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https://en.wikipedia.org/wiki/Sinclair%20QL%20character%20set | The Sinclair QL character set was developed by Sinclair Research for the Sinclair QL personal computer.
Character set |
https://en.wikipedia.org/wiki/Interindividual%20differences%20in%20perception | Interindividual differences in perception describes the effect that differences in brain structure or factors such as culture, upbringing and environment have on the perception of humans.
Interindividual (differing from person to person) variability is usually regarded as a source of noise for research. However, in recent years, it has become an interesting source to study sensory mechanisms and understand human behavior. With the help of modern neuroimaging methods such as fMRI and EEG, individual differences in perception could be related to the underlying brain mechanisms. This has helped to explain differences in behavior and cognition across the population. Common methods include studying the perception of illusions, as they can effectively demonstrate how different aspects such as culture, genetics and the environment can influence human behavior.
Optical Illusions
Bistable Motion
A motion quartet is a bistable stimulus - it consists of two dots that change their position from frame to frame. This position change can either be interpreted as horizontal or vertical movement by viewers, and this experience can switch during viewing between interpretations. Depending on the aspect ratio of the two dots' positions, one or the other state is perceived longer or more often. At an aspect ratio of one, the illusion is biased towards the vertical perception. The reason for this might be the way the human brain processes the signals from both eyes in the visual system. The right half of an eye's field of view is processed by the left hemisphere, and the left half by the right hemisphere. A stimulus moving vertically only involves one field of view and so one hemisphere, while a stimulus moving vertically from one field of view to the other involves both hemispheres, and requires communication between them. The delay caused by this additional signalling might be the cause for the bias. There are also individual differences in the way the motion quartet is perceived |
https://en.wikipedia.org/wiki/Alfred%20Tarski | Alfred Tarski (, born Alfred Teitelbaum; January 14, 1901 – October 26, 1983) was a Polish-American logician and mathematician. A prolific author best known for his work on model theory, metamathematics, and algebraic logic, he also contributed to abstract algebra, topology, geometry, measure theory, mathematical logic, set theory, and analytic philosophy.
Educated in Poland at the University of Warsaw, and a member of the Lwów–Warsaw school of logic and the Warsaw school of mathematics, he immigrated to the United States in 1939 where he became a naturalized citizen in 1945. Tarski taught and carried out research in mathematics at the University of California, Berkeley, from 1942 until his death in 1983.
His biographers Anita Burdman Feferman and Solomon Feferman state that, "Along with his contemporary, Kurt Gödel, he changed the face of logic in the twentieth century, especially through his work on the concept of truth and the theory of models."
Life
Early life and education
Alfred Tarski was born Alfred Teitelbaum (Polish spelling: "Tajtelbaum"), to parents who were Polish Jews in comfortable circumstances. He first manifested his mathematical abilities while in secondary school, at Warsaw's Szkoła Mazowiecka. Nevertheless, he entered the University of Warsaw in 1918 intending to study biology.
After Poland regained independence in 1918, Warsaw University came under the leadership of Jan Łukasiewicz, Stanisław Leśniewski and Wacław Sierpiński and quickly became a world-leading research institution in logic, foundational mathematics, and the philosophy of mathematics. Leśniewski recognized Tarski's potential as a mathematician and encouraged him to abandon biology. Henceforth Tarski attended courses taught by Łukasiewicz, Sierpiński, Stefan Mazurkiewicz and Tadeusz Kotarbiński, and in 1924 became the only person ever to complete a doctorate under Leśniewski's supervision. His thesis was entitled O wyrazie pierwotnym logistyki (On the Primitive Term of Logis |
https://en.wikipedia.org/wiki/Strangeness%20and%20quark%E2%80%93gluon%20plasma | In high-energy nuclear physics, strangeness production in relativistic heavy-ion collisions is a signature and diagnostic tool of quark–gluon plasma (QGP) formation and properties. Unlike up and down quarks, from which everyday matter is made, heavier quark flavors such as strange and charm typically approach chemical equilibrium in a dynamic evolution process. QGP (also known as quark matter) is an interacting localized assembly of quarks and gluons at thermal (kinetic) and not necessarily chemical (abundance) equilibrium. The word plasma signals that color charged particles (quarks and/or gluons) are able to move in the volume occupied by the plasma. The abundance of strange quarks is formed in pair-production processes in collisions between constituents of the plasma, creating the chemical abundance equilibrium. The dominant mechanism of production involves gluons only present when matter has become a quark–gluon plasma. When quark–gluon plasma disassembles into hadrons in a breakup process, the high availability of strange antiquarks helps to produce antimatter containing multiple strange quarks, which is otherwise rarely made. Similar considerations are at present made for the heavier charm flavor, which is made at the beginning of the collision process in the first interactions and is only abundant in the high-energy environments of CERN's Large Hadron Collider.
Quark–gluon plasma in the early universe and in the laboratory
Free quarks probably existed in the extreme conditions of the very early universe until about 30 microseconds after the Big Bang, in a very hot gas of free quarks, antiquarks and gluons. This gas is called quark–gluon plasma (QGP), since the quark-interaction charge (color charge) is mobile and quarks and gluons move around. This is possible because at a high temperature the early universe is in a different vacuum state, in which normal matter cannot exist but quarks and gluons can; they are deconfined (able to exist independently as se |
https://en.wikipedia.org/wiki/Hyperphantasia | Hyperphantasia is the condition of having extremely vivid mental imagery. It is the opposite condition to aphantasia, where mental visual imagery is not present. The experience of hyperphantasia is more common than aphantasia and has been described as being "as vivid as real seeing". Hyperphantasia constitutes all five senses within vivid mental imagery, although literature on the subject is dominated by "visual" mental imagery research, with a lack of research on the other four senses.
Research into hyperphantasia is most commonly completed by self-report questionnaires, such as the Vividness of Visual Imagery Questionnaire (VVIQ), developed by David Marks in 1973, which evaluates the vividness of an individual's mental imagery out of a score of 80. Individuals scoring from 75 to 80 are deemed hyperphantasics and are estimated to constitute around 2.5% of the population.
Mechanism
There is no reliably specific mental imagery cortical network; the formation of mental imagery involves many regions of the brain, as mental imagery shares many common brain regions with other cognitive functions. Neurological evidence has shown that in the creation of imagery, neural activity spans prefrontal, parietal, temporal and visual areas. Within the neuroscience of imagery, it is often split into three primary aspects: the triggering of imagery, its generation/manipulation, and the underlying vividness of the imagery.
The mechanism underlying the vividness of imagery which may explain disorders like hyperphantasia is controversial amongst the literature. The current findings of the mechanism of hyperphantasia are related to two regions of the brain: the early visual cortex and the frontal cortex.
Recent research has shown the relationship between the size (surface area) of the early visual cortex (V1-V3), specifically V1 and to a lesser degree V2 (but not V3), negatively predicts imagery strength within individuals. This relationship is evidenced across both clinical and non |
https://en.wikipedia.org/wiki/Austrian%20Physical%20Society | The Austrian Physical Society () is the national physical society of Austria.
History
Until 1938, Austrian physicists were part of the German Physical Society. On 13 December 1950, it was decided to found a separate society for Austria and Fritz Kohlrausch was elected as first president in 1951.
Prizes
Every year it awards a prize to a promising young physicist. Alternating every year, this is the Ludwig Boltzmann Prize for theoretical physics
and the Fritz Kohlrausch Prize for experimental physics.
See also
Lise Meitner Lectures |
https://en.wikipedia.org/wiki/Everett%20C.%20Dade | Everett Clarence Dade is a mathematician at University of Illinois at Urbana–Champaign working on finite groups and representation theory, who introduced the Dade isometry and Dade's conjecture. While an undergraduate at Harvard University, he became a Putnam Fellow twice, in 1955 and 1957.
Work
The Dade isometry is an isometry from class functions on a subgroup H with support on a subset K of H to class functions on a group G . It was introduced by as a generalization and simplification of an isometry used by in their proof of the odd order theorem, and was used by in his revision of the character theory of the odd order theorem.
Dade's conjecture is a conjecture relating the numbers of characters of blocks of a finite group to the numbers of characters of blocks of local subgroups. |
https://en.wikipedia.org/wiki/Synsepal | A synsepal is a floral structure formed by the partial or complete fusion of two or more sepals. Such sepals are said to be gamosepalous.
It is common among Lady's Slipper orchids (Cypripedioideae) that the two lateral sepals are connate to form a synsepal in the outer whorl. This is located directly behind the pouch, opposite the upward-pointing dorsal sepal.
Synsepals may be bifid, i.e. divided into two equal lobes, or forked and divided in two by a deep cleft. |
https://en.wikipedia.org/wiki/Toasternet | Toasternets were an early-1990s instantiation of the decentralized Internet, featuring open-standards-based federated services, radical decentralization, ad-hoc routing and consisting of many small individual and collective networks rather than a cartel of large commercial Internet Service Provider networks. Today's "community networks" and decentralized social networks are the closest modern inheritors of the ethos of the 1991-1994 era Toasternets.
History
The first known use of the word was by Robert Ullmann, then active in the Internet Engineering Task Force developing next-generation Internet addressing and routing protocols. He circulated two documents, entitled Toasternet Part I (December 1989) and Toasternet Part II (March 1992) on the IETF mailing list, and then published RFCs 1475 and 1476 and the "CATNIP" Internet-Draft in June 1993.
Early toasternet proponent Tim Pozar described them thus:
Pozar, and other early toasternet builders Bill Woodcock and John Gilmore were participants in the cooperative The Little Garden, the first Internet service provider based on the west coast of the United States. Founded and led by Tom Jennings, The Little Garden (named for the Vietnamese restaurant where its foundational meetings were held) was an Internet Service Provider network built between 1992 and 1996 in the toasternet ethos, and consisting of constituent toasternet members; some individual, and some collective. Many of the initial Little Garden members went on to become founding members of Packet Clearing House, the not-for-profit which now supports core Internet infrastructure globally, but still continues to promulgate the toasternet values of collaborative competition and "permissionless" new market entry.
Writing contemporaneously in Wired, Jonathan Steuer said,
Gareth Bronwyn, also writing in Wired in 1993, defined them much more haphazardly, saying that they used "Cheap Internet routers made with old PCs" and coining the umbrella term "grunge computin |
https://en.wikipedia.org/wiki/Inverse%20consistency | In image registration, inverse consistency measures the consistency of mappings between images produced by a registration algorithm. The inverse consistency error, introduced by Christiansen and Johnson in 2001, quantifies the distance between the composition of the mappings from each image to the other, produced by the registration procedure, and the identity function, and is used as a regularisation constraint in the loss function of many registration algorithms to enforce consistent mappings. Inverse consistency is necessary for good image registration but it is not sufficient, since a mapping can be perfectly consistent but not register the images at all.
Definition
Image registration is the process of establishing a common coordinate system between two images, and given two images
registering a source image to a target image consists of determining a transformation that maps points from the target space to the source space. An ideal registration algorithm should not be sensitive to which image in the pair is used as source or target, and the registration operator should be antisymmetric such that the mappings
produced when registering to and to respectively should be the inverse of each other, i.e. and or, equivalently, and , where denotes the function composition operator.
Real algorithms are not perfect, and when swapping the role of source and target image in a registration problem the so obtained transformations are not the inverse of each other. Inverse consistency can be enforced by adding to the loss function of the registration a symmetric regularisation term that penalises inconsistent transformations
Inverse consistency can be used as a quality metric to evaluate image registration results. The inverse consistency error () measures the distance between the composition of the two transforms and the identity function, and it can be formulated in terms of both average () or maximum () over a region of interest of the image:
While inve |
https://en.wikipedia.org/wiki/Dana%20Scott | Dana Stewart Scott (born October 11, 1932) is an American logician who is the emeritus Hillman University Professor of Computer Science, Philosophy, and Mathematical Logic at Carnegie Mellon University; he is now retired and lives in Berkeley, California. His work on automata theory earned him the Turing Award in 1976, while his collaborative work with Christopher Strachey in the 1970s laid the foundations of modern approaches to the semantics of programming languages. He has worked also on modal logic, topology, and category theory.
Early career
He received his B.A. in Mathematics from the University of California, Berkeley, in 1954. He wrote his Ph.D. thesis on Convergent Sequences of Complete Theories under the supervision of Alonzo Church while at Princeton, and defended his thesis in 1958. Solomon Feferman (2005) writes of this period:
After completing his Ph.D. studies, he moved to the University of Chicago, working as an instructor there until 1960. In 1959, he published a joint paper with Michael O. Rabin, a colleague from Princeton, titled Finite Automata and Their Decision Problem (Scott and Rabin 1959) which introduced the idea of nondeterministic machines to automata theory. This work led to the joint bestowal of the Turing Award on the two, for the introduction of this fundamental concept of computational complexity theory.
University of California, Berkeley, 1960–1963
Scott took up a post as Assistant Professor of Mathematics, back at the University of California, Berkeley, and involved himself with classical issues in mathematical logic, especially set theory and Tarskian model theory. He proved that the axiom of constructibility is incompatible with the existence of a measurable cardinal, a result considered seminal in the evolution of Set Theory.
During this period he started supervising Ph.D. students, such as James Halpern (Contributions to the Study of the Independence of the Axiom of Choice) and Edgar Lopez-Escobar (Infinitely Long Formulas |
https://en.wikipedia.org/wiki/Ground%20vibration%20boom | Ground vibration boom is a phenomenon of very large increase in ground vibrations generated by high-speed railway trains travelling at speeds higher than the velocity of Rayleigh surface waves in the supporting ground.
Technical background
This phenomenon, which is similar to a sonic boom from supersonic aircraft, was theoretically predicted in 1994. Its first experimental observation took place in 1997-1998 on the newly built high-speed railway line in Sweden (from Gothenburg to Malmo) for high-speed trains X 2000. At some locations along this line characterised by very soft ground (near Ledsgard) the Rayleigh wave velocity was as low as , and train speeds of only were sufficient to observe the effect. In particular, the increase in train speeds from was accompanied by about tenfold increase in generated ground vibration level, which agrees with the theory. It is now understood that, with the increase of operating train speeds, this phenomenon represents a major environmental problem associated with building new high-speed railway lines.
Mitigation measures
The most efficient way to mitigate ground vibration boom is to reduce train speeds at locations where Rayleigh wave velocities in the ground are very low. If this is not desirable, e.g. for economic reasons, some mitigation measures can be applied, such as stiffening of railway embankments or building protective trenches and barriers between railways and residential or industrial buildings. Any mitigation measures would involve the specific ground investigation works along the route.
See also
High-speed trains
Rayleigh waves
Mach number
Supershear earthquake |
https://en.wikipedia.org/wiki/Human%20ethology | Human ethology is the study of human behavior.
Ethology as a discipline is generally thought of as a sub-category of biology, though psychological theories have been developed based on ethological ideas (e.g. sociobiology, evolutionary psychology, attachment theory, and theories about human universals such as gender differences, incest avoidance, mourning, hierarchy and pursuit of possession). The bridging between biological sciences and social sciences creates an understanding of human ethology. The International Society for Human Ethology is dedicated to advancing the study and understanding of human ethology.
History
Ethology has its roots in the study of evolution, especially after evolution's increasing popularity after Darwin's detailed observations. It became a distinct discipline in the 1930s with zoologists Konrad Lorenz, Niko Tinbergen and Karl Von Frisch. These three scientists are known as the major contributors to human ethology. They are also regarded as the fathers or founders of ethology. Konrad Lorenz and Niko Tinbergen rejected theories that relied on stimuli and learning alone, and elaborated on concepts that had not been well understood, such as instinct. They promoted the theory that evolution had placed within creatures innate abilities and responses to certain stimuli that advanced the thriving of the species. Konrad Lorenz also indicated in his earlier works that animal behavior can be a major reference for human behavior. He believed that the research and findings of animal behaviors can lead to findings of human behaviors as well. In 1943, Lorenz devoted much of his book, "" to human behavior. He designated that one of the most important factors of ethology was testing the hypothesis derived from animal behavioral studies on human behavioral studies. Due to Lorenz promoting the similarities between studying animal and human behavior, human ethology derived from the study of anima behavior. The other founders of ethology, Niko Tinbergen and |
https://en.wikipedia.org/wiki/Automated%20decision-making | Automated decision-making (ADM) involves the use of data, machines and algorithms to make decisions in a range of contexts, including public administration, business, health, education, law, employment, transport, media and entertainment, with varying degrees of human oversight or intervention. ADM involves large-scale data from a range of sources, such as databases, text, social media, sensors, images or speech, that is processed using various technologies including computer software, algorithms, machine learning, natural language processing, artificial intelligence, augmented intelligence and robotics. The increasing use of automated decision-making systems (ADMS) across a range of contexts presents many benefits and challenges to human society requiring consideration of the technical, legal, ethical, societal, educational, economic and health consequences.
