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https://en.wikipedia.org/wiki/Line%20of%20action
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In physics, the line of action (also called line of application) of a force () is a geometric representation of how the force is applied. It is the straight line through the point at which the force is applied in the same direction as the vector .
The concept is essential, for instance, for understanding the net effect of multiple forces applied to a body. For example, if two forces of equal magnitude act upon a rigid body along the same line of action but in opposite directions, they cancel and have no net effect. But if, instead, their lines of action are not identical, but merely parallel, then their effect is to create a moment on the body, which tends to rotate it.
Calculation of torque
For the simple geometry associated with the figure, there are three equivalent equations for the magnitude of the torque associated with a force directed at displacement from the axis whenever the force is perpendicular to the axis:
where is the cross-product, is the component of perpendicular to , is the moment arm, and is the angle between and
References
Force
A
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https://en.wikipedia.org/wiki/NNF
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NNF may mean:Net financial flows: financial assets- financial liabilities
Name Not Final, an abbreviation in creative works placed after a Working title
Namibia National Front
Namibia Nature Foundation
Food Union NNF, a Danish trade union
Negation Normal Form (in mathematics, computer science, logic)
Never Not Funny, Jimmy Pardo's award-winning weekly podcast
NoNonsense Forum, an open-source easy-to-deploy forum solution
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https://en.wikipedia.org/wiki/Padovan%20cuboid%20spiral
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In mathematics the Padovan cuboid spiral is the spiral created by joining the diagonals of faces of successive cuboids added to a unit cube. The cuboids are added sequentially so that the resulting cuboid has dimensions that are successive Padovan numbers.
The first cuboid is 1x1x1. The second is formed by adding to this a 1x1x1 cuboid to form a 1x1x2 cuboid. To this is added a 1x1x2 cuboid to form a 1x2x2 cuboid.
This pattern continues, forming in succession a 2x2x3 cuboid, a 2x3x4 cuboid etc. Joining the diagonals of the exposed end of each new added cuboid creates a spiral (seen as the black line in the figure). The points on this spiral all lie in the same plane.
The cuboids are added in a sequence that adds to the face in the positive y direction, then the positive x direction, then the positive z direction. This is followed by cuboids added in the negative y, negative x and negative z directions. Each new cuboid added has a length and width that matches the length and width of the face being added to. The height of the nth added cuboid is the nth Padovan number.
Connecting alternate points where the spiral bends creates a series of triangles, where each triangle has two sides that are successive Padovan numbers and that has an obtuse angle of 120 degrees between these two sides.
References
External links
Padovan Spiral Numbers, Robert Dickau, Wolfram Demonstrations Project
Spirals
Cuboids
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https://en.wikipedia.org/wiki/Magnetic%20photon
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In physics, a magnetic photon is a hypothetical particle. It is a mixture of even and odd C-parity states and, unlike the normal photon, does not couple to leptons. It is predicted by certain extensions of electromagnetism to include magnetic monopoles. There is no experimental evidence for the existence of this particle, and several versions have been ruled out by negative experiments.
The magnetic photon was predicted in 1966 by Nobel laureate Abdus Salam.
See also
Dual photon, a different extension for magnetic monopoles
References
Obsolete theories in physics
Hypothetical elementary particles
Photons
Magnetic monopoles
Force carriers
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https://en.wikipedia.org/wiki/Phosphotungstic%20acid
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Phosphotungstic acid (PTA) or tungstophosphoric acid (TPA), is a heteropoly acid with the chemical formula . It forms hydrates . It is normally isolated as the n = 24 hydrate but can be desiccated to the hexahydrate (n = 6). EPTA is the name of ethanolic phosphotungstic acid, its alcohol solution used in biology. It has the appearance of small, colorless-grayish or slightly yellow-green crystals, with melting point 89 °C (24 hydrate). It is odorless and soluble in water (200 g/100 ml). It is not especially toxic, but is a mild acidic irritant. The compound is known by a variety of names and acronyms (see 'other names' section of infobox).
In these names the "12" or "dodeca" reflects the fact that the anion contains 12 tungsten atoms. Some early workers who did not know the structure called it phospho-24-tungstic acid, formulating it as 3H2O·P2O5 24WO3·59H2O, , which correctly identifies the atomic ratios of P, W and O. This formula was still quoted in papers as late as 1970.
Phosphotungstic acid is used in histology as a component for staining of cell specimens, often together with haematoxylin as PTAH. It binds to fibrin, collagen, and fibres of connective tissues, and replaces the anions of dyes from these materials, selectively decoloring them.
Phosphotungstic acid is electron dense, opaque for electrons. It is a common negative stain for viruses, nerves, polysaccharides, and other biological tissue materials for imaging by a transmission electron microscope.
Structur
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https://en.wikipedia.org/wiki/Osculate
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In mathematics, osculate, meaning to touch (from the Latin osculum meaning kiss), may refer to:
osculant, an invariant of hypersurfaces
osculating circle
osculating curve
osculating plane
osculating orbit
osculating sphere
The obsolete Quinarian system of biological classification attempted to group creatures into circles which could touch or overlap with adjacent circles, a phenomenon called 'osculation'.
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https://en.wikipedia.org/wiki/Pyr
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Pyr may refer to:
Pyr (Encantadia), a character in the Encantadia franchise
Pyr (publisher)
Pyridine
Pyridoxine, vitamin B6
Pyrrolidonyl-β-naphthylamide, used in microbiology to distinguish certain Streptococcal organisms
Pyruvic acid
Saint Pyr
Caldey Island, called "Ynys Pyr" in Welsh
Andravida airbase (IATA: PYR)
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https://en.wikipedia.org/wiki/Eightfold%20Way
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Eightfold Way may refer to:
Noble Eightfold Path, Buddhist doctrine
Eightfold Way (physics), particle-physics theory
Eightfold Path (policy analysis)
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https://en.wikipedia.org/wiki/Isoproscaline
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Isoproscaline or 4-isopropoxy-3,5-dimethoxyphenethylamine is an analog of mescaline. It is closely related to proscaline and was first synthesized by David E. Nichols. It produces hallucinogenic, psychedelic, and entheogenic effects.
Chemistry
Isoproscaline is in a class of compounds commonly known as phenethylamines, and the full chemical name is 2-(4-isopropoxy-3,5-dimethoxyphenyl)ethanamine.
Effects
Little is known about the psychopharmacological effects of isoproscaline. In his book PiHKAL, Alexander Shulgin lists a psychedelic dosage as being 40–80 mg, with effects lasting 10–16 hours.
Pharmacology
The mechanism that produces the hallucinogenic and entheogenic effects of isoproscaline is most likely to result from action as a 5-HT2A serotonin receptor agonist in the brain, a mechanism of action shared by all of the hallucinogenic tryptamines and phenethylamines.
Dangers
The toxicity of isoproscaline is not known.
Legality
Isoproscaline is unscheduled in the United States; however, because of its close similarity in structure and effects to mescaline, possession and sale of isoproscaline may be subject to prosecution under the Federal Analog Act.
In the UK, its highly likely that this compound would be covered by the "phenylethylamine amendment" to the misuse of drugs act likely rendering it a Class A controlled drug.
See also
Proscaline
References
Psychedelic phenethylamines
Designer drugs
Phenol ethers
Mescalines
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https://en.wikipedia.org/wiki/Daniel%20Meyer%20%28engineer%29
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Daniel Meyer (February 6, 1932 – May 16, 1998) was the founder and president Southwest Technical Products Corporation. He was born in New Braunfels, Texas, and raised in San Marcos, Texas, where he earned a bachelor's degree in mathematics and physics in 1957 from Southwest Texas State. After college he married Helen Wentz, moved to San Antonio and became a research engineer in the electrical engineering department of Southwest Research Institute.
He soon started writing hobbyist articles. The first was in Electronics World (May 1960) and later he had a two part cover feature for Radio-Electronics (October, November 1962). The March 1963 issue of Popular Electronics featured his ultrasonic listening device on the cover. The projects would often require a printed circuit board or specialized components that were not available at the local electronics parts store. Readers could purchase them directly from Dan Meyer.
Dan Meyer saw the business opportunity in providing circuit boards and parts for the Popular Electronics projects. In January 1964 he left Southwest Research Institute to start an electronics kit company. He continued to write articles and ran the mail order kit business from his home garage in San Antonio, Texas. By 1965 he was providing the kits for other authors such as Lou Garner. In 1967 he sold a kit for Don Lancaster's "IC-67 Metal Locator". In early 1967 Meyer moved his growing business from his home to a new building on a site in San Antonio. The Daniel
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https://en.wikipedia.org/wiki/Syed%20Abu%20Nasar
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Syed Abu Nasar (December 25, 1932 – January 29, 2012) was a James R. Boyd Professor of Electrical Engineering (Emeritus) at the University of Kentucky. He was born in India and got his doctorate in electrical engineering at the University of California, Berkeley in 1963 . His research concerned electric motors. He served as the chair of the Electrical Engineering department at the University of Kentucky from 1989 to 1997. He was a Life Fellow of the IEEE and the recipient of the 2000 IEEE Nikola Tesla Award.
References
External links
Syed Abu Nasar's website
List of errors in Nasar's Schaum's Electric Power Systems
Quadrangle - University of Kentucky, College of Engineering
1932 births
2012 deaths
Fellow Members of the IEEE
American academics of Indian descent
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https://en.wikipedia.org/wiki/James%20H.%20McClellan
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James H. McClellan (born 5 October 1947) is the Byers Professor of Signal Processing at the Georgia Institute of Technology. He is widely known for his creation of the McClellan transform and for his co-authorship of the Parks–McClellan filter design algorithm.
Early life and education
James McClellan was born on October 5, 1947, in Guam. McClellan received his B.S. in Electrical Engineering from Louisiana State University in 1969. He went on to receive an M.S. (1972) and a Ph.D. (1973) from Rice University.
Career
In 1973, he joined the research staff of MIT's Lincoln Laboratory. In 1975, he became a professor at MIT's Electrical Engineering and Computer Science department before leaving to join Schlumberger. Since 1987, he has been at the Georgia Institute of Technology. Prof. McClellan is a Fellow of the IEEE. He received the Acoustics, Speech, and Signal Processing Technical Achievement Award in 1987, the IEEE Signal Processing Society Award in 1996, and the IEEE Jack S. Kilby Signal Processing Medal in 2004 (together with Thomas W. Parks).
Books
Number Theory in Digital Signal Processing, J. H. McClellan and C. M. Rader, Prentice-Hall, Inc., Englewood Cliffs, N.J., 1979, .
Computer-Based Exercises for Signal Processing Using MATLAB, J. H. McClellan, C. S. Burrus, A. V. Oppenheim, T. W. Parks, R.W. Schafer, H. W. Schuessler, Prentice Hall, 1998, .
Signal Processing First: A Multimedia Approach, J. H. McClellan, R.W. Schafer, M. A. Yoder, Upper Saddle River, NJ: P
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https://en.wikipedia.org/wiki/2%2C5-Dimethoxy-4-nitroamphetamine
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2,5-Dimethoxy-4-nitroamphetamine (DON) is a psychedelic drug and amphetamine. It is an analog of DOM and DOB. It is also closely related to 2C-N.
Chemistry
DON is in a class of compounds commonly known as alpha-methyl phenethylamines, or amphetamines and the full chemical name is 1-(2,5-dimethoxy-4-nitrophenyl)propan-2-amine. It has a stereocenter.
Effects
In his book PiHKAL, Alexander Shulgin lists a dosage of DON as being 3-4.5 mg orally with amphetamine-like stimulation lasting 8–15 hours.
Dangers
The toxicity of DON is not known.
Legality
DON is unscheduled in the United States, but because of its close similarity in structure and effects to DOM and DOB, possession and sale of DON may be subject to prosecution under the Federal Analog Act. DON is listed as a Class A drug in the Drugs controlled by the UK Misuse of Drugs Act after the table of contents of PiHKAL and TiHKAL were added to the schedules.
See also
DOx
References
Designer drugs
Substituted amphetamines
Nitrobenzenes
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https://en.wikipedia.org/wiki/Lagrange%27s%20theorem
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In mathematics, Lagrange's theorem usually refers to any of the following theorems, attributed to Joseph Louis Lagrange:
Lagrange's theorem (group theory)
Lagrange's theorem (number theory)
Lagrange's four-square theorem, which states that every positive integer can be expressed as the sum of four squares of integers
Mean value theorem in calculus
The Lagrange inversion theorem
The Lagrange reversion theorem
The method of Lagrangian multipliers for mathematical optimization
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https://en.wikipedia.org/wiki/INTERBUS
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INTERBUS is a serial bus system which transmits data between control systems (e.g., PCs, PLCs, VMEbus computers, robot controllers etc.) and spatially distributed I/O modules that are connected to sensors and actuators (e.g., temperature sensors, position switches).
The INTERBUS system was developed by Phoenix Contact and has been available since 1987. It is one of the leading Fieldbus systems in the automation industry and is fully standardized according to European Standard EN 50254 and IEC 61158.
At the moment, more than 600 manufacturers are involved in the implementation of INTERBUS technology in control systems and field devices.
Since 2011 is the INTERBUS technology hosted by the industry association Profibus and Profinet International.
See also
BiSS interface
External links
www.interbusclub.com
www.phoenixcontact.com
Explanation of Bit-based Sensor networks including SeriPlex
Serial buses
Industrial computing
Industrial automation
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https://en.wikipedia.org/wiki/Suppression
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Suppression may refer to:
Laws
Suppression of Communism Act
Suppression order a type of censorship where a court rules that certain information cannot be published
Tohunga Suppression Act 1907, an Act of the Parliament of New Zealand aimed to replace tohunga as traditional Māori healers with "modern" medicine
Mathematics and science
Biology, psychology and healthcare
Suppression (eye), of an eye is a subconscious adaptation by a person's brain to eliminate the symptoms of disorders of binocular vision such as strabismus, convergence insufficiency and aniseikonia
Appetite suppression
Bone marrow suppression, the decrease in cells responsible for providing immunity, carrying oxygen, and those responsible for normal blood clotting
Cough medicine, which may contain a cough suppressant, a medicinal drug used in an attempt to treat coughing
Expressive suppression, a psychological aspect of emotion regulation
Flash suppression, a phenomenon of visual perception in which an image presented to one eye is suppressed by a flash of another image presented to the other eye
Genetic suppression
Reflux suppressant, in medicine
Suppression subtractive hybridization, in biochemistry
Thought suppression, the psychological process of deliberately trying to stop thinking about certain thoughts, associated with obsessive-compulsive disorder
Other uses in mathematics and science
Compton suppression, in nuclear physics
Zero suppression, in mathematics and information theory
Pol
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https://en.wikipedia.org/wiki/Bergen%20school%20%28meteorology%29
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The "Bergen School of meteorology" is a school of thought which is the basis for much of modern weather forecasting.
