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https://en.wikipedia.org/wiki/Athanasios%20Tsakalidis
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Prof. Athanasios K. Tsakalidis (; born 1950) is a Greek computer scientist, a professor at the Graphics, Multimedia and GIS Laboratory, Computer Engineering and Informatics Department (CEID), University of Patras, Greece.
His scientific contributions extend diverse fields of computer science, including data structures, computational geometry, graph algorithms, GIS, bioinformatics, medical informatics, expert systems, databases, multimedia, information retrieval and more. Especially significant contributions include co-authoring Chapter 6: "Data Structures" in the Handbook of Theoretical Computer Science with his advisor prof. Kurt Mehlhorn, as well as numerous other elementary theoretical results that are cataloged in the article Some Results for Elementary Operations published in Efficient Algorithms in celebration of prof. K. Mehlhorn's 60th birthday.
Scientific Research
His research interests include: Data Structures, Graph Algorithms, Computational Geometry, GIS, Medical Informatics, Expert Systems, Databases, Multimedia, Information Retrieval, and Bioinformatics.
He has participated in many EU research programs, such as ESPRIT, RACE, AIM, STRIDE, Basic Research Actions in ESPRIT, ESPRIT Special Actions, TELEMATICS Applications, ADAPT, HORIZON, ΕΠΕΤ ΙΙ, ΥΠΕΡ, ΤΕΝ – TELECOM, IST, LEONARDO DA VINCI, MARIE CURIE, SOCRATES.
He is one of the 48 writers (6 of whom have received the ACM Turing Award) of the ground-laying computer science book, Handbook of Theoretical Comput
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https://en.wikipedia.org/wiki/Unmoved%20mover
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The unmoved mover () or prime mover () is a concept advanced by Aristotle as a primary cause (or first uncaused cause) or "mover" of all the motion in the universe. As is implicit in the name, the moves other things, but is not itself moved by any prior action. In Book 12 () of his Metaphysics, Aristotle describes the unmoved mover as being perfectly beautiful, indivisible, and contemplating only the perfect contemplation: self-contemplation. He equates this concept also with the active intellect. This Aristotelian concept had its roots in cosmological speculations of the earliest Greek pre-Socratic philosophers and became highly influential and widely drawn upon in medieval philosophy and theology. St. Thomas Aquinas, for example, elaborated on the unmoved mover in the .
First philosophy
Aristotle argues, in Book 8 of the Physics and Book 12 of the Metaphysics, "that there must be an immortal, unchanging being, ultimately responsible for all wholeness and orderliness in the sensible world".
In the Physics (VIII 4–6) Aristotle finds "surprising difficulties" explaining even commonplace change, and in support of his approach of explanation by four causes, he required "a fair bit of technical machinery". This "machinery" includes potentiality and actuality, hylomorphism, the theory of categories, and "an audacious and intriguing argument, that the bare existence of change requires the postulation of a first cause, an unmoved mover whose necessary existence underpins the cea
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https://en.wikipedia.org/wiki/Protection%20ring
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In computer science, hierarchical protection domains, often called protection rings, are mechanisms to protect data and functionality from faults (by improving fault tolerance) and malicious behavior (by providing computer security).
Computer operating systems provide different levels of access to resources. A protection ring is one of two or more hierarchical levels or layers of privilege within the architecture of a computer system. This is generally hardware-enforced by some CPU architectures that provide different CPU modes at the hardware or microcode level. Rings are arranged in a hierarchy from most privileged (most trusted, usually numbered zero) to least privileged (least trusted, usually with the highest ring number). On most operating systems, Ring 0 is the level with the most privileges and interacts most directly with the physical hardware such as certain CPU functionality (e.g. the control registers) and I/O controllers.
Special call gates between rings are provided to allow an outer ring to access an inner ring's resources in a predefined manner, as opposed to allowing arbitrary usage. Correctly gating access between rings can improve security by preventing programs from one ring or privilege level from misusing resources intended for programs in another. For example, spyware running as a user program in Ring 3 should be prevented from turning on a web camera without informing the user, since hardware access should be a Ring 1 function reserved for device dri
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https://en.wikipedia.org/wiki/Parnell%27s%20mustached%20bat
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Parnell's mustached bat (Pteronotus parnellii) is an insectivorous bat native to the Americas. It ranges from southern Sonora, Mexico, south to Brazil. It has a wider historical range; fossil specimens have been collected on the island of New Providence in the Bahamas.