Overview
There are different definitions of ADM based on the level of automation involved. Some definitions suggests ADM involves decisions made through purely technological means without human input, such as the EU's General Data Protection Regulation (Article 22). However, ADM technologies and applications can take many forms ranging from decision-support systems that make recommendations for human decision-makers to act on, sometimes known as augmented intelligence or 'shared decision-making', to fully automated decision-making processes that make decisions on behalf of individuals or organizations without human involvement. Models used in automated decision-making systems can be as simple as checklists and decision trees through to artificial intelligence and deep neural networks (DNN).
Since the 1950s computers have gone from being able to do basic processing to having the capacity to undertake complex, ambiguous and highly skilled tasks such as image and speech recognition, gameplay, scientific and medical analysis and inferencing across multiple data sources. ADM is now being increasingly deployed acr |
https://en.wikipedia.org/wiki/Dynamin%20superfamily | Dynamin Superfamily Protein (DSP) is a protein superfamily includes classical dynamins, GBPs, Mx proteins, OPA1, mitofusins in Eukaryote, and bacterial dynamin-like proteins (BDLPs) in Prokaryote. DSPs mediate eukaryotic membrane fusion and fission necessary for endocytosis, organelle biogenesis and maintenance, Mitochondrial fusion and fission, as well as for prokaryotic cytokinesis.
Structure
All DSPs have two common domains: a GTPase domain and an elongated α-helical bundle domain. |
https://en.wikipedia.org/wiki/Proactive%20network%20provider%20participation%20for%20P2P | P4P, or proactive network provider participation for P2P, is a method for internet service providers (ISPs) and peer-to-peer (P2P) software to optimize peer-to-peer connections. P4P proponents say that it can save an ISP significant costs, and that using local connections also speeds up download times for P2P downloaders by 45%, critics say that this will favor downloaders on some ISPs but come at the expense of others.
Description
Established in 2007, the P4P Working Group (P4PWG) has participants from the ISP, movie/content, and P2P industries. It is focused on helping ISPs handle the demands of large media files and enabling legal distribution – they are building what they believe will be a more effective model of transmitting movies and other large files to customers. The current P2P model shares data equally with all peers, regardless of whether they are nearby, and this results in several nearby peers sending and receiving data across the world but not to each other when this is possible – working group members say that currently "the pattern of traffic poses a problem".
P4P works by having an ISP use a new "iTracker" which provides information on how the ISP's network is configured. P2P client software (and P2P torrent servers, called trackers) can query the iTracker to identify the data routes the ISP prefers and connections to avoid, changing depending on the time of day. The P2P software can then co-operatively connect to peers which are closer (or cheaper for the ISP), selectively favoring peers instead of choosing peers randomly.
This provides three methods of finding local peers:
the P2P client receives network information from the ISP's iTracker without revealing what file is being downloaded. It separately receives a list of peers from the torrent's tracker as usual. Note that for torrents with thousands of peers, when queried only a short list of potential peers is sent and it can take many queries to find all local peers
the torrent's tracker |
https://en.wikipedia.org/wiki/HP%20250 | The HP 250 was a multiuser business computer by Hewlett-Packard running HP 250 BASIC language as its OS with access to HP's IMAGE database management. It was produced by the General Systems Division (GSD), but was a major repackaging of desktop workstation HP 9835 which had been sold in small business configurations. The HP 9835's processor was initially used in the first HP 250s.
The HP 250 borrowed the embedded keyboard design from the HP 300 and added a wider slide-able and tilt-able monitor with screen labeled function keys buttons physically placed just below on-screen labels (a configuration now used in ATMs and gas pumps) built into a large desk design.
Though the HP 250 had a different processor and operating system, it used similar interface cards to the HP 300, and then later also the HP 3000 models 30, 33, 40, 42, 44, and 48: HP-IB channel (GIC), Network, and serial (MUX) cards. Usually the HP250 was a small HP-IB single channel system (limited to seven HP-IB devices per GIC at a less than 1 MHz bandwidth).
Initially the HP 250 was like the HP300 as a single user, floppy based computer system. Later a multi-user ability was added, and the HP300's embedded hard drive was installed as a boot drive. Additionally, drivers were made available to connect and use more HP-IB devices: hard disc and tape drives, plus impact and matrix printers. This gave some business-growth scale-ability to the HP250 product line.
The HP 250 was advertised in 1978 and was promoted more in Europe as an easy-to-use, small space, low cost business system, and thus sold better in Europe. The next-gen HP 250 was the HP 260 which lost the table, embedded keyboard, and CRT for a small stand-alone box.
HP systems moved away from all-in-one table top designs to having the system in a remote secure location, and remotely connecting user's terminals and peripherals out to in their work area. In those days, RS-232 cables ran from desk side terminals (262x low cost terminals) to the HP 25 |
https://en.wikipedia.org/wiki/Holomorphic%20separability | In mathematics in complex analysis, the concept of holomorphic separability is a measure of the richness of the set of holomorphic functions on a complex manifold or complex-analytic space.
Formal definition
A complex manifold or complex space is said to be holomorphically separable, if whenever x ≠ y are two points in , there exists a holomorphic function , such that f(x) ≠ f(y).
Often one says the holomorphic functions separate points.
Usage and examples
All complex manifolds that can be mapped injectively into some are holomorphically separable, in particular, all domains in and all Stein manifolds.
A holomorphically separable complex manifold is not compact unless it is discrete and finite.
The condition is part of the definition of a Stein manifold. |
https://en.wikipedia.org/wiki/Oscarella%20carmela | Oscarella carmela, commonly known as the slime sponge, is a species of sponge in the order Homosclerophorida that was first described in 2004 by G. Muricy and J.S. Pearse. It is believed to be native to intertidal waters in the north east temperate Pacific Ocean and was first found in seawater aquaria in that region. It is used as a model organism in evolutionary biology.
Description
Oscarella carmela is either encrusting or massive and forms a slimy covering or a thicker layer of spongy matter with an uneven, lumpy, lobed surface. It grows in patches on hard substrates up to in diameter and overgrows other organisms. The colour is variable and ranges from orange-brown to tan or beige. This sponge does not contain spicules or spongin to reinforce its body wall and has a simple structure with only two types of cell with inclusions.
Distribution and habitat
Oscarella carmela is believed to be a native of northern and central Californian marine waters. It was first observed in Monterey Bay Aquarium and several research seawater aquaria in western California. It was later searched for, and eventually found, in the sea on the underside of boulders in rock pools in the high intertidal zone in Carmel Bay. Although it was not described until 2004, it is not believed to be an invasive species in the United States but is more likely to be indigenous and have been overlooked previously because it is uncommon and very similar to more common Halisarca species. It is in fact the only member of its genus Oscarella to be found in the eastern Pacific. It is hypothesized that in the wild it may be limited in its distribution by predation, whereas in the protected environment of an aquarium it grows profusely.
Biology
Like other sponges, Oscarella carmela is a filter feeder. It creates a current of water through its interior from which it extracts bacteria and planktonic food particles. Reproduction is viviparous and the planktonic larvae are the oval type known as amphiblastulae |
https://en.wikipedia.org/wiki/Quantifier%20rank | In mathematical logic, the quantifier rank of a formula is the depth of nesting of its quantifiers. It plays an essential role in model theory.
Notice that the quantifier rank is a property of the formula itself (i.e. the expression in a language). Thus two logically equivalent formulae can have different quantifier ranks, when they express the same thing in different ways.
Definition
Quantifier Rank of a Formula in First-order language (FO)
Let φ be a FO formula. The quantifier rank of φ, written qr(φ), is defined as
, if φ is atomic.
.
.
.
Remarks
We write FO[n] for the set of all first-order formulas φ with .
Relational FO[n] (without function symbols) is always of finite size, i.e. contains a finite number of formulas
Notice that in Prenex normal form the Quantifier Rank of φ is exactly the number of quantifiers appearing in φ.
Quantifier Rank of a higher order Formula
For Fixpoint logic, with a least fix point operator LFP:
Examples
A sentence of quantifier rank 2:
A formula of quantifier rank 1:
A formula of quantifier rank 0:
A sentence in prenex normal form of quantifier rank 3:
A sentence, equivalent to the previous, although of quantifier rank 2:
See also
Prenex normal form
Ehrenfeucht game
Quantifier |
https://en.wikipedia.org/wiki/Decision%20tree%20model | In computational complexity the decision tree model is the model of computation in which an algorithm is considered to be basically a decision tree, i.e., a sequence of queries or tests that are done adaptively, so the outcome of previous tests can influence the tests performed next.
Typically, these tests have a small number of outcomes (such as a yes–no question) and can be performed quickly (say, with unit computational cost), so the worst-case time complexity of an algorithm in the decision tree model corresponds to the depth of the corresponding decision tree. This notion of computational complexity of a problem or an algorithm in the decision tree model is called its decision tree complexity or query complexity.
Decision trees models are instrumental in establishing lower bounds for complexity theory for certain classes of computational problems and algorithms. Several variants of decision tree models have been introduced, depending on the computational model and type of query algorithms are allowed to perform.
For example, a decision tree argument is used to show that a comparison sort of items must take comparisons. For comparison sorts, a query is a comparison of two items , with two outcomes (assuming no items are equal): either or . Comparison sorts can be expressed as a decision tree in this model, since such sorting algorithms only perform these types of queries.
Comparison trees and lower bounds for sorting
Decision trees are often employed to understand algorithms for sorting and other similar problems; this was first done by Ford and Johnson.
For example, many sorting algorithms are comparison sorts, which means that they only gain information about an input sequence via local comparisons: testing whether , , or . Assuming that the items to be sorted are all distinct and comparable, this can be rephrased as a yes-or-no question: is ?
These algorithms can be modeled as binary decision trees, where the queries are comparisons: an internal no |
https://en.wikipedia.org/wiki/Model%20maker | A Model maker is a professional Craftsperson who creates a three-dimensional representation of a design or concept. Most products in use and in development today first take form as a model. This "model" may be an exacting duplicate (prototype) of the future design or a simple mock-up of the general shape or concept. Many prototype models are used for testing physical properties of the design, others for usability and marketing studies.
Mock-ups are generally used as part of the design process to help convey each new iteration. Some model makers specialize in "scale models" that allow an easier grasp of the whole design or for portability of the model to a trade show or an architect or client's office. Other scale models are used in museum displays and in the movie special effects industry. Model makers work in many environments from private studio/shops to corporate design and engineering facilities to research laboratories.
The model maker must be highly skilled in the use of many machines, such as manual lathes, manual mills, Computer Numeric Control (CNC) machines, lasers, wire EDM, water jet saws, tig welders, sheet metal fabrication tools and wood working tools. Fabrication processes model makers take part in are powder coating, shearing, punching, plating, folding, forming and anodizing. Some model makers also use increasingly automated processes, for example cutting parts directly with digital data from computer-aided design plans on a CNC mill or creating the parts through rapid prototyping. Hand tools used by a model maker are an exacto knife, tweezers, sprue cutter, tape, glue, paint, and paint brushes.
There are two basic processes used by the model maker to create models: additive and subtractive. Additive can be as simple as adding clay to create a form, sculpting and smoothing to the final shape. Body fillers, foam and resins are also used in the same manner. Most rapid prototyping technologies are based on the additive process, solidifying thin la |
https://en.wikipedia.org/wiki/Thermal%20energy%20storage | Thermal energy storage (TES) is achieved with widely different technologies. Depending on the specific technology, it allows excess thermal energy to be stored and used hours, days, months later, at scales ranging from the individual process, building, multiuser-building, district, town, or region. Usage examples are the balancing of energy demand between daytime and nighttime, storing summer heat for winter heating, or winter cold for summer air conditioning (Seasonal thermal energy storage). Storage media include water or ice-slush tanks, masses of native earth or bedrock accessed with heat exchangers by means of boreholes, deep aquifers contained between impermeable strata; shallow, lined pits filled with gravel and water and insulated at the top, as well as eutectic solutions and phase-change materials.
Other sources of thermal energy for storage include heat or cold produced with heat pumps from off-peak, lower cost electric power, a practice called peak shaving; heat from combined heat and power (CHP) power plants; heat produced by renewable electrical energy that exceeds grid demand and waste heat from industrial processes. Heat storage, both seasonal and short term, is considered an important means for cheaply balancing high shares of variable renewable electricity production and integration of electricity and heating sectors in energy systems almost or completely fed by renewable energy.
Categories
The different kinds of thermal energy storage can be divided into three separate categories: sensible heat, latent heat, and thermo-chemical heat storage. Each of these has different advantages and disadvantages that determine their applications.
Sensible heat storage
Sensible heat storage (SHS) is the most straightforward method. It simply means the temperature of some medium is either increased or decreased. This type of storage is the most commercially available out of the three; other techniques are less developed.
The materials are generally inexpens |
https://en.wikipedia.org/wiki/Idioblast | An idioblast is an isolated plant cell that differs from neighboring tissues. They have various functions such as storage of reserves, excretory materials, pigments, and minerals. They could contain oil, latex, gum, resin, tannin, or pigments etc. Some can contain mineral crystals such as acrid tasting and poisonous calcium oxalate, carbonate, or silica.
Any of the tissue or tissue systems of plants can contain idioblasts.
Idioblasts are divided into three main categories: excretory, tracheoid, and sclerenchymatous.
Idioblasts can contain biforine cells that form crystals. The chemicals are excreted by the plant and stored in liquid or crystalline form. In bundles they are known as druse and as crystals they can be of raphide [needle] form. When the end of an idioblast is broken the crystals or other substance is ejected by internal water pressure. Idioblasts of calcium oxalate may function as a deterrent to herbivores, as a means of sequestering or storing calcium, or as a means of stiffening tissue structure.
Three Types of Idioblast
Excretory idioblasts store oils, lipids, tannins, mucilage, and minerals. They are currently under research for their storage of the important medicinal qualities of plants. Selective culturing of excretory idioblasts allows better harvesting of their stored products.
Tracheoid idioblasts strongly resemble tracheids, or water-conducting cells. Tracheoids are elongated idioblasts with helical or reticulate secondary walls. They are not connected to the plant’s vascular system. Tracheoid idioblasts have also been known as lignified idioblasts, spiral cells, tracheoidal idioblasts, spirally thickened sclereids, and tracheoidioblasts.
Sclerenchymatous idioblasts are thickened structural cells that provide stability and rigidity to the plant. In multiples they are known as sclereids. A singular sclerenchymatous idioblast is less common than the grouped sclereids. Their development and differentiation is unknown.
Crystals
There |
https://en.wikipedia.org/wiki/ISheriff | iSheriff (formerly Internet Sheriff) is an Internet security software vendor that specializes in cloud-based security and compliance, with specialties in E-mail filtering, Web filters and endpoint security. The company is privately held and based in Redwood City, California. iSheriff sells their products through partners and distributors.
History
Founded in Brisbane, Australia in 1999 by Oscar Marquez, iSheriff products focused on content filtering, email and Web filtering software and appliances. In 2009 the company moved its products to a cloud computing service model.
iSheriff services include e-mail filtering, web filtering, email archiving, e-mail encryption and security reporting. The company holds a patent for its data modeling engine based on Bayesian spam filtering principals.
In 2006, iSheriff provided Internet filtering software to the Tasmanian government's first statewide trial of anti-pornography filters for children.
In July 2012, Total Defense, Inc., a provider of cybercrime-fighting technology, announced they had acquired iSheriff.
On April 21, 2014, Total Defense announced that, in conjunction with the sale of their consumer business unit to Untangle, they re-branded as iSheriff.
iSheriff’s Cloud Security Suite
Email Security and Archiving – Cloud-based anti-spam, email security and email archiving, removing incoming email of spam, providing a clean email connection which secures against viruses, unwanted content and data leakage, as well as cloud-based archiving.
Web security – Cloud-based content and malware filtering, providing secure internet browsing, enforcement of acceptable use policies and data leak protection.
Endpoint security – Cloud-based platform with a multi-layer anti-malware approach that protects from malware, secures & controls applications being used by end users and protects against threats from removable media. |
https://en.wikipedia.org/wiki/Lichen%20product | Lichen products, also known as lichen substances, are organic compounds produced by a lichen. Specifically, they are secondary metabolites. Lichen products are represented in several different chemical classes, including terpenoids, orcinol derivatives, chromones, xanthones, depsides, and depsidones. Over 800 lichen products of known chemical structure have been reported in the scientific literature, and most of these compound are exclusively found in lichens. Examples of lichen products include usnic acid (a dibenzofuran), atranorin (a depside), lichexanthone (a xanthone), salazinic acid (a depsidone), and isolichenan, an α-glucan. Many lichen products have biological activity, and research into these effects is ongoing.
Lichen products accumulate on the outer walls of the fungal hyphae, and are quite stable. Crystal deposits can be visualised using scanning electron microscopy. For this reason, even very old herbarium specimens can be analysed. The amount of lichen products in lichen (as a percentage of dry weight) is typically between 0.1%–10%, although in some instances it may be as high as 30%. They are usually found in the medulla, or less commonly, the cortex.
Most lichen products are biochemically synthesized via the acetyl-polymalonyl pathway (also known as polyketide pathway), while only a few originate from the mevalonate and shikimate biosynthetic pathways.