Founded by the meteorologist Prof. Vilhelm Bjerknes and his younger colleagues in 1917, the Bergen School attempts to define the motion of the atmosphere by means of the mathematics of interactions between hydro- and thermodynamics, some of which had originally been discovered or explained by Bjerknes himself, thus making mathematical predictions regarding the weather possible by systematic data analysis. Much of the work was done at the Geophysical Institute, University of Bergen, in Bergen, Norway.
The Bergen School was crucial in the early development and operationalization of numerical weather forecasting in the 1940s and 1950s, which was largely a cooperation between Scandinavian and US researchers. In this development, extant meteorological theories were synthesized. Due to the vast amount of calculations necessary for producing viable forecasts, the mathematical models were adapted to computer programs. The cross-Atlantic cooperations was also important to the development of the Bergen School and the Norwegian meteorology community
Bjerknes' assistants during the period 1917–1926
Jacob Bjerknes
Halvor Solberg
Tor Bergeron
Carl-Gustaf Rossby
Sverre Petterssen
Erik Palmén
Erik Björkdal
Svein Rosseland
Carl Ludvig Godske
Johan Sandström
See also
Norwegian cyclone model
Cyclogenesis
Surface weather analysis
Synoptic scale meteorology
References
V
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https://en.wikipedia.org/wiki/Harmonic%20motion
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Harmonic motion can mean:
the displacement of the particle executing oscillatory motion that can be expressed in terms of sine or cosine functions known as harmonic motion .
The motion of a Harmonic oscillator (in physics), which can be:
Simple harmonic motion
Complex harmonic motion
Keplers laws of planetary motion (in physics, known as the harmonic law)
Quasi-harmonic motion
Musica universalis (in medieval astronomy, the music of the spheres)
Chord progression (in music, harmonic progression)
See also
Pendulum
Harmonograph
Circular motion
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https://en.wikipedia.org/wiki/Victor%20Isakov
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Victor Isakov (1947 – May 14, 2021) was a mathematician working in the field of inverse problems for partial differential equations and related topics (potential theory, uniqueness of continuation and Carleman estimates, nonlinear functional analysis and calculus of variation). He was a distinguished professor in the Department of Mathematics and Statistics at Wichita State University.
His areas of professional interest included:
Inverse problems of gravimetry (general uniqueness conditions and local solvability theorems) and related problems of imaging including prospecting active part of the brain and the source of noise of the aircraft from exterior measurements of electromagnetic and acoustical fields.
Inverse problems of conductivity (uniqueness of discontinuous conductivity and numerical methods) and their applications to medical imaging and nondestructive testing of materials for cracks and inclusions.
Inverse scattering problems (uniqueness and stability of penetrable and soft scatterers).
Finding constitutional laws from experimental data (reconstructing nonlinear partial differential equation from all or some boundary data).
Uniqueness of the continuation for hyperbolic equations and systems of mathematical physics.
The inverse option pricing problem.
Publications
Isakov has over 90 publications in print or in preparation as of late 2005, which include:
Increased stability in the continuation of solutions to the Helmholtz equation (with Tomasz Hrycak), Inverse
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https://en.wikipedia.org/wiki/International%20Colloquium%20on%20Automata%2C%20Languages%20and%20Programming
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ICALP, the International Colloquium on Automata, Languages, and Programming is an academic conference organized annually by the European Association for Theoretical Computer Science and held in different locations around Europe. Like most theoretical computer science conferences its contributions are strongly peer-reviewed. The articles have appeared in proceedings published by Springer in their Lecture Notes in Computer Science, but beginning in 2016 they are instead published by the Leibniz International Proceedings in Informatics.
The ICALP conference series was established by Maurice Nivat, who organized the first ICALP in Paris, France in 1972. The second ICALP was held in 1974, and since 1976 ICALP has been an annual event, nowadays usually taking place in July.
Since 1999, the conference was thematically split into two tracks on "Algorithms, Complexity and Games" (Track A) and "Automata, Logic, Semantics, and Theory of Programming" (Track B), corresponding to the (at least until 2005) two main streams of the journal Theoretical Computer Science. Beginning with the 2005 conference, a third track (Track C) was added in order to allow deeper coverage of a particular topic. From 2005 until 2008, the third track was dedicated to "Security and Cryptography Foundations", and in 2009, it is devoted to the topic "Foundations of Networked Computation: Models, Algorithms and Information Management". Track C was dropped from the 2020 conference, with submissions from these areas
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https://en.wikipedia.org/wiki/Asymptotically%20optimal%20algorithm
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In computer science, an algorithm is said to be asymptotically optimal if, roughly speaking, for large inputs it performs at worst a constant factor (independent of the input size) worse than the best possible algorithm. It is a term commonly encountered in computer science research as a result of widespread use of big-O notation.
More formally, an algorithm is asymptotically optimal with respect to a particular resource if the problem has been proven to require of that resource, and the algorithm has been proven to use only
These proofs require an assumption of a particular model of computation, i.e., certain restrictions on operations allowable with the input data.
As a simple example, it's known that all comparison sorts require at least comparisons in the average and worst cases. Mergesort and heapsort are comparison sorts which perform comparisons, so they are asymptotically optimal in this sense.
If the input data have some a priori properties which can be exploited in construction of algorithms, in addition to comparisons, then asymptotically faster algorithms may be possible. For example, if it is known that the objects are integers from the range then they may be sorted time, e.g., by the bucket sort.
A consequence of an algorithm being asymptotically optimal is that, for large enough inputs, no algorithm can outperform it by more than a constant factor. For this reason, asymptotically optimal algorithms are often seen as the "end of the line" in researc
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https://en.wikipedia.org/wiki/Byrchall%20High%20School
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Byrchall High School is a secondary school and specialist mathematics and computing school with academy status, in the Ashton-in-Makerfield area of the Metropolitan Borough of Wigan, Greater Manchester.
Admissions
It has a mixed intake of both boys and girls aged 11–16. The current pupil population is approximately 1,200. The current headteacher is Alan Birchall. Byrchall High School is one of three secondary schools in Ashton, the other two being St Edmund Arrowsmith Catholic High School, next to Byrchall High School, and Cansfield High School.
The school is situated between the A49 and the M6 on the southern edge of the Wigan borough, neighbouring St Helens.
History
Grammar school
The school was founded in 1588 as Ashton Grammar School by Robert Byrchall on land donated by wealthy local land owner William Gerrard. The original building in Seneley Green is now Garswood Library. Through the school, Ashton-in-Makerfield Grammar School Old Boys F.C. (now known as Ashtonians AFC) entered the Lancashire Amateur Football League in 1951.
After the Second World War a prisoner-of-war camp for Germans, POW Camp 50, operated at its site. One of its inmates was footballer Bert Trautmann who was confined there until 1948.
In 1960, Lancashire Education Committee proposed to amalgamate the school with Upholland Grammar School when the school had around 450 pupils. The school was administered by Wigan Metropolitan Borough Council from April 1974. By 1973 the school had 700 pupils and
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https://en.wikipedia.org/wiki/William%20Douglas%20Wallach
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William Douglas Wallach (1812 – December 1, 1871) was an American surveyor and newspaper entrepreneur. Born in Washington, D.C., he earned a civil engineering degree at Columbian College and moved west doing survey work, reaching the Republic of Texas in 1838 where he supported Sam Houston and the annexation of Texas to the U.S.
In 1839 he was editor of the Matagorda Bulletin and purchased the Matagorda Colorado Gazette and Advertiser the following year, which printed until 1843. He returned to Washington in 1845 and joined the staff of the Washington Union. In 1853 he purchased a stake in the Washington Daily Evening Star, becoming its sole owner in 1855. He guided it to become one of the city's leading newspapers until 1867, when he sold his interests in the Star to the Noyes, Kauffman, and Adams families.
Wallach died on December 1, 1871, at his home in Montrose, Virginia.
His middle name Douglas can also be found spelled with 2 "s": Douglass. The Scottish spelling came from his mother and grandmother's family and he was called "Doug". Most online sources have one "s".
External links
1812 births
1871 deaths
19th-century American newspaper publishers (people)
People from Washington, D.C.
19th-century American journalists
American male journalists
19th-century American male writers
George Washington University alumni
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https://en.wikipedia.org/wiki/Queens%20High%20School%20for%20the%20Sciences
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Queens High School for the Sciences at York College (commonly called QHSSYC or QHSS) is a New York City public specialized high school operated by the New York City Department of Education specializing in mathematics and science. It admits students based only on their scores on the Specialized High Schools Admissions Test (commonly referred to as the SHSAT). The school was founded in 2002 along with the High School for Math, Science and Engineering at City College and the High School of American Studies at Lehman College. QHSSYC is a member of the National Consortium for Specialized Secondary Schools of Mathematics, Science and Technology (NCSSSMST).
In 2012, the U.S. News & World Report ranked QHSSYC as the 52nd best "Gold Medal" high school in the United States, and the 8th best "Gold Medal" high school in New York. In 2015, Queens High School for the Sciences at York College was named 3rd in the state and 25th overall in the country for best high schools statewide and nationally. The school is operated by the New York City Department of Education. In 2010, according to the Department of Education annual school reports, QHSSYC had one of the highest graduation rates, test scores, and attendance statistics in New York City, and was assigned the highest possible grade of 'A'.
Academics
The school collaborates with York College in an agreement that allows the high school students to use college facilities such as the library, cafeteria, and gymnasium. It is housed on the s
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https://en.wikipedia.org/wiki/Rip%20van%20Winkle%20cipher
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In cryptography, the Rip van Winkle cipher is a provably secure cipher with a finite key, assuming the attacker has only finite storage.
The cipher requires a broadcaster (perhaps a numbers station) publicly transmitting a series of random numbers.
The sender encrypts a plaintext message by XORing it with the random numbers, then holding it some length of time T.
At the end of that time, the sender finally transmits the encrypted message.
The receiver holds the random numbers the same length of time T.
As soon as the receiver gets the encrypted message, he XORs it with the random numbers he remembers were transmitted T ago, to recover the original plaintext message.
The delay T represents the "key" and must be securely communicated only once.
Ueli Maurer says the original Rip van Winkle cipher is completely impractical, but it motivated a new approach to provable security.
Sources
J.L. Massey and I. Ingemarsson. The Rip van Winkle cipher - a simple and provably computationally secure cipher with a finite key. In Proc. IEEE Int. Symp. Information Theory (Abstracts), page 146, 1985.
Cryptographic algorithms
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https://en.wikipedia.org/wiki/Penrose%20criterion
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The Penrose criterion in Plasma Physics is a criterion for the kinetic stability of a plasma with a given velocity-space distribution function. This criterion can be used to determine that all so-called "single-humped" distributions (those with a single maximum), are kinetically stable.
References
Plasma physics
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https://en.wikipedia.org/wiki/List%20of%20chemical%20element%20name%20etymologies
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This article lists the etymology of chemical elements of the periodic table.
History
Throughout the history of chemistry, several chemical elements have been discovered. In the nineteenth century, Dmitri Mendeleev formulated the periodic table, a table of elements which describes their structure. Because elements have been discovered at various times and places, from antiquity through the present day, their names have derived from several languages and cultures.
Named after places
Forty-one of the 118 chemical elements have names associated with, or specifically named for, places around the world or among astronomical objects. Thirty-two of these have names tied to the places on the Earth and the other nine have names connected to bodies in the Solar System: helium for the Sun; tellurium for the Earth; selenium for the Moon; mercury (indirectly), uranium, neptunium and plutonium for the major planets (note: Pluto was still considered a planet at the time of plutonium's naming); cerium for the dwarf planet Ceres (also considered a planet at the time of naming) and palladium for the asteroid Pallas.
Named after people
Nineteen elements are connected with the names of twenty people (as curium honours both Marie and Pierre Curie). Fifteen elements were named after scientists; four other have indirect connection to the names of non-scientists. Only gadolinium and samarium occur in nature; the rest are synthetic. Glenn T. Seaborg and Yuri Oganessian were the only two who wer
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https://en.wikipedia.org/wiki/Robot%20learning
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Robot learning is a research field at the intersection of machine learning and robotics. It studies techniques allowing a robot to acquire novel skills or adapt to its environment through learning algorithms. The embodiment of the robot, situated in a physical embedding, provides at the same time specific difficulties (e.g. high-dimensionality, real time constraints for collecting data and learning) and opportunities for guiding the learning process (e.g. sensorimotor synergies, motor primitives).
Example of skills that are targeted by learning algorithms include sensorimotor skills such as locomotion, grasping, active object categorization, as well as interactive skills such as joint manipulation of an object with a human peer, and linguistic skills such as the grounded and situated meaning of human language. Learning can happen either through autonomous self-exploration or through guidance from a human teacher, like for example in robot learning by imitation.
Robot learning can be closely related to adaptive control, reinforcement learning as well as developmental robotics which considers the problem of autonomous lifelong acquisition of repertoires of skills.
While machine learning is frequently used by computer vision algorithms employed in the context of robotics, these applications are usually not referred to as "robot learning".
Projects
Maya Cakmak, assistant professor of computer science and engineering at the University of Washington, is trying to create a robo
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https://en.wikipedia.org/wiki/Nikko%20Patrelakis
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Nikos "Nikko" Patrelakis was born in Athens, Greece. He studied music in the National Conservatory and mathematics in the University of Athens.
He releases albums, singles and compilations around the world under the electronica – idm genre through his label Smallhouse Records.
He has composed and produced music for featured films and theatrical plays. Ηe has created musical ids for national TV-stations and major radio-stations, as well as music for hundreds of TV-commercials.
As a dj he has contributed in the evolution of the Greek club scene, participating in the initiation of clubs like X-club, Factory, +Soda in Athens and Cavo Paradiso Club Mykonos in Mykonos as a resident Dj.
