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https://en.wikipedia.org/wiki/Stefano%20Nolfi
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Stefano Nolfi (born 23 September 1963, Rome) is a director of research of the Institute of Cognitive Sciences and Technologies at the Consiglio Nazionale delle Ricerche and head of the Laboratory of Autonomous Robots and Artificial Life. He is one of the founders of Evolutionary robotics (see his book
published by MIT Press in 2000). Nolfi's research interests include: evolution of communication and language, language and action, adaptive behavior, swarm robotics.
Stefano Nolfi's team at Institute is researching a new approach in developing artificial intelligence in relation to language.
An overview of his work is included in
Nolfi received his laurea (master's) degree in literature and philosophy from the University of Rome La Sapienza in 1986.
References
External links
Stefano Nolfi homepage
Stefano Nolfi's laboratory
Living people
1963 births
Italian roboticists
Italian cognitive scientists
National Research Council (Italy) people
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https://en.wikipedia.org/wiki/Cyclic%20compound
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A cyclic compound (or ring compound) is a term for a compound in the field of chemistry in which one or more series of atoms in the compound is connected to form a ring. Rings may vary in size from three to many atoms, and include examples where all the atoms are carbon (i.e., are carbocycles), none of the atoms are carbon (inorganic cyclic compounds), or where both carbon and non-carbon atoms are present (heterocyclic compounds with rings containing both carbon and non-carbon). Depending on the ring size, the bond order of the individual links between ring atoms, and their arrangements within the rings, carbocyclic and heterocyclic compounds may be aromatic or non-aromatic; in the latter case, they may vary from being fully saturated to having varying numbers of multiple bonds between the ring atoms. Because of the tremendous diversity allowed, in combination, by the valences of common atoms and their ability to form rings, the number of possible cyclic structures, even of small size (e.g., < 17 total atoms) numbers in the many billions.
Adding to their complexity and number, closing of atoms into rings may lock particular atoms with distinct substitution (by functional groups) such that stereochemistry and chirality of the compound results, including some manifestations that are unique to rings (e.g., configurational isomers). As well, depending on ring size, the three-dimensional shapes of particular cyclic structures – typically rings of five atoms and larger – can vary
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https://en.wikipedia.org/wiki/Joseph%20Bruno%20Slowinski
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Joseph Bruno Slowinski (November 15, 1962 – September 12, 2001) was an American herpetologist who worked extensively with elapid snakes.
Research and career
Slowinski was born on November 15, 1962, in New York City, New York. He attained his bachelor's degree in biology from the University of Kansas in 1984 and went on to receive his Ph.D. at the University of Miami in 1991, studying under herpetologist Jay M. Savage. He performed postdoctoral work at the National Museum of Natural History and Louisiana State University, eventually taking a position as a professor of biology at Southeastern Louisiana University.
Slowinski was a founder of the first online herpetological journal, Contemporary Herpetology, and served as its editor-in-chief. He was also the curator for the Department of Herpetology for the California Academy of Sciences. His primary area of research was venomous snakes, having written some 40 peer-reviewed articles and one book.
Death and legacy
On September 11, 2001, while researching in an isolated region of Myanmar, Slowinski was bitten by a Suzhen's krait (Bungarus suzhenae). He died 29 hours later after his team, which included Mark W. Moffett, made several failed attempts to obtain medical attention. The September 11 terrorist attacks made communication with the embassy difficult, and by the time the embassy prepared a helicopter, the weather was particularly bad, thus preventing a helicopter from transporting Slowinski to a hospital, and making it impo
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https://en.wikipedia.org/wiki/Polycyclic%20compound
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In the field of organic chemistry, a polycyclic compound is an organic compound featuring several closed rings of atoms, primarily carbon. These ring substructures include cycloalkanes, aromatics, and other ring types. They come in sizes of three atoms and upward, and in combinations of linkages that include tethering (such as in biaryls), fusing (edge-to-edge, such as in anthracene and steroids), links via a single atom (such as in spiro compounds), bridged compounds, and longifolene. Though poly- literally means "many", there is some latitude in determining how many rings are required to be considered polycyclic; many smaller rings are described by specific prefixes (e.g., bicyclic, tricyclic, tetracyclic, etc.), and so while it can refer to these, the title term is used with most specificity when these alternative names and prefixes are unavailable.
In general, the term polycyclic includes polycyclic aromatic compounds, including polycyclic aromatic hydrocarbons, as well as heterocyclic aromatic compounds with multiple rings (where heteroaromatic compounds are aromatic compounds that contain sulfur, nitrogen, oxygen, or another non-carbon atoms in their rings in addition to carbon).
An example of a polycyclic compound based on a nitrogen cage is hexanitrohexaazaisowurtzitane.
Naming
There is a scheme for naming polycyclic compounds using square brackets [] and numbers. (See and .)
See also
Polycyclic aromatic compound
Polycyclic aromatic hydrocarbon
References
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https://en.wikipedia.org/wiki/Isodesmic%20reaction
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An isodesmic reaction is a chemical reaction in which the type of chemical bonds broken in the reactant are the same as the type of bonds formed in the reaction product. This type of reaction is often used as a hypothetical reaction in thermochemistry.
An example of an isodesmic reaction is
CH3− + CH3X → CH4 + CH2X− (1)
X = F, Cl, Br, I
Equation 1 describes the deprotonation of a methyl halide by a methyl anion. The energy change associated with this exothermic reaction which can be calculated in silico increases going from fluorine to chlorine to bromine and iodine making the CH2I− anion the most stable and least basic of all the halides. Although this reaction is isodesmic the energy change in this example also depends on the difference in bond energy of the C-X bond in the base and conjugate acid. In other cases, the difference may be due to steric strain. This difference is small in fluorine but large in iodine (in favor of the anion) and therefore the energy trend is as described despite the fact that C-F bonds are stronger than C-I bonds.
The related term homodesmotic reaction also takes into account orbital hybridization and in addition there is no change in the number of carbon to hydrogen bonds.
References
Thermochemistry
Computational chemistry
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https://en.wikipedia.org/wiki/William%20Jackson%20Humphreys
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William Jackson Humphreys (February 3, 1862 – November 10, 1949) was an American physicist and atmospheric researcher.
Biography
Humphreys was born on February 3, 1862, in Gap Mills, Virginia, to Jackson and Eliza Ann (née Eads) Humphreys. He studied physics at Washington & Lee University in Virginia and later at Johns Hopkins University in Baltimore, where he earned his Ph.D. in 1897, studying under Henry Augustus Rowland.
He worked in the fields of spectroscopy, atmospheric physics and meteorology. In the field of spectroscopy he found the shift of spectral lines under pressure. In atmospheric physics he found a very good model for the stratosphere in 1909. He wrote numerous books, including a textbook titled Physics of the Air, first published in 1920 and considered a standard work of the time, though it was last published in 1940. He also held some teaching positions at universities. He concluded that the 1815 eruption of Mount Tambora was responsible for the subsequent cooling known as the Year Without a Summer.
From 1905 to 1935 he worked as a physicist for the U.S. Weather Bureau, predecessor of the National Weather Service. In 1919, he served as president of the Philosophical Society of Washington. He was elected to the American Academy of Arts and Sciences in 1921. In 1924 he was an Invited Speaker of the ICM in Toronto. He was elected to the American Philosophical Society in 1929.
He died on November 10, 1949, in Washington, D.C.
Bibliography
Physics of the Ai
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https://en.wikipedia.org/wiki/Malcolm%20Hooper
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Malcolm Hooper is a British pharmacist and emeritus professor of medicinal chemistry at the University of Sunderland. He is best known for his advocacy related to Gulf War syndrome.
Gulf War Syndrome advisor
Hooper is the Chief Scientific Adviser to the British Gulf War Veterans Association.
He has stated his concerns over initial studies that suggested miscarriages and children with physical abnormalities are more common in pregnancies of wives of male Gulf War veterans than those not sent to the region. In a news article in the Sunday Herald, Hooper was referred to as an expert on depleted uranium, and he said that soldiers were harmed by exposure to it during the war. He has also stated that the British Ministry of Defence's position on Gulf War syndrome is outdated in light of "a complete sea change in the United States".
Advocacy for chronic fatigue syndrome
In 2002, The Guardian reported on the conflict over the nature of chronic fatigue syndrome/myalgic encephalomyelitis, and whether there is an ongoing pathological process in the illness, contrasting advocates of a biological basis, such as Professors Hooper, Kenny de Meirleir and Anthony Komaroff, with advocates of a psychosocial basis, such as Professor Simon Wessely. The article stated that the absence of any mention of the physical basis of CFS in a 2002 report to the CMO on the illness prompted Hooper to publish a dissent on the internet. In the Guardian article, Hooper states there is an increasing volume
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https://en.wikipedia.org/wiki/El%20Nombre
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El Nombre is a children's educational programme about an anthropomorphic Mexican gerbil character, originally from a series of educational sketches on Numbertime, the BBC schools programme about mathematics. He was also the only character to appear in all Numbertime episodes. His voice was provided by Steve Steen, while the other characters' voices were provided by Sophie Aldred, Kate Robbins, and (from 1999) former Blue Peter host Janet Ellis. For the ninth (and final) series of Numbertime in 2001, Michael Fenton-Stevens also provided voices of certain other characters in the El Nombre sketches.
The character's name means "The Name" in Spanish, not "The Number", which would be "El Número", but does mean "The Number" in Catalan.
Setting
El Nombre is set in the fictional town of Santa Flamingo (originally known as Santo Flamingo), home of Little Juan, his Mama, Pedro Gonzales, Juanita Conchita, Maria Consuela Tequila Chiquita, Little Pepita Consuela Tequila Chiquita, Tanto the tarantula, Señor Gelato the ice-cream seller, Leonardo de Sombrero the pizza delivery boy, Señor Calculo the bank manager, Señor Manuel the greengrocer, Miss Constanza Bonanza the school teacher, Señora Fedora the balloon seller and mayor, Señor Loco the steam engine driver, Señor Chipito the carpenter and the local bandit Don Fandango (although it was not actually given a name until the fifth series of Numbertime premiered in January 1998); whenever he was needed, El Nombre swung into action to solve
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https://en.wikipedia.org/wiki/Pair%20bond
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In biology, a pair bond is the strong affinity that develops in some species between a mating pair, often leading to the production and rearing of offspring and potentially a lifelong bond. Pair-bonding is a term coined in the 1940s that is frequently used in sociobiology and evolutionary biology circles. The term often implies either a lifelong socially monogamous relationship or a stage of mating interaction in socially monogamous species. It is sometimes used in reference to human relationships.
Varieties
According to evolutionary psychologists David P. Barash and Judith Lipton, from their 2001 book The Myth of Monogamy, there are several varieties of pair bonds:
Short-term pair-bond: a transient mating or associations
Long-term pair-bond: bonded for a significant portion of the life cycle of that pair
Lifelong pair-bond: mated for life
Social pair-bond: attachments for territorial or social reasons
Clandestine pair-bond: quick extra-pair copulations
Dynamic pair-bond: e.g. gibbon mating systems being analogous to "divorce"
Human pair bonding
Humans can experience all of the above-mentioned varieties of pair bonds. These bonds can be temporary or last a lifetime. Pair bonding is a behavioral and physiological bond between two mated individuals, and is rare among non-human primates. Humans also engage in social pair bonding, where two individuals will form a close relationship that does not involve sex. In humans and other vertebrates, pair bonds are created by a combin
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https://en.wikipedia.org/wiki/Neutrino%20detector
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A neutrino detector is a physics apparatus which is designed to study neutrinos. Because neutrinos only weakly interact with other particles of matter, neutrino detectors must be very large to detect a significant number of neutrinos. Neutrino detectors are often built underground, to isolate the detector from cosmic rays and other background radiation. The field of neutrino astronomy is still very much in its infancy – the only confirmed extraterrestrial sources are the Sun and the supernova 1987A in the nearby Large Magellanic Cloud. Another likely source (three standard deviations) is the blazar TXS 0506+056 about 3.7 billion light years away. Neutrino observatories will "give astronomers fresh eyes with which to study the universe".
Various detection methods have been used. Super Kamiokande is a large volume of water surrounded by phototubes that watch for the Cherenkov radiation emitted when an incoming neutrino creates an electron or muon in the water. The Sudbury Neutrino Observatory is similar, but uses heavy water as the detecting medium. Other detectors have consisted of large volumes of chlorine or gallium which are periodically checked for excesses of argon or germanium, respectively, which are created by neutrinos interacting with the original substance. MINOS used a solid plastic scintillator watched by phototubes; Borexino uses a liquid pseudocumene scintillator also watched by phototubes; and the NOνA detector uses a liquid scintillator watched by avalanche
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https://en.wikipedia.org/wiki/Glycoprotein%20IIb/IIIa
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In biochemistry and medicine, glycoprotein IIb/IIIa (GPIIb/IIIa, also known as integrin αIIbβ3) is an integrin complex found on platelets. It is a transmembrane receptor for fibrinogen and von Willebrand factor, and aids platelet activation. The complex is formed via calcium-dependent association of gpIIb and gpIIIa, a required step in normal platelet aggregation and endothelial adherence. Platelet activation by ADP (blocked by clopidogrel) leads to the aforementioned conformational change in platelet gpIIb/IIIa receptors that induces binding to fibrinogen. The gpIIb/IIIa receptor is a target of several drugs including abciximab, eptifibatide, and tirofiban.
gpIIb/IIIa complex formation
Once platelets are activated, granules secrete clotting mediators, including both ADP and TXA2. These then bind their respective receptors on platelet surfaces, in both an autocrine and paracrine fashion (binds both itself and other platelets). The binding of these receptors result in a cascade of events resulting in an increase in intracellular calcium (e.g. via Gq receptor activation leading to Ca2+ release from platelet endoplasmic reticulum Ca2+ stores, which may activate Protein Kinase C). Hence, this calcium increase triggers the calcium-dependent association of gpIIb and gpIIIa to form the activated membrane receptor complex gpIIb/IIIa, which is capable of binding fibrinogen (factor I), resulting in many platelets "sticking together" as they may connect to the same strands of fibrinoge
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https://en.wikipedia.org/wiki/Juxtacrine%20signalling
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In biology, juxtacrine signalling (or contact-dependent signalling) is a type of cell–cell or cell–extracellular matrix signalling in multicellular organisms that requires close contact. In this type of signalling, a ligand on one surface binds to a receptor on another adjacent surface. Hence, this stands in contrast to releasing a signaling molecule by diffusion into extracellular space, the use of long-range conduits like membrane nanotubes and cytonemes (akin to 'bridges') or the use of extracellular vesicles like exosomes or microvesicles (akin to 'boats'). There are three types of juxtacrine signaling:
A membrane-bound ligand (protein, oligosaccharide, lipid) and a membrane protein of two adjacent cells interact.
A communicating junction links the intracellular compartments of two adjacent cells, allowing transit of relatively small molecules.
An extracellular matrix glycoprotein and a membrane protein interact.