In 1907, Wilhelm Zopf identified and classified about 150 lichen products. Seventy years later, this number had risen to 300, and by 1995, 850 lichen products were known; as of 2021, more than 1000 have been identified. Analytical methods were developed in the 1970s using thin-layer chromatography for the routine identification of lichen products. More recently, published techniques demonstrate ways to more efficiently harvest secondary metabolites from lichen samples. |
https://en.wikipedia.org/wiki/CARDboard%20Illustrative%20Aid%20to%20Computation | CARDIAC (CARDboard Illustrative Aid to Computation) is a learning aid developed by David Hagelbarger and Saul Fingerman for Bell Telephone Laboratories in 1968 to teach high school students how computers work. The kit consists of an instruction manual and a die-cut cardboard "computer".
The computer "operates" by means of pencil and sliding cards. Any arithmetic is done in the head of the person operating the computer. The computer operates in base 10 and has 100 memory cells which can hold signed numbers from 0 to ±999. It has an instruction set of 10 instructions which allows CARDIAC to add, subtract, test, shift, input, output and jump.
Hardware
The “CPU” of the computer consists of 4 slides that move various numbers and arrows to have the flow of the real CPU (the user's brain) move the right way. They have one flag (+/-), affected by the result in the accumulator.
Memory consists of the other half of the cardboard cutout. There are 100 cells. Cell 0 is “ROM”, always containing a numeric "1"; cells 1 to 98 are “RAM”; available for instructions and data; and cell 99 can best be described as “EEPROM”.
Memory cells hold signed decimal numbers from 0 to ±999 and are written with a pencil. Cells are erased with an eraser. A “bug” is provided to act as a program counter, and is placed in a hole beside the current memory cell.
Programming
CARDIAC has a 10 instruction machine language. An instruction is three decimal digits (the sign is ignored) in the form OAA. The first digit is the op code (O); the second and third digits are an address (AA). Addressing is one of accumulator to memory absolute, absolute memory to accumulator, input to absolute memory and absolute memory to output.
High level languages have never been developed for CARDIAC as they would defeat one of the purposes of the device: to introduce concepts of assembly language programming.
Programs are hand assembled and then are penciled into the appropriate memory cells.
Instruction Set
Operat |
https://en.wikipedia.org/wiki/Polyakov%20formula | In differential geometry and mathematical physics (especially string theory), the Polyakov formula expresses the conformal variation of the zeta functional determinant of a Riemannian manifold. Proposed by Alexander Markovich Polyakov this formula arose in the study of the quantum theory of strings. The corresponding density is local, and therefore is a Riemannian curvature invariant. In particular, whereas the functional determinant itself is prohibitively difficult to work with in general, its conformal variation can be written down explicitly. |
https://en.wikipedia.org/wiki/Recursive%20indexing | Recursive indexing is an algorithm used to represent large numeric values using members of a relatively small set.
Recursive indexing writes the successive differences of the number after extracting the maximum value of the alphabet set from the number, and continuing recursively till the difference falls in the range of the set.
Recursive indexing with a 2-letter alphabet is called unary code.
Encoding
To encode a number N, keep reducing the maximum element of this set (Smax) from N and output Smax for each such difference, stopping when the number lies in the half closed half open
range [0 – Smax).
Example
Let S = [0 1 2 3 4 … 10], be an 11-element set, and we have to recursively index the value N=49.
According to this method, subtract 10 from 49 and iterate until the difference is a number in the 0–10 range.
The values are 10 (N = 49 – 10 = 39), 10 (N = 39 – 10 = 29), 10 (N = 29 – 10 = 19), 10 (N = 19 – 10 = 9), 9. The recursively indexed sequence for N = 49 with set S, is 10, 10, 10, 10, 9.
Decoding
Compute the sum of the index values.
Example
Decoding the above example involves 10 + 10 + 10 + 10 + 9 = 49.
Uses
This technique is most commonly used in run-length encoding systems to encode longer runs than the alphabet sizes permit. |
https://en.wikipedia.org/wiki/Parallel%20transport | In geometry, parallel transport (or parallel translation) is a way of transporting geometrical data along smooth curves in a manifold. If the manifold is equipped with an affine connection (a covariant derivative or connection on the tangent bundle), then this connection allows one to transport vectors of the manifold along curves so that they stay parallel with respect to the connection.
The parallel transport for a connection thus supplies a way of, in some sense, moving the local geometry of a manifold along a curve: that is, of connecting the geometries of nearby points. There may be many notions of parallel transport available, but a specification of one — one way of connecting up the geometries of points on a curve — is tantamount to providing a connection. In fact, the usual notion of connection is the infinitesimal analog of parallel transport. Or, vice versa, parallel transport is the local realization of a connection.
As parallel transport supplies a local realization of the connection, it also supplies a local realization of the curvature known as holonomy. The Ambrose–Singer theorem makes explicit this relationship between the curvature and holonomy.
Other notions of connection come equipped with their own parallel transportation systems as well. For instance, a Koszul connection in a vector bundle also allows for the parallel transport of vectors in much the same way as with a covariant derivative. An Ehresmann or Cartan connection supplies a lifting of curves from the manifold to the total space of a principal bundle. Such curve lifting may sometimes be thought of as the parallel transport of reference frames.
Parallel transport on a vector bundle
Let M be a smooth manifold. Let E→M be a vector bundle with covariant derivative ∇ and γ: I→M a smooth curve parameterized by an open interval I. A section of along γ is called parallel if
By example, if is a tangent space in a tangent bundle of a manifold, this expression means that, for ever |
https://en.wikipedia.org/wiki/European%20Society%20for%20Paediatric%20Infectious%20Diseases | The European Society for Paediatric Infectious Diseases (ESPID) is a non-profit medical association registered in Germany that focuses on paediatric infectious diseases. Since its founding in 1983, it has grown to include over 1300 members, from all over Europe and beyond. ESPID forms the basis for European clinicians and scientists interested in all aspects of infectious diseases in children and their prevention. The society is engaged in a number of activities including the organization of multicentre trials, international exchange of paediatric infectious disease fellows, educational activities, and an annual scientific conference.
Mission
ESPID promotes "excellence in paediatric infectious diseases."
Activities
ESPID offers several grants and fellowship awards to facilitate information exchange, education, and research in the field of paediatric infectious diseases. The exact scope of each of these awards varies. The Small Grant Award and the Young Investigator Award fund individual research projects. The former focuses on projects designed to acquire preliminary data, while the latter funds researchers under 40 years of age. ESPID also supports research through its Collaborative Research Meeting Scheme, which funds projects conducted by members of more than one European nation. ESPID funds two sets of fellowship awards. The ESPID Fellowships Awards provide funding for basic research or clinical research.
More recently further awards have been introduced to its members and the full list of awards available are:
Fellowship Award
General Travel Award
Postgraduate Teaching Visits to Resource Poor Countries
Small Grant Award
Training Course and Workshop Award
Clinical Training Fellowship
Young Investigator Award
Collaborative Research Meeting Award
ESPID Annual Meeting Travel Award
Research Training Fellowship
ESPID/INOPSU Infection Surveillance Research Grant
ESPID-PIDJ Award
ESPID Supported Speaker Award
The criteria for each award is reviewed |
https://en.wikipedia.org/wiki/Trofeu | Trofeu is a line of 1/43 scale diecast vehicles made by Replicar in Portugal. The company was started in 1989, in Espinho just south of Oporto - the same town where Metosul and Luso Toys had previously been made in the 1960s and 1970s. Trofeu products are mainly contemporary rally cars alongside their stock counterparts.
Product history
The first model was a 1987 Ford Sierra Cosworth RAC Rally, which had been driven by Stig Blomqvist. It was released in March 1989. In 1990, the second model was introduced, a Toyota Celica GT4 ST165. Trofeu also manufactured the newer Toyota Celica GT-Four ST185 and ST205 in both rally and stock guises.
Trofeu miniature cars were made of diecast metal mounted on plastic chassis. Most cost about 40 Euros.
As is common with diecast makers today, one rally model would commonly be made in multiple liveries to save on tooling costs. For example, the mid-1970s European Ford Escort RS2000 appeared in Trofeu's line-up in more than 30 different variations, produced up through at least 2004.
Besides rally
Though rally cars were standard fare, Le Mans and prototype racing models often appeared such as the Porsche LMP and 936. The occasional taxi and police car also were produced. One odd model, considering the normal fare, was a Scandinavian Volvo Duett panel van.
Numbering and packaging
Early Trofeu models were numbered with 0 prefix such as 010-015 for Ford Sierra, 016-030 for Toyota Celica ST165 and 031-042 for the Mitusbishi Galant. The first Celica ST185 came with a 044 reference number, but later the whole Celica ST185 line was renumbered with four prefix numbers from 444 to 459. The next models also came with new reference numbers such as 7## for the Celica ST205.
Models were usually packaged in clear plastic display cases sometimes highlighted with folded card decor.
List of models
List of 1/43 scale cars by Trofeu:
Ford Sierra Cosworth
Toyota Celica GT4 ST165
Mitsubishi Galant VR4
Toyota Celica Turbo 4WD ST185
Ford Escort R |
https://en.wikipedia.org/wiki/Rectal%20tenesmus | Rectal tenesmus is a feeling of incomplete defecation. It is the sensation of inability or difficulty to empty the bowel at defecation, even if the bowel contents have already been evacuated. Tenesmus indicates the feeling of a residue, and is not always correlated with the actual presence of residual fecal matter in the rectum. It is frequently painful and may be accompanied by involuntary straining and other gastrointestinal symptoms. Tenesmus has both a nociceptive and a neuropathic component.
Often, rectal tenesmus is simply called tenesmus. The term rectal tenesmus is a retronym to distinguish defecation-related tenesmus from vesical tenesmus. Vesical tenesmus is a similar condition, experienced as a feeling of incomplete voiding despite the bladder being empty.
Tenesmus is a closely related topic to obstructed defecation. The term is from , from Greek , from to stretch, strain.
Considerations
Tenesmus is characterized by a sensation of needing to pass stool, accompanied by pain, cramping, and straining. Despite straining, little stool is passed. Tenesmus is generally associated with inflammatory diseases of the bowel, which may be caused by either infectious or noninfectious conditions. Conditions associated with tenesmus include:
Amebiasis
Chronic arsenic poisoning
Coeliac disease
Colorectal cancer
Anal melanoma
Cystocele
Cytomegalovirus (in immunocompromised patients)
Diverticular disease
Dysentery
Hemorrhoid, which are prolapsed
Imperforate hymen
Inflammatory bowel disease
Irritable bowel syndrome
Ischemic colitis
Kidney stones, when a stone is lodged in the lower ureter
Pelvic organ prolapse
Radiation proctitis
Rectal gonorrhea
Rectal lymphogranuloma venereum
Rectal parasitic infection, particularly Trichuris trichiura (whipworm)
Rectocele
Shigellosis
Ulcerative colitis
Tenesmus (rectal) is also associated with the installation of either a reversible or non reversible stoma where rectal disease may or may not be present. P |
https://en.wikipedia.org/wiki/IAU%20%281976%29%20System%20of%20Astronomical%20Constants | The International Astronomical Union at its XVIth General Assembly in Grenoble in 1976, accepted (Resolution No. 1) a whole new consistent set of astronomical constants recommended for reduction of astronomical observations, and for computation of ephemerides. It superseded the IAU's previous recommendations of 1964 (see IAU (1964) System of Astronomical Constants), became in effect in the Astronomical Almanac from 1984 onward, and remained in use until the introduction of the IAU (2009) System of Astronomical Constants. In 1994 the IAU recognized that the parameters became outdated, but retained the 1976 set for sake of continuity, but also recommended to start maintaining a set of "current best estimates".
this "sub group for numerical standards" had published a list, which included new constants (like those for relativistic time scales).
The system of constants was prepared by Commission 4 on ephemerides led by P. Kenneth Seidelmann (after whom asteroid 3217 Seidelmann is named).
At the time, a new standard epoch (J2000.0) was accepted; followed later by a new reference system with fundamental catalogue (FK5), and expressions for precession of the equinoxes,
and in 1979 by new expressions for the relation between Universal Time and sidereal time, and in 1979 and 1980 by a theory of nutation. There were no reliable rotation elements for most planets, but a joint working group on Cartographic Coordinates and Rotational Elements was installed to compile recommended values.
Units
The IAU(1976) system is based on the astronomical system of units:
The astronomical unit of time is the day (D) of 86,400 SI seconds, which is close to the mean solar day of civil clock time.
The astronomical unit of mass is the mass of the Sun (S).
The astronomical unit of length is known as the astronomical unit (A or au), which in the IAU(1976) system is defined as the length for which the gravitational constant, more specifically the Gaussian gravitational constant k expressed |
https://en.wikipedia.org/wiki/Ken%20Kennedy%20Award | The Ken Kennedy Award, established in 2009 by the Association for Computing Machinery and the IEEE Computer Society in memory of Ken Kennedy, is awarded annually and recognizes substantial contributions to programmability and productivity in computing and substantial community service or mentoring contributions. The award includes a $5,000 honorarium and the award recipient will be announced at the ACM - IEEE Supercomputing Conference.
Ken Kennedy Award Past Recipients
Source: IEEE
2022 Ian Foster. "For contributions to programmability and productivity in computing via the establishment of new programming models and foundational science services."
2021 David Abramson. "For innovation in parallel and distributed computing tools with broad applications, as well as leadership contributions to professional service, creating international technical communities, and mentoring."
2020 Vivek Sarkar. "For foundational technical contributions to the area of programmability and productivity in parallel computing, as well as leadership contributions to professional service, mentoring, and teaching."
2019 Geoffrey Charles Fox. "For foundational contributions to parallel computing methodology, algorithms and software, data analysis, and their interface with broad classes of applications, and mentoring students at minority-serving institutions".
2018 Sarita Adve. "For research contributions and leadership in the development of memory consistency models for C++ and Java, for service to numerous computer science organizations, and for exceptional mentoring".
2017 Jesus Labarta. "For his contributions to programming models and performance analysis tools for High Performance Computing".
2016 William Gropp. "For highly influential contributions to the programmability of high performance parallel and distributed computers."
2015 Katherine Yelick. "For advancing the programmability of HPC systems, strategic national leadership, and mentorship in academia and government labs."
2014 Cha |
https://en.wikipedia.org/wiki/List%20of%20valid%20argument%20forms | Of the many and varied argument forms that can possibly be constructed, only very few are valid argument forms. In order to evaluate these forms, statements are put into logical form. Logical form replaces any sentences or ideas with letters to remove any bias from content and allow one to evaluate the argument without any bias due to its subject matter.
Being a valid argument does not necessarily mean the conclusion will be true. It is valid because if the premises are true, then the conclusion has to be true. This can be proven for any valid argument form using a truth table which shows that there is no situation in which there are all true premises and a false conclusion.
Valid syllogistic forms
In syllogistic logic, there are 256 possible ways to construct categorical syllogisms using the A, E, I, and O statement forms in the square of opposition. Of the 256, only 24 are valid forms. Of the 24 valid forms, 15 are unconditionally valid, and 9 are conditionally valid.
Unconditionally valid
Conditionally valid
Valid propositional forms
The following is a list of some common valid argument forms in propositional logic. It is nowhere near exhaustive, and gives only a few examples of the better known valid argument forms.
Modus ponens
One valid argument form is known as modus ponens, not to be mistaken with modus tollens, which is another valid argument form that has a like-sounding name and structure. Modus ponens (sometimes abbreviated as MP) says that if one thing is true, then another will be. It then states that the first is true. The conclusion is that the second thing is true. It is shown below in logical form.
If A, then B
A
Therefore B
Before being put into logical form the above statement could have been something like below.
If Kelly does not finish his homework, he will not go to class
Kelly did not finish his homework
Therefore, Kelly will not go to class
The first two statements are the premises while the third is the conclusion derived fro |
https://en.wikipedia.org/wiki/Immunomagnetic%20separation | Immunomagnetic separation (IMS) is a laboratory tool that can efficiently isolate cells out of body fluid or cultured cells. It can also be used as a method of quantifying the pathogenicity of food, blood or feces. DNA analysis have supported the combined use of both this technique and Polymerase Chain Reaction (PCR). Another laboratory separation tool is the affinity magnetic separation (AMS), which is more suitable for the isolation of prokaryotic cells.
IMS deals with the isolation of cells, proteins, and nucleic acids through the specific capture of biomolecules through the attachment of small-magnetized particles, beads, containing antibodies and lectins. These beads are coated to bind to targeted biomolecules, gently separated and goes through multiple cycles of washing to obtain targeted molecules bound to these super paramagnetic beads, which can differentiate based on strength of magnetic field and targeted molecules, are then eluted to collect supernatant and then are able to determine the concentration of specifically targeted biomolecules. IMS obtains certain concentrations of specific molecules within targeted bacteria.
A mixture of cell population will be put into a magnetic field where cells then are attached to super paramagnetic beads, specific example are Dynabeads (4.5-μm), will remain once excess substrate is removed binding to targeted antigen. Dynabeads consists of iron-containing cores, which is covered by a thin layer of a polymer shell allowing the absorption of biomolecules. The beads are coated with primary antibodies, specific-specific antibodies, lectins, enzymes, or streptavidin; the linkage between magnetized beads coated materials are cleavable DNA linker cell separation from the beads when the culturing of cells is more desirable.
