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https://en.wikipedia.org/wiki/Blind%20deconvolution
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In electrical engineering and applied mathematics, blind deconvolution is deconvolution without explicit knowledge of the impulse response function used in the convolution. This is usually achieved by making appropriate assumptions of the input to estimate the impulse response by analyzing the output. Blind deconvolution is not solvable without making assumptions on input and impulse response. Most of the algorithms to solve this problem are based on assumption that both input and impulse response live in respective known subspaces. However, blind deconvolution remains a very challenging non-convex optimization problem even with this assumption.
In image processing
In image processing, blind deconvolution is a deconvolution technique that permits recovery of the target scene from a single or set of "blurred" images in the presence of a poorly determined or unknown point spread function (PSF). Regular linear and non-linear deconvolution techniques utilize a known PSF. For blind deconvolution, the PSF is estimated from the image or image set, allowing the deconvolution to be performed. Researchers have been studying blind deconvolution methods for several decades, and have approached the problem from different directions.
Most of the work on blind deconvolution started in early 1970s. Blind deconvolution is used in astronomical imaging and medical imaging.
Blind deconvolution can be performed iteratively, whereby each iteration improves the estimation of the PSF and the scene, or non-iteratively, where one application of the algorithm, based on exterior information, extracts the PSF. Iterative methods include maximum a posteriori estimation and expectation-maximization algorithms. A good estimate of the PSF is helpful for quicker convergence but not necessary.
Examples of non-iterative techniques include SeDDaRA, the cepstrum transform and APEX. The cepstrum transform and APEX methods assume that the PSF has a specific shape, and one must estimate the width of t
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https://en.wikipedia.org/wiki/Chv%C3%A1tal%E2%80%93Sankoff%20constants
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In mathematics, the Chvátal–Sankoff constants are mathematical constants that describe the lengths of longest common subsequences of random strings. Although the existence of these constants has been proven, their exact values are unknown. They are named after Václav Chvátal and David Sankoff, who began investigating them in the mid-1970s.
There is one Chvátal–Sankoff constant for each positive integer k, where k is the number of characters in the alphabet from which the random strings are drawn. The sequence of these numbers grows inversely proportionally to the square root of k. However, some authors write "the Chvátal–Sankoff constant" to refer to , the constant defined in this way for the binary alphabet.
Background
A common subsequence of two strings S and T is a string whose characters appear in the same order (not necessarily consecutively) both in S and in T. The problem of computing a longest common subsequence has been well studied in computer science. It can be solved in polynomial time by dynamic programming; this basic algorithm has additional speedups for small alphabets (the Method of Four Russians), for strings with few differences, for strings with few matching pairs of characters, etc. This problem and its generalizations to more complex forms of edit distance have important applications in areas that include bioinformatics (in the comparison of DNA and protein sequences and the reconstruction of evolutionary trees), geology (in stratigraphy), and computer science (in data comparison and revision control).
One motivation for studying the longest common subsequences of random strings, given already by Chvátal and Sankoff, is to calibrate the computations of longest common subsequences on strings that are not random. If such a computation returns a subsequence that is significantly longer than what would be obtained at random, one might infer from this result that the match is meaningful or significant.
Definition and existence
The Chvátal–Sanko
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https://en.wikipedia.org/wiki/Miraculin
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Miraculin is a taste modifier, a glycoprotein extracted from the fruit of Synsepalum dulcificum. The berry, also known as the miracle fruit, was documented by explorer Chevalier des Marchais, who searched for many different fruits during a 1725 excursion to its native West Africa.
Miraculin itself does not taste sweet. When taste buds are exposed to miraculin, the protein binds to the sweetness receptors. This causes normally sour-tasting acidic foods, such as citrus, to be perceived as sweet. The effect can last for one or two hours.
History
The sweetening properties of Synsepalum dulcificum berries were first noted by des Marchais during expeditions to West Africa in the 18th century. The term miraculin derived from experiments to isolate and purify the active glycoprotein that gave the berries their sweetening effects, results that were published simultaneously by Japanese and Dutch scientists working independently in the 1960s (the Dutch team called the glycoprotein mieraculin). The word miraculin was in common use by the mid-1970s.
Glycoprotein structure
Miraculin was first sequenced in 1989 and was found to be a 24.6 kilodalton glycoprotein consisting of 191 amino acids and 13.9% by weight of various sugars.
The sugars consist of a total of 3.4 kDa, composed of a molar ratio of glucosamine (31%), mannose (30%), fucose (22%), xylose (10%), and galactose (7%).
The native state of miraculin is a tetramer consisting of two dimers, each held together by a disulfide bridge. Both tetramer miraculin and native dimer miraculin in its crude state have the taste-modifying activity of turning sour tastes into sweet tastes. Miraculin belongs to the Kunitz STI protease inhibitor family.
Sweetness properties
Miraculin, unlike curculin (another taste-modifying agent), is not sweet by itself, but it can change the perception of sourness to sweetness, even for a long period after consumption. The duration and intensity of the sweetness-modifying effect depends on vari
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https://en.wikipedia.org/wiki/Biological%20rhythm
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Biological rhythms are repetitive biological processes. Some types of biological rhythms have been described as biological clocks. They can range in frequency from microseconds to less than one repetitive event per decade. Biological rhythms are studied by chronobiology. In the biochemical context biological rhythms are called biochemical oscillations.
The variations of the timing and duration of biological activity in living organisms occur for many essential biological processes. These occur (a) in animals (eating, sleeping, mating, hibernating, migration, cellular regeneration, etc.), (b) in plants (leaf movements, photosynthetic reactions, etc.), and in microbial organisms such as fungi and protozoa. They have even been found in bacteria, especially among the cyanobacteria (aka blue-green algae, see bacterial circadian rhythms).
Circadian rhythm
The best studied rhythm in chronobiology is the circadian rhythm, a roughly 24-hour cycle shown by physiological processes in all these organisms. The term circadian comes from the Latin circa, meaning "around" and dies, "day", meaning "approximately a day." It is regulated by circadian clocks.
The circadian rhythm can further be broken down into routine cycles during the 24-hour day:
Diurnal, which describes organisms active during daytime
Nocturnal, which describes organisms active in the night
Crepuscular, which describes animals primarily active during the dawn and dusk hours (ex: white-tailed deer, some bats)
While circadian rhythms are defined as regulated by endogenous processes, other biological cycles may be regulated by exogenous signals. In some cases, multi-trophic systems may exhibit rhythms driven by the circadian clock of one of the members (which may also be influenced or reset by external factors). The endogenous plant cycles may regulate the activity of the bacterium by controlling availability of plant-produced photosynthate.
Other cycles
Many other important cycles are also studied, includin
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https://en.wikipedia.org/wiki/List%20of%20algebraic%20constructions
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An algebraic construction is a method by which an algebraic entity is defined or derived from another.
Instances include:
Cayley–Dickson construction
Proj construction
Grothendieck group
Gelfand–Naimark–Segal construction
Ultraproduct
ADHM construction
Burnside ring
Simplicial set
Fox derivative
Mapping cone (homological algebra)
Prym variety
Todd class
Adjunction (field theory)
Vaughan Jones construction
Strähle construction
Coset construction
Plus construction
Algebraic K-theory
Gelfand–Naimark–Segal construction
Stanley–Reisner ring construction
Quotient ring construction
Ward's twistor construction
Hilbert symbol
Hilbert's arithmetic of ends
Colombeau's construction
Vector bundle
Integral monoid ring construction
Integral group ring construction
Category of Eilenberg–Moore algebras
Kleisli category
Adjunction (field theory)
Lindenbaum–Tarski algebra construction
Freudenthal magic square
Stone–Čech compactification
Mathematics-related lists
Algebra
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https://en.wikipedia.org/wiki/Lists%20of%20mathematics%20topics
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Lists of mathematics topics cover a variety of topics related to mathematics. Some of these lists link to hundreds of articles; some link only to a few. The template to the right includes links to alphabetical lists of all mathematical articles. This article brings together the same content organized in a manner better suited for browsing.
Lists cover aspects of basic and advanced mathematics, methodology, mathematical statements, integrals, general concepts, mathematical objects, and reference tables.
They also cover equations named after people, societies, mathematicians, journals, and meta-lists.
The purpose of this list is not similar to that of the Mathematics Subject Classification formulated by the American Mathematical Society. Many mathematics journals ask authors of research papers and expository articles to list subject codes from the Mathematics Subject Classification in their papers. The subject codes so listed are used by the two major reviewing databases, Mathematical Reviews and Zentralblatt MATH. This list has some items that would not fit in such a classification, such as list of exponential topics and list of factorial and binomial topics, which may surprise the reader with the diversity of their coverage.
Basic mathematics
This branch is typically taught in secondary education or in the first year of university.
Outline of arithmetic
Outline of discrete mathematics
List of calculus topics
List of geometry topics
Outline of geometry
List of trigonometry topics
Outline of trigonometry
List of trigonometric identities
List of logarithmic identities
List of integrals of logarithmic functions
List of set identities and relations
List of topics in logic
Areas of advanced mathematics
As a rough guide, this list is divided into pure and applied sections although in reality, these branches are overlapping and intertwined.
Pure mathematics
Algebra
Algebra includes the study of algebraic structures, which are sets and operations defined o
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https://en.wikipedia.org/wiki/WinGate
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WinGate is an integrated multi-protocol proxy server, email server and internet gateway from Qbik New Zealand Limited in Auckland. It was first released in October 1995, and began as a re-write of SocketSet, a product that had been previously released in prototype form by Adrien de Croy.
WinGate proved popular, and by the mid- to late 1990s, WinGate was used in homes and small businesses that needed to share a single Internet connection between multiple networked computers. The introduction of Internet Connection Sharing in Windows 98, combined with increasing availability of cheap NAT-enabled routers, forced WinGate to evolve to provide more than just internet connection sharing features. Today, focus for WinGate is primarily access control, email server, caching, reporting, bandwidth management and content filtering.
WinGate comes in three versions, Standard, Professional and Enterprise. The Enterprise edition also provides an easily configured virtual private network system, which is also available separately as WinGate VPN. Licensing is based on the number of concurrently connected users, and a range of license sizes are available. Multiple licenses can also be aggregated.
The current version of WinGate is version 9.4.5, released in October 2022.
Notoriety
Versions of WinGate prior to 2.1d (1997) shipped with an insecure default configuration that - if not secured by the network administrator - allowed untrusted third parties to proxy network traffic through the WinGate server. This made open WinGate servers common targets of crackers looking for anonymous redirectors through which to attack other systems. While WinGate was by no means the only exploited proxy server, its wide popularity amongst users with little experience administering networks made it almost synonymous with open SOCKS proxies in the late 1990s. Furthermore, since a restricted (two users) version of the product was freely available without registration, contacting all WinGate users t
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https://en.wikipedia.org/wiki/Sierpi%C5%84ski%27s%20constant
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Sierpiński's constant is a mathematical constant usually denoted as K. One way of defining it is as the following limit:
where r2(k) is a number of representations of k as a sum of the form a2 + b2 for integer a and b.
It can be given in closed form as:
where is Gauss's constant and is the Euler-Mascheroni constant.
Another way to define/understand Sierpiński's constant is,
Let r(n) denote the number of representations of by squares, then the Summatory Function of has the Asymptotic expansion
,
where is the Sierpinski constant. The above plot shows
,
with the value of indicated as the solid horizontal line.
See also
Wacław Sierpiński
External links
http://www.plouffe.fr/simon/constants/sierpinski.txt - Sierpiński's constant up to 2000th decimal digit.
https://archive.lib.msu.edu/crcmath/math/math/s/s276.htm
Mathematical constants
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https://en.wikipedia.org/wiki/List%20of%20mathematical%20abbreviations
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This following list features abbreviated names of mathematical functions, function-like operators and other mathematical terminology.
This list is limited to abbreviations of two or more letters (excluding number sets). The capitalization of some of these abbreviations is not standardized – different authors might use different capitalizations.
A – adele ring or algebraic numbers.
AC – Axiom of Choice, or set of absolutely continuous functions.
a.c. – absolutely continuous.
acrd – inverse chord function.
ad – adjoint representation (or adjoint action) of a Lie group.
adj – adjugate of a matrix.
a.e. – almost everywhere.
Ai – Airy function.
AL – Action limit.
Alt – alternating group (Alt(n) is also written as An.)
A.M. – arithmetic mean.
arccos – inverse cosine function.
arccosec – inverse cosecant function. (Also written as arccsc.)
arccot – inverse cotangent function.
arccsc – inverse cosecant function. (Also written as arccosec.)
arcexc – inverse excosecant function. (Also written as arcexcsc, arcexcosec.)
arcexcosec – inverse excosecant function. (Also written as arcexcsc, arcexc.)
arcexcsc – inverse excosecant function. (Also written as arcexcosec, arcexc.)
arcexs – inverse exsecant function. (Also written as arcexsec.)
arcexsec – inverse exsecant function. (Also written as arcexs.)
arcosech – inverse hyperbolic cosecant function. (Also written as arcsch.)
arcosh – inverse hyperbolic cosine function.
arcoth – inverse hyperbolic cotangent function.
arcsch – inverse hyperbolic cosecant function. (Also written as arcosech.)
arcsec – inverse secant function.
arcsin – inverse sine function.
arctan – inverse tangent function.
arctan2 – inverse tangent function with two arguments. (Also written as atan2.)
arg – argument of.
arg max – argument of the maximum.
arg min – argument of the minimum.
arsech – inverse hyperbolic secant function.
arsinh – inverse hyperbolic sine function.
artanh – inverse hyperbolic tangent function.
a.s. – a
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https://en.wikipedia.org/wiki/Relict
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A relict is a surviving remnant of a natural phenomenon.
Biology
A relict (or relic) is an organism that at an earlier time was abundant in a large area but now occurs at only one or a few small areas.
Geology and geomorphology
In geology, a relict is a structure or mineral from a parent rock that did not undergo metamorphosis when the surrounding rock did, or a rock that survived a destructive geologic process.
In geomorphology, a relict landform is a landform formed by either erosive or constructive surficial processes that are no longer active as they were in the past.
A glacial relict is a cold-adapted organism that is a remnant of a larger distribution that existed in the ice ages.
Human populations
As revealed by DNA testing, a relict population is an ancient people in an area, who have been largely supplanted by a later group of migrants and their descendants.
In various places around the world, minority ethnic groups represent lineages of ancient human migrations in places now occupied by more populous ethnic groups, whose ancestors arrived later. For example, the first human groups to inhabit the Caribbean islands were hunter-gatherer tribes from South and Central America. Genetic testing of natives of Cuba show that, in late pre-Columbian times, the island was home to agriculturalists of Taino ethnicity. In addition, a relict population of the original hunter-gatherers remained in western Cuba as the Ciboney people.
Other uses
In ecology, an ecosystem which originally ranged over a large expanse, but is now narrowly confined, may be termed a relict.
In agronomy, a relict crop is a crop which was previously grown extensively, but is now only used in one limited region, or a small number of isolated regions.
In real estate law, reliction is the gradual recession of water from its usual high-water mark so that the newly uncovered land becomes the property of the adjoining riparian property owner.
"Relict" was an ancient term still used in coloni
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https://en.wikipedia.org/wiki/PRODIGAL
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PRODIGAL (proactive discovery of insider threats using graph analysis and learning) is a computer system for predicting anomalous behavior among humans, by data mining network traffic such as emails, text messages and server log entries. It is part of DARPA's Anomaly Detection at Multiple Scales (ADAMS) project. The initial schedule is for two years and the budget $9 million.
It uses graph theory, machine learning, statistical anomaly detection, and high-performance computing to scan larger sets of data more quickly than in past systems. The amount of data analyzed is in the range of terabytes per day. The targets of the analysis are employees within the government or defense contracting organizations; specific examples of behavior the system is intended to detect include the actions of Nidal Malik Hasan and WikiLeaks source Chelsea Manning. Commercial applications may include finance. The results of the analysis, the five most serious threats per day, go to agents, analysts, and operators working in counterintelligence.
Primary participants
Georgia Institute of Technology College of Computing
Georgia Tech Research Institute
Defense Advanced Research Projects Agency
Army Research Office
Science Applications International Corporation
Oregon State University
University of Massachusetts Amherst
Carnegie Mellon University
See also
Cyber Insider Threat
Einstein (US-CERT program)
Threat (computer)
Intrusion detection
ECHELON, Thinthread, Trailblazer, Turbulence (NSA programs)
Fusion center, Investigative Data Warehouse (FBI)
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https://en.wikipedia.org/wiki/Zipf%27s%20law
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Zipf's law (, ) is an empirical law that often holds, approximately, when a list of measured values is sorted in decreasing order. It states that the value of the nth entry is inversely proportional to n.
The best known instance of Zipf's law applies to the frequency table of words in a text or corpus of natural language: It is usually found that the most common word occurs approximately twice as often as the next common one, three times as often as the third most common, and so on. For example, in the Brown Corpus of American English text, the word "the" is the most frequently occurring word, and by itself accounts for nearly 7% of all word occurrences (69,971 out of slightly over 1 million). True to Zipf's Law, the second-place word "of" accounts for slightly over 3.5% of words (36,411 occurrences), followed by "and" (28,852). It is often used in the following form, called Zipf-Mandelbrot law:where are fitted parameters, with , and .
This "law" is named after the American linguist George Kingsley Zipf, and is still an important concept in quantitative linguistics. It has been found to apply to many other types of data studied in the physical and social sciences.
In mathematical statistics, the concept has been formalized as the Zipfian distribution: a family of related discrete probability distributions whose rank-frequency distribution is an inverse power law relation. They are related to Benford's law and the Pareto distribution.
Some sets of time-dependent empirical data deviate somewhat from Zipf's law. Such empirical distributions are said to be quasi-Zipfian.
History
In 1913, the German physicist Felix Auerbach observed an inverse proportionality between the population sizes of cities, and their ranks when sorted by decreasing order of that variable.
Zipf's law has been discovered before Zipf, by the French stenographer Jean-Baptiste Estoup' Gammes Stenographiques (4th ed) in 1916, with G. Dewey in 1923, and with E. Condon in 1928.
The same relat
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https://en.wikipedia.org/wiki/Macrocell%20array
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Macrocell arrays in PLDs
Programmable logic devices, such as programmable array logic and complex programmable logic devices, typically have a macrocell on every output pin.
