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https://en.wikipedia.org/wiki/List%20of%20solids%20derived%20from%20the%20sphere | This page lists solids derived from a sphere.
Solids from cutting a sphere with one or more planes
Dome
Spherical cap
Spherical sector
Spherical segment
Spherical shell
Spherical wedge
Solids from deforming a sphere
Ellipsoid
Spheroid
Solid bounded by Morin surface
Any Genus 0 surface
Solids from intersecting a sphere with other solids or curved planes
Reuleaux tetrahedron
Spherical lens
Notes
Geometric shapes
Mathematics-related lists |
https://en.wikipedia.org/wiki/Israeli%20Transverse%20Mercator | Israeli Transverse Mercator (ITM), also known as the New Israel Grid (NIG; Reshet Yisra'el Ha-Ḥadasha) is the new geographic coordinate system for Israel. The name is derived from the transverse Mercator projection it uses and the fact that it is optimized for Israel. ITM has replaced the old coordinate system Israeli Cassini Soldner (ICS), also known as the Old Israel Grid (OIG). It became
the official grid for Israel in 1998.
The need for a new grid
ITM replaced the Old Israel Grid (OIG) (), also known as the Israel Cassini Soldner (ICS), which was based on the Cassini-Soldner projection. ICS in turn was a simple modification of the Palestine grid used during the British mandate. The central meridian in the new projection, as in the old one, crosses through Jerusalem. The new grid has two main advantages. One is that the Transverse Mercator projection is better for navigation than Cassini-Soldner. The other is that ICS was based on a 19th-century reference ellipsoid (approximation of the shape of the Earth) and this was replaced by a more accurate approximation.
Additional information on the creation of the new grid is available in Hebrew.
Examples
An ITM coordinate is generally given as a pair of six digit numbers (excluding any digits behind a decimal point which may be used in very precise surveying). The first number is always the Easting and the second is the Northing. The easting and northing are in metres from the false origin.
The ITM coordinate for the Western Wall at Jerusalem is 222286 632556, which means
E 222286 m
N 631556 m
The first figure is the easting and means that the location is 222,286 meters east from the false origin (along the X axis). The second figure is the northing and puts the location 631,556 meters north of the false origin (along the Y axis). Also notice how the easting in this example is indicated with an “E” and likewise an “N” for the northing.
The table below shows the same coordinate in 3 different grids:
Grid Para |
https://en.wikipedia.org/wiki/2000%20Today | 2000 Today was an internationally broadcast television special to commemorate the beginning of the Year 2000. This program included New Year's Eve celebrations, musical performances, and other features from participating nations.
Most international broadcasts such as the Olympic Games coverage originate from a limited area for worldwide distribution. 2000 Today was rare in that its live and taped programming originated from member countries and represented all continents including Europe, Asia, Africa, South America and North America & Oceania.
Development
2000 Today was conceived as part of the Millennium celebrations, given the numerical significance of the change from 1999 to 2000. 2000 Today was commissioned by the BBC as one of the five main millennium projects that were broadcast across TV, radio and online services throughout 1999 and 2000.
Most nations that observe the Islamic calendar were not involved in 2000 Today. However, a few predominantly Muslim nations were represented among the programme's worldwide broadcasters such as Egypt (ERTU) and Indonesia (RCTI). Africa was minimally represented in 2000 Today. The only participating nations from that continent were Egypt and South Africa. Portugal-based RTP África distributed the programme to some African nations.
Antarctica was mentioned on the programme schedule, although it was unclear if 2000 Today coverage was recorded or live.
Production
The programme was produced and televised by an international consortium of 60 broadcasters, headed by the BBC in the United Kingdom and WGBH (Now known as GBH) in Boston, United States. The editorial board also included representatives from ABC (Australia), CBC (Canada), CCTV (China), ETC (Egypt), RTL (Germany), SABC (South Africa), TF1 (France), TV Asahi (Japan), TV Globo (Brazil) and ABC (USA). The BBC provided the production hub for receiving and distributing the 78 international satellite feeds required for this broadcast. The idents for the programme were de |
https://en.wikipedia.org/wiki/Phorophyte | In botany phorophytes are plants, on which epiphytes grow. The term is composed of phoro, meaning bearer or carrier and phyte, meaning plant.
Commensalistic interactions
The epiphytes benefit from the habitats provided, but the phorophyte is unaffected. In other words, the obligate epiphytes utilize phorophytes as habitats, without parasitizing them.
Phorophyte specificity
Different phorophytes provide different conditions to the plants, which grown on their surface. The bark pH, degree of bark shedding, the presence of milk sap and the density and size of bark lenticels influence the occurrence of epiphytes. Bark ornamentations affect the establishment os seeds and the chemical composition of the bark may be inhibiting germination. Some epiphytic orchids tend to grow on phorophytes with rough bark. Conservation efforts of orchids need to account for the conservation of phorophytes as well. |
https://en.wikipedia.org/wiki/Erd%C5%91s%E2%80%93Stone%20theorem | In extremal graph theory, the Erdős–Stone theorem is an asymptotic result generalising Turán's theorem to bound the number of edges in an H-free graph for a non-complete graph H. It is named after Paul Erdős and Arthur Stone, who proved it in 1946, and it has been described as the “fundamental theorem of extremal graph theory”.
Statement for Turán graphs
The extremal number ex(n; H) is defined to be the maximum number of edges in a graph with n vertices not containing a subgraph isomorphic to H; see the Forbidden subgraph problem for more examples of problems involving the extremal number. Turán's theorem says that ex(n; Kr) = tr − 1(n), the number of edges of the Turán graph T(n, r − 1), and that the Turán graph is the unique such extremal graph. The Erdős–Stone theorem extends this result to H = Kr(t), the complete r-partite graph with t vertices in each class, which is the graph obtained by taking Kr and replacing each vertex with t independent vertices:
Statement for arbitrary non-bipartite graphs
If H is an arbitrary graph whose chromatic number is r > 2, then H is contained in Kr(t) whenever t is at least as large as the largest color class in an r-coloring of H, but it is not contained in the Turán graph T(n,r − 1), as this graph and therefore each of its subgraphs can be colored with r − 1 colors.
It follows that the extremal number for H is at least as large as the number of edges in T(n,r − 1), and at most equal to the extremal function for Kr(t); that is,
For bipartite graphs H, however, the theorem does not give a tight bound on the extremal function. It is known that, when H is bipartite, ex(n; H) = o(n2), and for general bipartite graphs little more is known. See Zarankiewicz problem for more on the extremal functions of bipartite graphs.
Turán density
Another way of describing the Erdős–Stone theorem is using the Turán density of a graph , which is defined by . This determines the extremal number up to an additive error term. It can also be |
https://en.wikipedia.org/wiki/Orthogonal%20diagonalization | In linear algebra, an orthogonal diagonalization of a symmetric matrix is a diagonalization by means of an orthogonal change of coordinates.
The following is an orthogonal diagonalization algorithm that diagonalizes a quadratic form q(x) on Rn by means of an orthogonal change of coordinates X = PY.
Step 1: find the symmetric matrix A which represents q and find its characteristic polynomial
Step 2: find the eigenvalues of A which are the roots of .
Step 3: for each eigenvalue of A from step 2, find an orthogonal basis of its eigenspace.
Step 4: normalize all eigenvectors in step 3 which then form an orthonormal basis of Rn.
Step 5: let P be the matrix whose columns are the normalized eigenvectors in step 4.
Then X=PY is the required orthogonal change of coordinates, and the diagonal entries of will be the eigenvalues which correspond to the columns of P. |
https://en.wikipedia.org/wiki/Abrikosov%20vortex | In superconductivity, a fluxon (also called an Abrikosov vortex or quantum vortex) is a vortex of supercurrent in a type-II superconductor, used by Alexei Abrikosov to explain magnetic behavior of type-II superconductors. Abrikosov vortices occur generically in the Ginzburg–Landau theory of superconductivity.
Overview
The solution is a combination of fluxon solution by Fritz London, combined with a concept of core of quantum vortex by Lars Onsager.
In the quantum vortex, supercurrent circulates around the normal (i.e. non-superconducting) core of the vortex. The core has a size — the superconducting coherence length (parameter of a Ginzburg–Landau theory). The supercurrents decay on the distance about (London penetration depth) from the core. Note that in type-II superconductors . The circulating supercurrents induce magnetic fields with the total flux equal to a single flux quantum . Therefore, an Abrikosov vortex is often called a fluxon.
The magnetic field distribution of a single vortex far from its core can be described by the same equation as in the London's fluxoid
where is a zeroth-order Bessel function. Note that, according to the above formula, at the magnetic field , i.e. logarithmically diverges. In reality, for the field is simply given by
where κ = λ/ξ is known as the Ginzburg–Landau parameter, which must be in type-II superconductors.
Abrikosov vortices can be trapped in a type-II superconductor by chance, on defects, etc. Even if initially type-II superconductor contains no vortices, and one applies a magnetic field larger than the lower critical field (but smaller than the upper critical field ), the field penetrates into superconductor in terms of Abrikosov vortices. Each vortex obeys London's magnetic flux quantization and carries one quantum of magnetic flux . Abrikosov vortices form a lattice, usually triangular, with the average vortex density (flux density) approximately equal to the externally applied magnetic field. As wit |
https://en.wikipedia.org/wiki/Dietary%20biology%20of%20the%20Eurasian%20eagle-owl | The Eurasian eagle-owl (Bubo bubo) may well be the most powerful extant species of owl, able to attack and kill large prey far beyond the capacities of most other living owls. However, the species is even more marked for its ability to live on more diverse prey than possibly any other comparably sized raptorial bird, which, given its considerable size, is almost fully restricted to eagles. This species can adapt to surprisingly small prey where it is the only kind available and to large prey where it is abundant. Eurasian eagle-owls feed most commonly on small mammals weighing or more, although nearly 45% of the prey species recorded have an average adult body mass of less than . Usually 55-80% of the food of eagle-owls is mammalian.
Hunting and digestion
Hunting mainly consist of the owl watching from a perch for prey activity and then swooping down swiftly once prey is spotted. The prey is often killed quickly by the eagle owl's powerful grip and talons though is sometimes bitten on the head to be killed as well. Then the prey item is swallowed whole or torn into pieces with the bill. The same basic hunting and killing methods are used by all owls in the genus Bubo, except that the snowy owls (Bubo scandiacus) and fish owls regularly watch for prey from a ground position (on a bank in the case of fish owls). Most hunting occurs in wood-cloaked openings, often those carved out by wetlands or watersheds. While they can and do hunt within woodlands, they are not well suited to hunting in areas with dense understories, thick foliage or tree thickets, as they seem to hunt firstly by vision and only secondarily by sounds, unlike some other owls. Eurasian eagle-owls are too heavy with relatively modest wing areas to hunt extensively on the wing although this species’ relatively short, broad wings allow it low-speed maneuverability in the moments of take off after spotting a prey item. Because of the limits of its flying abilities, the Eurasian eagle-owl requires ampl |
https://en.wikipedia.org/wiki/Lethic%20botnet | The Lethic Botnet (initially discovered around 2008) is a botnet consisting of an estimated 210 000 - 310 000 individual machines which are mainly involved in pharmaceutical and replica spam.
The botnet was most prevalent in Europe, India and Southeast Asia.
Dismantling and revival
Around early January 2010 the botnet was dismantled by Neustar employees, who contacted various Lethic internet service providers in a bid to take control of the botnet's command and control servers. This move temporarily caused the botnets' spam to decrease to a trickle of its original volume.
In February 2010 the owners of the botnet managed to re-establish control over the botnet, through the use of new command and control servers located in the United States. The takedown has decreased the spam volume of the botnet, however. As of February 2010 the botnets' amount of spam was down to a third of its original. As of April 2010 the botnet has an estimated 1.5% share of the spam market, sending about 2 billion spam messages a day.
See also
Botnet
Malware
Internet crime
Internet security
Command and control (malware)
Zombie (computer science) |
https://en.wikipedia.org/wiki/Ceiling%20temperature | Ceiling temperature () is a measure of the tendency of a polymer to revert to its constituent monomers. When a polymer is at its ceiling temperature, the rate of polymerization and depolymerization of the polymer are equal. Generally, the ceiling temperature of a given polymer is correlated to the steric hindrance of the polymer’s monomers. Polymers with high ceiling temperatures are often commercially useful. Polymers with low ceiling temperatures are more readily depolymerizable.
Thermodynamics of polymerization
At constant temperature, the reversibility of polymerization can be determined using the Gibbs free energy equation:
where is the change of entropy during polymerization. The change of enthalpy during polymerization, , is also known as the heat of polymerization, which is defined by
where and denote the activation energies for polymerization and depolymerization, respectively, on the assumption that depolymerization occurs by the reverse mechanism of polymerization.
Entropy is the measure of randomness or chaos. A system has a lower entropy when there are few objects in the system and has a higher entropy when there are many objects in the system. Because the process of depolymerization involves a polymer being broken down into its monomers, depolymerization increases entropy. In the Gibbs free energy equation, the entropy term is negative. Enthalpy drives polymerizations. At low temperatures, the enthalpy term is greater than the term, which allows polymerization to occur. At the ceiling temperature, the enthalpy term and the entropy term are equal, so that the rates of polymerization and depolymerization become equal and the net polymerization rate becomes zero. Above the ceiling temperature, the rate of depolymerization is greater than the rate of polymerization, which inhibits the formation of the given polymer. The ceiling temperature can be defined by
Monomer-polymer equilibrium
This phenomenon was first described by Snow and Frey in 1943 |
https://en.wikipedia.org/wiki/Heteronuclear%20molecule | A heteronuclear molecule is a molecule composed of atoms of more than one chemical element. For example, a molecule of water (H2O) is heteronuclear because it has atoms of two different elements, hydrogen (H) and oxygen (O).
Similarly, a heteronuclear ion is an ion that contains atoms of more than one chemical element. For example, the carbonate ion () is heteronuclear because it has atoms of carbon (C) and oxygen (O). The lightest heteronuclear ion is the helium hydride ion (HeH+). This is in contrast to a homonuclear ion, which contains all the same kind of atom, such as the dihydrogen cation, or atomic ions that only contain one atom such as the hydrogen anion (H−). |
https://en.wikipedia.org/wiki/Ansys | Ansys, Inc. is an American multinational company with its headquarters based in Canonsburg, Pennsylvania. It develops and markets CAE/multiphysics engineering simulation software for product design, testing and operation and offers its products and services to customers worldwide.
Origins
Ansys was founded in 1970 by John Swanson, who sold his interest in the company to venture capitalists in 1993. Ansys went public on NASDAQ in 1996. In the 2000s, the company acquired other engineering design companies, obtaining additional technology for fluid dynamics, electronics design, and physics analysis. Ansys became a component of the NASDAQ-100 index on December 23, 2019.
The idea for Ansys was first conceived by John Swanson while working at the Westinghouse Astronuclear Laboratory in the 1960s. At the time, engineers performed finite element analysis (FEA) by hand. Westinghouse rejected Swanson's idea to automate FEA by developing general purpose engineering software, so Swanson left the company in 1969 to develop the software on his own. He founded Ansys under the name Swanson Analysis Systems Inc. (SASI) the next year, working out of his farmhouse in Pittsburgh.
Swanson developed the initial Ansys software on punch-cards and used a mainframe computer that was rented by the hour. Westinghouse hired Swanson as a consultant, under the condition that any code he developed for Westinghouse could also be included in the Ansys product line. Westinghouse also became the first Ansys user.
History
By 1991, SASI had 153 employees and $29 million in annual revenue, controlling 10 percent of the market for finite element analysis software. According to The Engineering Design Revolution, the company became "well-respected" among engineering circles, but remained small.
In 1992, SASI acquired Compuflo, which marketed and developed fluid dynamics analysis software.
In 1994, Swanson sold his majority interest in the company to venture capitalist firm TA Associates. Peter Smith |
https://en.wikipedia.org/wiki/Thorne%E2%80%93Hawking%E2%80%93Preskill%20bet | The Thorne–Hawking–Preskill bet was a public bet on the outcome of the black hole information paradox made in 1997 by physics theorists Kip Thorne and Stephen Hawking on the one side, and John Preskill on the other, according to the document they signed 6 February 1997, as shown in Hawking's The Universe in a Nutshell.
Overview
Thorne & Hawking argued that since general relativity made it impossible for black holes to radiate, and lose information, the mass-energy and information carried by Hawking radiation must be "new", and must not originate from inside the black hole event horizon. Since this contradicted the idea under quantum mechanics of microcausality, quantum mechanics would need to be rewritten. Preskill argued the opposite, that since quantum mechanics suggests that the information emitted by a black hole relates to information that fell in at an earlier time, the view of black holes given by general relativity must be modified in some way. The winning side of the bet would receive an encyclopedia of their choice, "from which information can be retrieved at will".