Additionally, in unicellular organisms such as bacteria, juxtacrine signaling refers to interactions by membrane contact.
Juxtacrine signaling has been observed for some growth factors, cytokine and chemokine cellular signals, playing an important role in the immune response. It has a critical role in development, particularly of cardiac and neural function. Other types of cell signaling include paracrine signalling and autocrine signalling. Paracrine signaling occurs over short distances, while autocrine signaling involves a cell responding to its own paracr
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https://en.wikipedia.org/wiki/Boolean%20domain
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In mathematics and abstract algebra, a Boolean domain is a set consisting of exactly two elements whose interpretations include false and true. In logic, mathematics and theoretical computer science, a Boolean domain is usually written as {0, 1}, or
The algebraic structure that naturally builds on a Boolean domain is the Boolean algebra with two elements. The initial object in the category of bounded lattices is a Boolean domain.
In computer science, a Boolean variable is a variable that takes values in some Boolean domain. Some programming languages feature reserved words or symbols for the elements of the Boolean domain, for example false and true. However, many programming languages do not have a Boolean datatype in the strict sense. In C or BASIC, for example, falsity is represented by the number 0 and truth is represented by the number 1 or −1, and all variables that can take these values can also take any other numerical values.
Generalizations
The Boolean domain {0, 1} can be replaced by the unit interval , in which case rather than only taking values 0 or 1, any value between and including 0 and 1 can be assumed. Algebraically, negation (NOT) is replaced with conjunction (AND) is replaced with multiplication (), and disjunction (OR) is defined via De Morgan's law to be .
Interpreting these values as logical truth values yields a multi-valued logic, which forms the basis for fuzzy logic and probabilistic logic. In these interpretations, a value is interpreted as
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https://en.wikipedia.org/wiki/Hussein%20Sirri%20Pasha%20%281894%E2%80%931960%29
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Hussein Sirri Pasha (1894–1960) () was an Egyptian politician. He served as 25th Prime Minister of Egypt for three short periods, during which he also served as foreign minister.
Early life and education
Hussein Sirri was the son of Ismail Sirri Pasha (1861–1937). He received a degree in civil engineering in Paris.
Career
Sirri Pasha began his career as an engineer at the Ministry of Public Works, and was appointed as minister to the same body in 1937. He was minister of finance from 1939 to 1940. Sirri Pasha first served as prime minister from 1940 until 1942, the height of the Axis and Allied confrontation in Egypt's Western Desert in the Second World War, which concluded with the Second Battle of El Alamein. His cabinet was announced on 18 November 1940, and he formed it without having any affiliation with the political parties.
In February 1941, the Prime Minister of Australia, Robert Menzies, visited Cairo and met with Sirri. Writing in 1967, he said "We found that political problems are the same the wide world over, and laughed about them." He then wrote that "The great pity was that so good a Prime Minister had to serve under so poor a King. Sirri Pasha was... a good administrator, and completely honest."
Sirri next served as prime minister from July 1949 until January 1950. His final term was for three weeks in July 1952, amidst a political crisis which culminated in the Egyptian Revolution of 1952, and the abdication of King Farouk.
Personal life
Sirri Pasha was
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https://en.wikipedia.org/wiki/Jailbreak%20%28disambiguation%29
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Jailbreak, jailbreaking, gaolbreak or gaolbreaking refer to a prison escape. It may also refer to:
Computer science
Jailbreak (computer science), a jargon expression for (the act of) overcoming limitations in a computer system or device that were deliberately placed there for security, administrative, or marketing reasons:
iOS jailbreaking, overriding software limitations on the iPhone, iPod Touch, or iPad
Hackintosh, Apple's Macintosh operating system macOS running on unauthorized computer hardware
Rooting (Android), on Android phones and tablets
PlayStation 3 Jailbreak, on the Sony PlayStation such as a developer firmware to override all system holdbacks
Music
'74 Jailbreak, a 1984 album by AC/DC
"Jailbreak" (AC/DC song), a 1976 song by AC/DC
Jailbreak (album), a 1976 album by Thin Lizzy
"Jailbreak" (Thin Lizzy song), the title track of the Thin Lizzy album
"Jailbreak" (Dev Pandya song), 199
Film and television
Gaol Break, a 1936 British film directed by Ralph Ince
Gaolbreak, a 1962 British film directed by Francis Searle
Jailbreak (1936 film), a 1936 film, starring Barton MacLane and June Travis
Jailbreakers, a 1994 television film, starring Shannen Doherty and Antonio Sabàto Jr..
Jailbreak (TV series), a 2000 UK reality television series presented by Craig Charles
Prison Break, 2005–2009, an American TV series
"Jail Break" (Steven Universe), the 2015 final episode of the first season of the American animated television series Steven Universe
Jailbreak (2017 fil
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https://en.wikipedia.org/wiki/Monoid%20%28category%20theory%29
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In category theory, a branch of mathematics, a monoid (or monoid object, or internal monoid, or algebra) in a monoidal category is an object M together with two morphisms
μ: M ⊗ M → M called multiplication,
η: I → M called unit,
such that the pentagon diagram
and the unitor diagram
commute. In the above notation, is the identity morphism of , is the unit element and α, λ and ρ are respectively the associativity, the left identity and the right identity of the monoidal category C.
Dually, a comonoid in a monoidal category C is a monoid in the dual category Cop.
Suppose that the monoidal category C has a symmetry γ. A monoid M in C is commutative when .
Examples
A monoid object in Set, the category of sets (with the monoidal structure induced by the Cartesian product), is a monoid in the usual sense.
A monoid object in Top, the category of topological spaces (with the monoidal structure induced by the product topology), is a topological monoid.
A monoid object in the category of monoids (with the direct product of monoids) is just a commutative monoid. This follows easily from the Eckmann–Hilton argument.
A monoid object in the category of complete join-semilattices Sup (with the monoidal structure induced by the Cartesian product) is a unital quantale.
A monoid object in (Ab, ⊗Z, Z), the category of abelian groups, is a ring.
For a commutative ring R, a monoid object in
(R-Mod, ⊗R, R), the category of modules over R, is a R-algebra.
the category of graded
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https://en.wikipedia.org/wiki/ZZ
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ZZ or zz may refer to:
Music
ZZ (band), a Japanese rock band
ZZ Top, an American rock band
"Zz", a silent track on the 2014 album Sleepify by Vulfpeck
People
Z. Z. Hill (1935–1984), an American blues singer
ZZ Packer (born 1973), an American writer
ZZ Ward, Zsuzsanna Eva Ward (born 1986), an American musician
Science and mathematics
Astronomy
ZZ Boötis, a star system in the constellation Boötes
ZZ diboson, a pair of Z bosons
ZZ Ceti, a type of pulsating white dwarf star
G 29-38 or ZZ Piscium, a variable white dwarf star
Other uses in science and mathematics
ZZ zinc finger, a type of protein domain
, the Zahlen symbol, representing the set of integers
Zamioculcas or ZZ plant, a genus of flowering plant in the family Araceae
ZZ, homogametic males under the ZW sex-determination system
ZZ, homogametic males under the ZO sex-determination system
Transportation
Isuzu Gemini ZZ/R, a subcompact car
Tommykaira ZZ, a mid-engined sports car
Toyota ZZ engine, a straight-4 piston engine series
Kawasaki ZZ-R1200, a motorcycle
Other uses
ZZ Leiden, a basketball club based in Leiden, Netherlands
ZZ scale, a 1:300 model railroad scale
Živi zid ("Human Shield"), a political party in Croatia
Zhongzhi Capital or ZZ Capital, an asset management company
ZZ method, in speedcubing
ZZ, the production code for the 1969 Doctor Who serial The War Games
See also
Sleep (disambiguation)
Z (disambiguation)
Zzz (disambiguation)
Zzzz (disambiguation)
ZZR (disambiguati
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https://en.wikipedia.org/wiki/Join%20and%20meet
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In mathematics, specifically order theory, the join of a subset of a partially ordered set is the supremum (least upper bound) of denoted and similarly, the meet of is the infimum (greatest lower bound), denoted In general, the join and meet of a subset of a partially ordered set need not exist. Join and meet are dual to one another with respect to order inversion.
A partially ordered set in which all pairs have a join is a join-semilattice. Dually, a partially ordered set in which all pairs have a meet is a meet-semilattice. A partially ordered set that is both a join-semilattice and a meet-semilattice is a lattice. A lattice in which every subset, not just every pair, possesses a meet and a join is a complete lattice. It is also possible to define a partial lattice, in which not all pairs have a meet or join but the operations (when defined) satisfy certain axioms.
The join/meet of a subset of a totally ordered set is simply the maximal/minimal element of that subset, if such an element exists.
If a subset of a partially ordered set is also an (upward) directed set, then its join (if it exists) is called a directed join or directed supremum. Dually, if is a downward directed set, then its meet (if it exists) is a directed meet or directed infimum.
Definitions
Partial order approach
Let be a set with a partial order and let An element of is called the (or or ) of and is denoted by if the following two conditions are satisfied:
(that is, is a
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https://en.wikipedia.org/wiki/Solving%20the%20geodesic%20equations
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Solving the geodesic equations is a procedure used in mathematics, particularly Riemannian geometry, and in physics, particularly in general relativity, that results in obtaining geodesics. Physically, these represent the paths of (usually ideal) particles with no proper acceleration, their motion satisfying the geodesic equations. Because the particles are subject to no proper acceleration, the geodesics generally represent the straightest path between two points in a curved spacetime.
The differential geodesic equation
On an n-dimensional Riemannian manifold , the geodesic equation written in a coordinate chart with coordinates is:
where the coordinates xa(s) are regarded as the coordinates of a curve γ(s) in and are the Christoffel symbols. The Christoffel symbols are functions of the metric and are given by:
where the comma indicates a partial derivative with respect to the coordinates:
As the manifold has dimension , the geodesic equations are a system of ordinary differential equations for the coordinate variables. Thus, allied with initial conditions, the system can, according to the Picard–Lindelöf theorem, be solved. One can also use a Lagrangian approach to the problem: defining
and applying the Euler–Lagrange equation.
Heuristics
As the laws of physics can be written in any coordinate system, it is convenient to choose one that simplifies the geodesic equations. Mathematically, this means a coordinate chart is chosen in which the geodesic equations ha
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https://en.wikipedia.org/wiki/K%C3%A1roly%20Hadaly
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Károly Hadaly (1743, in Gúta, currently Kolárovo – 1834, in Pest) was a Hungarian mathematician. He studied at the University of Trnava, where he earned doctorates in philosophy and law. He was a professor of mathematics in Nagyszombat (currently Trnava), in Győr, in Pécs, in Pozsony (currently Bratislava) and in Budapest. From 1810 to 1831 he taught mathematics and physics in the Institutum geometricum.
Works of Károly Hadaly
Elementa hydrotechnica - Bratislava, 1783
Ars delineandi, coloribusque localibus adumbrandi cadem - Győr, 1784
Anfangsgründe der Mathematik - Bratislava, 1791
Mechanica solidorum Budapest, 1808
External links
Hadaly Károly
1743 births
1834 deaths
People from Kolárovo
19th-century Hungarian mathematicians
18th-century Hungarian mathematicians
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https://en.wikipedia.org/wiki/Marc%20Davis
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Marc Davis may refer to:
Marc Davis (academic), computer science professor
Mark Davis (actor) (born 1965), also credited as Marc Davis, British pornography actor
Marc Davis (animator) (1913–2000), Walt Disney Studios animator
Marc Davis (astronomer) (born 1947), astrophysicist and professor
Marc Davis (racing driver) (born 1990), NASCAR driver
Marc Davis (runner) (born 1969), American middle-distance runner
See also
Marcus Davis (born 1973), fighter
Marcus Davis (American football), (born 1989), wide receiver
Mark Davis (disambiguation)
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https://en.wikipedia.org/wiki/Adaptive%20optimization
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Adaptive optimization is a technique in computer science that performs dynamic recompilation of portions of a program based on the current execution profile. With a simple implementation, an adaptive optimizer may simply make a trade-off between just-in-time compilation and interpreting instructions. At another level, adaptive optimization may take advantage of local data conditions to optimize away branches and to use inline expansion to decrease the cost of procedure calls.
Consider a hypothetical banking application that handles transactions one after another. These transactions may be checks, deposits, and a large number of more obscure transactions. When the program executes, the actual data may consist of clearing tens of thousands of checks without processing a single deposit and without processing a single check with a fraudulent account number. An adaptive optimizer would compile assembly code to optimize for this common case. If the system then started processing tens of thousands of deposits instead, the adaptive optimizer would recompile the assembly code to optimize the new common case. This optimization may include inlining code.
Examples of adaptive optimization include HotSpot and HP's Dynamo system.
In some systems, notably the Java Virtual Machine, execution over a range of bytecode instructions can be provably reversed. This allows an adaptive optimizer to make risky assumptions about the code. In the above example, the optimizer may assume all trans
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https://en.wikipedia.org/wiki/Enantiomer%20self-disproportionation
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Enantiomer self-disproportionation is a process in stereochemistry describing the separation of a non-racemic mixture of enantiomers in an enantioenriched fraction and a more racemic fraction as a result of the formation of heterochiral or homochiral aggregates. This process is known to occur in achiral column chromatography.
The phenomenon was first reported in 1983 in the separation of an excess of
carbon-14 labeled (S)-(−)-nicotine enantiomer and its isomer. Two fractions were recorded, one containing racemic nicotine and the other pure (S) enantiomer.
In 2006, Vadim A. Soloshonok introduced the term Enantiomer self-disproportionation or self-disproportionation of enantiomers. He investigated achiral separations of several trifluoromethyl compounds.
By column chromatography on regular silica gel with a hexane / ethyl acetate eluent (5:1), a 66.6% ee sample of a trifluoromethyl substrate is separated into several fractions ranging from 8.1% ee for the first fraction collected to > 99.9% ee for the last fraction collected. A presence of a strong electronegative group in the substrate such as the trifluoromethyl group is a prerequisite. The effect disappears when a more polar eluent is selected. A possible explanation is offered. Compounds with large electronegative groups such as trifluoromethyl can form supramolecular associations or aggregates or clusters in which these groups are separated from each other as much as possible with minimized electrostatic repulsions.
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https://en.wikipedia.org/wiki/McMaster%20Faculty%20of%20Engineering
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The McMaster Faculty of Engineering is a faculty located at McMaster University in Hamilton, Ontario. The faculty was established in 1958 and was the first engineering program to developed problem-based learning curriculum. It currently has seven departments in chemical engineering, civil engineering, computing and software, electrical and computer engineering, engineering physics, material science and engineering and mechanical engineering. The faculty offers bachelors, masters, and doctoral degrees.
The faculty is home to 1 Canada Excellence Research Chair, 13 Canada Research Chairs, 4 Natural Sciences and Engineering Research Council chairs, and 14 Endowed Chairs.