Macrocell arrays in ASICs
A macrocell array is an approach to the design and manufacture of ASICs. Essentially, it is a small step up from the otherwise similar gate array, but rather than being a prefabricated array of simple logic gates, the macrocell array is a prefabricated array of higher-level logic functions such as flip-flops, ALU functions, registers, and the like. These logic functions are simply placed at regular predefined positions and manufactured on a wafer, usually called master slice. Creation of a circuit with a specified function is accomplished by adding metal interconnects to the chips on the master slice late in the manufacturing process, allowing the function of the chip to be customised as desired.
Macrocell array master slices are usually prefabricated and stockpiled in large quantities regardless of customer orders. The fabrication according to the individual customer specifications may be finished in a shorter time compared with standard cell or full custom design. The macrocell array approach reduces the mask costs since fewer custom masks need to be produced. In addition manufacturing test tooling lead time and costs are reduced since the same test fixtures may be used for all macrocell array products manufactured on the same die size.
Drawbacks are somewhat low density and performance than other approaches to ASIC design. However this style is often a viable approach for low production volumes.
A standard cell library is sometimes called a "macrocell library".
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https://en.wikipedia.org/wiki/Antibiosis
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Antibiosis is a biological interaction between two or more organisms that is detrimental to at least one of them; it can also be an antagonistic association between an organism and the metabolic substances produced by another. Examples of antibiosis include the relationship between antibiotics and bacteria or animals and disease-causing pathogens. The study of antibiosis and its role in antibiotics has led to the expansion of knowledge in the field of microbiology. Molecular processes such cell wall synthesis and recycling, for example, have become better understood through the study of how antibiotics affect beta-lactam development through the antibiosis relationship and interaction of the particular drugs with the bacteria subjected to the compound.
Antibiosis is typically studied in host plant populations and extends to the insects which feed upon them.
"Antibiosis resistance affects the biology of the insect so pest abundance and subsequent damage is reduced compared to that which would have occurred if the insect was on a susceptible crop variety. Antibiosis resistance often results in increased mortality or reduced longevity and reproduction of the insect."
During a study of antibiosis, it was determine that the means to achieving effective antibiosis is remaining still. "When you give antibiotic-producing bacteria a structured medium, they affix to substrate, grow clonally, and produce a “no mans land,” absent competitors, where the antibiotics diffuse outward." Antibiosis is most effective when resources are neither plentiful nor sparse. Antibiosis should be considered as the median on the scale of resource, due to its ideal performance.
See also
Antibiotic
Biological pest control
Biotechnology
Symbiosis
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https://en.wikipedia.org/wiki/System%20on%20a%20chip
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A system on a chip or system-on-chip (SoC ; pl. SoCs ) is an integrated circuit that integrates most or all components of a computer or other electronic system. These components almost always include on-chip central processing unit (CPU), memory interfaces, input/output devices and interfaces, and secondary storage interfaces, often alongside other components such as radio modems and a graphics processing unit (GPU) – all on a single substrate or microchip. SoCs may contain digital and also analog, mixed-signal and often radio frequency signal processing functions (otherwise it may be considered on a discrete application processor).
Higher-performance SoCs are often paired with dedicated and physically separate memory and secondary storage (such as LPDDR and eUFS or eMMC, respectively) chips, that may be layered on top of the SoC in what's known as a package on package (PoP) configuration, or be placed close to the SoC. Additionally, SoCs may use separate wireless modems.
SoCs are in contrast to the common traditional PC architecture, which separates hardware components based on function and connects them through a central interfacing circuit board called the motherboard. Whereas a motherboard houses and connects detachable or replaceable components, SoCs integrate all of these components into a single integral circuit. An SoC will typically integrate a CPU, graphics and memory interfaces, secondary storage and USB connectivity, I/O interfaces on a single chip, whereas a motherboard would connect these modules as discrete components or expansion cards.
An SoC integrates a microcontroller, microprocessor or perhaps several processor cores with peripherals like a GPU, Wi-Fi and cellular network radio modems, and/or one or more coprocessors. Similar to how a microcontroller integrates a microprocessor with peripheral circuits and memory, an SoC can be seen as integrating a microcontroller with even more advanced peripherals.
Compared to a multi-chip architecture,
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https://en.wikipedia.org/wiki/AP%20Biology
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Advanced Placement (AP) Biology (also known as AP Bio) is an Advanced Placement biology course and exam offered by the College Board in the United States. For the 2012–2013 school year, the College Board unveiled a new curriculum with a greater focus on "scientific practices".
This course is designed for students who wish to pursue an interest in the life sciences. The College Board recommends successful completion of high school biology and high school chemistry before commencing AP Biology, although the actual prerequisites vary from school to school and from state to state. This course, nevertheless, is considered very challenging and one of the most difficult AP classes, as shown with AP Finals grade distributions.
Topic outline
The exam covers the following 8 units. The percentage indicates the portion of the multiple-choice section of the exam focused on each content area:
The course is based on and tests six skills, called scientific practices which include:
In addition to the topics above, students are required to be familiar with general lab procedure. Students should know how to collect data, analyze data to form conclusions, and apply those conclusions.
Exam
Students are allowed to use a four-function, scientific, or graphing calculator.
The exam has two sections: a 90 minute multiple choice section and a 90 minute free response section. There are 60 multiple choice questions and six free responses, two long and four short. Both sections are worth 50% of the score.
Score distribution
Commonly used textbooks
Biology, AP Edition by Sylvia Mader (2012, hardcover )
Life: The Science of Biology (Sadava, Heller, Orians, Purves, and Hillis, )
Campbell Biology AP Ninth Edition (Reece, Urry, Cain, Wasserman, Minorsky, and Andrew Jackson )
See also
Glossary of biology
A.P Bio (TV Show)
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https://en.wikipedia.org/wiki/British%20Post%20Office%20scandal
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The British Post Office scandal is a miscarriage of justice involving the wrongful civil and criminal prosecutions of an unknown or unpublished number of sub-postmasters (SPMs) for theft, false accounting and/or fraud. The cases constitute the most widespread miscarriage of justice in British legal history, spanning a period of over twenty years; aspects of the scandal remain unresolved.
A group action (which is the English equivalent of a class action) was brought by SPMs in London's High Court. 555 SPMs successfully sued the Post Office. This resulted in two important judgments in favour of the SPMs. Since then the convictions have been overturned, compensation for other SPMs who did not take part in the case and what has now become a public inquiry into what happened, which is still ongoing.
The first important judgment in the group action was handed down on 15 March 2019 and was about the contracts between the Post Office and SPMs and whether the Post Office could carry on making SPMs liable for gaps in the accounts on the Post Office's Horizon software system, even when the cause of those gaps or shortfalls was not known. The Judge, Mr Justice Fraser, gave a comprehensive and detailed judgment (running to 1122 paragraphs) in which he analysed the legal relationship. The Judge found overwhelmingly in favour of the SPMs. As well as a victory for the SPMs, it is also considered an important case for lawyers because the Judge held that the Post Office owed SPMs an implied duty of "good faith" and "fair dealing".
The second important judgment was about whether the Horizon computer system worked and was "robust" (which the Post Office claimed it was). Again, the Judge found overwhelmingly in favour of the SPMs and that the original version of Horizon was "not robust" and, as to the later version, "its robustness was questionable, and did not justify the confidence placed in it by the Post Office in terms of its accuracy" (para 936).
Since then, those conv
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https://en.wikipedia.org/wiki/List%20of%20numeral%20system%20topics
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This is a list of Wikipedia articles on topics of numeral system and "numeric representations"
See also: computer numbering formats and number names.
Arranged by base
Radix, radix point, mixed radix, base (mathematics)
Unary numeral system (base 1)
Binary numeral system (base 2)
Negative base numeral system (base −2)
Ternary numeral system numeral system (base 3)
Balanced ternary numeral system (base 3)
Negative base numeral system (base −3)
Quaternary numeral system (base 4)
Quater-imaginary base (base 2)
Quinary numeral system (base 5)
Senary numeral system (base 6)
Septenary numeral system (base 7)
Octal numeral system (base 8)
Nonary (novenary) numeral system (base 9)
Decimal (denary) numeral system (base 10)
Negative base numeral system (base −10)
Duodecimal (dozenal) numeral system (base 12)
Hexadecimal numeral system (base 16)
Vigesimal numeral system (base 20)
Sexagesimal numeral system (base 60)
Arranged by culture
Other
Numeral system topics
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https://en.wikipedia.org/wiki/Nomogram
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A nomogram (from Greek , "law" and , "line"), also called a nomograph, alignment chart, or abac, is a graphical calculating device, a two-dimensional diagram designed to allow the approximate graphical computation of a mathematical function. The field of nomography was invented in 1884 by the French engineer Philbert Maurice d'Ocagne (1862–1938) and used extensively for many years to provide engineers with fast graphical calculations of complicated formulas to a practical precision. Nomograms use a parallel coordinate system invented by d'Ocagne rather than standard Cartesian coordinates.
A nomogram consists of a set of n scales, one for each variable in an equation. Knowing the values of n-1 variables, the value of the unknown variable can be found, or by fixing the values of some variables, the relationship between the unfixed ones can be studied. The result is obtained by laying a straightedge across the known values on the scales and reading the unknown value from where it crosses the scale for that variable. The virtual or drawn line created by the straightedge is called an index line or isopleth.
Nomograms flourished in many different contexts for roughly 75 years because they allowed quick and accurate computations before the age of pocket calculators. Results from a nomogram are obtained very quickly and reliably by simply drawing one or more lines. The user does not have to know how to solve algebraic equations, look up data in tables, use a slide rule, or substitute numbers into equations to obtain results. The user does not even need to know the underlying equation the nomogram represents. In addition, nomograms naturally incorporate implicit or explicit domain knowledge into their design. For example, to create larger nomograms for greater accuracy the nomographer usually includes only scale ranges that are reasonable and of interest to the problem. Many nomograms include other useful markings such as reference labels and colored regions. All of thes
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https://en.wikipedia.org/wiki/Subphylum
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In zoological nomenclature, a subphylum is a taxonomic rank below the rank of phylum.
The taxonomic rank of "subdivision" in fungi and plant taxonomy is equivalent to "subphylum" in zoological taxonomy. Some plant taxonomists have also used the rank of subphylum, for instance monocotyledons as a subphylum of phylum Angiospermae and vertebrates as a subphylum of phylum Chordata.
Taxonomic rank
Subphylum is:
subordinate to the phylum
superordinate to the infraphylum.
Where convenient, subphyla in turn can be divided into infraphyla; in turn such an infraphylum also would be superordinate to any classes or superclasses in the hierarchy.
Examples
Not all fauna phyla are divided into subphyla. Those that are include:
Arthropoda: divided into subphyla Trilobitomorpha, Chelicerata, Myriapoda, Hexapoda and Crustacea,
Brachiopoda: divided into subphyla Linguliformea, Craniformea and Rhynchonelliformea,
Chordata: divided into Tunicata, Cephalochordata, and its largest subphylum Vertebrata.
Examples of infraphyla include the Mycetozoa, the Gnathostomata and the Agnatha.
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https://en.wikipedia.org/wiki/List%20of%20number%20theory%20topics
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This is a list of number theory topics. See also:
List of recreational number theory topics
Topics in cryptography
Divisibility
Composite number
Highly composite number
Even and odd numbers
Parity
Divisor, aliquot part
Greatest common divisor
Least common multiple
Euclidean algorithm
Coprime
Euclid's lemma
Bézout's identity, Bézout's lemma
Extended Euclidean algorithm
Table of divisors
Prime number, prime power
Bonse's inequality
Prime factor
Table of prime factors
Formula for primes
Factorization
RSA number
Fundamental theorem of arithmetic
Square-free
Square-free integer
Square-free polynomial
Square number
Power of two
Integer-valued polynomial
Fractions
Rational number
Unit fraction
Irreducible fraction = in lowest terms
Dyadic fraction
Recurring decimal
Cyclic number
Farey sequence
Ford circle
Stern–Brocot tree
Dedekind sum
Egyptian fraction
Modular arithmetic
Montgomery reduction
Modular exponentiation
Linear congruence theorem
Method of successive substitution
Chinese remainder theorem
Fermat's little theorem
Proofs of Fermat's little theorem
Fermat quotient
Euler's totient function
Noncototient
Nontotient
Euler's theorem
Wilson's theorem
Primitive root modulo n
Multiplicative order
Discrete logarithm
Quadratic residue
Euler's criterion
Legendre symbol
Gauss's lemma (number theory)
Congruence of squares
Luhn formula
Mod n cryptanalysis
Arithmetic functions
Multiplicative function
Additive function
Dirichlet convolution
Erdős–Kac theorem
Möbius function
Möbius inversion formula
Divisor function
Liouville function
Partition function (number theory)
Integer partition
Bell numbers
Landau's function
Pentagonal number theorem
Bell series
Lambert series
Analytic number theory: additive problems
Twin prime
Brun's constant
Cousin prime
Prime triplet
Prime quadruplet
Sexy prime
Sophie Germain prime
Cunningham chain
Goldbach's conjecture
Goldbach's weak conjecture
Second Hardy–Littlewood conjecture
Hardy–Littlewood circle method
Schinzel's hypothesis H
Batema
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https://en.wikipedia.org/wiki/Bacteria
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Bacteria (; : bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were among the first life forms to appear on Earth, and are present in most of its habitats. Bacteria inhabit soil, water, acidic hot springs, radioactive waste, and the deep biosphere of Earth's crust. Bacteria play a vital role in many stages of the nutrient cycle by recycling nutrients and the fixation of nitrogen from the atmosphere. The nutrient cycle includes the decomposition of dead bodies; bacteria are responsible for the putrefaction stage in this process. In the biological communities surrounding hydrothermal vents and cold seeps, extremophile bacteria provide the nutrients needed to sustain life by converting dissolved compounds, such as hydrogen sulphide and methane, to energy. Bacteria also live in symbiotic and parasitic relationships with plants and animals. Most bacteria have not been characterised and there are many species that cannot be grown in the laboratory. The study of bacteria is known as bacteriology, a branch of microbiology.
Humans and most other animals carry vast numbers (approximately 1013 to 1014) of bacteria. Most are in the gut, and there are many on the skin. Most of the bacteria in and on the body are harmless or rendered so by the protective effects of the immune system, and many are beneficial, particularly the ones in the gut. However, several species of bacteria are pathogenic and cause infectious diseases, including cholera, syphilis, anthrax, leprosy, tuberculosis, tetanus and bubonic plague. The most common fatal bacterial diseases are respiratory infections. Antibiotics are used to treat bacterial infections and are also used in farming, making antibiotic resistance a growing problem. Bacteria are important in sewage treatment and the breakdown of oil spills, the production of cheese and yogurt through f
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https://en.wikipedia.org/wiki/Matheass
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MatheAss (former Math-Assist) is a computer program for numerical solutions in school mathematics and functions in some points similar to Microsoft Mathematics. "MatheAss is widely spread in math classes" in Germany. For schools in the federal state of Hessen (Germany) exists a state license, which allows all secondary schools to use MatheAss
Its functionality is limited compared to other numerical programs, for example, MatheAss has no script language and does no symbolic computation. On the other side it is easy to use and offers the user fully worked out solutions, in which only the necessary quantities need to be entered. MatheAss covers the topics algebra, geometry, analysis, stochastics, and linear algebra.
After a precursor for the home computers, usual around 1980, MatheAss appeared in 1983 as a shareware version for the PC, so it was one of the first shareware programs on the German market. MatheAss is available on the manufacturer's website for download for various versions of the Windows operating system.
Since version 8.2 (released in February 2011) MatheAss again offers a context-sensitive help, which was supplemented in many places by showing mathematical examples and background information. The MatheAss help file can also be viewed online.
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https://en.wikipedia.org/wiki/Possible%20Worlds%20%28play%29
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Possible Worlds is a play written in 1990 by John Mighton. The author, Mighton, is a mathematician and philosopher. His plays tend to meld science, drama and math into one cohesive piece. It is part murder mystery, part science-fiction, and part mathematical philosophy and follows the multiple parallel lives of the main character George Barber. Mighton, a mathematician from University of Toronto's Fields Institute, brought his considerable professional experience to bear on the writing of the play.
At the play's beginning, George is found dead, with his brain missing. Two detectives set out to uncover the truth behind his grisly death, and stumble upon several strange characters. This play may be classified as a sci-fi tragic drama The play itself does not have any music.
Possible Worlds won a Governor General's Literary Award for Drama in 1992 alongside Short History of Night.
A film adaptation of the same name was released in 2000. Directed by Robert Lepage and starring Tom McCamus and Tilda Swinton, it garnered wide critical acclaim, won two Genie Awards, and was nominated for a further four. The theatre book was published in 1997 by Playwrights Canada Press.
The play bears many conceptual similarities to Tom Stoppard's Hapgood, a play about spies and secret agents that takes place primarily in the men's changingroom of a municipal swimming baths.
Production history (selected)
Canadian Stage Company, Toronto, Ontario, Canada – Premiere 1990
Dionysus and Apollo Stage company, Dallas, Texas – 1997
Dr. Betty Mitchell Theatre, Calgary, Alberta, Canada –1999
Chicago Cultural Center Studio Theater, Chicago, Illinois – 1999
Company of the Silvershield, Toronto, Ontario, Canada - 2000
The group at Strasberg, Lee Strasberg Creative Center, Hollywood, California – 2001
Tron Theatre, Glasgow, Scotland – 2002
Hart House Theatre, Toronto, Canada – 2004
Sullivan Mahoney Court House Theatre, Ontario, Canada – 2008
Wakefield Players Theater Company, Wakefield,
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https://en.wikipedia.org/wiki/Comb%20generator
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A comb generator is a signal generator that produces multiple harmonics of its input signal. The appearance of the output at the spectrum analyzer screen, resembling teeth of a comb, gave the device its name.
Comb generators find wide range of uses in microwave technology. E.g., synchronous signals in wide frequency bandwidth can be produced by a comb generator. The most common use is in broadband frequency synthesizers, where the high frequency signals act as stable references correlated to the lower energy references; the outputs can be used directly, or to synchronize phase-locked loop oscillators. It may be also used to generate a complete set of substitution channels for testing, each of which carries the same baseband audio and video signal.