Many of these beads have the same principles of separation; however, the presence and different strength s of magnetic fields requires certain sizes of beads, based on the ramifications of the separation |
https://en.wikipedia.org/wiki/Signalling%20System%20No.%207 | Signalling System No. 7 (SS7) is a set of telephony signaling protocols developed in the 1970s, which is used to set up and tear down telephone calls in most parts of the world-wide public switched telephone network (PSTN). The protocol also performs number translation, local number portability, prepaid billing, Short Message Service (SMS), and other services.
The protocol was introduced in the Bell System in the United States by the name Common Channel Interoffice Signaling in the 1970s for signalling between No. 4ESS switch and No. 4A crossbar toll offices. In North America SS7 is also often referred to as Common Channel Signaling System 7 (CCSS7). In the United Kingdom, it is called C7 (CCITT number 7), number 7 and Common Channel Interoffice Signaling 7 (CCIS7). In Germany, it is often called Zentraler Zeichengabekanal Nummer 7 (ZZK-7).
The SS7 protocol is defined for international use by the Q.700-series recommendations of 1988 by the ITU-T. Of the many national variants of the SS7 protocols, most are based on variants standardized by the American National Standards Institute (ANSI) and the European Telecommunications Standards Institute (ETSI). National variants with striking characteristics are the Chinese and Japanese Telecommunication Technology Committee (TTC) national variants.
The Internet Engineering Task Force (IETF) has defined the SIGTRAN protocol suite that implements levels 2, 3, and 4 protocols compatible with SS7. Sometimes also called Pseudo SS7, it is layered on the Stream Control Transmission Protocol (SCTP) transport mechanism for use on Internet Protocol networks, such as the Internet.
History
Signaling System No. 5 and earlier systems use in-band signaling, in which the call-setup information is sent by generating special multi-frequency tones transmitted on the telephone line audio channels, also known as bearer channels. As the bearer channel are directly accessible by users, it can be exploited with devices such as the blue box, whic |
https://en.wikipedia.org/wiki/Disc%20theorem | In the area of mathematics known as differential topology, the disc theorem of states that two embeddings of a closed k-disc into a connected n-manifold are ambient isotopic provided that if k = n the two embeddings are equioriented.
The disc theorem implies that the connected sum of smooth oriented manifolds is well defined.
A different although related and similar named result is the disc embedding theorem proved by Freedman in 1982. |
https://en.wikipedia.org/wiki/Quantitative%20feedback%20theory | In control theory, quantitative feedback theory (QFT), developed by Isaac Horowitz (Horowitz, 1963; Horowitz and Sidi, 1972), is a frequency domain technique utilising the Nichols chart (NC) in order to achieve a desired robust design over a specified region of plant uncertainty. Desired time-domain responses are translated into frequency domain tolerances, which lead to bounds (or constraints) on the loop transmission function. The design process is highly transparent, allowing a designer to see what trade-offs are necessary to achieve a desired performance level.
Plant templates
Usually any system can be represented by its Transfer Function (Laplace in continuous time domain), after getting the model of a system.
As a result of experimental measurement, values of coefficients in the Transfer Function have a range of uncertainty. Therefore, in QFT every parameter of this function is included into an interval of possible values, and the system may be represented by a family of plants rather than by a standalone expression.
A frequency analysis is performed for a finite number of representative frequencies and a set of templates are obtained in the NC diagram which encloses the behaviour of the open loop system at each frequency.
Frequency bounds
Usually system performance is described as robustness to instability (phase and gain margins), rejection to input and output noise disturbances and reference tracking. In the QFT design methodology these requirements on the system are represented as frequency constraints, conditions that the compensated system loop (controller and plant) could not break.
With these considerations and the selection of the same set of frequencies used for the templates, the frequency constraints for the behaviour of the system loop are computed and represented on the Nichols Chart (NC) as curves.
To achieve the problem requirements, a set of rules on the Open Loop Transfer Function, for the nominal plant may be found. That means the n |
https://en.wikipedia.org/wiki/Message%20submission%20agent | A message submission agent (MSA), or mail submission agent, is a computer program or software agent that receives electronic mail messages from a mail user agent (MUA) and cooperates with a mail transfer agent (MTA) for delivery of the mail. It uses ESMTP, a variant of the Simple Mail Transfer Protocol (SMTP), as specified in RFC 6409.
Many MTAs perform the function of an MSA as well, but there are also programs that are specially designed as MSAs without full MTA functionality. Historically, in Internet mail, both MTA and MSA functions use port number 25, but the official port for MSAs is 587. The MTA accepts a user's incoming mail, while the MSA accepts a user's outgoing mail.
Benefits
Separation of the MTA and MSA functions produces several benefits.
One benefit is that an MSA, since it is interacting directly with the author's MUA, can correct minor errors in a message format (such as a missing Date, Message-ID, To fields, or an address with a missing domain name) and/or immediately report an error to the author so that it can be corrected before it is sent to any of the recipients. An MTA accepting a message from another site cannot reliably make those kinds of corrections, and any error reports generated by such an MTA will reach the author (if at all) only after the message has already been sent.
One more benefit is that with a dedicated port number, 587, it is always possible for users to connect to their domain to submit new mail. To combat spam (including spam being sent unwittingly by a victim of a botnet) many ISPs and institutional networks restrict the ability to connect to remote MTAs on port 25. The accessibility of an MSA on port 587 enables nomadic users (for example, those working on a laptop) to continue to send mail via their preferred submission servers even from within others' networks. Using a specific submission server is a requirement when sender policies or signing practices are enforced.
Another benefit is that separating the MTA and |
https://en.wikipedia.org/wiki/Adams%E2%80%93Oliver%20syndrome | Adams–Oliver syndrome (AOS) is a rare congenital disorder characterized by defects of the scalp and cranium (cutis aplasia congenita), transverse defects of the limbs, and mottling of the skin.
Signs and symptoms
Two key features of AOS are aplasia cutis congenita with or without underlying bony defects and terminal transverse limb defects. Cutis aplasia congenita is defined as missing skin over any area of the body at birth; in AOS skin aplasia occurs at the vertex of the skull. The size of the lesion is variable and may range from solitary round hairless patches to complete exposure of the cranial contents. There are also varying degrees of terminal limb defects (for example, shortened digits) of the upper extremities, lower extremities, or both. Individuals with AOS may have mild growth deficiency, with height in the low-normal percentiles. The skin is frequently observed to have a mottled appearance (cutis marmorata telangiectatica congenita). Other congenital anomalies, including cardiovascular malformations, cleft lip and/or palate, abnormal renal system, and neurologic disorders manifesting as seizure disorders and developmental delay are sometimes observed. Variable defects in blood vessels have been described, including hypoplastic aortic arch, middle cerebral artery, pulmonary arteries. Other vascular abnormalities described in AOS include absent portal vein, portal sclerosis, arteriovenous malformations, abnormal umbilical veins, and dilated renal veins.
Genetics
AOS was initially described as having autosomal dominant inheritance due to the reports of families with multiple affected family members in more than one generation. The severity of the condition can vary between family members, suggestive of variable expressivity and reduced penetrance of the disease-causing allele. Subsequently, it was reported that some cases of AOS appear to have autosomal recessive inheritance, perhaps with somewhat more severe phenotypic effects.
Six AOS genes have be |
https://en.wikipedia.org/wiki/TRADIC | The TRADIC (for TRAnsistor DIgital Computer or TRansistorized Airborne DIgital Computer) was the first transistorized computer in the USA, completed in 1954.
The computer was built by Jean Howard Felker of Bell Labs for the United States Air Force while L.C. Brown ("Charlie Brown") was a lead engineer on the project, which started in 1951. The project initially examined the feasibility of constructing a transistorized airborne digital computer. A second application was a transistorized digital computer to be used in a Navy track-while-scan shipboard radar system. Several models were completed: TRADIC Phase One computer, Flyable TRADIC, Leprechaun (using germanium alloy junction transistors in 1956) and XMH-3 TRADIC. TRADIC Phase One was developed to explore the feasibility, in the laboratory, of using transistors in a digital computer that could be used to solve aircraft bombing and navigation problems. Flyable TRADIC was used to establish the feasibility of using an airborne solid-state computer as the control element of a bombing and navigation system. Leprechaun was a second-generation laboratory research transistor digital computer designed to explore direct-coupled transistor logic (DCTL). The TRADIC Phase One computer was completed in January 1954.
The TRADIC Phase One computer has been claimed to be the world's first fully transistorized computer, ahead of the Mailüfterl in Austria or the Harwell CADET in the UK, which were each completed in 1955. In the UK, the Manchester University Transistor Computer demonstrated a working prototype in 1953 which incorporated transistors before TRADIC was operational, although that was not a fully transistorized computer because it used vacuum tubes to generate the clock signal. The 30 watts of power for the 1 MHz clock in the TRADIC was also supplied by a vacuum tube supply because no transistors were available that could supply that much power at that frequency. If the TRADIC can be called fully transistorized while in |
https://en.wikipedia.org/wiki/Unicast%20flood | In computer networking, a unicast flood is when a switch receives a unicast frame and treats it as a broadcast frame, flooding the frame to all other ports on the switch.
Background
The term unicast refers to a one-to-one transmission from one point in the network to another point. Conventionally, unicast is considered more secure because the frame is delivered solely to the intended recipient and not to multiple hosts. This diagram illustrates the unicast transmission of a frame from one network host to another:
When a switch receives a unicast frame with a destination address not in the switch’s forwarding table, the frame is treated like a broadcast frame and sent to all hosts on a network:
Causes
The learning process of transparent bridging requires that the switch receive a frame from a device before unicast frames can be forwarded to it. Before any such transmission is received, unicast flooding is used to assure transmissions reach their intended destination. This is normally a short-lived condition as receipt typically produces a response that completes the learning process. The process occurs when a device is initially connected to a network, or is purged from the forwarding information base. An entry is purged when the device is moved from one port to another (causing the link status to change on the original port) or after a MAC table entry expires due to inactivity (5 minutes is the default on Cisco switches).
A switch that has no room left in its address cache will flood the frame out to all ports. This is a common problem on networks with many hosts. Less common is the artificial flooding of address tables—this is termed MAC flooding.
Another common cause are hosts with ARP timers longer than the address cache timeout on switches—the switch forgets which port connects to the host. The solution to prevent this is to have the switch configured with a MAC address timeout longer than the ARP timeout. For example, set the MAC timeout to 360 sec |
https://en.wikipedia.org/wiki/Lists%20of%20integrals | Integration is the basic operation in integral calculus. While differentiation has straightforward rules by which the derivative of a complicated function can be found by differentiating its simpler component functions, integration does not, so tables of known integrals are often useful. This page lists some of the most common antiderivatives.
Historical development of integrals
A compilation of a list of integrals (Integraltafeln) and techniques of integral calculus was published by the German mathematician (also spelled Meyer Hirsch) in 1810. These tables were republished in the United Kingdom in 1823. More extensive tables were compiled in 1858 by the Dutch mathematician David Bierens de Haan for his Tables d'intégrales définies, supplemented by Supplément aux tables d'intégrales définies in ca. 1864. A new edition was published in 1867 under the title Nouvelles tables d'intégrales définies.
These tables, which contain mainly integrals of elementary functions, remained in use until the middle of the 20th century. They were then replaced by the much more extensive tables of Gradshteyn and Ryzhik. In Gradshteyn and Ryzhik, integrals originating from the book by Bierens de Haan are denoted by BI.
Not all closed-form expressions have closed-form antiderivatives; this study forms the subject of differential Galois theory, which was initially developed by Joseph Liouville in the 1830s and 1840s, leading to Liouville's theorem which classifies which expressions have closed-form antiderivatives. A simple example of a function without a closed-form antiderivative is , whose antiderivative is (up to constants) the error function.
Since 1968 there is the Risch algorithm for determining indefinite integrals that can be expressed in term of elementary functions, typically using a computer algebra system. Integrals that cannot be expressed using elementary functions can be manipulated symbolically using general functions such as the Meijer G-function.
Lists of integrals |
https://en.wikipedia.org/wiki/Budgie%20Toys | Morris & Stone, Ltd., which later changed its name to the more well-known Budgie Toys, was a British die-cast toy distributor turned manufacturer, based in London. The company first specialised in horse-drawn carriages and coaches. It later made a wide variety of miniature cars and trucks.
The company marketed its products under the brand name Morestone. Some models were manufactured by a separate company called "Modern Products". Vehicles were about Matchbox car size, though still slightly smaller and simpler.
History
Morestone got its name as a contraction of "Morris" and "Stone" who started distributing the toys in the 1940s. Vehicles were somewhat similar to Dinky Toys in concept, but other toys were also marketed, like a "dulcimer" xylophone and a toy drum. Some vehicles, like the mechanical road sweeper were equipped with clockwork motors. Often Morestone vehicles were made by the company Modern Products, thus "A Modern Product" or simply "Modern" would be stated on the boxes, and some models were marketed as 'A Modern Product' without any reference to Morestone. Some boxes say, "Modern" within a diamond-shaped logo. Models later in the 1950s were apparently made by Morestone as the Modern Product label was dropped, usually replaced by "Morestone Series". Morestone Series vehicles were varied, but commonly featured AA and RAC Land Rovers and motorcycles with sidecars. Later, reissues of Morestone Series vehicles were made in white metal by 'Zebra Toys'. Another company, Autocraft / DGM acquired many of the dies for early Morestone Series models and reintroduced various motorcycles.
Earlier models said "Morris & Stone" on the boxes, but the name was late. contracted Models were also marketed as promotionals for ESSO. The "Budgie" name, was introduced in 1959 and was more like other British toys named after dogs and other animals (Husky and Corgi, etc.).
The company was acquired by S. Guiterman in 1961, but went out of business in 1966. After this, Modern P |
https://en.wikipedia.org/wiki/MYRRHA | The MYRRHA (Multi-purpose hYbrid Research Reactor for High-tech Applications) is a design project of a nuclear reactor coupled to a proton accelerator (a so-called accelerator-driven system (ADS)). MYRRHA will be a lead-bismuth cooled fast reactor with two possible configurations: sub-critical or critical.
The project is managed by SCK CEN, the Belgian Centre for Nuclear Research. Its design will be adapted as a function of the experience gained from a first research project with a small proton accelerator and a lead-bismuth eutectic target: GUINEVERE.
MYRRHA is anticipated to be constructed in 2036, with a first phase (100 MeV LINAC accelerator) expected to be completed in 2026 if successfully demonstrated.
Components
MYRRHA is a project presently under development of a research reactor aiming to demonstrate the feasibility of the ADS and the lead-cooled fast reactor concepts, with various research applications from spent-fuel irradiation to material irradiation testing. A linear accelerator is under development to provide a beam of fast proton that hits a spallation target, producing neutrons. These neutrons are necessary to keep the nuclear reactor running when operated in sub-critical mode, but to increase its versatility the reactor is also designed to operate in critical mode with fast neutron and thermal neutron zones.
Accelerator
The accelerator will accelerate protons to an energy of 600 MeV with a beam current of up to 4 mA. In subcritical mode, if the accelerator stops the reactor power drops immediately. To avoid thermal cycles the accelerator needs to be extremely reliable. MYRRHA aims at no more than 10 outages longer than three seconds per 100 days. A first prototype stage of the accelerator was started in 2020.
ISOL@MYRRHA
The high reliability and intense beam current required for operating such a machine makes the proton accelerator potentially interesting for online isotope separation. Phase I of the project therefore also includes the de |
https://en.wikipedia.org/wiki/Two-port%20network | In electronics, a two-port network (a kind of four-terminal network or quadripole) is an electrical network (i.e. a circuit) or device with two pairs of terminals to connect to external circuits. Two terminals constitute a port if the currents applied to them satisfy the essential requirement known as the port condition: the current entering one terminal must equal the current emerging from the other terminal on the same port. The ports constitute interfaces where the network connects to other networks, the points where signals are applied or outputs are taken. In a two-port network, often port 1 is considered the input port and port 2 is considered the output port.
It is commonly used in mathematical circuit analysis.
Application
The two-port network model is used in mathematical circuit analysis techniques to isolate portions of larger circuits. A two-port network is regarded as a "black box" with its properties specified by a matrix of numbers. This allows the response of the network to signals applied to the ports to be calculated easily, without solving for all the internal voltages and currents in the network. It also allows similar circuits or devices to be compared easily. For example, transistors are often regarded as two-ports, characterized by their -parameters (see below) which are listed by the manufacturer. Any linear circuit with four terminals can be regarded as a two-port network provided that it does not contain an independent source and satisfies the port conditions.
Examples of circuits analyzed as two-ports are filters, matching networks, transmission lines, transformers, and small-signal models for transistors (such as the hybrid-pi model). The analysis of passive two-port networks is an outgrowth of reciprocity theorems first derived by Lorentz.
