Brezin map is given by
for every smooth function on the Heisenberg manifold that is in .
Fundamental unitary representation of the Heisenberg group
For each real number , the fundamental unitary representation of the Heisenberg group is an irreducible unitary representation of on defined by
.
By Stone–von Neumann theorem, this is the unique |
https://en.wikipedia.org/wiki/Symphytum%20peregrinum | Symphytum peregrinum may refer to the following comfrey species:
Symphytum peregrinum auct.: Symphytum × uplandicum, the Russian or Quaker comfrey
Symphytum peregrinum Ledeb.: Symphytum officinale subsp. officinale |
https://en.wikipedia.org/wiki/Glitch%20removal | Glitch removal is the elimination of glitchesunnecessary signal transitions without functionalityfrom electronic circuits. Power dissipation of a gate occurs in two ways: static power dissipation and dynamic power dissipation. Glitch power comes under dynamic dissipation in the circuit and is directly proportional to switching activity. Glitch power dissipation is 20%–70% of total power dissipation and hence glitching should be eliminated for low power design.
Switching activity occurs due to signal transitions which are of two types: functional transition and a glitch. Switching power dissipation is directly proportional to the switching activity (α), load capacitance (C), Supply voltage (V), and clock frequency (f) as:
P = α·C·V2·f
Switching activity means transition to different levels. Glitches are dependent on signal transitions and more glitches results in higher power dissipation. As per above equation switching power dissipation can be controlled by controlling switching activity (α), voltage scaling etc.
Glitch reduction techniques
Reducing switching activity
As discussed, more transition results in more glitches and hence more power dissipation. To minimize glitch occurrence, switching activity should be minimized. For example, Gray code could be used in counters instead of binary code, since every increment in Gray code only flips one bit.
Gate freezing
Gate freezing minimizes power dissipation by eliminating glitching. It relies on the availability of modified standard library cells such as the so-called F-Gate. This method consists of transforming high glitch gates into modified devices which filter out the glitches when a control signal is applied. When the control signal is high, the F-Gate operates as normal but when the control signal is low, the gate output is disconnected from the ground. As a result it can never be discharged to logic 0 and glitches are prevented.
Hazard filtering and balanced path delay
Hazards in digital circuits |
https://en.wikipedia.org/wiki/Number%20density | The number density (symbol: n or ρN) is an intensive quantity used to describe the degree of concentration of countable objects (particles, molecules, phonons, cells, galaxies, etc.) in physical space: three-dimensional volumetric number density, two-dimensional areal number density, or one-dimensional linear number density. Population density is an example of areal number density. The term number concentration (symbol: lowercase n, or C, to avoid confusion with amount of substance indicated by uppercase N) is sometimes used in chemistry for the same quantity, particularly when comparing with other concentrations.
Definition
Volume number density is the number of specified objects per unit volume:
where N is the total number of objects in a volume V.
Here it is assumed that N is large enough that rounding of the count to the nearest integer does not introduce much of an error, however V is chosen to be small enough that the resulting n does not depend much on the size or shape of the volume V because of large-scale features.
Area number density is the number of specified objects per unit area, A:
Similarly, linear number density is the number of specified objects per unit length, L:
Column number density is a kind of areal density, the number or count of a substance per unit area, obtained integrating volumetric number density along a vertical path:
It's related to column mass density, with the volumetric number density replaced by the volume mass density.
Units
In SI units, number density is measured in m−3, although cm−3 is often used. However, these units are not quite practical when dealing with atoms or molecules of gases, liquids or solids at room temperature and atmospheric pressure, because the resulting numbers are extremely large (on the order of 1020). Using the number density of an ideal gas at and as a yardstick: is often introduced as a unit of number density, for any substances at any conditions (not necessarily limited to an ideal gas at |
https://en.wikipedia.org/wiki/Covering%20problem%20of%20Rado | The covering problem of Rado is an unsolved problem in geometry concerning covering planar sets by squares. It was formulated in 1928 by Tibor Radó and has been generalized to more general shapes and higher dimensions by Richard Rado.
Formulation
In a letter to Wacław Sierpiński, motivated by some results of Giuseppe Vitali, Tibor Radó observed that for every covering of a unit interval, one can select a subcovering consisting of pairwise disjoint intervals with total length at least 1/2 and that this number cannot be improved. He then asked for an analogous statement in the plane.
If the area of the union of a finite set of squares in the plane with parallel sides is one, what is the guaranteed maximum total area of a pairwise disjoint subset?
Radó proved that this number is at least 1/9 and conjectured that it is at least 1/4 a constant which cannot be further improved. This assertion was proved for the case of equal squares independently by A. Sokolin, R. Rado, and V. A. Zalgaller. However, in 1973, Miklós Ajtai disproved Radó's conjecture, by constructing a system of squares of two different sizes for which any subsystem consisting of disjoint squares covers the area at most of the total area covered by the system.
Upper and lower bounds
Problems analogous to Tibor Radó's conjecture but involving other shapes were considered by Richard Rado starting in late 1940s. A typical setting is a finite family of convex figures in the Euclidean space Rd that are homothetic to a given X, for example, a square as in the original question, a disk, or a d-dimensional cube. Let
where S ranges over finite families just described, and for a given family S, I ranges over all subfamilies that are independent, i.e. consist of disjoint sets, and bars denote the total volume (or area, in the plane case). Although the exact value of F(X) is not known for any two-dimensional convex X, much work was devoted to establishing upper and lower bounds in various classes of shape |
https://en.wikipedia.org/wiki/Vagal%20tone | Vagal tone is activity of the vagus nerve, the 10th cranial nerve and a fundamental component of the parasympathetic branch of the autonomic nervous system. This branch of the nervous system is not under conscious control and is largely responsible for the regulation of several body compartments at rest. Vagal activity results in various effects, including: heart rate reduction, vasodilation/constriction of vessels, glandular activity in the heart, lungs, and digestive tract, liver, immune system regulation as well as control of gastrointestinal sensitivity, motility and inflammation.
In this context, tone specifically refers to the continual nature of baseline parasympathetic action that the vagus nerve exerts. While baseline vagal input is constant, the degree of stimulation it exerts is regulated by a balance of inputs from sympathetic and parasympathetic divisions of the autonomic nervous system, with parasympathetic activity generally being dominant. Vagal tone is frequently used to assess heart function, and is also useful in assessing emotional regulation and other processes that alter, or are altered by, changes in parasympathetic activity.
Measurements of vagal tone can be performed by means of either invasive or noninvasive procedures. Invasive procedures are in the minority and include vagus nerve stimulation by specific manual, breathing or electrical techniques. Noninvasive techniques mainly rely on the investigation of heart rate and heart rate variability.
Noninvasive vagal tone quantification
In most cases, vagal tone is not measured directly. Instead the processes affected by the vagus nerve – specifically heart rate and heart rate variability – are measured and used as a surrogate for vagal tone. Increased vagal tone (and thus vagal action) is generally associated with a lower heart rate and increased heart rate variability. However, during graded orthostatic tilt, vagal tone withdrawal is an indirect indicator of cardiovascular fitness.
Vaga |
https://en.wikipedia.org/wiki/OSF/1 | OSF/1 is a variant of the Unix operating system developed by the Open Software Foundation during the late 1980s and early 1990s. OSF/1 is one of the first operating systems to have used the Mach kernel developed at Carnegie Mellon University, and is probably best known as the native Unix operating system for DEC Alpha architecture systems.
In 1994, after AT&T had sold UNIX System V to Novell and the rival Unix International consortium had disbanded, the Open Software Foundation ceased funding of research and development of OSF/1. The Tru64 UNIX variant of OSF/1 was supported by HP until 2012.
Background
In 1988, during the so-called "Unix wars", Digital Equipment Corporation (DEC) joined with IBM, Hewlett-Packard, and others to form the Open Software Foundation (OSF) to develop a version of Unix named OSF/1. The aim was to compete with System V Release 4 from AT&T Corporation and Sun Microsystems, and it has been argued that a primary goal was for the operating system to be free of AT&T intellectual property. The fact that OSF/1 is one of the first operating systems to have used the Mach kernel is cited as support of this assertion. Digital also strongly promoted OSF/1 for real-time applications, and with traditional UNIX implementations at the time providing poor real-time support at best, the real-time and multi-threading support can be interpreted as having been heavily dependent on the Mach kernel. It also incorporates a large part of the BSD kernel (based on the 4.3-Reno release) to implement the UNIX API. At the time of its introduction, OSF/1 became the third major flavor of UNIX together with System V and BSD.
Vendor releases
DEC's first release of OSF/1 (OSF/1 Release 1.0) in January 1992 was for its line of MIPS-based DECstation workstations, however this was never a fully supported product. DEC ported OSF/1 to their new Alpha AXP platform as DEC OSF/1 AXP Release 1.2, released in March 1993. OSF/1 AXP is a full 64-bit operating system. After OSF/1 AX |
https://en.wikipedia.org/wiki/Online%20Protection%20and%20Enforcement%20of%20Digital%20Trade%20Act | The Online Protection and Enforcement of Digital Trade Act (OPEN Act) is a bill introduced in the United States Congress proposed as an alternative to the Stop Online Piracy Act and PROTECT IP Act, by Senator Ron Wyden of Oregon, a Democrat, and Representative Darrell Issa of California, a Republican. The text of the bill is available for public comment at keepthewebopen.com .
Wyden first introduced OPEN in the Senate (S. 2029) on December 17, 2011, with co-sponsors Jerry Moran of Kansas and Maria Cantwell of Washington. Issa and 25 co-sponsors introduced OPEN in the House (H.R. 3782) on January 18, 2012. The Senate bill has been referred to the Finance Committee, and the House bill has been referred to the Judiciary Committee.
On January 14, 2012, in response to two White House petitions, White House technology officials Victoria Espinel, Aneesh Chopra, and Howard Schmidt stated: "Any effort to combat online piracy must guard against the risk of online censorship of lawful activity and must not inhibit innovation by our dynamic businesses large and small...We must avoid creating new cybersecurity risks or disrupting the underlying architecture of the Internet."
Comparison with SOPA and PIPA/PROTECT IP Act
The OPEN Act was proposed as an alternative to the PROTECT IP Act (PIPA), which was approved by the United States Senate Judiciary Committee in May 2011, and the closely related Stop Online Piracy Act (SOPA), which was introduced by House Judiciary Chairman Lamar Smith (R-TX) in November. After an initial description on December 2 as an outline of possible approaches written by a bipartisan group of eleven lawmakers, a draft text was made public on December 8, 2011, in advance of a House Judiciary markup of the SOPA Act the following week. The OPEN Act seeks to stop transfers of money to foreign websites whose primary purpose is piracy or counterfeiting, whereas SOPA and PIPA also seek to require Internet providers and search engines to redirect users away from |
https://en.wikipedia.org/wiki/Calix%2C%20Inc. | Calix, Inc. is a telecommunications company that specializes in providing software platforms, systems, and services to support the delivery of broadband services. The company was founded in 1999 and is headquartered in San Jose, California.
Calix provides cloud, software platforms, systems and services to communications service providers.
Calix maintains facilities in Petaluma, CA, Minneapolis, MN, San Jose, CA, Richardson, TX in the USA and facilities in Nanjing, China and Bangalore, India..
Customers
Calix customers include SCTelcom, Verizon, ALLO Communications, CityFibre, Nex-Tech, Gibson Connect, ITS Fiber, Sogetel, and over 1,600 other broadband service providers globally, majority being in North America.
Competitors
Calix competitors include Cisco, Adtran, Nokia, Allied Telesis, Huawei, Tellabs, ZTE and DZS.
Industry News
With Amazon Alexa, Calix Translates Smart Home Opp Into Reality
Amazon expands white-box Alexa device lineup with new home hub and gateway hardware
How Verizon & Calix Unlocked NGPON2
Acquisitions history
In 2006, Calix purchased Optical Solutions, Inc., based in Minneapolis, MN.
In 2010, Calix announced acquisition of one-time rival Occam Networks, Inc., based in Santa Barbara, California. The acquisition was completed in February, 2011.
In Nov 2012, Calix completed acquisition of Ericsson’s fiber access assets.
Other Resources |
https://en.wikipedia.org/wiki/Butylparaben | Butylparaben, or butyl p-hydroxybenzoate, is an organic compound with the formula . It is a white solid that is soluble in organic solvents. It has proven to be a highly successful antimicrobial preservative in cosmetics. It is also used in medication suspensions, and as a flavoring additive in food.
Natural occurrence
Members of the paraben family are found in fruit and vegetable products, such as barley, flax seed, and grapes. Butylparaben has also been found to be produced in some microorganisms including Microbulbifer .
Preparation
Butylparaben is prepared by the esterification of 4-hydroxybenzoic acid with 1-butanol in the presence of an acid catalyst such as sulfuric acid. It is produced industrially.
Uses and reactions
Butylparaben is one of the most common bactericidal/fungicidal additives in cosmetics. It has been used in cosmetic products since the 1940s and in pharmaceutical products since 1924. The popularity of butylparaben in these products is due to its low toxicity in humans and its effective antimicrobial properties, in particular those against mold and yeast. It is now found in more than 20,000 cosmetic products including eye shadow, facial moisturizer/treatment, anti-aging cream, foundation, and sunscreen. It is also used as low-ionic strength solutions as a preservative in some foods and drugs. In most cosmetics paraben is used at low levels, ranging from 0.01 to 0.3%. Butylparaben is used in low concentrations in liquid and solid medication suspensions, such as Tylenol (acetaminophen) and ibuprofen.
Mechanism of action
The exact mechanism of how parabens work is unknown but they are proposed to act by inhibiting DNA and RNA synthesis, and enzymes like ATPase and phosphotransferase in some bacterial species. It has also been suggested that they interfere with membrane transport processes by disrupting the lipid bilayer and possibly causing the leakage of intracellular constituents.
Regulation and controversy
Butylparaben has not esca |
https://en.wikipedia.org/wiki/Stereotypy%20%28non-human%29 | In animal behaviour, stereotypy, stereotypic or stereotyped behaviour has several meanings, leading to ambiguity in the scientific literature. A stereotypy is a term for a group of phenotypic behaviours that are repetitive, morphologically identical and which possess no obvious goal or function. These behaviours have been defined as 'abnormal', as they exhibit themselves solely in animals subjected to barren environments, scheduled or restricted feedings, social deprivation and other cases of frustration, but do not arise in 'normal' animals in their natural environments. These behaviours may be maladaptive, involving self-injury or reduced reproductive success, and in laboratory animals can confound behavioural research. Stereotypical behaviours are thought to be caused ultimately by artificial environments that do not allow animals to satisfy their normal behavioural needs. Rather than refer to the behaviour as abnormal, it has been suggested that it be described as "behaviour indicative of an abnormal environment".
Stereotyped behaviour can also refer to normal behaviours that show low variation. For example, mammalian chewing cycles or fish capturing prey using suction feeding. Highly stereotyped movements may be due to mechanical constraint (such as the skull of a viper or fish, in which bones are mechanically linked), tight neural control (as in mammalian chewing), or both. The degree of stereotyping may vary markedly between closely related species engaging in the same behaviour.
Onset and persistence
The display of stereotypies is usually increased in an individual over time due to the changing motivation of the stereotypy. The establishment of a stereotypy may be due to a number of factors within a captive environment. One of the factors within a captive environment that may affect the establishment of stereotypies is exploratory behaviours that are directed to the outside of a cage. Research suggests that some common stereotypic behaviours seen in m |
https://en.wikipedia.org/wiki/Krste%20Asanovi%C4%87 | Krste Asanović from the University of California, Berkeley has written and co-authored many academic papers concerning computer architecture. , he is chairman of the Board of the RISC-V Foundation.
Asanović was named Fellow of the Institute of Electrical and Electronics Engineers (IEEE) in 2014 for contributions to computer architecture. He was elected as an ACM Fellow in 2018 for "contributions to computer architecture, including the open RISC-V instruction set and Agile hardware".
Asanović received a PhD in computer science from Berkeley in 1998 under John Wawrzynek. In 2015, along with RISC-V researchers he co-founded SiFive, a fabless semiconductor company and provider of commercial RISC-V processor IP, where he serves as its chief architect. |
https://en.wikipedia.org/wiki/Max%20Delbr%C3%BCck | Max Ludwig Henning Delbrück (; September 4, 1906 – March 9, 1981) was a German–American biophysicist who participated in launching the molecular biology research program in the late 1930s. He stimulated physical scientists' interest into biology, especially as to basic research to physically explain genes, mysterious at the time. Formed in 1945 and led by Delbrück along with Salvador Luria and Alfred Hershey, the Phage Group made substantial headway unraveling important aspects of genetics. The three shared the 1969 Nobel Prize in Physiology or Medicine "for their discoveries concerning the replication mechanism and the genetic structure of viruses". He was the first physicist to predict what is now called Delbrück scattering.