Comb generators are also used in RFI testing of consumer electronics, where their output is used as a simulated RF emissions, as it is a stable broadband noise source with repeatable output. It is also used during compliance testing to various government requirements for products such as medical devices (FDA), military electronics (MIL-STD-461), commercial avionics (Federal Aviation Administration), digital electronics (Federal Communications Commission), in the USA.
An optical comb generator can be used as generators of terahertz radiation. Internally, it is a resonant electro-optic modulator, with the capability of generating hundreds of sidebands with total span of at least 3 terahertz (limited by the optical dispersion of the lithium niobate crystal) and frequency spacing of 17 GHz. Other construction can be based on erbium-doped fiber laser or Ti-sapphire laser often in combination with carrier envelope offset control.
See also
Comb filter
Frequency comb
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https://en.wikipedia.org/wiki/Consolidation%20ratio
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Consolidation ratio within network infrastructure for Internet hosting, is the number of virtual servers that can run on each physical host machine. Many companies arrive at that figure through trial and error by stacking virtual machines on top of each other until performance slows to a crawl. “It’s sort of capacity planning by bloody nose,” observes Bob Gill, managing director of server research for analyst firm TheInfoPro Inc. of New York.
The recent V-index showed that the average consolidation ratio is actually lower than was expected - 6.3:1 VMs per physical host (actual ratio) vs. 9.8:1 (perceived)
See also
Nagle's algorithm
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https://en.wikipedia.org/wiki/RFIC
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RFIC is an abbreviation of radio-frequency integrated circuit. Applications for RFICs include radar and communications, although the term RFIC might be applied to any electrical integrated circuit operating in a frequency range suitable for wireless transmission.
There is considerable interest in RFIC research due to the cost benefit of shifting as much of the wireless transceiver as possible to a single technology, which in turn would allow for a system on a chip solution as opposed to the more common system-on-package. This interest is bolstered by the pervasiveness of wireless capabilities in electronics. Current research focuses on integrating the RF power amplifier (PA) with CMOS technology, either by using MOSFETs or SiGe HBTs, on RF CMOS mixed-signal integrated circuit chips.
RFIC-related research conferences
RFIC is also used to refer to the annual RFIC Symposium, a research conference held as part of Microwave Week, which is headlined by the International Microwave Symposium. Other peer-reviewed research conferences are listed in the table below.
Publications featuring RFIC research
IEEE Journal of Solid-State Circuits
IEEE Transactions on Microwave Theory and Techniques
See also
RF module
Radio-frequency identification
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https://en.wikipedia.org/wiki/List%20of%20properties%20of%20sets%20of%20reals
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This article lists some properties of sets of real numbers. The general study of these concepts forms descriptive set theory, which has a rather different emphasis from general topology.
Definability properties
Borel set
Analytic set
C-measurable set
Projective set
Inductive set
Infinity-Borel set
Suslin set
Homogeneously Suslin set
Weakly homogeneously Suslin set
Set of uniqueness
Regularity properties
Property of Baire
Lebesgue measurable
Universally measurable set
Perfect set property
Universally Baire set
Largeness and smallness properties
Meager set
Comeager set - A comeager set is one whose complement is meager.
Null set
Conull set
Dense set
Nowhere dense set
Real numbers
Real numbers
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https://en.wikipedia.org/wiki/List%20of%20planar%20symmetry%20groups
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This article summarizes the classes of discrete symmetry groups of the Euclidean plane. The symmetry groups are named here by three naming schemes: International notation, orbifold notation, and Coxeter notation.
There are three kinds of symmetry groups of the plane:
2 families of rosette groups – 2D point groups
7 frieze groups – 2D line groups
17 wallpaper groups – 2D space groups.
Rosette groups
There are two families of discrete two-dimensional point groups, and they are specified with parameter n, which is the order of the group of the rotations in the group.
Frieze groups
The 7 frieze groups, the two-dimensional line groups, with a direction of periodicity are given with five notational names. The Schönflies notation is given as infinite limits of 7 dihedral groups. The yellow regions represent the infinite fundamental domain in each.
Wallpaper groups
The 17 wallpaper groups, with finite fundamental domains, are given by International notation, orbifold notation, and Coxeter notation, classified by the 5 Bravais lattices in the plane: square, oblique (parallelogrammatic), hexagonal (equilateral triangular), rectangular (centered rhombic), and rhombic (centered rectangular).
The p1 and p2 groups, with no reflectional symmetry, are repeated in all classes. The related pure reflectional Coxeter group are given with all classes except oblique.
Wallpaper subgroup relationships
See also
List of spherical symmetry groups
Orbifold notation#Hyperbolic plane - Hyperbolic symmetry groups
Notes
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https://en.wikipedia.org/wiki/Outline%20of%20combinatorics
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Combinatorics is a branch of mathematics concerning the study of finite or countable discrete structures.
Essence of combinatorics
Matroid
Greedoid
Ramsey theory
Van der Waerden's theorem
Hales–Jewett theorem
Umbral calculus, binomial type polynomial sequences
Combinatorial species
Branches of combinatorics
Algebraic combinatorics
Analytic combinatorics
Arithmetic combinatorics
Combinatorics on words
Combinatorial design theory
Enumerative combinatorics
Extremal combinatorics
Geometric combinatorics
Graph theory
Infinitary combinatorics
Matroid theory
Order theory
Partition theory
Probabilistic combinatorics
Topological combinatorics
Multi-disciplinary fields that include combinatorics
Coding theory
Combinatorial optimization
Combinatorics and dynamical systems
Combinatorics and physics
Discrete geometry
Finite geometry
Phylogenetics
History of combinatorics
History of combinatorics
General combinatorial principles and methods
Combinatorial principles
Trial and error, brute-force search, bogosort, British Museum algorithm
Pigeonhole principle
Method of distinguished element
Mathematical induction
Recurrence relation, telescoping series
Generating functions as an application of formal power series
Cyclic sieving
Schrödinger method
Exponential generating function
Stanley's reciprocity theorem
Binomial coefficients and their properties
Combinatorial proof
Double counting (proof technique)
Bijective proof
Inclusion–exclusion principle
Möbius inversion formula
Parity, even and odd permutations
Combinatorial Nullstellensatz
Incidence algebra
Greedy algorithm
Divide and conquer algorithm
Akra–Bazzi method
Dynamic programming
Branch and bound
Birthday attack, birthday paradox
Floyd's cycle-finding algorithm
Reduction to linear algebra
Sparsity
Weight function
Minimax algorithm
Alpha–beta pruning
Probabilistic method
Sieve methods
Analytic combinatorics
Symbolic combinatorics
Combinatorial
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https://en.wikipedia.org/wiki/Microwave%20analog%20signal%20processing
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Real-time Analog Signal Processing (R-ASP), as an alternative to DSP-based processing, might be defined as the manipulation of signals in their pristine analog form and in real time to realize specific operations enabling microwave or millimeter-wave and terahertz applications.
The exploding demand for higher spectral efficiency in radio has spurred a renewed interest in analog real-time components and systems beyond conventional purely digital signal processing techniques. Although they are unrivaled at low microwave frequencies, due to their high flexibility, compact size, low cost and strong reliability, digital devices suffer of major issues, such as poor performance, high cost of A/D and D/A converters and excessive power consumption, at higher microwave and millimeter-wave frequencies. At such frequencies, analog devices and related real-time or analog signal processing (ASP) systems, which manipulate broadband signals in the time domain, may be far preferable, as they offer the benefits of lower complexity and higher speed, which may offer unprecedented solutions in the major areas of radio engineering, including communications, but also radars, sensors, instrumentation and imaging. This new technology might be seen as microwave and millimeter-wave counterpart of ultra-fast optics signal processing, and has been recently enabled by a wide range of novel phasers, that are components following arbitrary group delay versus frequency responses.
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https://en.wikipedia.org/wiki/Software%20metering
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Software metering is the monitoring and controlling of software for analytics and the enforcement of agreements. It can be either passive, where data is simply collected and no action is taken, or active, where access is restricted for enforcement.
Types
Software metering refers to several areas:
Tracking and maintaining software licenses. One needs to make sure that only the allowed number of licenses are in use, and at the same time, that there are enough licenses for everyone using it. This can include monitoring of concurrent usage of software for real-time enforcement of license limits. Such license monitoring usually includes when a license needs to be updated due to version changes or when upgrades or even rebates are possible.
Real-time monitoring of all (or selected) applications running on the computers within the organization in order to detect unregistered or unlicensed software and prevent its execution, or limit its execution to within certain hours. The systems administrator can configure the software metering agent on each computer in the organization, for example, to prohibit the execution of games before 17:00.
Fixed planning to allocate software usage to computers according to the policies a company specifies and to maintain a record of usage and attempted usage. A company can check out and check in licenses for mobile users, and can also keep a record of all licenses in use. This is often used when limited license counts are available to avoid violating strict license controls.
A method of software licensing where the licensed software automatically records how many times, or for how long one or more functions in the software are used, and the user pays fees based on this actual usage (also known as 'pay-per-use')
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https://en.wikipedia.org/wiki/Adequality
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Adequality is a technique developed by Pierre de Fermat in his treatise Methodus ad disquirendam maximam et minimam (a Latin treatise circulated in France c. 1636 ) to calculate maxima and minima of functions, tangents to curves, area, center of mass, least action, and other problems in calculus. According to André Weil, Fermat "introduces the technical term adaequalitas, adaequare, etc., which he says he has borrowed from Diophantus. As Diophantus V.11 shows, it means an approximate equality, and this is indeed how Fermat explains the word in one of his later writings." (Weil 1973). Diophantus coined the word παρισότης (parisotēs) to refer to an approximate equality. Claude Gaspard Bachet de Méziriac translated Diophantus's Greek word into Latin as adaequalitas. Paul Tannery's French translation of Fermat’s Latin treatises on maxima and minima used the words adéquation and adégaler.
Fermat's method
Fermat used adequality first to find maxima of functions, and then adapted it to find tangent lines to curves.
To find the maximum of a term , Fermat equated (or more precisely adequated) and and after doing algebra he could cancel out a factor of and then discard any remaining terms involving To illustrate the method by Fermat's own example, consider the problem of finding the maximum of (In Fermat's words, it is to divide a line of length at a point , such that the product of the two resulting parts be a maximum.) Fermat adequated with . That is (using the notation to denote adequality, introduced by Paul Tannery):
Canceling terms and dividing by Fermat arrived at
Removing the terms that contained Fermat arrived at the desired result that the maximum occurred when .
Fermat also used his principle to give a mathematical derivation of Snell's laws of refraction directly from the principle that light takes the quickest path.
Descartes' criticism
Fermat's method was highly criticized by his contemporaries, particularly Descartes. Victor Katz suggests this
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https://en.wikipedia.org/wiki/Pathatrix
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Pathatrix is a high volume recirculating immuno magnetic-capture system developed by Thermo Fisher Scientific (and supplier parts by Life Technologies) for the detection of pathogens in food and environmental samples.
History
Pathatrix and its Pathatrix Recirculating Immunomagnetic Separation System (RIMS) was used in 2006 to detect the E. coli O157:H7 strain in contaminated spinach using a polymerase chain reaction (PCR). The Pathatrix system is used by regulatory agencies and food companies around the world as a reliable method for detecting pathogens in food.
Unlike other detection methods, Pathatrix allows the entire pre-enriched sample or large pooled samples to be recirculated over antibody-coated paramagnetic beads. It can specifically isolate pathogens directly from food samples and in conjunction with quantitative PCR can provide results within hours. It is also used to improve the performance of other rapid methods such as PCR, lateral flow, ELISA and chromogenic media by reducing or eliminating the need for lengthy pre-enrichment and/or selective enrichment steps. The Pathatrix is useful in pathogen labs that would be running food samples and looking for foodborne diseases.
The Pathatrix is a rapid test method and Pathatrix pooling allows the screening of large numbers of food samples in a highly cost-effective way for specific pathogens such as E. coli O157, Salmonella or Listeria monocytogenes.
The Pathatrix will selectively bind and purify the target organism from a comprehensive range of complex food matrices (including raw ground beef, chocolate, peanut butter, leafy greens, spinach, tomatoes). The Pathatrix is a microbial detection system that allows for the entire sample to be analyzed.
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https://en.wikipedia.org/wiki/Complementary%20sequences
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For complementary sequences in biology, see complementarity (molecular biology). For integer sequences with complementary sets of members see Lambek–Moser theorem.
In applied mathematics, complementary sequences (CS) are pairs of sequences with the useful property that their out-of-phase aperiodic autocorrelation coefficients sum to zero. Binary complementary sequences were first introduced by Marcel J. E. Golay in 1949. In 1961–1962 Golay gave several methods for constructing sequences of length 2N and gave examples of complementary sequences of lengths 10 and 26. In 1974 R. J. Turyn gave a method for constructing sequences of length mn from sequences of lengths m and n which allows the construction of sequences of any length of the form 2N10K26M.
Later the theory of complementary sequences was generalized by other authors to polyphase complementary sequences, multilevel complementary sequences, and arbitrary complex complementary sequences. Complementary sets have also been considered; these can contain more than two sequences.
Definition
Let (a0, a1, ..., aN − 1) and (b0, b1, ..., bN − 1) be a pair of bipolar sequences, meaning that a(k) and b(k) have values +1 or −1. Let the aperiodic autocorrelation function of the sequence x be defined by
Then the pair of sequences a and b is complementary if:
for k = 0, and
for k = 1, ..., N − 1.
Or using Kronecker delta we can write:
So we can say that the sum of autocorrelation functions of complementary sequences is a delta function, which is an ideal autocorrelation for many applications like radar pulse compression and spread spectrum telecommunications.
Examples
As the simplest example we have sequences of length 2: (+1, +1) and (+1, −1). Their autocorrelation functions are (2, 1) and (2, −1), which add up to (4, 0).
As the next example (sequences of length 4), we have (+1, +1, +1, −1) and (+1, +1, −1, +1). Their autocorrelation functions are (4, 1, 0, −1) and (4, −1, 0, 1), which add up to (8, 0, 0, 0).
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https://en.wikipedia.org/wiki/Mutual%20coherence%20%28linear%20algebra%29
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In linear algebra, the coherence or mutual coherence of a matrix A is defined as the maximum absolute value of the cross-correlations between the columns of A.
Formally, let be the columns of the matrix A, which are assumed to be normalized such that The mutual coherence of A is then defined as
A lower bound is
A deterministic matrix with the mutual coherence almost meeting the lower bound can be constructed by Weil's theorem.
This concept was reintroduced by David Donoho and Michael Elad in the context of sparse representations. A special case of this definition for the two-ortho case appeared earlier in the paper by Donoho and Huo. The mutual coherence has since been used extensively in the field of sparse representations of signals. In particular, it is used as a measure of the ability of suboptimal algorithms such as matching pursuit and basis pursuit to correctly identify the true representation of a sparse signal. Joel Tropp introduced a useful extension of Mutual Coherence, known as the Babel function, which extends the idea of cross-correlation between pairs of columns to the cross-correlation from one column to a set of other columns. The Babel function for two columns is exactly the Mutual coherence, but it also extends the coherence relationship concept in a way that is useful and relevant for any number of columns in the sparse representation matix as well.
See also
Compressed sensing
Restricted isometry property
Babel function
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https://en.wikipedia.org/wiki/Activation
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Activation, in chemistry and biology, is the process whereby something is prepared or excited for a subsequent reaction.
Chemistry
In chemistry, "activation" refers to the reversible transition of a molecule into a nearly identical chemical or physical state, with the defining characteristic being that this resultant state exhibits an increased propensity to undergo a specified chemical reaction. Thus, activation is conceptually the opposite of protection, in which the resulting state exhibits a decreased propensity to undergo a certain reaction.
The energy of activation specifies the amount of free energy the reactants must possess (in addition to their rest energy) in order to initiate their conversion into corresponding products—that is, in order to reach the transition state for the reaction. The energy needed for activation can be quite small, and often it is provided by the natural random thermal fluctuations of the molecules themselves (i.e. without any external sources of energy).
The branch of chemistry that deals with this topic is called chemical kinetics.
Biology
Biochemistry
In biochemistry, activation, specifically called bioactivation, is where enzymes or other biologically active molecules acquire the ability to perform their biological function, such as inactive proenzymes being converted into active enzymes that are able to catalyze their substrates' reactions into products. Bioactivation may also refer to the process where inactive prodrugs are converted into their active metabolites, or the toxication of protoxins into actual toxins.
An enzyme may be reversibly or irreversibly bioactivated. A major mechanism of irreversible bioactivation is where a piece of a protein is cut off by cleavage, producing an enzyme that will then stay active. A major mechanism of reversible bioactivation is substrate presentation where an enzyme translocates near its substrate. Another reversible reaction is where a cofactor binds to an enzyme, which then rem
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https://en.wikipedia.org/wiki/Phototaxis
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Phototaxis is a kind of taxis, or locomotory movement, that occurs when a whole organism moves towards or away from a stimulus of light. This is advantageous for phototrophic organisms as they can orient themselves most efficiently to receive light for photosynthesis. Phototaxis is called positive if the movement is in the direction of increasing light intensity and negative if the direction is opposite.
Two types of positive phototaxis are observed in prokaryotes. The first is called scotophobotaxis (from the word "scotophobia"), which is observed only under a microscope. This occurs when a bacterium swims by chance out of the area illuminated by the microscope. Entering darkness signals the cell to reverse flagella rotation direction and reenter the light. The second type of phototaxis is true phototaxis, which is a directed movement up a gradient to an increasing amount of light. This is analogous to positive chemotaxis except that the attractant is light rather than a chemical.
Phototactic responses are observed in many organisms such as Serratia marcescens, Tetrahymena, and Euglena. Each organism has its own specific biological cause for a phototactic response, many of which are incidental and serve no end purpose.
Phototaxis in bacteria and archea
Phototaxis can be advantageous for phototrophic bacteria as they can orient themselves most efficiently to receive light for photosynthesis. Phototaxis is called positive if the movement is in the direction of increasing light intensity and negative if the direction is opposite.