In 1999 he co-wrote "Voice" with Paul McCartney that was presented by Heather Mills for the support of the people with kinetic disabilities. That year he released 'Habitat' his first solo album, introducing his unique sound, followed up two years later by "Elements", a continuous play release in a form of a soundtrack, with guests like famous Greek journalist Malvina Karali narrating, and Stamatis Kraounakis, one of the most important Greek contemporary songwriters, improvising on a piano. In 2003 he released the album “TIME”, which stayed for 9 weeks in the official IFPI national top-50. He also composed and produced three themes for the opening and closing ceremonies of the Olympic Games in Athens 2004, performed by him and London Philharmonic Orchestra, for the parade of the Greek flag and the
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https://en.wikipedia.org/wiki/Induced%20radioactivity
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Induced radioactivity, also called artificial radioactivity or man-made radioactivity, is the process of using radiation to make a previously stable material radioactive. The husband-and-wife team of Irène Joliot-Curie and Frédéric Joliot-Curie discovered induced radioactivity in 1934, and they shared the 1935 Nobel Prize in Chemistry for this discovery.
Irène Curie began her research with her parents, Marie Curie and Pierre Curie, studying the natural radioactivity found in radioactive isotopes. Irene branched off from the Curies to study turning stable isotopes into radioactive isotopes by bombarding the stable material with alpha particles (denoted α). The Joliot-Curies showed that when lighter elements, such as boron and aluminium, were bombarded with α-particles, the lighter elements continued to emit radiation even after the α−source was removed. They showed that this radiation consisted of particles carrying one unit positive charge with mass equal to that of an electron, now known as a positron.
Neutron activation is the main form of induced radioactivity. It occurs when an atomic nucleus captures one or more free neutrons. This new, heavier isotope may be either stable or unstable (radioactive), depending on the chemical element involved.
Because neutrons disintegrate within minutes outside of an atomic nucleus, free neutrons can be obtained only from nuclear decay, nuclear reaction, and high-energy interaction, such as cosmic radiation or particle accelerator em
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https://en.wikipedia.org/wiki/Mrinal%20Kumar%20Das%20Gupta
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Mrinal Kumar Das Gupta FNI (1 September 1923 – 28 November 2005, Kolkata) was an Indian astronomer. He was born in erstwhile Barishal district in present-day Bangladesh. He received his B.Sc and M.Sc degrees in Physics from Dhaka University in 1944 and 1945 respectively. Later he joined the department of Radio Physics and Electronics of the University of Calcutta as a researcher.
In 1954, he obtained his Ph.D. from the University of Manchester. Later he became the head of the department of the Institute of Radio Physics and Electronics at Calcutta University. Das Gupta worked with Robert Hanbury Brown and Roger Jennison, in building the first intensity interferometers at radio wavelength in the early 1950s and measured the apparent angular structures of two radio sources, Cygnus A and Cassiopeia A. Das Gupta was elected as a Fellow of the National Academy of Science in 1974 by the Indian National Science Academy, New Delhi and as a Fellow of the Academy of Science by the Indian Academy of Sciences, Bangalore. He was also the member of the now-infamous committee that investigated Dr. Subhash Mukhopadhyay who created the world's second and India's first child using in-vitro fertilisation. He died on 28 November 2005 in Kolkata.
Notes
1923 births
2005 deaths
20th-century Indian astronomers
Academic staff of the University of Calcutta
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https://en.wikipedia.org/wiki/Laser%20acronyms
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This is a list of acronyms and other initialisms used in laser physics and laser applications.
A
AOM – acousto-optic modulator
AOPDF – acousto-optic programmable dispersive filter
APD – avalanche photodiode
APM – additive-pulse mode locking
ASE – amplified spontaneous emission
ATD – above-threshold dissociation
ATI – above-threshold ionization
AWG – arrayed waveguide grating
B
BPP – beam parameter product
C
CD-ROM – compact disc read-only memory
CEO – carrier-envelope offset
CEP – carrier-envelope phase
CPA – chirped-pulse amplification
CRAB – complete reconstruction of attosecond bursts
CW – continuous wave
CWDM – coarse wavelength-division multiplexing
D
DBR – distributed Bragg reflector
DCM – dispersion-compensation module or double-chirped mirror
DFB laser – distributed feedback laser
DFG – difference-frequency generation
DIAL – differential absorption LIDAR
DOG – double optical gating
DOS – density of states
DPSS – diode-pumped solid-state (laser)
DWDM – dense wavelength-division multiplexing
E
ECDL – external-cavity diode laser
EDC – electronic dispersion compensation
EDFA – erbium-doped fiber amplifier
Er:YAG – erbium-doped yttrium aluminium garnet, Er:Y3Al5O12
EOM – electro-optic modulator
ESA – excited state absorption
F
FEL – free electron laser
FREAG – frequency-resolved electro-absorption gating
FROG – frequency-resolved optical gating
FROG-CRAB – frequency-resolved optical gating for complete reconstruction of attosecond bursts
FWM – four-wave mixing
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https://en.wikipedia.org/wiki/Nijenhuis%E2%80%93Richardson%20bracket
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In mathematics, the algebraic bracket or Nijenhuis–Richardson bracket is a graded Lie algebra structure on the space of alternating multilinear forms of a vector space to itself, introduced by A. Nijenhuis and R. W. Richardson, Jr (1966, 1967). It is related to but not the same as the Frölicher–Nijenhuis bracket and the Schouten–Nijenhuis bracket.
Definition
The primary motivation for introducing the bracket was to develop a uniform framework for discussing all possible Lie algebra structures on a vector space, and subsequently the deformations of these structures. If V is a vector space and is an integer, let
be the space of all skew-symmetric -multilinear mappings of V to itself. The direct sum Alt(V) is a graded vector space. A Lie algebra structure on V is determined by a skew-symmetric bilinear map . That is to say, μ is an element of Alt1(V). Furthermore, μ must obey the Jacobi identity. The Nijenhuis–Richardson bracket supplies a systematic manner for expressing this identity in the form .
In detail, the bracket is a bilinear bracket operation defined on Alt(V) as follows. On homogeneous elements and , the Nijenhuis–Richardson bracket is given by
Here the interior product iP is defined by
where denotes (q+1, p)-shuffles of the indices, i.e. permutations of such that and .
On non-homogeneous elements, the bracket is extended by bilinearity.
Derivations of the ring of forms
The Nijenhuis–Richardson bracket can be defined on the vector valued fo
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https://en.wikipedia.org/wiki/Fr%C3%B6licher%E2%80%93Nijenhuis%20bracket
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In mathematics, the Frölicher–Nijenhuis bracket is an extension of the Lie bracket of vector fields to vector-valued differential forms on a differentiable manifold.
It is useful in the study of connections, notably the Ehresmann connection, as well as in the more general study of projections in the tangent bundle.
It was introduced by Alfred Frölicher and Albert Nijenhuis (1956) and is related to the work of Schouten (1940).
It is related to but not the same as the Nijenhuis–Richardson bracket and the Schouten–Nijenhuis bracket.
Definition
Let Ω*(M) be the sheaf of exterior algebras of differential forms on a smooth manifold M. This is a graded algebra in which forms are graded by degree:
A graded derivation of degree ℓ is a mapping
which is linear with respect to constants and satisfies
Thus, in particular, the interior product with a vector defines a graded derivation of degree ℓ = −1, whereas the exterior derivative is a graded derivation of degree ℓ = 1.
The vector space of all derivations of degree ℓ is denoted by DerℓΩ*(M). The direct sum of these spaces is a graded vector space whose homogeneous components consist of all graded derivations of a given degree; it is denoted
This forms a graded Lie superalgebra under the anticommutator of derivations defined on homogeneous derivations D1 and D2 of degrees d1 and d2, respectively, by
Any vector-valued differential form K in Ωk(M, TM) with values in the tangent bundle of M defines a graded derivation of degree
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https://en.wikipedia.org/wiki/Verificationism
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Verificationism, also known as the verification principle or the verifiability criterion of meaning, is the philosophical doctrine which asserts that a statement is meaningful only if it is either empirically verifiable (i.e. confirmed through the senses) or a truth of logic (e.g., tautologies).
Verificationism rejects statements of metaphysics, theology, ethics, and aesthetics, as cognitively meaningless. Such statements may be meaningful in influencing emotions or behavior, but not in terms of conveying truth value, information, or factual content. Verificationism was a central theme of logical positivism, a movement in analytic philosophy that emerged in the 1920s by philosophers who sought to unify philosophy and science under a common naturalistic theory of knowledge.
Origins
Although earlier philosophical principles which aim to ground scientific theory in some verifiable experience are found within the work of American pragmatist C.S. Peirce and that of French conventionalist Pierre Duhem, who fostered instrumentalism, the project of verificationism was launched by the logical positivists who, emerging from the Berlin Circle and the Vienna Circle in the 1920s, sought an epistemology whereby philosophical discourse would be, in their perception, as authoritative and meaningful as an empirical science.
Logical positivists garnered the verifiability criterion of cognitive meaningfulness from Ludwig Wittgenstein's philosophy of language posed in his 1921 book Tractatus,
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https://en.wikipedia.org/wiki/Paulo%20S.%20L.%20M.%20Barreto
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Paulo S. L. M. Barreto (born 1965) is a Brazilian cryptographer and one of the designers of the Whirlpool hash function and the block ciphers Anubis and KHAZAD, together with Vincent Rijmen. He has also co-authored a number of research works on elliptic curve cryptography and pairing-based cryptography, including the eta pairing technique,
identity-based cryptographic protocols,
and the family of Barreto–Naehrig (BN) pairing-friendly elliptic curves.
More recently he has been focusing his research on post-quantum cryptography, being one of the discoverers of quasi-dyadic codes
and quasi-cyclic moderate-density parity-check (QC-MDPC) codes
to instantiate the McEliece and Niederreiter cryptosystems and related schemes.
His paper "Efficient Algorithms for Pairing-Based Cryptosystems", jointly written with Hae Y. Kim, Ben Lynn and Mike Scott and presented at the Crypto 2002 conference, has been identified in March 2005 as a "Hot Paper", and in December 2005 as "Fast Breaking Paper", by Thomson ISI's Essential Science Indicators (now Science Watch), by virtue of being among the top one-tenth of one percent (0.1%) most cited papers and by having the largest percentage increase in citations in the Computer Science category.
Barreto was born in Salvador, capital of the northeastern state of Bahia, Brazil. In 1987, he graduated in physics at the University of São Paulo. He subsequently worked at Unisys Brazil Ltd and Scopus Tecnologia S/A as a software developer and then as chief cr
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https://en.wikipedia.org/wiki/Mathematical%20Applications%20Group
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Mathematical Applications Group, Inc. (a.k.a. MAGi or MAGi/SynthaVision) was an early computer technology company founded in 1966 by Dr. Philip Mittelman and located in Elmsford, New York, where it was evaluating nuclear radiation exposure. By modeling structures using combinatorial geometry mathematics and applying monte carlo radiation ray tracing techniques, the mathematicians could estimate exposures at various distances and relative locations in and around fictional structures. In 1972, the graphics group called MAGi/SynthaVision was formed at MAGi by Robert Goldstein.
It was one of four companies hired to create the 3D computer animation for the 1982 film Tron. MAGi was responsible for most of the CG animation in the first half of Tron, while Triple-I worked mainly on the second half of the film. MAGi modeled and animated the light cycles, recognizers and tanks.
Product and legacy
MAGi developed a software program called SynthaVision to create CG images and films. SynthaVision was one of the first systems to implement a ray tracing algorithmic approach to hidden surface removal in rendering images. The software was a constructive solid geometry (CSG) system, in that the geometry was solid primitives with combinatorial operators (such as Boolean operators). SynthaVision's modeling method does not use polygons or wireframe meshes that most CG companies use today. The combination of the solid modeling and ray tracing (later to become plane firing) made it a very robust
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https://en.wikipedia.org/wiki/Ken%20Castleman
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Kenneth R. Castleman is a retired NASA engineer who now lives in League City, Texas. He holds B.S, M.S. and Ph.D. degrees in electrical engineering from The University of Texas at Austin. He was a Senior Scientist at NASA's Jet Propulsion Laboratory from 1970 through 1985. During that time he headed the Automated Light Microscope project, which paved the way for landing an intelligent microscope on Mars, and he was inducted into the National Space Foundation's Space Technology Hall of Fame. He also served on the faculty at Caltech and on the research staff at USC and at UCLA.
In 1984, Castleman teamed up with Donald Winkler of the NASA Johnson Space Center and founded Perceptive Systems, Inc (PSI) in Houston, Texas. That company manufactured automated microscope systems for use in genetic diagnosis and sold them internationally. PSI was later reformed as Perceptive Scientific Instruments, Inc. (PSII) and eventually sold to IRIS International in 1996. IRIS established it as a Research and Development Center under the name Advanced Digital Imaging Research (ADIR), with Dr. Castleman as president. He retired in 2008.
Castleman is the author of the textbooks Digital Image Processing (1979) , Digital Image Processing (1996) and a co-editor of Microscope Image Processing (2008) . The 1996 book has been translated int Japanese and Chinese and is used in universities internationally. He is also the author or co-author of four patents and more than sixty scientific articles.
Castl
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https://en.wikipedia.org/wiki/Clay%20Hine
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Clay Hine (born 1963) is a barbershop musician and arranger.
He is a native Chicagoan, but has lived in the Atlanta Metro area since the late-80's since he graduated from the University of Illinois (Urbana-Champaign) in 1986 with a degree in electrical engineering. Before college he sang with The West Towns Chorus (Lombard, Illinois) winning 2 silver medals (1985, 1986). He started arranging when he was a teenager for fun, mostly tags and parts of songs. After college he began arranging for a newly chartered chorus in Marietta, Georgia (The Big Chicken Chorus) and his first post-college quartet Atlanta Forum (1987 Dixie District Champs). His early arrangements were for the purpose of helping out Atlanta-area and Dixie District quartets and choruses, but he soon had requests nationwide from internationally competing choruses and quartets. Clay has arranged music for: Keepsake, PLATINUM, FRED, Four Voices, Riptide, Backbeat, Marquis, Nightlife, BSQ, Max Q, Bank Street, State Line Grocery, Overture, Sound Standard, Svelte Brothers, and other groups.
Although Clay had many years of piano as a child, he is a self-taught arranger having little formal music education at the university level. Clay directed the Big Chicken Chorus from 1989 through 2004 and began directing the newly chartered Atlanta Metro (Atlanta Vocal Project) chapter in 2005. In his 20 years of directing Clay has won 16 international chorus preliminary contests with the Big Chicken Chorus (1989–2004) and 6 with T
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https://en.wikipedia.org/wiki/Vicious%20Engine
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The Vicious Engine is a game engine that offers functionality for rendering, sound, networking, physics, game play scripting, and lighting. It was developed by Vicious Cycle Software, and was first released in January 2005. No additional third-party libraries are required, and all source code is included. It supports GameCube, Wii, WiiWare, Xbox, Xbox 360, Xbox Live Arcade, PlayStation 2, PlayStation Portable, PlayStation Network, and Microsoft Windows. The engine would become dormant as a part of the closure of Vicious Cycle Software in 2016.