In 2004, Hawking announced that he was conceding the bet, and that he now believed that black hole horizons should fluctuate and leak information, in doing so providing Preskill with a copy of Total Baseball, The Ultimate Baseball Encyclopedia. Comparing the useless information obtainable from a black hole to "burning an encyclopedia", Hawking later joked, "I gave John an encyclopedia of baseball, but maybe I should just have given him the ashes." Thorne, however, remained unconvinced of Hawking's proof and declined to contribute to the award. Hawking's argument that he solved the paradox has not yet been wholly accepted by the scientific community, and a consensus has not yet been reached that Hawking provided a strong enough argument that this is in fact what happens.
Hawking had earlier speculated that the singularity at the centre of a black hole could form a bridge to a "baby universe", |
https://en.wikipedia.org/wiki/Roller%20mill | Roller mills are mills that use cylindrical rollers, either in opposing pairs or against flat plates, to crush or grind various materials, such as grain, ore, gravel, plastic, and others. Roller grain mills are an alternative to traditional millstone arrangements in gristmills. Roller mills for rock complement other types of mills, such as ball mills and hammermills, in such industries as the mining and processing of ore and construction aggregate; cement milling; and recycling.
Types
Two-roller mills
Two-roller mills are the simplest variety, in which the material is crushed between two rollers before it continues on to its final destination. The spacing between these two rollers can be adjusted by the operator. Thinner spacing usually leads to that material being crushed into smaller pieces.
Four-roller mills
Four-roller mills have two sets of rollers. When using a four-roller mill to mill grain, the grain first goes through rollers with a rather wide gap, which separates the seed from the husk without much damage to the husk, but leaves large grits. Flour is sieved out of the cracked grain, and then the coarse grist and husks are sent through the second set of rollers, which further crush the grist without damaging the crusts. Similarly, there are three-roller mills, in which one of the rollers is used twice.
Five- and six-roller mills
Six-roller mills have three sets of rollers. When using this type of mill on grain, the first set of rollers crush the whole kernel, and its output is divided three ways: Flour immediately is sent out the mill, grits without a husk proceed to the last roller, and husk, possibly still containing parts of the seed, go to the second set of rollers. From the second roller flour is directly output, as are husks and any possible seed still in them, and the husk-free grits are channeled into the last roller. Five-roller mills are six-roller mills in which one of the rollers performs double duty.
Gristmill conversion
In the 19th |
https://en.wikipedia.org/wiki/Integrodifference%20equation | In mathematics, an integrodifference equation is a recurrence relation on a function space, of the following form:
where is a sequence in the function space and is the domain of those functions. In most applications, for any , is a probability density function on . Note that in the definition above, can be vector valued, in which case each element of has a scalar valued integrodifference equation associated with it. Integrodifference equations are widely used in mathematical biology, especially theoretical ecology, to model the dispersal and growth of populations. In this case, is the population size or density at location at time , describes the local population growth at location and , is the probability of moving from point to point , often referred to as the dispersal kernel. Integrodifference equations are most commonly used to describe univoltine populations, including, but not limited to, many arthropod, and annual plant species. However, multivoltine populations can also be modeled with integrodifference equations, as long as the organism has non-overlapping generations. In this case, is not measured in years, but rather the time increment between broods.
Convolution kernels and invasion speeds
In one spatial dimension, the dispersal kernel often depends only on the distance between the source and the destination, and can be
written as . In this case, some natural conditions on f and k imply that there is a well-defined
spreading speed for waves of invasion generated from compact initial conditions. The wave speed is often calculated
by studying the linearized equation
where .
This can be written as the convolution
Using a moment-generating-function transformation
it has been shown that the critical wave speed
Other types of equations used to model population dynamics through space include reaction–diffusion equations and metapopulation equations. However, diffusion equations do not as easily allow for the inclusion of explicit dispersa |
https://en.wikipedia.org/wiki/Beth%20Chance | Beth L. Chance (born 1968) is an American statistics educator. She is a professor of statistics at the California Polytechnic State University.
Education and career
Chance is originally from San Diego, California. She graduated from Harvey Mudd College in 1990, majoring in mathematics with a minor in psychology. She completed a Ph.D. in operations research, concentrating in statistics, at Cornell University in 1994. Her dissertation, Behavior Characterization and Estimation for General Hierarchical Multivariate Linear Regression Models, was supervised by Martin Wells.
She was a faculty member at the University of the Pacific from 1994 until 1999, when she moved to the California Polytechnic State University.
She was chair of the American Statistical Association Section on Statistics and Data Science Education for 2018.
Books
Chance is the author or coauthor of multiple statistics textbooks including:
Workshop Statistics: Discovery with Data (with A. Rossman and R. Lock, 1998; 4th ed., 2011)
Statistics: Preparing for the AP Exam (with J. Bohan, 2005)
Statistical Questions from the Classroom (with J. M. Shaughnessy, 2005)
Focus in High School Mathematics: Reasoning and Sense Making in Statistics and Probability (with J. M. Shaughnessy and H. Kranendonk, 2009)
Introduction to Statistical Inference (with N. Tintle, G. Cobb, A. Rossman, S. Roy, T. Swanson, and J. VanderStoep, 2016)
Intermediate Statistical Investigations (N. Tintle, K. McGaughey, S. Roy, T. Swanson, and J. VanderStoep, 2019)
Recognition
In 2002, Chance became the inaugural recipient of the Waller Education Award of the American Statistical Association Section on Statistics and Data Science Education. In 2003, she won the Mu Sigma Rho Statistics Education Award.
She became a Fellow of the American Statistical Association in 2005. She is also an Elected Member of the International Statistical Institute. |
https://en.wikipedia.org/wiki/History%20of%20hospitals | The history of hospitals began in antiquity with hospitals in Greece, the Roman Empire and on the Indian subcontinent as well, starting with precursors in the Asclepian temples in ancient Greece and then the military hospitals in ancient Rome. The Greek temples were dedicated to the sick and infirm but did not look anything like modern hospitals. The Romans did not have dedicated, public hospitals. Public hospitals, per se, did not exist until the Christian period. Towards the end of the 4th century, the "second medical revolution" took place with the founding of the first Christian hospital in the eastern Byzantine Empire by Basil of Caesarea, and within a few decades, such hospitals had become ubiquitous in Byzantine society. The hospital would undergo development and progress throughout Byzantine, medieval European and Islamic societies from the 5th to the 15th century. European exploration brought hospitals to colonies in North America, Africa, and Asia.
St Bartholomew's hospital in West Smithfield in London, founded in 1123, is widely considered the oldest functioning hospital today. Originally a charitable institution, currently an NHS hospital it continues to provide free care to Londoners, as it has for 900 years. In contrast, the Mihintale Hospital in Sri Lanka, established in the 9th century is probably the site with the oldest archaeological evidence available for a hospital in the world. Serving monks and the local community, it represents early advancements in healthcare practices.
Early Chinese and Japanese hospitals were established by Western missionaries in the 1800s. In the early modern era care and healing would transition into a secular affair in the West for many hospitals. During World War I and World War II, many military hospitals and hospital innovations were created. Government run hospitals increased in Korea, Japan, China, and the Middle East after World War II. In the late 1900s and 21st century, hospital networks and governmen |
https://en.wikipedia.org/wiki/Tiny%20Internet%20Interface | The Tiny Internet Interface (known as TINI or MxTNI) is a microcontroller that includes the facilities necessary to connect to the Internet. The MxTNI platform is a microcontroller-based development platform that executes code for embedded web servers. The platform is a combination of broad-based I/O, a full TCP/IP stack, and an extensible Java runtime environment that simplifies development of network-connected equipment.
MxTNI was developed by Dallas Semiconductor, now Maxim Integrated Products. The interface was originally known as "TINI". The company renamed it MxTNI in December 2011. |
https://en.wikipedia.org/wiki/The%20Atom%20Besieged | The Atom Besieged: Extraparliamentary Dissent in France and Germany is a 1981 book by Dorothy Nelkin and Michael Pollak. This book examines the opposition to nuclear power in France and West Germany in the 1970s, which is assessed as being broadly based and widespread. The authors argue that the basic fear which accounted for the vehemence of the opposition is that nuclear power fundamentally alters the makeup of society. |
https://en.wikipedia.org/wiki/Service%20account | A service account or application account is a digital identity used by an application software or service to interact with other applications or the operating system. They are often used for machine to machine communication (M2M), for example for application programming interfaces (API). The service account may be a privileged identity within the context of the application.
Updating passwords
Local service accounts can interact with various components of the operating system, which makes coordination of password changes difficult. In practice this causes passwords for service accounts to rarely be changed, which poses a considerable security risk for an organization.
Some types of service accounts do not have a password.
Wide access
Service accounts are often used by applications for access to databases, running batch jobs or scripts, or for accessing other applications. Such privileged identities often have extensive access to an organization's underlying data stores laying in applications or databases.
Passwords for such accounts are often built and saved in plain textfiles, which is a vulnerability which may be replicated across several servers to provide fault tolerance for applications. This vulnerability poses a significant risk for an organization since the application often hosts the type of data which is interesting to advanced persistent threats.
Service accounts are non-personal digital identities and can be shared.
Misuse
Google Cloud lists several possibilities for misuse of service accounts:
Privilege escalation: Someone impersonates the service account
Spoofing: Someone impersonates the service account to hide their identity
Non-repudiation: Performing actions on their behalf with a service account in cases where it is not possible to trace the actions of the abuser
Information disclosure: Unauthorized persons extract information about infrastructure, applications or processes
See also
Kerberos Service Account, a service account in Ker |
https://en.wikipedia.org/wiki/Census%20of%20Marine%20Life | The Census of Marine Life was a 10-year, US $650 million scientific initiative, involving a global network of researchers in more than 80 nations, engaged to assess and explain the diversity, distribution, and abundance of life in the oceans. The world's first comprehensive Census of Marine Life — past, present, and future — was released in 2010 in London. Initially supported by funding from the Alfred P. Sloan Foundation, the project was successful in generating many times that initial investment in additional support and substantially increased the baselines of knowledge in often underexplored ocean realms, as well as engaging over 2,700 different researchers for the first time in a global collaborative community united in a common goal, and has been described as "one of the largest scientific collaborations ever conducted".
Project history
According to Jesse Ausubel, Senior Research Associate of the Program for the Human Environment of Rockefeller University and science advisor to the Alfred P. Sloan Foundation, the idea for a "Census of Marine Life" originated in conversations between himself and Dr. J. Frederick Grassle, an oceanographer and benthic ecology professor at Rutgers University, in 1996. Grassle had been urged to talk with Ausubel by former colleagues at the Woods Hole Oceanographic Institution and was at that time unaware that Ausubel was also a program manager at the Alfred P. Sloan Foundation, funders of a number of other large scale "public good" science-based projects such as the Sloan Digital Sky Survey. Ausubel was instrumental in persuading the Foundation to fund a series of "feasibility workshops" over the period 1997-1998 into how the project might be conducted, one result of these workshops being the broadening of the initial concept from a "Census of the Fishes" into a comprehensive "Census of Marine Life". Results from these workshops, plus associated invited contributions, formed the basis of a special issue of Oceanography magazine i |
https://en.wikipedia.org/wiki/Modes%20of%20convergence%20%28annotated%20index%29 | The purpose of this article is to serve as an annotated index of various modes of convergence and their logical relationships. For an expository article, see Modes of convergence. Simple logical relationships between different modes of convergence are indicated (e.g., if one implies another), formulaically rather than in prose for quick reference, and indepth descriptions and discussions are reserved for their respective articles.
Guide to this index. To avoid excessive verbiage, note that each of the following types of objects is a special case of types preceding it: sets, topological spaces, uniform spaces, topological abelian groups (TAG), normed vector spaces, Euclidean spaces, and the real/complex numbers. Also note that any metric space is a uniform space. Finally, subheadings will always indicate special cases of their superheadings.
The following is a list of modes of convergence for:
A sequence of elements {an} in a topological space (Y)
Convergence, or "topological convergence" for emphasis (i.e. the existence of a limit).
...in a uniform space (U)
Cauchy-convergence
Implications:
- Convergence Cauchy-convergence
- Cauchy-convergence and convergence of a subsequence together convergence.
- U is called "complete" if Cauchy-convergence (for nets) convergence.
Note: A sequence exhibiting Cauchy-convergence is called a cauchy sequence to emphasize that it may not be convergent.
A series of elements Σbk in a TAG (G)
Convergence (of partial sum sequence)
Cauchy-convergence (of partial sum sequence)
Unconditional convergence
Implications:
- Unconditional convergence convergence (by definition).
...in a normed space (N)
Absolute-convergence (convergence of )
Implications:
- Absolute-convergence Cauchy-convergence absolute-convergence of some grouping1.
- Therefore: N is Banach (complete) if absolute-convergence convergence.
- Absolute-convergence and convergence together unconditional convergence.
|
https://en.wikipedia.org/wiki/Thomsen%E2%80%93Friedenreich%20antigen | Thomsen–Friedenreich antigen (Galβ1-3GalNAcα1-Ser/Thr) is a disaccharide that serves as a core 1 structure in O-linked glycosylation. First described by Thomsen as a red blood cell's antigen, later research have determined it to be an oncofetal antigen. it is present in the body as a part of membrane transport proteins where it is normally masked from the immune system. It is commonly demasked in cancer cells, with it being expressed in up to 90% of carcinomas, making it a potential target for immunotherapy. |
https://en.wikipedia.org/wiki/Thermales-rpoB%20RNA%20motif | The Thermales-rpoB RNA motif is a conserved RNA structure that was discovered by bioinformatics.
Thermales-rpoB motifs are found in Thermales.
Thermales-rpoB motif RNAs likely function as cis-regulatory elements, in view of their positions upstream of protein-coding genes, which invariably encode subunits of RNA polymerase. Such genes are also believed to be regulated by the Rhodo-rpoB RNA motif, although these two motifs occur in quite diverged lineages of bacteria. |
https://en.wikipedia.org/wiki/Hartogs%27s%20extension%20theorem | In the theory of functions of several complex variables, Hartogs's extension theorem is a statement about the singularities of holomorphic functions of several variables. Informally, it states that the support of the singularities of such functions cannot be compact, therefore the singular set of a function of several complex variables must (loosely speaking) 'go off to infinity' in some direction. More precisely, it shows that an isolated singularity is always a removable singularity for any analytic function of complex variables. A first version of this theorem was proved by Friedrich Hartogs, and as such it is known also as Hartogs's lemma and Hartogs's principle: in earlier Soviet literature, it is also called Osgood–Brown theorem, acknowledging later work by Arthur Barton Brown and William Fogg Osgood. This property of holomorphic functions of several variables is also called Hartogs's phenomenon: however, the locution "Hartogs's phenomenon" is also used to identify the property of solutions of systems of partial differential or convolution equations satisfying Hartogs type theorems.
Historical note
The original proof was given by Friedrich Hartogs in 1906, using Cauchy's integral formula for functions of several complex variables. Today, usual proofs rely on either the Bochner–Martinelli–Koppelman formula or the solution of the inhomogeneous Cauchy–Riemann equations with compact support. The latter approach is due to Leon Ehrenpreis who initiated it in the paper . Yet another very simple proof of this result was given by Gaetano Fichera in the paper , by using his solution of the Dirichlet problem for holomorphic functions of several variables and the related concept of CR-function: later he extended the theorem to a certain class of partial differential operators in the paper , and his ideas were later further explored by Giuliano Bratti. Also the Japanese school of the theory of partial differential operators worked much on this topic, with notable contri |
https://en.wikipedia.org/wiki/Tricholoma%20murrillianum | Tricholoma murrillianum is a gilled mushroom found west of the Rocky Mountains in North America growing in coniferous woodland. This ectomycorrhizal fungus is an edible species that exists in a symbiotic relationship with various species of conifer as well as tan oak and madrone. It belongs to the genus Tricholoma in the matsutake species complex, which includes the closely related East Asian songi or matsutake as well as the American matsutake (T. magnivelare) and Mexican matsutake (T. mesoamericanum). T. murrillianum is also known as the ponderosa mushroom, pine mushroom, and Western matsutake.
Edibility
Matsutake mushrooms (including T. murrillianum) are choice edibles with high desirability, especially in Asian markets. They are prized for their distinctive spicy odor and flavor and firm, meaty texture. Serious poisonings have occurred due to confusion with poisonous look-alikes, most notably Amanita smithiana.
Harvest
As Japanese production of T. matsutake has declined with the growing presence of the pine-killing nematode, Bursaphelenchus xylophilus, there is an increasingly global matsutake harvesting market of related species. Exports from western North America bloomed over the last four decades, driving prices to a peak in the 1990s when Western matsutakes reached up to $600 per pound. Prices have since declined dramatically, but the annual matsutake harvest still drives economies in many rural Pacific Northwest areas.
Button matsutakes are especially prized, and illegal raking of wild matsutake patches can cause serious ecological damage. Matsutake harvests in the Pacific Northwest have been on the decline in recent years, possibly as a result of deep raking and over-harvesting.