Two types of positive phototaxis are observed in prokaryotes (bacteria and archea). The first is called "scotophobotaxis" (from the word "scotophobia"), which is observed only under a microscope. This occurs when a bacterium swims by chance out of the area illuminated by the microscope. Entering darkness signals the cell to reverse flagella rotation direction and reenter the light. The second type of phototaxis is true phototaxis, which
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https://en.wikipedia.org/wiki/Hazards%20of%20synthetic%20biology
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The hazards of synthetic biology include biosafety hazards to workers and the public, biosecurity hazards stemming from deliberate engineering of organisms to cause harm, and hazards to the environment. The biosafety hazards are similar to those for existing fields of biotechnology, mainly exposure to pathogens and toxic chemicals; however, novel synthetic organisms may have novel risks. For biosecurity, there is concern that synthetic or redesigned organisms could theoretically be used for bioterrorism. Potential biosecurity risks include recreating known pathogens from scratch, engineering existing pathogens to be more dangerous, and engineering microbes to produce harmful biochemicals. Lastly, environmental hazards include adverse effects on biodiversity and ecosystem services, including potential changes to land use resulting from agricultural use of synthetic organisms.
In general, existing hazard controls, risk assessment methodologies, and regulations developed for traditional genetically modified organisms (GMOs) also apply to synthetic organisms. "Extrinsic" biocontainment methods used in laboratories include biosafety cabinets and gloveboxes, as well as personal protective equipment. In agriculture, they include isolation distances and pollen barriers, similar to methods for biocontainment of GMOs. Synthetic organisms might potentially offer increased hazard control because they can be engineered with "intrinsic" biocontainment methods that limit their growth in an uncontained environment, or prevent horizontal gene transfer to natural organisms. Examples of intrinsic biocontainment include auxotrophy, biological kill switches, inability of the organism to replicate or to pass synthetic genes to offspring, and the use of xenobiological organisms using alternative biochemistry, for example using artificial xeno nucleic acids (XNA) instead of DNA.
Existing risk analysis systems for GMOs are generally applicable to synthetic organisms, although there may be
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https://en.wikipedia.org/wiki/Big%20O%20notation
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Big O notation is a mathematical notation that describes the limiting behavior of a function when the argument tends towards a particular value or infinity. Big O is a member of a family of notations invented by German mathematicians Paul Bachmann, Edmund Landau, and others, collectively called Bachmann–Landau notation or asymptotic notation. The letter O was chosen by Bachmann to stand for Ordnung, meaning the order of approximation.
In computer science, big O notation is used to classify algorithms according to how their run time or space requirements grow as the input size grows. In analytic number theory, big O notation is often used to express a bound on the difference between an arithmetical function and a better understood approximation; a famous example of such a difference is the remainder term in the prime number theorem. Big O notation is also used in many other fields to provide similar estimates.
Big O notation characterizes functions according to their growth rates: different functions with the same asymptotic growth rate may be represented using the same O notation. The letter O is used because the growth rate of a function is also referred to as the order of the function. A description of a function in terms of big O notation usually only provides an upper bound on the growth rate of the function.
Associated with big O notation are several related notations, using the symbols , and , to describe other kinds of bounds on asymptotic growth rates.
Formal definition
Let , the function to be estimated, be a real or complex valued function and let , the comparison function, be a real valued function. Let both functions be defined on some unbounded subset of the positive real numbers, and be strictly positive for all large enough values of . One writes
and it is read " is big O of " if the absolute value of is at most a positive constant multiple of for all sufficiently large values of . That is, if there exists a positive real number and a re
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https://en.wikipedia.org/wiki/Kinetic%20proofreading
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Kinetic proofreading (or kinetic amplification) is a mechanism for error correction in biochemical reactions, proposed independently by John Hopfield (1974) and Jacques Ninio (1975). Kinetic proofreading allows enzymes to discriminate between two possible reaction pathways leading to correct or incorrect products with an accuracy higher than what one would predict based on the difference in the activation energy between these two pathways.
Increased specificity is obtained by introducing an irreversible step exiting the pathway, with reaction intermediates leading to incorrect products more likely to prematurely exit the pathway than reaction intermediates leading to the correct product. If the exit step is fast relative to the next step in the pathway, the specificity can be increased by a factor of up to the ratio between the two exit rate constants. (If the next step is fast relative to the exit step, specificity will not be increased because there will not be enough time for exit to occur.) This can be repeated more than once to increase specificity further.
Specificity paradox
In protein synthesis, the error rate is on the order of . This means that when a ribosome is matching anticodons of tRNA to the codons of mRNA, it matches complementary sequences correctly nearly all the time. Hopfield noted that because of how similar the substrates are (the difference between a wrong codon and a right codon can be as small as a difference in a single base), an error rate that small is unachievable with a one-step mechanism. Both wrong and right tRNA can bind to the ribosome, and if the ribosome can only discriminate between them by complementary matching of the anticodon, it must rely on the small free energy difference between binding three matched complementary bases or only two.
A one-shot machine which tests whether the codons match or not by examining whether the codon and anticodon are bound will not be able to tell the difference between wrong and right codon
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https://en.wikipedia.org/wiki/Formula%20calculator
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A formula calculator is a software calculator that can perform a calculation in two steps:
Enter the calculation by typing it in from the keyboard.
Press a single button or key to see the final result.
This is unlike button-operated calculators, such as the Windows calculator or the Mac OS X calculator, which require the user to perform one step for each operation, by pressing buttons to calculate all the intermediate values, before the final result is shown.
In this context, a formula is also known as an expression, and so formula calculators may be called expression calculators. Also in this context, calculation is known as evaluation, and so they may be called formula evaluators, rather than calculators.
How they work
Formulas as they are commonly written use infix notation for binary operators, such as addition, multiplication, division and subtraction. This notation also uses:
Parentheses to enclose parts of a formula that must be calculated first.
In the absence of parentheses, operator precedence, so that higher precedence operators, such as multiplication, must be applied before lower precedence operators, such as addition. For example, in 2 + 3*4, the multiplication, 3*4, is done first.
Among operators with the same precedence, associativity, so that the left-most operator must be applied first. For example, in 2 - 3 + 4, the subtraction, 2 - 3, is done first.
Also, formulas may contain:
Non-commutative operators that must be applied to numbers in the correct order, such as subtraction and division.
The same symbol used for more than one purpose, such as - for negative numbers and subtraction.
Once a formula is entered, a formula calculator follows the above rules to produce the final result by automatically:
Analysing the formula and breaking it down into its constituent parts, such as operators, numbers and parentheses.
Finding both operands of each binary operator.
Working out the values of these operands.
Applying the operator to th
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https://en.wikipedia.org/wiki/Gauss%20notation
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Gauss notation (also known as a Gauss code or Gauss words) is a notation for mathematical knots. It is created by enumerating and classifying the crossings of an embedding of the knot in a plane. It is named after the German mathematician Carl Friedrich Gauss (1777–1855).
Gauss code represents a knot with a sequence of integers. However, rather than every crossing being represented by two different numbers, crossings are labelled with only one number. When the crossing is an overcrossing, a positive number is listed. At an undercrossing, a negative number.
For example, the trefoil knot in Gauss code can be given as: 1,−2,3,−1,2,−3.
Gauss code is limited in its ability to identify knots by a few problems. The starting point on the knot at which to begin tracing the crossings is arbitrary, and there is no way to determine which direction to trace in. Also, Gauss code is unable to indicate the handedness of each crossing, which is necessary to identify a knot versus its mirror. For example, the Gauss code for the trefoil knot does not specify if it is the right-handed or left-handed trefoil.
This last issue is often solved by using the extended Gauss code. In this modification, the positive/negative sign on the second instance of every number is chosen to represent the handedness of that crossing, rather than the over/under sign of the crossing, which is made clear in the first instance of the number. A right-handed crossing is given a positive number, and a left handed crossing is given a negative number.
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https://en.wikipedia.org/wiki/Observer%20%28quantum%20physics%29
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Some interpretations of quantum mechanics posit a central role for an observer of a quantum phenomenon. The quantum mechanical observer is tied to the issue of observer effect, where a measurement necessarily requires interacting with the physical object being measured, affecting its properties through the interaction. The term "observable" has gained a technical meaning, denoting a Hermitian operator that represents a measurement.
The prominence of seemingly subjective or anthropocentric ideas like "observer" in the early development of the theory has been a continuing source of disquiet and philosophical dispute. A number of new-age religious or philosophical views give the observer a more special role, or place constraints on who or what can be an observer. There is no credible peer-reviewed research that backs such claims. As an example of such claims, Fritjof Capra declared, "The crucial feature of atomic physics is that the human observer is not only necessary to observe the properties of an object, but is necessary even to define these properties."
The Copenhagen interpretation, which is the most widely accepted interpretation of quantum mechanics among physicists, posits that an "observer" or a "measurement" is merely a physical process. One of the founders of the Copenhagen interpretation, Werner Heisenberg, wrote:
Of course the introduction of the observer must not be misunderstood to imply that some kind of subjective features are to be brought into the description of nature. The observer has, rather, only the function of registering decisions, i.e., processes in space and time, and it does not matter whether the observer is an apparatus or a human being; but the registration, i.e., the transition from the "possible" to the "actual," is absolutely necessary here and cannot be omitted from the interpretation of quantum theory.
Niels Bohr, also a founder of the Copenhagen interpretation, wrote:
all unambiguous information concerning atomic objects is
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https://en.wikipedia.org/wiki/Printed%20circuit%20board
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A printed circuit board (PCB), also called printed wiring board (PWB), is a medium used to connect or "wire" components to one another in a circuit. It takes the form of a laminated sandwich structure of conductive and insulating layers: each of the conductive layers is designed with an artwork pattern of traces, planes and other features (similar to wires on a flat surface) etched from one or more sheet layers of copper laminated onto and/or between sheet layers of a non-conductive substrate. Electrical components may be fixed to conductive pads on the outer layers in the shape designed to accept the component's terminals, generally by means of soldering, to both electrically connect and mechanically fasten them to it. Another manufacturing process adds vias, plated-through holes that allow interconnections between layers.
Printed circuit boards are used in nearly all electronic products. Alternatives to PCBs include wire wrap and point-to-point construction, both once popular but now rarely used. PCBs require additional design effort to lay out the circuit, but manufacturing and assembly can be automated. Electronic design automation software is available to do much of the work of layout. Mass-producing circuits with PCBs is cheaper and faster than with other wiring methods, as components are mounted and wired in one operation. Large numbers of PCBs can be fabricated at the same time, and the layout has to be done only once. PCBs can also be made manually in small quantities, with reduced benefits.
PCBs can be single-sided (one copper layer), double-sided (two copper layers on both sides of one substrate layer), or multi-layer (outer and inner layers of copper, alternating with layers of substrate). Multi-layer PCBs allow for much higher component density, because circuit traces on the inner layers would otherwise take up surface space between components. The rise in popularity of multilayer PCBs with more than two, and especially with more than four, copper p
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https://en.wikipedia.org/wiki/Modularity%20%28biology%29
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Modularity refers to the ability of a system to organize discrete, individual units that can overall increase the efficiency of network activity and, in a biological sense, facilitates selective forces upon the network. Modularity is observed in all model systems, and can be studied at nearly every scale of biological organization, from molecular interactions all the way up to the whole organism.
Evolution of Modularity
The exact evolutionary origins of biological modularity has been debated since the 1990s. In the mid 1990s, Günter Wagner argued that modularity could have arisen and been maintained through the interaction of four evolutionary modes of action:
[1] Selection for the rate of adaptation: If different complexes evolve at different rates, then those evolving more quickly reach fixation in a population faster than other complexes. Thus, common evolutionary rates could be forcing the genes for certain proteins to evolve together while preventing other genes from being co-opted unless there is a shift in evolutionary rate.
[2] Constructional selection: When a gene exists in many duplicated copies, it may be maintained because of the many connections it has (also termed pleiotropy). There is evidence that this is so following whole genome duplication, or duplication at a single locus. However, the direct relationship that duplication processes have with modularity has yet to be directly examined.
[3] Stabilizing selection: While seeming antithetical to forming novel modules, Wagner maintains that it is important to consider the effects of stabilizing selection as it may be "an important counter force against the evolution of modularity". Stabilizing selection, if ubiquitously spread across the network, could then be a "wall" that makes the formation of novel interactions more difficult and maintains previously established interactions. Against such strong positive selection, other evolutionary forces acting on the network must exist, with gaps of relaxed
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https://en.wikipedia.org/wiki/Named%20data%20networking
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Named Data Networking (NDN) (related to content-centric networking (CCN), content-based networking, data-oriented networking or information-centric networking (ICN)) is a proposed Future Internet architecture inspired by years of empirical research into network usage and a growing awareness of unsolved problems in contemporary internet architectures like IP. NDN has its roots in an earlier project, Content-Centric Networking (CCN), which Van Jacobson first publicly presented in 2006. The NDN project is investigating Jacobson's proposed evolution from today's host-centric network architecture IP to a data-centric network architecture (NDN). The belief is that this conceptually simple shift will have far-reaching implications for how people design, develop, deploy, and use networks and applications.
NDN has three core concepts that distinguish NDN from other network architectures. First, applications name data and data names will directly be used in network packet forwarding; consumer applications request desired data by its name, so communications in NDN are consumer-driven. Second, NDN communications are secured in a data-centric manner, that is, each piece of data (called a Data packet) will be cryptographically signed by its producer and sensitive payload or name components can also be encrypted for the purpose of privacy; in this way, consumers can verify the packet regardless of how the packet is fetched. Third, NDN adopts a stateful forwarding plane where forwarders will keep a state for each data request (called an Interest packet) and erase the state when a corresponding Data packet comes back; NDN's stateful forwarding allows intelligent forwarding strategies and eliminates loops.
Its premise is that the Internet is primarily used as an information distribution network, which is not a good match for IP, and that the future Internet's "thin waist" should be based on named data rather than numerically addressed hosts. The underlying principle is that a comm
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https://en.wikipedia.org/wiki/Decimal%20representation
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A decimal representation of a non-negative real number is its expression as a sequence of symbols consisting of decimal digits traditionally written with a single separator:
Here is the decimal separator, is a nonnegative integer, and are digits, which are symbols representing integers in the range 0, ..., 9.
Commonly, if The sequence of the —the digits after the dot—is generally infinite. If it is finite, the lacking digits are assumed to be 0. If all are , the separator is also omitted, resulting in a finite sequence of digits, which represents a natural number.
The decimal representation represents the infinite sum:
Every nonnegative real number has at least one such representation; it has two such representations (with if ) if and only if one has a trailing infinite sequence of , and the other has a trailing infinite sequence of . For having a one-to-one correspondence between nonnegative real numbers and decimal representations, decimal representations with a trailing infinite sequence of are sometimes excluded.
Integer and fractional parts
The natural number , is called the integer part of , and is denoted by in the remainder of this article. The sequence of the represents the number
which belongs to the interval and is called the fractional part of (except when all are ).
Finite decimal approximations
Any real number can be approximated to any desired degree of accuracy by rational numbers with finite decimal representations.
Assume . Then for every integer there is a finite decimal such that:
Proof:
Let , where .
Then , and the result follows from dividing all sides by .
(The fact that has a finite decimal representation is easily established.)
Non-uniqueness of decimal representation and notational conventions
Some real numbers have two infinite decimal representations. For example, the number 1 may be equally represented by 1.000... as by 0.999... (where the infinite sequences of trailing 0's or 9's, respectively, are repre
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https://en.wikipedia.org/wiki/Prime%20factor%20exponent%20notation
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In his 1557 work The Whetstone of Witte, British mathematician Robert Recorde proposed an exponent notation by prime factorisation, which remained in use up until the eighteenth century and acquired the name Arabic exponent notation. The principle of Arabic exponents was quite similar to Egyptian fractions; large exponents were broken down into smaller prime numbers. Squares and cubes were so called; prime numbers from five onwards were called sursolids.
Although the terms used for defining exponents differed between authors and times, the general system was the primary exponent notation until René Descartes devised the Cartesian exponent notation, which is still used today.
This is a list of Recorde's terms.
By comparison, here is a table of prime factors:
See also
Surd
External links (references)
Mathematical dictionary, Chas Hutton, pg 224
Mathematical notation
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https://en.wikipedia.org/wiki/Outline%20of%20algebra
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The following outline is provided as an overview of and topical guide to algebra:
Algebra is one of the main branches of mathematics, covering the study of structure, relation and quantity. Algebra studies the effects of adding and multiplying numbers, variables, and polynomials, along with their factorization and determining their roots. In addition to working directly with numbers, algebra also covers symbols, variables, and set elements. Addition and multiplication are general operations, but their precise definitions lead to structures such as groups, rings, and fields.
Branches
Pre-algebra
Elementary algebra
Boolean algebra
Abstract algebra
Linear algebra
Universal algebra
Algebraic equations
An algebraic equation is an equation involving only algebraic expressions in the unknowns. These are further classified by degree.
Linear equation – algebraic equation of degree one.
Polynomial equation – equation in which a polynomial is set equal to another polynomial.
Transcendental equation – equation involving a transcendental function of one of its variables.
Functional equation – equation in which the unknowns are functions rather than simple quantities.
Differential equation – equation involving derivatives.
Integral equation – equation involving integrals.
Diophantine equation – equation where the only solutions of interest of the unknowns are the integer ones.
History
History of algebra
General algebra concepts
Fundamental theorem of algebra – states that every non-constant single-variable polynomial with complex coefficients has at least one complex root. This includes polynomials with real coefficients, since every real number is a complex number with an imaginary part equal to zero.
Equations – equality of two mathematical expressions
Linear equation – an algebraic equation with a degree of one
Quadratic equation – an algebraic equation with a degree of two
Cubic equation – an algebraic equation with a degree of three
Quartic equati
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https://en.wikipedia.org/wiki/Device%20under%20test
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A device under test (DUT), also known as equipment under test (EUT) and unit under test (UUT), is a manufactured product undergoing testing, either at first manufacture or later during its life cycle as part of ongoing functional testing and calibration checks. This can include a test after repair to establish that the product is performing in accordance with the original product specification.
Electronics testing
In the electronics industry a DUT is any electronic assembly under test. For example, cell phones coming off of an assembly line may be given a final test in the same way as the individual chips were earlier tested. Each cell phone under test is, briefly, the DUT.
For circuit boards, the DUT is often connected to the test equipment using a bed of nails tester of pogo pins.
Semiconductor testing
In semiconductor testing, the device under test is a die on a wafer or the resulting packaged part. A connection system is used, connecting the part to automatic or manual test equipment. The test equipment then applies power to the part, supplies stimulus signals, then measures and evaluates the resulting outputs from the device. In this way, the tester determines whether the particular device under test meets the device specifications.