The bat was named for the British zoologist Richard Parnell.
Biology
This is a large bat with a forearm length of about . The ears are short and pointed, and lack noseleafs. The lips are wrinkled up and modified into a funnel shape.
This bat is most common in moist habitat types, and it can be found in some dry deciduous forests. It is mostly nocturnal, roosting in caves and mines during the day and emerging shortly after sunset for five to seven hours of activity.
Parnell's mustached bat is an insectivore, taking a variety of insects such as beetles, moths, flies, and dragonflies. While many insectivorous bats prefer river habitats for the availability of aquatic insects, it generally hunts in non-river habitats due to the availability of more nutritious food items. This comes with a greater energy cost, as such habitats typically have more foliage, requiring increased maneuverability.
Females gather in warm caves with other species, including the Cuban flower bat (Phyllonycteris poeyi), during the breeding season. They give birth around July and nurse pups until around October. The pups only leave the safety of their birth cave to forage and hunt when their forearm length reaches adult size. In all spec
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https://en.wikipedia.org/wiki/Lucy%20Weston%20Pickett
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Lucy Weston Pickett (January 19, 1904 – November 23, 1997) was a Mary Lyon Professor and Camille and Henry Dreyfus Chair in Chemistry at Mount Holyoke College.
Her research on X-ray crystallography and ultraviolet absorption spectroscopy of organic molecules received numerous honors and was supported by grants from the Office of Naval Research, the National Science Foundation and the Petroleum Research Fund of the American Chemical Society.
Early life
Pickett was born on January 19, 1904, in Beverly, Massachusetts, to Lucy Weston, a former school teacher and elementary school principal, and George Ernest Pickett, a former seaman. She had one brother, Thomas Austin Pickett, who also became a chemist. Both Lucy and Thomas led similar academic and professional lives, while still holding a close relationship.
Education
Lucy W. Pickett attended high school in Beverly and later entered Mount Holyoke College in South Hadley, Massachusetts, in 1921 and graduated in 1925. Lucy planned on majoring in Latin but changed her mind to work in the sciences, having an attraction to chemistry. She double majored in chemistry and mathematics.
In, 1925, Pickett graduated with summa cum laude, both in chemistry, and in mathematics at Mount Holyoke. She continued to a master's degree in two years before moving to the University of Illinois, where she studied for her doctoral degree. Lucy earned a Ph.D. from the University of Illinois majoring in analytical chemistry with minors in both physic
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https://en.wikipedia.org/wiki/Ankara%20Science%20High%20School
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High School of Science (; after the founding of other science high schools in Turkey also referred as Ankara High School of Science [Ankara Fen Lisesi - (A)FL]) is a public boarding high school in Ankara, Turkey with a curriculum concentrated on natural sciences and mathematics for top-notch students. It was established in 1964 as the first science high school in Turkey with a funding from the Ford Foundation. The school is modeled after the American counterparts like the Bronx High School of Science. Due to the considerable success of its alumni in all aspects of professional life and academia, science high school concept is spread around the country and now there are public and private science high schools in all major cities. Its alumni includes many scientists (like Tekin Dereli, Ekmel Ozbay, Halil Mete Soner), top managers (like Süreyya Ciliv and Onat Menzilcioglu) engineers and doctors (like İzge Günal) as well as famed musicians (like Derya Köroğlu and Ahmet Kanneci) and famous Performanceartist like Ninel Cam.
Notable alumni
Tayfun Gönül, a writer, doctor, and Turkey's first conscientious objector.
See also
Science High School (disambiguation)
References
External links
Official website
AFL Alumni Association
High schools in Ankara
Educational institutions established in 1964
1964 establishments in Turkey
Science High Schools in Turkey
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https://en.wikipedia.org/wiki/Quantum%20eraser%20experiment
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In quantum mechanics, a quantum eraser experiment is an interferometer experiment that demonstrates several fundamental aspects of quantum mechanics, including quantum entanglement and complementarity.