Distribution
T. murrillianum is found predominantly in the Pacific Northwest of the United States and Canada. It was previously included with the American matsutake, T. magnivelare, but in 2017 scholarship based on molecular analysis separated the two and determined that T. |
https://en.wikipedia.org/wiki/List%20of%20Commonwealth%20Games%20mascots | Since 1978, the Commonwealth Games have had a mascot in each edition.
See also
List of Olympic mascots |
https://en.wikipedia.org/wiki/Forward%20volatility | Forward volatility is a measure of the implied volatility of a financial instrument over a period in the future, extracted from the term structure of volatility (which refers to how implied volatility differs for related financial instruments with different maturities).
Underlying principle
The variance is the square of differences of measurements from the mean divided by the number of samples. The standard deviation is the square root of the variance.
The standard deviation of the continuously compounded returns of a financial instrument is called volatility.
The (yearly) volatility in a given asset price or rate over a term that starts from corresponds to the spot volatility for that underlying, for the specific term. A collection of such volatilities forms a volatility term structure, similar to the yield curve. Just as forward rates can be derived from a yield curve, forward volatilities can be derived from a given term structure of volatility.
Derivation
Given that the underlying random variables for non overlapping time intervals are independent, the variance is additive (see variance). So for yearly time slices we have the annualized volatility as
where
is the number of years and the factor scales the variance so it is a yearly one
is the current (at time 0) forward volatility for the period
the spot volatility for maturity .
To ease computation and get a non-recursive representation, we can also express the forward volatility directly in terms of spot volatilities:
Following the same line of argumentation we get in the general case with for the forward volatility seen at time :
,
which simplifies in the case of to
.
Example
The volatilities in the market for 90 days are 18% and for 180 days 16.6%. In our notation we have = 18% and = 16.6% (treating a year as 360 days).
We want to find the forward volatility for the period starting with day 91 and ending with day 180. Using the above formula and setting we get
. |
https://en.wikipedia.org/wiki/Steen%20Rasmussen%20%28physicist%29 | Steen Rasmussen (born 7 July 1955) is a Danish physicist mainly working in the areas of artificial life and complex systems. He is currently a professor in physics and a center director at University of Southern Denmark as well as an external research professor at the Santa Fe Institute. His formal training was at the Technical University of Denmark (1985 PhD in physics of complex systems) and University of Copenhagen (philosophy). He spent 20 years as a researcher at Los Alamos National Laboratory (1988-2007) the last five years as a leader of the Self-Organized Systems team. He has been part of the Santa Fe Institute since 1988.
The main scientific effort of Rasmussen has since 2001 has been to explore, understand and construct a transition from nonliving to living materials. Bridging this gap requires an interdisciplinary scientific effort, which is why he has assembled, sponsored and lead research teams in the US, across Europe and in Denmark. He became a scientific team leader in 2002 at Los Alamos National Laboratory, USA, and he has since held research leadership positions at the Santa Fe Institute, University of Copenhagen and University of Southern Denmark. In 2004 he represented Los Alamos National Laboratory scientifically in cofounding together with primarily European scientific institutions the European Centre for Living Technology in Venice, Italy where he later served as Chairman of the Science Board. Since late 2007 he has been the director of the Center for Fundamental Living Technology at University of Southern Denmark. In 2018 he received the Lifetime Achievement Award form the International Society of Artificial Life (ISAL)
Rasmussen has for many years been actively engaged in the public discourse regarding science and society and on this background he founded The Initiative for Science, Society and Policy (ISSP) in 2009. ISSP is currently funded by two Danish universities, has a Director, five Science Focus Leaders and a Science Board. In 2018 |
https://en.wikipedia.org/wiki/Baumslag%E2%80%93Gersten%20group | In the mathematical subject of geometric group theory, the Baumslag–Gersten group, also known as the Baumslag group, is a particular one-relator group exhibiting some remarkable properties regarding its finite quotient groups, its Dehn function and the complexity of its word problem.
The group is given by the presentation
Here exponential notation for group elements denotes conjugation, that is, for .
History
The Baumslag–Gersten group G was originally introduced in a 1969 paper of Gilbert Baumslag, as an example of a non-residually finite one-relator group with an additional remarkable property that all finite quotient groups of this group are cyclic. Later, in 1992, Stephen Gersten showed that G, despite being a one-relator group given by a rather simple presentation, has the Dehn function growing very quickly, namely faster than any fixed iterate of the exponential function. This example remains the fastest known growth of the Dehn function among one-relator groups. In 2011 Alexei Myasnikov, Alexander Ushakov, and Dong Wook Won proved that G has the word problem solvable in polynomial time.
Baumslag-Gersten group as an HNN extension
The Baumslag–Gersten group G can also be realized as an HNN extension of the Baumslag–Solitar group with stable letter t and two cyclic associated subgroups:
Properties of the Baumslag–Gersten group G
Every finite quotient group of G is cyclic. In particular, the group G is not residually finite.
An endomorphism of G is either an automorphism or its image is a cyclic subgroup of G. In particular the group G is Hopfian and co-Hopfian.
The outer automorphism group Out(G) of G is isomorphic to the additive group of dyadic rationals and in particular is not finitely generated.
Gersten proved that the Dehn function f(n) of G grows faster than any fixed iterate of the exponential. Subsequently A. N. Platonov proved that f(n) is equivalent to
Myasnikov, Ushakov, and Won, using compression methods of ``power circuits" ari |
https://en.wikipedia.org/wiki/Trilogy%20Education%20Services | Trilogy Education Services (often shortened to Trilogy Education) is a New York City-based technology education company that offers non-credit technology training programs, colloquially known as coding bootcamps, through affiliate universities. In-person courses are held on the affiliate university campus. Revenue from the tuition is shared with the affiliate university.
Program graduates receive a non-credited professional certificate from the partner school and career advisement. There is no job placement guarantee and no third-party verified jobs reports have been released, though outcome data is privately shared with partner universities. The partner schools do not regard program graduates as university alumni, nor program enrollees as university students. The programs cost to and are not eligible for federal loans, nor do students receive a Form 1098-T.
The company was founded in 2015. In June 2017, the company received US$30 million in a Series A funding, followed by US$50 million in Series B funding in May 2018. It was bought by Maryland-based education technology company 2U in April 2019 for US$750 million.
History
Trilogy Education was founded in 2015 by Dan Sommer, whose father was a trustee for State University of New York. The younger Sommer had previously worked for an OPM, an acronym for companies which help universities bring their courses online. Rutgers was the company's first university partner.
In June 2017, the company received $30 million in a Series A funding round led by investment firm Highland Capital Partners. By then, the company had 250 employees. In September, the company announced it was partnering with Monterrey, Mexico-based Tecnológico de Monterrey (ITESM), to create a tech training program on ITESM's Mexico campus. Trilogy Education also started working with the University of Toronto in Canada.
In May 2018, the company received an additional $50 million, in a Series B funding round co-led by Highland Capital Partners, Macquar |
https://en.wikipedia.org/wiki/Switched%20video | Switched video or switched digital video (SDV), sometimes referred to as switched broadcast (SWB), is a telecommunications industry term for a network scheme for distributing digital video via a cable. Switched video sends the digital video more efficiently freeing bandwidth. The scheme applies to digital video distribution both on typical cable TV systems using QAM channels, or on IPTV systems.
Description
In hybrid fibre-coaxial systems, a fiber optic network extending from the operator's head end carries video channels out to a fiber optic node that services up to 2000 end points. Video is then sent via coaxial cable. Note that only a percentage of these homes are actively watching channels at a given time. Rarely are all channels being accessed by the homes in the service group.
In a switched video system, the unwatched channels do not need to be sent.
In US cable systems, equipment in the home sends a channel request signal back to the distribution hub. If a channel is requested, the distribution hub allocates a QAM channel and transmits the channel to the coaxial cable. For this to work, the home equipment must have two-way communication ability. Switched video uses the same mechanisms as video on demand and may be viewed as non-ending video on demand that users share.
Technical
Two-way communication is handled differently between cable and IPTV schemes. IPTV uses Internet communication protocols but requires a different distribution infrastructure. US cable companies elected the less costly approach of upgrading existing infrastructure. In the upgrade approach, various proprietary schemes use specific frequencies for messaging the distribution hub.
For switched video to work on cable systems, digital television users in a subscription group must have devices capable of communicating to the distribution hub in a compatible manner. Unlike other features dependent on two-way communication such as video on demand, the requirement to upgrade all digital se |
https://en.wikipedia.org/wiki/Non-functional%20testing | Non-functional testing is the testing process of a software application, web application or system for its non-functional requirements: the way a system operates, rather than specific behaviours of that system. This is in contrast to functional testing, which tests against functional requirements that describe the functions of a system and its components.
The names of many non-functional tests are often used interchangeably because of the overlap in scope between various non-functional requirements. For example, software performance is a broad term that includes many specific requirements like reliability and scalability.
Non-functional testing includes:
Accessibility testing
Baseline testing
Compliance testing
Documentation testing
Endurance testing or reliability testing
Load testing
Localization testing and Internationalization testing
Performance testing
Recovery testing
Resilience testing
Security testing
Scalability testing
Stress testing
Usability testing
Volume testing |
https://en.wikipedia.org/wiki/Dichromatic%20reflectance%20model | In Shafer’s dichromatic reflection model, scene radiance has two components:
λ is the wavelength,
cb is the body (diffuse) reflected component,
cs is the surface (interface) (specular) reflected component,
mb and ms are scale factors depending on illumination, view directions and surface orientation.
Separation algorithm
BREN (body reflection essence-neuter) model based
Body essence is an entity invariant to interface reflection, and has two degrees of freedom. The Gaussian coefficient generalizes a conventional simple thresholding scheme, and it provides detailed use of body color similarity. |
https://en.wikipedia.org/wiki/HSMP%20LSP | HSMP LSP is hub & spoke multipoint Label Switched Path (LSP), which allows traffic both from root to leaf through point-to-multipoint (P2MP) LSP and also leaf to root along the reverse path. That means traffic entering the HSMP LSP from application/customer at the root node travels downstream to each leaf node, exactly as if it is travelling downstream along a P2MP LSP to each leaf node. Upstream traffic entering the HSMP LSP at any leaf node travels upstream along the tree to the root, as if it is unicast to the root. Direct communication among the leaf nodes is not allowed.
HSMP LSP is an MPLS Technology, and it is one kind of multipoint Label Switched Path (LSP). Other kinds of multipoint Label Switched Path (LSP) will include: P2MP LSP and MP2MP LSP.
IETF MPLS Working Group is standardizing the HSMP LSP. The LDP based HSMP LSP is standardized in http://tools.ietf.org/html/draft-ietf-mpls-mldp-hsmp-06. The RSVP-TE based HSMP LSP is standardized in http://tools.ietf.org/html/draft-ietf-mpls-rsvp-te-hsmp-lsp-01.
HSMP LSP could be used in various scenarios, e.g., IEEE 1588 time synchronization, P2MP LSP protection, etc.
External links
MPLS Architecture, RFC 3031
LDP Extensions for Hub & Spoke Multipoint Label Switched Path
Hub and Spoke Multipoint Label Switched Path Tunnels
MPLS networking |
https://en.wikipedia.org/wiki/Ise%20katagami | is the Japanese craft of making paper stencils for dyeing textiles (). It is designated one of the Important Intangible Cultural Properties of Japan. The art is traditionally centered on the city of Suzuka in Mie Prefecture. It is different from , though both are made in Mie Prefecture.
Description
Multiple layers of thin paper are bonded with a glue extracted from persimmon, which makes a strong flexible brown coloured paper. The designs can be extremely intricate, and consequently fragile. Nowadays the stencils are sometimes sold as artwork, attached to hand fans, or used to decorate screens and doors in Japanese rooms. For kimono printing the stencils are stabilized by attaching them to a fine silk net. In past times, human hair was used instead of silk, but silk is less likely to warp and can be finer.
Technique
Three sheets of or Japanese paper are pasted together with , tannin-rich persimmon juice. The pattern is excised using a variety of tools known as . Four principal cutting techniques are used:
Pulling the knife towards the artist, which results in long straight cuts.
Carving patterns, which allows for figurative designs.
Cutting circular holes, often in fan-like designs
Using shaped punches.
The stencils are then used for resist dyeing. Rice paste is passed through the stencil onto silk. When dyed, the color does not adhere to the areas with rice paste. By multiple alignments of the stencil, large areas can be patterned. This technique was developed in France as silk screen printing. The stencil is not generally used for more than one kimono, though multiple stencils can be cut at the same time.
History
The use of stencils was known by the Nara period, as is evident from objects in the . Later paper stencils developed alongside kimono. The technique is known as since towns in Ise Province, now Mie Prefecture, were historic centres of the craft. Production is now primarily localised around the town of Suzuka.
Conservation
Former practitione |
https://en.wikipedia.org/wiki/Exchange%20matrix | In mathematics, especially linear algebra, the exchange matrices (also called the reversal matrix, backward identity, or standard involutory permutation) are special cases of permutation matrices, where the 1 elements reside on the antidiagonal and all other elements are zero. In other words, they are 'row-reversed' or 'column-reversed' versions of the identity matrix.
Definition
If J is an n × n exchange matrix, then the elements of J are
Properties
Premultiplying a matrix by an exchange matrix flips vertically the positions of the former's rows, i.e.,
Postmultiplying a matrix by an exchange matrix flips horizontally the positions of the former's columns, i.e.,
Exchange matrices are symmetric; that is, JnT = Jn.
For any integer k, Jnk = I if k is even and Jnk = Jn if k is odd. In particular, Jn is an involutory matrix; that is, Jn−1 = Jn.
The trace of Jn is 1 if n is odd and 0 if n is even. In other words, the trace of Jn equals .
The determinant of Jn equals . As a function of n, it has period 4, giving 1, 1, −1, −1 when n is congruent modulo 4 to 0, 1, 2, and 3 respectively.
The characteristic polynomial of Jn is when n is even, and when n is odd.
The adjugate matrix of Jn is .
Relationships
An exchange matrix is the simplest anti-diagonal matrix.
Any matrix A satisfying the condition AJ = JA is said to be centrosymmetric.
Any matrix A satisfying the condition AJ = JAT is said to be persymmetric.
Symmetric matrices A that satisfy the condition AJ = JA are called bisymmetric matrices. Bisymmetric matrices are both centrosymmetric and persymmetric.
See also
Pauli matrices (the first Pauli matrix is a 2 × 2 exchange matrix) |
https://en.wikipedia.org/wiki/Anatomical%20terms%20of%20muscle | Anatomical terminology is used to uniquely describe aspects of skeletal muscle, cardiac muscle, and smooth muscle such as their actions, structure, size, and location.
Types
There are three types of muscle tissue in the body: skeletal, smooth, and cardiac.
Skeletal muscle
Skeletal muscle, or "voluntary muscle", is a striated muscle tissue that primarily joins to bone with tendons. Skeletal muscle enables movement of bones, and maintains posture. The widest part of a muscle that pulls on the tendons is known as the belly.
Muscle slip
A muscle slip is a slip of muscle that can either be an anatomical variant, or a branching of a muscle as in rib connections of the serratus anterior muscle.
Smooth muscle
Smooth muscle is involuntary and found in parts of the body where it conveys action without conscious intent. The majority of this type of muscle tissue is found in the digestive and urinary systems where it acts by propelling forward food, chyme, and feces in the former and urine in the latter. Other places smooth muscle can be found are within the uterus, where it helps facilitate birth, and the eye, where the pupillary sphincter controls pupil size.
Cardiac muscle
Cardiac muscle is specific to the heart. It is also involuntary in its movement, and is additionally self-excitatory, contracting without outside stimuli.
Actions of skeletal muscle
As well as anatomical terms of motion, which describe the motion made by a muscle, unique terminology is used to describe the action of a set of muscles.
Agonists and antagonists
Agonist muscles and antagonist muscles are muscles that cause or inhibit a movement.
Agonist muscles are also called prime movers since they produce most of the force, and control of an action. Agonists cause a movement to occur through their own activation. For example, the triceps brachii contracts, producing a shortening (concentric) contraction, during the up phase of a push-up (elbow extension). During the down phase of a push-up, th |
https://en.wikipedia.org/wiki/Avoidance%20response | An avoidance response is a response that prevents an aversive stimulus from occurring. It is a kind of negative reinforcement. An avoidance response is a behavior based on the concept that animals will avoid performing behaviors that result in an aversive outcome. This can involve learning through operant conditioning when it is used as a training technique. It is a reaction to undesirable sensations or feedback that leads to avoiding the behavior that is followed by this unpleasant or fear-inducing stimulus.