While packaged as a wafer, automatic test equipment (ATE) can connect to the individual units using a set of microscopic needles. Once the chips are sawn apart and packaged, test equipment can connect to the chips using ZIF sockets (sometimes called contactors).
See also
Automatic test equipment
DUT board
Product testing
System under test
Test bench
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https://en.wikipedia.org/wiki/C-Thru%20Ruler
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The C-Thru Ruler Company is an American maker of measuring devices and specialized products for drafting, designing and drawing. The company was formed in 1939 in Bloomfield, Connecticut, by Jennie R. Zachs, a schoolteacher, who saw the need for transparent measuring tools such as rulers, triangles, curves and protractors.
During the 1990s, the company expanded into the paper crafting and scrapbooking fields under the Little Yellow Bicycle and Déjà Views brands.
In June 2012, Acme United Corporation bought the ruler, lettering and drafting portions of C-Thru Ruler. The scrap booking part of the business, continues to be managed by the Zachs family under the Little Yellow Bicycle Inc. name.
History
Jennie Zachs
Jennie R. Zachs, born in 1898, was the daughter of Benjamin and Julia Zachs who emigrated from Russia to the United States in the early 1900s. She graduated from high school in Hartford, CT. A few years later, she graduated from college and became a schoolteacher.
While teaching, she developed the idea that when students would be able to see through their rulers, it would make the tool much more useful in the classroom. As a result, Ms. Zachs started the development of two transparent rulers made out of plastic.
In 1939, she founded C-Thru Ruler Company in Bloomfield, Connecticut and designed a whole family of transparent measuring tools like rulers, triangles, curves and protractors. Shortly after, she engaged a supplier to mill the tools out of plastic sheet and began to attend different trade shows and conventions for blue printers and art materials dealers to sell the products. She noticed that the transparent measuring tools could effectively replace wood and metal measuring devices for many applications in drafting, designing and drawing.
1940–1969
Only one year after founding the company, Jennie Zachs took in two partners to handle the expansion of C-Thru. Edward Zachs, her brother, joined C-Thru and Anna Zachs, her sister, became an investor. O
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https://en.wikipedia.org/wiki/Organisms%20at%20high%20altitude
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Organisms can live at high altitude, either on land, in water, or while flying. Decreased oxygen availability and decreased temperature make life at such altitudes challenging, though many species have been successfully adapted via considerable physiological changes. As opposed to short-term acclimatisation (immediate physiological response to changing environment), high-altitude adaptation means irreversible, evolved physiological responses to high-altitude environments, associated with heritable behavioural and genetic changes. Among vertebrates, only few mammals (such as yaks, ibexes, Tibetan gazelles, vicunas, llamas, mountain goats, etc.) and certain birds are known to have completely adapted to high-altitude environments.
Human populations such as some Tibetans, South Americans and Ethiopians live in the otherwise uninhabitable high mountains of the Himalayas, Andes and Ethiopian Highlands respectively. The adaptation of humans to high altitude is an example of natural selection in action.
High-altitude adaptations provide examples of convergent evolution, with adaptations occurring simultaneously on three continents. Tibetan humans and Tibetan domestic dogs share a genetic mutation in EPAS1, but it has not been seen in Andean humans.
Invertebrates
Tardigrades live over the entire world, including the high Himalayas. Tardigrades are also able to survive temperatures of close to absolute zero (), temperatures as high as , radiation that would kill other animals, and almost a decade without water. Since 2007, tardigrades have also returned alive from studies in which they have been exposed to the vacuum of outer space in low Earth orbit.
Other invertebrates with high-altitude habitats are Euophrys omnisuperstes, a spider that lives in the Himalaya range at altitudes of up to ; it feeds on stray insects that are blown up the mountain by the wind. The springtail Hypogastrura nivicola (one of several insects called snow fleas) also lives in the Himalayas. It
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https://en.wikipedia.org/wiki/Manycore%20processor
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Manycore processors are special kinds of multi-core processors designed for a high degree of parallel processing, containing numerous simpler, independent processor cores (from a few tens of cores to thousands or more). Manycore processors are used extensively in embedded computers and high-performance computing.
Contrast with multicore architecture
Manycore processors are distinct from multi-core processors in being optimized from the outset for a higher degree of explicit parallelism, and for higher throughput (or lower power consumption) at the expense of latency and lower single-thread performance.
The broader category of multi-core processors, by contrast, are usually designed to efficiently run both parallel and serial code, and therefore place more emphasis on high single-thread performance (e.g. devoting more silicon to out of order execution, deeper pipelines, more superscalar execution units, and larger, more general caches), and shared memory. These techniques devote runtime resources toward figuring out implicit parallelism in a single thread. They are used in systems where they have evolved continuously (with backward compatibility) from single core processors. They usually have a 'few' cores (e.g. 2, 4, 8) and may be complemented by a manycore accelerator (such as a GPU) in a heterogeneous system.
Motivation
Cache coherency is an issue limiting the scaling of multicore processors. Manycore processors may bypass this with methods such as message passing, scratchpad memory, DMA, partitioned global address space, or read-only/non-coherent caches. A manycore processor using a network on a chip and local memories gives software the opportunity to explicitly optimise the spatial layout of tasks (e.g. as seen in tooling developed for TrueNorth).
Manycore processors may have more in common (conceptually) with technologies originating in high-performance computing such as clusters and vector processors.
GPUs may be considered a form of manycore process
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https://en.wikipedia.org/wiki/Gas%20exchange
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Gas exchange is the physical process by which gases move passively by diffusion across a surface. For example, this surface might be the air/water interface of a water body, the surface of a gas bubble in a liquid, a gas-permeable membrane, or a biological membrane that forms the boundary between an organism and its extracellular environment.
Gases are constantly consumed and produced by cellular and metabolic reactions in most living things, so an efficient system for gas exchange between, ultimately, the interior of the cell(s) and the external environment is required. Small, particularly unicellular organisms, such as bacteria and protozoa, have a high surface-area to volume ratio. In these creatures the gas exchange membrane is typically the cell membrane. Some small multicellular organisms, such as flatworms, are also able to perform sufficient gas exchange across the skin or cuticle that surrounds their bodies. However, in most larger organisms, which have small surface-area to volume ratios, specialised structures with convoluted surfaces such as gills, pulmonary alveoli and spongy mesophylls provide the large area needed for effective gas exchange. These convoluted surfaces may sometimes be internalised into the body of the organism. This is the case with the alveoli, which form the inner surface of the mammalian lung, the spongy mesophyll, which is found inside the leaves of some kinds of plant, or the gills of those molluscs that have them, which are found in the mantle cavity.
In aerobic organisms, gas exchange is particularly important for respiration, which involves the uptake of oxygen () and release of carbon dioxide (). Conversely, in oxygenic photosynthetic organisms such as most land plants, uptake of carbon dioxide and release of both oxygen and water vapour are the main gas-exchange processes occurring during the day. Other gas-exchange processes are important in less familiar organisms: e.g. carbon dioxide, methane and hydrogen are exchanged a
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https://en.wikipedia.org/wiki/Logic%20redundancy
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Logic redundancy occurs in a digital gate network containing circuitry that does not affect the static logic function. There are several reasons why logic redundancy may exist. One reason is that it may have been added deliberately to suppress transient glitches (thus causing a race condition) in the output signals by having two or more product terms overlap with a third one.
Consider the following equation:
The third product term is a redundant consensus term. If switches from 1 to 0 while and , remains 1. During the transition of signal in logic gates, both the first and second term may be 0 momentarily. The third term prevents a glitch since its value of 1 in this case is not affected by the transition of signal .
Another reason for logic redundancy is poor design practices which unintentionally result in logically redundant terms. This causes an unnecessary increase in network complexity, and possibly hampering the ability to test manufactured designs using traditional test methods (single stuck-at fault models). Testing might be possible using IDDQ models.
Removing logic redundancy
Logic redundancy is, in general, not desired.
Redundancy, by definition, requires extra parts (in this case: logical terms) which raises the cost of implementation (either actual cost of physical parts or CPU time to process).
Logic redundancy can be removed by several well-known techniques, such as Karnaugh maps, the Quine–McCluskey algorithm, and the heuristic computer method.
Adding logic redundancy
In some cases it may be desirable to add logic redundancy. One of those cases is to avoid race conditions whereby an output can fluctuate because different terms are "racing" to turn off and on. To explain this in more concrete terms the Karnaugh map to the right shows the minterms for the following function:
The boxes represent the minimal AND/OR terms needed to implement this function:
The k-map visually shows where race conditions occur in the minimal expression by h
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https://en.wikipedia.org/wiki/Universal%20Test%20Specification%20Language
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Universal Test Specification Language (UTSL) is a programming language used to describe ASIC tests in a format that leads to an automated translation of the test specification into an executable test code. UTSL is platform independent and provided a code generation interface for a specific platform is available, UTSL code can be translated into the programming language of a specific Automatic Test Equipment (ATE).
History
Increased complexity of ASICs leads to requirements of more complex test programs with longer development times. An automated test program generation could simplify and speed up this process. Teradyne Inc. together with Robert Bosch GmbH agreed to develop a concept and a tool chain for an automated test-program generation. To achieve this a tester independent programming language was required. Hence, UTSL, a programming language that enables detailed description of tests that can be translated into the ATE specific programming language was developed. The ATE manufacturers need to provide a Test Program Generator that uses the UTSL test description as inputs and generates the ATE-specific test code with optimal resource mapping and better practice program code.
As long as the ATE manufacturer provides with the test program generator that can use UTSL as an input the cumbersome task of translating a test program from one platform to another can be significantly simplified. In other words, the task of rewriting of the test programs for a specific platform can be replaced by the automatically generating the code from the UTSL based test specification. Prerequisite for this is that the UTSL description of tests is sufficiently detailed with definition of the test technique as well as the description of all the necessary inputs and outputs.
Being a platform independent programming language, UTSL allows the engineers to read, analyse and modify the tests in the test specification regardless of the ATE at which the testing of the ASIC will be done. UTS
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https://en.wikipedia.org/wiki/ERP%20security
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ERP Security is a wide range of measures aimed at protecting Enterprise resource planning (ERP) systems from illicit access ensuring accessibility and integrity of system data. ERP system is a computer software that serves to unify the information intended to manage the organization including Production, Supply Chain Management, Financial Management, Human Resource Management, Customer Relationship Management, Enterprise Performance Management.
Review
ERP system integrates business processes enabling procurement, payment, transport, human resources management, product management, and financial planning.
As ERP system stores confidential information, the Information Systems Audit and Control Association (ISACA) recommends to regularly conduct a comprehensive assessment of ERP system security, checking ERP servers for software vulnerabilities, configuration errors, segregation of duties conflicts, compliance with relevant standards and recommendations, and recommendations of vendors.
Causes for vulnerabilities in ERP systems
Complexity
ERP systems process transactions and implement procedures to ensure that users have different access privileges. There are hundreds of authorization objects in SAP permitting users to perform actions in the system. In case of 200 users of the company, there are approximately 800,000 (100*2*20*200) ways to customize security settings of ERP systems. With the growth of complexity, the possibility of errors and segregation of duties conflicts increases.
Specificity
Vendors fix vulnerabilities on the regular basis since hackers monitor business applications to find and exploit security issues. SAP releases patches monthly on Patch Tuesday, Oracle issues security fixes every quarter in Oracle Critical Patch Update. Business applications are becoming more exposed to the Internet or migrate to the cloud.
Lack of competent specialists
ERP Cybersecurity survey revealed that organizations running ERP systems "lack both awareness and a
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https://en.wikipedia.org/wiki/List%20of%20graphical%20methods
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This is a list of graphical methods with a mathematical basis.
Included are diagram techniques, chart techniques, plot techniques, and other forms of visualization.
There is also a list of computer graphics and descriptive geometry topics.
Simple displays
Area chart
Box plot
Dispersion fan diagram
Graph of a function
Logarithmic graph paper
Heatmap
Bar chart
Histogram
Line chart
Pie chart
Plotting
Scatterplot
Sparkline
Stemplot
Radar chart
Set theory
Venn diagram
Karnaugh diagram
Descriptive geometry
Isometric projection
Orthographic projection
Perspective (graphical)
Engineering drawing
Technical drawing
Graphical projection
Mohr's circle
Pantograph
Circuit diagram
Smith chart
Sankey diagram
Systems analysis
Binary decision diagram
Control-flow graph
Functional flow block diagram
Information flow diagram
IDEF
N2 chart
Sankey diagram
State diagram
System context diagram
Data-flow diagram
Cartography
Map projection
Orthographic projection (cartography)
Robinson projection
Stereographic projection
Dymaxion map
Topographic map
Craig retroazimuthal projection
Hammer retroazimuthal projection
Biological sciences
Cladogram
Punnett square
Systems Biology Graphical Notation
Physical sciences
Free body diagram
Greninger chart
Phase diagram
Wavenumber-frequency diagram
Bode plot
Nyquist plot
Dalitz plot
Feynman diagram
Carnot Plot
Business methods
Flowchart
Workflow
Gantt chart
Growth-share matrix (often called BCG chart)
Work breakdown structure
Control chart
Ishikawa diagram
Pareto chart (often used to prioritise outputs of an Ishikawa diagram)
Conceptual analysis
Mind mapping
Concept mapping
Conceptual graph
Entity-relationship diagram
Tag cloud, also known as word cloud
Statistics
Autocorrelation plot
Bar chart
Biplot
Box plot
Bullet graph
Chernoff faces
Control chart
Fan chart
Forest plot
Funnel plot
Galbraith plot
Histogram
Mosaic plot
Multidimensional scaling
np-chart
p-chart
Pie chart
Probability plot
Normal probability plot
Poincaré plot
Probability plot
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https://en.wikipedia.org/wiki/Clockwise
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Two-dimensional rotation can occur in two possible directions or senses of rotation. Clockwise motion (abbreviated CW) proceeds in the same direction as a clock's hands: from the top to the right, then down and then to the left, and back up to the top. The opposite sense of rotation or revolution is (in Commonwealth English) anticlockwise (ACW) or (in North American English) counterclockwise (CCW).
Three-dimensional rotation can have similarly defined senses when considering the corresponding angular velocity vector.
Terminology
Before clocks were commonplace, the terms "sunwise" and "deasil", "deiseil" and even "deocil" from the Scottish Gaelic language and from the same root as the Latin "dexter" ("right") were used for clockwise. "Widdershins" or "withershins" (from Middle Low German "weddersinnes", "opposite course") was used for counterclockwise.
The terms clockwise and counterclockwise can only be applied to a rotational motion once a side of the rotational plane is specified, from which the rotation is observed. For example, the daily rotation of the Earth is clockwise when viewed from above the South Pole, and counterclockwise when viewed from above the North Pole (considering "above a point" to be defined as "farther away from the center of earth and on the same ray").
Clocks traditionally follow this sense of rotation because of the clock's predecessor: the sundial. Clocks with hands were first built in the Northern Hemisphere (see Clock), and they were made to work like horizontal sundials. In order for such a sundial to work north of the equator during spring and summer, and north of the Tropic of Cancer the whole year, the noon-mark of the dial must be placed northward of the pole casting the shadow. Then, when the Sun moves in the sky (from east to south to west), the shadow, which is cast on the sundial in the opposite direction, moves with the same sense of rotation (from west to north to east). This is why hours must be drawn in horizontal sundi
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https://en.wikipedia.org/wiki/Vintage%20computer
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A vintage computer is an older computer system that is largely regarded as obsolete.
The personal computer has been around since approximately 1971. But in that time, numerous technological revolutions have left generations of obsolete computing equipment on the junk heap. Nevertheless, in that time, these otherwise useless computers have spawned a sub-culture of vintage computer collectors, who often spend large sums to acquire the rarest of these items, not only to display but restore to their fully functioning glory, including active software development and adaptation to modern uses. This often includes homebrew developers and hackers who add on, update and create hybrid composites from new and old computers for uses for which they were otherwise never intended. Ethernet interfaces have been designed for many vintage 8-bit machines to allow limited connectivity to the Internet; where users can access user groups, bulletin boards, and databases of software. Most of this hobby centers on those computers manufactured after 1960, though some collectors specialize in pre-1960 computers as well.
The Vintage Computer Festival, an event held by the Vintage Computer Federation for the exhibition and celebration of vintage computers, has been held annually since 1997 and has expanded internationally.
By platform
MITS Inc.
Micro Instrumentation and Telemetry Systems (MITS) produced the Altair 8800 in 1975. According to Harry Garland, the Altair 8800 was the product that catalyzed the microcomputer revolution of the 1970s.
IMSAI
IMSAI produced a machine similar to the Altair 8800. It was introduced in 1975, first as a kit, and later as an assembled system. The list price was $591 () for a kit, and $931 () assembled.
Processor Technology
Processor Technology produced the Sol-20. This was one of the first machines to have a case that included a keyboard; a design feature copied by many of later "home computers".
SWTPC
Southwest Technical Products Corporation (
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https://en.wikipedia.org/wiki/List%20of%20finite%20simple%20groups
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In mathematics, the classification of finite simple groups states that every finite simple group is cyclic, or alternating, or in one of 16 families of groups of Lie type, or one of 26 sporadic groups.
The list below gives all finite simple groups, together with their order, the size of the Schur multiplier, the size of the outer automorphism group, usually some small representations, and lists of all duplicates.
Summary
The following table is a complete list of the 18 families of finite simple groups and the 26 sporadic simple groups, along with their orders. Any non-simple members of each family are listed, as well as any members duplicated within a family or between families. (In removing duplicates it is useful to note that no two finite simple groups have the same order, except that the group A8 = A3(2) and A2(4) both have order 20160, and that the group Bn(q) has the same order as Cn(q) for q odd, n > 2. The smallest of the latter pairs of groups are B3(3) and C3(3) which both have order 4585351680.)
There is an unfortunate conflict between the notations for the alternating groups An and the groups of Lie type An(q). Some authors use various different fonts for An to distinguish them. In particular,
in this article we make the distinction by setting the alternating groups An in Roman font and the Lie-type groups An(q) in italic.
In what follows, n is a positive integer, and q is a positive power of a prime number p, with the restrictions noted. The notation (a,b) represents the greatest common divisor of the integers a and b.