The quantum eraser experiment is a variation of Thomas Young's classic double-slit experiment. It establishes that when action is taken to determine which of 2 slits a photon has passed through, the photon cannot interfere with itself. When a stream of photons is marked in this way, then the interference fringes characteristic of the Young experiment will not be seen. The experiment also creates situations in which a photon that has been "marked" to reveal through which slit it has passed can later be "unmarked." A photon that has been "unmarked" will interfere with itself and once again produce the fringes characteristic of Young's experiment.
The experiment
Concept
This experiment involves an apparatus with two main sections. After two entangled photons are created, each is directed into its own section of the apparatus. Anything done to learn the path of the entangled partner of the photon being examined in the double-slit part of the apparatus will influence the second photon, and vice versa. The advantage of manipulating the entangled partners of the photons in the double-slit part of the experimental apparatus is that experimenters can destroy or restore the interference pattern in the latter without changing anything in that part of the apparatus. Experimenters do so
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https://en.wikipedia.org/wiki/Coincidence%20detector
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Coincidence detector or coincidence detection can refer to:
Coincidence circuit, a device that can detect simultaneous electric signals
Coincidence detection in neurobiology, the detection of temporally close but spatially distributed input signals
Coincidence Detector (app), an anti-semitic web browser extension to automatically highlight names of individuals of a Jewish background on the web.
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https://en.wikipedia.org/wiki/Jeffrey%20Goldstone
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Jeffrey Goldstone (born 3 September 1933) is a British theoretical physicist and an emeritus physics faculty member at the MIT Center for Theoretical Physics.
He worked at the University of Cambridge until 1977. He is famous for the discovery of the Nambu–Goldstone boson. He is currently working on quantum computation.
Biography
Born in Manchester, he was educated at Manchester Grammar School and Trinity College, Cambridge, (B.A. 1954, Ph.D. 1958). He worked on the theory of nuclear matter under the guidance of Hans Bethe and developed modifications of Feynman diagrams for non-relativistic many-fermion systems, which are currently referred to as Goldstone diagrams.
Goldstone was a research fellow of Trinity College, Cambridge, from 1956 to 1960 and held visiting research posts at Copenhagen, CERN and Harvard. During this time, his research focus shifted to particle physics and he investigated the nature of relativistic field theories with spontaneously broken symmetries. With Abdus Salam and Steven Weinberg, he proved that in such theories zero-mass particles (Nambu–Goldstone bosons) must exist.
From 1962 to 1976, Goldstone was a faculty member at Cambridge. In the early 1970s, with Peter Goddard, Claudio Rebbi and Charles Thorn, he worked out the light-cone quantization theory of relativistic strings. He moved to the USA in 1977 as Professor of Physics at MIT, where he has been the Cecil and Ida Green Professor of Physics since 1983 and was Director of the MIT Center for
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https://en.wikipedia.org/wiki/Nihat%20Berker
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Ahmet Nihat Berker (born 20 September 1949) is a Turkish scientist, theoretical chemist, physicist and emeritus professor of physics at MIT. Currently, he is the acting Dean of Engineering and Natural Sciences in Kadir Has University, Turkey. He is the son of a notable scientist and engineer Ratip Berker, who was deceased on 17 October 1997. His wife, Bedia Erim Berker is a professor of chemistry at Istanbul Technical University, and one of his sons, Selim Berker is a professor of epistemology in the department of philosophy at Harvard University and his other son, Ratip Emin Berker is currently a junior at Harvard.
Academic life
After graduating from Robert College at first place in 1967, Nihat Berker received B.S. degrees in physics and chemistry from MIT in 1971. He received his M.S. and PhD degrees in physics from University of Illinois at Urbana–Champaign in 1972 and 1977, respectively. During 1977–79, he was a postdoctoral research fellow in the department of physics at Harvard University. He was an assistant professor during 1979–82, associate professor during 1982–1988, and professor of theoretical physics during 1988–04 at MIT. From 1999 to 2004, he served as a professor and dean of the School of Sciences and Letters at The Istanbul Technical University. After losing the president (rector) elections in İTÜ, he left the Technical University of Istanbul for a professor position at Koç University. He became emeritus professor of Physics at MIT in 2004. He was an adjunc
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https://en.wikipedia.org/wiki/Partial%20equivalence%20relation
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In mathematics, a partial equivalence relation (often abbreviated as PER, in older literature also called restricted equivalence relation) is a homogeneous binary relation that is symmetric and transitive. If the relation is also reflexive, then the relation is an equivalence relation.