Early and personal life
Delbrück was born in Berlin, German Empire. His mother was granddaughter of Justus von Liebig, an eminent chemist, while his father Hans Delbrück was a history professor at the University of Berlin. In 1937, Delbrück left Nazi Germany for America—first California, then Tennessee—becoming a US citizen in 1945. In 1941, he married Mary Bruce. They had four children.
Delbrück's brother Justus, a lawyer, as well as his sister Emmi Bonhoeffer were active along with his brothers-in-law Klaus Bonhoeffer and Dietrich Bonhoeffer in resistance to Nazism. Found guilty by the People's Court for roles in the July 20, 1944 plot to assassinate Hitler, Dietrich and Klaus were executed in 1945 by the RSHA. Justus died in Soviet custody that same year. His son, Tobias Delbruck is a professor at the Institute of Neuroinformatics at the University of Zurich and ETH Zurich. Professor Tobias Delbruck is also one of the pioneers in the domain of event cameras, now increasingly being deployed in dynamic vision systems.
Education
Delbrück studied astrophysics, shifting towards theoretical physics, at the University of Göttingen. After completing his Ph.D. there in 1930, he traveled through England, Denmark, and Switzerland. He met Wolfgan |
https://en.wikipedia.org/wiki/Marine%20restoration | Marine restoration involves actions taken to restore the marine environment to its state prior to anthropogenic damage. This is particularly disastrous given that the ocean takes up the largest part of our planet and serves as the home to many organisms, including the algae that provides most. The ocean is currently suffering from the impacts of human damage including pollution, acidification, species loss, and more. This could prove particularly catastrophic given that the ocean takes up the largest part of the planet and serves as the home to many organisms, including the algae that provides around half of the oxygen on Earth. Efforts have been made by various agencies to help alleviate these issues.
Methods
Carbon dioxide removal
The ocean has long helped get rid of excess carbon on Earth with its role in the Carbon cycle. However, the excess emissions and warming temperature as the result of climate change may change the ocean's ability to cycle carbon as efficiently. This has made it necessary to augment natural processes to increase the natural amount of Carbon Dioxide Removal (CDR). Electrochemical approaches remain the most popular. Current methods involve applying voltage to a membrane stack to split the stream of water. A team of professors from MIT have hypothesized ways to make the methods cheaper and more efficient. Efforts to improve carbon capture naturally by means of preserving the seagrass meadows have been enacted by various British conservation efforts.
Coral restoration
Coral reefs provide a vital part of the ocean ecosystem, serving as the habitat to many species and protection for the coastline from erosion and storms. At this time, thirty to fifty percent of Earth's coral reefs have already been lost . Coral has been threatened by pollution, overfishing, and unsafe fishing techniques. Methods to restore coral reefs have involved the gardening and transplanting of coral developed at different sites to locations previously inhabited by co |
https://en.wikipedia.org/wiki/List%20of%20Xbox%20games%20compatible%20with%20Xbox%20360 | The Xbox 360 gaming console has received updates from Microsoft from its launch in 2005 until November 2007 that enable it to play select games from its predecessor, Xbox. The Xbox 360 launched with backward compatibility with the number of supported Xbox games varying depending on region. Microsoft continued to update the list of Xbox games that were compatible with Xbox 360 until November 2007 when the list was finalized. Microsoft later launched the Xbox Originals program on December 7, 2007 where select backward compatible Xbox games could be purchased digitally on Xbox 360 consoles with the program ending less than two years later in June 2009. The following is a list of all backward compatible games on Xbox 360 under this functionality.
History
At its launch in November 2005, the Xbox 360 did not possess hardware-based backward compatibility with Xbox games due to the different types of hardware and architecture used in the Xbox and Xbox 360. Instead backward compatibility was achieved using software emulation. When the Xbox 360 launched in North America 212 Xbox games were supported while in Europe 156 games were supported. The Japanese market had the fewest titles supported at launch with only 12 games. Microsoft's final update to the list of backward compatible titles was in November 2007 bringing the final total to 461 Xbox games.
In order to use the backwards compatibility feature on Xbox 360 a hard drive is required. Updates to the list were provided from Microsoft as part of regular software updates via the Internet, ordering a disc by mail from the official website or downloading the update from the official website then burning it to either a CD or DVD. Subscribers to Official Xbox Magazine would also have updates to the backwards compatibility list on the demo discs included with the magazine.
Supported original Xbox games will run each with an emulation profile that has been recompiled for each game with the emulation profiles stored on the cons |
https://en.wikipedia.org/wiki/Whewell%20equation | The Whewell equation of a plane curve is an equation that relates the tangential angle () with arclength (), where the tangential angle is the angle between the tangent to the curve and the -axis, and the arc length is the distance along the curve from a fixed point. These quantities do not depend on the coordinate system used except for the choice of the direction of the -axis, so this is an intrinsic equation of the curve, or, less precisely, the intrinsic equation. If a curve is obtained from another by translation then their Whewell equations will be the same.
When the relation is a function, so that tangential angle is given as a function of arclength, certain properties become easy to manipulate. In particular, the derivative of the tangential angle with respect to arclength is equal to the curvature. Thus, taking the derivative of the Whewell equation yields a Cesàro equation for the same curve.
The concept is named after William Whewell, who introduced it in 1849, in a paper in the Cambridge Philosophical Transactions. In his conception, the angle used is the deviation from the direction of the curve at some fixed starting point, and this convention is sometimes used by other authors as well. This is equivalent to the definition given here by the addition of a constant to the angle or by rotating the curve.
Properties
If the curve is given parametrically in terms of the arc length , then is determined by
which implies
Parametric equations for the curve can be obtained by integrating:
Since the curvature is defined by
the Cesàro equation is easily obtained by differentiating the Whewell equation.
Examples |
https://en.wikipedia.org/wiki/Szeg%C5%91%20kernel | In the mathematical study of several complex variables, the Szegő kernel is an integral kernel that gives rise to a reproducing kernel on a natural Hilbert space of holomorphic functions. It is named for its discoverer, the Hungarian mathematician Gábor Szegő.
Let Ω be a bounded domain in Cn with C2 boundary, and let A(Ω) denote the space of all holomorphic functions in Ω that are continuous on . Define the Hardy space H2(∂Ω) to be the closure in L2(∂Ω) of the restrictions of elements of A(Ω) to the boundary. The Poisson integral implies that each element ƒ of H2(∂Ω) extends to a holomorphic function Pƒ in Ω. Furthermore, for each z ∈ Ω, the map
defines a continuous linear functional on H2(∂Ω). By the Riesz representation theorem, this linear functional is represented by a kernel kz, which is to say
The Szegő kernel is defined by
Like its close cousin, the Bergman kernel, the Szegő kernel is holomorphic in z. In fact, if φi is an orthonormal basis of H2(∂Ω) consisting entirely of the restrictions of functions in A(Ω), then a Riesz–Fischer theorem argument shows that |
https://en.wikipedia.org/wiki/Loopback | Loopback (also written loop-back) is the routing of electronic signals or digital data streams back to their source without intentional processing or modification. It is primarily a means of testing the communications infrastructure.
Applications
There are many example applications. It may be a communication channel with only one communication endpoint. Any message transmitted by such a channel is immediately and only received by that same channel. In telecommunications, loopback devices perform transmission tests of access lines from the serving switching center, which usually does not require the assistance of personnel at the served terminal. Loop around is a method of testing between stations that are not necessarily adjacent, wherein two lines are used, with the test being done at one station and the two lines are interconnected at the distant station. A patch cable may also function as loopback, when applied manually or automatically, remotely or locally, facilitating a loop-back test.
Where a system (such as a modem) involves round-trip analog-to-digital processing, a distinction is made between analog loopback, where the analog signal is looped back directly, and digital loopback, where the signal is processed in the digital domain before being re-converted to an analog signal and returned to the source.
Telecommunications
In telecommunications, loopback, or a loop, is a hardware or software method which feeds a received signal or data back to the sender. It is used as an aid in debugging physical connection problems. As a test, many data communication devices can be configured to send specific patterns (such as all ones) on an interface and can detect the reception of this signal on the same port. This is called a loopback test and can be performed within a modem or transceiver by connecting its output to its own input. A circuit between two points in different locations may be tested by applying a test signal on the circuit in one location, and having |
https://en.wikipedia.org/wiki/Universe%20%28mathematics%29 | In mathematics, and particularly in set theory, category theory, type theory, and the foundations of mathematics, a universe is a collection that contains all the entities one wishes to consider in a given situation.
In set theory, universes are often classes that contain (as elements) all sets for which one hopes to prove a particular theorem. These classes can serve as inner models for various axiomatic systems such as ZFC or Morse–Kelley set theory. Universes are of critical importance to formalizing concepts in category theory inside set-theoretical foundations. For instance, the canonical motivating example of a category is Set, the category of all sets, which cannot be formalized in a set theory without some notion of a universe.
In type theory, a universe is a type whose elements are types.
In a specific context
Perhaps the simplest version is that any set can be a universe, so long as the object of study is confined to that particular set. If the object of study is formed by the real numbers, then the real line R, which is the real number set, could be the universe under consideration. Implicitly, this is the universe that Georg Cantor was using when he first developed modern naive set theory and cardinality in the 1870s and 1880s in applications to real analysis. The only sets that Cantor was originally interested in were subsets of R.
This concept of a universe is reflected in the use of Venn diagrams. In a Venn diagram, the action traditionally takes place inside a large rectangle that represents the universe U. One generally says that sets are represented by circles; but these sets can only be subsets of U. The complement of a set A is then given by that portion of the rectangle outside of As circle. Strictly speaking, this is the relative complement U \ A of A relative to U; but in a context where U is the universe, it can be regarded as the absolute complement AC of A. Similarly, there is a notion of the nullary intersection, that is the intersect |
https://en.wikipedia.org/wiki/Potrzebie | Potrzebie (; dative/locative of potrzeba, "a need") is a Polish word popularized by its non sequitur use as a running gag in the early issues of Mad not long after the comic book began in 1952.
Origin
Mad editor Harvey Kurtzman spotted the word printed in the Polish language section of a multi-languaged "Instructions for Use" sheet accompanying a bottle of aspirin, and Kurtzman, who was fascinated with unusual words, decided it would make an appropriate but meaningless background gag. After cutting the word out of the instruction sheet, he made copies and used rubber cement to paste "Potrzebie" randomly into the middle of Mad satires.
Appearances
Potrzebie was first used in a story in Mad #11 (May 1954), where it was the exclamation of a character who spoke only in foreign languages and song lyrics, in "Murder the Story", a parody illustrated by Jack Davis. It was used again in Bernard Krigstein's "From Eternity Back to Here!" in Mad #12 (June 1954) on an airplane advertising banner. With the same type font, it reappeared in Jack Davis's "Book! Movie!" in Mad #13 (July 1954), pasted into a panel as the title of an abstract painting seen in the background. In the same issue the word appears as POTS-REBIE, emblazoned on a cauldron in which Robinson Crusoe is roasting a frankfurter. This piece reappeared in one of the earliest Mad paperbacks, Bedside Mad It was illustrated as a rebus in "Puzzle Pages!" in Mad #19 (January 1955). These stories, like others in Mad comics, were written by Harvey Kurtzman. Frequent repetition gave it the status of a catch phrase or in-joke among the readership which continues to the present day. In the first Mad Style Guide, edited by Bhob Stewart in 1994, the word was made available for display on T-shirts and other licensed Mad products. It also sees occasional use as a metasyntactic variable by hackers.
A typical appearance of the word is exemplified by the Mad version of Chaucer's Canterbury Tales (from Mad #43, December 1958) |
https://en.wikipedia.org/wiki/Bisdemethoxycurcumin | Bisdemethoxycurcumin is a curcuminoid found (along with the curcuminoids curcumin and demethoxycurcumin) in turmeric (Curcuma longa), but absent in Javanese turmeric (Curcuma xanthorrhiza). Bisdemethoxycurcumin is used as a pigment and nutraceutical with antimutagenic properties. All three of the curcuminoids found in Curcuma longa have been shown to have antioxidant properties, but bisdemethoxycurcumin is more resistant than the others to alkaline degradation. It was found to be effective in sensitizing PC cells resistance against gemcitabine.
See also
Curcumin
Desmethoxycurcumin |
https://en.wikipedia.org/wiki/Curvature%20form | In differential geometry, the curvature form describes curvature of a connection on a principal bundle. The Riemann curvature tensor in Riemannian geometry can be considered as a special case.
Definition
Let G be a Lie group with Lie algebra , and P → B be a principal G-bundle. Let ω be an Ehresmann connection on P (which is a -valued one-form on P).
Then the curvature form is the -valued 2-form on P defined by
(In another convention, 1/2 does not appear.) Here stands for exterior derivative, is defined in the article "Lie algebra-valued form" and D denotes the exterior covariant derivative. In other terms,
where X, Y are tangent vectors to P.
There is also another expression for Ω: if X, Y are horizontal vector fields on P, then
where hZ means the horizontal component of Z, on the right we identified a vertical vector field and a Lie algebra element generating it (fundamental vector field), and is the inverse of the normalization factor used by convention in the formula for the exterior derivative.
A connection is said to be flat if its curvature vanishes: Ω = 0. Equivalently, a connection is flat if the structure group can be reduced to the same underlying group but with the discrete topology.
Curvature form in a vector bundle
If E → B is a vector bundle, then one can also think of ω as a matrix of 1-forms and the above formula becomes the structure equation of E. Cartan:
where is the wedge product. More precisely, if and denote components of ω and Ω correspondingly, (so each is a usual 1-form and each is a usual 2-form) then
For example, for the tangent bundle of a Riemannian manifold, the structure group is O(n) and Ω is a 2-form with values in the Lie algebra of O(n), i.e. the antisymmetric matrices. In this case the form Ω is an alternative description of the curvature tensor, i.e.
using the standard notation for the Riemannian curvature tensor.
Bianchi identities
If is the canonical vector-valued 1-form on the frame bundle, the torsio |
https://en.wikipedia.org/wiki/Immune%20privilege | Certain sites of the mammalian body have immune privilege, meaning they are able to tolerate the introduction of antigens without eliciting an inflammatory immune response. Tissue grafts are normally recognised as foreign antigens by the body and attacked by the immune system. However, in immune privileged sites, tissue grafts can survive for extended periods of time without rejection occurring. Immunologically privileged sites include:
the eyes
the placenta and fetus
the testicles
the central nervous system
Immune privilege is also believed to occur to some extent or able to be induced in articular cartilage. This was once thought to also include the brain, but this is now known to be incorrect, as it has been shown that immune cells of the central nervous system contribute to the maintenance of neurogenesis and spatial learning abilities in adulthood.
Immune privilege is thought to be an evolutionary adaptation to protect vital structures from the potentially damaging effects of an inflammatory immune response. Inflammation in the brain or eye can lead to loss of organ function, while immune responses directed against a fetus can lead to miscarriage.
Medically, a cornea transplant takes advantage of this, as does knee meniscal transplantation.
Mechanisms
Antigens from immune privileged regions have been found to interact with T cells in an unusual way: inducing tolerance of normally rejected stimuli. Immune privilege has emerged as an active rather than a passive process.
Physical structures surrounding privileged sites cause a lack of lymphatic drainage, limiting the immune system's ability to enter the site. Other factors that contribute to the maintenance of immune privilege include:
low expression of classical MHC class Ia molecules
expression of immunoregulatory nonclassical, low polymorphic class Ib MHC molecules
increased expression of surface molecules that inhibit complement activation
local production of immunosuppressive cytokines such as T |
https://en.wikipedia.org/wiki/SOS%20Mata%20Atl%C3%A2ntica%20Foundation | The SOS Mata Atlântica Foundation was created in 1986 as a non-governmental and non-profit organization, with the goal of defending what remains of Mata Atlântica (the Atlantic Forest) in Brazil. Its actions are divided in six areas: public policies; campaigns; documentation, information and communication for conservation; environmental education and good citizenship; institutional development; and sustainable development, protection and handling of ecosystems.
Projects
Its most notable project, ClickArvore, aims at the reforestation of the Atlantic Forest. Since the year 2000, it has planted about 22 million native trees, covering an area of approximately 130 km2. ClickArvore was idealized by Rodrigo Agostinho, who was elected mayor of Bauru in 2008. |
https://en.wikipedia.org/wiki/Peripheral%20bus | In computing, a peripheral bus is a computer bus designed to support computer peripherals like printers and hard drives. The term is generally used to refer to systems that offer support for a wide variety of devices, like Universal Serial Bus, as opposed to those that are dedicated to specific types of hardware. Serial AT Attachment, or SATA is designed and optimized for communication with mass storage devices.