Vicious Engine 2
Vicious Engine 2 (sometimes stylized as Ve2) has been optimized for eighth-generation consoles and high-end PCs. It was released on March 25, 2009, at the Game Developers Conference. It features improvements for next-generation consoles, especially the Xbox 360 and PlayStation 3. D3P and Vicious Cycle Software's Eat Lead: The Return of Matt Hazard is the first retail title to use the new technology. In addition to the previous platforms, it supports PlayStation 3.
Games using the Vicious Engine
300: March to Glory (2007)
Alien Syndrome (2007)
Curious George (2006)
Dead Head Fred (2007)
Spy vs. Spy (2005)
Dora the Explorer: Journey to the Purple Planet (2005)
Eat Lead: The Return of Matt Hazard (2009, PS3/X360)
Real Heroes: Firefighter (2009, Wii/Xbox One/PS4/Nintendo Switch)
Matt Hazard: Blood Bath and Beyond (2010, PS3/X360)
Flushed Away (2006, PS2/3DS)
Marvel Trading Card Game (2007)
Puzzle Quest: Challenge of the
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https://en.wikipedia.org/wiki/Molecular%20anthropology
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Molecular anthropology, also known as genetic anthropology, is the study of how molecular biology has contributed to the understanding of human evolution. This field of anthropology examines evolutionary links between ancient and modern human populations, as well as between contemporary species. Generally, comparisons are made between sequences, either DNA or protein sequences; however, early studies used comparative serology.
By examining DNA sequences in different populations, scientists can determine the closeness of relationships between populations (or within populations). Certain similarities in genetic makeup let molecular anthropologists determine whether or not different groups of people belong to the same haplogroup, and thus if they share a common geographical origin. This is significant because it allows anthropologists to trace patterns of migration and settlement, which gives helpful insight as to how contemporary populations have formed and progressed over time.
Molecular anthropology has been extremely useful in establishing the evolutionary tree of humans and other primates, including closely related species like chimps and gorillas. While there are clearly many morphological similarities between humans and chimpanzees, for example, certain studies also have concluded that there is roughly a 98 percent commonality between the DNA of both species. However, more recent studies have modified the commonality of 98 percent to a commonality of 94 percent, showi
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https://en.wikipedia.org/wiki/SiGNa%20chemistry
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SiGNa chemistry is a type of chemistry in which alkali metals are encapsulated into porous oxides of silica gel in order to reduce their pyrophoric and highly combustible properties while preserving the desirable reduction reactivity of the metals (Dye, et al.). One can deconstruct the term "SiGNa" to derive Si (symbol for silicon), G (gel), and Na (symbol for sodium, a popular alkali metal).
SiGNa chemistry was pioneered by Michael Lefenfeld, a PhD student at Columbia University with the help of Dr. James Dye of Michigan State University.
References
Dye, James L., Kevin D. Cram, Stephanie A. Urbin, Mikhail Y. Redko, James E. Jackson, and Michael Lefenfeld. "Alkali Metals Plus Silica Gel: Powerful Reducing Agents and Convenient Hydrogen Sources." Journal of the American Chemical Society. July 2005; 127(26); 9338–9339.
External links
SiGNa Chemistry Company
Reducing agents
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https://en.wikipedia.org/wiki/Benjamin%20Cravatt%20III
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Benjamin Franklin Cravatt III is a professor in the Department of Chemistry at The Scripps Research Institute in La Jolla, California. Considered a co-inventor of activity-based proteomics and a substantial contributor to research on the endocannabinoid system, he is a prominent figure in the nascent field of chemical biology. Cravatt was elected to the National Academy of Sciences in 2014, and the American Academy of Arts and Sciences in 2016. He is Gilula Chair of Chemical Biology, a Cope Scholar, and a Searle Scholar.
Early life and education
His father was a dentist and his mother a dental hygienist, both of whom instilled in Cravatt an interest in biology as a child.
Cravatt entered Stanford University in 1988, graduating in 1992 with a BS in the Biological Sciences and a BA in History. He then received a PhD in Macromolecular and Cellular Structure and Chemistry from The Scripps Research Institute in 1996, where he worked under the joint supervision of Dale L. Boger and Richard Lerner.
Research
His early contributions to the cannabinoid field include identification and characterization of the endocannabinoid-terminating enzyme fatty acid amide hydrolase (FAAH), as well as the isolation of the novel soporific compound oleamide from cerebrospinal fluid.
Cravatt and colleagues pioneered the activity-based protein profiling (ABPP) chemical proteomic technology, which they used in 2010 to elucidate certain global proteomic features of cysteine proteases. Cravatt's
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https://en.wikipedia.org/wiki/University%20of%20Electro-Communications
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The is a national university in the city of Chōfu, Tokyo, Japan.
It specialises in the disciplines of computer science, the physical sciences, engineering and technology. It was founded in 1918 as the Technical Institute for Wireless-Communications.
History
The University of Electro-communications was founded in the Azabu district, Tokyo city as the Technical Institute for Wireless-Communications by Wireless Association in 1918. The Technical Institute for Wireless-Communications was transferred to the Ministry of Communications in 1942 and renamed to the Central Technical Institute for Wireless-Communications in 1945. Following to the transfer from the Ministry of Communications to the Ministry of Education in 1948, the University of Electro-communications was established as a national university in 1949. The campus was moved to the city of Chōfu, Tokyo in 1957. The university has been run by the National University Corporation since 2004.
School symbol
The school symbol was set in 1949. The design shows a Lissajous figure of the frequency ratio of 5 to 6 with Kanji character "学" which means "University". The frequency ratio of 5 to 6 means the commercial power frequency of 50 Hz (eastern Japan) and 60 Hz (western Japan), and indicates Japan-wide harmonization. The meaning of school symbol is common with that of school name which is "to establish an university which is open to all over Japan, by call it by a name without any geographical name".
Rankings
Global
The Time
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https://en.wikipedia.org/wiki/Moore%20Observatory
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Moore Observatory is an astronomical observatory owned and operated by University of Louisville (U of L). It is located on the Horner Wildlife Refuge in Oldham County, Kentucky (USA) approximately northeast of Louisville. It opened in 1978, and was dedicated to Walter Lee Moore, a Professor of Mathematics at U of L from 1929 to 1967.
Moore Observatory is a research and advanced teaching facility of the University of Louisville. The observatory operates two research telescopes at the site, and a companion telescope at Mount Kent near Toowoomba, Australia. The observatory is located on the Horner Wildlife Refuge. The Horner Family donated this land to the U of L in the early 1960s and another of the original farm surrounds the preserve.
Telescopes
A Ritchey–Chrétien telescope manufactured by RC Optical Systems was installed in August 2006. It is currently used to measure transiting exoplanets. Other research performed with the telescope includes observing the physical process of nebula.
A Ritchey–Chrétien telescope manufactured by RC Optical Systems on an altitude-azimuth mount was added in 2019. It is primarily used for low Earth orbit (LEO) satellite observations, for near Earth object (NEO) characterization.
A modified Dall–Kirkham telescope built by Planewave Instruments is at Mount Kent Observatory in Queensland, Australia.
Two identical modified Dall–Kirkham telescopes at Moore Observatory and at Mount Kent are collaboratively operated by U of L and t
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https://en.wikipedia.org/wiki/P-compact%20group
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In mathematics, in particular algebraic topology, a p-compact group is a homotopical version of a compact Lie group, but with all the local structure concentrated at a single prime p. This concept was introduced in , making precise earlier notions of a mod p finite loop space. A p-compact group has many Lie-like properties like maximal tori and Weyl groups, which are defined purely homotopically in terms of the classifying space, but with the important difference that the Weyl group, rather than being a finite reflection group over the integers, is now a finite p-adic reflection group. They admit a classification in terms of root data, which mirrors the classification of compact Lie groups, but with the integers replaced by the p-adic integers.
Definition
A p-compact group is a pointed space BG, with is local with respect to mod p homology, and such the pointed loop space G = ΩBG has finite mod p homology. One sometimes also refer to the p-compact group by G, but then one needs to keep in mind that the loop space structure is part of the data (which then allows one to recover BG).
A p-compact group is said to be connected if G is a connected space (in general the group of components of G will be a finite p-group). The rank of a p-compact group is the rank of its maximal torus.
Examples
The p-completion, in the sense of homotopy theory, of (the classifying space of) a compact connected Lie group defines a connected p-compact group. (The Weyl group is just its ordinary
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https://en.wikipedia.org/wiki/Transversality%20%28mathematics%29
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In mathematics, transversality is a notion that describes how spaces can intersect; transversality can be seen as the "opposite" of tangency, and plays a role in general position. It formalizes the idea of a generic intersection in differential topology. It is defined by considering the linearizations of the intersecting spaces at the points of intersection.
Definition
Two submanifolds of a given finite-dimensional smooth manifold are said to intersect transversally if at every point of intersection, their separate tangent spaces at that point together generate the tangent space of the ambient manifold at that point. Manifolds that do not intersect are vacuously transverse. If the manifolds are of complementary dimension (i.e., their dimensions add up to the dimension of the ambient space), the condition means that the tangent space to the ambient manifold is the direct sum of the two smaller tangent spaces. If an intersection is transverse, then the intersection will be a submanifold whose codimension is equal to the sums of the codimensions of the two manifolds. In the absence of the transversality condition the intersection may fail to be a submanifold, having some sort of singular point.
In particular, this means that transverse submanifolds of complementary dimension intersect in isolated points (i.e., a 0-manifold). If both submanifolds and the ambient manifold are oriented, their intersection is oriented. When the intersection is zero-dimensional, the orientation
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https://en.wikipedia.org/wiki/Leopold%20Biwald
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Leopold Gottlieb Biwald (February 26, 1731 in Vienna – September 8, 1805 in Graz) was a professor at the University of Graz.
At the age of sixteen Biwald joined the Jesuits. He became teacher of rhetoric at a secondary school in Laibach and graduated as Dr. theol. in 1761. He became professor of logic and soon afterwards of physics at the University of Graz. In 1786-1787 and again 1798-1799 he was rector of the University of Graz.
His Latin physics textbooks included Physica Generalis (1760s, 460pp), dealing with mechanics including celestial mechanics, and Physica Particularis (1760s, 403pp), dealing with diverse topics including optics. Physica Particularis was also widely distributed throughout Austria-Hungary (in modified form) as Institutiones Physicae (1779, 349pp). He was a contemporary of Johann Baptiste Horvath, Andreas Jaszlinszky and Joseph Redlhamer.
His bust, made in 1807 by Johann Martin Fischer, is now displayed in the main reading room of the University Library of Graz.
Works
Theoria philosophiae naturalis, redacta ad unam legem virium in natura existentium auctore J. R. Boscovich S. J. ab ipso perpolita et aucta. Ex prima Editione Veneta com Catalogo operum ejus ad annum 1763. Graz 1765
De objectivi Micrometri usu in Planetarum diametris metiendis. Exercitatio optico-astronomica habita in Coll. P. P. S. J. Rome 1765; Graz 1768.
Physica generalis et particularis quam auditorium philosophiae usibus accomodavit Leopoldus Biwald etc. etc. Graz 1766; 2nd ed.
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https://en.wikipedia.org/wiki/Alain%20Fournier
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Alain Fournier (1943–2000) was a computer graphics researcher.
Biography
Alain Fournier was born on November 5, 1943, in Lyon, France. He was married twice, first to Beverly Bickle (married 1968, divorced 1984) and later to Adrienne Drobnies, with whom he had one daughter, Ariel.
Fournier's early training was in chemistry, culminating in a B.Sc. from INSA, France, in 1965. After emigrating from France to Montreal, Quebec, Canada in the 1970s, he co-wrote a textbook on chemistry, and taught the subject in Quebec. His career in computer graphics spanned only about 20 years. In 1980 he received a Ph.D. in computer science from the University of Texas at Dallas under the supervision of Zvi Meir Kedem, and with Donald Fussell and Loren Carpenter reported the results of his Ph.D. work on stochastic modelling in a seminal paper in 1980. He then went on to an outstanding academic career, first at the University of Toronto as part of the Dynamic Graphics Project and subsequently at the University of British Columbia. He has contributed to ACM Transactions on Graphics as an author, as co-guest editor of a special issue in 1987, and, from 1990 to 1992, as an associate editor.
Fournier made contributions to computer graphics dealing with modelling of natural phenomena. He advocated a methodology that required validation against real visual phenomena. He once called his approach impressionistic graphics and it both revolutionized the field and drove it forward. An example is his bea
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https://en.wikipedia.org/wiki/Collection%20of%20Computer%20Science%20Bibliographies
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The Collection of Computer Science Bibliographies (1993–2023) was one of the oldest (if not the oldest) bibliography collections freely accessible on the Internet. As of July 2023 it ceased operations. It is a collection of bibliographies of scientific literature in computer science and (computational) mathematics from various sources, covering most aspects of computer science. The bibliographies are updated weekly from their original locations.
As of 2009 the collection contains more than 2.8 million unique references (mostly to journal articles, conference papers and technical reports), clustered in about 1700 bibliographies, and consists of more than 4.4 Gb (950 Mb gzipped) of BibTeX entries. More than 600,000 references contain cross-references to citing or cited publications.
More than 1 million references contain URLs to online versions of the papers. Abstracts are available for more than 1 million entries. There are more than 2,000 links to other sites carrying bibliographic information.
Duplicates and links
As the Collection of Computer Science Bibliographies consists of many subcollections there is a substantial overlap (roughly 1/3). At the end of 2008 there were more than 4.2 million records which represent about 2.8 million unique (in terms of normalized title and authors' last names) bibliographic entries.
The number of duplicates may be seen as an advantage, because there is a greater chance for finding a freely available full text PDF of a searched public
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https://en.wikipedia.org/wiki/Selwyn%20Maister
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Selwyn Gerald Maister (born 24 May 1946) is a former New Zealand field hockey player, who was a member of the national team that won the golden medal at the 1976 Summer Olympics in Montreal.
Maister was awarded the Queen's Service Medal in the 2012 New Year Honours, for services to hockey. Maister earned a DPhil in inorganic chemistry from Magdalen College, Oxford, as a Rhodes Scholar, arriving in 1969.
He is a brother of hockey player Barry Maister.