Cyclic groups, Zp
Simplicity: Simple for p a prime number.
Order: p
Schur multiplier: Trivial.
Outer automorphism group: Cyclic of order p − 1.
Other names: Z/pZ, Cp
Remarks: These are the only simple groups that are not perfect.
Alternating groups, An, n > 4
Simplicity: Solvable for n < 5, otherwise simple.
Order: n!/2 when n > 1.
Schur multiplier: 2 for n = 5 or n > 7, 6 for n = 6 or 7; see Covering groups of the alt
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https://en.wikipedia.org/wiki/West%20Bridge
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The West Bridge is a growing architectural approach, originally developed by Cypress Semiconductor, which enhances and modularizes a peripheral controller in an embedded computer architecture. Conceptually, the West Bridge parallels and complements the decentralization represented by the North Bridge and the South Bridge. Most notably, it has been used by Research in Motion to permit extremely high data transfer rates in its BlackBerry devices.
Overview
While the North Bridge focuses on memory control and the South Bridge focuses on "slower" capabilities of the motherboard, the West Bridge focuses on peripheral control. The new architectural modularization opens the potential for increased system performance. Being directly connected, peripheral control can be handled wholly and independently through a West Bridge's controller, leaving a processor offloaded and free to focus on other data intensive operations. While it enhances performance of the system via the processor, a West Bridge companion chip itself may also serve directly as a peripheral accelerator.
Etymology
The term West Bridge was first introduced by Cypress Semiconductor, which designs products to provide optimal performance and connectivity in the embedded world. The name was chosen deliberately to be a meme consistent with the North Bridge and South Bridge concepts. "West Bridge" refers both to the architectural scheme in general and to the product family with which it was introduced by Cypress.
Interface Support
Interfaces regularly change towards faster, lower power, fewer pins, and newer standards, making it a difficult task for processors to follow and integrate them. A prime function of West Bridge devices is to enable connection to these varied interfaces.
An example of such an interface is NAND Flash, which keeps evolving with new generations of Multi-Level Cell NAND. A West Bridge device might handle the MLC NAND management and enable lowest-cost memory support for a main processor, whi
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https://en.wikipedia.org/wiki/Highly%20composite%20number
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A highly composite number or antiprime is a positive integer with more divisors than any smaller positive integer has. A related concept is that of a largely composite number, a positive integer which has at least as many divisors as any smaller positive integer. The name can be somewhat misleading, as the first two highly composite numbers (1 and 2) are not actually composite numbers; however, all further terms are.
Ramanujan wrote a paper on highly composite numbers in 1915.
The mathematician Jean-Pierre Kahane suggested that Plato must have known about highly composite numbers as he deliberately chose such a number, 5040 (= 7!), as the ideal number of citizens in a city.
Examples
The initial or smallest 40 highly composite numbers are listed in the table below . The number of divisors is given in the column labeled d(n). Asterisks indicate superior highly composite numbers.
The divisors of the first 19 highly composite numbers are shown below.
The table below shows all 72 divisors of 10080 by writing it as a product of two numbers in 36 different ways.
The 15,000th highly composite number can be found on Achim Flammenkamp's website. It is the product of 230 primes:
where is the sequence of successive prime numbers, and all omitted terms (a22 to a228) are factors with exponent equal to one (i.e. the number is ). More concisely, it is the product of seven distinct primorials:
where is the primorial .
Prime factorization
Roughly speaking, for a number to be highly composite it has to have prime factors as small as possible, but not too many of the same. By the fundamental theorem of arithmetic, every positive integer n has a unique prime factorization:
where are prime, and the exponents are positive integers.
Any factor of n must have the same or lesser multiplicity in each prime:
So the number of divisors of n is:
Hence, for a highly composite number n,
the k given prime numbers pi must be precisely the first k prime numbers (2, 3, 5, ...
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https://en.wikipedia.org/wiki/Glossary%20of%20areas%20of%20mathematics
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Mathematics is a broad subject that is commonly divided in many areas that may be defined by their objects of study, by the used methods, or by both. For example, analytic number theory is a subarea of number theory devoted to the use of methods of analysis for the study of natural numbers.
This glossary is alphabetically sorted. This hides a large part of the relationships between areas. For the broadest areas of mathematics, see . The Mathematics Subject Classification is a hierarchical list of areas and subjects of study that has been elaborated by the community of mathematicians. It is used by most publishers for classifying mathematical articles and books.
A
B
C
D
E
F
G
H
I
J
K
L
M
N
O
P
Q
R
S
T
U
V
W
See also
Lists of mathematics topics
Outline of mathematics
:Category:Glossaries of mathematics
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https://en.wikipedia.org/wiki/Host%20Based%20Security%20System
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Host Based Security System (HBSS) is the official name given to the United States Department of Defense (DOD) commercial off-the-shelf (COTS) suite of software applications used within the DOD to monitor, detect, and defend the DOD computer networks and systems. The Enterprise-wide Information Assurance and computer Network Defense Solutions Steering Group (ESSG) sponsored the acquisition of the HBSS System for use within the DOD Enterprise Network. HBSS is deployed on both the Non-Classified Internet Protocol Routed Network (NIPRNet) and Secret Internet Protocol Routed Network (SIPRNet) networks, with priority given to installing it on the NIPRNet. HBSS is based on McAfee, Inc's ePolicy Orchestrator (ePO) and other McAfee point product security applications such as Host Intrusion Prevention System (HIPS).
History
Seeing the need to supply a comprehensive, department-wide security suite of tools for DOD System Administrators, the ESSG started to gather requirements for the formation of a host-based security system in the summer of 2005. In March 2006, BAE Systems and McAfee were awarded a contract to supply an automated host-based security system to the department. After the award, 22 pilot sites were identified to receive the first deployments of HBSS. During the pilot roll out, DOD System Administrators around the world were identified and trained on using the HBSS software in preparation for software deployment across DOD.
On October 9, 2007, the Joint Task Force for Global Network Operations (JTF-GNO) released Communications Tasking Order (CTO) 07-12 (Deployment of Host Based Security System (HBSS)) mandating the deployment of HBSS on all Combatant Command, Service and Agency (CC/S/A) networks within DOD with the completion date by the 3rd quarter of 2008. The release of this CTO brought HBSS to the attention of all major department heads and CC/S/A's, providing the ESSG with the necessary authority to enforce its deployment. Agencies not willing to co
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https://en.wikipedia.org/wiki/List%20of%20physics%20concepts%20in%20primary%20and%20secondary%20education%20curricula
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This is a list of topics that are included in high school physics curricula or textbooks.
Mathematical Background
SI Units
Scalar (physics)
Euclidean vector
Motion graphs and derivatives
Pythagorean theorem
Trigonometry
Motion and forces
Motion
Force
Linear motion
Linear motion
Displacement
Speed
Velocity
Acceleration
Center of mass
Mass
Momentum
Newton's laws of motion
Work (physics)
Free body diagram
Rotational motion
Angular momentum (Introduction)
Angular velocity
Centrifugal force
Centripetal force
Circular motion
Tangential velocity
Torque
Conservation of energy and momentum
Energy
Conservation of energy
Elastic collision
Inelastic collision
Inertia
Moment of inertia
Momentum
Kinetic energy
Potential energy
Rotational energy
Electricity and magnetism
Ampère's circuital law
Capacitor
Coulomb's law
Diode
Direct current
Electric charge
Electric current
Alternating current
Electric field
Electric potential energy
Electron
Faraday's law of induction
Ion
Inductor
Joule heating
Lenz's law
Magnetic field
Ohm's law
Resistor
Transistor
Transformer
Voltage
Heat
Entropy
First law of thermodynamics
Heat
Heat transfer
Second law of thermodynamics
Temperature
Thermal energy
Thermodynamic cycle
Volume (thermodynamics)
Work (thermodynamics)
Waves
Wave
Longitudinal wave
Transverse waves
Transverse wave
Standing Waves
Wavelength
Frequency
Light
Light ray
Speed of light
Sound
Speed of sound
Radio waves
Harmonic oscillator
Hooke's law
Reflection
Refraction
Snell's law
Refractive index
Total internal reflection
Diffraction
Interference (wave propagation)
Polarization (waves)
Vibrating string
Doppler effect
Gravity
Gravitational potential
Newton's law of universal gravitation
Newtonian constant of gravitation
See also
Outline of physics
Physics education
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https://en.wikipedia.org/wiki/Epibiont
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An epibiont (from the Ancient Greek meaning "living on top of") is an organism that lives on the surface of another living organism, called the basibiont ("living underneath"). The interaction between the two organisms is called epibiosis. An epibiont is, by definition, harmless to its host. In this sense, the interaction between the two organisms can be considered neutralistic or commensalistic; as opposed to being, for example, parasitic, in which case one organism benefits at the expense of the other, or mutualistic, in which both organisms obtain some explicit benefit from their coexistence. Examples of common epibionts are bacteria, barnacles, remoras, and algae, many of which live on the surfaces of larger marine organisms such as whales, sharks, sea turtles, and mangrove trees.
Although there is no direct effect of the epibiont to the host, there are often indirect effects resulting from this interaction and change in the surface of the host. This has been found to be especially important to marine organisms and aquatic ecosystems, as surface qualities do impact necessary ecological functions such as drag, radiation absorption, nutrient uptake, etc.
Types
Epiphytes are plants that grow on the surface of other plants.
Epizoic organisms are those that live on the surface of animals.
Epibionts and their basibiont
Epibiont: Korshikoviella gracilipes, Basibiont: Daphnia pulicaria
Epibiont: Deltaproteobacteria, Basibiont: "Candidatus Desulfobulbus rimicarensis"
Further examples
Pagurus bernhardus and its epibionts
P. bernhardus, or hermit crabs, acts as basibionts to many species of varying protozoa, hydrozoa, entoprocts, cirripeds, and polychaetes. The different types of epibionts are found on either the crab, the shell, or both the crab and the shell. In a study done over the course of two years, densities and diversity of epibionts were measured and considered. Multiple studies have found that P. bernardus in shells colonized with epibionts were likel
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https://en.wikipedia.org/wiki/Augmented%20Reality%20Sandtable
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The Augmented Reality Sandtable (ARES) is an interactive, digital sand table that uses augmented reality (AR) technology to create a 3D battlespace map. It was developed by the Human Research and Engineering Directorate (HRED) at the Army Research Laboratory (ARL) to combine the positive aspects of traditional military sand tables with the latest digital technologies to better support soldier training and offer new possibilities of learning. It uses a projector to display a topographical map on top of the sand in a regular sandbox as well as a motion sensor that keeps track of changes in the layout of the sand to appropriately adjust the computer-generated terrain display.
An ARL study conducted in 2017 with 52 active duty military personnel (36 males and 16 females) found that the participants who used ARES spent less time setting up the table compared to participants who used a traditional sand table. In addition, ARES demonstrated a lower perceived workload score, as measured using the NASA Task Load Index (NASA-TLX) ratings, compared to the traditional sand table. However, there was no significant difference in post-knowledge test scores in recreating the visual map.
Development
The ARES project was one of the 25 ARL initiatives in development from 1995 to 2015 that focused on visualizing spatial data on virtual or sand table interfaces. It was developed by HRED's Simulation and Training Technology Center (STTC) with Charles Amburn as the principal investigator. Collaborations involved with ARES included Dignitas Technologies, Design Interactive (DI), the University of Central Florida's Institute for Simulation and Training, and the U.S. Military Academy at West Point.
ARES was largely designed to be a tangible user interface (TUI), in which digital information can be manipulated using physical objects such as a person's hand. It was constructed using commercial off-the-shelf components, including a projector, a laptop, an LCD monitor, Microsoft's Xbox Kinec
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https://en.wikipedia.org/wiki/Router%20on%20a%20stick
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A router on a stick, also known as a one-armed router, is a router that has a single physical or logical connection to a network. It is a method of inter-VLAN routing where one router is connected to a switch via a single cable. The router has physical connections to the broadcast domains where one or more VLANs require the need for routing between them.
Devices on separate VLANs or in a typical local area network are unable to communicate with each other. Therefore, it is often used to forward traffic between locally attached hosts on separate logical routing domains or to facilitate routing table administration, distribution and relay.
Details
One-armed routers that perform traffic forwarding are often implemented on VLANs. They use a single Ethernet network interface port that is part of two or more Virtual LANs, enabling them to be joined. A VLAN allows multiple virtual LANs to coexist on the same physical LAN. This means that two machines attached to the same switch cannot send Ethernet frames to each other even though they pass over the same wires. If they need to communicate, then a router must be placed between the two VLANs to forward packets, just as if the two LANs were physically isolated. The only difference is that the router in question may contain only a single Ethernet network interface controller (NIC) that is part of both VLANs. Hence, "one-armed". While uncommon, hosts on the same physical medium may be assigned with addresses and to different networks. A one-armed router could be assigned addresses for each network and be used to forward traffic between locally distinct networks and to remote networks through another gateway.
One-armed routers are also used for administration purposes such as route collection, multi hop relay and looking glass servers.
All traffic goes over the trunk twice, so the theoretical maximum sum of up and download speed is the line rate. For a two-armed configuration, uploading does not need to impact downloa
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https://en.wikipedia.org/wiki/Polymath%20Project
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The Polymath Project is a collaboration among mathematicians to solve important and difficult mathematical problems by coordinating many mathematicians to communicate with each other on finding the best route to the solution. The project began in January 2009 on Timothy Gowers's blog when he posted a problem and asked his readers to post partial ideas and partial progress toward a solution. This experiment resulted in a new answer to a difficult problem, and since then the Polymath Project has grown to describe a particular crowdsourcing process of using an online collaboration to solve any math problem.
Origin
In January 2009, Gowers chose to start a social experiment on his blog by choosing an important unsolved mathematical problem and issuing an invitation for other people to help solve it collaboratively in the comments section of his blog. Along with the math problem itself, Gowers asked a question which was included in the title of his blog post, "is massively collaborative mathematics possible?" This post led to his creation of the Polymath Project.
Projects for high school and college
Since its inception, it has now sponsored a "Crowdmath" project in collaboration with MIT PRIMES program and the Art of Problem Solving. This project is built upon the same idea of the Polymath project that massive collaboration in mathematics is possible and possibly quite fruitful. However, this is specifically aimed at only high school and college students with a goal of creating "a specific opportunity for the upcoming generation of math and science researchers." The problems are original research and unsolved problems in mathematics. All high school and college students from around the world with advanced background of mathematics are encouraged to participate. Older participants are welcomed to participate as mentors and encouraged not to post solutions to the problems. The first Crowdmath project began on March 1, 2016.
Problems solved
Polymath1
The initial propose
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https://en.wikipedia.org/wiki/Integrator
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An integrator in measurement and control applications is an element whose output signal is the time integral of its input signal. It accumulates the input quantity over a defined time to produce a representative output.
Integration is an important part of many engineering and scientific applications. Mechanical integrators are the oldest type and are still used for metering water flow or electrical power. Electronic analogue integrators are the basis of analog computers and charge amplifiers. Integration can also be performed by algorithms in digital computers.
In signal processing circuits
An electronic integrator is a form of first-order low-pass filter, which can be performed in the continuous-time (analog) domain or approximated (simulated) in the discrete-time (digital) domain. An integrator will have a low pass filtering effect but when given an offset it will accumulate a value building it until it reaches a limit of the system or overflows.
A current integrator is an electronic device performing a time integration of an electric current, thus measuring a total electric charge. A capacitor's current–voltage relation makes it a very simple current integrator:
More sophisticated current integrator circuits build on this relation, such as the charge amplifier. A current integrator is also used to measure the electric charge on a Faraday cup in a residual gas analyzer to measure partial pressures of gasses in a vacuum. Another application of current integration is in ion beam deposition, where the measured charge directly corresponds to the number of ions deposited on a substrate, assuming the charge state of the ions is known. The two current-carrying electrical leads must to be connected to the ion source and the substrate, closing the electric circuit which in part is given by the ion beam.
A voltage integrator is an electronic device performing a time integration of an electric voltage, thus measuring the total volt-second product. A simple resistor–capa
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https://en.wikipedia.org/wiki/Canadian%20Stem%20Cell%20Foundation
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The Canadian Stem Cell Foundation is an independent, non-profit organization established in 2008 and situated in Ottawa, Ontario. Stem Cell science is a Canadian innovation through the discovery of stem cells by Drs. James Till and Ernest McCulloch. It is globally known as the leading organization for stem cell research and support in the study of treatments and cures for diseases such as cancer, diabetes, blindness and stroke.
The Canadian Stem Cell Strategy
Their first strategy was created in 2013 to determine the concerns and actions required to develop an innovation that can advance stem cell research and clinics. The Canadian Stem Cell Foundation's goals are to invest a strategy for new treatments, sustainable healthcare, therapies and beneficial products. Their goals are beyond their capacity, such as "using cells to treat respiratory heart diseases, restore lost vision, create a source of insulin-producing cells to treat diabetes, repair damaged spinal cords, reverse the effect of MS, Crohn's disease and other autoimmune disorders, reduce the ravages of Parkinson's disease and reverse tumour formation in the brain, breast and other solid tissues." Their other goals are to bring together scientists, institutions, health charities, industry partners, regulators, funders and philanthropists in a universal vision in the developments of stem cell science research and have public and private sectors support in the funding for stem cell research in the long-term.
There are many organizations involved such as the Stem Cell Network, Health Charities Coalition of Canada, Ontario Stem Cell Initiative, Centre for Commercialization of Regenerative Medicine, Ontario Bioscience Innovation Organization, and Cell CAN Regenerative Medicine and Cell Therapy Network.
To follow updates regarding "The Canadian Stem Cell Strategy," visit the site: http://www.stemcellfoundation.ca/en/blog/categories/listings/strategy-updates
The Stem Cell Charter
The Stem Cell Charter is an
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https://en.wikipedia.org/wiki/Entrance%20facility
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In telecommunications, Entrance facility refers to the entrance to a building for both public and private network service cables (including antenna transmission lines, where applicable), including the entrance point at the building wall or floor, and continuing to the entrance room or entrance space.
Entrance facilities are the transmission facilities (typically wires or cables) that connect competitive LECs’ networks with incumbent LECs’ networks.