This usage is not universal, some definitions of peripheral bus include any bus that is not a system bus, including examples like PCI. Others treat PCI and similar systems as a third category, the expansion bus.
Examples
Universal Serial Bus (USB)
FireWire
ACCESS.bus
Apple Desktop Bus |
https://en.wikipedia.org/wiki/Torque%20amplifier | A torque amplifier is a mechanical device that amplifies the torque of a rotating shaft without affecting its rotational speed. It is mechanically related to the capstan seen on ships. Its most widely known use is in power steering on automobiles. Another use is on the differential analyser, where it was used to increase the output torque of the otherwise limited ball-and-disk integrator. The term is also applied to some gearboxes used on tractors, although this is unrelated. It differs from a torque converter, in which the rotational speed of the output shaft decreases as the torque increases.
History
The first electric-powered torque amplifier was invented in 1925 by Henry W. Nieman of the Bethlehem Steel Company of Bethlehem, Pennsylvania. It was intended to allow manual control of heavy equipment; e.g., industrial cranes, artillery, etc.
Vannevar Bush used Nieman's torque amplifier as part of his differential analyzer project at M.I.T in the early 1930s. Lord Kelvin had already discussed the possible construction of such calculators as early as the 1880s, but had been stymied by the limited output torque of the ball-and-disk integrators. These integrators used a ball bearing pressed between the surface of a rotating shaft and a disk, transmitting the rotational force of the shaft to the disk. By moving the ball along the shaft, the speed of the disk could be smoothly varied. The torque on the output shaft was limited by the friction between the bearing and the disk, and as these were generally made out of friction-limiting metals such as bronze to allow smooth motion, the output torque was quite low. Some calculating devices could use the output directly, and Kelvin and others built several systems, but in the case of a differential analyzer, the output of one integrator drove the input of the next integrator, or a graphing output. The torque amplifier was the advance that allowed these machines to work.
Principle
A torque amplifier is essentially two capst |
https://en.wikipedia.org/wiki/Ross%27s%20conjecture | In queueing theory, a discipline within the mathematical theory of probability, Ross's conjecture gives a lower bound for the average waiting-time experienced by a customer when arrivals to the queue do not follow the simplest model for random arrivals. It was proposed by Sheldon M. Ross in 1978 and proved in 1981 by Tomasz Rolski. Equality can be obtained in the bound; and the bound does not hold for finite buffer queues.
Bound
Ross's conjecture is a bound for the mean delay in a queue where arrivals are governed by a doubly stochastic Poisson process
or by a non-stationary Poisson process. The conjecture states that the average amount of time that a customer spends waiting in a queue is greater than or equal to
where S is the service time and λ is the average arrival rate (in the limit as the length of the time period increases). |
https://en.wikipedia.org/wiki/Reversibly%20assembled%20cellular%20composite%20materials | Reversibly assembled cellular composite materials (RCCM) are three-dimensional lattices of modular structures that can be partially disassembled to enable repairs or other modifications. Each cell incorporates structural material and a reversible interlock, allowing lattices of arbitrary size and shape. RCCM display three-dimensional symmetry derived from the geometry as linked.
The discrete construction of reversibly assembled cellular composites introduces a new degree of freedom that determines global functional properties from the local placement of heterogeneous components. Because the individual parts are literally finite elements, a hierarchical decomposition describes the part types and their combination in a structure.
RCCM can be viewed as a “digital” material in which discrete parts link with a discrete set of relative positions and orientations. An assembler can place them using only local information. Placement errors can be detected and corrected by assembly reversal. These materials combine the size and strength of composites with the low density of cellular materials and the convenience of additive manufacturing.
History
RCCM were introduced in 2013 by researchers at the MIT Center for Bits and Atoms.
Behavior
Elasticity
RCCM lattices behave as an elastic solid in both tension and compression. They offer both a linear regime and a nonlinear super-elastic deformation mode a modulus an order of magnitude greater than for an ultralight material (12.3 megapascals at a density of 7.2 mg per cubic centimeter). Bulk properties can be predicted from component measurements and deformation modes determined by the placement of part types. Site locations are locally constrained, yielding structures that merge desirable features of carbon fiber composites, cellular materials and additive manufacturing.
Nonlinear elastic behavior derives from a multi-axial elastic instability of the lattice, a complex coordinated elastic buckling of the strut members. The |
https://en.wikipedia.org/wiki/Doctrine%20of%20signatures | The doctrine of signatures, dating from the time of Dioscorides and Galen, states that herbs resembling various parts of the body can be used by herbalists to treat ailments of those body parts. A theological justification, as stated by botanists such as William Coles, was that God would have wanted to show men what plants would be useful for.
It is today considered to be pseudoscience, and has led to many deaths and severe illnesses. For instance birthwort (so-called because of its resemblance to the uterus), once used widely for pregnancies, is carcinogenic and very damaging to the kidneys, owing to its aristolochic acid content. As a defense against predation, many plants contain toxic chemicals, the action of which is not immediately apparent, or easily tied to the plant rather than other factors.
History
The concept dates from the time of Dioscorides and Galen.
Paracelsus (1493–1541) developed the concept, writing that "Nature marks each growth ... according to its curative benefit", and it was followed by Giambattista della Porta in his Phytognomonica (1588).
The writings of Jakob Böhme (1575–1624) spread the doctrine of signatures. He suggested that God marked objects with a sign, or "signature", for their purpose.
Plants bearing parts that resembled human body-parts, animals, or other objects were thought to have useful relevance to those parts, animals or objects. The "signature" could sometimes also be identified in the environments or specific sites in which plants grew. Böhme's 1621 book The Signature of All Things gave its name to the doctrine. The English physician-philosopher Sir Thomas Browne in his discourse The Garden of Cyrus (1658) uses the Quincunx pattern as an archetype of the 'doctrine of signatures' pervading the design of gardens and orchards, botany and the Macrocosm at large.
The 17th century botanist William Coles supposed that God had made 'Herbes for the use of men, and hath given them particular Signatures, whereby a man may read |
https://en.wikipedia.org/wiki/Atomic%20orbital | In atomic theory and quantum mechanics, an atomic orbital () is a function describing the location and wave-like behavior of an electron in an atom. This function can be used to calculate the probability of finding any electron of an atom in any specific region around the atom's nucleus. The term atomic orbital may also refer to the physical region or space where the electron can be calculated to be present, as predicted by the particular mathematical form of the orbital.
Each orbital in an atom is characterized by a set of values of the three quantum numbers , , and , which respectively correspond to the electron's energy, its angular momentum, and an angular momentum vector component (magnetic quantum number). As an alternative to the magnetic quantum number, the orbitals are often labeled by the associated harmonic polynomials (e.g., xy, ). Each such orbital can be occupied by a maximum of two electrons, each with its own projection of spin . The simple names s orbital, p orbital, d orbital, and f orbital refer to orbitals with angular momentum quantum number and respectively. These names, together with the value of , are used to describe the electron configurations of atoms. They are derived from the description by early spectroscopists of certain series of alkali metal spectroscopic lines as sharp, principal, diffuse, and fundamental. Orbitals for > 3 continue alphabetically (g, h, i, k, ...), omitting j because some languages do not distinguish between the letters "i" and "j".
Atomic orbitals are the basic building blocks of the atomic orbital model (or electron cloud or wave mechanics model), a modern framework for visualizing the submicroscopic behavior of electrons in matter. In this model the electron cloud of an atom may be seen as being built up (in approximation) in an electron configuration that is a product of simpler hydrogen-like atomic orbitals. The repeating periodicity of blocks of 2, 6, 10, and 14 elements within sections of the periodic ta |
https://en.wikipedia.org/wiki/Footedness | In human biology, footedness is the natural preference of one's left or right foot for various purposes. It is the foot equivalent of handedness. While purposes vary, such as applying the greatest force in a certain foot to complete the action of kick as opposed to stomping, footedness is most commonly associated with the preference of a particular foot in the leading position while engaging in foot- or kicking-related sports, such as association football and kickboxing. A person may thus be left-footed, right-footed or ambipedal (able to use both feet equally well).
Ball games
In association football, the ball is predominantly struck by the foot. Footedness may refer to the foot a player uses to kick with the greatest force and skill. Most people are right-footed, kicking with the right leg. Capable left-footed footballers are rare and therefore quite sought after. As rare are "two-footed" players, who are equally capable with both feet. Such players make up only one sixth of players in the top professional leagues in Europe. Two-footedness can be learnt, a notable case being England international Tom Finney, but can only be properly developed in the early years. In Australian Rules Football, several players are equally adept at using both feet to kick the ball, such as Sam Mitchell and Charles Bushnell (footballer, retired).
In basketball, a sport composed almost solely of right-handed players, it is common for most athletes to have a dominant left leg which they would use when jumping to complete a right-hand layup. Hence, left-handed basketball players tend to use their right leg more as they finish a left handed layup (although both right- and left-handed players are usually able to use both hands when finishing near the basket).
In the National Football League, a disproportionate, and increasing, number of punters punt with their left leg, where punting is the position in play that receives and kicks the ball once it leaves the line of scrimmage. At the |
https://en.wikipedia.org/wiki/254%20%28number%29 | 254 (two hundred [and] fifty-four) is the natural number following 253 and preceding 255.
In mathematics
It is a deficient number, since the sum of its divisors (excluding the same number) is 130 < 254.
It is a semiprime number. Moreover, in American English, its name has a semiprime number of syllables.
It is a square-free integer.
It is a nontotient.
It is a lazy caterer number.
It is a congruent number. |
https://en.wikipedia.org/wiki/DinI-like%20protein%20family | In molecular biology, the DinI-like protein family is a family of short proteins. The family includes DNA-damage-inducible protein I (DinI) and related proteins. The SOS response, a set of cellular phenomena exhibited by eubacteria, is initiated by various causes that include DNA damage-induced replication arrest, and is positively regulated by the co-protease activity of RecA. Escherichia coli DinI, a LexA-regulated SOS gene product, shuts off the initiation of the SOS response when overexpressed in vivo. Biochemical and genetic studies indicated that DinI physically interacts with RecA to inhibit its co-protease activity. The structure of DinI is known. |
https://en.wikipedia.org/wiki/Pi-system | In mathematics, a -system (or pi-system) on a set is a collection of certain subsets of such that
is non-empty.
If then
That is, is a non-empty family of subsets of that is closed under non-empty finite intersections.
The importance of -systems arises from the fact that if two probability measures agree on a -system, then they agree on the -algebra generated by that -system. Moreover, if other properties, such as equality of integrals, hold for the -system, then they hold for the generated -algebra as well. This is the case whenever the collection of subsets for which the property holds is a -system. -systems are also useful for checking independence of random variables.
This is desirable because in practice, -systems are often simpler to work with than -algebras. For example, it may be awkward to work with -algebras generated by infinitely many sets So instead we may examine the union of all -algebras generated by finitely many sets This forms a -system that generates the desired -algebra. Another example is the collection of all intervals of the real line, along with the empty set, which is a -system that generates the very important Borel -algebra of subsets of the real line.
Definitions
A -system is a non-empty collection of sets that is closed under non-empty finite intersections, which is equivalent to containing the intersection of any two of its elements.
If every set in this -system is a subset of then it is called a
For any non-empty family of subsets of there exists a -system called the , that is the unique smallest -system of containing every element of
It is equal to the intersection of all -systems containing and can be explicitly described as the set of all possible non-empty finite intersections of elements of
A non-empty family of sets has the finite intersection property if and only if the -system it generates does not contain the empty set as an element.
Examples
For any real numbers and the intervals form a |
https://en.wikipedia.org/wiki/Lessac%20Technologies | Lessac Technologies, Inc. (LTI) is an American firm which develops voice synthesis software, licenses technology and sells synthesized novels as MP3 files. The firm currently has seven patents granted
and three more pending for its automated methods of converting digital text into human-sounding speech, more accurately recognizing human speech and outputting the text representing the words and phrases of said speech, along with recognizing the speaker's emotional state.
The LTI technology is partly based on the work of the late Arthur Lessac, a Professor of Theater at the State University of New York and the creator of Lessac Kinesensic Training, and LTI has licensed exclusive rights to exploit Arthur Lessac's copyrighted works in the fields of speech synthesis and speech recognition. Based on the view that music is speech and speech is music, Lessac's work and books focused on body and speech energies and how they go together. Arthur Lessac's textual annotation system, which was originally developed to assist actors, singers, and orators in marking up scripts to prepare for performance, is adapted in LTI's speech synthesis system as the basic representation of the speech to be synthesized (Lessemes), in contrast to many other systems which use a phonetic representation.
LTI's software has two major components: (1) a linguistic front-end that converts plain text to a sequence of prosodic and phonosensory graphic symbols (Lessemes) based on Arthur Lessac's annotation system, which specify the speech units to be synthesized; (2) a signal-processing back-end that takes the Lessemes as acoustic data and produces human-sounding synthesized speech as output, using unit selection and concatenation.
LTI's text-to-speech system came in second in the world-wide Blizzard Challenge 2011 and 2012. The first-place team in 2011 also employed LTI's "front-end" technology, but with its own back-end. The Blizzard Challenge, conducted by the Language Technologies Institute of Carn |
https://en.wikipedia.org/wiki/Iron%28III%29%20oxide | Iron(III) oxide or ferric oxide is the inorganic compound with the formula Fe2O3. It is one of the three main oxides of iron, the other two being iron(II) oxide (FeO), which is rare; and iron(II,III) oxide (Fe3O4), which also occurs naturally as the mineral magnetite. As the mineral known as hematite, Fe2O3 is the main source of iron for the steel industry. Fe2O3 is readily attacked by acids. Iron(III) oxide is often called rust, and to some extent this label is useful, because rust shares several properties and has a similar composition; however, in chemistry, rust is considered an ill-defined material, described as Hydrous ferric oxide.
Structure
Fe2O3 can be obtained in various polymorphs. In the main one, α, iron adopts octahedral coordination geometry. That is, each Fe center is bound to six oxygen ligands. In the γ polymorph, some of the Fe sit on tetrahedral sites, with four oxygen ligands.
Alpha phase
α-Fe2O3 has the rhombohedral, corundum (α-Al2O3) structure and is the most common form. It occurs naturally as the mineral hematite which is mined as the main ore of iron. It is antiferromagnetic below ~260 K (Morin transition temperature), and exhibits weak ferromagnetism between 260 K and the Néel temperature, 950 K. It is easy to prepare using both thermal decomposition and precipitation in the liquid phase. Its magnetic properties are dependent on many factors, e.g. pressure, particle size, and magnetic field intensity.
Gamma phase
γ-Fe2O3 has a cubic structure. It is metastable and converted from the alpha phase at high temperatures. It occurs naturally as the mineral maghemite. It is ferromagnetic and finds application in recording tapes, although ultrafine particles smaller than 10 nanometers are superparamagnetic. It can be prepared by thermal dehydratation of gamma iron(III) oxide-hydroxide. Another method involves the careful oxidation of iron(II,III) oxide (Fe3O4). The ultrafine particles can be prepared by thermal decomposition of iron(III) oxala |
https://en.wikipedia.org/wiki/Mary%20MacArthur | Mary MacArthur (January 20, 1904 – April 26, 1959) was a Canadian scientist who performed research on the principles of the successful dehydration and freezing of fresh foods.
She performed this research while employed by the federal government of Canada's Department of Agriculture at the Central Experimental Farm in Ottawa, Ontario.
In 1952 she was the first woman to be named as Fellow of the Agricultural Institute of Canada (FAIC) for her contributions to Canadian agriculture.
Biography
Mary MacArthur was born in Glasgow, Scotland. She came to Canada as a child and her family settled in Pugwash, Nova Scotia. She became interested in botany at an early age.
She obtained a B.Sc. with Honors from Acadia University, Nova Scotia, in 1933, after attending a botany course at the Marine Biological Laboratory in Woods Hole, Massachusetts the prior year. She then earned an M.A. at Radcliffe College (affiliated with Harvard University) in 1934 and received her PhD from Harvard in 1937.
Career
After graduation, MacArthur was an assistant professor of botany at a woman's college in Elmira, New York, from 1937 to 1938.
In 1938 she accepted a position as an agricultural scientist, Horticulture Division, at the Central Experimental Farm in Ottawa, Ontario, Canada.
Her early specialty was plant histology and cytology.
MacArthur became well known for her leadership of Canadian research into dehydration, which included fundamental research on methods for determining the inactivation of enzymes in plant tissues prior to dehydration.