In two-port mathematical models, the network is described by a 2 by 2 square matrix of complex numbers. The common models that are used are referred to as -parameters, -parameters, -param |
https://en.wikipedia.org/wiki/M.%20Lothaire | M. Lothaire is the pseudonym of a group of mathematicians, many of whom were students of Marcel-Paul Schützenberger. The name is used as the author of several of their joint books about combinatorics on words. The group is named for Lothair I.
Members
Mathematicians in the group have included
Jean-Paul Allouche,
Jean Berstel,
Valérie Berthé,
Véronique Bruyère,
Julien Cassaigne,
Christian Choffrut,
Robert Cori,
Maxime Crochemore
Jacques Desarmenien,
Volker Diekert,
Dominique Foata,
Christiane Frougny,
Guo-Niu Han,
Tero Harju,
Philippe Jacquet,
Juhani Karhumäki,
Roman Kolpakov,
Gregory Koucherov,
Eric Laporte,
Alain Lascoux,
Bernard Leclerc,
Aldo De Luca,
Filippo Mignosi,
Mehryar Mohri,
Dominique Perrin,
Jean-Éric Pin,
Giuseppe Pirillo,
Nadia Pisanti,
Wojciech Plandowski,
Dominique Poulalhon,
Gesine Reinert,
Antonio Restivo,
Christophe Reutenauer,
Marie-France Sagot,
Jacques Sakarovitch,
Gilles Schaeffer,
Sophie Schbath,
Marcel-Paul Schützenberger,
Patrice Séébold,
Imre Simon,
Wojciech Szpankowski,
Jean-Yves Thibon,
Stefano Varricchio,
and Michael Waterman.
See also
Séminaire Lotharingien de Combinatoire
Publications |
https://en.wikipedia.org/wiki/Time-driven%20switching | In telecommunication and computer networking, time-driven switching (TDS) is a node by node time variant implementation of circuit switching, where the propagating datagram is shorter in space than the distance between source and destination. With TDS it is no longer necessary to own a complete circuit between source and destination, but only the fraction of circuit where the propagating datagram is temporarily located.
TDS adds flexibility and capacity to circuit-switched networks but requires precise synchronization among nodes and propagating datagrams.
Datagrams are formatted according to schedules that depend on quality of service and availability of switching nodes and physical links. In respect to circuit switching, the added time dimension introduces additional complexity to network management. Like circuit switching, TDS operates without buffers and header processing according to the pipeline forwarding principle; therefore an all optical implementation with optical fibers and optical switches is possible with low cost. The TDS concept itself pervades and is applicable with advantage to existing data switching technologies, including packet switching, where packets, or sets of packets become the datagrams that are routed through the network.
TDS has been invented in 2002 by Prof. Mario Baldi and Prof. Yoram Ofek of Synchrodyne Networks that is the assignee of several patents issued by both the United States Patent and Trademark Office and the European Patent Office. |
https://en.wikipedia.org/wiki/Fallopian%20tube | The fallopian tubes, also known as uterine tubes, oviducts or salpinges (: salpinx), are paired tubes in the human female body that stretch from the uterus to the ovaries. The fallopian tubes are part of the female reproductive system. In other mammals they are only called oviducts.
Each tube is a muscular hollow organ that is on average between in length, with an external diameter of . It has four described parts: the intramural part, isthmus, ampulla, and infundibulum with associated fimbriae. Each tube has two openings a proximal opening nearest and opening to the uterus, and a distal opening furthest and opening to the abdomen. The fallopian tubes are held in place by the mesosalpinx, a part of the broad ligament mesentery that wraps around the tubes. Another part of the broad ligament, the mesovarium suspends the ovaries in place.
An egg cell is transported from an ovary to a fallopian tube where it may be fertilized in the ampulla of the tube. The fallopian tubes are lined with simple columnar epithelium with hairlike extensions called cilia which together with peristaltic contractions from the muscular layer, move the fertilized egg (zygote) along the tube. On its journey to the uterus the zygote undergoes cell divisions that changes it to a blastocyst an early embryo, in readiness for implantation.
Almost a third of cases of infertility are caused by fallopian tube pathologies. These include inflammation, and tubal obstructions. A number of tubal pathologies cause damage to the cilia of the tube which can impede movement of the sperm or egg.
The name comes from the Italian Catholic priest and anatomist Gabriele Falloppio, for whom other anatomical structures are also named.
Structure
Each fallopian tube leaves the uterus at an opening at the uterine horns known as the proximal tubal opening or proximal ostium. The tubes have an average length of that includes the intramural part of the tube. The tubes extend to near the ovaries where they open into |
https://en.wikipedia.org/wiki/Sendov%27s%20conjecture | In mathematics, Sendov's conjecture, sometimes also called Ilieff's conjecture, concerns the relationship between the locations of roots and critical points of a polynomial function of a complex variable. It is named after Blagovest Sendov.
The conjecture states that for a polynomial
with all roots r1, ..., rn inside the closed unit disk |z| ≤ 1, each of the n roots is at a distance no more than 1 from at least one critical point.
The Gauss–Lucas theorem says that all of the critical points lie within the convex hull of the roots. It follows that the critical points must be within the unit disk, since the roots are.
The conjecture has been proven for n < 9 by Brown-Xiang and for n sufficiently large by Tao.
History
The conjecture was first proposed by Blagovest Sendov in 1959; he described the conjecture to his colleague Nikola Obreshkov. In 1967 the conjecture was misattributed to Ljubomir Iliev by Walter Hayman. In 1969 Meir and Sharma proved the conjecture for polynomials with n < 6. In 1991 Brown proved the conjecture for n < 7. Borcea extended the proof to n < 8 in 1996. Brown and Xiang proved the conjecture for n < 9 in 1999. Terence Tao proved the conjecture for sufficiently large n in 2020. |
https://en.wikipedia.org/wiki/Energy%20level | A quantum mechanical system or particle that is bound—that is, confined spatially—can only take on certain discrete values of energy, called energy levels. This contrasts with classical particles, which can have any amount of energy. The term is commonly used for the energy levels of the electrons in atoms, ions, or molecules, which are bound by the electric field of the nucleus, but can also refer to energy levels of nuclei or vibrational or rotational energy levels in molecules. The energy spectrum of a system with such discrete energy levels is said to be quantized.
In chemistry and atomic physics, an electron shell, or principal energy level, may be thought of as the orbit of one or more electrons around an atom's nucleus. The closest shell to the nucleus is called the " shell" (also called "K shell"), followed by the " shell" (or "L shell"), then the " shell" (or "M shell"), and so on farther and farther from the nucleus. The shells correspond with the principal quantum numbers (n = 1, 2, 3, 4 ...) or are labeled alphabetically with letters used in the X-ray notation (K, L, M, N...).
Each shell can contain only a fixed number of electrons: The first shell can hold up to two electrons, the second shell can hold up to eight (2 + 6) electrons, the third shell can hold up to 18 (2 + 6 + 10) and so on. The general formula is that the nth shell can in principle hold up to 2n2 electrons. Since electrons are electrically attracted to the nucleus, an atom's electrons will generally occupy outer shells only if the more inner shells have already been completely filled by other electrons. However, this is not a strict requirement: atoms may have two or even three incomplete outer shells. (See Madelung rule for more details.) For an explanation of why electrons exist in these shells see electron configuration.
If the potential energy is set to zero at infinite distance from the atomic nucleus or molecule, the usual convention, then bound electron states have negative pot |
https://en.wikipedia.org/wiki/Waterleaf%20%28architecture%29 | In architecture, a waterleaf is a distinctive sculptural motif used on the capitals of columns and pilasters in European buildings during the late twelfth century. It is a highly simplified plant motif, characteristic of the "late Norman" style of Romanesque architecture.
A waterleaf capital is formed of broad, smooth leaf-shapes (typically four in number), unribbed except for a central fold, which curve upward and outward before curling over at the tips where they meet the abacus (the flat slab at the top of the column, normally square but sometimes octagonal). The curled tip of the waterleaf may be small and neat or large and bulbous; it usually curves inward towards the abacus, but may occasionally turn outwards (both forms can sometimes be seen in adjacent capitals of the same period, as for example at Geddington, Northamptonshire, UK.).
Gallery
See also
Abacus (architecture)
Branchwork
Pulvino
Rais-de-cœur may incorporate waterleaves. |
https://en.wikipedia.org/wiki/Mobage | is a portal and social network for games, owned by DeNA. The service had 30 million users, who largely play on feature phones.
On February 14, 2011, DeNA announced renaming Mobage Town service name to Mobage, which also merged the Plus+ network operated by ngmoco under the new branding. Also that year, the service has been described as highly successful in academic research.
On December 19, 2014, ngmoco, LLC announced the renaming of Mobage to DeNA. However, the Japanese site still operates under the mobage name.
On August 9, 2018, the English version of the website was reportedly shut down for unknown reasons. |
https://en.wikipedia.org/wiki/Moxibustion | Moxibustion () is a traditional Chinese medicine therapy which consists of burning dried mugwort (wikt:moxa) on particular points on the body. It plays an important role in the traditional medical systems of China, Japan, Korea, Vietnam, and Mongolia. Suppliers usually age the mugwort and grind it up to a fluff; practitioners burn the fluff or process it further into a cigar-shaped stick. They can use it indirectly, with acupuncture needles, or burn it on the patient's skin.
Moxibustion is promoted as a treatment for a wide variety of conditions, but its use is not backed by good evidence and it carries a risk of adverse effects.
Terminology
The first Western remarks on moxibustion can be found in letters and reports written by Portuguese missionaries in 16th-century Japan. They called it botão de fogo (), a term originally used for round-headed Western cautery irons. Hermann Buschoff, who published the first Western book on this matter in 1674 (English edition 1676), used the Japanese pronunciation mogusa. As the u is not very strongly enunciated, he spelled it "Moxa". Later authors blended "Moxa" with the Latin word combustio ("burning").
The name of the herb Artemisia (mugwort) species used to produce Moxa is called ài or àicǎo (, ) in Chinese and yomogi () in Japan.
The Chinese names for moxibustion are jiǔ ( ) or jiǔshù ( ); the Japanese use the same characters and pronounce them as kyū and kyūjutsu. In Korean the reading is tteum (). Korean folklore attributes the development of moxibustion to the legendary emperor Dangun.
Theory and practice
Practitioners use moxa to warm regions and meridian points with the intention of stimulating circulation through the points and inducing a smoother flow of blood and qi. Some believe it can treat conditions associated with the "cold" or "yang deficiencies" in Chinese Medicine. It is claimed that moxibustion mitigates against cold and dampness in the body, and can be used to treat lymphedema following intrapelvic lym |
https://en.wikipedia.org/wiki/Einstein%20Prize%20for%20Laser%20Science | The Einstein Prize for Laser Science was a recognition awarded by the former Society for Optical and Quantum Electronics and sponsored by the Eastman Kodak Company. The prize, awarded in the 1988–1999 period, consisted of a 3-inch brass medal including Einstein's image and a depiction of a two-level transition including the A and B coefficients. Recipients of the prize include:
Serge Haroche, 1988
Herbert Walther, 1988
H. Jeff Kimble, 1989
Richart E. Slusher, 1989
Carlton M. Caves, 1990
Daniel Frank Walls, 1990
S. E. Harris, 1991
L. M. Narducci, 1991
John L. Hall, 1992
Willis E. Lamb, 1992
Raymond Chiao, 1993
Norman F. Ramsey, 1993
G. S. Agarwal, 1994
Theodor W. Hänsch, 1995
Carl E. Wieman, 1995
David J. Wineland, 1996
Peter L. Knight, 1996
Paul Corkum, 1999
In retrospect, the prize was mainly awarded for significant contributions in quantum optics. Two recipients of the Einstein Prize for Laser Science were already Nobel laureates in physics (W. E. Lamb and N. F. Ramsey) and five other recipients went on to win the Nobel Prize in Physics (S. Haroche, J. L. Hall, T. W. Hänsch, C. E. Wieman, and D. J. Wineland). Presentation of the prize was done at the Lasers'88 to Lasers'99 conferences.
Note: the official name of these conferences was The International Conference on Lasers and Applications, Lasers 'XX.
See also
List of physics awards |
https://en.wikipedia.org/wiki/Bacillus%20odysseyi | Bacillus odysseyi is a Gram-positive, aerobic, rod-shaped, round-spore- and endospore-forming eubacterium of the genus Bacillus. This novel species was discovered by scientist Myron T. La Duc of NASA’s Biotechnology and Planetary Protection Group, a unit whose purpose is to clean and sterilize spacecraft so as not to have microorganisms contaminate other celestial bodies or foreign microorganisms contaminate Earth, on the surface of the Mars Odyssey in a clean room at the Jet Propulsion Laboratory in La Cañada Flintridge before the spacecraft was launched to space. La Duc named the bacterium Bacillus odysseyi sp. nov. after the Odyssey mission. It had apparently evolved to live in the sparse environment of a clean room, and its secondary spore coat makes it especially resistant to radiation.
B. odysseyi consists of an exosporium, spore coat, cortex, and core. In a test performed by the Planetary Protection unit, its spores were the most consistently resistant, and it survived exposure to all of the challenges posed against it: desiccation (100% survival), Hydrogen peroxide (H2O2, 26% survival), ultraviolet radiation (10% survival at 660 J ∙ m−2), and gamma radiation (0.4% survival). B. odysseyi shares many DNA similarities with Bacillus fusiformis and Solibacillus silvestris. The type strain for B. odysseyi is 34hs-1T (=ATCC PTA-4993T=NRRL B-30641T=NBRC 100172T). |
https://en.wikipedia.org/wiki/Landau%E2%80%93Yang%20theorem | In quantum mechanics, the Landau–Yang theorem is a selection rule for particles that decay into two on-shell photons. The theorem states that a massive particle with spin 1 cannot decay into two photons.
Assumptions
A photon here is any particle with spin 1, without mass and without internal degrees of freedom. The photon is the only known particle with these properties.
Consequences
The theorem has several consequences in particle physics. For example:
The meson ρ cannot decay into two photons, differently from the neutral pion, that almost always decays into this final state (98.8% of times).
The boson Z cannot decay into two photons.
The Higgs boson, whose spin was not measured before 2013, but whose decay into two photons was observed in 2012 cannot have spin 1 in models that assume the Landau–Yang theorem.
Original references
Additional references
Theorems in quantum mechanics
Lev Landau |
https://en.wikipedia.org/wiki/Swain%E2%80%93Lupton%20equation | In physical organic chemistry, the Swain–Lupton equation is a linear free energy relationship (LFER) that is used in the study of reaction mechanisms and in the development of quantitative structure activity relationships for organic compounds. It was developed by C. Gardner Swain and Elmer C. Lupton Jr. in 1968 as a refinement of the Hammett equation to include both field effects and resonance effects.
Background
In organic chemistry, the Hammett plot provides a means to assess substituent effects on a reaction equilibrium or rate using the Hammett equation (1):
Hammett developed this equation from equilibrium constants from the dissociation of benzoic acid and derivatives (Fig. 1):
Hammett defined the equation based on two parameters: the reaction constant (ρ) and the substituent parameter (σ). When other reactions were studied using these parameters, a correlation was not always found due to the specific derivation of these parameters from the dissociation equilibrium of substituted benzoic acids and the original negligence of resonance effects. Therefore, the effects of substituents on an array of compounds must be studied on an individual reaction basis using the equation Hammett derived either for field or resonance effects, but not both.
Redefining the equation
C. Gardner Swain and Elmer C. Lupton Jr. from the Massachusetts Institute of Technology redefined the substituent parameter, σ, based on the idea that no more than two variables (resonance effects and field effects) are necessary to describe the effects of any given substituent. Field effects, F, are defined to include all effects (inductive and pure field). Likewise, effects due to resonance, R, are due to the average of electron-donating ability and electron-accepting ability. These two effects are assumed to be independent of each other and therefore can be written as a linear combination:
These two parameters are treated as independent terms because of the assumption that Swain and Lupto |
https://en.wikipedia.org/wiki/TV%20Site | A TV site is a website designed for viewing on a television set.
Unlike mobile and PC access, the use of internet sites through the TV has been small, mostly due to the poor user experience of many "web on TV" deployments, and the "walled garden" or closed platform business models adopted by many TV network operators.
With the advent of IPTV and Broadband enabled TV Devices web site owners have realized, that like Mobile, TV needs to be considered as a different media, and that Mobile, TV and PC based internet access all present different user interface design challenges in order to make the services usable and acceptable to consumers on the device they are using.
TV Sites can be developed and deployed using a number of different technologies including Adobe Flash, WTVML, Java and HTML, although the same design principles apply whatever the development technology.
Typically TV Sites are differentiated from other web sites by having a "wtv." rather than a "www." subdomain.