Whether the aversive stimulus is brought on intentionally by another or is naturally occurring, it is adaptive to learn to avoid situations that have previously yielded negative outcomes. A simple example of this is conditioned food aversion, or the aversion developed to food that has previously resulted in sickness. Food aversions can also be conditioned using classical conditioning, so that an animal learns to avoid a stimulus previously neutral that has been associated with a negative outcome. This is displayed nearly universally in animals since it is a defense against potential poisoning. A wide variety of species, even slugs, have developed the ability to learn food aversions.
Experiments
An experiment conducted by Solomon and Wynne in 1953 shows the properties of negative reinforcement. The subjects, dogs, were put in a shuttle box (a chamber containing two rectangular compartments divided by a barrier a few inches high). The dogs had the ability to move freely between compartments by going over the barrier. Both compartments had a metal floor designed to administer an unpleasant electric shock. Each compartment also had a light above each, which would turn on and off. Every few minutes, the light in the room the dog was occupying was turned off, while the other remained on. If after 10 seconds in the dark, the dog did not move to the lit compartment, a shock was delivered to the floor of the room the dog was in. The shock continued until the dog mov |
https://en.wikipedia.org/wiki/Helicity%20%28particle%20physics%29 | In physics, helicity is the projection of the spin onto the direction of momentum.
Overview
The angular momentum J is the sum of an orbital angular momentum L and a spin S. The relationship between orbital angular momentum L, the position operator r and the linear momentum (orbit part) p is
so L's component in the direction of p is zero. Thus, helicity is just the projection of the spin onto the direction of linear momentum. The helicity of a particle is positive (" right-handed") if the direction of its spin is the same as the direction of its motion and negative ("left-handed") if opposite.
Helicity is conserved. That is, the helicity commutes with the Hamiltonian, and thus, in the absence of external forces, is time-invariant. It is also rotationally invariant, in that a rotation applied to the system leaves the helicity unchanged. Helicity, however, is not Lorentz invariant; under the action of a Lorentz boost, the helicity may change sign. Consider, for example, a baseball, pitched as a gyroball, so that its spin axis is aligned with the direction of the pitch. It will have one helicity with respect to the point of view of the players on the field, but would appear to have a flipped helicity in any frame moving faster than the ball.
Comparison with chirality
In this sense, helicity can be contrasted
to chirality, which is Lorentz invariant, but is not a constant of motion for massive particles. For massless particles, the two coincide: The helicity is equal to the chirality, both are Lorentz invariant, and both are constants of motion.
In quantum mechanics, angular momentum is quantized, and thus helicity is quantized as well. Because the eigenvalues of spin with respect to an axis have discrete values, the eigenvalues of helicity are also discrete. For a massive particle of spin , the eigenvalues of helicity are , , , ..., −.
For massless particles, not all of spin eigenvalues correspond to physically meaningful degrees of freedom: For example, the pho |
https://en.wikipedia.org/wiki/Capacitance%20probe | Capacitance sensors (or Dielectric sensors) use capacitance to measure the dielectric permittivity of a surrounding medium.
The configuration is like the neutron probe where an access tube made of PVC is installed in the soil; probes can also be modular (comb-like) and connected to a logger. The sensing head consists of an oscillator circuit, the frequency is determined by an annular electrode, fringe-effect capacitor, and the dielectric constant of the soil.
Each capacitor sensor consists of two metal rings mounted on the circuit board at some distance from the top of the access tube. These rings are a pair of electrodes, which form the plates of the capacitor with the soil acting as the dielectric in between. The plates are connected to an oscillator, consisting of an inductor and a capacitor. The oscillating electrical field is generated between the two rings and extends into the soil medium through the wall of the access tube. The capacitor and the oscillator form a circuit, and changes in dielectric constant of surrounding media are detected by changes in the operating frequency. The capacitance sensors are designed to oscillate in excess of 100 MHz inside the access tube in free air. The output of the sensor is the frequency response of the soil’s capacitance due to its soil moisture level.
Applications
One application for such a device is measuring the water content of soil, where the volume of water in the total volume of soil most heavily influences the dielectric permittivity of the soil because the dielectric of water (80) is much greater than the other constituents of the soil (mineral soil: 4, organic matter: 4, air: 1). When the amount of water changes in the soil, a probe will measure a change in capacitance due to the change in dielectric permittivity that can be directly correlated with a change in water content. Capacitance sensors are now widely used in irrigation scheduling in agriculture around the world.
Cure monitoring of Composite mater |
https://en.wikipedia.org/wiki/Point%20reflection | In geometry, a point reflection (also called a point inversion or central inversion) is a transformation of affine space in which every point is reflected across a specific fixed point. When dealing with crystal structures and in the physical sciences the terms inversion symmetry, inversion center or centrosymmetric are more commonly used.
A point reflection is an involution: applying it twice is the identity transformation. It is equivalent to a homothetic transformation with scale factor . The point of inversion is also called homothetic center.
An object that is invariant under a point reflection is said to possess point symmetry; if it is invariant under point reflection through its center, it is said to possess central symmetry or to be centrally symmetric. A point group including a point reflection among its symmetries is called centrosymmetric.
In Euclidean space, a point reflection is an isometry (preserves distance). In the Euclidean plane, a point reflection is the same as a half-turn rotation (180° or radians); a point reflection through the object's centroid is the same as a half-turn spin.
Terminology
The term reflection is loose, and considered by some an abuse of language, with inversion preferred; however, point reflection is widely used. Such maps are involutions, meaning that they have order 2 – they are their own inverse: applying them twice yields the identity map – which is also true of other maps called reflections. More narrowly, a reflection refers to a reflection in a hyperplane ( dimensional affine subspace – a point on the line, a line in the plane, a plane in 3-space), with the hyperplane being fixed, but more broadly reflection is applied to any involution of Euclidean space, and the fixed set (an affine space of dimension k, where ) is called the mirror. In dimension 1 these coincide, as a point is a hyperplane in the line.
In terms of linear algebra, assuming the origin is fixed, involutions are exactly the diagonalizable maps w |
https://en.wikipedia.org/wiki/Acid%20orange%2020 | Acid orange 20 (also Orange I) is an organic compound and an azo dye. It is one of the first water soluble dyes to be commercialized, and one of seven original food dyes allowed under the U.S. Pure Food and Drug Act of June 30, 1906. It is analyzed by HPLC.
Use and discontinuation
At one time it was a popular food colorant but it was delisted in 1959 in the U.S.
In the early 1950s, after several cases were reported of sickness in children who had eaten Halloween candy colored with the dye, the FDA conducted new, more thorough and rigorous testing on food dyes. Orange 1 was outlawed for food use in 1956.
Related compounds
Orange II (Acid Orange 7), an isomer |
https://en.wikipedia.org/wiki/KMT2A | Histone-lysine N-methyltransferase 2A, also known as acute lymphoblastic leukemia 1 (ALL-1), myeloid/lymphoid or mixed-lineage leukemia 1 (MLL1), or zinc finger protein HRX (HRX), is an enzyme that in humans is encoded by the KMT2A gene.
MLL1 is a histone methyltransferase deemed a positive global regulator of gene transcription. This protein belongs to the group of histone-modifying enzymes comprising transactivation domain 9aaTAD and is involved in the epigenetic maintenance of transcriptional memory. Its role as an epigenetic regulator of neuronal function is an ongoing area of research.
Function
Transcriptional regulation
KMT2A gene encodes a transcriptional coactivator that plays an essential role in regulating gene expression during early development and hematopoiesis. The encoded protein contains multiple conserved functional domains. One of these domains, the SET domain, is responsible for its histone H3 lysine 4 (H3K4) methyltransferase activity which mediates chromatin modifications associated with epigenetic transcriptional activation. Enriched in the nucleus, the MLL1 enzyme trimethylates H3K4 (H3K4me3). It also upregulates mono- and dimethylation of H3K4. This protein is processed by the enzyme Taspase 1 into two fragments, MLL-C (~180 kDa) and MLL-N (~320 kDa). These fragments then assemble into different multi-protein complexes that regulate the transcription of specific target genes, including many of the HOX genes.
Transcriptome profiling after deletion of MLL1 in cortical neurons revealed decreased promoter-bound H3K4me3 peaks at 318 genes, with 31 of these having significantly decreased expression and promoter binding. Among them were Meis2, a homeobox transcription factor critical for development of forebrain neurons and Satb2, a protein involved in neuronal differentiation.
Multiple chromosomal translocations involving this gene are the cause of certain acute lymphoid leukemias and acute myeloid leukemias. Alternate splicing results in mu |
https://en.wikipedia.org/wiki/Tomosynthesis | Tomosynthesis, also digital tomosynthesis (DTS), is a method for performing high-resolution limited-angle tomography at radiation dose levels comparable with projectional radiography. It has been studied for a variety of clinical applications, including vascular imaging, dental imaging, orthopedic imaging, mammographic imaging, musculoskeletal imaging, and chest imaging.
History
The concept of tomosynthesis was derived from the work of Ziedses des Plantes, who developed methods of reconstructing an arbitrary number of planes from a set of projections. Though this idea was displaced by the advent of computed tomography, tomosynthesis later gained interest as a low-dose tomographic alternative to CT.
Reconstruction
Tomosynthesis reconstruction algorithms are similar to CT reconstructions, in that they are based on performing an inverse Radon transform. Due to partial data sampling with very few projections, approximation algorithms have to be used. Filtered back projection and iterative, expectation-maximization algorithms have both been used to reconstruct the data.
Reconstruction algorithms for tomosynthesis are different from those of conventional CT because the conventional filtered back projection algorithm requires a complete set of data. Iterative algorithms based upon expectation maximization are most commonly used, but are computationally intensive. Some manufacturers have produced practical systems using off-the-shelf GPUs to perform the reconstruction in a few seconds.
Differences from other imaging modalities
Digital tomosynthesis combines digital image capture and processing with simple tube/detector motion as used in conventional computed tomography (CT). However, though there are some similarities to CT, it is a separate technique. In modern (helical) CT, the source/detector makes at least a complete 180-degree rotation about the subject obtaining a complete set of data from which images may be reconstructed. Digital tomosynthesis, on the other han |
https://en.wikipedia.org/wiki/Buccal%20artery | The buccal artery (buccinator artery) is a small artery in the head. It branches off the second part of the maxillary artery and supplies the cheek and buccinator muscle.
Course
It runs obliquely forward, between the pterygoideus internus and the insertion of the temporalis, to the outer surface of the buccinator, to which it is distributed, anastomosing with branches of the facial artery and with the infraorbital. From the infraorbital area, it descends bilaterally in the superficial face along the lateral margin of the nose, then running anti-parallel to the facial artery across the lateral oral region.
Additional images |
https://en.wikipedia.org/wiki/Fuzzy%20cold%20dark%20matter | Fuzzy cold dark matter is a hypothetical form of cold dark matter proposed to solve the cuspy halo problem. It would consist of extremely light scalar particles with masses on the order of eV; so a Compton wavelength on the order of 1 light year. Fuzzy cold dark matter halos in dwarf galaxies would manifest wave behavior on astrophysical scales, and the cusps would be avoided through the Heisenberg uncertainty principle.
The wave behavior leads to interference patterns, spherical soliton cores in dark matter halo centers, and cylindrical soliton-like cores in dark matter cosmic web filaments.
Fuzzy cold dark matter is a limit of scalar field dark matter without self-interaction. It is governed by the Schrödinger–Poisson equation.
New research (2023) has uncovered evidence that fuzzy dark matter, specifically ultralight axions, may better fit gravitational lense data than WIMP dark matter.
Notes
Physical cosmology
Dark matter
Hypothetical objects |
https://en.wikipedia.org/wiki/Descending%20aorta | In human anatomy, the descending aorta is part of the aorta, the largest artery in the body. The descending aorta begins at the aortic arch and runs down through the chest and abdomen. The descending aorta anatomically consists of two portions or segments, the thoracic and the abdominal aorta, in correspondence with the two great cavities of the trunk in which it is situated. Within the abdomen, the descending aorta branches into the two common iliac arteries which serve the pelvis and eventually legs.
The ductus arteriosus connects to the junction between the pulmonary artery and the descending aorta in foetal life. This artery later regresses as the ligamentum arteriosum.
See also
Abbott artery |
https://en.wikipedia.org/wiki/Acceptance%20and%20commitment%20therapy | Acceptance and commitment therapy (ACT, typically pronounced as the word "act") is a form of psychotherapy, as well as a branch of clinical behavior analysis. It is an empirically based psychological intervention that uses acceptance and mindfulness strategies along with commitment and behavior-change strategies to increase psychological flexibility.
This approach was originally termed comprehensive distancing. Steven C. Hayes developed the treatment starting around 1982 in order to create an approach that integrated both key features of cognitive therapy and behavior analysis, especially behavior analytic data on the often negative effects of verbal rules and how they might be ameliorated.
There are a variety of protocols for ACT, depending on the target behavior and setting. For example, in behavioral health areas, a brief version of ACT is called focused acceptance and commitment therapy (FACT).
The objective of ACT is not elimination of difficult feelings; rather, it is to be present with what life brings and to "move toward valued behavior". Acceptance and commitment therapy invites people to open up to unpleasant feelings, learn not to overreact to them, and not avoid situations where they are invoked.
Its therapeutic effect aims to be a positive spiral where a greater understanding of one's emotions leads to a better understanding of the truth. In ACT, "truth" is measured through the concept of "workability", or what works to take another step toward what matters (e.g., values, meaning).
Technique
Basics
ACT is developed within a pragmatic philosophy called functional contextualism. ACT is based on relational frame theory (RFT), a comprehensive theory of language and cognition that is derived from behavior analysis. Both ACT and RFT are based on B. F. Skinner's philosophy of radical behaviorism.
ACT differs from some other kinds of cognitive behavioral therapy (CBT) in that rather than trying to teach people to better control their thoughts, feeling |
https://en.wikipedia.org/wiki/Cranial%20neural%20crest | The cranial neural crest is one of the four regions of the neural crest.
The cranial neural crest arises in the anterior and populates the face and the pharyngeal arches giving rise to bones, cartilage, nerves and connective tissue. The endocranium and facial bones of the skull are ultimately derived from crest cells.
Other Migration Locations:
Into the pharyngeal arches and play an inductive role in thymus development.
Into the pharyngeal arches and form the parafollicular cell or ultimobranchial bodies of the thyroid gland.
Into the pharyngeal arches and play an inductive role in parathyroid gland development.
Facial ectomesenchyme of the pharyngeal arches forming skeletal muscle, bone, and cartilage in the face.
Odontoblasts (dentin-producing cells) of the teeth.
Around the optic vesicle and the developing eye and contributes to many eye elements such the choroid, sclera, iris, and ciliary body. It also contributes to the attaching skeletal muscles of the eye.
Into the otic placode and participates in the inner ear development.
Sensory ganglia of the fifth, seventh, ninth and tenth cranial nerves.
Schwann cells |
https://en.wikipedia.org/wiki/Pillai%20prime | In number theory, a Pillai prime is a prime number p for which there is an integer n > 0 such that the factorial of n is one less than a multiple of the prime, but the prime is not one more than a multiple of n. To put it algebraically, but . The first few Pillai primes are
23, 29, 59, 61, 67, 71, 79, 83, 109, 137, 139, 149, 193, ...
Pillai primes are named after the mathematician Subbayya Sivasankaranarayana Pillai, who studied these numbers. Their infinitude has been proved several times, by Subbarao, Erdős, and Hardy & Subbarao. |
https://en.wikipedia.org/wiki/FRAXD | FRAXD or FRAXD gene is a gene symbol for fragile site, aphidicolin type, common, fra(X)(q27.2) D. The locus of the gene is located on fragile site of the q arm of chromosome X at position 27.2. It is used for gene testing in Homo sapiens (Human beings). |
https://en.wikipedia.org/wiki/Catherine%20gardens | Catherine gardens is an architectural concept where large ecosystems are enclosed in huge shells around buildings to protect them from pollution. This is also referred to as "floating ecosystems" that can be retrofitted on high rise buildings or "hollow ecosystems" because of the empty spaces predicted in the design.
Etymology
The Catherine garden gets its name from circular growth pattern of the ivy plants as a projection of the architect's thought, similar to the Catherine wheel.
Aim
The concept is aimed at providing an isolated and protective environment for the bird species amidst the disturbing activities of densely built cities.
Concept adopts vulcanized rubber tubes with growing plants running spirally downwards to facilitate the water flow which gets collected at the bottom. The experiment was done as an attempt to blend high tech architecture and nature together but turned out only to be an utopian concept as the concern of materials were not paid importance to. More over, economic constrictions were not considered assuming humankind must come together to produce something that benefits all using all what it can offer.
Development
The circular structure with plants was conceived together by Amartya Deb and Nidhi Tekwani in 2010 with mentoring and support from Nagendra Manikya, professor of architecture at Bangalore University. It was originally conceptualized to create layers and pockets of green on high rise buildings through a network of tubes and shells. In 2012, it was showcased in the International Conference on Conservation of Sparrows held at Bangalore. Adapted through a collaborative effort between zoologist Jayashankar and Deb it was argued to provide a safe haven to bird species shielding them from pollution, noise and continuous human interference.