Programs
The B.Eng. undergraduate programs are accredited through the Canadian Engineering Accreditation Board. All undergraduate students take a common first-year program which outlines the fundamentals of engineering disciplines. At the end of the first year, students choose one of fourteen program disciplines. This includes some five-year programs such as Engineering & Management, Engineering & Society, or streams in Integrated Biomedical Engineering and Health Sciences.
Graduate programs in biomedical engineering are offered through the School of Biomedical Engineering, and graduate engineering practice programs through the Walter G. Booth School of Engineering Practice.
The joint McMaster-Mohawk Bachelor of Technology program offers four-year bachelor-degree programs in engineering technology, including
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https://en.wikipedia.org/wiki/International%20Aerial%20Robotics%20Competition
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The International Aerial Robotics Competition (IARC) began in 1991 on the campus of the Georgia Institute of Technology and is the longest running university-based robotics competition in the world. Since 1991, collegiate teams with the backing of industry and government have fielded autonomous flying robots in an attempt to perform missions requiring robotic behaviors never before exhibited by a flying machine. In 1990, the term “aerial robotics” was coined by competition creator Robert Michelson to describe a new class of small highly intelligent flying machines. The successive years of competition saw these aerial robots grow in their capabilities from vehicles that could at first barely maintain themselves in the air, to the most recent automatons which are self-stable, self-navigating, and able to interact with their environment—especially objects on the ground.
The primary goal of the competition has been to provide a reason for the state of the art in aerial robotics to move forward. Challenges set before the international collegiate community have been geared towards producing advances in the state of the art at an increasingly aggressive pace. From 1991 through 2009, a total of six missions have been proposed. Each of them involved fully autonomous robotic behavior that was undemonstrated at the time and impossible for any robotic system fielded anywhere in the world, even by the most sophisticated military robots belonging to the super powers.
In October 2013 a
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https://en.wikipedia.org/wiki/XTR
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In cryptography, XTR is an algorithm for public-key encryption. XTR stands for 'ECSTR', which is an abbreviation for Efficient and Compact Subgroup Trace Representation. It is a method to represent elements of a subgroup of a multiplicative group of a finite field. To do so, it uses the trace over to represent elements of a subgroup of .
From a security point of view, XTR relies on the difficulty of solving Discrete Logarithm related problems in the full multiplicative group of a finite field. Unlike many cryptographic protocols that are based on the generator of the full multiplicative group of a finite field, XTR uses the generator of a relatively small subgroup of some prime order of a subgroup of . With the right choice of , computing Discrete Logarithms in the group, generated by , is, in general, as hard as it is in and thus cryptographic applications of XTR use arithmetics while achieving full security leading to substantial savings both in communication and computational overhead without compromising security. Some other advantages of XTR are its fast key generation, small key sizes and speed.
Fundamentals of XTR
XTR uses a subgroup, commonly referred to as XTR subgroup or just XTR group, of a subgroup called XTR supergroup, of the multiplicative group of a finite field with elements. The XTR supergroup is of order , where p is a prime such that a sufficiently large prime q divides . The XTR subgroup has now order q and is, as a subgroup of , a cyclic g
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https://en.wikipedia.org/wiki/Landon%20Garland
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Landon Cabell Garland (1810–1895), an American, was professor of physics and history and university president three times at different Southern Universities (Randolph Macon, Alabama, Vanderbilt) while living in the Southern United States for his entire life. He served as the second president of Randolph–Macon College in Ashland, Virginia, from 1836 to 1846; then professor from 1847 to 1855, and then third president of the University of Alabama in Tuscaloosa, Alabama, from 1855 to 1867; and first chancellor of Vanderbilt University in Nashville, Tennessee, from 1875 to 1893. He was an apologist for slavery in the United States before the Civil War, but afterward became a vociferous spokesperson against slavery.
Early life
Landon Garland was born March 21, 1810, in Nelson County, Virginia. He graduated with first honors from Hampden–Sydney College in 1829. His older brother, Hugh A. Garland, who was one of the lawyers involved in the Dred Scott case and author of a biography of John Randolph of Roanoke, was also a Hampden-Sydney graduate. Their parents were Alexander Spotswood Garland and Lucinda Rose. Confederate Army General Samuel Garland, Jr. was the son of his only sister, Caroline Garland (1807-1901), and United States Founding Father and fourth President of the United States James Madison was his great uncle.
Career
Garland taught chemistry and natural philosophy at Washington College in Lexington, Virginia, from 1829 to 1830.
Garland taught chemistry and natural hist
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https://en.wikipedia.org/wiki/Hong%20Kong%20Mathematics%20Olympiad
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Hong Kong Mathematics Olympiad (HKMO, ) is a Mathematics Competition held in Hong Kong every year, jointly organized by The Education University of Hong Kong and Education Bureau. At present, more than 250 secondary schools send teams of 4-6 students of or below Form 5 to enter the competition. It is made up of a Heat Event and a Final Event, which both forbid the usage of calculators and calculation assisting equipments (e.g. printed mathematical table). Though it bears the term Mathematics Olympiad, it has no relationship with the International Mathematical Olympiad.
History
The predecessor of HKMO is the Inter-school Mathematics Olympiad initiated by the Mathematics Society of Northcote College of Education in 1974, which had attracted 20 secondary schools to participate. Since 1983, the competition is jointly conducted by the Mathematics Department of Northcote College of Education and the Mathematics Section of the Advisory Inspectorate Division of the Education Department. Also in 1983, the competition is formally renamed as Hong Kong Mathematics Olympiad.
Format and Scoring in the Heat Event
The Heat Event is usually held in four venues, for contestants from schools on Hong Kong Island, and in Kowloon, New Territories East and New Territories West respectively. It comprises an individual event and a group event. Each team sends 4 contestants among 4-6 team members for each event.
For the individual event, 1 mark and 2 marks will be given to each correct answer in Pa
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https://en.wikipedia.org/wiki/Request
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Request may refer to:
a question, a request for information
a petition, a formal document demanding something that is submitted to an authority.
Request may also refer to:
Computing and technology
in computer science, a message sent between objects
in computer science, a request in Hypertext Transfer Protocol
Request TV, a defunct pay-per-view service
Requests (software), a Python HTTP library
Albums
Request (The Awakening album), a 1997 album by South African band The Awakening
Request (Juju album), a 2010 cover album by Japanese singer Juju
Requests, an album by The Johnson Mountain Boys
Requests, a classical album by Victor Borge
Requests, a 1964 Parlophone EP by The Beatles; "Long Tall Sally" "I Call Your Name" "Can't Buy Me Love" "You Can't Do That"
Requests, a 1965 EP by Pat Carroll
Further Requests, the second 1964 Parlophone EP by The Beatles; "She Loves You", "I Want To Hold Your Hand", "Roll Over Beethoven", "Can't Buy Me Love"
Requests, an album by Gracie Fields
Requests, an album by Jim McDonough
Other uses
"Requests", a song by Dr. Dre
Request (broadcasting), audience interaction in broadcasting
ReQuest Dance Crew, a hip hop dance crew from New Zealand
See also
Request–response
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https://en.wikipedia.org/wiki/Hkmo
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HKMO may refer to:
Hong Kong Mathematics Olympiad
ICAO-Code for Mombasa Moi International Airport
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https://en.wikipedia.org/wiki/Association%20of%20Environmental%20Professionals
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The Association of Environmental Professionals (AEP) is a California-based non-profit organization of interdisciplinary professionals including environmental science, resource management, environmental planning and other professions contributing to this field. AEP is the first organization of its kind in the USA, and its influence and model have spawned numerous other regional organizations throughout the United States, as well as the separate National Association of Environmental Professionals (NAEP). From inception in the mid-1970s the organization has been closely linked with the upkeep of the California Environmental Quality Act (CEQA), California being one of the first states to adopt a comprehensive law to govern the environmental review of public policy and project review.
History, organization and governance
AEP was founded in the State of California in 1974 and held its first organization wide meeting of members in Palo Alto, California, on the Stanford University campus. At that meeting the first directors and officers were elected and by-laws adopted. From then on the board of directors has met quarterly to establish governance, coordinate legislative liaison and plan annual meeting. There are nine AEP chapters, covering the California geographical regions of: Channel Counties, Inland Empire, Los Angeles County, Monterey Bay-Silicon Valley, Orange County, San Diego, San Francisco Bay Area, Superior, and Central.
Publications and member activities
AEP publis
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https://en.wikipedia.org/wiki/Logical%20model
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Logical model can refer to:
A model in logic, see model theory
In computer science a logical data model
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https://en.wikipedia.org/wiki/Frobenius%20theorem%20%28real%20division%20algebras%29
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In mathematics, more specifically in abstract algebra, the Frobenius theorem, proved by Ferdinand Georg Frobenius in 1877, characterizes the finite-dimensional associative division algebras over the real numbers. According to the theorem, every such algebra is isomorphic to one of the following:
(the real numbers)
(the complex numbers)
(the quaternions).
These algebras have real dimension , and , respectively. Of these three algebras, and are commutative, but is not.
Proof
The main ingredients for the following proof are the Cayley–Hamilton theorem and the fundamental theorem of algebra.
Introducing some notation
Let be the division algebra in question.
Let be the dimension of .
We identify the real multiples of with .
When we write for an element of , we imply that is contained in .
We can consider as a finite-dimensional -vector space. Any element of defines an endomorphism of by left-multiplication, we identify with that endomorphism. Therefore, we can speak about the trace of , and its characteristic and minimal polynomials.
For any in define the following real quadratic polynomial:
Note that if then is irreducible over .
The claim
The key to the argument is the following
Claim. The set of all elements of such that is a vector subspace of of dimension . Moreover as -vector spaces, which implies that generates as an algebra.
Proof of Claim: Let be the dimension of as an -vector space, and pick in with characteristic polynom
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https://en.wikipedia.org/wiki/Noise%20%28electronics%29
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In electronics, noise is an unwanted disturbance in an electrical signal.
Noise generated by electronic devices varies greatly as it is produced by several different effects.
In particular, noise is inherent in physics and central to thermodynamics. Any conductor with electrical resistance will generate thermal noise inherently. The final elimination of thermal noise in electronics can only be achieved cryogenically, and even then quantum noise would remain inherent.
Electronic noise is a common component of noise in signal processing.
In communication systems, noise is an error or undesired random disturbance of a useful information signal in a communication channel. The noise is a summation of unwanted or disturbing energy from natural and sometimes man-made sources. Noise is, however, typically distinguished from interference, for example in the signal-to-noise ratio (SNR), signal-to-interference ratio (SIR) and signal-to-noise plus interference ratio (SNIR) measures. Noise is also typically distinguished from distortion, which is an unwanted systematic alteration of the signal waveform by the communication equipment, for example in signal-to-noise and distortion ratio (SINAD) and total harmonic distortion plus noise (THD+N) measures.
While noise is generally unwanted, it can serve a useful purpose in some applications, such as random number generation or dither.
Noise types
Different types of noise are generated by different devices and different processes. Thermal
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https://en.wikipedia.org/wiki/River%20engineering
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River engineering is a discipline of civil engineering which studies human intervention in the course, characteristics, or flow of a river with the intention of producing some defined benefit. People have intervened in the natural course and behaviour of rivers since before recorded history—to manage the water resources, to protect against flooding, or to make passage along or across rivers easier. Since the Yuan Dynasty and Ancient Roman times, rivers have been used as a source of hydropower. From the late 20th century, the practice of river engineering has responded to environmental concerns broader than immediate human benefit. Some river engineering projects have focused exclusively on the restoration or protection of natural characteristics and habitats.
Hydromodification encompasses the systematic response to alterations to riverine and non-riverine water bodies such as coastal waters (estuaries and bays) and lakes. The U.S. Environmental Protection Agency (EPA) has defined hydromodification as the "alteration of the hydrologic characteristics of coastal and non-coastal waters, which in turn could cause degradation of water resources." River engineering has often resulted in unintended systematic responses, such as reduced habitat for fish and wildlife, and alterations of water temperature and sediment transport patterns.
Beginning in the late 20th century, the river engineering discipline has been more focused on repairing hydromodified degradations and accounting fo
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https://en.wikipedia.org/wiki/Reflective%20subcategory
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In mathematics, a full subcategory A of a category B is said to be reflective in B when the inclusion functor from A to B has a left adjoint. This adjoint is sometimes called a reflector, or localization. Dually, A is said to be coreflective in B when the inclusion functor has a right adjoint.
Informally, a reflector acts as a kind of completion operation. It adds in any "missing" pieces of the structure in such a way that reflecting it again has no further effect.
Definition
A full subcategory A of a category B is said to be reflective in B if for each B-object B there exists an A-object and a B-morphism such that for each B-morphism to an A-object there exists a unique A-morphism with .
The pair is called the A-reflection of B. The morphism is called the A-reflection arrow. (Although often, for the sake of brevity, we speak about only as being the A-reflection of B).
This is equivalent to saying that the embedding functor is a right adjoint. The left adjoint functor is called the reflector. The map is the unit of this adjunction.
The reflector assigns to the A-object and for a B-morphism is determined by the commuting diagram
If all A-reflection arrows are (extremal) epimorphisms, then the subcategory A is said to be (extremal) epireflective. Similarly, it is bireflective if all reflection arrows are bimorphisms.
All these notions are special case of the common generalization—-reflective subcategory, where is a class of morphisms.
The -reflective hul
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https://en.wikipedia.org/wiki/Leo%20J.%20Enright
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Leo J. Enright (born 18 March 1955) is an Irish radio broadcaster and news reporter. He is a member of the Board of Governors of the School of Cosmic Physics at the Dublin Institute for Advanced Studies.
Early life and career
Leo Enright was born in London, but considers Dublin his home town. He was educated at St. Fintan's High School, Sutton and University College Dublin. As a Fellow of the World Press Institute, he studied American history, economics and culture at Macalester College, in St. Paul, Minnesota.
Major achievements
In 1978, Enright won a Jacob's Award for his report on Dublin delinquents, broadcast on RTÉ Radio's This Week programme.
In 2000, with support from NASA's Astrobiology Institute, he completed the Workshop on Molecular Evolution at the Josephine Bay Paul Center for Comparative Molecular Biology and Evolution.
In 2008 he shared in a Thea Award for his work as science advisor on "Cosmos at the Castle", an interactive exhibition at Blackrock Castle Observatory exploring extreme life on earth and in space. The award was presented by the Themed Entertainment Association, a worldwide association of designers and producers of themed experiences such as museums, zoos and theme parks.
References
1955 births
Jacob's Award winners
RTÉ 2fm presenters
Living people
People educated at St. Fintan's High School
Academics of the Dublin Institute for Advanced Studies
Broadcasters from County Dublin
Alumni of University College Dublin
Macalester College alumni
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https://en.wikipedia.org/wiki/John%20Shimmin
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John Shimmin (born 1 July 1960) is a former Member of the House of Keys for Douglas West.
Early life
Shimmin was born in Douglas in 1960 and educated at St Ninian's High School and the Worcester College of Higher Education.