Interfaces
The following styles of interface are often considered:
The "one foot" user experience - used to describe mobile apps, which are typically "personal" and used at a short distance from the device
The "three foot" user experience - used to describe PC applications, which are typically used "personal" and accessed via a PC, with mouse, windows and a high resolution screen
The "10-foot user interface" - used to describe TV applications, which are typically used in a "shared" environment, via a TV, with only a TV remote control as the input mechanism
These interfaces are characterized as follows:
Mobile: narrow screen 1D scrolling, simplified layout, limited graphics and media types, limited transactional capability, limited keyboard, no pointer (see Post-WIMP)
PC: wide screen, scrollable interfaces, complex layouts, complex media types, fully transactional, keyboard, pointer
TV: wide screen, explicit layout, embedded scrolling, limited media types, video support, fully transa |
https://en.wikipedia.org/wiki/Sherpa.ai | Sherpa (also known as Sherpa.ai) is a Spanish artificial intelligence company specializing in predictive conversational digital assistants. It was founded by Xabi Uribe-Etxebarria in 2012 and is based in Erandio and Silicon Valley. In 2018, Fortune magazine included Sherpa in its ranking of the 100 best artificial intelligence companies.
Trajectory
The company was created in 2012 with the conviction to develop a predictive conversational digital assistant based on artificial intelligence algorithms for different companies and to provide consultancy in artificial intelligence. They are based in Erandio (Vizcaya, Spain) and Silicon Valley (California, United States), and are a ISO/IEC 27001 certified company.
In 2016, they obtained $6.5 million in a round of funding from Mundi Ventures and other private investors. In a second round in 2019, they obtained $8.5 million; and in 2021, they secured an additional $8.5 million in funding from Mundi Ventures, Ekarpen, Marcelo Gigliani of Apax Digital, and Alex Cruz of British Airways.
Products
Sherpa's first product was a mobile phone application of the same name. Their products are predictive conversational digital assistants that learn from the user's context to anticipate their needs. Sherpa uses 100,000 parameters from each user to answer requests. Additionally, they have developed a multi-purpose recommendation system for news, music, and filtering important emails.
Among their products are free applications for smartphones and tablets such as Sherpa Assistant and Sherpa News which have garnered over 3 million downloads. Sherpa also came pre-installed on Samsung smartphones as the default digital assistant, until Samsung Electronics launched Bixby.
Focused on business services, their AI assistants and operating systems are embedded in cars, smartphones, home speakers, and appliances. Sherpa also has agreements with companies such as Porsche and Samsung.
Work team
By 2018, Sherpa had 35 employees, most of whom we |
https://en.wikipedia.org/wiki/8K%20resolution | 8K resolution refers to an image or display resolution with a width of approximately 8,000 pixels. 8K UHD () is the highest resolution defined in the Rec. 2020 (UHDTV) standard.
8K display resolution is the successor to 4K resolution. TV manufacturers pushed to make 4K a new standard by 2017. At CES 2019, the first 8K TVs were unveiled. The feasibility of a fast transition to this new standard is questionable in view of the absence of broadcasting resources. It is predicted (2018 forecast by Strategy Analytics) that 8K-ready devices will still only account for 3% of UHD TVs by 2023 with global sales of 11 million units a year. However, TV manufacturers remain optimistic as the 4K market grew much faster than expected, with actual sales exceeding projections nearly six-fold in 2016.
In 2013, a transmission network's capability to carry HDTV resolution was limited by internet speeds and relied on satellite broadcast to transmit the high data rates. The demand is expected to drive the adoption of video compression standards and to place significant pressure on physical communication networks in the near future.
, few cameras had the capability to shoot video in 8K, NHK being one of the few companies to have created a small broadcasting camera with an 8K image sensor. By 2018, Red Digital Cinema camera company had delivered three 8K cameras in both a Full Frame sensor and Super 35 sensor. Additionally some
filmmakers are pushing demand for 8K cameras due to their ability to capture better 4K footage.
8K standards and technology
The term "8K" is generic and refers to any resolution with a horizontal pixel count of approximately 8,000. Several different 8K resolutions have been standardized by various organizations.
History
Japan's public broadcaster NHK was the first to start research and development of 4320p resolution in 1995. The format was standardized by SMPTE in October 2007, Interface standardized by SMPTE in August 2010 and recommended as the internationa |
https://en.wikipedia.org/wiki/Robert%20N.%20Klein%20II | Robert Nicholas "Bob" Klein II is a stem cell advocate. He initiated California Proposition 71, which succeeded in establishing the California Institute for Regenerative Medicine, of which Klein was the chairman of the governing board.
Before getting involved in stem cell advocacy, he was a housing developer and lawyer. He lives in Portola Valley, California and works in Palo Alto, where he used to live.
Stem cell advocacy
He was a chief author of Proposition 71 and was the chair of the Yes on 71 campaign. He donated $3 million to the cause, the largest donation, and ran the campaign from the Klein Financial Corporation.
After the election, Proposition 71 became Article XXXV of the California Constitution and the Yes on 71 campaign became the California Research and Cures Coalition, a stem cell advocacy organization. Klein was the head of that organization until he took the position at the California Institute for Regenerative Medicine, the organization created by the ballot initiative. In 2005, he was named as one of TIME Magazine's 100 Most Influential People; and, that same year Scientific American named Klein one of “The Scientific American 50” as a leader shaping the future of science. Klein was honored at the 2010 BIO International Convention as the second annual Biotech Humanitarian. Also, in 2010, Klein received the 2010 Research!America Gordon and Llura Gund Leadership Award for his advocacy of stem cell and diabetes research.
In 2020, the original funding for the Institute for Regenerative Medicine had run out, so Klein spearheaded another initiative to fund it, known as Proposition 14.
Early career
Klein has a Bachelor of Arts in History with Honors from Stanford University and a Juris Doctor from Stanford University Law School, 1970. Additional education includes: Executive Summer Finance Program at Stanford University Business School and an internship with the United Nations Economic and Social Council in Switzerland on Economic Development Pol |
https://en.wikipedia.org/wiki/Recombination%20%28cosmology%29 | In cosmology, recombination refers to the epoch during which charged electrons and protons first became bound to form electrically neutral hydrogen atoms. Recombination occurred about 378,000 years after the Big Bang (at a redshift of z = ). The word "recombination" is misleading, since the Big Bang theory doesn't posit that protons and electrons had been combined before, but the name exists for historical reasons since it was named before the Big Bang hypothesis became the primary theory of the birth of the universe.
Immediately after the Big Bang, the universe was a hot, dense plasma of photons, leptons, and quarks: the quark epoch. At 10−6 seconds, the Universe had expanded and cooled sufficiently to allow for the formation of protons: the hadron epoch. This plasma was effectively opaque to electromagnetic radiation due to Thomson scattering by free electrons, as the mean free path each photon could travel before encountering an electron was very short. This is the current state of the interior of the Sun. As the universe expanded, it also cooled. Eventually, the universe cooled to the point that the formation of neutral hydrogen was energetically favored, and the fraction of free electrons and protons as compared to neutral hydrogen decreased to a few parts in 10,000.
Recombination involves electrons binding to protons (hydrogen nuclei) to form neutral hydrogen atoms. Because direct recombinations to the ground state (lowest energy) of hydrogen are very inefficient, these hydrogen atoms generally form with the electrons in a high energy state, and the electrons quickly transition to their low energy state by emitting photons. Two main pathways exist: from the 2p state by emitting a Lyman-a photon – these photons will almost always be reabsorbed by another hydrogen atom in its ground state – or from the 2s state by emitting two photons, which is very slow.
This production of photons is known as decoupling, which leads to recombination sometimes being called ph |
https://en.wikipedia.org/wiki/Diple%20%28textual%20symbol%29 | Diple (, meaning double, referring to the two lines in the mark ) was a mark used in the margins of ancient Greek manuscripts to draw attention to something in the text. It is sometimes also called antilambda because the sign resembles a Greek capital letter lambda () turned upon its side. In some ways its usage was similar to modern day quotation marks; guillemets (« »), used for quotations in French, are derived from it.
Isidore remarks in his Etymologiae (I.21.13) that the diple was used to mark quotations from the Bible. He also talks about diple peri strichon (or sticon), which was used to draw attention to separate concepts, and diple periestigmene used (like obelos) to mark dubious passages. Diple obolismene was used according to Isidore to separate sentences in comedies and tragedies, so its usage was similar to that of paragraphos.
See also |
https://en.wikipedia.org/wiki/ADISA%20certification | Founded in 2010, ADISA Certification Limited (formerly Asset Disposal and Information Security Alliance) is a certification body for companies that provide IT Asset Disposal services.
In July 2021, the ADISA ICT Asset Recovery Standard 8.0 was formally approved by the UK Information Commissioner's Office as a UK GDPR Certification Scheme.
In 2019, ADISA launched the ADISA Research Centre (ARC). ARC delivers product certification schemes for software and hardware data sanitization tools. The ADISA Product Claims and Product Assurance Schemes are different levels of product testing for data sanitization tools.
The Product Claims Test (PCT) scientifically evaluates the claim behind the data sanitization capabilities of a software or hardware device to determine its validity.
The Product Assurance Test offers a higher level of assurance than the PCT; it requires a larger sample size to be forensically analyzed and measures the vendors of the software or hardware device against a range of requirements.
ADISA won the 2020 Computer Security Magazine "One to Watch" award to follow up on previous wins including the 2019 "Computer Security Compliance Company of the Year " award and Training Provider of the Year (2015). The ADISA Standard is recognized as an industry standard of merit by the UK Defence Infosec Product Co-Operation Group (DIPCOG) and is listed on the National Cyber Security Centre's guidance for companies when disposing of IT assets.
ADISA owns a YouTube channel called "ADISA Media Centre" where they provide information from the group in various formats.
See also
Computer recycling
Data remanence
Electronic waste
Sanitization (classified information) |
https://en.wikipedia.org/wiki/Predictor%E2%80%93corrector%20method | In numerical analysis, predictor–corrector methods belong to a class of algorithms designed to integrate ordinary differential equationsto find an unknown function that satisfies a given differential equation. All such algorithms proceed in two steps:
The initial, "prediction" step, starts from a function fitted to the function-values and derivative-values at a preceding set of points to extrapolate ("anticipate") this function's value at a subsequent, new point.
The next, "corrector" step refines the initial approximation by using the predicted value of the function and another method to interpolate that unknown function's value at the same subsequent point.
Predictor–corrector methods for solving ODEs
When considering the numerical solution of ordinary differential equations (ODEs), a predictor–corrector method typically uses an explicit method for the predictor step and an implicit method for the corrector step.
Example: Euler method with the trapezoidal rule
A simple predictor–corrector method (known as Heun's method) can be constructed from the Euler method (an explicit method) and the trapezoidal rule (an implicit method).
Consider the differential equation
and denote the step size by .
First, the predictor step: starting from the current value , calculate an initial guess value via the Euler method,
Next, the corrector step: improve the initial guess using trapezoidal rule,
That value is used as the next step.
PEC mode and PECE mode
There are different variants of a predictor–corrector method, depending on how often the corrector method is applied. The Predict–Evaluate–Correct–Evaluate (PECE) mode refers to the variant in the above example:
It is also possible to evaluate the function f only once per step by using the method in Predict–Evaluate–Correct (PEC) mode:
Additionally, the corrector step can be repeated in the hope that this achieves an even better approximation to the true solution. If the corrector method is ru |
https://en.wikipedia.org/wiki/Kingmax | Kingmax is a Taiwan-based corporate group and manufacturer of RAM modules and memory cards. The principal company of the group is Kingmax Semiconductor Inc. was established in 1989, headquartered in Zhubei City, Hsinchu County, Taiwan, and the group manufactures and offers computer hardware and electronics products all over the world.
Overview
Originally, in 1989, Kingmax Semiconductor Inc. was established. The Group has several manufacturing facilities in Taiwan, China, and Hong Kong. The group manufactures and offers flash memory products (SD cards, USB flash drives and Solid state drives), Hard disk drives, DRAM, Card readers, USB adapters, and other electronics products all over the world. The business type and scope is same as ADATA, Silicon Power and Transcend Information, these are also the companies in Taiwan. In 2011, Kingmax was known that introduced the first 64GB microSD card in the world. In 2015, Kingpak Technology Inc. was merged into International Branding Marketing Inc. (English name is still Kingpak Technology Inc). And then, it was the first company of the group that changed status from private to public listed on the Taiwan OTC Market (6238.TWO). In 2017, Kingmax was also known that AirQ Check, the portable air quality checker for checking PM2.5 etc., received Taiwan Excellence Award.
In the aspect of business-to-business, as the supplier of computer hardware, Kingmax has contributed to offer the various products to major computer companies. The group has offered TinyBGA to IBM, hp, Sun Microsystems, Compaq, Dell, NEC, Acer, Asus
, CMOS image sensor to ON Semiconductor, etc. However, the group has been offered flash memory and DRAM by Lexar (Micron Technology) and Elixir (Nanya Technology).
Group Companies
Kingmax Semiconductor Inc. (勝創科技股份有限公司)
Kingmax Digital Inc. (協泰國際股份有限公司)
Kingpak Technology Inc. (勝麗國際股份有限公司)
See also
List of companies of Taiwan |
https://en.wikipedia.org/wiki/Proactive%20disclosure | Proactive disclosure is the act of releasing information before it is requested. In Canada, this refers to an environment where information is released routinely through electronic means with the exception of information that the government is required to protect due to privacy risks. This could refer to information regarding citizens' social insurance numbers or military operations.
Proactive disclosure differs from reactive disclosure, as reactive disclosure occurs when a request is made, while proactive disclosure occurs without the filing of the request. Proactive disclosure has also been referred to as stealing thunder, active disclosure in the United States and suo moto disclosure in Latin which means upon its own initiative.
History
The earliest way information was disclosed was seen in ancient Greece through criers or bellmen. Criers were hired in medieval times to walk the streets and call for attention, then read out important news such as royal proclamations or local bylaws. They would also play a role in passing the information across villages. This role changed when newspapers, radios, television and the internet became innovative parts of society.
Governments
Within the government, proactive disclosure is meant to inform citizens of information that allows them to hold the government accountable. Information that puts private or public good in harm's way is not disclosed. This term is used frequently when discussing open government, meaning information is easily available to the public and at a regular basis due to the benefit of technology on disseminating information.
Many consider proactive disclosure and the ability to have access to information as a way to watch over those in power within society. This is especially true for governments who collect a wide range of information, which citizens often use to hold the government accountable.
Transparency and proactive disclosure are often associated in terms of creating open government.
Canada |
https://en.wikipedia.org/wiki/Airport%20City | Airport City is a free-to-play city-building simulation game developed and published by Game Insight. Airport City was first launched on the Facebook social media platform on September 1, 2011. The game was released for Google Play on February 11, 2012, and for iOS on August 16, 2012, followed by Amazon Appstore on October 26, 2012, and Microsoft Windows on April 3, 2014. The game features mobile cross-platform play, allowing players on any supported device to cooperate and compete with each other.
As of September 2019, Game Insight has reported over 75 million Airport City registered players worldwide across all platforms.
Gameplay
Airport City tasks the player with expanding a small airport into a major one, while developing a nearby town to support the airport operations with passengers from residential buildings and taxes from commercial properties.
As both city and airport grow, the space program becomes available that challenges the player to launch space missions either solo or together with other players. Another group-based activity is airline alliances that players can create to complete missions together with team members and to compete against other alliances. New content for the game involves the addition of new aircraft, buildings, destinations, and collectible items to bring back from those flights, taking the form of either expansion packs or limited time special events released roughly every month.
Seasonal events either reflect real world events, such as Halloween, Christmas, and Easter, or fictitious, such as a UFO crash landing near the city or loosely based on the events from Adventures in Wonderland novel.
Reception
Critical response
Pocket-lints Ian Morris called Airport City "the stupidest, most annoying game we've ever played on Android" that manages to be quite addictive with something to do all the time, and "perfecty possible, and enjoyable" to play for free despite its repetitive nature. Pete Davison writing for the Adweek nam |
https://en.wikipedia.org/wiki/Water%20Wally | Water Wally is the official Singapore Public Utilities Board (PUB) mascot. Water Wally is blue in colour and shaped like a water droplet. Water Wally conveys messages about water conservation and usage to the public.
Mascot unveiling
Water Wally was unveiled on 4 August 2005 by Dr Yaacob Ibrahim, Minister for the Environment and Water Resources at an official launch held at MacRitchie Reservoir.
In a two-week "teaser" campaign leading up to the official unveiling, thirty three-metre-high Water Wally inflatable balloons were displayed suspended above various reservoirs and canals around Singapore. A "Where's Wally"-inspired contest to spot the mascot was publicized in national newspapers, receiving over two thousand SMS and email entries. Five of the inflatables were reported as having gone missing during the campaign.
Water Wally as a publicity tool
Singapore's Public Utilities Board (PUB) aims for Water Wally to put a "face" to water management issues which the public, and children in particular, can relate to. Water Wally is prominent in a wide range of PUB publicity materials and souvenirs, including toys, T-shirts, calendars and posters.
At the 2007 Singapore National Day Parade (NDP), Water Wally was featured in 5 different commemorative NEWater bottle designs and tattoos included in the free NDP fun pack given to all attendants. The mascot also makes appearances at talks in schools and libraries.