References
External links
1946 births
Living people
Field hockey players at the 1968 Summer Olympics
Field hockey players at the 1972 Summer Olympics
Field hockey players at the 1976 Summer Olympics
New Zealand field hockey coaches
New Zealand male field hockey players
Olympic field hockey players for New Zealand
Olympic gold medalists for New Zealand
Field hockey players from Christchurch
Olympic medalists in field hockey
Medalists at the 1976 Summer Olympics
Recipients of the Queen's Service Medal
New Zealand Rhodes Scholars
Alumni of Magdalen College, Oxford
20th-century New Zealand people
21st-century New Zealand people
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https://en.wikipedia.org/wiki/Andreotti%E2%80%93Frankel%20theorem
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In mathematics, the Andreotti–Frankel theorem, introduced by , states that if is a smooth, complex affine variety of complex dimension or, more generally, if is any Stein manifold of dimension , then
admits a Morse function with critical points of index at most n, and so is homotopy equivalent to a CW complex of real dimension at most n.
Consequently, if is a closed connected complex submanifold of complex dimension , then has the homotopy type of a CW complex of real dimension .
Therefore
and
This theorem applies in particular to any smooth, complex affine variety of dimension .
References
Chapter 7.
Complex manifolds
Theorems in homotopy theory
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https://en.wikipedia.org/wiki/Weighing%20matrix
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In mathematics, a weighing matrix of order and weight is a matrix with entries from the set such that:
Where is the transpose of and is the identity matrix of order . The weight is also called the degree of the matrix. For convenience, a weighing matrix of order and weight is often denoted by .
Weighing matrices are so called because of their use in optimally measuring the individual weights of multiple objects. When the weighing device is a balance scale, the statistical variance of the measurement can be minimized by weighing multiple objects at once, including some objects in the opposite pan of the scale where they subtract from the measurement.
Properties
Some properties are immediate from the definition. If is a , then:
The rows of are pairwise orthogonal (that is, every pair of rows you pick from will be orthogonal). Similarly, the columns are pairwise orthogonal.
Each row and each column of has exactly non-zero elements.
, since the definition means that where is the inverse of
where is the determinant of
A weighing matrix is a generalization of Hadamard matrix, which does not allow zero entries. As two special cases, a is a Hadamard matrix and a is equivalent to a conference matrix.
Applications
Experiment design
Weighing matrices take their name from the problem of measuring the weight of multiple objects. If a measuring device has a statistical variance of , then measuring the weights of objects and subtracting the (equally impre
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https://en.wikipedia.org/wiki/Kyiv%20National%20University%20of%20Construction%20and%20Architecture
|
The Kyiv National University of Construction and Architecture (informally referred to as KNUCA) – better known under its former name Kyiv Civil Engineering Institute – is the largest and most important building and architectural university of Ukraine located in the nation's capital, Kyiv.
History
The institution was founded in 1930 as the Kyiv Civil Engineering Institute on the basis of factory and communal construction branch of the Kyiv Polytechnic Institute (KPI) and the architecture faculty of the Kyiv Art Institute. During the post-World War II Soviet period, KISI rose to become the second highest engineering and architecture faculty in the USSR, behind the Moscow Civil Engineering Institute (МИСИ).
By the Decree of the Cabinet of Ministers of Ukraine of August 13, 1993, the Kyiv State Technical University of Construction and Architecture was created on the basis of the Kyiv Civil Engineering Institute. On February 28, 1999, by the Decree of the President of Ukraine (217/99) the university was accorded the status of a National University as "Kyiv National University of Construction and Architecture."
Student life
Educational and scientific work is organized and carried out by more than 96 chairs numbering about 800 professors and instructors.
About 10,500 students study at the university. After the graduation, they acquire the education qualification levels of Bachelor, Specialist, and Master of Science. The postgraduate courses in about 30 specialities are availa
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https://en.wikipedia.org/wiki/Jean-Pierre%20Sauvage
|
Jean-Pierre Sauvage (; born 21 October 1944) is a French coordination chemist working at Strasbourg University. He graduated from the National School of Chemistry of Strasbourg (now known as ECPM Strasbourg), in 1967. He has specialized in supramolecular chemistry for which he has been awarded the 2016 Nobel Prize in Chemistry along with Sir J. Fraser Stoddart and Bernard L. Feringa.
Biography
Sauvage was born in Paris in 1944, and earned his PhD degree from the Université Louis-Pasteur under the supervision of Jean-Marie Lehn, himself a 1987 laureate of the Nobel Prize in Chemistry. During his doctoral work, he contributed to the first syntheses of the cryptand ligands. After postdoctoral research with Malcolm L. H. Green, he returned to Strasbourg, where he is now emeritus professor.
Sauvage's scientific work has focused on creating molecules that mimic the functions of machines by changing their conformation in response to an external signal.
His Nobel Prize work was done in 1983, when he was the first to synthesize a catenane, a complex of two interlocking ring-shaped molecules, which were bonded mechanically rather than chemically. Because these two rings can move relative to each other, the Nobel Prize cited this as a vital initial effort towards making molecular machine. The other two recipients of the prize followed up by later creating a rotaxane and a molecular rotor.
Other research includes electrochemical reduction of CO2 and models of the photosynthetic re
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https://en.wikipedia.org/wiki/Microsoft%20CryptoAPI
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The Microsoft Windows platform specific Cryptographic Application Programming Interface (also known variously as CryptoAPI, Microsoft Cryptography API, MS-CAPI or simply CAPI) is an application programming interface included with Microsoft Windows operating systems that provides services to enable developers to secure Windows-based applications using cryptography. It is a set of dynamically linked libraries that provides an abstraction layer which isolates programmers from the code used to encrypt the data. The Crypto API was first introduced in Windows NT 4.0 and enhanced in subsequent versions.
CryptoAPI supports both public-key and symmetric key cryptography, though persistent symmetric keys are not supported. It includes functionality for encrypting and decrypting data and for authentication using digital certificates. It also includes a cryptographically secure pseudorandom number generator function CryptGenRandom.
CryptoAPI works with a number of CSPs (Cryptographic Service Providers) installed on the machine. CSPs are the modules that do the actual work of encoding and decoding data by performing the cryptographic functions. Vendors of HSMs may supply a CSP which works with their hardware.
Cryptography API: Next Generation
Windows Vista features an update to the Crypto API known as Cryptography API: Next Generation (CNG). It has better API factoring to allow the same functions to work using a wide range of cryptographic algorithms, and includes a number of newer al
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https://en.wikipedia.org/wiki/Uniform-machines%20scheduling
|
Uniform machine scheduling (also called uniformly-related machine scheduling or related machine scheduling) is an optimization problem in computer science and operations research. It is a variant of optimal job scheduling. We are given n jobs J1, J2, ..., Jn of varying processing times, which need to be scheduled on m different machines. The goal is to minimize the makespan - the total time required to execute the schedule. The time that machine i needs in order to process job j is denoted by pi,j. In the general case, the times pi,j are unrelated, and any matrix of positive processing times is possible. In the specific variant called uniform machine scheduling, some machines are uniformly faster than others. This means that, for each machine i, there is a speed factor si, and the run-time of job j on machine i is pi,j = pj / si.
In the standard three-field notation for optimal job scheduling problems, the uniform-machine variant is denoted by Q in the first field. For example, the problem denoted by " Q||" is a uniform machine scheduling problem with no constraints, where the goal is to minimize the maximum completion time. A special case of uniform machine scheduling is identical machine scheduling, in which all machines have the same speed. This variant is denoted by P in the first field.
In some variants of the problem, instead of minimizing the maximum completion time, it is desired to minimize the average completion time (averaged over all n jobs); it is denoted by Q|
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https://en.wikipedia.org/wiki/String%20%28physics%29
|
In physics, a string is a physical entity postulated in string theory and related subjects. Unlike elementary particles, which are zero-dimensional or point-like by definition, strings are one-dimensional extended entities. Researchers often have an interest in string theories because theories in which the fundamental entities are strings rather than point particles automatically have many properties that some physicists expect to hold in a fundamental theory of physics. Most notably, a theory of strings that evolve and interact according to the rules of quantum mechanics will automatically describe quantum gravity.
Overview
In string theory, the strings may be open (forming a segment with two endpoints) or closed (forming a loop like a circle) and may have other special properties. Prior to 1995, there were five known versions of string theory incorporating the idea of supersymmetry (these five are known as superstring theories) and two versions without supersymmetry known as bosonic string theories, which differed in the type of strings and in other aspects. Today these different s superstring theories are thought to arise as different limiting cases of a single theory called M-theory.
In string theories of particle physics, the strings are very tiny; much smaller than can be observed in today's particle accelerators. The characteristic length scale of strings is typically on the order of the Planck length, about 10−35 meter, the scale at which the effects of quantum gra
|
https://en.wikipedia.org/wiki/Quentin%20Smith
|
Quentin Persifor Smith (August 27, 1952, Rhinebeck, New York – November 12, 2020, Kalamazoo, Michigan) was an American philosopher.
He was professor emeritus of philosophy at Western Michigan University in Kalamazoo, Michigan. He worked in the philosophy of time, philosophy of language, philosophy of physics and philosophy of religion.
Smith published over 140 articles. Of his published books, he authored three, co-authored two, and co-authored and edited seven.
He was an editor for Prometheus Books and was the chief editor for Philo from 2001 to 2007.
He debated William Lane Craig over the existence of God.
Early life and education
Quentin Smith was born in Rhinebeck, New York. His father was a psychology professor at Bennington College and he spent most of his early life in Canada.
He received his bachelor's degree in philosophy from Antioch College, advancing to receive a PhD in philosophy from Boston College.
Career
After college, he received a job as assistant professor of philosophy at the University of Kentucky. Smith found that he could not afford to lose the time he spent teaching, so he resigned from the university to become an independent scholar.
After accepting a position as a visiting professor at Antioch College, he took a position as professor of philosophy at Western Michigan University in 1993 and retired in 2015.
Death
Smith died on November 12, 2020.
Published works
Epistemology: New Essays (Editor) Oxford: Oxford University Press, 2008.
Eins
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https://en.wikipedia.org/wiki/Mathematics%20in%20the%20medieval%20Islamic%20world
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Mathematics during the Golden Age of Islam, especially during the 9th and 10th centuries, was built on Greek mathematics (Euclid, Archimedes, Apollonius) and Indian mathematics (Aryabhata, Brahmagupta). Important progress was made, such as full development of the decimal place-value system to include decimal fractions, the first systematised study of algebra, and advances in geometry and trigonometry.
Arabic works played an important role in the transmission of mathematics to Europe during the 10th—12th centuries.
Concepts
Algebra
The study of algebra, the name of which is derived from the Arabic word meaning completion or "reunion of broken parts", flourished during the Islamic golden age. Muhammad ibn Musa al-Khwarizmi, a Persian scholar in the House of Wisdom in Baghdad was the founder of algebra, is along with the Greek mathematician Diophantus, known as the father of algebra. In his book The Compendious Book on Calculation by Completion and Balancing, Al-Khwarizmi deals with ways to solve for the positive roots of first and second-degree (linear and quadratic) polynomial equations. He introduces the method of reduction, and unlike Diophantus, also gives general solutions for the equations he deals with.
Al-Khwarizmi's algebra was rhetorical, which means that the equations were written out in full sentences. This was unlike the algebraic work of Diophantus, which was syncopated, meaning that some symbolism is used. The transition to symbolic algebra, where only symb
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https://en.wikipedia.org/wiki/Causal%20filter
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In signal processing, a causal filter is a linear and time-invariant causal system. The word causal indicates that the filter output depends only on past and present inputs. A filter whose output also depends on future inputs is non-causal, whereas a filter whose output depends only on future inputs is anti-causal. Systems (including filters) that are realizable (i.e. that operate in real time) must be causal because such systems cannot act on a future input. In effect that means the output sample that best represents the input at time comes out slightly later. A common design practice for digital filters is to create a realizable filter by shortening and/or time-shifting a non-causal impulse response. If shortening is necessary, it is often accomplished as the product of the impulse-response with a window function.
An example of an anti-causal filter is a maximum phase filter, which can be defined as a stable, anti-causal filter whose inverse is also stable and anti-causal.
Example
The following definition is a sliding or moving average of input data . A constant factor of is omitted for simplicity:
where could represent a spatial coordinate, as in image processing. But if represents time , then a moving average defined that way is non-causal (also called non-realizable), because depends on future inputs, such as . A realizable output is
which is a delayed version of the non-realizable output.
Any linear filter (such as a moving average) can be characterized b
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https://en.wikipedia.org/wiki/Quadrature%20filter
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In signal processing, a quadrature filter is the analytic representation of the impulse response of a real-valued filter:
If the quadrature filter is applied to a signal , the result is
which implies that is the analytic representation of .
Since is an analytic signal, it is either zero or complex-valued. In practice, therefore, is often implemented as two real-valued filters, which correspond to the real and imaginary parts of the filter, respectively.
An ideal quadrature filter cannot have a finite support. It has single sided support, but by choosing the (analog) function carefully, it is possible to design quadrature filters which are localized such that they can be approximated by means of functions of finite support. A digital realization without feedback (FIR) has finite support.
Applications
This construction will simply assemble an analytic signal with a starting point to finally create a causal signal with finite energy. The two Delta Distributions will perform this operation. This will impose an additional constraint on the filter.
Single frequency signals
For single frequency signals (in practice narrow bandwidth signals) with frequency the magnitude of the response of a quadrature filter equals the signal's amplitude A times the frequency function of the filter at frequency .
This property can be useful when the signal s is a narrow-bandwidth signal of unknown frequency. By choosing a suitable frequency function Q of the filter, we may generate k
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https://en.wikipedia.org/wiki/Serge%20Rudaz
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Serge Rudaz (born August 19, 1954, pronounced "Rü-DAH") is a Canadian theoretical physicist and professor of physics at the University of Minnesota. He previously served as the director of undergraduate studies of the University of Minnesota's physics department, and is now the director of undergraduate honors at the University of Minnesota. Rudaz received his Ph.D. in 1979 from Cornell University and his undergraduate degree from McGill University.
Teaching
In the spring of 2007, Rudaz was named as the director of the University of Minnesota's new campus-wide honors program, which began operation during the fall of 2008.
Research
In 1995, he was elected Fellow of the American Physical Society "for original and influential contributions to the phenomenology of heavy quarks, supersymmetry and grand unification, and particle astrophysics." In 1985, Rudaz was the recipient of the Canadian Association of Physicists Herzberg Medal. He is the only physicist in the Herzberg Medal's history from a non-Canadian institution.