He was then a teacher (Physical Education, Mathematics, General Studies) from 1982 in several areas of the UK - Crewe, Tamworth, Knowsley before returning to teach in Douglas (St Ninian’s High School) where he was also Head of Year from 1989-96 until entering politics.
Political career
Shimmin was elected as MHK for Douglas West in 1996 at his first attempt. He became Chairman of the Isle of Man Post Office in 1999 before becoming Minister of Transport in 2002.
In 2005, he swapped departments with the Minister of Home Affairs Phil Braidwood.
In November 2006, he was re-elected into Tynwald, alongside Geoff Corkish in West Douglas.
He was appointed Local Government and the Environment Minister by newly elected Chief Minister Tony Brown in November 2006.
After the restructuring of Tynwald in 2010, he became Minister of Environment, Food and Agriculture before being promoted to Minister of Economic Development after the 2011 General Election.
He remained Minister of Economic Development of the Isle of Man Government until, following questions in regards to the Isle of Man Government's handling of the loans to the Manx-based Sefton Group, he resigned his ministerial post .
On 16 February 2015 he was appointed Minister for Policy and Reform, replacing
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https://en.wikipedia.org/wiki/Gerdt
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Gerdt may refer to:
Zinovy Efimovich Gerdt, Russian actor
Pavel Andreyevich Gerdt or Paul Gerdt (1844–1917), Russian dancer for the Mariinsky Theatre
Elizaveta Pavlovna Gerdt (Елизавета Павловна Гердт) (1891–1975), Russian dancer and teacher
Petri Erkki Tapio Gerdt (1983–2002), Finnish chemistry student and Myyrmanni bombing culprit
Tuomas Gerdt (1922–2020), Finnish soldier, last living Knight of the Mannerheim Cross
Surnames from given names
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https://en.wikipedia.org/wiki/Chemical%20garden
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A chemical garden is a set of complex biological-looking structures created by mixing inorganic chemicals. Chemical gardening is an experiment in chemistry usually performed by adding metal salts, such as copper sulfate or cobalt(II) chloride, to an aqueous solution of sodium silicate (otherwise known as waterglass). This results in the growth of plant-like forms in minutes to hours.
The chemical garden was first observed and described by Johann Rudolf Glauber in 1646. In its original form, the chemical garden involved the introduction of ferrous chloride (FeCl2) crystals into a solution of potassium silicate (K2SiO3).
Process
The chemical garden relies on most transition metal silicates being insoluble in water and colored.
When a metal salt, such as cobalt chloride, is added to a sodium silicate solution, it will start to dissolve. It will then form insoluble cobalt silicate by a double displacement reaction. This cobalt silicate is a semipermeable membrane. Because the ionic strength of the cobalt solution inside the membrane is higher than the sodium silicate solution's, which forms the bulk of the tank contents, osmotic effects will increase the pressure within the membrane. This will cause the membrane to tear, forming a hole. The cobalt cations will react with the silicate anions at this tear to form a new solid. In this way, growths will form in the tanks; they will be colored (according to the metal cation) and may look like plant-like structures. The crystals f
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https://en.wikipedia.org/wiki/Evolution%20of%20insects
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The most recent understanding of the evolution of insects is based on studies of the following branches of science: molecular biology, insect morphology, paleontology, insect taxonomy, evolution, embryology, bioinformatics and scientific computing. It is estimated that the class of insects originated on Earth about 480 million years ago, in the Ordovician, at about the same time terrestrial plants appeared. Insects are thought to have evolved from a group of crustaceans. The first insects were landbound, but about 400 million years ago in the Devonian period one lineage of insects evolved flight, the first animals to do so. The oldest insect fossil has been proposed to be Rhyniognatha hirsti, estimated to be 400 million years old, but the insect identity of the fossil has been contested. Global climate conditions changed several times during the history of Earth, and along with it the diversity of insects. The Pterygotes (winged insects) underwent a major radiation in the Carboniferous (356 to 299 million years ago) while the Endopterygota (insects that go through different life stages with metamorphosis) underwent another major radiation in the Permian (299 to 252 million years ago).
Most extant orders of insects developed during the Permian period. Many of the early groups became extinct during the mass extinction at the Permo-Triassic boundary, the largest extinction event in the history of the Earth, around 252 million years ago. The survivors of this event evolved in th
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https://en.wikipedia.org/wiki/Length%20constant
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In neurobiology, the length constant (λ) is a mathematical constant used to quantify the distance that a graded electric potential will travel along a neurite via passive electrical conduction. The greater the value of the length constant, the farther the potential will travel. A large length constant can contribute to spatial summation—the electrical addition of one potential with potentials from adjacent areas of the cell.
The length constant can be defined as:
where rm is the membrane resistance (the force that impedes the flow of electric current from the outside of the membrane to the inside, and vice versa), ri is the axial resistance (the force that impedes current flow through the axoplasm, parallel to the membrane), and ro is the extracellular resistance (the force that impedes current flow through the extracellular fluid, parallel to the membrane). In calculation, the effects of ro are negligible, so the equation is typically expressed as:
The membrane resistance is a function of the number of open ion channels, and the axial resistance is generally a function of the diameter of the axon. The greater the number of open channels, the lower the rm. The greater the diameter of the axon, the lower the ri.
The length constant is used to describe the rise of potential difference across the membrane
The fall of voltage can be expressed as:
Where voltage, V, is measured in millivolts, x is distance from the start of the potential (in millimeters), and λ is
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https://en.wikipedia.org/wiki/Space%20Nanotechnology%20Laboratory
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The Space Nanotechnology Laboratory performs research in interference lithography and diffraction grating fabrication. It has fabricated the high energy transmission gratings for one of NASA's Great Observatories, the Chandra X-Ray Observatory. It is also the home of the Nanoruler, a unique and high-precision grating patterning tool.
External links
Space Nanotechnology Laboratory
Space telescopes
Massachusetts Institute of Technology
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https://en.wikipedia.org/wiki/MRI%20%28disambiguation%29
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Magnetic resonance imaging is a medical imaging technique
MRI can also refer to:
Science, healthcare, and technology
Magnetic Resonance Imaging (journal), a scientific journal
Magnetorotational instability, in astrophysics
Meuse-Rhine-Issel, a breed of cattle
Monoamine reuptake inhibitor, a type of drug class
Ruby MRI (Matz's Ruby Interpreter), the reference implementation of the Ruby programming language
Places
Manchester Royal Infirmary, a hospital in Manchester, England
Manggarai railway station, a railway station in Jakarta, Indonesia (station code MRI)
Maritime Rescue Institute, a former maritime training and rescue charity
Mauritius, IOC country code
Max Rubner Institute, a government health agency in Germany
Member of the Royal Institution of Great Britain
Mental Research Institute, Palo Alto, California, USA
Merrill Field, airport in Alaska, IATA code
Microwave Research Institute, now called Weber Research Institute, a research group at the Polytechnic Institute of New York University
Midwest Research Institute, based in Kansas City, Missouri, USA
Other uses
Mri (fictional alien species), in the Faded Sun Trilogy
mri, ISO 639-3 code for the Māori language
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https://en.wikipedia.org/wiki/Carcerand
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In host–guest chemistry, a carcerand () is a host molecule that completely entraps its guest (which can be an ion, atom or other chemical species) so that it will not escape even at high temperatures. This type of molecule was first described in 1985 by Donald J. Cram and coworkers. The complexes formed by a carcerand with permanently imprisoned guests are called carceplexes.
In contrast, hemicarcerands allow guests to enter and exit the cavity at high temperatures but will form stable complexes at ambient temperatures. The complexes formed by a hemicarcerand and a guest are called hemicarceplexes.
Reactivity of bound guests
Cram described the interior of the container compound as the inner phase in which radically different reactivity was observed. He used a hemicarcerand to isolate highly unstable, antiaromatic cyclobutadiene at room temperature. The hemicarcerand stabilizes guests within its cavity by preventing their reaction with other molecules...
Synthesis
The first generation carcerands are based on calixarene hemicarcerands with 4 alkyl substituents on the upper rim and 4 reactive substituents on the lower rim. The coupling of both hemicarcerands takes place through a spacer group. In the original 1985 publication two different hemicarcerands react, one with chloromethyl reactive groups and one with thiomethyl reactive groups in a nucleophilic displacement and the resulting the spacer group is a dimethylsulfide (CH2SCH2). In this experiment the guests were the mo
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https://en.wikipedia.org/wiki/William%20A.%20Martin
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William Arthur Martin (1938-1981) was a computer scientist from Oklahoma City, Oklahoma.
After graduating from Northwest Classen High School, where he was a state wrestling champion, he attended MIT where he received a bachelor's degree (1960), master's (1962) and a Ph.D. (1967) in electrical engineering under supervision of Marvin Minsky, with a dissertation on Symbolic Mathematical Laboratory. He joined MIT as an assistant professor of electrical engineering in 1968 and was promoted to associate professor in 1972. In 1975, he received tenure. He held a joint appointment at the MIT Sloan School of Management.
His research pulled him towards the Project MAC, which became the Laboratory for Computer Science and the Artificial Intelligence Laboratory, where he researched expert systems.
Martin co-founded the Macsyma project in 1968 and directed it until 1971. Macsyma later became a successful commercial product and is the core of the free Maxima system.
Martin then worked in automatic programming, knowledge representation and natural language processing.
Bibliography
External links
Obituary from Tech Talk
References
1981 deaths
1938 births
People from Oklahoma City
American computer scientists
MIT Sloan School of Management faculty
Lisp (programming language) people
Natural language processing researchers
Computational linguistics researchers
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https://en.wikipedia.org/wiki/Ancient%20Egyptian%20multiplication
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In mathematics, ancient Egyptian multiplication (also known as Egyptian multiplication, Ethiopian multiplication, Russian multiplication, or peasant multiplication), one of two multiplication methods used by scribes, is a systematic method for multiplying two numbers that does not require the multiplication table, only the ability to multiply and divide by 2, and to add. It decomposes one of the multiplicands (preferably the smaller) into a set of numbers of powers of two and then creates a table of doublings of the second multiplicand by every value of the set which is summed up to give result of multiplication.
This method may be called mediation and duplation, where mediation means halving one number and duplation means doubling the other number. It is still used in some areas.
The second Egyptian multiplication and division technique was known from the hieratic Moscow and Rhind Mathematical Papyri written in the seventeenth century B.C. by the scribe Ahmes.
Although in ancient Egypt the concept of base 2 did not exist, the algorithm is essentially the same algorithm as long multiplication after the multiplier and multiplicand are converted to binary. The method as interpreted by conversion to binary is therefore still in wide use today as implemented by binary multiplier circuits in modern computer processors.
Method
The ancient Egyptians had laid out tables of a great number of powers of two, rather than recalculating them each time. The decomposition of a number t
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https://en.wikipedia.org/wiki/Sensory%20neuroscience
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Sensory neuroscience is a subfield of neuroscience which explores the anatomy and physiology of neurons that are part of sensory systems such as vision, hearing, and olfaction. Neurons in sensory regions of the brain respond to stimuli by firing one or more nerve impulses (action potentials) following stimulus presentation. How is information about the outside world encoded by the rate, timing, and pattern of action potentials? This so-called neural code is currently poorly understood and sensory neuroscience plays an important role in the attempt to decipher it. Looking at early sensory processing is advantageous since brain regions that are "higher up" (e.g. those involved in memory or emotion) contain neurons which encode more abstract representations. However, the hope is that there are unifying principles which govern how the brain encodes and processes information. Studying sensory systems is an important stepping stone in our understanding of brain function in general.
Typical experiments
A typical experiment in sensory neuroscience involves the presentation of a series of relevant stimuli to an experimental subject while the subject's brain is being monitored. This monitoring can be accomplished by noninvasive means such as functional magnetic resonance imaging (fMRI) or electroencephalography (EEG), or by more invasive means such as electrophysiology, the use of electrodes to record the electrical activity of single neurons or groups of neurons. fMRI measures chang
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https://en.wikipedia.org/wiki/Baire%20set
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In mathematics, more specifically in measure theory, the Baire sets form a σ-algebra of a topological space that avoids some of the pathological properties of Borel sets.
There are several inequivalent definitions of Baire sets, but in the most widely used, the Baire sets of a locally compact Hausdorff space form the smallest σ-algebra such that all compactly supported continuous functions are measurable. Thus, measures defined on this σ-algebra, called Baire measures, are a convenient framework for integration on locally compact Hausdorff spaces. In particular, any compactly supported continuous function on such a space is integrable with respect to any finite Baire measure.
Every Baire set is a Borel set. The converse holds in many, but not all, topological spaces. Baire sets avoid some pathological properties of Borel sets on spaces without a countable base for the topology. In practice, the use of Baire measures on Baire sets can often be replaced by the use of regular Borel measures on Borel sets.
Baire sets were introduced by , and , who named them after Baire functions, which are in turn named after René-Louis Baire.
Basic definitions
There are at least three inequivalent definitions of Baire sets on locally compact Hausdorff spaces, and even more definitions for general topological spaces, though all these definitions are equivalent for locally compact σ-compact Hausdorff spaces. Moreover, some authors add restrictions on the topological space that Baire
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https://en.wikipedia.org/wiki/Persis%20Drell
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Persis S. Drell is an American physicist best known for her expertise in the field of particle physics. She was the director of the SLAC National Accelerator Laboratory from 2007 to 2012. She was dean of the Stanford University School of Engineering from 2014 until 2017. Drell has been the Provost of Stanford University since February 1, 2017. She plans to step down as Provost at the end of September 2023, and will be replaced by Jenny S. Martinez, dean of Stanford Law School.
Early life and education
The daughter of noted physicist Sidney Drell, Persis Drell grew up on the Stanford University campus. She earned a Bachelor of Arts in mathematics and physics from Wellesley College and a Ph.D. in atomic physics from University of California, Berkeley, studying under Eugene Commins. She completed her postdoctoral work in high-energy physics at Lawrence Berkeley National Laboratory.
Career
She joined the physics faculty at Cornell University in 1988.
Stanford University
In 2002, Drell was hired as associate director of research at the SLAC National Accelerator Laboratory (then known as the Stanford Linear Accelerator Center) where she oversaw the BaBar experiment. In 2007, she was named the fourth director of SLAC, succeeding Jonathan M. Dorfan.
In November 2011, she announced her intention to step down as the head of SLAC and return to a position as a faculty member at Stanford.
In September 2014, Drell became the ninth dean of the Stanford University School of Engineerin
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https://en.wikipedia.org/wiki/Vanadate
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In chemistry, a vanadate is an anionic coordination complex of vanadium. Often vanadate refers to oxoanions of vanadium, most of which exist in its highest oxidation state of +5. The complexes and are referred to as hexacyanovanadate(III) and nonachlorodivanadate(III), respectively.
A simple vanadate ion is the tetrahedral orthovanadate anion, (which is also called vanadate(V)), which is present in e.g. sodium orthovanadate and in solutions of in strong base (pH > 13). Conventionally this ion is represented with a single double bond, however this is a resonance form as the ion is a regular tetrahedron with four equivalent oxygen atoms.