See also
Timothy Beatley
Urban ecology
Biophilic design
Ecological design
High-tech architecture |
https://en.wikipedia.org/wiki/Dauntless%20%28video%20game%29 | Dauntless is a free-to-play action role-playing game developed by Phoenix Labs and published and distributed by Epic Games. The game initially launched in beta in May 2018 for Microsoft Windows. An early access version launched on May 21, 2019 for PlayStation 4 and Xbox One, including full support for cross-platform play, and was fully released for those platforms on September 26, 2019. A Nintendo Switch version was released on December 10, 2019. Versions for PlayStation 5 and Xbox Series X/S were released on December 2, 2021.
Gameplay
Dauntless takes place in a fantasy setting, where a cataclysmic event has torn the world apart, releasing monstrous creatures known as Behemoths that prey on the surviving humans. Players take on the role of Slayers to take down Behemoths, collecting loot that they use to craft and upgrade weapons and equipment as to take down larger and more powerful Behemoths. While hunting, the game plays as a third-person action game; the player uses a combo system to attack the creature, while monitoring their own health and stamina gauge. Such hunts can take upwards of twenty minutes of in-game time to complete. The game can be played both as single-player, cooperatively in a party of up to four or in public cooperative instances of up to six people.
Development
Phoenix Labs was formed by former Riot Games developers Jesse Houston, Sean Bender, and Robin Mayne, and as of January 2017 includes 40 developers formerly from BioWare, Blizzard Entertainment, and Capcom. While a small studio compared to the AAA studios they left, Houston said that they are positioned in a way to offer "a new, unique approach to crafting AAA experiences".
Dauntless is the studio's first release. It was heavily inspired, as well as frequently compared to, Capcom's Monster Hunter series, which can see hundreds of hours put into a game by a player; the developers themselves have over a collective 6000 hours in various Monster Hunter titles. Dauntless was also influenced |
https://en.wikipedia.org/wiki/Cervical%20conization | Cervical conization (CPT codes 57520 (Cold Knife) and 57522 (Loop Excision)) refers to an excision of a cone-shaped sample of tissue from the mucous membrane of the cervix. Conization may be used for either diagnostic purposes as part of a biopsy or therapeutic purposes to remove pre-cancerous cells.
Types include:
Cold knife conization (CKC): usually outpatient, occasionally inpatient
Loop electrical excision procedure (LEEP): usually outpatient.
Conization of the cervix is a common treatment for dysplasia following abnormal results from a pap smear.
Side effects
Cervical conization causes a risk for subsequent pregnancies ending up in preterm birth of approximately 30% on average, due to cervical incompetence.
See also
Cervicectomy |
https://en.wikipedia.org/wiki/2012%20United%20States%20presidential%20debates | The bipartisan Commission on Presidential Debates (CPD) held four debates for the 2012 U.S. presidential general election, slated for various locations around the United States in October 2012 – three of them involving the major party presidential nominees; those being Democratic President Barack Obama from Illinois and Republican Governor Mitt Romney of Massachusetts, and one involving the vice-presidential nominees, those being Vice President Joe Biden from Delaware and Congressman Paul Ryan of Wisconsin.
The CPD stipulates three criteria for eligibility: constitutionally eligible, appearance on enough ballots to potentially reach 270 electoral votes, and average at least 15% on five selected national polls. Two candidates satisfied all requirements to participate: Obama and Romney.
The moderators for the debates were announced on August 13, 2012.
All four debates took place between 9 p.m. and 10:30 p.m. EDT (6 p.m. to 7:30 p.m. PDT).
Subsequently, on October 3, 2012, both campaigns executed a memorandum of understanding governing technical and administrative details of the debate. The agreement describes the role of the moderator, rules applicable to each debate, staging and seating arrangements, and ticket distribution, and was signed by Robert Bauer and Benjamin Ginsberg, general counsel of the Obama and Romney campaigns, respectively.
Several non-CPD sanctioned debates among third party candidates took place. The first, moderated by Larry King and organized by the Free and Equal Elections Foundation, took place on October 23, 2012, between Rocky Anderson, Virgil Goode, Gary Johnson, and Jill Stein. Stein and Johnson were selected using instant-runoff voting for a second Free and Equal Elections Foundation debate, which was hosted by RT and took place on November 5, 2012. Ralph Nader hosted and moderated a debate between Anderson, Stein, Goode, and Johnson, on November 4, 2012.
Debate schedule
First presidential debate (domestic policy)
Wednesday, Octo |
https://en.wikipedia.org/wiki/Microbial%20food%20cultures | Microbial food cultures are live bacteria, yeasts or moulds used in food production. Microbial food cultures carry out the fermentation process in foodstuffs. Used by humans since the Neolithic period (around 10 000 years BC) fermentation helps to preserve perishable foods and to improve their nutritional and organoleptic qualities (in this case, taste, sight, smell, touch). As of 1995, fermented food represented between one quarter and one third of food consumed in Central Europe. More than 260 different species of microbial food culture are identified and described for their beneficial use in fermented food products globally, showing the importance of their use.
The scientific rationale of the function of microbes in fermentation started to be built with the discoveries of Louis Pasteur in the second half of the 19th century. Extensive scientific study continues to characterize microbial food cultures traditionally used in food fermentation taxonomically, physiologically, biochemically and genetically. This allows better understanding and improvement of traditional food processing and opens up new fields of applications.
Historical overview
Microorganisms are the earliest form of life on earth, first evolving more than three billion years ago. Our ancestors discovered how to harness the power of microorganisms to make new foods, even if they did not know the science behind what they were doing.
Milestones
1665—Robert Hooke and Antoni Van Leeuwenhoek first observe and describe microorganisms.
1857–1876—Louis Pasteur proves the function of microorganisms in lactic and alcoholic fermentation.
1881—Emil Christian Hansen isolates Saccharomyces carlsbergensis, a pure yeast culture, which is today widely used in brewing of lager beers.
1889–1896—Herbert William Conn, Vilhelm Storch and Hermann Weigmann demonstrate that bacteria are responsible for the acidification of milk and of cream.
1897—Eduard von Freudenreich isolates Lactobacillus brevis.
1919—Sigurd O |
https://en.wikipedia.org/wiki/Common%20Locale%20Data%20Repository | The Common Locale Data Repository (CLDR) is a project of the Unicode Consortium to provide locale data in XML format for use in computer applications. CLDR contains locale-specific information that an operating system will typically provide to applications.
CLDR is written in the Locale Data Markup Language (LDML).
Details
Among the types of data that CLDR includes are the following:
Translations for language names
Translations for territory and country names
Translations for currency names, including singular/plural modifications
Translations for weekday, month, era, period of day, in full and abbreviated forms
Translations for time zones and example cities (or similar) for time zones
Translations for calendar fields
Patterns for formatting/parsing dates or times of day
Exemplar sets of characters used for writing the language
Patterns for formatting/parsing numbers
Rules for language-adapted collation
Rules for spelling out numbers as words
Rules for formatting numbers in traditional numeral systems (such as Roman and Armenian numerals)
Rules for transliteration between scripts, much of it based on BGN/PCGN romanization
The information is currently used in International Components for Unicode, Apple's macOS, LibreOffice, MediaWiki, and IBM's AIX, among other applications and operating systems.
CLDR overlaps somewhat with ISO/IEC 15897 (POSIX locales). POSIX locale information can be derived from CLDR by using some of CLDR's conversion tools.
CLDR is maintained by a technical committee which includes employees from IBM, Apple, Google, Microsoft, and some government-based organizations. The committee is chaired by John Emmons, of IBM; Mark Davis, of Google, is vice-chair.
The CLDR covers 400+ languages. |
https://en.wikipedia.org/wiki/List%20of%20Panasonic%20video%20projectors | This is an incomplete list of Panasonic Projectors
Home Theater Projectors
Front projection with a widescreen ratio for home use and budget. |
https://en.wikipedia.org/wiki/Underdetermined%20system | In mathematics, a system of linear equations or a system of polynomial equations is considered underdetermined if there are fewer equations than unknowns (in contrast to an overdetermined system, where there are more equations than unknowns). The terminology can be explained using the concept of constraint counting. Each unknown can be seen as an available degree of freedom. Each equation introduced into the system can be viewed as a constraint that restricts one degree of freedom.
Therefore, the critical case (between overdetermined and underdetermined) occurs when the number of equations and the number of free variables are equal. For every variable giving a degree of freedom, there exists a corresponding constraint removing a degree of freedom. The underdetermined case, by contrast, occurs when the system has been underconstrained—that is, when the unknowns outnumber the equations.
Solutions of underdetermined systems
An underdetermined linear system has either no solution or infinitely many solutions.
For example,
is an underdetermined system without any solution; any system of equations having no solution is said to be inconsistent. On the other hand, the system
is consistent and has an infinitude of solutions, such as , , and . All of these solutions can be characterized by first subtracting the first equation from the second, to show that all solutions obey ; using this in either equation shows that any value of y is possible, with .
More specifically, according to the Rouché–Capelli theorem, any system of linear equations (underdetermined or otherwise) is inconsistent if the rank of the augmented matrix is greater than the rank of the coefficient matrix. If, on the other hand, the ranks of these two matrices are equal, the system must have at least one solution; since in an underdetermined system this rank is necessarily less than the number of unknowns, there are indeed an infinitude of solutions, with the general solution having k free parameters |
https://en.wikipedia.org/wiki/Record%20press | A record press is a machine for manufacturing vinyl records. It is essentially a hydraulic press fitted with thin nickel stampers which are negative impressions of a master disc. Labels and a pre-heated vinyl patty (or "biscuit") are placed in a heated mold cavity. Two stampers are used, one for each of side of the disc. The record press closes under a pressure of about 150 tons. The process of compression molding forces the hot vinyl to fill the grooves in the stampers, and take the form of the finished record.
Vacuum molding
In the mid-1960s, Emory Cook developed a system of record forming wherein the mold pressure was replaced by a vacuum. In this technique, the mold cavity was evacuated and vinyl was introduced in micro-particle form. The particles were then flash-fused instantaneously at a high temperature forming a coherent solid. Cook called this disc manufacturing technology microfusion. A small pressing plant in Hollywood also employed a similar system which they maintained fused the particles more evenly throughout the disc thickness calling their product polymax. Both claimed the resultant disc grooves exhibited less surface noise and greater resistance to deformation from stylus tip inertia than convention pressure molded vinyl discs. |
https://en.wikipedia.org/wiki/EDXL%20Sharp | EDXL Sharp is a C# / .NET 3.5 implementation of the OASIS Emergency Data Exchange Language (EDXL) family of standards.
The purpose of these libraries is to allow developers to:
Parse EDXL Messages from a string or underlying stream
Programmatically create EDXL messages
Validate EDXL Messages to the schema
Validate that EDXL Messages conform to the additional business rules specified in the standards documentation
Write EDXL messages to a string or underlying stream
About the project
EDXL Sharp is licensed under the Apache 2.0 license and is part of a collaborative research project of The MITRE Corporation.
What's in EDXL Sharp
Version 1.0 includes the following:
Library for CAP (Common Alerting Protocol) v1.2
Library for Common Types across the EDXL Standards
Library for EDXL-DE (Distribution Element) v1.0
Library for EDXL-HAVE (Hospital Availability Exchange) v1.0
Library for EDXL-RM (Resource Message) v1.0
Graphical User Interface (GUI) EDXL-DE Test Tool
Library for GeoOASIS Where GML Profile
Library for EDXL xPIL (Extensible Party Information Language) Profile
Beta Library for EDXL-SitRep (Situation Reporting)
Beta Library for EDXL-TEP (Tracking of Emergency Patients)
the 2.0 version is released. Some of the draft standards implementations are in a separate source tree branch as stable alphas.
Online Testbed
This effort is a part of a larger interoperability testbed. The interop testbed serves as an online presence for learning about EDXL, how to implement systems using EDXL, online validation and information sharing tools, and a place to perform integration with other systems that use EDXL.
See also
EDXL
OASIS
XML
NIEM
External links
EDXL Sharp Codeplex Page
EDXL Wiki
OASIS EM-TC Public Page
OASIS EMA-TC Wiki
XML parsers
Computer libraries
Emergency management software |
https://en.wikipedia.org/wiki/Arthropod%20defensin | Arthropod defensins are a family defensin proteins found in mollusks, insects, and arachnids. These cysteine-rich antibacterial peptides are primarily active against Gram-positive bacteria and fungi in vitro. However Drosophila fruit flies mutant for the fly defensin were more susceptible to infection by the Gram-negative bacteria Providencia burhodogranariea, and resisted infection against Gram-positive bacteria like wild-type flies. It remains to be seen how in vitro activity relates to in vivo function. Mutants for the defensin-like antimicrobial peptide Drosomycin were more susceptible to fungi, validating a role for defensin-like peptides in anti-fungal defence.
Structure
Arthropod defensin peptides range in length from 38 to 51 amino acids. There are six conserved cysteines all involved in intrachain disulfide bonds. Studies have shown that the cysteine-bridge disulfide bonds are not required for antimicrobial activity, similar to findings in mammalian defensins. Furthermore, it was also shown that the N-terminal helix region in arthropod or insect defensins is also not required for antimicrobial activity of these peptides.
A schematic representation of peptides from the arthropod defensin family is shown below.
+----------------------------+
| |
| | | |
+---|---------------+ |
+-----------------+
'C': conserved cysteine involved in a disulfide bond.
Relation to other defensins
Sequence similarities have been reported between the arthropod defensins and mammalian defensins. However it appears that defensins of vertebrates, arthropods, plants, and fungi arose independently. This is supported by 3D structural differences between arthropod defensins and vertebrate beta defensins. However structural similarities exist between these defensins, notably in two structural motifs termed "C6" and "C8". |
https://en.wikipedia.org/wiki/Sidearm%20%28baseball%29 | In baseball, sidearm is a motion for throwing a ball along a low, approximately horizontal plane rather than a high, mostly vertical plane (overhand).
Sidearm is a common way of throwing the ball in the infield, because many throws must be made hurriedly from the glove after fielding ground balls. An infielder's quickest throw to the bases is often from just above ground level, necessitating a horizontal release of the ball.
Sidearm pitchers, also known as sidewinders, are uncommon at all levels of baseball except in Japan, where sidearm pitchers are widely popular. Few find sidearm a natural delivery, and those who do are often discouraged by coaches who know little about sidearm mechanics, and who believe that overhand pitching affords greater velocity. This is generally true, since overhand pitching provides better mechanical leverage with which the body can use to accelerate the ball. But what the sidearm pitcher loses in velocity, they gain in ball movement and unusual release point.
Historical progression of pitching
In the middle of the nineteenth century, the game of baseball began to evolve from a sport played by amateurs for recreation into a more serious game played by professionals. One of the most dramatic changes was the transition of the pitcher's delivery from an underhand motion to an overhanded throw. Before the American Civil War, the pitcher's role was to initiate the action by offering an underhanded throw to the batter, in much the same way that a basketball referee offers up a jump ball to begin play. As the game progressed towards professionalism and became more serious, pitchers began to attempt to prevent the batter from hitting the ball by throwing faster pitches. The rules governing the delivery of pitches proved to be hard to enforce, and pitchers continued to stretch the boundaries of the rules until by the 1870s, the release point of pitches had reached the pitcher's waist level. As the game continued to evolve into the 20th centu |
https://en.wikipedia.org/wiki/Gofio | Gofio is a sort of Canarian flour made from roasted grains (typically wheat or certain varieties of maize) or other starchy plants (e.g. beans and, historically, fern root), some varieties containing a little added salt. Gofio has been an important ingredient in Canarian cooking for some time, and Canarian emigrants have spread its use to the Caribbean (notably in Cuba, Dominican Republic, Puerto Rico, and Venezuela) and the Western Sahara. There are various ways to use it, such as kneading, dissolving in soup, and baking. It can also be used as a thickener. It is also found in Argentina, Uruguay, and Chile, where it is known as harina tostada and is employed in a wide variety of recipes. The gofio commercially available in the Canary Islands is always finely ground, like ordinary flour, despite the definition given in the Spanish Dictionary of the Royal Academy. It can't be seen at shops other than the Canary Islands.
In 2014, the name Gofio Canario was added to the register of Protected designation of origin and Protected geographical indication by the European Commission.