Rudaz's research interests include:
unified theories of elementary particle interactions and their phenomenology, applications to cosmology and the particle/astrophysics interface
relativistic many-body physics, including phase transitions in field theories at finite temperature and density; models of hadronic interactions
physics of topological defect formation in the early universe and in condensed systems
See also
Penguin diagrams
References
External
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https://en.wikipedia.org/wiki/Synchronous%20condenser
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In electrical engineering, a synchronous condenser (sometimes called a syncon, synchronous capacitor or synchronous compensator) is a DC-excited synchronous motor, whose shaft is not connected to anything but spins freely. Its purpose is not to convert electric power to mechanical power or vice versa, but to adjust conditions on the electric power transmission grid. Its field is controlled by a voltage regulator to either generate or absorb reactive power as needed to adjust the grid's voltage, or to improve power factor. The condenser’s installation and operation are identical to large electric motors and generators (some generators are actually designed to be able to operate as synchronous condensers with the prime mover disconnected).
Increasing the device's field excitation results in its furnishing reactive power (measured in units of var) to the system. Its principal advantage is the ease with which the amount of correction can be adjusted.
Synchronous condensers are an alternative to capacitor banks for power-factor correction in power grids. One advantage is that the amount of reactive power from a synchronous condenser can be continuously adjusted. Reactive power from a capacitor bank decreases when grid voltage decreases while the reactive power from a synchronous condenser inherently increases as voltage decreases. However, synchronous machines have higher energy losses than static capacitor banks. Most synchronous condensers connected to electrical grids are
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https://en.wikipedia.org/wiki/William%20Curtis%20Farabee
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William Curtis Farabee (1865–1925), the second individual to obtain a doctorate in physical anthropology from Harvard University, engaged in a wide range of anthropological work during his time as a professor at Harvard and then as a researcher at the University Museum, Philadelphia, but is best known for his work in human genetics and his ethnographic and geographic work in South America.
Early life and education
William Curtis Farabee was born in Washington County, Pennsylvania on February 7, 1865. He attended public schools, and enrolled at the California State Normal School from 1885 to 1887. He was an 1894 graduate of Waynesburg College.
He married Sylvia Manilla Holdren in 1897.
Genetics research
Farabee demonstrated that Mendelian genetics operate in man. The founder of genetics, Gregor Mendel, published the results of his studies on pea plants and heredity in 1865. The work of Mendel was not recognized for its importance until it was rediscovered in 1900. During the intervening 35 years, the "discovery of chromosomes and their behavior in cell division and gametogenesis, and intensive study of cell biological variation, and…a conceptual framework for a theory of heredity, development, and evolution" all came about. "The time was ripe for Mendelism" according to Stern. Mendel had been interested in seeing if his work with dominant and recessive characteristics was applicable to men, but it was Farabee's work that confirmed this and helped found the study of hum
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https://en.wikipedia.org/wiki/Reprogramming
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In biology, reprogramming refers to erasure and remodeling of epigenetic marks, such as DNA methylation, during mammalian development or in cell culture. Such control is also often associated with alternative covalent modifications of histones.
Reprogrammings that are both large scale (10% to 100% of epigenetic marks) and rapid (hours to a few days) occur at three life stages of mammals. Almost 100% of epigenetic marks are reprogrammed in two short periods early in development after fertilization of an ovum by a sperm. In addition, almost 10% of DNA methylations in neurons of the hippocampus can be rapidly altered during formation of a strong fear memory.
After fertilization in mammals, DNA methylation patterns are largely erased and then re-established during early embryonic development. Almost all of the methylations from the parents are erased, first during early embryogenesis, and again in gametogenesis, with demethylation and remethylation occurring each time. Demethylation during early embryogenesis occurs in the preimplantation period. After a sperm fertilizes an ovum to form a zygote, rapid DNA demethylation of the paternal DNA and slower demethylation of the maternal DNA occurs until formation of a morula, which has almost no methylation. After the blastocyst is formed, methylation can begin, and with formation of the epiblast a wave of methylation then takes place until the implantation stage of the embryo. Another period of rapid and almost complete demet
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https://en.wikipedia.org/wiki/Materials%20Today
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Materials Today is a monthly peer-reviewed scientific journal, website, and journal family. The parent journal was established in 1998 and covers all aspects of materials science. It is published by Elsevier and the editors-in-chief are Jun Lou (Rice University) and Gleb Yushin (Georgia Institute of Technology). The journal principally publishes invited review articles, but other formats are also included, such as primary research articles, news items, commentaries, and opinion pieces on subjects of interest to the field. The website publishes news, educational webinars, podcasts, and blogs, as well as a jobs and events board. According to the Journal Citation Reports, the journal has a 2020 impact factor of 31.041.
The journal family includes Applied Materials Today, Materials Today Chemistry, Materials Today Energy, Materials Today Physics, Materials Today Nano, Materials Today Sustainability, Materials Today Communications, Materials Today Advances and Materials Today: Proceedings; as well as an extended collection of related publications.
History
The journal was established in 1998 as a collaboration between Elsevier and the European Materials Research Society. The founding editor was Phil Mestecky. The journal was distributed free of charge to society members and to anyone else who requested a subscription. The spin-off titles Materials Today Communications, Materials Today: Proceedings, and Applied Materials Today were launched between 2014 and 2015. In October 2016,
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https://en.wikipedia.org/wiki/2%2C5-Dimethoxy-4-ethylamphetamine
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2,5-Dimethoxy-4-ethylamphetamine (DOET, DOE, Hecate) is a psychedelic drug of the phenethylamine and amphetamine chemical classes. It was first synthesized by Alexander Shulgin, and was described in his book PiHKAL (Phenethylamines i Have Known And Loved).
Chemistry
DOET is in a class of compounds commonly known as substituted amphetamines; its full chemical name is 4-ethyl-2,5-dimethoxy-alpha-methylbenzeneethanamine, or 1-(2,5-dimethoxy-4-ethylphenyl)propan-2-amine. It has an active stereocenter and (R)-DOET is the more active enantiomer. DOET is an extremely rare compound and reports of its effects and toxicology in humans are sparse. However, like the more common 2,5-dimethoxy-amphetamine analogues DOB, DOI and DOM, it is a potent and long-acting psychedelic. Removal of the alpha-methyl moiety yields the 2-carbon analogue, commonly known as 2C-E, another psychedelic compound first synthesized by Dr. Alexander Shulgin.
Pharmacology
Similarly to related drugs like DOM, DOET likely acts as a 5-HT2A, 5-HT2B, and 5-HT2C receptor partial agonist. It is an agonist of human TAAR1.
Effects
DOET produces psychedelic effects that last up 14–20 hours. In PiHKAL, Shulgin lists the dosage of DOET as being 2–7 mg orally, with 6–7 mg being the dosage for full, desired effects.
Legal status
Internationally, DOET is a Schedule I controlled drug; under the Convention on Psychotropic Substances, it's legal only for medical uses or scientific research:.
United States
DOET is classifi
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https://en.wikipedia.org/wiki/Toxic%20%28disambiguation%29
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Toxicity is a measure of the degree to which something is toxic or poisonous.
Toxic, toxicity, or similar terms may also refer to:
Science
Biology
Toxicant, a chemical compound having an effect on living organisms
Toxin, a substance produced by living cells or organisms
Mycotoxin, toxins produced by fungi
Social sciences
Toxicicity, a personality trait across several types:
Toxic femininity
Toxic leader
Toxic masculinity
Toxic positivity
Toxic workplace
Toxicity, a gamer slang term for poor player behavior
Arts, entertainment, and media
Music
Toxic (album), a 2011 album by the Gazette
Toxicity (album), a 2001 album by System of a Down
"Toxicity" (song), the album's title track
"Toxic" (song), a 2003 song by Britney Spears
"Toxic" (BoyWithUke song), a 2021 song by BoyWithUke
"Toxic" (YG song), a 2022 song by YG
"Toxic", a song by 2WEI
"Toxic", a song by Ashnikko from Demidevil
"Toxic", a song by Kehlani from It Was Good Until It Wasn't
"Toxic", a song by Crazy Town from The Gift of Game
"Toxic", a song by Digga D from Made in the Pyrex
Toxik, an American thrash metal band
Other arts, entertainment, and media
Toxic (graffiti artist), born 1965
Toxic (film), a 2010 thriller film
Toxic (magazine), a British boys' magazine and comic, 2000s
Toxic! (1990s comic), a British comic
Toxikk, a 2015 video game
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https://en.wikipedia.org/wiki/List%20of%20pioneers%20in%20computer%20science
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This is a list of people who made transformative breakthroughs in the creation, development and imagining of what computers could do.
Pioneers
To arrange the list either chronologically by year or alphabetically by person (ascending or descending), click that column's small "up-down" icon.
~ Items marked with a tilde are circa dates.
See also
Computer Pioneer Award
IEEE John von Neumann Medal
Grace Murray Hopper Award
History of computing
History of computing hardware
History of computing hardware (1960s–present)
History of software
List of computer science awards
List of computer scientists
List of Internet pioneers
List of people considered father or mother of a field § Computing
The Man Who Invented the Computer (2010 book)
List of Russian IT developers
List of Women in Technology International Hall of Fame inductees
Timeline of computing
Turing Award
Women in computing
References
Sources
External links
Internet pioneers
Pioneers
Computer, List
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https://en.wikipedia.org/wiki/Intergranular%20corrosion
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In materials science, intergranular corrosion (IGC), also known as intergranular attack (IGA), is a form of corrosion where the boundaries of crystallites of the material are more susceptible to corrosion than their insides. (Cf. transgranular corrosion.)
Description
This situation can happen in otherwise corrosion-resistant alloys, when the grain boundaries are depleted, known as , of the corrosion-inhibiting elements such as chromium by some mechanism. In nickel alloys and austenitic stainless steels, where chromium is added for corrosion resistance, the mechanism involved is precipitation of chromium carbide at the grain boundaries, resulting in the formation of chromium-depleted zones adjacent to the grain boundaries (this process is called sensitization). Around 12% chromium is minimally required to ensure passivation, a mechanism by which an ultra thin invisible film, known as passive film, forms on the surface of stainless steels. This passive film protects the metal from corrosive environments. The self-healing property of the passive film make the steel stainless. Selective leaching often involves grain boundary depletion mechanisms.
These zones also act as local galvanic couples, causing local galvanic corrosion. This condition happens when the material is heated to temperatures around 700 °C for too long a time, and often occurs during welding or an improper heat treatment. When zones of such material form due to welding, the resulting corrosion is termed we
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https://en.wikipedia.org/wiki/European%20Centre%20for%20Disease%20Prevention%20and%20Control
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The European Centre for Disease Prevention and Control (ECDC) is an agency of the European Union (EU) whose mission is to strengthen Europe's defences against infectious diseases. It covers a wide spectrum of activities, such as: surveillance, epidemic intelligence, response, scientific advice, microbiology, preparedness, public health training, international relations, health communication, and the scientific journal Eurosurveillance. The centre was established in 2004 and is headquartered in Solna, Sweden.
History and operations
As EU economic integration and open frontiers increased, cooperation on public health issues became more important. While the idea of creating a European centre for disease control had been discussed previously by public health experts, the 2003 SARS outbreak and the rapid spread of SARS across country borders confirmed the urgency of the creation of an EU-wide institution for public health. ECDC was set up in record time for an EU agency: the European Commission presented draft legislation in July 2003; by the spring of 2004, Regulation (EC) 851/2004 had been passed, and in May 2005 the Centre became operational. The relevance of the centre's mission was confirmed shortly after it began operating, when the arrival of H5N1 avian influenza in the EU's neighbourhood led to fears that the disease could adapt or mutate into a pandemic strain of human influenza. The Centre moved to its current location at Gustav III:s Boulevard 40, 16973 Solna, Sweden,
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https://en.wikipedia.org/wiki/Scott%20Baker
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Scott Baker may refer to:
Scott Baker (marine biologist) (born 1954), American specialist in conservation genetics of whale, dolphins and porpoises
Scott Baker (right-handed pitcher) (born 1981), American professional baseball pitcher
Scott Baker (left-handed pitcher) (born 1970), American left-handed baseball pitcher
Scott Baker (racing driver) (1957–2000), American stock car racer
Scott Baker (judge) (born 1937), British Lord Justice of Appeal
Scott Baker (writer) (born 1947), American writer of fantasy, horror, & science fiction; also a translator from the French
Scott Baker (journalist) (born 1964), American editor of The Blaze
Scott Thompson Baker (born 1960), American television actor
Scott Baker (darts player) (born 1986), English darts player
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https://en.wikipedia.org/wiki/George%20L.%20Paddison
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George Lucas Paddison (August 9, 1883 – October 17, 1954) was an American assistant professor, lawyer, and sales supervisor.
Biography
Paddison was born in Burgaw, North Carolina on August 9, 1883. He studied chemistry at the University of North Carolina at Chapel Hill. He graduated Phi Beta Kappa in 1905. He studied further at Kentucky State University and received a Master's degree in Chemistry. Afterwards Paddison taught as assistant professor of Chemistry at the University of Mississippi while he earned a degree in law. Upon completing his law degree, Paddison practiced law in Greenwood, Mississippi for five years. In 1914 Paddison took a position with West Publishing Company, where he would work for 32 years, retiring in 1946 as supervisor of sales. West Publishing Co. produced law books, primarily. Upon retiring he returned to North Carolina.
Upon his death he established, by bequest, an endowment at the University of North Carolina at Chapel Hill in the Department of Classics there. This endowment established permanent faculty positions in Classics. The Paddison chair has been held by several luminaries in the field of Classical studies, including Thomas Robert Shannon Broughton, Robert J. Getty, Brooks Otis, George Alexander Kennedy, Jerzy Linderski, and William H. Race. Current Paddison professors at UNC are James O'Hara and Patricia A. Rosenmeyer.
He retired to his hometown of Burgaw, North Carolina. He died on October 17, 1954. He is buried in Burgaw Cemete
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https://en.wikipedia.org/wiki/EAM
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EAM may refer to:
East Art Map, an art history project
Electric accounting machine
Electro-absorption modulator
Embedded atom model
Emergency Action Message
Enterprise architecture management
Enterprise asset management
European Academy of Microbiology
Equine atypical myopathy
External Affairs Minister
External auditory meatus
Henry Eam (died before 1360), Founder Knight of the Order of the Garter
Najran Domestic Airport, in Saudi Arabia
National Liberation Front (Greece), a Greek World War II Resistance movement
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https://en.wikipedia.org/wiki/Circle-valued%20Morse%20theory
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In mathematics, circle-valued Morse theory studies the topology of a smooth manifold by analyzing the critical points of smooth maps from the manifold to the circle, in the framework of Morse homology. It is an important special case of Sergei Novikov's Morse theory of closed one-forms.