Definition
Formally, a relation on a set is a PER if it holds for all that:
if , then (symmetry)
if and , then (transitivity)
Another more intuitive definition is that on a set is a PER if there is some subset of such that and is an equivalence relation on . The two definitions are seen to be equivalent by taking .
Properties and applications
The following properties hold for a partial equivalence relation on a set :
is an equivalence relation on the subset .
difunctional: the relation is the set for two partial functions and some indicator set
right and left Euclidean: For , and implies and similarly for left Euclideanness and imply
quasi-reflexive: If and , then and .
None of these properties is sufficient to imply that the relation is a PER.
In non-set-theory settings
In type theory, constructive mathematics and their applications to computer science, constructing analogues of subsets is often problematic—in these contexts PERs are therefore more commonly used, particularly to define setoids, sometimes called partial setoids. Forming a partial setoid from a type and a PER is analogous to forming subsets and quotients in classical set-theoretic mathe
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https://en.wikipedia.org/wiki/Sufi%20metaphysics
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In Islamic philosophy, Sufi metaphysics is centered on the concept of or . Two main Sufi philosophies prevail on this topic. literally means "the Unity of Existence" or "the Unity of Being." , meaning "existence" or "presence", here refers to God. On the other hand, , meaning "Apparentism" or "Monotheism of Witness", holds that God and his creation are entirely separate.
Some scholars have claimed that the difference between the two philosophies differ only in semantics and that the entire debate is merely a collection of "verbal controversies" which have come about because of ambiguous language. However, the concept of the relationship between God and the universe is still actively debated both among Sufis and between Sufis and non-Sufi Muslims.
Waḥdat al-Wujūd (unity of existence)
The mystical thinker and theologian Abu Saeed Mubarak Makhzoomi discussed this concept in his book called Tohfa Mursala. An Andalusian Sufi saint Ibn Sabin is also known to employ this term in his writings. But the Sufi saint who is most characterized in discussing the ideology of Sufi metaphysics in deepest details is Ibn Arabi. He employs the term wujud to refer to God as the Necessary Being. He also attributes the term to everything other than God, but he insists that wujud does not belong to the things found in the cosmos in any real sense. Rather, the things borrow wujud from God, much as the earth borrows light from the sun.
The issue is how wujūd can rightfully be attributed to the th
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https://en.wikipedia.org/wiki/Propagule
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In biology, a propagule is any material that functions in propagating an organism to the next stage in its life cycle, such as by dispersal. The propagule is usually distinct in form from the parent organism. Propagules are produced by organisms such as plants (in the form of seeds or spores), fungi (in the form of spores), and bacteria (for example endospores or microbial cysts).
In disease biology, pathogens are said to generate infectious propagules, the units that transmit a disease. These can refer to bacteria, viruses, fungi, or protists, and can be contained within host material. For instance, for influenza, the infectious propagules are carried in droplets of host saliva or mucus that are expelled during coughing or sneezing.
In horticulture, a propagule is any plant material used for the purpose of plant propagation. In asexual reproduction, a propagule is often a stem cutting. In some plants, a leaf section or a portion of root can be used. In sexual reproduction, a propagule is a seed or spore. In micropropagation, a type of asexual reproduction, any part of the plant may be used, though it is usually a highly meristematic part such as root and stem ends or buds.
See also
Disseminule
Gemma (botany)
Plantlet
Propagule pressure
Seed dispersal
References
Horticulture
Plant reproduction
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https://en.wikipedia.org/wiki/Topological%20string%20theory
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In theoretical physics, topological string theory is a version of string theory. Topological string theory appeared in papers by theoretical physicists, such as Edward Witten and Cumrun Vafa, by analogy with Witten's earlier idea of topological quantum field theory.
Overview
There are two main versions of topological string theory: the topological A-model and the topological B-model. The results of the calculations in topological string theory generically encode all holomorphic quantities within the full string theory whose values are protected by spacetime supersymmetry. Various calculations in topological string theory are closely related to Chern–Simons theory, Gromov–Witten invariants, mirror symmetry, geometric Langlands Program, and many other topics.
The operators in topological string theory represent the algebra of operators in the full string theory that preserve a certain amount of supersymmetry. Topological string theory is obtained by a topological twist of the worldsheet description of ordinary string theory: the operators are given different spins. The operation is fully analogous to the construction of topological field theory which is a related concept. Consequently, there are no local degrees of freedom in topological string theory.