Additionally a range of polyoxovanadate ions exist which include discrete ions and "infinite" polymeric ions. There are also vanadates, such as rhodium vanadate, , which has a statistical rutile structure where the and ions randomly occupy the positions in the rutile lattice, that do not contain a lattice of cations and balancing vanadate anions but are mixed oxides.
In chemical nomenclature when vanadate forms part of the name, it indicates that the compound contains an anion with a central vanadium atom, e.g. ammonium hexafluorovanadate is a common name for the compound with the IUPAC name of ammonium hexafluoridovanadate(III).
Examples of oxovanadate ions
Some examples of discrete ions are
"orthovanadate", tetrahedral.
"pyrovanadate", corner-shared tetrahedra, similar to the dichromate ion
, cyclic with corner-shared tetrahed
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https://en.wikipedia.org/wiki/Universidad%20Aut%C3%B3noma%20Agraria%20Antonio%20Narro
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The Antonio Narro Agrarian Autonomous University or Universidad Autónoma Agraria Antonio Narro in Spanish (UAAAN) is a public university in Mexico dedicated to the Agricultural, Silvicultural, Animal Production, food and Environmental Sciences. It is located south of Saltillo, in the Mexican state of Coahuila. The Antonio Narro Agrarian Autonomous University is one of the most important agricultural college of America Latina and the "Narro" have national and international recognition in the agricultural and animal industry and the high academic level. There is also a campus in Torreón, Coahuila. It is also called "Universidad Antonio Narro" for short, or simply, "La Narro". In 2008 the UAAAN has an enrollment of about 4,500 students in both campuses, all in agriculture and related sciences.
History
The Antonio Narro Agrarian Autonomous University (UAAAN) was founded on March 4, 1923, after the philanthropist Antonio Narro Rodríguez donated his Buenavista Estate for a public agricultural university, which became the "Regional School of Agriculture Antonio Narro". The main objective of this university consisted on preparing young people in a professional discipline of agricultural work in the field. Two months before dying on September 24, 1912, Antonio Narro Rodriguez had bequeathed a substantial part of its personal fortune: his property in Buenavista and $22,000 Mexican pesos, the value of six urban properties in the city of Saltillo, for constituting a school of agricu
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https://en.wikipedia.org/wiki/Mohammad-Ali%20Najafi
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Mohammad-Ali Najafi (; born 13 January 1952) is an Iranian mathematician and reformist politician who was the Mayor of Tehran, serving in the post for eight months, until April 2018. He held cabinet portfolios during the 1980s, 1990s and 2010s. He is also a retired professor of mathematics at Sharif University of Technology.
Early life and education
Najafi was born in Tehran on 13 January 1952. He ranked first in Iranian national university entrance exam and enrolled in Sharif University of Technology (then known as Aryamehr University of Technology). He earned a Bachelor of Science degree in mathematics from the Sharif University of Technology. Following his bachelors, he enrolled in the graduate program at the Massachusetts Institute of Technology. He received his Master of Science degree in mathematics with the final grade of A+ in 1976 but dropped out of PhD program in 1978 during the Iranian revolution to return to Iran.
Career
Following the Iranian revolution of 1979, Najafi returned to Iran and became a faculty member at Isfahan University of Technology in 1979 and he was the chair of the university from 1980 to 1981. He was a faculty member at department of mathematical sciences in Sharif University of Technology from 1984 to 1988, when he moved to government.
At the end of the reformist government of Mohammad Khatami and following Mahmoud Ahmadinejad's election Najafi moved back to university and has been faculty in the department of mathematics at Sharif Universi
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https://en.wikipedia.org/wiki/Pointwise%20product
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In mathematics, the pointwise product of two functions is another function, obtained by multiplying the images of the two functions at each value in the domain. If and are both functions with domain and codomain , and elements of can be multiplied (for instance, could be some set of numbers), then the pointwise product of and is another function from to which maps in to in .
Formal definition
Let and be sets such that has a notion of multiplication — that is, there is a binary operation
given by
Then given two functions the pointwise product is defined by
for all in . Just as we often omit the symbol for the binary operation ⋅ (i.e. we write instead of ), we often write for .
Examples
The most common case of the pointwise product of two functions is when the codomain is a ring (or field), in which multiplication is well-defined.
Algebraic application of pointwise products
Let be a set and let be a ring. Since addition and multiplication are defined in , we can construct an algebraic structure known as an algebra out of the functions from to by defining addition, multiplication, and scalar multiplication of functions to be done pointwise.
If denotes the set of functions from to , then we say that if are elements of , then , , and — the last of which is defined by
for all in — are all elements of .
Generalization
If both and have as their domain all possible assignments of a set of discrete variables, then their pointwise product
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https://en.wikipedia.org/wiki/Victor%20Shoup
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Victor Shoup is a computer scientist and mathematician. He obtained a PhD in computer science from the University of Wisconsin–Madison in 1989, and he did his undergraduate work at the University of Wisconsin-Eau Claire. He is a professor at the Courant Institute of Mathematical Sciences at New York University, focusing on algorithm and cryptography courses. He is currently a Principal Research Scientist at DFINITY and has held positions at AT&T Bell Labs, the University of Toronto, Saarland University, and the IBM Zurich Research Laboratory.
Shoup's main research interests and contributions are computer algorithms relating to number theory, algebra, and cryptography. His contributions to these fields include:
The Cramer–Shoup cryptosystem asymmetric encryption algorithm bears his name.
His freely available (under the terms of the GNU GPL) C++ library of number theory algorithms, NTL, is widely used and well regarded for its high performance.
He is the author of a widely used textbook, A Computational Introduction to Number Theory and Algebra, which is freely available online.
He has proved (while at IBM Zurich) a lower bound to the computational complexity for solving the discrete logarithm problem in the generic group model. This is a problem in computational group theory which is of considerable importance to public-key cryptography.
He acted as editor for the ISO 18033-2 standard for public-key cryptography.
One of the primary developers of HElib.
Bibliography
A
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https://en.wikipedia.org/wiki/Grant%20O.%20Gale
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Grant Oscar Gale (December 29, 1903 – April 14, 1998) was the S.S. Williston Professor of physics at Grinnell College in Grinnell, Iowa, the curator of Grinnell's Physics Historical Museum, and the namesake of the Grant O. Gale Observatory on the Grinnell campus.
Education
While an undergraduate at the University of Wisconsin, Gale was a classmate of John Bardeen with whom he kept in touch in later years.
Career and notable students
After graduation in 1928 Gale was offered an instructor position in physics at Grinnell College, and eventually became professor of physics. Until his death in 1998 he collected science equipment which had become obsolete and maintained a series of exhibits which now form the core of Grinnell's Physics Historical Museum.
From Bardeen, Gale acquired early versions of the transistor. One of Gale's most noted students was his former baby sitter, Robert Noyce, co-inventor of the integrated circuit and founder of Intel. While Noyce was his student at Grinnell:
Gale had kept up with Bardeen and his work, and he obtained two transistors in 1948 while Noyce was an undergraduate. Noyce worked with Gale on the transistor and was thus among the first to encounter its limitless potential.
Gale's mentorship of Noyce was also instrumental in protecting him from disciplinary action when Noyce stole a pig from a nearby farmer (who actually was also the Mayor) and then slaughtered it in Clark Hall for a college luau. The prank would have earned him expulsio
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https://en.wikipedia.org/wiki/Computational%20scientist
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A computational scientist is a person skilled in scientific computing. This person is usually a scientist, a statistician, an applied mathematician, or an engineer who applies high-performance computing and sometimes cloud computing in different ways to advance the state-of-the-art in their respective applied discipline; physics, chemistry, social sciences and so forth. Thus scientific computing has increasingly influenced many areas such as economics, biology, law, and medicine to name a few. Because a computational scientist's work is generally applied to science and other disciplines, they are not necessarily trained in computer science specifically, though concepts of computer science are often used. Computational scientists are typically researchers at academic universities, national labs, or tech companies.
One of the tasks of a computational scientist is to analyze large amounts of data, often from astrophysics or related fields, as these can often generate huge amounts of data. Computational scientists often have to clean up and calibrate the data to a usable form for an effective analysis. Computational scientists are also tasked with creating artificial data through computer models and simulations.
References
Computational science
Computer occupations
Science occupations
Computational fields of study
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https://en.wikipedia.org/wiki/Longest%20repeated%20substring%20problem
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In computer science, the longest repeated substring problem is the problem of finding the longest substring of a string that occurs at least twice.
This problem can be solved in linear time and space by building a suffix tree for the string (with a special end-of-string symbol like '$' appended), and finding the deepest internal node in the tree with more than one child. Depth is measured by the number of characters traversed from the root. The string spelled by the edges from the root to such a node is a longest repeated substring. The problem of finding the longest substring with at least occurrences can be solved by first preprocessing the tree to count the number of leaf descendants for each internal node, and then finding the deepest node with at least leaf descendants. To avoid overlapping repeats, you can check that the list of suffix lengths has no consecutive elements with less than prefix-length difference.
In the figure with the string "ATCGATCGA$", the longest substring that repeats at least twice is "ATCGA".
External links
C implementation of Longest Repeated Substring using Suffix Tree
Online Demo: Longest Repeated Substring
Problems on strings
Formal languages
Combinatorics
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https://en.wikipedia.org/wiki/Eigenspinor
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In quantum mechanics, eigenspinors are thought of as basis vectors representing the general spin state of a particle. Strictly speaking, they are not vectors at all, but in fact spinors. For a single spin 1/2 particle, they can be defined as the eigenvectors of the Pauli matrices.
General eigenspinors
In quantum mechanics, the spin of a particle or collection of particles is quantized. In particular, all particles have either half integer or integer spin. In the most general case, the eigenspinors for a system can be quite complicated. If you have a collection of the Avogadro number of particles, each one with two (or more) possible spin states, writing down a complete set of eigenspinors would not be practically possible. However, eigenspinors are very useful when dealing with the spins of a very small number of particles.
The spin 1/2 particle
The simplest and most illuminating example of eigenspinors is for a single spin 1/2 particle. A particle's spin has three components, corresponding to the three spatial dimensions: , , and . For a spin 1/2 particle, there are only two possible eigenstates of spin: spin up, and spin down. Spin up is denoted as the column matrix:
and spin down is
.
Each component of the angular momentum thus has two eigenspinors. By convention, the z direction is chosen as having the and states as its eigenspinors. The eigenspinors for the other two orthogonal directions follow from this convention:
:
:
:
All of these results are
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https://en.wikipedia.org/wiki/Epsilon%20number
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In mathematics, the epsilon numbers are a collection of transfinite numbers whose defining property is that they are fixed points of an exponential map. Consequently, they are not reachable from 0 via a finite series of applications of the chosen exponential map and of "weaker" operations like addition and multiplication. The original epsilon numbers were introduced by Georg Cantor in the context of ordinal arithmetic; they are the ordinal numbers ε that satisfy the equation
in which ω is the smallest infinite ordinal.
The least such ordinal is ε0 (pronounced epsilon nought or epsilon zero), which can be viewed as the "limit" obtained by transfinite recursion from a sequence of smaller limit ordinals:
where is the supremum function, which is equivalent to set union in the case of the von Neumann representation of ordinals.
Larger ordinal fixed points of the exponential map are indexed by ordinal subscripts, resulting in . The ordinal ε0 is still countable, as is any epsilon number whose index is countable (there exist uncountable ordinals, and uncountable epsilon numbers whose index is an uncountable ordinal).
The smallest epsilon number ε0 appears in many induction proofs, because for many purposes, transfinite induction is only required up to ε0 (as in Gentzen's consistency proof and the proof of Goodstein's theorem). Its use by Gentzen to prove the consistency of Peano arithmetic, along with Gödel's second incompleteness theorem, show that Peano arithmetic cannot
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https://en.wikipedia.org/wiki/Paul%20von%20Ragu%C3%A9%20Schleyer
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Paul von Ragué Schleyer (February 27, 1930 – November 21, 2014) was an American physical organic chemist whose research is cited with great frequency. A 1997 survey indicated that Dr. Schleyer was, at the time, the world's third most cited chemist, with over 1100 technical papers produced. He was Eugene Higgins Professor of Chemistry at Princeton University, professor and co-director of the Institute for Organic Chemistry (Institut für organische Chemie) at the University of Erlangen–Nuremberg in Germany, and later Graham Perdue Professor of Chemistry at the University of Georgia in Athens, Georgia. He published twelve books in the fields of lithium chemistry, ab initio molecular orbital theory and carbonium ions. He was past president of the World Association of Theoretically Oriented Chemists, a fellow of the International Academy of Quantum Molecular Science and editor-in-chief of the Encyclopedia of Computational Chemistry.
Early life
Born on February 27, 1930, in Cleveland, Ohio, Schleyer graduated as the valedictorian from his class at Cleveland West Technical High School in 1947. Schleyer received his A.B. degree from Princeton University in 1951 magna cum laude. He then earned his Ph.D. degree from Harvard University in 1957, where he worked under physical organic chemist Paul Doughty Bartlett.
Princeton University years
Schleyer began teaching at Princeton in 1954 and became Eugene Higgins Professor of Chemistry there. Working within the Frick Laboratory on the Pri
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https://en.wikipedia.org/wiki/Lattice%20of%20subgroups
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In mathematics, the lattice of subgroups of a group is the lattice whose elements are the subgroups of , with the partial order relation being set inclusion.
In this lattice, the join of two subgroups is the subgroup generated by their union, and the meet of two subgroups is their intersection.
Example
The dihedral group Dih4 has ten subgroups, counting itself and the trivial subgroup. Five of the eight group elements generate subgroups of order two, and the other two non-identity elements both generate the same cyclic subgroup of order four. In addition, there are two subgroups of the form Z2 × Z2, generated by pairs of order-two elements. The lattice formed by these ten subgroups is shown in the illustration.
This example also shows that the lattice of all subgroups of a group is not a modular lattice in general. Indeed, this particular lattice contains the forbidden "pentagon" N5 as a sublattice.
Properties
For any A, B, and C subgroups of a group with A ≤ C (A subgroup of C) then AB ∩ C = A(B ∩ C); the multiplication here is the product of subgroups. This property has been called the modular property of groups or (Dedekind's) modular law (, ). Since for two normal subgroups the product is actually the smallest subgroup containing the two, the normal subgroups form a modular lattice.
The Lattice theorem establishes a Galois connection between the lattice of subgroups of a group and that of its quotients.
The Zassenhaus lemma gives an isomorphism between certain c
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https://en.wikipedia.org/wiki/AP%20Computer%20Science%20A
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Advanced Placement (AP) Computer Science A (also known as AP CompSci, AP CompSci A, APCSA, AP Computer Science Applications, or AP Java) is an AP Computer Science course and examination offered by the College Board to high school students as an opportunity to earn college credit for a college-level computer science course. AP Computer Science A is meant to be the equivalent of a first-semester course in computer science. The AP exam currently tests students on their knowledge of Java.