Computer networking
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https://en.wikipedia.org/wiki/Transmission-line%20pulse
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Transmission-Line Pulse (TLP) is a way to study integrated circuit technologies and circuit behavior in the current and time domain of electrostatic-discharge (ESD) events. The concept was described shortly after WWII in pp. 175–189 of Pulse Generators, Vol. 5 of the MIT Radiation Lab Series. Also, D. Bradley, J. Higgins, M. Key, and S. Majumdar realized a TLP-based laser-triggered spark gap for kilovolt pulses of accurately variable timing in 1969. For investigation of ESD and electrical-overstress (EOS) effects a measurement system using a TLP generator has been introduced first by T. Maloney and N. Khurana in 1985. Since then, the technique has become indispensable for integrated circuit ESD protection development.
The TLP technique is based on charging a long, floating cable to a pre-determined voltage, and discharging it into a Device-Under-Test (DUT). The cable discharge emulates an electro-static discharge event, but employing time-domain reflectometry (TDR), the change in DUT impedance can be monitored as a function of time.
The first commercial TLP system was developed by Barth Electronics in 1990s. Since then, other commercial systems have been developed (e.g., by Thermo Fisher Scientific, Grundtech, ESDEMC Technology, High Power Pulse Instruments, Hanwa, TLPsol).
A subset of TLP, VF-TLP (Very-Fast Transmission-Line Pulsing), has lately gained popularity with its improved resolution and bandwidth for analysis of ephemeral ESD events such as CDM (Charged Device Model) events. Pioneered by academia (University of Illinois) and commercialized by Barth Electronics, VF-TLP has become an important ESD analysis tool for analyzing modern high-speed semiconductor circuits.
TLP Standards
ANSI/ESD STM5.5.1-2016 Electrostatic Discharge Sensitivity Testing – Transmission Line Pulse (TLP) – Component Level
ANSI/ESD SP5.5.2-2007 Electrostatic Discharge Sensitivity Testing - Very Fast Transmission Line Pulse (VF-TLP) - Component Level
IEC 62615:2010 Electros
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https://en.wikipedia.org/wiki/Optomyography
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Optomyography (OMG) was proposed in 2015 as a technique that could be used to monitor muscular activity. It is possible to use OMG for the same applications where Electromyography (EMG) and Mechanomyography (MMG) are used. However, OMG offers superior signal-to-noise ratio and improved robustness against the disturbing factors and limitations of EMG and MMG.
The basic principle of OMG is to use active near-infra-red optical sensors to measure the variations in the measured signals that are reflected from the surface of the skin while activating the muscles below and around the skin spot where the photoelectric sensor is focusing to measure the signals reflected from this spot.
Applications
A glasses based optomyography device was patented for measuring facial expressions and emotional responses particularly for mental health monitoring . Generating proper control signals is the most important task to be able to control any kind of a prosthesis, computer game or any other system which contains a human-computer interaction unit or module. For this purpose, surface-Electromyographic (s-EMG) and Mechanomyographic (MMG) signals are measured during muscular activities and used, not only for monitoring and assessing these activities, but also to help in providing efficient rehabilitation treatment for patients with disabilities as well as in constructing and controlling sophisticated prostheses for various types of amputees and disabilities. However, while the existing s-EMG and MMG based systems have compelling benefits, many engineering challenges still remain unsolved, especially with regard to the sensory control system.
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https://en.wikipedia.org/wiki/Garden%20waste%20dumping
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Garden waste, or green waste dumping is the act of discarding or depositing garden waste somewhere it does not belong.
Garden waste is the accumulated plant matter from gardening activities which involve cutting or removing vegetation, i.e. cutting the lawn, weed removal, hedge trimming or pruning consisting of lawn clippings. leaf matter, wood and soil.
The composition and volume of garden waste can vary from season to season and location to location. A study in Aarhus, Denmark, found that on average, garden waste generation per person ranged between 122 kg to 155 kg per year.
Garden waste may be used to create compost or mulch, which can be used as a soil conditioner, adding valuable nutrients and building humus. The creation of compost requires a balance between, nitrogen, carbon, moisture and oxygen. Without the ideal balance, plant matter may take a long time to break down, drawing nitrogen from other sources, reducing nitrogen availability to existing vegetation which requires it for growth.
The risk of dumping garden waste is that it may contain seeds and plant parts that may grow (propagules), as well as increase fire fuel loads, disrupt visual amenity, accrue economic costs associated with the removal of waste as well as costs associated with the mitigation of associated impacts such as weed control, forest fire.
Cause
There are strong links between weed invasion of natural areas and the proximity and density of housing. The size and duration of the community have a direct relation to the density of weed infestation. Of the various means in which migration of exotic species from gardens take place, such as vegetative dispersal of runners, wind born and fallen seed, garden waste dumping can play a significant role. The results of one North German study found that of the problematic population of Fallopia, app. 29% originated from garden waste. Of a population of Heracleum mantegazzianum, 18% was found by Schepker to be generated by garden waste (as
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https://en.wikipedia.org/wiki/Wideband%20audio
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Wideband audio, also known as wideband voice or HD voice, is high definition voice quality for telephony audio, contrasted with standard digital telephony "toll quality". It extends the frequency range of audio signals transmitted over telephone lines, resulting in higher quality speech. The range of the human voice extends from 100 Hz to 17 kHz but traditional, voiceband or narrowband telephone calls limit audio frequencies to the range of 300 Hz to 3.4 kHz. Wideband audio relaxes the bandwidth limitation and transmits in the audio frequency range of 50 Hz to 7 kHz. In addition, some wideband codecs may use a higher audio bit depth of 16 bits to encode samples, also resulting in much better voice quality.
Wideband codecs have a typical sample rate of 16 kHz. For superwideband codecs the typical value is 32 kHz.
History
In 1987, the International Telecommunication Union (ITU) standardized a version of wideband audio known as G.722. Radio broadcasters began using G.722 over Integrated Services Digital Network (ISDN) to provide high-quality audio for remote broadcasts, such as commentary from sports venues. AMR-WB (G.722.2) was developed by Nokia and VoiceAge and it was first specified by 3GPP.
The traditional telephone network (PSTN) is generally limited to narrowband audio by the intrinsic nature of its transmission technology, TDM (time-division multiplexing), and by the analogue-to-digital converters used at the edge of the network, as well as the speakers, microphones and other elements in the endpoints themselves.
Wideband audio has been broadly deployed in conjunction with videoconferencing. Providers of this technology quickly discovered that despite the explicit emphasis on video transmission, the quality of the participant experience was significantly influenced by the fidelity of the associated audio signal.
Communications via Voice over Internet Protocol (VoIP) can readily employ wideband audio. When PC-to-PC calls are placed via VoIP services, such
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https://en.wikipedia.org/wiki/Archaeobiology
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Archaeobiology, the study of the biology of ancient times through archaeological materials, is a subspecialty of archaeology. It can be seen as a blanket term for paleobotany, animal osteology, zooarchaeology, microbiology, and many other sub-disciplines. Specifically, plant and animal remains are also called ecofacts. Sometimes these ecofacts can be left by humans and sometimes they can be naturally occurring. Archaeobiology tends to focus on more recent finds, so the difference between archaeobiology and palaeontology is mainly one of date: archaeobiologists typically work with more recent, non-fossilised material found at archaeological sites. Only very rarely are archaeobiological excavations performed at sites with no sign of human presence.
Flora and Fauna in Archaeology
The prime interest of paleobotany is to reconstruct the vegetation that people in the past would have encountered in a particular place and time. Plant studies have always been overshadowed by faunal studies because bones are more conspicuous than plant remains when excavating. Collection of plant remains could everything including pollen, soil, diatoms, wood, plant remains and phytoliths. Phytoliths are sediments and diatoms are water deposits. Each plant remain can tell the archaeologist different things about the environment during a certain time period. Animal remains were the first evidence used by 19th century archaeologists. Today, archaeologists use faunal remains as a guide to the environment. It helps archaeologists understand whether the fauna were present naturally or through activities of carnivores or people. Archaeologists deal with macrofauna and microfauna. Microfauna are better indicators of climate and environmental change than larger species. These can be as small as a bug or as big as a fish or bird. Macrofauna helps archaeologists build a picture of past human diet.
Bacteria and Protists in Archaeology
Bacteria and Protists form two separate kingdoms, but both are fa
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https://en.wikipedia.org/wiki/Biofact%20%28biology%29
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In biology, a biofact is dead material of a once-living organism.
In 1943, the protozoologist Bruno M. Klein of Vienna (1891–1968) coined the term in his article Biofakt und Artefakt in the microscopy journal Mikrokosmos, though at that time it was not adopted by the scientific community. Klein's concept of biofact stressed the dead materials produced by living organisms as sheaths, such as shells.
The word biofact is now widely used in the zoo/aquarium world, but was first used by Lisbeth Bornhofft in 1993 in the Education Department at the New England Aquarium, Boston, to refer to preserved items such as animal bones, skins, molts and eggs. The Accreditation Standards and Related Policies of the Association of Zoos and Aquariums states that biofacts can be useful education tools, and are preferable to live animals because of potential ethical considerations.
See also
Biofact (archaeology)
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https://en.wikipedia.org/wiki/Fingerprint%20scanner
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Fingerprint scanners are security systems of biometrics. They are used in police stations, security industries, smartphones, and other mobile devices.
Fingerprints
People have patterns of friction ridges on their fingers, these patterns are called the fingerprints. Fingerprints are uniquely detailed, durable over an individual's lifetime, and difficult to alter. Due to the unique combinations, fingerprints have become an ideal means of identification.
Types of fingerprint scanners
There are four types of fingerprint scanners: optical scanners, capacitance scanners, ultrasonic scanners, and thermal scanners. The basic function of every type of scanner is to obtain an image of a person's fingerprint and find a match for it in its database. The measure of the fingerprint image quality is in dots per inch (DPI).
Optical scanners take a visual image of the fingerprint using a digital camera.
Capacitive or CMOS scanners use capacitors and thus electric current to form an image of the fingerprint. This type of scanner tends to excel in terms of precision.
Ultrasonic fingerprint scanners use high frequency sound waves to penetrate the epidermal (outer) layer of the skin.
Thermal scanners sense the temperature differences on the contact surface, in between fingerprint ridges and valleys.
All fingerprint scanners are susceptible to be fooled by a technique that involves photographing fingerprints, processing the photographs using special software, and printing fingerprint replicas using a 3D printer.
Construction forms
There are two construction forms: the stagnant and the moving fingerprint scanner.
Stagnant: The finger must be dragged over the small scanning area. This is cheaper and less reliable than the moving form. Imaging can be less than ideal when the finger is not dragged over the scanning area at constant speed.
Moving: The finger lies on the scanning area while the scanner runs underneath. Because the scanner moves at constant speed over the fingerpri
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https://en.wikipedia.org/wiki/Negative-bias%20temperature%20instability
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Negative-bias temperature instability (NBTI) is a key reliability issue in MOSFETs, a type of transistor aging. NBTI manifests as an increase in the threshold voltage and consequent decrease in drain current and transconductance of a MOSFET. The degradation is often approximated by a power-law dependence on time. It is of immediate concern in p-channel MOS devices (pMOS), since they almost always operate with negative gate-to-source voltage; however, the very same mechanism also affects nMOS transistors when biased in the accumulation regime, i.e. with a negative bias applied to the gate.
More specifically, over time positive charges become trapped at the oxide-semiconductor boundary underneath the gate of a MOSFET. These positive charges partially cancel the negative gate voltage without contributing to conduction through the channel as electron holes in the semiconductor are supposed to. When the gate voltage is removed, the trapped charges dissipate over a time scale of milliseconds to hours. The problem has become more acute as transistors have shrunk, as there is less averaging of the effect over a large gate area. Thus, different transistors experience different amounts of NBTI, defeating standard circuit design techniques for tolerating manufacturing variability which depend on the close matching of adjacent transistors.
NBTI has become significant for portable electronics because it interacts badly with two common power-saving techniques: reduced operating voltages and clock gating. With lower operating voltages, the NBTI-induced threshold voltage change is a larger fraction of the logic voltage and disrupts operations. When a clock is gated off, transistors stop switching and NBTI effects accumulate much more rapidly. When the clock is re-enabled, the transistor thresholds have changed and the circuit may not operate. Some low-power designs switch to a low-frequency clock rather than stopping completely in order to mitigate NBTI effects.
Physics
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https://en.wikipedia.org/wiki/Biological%20systems%20engineering
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Biological systems engineering or Biosystems engineering is a broad-based engineering discipline with particular emphasis on non-medical biology. It can be thought of as a subset of the broader notion of biological engineering or bio-technology though not in the respects that pertain to biomedical engineering as biosystems engineering tends to focus less on medical applications than on agriculture, ecosystems, and food science. The discipline focuses broadly on environmentally sound and sustainable engineering solutions to meet societies' ecologically related needs. Biosystems engineering integrates the expertise of fundamental engineering fields with expertise from non-engineering disciplines.
Background and organization
Many college and university biological engineering departments have a history of being grounded in agricultural engineering and have only in the past two decades or so changed their names to reflect the movement towards more diverse biological based engineering programs. This major is sometimes called agricultural and biological engineering, biological and environmental engineering, etc., in different universities, generally reflecting interests of local employment opportunities.
Since biological engineering covers a wide spectrum, many departments now offer specialization options. Depending on the department and the specialization options offered within each program, curricula may overlap with other related fields. There are a number of different titles for BSE-related departments at various universities. The professional societies commonly associated with many Biological Engineering programs include the American Society of Agricultural and Biological Engineers (ASABE) and the Institute of Biological Engineering (IBE), which generally encompasses BSE. Some program also participate in the Biomedical Engineering Society (BMES) and the American Institute of Chemical Engineers (AIChE).
A biological systems engineer has a background in what bot
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https://en.wikipedia.org/wiki/Host%20%28biology%29
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In biology and medicine, a host is a larger organism that harbours a smaller organism; whether a parasitic, a mutualistic, or a commensalist guest (symbiont). The guest is typically provided with nourishment and shelter. Examples include animals playing host to parasitic worms (e.g. nematodes), cells harbouring pathogenic (disease-causing) viruses, or a bean plant hosting mutualistic (helpful) nitrogen-fixing bacteria. More specifically in botany, a host plant supplies food resources to micropredators, which have an evolutionarily stable relationship with their hosts similar to ectoparasitism. The host range is the collection of hosts that an organism can use as a partner.
Symbiosis
Symbiosis spans a wide variety of possible relationships between organisms, differing in their permanence and their effects on the two parties. If one of the partners in an association is much larger than the other, it is generally known as the host. In parasitism, the parasite benefits at the host's expense. In commensalism, the two live together without harming each other, while in mutualism, both parties benefit.
Most parasites are only parasitic for part of their life cycle. By comparing parasites with their closest free-living relatives, parasitism has been shown to have evolved on at least 233 separate occasions. Some organisms live in close association with a host and only become parasitic when environmental conditions deteriorate.
A parasite may have a long-term relationship with its host, as is the case with all endoparasites. The guest seeks out the host and obtains food or another service from it, but does not usually kill it. In contrast, a parasitoid spends a large part of its life within or on a single host, ultimately causing the host's death, with some of the strategies involved verging on predation. Generally, the host is kept alive until the parasitoid is fully grown and ready to pass on to its next life stage. A guest's relationship with its host may be intermitten
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https://en.wikipedia.org/wiki/Li-Fi%20Consortium
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The Li-Fi Consortium is an international organization focusing on optical wireless technologies.
It was founded by four technology-based organizations in October 2011. The goal of the Li-Fi Consortium is to foster the development and distribution of (Li-Fi) optical wireless technologies such as communication, navigation, natural user interfaces and others.
Status
the Li-Fi Consortium outlined a roadmap for different types of optical communication such as gigabit-class communication as well as a full featured Li-Fi cloud which includes many more besides wireless infrared and visible light communication.
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https://en.wikipedia.org/wiki/Isochore%20%28genetics%29
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In genetics, an isochore is a large region of genomic DNA (greater than 300 kilobases) with a high degree of uniformity in GC content; that is, guanine (G) and cytosine (C) bases. The distribution of bases within a genome is non-random: different regions of the genome have different amounts of G-C base pairs, such that regions can be classified and identified by the proportion of G-C base pairs they contain.
Bernardi and colleagues first noticed the compositional non-uniformity of vertebrate genomes using thermal melting and density gradient centrifugation.
The DNA fragments extracted by the gradient centrifugation were later termed "isochores", which was subsequently defined as "very long (much greater than 200 KB) DNA segments" that "are fairly homogeneous in base composition and belong to a small number of major classes distinguished by differences in guanine-cytosine (GC) content". Subsequently, the isochores "grew" and were claimed to be ">300 kb in size."
The theory proposed that the isochore composition of genomes varies markedly between "warm-blooded" (homeotherm) vertebrates and "cold-blooded" (poikilotherm) vertebrates and later became known as the isochore theory.
The thermodynamic stability hypothesis
The isochore theory purported that the genome of "warm-blooded" vertebrates (mammals and birds) are mosaics of long isochoric regions of alternating GC-poor and GC-rich composition, as opposed to the genome of "cold-blooded" vertebrates (fishes and amphibians) that were supposed to lack GC-rich isochores.
These findings were explained by the thermodynamic stability hypothesis, attributing genomic structure to body temperature. GC-rich isochores were purported to be a form of adaptation to environmental pressures, as an increase in genomic GC-content could protect DNA, RNA, and proteins from degradation by heat.
Despite its attractive simplicity, the thermodynamic stability hypothesis has been repeatedly shown to be in error
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Many authors show
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https://en.wikipedia.org/wiki/Pipeline%20forwarding
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Pipeline forwarding (PF) applies to packet forwarding in computer networks the basic concept of pipelining, which has been widely and successfully used in computing — specifically, in the architecture of all major central processing units (CPUs) — and manufacturing — specifically in assembly lines of various industries starting from automotive to many others. Pipelining is known to be optimal independent of the specific instantiation. In particular, PF is optimal from various points of view:
High efficiency in utilization of network resources, which enables accommodating a larger amount of traffic on the network, thus lowering operation cost and being the foundation for accommodating the exponential growth of modern networks.
Low implementation complexity, which enables the realization of larger and more powerful networking systems at low cost, thus offering further support to network growth.
High scalability, which is an immediate consequence of the above two features.