She had a large dehydration tunnel built in Ottawa, Ontario in 1942, in which she conducted more than 2000 experiments during the last four years of World War II. She is credited with identifying that vegetables needed blanching to inactivate enzymes before dehydration. She worked jointly with scientists at Kentville, Nova Scotia, who provided her with the dehydrated vegetables for further analysis in Ottawa, Ontario. This was an important activity |
https://en.wikipedia.org/wiki/Angular%20acceleration | In physics, angular acceleration (symbol α, alpha) is the time rate of change of angular velocity. Following the two types of angular velocity, spin angular velocity and orbital angular velocity, the respective types of angular acceleration are: spin angular acceleration, involving a rigid body about an axis of rotation intersecting the body's centroid; and orbital angular acceleration, involving a point particle and an external axis.
Angular acceleration has physical dimensions of angle per time squared, measured in SI units of radians per second squared (rads-2). In two dimensions, angular acceleration is a pseudoscalar whose sign is taken to be positive if the angular speed increases counterclockwise or decreases clockwise, and is taken to be negative if the angular speed increases clockwise or decreases counterclockwise. In three dimensions, angular acceleration is a pseudovector.
For rigid bodies, angular acceleration must be caused by a net external torque. However, this is not so for non-rigid bodies: For example, a figure skater can speed up their rotation (thereby obtaining an angular acceleration) simply by contracting their arms and legs inwards, which involves no external torque.
Orbital angular acceleration of a point particle
Particle in two dimensions
In two dimensions, the orbital angular acceleration is the rate at which the two-dimensional orbital angular velocity of the particle about the origin changes. The instantaneous angular velocity ω at any point in time is given by
where is the distance from the origin and is the cross-radial component of the instantaneous velocity (i.e. the component perpendicular to the position vector), which by convention is positive for counter-clockwise motion and negative for clockwise motion.
Therefore, the instantaneous angular acceleration α of the particle is given by
Expanding the right-hand-side using the product rule from differential calculus, this becomes
In the special case where the p |
https://en.wikipedia.org/wiki/Boolean%20flag | A Boolean flag, truth bit or truth flag in computer science is a Boolean value represented as one or more bits, which encodes a state variable with two possible values.
Memory usage
A single byte can contain up to 8 separate Boolean flags by mapping one Boolean flag to each bit, making it a very economical and dense method of data storage. This is known as a packed representation or bit-packing, and the opposite encoding with only one Boolean flag per byte used is known as a sparse representation. For byte-addressable memory the packed representation requires a bit mask and bit-shift to access individual flags in each byte, which can require additional instructions, whereas the sparse representation requires no bit masking. Packed representations are more commonly found in hardware and processor registers as bit fields whereas sparse representations are more commonly found in software as variables of one or more bytes in width, although packed representations can also be supported.
Efficiency
Most computer languages support the setting and testing of single or multiple bits in combination for use as truth indicators and usually up to 256 different combinations of conditions can be tested for with just a single instruction on one byte using bitwise operations. Advancements in processor design and parallel computing mean even more Boolean algebra operations on Boolean flags can be done with just a single instruction using SIMD technology, often implemented in programming languages as compiler intrinsic functions.
Usage
Sometimes, programs are written to simply set flags when certain conditions are detected, rather than have multiple nested conditional statements (e.g. ifs) that can get quite complex. When all the conditions are tested for and all flags set on or off appropriately, testing can commence on various combinations of conditions - by reference to the flags instead of the variables themselves. This can simplify processing considerably and allows decision t |
https://en.wikipedia.org/wiki/Desnitro-imidacloprid | Desnitro-imidacloprid is a metabolite of the insecticide imidacloprid, a very common insecticide and the most important member of the class of insecticides called neonicotinoids, the only significant new class of insecticides to be developed between 1970 and 2000. While imidacloprid has proved highly selective against insects, the desnitro- version is highly toxic to mammals, due to its agonist action at the alpha4beta2 nicotinic acetylcholine receptor (nAChR) in the mammalian brain, at least as demonstrated in experiments involving mice. |
https://en.wikipedia.org/wiki/Macacine%20gammaherpesvirus%205 | Macacine gammaherpesvirus 5 (McHV-5) is a species of virus in the genus Rhadinovirus, subfamily Gammaherpesvirinae, family Herpesviridae, and order Herpesvirales. |
https://en.wikipedia.org/wiki/Towers%20Perrin | Towers Perrin was a professional services firm specializing in human resources and financial services consulting, which merged in January 2010 with Watson Wyatt to form Towers Watson. The firm was a provider of reinsurance intermediary services and was active in the actuarial consulting arena with its Tillinghast insurance consulting practice.
History
On March 1, 1934, Towers, Perrin, Forster & Crosby opened for business in Philadelphia, Pennsylvania. In 1987, Towers Perrin was established as the umbrella name for the firm. On June 28, 2009, Towers, Perrin, Forster & Crosby and Watson Wyatt Worldwide (NYSE:WW) announced their agreement to merge into a new publicly traded company called Towers Watson & Co. The merger was completed in January 2010.
Offices
Towers Perrin had offices and alliance partners in the United States, Canada, Europe, Asia, Latin America, South Africa, Australia and New Zealand. |
https://en.wikipedia.org/wiki/Random%20oracle | In cryptography, a random oracle is an oracle (a theoretical black box) that responds to every unique query with a (truly) random response chosen uniformly from its output domain. If a query is repeated, it responds the same way every time that query is submitted.
Stated differently, a random oracle is a mathematical function chosen uniformly at random, that is, a function mapping each possible query to a (fixed) random response from its output domain.
Random oracles as a mathematical abstraction were first used in rigorous cryptographic proofs in the 1993 publication by Mihir Bellare and Phillip Rogaway (1993). They are typically used when the proof cannot be carried out using weaker assumptions on the cryptographic hash function. A system that is proven secure when every hash function is replaced by a random oracle is described as being secure in the random oracle model, as opposed to secure in the standard model of cryptography.
Applications
Random oracles are typically used as an idealised replacement for cryptographic hash functions in schemes where strong randomness assumptions are needed of the hash function's output. Such a proof often shows that a system or a protocol is secure by showing that an attacker must require impossible behavior from the oracle, or solve some mathematical problem believed hard in order to break it. However, it only proves such properties in the random oracle model, making sure no major design flaws are present. It is in general not true that such a proof implies the same properties in the standard model. Still, a proof in the random oracle model is considered better than no formal security proof at all.
Not all uses of cryptographic hash functions require random oracles: schemes that require only one or more properties having a definition in the standard model (such as collision resistance, preimage resistance, second preimage resistance, etc.) can often be proven secure in the standard model (e.g., the Cramer–Shoup cryptosyst |
https://en.wikipedia.org/wiki/Mechanical%20equilibrium | In classical mechanics, a particle is in mechanical equilibrium if the net force on that particle is zero. By extension, a physical system made up of many parts is in mechanical equilibrium if the net force on each of its individual parts is zero.
In addition to defining mechanical equilibrium in terms of force, there are many alternative definitions for mechanical equilibrium which are all mathematically equivalent. In terms of momentum, a system is in equilibrium if the momentum of its parts is all constant. In terms of velocity, the system is in equilibrium if velocity is constant. In a rotational mechanical equilibrium the angular momentum of the object is conserved and the net torque is zero. More generally in conservative systems, equilibrium is established at a point in configuration space where the gradient of the potential energy with respect to the generalized coordinates is zero.
If a particle in equilibrium has zero velocity, that particle is in static equilibrium. Since all particles in equilibrium have constant velocity, it is always possible to find an inertial reference frame in which the particle is stationary with respect to the frame.
Stability
An important property of systems at mechanical equilibrium is their stability.
Potential energy stability test
If we have a function which describes the system's potential energy, we can determine the system's equilibria using calculus. A system is in mechanical equilibrium at the critical points of the function describing the system's potential energy. We can locate these points using the fact that the derivative of the function is zero at these points. To determine whether or not the system is stable or unstable, we apply the second derivative test. With denoting the static equation of motion of a system with a single degree of freedom we can perform the following calculations:
Second derivative < 0 The potential energy is at a local maximum, which means that the system is in an unstable equilibri |
https://en.wikipedia.org/wiki/Calculus%20of%20variations | The calculus of variations (or variational calculus) is a field of mathematical analysis that uses variations, which are small changes in functions
and functionals, to find maxima and minima of functionals: mappings from a set of functions to the real numbers. Functionals are often expressed as definite integrals involving functions and their derivatives. Functions that maximize or minimize functionals may be found using the Euler–Lagrange equation of the calculus of variations.
A simple example of such a problem is to find the curve of shortest length connecting two points. If there are no constraints, the solution is a straight line between the points. However, if the curve is constrained to lie on a surface in space, then the solution is less obvious, and possibly many solutions may exist. Such solutions are known as geodesics. A related problem is posed by Fermat's principle: light follows the path of shortest optical length connecting two points, which depends upon the material of the medium. One corresponding concept in mechanics is the principle of least/stationary action.
Many important problems involve functions of several variables. Solutions of boundary value problems for the Laplace equation satisfy the Dirichlet's principle. Plateau's problem requires finding a surface of minimal area that spans a given contour in space: a solution can often be found by dipping a frame in soapy water. Although such experiments are relatively easy to perform, their mathematical formulation is far from simple: there may be more than one locally minimizing surface, and they may have non-trivial topology.
History
The calculus of variations may be said to begin with Newton's minimal resistance problem in 1687, followed by the brachistochrone curve problem raised by Johann Bernoulli (1696). It immediately occupied the attention of Jakob Bernoulli and the Marquis de l'Hôpital, but Leonhard Euler first elaborated the subject, beginning in 1733. Lagrange was influenced by |
https://en.wikipedia.org/wiki/Water%20retention%20curve | Water retention curve is the relationship between the water content, θ, and the soil water potential, ψ. This curve is characteristic for different types of soil, and is also called the soil moisture characteristic.
It is used to predict the soil water storage, water supply to the plants (field capacity) and soil aggregate stability. Due to the hysteretic effect of water filling and draining the pores, different wetting and drying curves may be distinguished.
The general features of a water retention curve can be seen in the figure, in which the volume water content, θ, is plotted against the matric potential, . At potentials close to zero, a soil is close to saturation, and water is held in the soil primarily by capillary forces. As θ decreases, binding of the water becomes stronger, and at small potentials (more negative, approaching wilting point) water is strongly bound in the smallest of pores, at contact points between grains and as films bound by adsorptive forces around particles.
Sandy soils will involve mainly capillary binding, and will therefore release most of the water at higher potentials, while clayey soils, with adhesive and osmotic binding, will release water at lower (more negative) potentials. At any given potential, peaty soils will usually display much higher moisture contents than clayey soils, which would be expected to hold more water than sandy soils. The water holding capacity of any soil is due to the porosity and the nature of the bonding in the soil.
Curve models
The shape of water retention curves can be characterized by several models, one of them known as the Van Genuchten model:
where
is the water retention curve [L3L−3];
is suction pressure ([L] or cm of water);
saturated water content [L3L−3];
residual water content [L3L−3];
is related to the inverse of the air entry suction, ([L−1], or cm−1); and,
is a measure of the pore-size distribution, (dimensionless).
Based on this parametrization a prediction model for the |
https://en.wikipedia.org/wiki/Local%20Peer%20Discovery | The Local Peer Discovery protocol, specified as BEP-14, is an extension to the BitTorrent file-distribution system. It is designed to support the discovery of local BitTorrent peers, aiming to minimize the traffic through the Internet service provider's (ISP) channel and maximize use of higher-bandwidth local area network (LAN).
Local Peer Discovery is implemented with HTTP-like messages on User Datagram Protocol (UDP) multicast group 239.192.152.143:6771 (IPv4) or ff15::efc0:988f (IPv6) which are administratively scoped multicast addresses. Since implementation is simple, Local Peer Discovery is implemented in several clients (μTorrent, BitTorrent/Mainline, MonoTorrent, libtorrent and its derivatives, Transmission, aria2). An alternative multicast peer discovery protocol is published as BEP 26, but is not widely adopted since it is considered too complex in comparison. |
https://en.wikipedia.org/wiki/EchoStar%20Mobile | EchoStar Mobile, an Irish company with commercial operations headquartered in the United Kingdom and a data centre based in Griesheim, Germany, is a mobile operator that provides connectivity across Europe through a converged satellite and terrestrial network. EchoStar Mobile is a subsidiary of EchoStar Corporation, a provider of satellite communications devices.
History
EchoStar Mobile Limited was established in 2008 as Solaris Mobile, a joint venture company between SES and Eutelsat Communications to develop and commercialize the first geostationary satellite systems in Europe for broadcasting video, radio and data to in-vehicle receivers and to mobile devices, such as mobile phones, portable media players and PDAs. In January 2014 all stock in Solaris Mobile was acquired by EchoStar Corporation and in March 2015 the company was renamed EchoStar Mobile.
The agreement to set up Solaris Mobile was reached in 2006 with the company formed in 2008. SES and Eutelsat – both successful European satellite operators, providing TV and other services from geostationary satellites to millions of cable and direct-to-home viewers – invested €130m in the venture. The services to be developed included video, radio, multimedia data, interactive services, and voice communications, with the primary aim of delivering mobile television any time, anywhere. Its headquarters is in Dublin, Ireland.
Solaris Mobile's first commercial contract was with Italian media publishing group Class Editori, to launch a digital radio service in Italy. A hybrid satellite/terrestrial network will initially be deployed in Milan, in October 2011 and extended across the country in 2012. Solaris claims that the network will enable Italians to access dozens of new digital radio channels broadcasting music, news, entertainment and sports, in their original format with continuity of reception across the entire country, and that the digital audio signal will be complemented with new visual media services such |
https://en.wikipedia.org/wiki/Precision%20rectifier | The precision rectifier is a configuration obtained with an operational amplifier in order to have a circuit behave like an ideal diode and rectifier. It is very useful for high-precision signal processing. With the help of a precision rectifier the high-precision signal processing can be done very easily.
The op-amp-based precision rectifier should not be confused with the power MOSFET-based active rectification ideal diode.
Basic circuit
The basic circuit implementing such a feature is shown on the right, where can be any load. When the input voltage is negative, there is a negative voltage on the diode, so it works like an open circuit, no current flows through the load, and the output voltage is zero. When the input is positive, it is amplified by the operational amplifier, which switches the diode on. Current flows through the load and, because of the feedback, the output voltage is equal to the input voltage.
The actual threshold of the super diode is very close to zero, but is not zero. It equals the actual threshold of the diode, divided by the gain of the operational amplifier.
This basic configuration has a problem, so it is not commonly used. When the input becomes (even slightly) negative, the operational amplifier runs open-loop, as there is no feedback signal through the diode. For a typical operational amplifier with high open-loop gain, the output saturates. If the input then becomes positive again, the op-amp has to get out of the saturated state before positive amplification can take place again. This change generates some ringing and takes some time, greatly reducing the frequency response of the circuit.
Improved circuit
An alternative version is given on the right. In this case, when the input is greater than zero, D1 is off, and D2 is on, so the output is zero because the other end of is connected to the virtual ground and there is no current through . When the input is less than zero, D1 is on and D2 is off, so the output is like th |
https://en.wikipedia.org/wiki/Autoregressive%20model | In statistics, econometrics, and signal processing, an autoregressive (AR) model is a representation of a type of random process; as such, it is used to describe certain time-varying processes in nature, economics, behavior, etc. The autoregressive model specifies that the output variable depends linearly on its own previous values and on a stochastic term (an imperfectly predictable term); thus the model is in the form of a stochastic difference equation (or recurrence relation which should not be confused with differential equation). Together with the moving-average (MA) model, it is a special case and key component of the more general autoregressive–moving-average (ARMA) and autoregressive integrated moving average (ARIMA) models of time series, which have a more complicated stochastic structure; it is also a special case of the vector autoregressive model (VAR), which consists of a system of more than one interlocking stochastic difference equation in more than one evolving random variable.
Contrary to the moving-average (MA) model, the autoregressive model is not always stationary as it may contain a unit root.
Definition
The notation indicates an autoregressive model of order p. The AR(p) model is defined as
where are the parameters of the model, and is white noise. This can be equivalently written using the backshift operator B as
so that, moving the summation term to the left side and using polynomial notation, we have
An autoregressive model can thus be viewed as the output of an all-pole infinite impulse response filter whose input is white noise.
Some parameter constraints are necessary for the model to remain weak-sense stationary. For example, processes in the AR(1) model with are not stationary. More generally, for an AR(p) model to be weak-sense stationary, the roots of the polynomial must lie outside the unit circle, i.e., each (complex) root must satisfy (see pages 89,92 ).