AP Computer Science AB, which was equal to a full year, was discontinued following the May 2009 exam administration.
Course
AP Computer Science emphasizes object-oriented programming methodology with an emphasis on problem solving and algorithm development. It also includes the study of data structures and abstraction, but these topics were not covered to the extent that they were covered in AP Computer Science AB. The Microsoft-sponsored program Technology Education and Literacy in Schools (TEALS) aims to increase the number of students taking AP Computer Science classes.
The units of the exam are as follows:
Case studies and labs
Historically, the AP exam used several programs in its free-response section to test students' knowledge of object-oriented programs without requiring them to develop an entire environment. These programs were called Case Studies.
This practice was discontinued as of the 2014–15 school year and replaced with optional labs that teach concepts.
Case studies (disc
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https://en.wikipedia.org/wiki/Mathematics%20of%20Computation
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Mathematics of Computation is a bimonthly mathematics journal focused on computational mathematics. It was established in 1943 as Mathematical Tables and Other Aids to Computation, obtaining its current name in 1960. Articles older than five years are available electronically free of charge.
Abstracting and indexing
The journal is abstracted and indexed in Mathematical Reviews, Zentralblatt MATH, Science Citation Index, CompuMath Citation Index, and Current Contents/Physical, Chemical & Earth Sciences. According to the Journal Citation Reports, the journal has a 2020 impact factor of 2.417.
References
External links
Delayed open access journals
English-language journals
Mathematics journals
Academic journals established in 1943
American Mathematical Society academic journals
Bimonthly journals
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https://en.wikipedia.org/wiki/Linear%20group
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In mathematics, a matrix group is a group G consisting of invertible matrices over a specified field K, with the operation of matrix multiplication. A linear group is a group that is isomorphic to a matrix group (that is, admitting a faithful, finite-dimensional representation over K).
Any finite group is linear, because it can be realized by permutation matrices using Cayley's theorem. Among infinite groups, linear groups form an interesting and tractable class. Examples of groups that are not linear include groups which are "too big" (for example, the group of permutations of an infinite set), or which exhibit some pathological behavior (for example, finitely generated infinite torsion groups).
Definition and basic examples
A group G is said to be linear if there exists a field K, an integer d and an injective homomorphism from G to the general linear group GLd(K) (a faithful linear representation of dimension d over K): if needed one can mention the field and dimension by saying that G is linear of degree d over K. Basic instances are groups which are defined as subgroups of a linear group, for example:
The group GLn(K) itself;
The special linear group SLn(K) (the subgroup of matrices with determinant 1);
The group of invertible upper (or lower) triangular matrices
If gi is a collection of elements in GLn(K) indexed by a set I, then the subgroup generated by the gi is a linear group.
In the study of Lie groups, it is sometimes pedagogically convenient to restrict at
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https://en.wikipedia.org/wiki/Omega%20language
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In formal language theory within theoretical computer science, an infinite word is an infinite-length sequence (specifically, an ω-length sequence) of symbols, and an ω-language is a set of infinite words. Here, ω refers to the first ordinal number, the set of natural numbers.
Formal definition
Let Σ be a set of symbols (not necessarily finite). Following the standard definition from formal language theory, Σ* is the set of all finite words over Σ. Every finite word has a length, which is a natural number. Given a word w of length n, w can be viewed as a function from the set {0,1,...,n−1} → Σ, with the value at i giving the symbol at position i. The infinite words, or ω-words, can likewise be viewed as functions from to Σ. The set of all infinite words over Σ is denoted Σω. The set of all finite and infinite words over Σ is sometimes written Σ∞ or Σ≤ω.
Thus an ω-language L over Σ is a subset of Σω.
Operations
Some common operations defined on ω-languages are:
Intersection and union Given ω-languages L and M, both and are ω-languages.
Left concatenation Let L be an ω-language, and K be a language of finite words only. Then K can be concatenated on the left, and only on the left, to L to yield the new ω-language KL.
Omega (infinite iteration) As the notation hints, the operation is the infinite version of the Kleene star operator on finite-length languages. Given a formal language L, Lω is the ω-language of all infinite sequences of words from L; in the functio
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https://en.wikipedia.org/wiki/Paris%20Dauphine%20University
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Paris Dauphine University - PSL () is a Grande École and public institution of higher education and research based in Paris, France. As of 2022, Dauphine has 9,400 students in 8 fields of study (law, economics, finance, computer science, journalism, management, mathematics, social sciences), plus 3,800 in executive education. Its status as a , adopted in 2004, allows it to select its students. On average, 90 to 95% of accepted students received either high distinctions or the highest distinctions at their French High School National Exam results (Examen National du Baccalauréat). While not itself having the legal status of a public university, it is a constituent college of PSL University. Dauphine is also a member of the Conférence des Grandes Écoles.
Research at Dauphine concerns "organization and decision sciences", organized in 6 research laboratories (5 of which are mixed units also staffed by CNRS researchers): the CEREMADE Center for Research in Decision Mathematics, the CR2D Dauphine Law Research Center, DRM Dauphine Management Research, the IRISSO Interdisciplinary Research Institute in Social Science, the LAMSADE Laboratory for Analysis and Modeling of Decision Support Systems, and the LEDa Dauphine Economics Laboratory. A total of 519 research staff work at Dauphine.
History
Dauphine was founded on 24 October 1968 as a university center with the status of a faculty, named Centre universitaire Dauphine. On 17 December 1970, as part of the division of the ancient U
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https://en.wikipedia.org/wiki/Generalized%20tree%20alignment
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In computational phylogenetics, generalized tree alignment is the problem of producing a multiple sequence alignment and a phylogenetic tree on a set of sequences simultaneously, as opposed to separately.
Formally, Generalized tree alignment is the following optimization problem.
Input: A set and an edit distance function between sequences,
Output: A tree leaf-labeled by and labeled with sequences at the internal nodes, such that is minimized, where is the edit distance between the endpoints of .
Note that this is in contrast to tree alignment, where the tree is provided as input.
References
Computational phylogenetics
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https://en.wikipedia.org/wiki/Tree%20alignment
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In computational phylogenetics, tree alignment is a computational problem concerned with producing multiple sequence alignments, or alignments of three or more sequences of DNA, RNA, or protein. Sequences are arranged into a phylogenetic tree, modeling the evolutionary relationships between species or taxa. The edit distances between sequences are calculated for each of the tree's internal vertices, such that the sum of all edit distances within the tree is minimized. Tree alignment can be accomplished using one of several algorithms with various trade-offs between manageable tree size and computational effort.
Definition
Input: A set of sequences, a phylogenetic tree leaf-labeled by and an edit distance function between sequences.
Output: A labeling of the internal vertices of such that is minimized, where is the edit distance between the endpoints of .
The task is NP-hard.
Background
Sequence alignment
In bioinformatics, the basic method of information processing is to contrast the sequence data. Biologists use it to discover the function, structure, and evolutionary information in biological sequences. The following analyses are based on the sequence assembly: the phylogenetic analysis, the haplotype comparison, and the prediction of RNA structure. Therefore, the efficiency of sequence alignment will directly affect the efficacy of solving these problems. In order to design a rational and efficient sequence alignment, the algorithm derivation becomes an import
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https://en.wikipedia.org/wiki/Cofunction
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In mathematics, a function f is cofunction of a function g if f(A) = g(B) whenever A and B are complementary angles (pairs that sum to one right angle). This definition typically applies to trigonometric functions. The prefix "co-" can be found already in Edmund Gunter's Canon triangulorum (1620).
For example, sine (Latin: sinus) and cosine (Latin: cosinus, sinus complementi) are cofunctions of each other (hence the "co" in "cosine"):
The same is true of secant (Latin: secans) and cosecant (Latin: cosecans, secans complementi) as well as of tangent (Latin: tangens) and cotangent (Latin: cotangens, tangens complementi):
These equations are also known as the cofunction identities.
This also holds true for the versine (versed sine, ver) and coversine (coversed sine, cvs), the vercosine (versed cosine, vcs) and covercosine (coversed cosine, cvc), the haversine (half-versed sine, hav) and hacoversine (half-coversed sine, hcv), the havercosine (half-versed cosine, hvc) and hacovercosine (half-coversed cosine, hcc), as well as the exsecant (external secant, exs) and excosecant (external cosecant, exc):
See also
Hyperbolic functions
Lemniscatic cosine
Jacobi elliptic cosine
Cologarithm
Covariance
List of trigonometric identities
References
Trigonometry
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https://en.wikipedia.org/wiki/Computational%20phylogenetics
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Computational phylogenetics, phylogeny inference, or phylogenetic inference focuses on computational and optimization algorithms, heuristics, and approaches involved in phylogenetic analyses. The goal is to find a phylogenetic tree representing optimal evolutionary ancestry between a set of genes, species, or taxa. Maximum likelihood, parsimony, Bayesian, and minimum evolution are typical optimality criteria used to assess how well a phylogenetic tree topology describes the sequence data. Nearest Neighbour Interchange (NNI), Subtree Prune and Regraft (SPR), and Tree Bisection and Reconnection (TBR), known as tree rearrangements, are deterministic algorithms to search for optimal or the best phylogenetic tree. The space and the landscape of searching for the optimal phylogenetic tree is known as phylogeny search space.
Maximum Likelihood (also likelihood) optimality criterion is the process of finding the tree topology along with its branch lengths that provides the highest probability observing the sequence data, while parsimony optimality criterion is the fewest number of state-evolutionary changes required for a phylogenetic tree to explain the sequence data.
Traditional phylogenetics relies on morphological data obtained by measuring and quantifying the phenotypic properties of representative organisms, while the more recent field of molecular phylogenetics uses nucleotide sequences encoding genes or amino acid sequences encoding proteins as the basis for classification.
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https://en.wikipedia.org/wiki/Perfect%20phylogeny
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Perfect phylogeny is a term used in computational phylogenetics to denote a phylogenetic tree in which all internal nodes may be labeled such that all characters evolve down the tree without homoplasy. That is, characteristics do not hold to evolutionary convergence, and do not have analogous structures. Statistically, this can be represented as an ancestor having state "0" in all characteristics where 0 represents a lack of that characteristic. Each of these characteristics changes from 0 to 1 exactly once and never reverts to state 0. It is rare that actual data adheres to the concept of perfect phylogeny.
Building
In general there are two different data types that are used in the construction of a phylogenetic tree. In distance-based computations a phylogenetic tree is created by analyzing relationships among the distance between species and the edge lengths of a corresponding tree. Using a character-based approach employs character states across species as an input in an attempt to find the most "perfect" phylogenetic tree.
The statistical components of a perfect phylogenetic tree can best be described as follows:
<p>A perfect phylogeny for an n x m character state matrix M is a rooted tree T with n leaves satisfying:
i. Each row of M labels exactly one leaf of T
ii. Each column of M labels exactly one edge of T
iii. Every interior edge of T is labeled by at least one column of M
iv. The characters associated with the edges along the unique path from root
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https://en.wikipedia.org/wiki/Palle%20R%C3%B8mer%20Fleischer
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Palle Rømer Fleischer (25 October 1781 – 4 April 1851) was a Norwegian Military Officer and Government Minister. He served as a representative at the Norwegian Constitutional Assembly.
Palle Rømer Fleischer was born at Moss in Østfold, Norway. During 1792, he was enrolled as a cadet and student at The Free Mathematics School in Christiania (now Oslo) (Den frie matematiske skole i Christiania) . In 1796, he became a Second Lieutenant in the Norwegian Ranger Corps (Norske Jægerkorps) where he served until 1802 when he was promoted to captain in the North Zealand Land Protection Regiment (Nordsjællandske landvernsregiment) in Denmark. He subsequently returned to Norway as a staff Captain in the Ranger Corps where he was named Company Commander in 1813. In 1814, he was appointed Major. From 1815 to 1817 he was Commander of Akershus Fortress. In 1817, he became Lieutenant Colonel. He was promoted to Adjutant General in 1823, Major General in 1825 and Lieutenant General in 1835. He was the Norwegian Minister of the Army in five periods between 1837 and 1848, and a member of the Council of State Division in Stockholm three times between 1839 and 1847.
He attended the Norwegian Constitutional Assembly at Eidsvoll during 1814 where he represented the Norske Jægerkorps along with Corporal Niels Fredriksen Dyhren where they both supported the independence party (Selvstendighetspartiet ).
References
External links
Representantene på Eidsvoll 1814 (Cappelen Damm AS)
Men of Eid
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https://en.wikipedia.org/wiki/Walter%20M.%20Fitch
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Walter Monroe Fitch (May 21, 1929 – March 10, 2011) was a pioneering American researcher in molecular evolution.
Education and career
Fitch attended University of California, Berkeley, where he graduated with an A.B. in chemistry in 1953 and a Ph.D. in comparative biochemistry in 1958. Fitch spent 24 years at the University of Wisconsin–Madison, followed by three years at the University of Southern California and then was professor of molecular evolution at the University of California, Irvine, until his death. He was a member of the National Academy of Sciences, the American Philosophical Society, and the American Association for the Advancement of Science, and was a Foreign Member of the London Linnean Society. He co-founded the journal Molecular Biology and Evolution, with Masatoshi Nei, and was the first president of the Society for Molecular Biology and Evolution.
Research
Fitch is noted for his pioneering work on reconstruction of phylogenies (evolutionary trees) from protein and DNA sequences. Among his achievements are the first major paper on distance matrix methods, which introduced the Fitch–Margoliash method (with Emanuel Margoliash) which seeks the tree that best predicts a set of pairwise distances among species. He also developed the Fitch maximum parsimony algorithm, which evaluates rapidly and exactly the minimum number of changes of state of a sequence on a given phylogeny. His definition of orthologous sequences has been frequently cited and is used as
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https://en.wikipedia.org/wiki/Syndetic%20set
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In mathematics, a syndetic set is a subset of the natural numbers having the property of "bounded gaps": that the sizes of the gaps in the sequence of natural numbers is bounded.
Definition
A set is called syndetic if for some finite subset of
where . Thus syndetic sets have "bounded gaps"; for a syndetic set , there is an integer such that for any .
See also
Ergodic Ramsey theory
Piecewise syndetic set
Thick set
References
Semigroup theory
Ergodic theory
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https://en.wikipedia.org/wiki/Bochner%27s%20formula
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In mathematics, Bochner's formula is a statement relating harmonic functions on a Riemannian manifold to the Ricci curvature. The formula is named after the American mathematician Salomon Bochner.
Formal statement
If is a smooth function, then
,
where is the gradient of with respect to , is the Hessian of with respect to and is the Ricci curvature tensor. If is harmonic (i.e., , where is the Laplacian with respect to the metric ), Bochner's formula becomes
.
Bochner used this formula to prove the Bochner vanishing theorem.
As a corollary, if is a Riemannian manifold without boundary and is a smooth, compactly supported function, then
.
This immediately follows from the first identity, observing that the integral of the left-hand side vanishes (by the divergence theorem) and integrating by parts the first term on the right-hand side.