Michael Hutchings and Yi-Jen Lee have connected it to Reidemeister torsion and Seiberg–Witten theory.
References
Morse theory
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https://en.wikipedia.org/wiki/List%20of%20University%20of%20Colorado%20Boulder%20alumni
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The following is a list of some notable people associated with the University of Colorado Boulder.
Nobel laureates faculty and staff
Thomas R. Cech, Nobel laureate in Chemistry in 1989
Stanley Cohen, Nobel laureate in Physiology or Medicine in 1986
Eric Allin Cornell, Nobel laureate in Physics in 2001
John L. Hall, Nobel laureate in Physics in 2005
Herbert Kroemer, Nobel laureate in Physics in 2000
Carl Wieman, Nobel laureate in Physics in 2001
Paul Komor, co-recipient of the Nobel Peace Prize in 2007
David J. Wineland, Nobel laureate in Physics in 2012
Muhammad Yunus, recipient of the Nobel Peace Prize in 2006
Nobel laureates alumni
Sidney Altman, Nobel laureate in Chemistry in 1989
Craig Mello, Nobel laureate in Physiology or Medicine in 2006
Norman Ramsey, Nobel laureate in Physics in 1989
Ellen Johnson Sirleaf, co-recipient of the Nobel Peace Prize in 2011
Jennifer Doudna, Nobel laureate in Chemistry in 2020
Notable faculty and staff
Waleed Abdalati, scientist, Chief Scientist of NASA
Patricia A. Adler, professor emerita of sociology
Bernard Amadei, civil engineer, founder of Engineers Without Borders
Mark Amerika, artist and author
Fred Anderson, historian, author of The Crucible of War
Albert Allen Bartlett, physicist, popular writer on exponential growth in populations and energy resources
Petr Beckmann, physicist, engineer
Kenneth Boulding, economist
Stan Brakhage, filmmaker
Sara Branham Matthews, microbiologist
Storm Bull, Professor Emeri
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https://en.wikipedia.org/wiki/Pythagorean%20means
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In mathematics, the three classical Pythagorean means are the arithmetic mean (AM), the geometric mean (GM), and the harmonic mean (HM). These means were studied with proportions by Pythagoreans and later generations of Greek mathematicians because of their importance in geometry and music.
Definition
They are defined by:
Properties
Each mean, , has the following properties:
First-order homogeneity
Invariance under exchange
for any and .
Monotonicity
Idempotence
Monotonicity and idempotence together imply that a mean of a set always lies between the extremes of the set:
The harmonic and arithmetic means are reciprocal duals of each other for positive arguments,
while the geometric mean is its own reciprocal dual:
Inequalities among means
There is an ordering to these means (if all of the are positive)
with equality holding if and only if the are all equal.
This is a generalization of the inequality of arithmetic and geometric means and a special case of an inequality for generalized means. The proof follows from the arithmetic–geometric mean inequality, , and reciprocal duality ( and are also reciprocal dual to each other).
The study of the Pythagorean means is closely related to the study of majorization and Schur-convex functions. The harmonic and geometric means are concave symmetric functions of their arguments, and hence Schur-concave, while the arithmetic mean is a linear function of its arguments and hence is both concave and convex.
History
|
https://en.wikipedia.org/wiki/Mechanical%20engineering%20technology
|
Mechanical engineering technology is the application of engineering principles and technological developments for the creation of useful products and production machinery.
Technologists
Mechanical engineering technologists are expected to apply current technologies and principles from machine and product design, production and material and manufacturing processes.
Expandable specialties may include aerospace, automotive, energy, nuclear, petroleum, manufacturing, product development, and industrial design.
Mechanical engineering technologists can have many different titles, including in the United States:
Mechanical Engineering Technologist
Mechanical Engineer
Product Engineering Technologist
Mechanical Designer
Product Development Engineering Technologist
Manufacturing Engineering Technologist
Training
Mechanical Engineering Technology coursework is less theoretical, and more application based than a mechanical engineering degree. This is evident through the additional laboratory coursework required for a degree. The ability to apply concepts from the chemical engineering and electrical engineering fields is important.
Some university Mechanical Engineering Technology degree programs require mathematics through differential equations and statistics. Most courses involve algebra and calculus.
Oftentimes, a MET graduate could get hired as an engineer; job titles may include Mechanical Engineer and Manufacturing Engineer.
In the U.S. it is possible to get an a
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https://en.wikipedia.org/wiki/Franz%20Alt%20%28mathematician%29
|
Franz Leopold Alt (November 30, 1910 – July 21, 2011) was an Austrian-born American mathematician who made major contributions to computer science in its early days. He was best known as one of the founders of the Association for Computing Machinery, and served as its president from 1950 to 1952.
Vienna
Alt was born in Vienna, Austria, on November 30, 1910 to a secular Jewish family. He received a PhD in mathematics in 1932 from the University of Vienna, with a thesis entitled Metrische Definition der Krümmung einer Kurve ("Metrical Definition of the Curvature of a Curve"). His principal teachers were Hans Hahn and Karl Menger. He was one of the regular participants in, and contributors to, Menger's "Mathematisches Kolloquium." [Afterword, Karl Menger, Ergebnisse eines Mathematischen Kolloquiums, Springer-Verlag/Wien, 1998] Alt engaged in research in set-theoretic topology and logical foundations of geometry.
In addition, in the next few years he became interested in econometrics, stimulated by Oskar Morgenstern, then professor of economics at the University of Vienna, later at Princeton University. In 1936, Alt developed an axiomatic foundation for economic concepts, described in "Ueber die Messbarkeit des Nutzens," which he presented at the International Congress of Mathematicians in Oslo (published in Zeitschrift für Nationalökonomie, VII/2, 1936; in German). The English translation of this paper was published as "On the Measurability of Utility" in Preferences, Util
|
https://en.wikipedia.org/wiki/Advanced%20process%20control
|
In control theory, advanced process control (APC) refers to a broad range of techniques and technologies implemented within industrial process control systems. Advanced process controls are usually deployed optionally and in addition to basic process controls. Basic process controls are designed and built with the process itself, to facilitate basic operation, control and automation requirements. Advanced process controls are typically added subsequently, often over the course of many years, to address particular performance or economic improvement opportunities in the process.
Process control (basic and advanced) normally implies the process industries, which includes chemicals, petrochemicals, oil and mineral refining, food processing, pharmaceuticals, power generation, etc. These industries are characterized by continuous processes and fluid processing, as opposed to discrete parts manufacturing, such as automobile and electronics manufacturing. The term process automation is essentially synonymous with process control.
Process controls (basic as well as advanced) are implemented within the process control system, which may mean a distributed control system (DCS), programmable logic controller (PLC), and/or a supervisory control computer. DCSs and PLCs are typically industrially hardened and fault-tolerant. Supervisory control computers are often not hardened or fault-tolerant, but they bring a higher level of computational capability to the control system, to hos
|
https://en.wikipedia.org/wiki/Macromerine
|
Macromerine is a phenethylamine derivative. It was first identified from the cactus Coryphantha macromeris. It can also be found in C. runyonii, C. elephantidens, and other related members of the family Cactaceae. The plants may have been used by Tarahumara shamans for their entheogenic effects.
Chemistry
Macromerine is a phenethylamine derivative with the molecular formula C12H19NO3.
Effects
At least one study found macromerine to be non-psychoactive, however as a phenethylamine derivative, it may be psychoactive.
See also
Phenethylamine cactus
Mescaline
References
Phenethylamine alkaloids
Phenethylamines
Phenol ethers
Phenylethanolamines
|
https://en.wikipedia.org/wiki/Josiah%20Latimer%20Clark
|
Josiah Latimer Clark FRS FRAS (10 March 1822 – 30 October 1898), was an English electrical engineer, born in Great Marlow, Buckinghamshire.
Biography
Josiah Latimer Clark was born in Great Marlow, Buckinghamshire, and was younger brother to Edwin Clark (1814–1894). Latimer Clark studied chemistry at school. His first job was a large Dublin chemical manufacturing establishment. In 1848 he started to work in his brother Edwin's civil engineering practice and became assistant engineer at the Menai Strait bridge. Two years later, when his brother was appointed Engineer to the Electric Telegraph Company, he again acted as his assistant, and subsequently succeeded him as Chief Engineer. In 1854, he took out a patent "for conveying letters or parcels between places by the pressure of air and vacuum," and later, in 1863, was concerned in the construction, by the London Pneumatic Despatch Company, of a tube between the London North-West District post office and Euston station, London.
About the same period he was engaged in experimental researches on the propagation of the electric current in submarine cables, on which he published a pamphlet in 1855, and in 1859 he was a member of the committee that was appointed by the government to consider the numerous failures of submarine cable enterprises. He later realised that Francis Ronalds had described the risk and cause of signal retardation in telegraph lines as early as 1816 and he thereafter devoted significant effort to bringing R
|
https://en.wikipedia.org/wiki/Weston%20cell
|
The Weston cell or Weston standard cell is a wet-chemical cell that produces a highly stable voltage suitable as a laboratory standard for calibration of voltmeters. Invented by Edward Weston in 1893, it was adopted as the International Standard for EMF from 1911 until superseded by the Josephson voltage standard in 1990.
Chemistry
The anode is an amalgam of cadmium with mercury with a cathode of pure mercury over which a paste of mercurous sulfate and mercury is placed. The electrolyte is a saturated solution of cadmium sulfate, and the depolarizer is a paste of mercurous sulfate.
As shown in the illustration, the cell is set up in an H-shaped glass vessel with the cadmium amalgam in one leg and the pure mercury in the other. Electrical connections to the cadmium amalgam and the mercury are made by platinum wires fused through the lower ends of the legs.
Anode reaction Cd(s) → Cd2+(aq) + 2e−
Cathode reaction (Hg+)2(s) + 2e− → 2Hg(l) + (aq)
Reference cells must be applied in such a way that no current is drawn from them.
Characteristics
The original design was a saturated cadmium cell producing a reference and had the advantage of having a lower temperature coefficient than the previously used Clark cell.
One of the great advantages of the Weston normal cell is its small change of electromotive force with change of temperature. At any temperature between and ,
.
This temperature formula was adopted by the London conference of 1908
The temperature coefficien
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https://en.wikipedia.org/wiki/Reinnervation
|
Reinnervation is the restoration, either by spontaneous cellular regeneration or by surgical grafting, of nerve supply to a body part from which it has been lost or damaged.
See also
Denervation
Neuroregeneration
Targeted reinnervation
References
Neuroscience
|
https://en.wikipedia.org/wiki/Igor%20Pak
|
Igor Pak () (born 1971, Moscow, Soviet Union) is a professor of mathematics at the University of California, Los Angeles, working in combinatorics and discrete probability. He formerly taught at the Massachusetts Institute of Technology and the University of Minnesota, and he is best known for his bijective proof of the hook-length formula for the number of Young tableaux, and his work on random walks. He was a keynote speaker alongside George Andrews and Doron Zeilberger at the 2006 Harvey Mudd College Mathematics Conference on Enumerative Combinatorics.
Pak is an Associate Editor for the journal Discrete Mathematics. He gave a Fejes Tóth Lecture at the University of Calgary in February 2009.
In 2018, he was an invited speaker at the International Congress of Mathematicians in Rio de Janeiro.
Background
Pak went to Moscow High School № 57. After graduating, he worked for a year at Bank Menatep.
He did his undergraduate studies at Moscow State University. He was a PhD student of Persi Diaconis at Harvard University, where he received a doctorate in Mathematics in 1997, with a thesis titled Random Walks on Groups: Strong Uniform Time Approach. Afterwards, he worked with László Lovász as a postdoc at Yale University. He was a fellow at the Mathematical Sciences Research Institute and a long-term visitor at the Hebrew University of Jerusalem.
References
External links
Personal site.
List of published papers, with abstracts.
MIT Mathematics Department website.
MathSciN
|
https://en.wikipedia.org/wiki/Polyunsaturated%20fat
|
In biochemistry and nutrition, a polyunsaturated fat is a fat that contains a polyunsaturated fatty acid (abbreviated PUFA), which is a subclass of fatty acid characterized by a backbone with two or more carbon–carbon double bonds.
Some polyunsaturated fatty acids are essentials. Polyunsaturated fatty acids are precursors to and are derived from polyunsaturated fats, which include drying oils.
Nomenclature
The position of the carbon-carbon double bonds in carboxylic acid chains in fats is designated by Greek letters. The carbon atom closest to the carboxyl group is the alpha carbon, the next carbon is the beta carbon and so on. In fatty acids the carbon atom of the methyl group at the end of the hydrocarbon chain is called the omega carbon because omega is the last letter of the Greek alphabet. Omega-3 fatty acids have a double bond three carbons away from the methyl carbon, whereas omega-6 fatty acids have a double bond six carbons away from the methyl carbon. The illustration below shows the omega-6 fatty acid, linoleic acid.
Polyunsaturated fatty acids can be classified in various groups by their chemical structure:
methylene-interrupted polyenes
conjugated fatty acids
other PUFAs
Based on the length of their carbon backbone, they are sometimes classified in two groups:
short chain polyunsaturated fatty acids (SC-PUFA), with 18 carbon atoms
long-chain polyunsaturated fatty acids (LC-PUFA) with 20 or more carbon atoms
Production
PUFAs with 18 carbon atoms, which ar
|
https://en.wikipedia.org/wiki/Michael%20A.%20O%27Keefe
|
Michael A. O'Keefe (born 8 September 1942, in East Melbourne, Australia) is a physicist who has worked in materials science and electron microscopy. He is perhaps best known for his production of the seminal computer code for modeling of high-resolution transmission electron microscopy (HRTEM) images; his software was later made available as part of the DeepView package for remote electron microscopy and control. O'Keefe's tutorial on theory and application of high-resolution electron microscope image simulation is available online.
O'Keefe has established methods of quantifying resolution quality, and methods of deriving accurate atom positions from high-resolution images. He used these methods to help establish high-resolution electron microscopy as a precise science; in addition to its more-pedestrian role of pictorial confirmation of nano measurements, he demonstrated HRTEM's value in measurement of nano-properties. The video and associated slides illustrate the role of his work in providing tools for nano-characterization.