Intertemporal effect of shocks
In an AR process, a one-time |
https://en.wikipedia.org/wiki/Feynman%20checkerboard | The Feynman checkerboard, or relativistic chessboard model, was Richard Feynman’s sum-over-paths formulation of the kernel for a free spin-½ particle moving in one spatial dimension. It provides a representation of solutions of the Dirac equation in (1+1)-dimensional spacetime as discrete sums.
The model can be visualised by considering relativistic random walks on a two-dimensional spacetime checkerboard. At each discrete timestep the particle of mass moves a distance to the left or right ( being the speed of light). For such a discrete motion, the Feynman path integral reduces to a sum over the possible paths. Feynman demonstrated that if each "turn" (change of moving from left to right or conversely) of the space–time path is weighted by (with denoting the reduced Planck's constant), in the limit of infinitely small checkerboard squares the sum of all weighted paths yields a propagator that satisfies the one-dimensional Dirac equation. As a result, helicity (the one-dimensional equivalent of spin) is obtained from a simple cellular-automata-type rule.
The checkerboard model is important because it connects aspects of spin and chirality with propagation in spacetime and is the only sum-over-path formulation in which quantum phase is discrete at the level of the paths, taking only values corresponding to the 4th roots of unity.
History
Feynman invented the model in the 1940s while developing his spacetime approach to quantum mechanics. He did not publish the result until it appeared in a text on path integrals coauthored by Albert Hibbs in the mid 1960s. The model was not included with the original path-integral article because a suitable generalization to a four-dimensional spacetime had not been found.
One of the first connections between the amplitudes prescribed by Feynman for the Dirac particle in 1+1 dimensions, and the standard interpretation of amplitudes in terms of the kernel, or propagator, was established by Jayant Narlikar in a detailed a |
https://en.wikipedia.org/wiki/Topos | In mathematics, a topos (, ; plural topoi or , or toposes) is a category that behaves like the category of sheaves of sets on a topological space (or more generally: on a site). Topoi behave much like the category of sets and possess a notion of localization; they are a direct generalization of point-set topology. The Grothendieck topoi find applications in algebraic geometry; the more general elementary topoi are used in logic.
The mathematical field that studies topoi is called topos theory.
Grothendieck topos (topos in geometry)
Since the introduction of sheaves into mathematics in the 1940s, a major theme has been to study a space by studying sheaves on a space. This idea was expounded by Alexander Grothendieck by introducing the notion of a "topos". The main utility of this notion is in the abundance of situations in mathematics where topological heuristics are very effective, but an honest topological space is lacking; it is sometimes possible to find a topos formalizing the heuristic. An important example of this programmatic idea is the étale topos of a scheme. Another illustration of the capability of Grothendieck toposes to incarnate the “essence” of different mathematical situations is given by their use as bridges for connecting theories which, albeit written in possibly very different languages, share a common mathematical content.
Equivalent definitions
A Grothendieck topos is a category C which satisfies any one of the following three properties. (A theorem of Jean Giraud states that the properties below are all equivalent.)
There is a small category D and an inclusion C ↪ Presh(D) that admits a finite-limit-preserving left adjoint.
C is the category of sheaves on a Grothendieck site.
C satisfies Giraud's axioms, below.
Here Presh(D) denotes the category of contravariant functors from D to the category of sets; such a contravariant functor is frequently called a presheaf.
Giraud's axioms
Giraud's axioms for a category C are:
C has a small |
https://en.wikipedia.org/wiki/Rising%20moving%20average | The rising moving average is a technical indicator used in stock market trading. Most commonly found visually, the pattern is spotted with a moving average overlay on a stock chart or price series. When the moving average has been rising consecutively for a number of days, this is used as a buy signal, to indicate a rising trend forming.
While the rising moving average indicator is commonly used by investors without realising, there has been significant backtesting on historic stock data to calculate the performance of the rising moving average. Simulations have found that shorter rising averages, within the 3- to 10-day period, are more profitable overall than longer rising averages (e.g. 20 days). These have only been tested on US equity stocks however.
Notes
Mathematical finance
Time series
Technical indicators |
https://en.wikipedia.org/wiki/Melanotroph | A melanotroph (or melanotrope) is a cell in the pituitary gland that generates melanocyte-stimulating hormone (α‐MSH) from its precursor pro-opiomelanocortin. Chronic stress can induce the secretion of α‐MSH in melanotrophs and lead to their subsequent degeneration.
See also
Chromophobe cell
Chromophil
Acidophil cell
Basophil cell
Oxyphil cell
Oxyphil cell (parathyroid)
Pituitary gland
Neuroendocrine cell
List of distinct cell types in the adult human body |
https://en.wikipedia.org/wiki/Train%20Mountain%20Railroad | Train Mountain Railroad is the world's largest miniature hobbyist railroad near Chiloquin, Oregon, in Klamath County, which is in the south central region of Oregon. It is situated between Klamath Falls, Oregon, approximately to the south, and Crater Lake National Park to the north.
Physical Location: 36941 South Chiloquin Road, Chiloquin, OR 97624, USA.
Geography
The property borders Highway 97 on the east side, Highway 62 (Crater Lake Highway) on the west side, and Highway 422 on the north. The track and facilities which are not obscured by trees are clearly visible on public satellite images.
The elevation at Train Mountain varies from at South Meadow, at Central Station, at Ward Passing Track (the highest point accessible by train), to at Steiger Butte, the highest point on Train Mountain property.
Longest miniature hobby railroad
In the 2004 Guinness World Records, Train Mountain is recognized as the “Longest Miniature Hobby Railroad”. At the time Train Mountain was recognized by Guinness, it was reported to have of gauge mainline track and of total track including yards, sidings, spurs, and connector tracks. During the following years, approximately 10 additional miles (16 km) of new track has been added.
Gauge and scale
The Train Mountain gauge miniature railway track is typically used for 1.5" scale trains (1.5" to 12" or approx. 1/8 scale). Trains of 2.5" scale (2.5" to 12", or approx. 1/5 scale) are also common at Train Mountain. Some of these 2.5" scale steam locomotives can weigh in excess of for the engine and tender when fully loaded with water and fuel.
Live steam
Train Mountain is well known to members of the live steam hobby who visit regularly from all over the world.
Media coverage
Train Mountain was featured on Oregon Public Broadcasting 2005 video on Train Mountain and "The Dream." "The Dream" refers to late founder of Train Mountain, Quentin Breen, whose dream was to build the railroad at Train Mountain as explained i |
https://en.wikipedia.org/wiki/Child%20sex%20ratio%20in%20India | The child sex ratio in India is defined as the number of females per thousand males in the age group 0–6 years in a human population. Thus it is equal to 1000 x the reciprocal of the sex ratio (ratio of males to females in a population) in the same age group, i.e. under age seven. An imbalance in this age group will extend to older age groups in future years. Currently, the ratio of males to females is generally significantly greater than 1, i.e. there are more boys than girls.
According to the decennial Indian census, the sex ratio in the 0-6 age group in India went from 104.0 males per 100 females in 1981 to 105.8 in 1991, to 107.8 in 2001, to 108.8 in 2011. The ratio is significantly higher in certain states such as Punjab and Haryana (118 and 120 respectively per 2011 census). The child sex ratio has been more prominent for males in India for quite a while, since the 1980s with thirty fewer females to males
Likelihood of an imbalanced child sex ratio
The natural "sex ratio at birth" is often considered to be around 105. This means that at birth on average, there are 105 males for every 100 females. Thus a significant departure from the ratio of 1.05 boys per every girl born indicates an imbalanced child sex ratio. Thus, India had a natural child sex ratio before 1981. But according to the 2011 census, a large city in India, Jhajjar had almost 15,000 more baby boys than baby girls, that is 128 boys per 100 girls.
Variables that change the child sex ratio
Sex-Selective Abortions
In the Asian culture, families want baby boys, because it is traditional that the boys take care of the parents, while the daughters marry and leave the family. These families want to ensure elderly security, therefore they want more boys in the family. Typically it cost more to have a daughter and they cannot contribute to the family nearly as much as the son can. These factors cause family to get an abortion because they want the variables that the boys have to offer, and unfortu |
https://en.wikipedia.org/wiki/SCR-584%20radar | The SCR-584 (short for Set, Complete, Radio # 584) was an automatic-tracking microwave radar developed by the MIT Radiation Laboratory during World War II. It was one of the most advanced ground-based radars of its era, and became one of the primary gun laying radars used worldwide well into the 1950s. A trailer-mounted mobile version was the SCR-784.
In 1937, America's first fire-control radar, the SCR-268 radar, had proven to be insufficiently accurate due in part to its long wavelength. In 1940, Vannevar Bush, heading the National Defense Research Committee, established the "Microwave Committee" (section D-1) and the "Fire Control" division (D-2) to develop a more advanced radar anti-aircraft system in time to assist the British air-defense effort. In September of that year, a British delegation, the Tizard Mission, revealed to US and Canadian researchers that they had developed a magnetron oscillator operating at the top end of the UHF band (10 cm wavelength/3 GHz), allowing greatly increased accuracy. Bush organized the Radiation Laboratory (Rad Lab) at the MIT to develop applications using it. This included a new short-range air-defense radar.
Alfred Lee Loomis, running the Rad Lab, advocated the development of an entirely automatic tracking system controlled by servomechanisms. This greatly eased the task of tracking targets and reduced the manpower needed to do it. They were also able to take advantage of a newly developed microwave switch that allowed them to use a single antenna for broadcast and reception, greatly simplifying the mechanical layout. The resulting design fit into a single trailer, could provide all-sky search and single target tracking, and followed the targets automatically. In close contact with the Rad Lab, Bell Telephone Laboratories was developing an electronic analog gun-director that would be used in conjunction with the radar and servo-actuated 90 mm anti-aircraft guns.
The radar was intended to be introduced in late 1943, but de |
https://en.wikipedia.org/wiki/Legendre%20transform%20%28integral%20transform%29 | In mathematics, Legendre transform is an integral transform named after the mathematician Adrien-Marie Legendre, which uses Legendre polynomials as kernels of the transform. Legendre transform is a special case of Jacobi transform.
The Legendre transform of a function is
The inverse Legendre transform is given by
Associated Legendre transform
Associated Legendre transform is defined as
The inverse Legendre transform is given by
Some Legendre transform pairs |
https://en.wikipedia.org/wiki/IBM%20702 | The IBM 702 was an early generation tube-based digital computer produced by IBM in the early to mid-1950s. It was the company's response to Remington Rand's UNIVAC—the first mainframe computer to use magnetic tapes. As these machines were aimed at the business market, they lacked the leading-edge computational power of the IBM 701 and ERA 1103, which were favored for scientific computing, weather forecasting, the aircraft industry, and the military and intelligence communities.
Within IBM, the 702 was notable for adapting the new technology of magnetic-core memory for random-access applications.
The 702 was announced September 25, 1953, and withdrawn October 1, 1954, but the first production model was not installed until July 1955. It was superseded by the IBM 705.
History
Fourteen 702s were built. The first one was used at IBM. Due to problems with the Williams tubes, the decision was made to switch to magnetic-core memory instead. The fourteenth 702 was built using magnetic-core memory, and the others were retrofitted with magnetic-core memory.
The successor to the 702 in the 700/7000 series was the IBM 705, which marked the transition to magnetic-core memory.
Overview
The 702 was designed for business data processing. Therefore, the memory of the computer was oriented toward storing characters. The system used electrostatic storage, consisting of 14, 28, 42, 56, or 70 Williams tubes with a capacity of 1000 bits each for the main memory, giving a memory of 2,000 to 10,000 characters of seven bits each (in increments of 2,000 characters), and 14 Williams tubes with a capacity of 512 bits each for the two 512-character accumulators.
A complete system included the following units:
IBM 702 Central Processing Unit
IBM 712 Card Reader
IBM 756 Card Reader Control Unit
IBM 717 Printer
IBM 757 Printer Control Unit
IBM 722 Card Punch
IBM 758 Card Punch Control Unit
IBM 727 Magnetic Tape Unit
IBM 752 Tape Control Unit
IBM 732 Magnetic Drum Storage Unit
Total weig |
https://en.wikipedia.org/wiki/Common%20Technical%20Document | The Common Technical Document (CTD) is a set of specifications for an application dossier for the registration of Medicines and designed to be used across Europe, Japan and the United States and beyond.
Synopsis
The CTD is an internationally agreed format for the preparation of applications regarding new drugs intended to be submitted to regional regulatory authorities in participating countries. It was developed by the European Medicines Agency (EMA, Europe), the Food and Drug Administration (FDA, US) and the Ministry of Health, Labour and Welfare (Japan) starting at the World Health Organization International Conference of Drug Regulatory Authorities (ICDRA) at Paris in 1989.
The CTD is maintained by the International Council on Harmonisation of Technical Requirements for Registration of Pharmaceuticals for Human Use (ICH).
After the United States, European Union and Japan, the CTD was adopted by several other countries including Canada and Switzerland.
The Paper CTD is destined to be replaced by its electronic counterpart, the eCTD.
Document contents
The Common Technical Document is divided into five modules:
Administrative and prescribing information
Overview and summary of modules 3 to 5
Quality (pharmaceutical documentation)
Preclinical (Pharmacology/Toxicology)
Clinical – efficacy and safety (Clinical Trials)
Detailed subheadings for each Module are specified for all jurisdictions. The contents of Module 1 and certain subheadings of other Modules will differ, based on national requirements.
See also
Clinical Data Interchange Standards Consortium
Clinical trial
eCTD
Harmonization in clinical trials |
https://en.wikipedia.org/wiki/Butylated%20hydroxytoluene | Butylated hydroxytoluene (BHT), also known as dibutylhydroxytoluene, is a lipophilic organic compound, chemically a derivative of phenol, that is useful for its antioxidant properties. BHT is widely used to prevent free radical-mediated oxidation in fluids (e.g. fuels, oils) and other materials, and the regulations overseen by the U.S. F.D.A.—which considers BHT to be "generally recognized as safe"—allow small amounts to be added to foods. Despite this, and the earlier determination by the National Cancer Institute that BHT was noncarcinogenic in an animal model, societal concerns over its broad use have been expressed. BHT has also been postulated as an antiviral drug, but as of December 2022, use of BHT as a drug is not supported by the scientific literature and it has not been approved by any drug regulatory agency for use as an antiviral.
Natural occurrence
Phytoplankton, including the green algae Botryococcus braunii, as well as three different cyanobacteria (Cylindrospermopsis raciborskii, Microcystis aeruginosa and Oscillatoria sp.) are capable of producing BHT as a natural product. The fruit lychee also produces BHT in its pericarp. Several fungi (for example Aspergillus conicus) living in olives produce BHT.
Production
Industrial production
The chemical synthesis of BHT in industry has involved the reaction of p-cresol (4-methylphenol) with isobutylene (2-methylpropene), catalyzed by sulfuric acid:
CH3(C6H4)OH + 2 CH2=C(CH3)2 → ((CH3)3C)2CH3C6H2OH
Alternatively, BHT has been prepared from 2,6-di-tert-butylphenol by hydroxymethylation or aminomethylation followed by hydrogenolysis.
Reactions
The species behaves as a synthetic analog of vitamin E, primarily acting as a terminating agent that suppresses autoxidation, a process whereby unsaturated (usually) organic compounds are attacked by atmospheric oxygen. BHT stops this autocatalytic reaction by converting peroxy radicals to hydroperoxides. It effects this function by donating a hydrogen atom |
https://en.wikipedia.org/wiki/Nanophotonic%20coherent%20imager | Nanophotonic coherent imagers (NCI) are image sensors that determine both the appearance and distance of an imaged scene at each pixel. It uses an array of LIDARs (scanning laser beams) to gather this information about size and distance, using an optical concept called coherence (wherein waves of the same frequency align perfectly.)
NCIs can capture 3D images of objects with sufficient accuracy to permit the creation of high resolution replicas using 3D printing technology.
The detection of both intensity and relative delay enables applications such as high-resolution 3D reflective and transmissive imaging as well as index contrast imaging.
Prototype
An NCI using a 4×4 pixel grid of 16 grating couplers operates based on a modified time-domain Frequency Modulated Continuous Wave (FMCW) ranging scheme, where concurrent time-domain measurements of both period and the zero-crossing time of each electrical output of the nanophotonic chip allows the NCI to overcome the resolution limits of frequency domain detection. Each pixel on the chip is an independent interferometer that detects the phase and frequency of the signal in addition to the intensity. Each LIDAR pixel spanned only a few hundred microns such that the area fit in area of 300 microns square.