Television series
The Adventures of Water Wally is an nine-episode short non-dialogue animated series featuring Water Wally titled "The Adventures of Water Wally". It was produced by Scrawl Studios Pte. Ltd in Singapore and Media Development Authority of Singapore (now Infocomm Media Development Authority). There is no dialogue. The show was telecast on MediaCorp's okto channel from 23 January to 14 February 2009, also made available online at www.pub.gov.sg/waterwally. |
https://en.wikipedia.org/wiki/Molecular%20evolution | Molecular evolution is the process of change in the sequence composition of cellular molecules such as DNA, RNA, and proteins across generations. The field of molecular evolution uses principles of evolutionary biology and population genetics to explain patterns in these changes. Major topics in molecular evolution concern the rates and impacts of single nucleotide changes, neutral evolution vs. natural selection, origins of new genes, the genetic nature of complex traits, the genetic basis of speciation, the evolution of development, and ways that evolutionary forces influence genomic and phenotypic changes.
History
The history of molecular evolution starts in the early 20th century with comparative biochemistry, and the use of "fingerprinting" methods such as immune assays, gel electrophoresis, and paper chromatography in the 1950s to explore homologous proteins.
The field of molecular evolution came into its own in the 1960s and 1970s, following the rise of molecular biology. The advent of protein sequencing allowed molecular biologists to create phylogenies based on sequence comparison, and to use the differences between homologous sequences as a molecular clock to estimate the time since the last universal common ancestor. In the late 1960s, the neutral theory of molecular evolution provided a theoretical basis for the molecular clock, though both the clock and the neutral theory were controversial, since most evolutionary biologists held strongly to panselectionism, with natural selection as the only important cause of evolutionary change. After the 1970s, nucleic acid sequencing allowed molecular evolution to reach beyond proteins to highly conserved ribosomal RNA sequences, the foundation of a reconceptualization of the early history of life.
Forces in molecular evolution
The content and structure of a genome is the product of the molecular and population genetic forces which act upon that genome. Novel genetic variants will arise through mutation and |
https://en.wikipedia.org/wiki/Diaconescu%27s%20theorem | In mathematical logic, Diaconescu's theorem, or the Goodman–Myhill theorem, states that the full axiom of choice is sufficient to derive the law of the excluded middle or restricted forms of it.
The theorem was discovered in 1975 by Radu Diaconescu and later by Goodman and Myhill. Already in 1967, Errett Bishop posed the theorem as an exercise (Problem 2 on page 58 in Foundations of constructive analysis).
Proof
The proof given here is in the context of a constructive set theory with an axiom of specification that allows for comprehension involving some proposition . One considers two subsets of a set with two distinguishable members, such as with :
and
If can be proven, then both of these sets equal . In particular, by the axiom of extensionality, .
In turn, for any mathematical function that can take both of these sets as an argument, one finds , the contrapositive of which is .
Both sets are inhabited, as witnessed by and . So assuming the axiom of choice, there exists a choice function for the set into their union . By definition of the axiom, it fulfills
Using the definition of the two subsets and having already established the codomain, this reduces to
Using the law of distributivity, this implies . By the previous comment on functions, this in turn implies .
Discussion
As noted, implies that both defined sets equal . In that case, the pair equals the singleton set and there are two possible choice functions on that domain, picking either or . If, instead, can be rejected, i.e. if can be proven, then and . So in that case , and on the proper pair there is only one possible choice function, picking the unique inhabitant of each singleton set. This last assignment " and " is not viable if holds, as then the two inputs are actually the same. Similarly, the former two assignments are not viable if holds, as then the two inputs share no common member. What can be said is that if a choice function exists at all, then there exists a choic |
https://en.wikipedia.org/wiki/Journal%20of%20Applied%20Physics | The Journal of Applied Physics is a peer-reviewed scientific journal with a focus on the physics of modern technology. The journal was originally established in 1931 under the name of Physics, and was published by the American Physical Society for its first 7 volumes. In January 1937, ownership was transferred to the American Institute of Physics "in line with the efforts of the American Physical Society to enhance the standing of physics as a profession". The journal's current editor-in-chief is André Anders (Leibniz Institute of Surface Engineering). According to the Journal Citation Reports, the journal has a 2022 impact factor of 3.2. |
https://en.wikipedia.org/wiki/Bromine%20monochloride | Bromine monochloride, also called bromine(I) chloride, bromochloride, and bromine chloride, is an interhalogen inorganic compound with chemical formula BrCl. It is a very reactive golden yellow gas with boiling point 5 °C and melting point −66 °C. Its CAS number is 13863-41-7, and its EINECS number is 237-601-4. It is a strong oxidizing agent. Its molecular structure in the gas phase was determined by microwave spectroscopy; the Br-Cl bond has a length of re = 2.1360376(18) Å. Its crystal structure was determined by single crystal X-ray diffraction; the bond length in the solid state is 2.179(2) Å and the shortest intermolecular interaction is r(Cl···Br) = 3.145(2) Å.
Uses
Bromine monochloride is used in analytical chemistry in determining low levels of mercury, to quantitatively oxidize mercury in the sample to Hg(II) state.
A common use of bromine monochloride is as an algaecide, fungicide, and disinfectant of industrial recirculating cooling water systems.
Addition of bromine monochloride is used in some types of Li-SO2 batteries to increase voltage and energy density.
See also
List of highly toxic gases
Interhalogen compounds |
https://en.wikipedia.org/wiki/Fagus%20%C3%97%20taurica | Fagus × taurica, the Crimean beech, is a deciduous tree in the beech genus Fagus.
Taxonomy
The Balkan beech or Moesian beech (Fagus moesiaca), is considered to be the same species. It has been thought to be a hybrid between F. orientalis and F. sylvatica, but the relationships between Eurasian beeches are still unclear, and it may show greater affinity with F. orientalis. |
https://en.wikipedia.org/wiki/Anterior%20talofibular%20ligament | The anterior talofibular ligament is a ligament in the ankle.
It passes from the anterior margin of the fibular malleolus, passing anteromedially to insert at the lateral aspect of the talus at the talar neck , in front of its lateral articular facet. It is one of the lateral ligaments of the ankle and prevents the foot from sliding forward in relation to the shin. It is the most commonly injured ligament in a sprained ankle—from an inversion injury—and will allow a positive anterior drawer test of the ankle if completely torn.
See also
Sprained ankle
Posterior talofibular ligament |
https://en.wikipedia.org/wiki/Subcountability | In constructive mathematics, a collection is subcountable if there exists a partial surjection from the natural numbers onto it.
This may be expressed as
where denotes that is a surjective function from a onto . The surjection is a member of and here the subclass of is required to be a set.
In other words, all elements of a subcountable collection are functionally in the image of an indexing set of counting numbers and thus the set can be understood as being dominated by the countable set .
Discussion
Nomenclature
Note that nomenclature of countability and finiteness properties vary substantially - in part because many of them coincide when assuming excluded middle. To reiterate, the discussion here concerns the property defined in terms of surjections onto the set being characterized. The language here is common in constructive set theory texts, but the name subcountable has otherwise also been given to properties in terms of injections out of the set being characterized.
The set in the definition can also be abstracted away, and in terms of the more general notion may be called a subquotient of .
Example
Important cases are where the set in question is some subclass of a bigger class of functions as studied in computability theory.
There cannot be a computable surjection from onto the set of total computable functions , as demonstrated via the function from the diagonal construction, which could never be in such a surjections image. However, via the codes of all possible partial computable functions, which also allows non-terminating programs, such subsets of functions, such as the total functions, are seen to be subcountable sets: The total functions are the range of some strict subset of the natural numbers. Being dominated by an uncomputable, and so constructively uncountable, set of numbers, the name subcountable thus conveys that the constructively uncountable set is no bigger than . Note that no effective map between all counting n |
https://en.wikipedia.org/wiki/Cubital%20index | Cubital index is the ratio of two of the wing vein segments of honeybees. The cubital index is used in morphology, the study of form and structure, one way to differentiate species and sub species of living organisms. The pattern of the veins of the fore wings is specific for each breed of bees. The cubital index is consistent for a given race of bee. It can be used to distinguish between similar populations of honeybees and to determine degrees of hybridization.
Procedure
To obtain reliable average results, at least 100 bee fore wings have to be analyzed. Measurements are taken under a dissecting microscope with a magnification of 10x to 20x.
See also
Beekeeping
Western honeybee
Comparative anatomy
Beekeeping |
https://en.wikipedia.org/wiki/Methenium | In organic chemistry, methenium (also called methylium, carbenium, methyl cation, or protonated methylene) is a cation with the formula . It can be viewed as a methylene radical (:) with an added proton (), or as a methyl radical (•) with one electron removed. It is a carbocation and an enium ion, making it the simplest of the carbenium ions.
Structure
Experiments and calculations generally agree that the methenium ion is planar, with threefold symmetry. The carbon atom is a prototypical (and exact) example of sp2 hybridization.
Preparation and reactions
For mass spectrometry studies at low pressure, methenium can be obtained by ultraviolet photoionization of methyl radical, or by collisions of monatomic cations such as and with neutral methane. In such conditions, it will react with acetonitrile to form the ion .
Upon capture of a low-energy electron (less than ), it will spontaneously dissociate.
It is seldom encountered as an intermediate in the condensed phase. It is proposed as a reactive intermediate that forms upon protonation or hydride abstraction of methane with FSO3H-SbF5. The methenium ion is very reactive, even towards alkanes.
Detection
Origins of life
In June 2023, astronomers detected, for the first time, methyl cation, CH3+ (and/or carbon cation, C+), the known basic ingredients of life, in interstellar space.
See also
Ammonium
Ethanium
Methanium |
https://en.wikipedia.org/wiki/Klein%20configuration | In geometry, the Klein configuration, studied by , is a geometric configuration related to Kummer surfaces that consists of 60 points and 60 planes, with each point lying on 15 planes and each plane passing through 15 points. The configurations uses 15 pairs of lines, 12 . 13 . 14 . 15 . 16 . 23 . 24 . 25 . 26 . 34 . 35 . 36 . 45 . 46 . 56 and their reverses. The 60 points are three concurrent lines forming an odd permutation, shown below. The sixty planes are 3 coplanar lines forming even permutations, obtained by reversing the last two digits in the points. For any point or plane there are 15 members in the other set containing those 3 lines. [Hudson, 1905]
Coordinates of points and planes
A possible set of coordinates for points (and also for planes!) is the following: |
https://en.wikipedia.org/wiki/Aron%20Mosnaim | Aron David Mosnaim is a neuroscientist, researcher, and academic. He is a professor of Cellular and Molecular Pharmacology and an adjunct professor of Psychiatry and Behavioral Sciences in the Chicago Medical School at Rosalind Franklin University of Medicine and Science.
Mosnaim is most known for his research covering the areas of basic and clinical neuro- and immunopharmacology of biogenic amines and opioid peptides in neuropsychiatric conditions, including depression, headache pain, as well as movement and posttraumatic stress disorders. He has co-edited four scientific books on Noncatecholic Phenylethylamines (2 volumes), Posttraumatic Stress Disorder, and Tardive Dyskinesia.
Mosnaim has served as a Consultant to the Pan American Health Organization (1982–1985), Member of the United States Pharmacopeia Convention (1990 and 1995), and Director of International Neuropsychiatry Consultants (1987–2020). Additionally, he is a Fellow of The Chemical Society (1977) and a Senior Fellow of the American Institute of Therapeutics (2019).
Early life and education
Mosnaim earned a Doctor of Pharmaceutical Sciences degree from the University of Chile (1964) and joined the Faculty of the university's School of Medicine. He was awarded a PhD degree in Organic Chemistry from Glasgow’s Strathclyde University (1969). After a brief tenure at the University of Chicago, he received a postdoctoral fellowship at Northwestern University (1970).
Career
In 1971, Mosnaim joined the University of Health Sciences/The Chicago Medical School as an assistant professor in the Department of Pharmacology. He was promoted to Associate Professor and Acting Chairman (1974), and to a Full Professorship in 1979. He has been serving as a professor of Cellular and Molecular Pharmacology and adjunct professor of Psychiatry and Behavioral Sciences at The Chicago Medical School/Rosalind Franklin University.
Mosnaim holds an Honorary Full Professorship at the University of Chile College of Pharmaceutica |
https://en.wikipedia.org/wiki/Curvature%20collineation | A curvature collineation (often abbreviated to CC) is vector field which preserves the Riemann tensor in the sense that,
where are the components of the Riemann tensor. The set of all smooth curvature collineations forms a Lie algebra under the Lie bracket operation (if the smoothness condition is dropped, the set of all curvature collineations need not form a Lie algebra). The Lie algebra is denoted by and may be infinite-dimensional. Every affine vector field is a curvature collineation.
See also
Conformal vector field
Homothetic vector field
Killing vector field
Matter collineation
Spacetime symmetries
Mathematical methods in general relativity |
https://en.wikipedia.org/wiki/Max%E2%80%93min%20inequality | In mathematics, the max–min inequality is as follows:
For any function
When equality holds one says that , , and satisfies a strong max–min property (or a saddle-point property). The example function illustrates that the equality does not hold for every function.
A theorem giving conditions on , , and which guarantee the saddle point property is called a minimax theorem.
Proof
Define For all , we get for all by definition of the infimum being a lower bound. Next, for all , for all by definition of the supremum being an upper bound. Thus, for all and , making an upper bound on for any choice of . Because the supremum is the least upper bound, holds for all . From this inequality, we also see that is a lower bound on . By the greatest lower bound property of infimum, . Putting all the pieces together, we get
which proves the desired inequality. |
https://en.wikipedia.org/wiki/Computer%20programming%20in%20the%20punched%20card%20era | From the invention of computer programming languages up to the mid-1970s, most computer programmers created, edited and stored their programs line by line on punch cards.
Punched cards
A punched card is a flexible write-once medium that encodes data, most commonly 80 characters. Groups or "decks" of cards form programs and collections of data. The term is often used interchangeably with punch card, the difference being that an unused card is a "punch card," but once information had been encoded by punching holes in the card, it was now a "punched card." For simplicity, this article will use the term punched card to refer to either.
Often programmers first wrote their program out on special forms called coding sheets, taking care to distinguish the digit zero from the letter O, the digit one from the letter I, eight from B, two from Z, and so on using local conventions such as the "slashed zero". These forms were then taken by keypunch operators, who using a keypunch machine such as the IBM 026 (later IBM 029) punched the deck. Often another keypunch operator would then take that deck and re-punch from the coding sheets – but using a "verifier" such as the IBM 059 that checked that the original punching had no errors.
A typing error generally necessitated re-punching an entire card. The editing of programs was facilitated by reorganizing the cards, and removing or replacing the lines that had changed; programs were backed up by duplicating the deck, or writing it to magnetic tape.
In smaller organizations programmers might do their own punching, and in all cases would often have access to a keypunch to make small changes to a deck.
Work environment
The description below describes an all-IBM shop (a "shop" is programmer jargon for a programming site) but shops using other brands of mainframes (or minicomputers) would have similar equipment although because of cost or availability might have different manufacturer's equipment, e.g. an NCR, ICL, Hewlett-Packard (H |
https://en.wikipedia.org/wiki/Game%20Off | Game Off is an annual game jam celebrating open source created by Lee Reilly in 2012 and sponsored by GitHub. Participants are given the entire month of November to build a game based on a theme–individually or as a team. Inspired by the Global Game Jam, it encourages collaborative game development and promotes the use and sharing of open source software.
Intellectual property and licensing
The use of open source code and freely availably assets is encouraged, but it is not a strict requirement. Participants are required to share the code in a public GitHub repository, but the creators own the intellectual property and may license the code however they like. E.g. the overall winner of Game Off V was Daemon vs. Demon, a game built with the open source Godot game engine, with the source licensed under the MIT license and some assets made available under CC-BY-NC 4.0 licenses.
Past Themes
Competition Structure
Game Off I and II required participants to "fork" an empty GitHub source code repository. Many other game jams and hackathons have adopted this approach e.g. Netflix's Cloud Prize, and Canonical's Juju Charm Championship.
Game Off III required participants to choose an existing open source game jam entry to fork it as a starting point.
Game Off IV allowed participants to start with a new repository.
Game Off V was hosted on itch.io, and was recognized the 2nd most popular game jam by number participants and 5th most popular by number of submissions in their yearly review.
Game Off VI was also hosted on itch.io. Overall winner was the game Singularity. There were 329 successful submissions. |
https://en.wikipedia.org/wiki/Signal%20Protocol | The Signal Protocol (formerly known as the TextSecure Protocol) is a non-federated cryptographic protocol that provides end-to-end encryption for voice and instant messaging conversations. The protocol was developed by Open Whisper Systems in 2013 and was first introduced in the open-source TextSecure app, which later became Signal. Several closed-source applications have implemented the protocol, such as WhatsApp, which is said to encrypt the conversations of "more than a billion people worldwide" or Google who provides end-to-end encryption by default to all RCS-based conversations between users of their Messages app for one-to-one conversations. Facebook Messenger also say they offer the protocol for optional Secret Conversations, as does Skype for its Private Conversations.
The protocol combines the Double Ratchet algorithm, prekeys, and a triple Elliptic-curve Diffie–Hellman (3-DH) handshake, and uses Curve25519, AES-256, and HMAC-SHA256 as primitives.