O'Keefe designed and developed the one-Ångström microscope (OÅM) for the National Center for Electron Microscopy at Lawrence Berkeley National Laboratory based on an FEI Company CM300 microscope that he modified extensively to improve coherence and correct three-fold astigmatism. He was successful in breaking the "one-Ångström barrier" to resolution using his combination of hardware and software correction of microscope aberrations. He produced
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https://en.wikipedia.org/wiki/OCCRA
|
OCCRA stands for Oakland County Competitive Robotics Association. OCCRA is an organized competition between the robotics teams of about 30 different high schools in Oakland County, Michigan, United States, that takes place each fall, beginning in early September and ending in early December.
OCCRA vs. FIRST Robotics
Although inspired by FIRST Robotics, OCCRA differs from FIRST in several key ways. Firstly, the student members of the robotics teams are expected to design and build the robots without direct assistance from their adult mentors. This gives students more responsibility and allows them to develop leadership skills.
In OCCRA, teams are also forbidden from having corporate sponsorships. Each team is responsible for raising its own money to promote teamwork and to teach students to work within a budget. The league as a whole has corporate sponsors.
Furthermore, "heavy machinery" is restricted. Lathes and other types of precision machinery are not to be used in the construction of OCCRA-bound robots. Instead, students build their robots with rulers, hacksaws, and cordless drills. This rule is intended to ensure equality among teams with varying resources (e.g. having a machine shop in the team's high school or in a team member's garage).
One key way in which OCCRA does emulate FIRST is that OCCRA maintains a policy of gracious professionalism.
See also
FIRST
External links
Official OCCRA website
ChiefDelphi Forums - OCCRA
AdamBots (Team 245) - OCCRA
Monster
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https://en.wikipedia.org/wiki/Weinreb%20ketone%20synthesis
|
The Weinreb ketone synthesis or Weinreb–Nahm ketone synthesis is a chemical reaction used in organic chemistry to make carbon–carbon bonds. It was discovered in 1981 by Steven M. Weinreb and Steven Nahm as a method to synthesize ketones. The original reaction involved two subsequent nucleophilic acyl substitutions: the conversion of an acid chloride with N,O-Dimethylhydroxylamine, to form a Weinreb–Nahm amide, and subsequent treatment of this species with an organometallic reagent such as a Grignard reagent or organolithium reagent. Nahm and Weinreb also reported the synthesis of aldehydes by reduction of the amide with an excess of lithium aluminum hydride (see amide reduction).
The major advantage of this method over addition of organometallic reagents to more typical acyl compounds is that it avoids the common problem of over-addition. For these latter reactions, two equivalents of the incoming group add to form an alcohol rather than a ketone or aldehyde. This occurs even if the equivalents of nucleophile are closely controlled.
The Weinreb–Nahm amide has since been adopted into regular use by organic chemists as a dependable method for the synthesis of ketones. These functional groups are present in a large number of natural products and can be reliably reacted to form new carbon–carbon bonds or converted into other functional groups. This method has been used in a number of syntheses, including macrosphelides A and B, amphidinolide J, and spirofungins A and B. (See Sc
|
https://en.wikipedia.org/wiki/Humberto%20Guerra%20Allison
|
Humberto Guerra Allison (born 1940), is a physician and scientist. He graduated from Universidad Peruana Cayetano Heredia (MD) and Baylor College of Medicine (PhD in Microbiology). With Hugo Lumbreras, he co-founded a Tropical Medicine Institute at Cayetano Heredia University, the Instituto de Medicina Tropical Alexander von Humboldt at Lima, Peru. Guerra later directed the Institute.
Guerra's research focuses on the pathogenesis and immunology of bacterial diseases including brucellosis, leishmania and tuberculosis. He is the head of the Clinical Microbiology Laboratory at the IMT AvH.j
Sources
The Peru Report's Guide to Top People in Peru. Vol 1, p 303, 1992
External links
Link to Pub Med list of publications
Peruvian scientists
Peruvian tropical physicians
1940 births
Living people
Baylor University alumni
Peruvian expatriates in the United States
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https://en.wikipedia.org/wiki/Concept%20class
|
In computational learning theory in mathematics, a concept over a domain X is a total Boolean function over X. A concept class is a class of concepts. Concept classes are a subject of computational learning theory.
Concept class terminology frequently appears in model theory associated with probably approximately correct (PAC) learning. In this setting, if one takes a set Y as a set of (classifier output) labels, and X is a set of examples, the map , i.e. from examples to classifier labels (where and where c is a subset of X), c is then said to be a concept. A concept class is then a collection of such concepts.
Given a class of concepts C, a subclass D is reachable if there exists a sample s such that D contains exactly those concepts in C that are extensions to s. Not every subclass is reachable.
Background
A sample is a partial function from to . Identifying a concept with its characteristic function mapping to , it is a special case of a sample.
Two samples are consistent if they agree on the intersection of their domains. A sample extends another sample if the two are consistent and the domain of is contained in the domain of .
Examples
Suppose that . Then:
the subclass is reachable with the sample ;
the subclass for are reachable with a sample that maps the elements of to zero;
the subclass , which consists of the singleton sets, is not reachable.
Applications
Let be some concept class. For any concept , we call this concept -good for a positi
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https://en.wikipedia.org/wiki/Bondy%27s%20theorem
|
In mathematics, Bondy's theorem is a bound on the number of elements needed to distinguish the sets in a family of sets from each other. It belongs to the field of combinatorics, and is named after John Adrian Bondy, who published it in 1972.
Statement
The theorem is as follows:
Let X be a set with n elements and let A1, A2, ..., An be distinct subsets of X. Then there exists a subset S of X with n − 1 elements such that the sets Ai ∩ S are all distinct.
In other words, if we have a 0-1 matrix with n rows and n columns such that each row is distinct, we can remove one column such that the rows of the resulting n × (n − 1) matrix are distinct.
Example
Consider the 4 × 4 matrix
where all rows are pairwise distinct. If we delete, for example, the first column, the resulting matrix
no longer has this property: the first row is identical to the second row. Nevertheless, by Bondy's theorem we know that we can always find a column that can be deleted without introducing any identical rows. In this case, we can delete the third column: all rows of the 3 × 4 matrix
are distinct. Another possibility would have been deleting the fourth column.
Learning theory application
From the perspective of computational learning theory, Bondy's theorem can be rephrased as follows:
Let C be a concept class over a finite domain X. Then there exists a subset S of X with the size at most |C| − 1 such that S is a witness set for every concept in C.
This implies that every finite concept class
|
https://en.wikipedia.org/wiki/Nanorod
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In nanotechnology, nanorods are one morphology of nanoscale objects. Each of their dimensions range from 1–100 nm. They may be synthesized from metals or semiconducting materials. Standard aspect ratios (length divided by width) are 3-5. Nanorods are produced by direct chemical synthesis. A combination of ligands act as shape control agents and bond to different facets of the nanorod with different strengths. This allows different faces of the nanorod to grow at different rates, producing an elongated object.
One potential application of nanorods is in display technologies, because the reflectivity of the rods can be changed by changing their orientation with an applied electric field. Another application is for microelectromechanical systems (MEMS). Nanorods, along with other noble metal nanoparticles, also function as theragnostic agents. Nanorods absorb in the near IR, and generate heat when excited with IR light. This property has led to the use of nanorods as cancer therapeutics. Nanorods can be conjugated with tumor targeting motifs and ingested. When a patient is exposed to IR light (which passes through body tissue), nanorods selectively taken up by tumor cells are locally heated, destroying only the cancerous tissue while leaving healthy cells intact.
Nanorods based on semiconducting materials have also been investigated for application as energy harvesting and light emitting devices. In 2006, Ramanathan et al. demonstrated1 electric-field mediated tunable p
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https://en.wikipedia.org/wiki/Invariant%20basis%20number
|
In mathematics, more specifically in the field of ring theory, a ring has the invariant basis number (IBN) property if all finitely generated free left modules over R have a well-defined rank. In the case of fields, the IBN property becomes the statement that finite-dimensional vector spaces have a unique dimension.
Definition
A ring R has invariant basis number (IBN) if for all positive integers m and n, Rm isomorphic to Rn (as left R-modules) implies that .
Equivalently, this means there do not exist distinct positive integers m and n such that Rm is isomorphic to Rn.
Rephrasing the definition of invariant basis number in terms of matrices, it says that, whenever A is an m-by-n matrix over R and B is an n-by-m matrix over R such that and , then . This form reveals that the definition is left–right symmetric, so it makes no difference whether we define IBN in terms of left or right modules; the two definitions are equivalent.
Note that the isomorphisms in the definitions are not ring isomorphisms, they are module isomorphisms, even when one of n or m is 1.
Properties
The main purpose of the invariant basis number condition is that free modules over an IBN ring satisfy an analogue of the dimension theorem for vector spaces: any two bases for a free module over an IBN ring have the same cardinality. Assuming the ultrafilter lemma (a strictly weaker form of the axiom of choice), this result is actually equivalent to the definition given here, and can be taken as an alte
|
https://en.wikipedia.org/wiki/Ramesh%20Jain
|
Ramesh Chandra Jain (born 8 June 1949) is a scientist and entrepreneur in the field of information and computer science. He is a Bren Professor in Information & Computer Sciences, Donald Bren School of Information and Computer Sciences, University of California, Irvine.
Education
He graduated with a bachelor's degree from Visvesvaraya National Institute of Technology, Nagpur, India and has a Ph.D. in electronics engineering (1975) from Indian Institute of Technology, Kharagpur, India.
Career
Ramesh Jain has been a researcher, an entrepreneur, and an educator. His activities have been mostly in the areas of Computer Vision, Artificial Intelligence, Multimedia and using these to build real world systems.
He served in academic positions at many universities. He served as a professor of computer science and engineering at the University of Michigan, Ann Arbor and the University of California, San Diego; in each case he founded and directed artificial intelligence and visual information systems labs. He served as Farmer Professor at Georgia Tech from 2002 to 2004. In 2005 he was named the first Bren Professor in Information and Computer Science for the Donald Bren School of Information and Computer Sciences, University of California, Irvine.
His research interests started in cybernetic systems. That interest brought him to research in pattern recognition, computer vision. and artificial intelligence. He was the coauthor of the first computer vision paper addressing analysis
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https://en.wikipedia.org/wiki/Star%20Schools%20Program
|
The Star Schools Program is a United States government program created to honor schools. Established as part of the United States Department of Education in 1988, the purpose of this program is to:
Encourage improved instruction in mathematics, science, foreign languages, and other subjects.
Serve underserved populations, including disadvantaged, non-reading, and limited English proficient populations and individuals with disabilities. Star Schools grants are made to eligible telecommunications partnerships, to enable such partnerships to:
develop, construct, acquire, maintain, and operate telecommunications audio and visual facilities and equipment;
develop and acquire educational and instructional programming; and
obtain technical assistance for the use of such facilities and instructional programming.
See also
United States Department of Education
Education for Economic Security Act
No Child Left Behind
References
Star Schools Program
Education in the United States
United States Department of Education
Schools programs
|
https://en.wikipedia.org/wiki/Higher-order%20differential%20cryptanalysis
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In cryptography, higher-order differential cryptanalysis is a generalization of differential cryptanalysis, an attack used against block ciphers. While in standard differential cryptanalysis the difference between only two texts is used, higher-order differential cryptanalysis studies the propagation of a set of differences between a larger set of texts. Xuejia Lai, in 1994, laid the groundwork by showing that differentials are a special case of the more general case of higher order derivates. Lars Knudsen, in the same year, was able to show how the concept of higher order derivatives can be used to mount attacks on block ciphers. These attacks can be superior to standard differential cryptanalysis. Higher-order differential cryptanalysis has notably been used to break the KN-Cipher, a cipher which had previously been proved to be immune against standard differential cryptanalysis.
Higher-order derivatives
A block cipher which maps -bit strings to -bit strings can, for a fixed key, be thought of as a function . In standard differential cryptanalysis, one is interested in finding a pair of an input difference and an output difference such that two input texts with difference are likely to result in output texts with a difference i.e., that is true for many . Note that the difference used here is the XOR which is the usual case, though other definitions of difference are possible.
This motivates defining the derivative of a function at a point as
Using this definitio
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https://en.wikipedia.org/wiki/Impossible%20differential%20cryptanalysis
|
In cryptography, impossible differential cryptanalysis is a form of differential cryptanalysis for block ciphers. While ordinary differential cryptanalysis tracks differences that propagate through the cipher with greater than expected probability, impossible differential cryptanalysis exploits differences that are impossible (having probability 0) at some intermediate state of the cipher algorithm.
Lars Knudsen appears to be the first to use a form of this attack, in the 1998 paper where he introduced his AES candidate, DEAL. The first presentation to attract the attention of the cryptographic community was later the same year at the rump session of CRYPTO '98, in which Eli Biham, Alex Biryukov, and Adi Shamir introduced the name "impossible differential" and used the technique to break 4.5 out of 8.5 rounds of IDEA and 31 out of 32 rounds of the NSA-designed cipher Skipjack. This development led cryptographer Bruce Schneier to speculate that the NSA had no previous knowledge of impossible differential cryptanalysis. The technique has since been applied to many other ciphers: Khufu and Khafre, E2, variants of Serpent, MARS, Twofish, Rijndael (AES), CRYPTON, Zodiac, Hierocrypt-3, TEA, XTEA, Mini-AES, ARIA, Camellia, and SHACAL-2.
Biham, Biryukov and Shamir also presented a relatively efficient specialized method for finding impossible differentials that they called a miss-in-the-middle attack. This consists of finding "two events with probability one, whose conditions canno
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https://en.wikipedia.org/wiki/Interpolation%20attack
|
In cryptography, an interpolation attack is a type of cryptanalytic attack against block ciphers.
After the two attacks, differential cryptanalysis and linear cryptanalysis, were presented on block ciphers, some new block ciphers were introduced, which were proven secure against differential and linear attacks. Among these there were some iterated block ciphers such as the KN-Cipher and the SHARK cipher. However, Thomas Jakobsen and Lars Knudsen showed in the late 1990s that these ciphers were easy to break by introducing a new attack called the interpolation attack.
In the attack, an algebraic function is used to represent an S-box. This may be a simple quadratic, or a polynomial or rational function over a Galois field. Its coefficients can be determined by standard Lagrange interpolation techniques, using known plaintexts as data points. Alternatively, chosen plaintexts can be used to simplify the equations and optimize the attack.
In its simplest version an interpolation attack expresses the ciphertext as a polynomial of the plaintext. If the polynomial has a relative low number of unknown coefficients, then with a collection of plaintext/ciphertext (p/c) pairs, the polynomial can be reconstructed. With the polynomial reconstructed the attacker then has a representation of the encryption, without exact knowledge of the secret key.
The interpolation attack can also be used to recover the secret key.
It is easiest to describe the method with an example.
Example
Let a
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