Variations and generalizations
Bochner identity
Weitzenböck identity
References
Differential geometry
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https://en.wikipedia.org/wiki/The%20Music%20of%20the%20Primes
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The Music of the Primes (British subtitle: Why an Unsolved Problem in Mathematics Matters; American subtitle: Searching to Solve the Greatest Mystery in Mathematics) is a 2003 book by Marcus du Sautoy, a professor in mathematics at the University of Oxford, on the history of prime number theory. In particular he examines the Riemann hypothesis, the proof of which would revolutionize our understanding of prime numbers. He traces the prime number theorem back through history, highlighting the work of some of the greatest mathematical minds along the way.
The cover design for the hardback version of the book contains several pictorial depictions of prime numbers, such as the number 73 bus. It also has an image of a clock, referring to clock arithmetic, which is a significant theme in the text.
References
2003 non-fiction books
Mathematics books
Analytic number theory
Prime numbers
Fourth Estate books
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https://en.wikipedia.org/wiki/Siegel%27s%20theorem%20on%20integral%20points
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In mathematics, Siegel's theorem on integral points states that for a smooth algebraic curve C of genus g defined over a number field K, presented in affine space in a given coordinate system, there are only finitely many points on C with coordinates in the ring of integers O of K, provided g > 0.
The theorem was first proved in 1929 by Carl Ludwig Siegel and was the first major result on Diophantine equations that depended only on the genus and not any special algebraic form of the equations. For g > 1 it was superseded by Faltings's theorem in 1983.
History
In 1929, Siegel proved the theorem by combining a version of the Thue–Siegel–Roth theorem, from diophantine approximation, with the Mordell–Weil theorem from diophantine geometry (required in Weil's version, to apply to the Jacobian variety of C).
In 2002, Umberto Zannier and Pietro Corvaja gave a new proof by using a new method based on the subspace theorem.
Effective versions
Siegel's result was ineffective (see effective results in number theory), since Thue's method in diophantine approximation also is ineffective in describing possible very good rational approximations to algebraic numbers. Effective results in some cases derive from Baker's method.
See also
Diophantine geometry
References
Diophantine equations
Theorems in number theory
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https://en.wikipedia.org/wiki/Memetic%20algorithm
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A memetic algorithm (MA) in computer science and operations research, is an extension of the traditional genetic algorithm (GA) or more general evolutionary algorithm (EA). It may provide a sufficiently good solution to an optimization problem. It uses a suitable heuristic or local search technique to improve the quality of solutions generated by the EA and to reduce the likelihood of premature convergence.
Memetic algorithms represent one of the recent growing areas of research in evolutionary computation. The term MA is now widely used as a synergy of evolutionary or any population-based approach with separate individual learning or local improvement procedures for problem search. Quite often, MAs are also referred to in the literature as Baldwinian evolutionary algorithms (EAs), Lamarckian EAs, cultural algorithms, or genetic local search.
Introduction
Inspired by both Darwinian principles of natural evolution and Dawkins' notion of a meme, the term memetic algorithm (MA) was introduced by Pablo Moscato in his technical report in 1989 where he viewed MA as being close to a form of population-based hybrid genetic algorithm (GA) coupled with an individual learning procedure capable of performing local refinements. The metaphorical parallels, on the one hand, to Darwinian evolution and, on the other hand, between memes and domain specific (local search) heuristics are captured within memetic algorithms thus rendering a methodology that balances well between generality and p
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https://en.wikipedia.org/wiki/161%20%28number%29
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161 (one hundred [and] sixty-one) is the natural number following 160 and preceding 162.
In mathematics
161 is the sum of five consecutive prime numbers: 23, 29, 31, 37, and 41
161 is a hexagonal pyramidal number.
161 is a semiprime. Since its prime factors 7 and 23 are both Gaussian primes, 161 is a Blum integer.
161 is a palindromic number
is a commonly used rational approximation of the square root of 5 and is the closest fraction with denominator <300 to that number.
In the military
was a U.S. Navy Type T2 tanker during World War II
was a U.S. Navy during World War II
was a U.S. Navy Trefoil-class concrete barge during World War II
was a U.S. Navy during World War II
was a U.S. Navy during World War II
was a U.S. Navy during World War II
was a U.S. Navy wooden yacht during World War I
was a U.S. Navy during World War II
was a U.S. Navy Achomawi-class fleet ocean tug following World War II
was a U.S. Navy fourth-group S-class submarine between 1920 and 1931
is a fictional U.S. Navy diesel engine submarine featured in the 1996 film Down Periscope
The 161st Intelligence Squadron unit of the Kansas Air National Guard. Its parent unit is the 184th Intelligence Wing
In music
The Bose 161 Speaker System (2001)
The Kay K-161 ThinTwin guitar
In transportation
MTA Maryland commuter bus 161
New Jersey Bus Route 161
London Bus route 161
In other fields
161 is also:
The year AD 161 or 161 BC
161 AH is a year in the Islamic calendar that co
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https://en.wikipedia.org/wiki/%C3%89douard%20Br%C3%A9zin
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Édouard Brézin (; born 1 December 1938 Paris) is a French theoretical physicist. He is professor at Université Paris 6, working at the laboratory for theoretical physics (LPT) of the École Normale Supérieure since 1986.
Biography
Brézin was born in Paris, France, to agnostic Jewish parents from Poland. His father served in the French army during World War II and was taken prisoner by the Germans in 1940, but escaped, The family used false names and Brézin was hidden by farmers.
Brézin studied at École Polytechnique before doing a PhD. He worked at the theory division of the Commissariat à l'énergie atomique in Saclay until 1986.
Brezin contributed to the field of physics that deals with the macroscopic physical properties of matter and high energy physics. He was a leader in critical behavior theory and developed methods for distilling testable predictions for critical exponents. In using field theoretic techniques in the study of condensed matter, Brezin helped further modern theories of magnetism and the quantum Hall effect.
Brézin was elected a member of the French Academy of Sciences on 18 February 1991 and served as president of the academy in 2005–2006. He also is a foreign associate of the United States National Academy of Sciences (since 2003), a foreign honorary member of the American Academy of Arts and Sciences (since 2002), a foreign member of the Royal Society (since 2006) and a member of the Academia Europaea (since 2003). He is a commander in the French
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https://en.wikipedia.org/wiki/David%20Britz
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David Alexander Britz (born November 23, 1980) is an American scientist and engineer who is best known for his contributions to the field of materials science and nanotechnology.
In 2004, Britz and his colleagues at Oxford and the University of Nottingham won a place in the Guinness Book of World Records for creating the world's smallest test tube, by performing chemical reactions inside carbon nanotubes: "the nanotube has an inner diameter of approximately 1.2 nanometres, and a length of about 2 micrometers. Its volume is two zeptolitres (a zeptolitre is 10−21 litres), and around 2,000 molecules react in that space."
Britz graduated magna cum laude from the University of Virginia School of Engineering and Applied Science in Mechanical Engineering. He completed his Doctor of Philosophy in Materials Science in the UK at the University of Oxford, Christ Church, Oxford college in the Department of Materials, and completed his doctoral thesis, titled "Structure and Bonding of Fullerenes and Nanotubes", in 2005. During his work at Oxford, David Britz created more than ten new carbon nanotube- and fullerene-based materials and processes. He has been awarded Honorable Mention for the 2002 National Science Foundation Graduate Research Fellowship.
Dave Britz also competed for Oxford University in the 2005 Varsity Boxing Match against Cambridge, earning a Full Blue.
Britz worked for the nanotechnology company Eikos in Franklin, Massachusetts, and developed carbon nanotube inks
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https://en.wikipedia.org/wiki/Jeff%20Eppinger
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Jeffrey Lee Eppinger (born ca 1960) is an American computer scientist, entrepreneur and Professor of the Practice at the Carnegie Mellon University, School of Computer Science.
Eppinger was a co-founder of Transarc Corporation, which was bought by IBM in 1994.
Eppinger was a student at Carnegie Mellon University where he earned a Bachelor of Science in 1982, a Master of Science in 1987, and a PhD in Computer Science in 1988. His advisors were Alfred Spector and Richard Rashid.
At Carnegie Mellon, Eppinger's dissertation demonstrated the integration of the Mach Operating System's virtual memory with the Camelot Transaction System. This recoverable virtual memory concept was subsequently used to implement the Coda File System.
In 1983, Eppinger won the George E. Forsythe Award for his research in binary search trees.
Eppinger had made empirical studies of their behaviour under random deletions and insertions.
References
External links
Jeff Eppinger's Home
1960s births
Living people
American computer scientists
Carnegie Mellon University alumni
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https://en.wikipedia.org/wiki/Livic
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LIVIC ("civil" spelt backwards, hence a "reflection of Civil Engineering") is the newspaper of the Civil Engineering Society (CivSoc) at Imperial College London. It is a monthly, free, A4-sized paper established in 2004, edited by an elected committee member of the society. The newspaper has a typical circulation of 250.
In 2006, LIVIC launched 'livique', a one-off special printed for the International Trip to Paris. Similar spin-offs have included 'livek', prepared for the trip to Budapest in 2007 and 'livøc' for the 2008 trip to Copenhagen.
While not a notable student publication, LIVIC aims to highlight current Civil & Environmental Engineering concerns and complications to undergraduates who are likely to be contributing to the shaping of the built environment in the long-term, and is therefore an invaluable resource to them.
Articles from LIVIC were published online through the City and Guilds College Union's media website 'Live' in order to help expand its readership numbers and so it is accessible to all at any time. It could be found here: Livic at Live
The articles are now posted to the Imperial College Union's website which can be found here: LIVIC
Student newspapers published in the United Kingdom
Newspapers established in 2004
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https://en.wikipedia.org/wiki/Maine%20School%20of%20Science%20and%20Mathematics
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The Maine School of Science and Mathematics (MSSM) is a public residential magnet high school in Limestone, Maine, United States.
MSSM serves students from all over the state of Maine, as well as youth from other states and international students. It is a public high school for students in grades 9–12, and its summer program is for boys and girls from grades 5–9. MSSM is an all-residential boarding school with a total capacity of 156 students.
The school is a member of the National Consortium of Secondary STEM Schools (NCSSS).
History
After the announcement that Loring Air Force Base would be closed, funding from the Defense Reauthorization Bill provided for the creation of the Maine School of Science and Mathematics at the site of Limestone High School, which was going to lose many of its students upon the closure of the base. The town's elementary school was eventually converted into dormitories for the school, as they are located on the same property. MSSM continues to share the former Limestone High School building with the local Limestone Community School. Each school occupies approximately half of the building. Due to their small size and physical proximity, the two schools also share most of their sports teams. In 2014, the school acquired a new dormitory, dubbed "Limestone Manor", in the center of town. The building housed a nursing home until the business relocated in 2013. As of 2014, the Limestone Manor, a male-only dormitory, houses close to 30 students.
Char
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https://en.wikipedia.org/wiki/Arthur%20Butz
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Arthur R. Butz is an associate professor of electrical engineering at Northwestern University and a Holocaust denier, best known as the author of the pseudohistorical book The Hoax of the Twentieth Century. He achieved tenure in 1974 and currently teaches classes in control system theory and digital signal processing.
Education and career
Born in 1933, Butz attended the Massachusetts Institute of Technology from which he received both his Bachelor of Science and, in 1956, his Master of Science degrees. In 1965, he received his PhD from the University of Minnesota. His doctoral dissertation considered a problem in control engineering.
Holocaust denial
In 1976, after he received tenure, Butz published The Hoax of the Twentieth Century: The Case Against the Presumed Extermination of European Jewry, an antisemitic, pseudohistorical book which argues that the Holocaust was a propaganda hoax. From 1980 to 2001, Butz was on the editorial board of the Journal of Historical Review, a publication of the Institute for Historical Review, a Holocaust-denying organization.
Faculty reaction
Butz's Holocaust denial sparked an outrage among the Northwestern University's faculty and community, after the existence of the book was disclosed by The Daily Northwestern in 1977. His views were also criticized by Robert H. Strotz, Northwestern University's then-president at the time of the book's publication. In 1997, Butz drew further criticism after using the university's Internet domain to pub
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https://en.wikipedia.org/wiki/Subcompact%20cardinal
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In mathematics, a subcompact cardinal is a certain kind of large cardinal number.
A cardinal number κ is subcompact if and only if for every A ⊂ H(κ+) there is a non-trivial elementary embedding j:(H(μ+), B) → (H(κ+), A) (where H(κ+) is the set of all sets of cardinality hereditarily less than κ+) with critical point μ and j(μ) = κ.
Analogously, κ is a quasicompact cardinal if and only if for every A ⊂ H(κ+) there is a non-trivial elementary embedding j:(H(κ+), A) → (H(μ+), B) with critical point κ and j(κ) = μ.
H(λ) consists of all sets whose transitive closure has cardinality less than λ.
Every quasicompact cardinal is subcompact. Quasicompactness is a strengthening of subcompactness in that it projects large cardinal properties upwards. The relationship is analogous to that of extendible versus supercompact cardinals. Quasicompactness may be viewed as a strengthened or "boldface" version of 1-extendibility. Existence of subcompact cardinals implies existence of many 1-extendible cardinals, and hence many superstrong cardinals. Existence of a 2κ-supercompact cardinal κ implies existence of many quasicompact cardinals.
Subcompact cardinals are noteworthy as the least large cardinals implying a failure of the square principle. If κ is subcompact, then the square principle fails at κ. Canonical inner models at the level of subcompact cardinals satisfy the square principle at all but subcompact cardinals. (Existence of such models has not yet been proved, but in any
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https://en.wikipedia.org/wiki/Hall%20Hibbard
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Hall Livingstone Hibbard (July 26, 1903 – June 6, 1996) was an engineer and administrator of the Lockheed Corporation beginning with the company's purchase by a board of investors led by Robert E. Gross in 1932. Born in Kansas, he received a bachelor's degree in mathematics and physics at the College of Emporia in 1925. He graduated from the Massachusetts Institute of Technology two years later. He worked for Stearman as a draftsman, before joining Robert Gross' Viking Flying Boat Company. He served on the board of the newly revived Lockheed Corporation and led the design departments as chief engineer. Engineers such as Clarence "Kelly" Johnson and Willis Hawkins worked under him.
He died in 1996 in Los Angeles at the age of 92.
References
Boyne, Walter J., Beyond the Horizons: The Lockheed Story. St. Martin's Press: New York, 1998.
1903 births
1996 deaths
People from Kansas
Emporia State University alumni
Massachusetts Institute of Technology alumni
American aerospace engineers
Businesspeople in aviation
Lockheed people
20th-century American engineers
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https://en.wikipedia.org/wiki/Piecewise%20syndetic%20set
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In mathematics, piecewise syndeticity is a notion of largeness of subsets of the natural numbers.
A set is called piecewise syndetic if there exists a finite subset G of such that for every finite subset F of there exists an such that
where . Equivalently, S is piecewise syndetic if there is a constant b such that there are arbitrarily long intervals of where the gaps in S are bounded by b.