History
The development of the Signal Protocol was started by Trevor Perrin and Moxie Marlinspike (Open Whisper Systems) in 2013. The first version of the protocol, TextSecure v1, was based on Off-the-Record Messaging (OTR).
On 24 February 2014, Open Whisper Systems introduced TextSecure v2, which migrated to the Axolotl Ratchet. The design of the Axolotl Ratchet is based on the ephemeral key exchange that was introduced by OTR and combines it with a symmetric-key ratchet modeled after the Silent Circle Instant Messaging Protocol (SCIMP). It brought about support for asynchronous communication ("offline messages") as its major new feature, as well as better resilience with distorted order of messages and simpler support for conversations with multiple participants. The Axolotl Ratchet was named after the critically endangered aquatic salamander Axolotl, which has extraordinary self-healing capabilities. The developers refer to the algorithm as self-healing because it automatically disables an attacker from acc |
https://en.wikipedia.org/wiki/KTXH | KTXH (channel 20), branded on-air as My 20 Vision, is a television station in Houston, Texas, United States, serving as the local outlet for the MyNetworkTV programming service. It is owned and operated by Fox Television Stations alongside Fox outlet KRIV (channel 26). Both stations share studios on Southwest Freeway (I-69/US 59) in Houston, while KTXH's transmitter is located near Missouri City, Texas.
KTXH began broadcasting in November 1982 as Houston's third independent station. A month after going on air, its broadcast tower collapsed in a construction accident that killed five people. The station recovered and emerged as Houston's sports independent, beginning long associations with the Houston Astros and Houston Rockets that continued uninterrupted through the late 1990s and sporadically until the early 2010s. Not long after starting up, KTXH was sold twice in rapid succession for large amounts. However, when the independent station trade, advertising market, and regional economy cooled, it was sold again for less than half of its previous value. The Paramount Stations Group acquired KTXH and other stations in two parts between 1989 and 1991, bringing much-needed stability.
KTXH was one of several Paramount-owned stations to be charter outlets for the United Paramount Network (UPN) in 1995; in 2001, after UPN was acquired by CBS, Fox took possession of the station in a trade and merged its operations with KRIV. When UPN merged into The CW in 2006, bypassing all of Fox's UPN and independent stations in the process, the station became part of Fox's MyNetworkTV service. In 2021, the station became one of two ATSC 3.0 (NextGen TV) transmitters for the Houston area; its subchannels are now transmitted by other local stations on its behalf.
History
Construction, start-up, and tragedy
Interest in channel 20 in Houston began to emerge in 1976, as three groups filed applications for new television stations in light of the emerging technology of subscription televi |
https://en.wikipedia.org/wiki/List%20of%20glycoside%20hydrolase%20families | Glycoside hydrolases (O-Glycosyl hydrolases) are a widespread group of enzymes that hydrolyse the glycosidic bond between two or more carbohydrates, or between a carbohydrate and a non-carbohydrate moiety. A classification system for glycosyl hydrolases, based on sequence similarity, has led to the definition of numerous different families. This classification is available on the CAZy (CArbohydrate-Active EnZymes) web site. Because the fold of proteins is better conserved than their sequences, some of the families can be grouped in 'clans'. As of October 2011, CAZy includes 128 families of glycosyl hydrolases and 14 clans.
Glycoside hydrolase family 1
Glycoside hydrolase family 2
Glycoside hydrolase family 3
Glycoside hydrolase family 4
Glycoside hydrolase family 5
Glycoside hydrolase family 6
Glycoside hydrolase family 7
Glycoside hydrolase family 8
Glycoside hydrolase family 9
Glycoside hydrolase family 10
Glycoside hydrolase family 11
Glycoside hydrolase family 12
Glycoside hydrolase family 13
Glycoside hydrolase family 14
Glycoside hydrolase family 15
Glycoside hydrolase family 16
Glycoside hydrolase family 17
Glycoside hydrolase family 18
Glycoside hydrolase family 19
Glycoside hydrolase family 20
Glycoside hydrolase family 21
Glycoside hydrolase family 22
Glycoside hydrolase family 23
Glycoside hydrolase family 24
Glycoside hydrolase family 25
Glycoside hydrolase family 26
Glycoside hydrolase family 27
Glycoside hydrolase family 28
Glycoside hydrolase family 29
Glycoside hydrolase family 30
Glycoside hydrolase family 31
Glycoside hydrolase family 32
Glycoside hydrolase family 33
Glycoside hydrolase family 34
Glycoside hydrolase family 35
Glycoside hydrolase family 36
Glycoside hydrolase family 37
Glycoside hydrolase family 38
Glycoside hydrolase family 39
Glycoside hydrolase family 40
Glycoside hydrolase family 41
Glycoside hydrolase family 42
Glycoside hydrolase family 43
Glycoside hydrolase family 44
Glycoside hydrolase family 45
Glycoside hydrolase family |
https://en.wikipedia.org/wiki/Rob%20Sias%20Award | The Robert J. Sias senior resident award for excellence in clinical dermatology recognizes the outstanding clinical skills of a graduating resident at the University of Minnesota department of dermatology, and is presented annually at the Resident Graduation Celebration in June. The recipient is chosen by faculty and staff as the resident doctor they would most want to care for family and friends.
See also
List of medicine awards |
https://en.wikipedia.org/wiki/Geary%27s%20C | Geary's C is a measure of spatial autocorrelation that attempts to determine if observations of the same variable are spatially autocorrelated globally (rather than at the neighborhood level). Spatial autocorrelation is more complex than autocorrelation because the correlation is multi-dimensional and bi-directional.
Geary's C is defined as
where is the number of spatial units indexed by and ; is the variable of interest; is the mean of ; is the row of the spatial weights matrix with zeroes on the diagonal (i.e., ); and is the sum of all weights in .
The value of Geary's C lies between 0 and some unspecified value greater than 1. Values significantly lower than 1 demonstrate increasing positive spatial autocorrelation, whilst values significantly higher than 1 illustrate increasing negative spatial autocorrelation.
Geary's C is inversely related to Moran's I, but it is not identical. While Moran's I and Geary's C are both measures of global spatial autocorrelation, they are slightly different. Geary's C uses the sum of squared distances whereas Moran's I uses standardized spatial covariance. By using squared distances Geary's C is less sensitive to linear associations and may pickup autocorrelation where Moran's I may not.
Geary's C is also known as Geary's contiguity ratio or simply Geary's ratio.
This statistic was developed by Roy C. Geary.
Sources
Spatial analysis
Covariance and correlation |
https://en.wikipedia.org/wiki/Quad-edge | A quad-edge data structure is a computer representation of the topology of a two-dimensional or three-dimensional map, that is, a graph drawn on a (closed) surface. It was first described by Jorge Stolfi and Leonidas J. Guibas. It is a variant of the earlier winged edge data structure.
Overview
The fundamental idea behind the quad-edge structure is the recognition that a single edge, in a closed polygonal mesh topology, sits between exactly two faces and exactly two vertices.
The Quad-Edge Data Structure
The quad-edge data structure represents an edge, along with the edges it is connected to around the adjacent vertices and faces to encode the topology of the graph.
An example implementation of the quad-edge data-type is as follows
typedef struct {
quadedge_ref e[4];
} quadedge;
typedef struct {
quadedge *next;
unsigned int rot;
} quadedge_ref;
Each quad-edge contains four references to adjacent quad-edges. Each of the four references points to the next edge counter-clockwise around either a vertex or a face. Each of these references represent either the origin vertex of the edge, the right face, the destination vertex, or the left face. Each quad-edge reference points to a quad-edge and the rotation (from 0 to 3) of the 'arm' it points at.
Due to this representation, the quad-edge:
represents a graph, its dual, and its mirror image.
the dual of the graph can be obtained simply by reversing the convention on what is a vertex and what is a face; and
can represent the most general form of a map, admitting vertices and faces of degree 1 and 2.
Details
The quad-edge structure gets its name from the general mechanism by which they are stored. A single Edge structure conceptually stores references to up to two faces, two vertices, and 4 edges. The four edges stored are the edges starting with the two vertices that are attached to the two stored faces.
Uses
Much like Winged Edge, quad-edge structures are used in programs to store the topology of a 2D or |
https://en.wikipedia.org/wiki/Charles%20Robertson%20Maier | Charles Robertson Maier, C StJ, CD, FRSA, FHSC,(born 1945) is the current Priory Historian for St John Ambulance, The Priory of Canada.
Maier was born in St Louis, Missouri in 1945. He received a Bachelor of Arts in 1969 from the University of British Columbia and a Master of Arts in 1970 from King's College London, University of London. He was an archivist for the Yukon Territory until the foundation of the Canadian Heraldic Authority in 1988 when he was commissioned Athabaska Herald. He was made a fellow of the Royal Heraldry Society of Canada in 1991. He was promoted Commander of the Order of St John in 2005. |
https://en.wikipedia.org/wiki/Wafer%20fabrication | Wafer fabrication is a procedure composed of many repeated sequential processes to produce complete electrical or photonic circuits on semiconductor wafers in semiconductor device fabrication process. Examples include production of radio frequency (RF) amplifiers, LEDs, optical computer components, and microprocessors for computers. Wafer fabrication is used to build components with the necessary electrical structures.
The main process begins with electrical engineers designing the circuit and defining its functions, and specifying the signals, inputs/outputs and voltages needed. These electrical circuit specifications are entered into electrical circuit design software, such as SPICE, and then imported into circuit layout programs, which are similar to ones used for computer aided design. This is necessary for the layers to be defined for photomask production. The resolution of the circuits increases rapidly with each step in design, as the scale of the circuits at the start of the design process is already being measured in fractions of micrometers. Each step thus increases circuit density for a given area.
The silicon wafers start out blank and pure. The circuits are built in layers in clean rooms. First, photoresist patterns are photo-masked in micrometer detail onto the wafers' surface. The wafers are then exposed to short-wave ultraviolet light and the unexposed areas are thus etched away and cleaned. Hot chemical vapors are deposited on to the desired zones and baked in high heat, which permeate the vapors into the desired zones. In some cases, ions, such as O2+ or O+, are implanted in precise patterns and at a specific depth by using RF-driven ion sources.
These steps are often repeated many hundreds of times, depending on the complexity of the desired circuit and its connections.
New processes to accomplish each of these steps with better resolution and in improved ways emerge every year, with the result of constantly changing technology in the wafer fa |
https://en.wikipedia.org/wiki/Impulse%20generator | An impulse generator is an electrical apparatus which produces very short high-voltage or high-current surges. Such devices can be classified into two types: impulse voltage generators and impulse current generators. High impulse voltages are used to test the strength of electric power equipment against lightning and switching surges. Also, steep-front impulse voltages are sometimes used in nuclear physics experiments. High impulse currents are needed not only for tests on equipment such as lightning arresters and fuses but also for many other technical applications such as lasers, thermonuclear fusion, and plasma devices.
Jedlik's tubular voltage generator
In 1863 Hungarian physicist Ányos Jedlik discovered the possibility of voltage multiplication and in 1868 demonstrated it with a "tubular voltage generator", which was successfully displayed at the Vienna World Exposition in 1873. It was an early form of the impulse generators now applied in nuclear research.
The jury of the World Exhibition of 1873 in Vienna awarded his voltage multiplying condenser of cascade connection with prize "For Development". Through this condenser, Jedlik framed the principle of surge generator of cascaded connection. (The Cascade connection was another important invention of Ányos Jedlik.)
Marx generator
One form is the Marx generator, named after Erwin Otto Marx, who first proposed it in 1923. This consists of multiple capacitors that are first charged in parallel through charging resistors as by a high-voltage, direct-current source and then connected in series and discharged through a test object by a simultaneous spark-over of the spark gaps. The impulse current generator comprises many capacitors that are also charged in parallel by a high-voltage, low-current, direct-current source, but it is discharged in parallel through resistances, inductances, and a test object by a spark gap.
See also
Pulsed power
Pulse-forming network
Marx generator
Cockcroft–Walton generator
|
https://en.wikipedia.org/wiki/Lebesgue%27s%20universal%20covering%20problem | Lebesgue's universal covering problem is an unsolved problem in geometry that asks for the convex shape of smallest area that can cover every planar set of diameter one. The diameter of a set by definition is the least upper bound of the distances between all pairs of points in the set. A shape covers a set if it contains a congruent subset. In other words the set may be rotated, translated or reflected to fit inside the shape.
Formulation and early research
The problem was posed by Henri Lebesgue in a letter to Gyula Pál in 1914. It was published in a paper by Pál in 1920 along with Pál's analysis. He showed that a cover for all curves of constant width one is also a cover for all sets of diameter one and that a cover can be constructed by taking a regular hexagon with an inscribed circle of diameter one and removing two corners from the hexagon to give a cover of area
In 1936, Roland Sprague showed that a part of Pál's cover could be removed near one of the other corners while still retaining its property as a cover. This reduced the upper bound on the area to .
Current bounds
After a sequence of improvements to Sprague's solution, each removing small corners from the solution,
a 2018 preprint of Philip Gibbs claimed the best upper bound known, a further reduction to area 0.8440935944.
The best known lower bound for the area was provided by Peter Brass and Mehrbod Sharifi using a combination of three shapes in optimal alignment, proving that the area of an optimal cover is at least 0.832.
See also
Moser's worm problem, what is the minimum area of a shape that can cover every unit-length curve?
Moving sofa problem, the problem of finding a maximum-area shape that can be rotated and translated through an L-shaped corridor
Kakeya set, a set of minimal area that can accommodate every unit-length line segment (with translations allowed, but not rotations)
Blaschke selection theorem, which can be used to prove that Lebesgue's universal covering problem has a so |
https://en.wikipedia.org/wiki/Pseudo-Zernike%20polynomials | In mathematics, pseudo-Zernike polynomials are well known and widely used in the analysis of optical systems. They are also widely used in image analysis as shape descriptors.
Definition
They are an orthogonal set of complex-valued polynomials
defined as
where and orthogonality on the unit disk is given as
where the star means complex conjugation, and
, ,
are the standard transformations between polar and Cartesian coordinates.
The radial polynomials are defined as
with integer coefficients
Examples
Examples are:
Moments
The pseudo-Zernike Moments (PZM) of order and repetition are defined as
where , and takes on positive and negative integer
values subject to .
The image function can be reconstructed by expansion of the pseudo-Zernike coefficients on the unit disk as
Pseudo-Zernike moments are derived from conventional Zernike moments and shown
to be more robust and less sensitive to image noise than the Zernike moments.
See also
Zernike polynomials
Image moment |
https://en.wikipedia.org/wiki/Interleaved%20polling%20with%20adaptive%20cycle%20time | Interleaved polling with adaptive cycle time (IPACT) is an algorithm designed by Glen Kramer, Biswanath Mukherjee and Gerry Pesavento of the Advanced Technology Lab at the University of California, Davis in 2002. IPACT is a dynamic bandwidth allocation algorithm for use in Ethernet passive optical networks (EPONs).
IPACT uses the Gate and Report messages provided by the EPON Multi-Point Control Protocol (MPCP) to allocate bandwidth to Optical Network Units (ONUs). If the optical line terminal grants bandwidth to an ONU and waits until it has received that particular ONU's transmission before granting bandwidth to another ONU, then time equivalent to a whole messaging round-trip is wasted during which the upstream may remain idle. IPACT eliminates this idle time by sending downstream grant messages to succeeding ONUs while receiving transmissions from previously granted ONUs. It accomplishes this by calculating the time at which a transmission grant allocated to a previous ONU ends. |
https://en.wikipedia.org/wiki/Cryptographically%20secure%20pseudorandom%20number%20generator | A cryptographically secure pseudorandom number generator (CSPRNG) or cryptographic pseudorandom number generator (CPRNG) is a pseudorandom number generator (PRNG) with properties that make it suitable for use in cryptography. It is also loosely known as a cryptographic random number generator (CRNG).
Background
Most cryptographic applications require random numbers, for example:
key generation
nonces
salts in certain signature schemes, including ECDSA, RSASSA-PSS
The "quality" of the randomness required for these applications varies.
For example, creating a nonce in some protocols needs only uniqueness.
On the other hand, the generation of a master key requires a higher quality, such as more entropy. And in the case of one-time pads, the information-theoretic guarantee of perfect secrecy only holds if the key material comes from a true random source with high entropy, and thus any kind of pseudorandom number generator is insufficient.
Ideally, the generation of random numbers in CSPRNGs uses entropy obtained from a high-quality source, generally the operating system's randomness API. However, unexpected correlations have been found in several such ostensibly independent processes. From an information-theoretic point of view, the amount of randomness, the entropy that can be generated, is equal to the entropy provided by the system. But sometimes, in practical situations, more random numbers are needed than there is entropy available. Also, the processes to extract randomness from a running system are slow in actual practice. In such instances, a CSPRNG can sometimes be used. A CSPRNG can "stretch" the available entropy over more bits.
Requirements
A cryptographically secure pseudorandom number generator (CSPRNG) or cryptographic pseudorandom number generator (CPRNG) is a pseudorandom number generator (PRNG) with properties that make it suitable for use in cryptography. It is also loosely known as a cryptographic random number generator (CRNG), which can be |
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