Admissible spacetimes
The fundamental strings of string theory are two-dimensional surfaces. A quantum field theory known as the N = (1,1) sigma model is defined on each surface. This theory consist of maps from the surface t
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https://en.wikipedia.org/wiki/Nikolay%20Sevastyanov
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Nikolai Sevastianov (born 1961, Chelyabinsk, USSR (now Russia)) graduated from the Aerodynamics and Space Exploration Department of the Moscow Institute of Physics and Technology in 1984. In 1984 he took a job at NPO Energia as an engineer and rose through the ranks to the position of a deputy general designer. Since 2000 he has been director general of Gascom joint-stock company. In May 2005 – June 2007 he was President of Energia corporation.
External links
1961 births
Soviet engineers
20th-century Russian engineers
Russian aerospace engineers
Moscow Institute of Physics and Technology alumni
Academic staff of the Moscow Institute of Physics and Technology
Living people
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https://en.wikipedia.org/wiki/Mevalonic%20acid
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Mevalonic acid (MVA) is a key organic compound in biochemistry; the name is a contraction of dihydroxymethylvalerolactone. The carboxylate anion of mevalonic acid, which is the predominant form in biological environments, is known as mevalonate and is of major pharmaceutical importance. Drugs like statins (which lower levels of cholesterol) stop the production of mevalonate by inhibiting HMG-CoA reductase.
Chemistry
Mevalonic acid is very soluble in water and polar organic solvents. It exists in equilibrium with its lactone form, called mevalonolactone, that is formed by internal condensation of its terminal alcohol and carboxylic acid functional groups. Mevalonolactone acts to correct statin linked myopathy and limb girdle muscular disease caused by HMG co-A reductase mutation.
Biology
Mevalonic acid is a precursor in the biosynthetic pathway known as the mevalonate pathway that produces terpenes and steroids. Mevalonic acid is the primary precursor of isopentenyl pyrophosphate (IPP), that is in turn the basis for all terpenoids. Mevalonic acid is chiral and the (3R)-enantiomer is the only one that is biologically active.
References
Beta hydroxy acids
Diols
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https://en.wikipedia.org/wiki/Frank%20Hugh%20Foster
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Frank Hugh Foster, Ph. D., D.D. (June 19, 1851 – October 20, 1935) was an American clergyman of the Congregational church. He was born in Springfield, Massachusetts, and graduated at Harvard in 1873.
In his activities, he was assistant professor of mathematics in the United States Naval Academy, graduated at Andover Theological Seminary (1877), served as pastor at North Reading, Massachusetts, studied at Göttingen and Leipzig (1879–1882), and from 1882 to 1884 was professor of philosophy in Middlebury College. In 1884 he was appointed professor of Church history in the Oberlin Theological Seminary; from 1892 to 1902, he served at Berkeley, California in the Pacific Seminary; and in 1904 he went to Olivet, Michigan as pastor of the college and the village church.
He was an editor of the Bibliotheca Sacra; translated Grotius' Defense (1889); and wrote Christian Life and Theology (1900), and A Genetic History of the New England Theology (on the New England Theology).
External links
Oberlin College Archives
1851 births
1935 deaths
American theologians
Harvard University alumni
Leipzig University alumni
Middlebury College faculty
People from Springfield, Massachusetts
United States Naval Academy faculty
University of Göttingen alumni
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https://en.wikipedia.org/wiki/Vinyl%20halide
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In organic chemistry, a vinyl halide is a compound with the formula CH2=CHX (X = halide). The term vinyl is often used to describe any alkenyl group. For this reason, alkenyl halides with the formula RCH=CHX are sometimes called vinyl halides. From the perspective of applications, the dominant member of this class of compounds is vinyl chloride, which is produced on the scale of millions of tons per year as a precursor to polyvinyl chloride. Polyvinyl fluoride is another commercial product. Related compounds include vinylidene chloride and vinylidene fluoride.
Synthesis
Vinyl chloride is produced by dehydrochlorination of 1,2-dichloroethane.