The prototype achieved 15μm depth resolution and 50μm lateral resolution (limited by the pixel spacing) at up to 0.5-meter range. It was capable of detecting a 1% equivalent refractive index contrast at 1mm thickness. |
https://en.wikipedia.org/wiki/Peter%20Liljedahl | Peter Liljedahl (born February 18, 1967) is a Swedish sprint canoer who competed in the early 1990s. At the 1992 Summer Olympics in Barcelona, he was eliminated in the semifinals of the C-1 500 m event while being disqualified in the semifinals of the C-1 1000 m event. |
https://en.wikipedia.org/wiki/Alexander%20Bogomolny | Alexander Bogomolny (January 4, 1948 July 7, 2018) was a Soviet-born Israeli-American mathematician. He was Professor Emeritus of Mathematics at the University of Iowa, and formerly research fellow at the Moscow Institute of Electronics and Mathematics, senior instructor at Hebrew University and software consultant at Ben Gurion University. He wrote extensively about arithmetic, probability, algebra, geometry, trigonometry and mathematical games.
He was known for his contribution to heuristics and mathematics education, creating and maintaining the mathematically themed educational website Cut-the-Knot for the Mathematical Association of America (MAA) Online. He was a pioneer in mathematical education on the internet, having started Cut-the-Knot in October 1996.
Education and academic career
Bogomolny attended Moscow school No. 444, for gifted children, then entered Moscow State University, where he graduated with a master's degree in mathematics in 1971. From 1971 to 1974 he was a junior research fellow at the Moscow Institute of Electronic Machine Building (MIEM). He emigrated to Israel and became a senior programmer at Lake Kinneret Research Laboratory in Tiberias, Israel (19741977) and a software consultant at Ben Gurion University in Negev, Be’er Sheva, Israel (19761977). From 1976 to 1983 he was a senior instructor and researcher at Hebrew University in Jerusalem. He received his Ph.D. in mathematics at Hebrew University in 1981. His dissertation is titled, A New Numerical Solution for the Stamp Problem and his thesis advisor was Gregory I. Eskin. From 1981 to 1982 he was also a visiting professor at Ohio State University, where he taught mathematics.
From 1982 to 1987 he was professor of mathematics at the University of Iowa. From August 1987 to August 1991 he was vice president of software development at CompuDoc, Inc.
Cut-the-Knot
Cut-the-Knot (CTK) is a free, advertisement-funded educational website which Bogomolny maintained from 1996 to 2018. It |
https://en.wikipedia.org/wiki/Phipps%20Institute%20for%20the%20Study%2C%20Treatment%20and%20Prevention%20of%20Tuberculosis | The Phipps Institute for the Study, Treatment and Prevention of Tuberculosis at the University of Pennsylvania was established in 1903 with a grant from Henry Phipps, a former business partner of Andrew Carnegie. |
https://en.wikipedia.org/wiki/V%20%28operating%20system%29 | The V operating system (sometimes written V-System) is a discontinued microkernel distributed operating system that was developed by faculty and students in the Distributed Systems Group at Stanford University from 1981 to 1988, led by Professors David Cheriton and Keith A. Lantz. V was the successor to the Thoth operating system and Verex kernel that Cheriton had developed in the 1970s. Despite similar names and close development dates, it is unrelated to UNIX System V.
Features
The key concepts in V are multithreading and synchronous message passing. The original V terminology uses process for what is now commonly called a thread, and team for what is now commonly called a process consisting of multiple threads sharing an address space. Communication between threads in V uses synchronous message passing, with short, fixed-length messages that can include access rights for the receiver to read or write part of the sender's address space before replying. The same message-passing interface is used both between threads within one process, between threads of different processes within one machine, and between threads on different machines connected by a local Ethernet. A thread receiving a message is not required to reply to it before receiving other messages; this distinguished the model from Ada rendezvous.
One common pattern for using the messaging facility is for clients to send messages to a server requesting some form of service. From the client side, this looks much like a remote procedure call (RPC). The convenience of an automatic stub generator was lacking, but in contrast, the client can pass one parameter by reference, which is not possible with other RPC implementations. From the server side the model differs more from RPC, since by default all client requests are multiplexed onto one server thread. The server is free to explicitly fork threads to handle client requests in parallel, however; if this is done, the server-side model is much like RPC too.
|
https://en.wikipedia.org/wiki/Lampricide | A lampricide is any chemical designed to target the larvae of lampreys in river systems before they develop into parasitic adults. One lampricide is used in the headwaters of Lake Champlain and the Great Lakes to control the sea lamprey (Petromyzon marinus), an invasive species to these lakes.
TFM (3-trifluoromethyl-4-nitrophenol) is the main chemical used for this purpose. As it is hydrophobic, it passes through biological membranes.
TFM is a metabolic uncoupler—that is, TFM separates the electron transport chain from ATP synthesis, resulting in the failure of the aerobic respiration process. It accomplishes this by disrupting the electrochemical gradient that powers ATP synthase—as an acid, it donates H+ ions to the mitochondrial matrix. The electron transport chain is not affected and continues using oxygen, without producing ATP.
While the general opinion is that TFM typically does not harm other fish (due to the relationship between true fish and lampreys), lampricide can be problematic for many amphibians, such as mudpuppies (genus Necturus) which often share the same habitats. Also, some more "primitive" species of fish, such as the sturgeon in the Great Lakes are sensitive to chemicals such as TFM. |
https://en.wikipedia.org/wiki/Gunnar%20Kaasen | Gunnar Kaasen (March 11, 1882 – November 27, 1960) was a Norwegian-born musher who delivered a cylinder containing 300,000 units of diphtheria antitoxin to Nome, Alaska, in 1925, as the last leg of a dog sled relay that saved the U.S. city from an epidemic.
Background
Gunnar E. Kaasen was born the son of Hans and Anna Kaasen in Burfjorddalen, in Troms, Norway. He went to the United States to mine for gold in 1903, in the wake of the discovery of gold-bearing sands on Cape Nome in 1898, which triggered one of several gold rushes in the state between 1891 and 1898. Kaasen became an experienced musher and a resident of Nome. While the boom was spent by 1905, the port of Nome sits on Norton Sound, which is usually ice locked and inaccessible by ship between October and June. Dog sledding remained the primary transportation and communication link to the outside world during the winter months.
Last leg of the Great Race of Mercy
In 1925, an outbreak of diphtheria threatened Kaasen's adopted home, and the disease could easily spread across the northern Alaska villages of which Nome was the hub. The Iñupiaq children in particular had no immunity to the "white man's disease". The port was frozen. No train routes or regular roads extended to the northern coast of Alaska. Bush piloting was in its infancy; the only two aircraft in the state had open-cockpits, and had never been flown in the winter. Given the choices, Governor Scott Bone authorized the transport of 300,000 units of serum in Anchorage to Nenana by train, where it was picked up by the first of twenty mushers and more than one hundred dogs who relayed the serum the remaining 674 miles (1,085 km) to Nome.
Kaasen was scheduled to transport the 20 pound (9 kg) cylinder of serum along the next-to-last leg of the relay, from Bluff to Point Safety, Alaska. At Bluff, Charlie Olson passed the serum to Kaasen, who left with a team of 13 dogs, led by the husky, Balto. Kaasen traveled through the night, in the middle of |
https://en.wikipedia.org/wiki/Jack%20Silver | Jack Howard Silver (23 April 1942 – 22 December 2016) was a set theorist and logician at the University of California, Berkeley.
Born in Montana, he earned his Ph.D. in Mathematics at Berkeley in 1966 under Robert Vaught before taking a position at the same institution the following year. He held an Alfred P. Sloan Research Fellowship from 1970 to 1972. Silver made several contributions to set theory in the areas of large cardinals and the constructible universe L.
Contributions
In his 1975 paper "On the Singular Cardinals Problem", Silver proved that if a cardinal κ is singular with uncountable cofinality and 2λ = λ+ for all infinite cardinals λ < κ, then 2κ = κ+. Prior to Silver's proof, many mathematicians believed that a forcing argument would yield that the negation of the theorem is consistent with ZFC. He introduced the notion of a master condition, which became an important tool in forcing proofs involving large cardinals.
Silver proved the consistency of Chang's conjecture using the Silver collapse (which is a variation of the Levy collapse). He proved that, assuming the consistency of a supercompact cardinal, it is possible to construct a model where 2κ=κ++ holds for some measurable cardinal κ. With the introduction of the so-called Silver machines he was able to give a fine structure free proof of Jensen's covering lemma. He is also credited with discovering Silver indiscernibles and generalizing the notion of a Kurepa tree (called Silver's Principle). He discovered 0# ("zero sharp") in his 1966 Ph.D. thesis, discussed in the graduate textbook Set Theory: An Introduction to Large Cardinals by Frank R. Drake.
Silver's original work involving large cardinals was perhaps motivated by the goal of showing the inconsistency of an uncountable measurable cardinal; instead he was led to discover indiscernibles in L assuming a measurable cardinal exists.
Selected publications
Silver, Jack H. (1971). "Some applications of model theory in set theory". Annal |
https://en.wikipedia.org/wiki/Phallus%20impudicus | Phallus impudicus, known colloquially as the common stinkhorn, is a widespread fungus in the Phallaceae (stinkhorn) family. It is recognizable for its foul odor and its phallic shape when mature, the latter feature giving rise to several names in 17th-century England. It is a common mushroom in Europe and North America, where it occurs in habitats rich in wood debris such as forests and mulched gardens. It appears from summer to late autumn. The fruiting structure is tall and white with a slimy, dark olive colored conical head. Known as the gleba, this material contains the spores, and is transported by insects which are attracted by the odor—described as resembling carrion. Despite its foul smell, it is not usually poisonous and immature mushrooms are consumed in parts of France, Germany and the Czech Republic.
Taxonomy
The Italian naturalist Ulisse Aldrovandi described the fungus in 1560 with name fungus priapeus, and he depicted it in his series of water-coloured plates called teatro della natura ('nature's theater' 1560–1590). Another botanist, John Gerard called it the "pricke mushroom" or "fungus virilis penis effigie" in his General Historie of Plants of 1597, and John Parkinson referred to it as "Hollanders workingtoole" or "phallus hollandicus" in his Theatrum botanicum of 1640. Linnaeus described it in his 1753 Species Plantarum, and it still bears its original binomial name. Its specific epithet, impudicus, is derived from the Latin for "shameless" or "immodest".
Description
Sometimes called the witch's egg, the immature stinkhorn is whitish or pinkish, egg-shaped, and typically by .On the outside is a thick whitish volva, also known as the peridium, covering the olive-colored gelatinous gleba. It is the latter that contains the spores and later stinks and attracts the flies; within this layer is a green layer which will become the 'head' of the expanded fruit body; and inside this is a white structure called the receptaculum (the stalk when expanded), |
https://en.wikipedia.org/wiki/Dephasing | In physics, dephasing is a mechanism that recovers classical behaviour from a quantum system. It refers to the ways in which coherence caused by perturbation decays over time, and the system returns to the state before perturbation. It is an important effect in molecular and atomic spectroscopy, and in the condensed matter physics of mesoscopic devices.
The reason can be understood by describing the conduction in metals as a classical phenomenon with quantum effects all embedded into an effective mass that can be computed quantum mechanically, as also happens to resistance that can be seen as a scattering effect of conduction electrons. When the temperature is lowered and the dimensions of the device are meaningfully reduced, this classical behaviour should disappear and the laws of quantum mechanics should govern the behavior of conducting electrons seen as waves that move ballistically inside the conductor without any kind of dissipation. Most of the time this is what one observes. But it appeared as a surprise to uncover that the so-called dephasing time, that is the time it takes for the conducting electrons to lose their quantum behavior, becomes finite rather than infinite when the temperature approaches zero in mesoscopic devices violating the expectations of the theory of Boris Altshuler, Arkady Aronov and David E. Khmelnitskii. This kind of saturation of the dephasing time at low temperatures is an open problem even as several proposals have been put forward.
The coherence of a sample is explained by the off-diagonal elements of a density matrix. An external electric or magnetic field can create coherences between two quantum states in a sample if the frequency corresponds to the energy gap between the two states. The coherence terms decay with the dephasing time or spin–spin relaxation, T2.
After coherence is created in a sample by light, the sample emits a polarization wave, the frequency of which is equal to and the phase of which is inverted from the |
https://en.wikipedia.org/wiki/Norator | In electronics, a norator is a theoretical linear, time-invariant one-port which can have an arbitrary current and voltage between its terminals. A norator represents a controlled voltage or current source with infinite gain.
Inserting a norator in a circuit schematic provides whatever current and voltage the outside circuit demands, in particular, the demands of Kirchhoff's circuit laws. For example, the output of an ideal opamp behaves as a norator, producing nonzero output voltage and current that meet circuit requirements despite a zero input.
A norator is often paired with a nullator to form a nullor.
Two trivial cases are worth noting: A nullator in parallel with a norator is equivalent to a short (zero voltage any current) and a nullator in series with a norator is an open circuit (zero current, any voltage). |
https://en.wikipedia.org/wiki/Dmidecode | dmidecode is a free userspace command-line utility for Linux that can parse the SMBIOS data. The name dmidecode is derived from Desktop Management Interface, a related standard with which dmidecode originally interfaced. SMBIOS was originally named DMIBIOS. The Linux kernel and other modern operating systems such as the BSD family contain an SMBIOS decoder, allowing systems administrators to inspect system hardware configuration and to enable or disable certain workarounds for problems with specific systems, based on the provided SMBIOS information. Information provided by this utility typically includes the system manufacturer, model name, serial number, BIOS version and asset tag, as well other details of varying level of interest and reliability, depending on the system manufacturer. The information often includes usage status for the CPU sockets, expansion slots (including AGP, PCI and ISA) and memory module slots, and the list of I/O ports (including serial, parallel and USB). Decoded DMI tables for various computer models are collected in a public GitHub repository.
For Dell systems there is a libsmbios utility. |
https://en.wikipedia.org/wiki/Qore%20%28programming%20language%29 | Qore is an interpreted, high-level, general-purpose, garbage collected dynamic programming language, featuring support for code embedding and sandboxing with optional strong typing and a focus on fundamental support for multithreading and SMP scalability.
Qore is unique because it is an interpreted scripting language with fundamental support for multithreading (meaning more than one part of the same code can run at the same time), and additionally because it features automatic memory management (meaning programmers do not have to allocate and free memory explicitly) while also supporting the RAII idiom with destructors for scope-based resource management and exception-safe programming. This is due to Qore's unique prompt collection implementation for garbage collection.
Qore Scripts
Qore scripts typically have the following extensions:
.q: for Qore scripts
.qm: for Qore user modules
.qtest: for Qore test scripts
Executable Qore scripts on Unix-like operating systems will typically start with a hashbang to specify the filename of the interpreter as follows:
#!/usr/bin/env qore
Syntax
Qore syntax is similar to and inspired from the following programming languages:
Perl: without %new-style, Qore's syntax is highly similar to Perl; the foreach statement, splice, push, pop, chomp operators, Perl5-compatible regular expressions, and more
Java: with %new-style, Qore code looks more similar to Java; the synchronized keyword, the instanceof operator, object and class implementation
C++: multiple inheritance, exception handling, static methods, abstract methods
D: the on_exit, on_success, and on_error statements provide exception-aware functionality similar to D's scope(exit), scope(failure), allowing exception-aware cleanup code to be placed next to the code requiring cleanup
Haskell: the map, foldl, foldr, and select operators with lazy evaluation of functional and list operators and statements
Data Types
Basic types include: boolean, string, integer, flo |
https://en.wikipedia.org/wiki/Thermal%20runaway | Thermal runaway describes a process that is accelerated by increased temperature, in turn releasing energy that further increases temperature. Thermal runaway occurs in situations where an increase in temperature changes the conditions in a way that causes a further increase in temperature, often leading to a destructive result. It is a kind of uncontrolled positive feedback.
In chemistry (and chemical engineering), thermal runaway is associated with strongly exothermic reactions that are accelerated by temperature rise. In electrical engineering, thermal runaway is typically associated with increased current flow and power dissipation. Thermal runaway can occur in civil engineering, notably when the heat released by large amounts of curing concrete is not controlled. In astrophysics, runaway nuclear fusion reactions in stars can lead to nova and several types of supernova explosions, and also occur as a less dramatic event in the normal evolution of solar-mass stars, the "helium flash".