Deterministic and predictable operation with minimum delay and no packet loss even under full load condition, which is key in supporting the demanding requirements of the new and valuable services that are being deployed, or envisioned to be deployed, on modern networks, such as telephony, videoconferencing, virtual presence, video on demand, distributed gaming.
Various aspects of the technology are covered by several patents issued by both the United States Patent and Trademark Office and the European Patent Office.
Operating principles
As in other pipelining implementations, a common time reference (CTR) is needed to perform pipeline forwarding. In the context of global networks the CTR can be effectively realized by using UTC (coordinated universal time) that is globally available via GPS (global positioning system) or Galileo in the near future. For example, the UTC second is divided into fixed duration time frames, which are grouped into time cycles so that in each UTC second there is a
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https://en.wikipedia.org/wiki/Wireless%20engineering
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Wireless Engineering is the branch of engineering which addresses the design, application, and research of wireless communication systems and technologies.
Overview
Wireless engineering is an engineering subject dealing with engineering problems using wireless technology such as radio communications and radar, but it is more general than the conventional radio engineering. It may include using other techniques such as acoustic, infrared, and optical technologies.
History
Wireless technologies have skyrocketed since their late 19th Century advancements. With the invention of the FM radio in 1935, wireless communications have become a concentrated focus of both private and government sectors.
In Education
Auburn University's Samuel Ginn College of Engineering was the first in the United States to offer a formalized undergraduate degree in such a field. The program was initiated by Samuel Ginn, an Auburn Alumni, in 2001.
Auburn University's college of engineering divides their wireless engineering program into two areas of applicable study: electrical engineering (pertaining to circuit design, digital signal processing, antenna design, etc.), and software-oriented wireless engineering (communications networks, mobile platform applications, systems software, etc.)
Macquarie University in Sydney, was the first University to offer Wireless Engineering in Australia. The university works closely with nearby industries in research and teaching development in wireless engineering.
Universiti Teknikal Malaysia Melaka in Malacca, was the first University to offer Wireless Communication Engineering in Malaysia.
Applications
Wireless engineering contains a wide spectrum of application, most notably cellular networks. The recent popularity of cellular networks has created a vast career demand with a large repository. The popularity has also sparked many wireless innovations, such as increased network capacity, 3G, cryptology and network security technologies.
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https://en.wikipedia.org/wiki/FI6%20%28antibody%29
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FI6 is an antibody that targets a protein found on the surface of all influenza A viruses called hemagglutinin. FI6 is the only known antibody found to bind all 16 subtypes of the influenza A virus hemagglutinin and is hoped to be useful for a universal influenza virus therapy.
The antibody binds to the F domain HA trimer, and prevents the virus from attaching to the host cell. The antibody has been refined in order to remove any excess, unstable mutations that could negatively affect its neutralising ability, and this new version of the antibody has been termed "FI6v3"
Research
Researchers from Britain and Switzerland have previously found antibodies that work in Group 1 influenza A viruses or against most Group 2 viruses (CR8020), but not against both.
This team developed a method using single-cell screening to test very large numbers of human plasma cells, to increase their odds of finding an antibody even if it was extremely rare. When they identified FI6, they injected it into mice and ferrets and found that it protected the animals against infection by either a Group 1 or Group 2 influenza A virus.
Scientists screened 104,000 peripheral-blood plasma cells from eight recently infected or vaccinated donors for antibodies that recognize each of three diverse influenza strains: H1N1 (swine-origin) and H5N1 and H7N7 (highly pathogenic avian influenzas.) From one donor, they isolated four plasma cells that produced an identical antibody, which they called FI6. This antibody binds all 16 HA subtypes, neutralizes infection, and protects mice and ferrets from lethal infection. The most broadly reactive antibodies that had previously been discovered recognized either one group of HA subtypes or the other, highlighting how remarkable FI6 is in its ability to target the gamut of influenza subtypes.
Clinical implication
Researchers determined the crystal structure of the FI6 antibody when it was bound to H1 and H3 HA proteins. Sitting atop the HA spike is a globular h
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https://en.wikipedia.org/wiki/Mikroelektronika
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MikroElektronika (stylized as MikroE) is a Serbian manufacturer and retailer of hardware and software tools for developing embedded systems. The company headquarters is in Belgrade, Serbia.
Its best known software products are mikroC, mikroBasic and mikroPascal compilers for programming microcontrollers. Its flagship hardware product line is Click boards, a range of more than 550 add-on boards for interfacing microcontrollers with peripheral sensors or transceivers. These boards conform to mikroBUS – a standard conceived by MikroElektronika and later endorsed by NXP Semiconductors and Microchip Technology, among others. MikroElektronika is also known for Hexiwear, an Internet of things development kit developed in partnership with NXP Semiconductors.
History
Serbian entrepreneur – and current company owner and CEO – Nebojša Matić started publishing an electronics magazine called "MikroElektronika" in 1997. In 2001, the magazine was shut down and MikroElektronika repositioned itself as a company focused on producing development boards for microcontrollers and publishing books for developing embedded systems.
The company started offering compilers in 2004, with the release of mikroPascal for PIC and mikroBasic for PIC – compilers for programming 8-bit microcontrollers from Microchip Technology. Between 2004 and 2015 the company released C, Basic and Pascal compilers for seven microcontroller architectures: PIC, PIC32, dsPIC/PIC24, FT90x, AVR, 8051, and ARM® (supporting STMicroelectronics, Texas Instruments and Microchip-based ARM® Cortex microcontrollers).
In conjunction with compilers, MikroElektronika kept its focus on producing development boards while gradually ceasing its publishing activities. Its current generation of the "Easy" boards brand was released in 2012. One of the flagship models, EasyPIC Fusion v7 was nominated for best tool at the Embedded World 2013 exhibition in Nurembeg, an important embedded systems industry gathering. Other product lines we
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https://en.wikipedia.org/wiki/Discrete%20system
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In theoretical computer science, a discrete system is a system with a countable number of states. Discrete systems may be contrasted with continuous systems, which may also be called analog systems. A final discrete system is often modeled with a directed graph and is analyzed for correctness and complexity according to computational theory. Because discrete systems have a countable number of states, they may be described in precise mathematical models.
A computer is a finite-state machine that may be viewed as a discrete system. Because computers are often used to model not only other discrete systems but continuous systems as well, methods have been developed to represent real-world continuous systems as discrete systems. One such method involves sampling a continuous signal at discrete time intervals.
See also
Digital control
Finite-state machine
Frequency spectrum
Mathematical model
Sample and hold
Sample rate
Sample time
Z-transform
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https://en.wikipedia.org/wiki/Process%20corners
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In semiconductor manufacturing, a process corner is an example of a design-of-experiments (DoE) technique that refers to a variation of fabrication parameters used in applying an integrated circuit design to a semiconductor wafer. Process corners represent the extremes of these parameter variations within which a circuit that has been etched onto the wafer must function correctly. A circuit running on devices fabricated at these process corners may run slower or faster than specified and at lower or higher temperatures and voltages, but if the circuit does not function at all at any of these process extremes the design is considered to have inadequate design margin.
To verify the robustness of an integrated circuit design, semiconductor manufacturers will fabricate corner lots, which are groups of wafers that have had process parameters adjusted according to these extremes, and will then test the devices made from these special wafers at varying increments of environmental conditions, such as voltage, clock frequency, and temperature, applied in combination (two or sometimes all three together) in a process called characterization. The results of these tests are plotted using a graphing technique known as a shmoo plot that indicates clearly the boundary limit beyond which a device begins to fail for a given combination of these environmental conditions.
Corner-lot analysis is most effective in digital electronics because of the direct effect of process variations on the speed of transistor switching during transitions from one logic state to another, which is not relevant for analog circuits, such as amplifiers.
Significance to digital electronics
In Very-Large-Scale Integration (VLSI) integrated circuit microprocessor design and semiconductor fabrication, a process corner represents a three or six sigma variation from nominal doping concentrations (and other parameters) in transistors on a silicon wafer. This variation can cause significant changes in the dut
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https://en.wikipedia.org/wiki/Circuit%20extraction
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The electric circuit extraction or simply circuit extraction, also netlist extraction, is the translation of an integrated circuit layout back into the electrical circuit (netlist) it is intended to represent. This extracted circuit is needed for various purposes including circuit simulation, static timing analysis, signal integrity, power analysis and optimization, and logic to layout comparison. Each of these functions require a slightly different representation of the circuit, resulting in the need for multiple layout extractions. In addition, there may be a postprocessing step of converting the device-level circuit into a purely digital circuit, but this is not considered part of the extraction process.
The detailed functionality of an extraction process will depend on its system environment. The simplest form of extracted circuit may be in the form of a netlist, which is formatted for a particular simulator or analysis program. A more complex extraction may involve writing the extracted circuit back into the original database containing the physical layout and the logic diagram. In this case, by associating the extracted circuit with the layout and the logic network, the user can cross-reference any point in the circuit to its equivalent points in the logic and layout (cross-probing). For simulation or analysis, various formats of netlist can then be generated using programs that read the database and generate the appropriate text information.
In extraction, it is often helpful to make an (informal) distinction between designed devices, which are devices that are deliberately created by the designer, and parasitic devices, which were not explicitly intended by the designer but are inherent in the layout of the circuit.
Primarily there are three different parts to the extraction process. These are designed device extraction, interconnect extraction, and parasitic device extraction. These parts are inter-related since various device extractions can change th
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https://en.wikipedia.org/wiki/Sessility%20%28motility%29
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Sessility is the biological property of an organism describing its lack of a means of self-locomotion. Sessile organisms for which natural motility is absent are normally immobile. This is distinct from the botanical concept of sessility, which refers to an organism or biological structure attached directly by its base without a stalk.
Sessile organisms can move via external forces (such as water currents), but are usually permanently attached to something. Organisms such as corals lay down their own substrate from which they grow. Other sessile organisms grow from a solid object, such as a rock, a dead tree trunk, or a man-made object such as a buoy or ship's hull.
Mobility
Sessile animals typically have a motile phase in their development. Sponges have a motile larval stage and become sessile at maturity. Conversely, many jellyfish develop as sessile polyps early in their life cycle. In the case of the cochineal, it is in the nymph stage (also called the crawler stage) that the cochineal disperses. The juveniles move to a feeding spot and produce long wax filaments. Later they move to the edge of the cactus pad where the wind catches the wax filaments and carries the tiny larval cochineals to a new host.
Reproduction
Many sessile animals, including sponges, corals and hydra, are capable of asexual reproduction in situ by the process of budding. Sessile organisms such as barnacles and tunicates need some mechanism to move their young into new territory. This is why the most widely accepted theory explaining the evolution of a larval stage is the need for long-distance dispersal ability. Biologist Wayne Sousa's 1979 study in intertidal disturbance added support for the theory of nonequilibrium community structure, "suggesting that open space is necessary for the maintenance of diversity in most communities of sessile organisms".
Clumping
Clumping is a behavior in sessile organisms in which individuals of a particular species group closely to one another for ben
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https://en.wikipedia.org/wiki/List%20of%20multivariable%20calculus%20topics
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This is a list of multivariable calculus topics. See also multivariable calculus, vector calculus, list of real analysis topics, list of calculus topics.
Closed and exact differential forms
Contact (mathematics)
Contour integral
Contour line
Critical point (mathematics)
Curl (mathematics)
Current (mathematics)
Curvature
Curvilinear coordinates
Del
Differential form
Differential operator
Directional derivative
Divergence
Divergence theorem
Double integral
Equipotential surface
Euler's theorem on homogeneous functions
Exterior derivative
Flux
Frenet–Serret formulas
Gauss's law
Gradient
Green's theorem
Green's identities
Harmonic function
Helmholtz decomposition
Hessian matrix
Hodge star operator
Inverse function theorem
Irrotational vector field
Isoperimetry
Jacobian matrix
Lagrange multiplier
Lamellar vector field
Laplacian
Laplacian vector field
Level set
Line integral
Matrix calculus
Mixed derivatives
Monkey saddle
Multiple integral
Newtonian potential
Parametric equation
Parametric surface
Partial derivative
Partial differential equation
Potential
Real coordinate space
Saddle point
Scalar field
Solenoidal vector field
Stokes' theorem
Submersion
Surface integral
Symmetry of second derivatives
Taylor's theorem
Total derivative
Vector field
Vector operator
Vector potential
list
Mathematics-related lists
Outlines of mathematics and logic
Outlines
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https://en.wikipedia.org/wiki/Lee%20algorithm
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The Lee algorithm is one possible solution for maze routing problems based on breadth-first search.
It always gives an optimal solution, if one exists, but is slow and requires considerable memory.
Algorithm
1) Initialization
- Select start point, mark with 0
- i := 0
2) Wave expansion
- REPEAT
- Mark all unlabeled neighbors of points marked with i with i+1
- i := i+1
UNTIL ((target reached) or (no points can be marked))
3) Backtrace
- go to the target point
REPEAT
- go to next node that has a lower mark than the current node
- add this node to path
UNTIL (start point reached)
4) Clearance
- Block the path for future wirings
- Delete all marks
Of course the wave expansion marks only points in the routable area of the chip, not in the blocks or already wired parts, and to minimize segmentation you should keep in one direction as long as possible.
External links
http://www.eecs.northwestern.edu/~haizhou/357/lec6.pdf
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https://en.wikipedia.org/wiki/On-Line%20Encyclopedia%20of%20Integer%20Sequences
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The On-Line Encyclopedia of Integer Sequences (OEIS) is an online database of integer sequences. It was created and maintained by Neil Sloane while researching at AT&T Labs. He transferred the intellectual property and hosting of the OEIS to the OEIS Foundation in 2009. Sloane is the chairman of the OEIS Foundation.
OEIS records information on integer sequences of interest to both professional and amateur mathematicians, and is widely cited. , it contains over 360,000 sequences, making it the largest database of its kind.
Each entry contains the leading terms of the sequence, keywords, mathematical motivations, literature links, and more, including the option to generate a graph or play a musical representation of the sequence. The database is searchable by keyword, by subsequence, or by any of 16 fields.
History
Neil Sloane started collecting integer sequences as a graduate student in 1964 to support his work in combinatorics. The database was at first stored on punched cards. He published selections from the database in book form twice:
A Handbook of Integer Sequences (1973, ), containing 2,372 sequences in lexicographic order and assigned numbers from 1 to 2372.
The Encyclopedia of Integer Sequences with Simon Plouffe (1995, ), containing 5,488 sequences and assigned M-numbers from M0000 to M5487. The Encyclopedia includes the references to the corresponding sequences (which may differ in their few initial terms) in A Handbook of Integer Sequences as N-numbers from N0001 to N2372 (instead of 1 to 2372.) The Encyclopedia includes the A-numbers that are used in the OEIS, whereas the Handbook did not.
These books were well received and, especially after the second publication, mathematicians supplied Sloane with a steady flow of new sequences. The collection became unmanageable in book form, and when the database had reached 16,000 entries Sloane decided to go online—first as an email service (August 1994), and soon after as a website (1996). As a spin-off fro
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https://en.wikipedia.org/wiki/EDA%20database
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An EDA database is a database specialized for the purpose of electronic design automation. These application specific databases are required because general purpose databases have historically not provided enough performance for EDA applications.
In examining EDA design databases, it is useful to look at EDA tool architecture, to determine which parts are to be considered part of the design database, and which parts are the application levels. In addition to the database itself, many other components are needed for a useful EDA application. Associated with a database are one or more language systems (which, although not directly part of the database, are used by EDA applications such as parameterized cells and user scripts). On top of the database are built the algorithmic engines within the tool (such as timing, placement, routing, or simulation engines ), and the highest level represents the applications built from these component blocks, such as floorplanning. The scope of the design database includes the actual design, library information, technology information, and the set of translators to and from external formats such as Verilog and GDSII.
Mature design databases
Many instances of mature design databases exist in the EDA industry, both as a basis for commercial EDA tools as well as proprietary EDA tools developed by the CAD groups of major electronics companies.
IBM, Hewlett-Packard, SDA Systems and ECAD (now Cadence Design Systems), High Level Design Systems, and many other companies developed EDA specific databases over the last 20 years, and these continue to be the basis of IC-design systems today. Many of these systems took ideas from university research and successfully productized them. Most of the mature design databases have evolved to the point where they can represent netlist data, layout data, and the ties between the two. They are hierarchical to allow for reuse and smaller designs. They can support styles of layout from digital through pur
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https://en.wikipedia.org/wiki/Aliasing
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In signal processing and related disciplines, aliasing is the overlapping of frequency components resulting from a sample rate below the Nyquist rate. This overlap results in distortion or artifacts when the signal is reconstructed from samples which causes the reconstructed signal to differ from the original continuous signal.
Aliasing that occurs in signals sampled in time, for instance in digital audio or the stroboscopic effect, is referred to as temporal aliasing. Aliasing in spatially sampled signals (e.g., moiré patterns in digital images) is referred to as spatial aliasing.
Aliasing is generally avoided by applying low-pass filters or anti-aliasing filters (AAF) to the input signal before sampling and when converting a signal from a higher to a lower sampling rate. Suitable reconstruction filtering should then be used when restoring the sampled signal to the continuous domain or converting a signal from a lower to a higher sampling rate. For spatial anti-aliasing, the types of anti-aliasing include fast approximate anti-aliasing (FXAA), multisample anti-aliasing, and supersampling.
Description
When a digital image is viewed, a reconstruction is performed by a display or printer device, and by the eyes and the brain. If the image data is processed in some way during sampling or reconstruction, the reconstructed image will differ from the original image, and an alias is seen.
An example of spatial aliasing is the moiré pattern observed in a poorly pixelized image of a brick wall. Spatial anti-aliasing techniques avoid such poor pixelizations. Aliasing can be caused either by the sampling stage or the reconstruction stage; these may be distinguished by calling sampling aliasing prealiasing and reconstruction aliasing postaliasing.
Temporal aliasing is a major concern in the sampling of video and audio signals. Music, for instance, may contain high-frequency components that are inaudible to humans. If a piece of music is sampled at 32,000 samples per sec
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https://en.wikipedia.org/wiki/European%20Society%20for%20Mathematics%20and%20the%20Arts
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European Society for Mathematics and the Arts (ESMA) is a European society to promoting mathematics and the arts. The first Conference of ESMA, took place in July 2010 at the Institute Henri Poincaré in Paris.
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