Elements
Gofio is thought to have been the main staple of the diet of the Guanches, the original inhabitants of the Canary Islands, who produced it from barley and the rhizome of certain ferns. The latter is also known to have been used in historical times, especially in famine, even up until the 20th century. Gofio derives from the name for the product in the aboriginal language of Gran Canaria, while in neighbouring Tenerife it was known as ahoren. Among the Berbers of North Africa, from whom the Guanche population largely derived, there existed a toasted barley flour with similar usage as a food, called arkul. In Morocco, toasted flour is also mixed with, among other ingredients, almond paste, honey, argan oil, anise, fennel, and sesame seeds to make "sellou" (also called "zamita" or "slilou" in some regions), a sweet paste known for its long shelf life and high nutritive value. It was |
https://en.wikipedia.org/wiki/Interruptible%20operating%20system | An interruptible operating system is an operating system with ability to handle multiple interrupts concurrently, or in other words, which allow interrupts to be interrupted.
Concurrent interrupt handling essentially mean concurrent execution of kernel code and hence induces the additional complexity of concurrency control in accessing kernel datastructures.
It also means that the system can stop any program that is already running, which is a feature on nearly all modern operating systems.
See also
Operating system
Operating System Projects
Interrupts |
https://en.wikipedia.org/wiki/Filter%20%28signal%20processing%29 | In signal processing, a filter is a device or process that removes some unwanted components or features from a signal. Filtering is a class of signal processing, the defining feature of filters being the complete or partial suppression of some aspect of the signal. Most often, this means removing some frequencies or frequency bands. However, filters do not exclusively act in the frequency domain; especially in the field of image processing many other targets for filtering exist. Correlations can be removed for certain frequency components and not for others without having to act in the frequency domain. Filters are widely used in electronics and telecommunication, in radio, television, audio recording, radar, control systems, music synthesis, image processing, computer graphics, and structural dynamics.
There are many different bases of classifying filters and these overlap in many different ways; there is no simple hierarchical classification. Filters may be:
non-linear or linear
time-variant or time-invariant, also known as shift invariance. If the filter operates in a spatial domain then the characterization is space invariance.
causal or non-causal: A filter is non-causal if its present output depends on future input. Filters processing time-domain signals in real time must be causal, but not filters acting on spatial domain signals or deferred-time processing of time-domain signals.
analog or digital
discrete-time (sampled) or continuous-time
passive or active type of continuous-time filter
infinite impulse response (IIR) or finite impulse response (FIR) type of discrete-time or digital filter.
Linear continuous-time filters
Linear continuous-time circuit is perhaps the most common meaning for filter in the signal processing world, and simply "filter" is often taken to be synonymous. These circuits are generally designed to remove certain frequencies and allow others to pass. Circuits that perform this function are generally linear in their response, or a |
https://en.wikipedia.org/wiki/Shade%20tolerance | In ecology, shade tolerance is a plant's ability to tolerate low light levels. The term is also used in horticulture and landscaping, although in this context its use is sometimes imprecise, especially in labeling of plants for sale in commercial nurseries.
Shade tolerance is a complex, multi-faceted property of plants. Different plant species exhibit different adaptations to shade, and a particular plant can exhibit varying degrees of shade tolerance, or even of requirement for light, depending on its history or stage of development.
Basic concepts
Except for some parasitic plants, all land plants need sunlight to survive. However, in general, more sunlight does not always make it easier for plants to survive. In direct sunlight, plants face desiccation and exposure to UV rays, and must expend energy producing pigments to block UV light, and waxy coatings to prevent water loss.
Plants adapted to shade have the ability to use far-red light (about 730 nm) more effectively than plants adapted to full sunlight. Most red light gets absorbed by the shade-intolerant canopy plants, but more of the far-red light penetrates the canopy, reaching the understorey. The shade-tolerant plants found here are capable of photosynthesis using light at such wavelengths.
The situation with respect to nutrients is often different in shade and sun. Most shade is due to the presence of a canopy of other plants, and this is usually associated with a completely different environment—richer in soil nutrients—than sunny areas.
Shade-tolerant plants are thus adapted to be efficient energy-users. In simple terms, shade-tolerant plants grow broader, thinner leaves to catch more sunlight relative to the cost of producing the leaf. Shade-tolerant plants are also usually adapted to make more use of soil nutrients than shade-intolerant plants.
A distinction may be made between "shade-tolerant" plants and "shade-loving" or sciophilous plants. Sciophilous plants are dependent on a degree of sha |
https://en.wikipedia.org/wiki/Carbohydrate%20deficient%20transferrin | Carbohydrate-deficient transferrin (CDT, also known as desialotransferrin or asialotransferrin) is a laboratory test used to help detect heavy ethanol consumption.
Physiology
Transferrin is a serum protein that carries iron through the bloodstream to the bone marrow, where red blood cells are manufactured, as well as to the liver and spleen. Structurally, transferrin is a polypeptide with two N-linked polysaccharide chains. These polysaccharide chains are branched with sialic acid residues. Sialic acid is a monosaccharide carbohydrate.
Various forms of transferrin exist, with differing levels of sialylation. The most common form is tetrasialotransferrin, with four sialic acid chains. In persons who consume significant quantities of alcohol (usually more than 4 or 5 alcoholic beverages a day for two weeks or more) , the proportion of transferrin with zero, one, or two sialic acid chains is increased. These are referred to as carbohydrate-deficient transferrins. These carbohydrate-deficient transferrins can be measured in the bloodstream, and are important markers for alcohol use disorder.
Test for alcohol consumption
Carbohydrate-deficient transferrin is elevated in the blood of people with heavy alcohol consumption but elevated levels can also be found in a number of medical conditions. The limitations of the assay depend upon the methodology of the test. HPLC (High Performance Liquid Chromatography) can detect certain genetic variants and potential liver diseases affecting CDT.
Used with other tests, such as gamma glutamyl transferase (GGT), aspartate aminotransferase (AST), and alanine aminotransferase (ALT), carbohydrate-deficient transferrin can be a useful tool in identifying problem drinking, such as alcohol use disorder. However, it is less sensitive than phosphatidylethanol (PEth) in detecting current regular alcohol consumption. The ethanol conjugates ethyl glucuronide and ethyl sulfate remain positive for up to three days after ethanol consumption |
https://en.wikipedia.org/wiki/Solomon%27s%20knot | Solomon's knot () is a traditional decorative motif used since ancient times, and found in many cultures. Despite the name, it is classified as a link, and is not a true knot according to the definitions of mathematical knot theory.
Structure
The Solomon's knot consists of two closed loops, which are doubly interlinked in an interlaced manner. If laid flat, the Solomon's knot is seen to have four crossings where the two loops interweave under and over each other. This contrasts with two crossings in the simpler Hopf link.
In most artistic representations, the parts of the loops that alternately cross over and under each other become the sides of a central square, while four loopings extend outward in four directions. The four extending loopings may have oval, square, or triangular endings, or may terminate with free-form shapes such as leaves, lobes, blades, wings etc.
Occurrences
The Solomon's knot often occurs in ancient Roman mosaics, usually represented as two interlaced ovals.
Sepphoris National Park, Israel, has Solomon's Knots in stone mosaics at the site of an ancient synagogue.
Across the Middle East, historical Islamic sites show Solomon's knot as part of Muslim tradition. It appears over the doorway of an early twentieth century CE mosque/madrasa in Cairo. Two versions of Solomon's knot are included in the recently excavated Yattir Mosaic in Jordan. To the east, it is woven into an antique Central Asian prayer rug. To the west, Solomon's knot appeared in Moorish Spain, and it shines in leaded glass windows in a late twentieth century CE mosque in the United States. The British Museum, London, England has a fourteenth-century CE Egyptian Qur'an with a Solomon's Knot as its frontispiece.
University of California at Los Angeles Fowler Museum of Cultural History, USA has a large African collection that includes nineteenth and twentieth century CE Yoruba glass beadwork crowns and masks decorated with Solomon's Knots.
Home of Peace Mausoleum, a Jewis |
https://en.wikipedia.org/wiki/Snaiad | Snaiad is a speculative evolution, science fiction and artistic worldbuilding project by Turkish artist C. M. Kösemen, focused on a fictional exoplanet of the same name. Begun in the early 2000s and inspired by earlier works such as Wayne Barlowe's 1990 book Expedition, Kösemen has produced hundreds of paintings and sketches of creatures of Snaiad, with detailed ecological roles and taxonomic relationships to each other. The sheer number of invented creatures and lineages makes Snaiad one of the most biologically diverse fictional worlds.
Since Snaiad artwork was first published by Kösemen online, the project has garnered a following and international attention, especially online. Fans of Snaiad have produced fan art, not only of Kösemen's own creatures but also of their own imagined Snaiadi creatures, consistent with the biological principles followed by the rest of the project's lifeforms. Kösemen hopes to eventually publish the project in book form.
Premise
Snaiad is an exoplanet slightly larger than Earth located outside of the Milky Way. The planet is home to a large variety of fauna, which Kösemen has designed and meticulously documented, along with creating maps and a geopolitical story of Snaiad as it undergoes the process of human colonization about 300 years in the future, Snaiad being one of Earth's first interstellar colonies.
According to science writer Darren Naish, Snaiad "might well break the record as goes the number of fictional entities invented so far" due to the sheer number of lineages and lifeforms designed by Kösemen. The equivalents of tetrapods on Snaiad, so-called 'para-tetrapods' have two "heads"; the first head, typically most similar to heads on Earth animals is a modified set of genitalia which is also used to catch or grab food, and the second head, located below, has only a digestive function. The 'para-tetrapods' of Snaiad have hydraulic muscles (i.e. powered by fluids being pumped in and out) and their skeletons are not made of |
https://en.wikipedia.org/wiki/Picard%20horn | A Picard horn, also called the Picard topology or Picard model, is one of the oldest known hyperbolic 3-manifolds, first described by Émile Picard in 1884. The manifold is the quotient of the upper half-plane model of hyperbolic 3-space by the projective special linear group, . It was proposed as a model for the
shape of the universe in 2004. The term "horn" is due to pseudosphere models of hyperbolic space.
Geometry and topology
A modern description, in terms of fundamental domain and identifications, can be found in section 3.2, page 63 of Grunewald and Huntebrinker, along with the first 80 eigenvalues of the Laplacian, tabulated on page 72, where is a fundamental domain of the Picard space.
Cosmology
The term was coined in 2004 by Ralf Aurich, Sven Lustig, Frank Steiner, and Holger Then in their paper Hyperbolic Universes with a Horned Topology and the CMB Anisotropy.
The model was chosen in an attempt to describe the microwave background radiation apparent in the universe, and has finite volume and useful spectral characteristics (the first several eigenvalues of the Laplacian are computed and in good accord with observation). In this model one end of the figure curves finitely into the bell of the horn. The curve along any side of horn is considered to be a negative curve. The other end extends to infinity.
See also
Gabriel's Horn |
https://en.wikipedia.org/wiki/OpenShift | OpenShift is a family of containerization software products developed by Red Hat. Its flagship product is the OpenShift Container Platform — a hybrid cloud platform as a service built around Linux containers orchestrated and managed by Kubernetes on a foundation of Red Hat Enterprise Linux. The family's other products provide this platform through different environments: OKD serves as the community-driven upstream (akin to the way that Fedora is upstream of Red Hat Enterprise Linux), Several deployment methods are available including self-managed, cloud native under ROSA (Red Hat OpenShift Service on AWS), ARO (Azure Red Hat OpenShift) and RHOIC (Red Hat OpenShift on IBM Cloud) on AWS, Azure, and IBM Cloud respectively, OpenShift Online as software as a service, and OpenShift Dedicated as a managed service.
The OpenShift Console has developer and administrator oriented views. Administrator views allow one to monitor container resources and container health, manage users, work with operators, etc. Developer views are oriented around working with application resources within a namespace. OpenShift also provides a CLI that supports a superset of the actions that the Kubernetes CLI provides.
History
OpenShift originally came from Red Hat's acquisition of Makara, a company marketing a platform as a service (PaaS) based on Linux containers, in November 2010.
OpenShift was announced in May 2011 as proprietary technology and did not become open-source until May of 2012. Up until v3, released in June 2015, the container technology and container orchestration technology used custom developed technologies. This changed in v3 with the adoption of Docker as the container technology, and Kubernetes as the container orchestration technology. The v4 product has many other architectural changes - a prominent one being a shift to using CRI-O, as the container runtime (and Podman for interacting with pods and containers), and Buildah as the container build tool, thus breaking the |
https://en.wikipedia.org/wiki/Game-theoretic%20rough%20sets | Game-theoretic rough sets are the use of rough sets to induce three-way classification decisions. The positive, negative, and boundary regions can be interpreted as regions of acceptance, rejection, and deferment decisions, respectively. The probabilistic rough set model extends the conventional rough sets by providing a more effective way of classifying objects. A main result of probabilistic rough sets is the interpretation of three-way decisions using a pair of probabilistic thresholds. The game-theoretic rough set model determines and interprets the required thresholds by utilizing a game-theoretic environment for analyzing strategic situations between cooperative or conflicting decision-making criteria. The essential idea is to implement a game for investigating how the probabilistic thresholds may change in order to improve the rough set-based decision-making. |
https://en.wikipedia.org/wiki/Natural%20Color%20System | The Natural Color System (NCS) is a proprietary perceptual color model. It is based on the color opponency hypothesis of color vision, first proposed by German physiologist Ewald Hering. The current version of the NCS was developed by the Swedish Colour Centre Foundation, from 1964 onwards. The research team consisted of Anders Hård, Lars Sivik and Gunnar Tonnquist, who in 1997 received the AIC Judd award for their work. The system is based entirely on the phenomenology of human perception and not on color mixing. It is illustrated by a color atlas, marketed by NCS Colour AB in Stockholm.
Definition
The NCS states that there are six elementary color percepts of human vision—which might coincide with the psychological primaries—as proposed by the hypothesis of color opponency: white, black, red, yellow, green, and blue. The last four are also called unique hues. In the NCS all six are defined as elementary colors, irreducible qualia, each of which would be impossible to define in terms of the other elementary colors. All other experienced colors are considered composite perceptions, i.e. experiences that can be defined in terms of similarity to the six elementary colors. E.g. a saturated pink would be fully defined by its visual similarity to red, blue, black and white.
Colors in the NCS are defined by three values, expressed in percentages, specifying the degree of blackness (s , = relative visual similarity to the black elementary color), chromaticness (c, = relative visual similarity to the "strongest", most saturated, color in that hue triangle), and hue (Φ, = relative similarity to one or two of the chromatic elementary colors red, yellow, green and blue, expressed in at most two percentages). This means that a color can be expressed as either Y (yellow), YR (yellow with a red component), R (Red), RB (red with a blue component), B (blue), etc. No hue is considered to have visual similarity to both hues of an opponent pair; i.e. there is no "redgreen" or "yell |
https://en.wikipedia.org/wiki/White%20flag | White flags have had different meanings throughout history and depending on the locale.
Contemporary use
The white flag is an internationally recognized protective sign of truce or ceasefire, and for negotiation. It is also used to symbolize surrender, since it is often the weaker party that requests negotiation. It is also flown on ships serving as cartels. A white flag signifies to all that an approaching negotiator is unarmed, with an intent to surrender or a desire to communicate. Persons carrying or waving a white flag are not to be fired upon, nor are they allowed to open fire. The use of the flag to request parley is included in the Hague Conventions of 1899 and 1907:
The improper use of the flag is forbidden by the rules of war and constitutes a war crime of perfidy. There have been numerous reported cases of such behavior in conflicts, such as combatants using white flags as a ruse to approach and attack enemy combatants, or killings of combatants attempting to surrender by carrying white flags.
Origin
The first mention of the usage of white flags to surrender is made during the Eastern Han dynasty (AD 25–220). In the Roman Empire, the historian Cornelius Tacitus mentions a white flag of surrender in AD 109. Before that time, Roman armies would surrender by holding their shields above their heads. The white flag was widely used in the Middle Ages in Western Europe to indicate an intent to surrender. The color white was used generally to indicate a person was exempt from combat; heralds bore white wands, prisoners or hostages captured in battle would attach a piece of white paper to their hat or helmet, and garrisons that had surrendered and been promised safe passage would carry white batons.
Its use may have expanded across continents, e.g. Portuguese chronicler Gaspar Correia (writing in the 1550s), claims that in 1502, an Indian ruler, the Zamorin of Calicut, dispatched negotiators bearing a "white cloth tied to a stick", "as a sign of peace", to |
https://en.wikipedia.org/wiki/System%20requirements%20specification | A System Requirements Specification (SyRS) (abbreviated SysRS to be distinct from a software requirements specification (SRS)) is a structured collection of information that embodies the requirements of a system.
A business analyst (BA), sometimes titled system analyst, is responsible for analyzing the business needs of their clients and stakeholders to help identify business problems and propose solutions. Within the systems development life cycle domain, the BA typically performs a liaison function between the business side of an enterprise and the information technology department or external service providers.
See also
Business analysis
Business process reengineering
Business requirements
Concept of operations
Data modeling
Information technology
Process modeling
Requirement
Requirements analysis
Software requirements specification
Systems analysis
Use case |
https://en.wikipedia.org/wiki/Portable%20Game%20Notation | Portable Game Notation (PGN) is a standard plain text format for recording chess games (both the moves and related data), which can be read by humans and is also supported by most chess software.