Chemical engineering
Chemical reactions involving thermal runaway are also called thermal explosions in chemical engineering, or runaway reactions in organic chemistry. It is a process by which an exothermic reaction goes out of control: the reaction rate increases due to an increase in temperature, causing a further increase in temperature and hence a further rapid increase in the reaction rate. This has contributed to industrial chemical accidents, most notably the 1947 Texas City disaster from overheated ammonium nitrate in a ship's hold, and the 1976 explosion of zoalene, in a drier, at King's Lynn. Frank-Kamenetskii theory provides a simplified analytical model for thermal explosion. Chain branching is an additional positive feedback mechanism which may also cause temperature to skyrocket because of rapidly increasing reaction rate.
Chemical reactions are either endothermic or exothermic, as expressed by their change in enthalpy. Many reactions are highly exothermic, so ma |
https://en.wikipedia.org/wiki/C-nario | Founded in 2002, C-nario is a provider of digital signage software, headquartered in Israel.
The company, which was recently acquired by YCD Multimedia, has customers in a variety of industries: Retail, Banking, Transportation, Advertising and Media, Entertainment, Sporting events and Facilities, Education, and Telecom, among others.
The company has offices in the United States, Europe, and Israel.
C-nario is a privately held company, backed by leading VCs: Carmel Ventures (Israel) and Opus Capital (USA).
History
C-nario was established in 2002 in Israel, as a spin-off of Disk-In. In 2003 the company started its international activity and signed an agreement with Philips. In 2004 the company opened its US office.
In 2005, C-nario installed a digital signage network in 250 branches of Israel's Bank Hapoalim, and in 2007 the company's platform was selected by JCDecaux as the digital signage software in a digital signage network at JFK and LAX airports in the US. This network was later expanded to more than a dozen US airports. In addition, C-nario's software was implemented at McDonald's in Singapore and London's O2 Arena.
In 2008, C-nario opened its office in Paris. Later that year C-nario won the Digi Award for Excellence in Entertainment Technology, and the company announced a new worldwide value-added partner program for selling and marketing its digital signage software-based platforms. Some of the prominent projects in which C-nario software was implemented included Shanghai Airport, Casino da Madeira in Portugal, New York Stock Exchange (NYSE), Harrah's Resort in Atlantic City, USA, Comcast and Club Med. The company also announced partnerships with PlayNetwork and Mitsubishi Electric. C-nario won the Digi award for the O2 Arena project.
In 2009, C-nario expanded its partners network and signed agreements with T-Systems – Deutsche Telekom's corporate customer division, TruMedia Technologies –a provider of real-time audience measurement and proactive adv |
https://en.wikipedia.org/wiki/Continuous-variable%20quantum%20information | Continuous-variable (CV) quantum information is the area of quantum information science that makes use of physical observables, like the strength of an electromagnetic field, whose numerical values belong to continuous intervals. One primary application is quantum computing. In a sense, continuous-variable quantum computation is "analog", while quantum computation using qubits is "digital." In more technical terms, the former makes use of Hilbert spaces that are infinite-dimensional, while the Hilbert spaces for systems comprising collections of qubits are finite-dimensional. One motivation for studying continuous-variable quantum computation is to understand what resources are necessary to make quantum computers more powerful than classical ones.
Implementation
One approach to implementing continuous-variable quantum information protocols in the laboratory is through the techniques of quantum optics. By modeling each mode of the electromagnetic field as a quantum harmonic oscillator with its associated creation and annihilation operators, one defines a canonically conjugate pair of variables for each mode, the so-called "quadratures", which play the role of position and momentum observables. These observables establish a phase space on which Wigner quasiprobability distributions can be defined. Quantum measurements on such a system can be performed using homodyne and heterodyne detectors.
Quantum teleportation of continuous-variable quantum information was achieved by optical methods in 1998. (Science deemed this experiment one of the "top 10" advances of the year.) In 2013, quantum-optics techniques were used to create a "cluster state", a type of preparation essential to one-way (measurement-based) quantum computation, involving over 10,000 entangled temporal modes, available two at a time. In another implementation, 60 modes were simultaneously entangled in the frequency domain, in the optical frequency comb of an optical parametric oscillator.
Another propo |
https://en.wikipedia.org/wiki/System%20context%20diagram | A system context diagram in engineering is a diagram that defines the boundary between the system, or part of a system, and its environment, showing the entities that interact with it. This diagram is a high level view of a system. It is similar to a block diagram.
Overview
System context diagrams show a system, as a whole and its inputs and outputs from/to external factors. According to Kossiakoff and Sweet (2011):
System context diagrams are used early in a project to get agreement on the scope under investigation. Context diagrams are typically included in a requirements document. These diagrams must be read by all project stakeholders and thus should be written in plain language, so the stakeholders can understand items within the document.
Building blocks
Context diagrams can be developed with the use of two types of building blocks:
Entities (Actors): labeled boxes; one in the center representing the system, and around it multiple boxes for each external actor
Relationships: labeled lines between the entities and system
For example, "customer places order." Context diagrams can also use many different drawing types to represent external entities. They can use ovals, stick figures, pictures, clip art or any other representation to convey meaning. Decision trees and data storage are represented in system flow diagrams.
A context diagram can also list the classifications of the external entities as one of a set of simple categories (Examples:), which add clarity to the level of involvement of the entity with regards to the system. These categories include:
Active: Dynamic to achieve some goal or purpose (Examples: "Article readers" or "customers").
Passive: Static external entities which infrequently interact with the system (Examples: "Article editors" or "database administrator").
Cooperative: Predictable external entities which are used by the system to bring about some desired outcome (Examples: "Internet service providers" or "shipping companie |
https://en.wikipedia.org/wiki/Lawvere%20theory | In category theory, a Lawvere theory (named after American mathematician William Lawvere) is a category that can be considered a categorical counterpart of the notion of an equational theory.
Definition
Let be a skeleton of the category FinSet of finite sets and functions. Formally, a Lawvere theory consists of a small category L with (strictly associative) finite products and a strict identity-on-objects functor preserving finite products.
A model of a Lawvere theory in a category C with finite products is a finite-product preserving functor . A morphism of models where M and N are models of L is a natural transformation of functors.
Category of Lawvere theories
A map between Lawvere theories (L, I) and (L′, I′) is a finite-product preserving functor that commutes with I and I′. Such a map is commonly seen as an interpretation of (L, I) in (L′, I′).
Lawvere theories together with maps between them form the category Law.
Variations
Variations include multisorted (or multityped) Lawvere theory, infinitary Lawvere theory, and finite-product theory.
See also
Algebraic theory
Clone (algebra)
Monad (category theory)
Notes |
https://en.wikipedia.org/wiki/Chat%20log | A chat log is an archive of transcripts from online chat and instant messaging conversations. Many chat or IM applications allow for the client-side archiving of online chat conversations, while a subset of chat or IM clients (i.e., Google Talk and Yahoo! Messenger 11 Beta) allow for the saving of chat archives on a server for future retrieval. Most IRC clients and many IRC bots include chat logging to a local file as a standard feature.
Web sites exist that publish chat logs, usually dedicated to a single channel and including a search engine. This can conflict with users' expectations of privacy. Some IRC networks have published guidelines on making chat logs public. Due to their real time nature, chat logs may be used to identify anonymous users by correlating information posted on different mediums.
Examples
Google has integrated its own chat archiving feature into Gmail, which lists Google Talk conversations alongside email conversations.
Yahoo first experimented with online archiving of Yahoo Messenger chat logs through its Yahoo! Messenger for the Web application, which separately saves its own chat archive when users communicate through that client. In 2010, the beta of the 11th version of the standalone Messenger client featured online archiving of chat logs, although the archive is only available and viewable from within the logged-in client.
bash.org is a website hosting user-posted chat logs from IRC. |
https://en.wikipedia.org/wiki/JModelica.org | JModelica.org is a commercial software platform based on the Modelica modeling language for modeling, simulating, optimizing and analyzing complex dynamic systems. The platform is maintained and developed by Modelon AB in collaboration with academic and industrial institutions, notably Lund University and the Lund Center for Control of Complex Systems (LCCC). The platform has been used in industrial projects with applications in robotics, vehicle systems, energy systems, separation and polyethylene production.
The key components of the platform are:
A Modelica compiler for translating Modelica source code into C or XML code. The compiler also generates models compliant with the Functional Mock-up Interface standard.
A Python package for simulation of dynamic models, Assimulo. Assimulo provides interfaces to several state of the art integrators and is used as a simulation engine in JModelica.org.
Algorithms for solving large scale dynamic optimization problems implementing local collocation methods on finite elements and pseudospectral collocation methods.
A Python package for user interaction. All parts of the platform are accessed from Python, including compiling and loading models, simulating and optimizing.
JModelica.org supports the Modelica modeling language for modeling of physical systems. Modelica provides high-level descriptions of hybrid dynamic systems, which are used as a basis for different kinds of computations in JModelica.org including simulation, sensitivity analysis and optimization.
Dynamic optimization problems, including optimal control, trajectory optimization, parameter optimization and model calibration can be formulated and solved using JModelica.org. The Optimica extension enables high-level formulation of dynamic optimization problems based on Modelica models. The mintOC project provides a number of benchmark problems encoded in Optimica.
The platform promotes open interfaces for integration with numerical packages. The Sundials |
https://en.wikipedia.org/wiki/Ogden%20hyperelastic%20model | The Ogden material model is a hyperelastic material model used to describe the non-linear stress–strain behaviour of complex materials such as rubbers, polymers, and biological tissue. The model was developed by Raymond Ogden in 1972. The Ogden model, like other hyperelastic material models, assumes that the material behaviour can be described by means of a strain energy density function, from which the stress–strain relationships can be derived.
Ogden material model
In the Ogden material model, the strain energy density is expressed in terms of the principal stretches , as:
where , and are material constants. Under the assumption of incompressibility one can rewrite as
In general the shear modulus results from
With and by fitting the material parameters, the material behaviour of rubbers can be described very accurately. For particular values of material constants the Ogden model will reduce to either the Neo-Hookean solid (, ) or the Mooney-Rivlin material (, , , with the constraint condition ).
Using the Ogden material model, the three principal values of the Cauchy stresses can now be computed as
.
Uniaxial tension
We now consider an incompressible material under uniaxial tension, with the stretch ratio given as , where is the stretched length and is the original unstretched length. The pressure is determined from incompressibility and boundary condition , yielding:
.
Equi-biaxial tension
Considering an incompressible material under eqi-biaxial tension, with . The pressure is determined from incompressibility, and boundary condition , gives:
.
Other hyperelastic models
For rubber and biological materials, more sophisticated models are necessary. Such materials may exhibit a non-linear stress–strain behaviour at modest strains, or are elastic up to huge strains. These complex non-linear stress–strain behaviours need to be accommodated by specifically tailored strain-energy density functions.
The simplest of these hyperelastic models, |
https://en.wikipedia.org/wiki/Davydov%20soliton | In quantum biology, the Davydov soliton (after the Soviet Ukrainian physicist Alexander Davydov) is a quasiparticle representing an excitation propagating along the self-trapped amide I groups within the α-helices of proteins. It is a solution of the Davydov Hamiltonian.
The Davydov model describes the interaction of the amide I vibrations with the hydrogen bonds that stabilize the α-helices of proteins. The elementary excitations within the α-helix are given by the phonons which correspond to the deformational oscillations of the lattice, and the excitons which describe the internal amide I excitations of the peptide groups. Referring to the atomic structure of an α-helix region of protein the mechanism that creates the Davydov soliton (polaron, exciton) can be described as follows: vibrational energy of the C=O stretching (or amide I) oscillators that is localized on the α-helix acts through a phonon coupling effect to distort the structure of the α-helix, while the helical distortion reacts again through phonon coupling to trap the amide I oscillation energy and prevent its dispersion. This effect is called self-localization or self-trapping. Solitons in which the energy is distributed in a fashion preserving the helical symmetry are dynamically unstable, and such symmetrical solitons once formed decay rapidly when they propagate. On the other hand, an asymmetric soliton which spontaneously breaks the local translational and helical symmetries possesses the lowest energy and is a robust localized entity.
Davydov Hamiltonian
Davydov Hamiltonian is formally similar to the Fröhlich-Holstein Hamiltonian for the interaction of electrons with a polarizable lattice. Thus the Hamiltonian of the energy operator is
where is the exciton Hamiltonian, which describes the motion of the amide I excitations between adjacent sites; is the phonon Hamiltonian, which describes
the vibrations of the lattice; and is the interaction Hamiltonian, which describes the interaction |
https://en.wikipedia.org/wiki/N-ary%20code | In telecommunication, an n-ary code is a code that has n significant conditions, where n is a positive integer greater than 1. The integer substituted for n indicates the specific number of significant conditions, i.e., quantization states, in the code. For example, an 8-ary code has eight significant conditions and can convey three bits per code symbol. A prefix that indicates an integer, e.g., "bin", "tern," or "quatern", may be used in lieu of a numeral, to produce "binary", "ternary", or "quaternary" (2, 3, and 4 states respectively).
See also
Arity
Source: from Federal Standard 1037C and from MIL-STD-188
Line codes |
https://en.wikipedia.org/wiki/Criticism%20of%20Windows%2010 | Windows 10, a proprietary operating system released by Microsoft in July 2015, has been criticized by reviewers and users. Due to issues mostly about privacy, it has been the subject of a number of negative assessments by various groups.
General criticism
Critics have noted that Windows10 heavily emphasizes freemium services and contains various advertising facilities. Some outlets have considered these to be a hidden "cost" of the free upgrade offer. Examples include media storefronts, Office 365, paid functionality in bundled games such as Microsoft Solitaire Collection, default settings that display promotions of "suggested" apps in Start menu and "tips" on the lock screen that may contain advertising, ads displayed in File Explorer for Office 365 subscriptions on Redstone 2 builds, and notifications promoting the Microsoft Edge web browser when a different browser is set as default.
Update system
Windows 10 Home is permanently set to download all updates automatically, including cumulative updates, security patches, and drivers, and users cannot individually select updates to install or not. Microsoft offers a diagnostic tool that can be used to hide updates and prevent them from being reinstalled, but only after they had been already installed, then uninstalled without rebooting the system. However, the software agreement states, specifically for users of Windows10 in Canada, that they may pause updates by disconnecting their device from the Internet. Tom Warren of The Verge felt that, given web browsers such as Google Chrome had already adopted such an automatic update system, such a requirement would help to keep all Windows10 devices secure, and felt that "if you're used to family members calling you for technical support because they've failed to upgrade to the latest Windows service pack or some malware disabled Windows Update then those days will hopefully be over."
Concerns were raised that due to these changes, users would be unable to skip the au |
https://en.wikipedia.org/wiki/Insect%20sting%20allergy | Insect sting allergy is the term commonly given to the allergic response of an animal in response to the bite or sting of an insect. Typically, insects which generate allergic responses are either stinging insects (wasps, bees, hornets and ants ) or biting insects (mosquitoes, ticks). Stinging insects inject venom into their victims, whilst biting insects normally introduce anti-coagulants into their victims.
The great majority of insect allergic animals just have a simple allergic response – a reaction local to the sting site which appears as just a swelling arising from the release of histamine and other chemicals from the body tissues near to the sting site. The swelling, if allergic, can be helped by the provision of an anti-histamine ointment as well as an ice pack. This is the typical response for all biting insects and many people have this common reaction.
Mosquito allergy may result in a collection of symptoms called skeeter syndrome that occur after a bite. This syndrome may be mistaken for an infection such as cellulitis.
In anaphylactic patients the response is more aggressive leading to a systemic reaction where the response progresses from the sting site around the whole body. This is potentially something very serious and can lead to anaphylaxis, which is potentially life-threatening.
Epidemiology
The majority of individuals who receive a sting from an insect experience local reactions. It is estimated that 5-10% of individuals will experience a generalized systemic reaction that can involve symptoms ranging from hives to wheezing and even anaphylaxis. In the United States approximately 40 people die each year from anaphylaxis due to stinging insect allergy. Potentially life-threatening reactions occur in 3% of adults and 0.4–0.8% of children.
Prevention
A 2012 meta-analysis found that venom immunotherapy is an effective prophylactic treatment against insect bite and sting allergic reactions, and significantly improves the quality of life of pe |
https://en.wikipedia.org/wiki/Subsumption%20architecture | Subsumption architecture is a reactive robotic architecture heavily associated with behavior-based robotics which was very popular in the 1980s and 90s. The term was introduced by Rodney Brooks and colleagues in 1986. Subsumption has been widely influential in autonomous robotics and elsewhere in real-time AI.
Overview
Subsumption architecture is a control architecture that was proposed in opposition to traditional symbolic AI. Instead of guiding behavior by symbolic mental representations of the world, subsumption architecture couples sensory information to action selection in an intimate and bottom-up fashion.