Properties
A set is piecewise syndetic if and only if it is the intersection of a syndetic set and a thick set.
If S is piecewise syndetic then S contains arbitrarily long arithmetic progressions.
A set S is piecewise syndetic if and only if there exists some ultrafilter U which contains S and U is in the smallest two-sided ideal of , the Stone–Čech compactification of the natural numbers.
Partition regularity: if is piecewise syndetic and , then for some , contains a piecewise syndetic set. (Brown, 1968)
If A and B are subsets of with positive upper Banach density, then is piecewise syndetic.
Other notions of largeness
There are many alternative definitions of largeness that also usefully distinguish subsets of natural numbers:
Cofiniteness
IP set
member of a nonprincipal ultrafilter
positive upper density
syndetic set
thick set
See also
Ergodic Ramsey theory
Notes
References
Semigroup theory
Ergodic theory
Ramsey theory
Combinatorics
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https://en.wikipedia.org/wiki/Richard%20Klein%20%28paleoanthropologist%29
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Richard G. Klein (born April 11, 1941) is a Professor of Biology and Anthropology at Stanford University. He is the Anne T. and Robert M. Bass Professor in the School of Humanities and Sciences. He earned his PhD at the University of Chicago in 1966, and was elected to the National Academy of Sciences in April 2003. His research interests include paleoanthropology, Africa and Europe. His primary thesis is that modern humans evolved in East Africa, perhaps 100,000 years ago and, starting 50,000 years ago, began spreading throughout the non-African world, replacing archaic human populations over time. He is a critic of the idea that behavioral modernity arose gradually over the course of tens of thousands, hundreds of thousands of years or millions of years, instead supporting the view that modern behavior arose suddenly in the transition from the Middle Stone Age to the Later Stone Age around 50-40,000 years ago.
Early life and education
Klein was born in 1941 in Chicago, and went to college at the University of Michigan, Ann Arbor. In 1962, he enrolled as a graduate student at the University of Chicago to study with the Neanderthal expert, Francis Clark Howell. Of the two theories in vogue then, that Neanderthals had evolved into the Cro-Magnons of Europe or that they had been replaced by the Cro-Magnons, Klein favored the replacement theory. Klein completed a master's degree in 1964, and then studied at the University of Bordeaux with François Bordes, who specialized in pr
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https://en.wikipedia.org/wiki/Thick%20set
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In mathematics, a thick set is a set of integers that contains arbitrarily long intervals. That is, given a thick set , for every , there is some such that .
Examples
Trivially is a thick set. Other well-known sets that are thick include non-primes and non-squares. Thick sets can also be sparse, for example:
Generalisations
The notion of a thick set can also be defined more generally for a semigroup, as follows. Given a semigroup and , is said to be thick if for any finite subset , there exists such that
It can be verified that when the semigroup under consideration is the natural numbers with the addition operation , this definition is equivalent to the one given above.
See also
Cofinal (mathematics)
Cofiniteness
Ergodic Ramsey theory
Piecewise syndetic set
Syndetic set
References
J. McLeod, "Some Notions of Size in Partial Semigroups", Topology Proceedings, Vol. 25 (Summer 2000), pp. 317-332.
Vitaly Bergelson, "Minimal Idempotents and Ergodic Ramsey Theory", Topics in Dynamics and Ergodic Theory 8-39, London Math. Soc. Lecture Note Series 310, Cambridge Univ. Press, Cambridge, (2003)
Vitaly Bergelson, N. Hindman, "Partition regular structures contained in large sets are abundant", Journal of Combinatorial Theory, Series A 93 (2001), pp. 18-36
N. Hindman, D. Strauss. Algebra in the Stone-Čech Compactification. p104, Def. 4.45.
Semigroup theory
Ergodic theory
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https://en.wikipedia.org/wiki/Vop%C4%9Bnka%27s%20principle
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In mathematics, Vopěnka's principle is a large cardinal axiom.
The intuition behind the axiom is that the set-theoretical universe is so large that in every proper class, some members are similar to others, with this similarity formalized through elementary embeddings.
Vopěnka's principle was first introduced by Petr Vopěnka and independently considered by H. Jerome Keisler, and was written up by .
According to , Vopěnka's principle was originally intended as a joke: Vopěnka was apparently unenthusiastic about large cardinals and introduced his principle as a bogus large cardinal property, planning to show later that it was not consistent. However, before publishing his inconsistency proof he found a flaw in it.
Definition
Vopěnka's principle asserts that for every proper class of binary relations (each with set-sized domain), there is one elementarily embeddable into another. This cannot be stated as a single sentence of ZFC as it involves a quantification over classes. A cardinal κ is called a Vopěnka cardinal if it is inaccessible and Vopěnka's principle holds in the rank Vκ (allowing arbitrary S ⊂ Vκ as "classes").
Many equivalent formulations are possible.
For example, Vopěnka's principle is equivalent to each of the following statements.
For every proper class of simple directed graphs, there are two members of the class with a homomorphism between them.
For any signature Σ and any proper class of Σ-structures, there are two members of the class with an element
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https://en.wikipedia.org/wiki/John%20Pendry
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Sir John Brian Pendry, (born 4 July 1943) is an English theoretical physicist known for his research into refractive indices and creation of the first practical "Invisibility Cloak". He is a professor of theoretical solid state physics at Imperial College London where he was head of the department of physics (1998–2001) and principal of the faculty of physical sciences (2001–2002). He is an honorary fellow of Downing College, Cambridge, (where he was an undergraduate) and an IEEE fellow. He received the Kavli Prize in Nanoscience "for transformative contributions to the field of nano-optics that have broken long-held beliefs about the limitations of the resolution limits of optical microscopy and imaging.", together with Stefan Hell, and Thomas Ebbesen, in 2014.
Education
Pendry was educated at Downing College, Cambridge, graduating with a Master of Arts degree in Natural Sciences and a PhD in 1969.
Career
John Pendry was born in Manchester, where his father was an oil representative, and took a degree in Natural Sciences at the University of Cambridge after which he was appointed as a research fellow at Downing College, Cambridge, between 1969 and 1975. He spent time at Bell Labs in 1972-3 and was head of the theory group at the SERC Daresbury Laboratory from 1975 to 1981, when he was appointed to the chair in theoretical physics at Imperial College, London, where he stayed for the rest of his career. Preferring administration to teaching, he was Dean of the Royal College
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https://en.wikipedia.org/wiki/Felice%20Varini
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Felice Varini (born in Locarno in 1952) is a Paris-based, Swiss artist who was nominated for the 2000/2001 Marcel Duchamp Prize. Mostly known for his geometric perspective-localized paintings in rooms and other spaces, using projector-stencil techniques, according to mathematics professor and art critic Joël Koskas, "A work of Varini is an anti-Mona Lisa."
Style
Felice paints on architectural and urban spaces, such as buildings, walls and streets. The paintings are characterized by one vantage point from which the viewer can see the complete painting (usually a simple geometric shape such as circle, square, line), while from other view points the viewer will see 'broken' fragmented shapes. Varini argues that the work exists as a whole - with its complete shape as well as the fragments. "My concern," he says "is what happens outside the vantage point of view."
Carcassonne 2018
In May 2018, Varini's project "Concentric, eccentric" saw large yellow concentric circles mounted on the monument at Carcassonne as part of the 7th edition of "IN SITU, Heritage and contemporary art", a summer event in the Occitanie / Pyrenees-Mediterranean region focusing on the relationship between modern art and architectural heritage. This monumental work was to celebrate the 20th anniversary of Carcassonne's inscription on the World Heritage List of UNESCO. Exceptional in its size and its visibility and use of architectural space, the exhibit extended on the western front of the fortifications o
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https://en.wikipedia.org/wiki/Mercator%20series
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In mathematics, the Mercator series or Newton–Mercator series is the Taylor series for the natural logarithm:
In summation notation,
The series converges to the natural logarithm (shifted by 1) whenever .
History
The series was discovered independently by Johannes Hudde and Isaac Newton. It was first published by Nicholas Mercator, in his 1668 treatise Logarithmotechnia.
Derivation
The series can be obtained from Taylor's theorem, by inductively computing the nth derivative of at , starting with
Alternatively, one can start with the finite geometric series ()
which gives
It follows that
and by termwise integration,
If , the remainder term tends to 0 as .
This expression may be integrated iteratively k more times to yield
where
and
are polynomials in x.
Special cases
Setting in the Mercator series yields the alternating harmonic series
Complex series
The complex power series
is the Taylor series for , where log denotes the principal branch of the complex logarithm. This series converges precisely for all complex number . In fact, as seen by the ratio test, it has radius of convergence equal to 1, therefore converges absolutely on every disk B(0, r) with radius r < 1. Moreover, it converges uniformly on every nibbled disk , with δ > 0. This follows at once from the algebraic identity:
observing that the right-hand side is uniformly convergent on the whole closed unit disk.
See also
John Craig
References
Anton von Braunmühl (1903) Vorlesungen üb
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https://en.wikipedia.org/wiki/David%20L.%20Tennenhouse
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David Lawrence Tennenhouse (born c. 1957) is a Canadian–American computer researcher and technology executive.
Life
Tennenhouse was born about 1957 in Ottawa, Canada.
He received a bachelor's and master's degree in electrical engineering from the University of Toronto. In 1989 he completed a PhD at the University of Cambridge under advisor Roger Needham.
His dissertation was Site interconnection and the exchange architecture.
He then joined the faculty of Massachusetts Institute of Technology (MIT).
He was chairman of the Technology and Policy Working Group of the US National Information Infrastructure Task Force at some time point.
In 1996 he became director of the Information Technology Office of the Defense Advanced Research Projects Agency (DARPA), overseeing US government research.
In 1999, he joined Intel as a director of research.
In 2001, he founded what were sometimes called the Intel Research Lablets. One of the projects sponsored was TinyOS.
In February 2006 he became the chief executive officer of A9.com, the search subsidiary of Amazon.com, replacing Udi Manber.
He left Amazon in September 2006. In 2007 he became a partner at the venture capital firm New Venture Partners.
In 2004, he was granted IEEE fellowship for leadership in the development of active networks.
In September 2012 he became vice president for technology policy at Microsoft.
In May 2014 he joined VMware to direct its research.
References
Living people
Year of birth missing (living peopl
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https://en.wikipedia.org/wiki/Denham%20Harman
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Denham Harman (February 14, 1916 – November 25, 2014) was an American medical academic who latterly served as professor emeritus at the University of Nebraska Medical Center. Harman is known as the "father of the free radical theory of aging".
Background
Born in San Francisco, he earned his BS and Ph.D. in 1943 from the College of Chemistry at the University of California, Berkeley and his M.D. from Stanford University, finishing his internship in 1954.
Immediately after earning his Ph.D., in 1943, Harman joined the reaction kinetics department of Shell Oil in Emeryville, California. He worked for six years as a Shell research chemist, in part studying free radical reactions in petroleum products. During that period he was granted 35 patents, one for a compound used in plastic strips to kill flies ("Shell No Pest Strip").
Harman became fascinated with the phenomenon of aging, its cause and possible cure. To assist him in understanding this problem, he went to medical school at Stanford University. Harman became chair of cardiovascular research at the University of Nebraska College of Medicine in 1958.
Harman was married to the same woman for most of his life, a journalism student whom he met at a fraternity dance while at the University of California. The couple had four children and four grandchildren. Harman maintained a healthy lifestyle throughout his life. He never smoked and drank alcohol in moderation. He ran two miles a day until he was 82. He quit because of a b
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https://en.wikipedia.org/wiki/Blacking
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Blacking may refer to:
Blacking (polish), a nineteenth-century shoe polish
Blacking up, putting on a style of theatrical makeup to take on the appearance of certain archetypes of American racism
Blacking (cryptography) In NSA jargon, encryption devices are often called blackers, because they convert red signals to black
Sanitization (classified information)
People with the surname
John Blacking (1928–1990), British ethnomusicologist and anthropologist
See also
Blackening (disambiguation)
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https://en.wikipedia.org/wiki/Stewart%20Shapiro
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Stewart Shapiro (; born 1951) is O'Donnell Professor of Philosophy at the Ohio State University and distinguished visiting professor at the University of Connecticut. He is a leading figure in the philosophy of mathematics where he defends the abstract variety of structuralism.
Education and career
Shapiro studied mathematics and philosophy at Case Western Reserve University in 1973. Then, he got his M.A. in mathematics at the State University of New York at Buffalo in 1975. He transferred to the University at Buffalo Philosophy Department, where three years later he received a Ph.D. His doctoral supervisor was John Corcoran.
He was elected a Fellow of the American Academy of Arts & Sciences in 2021.
Publications
Books
Philosophy of Mathematics: Structure and Ontology. Oxford University Press, 1997.
Thinking about Mathematics: The Philosophy of Mathematics. Oxford University Press, 2000.
Foundations without Foundationalism: A Case for Second-Order Logic. Oxford University Press, 1991.
Vagueness in Context. Oxford University Press, 2006.
Varieties of Logic. Oxford University Press, 2014.
Editorships
Intensional Mathematics, Studies in Logic and the Foundations of Mathematics 113, Amsterdam, North Holland Publishing Company, 1985. Contributors: S. Shapiro, J. Myhill, N. D. Goodman, A. Scedrov, V. Lifschitz, R. Flagg, R. Smullyan.
The Limits of Logic: Higher-Order Logic and the Löwenheim-Skolem Theorem, Routledge, 1996.
Special issue of Philosophia Ma
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https://en.wikipedia.org/wiki/Fernando%20Quevedo
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Fernando Quevedo Rodríguez (born 12 May 1956) is a Guatemalan physicist. He was the director of the Abdus Salam International Centre for Theoretical Physics (ICTP) between October 2009 and November 2019.
Quevedo was born in 1956 in San José, Costa Rica and obtained his early education in Guatemala. He obtained his BSc in physics from the Universidad del Valle de Guatemala in 1979, and his Ph.D. from the University of Texas at Austin in 1986 under the supervision of Nobel laurate Steven Weinberg. Following a string of research appointments at CERN, Switzerland, McGill University in Canada, Institut de Physique in Neuchatel, Switzerland, and the Los Alamos National Laboratory, USA, as well as a brief term as professor of physics at the National Autonomous University of Mexico (UNAM). Dr. Quevedo later joined the Department of Applied Mathematics and Theoretical Physics at the University of Cambridge, UK, in 1998, where he has been Professor of Theoretical Physics and Fellow of Gonville and Caius College.
He has been awarded the Royal Society Wolfson Research Merit Award, Doctorate Honoris Causa from Universidad de San Carlos de Guatemala and Universidad del Valle de Guatemala, John Solomon Guggenheim Foundation Fellowship and, alongside Anamaría Font, won the 1998 ICTP Prize. He has been a fellow of the World Academy of Sciences since 2010. He has authored more than 100 papers.
He has taught courses on the Standard Model, differential equations, complex methods, supersymmet
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