History
PGN was devised around 1993, by Steven J. Edwards, and was first popularized and specified via the Usenet newsgroup rec.games.chess.
Usage
PGN is structured "for easy reading and writing by human users and for easy parsing and generation by computer programs." The chess moves themselves are given in algebraic chess notation using English initials for the pieces. The filename extension is .pgn.
There are two formats in the PGN specification, the "import" format and the "export" format. The import format describes data that may have been prepared by hand, and is intentionally lax; a program that can read PGN data should be able to handle the somewhat lax import format. The export format is rather strict and describes data prepared under program control, similar to a pretty printed source program reformatted by a compiler. The export format representations generated by different programs on the same computer should be exactly equivalent, byte for byte.
PGN text begins with a set of "tag pairs" (a tag name and its value), followed by the "movetext" (chess moves with optional commentary).
Tag pairs
Tag pairs begin with an initial left bracket , followed by the name of the tag in plain ASCII text. The tag value is enclosed in double-quotes, and the tag is then terminated with a closing right bracket . A quote inside a tag value is represented by the backslash immediately followed by a quote. A backslash inside a tag value is represented by two adjacent backslashes. There are no special control codes involving escape characters, or carriage returns, and linefeeds to separate the fields, and superfluous embedded spaces are usually skipped when parsing.
Seven Tag Roster
PGN data for archival storage is required to provide seven tag pairs – together known as the "Sev |
https://en.wikipedia.org/wiki/Ettore%20Bortolotti | Ettore Bortolotti (6 March 1866 – 17 February 1947) was an Italian mathematician.
Biography
Bortolotti was born in Bologna. He studied mathematics under Salvatore Pincherle and Cesare Arzelà in Bologna. He graduated in mathematics in 1889 at the University of Bologna, under Pincherle. He was appointed as lecturer to the Lyceum of Modica in Sicily in 1891, then studied one year in Paris as a post-graduate, before lecturing at the University of Rome in 1893.
In 1900, he became professor for infinitesimal calculus at Modena. There, he became dean from 1913 to 1919, then moved back to the University of Bologna, where he retired in 1936.
He was an Invited Speaker of the ICM in 1924 in Toronto and in 1928 in Bologna.
Bortolotti must also be considered a differential geometer and a relativist too. In fact, in the year 1929, he commented on the geometric basis for Einstein’s absolute parallelism theory in a paper entitled "Stars of congruences and absolute parallelism: Geometric basis for a recent theory of Einstein".
His son Enea was a mathematician too. Bortolotti died in Bologna.
Selected works
On metric connections with absolute parallelism, Proc. Kon. Akad. Wet. Amsterdam 30 (1927), 216-218.
Reti di Cebiceff e sistemi coniugati nelle Vn riemanniane, Rend. Reale Acc. dei Lincei (6a) 5 (1927), 741-747.
Stelle di congruenze e parallelismo assoluto: basi geometriche di una recente teoria di Einstein, Rend. Reale Acc. dei Lincei 9 (1929), 530-538.
I primi algoritmi infiniti nelle opere dei matematici italiani del secolo XVII (1939)
L'Opera geometrica di Evangelista Torricelli (1939)
Le fonti della matematica moderna. Matematica sumerica e matematica babilonese (1940)
Influenza del campo numerico sullo sviluppo delle teorie algebriche (1941)
Il carteggio matematico di Giovanni Regiomontano con Giovanni Bianchini, Giacomo Speier e Cristiano Roder (1942)
La pubblicazione delle opere e del carteggio matematico di Paolo Ruffini (1943)
Il problema della tangente |
https://en.wikipedia.org/wiki/Veselin%20Jevrosimovi%C4%87 | Veselin Jevrosimovic (; ) is the owner and chairman of IT company Comtrade, headquartered in Belgrade. He is also the president of the Athletics Association of Serbia
Background
Veselin Jevrosimović was born in Belgrade, Serbia, in 1965, he grew up in a middle-class family, in the Belgrade municipality and neighbourhood of Voždovac. He has an older brother Veljko. He earned a place in the national athletics team and later became the national University league pole vault champion. As part of the Düsseldorf Athletics Club he spent time in Germany, later in the United States. Jevrosimović would later advance his education with an IT engineering degree from the Information Technology School in Belgrade.
Career
In 1986 Jevrosimovic became the co-owner of an IT equipment distribution company in Germany. Keeping his connections in the U.S., he started a computer distribution business there, which led to him becoming a partner in CHS Electronics later in the 90s. Parallel to businesses in Germany and the U.S. he founded Comtrade Group in Serbia in 1991, a company that would become one of the largest IT organizations in Southeast Europe. In 1996, CHS Electronics, at which Mr. Jevrosimović was a partner, had become the no.2 computer equipment distribution company in the world, with a turnover of 12.5 billion dollars. Later that year Veselin sold his shares in the company and returned to Serbia to focus on the development of Comtrade's business.
Favouring a regional expansion strategy, Mr. Jevrosimović opened a company in Bosnia and Herzegovina in 1997, and proceeded to expand the network into Montenegro, Macedonia, Croatia and Albania. In 2008 he led the acquisition of the largest Slovenian software company, Hermes Softlab. This purchase was a confirmation of Comtrade's evolution to software engineering and development, which began in 2000, when Jevrosimović founded Spinnaker, a system integration company that later changed its name to Comtrade System Integration. The soft |
https://en.wikipedia.org/wiki/Calculation%20of%20buoyancy%20flows%20and%20flows%20inside%20buildings | Buoyancy force is the defined as the force exerted on the body or an object when inserted in a fluid. Buoyancy force is based on the basic principle of pressure variation with depth, since pressure increases with depth. Hence buoyancy force arises as pressure on the bottom surface of the immersed object is greater than that at the top.
Flow problems in buildings were studied since 700 B.C. Recent advancements in CFD and CAE have led to comprehensive calculation of buoyancy flows and flows in buildings.
Calculation of buoyant flows and flow inside buildings
Since there is natural driven ventilation resulting from the difference in temperature inside the buildings hence flows inside buildings fall under buoyancy force category. The momentum equation in the direction of gravity should be modeled for buoyant forces resulting from buoyancy. Hence the momentum equation is given by
∂ρv/∂t + V.∇(ρv)= -g((ρ-ρ°) - ∇P+μ∇2v + Sv
In the above equation -g((ρ-ρ°) is the buoyancy term, where ρ° is the reference density.
On discretizing the above equation several instabilities are obtained during the solution process. Hence we use a transient approach as several relaxations are often required in obtaining a steady state solution.
When applied to turbulent flows some additional modifications are to be applied to the calculation of buoyant flows. Hence an additional term is added, as recommended by Rodi(1978) in the k equation of the k- ε model is used below in modelling turbulent buoyant flows. Therefore, the k-equations takes the form
∂ρk/∂t + ∇(ρku)= -g((ρ-ρ°) - ∇(τ∇×k) + G + B - ρε
Where
G= Usual Production or generation term = 2µE.E
B = Generation term related to buoyancy
Also B = βgi (μ/σ) ∂T/∂xi
Where,
T = Temperature
gi = Gravitational acceleration in x-direction
β = Volumetric expansion coefficient = -(1/ρ) ∂ρ/∂T
Hence for turbulent kinetic energy the modeled transport equation is given as
∂ρε/∂t + ∇(ρεu) = ∇(τ∇×k) + C1ε (ε/k)(G+B)(1+C3 Rf ) - C2 ε ρ(ε2/k)
|
https://en.wikipedia.org/wiki/Closed%20graph%20theorem%20%28functional%20analysis%29 | In mathematics, particularly in functional analysis and topology, the closed graph theorem is a result connecting the continuity of certain kinds of functions to a topological property of their graph. In its most elementary form, the closed graph theorem states that a linear function between two Banach spaces is continuous if and only if the graph of that function is closed.
The closed graph theorem has extensive application throughout functional analysis, because it can control whether a partially-defined linear operator admits continuous extensions. For this reason, it has been generalized to many circumstances beyond the elementary formulation above.
Preliminaries
The closed graph theorem is a result about linear map between two vector spaces endowed with topologies making them into topological vector spaces (TVSs). We will henceforth assume that and are topological vector spaces, such as Banach spaces for example, and that Cartesian products, such as are endowed with the product topology.
The of this function is the subset
of where denotes the function's domain.
The map is said to have a (in ) if its graph is a closed subset of product space (with the usual product topology).
Similarly, is said to have a if is a sequentially closed subset of
A is a linear map whose graph is closed (it need not be continuous or bounded).
It is common in functional analysis to call such maps "closed", but this should not be confused the non-equivalent notion of a "closed map" that appears in general topology.
Partial functions
It is common in functional analysis to consider partial functions, which are functions defined on a dense subset of some space
A partial function is declared with the notation which indicates that has prototype (that is, its domain is and its codomain is ) and that is a dense subset of
Since the domain is denoted by it is not always necessary to assign a symbol (such as ) to a partial function's domain, in which case |
https://en.wikipedia.org/wiki/Bigyrate%20diminished%20rhombicosidodecahedron | In geometry, the bigyrate diminished rhombicosidodecahedron is one of the Johnson solids (). It can be constructed as a rhombicosidodecahedron with two pentagonal cupolae rotated through 36 degrees, and a third pentagonal cupola removed. (None of the cupolae can be adjacent.)
External links
Johnson solids |
https://en.wikipedia.org/wiki/Anomalous%20cancellation | An anomalous cancellation or accidental cancellation is a particular kind of arithmetic procedural error that gives a numerically correct answer. An attempt is made to reduce a fraction by cancelling individual digits in the numerator and denominator. This is not a legitimate operation, and does not in general give a correct answer, but in some rare cases the result is numerically the same as if a correct procedure had been applied. The trivial cases of cancelling trailing zeros or where all of the digits are equal are ignored.
Examples of anomalous cancellations which still produce the correct result include (these and their inverses are all the cases in base 10 with the fraction different from 1 and with two digits):
The article by Boas analyzes two-digit cases in bases other than base 10, e.g., = and its inverse are the only solutions in base 4 with two digits.
An example of anomalous cancellation with more than two digits is = , and an example with different numbers of digits is =.
Elementary properties
When the base is prime, no two-digit solutions exist. This can be proven by contradiction: suppose a solution exists. Without loss of generality, we can say that this solution is
where the double vertical line indicates digit concatenation. Thus, we have
But , as they are digits in base ; yet divides , which means that . Therefore. the right hand side is zero, which means the left hand side must also be zero, i.e., , a contradiction by the definition of the problem. (If , the calculation becomes , which is one of the excluded trivial cases.)
Another property is that the numbers of solutions in a base is odd if and only if is an even square. This can be proven similarly to the above: suppose that we have a solution
Then, doing the same manipulation, we get
Suppose that . Then note that is also a solution to the equation. This almost sets up an involution from the set of solutions to itself. But we can also substitute in to get , which onl |
https://en.wikipedia.org/wiki/Television%20antenna | A television antenna (TV aerial) is an antenna specifically designed for use with a television receiver (TV) to receive over-the-air broadcast television signals from a television station. Television reception is dependent upon the antenna as well as the transmitter. Terrestrial television is broadcast on frequencies from about 47 to 250 MHz in the very high frequency (VHF) band, and 470 to 960 MHz in the ultra high frequency (UHF) band in different countries. Television antennas are manufactured in two different types: "indoor" antennas, to be located on top of or next to the television set, and "outdoor" antennas, mounted on a mast on top of the owner's house. They can also be mounted in a loft or attic, where the dry conditions and increased elevation are advantageous for reception and antenna longevity. Outdoor antennas are more expensive and difficult to install, but are necessary for adequate reception in fringe areas far from television stations. The most common types of indoor antennas are the dipole ("rabbit ears") and loop antennas, and for outdoor antennas the Yagi, log periodic, and for UHF channels the multi-bay reflective array antenna.
Description
The purpose of the antenna is to intercept radio waves from the desired television stations and convert them to tiny radio frequency alternating currents which are applied to the television's tuner, which extracts the television signal. The antenna is connected to the television with a specialized cable designed to carry radio current, called transmission line. Earlier antennas used a flat cable called 300 Ω twin-lead. The standard today is 75 Ω coaxial cable, which is less susceptible to interference, which plugs into an F connector or Belling-Lee connector (depending on region) on the back of the TV. To convert the signal from antennas that use twin-lead line to the modern coaxial cable input, a small transformer called a balun is used in the line.
In most countries, television broadcasting is all |
https://en.wikipedia.org/wiki/Ghana%20Society%20for%20Medical%20Physics | The Ghana Society for Medical Physics is Ghana's representative body for all medical physicists in the country. The organization's purpose is to unite and support its members in Ghana. It was set up in January 2011 to advance the use of principles of physics in medicine. The Society is the governing body for all medical physicists in Ghana, and contributes to their training.
The Society operates under a constitution, code of ethics, and Practice Standards. All its operations are subject to the Ghana Health Professions Regulatory Bodies Act 857 of 2013. The organization carries out research in the areas of radiation therapy, medical imaging and nuclear medicine, and collaborates with other organizations to host seminars and training courses. The Ghana Society for Medical Physics is Ghana's national representative to the Federation of African Medical Physics Organizations (FAMPO), and represents the International Organization for Medical Physics (IOMP) in Ghana.
The Society's headquarters is in Accra, at the Medical Physics Department of the School of Nuclear and Allied Sciences of the University of Ghana.
Affiliations
International Organization for Medical Physics (IOMP)
Federation of African Medical Physics Organizations (FAMPO)
International Atomic Energy Agency (IAEA)
Allied Health Professional Council of Ghana (AHPC)
Past presidents of GSMP
Professor John Humphery Amuasi (2011 - 2017) |
https://en.wikipedia.org/wiki/Integrative%20neuroscience | Integrative neuroscience is the study of neuroscience that works to unify functional organization data to better understand complex structures and behaviors. The relationship between structure and function, and how the regions and functions connect to each other. Different parts of the brain carrying out different tasks, interconnecting to come together allowing complex behavior. Integrative neuroscience works to fill gaps in knowledge that can largely be accomplished with data sharing, to create understanding of systems, currently being applied to simulation neuroscience: Computer Modeling of the brain that integrates functional groups together.
Overview
The roots of integrative neuroscience originated from the Rashevsky-Rosen school of relational biology that characterizes functional organization mathematically by abstracting away the structure (i.e., physics and chemistry). It was further expanded by Chauvet who introduced hierarchical and functional integration.
Hierarchical integration is structural involving spatiotemporal dynamic continuity in Euclidean space to bring about functional organization, viz.
Hierarchical organization + Hierarchical integration = Functional organization
However, functional integration is relational and as such this requires a topology not restricted to Euclidean space, but rather occupying vector spaces This means that for any given functional organization the methods of functional analysis enable a relational organization to be mapped by the functional integration, viz.
Functional organization + Functional integration = Relational Organization
Thus hierarchical and functional integration entails a "neurobiology of cognitive semantics" where hierarchical organization is associated with the neurobiology and relational organization is associated with the cognitive semantics. Relational organization throws away the matter; "function dictates structure", hence material aspects are entailed, while in reductionism the causal nexus b |
https://en.wikipedia.org/wiki/SimThyr | SimThyr is a free continuous dynamic simulation program for the pituitary-thyroid feedback control system. The open-source program is based on a nonlinear model of thyroid homeostasis. In addition to simulations in the time domain the software supports various methods of sensitivity analysis. Its simulation engine is multi-threaded and supports multiple processor cores. SimThyr provides a GUI, which allows for visualising time series, modifying constant structure parameters of the feedback loop (e.g. for simulation of certain diseases), storing parameter sets as XML files (referred to as "scenarios" in the software) and exporting results of simulations in various formats that are suitable for statistical software. SimThyr is intended for both educational purposes and in-silico research.
Mathematical model
The underlying model of thyroid homeostasis is based on fundamental biochemical, physiological and pharmacological principles, e.g. Michaelis-Menten kinetics, non-competitive inhibition and empirically justified kinetic parameters. The model has been validated in healthy controls and in cohorts of patients with hypothyroidism and thyrotoxicosis.
Scientific uses
Multiple studies have employed SimThyr for in silico research on the control of thyroid function.
The original version was developed to check hypotheses about the generation of pulsatile TSH release. Later and expanded versions of the software were used to develop the hypothesis of the TSH-T3 shunt in the hypothalamus-pituitary-thyroid axis, to assess the validity of calculated parameters of thyroid homeostasis (including SPINA-GT and SPINA-GD) and to study allostatic mechanisms leading to non-thyroidal illness syndrome.
SimThyr was also used to show that the release rate of thyrotropin is controlled by multiple factors other than T4 and that the relation between free T4 and TSH may be different in euthyroidism, hypothyroidism and thyrotoxicosis.