It does this by decomposing the complete behavior into sub-behaviors. These sub-behaviors are organized into a hierarchy of layers. Each layer implements a particular level of behavioral competence, and higher levels are able to subsume lower levels (= integrate/combine lower levels to a more comprehensive whole) in order to create viable behavior. For example, a robot's lowest layer could be "avoid an object". The second layer would be "wander around", which runs beneath the third layer "explore the world". Because a robot must have the ability to "avoid objects" in order to "wander around" effectively, the subsumption architecture creates a system in which the higher layers utilize the lower-level competencies. The layers, which all receive sensor-information, work in parallel and generate outputs. These outputs can be commands to actuators, or signals that suppress or inhibit other layers.
Goal
Subsumption architecture attacks the problem of intelligence from a significantly different perspective than traditional AI. Disappointed with the performance of Shakey the robot and similar conscious mind representation-inspired projects, Rodney Brooks started creating robots based on a different notion of intelligence, resembling unconscious mind processes. Instead of modelling aspects of human intelligence via symbol manipulation, this approach is ai |
https://en.wikipedia.org/wiki/Candidalysin | Candidalysin is a cytolytic 31-amino acid α-helical amphipathic peptide toxin secreted by the opportunistic pathogen Candida albicans. This toxin is a fungal example of a classical virulence factor. Hyphal morphogenesis in C. albicans is associated with damage to host epithelial cells; during this process Candidalysin is released and intercalates in host membranes. Candidalysin promotes damage of oral epithelial cells and induces lactate dehydrogenase release and calcium ion influx. It is unique in the fact that it is the first peptide toxin to be identified in any human fungal pathogen.
Candidalysin is a product of the larger protein Ece1 (extent of cell elongation 1). Sequential processing of Ece1 at lysine/arginine residues by the proteases Kex2 and Kex1 releases several peptides, including the toxin Candidalysin. Consequently, Candidalysin is also known as Ece1-III62–92K. C. albicans strains missing Candidalysin do not damage epithelial cells and are said to be avirulent with respect to mucosal infections. The toxin is also responsible for the activation and propagation of a cellular immune response.
Epithelial damage
During epithelial infection, as candidalysin levels accumulate, tissue damage occurs. Candidalysin promotes damage of oral epithelial cells, which can be measured by the release of lactate dehydrogenase, and calcium ion influx which are characteristics of membrane destabilization and cell damage. Candidalysin is able to cause epithelial damage through membrane intercalation and permeabilization. It causes IL-1β release and is a driver of inflammasome activation in macrophages.
Immune response
Epithelial immunity can recognize Ece1-III62–92K without harming cells. Epithelial cells have evolved to particularly recognize the peptide, which indicates that during mucosal infection the fungus secretes this toxin. Immune cells can either be exposed extracellularly or intracellularly and this is due to the fact that phagocytes can be exposed to the f |
https://en.wikipedia.org/wiki/Sprouting | Sprouting is the natural process by which seeds or spores germinate and put out shoots, and already established plants produce new leaves or buds, or other structures experience further growth.
In the field of nutrition, the term signifies the practice of germinating seeds (for example, mung beans or sunflower seeds) to be eaten raw or cooked, which is considered more nutritious.
Suitable seeds
All viable seeds can be sprouted, but some sprouts, such as kidney beans, should not be eaten raw.
Bean sprouts are a common ingredient across the world. They are particularly common in Eastern Asian cuisine. It typically takes one week for them to become fully grown. The sprouted beans are more nutritious than the original beans, and they require much less cooking time. There are two common types of bean sprouts:
Mung bean sprouts, made from greenish-capped mung beans
Soybean sprouts, made from yellow, large-grained soybeans
Common sprouts used as food include:
Pulses/legumes (pea family) - bean sprouts:
alfalfa, clover, fenugreek, lentil, pea, chickpea (garbanzo), mung bean, and soy bean
Cereals (grasses):
oat, wheat, maize (corn), rice, barley, and rye
Pseudocereals:
quinoa, amaranth, and buckwheat
Oilseeds:
sesame, sunflower, almond, hazelnut, hemp, linseed, and peanut
Brassica (cabbage family):
broccoli, cabbage, watercress, mustard, mizuna, radish, and daikon (kaiware-daikon in Japanese cuisine), arugula, tatsoi, and turnip
Umbelliferous vegetables (parsley family) - these may be used more as microgreens than sprouts:
carrot, celery, fennel, and parsley.
Allium (onion family) - cannot distinguish sprouts from microgreens:
onion, leek, and green onion (me-negi in Japanese cuisine)
Other vegetables and herbs:
spinach, lettuce, milk thistle, and lemon grass
Although whole oats can be sprouted, oat groats sold in food stores, which are dehulled and have been steamed or roasted to prevent rancidity, will not sprout. Whole oats may have an indigestible hull w |
https://en.wikipedia.org/wiki/Silicon%20nanowire | Silicon nanowires, also referred to as SiNWs, are a type of semiconductor nanowire most often formed from a silicon precursor by etching of a solid or through catalyzed growth from a vapor or liquid phase. Such nanowires have promising applications in lithium ion batteries, thermoelectrics and sensors. Initial synthesis of SiNWs is often accompanied by thermal oxidation steps to yield structures of accurately tailored size and morphology.
SiNWs have unique properties that are not seen in bulk (three-dimensional) silicon materials. These properties arise from an unusual quasi one-dimensional electronic structure and are the subject of research across numerous disciplines and applications. The reason that SiNWs are considered one of the most important one-dimensional materials is they could have a function as building blocks for nanoscale electronics assembled without the need for complex and costly fabrication facilities. SiNWs are frequently studied towards applications including photovoltaics, nanowire batteries, thermoelectrics and non-volatile memory.
Applications
Owing to their unique physical and chemical properties, silicon nanowires are a promising candidate for a wide range of applications that draw on their unique physico-chemical characteristics, which differ from those of bulk silicon material.
SiNWs exhibit charge trapping behavior which renders such systems of value in applications necessitating electron hole separation such as photovoltaics, and photocatalysts. Recent experiment on nanowire solar cells has led to a remarkable improvement of the power conversion efficiency of SiNW solar cells from <1% to >17% in the last few years.
Charge trapping behaviour and tuneable surface governed transport properties of SiNWs render this category of nanostructures of interest towards use as metal insulator semiconductors and field effect transistors, with further applications as nanoelectronic storage devices, in flash memory, logic devices as well as chemic |
https://en.wikipedia.org/wiki/Bingham%20plastic | In materials science, a Bingham plastic is a viscoplastic material that behaves as a rigid body at low stresses but flows as a viscous fluid at high stress. It is named after Eugene C. Bingham who proposed its mathematical form.
It is used as a common mathematical model of mud flow in drilling engineering, and in the handling of slurries. A common example is toothpaste, which will not be extruded until a certain pressure is applied to the tube. It is then pushed out as a relatively coherent plug.
Explanation
Figure 1 shows a graph of the behaviour of an ordinary viscous (or Newtonian) fluid in red, for example in a pipe. If the pressure at one end of a pipe is increased this produces a stress on the fluid tending to make it move (called the shear stress) and the volumetric flow rate increases proportionally. However, for a Bingham Plastic fluid (in blue), stress can be applied but it will not flow until a certain value, the yield stress, is reached. Beyond this point the flow rate increases steadily with increasing shear stress. This is roughly the way in which Bingham presented his observation, in an experimental study of paints. These properties allow a Bingham plastic to have a textured surface with peaks and ridges instead of a featureless surface like a Newtonian fluid.
Figure 2 shows the way in which it is normally presented currently. The graph shows shear stress on the vertical axis and shear rate on the horizontal one. (Volumetric flow rate depends on the size of the pipe, shear rate is a measure of how the velocity changes with distance. It is proportional to flow rate, but does not depend on pipe size.) As before, the Newtonian fluid flows and gives a shear rate for any finite value of shear stress. However, the Bingham plastic again does not exhibit any shear rate (no flow and thus no velocity) until a certain stress is achieved. For the Newtonian fluid the slope of this line is the viscosity, which is the only parameter needed to describe its flow |
https://en.wikipedia.org/wiki/Zwittermicin%20A | Zwittermicin A is an antibiotic that has been identified from the bacterium Bacillus cereus UW85. It is a molecule of interest to agricultural industry because it has the potential to suppress plant disease due to its broad spectrum activity against certain gram positive and gram negative prokaryotic micro-organisms. The molecule is also of interest from a metabolic perspective because it represents a new structural class of antibiotic and suggests a crossover between polyketide and non-ribosomal peptide biosynthetic pathways. Zwittermicin A is linear aminopolyol.
Biosynthesis
Zwittermycin A biosynthesis is a hybrid of polyketide and non-ribosomal peptide synthetic pathways. Most likely, all of the synthases are located on one megasynthase much like a type I fatty acid synthase. Based on mutant studies, the biosynthetic cluster involved in zwittermicin production has been identified and the pathway has been proposed. The genes responsible for the production of zwittermicin A are located on a 16 kb cluster containing nine orfs and a self resistant gene zmaR, a gene that encodes an acylation enzyme that deactivate zwittermicin A. The hybrid synthase used in zwittermicin A production utilizes modified extender units such as hydroxymalonyl-ACP, aminomalonyl-ACP and 2,3-diaminopropionate. Therefore, many of the genes in the biosynthetic cluster encode for enzymes responsible for the synthesis of these extender units used in the hybrid synthase. For example, orf5 encodes ZWA5A, an enzyme that is responsible for the PLP mediated amination that converts L-serine to 2,3-diaminopropionate. It has also been shown that orf5, orf7, orf4 and orf6 participate in the biosynthesis of aminomalonyl-ACP and orf3, orf2 and orf1 synthesize hydroxymalonyl-ACP.
Gene organization of the Zwittermicin A biosynthetic cluster.
Genes encoding for the seven component hybrid synthase responsible for the assembly of the backbone is likely located on the largest gene, orf8. Assembly begins by the |
https://en.wikipedia.org/wiki/Siemens%20Communications | Siemens Communications was the communications and information business arm of German industrial conglomerate Siemens AG, until 2006. It was the largest division of Siemens, and had two business units – Mobile Networks and Fixed Networks; and Enterprise.
Siemens Communications division was founded in 1998 through the amalgamation of a number of early groups / divisions of Siemens AG, the oldest of which traces back to the company 'Siemens & Halske Telegraph Construction Company' founded in 1847, and the most prominent predecessor being the 1978-founded 'Siemens Communication Systems'. On October 1, 2006, Siemens AG decided to divide Siemens Communications into two companies: 'Siemens Networks GmbH & Co. KG' and 'Siemens Enterprise Communications GmbH & Co. KG'.
The company remains extant, through a series of mergers and divisions, as Siemens Enterprise Communications – a 2008 joint venture with the Gores Group where Siemens AG hold 49% with the balance of 51% held by the American partner.
History
Origins (1847–1978)
Siemens Communications traces its origins to the company Siemens & Halske Telegraph Construction Company (German legal name: Telegraphen-Bauanstalt von Siemens & Halske) founded by Werner von Siemens on 12 October 1847. Based on the telegraph, his invention used a needle to point to the sequence of letters, instead of using Morse code.
In 1848, the company built the first long-distance telegraph line in Europe – 500 km from Berlin to Frankfurt am Main – and by the early 1850s the company was involved in building long distance telegraph networks in Russia. In 1867, Siemens completed the monumental Indo-European telegraph line stretching over 11,000 km from London to Calcutta. In 1897, Siemens & Halske went public.
During the first half of the 20th century, there were a series of mergers and divisions, which led to formation of three separate companies. First was the original company, Siemens & Halske, which focused on communications engineering; the |
https://en.wikipedia.org/wiki/Ricochet | A ricochet ( ; ) is a rebound, bounce, or skip off a surface, particularly in the case of a projectile. Most ricochets are caused by accident and while the force of the deflection decelerates the projectile, it can still be energetic and almost as dangerous as before the deflection. The possibility of ricochet is one of the reasons for the common firearms safety rule "Never shoot a bullet at a flat, hard surface." Ricochets can occur with any caliber, but short or round ricocheting bullets may not produce the audible whine caused by tumbling irregular shapes. Ricochets are a hazard of shooting because, for as long as they retain sufficient velocity, ricocheting bullets or bullet fragments may cause collateral damage to animals, objects, or even the person who fired the shot.
Variables
Ricochets occur when a bullet or bullet fragment is deflected by an object rather than penetrating and becoming embedded in that object. Ricochet behavior may vary with bullet shape, bullet material, spin, velocity (and distance), target material and the angle of incidence.
Velocity
High-velocity rifle cartridges have higher probability of bullet penetration, because increased energy released by an identical bullet may fracture or temporarily melt the target at the point of impact. Alternatively, the same energy release may melt and/or disintegrate the bullet to reduce size and range of deflected particles. Ricochets are more likely with handgun cartridges and low velocity rifle cartridges such as .22 Long Rifle. Buckshot and shotgun slugs have similarly high ricochet probability, but ricochet range of smaller shot is lower than intact rifle or handgun bullet ricochets.
Bullet
Sectional density, or mass of the bullet divided by the frontal area of the bullet, increases penetration of resistant surfaces. Elongated, spin-stabilized bullets fired from rifled firearms have greater sectional density than spherical bullets of the same diameter made from the same material; and elongated r |
https://en.wikipedia.org/wiki/DexNet | Dex-net is a robotic manipulator. It uses a Grasp Quality Convolutional Neural Network to learn how to grasp unusually shaped objects.
History
Dex-net was developed by University of California, Berkeley professor Ken Goldberg and graduate student Jeff Mahler.
Design
Dex-net includes a high-resolution 3-D sensor and two arms, each controlled by a different neural network. One arm is equipped with a conventional robot gripper and another with a suction system. The robot’s software scans an object and then asks both neural networks to decide, on the fly, whether to grab or suck a particular object. It runs on an off-the-shelf industrial machine made by Swiss robotics company ABB.
The software learns by attempting to pick up objects in a virtual environment. Dex-Net can generalize from an object it has seen before to a new one. The robot can "nudge" such virtual objects to examine it if it is unsure how to grasp it. The trial data set was 6.7 million point clouds, grasps and analytic grasp metrics generated from thousands of 3D models. Grasps are defined as a gripper's planar position, angle and depth relative to an RGB-D sensor.
Mean picks per hour
A metric called mean picks per hour (MPPH) is calculated by multiplying the average time per pick and the average probability of success for a specific set of objects. The new metric allows labs working on picking robots to compare their results.
Humans are capable of between 400 and 600 MPPH. In a contest organized by Amazon recently, the best robots were capable of between 70 and 95. Dex-net has achieved 200 to 300. |
https://en.wikipedia.org/wiki/Peak%20power%20output | Peak power output (PPO), also known as "peak work rate" is a common measure of exercise intensity. For example, researchers may ask subjects to complete an incremental exercise test where VO2max is measured while the person cycles at increasingly difficult power generation levels as measured by a cycle ergometer.
See also
Human power |
https://en.wikipedia.org/wiki/List%20of%20products%20that%20support%20SMB | List of products that support the proprietary Server Message Block protocol by IBM and later Microsoft.
Implementations
The list below explicitly refers to "SMB" as including an SMB client or an SMB server, plus the various protocols that extend SMB, such as the Network Neighborhood suite of protocols and the NT Domains suite.
Microsoft Windows includes an SMB client and server in all members of the Windows NT family and in Windows 95, Windows 98, and Windows Me.
The Linux kernel includes two SMB client implementations that use the Linux VFS, providing access to files on an SMB server through the standard file system API: smbfs and cifs. Also it is possible to mount the whole hierarchy of workgroups/servers/shares ("neighborhood") through FUSE kernel module and its userspace counterpart fusesmb. CIFSD, which is an In-kernel CIFS/SMB server implementation for Linux kernel, is available. It has the following advantages over user-space implementations: 1. It provides better performance, 2. It's easier to implement some features like SMB Direct.
Plan 9 from Bell Labs contained both a CIFS/SMB server aquarela and client cifs.
FreeBSD includes an SMB client implementation called smbfs that uses its VFS.
NetBSD and macOS include SMB client implementations called smbfs, originally derived from the FreeBSD smbfs; they use the NetBSD and macOS VFSes, respectively.
macOS, starting with Mac OS X Lion, has an Apple-developed SMB server implementation called SMBX.
Solaris has a project called CIFS client for Solaris, based on the Mac OS X smbfs.
OpenSolaris added in-kernel CIFS server support in October 2007. This is also present in OpenIndiana and NexentaStor.
Sun Microsystems Cascade, which became known as PC-Netlink, represents a port of Advanced Server for Unix. Sun took over two years making the code useful, due to the poor quality of the original port.
Novell NetWare version 6 and newer has a CIFS server implementation providing access to NetWare volumes for Mi |
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