Public perception, reception and discussion of the sof |
https://en.wikipedia.org/wiki/Selenoyl%20fluoride | Selenoyl fluoride, selenoyl difluoride, selenium oxyfluoride, or selenium dioxydifluoride is a chemical compound with the formula SeO2F2.
Structure
The shape of the molecule is a distorted tetrahedron with the O-Se-O angle being 126.2°, the O-Se-F angle being 108.0° and F-Se-F being 94.1°. The Se-F bond length is 1.685 Å and the selenium to oxygen bond is 1.575 Å long.
Formation
Selenoyl fluoride can be formed by the action of warm fluorosulfonic acid on barium selenate or selenic acid. SeO3 + SeF4 can give this gas along with other oxyfluorides.
Reactions
Selenoyl fluoride is more reactive than its analogon sulfuryl fluoride. It is easier to hydrolyse and to reduce. It may react violently upon contact with ammonia.
Selenoyl fluoride reacting with xenon difluoride gives FXeOSeF5. |
https://en.wikipedia.org/wiki/Statistics%20of%20Deadly%20Quarrels | Statistics of Deadly Quarrels is a 1960 book by English mathematician and physicist Lewis Fry Richardson 11 October 1881 - 30 September 1953 published by Boxwood Press. The book is a mathematical and social science study on the origins of war; topics that informed much of Richardson's research throughout his life.
The book received mixed reviews in academia, with overall critical consensus that the works therein are important pioneering endeavors.
Background
The book can be seen as a follow-up to Richardson's book Arms and Insecurity (1949) with a number of reviewers commenting on both books, treating them as a related set. It was published posthumously, based on published and unpublished works of Richardson, and was edited by American political scientists Quincy Wright and C. C. Lienau.
Contents
In Statistics of Deadly Quarrels Richardson presented data on most conflicts, in particular, wars, from early 19th century to mid-20th century. He hypothesized a base 10 logarithmic scale for conflicts (not just wars but at the bottom of the scale, even simple homicides). He illustrated the fact that there are many more small fights, in which only a few people die, than large ones that kill many. While no conflict's size can be predicted beforehand and it is impossible to give an upper limit to the series, overall they do form a Poisson distribution.
Richardson also attempted to correlate factors such as economics, language, and religion with the causes of war. Most proved insignificant, except religion; data indicated that countries with differing religions are more likely to engage in hostilities. Some of his findings suggested that Christian nations participated in an above-average number of hostilities, particularly against Islamic nations; and that Spanish speakers tended to war against one another more than other language speakers, while Chinese speakers fought against one another less than expected. (Here Richardson criticizes individualism and praises collect |
https://en.wikipedia.org/wiki/Slater%E2%80%93Condon%20rules | Within computational chemistry, the Slater–Condon rules express integrals of one- and two-body operators over wavefunctions constructed as Slater determinants of orthonormal orbitals in terms of the individual orbitals. In doing so, the original integrals involving N-electron wavefunctions are reduced to sums over integrals involving at most two molecular orbitals, or in other words, the original 3N dimensional integral is expressed in terms of many three- and six-dimensional integrals.
The rules are used in deriving the working equations for all methods of approximately solving the Schrödinger equation that employ wavefunctions constructed from Slater determinants. These include Hartree–Fock theory, where the wavefunction is a single determinant, and all those methods which use Hartree–Fock theory as a reference such as Møller–Plesset perturbation theory, and Coupled cluster and Configuration interaction theories.
In 1929 John C. Slater derived expressions for diagonal matrix elements of an approximate Hamiltonian while investigating atomic spectra within a perturbative approach. The following year Edward Condon extended the rules to non-diagonal matrix elements. In 1955 Per-Olov Löwdin further generalized these results for wavefunctions constructed from non-orthonormal orbitals, leading to what are known as the Löwdin rules.
Mathematical background
In terms of an antisymmetrization operator () acting upon a product of N orthonormal spin-orbitals (with r and σ denoting spatial and spin variables), a determinantal wavefunction is denoted as
A wavefunction differing from this by only a single orbital (the m'''th orbital) will be denoted as
and a wavefunction differing by two orbitals will be denoted as
For any particular one- or two-body operator, Ô, the Slater–Condon rules show how to simplify the following types of integrals:
Matrix elements for two wavefunctions differing by more than two orbitals vanish unless higher order interactions are introduced.
I |
https://en.wikipedia.org/wiki/IEC%20Electronics | IEC Electronics Corp. was set up in 1966 and now is based in Newark, New York. The company focuses on electronic contract manufacturing services (EMS), such as the circuit cards, loads of cable and wire harness assemblies, and precision sheet metal components, for military, aerospace, medical devices, and other industry markets. In addition, the company provides services like testing and detection of counterfeit electronic parts, component risk mitigation and advanced failure analysis. IEC Electronics acquired Southern California Braiding, Inc. in 2010 to further develop IEC’s subsidiary, IEC Electronics Wire and Cable, Inc.. The company also has another subsidiary, namely Albuquerque. In October 2021, the company was acquired by Creation Technologies.
History
In June 2013, Glancy Binkow & Goldberg LLP, on behalf of investors of IEC, filed a class action lawsuit against the Company for issuing false and/or misleading statements.
On February 17, 2015, the company received a deficiency letter from the New York Stock Exchange (NYSE). The reasons for deficiency included failure to file a quarterly report in a timely manner. The company has been actively trying to prevent their stock from being delisted. IEC had until May 11, 2015, to submit a plan to the NYSE. Failure to submit and follow their approved plan, would get them delisted.
In February 2018, IEC Electronics announced they would be building a new facility in Newark, New York to expand production capabilities. The new 150,000 square foot facility, which will be located at the Silver Hill Technology Park, is projected to open in mid-2020. This business expansion is expected to create 362 new jobs while retaining 463 positions in New York State.
Products
All the related products are based on the company’s on-site analytical laboratories, real-time and automated data surveillance, component tracking systems, and the new product incubation centers, under ISO 9001:2008, ISO 13485 and ISO 14001 and many other st |
https://en.wikipedia.org/wiki/Petar%20V.%20Kokotovic | Petar V. Kokotovic (Serbian Cyrillic: Петар В. Кокотовић) is professor emeritus in the College of Engineering at the University of California, Santa Barbara, USA. He has made contributions in the areas of adaptive control, singular perturbation techniques, and nonlinear control especially the backstepping stabilization method.
Biography
Kokotovic was born in Belgrade in 1934. He received his B.S. (1958) and M.S. (1963) degrees from the University of Belgrade Faculty of Electrical Engineering, and his Ph.D. (1965) from the USSR Academy of Sciences (Institute of Automation and Remote Control), Moscow.
He came to the United States in 1965 and was professor at the University of Illinois for 25 years. He joined the University of California, Santa Barbara, in 1991, where he was the founding and long-serving director of the Center for Control, Dynamical Systems and Computation. This center has become a role model of cross-disciplinary research and education. One of the Center’s achievements is a fully integrated cross-disciplinary graduate program for electrical and computer, mechanical and environmental, and chemical engineering fields.
At UC Santa Barbara his group developed constructive nonlinear control methods and applied them, with colleagues from MIT, Caltech and United Technologies Research Center, to new jet engine designs. As a long-term industrial consultant, he has contributed to computer controls at Ford and to power system stability at General Electric.
For his control systems contributions, Professor Kokotovic has been recognized with the triennial Quazza Medal from the International Federation of Automatic Control (IFAC), the Control Systems Field Award from the Institute of Electrical and Electronics Engineers (IEEE), and the 2002 Richard E. Bellman Control Heritage Award from the American Automatic Control Council, with the citation "for pioneering contributions to control theory and engineering, and for inspirational leadership as mentor, advisor, an |
https://en.wikipedia.org/wiki/Bacteriorhodopsin | Bacteriorhodopsin (Bop) is a protein used by Archaea, most notably by haloarchaea, a class of the Euryarchaeota. It acts as a proton pump; that is, it captures light energy and uses it to move protons across the membrane out of the cell. The resulting proton gradient is subsequently converted into chemical energy.
Function
Bacteriorhodopsin is a light-driven H+ ion transporter found in some haloarchaea, most notably Halobacterium salinarum (formerly known as syn. H. halobium). The proton-motive force generated by the protein is used by ATP synthase to generate adenosine triphosphate (ATP). By expressing bacteriorhodopsin, the archaea cells are able to synthesise ATP in the absence of a carbon source.
Structure
Bacteriorhodopsin is a 27 kDa integral membrane protein usually found in two-dimensional crystalline patches known as "purple membrane", which can occupy almost 50% of the surface area of the archaeal cell. The repeating element of the hexagonal lattice is composed of three identical protein chains, each rotated by 120 degrees relative to the others. Each monomer has seven transmembrane alpha helices and an extracellular-facing, two-stranded beta sheet.
Bacteriorhodopsin is synthesized as a protein precursor, known as bacterio-opsin, which is extensively modified after translation. The modifications are:
Covalent conjugation of a retinal molecule to residue Lys216, via a Schiff base, to create the retinylidene chromophore.
Cleavage of the signal peptide, the first 13 amino acids at the N-terminus, and the conversion of residue Gln14 to pyroglutamate
Removal of residue Asp262 at the C-terminus
Spectral properties
Bacteriorhodopsin molecule is purple and is most efficient at absorbing green light (in the wavelength range 500-650 nm). In the native membrane, the protein has a maximum absorbance at 553 nm, however addition of detergent disrupts the trimeric form, leading a loss of exciton coupling between the chromophores, and the monomeric form consequ |
https://en.wikipedia.org/wiki/Operational%20availability | Operational availability in systems engineering is a measurement of how long a system has been available to use when compared with how long it should have been available to be used.
Definition
Operational availability is a management concept that evaluates the following.
Diagnostic down time
Criticality
Fault isolation down time
Logistics delay down time
Corrective maintenance down time
Any failed item that is not corrected will induce operational failure. is used to evaluate that risk. Operational failure is unacceptable in any situation where the following can occur.
Capital equipment loss
Injury or loss of life
Sustained failure to accomplish mission
In military acquisition, operational availability is used as one of the Key Performance Parameters in requirements documents, to form the basis for decision support analyses.
History
Aircraft systems, ship systems, missile systems, and space systems have a large number of failure modes that must be addressed with limited resources.
Formal reliability modeling during development is required to prioritize resource allocation before operation begins. Estimated failure rates and logistics delay are used to identify the number of forward positioned spare parts required to avoid excessive down time. This is also used to justify the expense associated with redundancy.
Formal availability measurement is used during operation to prioritize management decisions involving upgrade resource allocation, manpower allocation, and spare parts planning.
Principle
Operational availability is used to evaluate the following performance characteristic.
For a system that is expected to be available constantly, the below operational availability figures translate to the system being unavailable for approximately the following lengths of time (when all outages during a year are added together):
The following data is collected for maintenance actions while in operation to prioritize corrective funding.
Diagnostic down ti |
https://en.wikipedia.org/wiki/Indicator%20of%20compromise | Indicator of compromise (IoC) in computer forensics is an artifact observed on a network or in an operating system that, with high confidence, indicates a computer intrusion.
Types of indication
Typical IoCs are virus signatures and IP addresses, MD5 hashes of malware files, or URLs or domain names of botnet command and control servers. After IoCs have been identified via a process of incident response and computer forensics, they can be used for early detection of future attack attempts using intrusion detection systems and antivirus software.
Automation
There are initiatives to standardize the format of IoC descriptors for more efficient automated processing. Known indicators are usually exchanged within the industry, where the Traffic Light Protocol is being used.
See also
AlienVault
Mandiant
Malware
Malware Information Sharing Platform |
https://en.wikipedia.org/wiki/Photothermal%20time | Photothermal time (PTT) is a product between growing degree-days (GDD) and day length (hours) for each day. PTT = GDD × DL It can be used to quantify environment, as well as the timing of developmental stages of plants. |
https://en.wikipedia.org/wiki/Second-order%20intercept%20point | The Second-order intercept point, also known as the SOI, IP2, or IIP2 (Input intercept point), is a measure of linearity that quantifies the second-order distortion generated by nonlinear systems and devices. Examples of frequently used devices that are concerned with this measure are amplifiers and mixers. It is related to the third-order intercept point, which is generally used for quantifying degree of nonlinearity of a nonlinear system or it can also be used to estimate the nonlinear products present at the output of such a system.
Definition
At low power levels, the fundamental output power rises in a one-to-one ratio (in terms of dB) of the input power, while the second-order output power rises in a two-to-one ratio. If the input power is high enough for the device to reach saturation, the output power flattens out in both the first- and second-order cases.
The second order intercept point is the output power point at which the extrapolated first- and second-order lines intersect on a plot, since the actual power levels will flatten off due to saturation at much lower power level typically. In other words, the response is assumed to be perfect all the way to infinity. There are actually values for both the input and output SOI (known as the ISOI & OSOI or IIP2 & OIP2) of a device or system, being related by the small signal gain of the device or system. The OSOI in dB is simply the ISOI in dB plus the small signal gain of the device or system.
Derivation
To determine the second-order characteristics of a device, a strong signal is put through the device, and the output are measured. Both single- and two-tone techniques can be used, and while there will be frequencies components off to infinity, for SOI analysis the fundamental and second-order distortion products are the desired results.
Single-tone analysis
In single-tone analysis, one tone at the desired frequency is generated and put through the device. There will be output at the fundamental, and the o |
https://en.wikipedia.org/wiki/Vertus%20Hardiman | Vertus Wellborn Hardiman (March 9, 1922 – June 1, 2007) was a victim of a US government human radiation experiment at the age of five that left him with a painful skull deformity that forced him to cover his head for 80 years.
Life
Hardiman was born in Lyles Station, Indiana. In 1928, he attended Lyles Consolidated School where he and nine other children were severely irradiated during a medical experiment conducted at the local county hospital. To get parental consent the experiment was misrepresented as a new therapy for the scalp fungus known as ringworm. The radiation of the skull led to immediate symptoms but also to a severe progressive necrosis of the bone throughout his life.
The school children from Lyles Station School were delivered by their schoolbus, including Hardiman who was only five years old at the time and not technically enrolled in school. His mother sent him with his older brother to receive what they had been told was treatment for ringworm. All of the children treated with the radiation complained of the same symptoms: they all experienced headaches, suffered from dizziness, and felt extreme burning of the scalp. Eventually all the children lost their hair permanently.
The parents of the children met with a local lawyer and filed a lawsuit against the hospital, focusing on how the parents had been misled and tricked, but the hospital were found not liable. Many suffered long-term effects, but Hardiman's were the most pronounced.
In 1945 Hardiman traveled to California in search of broader opportunity. In 1946 he worked for the County of Los Angeles General Hospital, where he served with distinction. He lived his last years in Altadena, California and died at age 85.
Hardiman's life is the subject of a documentary released in 2011 that was written and produced by Wilbert Smith and directed by Brett Leonard. |
https://en.wikipedia.org/wiki/List%20of%20infections%20of%20the%20central%20nervous%20system | Infections of the central nervous system (CNS) consist of infections primarily of the brain and spinal cord. They include mostly viral infections, less commonly bacterial infections, fungal infections, prion diseases and protozoan infections. Neonatal meningitis is a particular classification by age.
By anatomical site
Brain abscess, Epidural abscess, including spinal epidural and cranial epidural
Encephalitis
Meningitis
By cause
There are five main causes of CNS infections, namely bacterial, viral, fungal, protozoal, protozoan infections and prionic infections.
Viral
Most forms of aseptic meningitis are viral in origin, though neoplastic and Lyme disease meningitis are also aseptic.
California encephalitis virus
Central nervous system viral disease
Cytomegalovirus encephalitis
SARS-CoV-2
Eastern equine encephalitis
Enterovirus encephalitis
Epstein Barr Virus encephalitis
Herpes simplex encephalitis
Influenza encephalitis
Japanese encephalitis
La Crosse encephalitis
Lymphocytic choriomeningitis by Arenavirus
Measles encephalitis
Mumps
Nipah virus encephalitis
Poliomyelitis
Progressive rubella panencephalitis, a late complication of congenital rubella syndrome
St. Louis encephalitis
Slow virus infections, which include:
Acquired immunodeficiency syndrome (AIDS)
Subacute sclerosing panencephalitis by Measles virus
Progressive multifocal leukoencephalopathy
Rabies
Tick-borne encephalitis
Varicella
Viral encephalitis lists 37 causes
Viral meningitis
Western equine encephalitis
Prionic
These are transmissible spongiform encephalopathies like:
Bovine spongiform encephalopathy in cattle
Chronic wasting disease in deer
Creutzfeldt–Jakob disease and its variant
Gerstmann–Sträussler–Scheinker syndrome
Kuru
Scrapie in sheep and goat
Transmissible mink encephalopathy
Variably protease-sensitive prionopathy
Fungal
Cryptococcal meningitis
Protozoan
Amoebic brain abscess
Granulomatous amoebic encephalitis
Malaria
Primary amoebic meningoencepha |
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