Due to their high utility, many approaches to vinyl halides have been developed, such as:
reactions of vinyl organometallic species with halogens
Takai olefination
Stork-Zhao olefination - a modification of the Wittig reaction
Olefin metathesis
Reactions
Vinyl bromide and related alkenyl halides form the Grignard reagent and related organolithium reagents. Alkenyl halides undergo base elimination to give the corresponding alkyne. Most important is their use in cross-coupling reactions (e.g. Suzuki-Miyaura coupling, Stille coupling, Heck coupling, etc.).
See also
Vinyl iodide functional group
References
Organohalides
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https://en.wikipedia.org/wiki/Implicit%20parallelism
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In computer science, implicit parallelism is a characteristic of a programming language that allows a compiler or interpreter to automatically exploit the parallelism inherent to the computations expressed by some of the language's constructs. A pure implicitly parallel language does not need special directives, operators or functions to enable parallel execution, as opposed to explicit parallelism.
Programming languages with implicit parallelism include Axum, BMDFM, HPF, Id, LabVIEW, MATLAB M-code, NESL, SaC, SISAL, ZPL, and pH.
Example
If a particular problem involves performing the same operation on a group of numbers (such as taking the sine or logarithm of each in turn), a language that provides implicit parallelism might allow the programmer to write the instruction thus:
numbers = [0 1 2 3 4 5 6 7];
result = sin(numbers);
The compiler or interpreter can calculate the sine of each element independently, spreading the effort across multiple processors if available.
Advantages
A programmer that writes implicitly parallel code does not need to worry about task division or process communication, focusing instead on the problem that his or her program is intended to solve. Implicit parallelism generally facilitates the design of parallel programs and therefore results in a substantial improvement of programmer productivity.
Many of the constructs necessary to support this also add simplicity or clarity even in the absence of actual parallelism. The example above, of
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https://en.wikipedia.org/wiki/George%20Downs
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George Downs may refer to:
George Downs (umpire) (1856–1936), Australian Test cricket umpire
George W. Downs (physicist), co-founder of Applied Physics Corporation (aka Cary Instruments)
George W. Downs (political scientist) (1946–2015), American political scientist
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https://en.wikipedia.org/wiki/Trihalide
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A trihalide in chemistry is an organohalide consisting of three halide atoms bonded to a single atom or compound. An example of a trihalide is chloroform.
The trihalomethanes are the simplest trihalides, because only one hydrogen is connected to the carbon. The 1,1,1-Trichloroethane is one of the trihalides of ethane.
See also
Fluoroform
Bromoform
Iodoform
References
Organohalides
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https://en.wikipedia.org/wiki/Thione
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Thione may refer to:
Thione (chemistry), the organosulfur analog of ketone
Thione (beetle), a genus in the family Monotomidae
Thione Seck (born 1955), Senegalese musician
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https://en.wikipedia.org/wiki/Thioketal
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In organosulfur chemistry, a thioketal is the sulfur analogue of a ketal (), with one of the oxygen replaced by sulfur (as implied by the thio- prefix), giving the structure . A dithioketal has both oxygens replaced by sulfur ().
Thioketals can be obtained by reacting ketones () or aldehydes () with thiols ().
An oxidative cleavage mechanism has been proposed for dithioketals, which involves thioether oxidation, the formation of thionoiums, and hydrolysis, resulting in the formation of aldehyde and ketone products.
Thioketal moieties are found to be responsive to reactive oxygen species (ROS). In the presence of ROS, thioketals can be selectively cleaved. ROS successfully cleave heterobifunctional thioketal linkers, which have been found to have therapeutic potential, as they can produce ROS-responsive agents with two different functionalities.
Ketones can be reduced at neutral pH via conversion to thioketals; the thioketal prepared from the ketone can be easily reduced by catalytic hydrogenation using Raney nickel in a reaction known as the Mozingo reduction.
See also
Thioacetal
References
Functional groups
Organosulfur compounds
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https://en.wikipedia.org/wiki/Pseudorandom%20function%20family
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In cryptography, a pseudorandom function family, abbreviated PRF, is a collection of efficiently-computable functions which emulate a random oracle in the following way: no efficient algorithm can distinguish (with significant advantage) between a function chosen randomly from the PRF family and a random oracle (a function whose outputs are fixed completely at random). Pseudorandom functions are vital tools in the construction of cryptographic primitives, especially secure encryption schemes.
Pseudorandom functions are not to be confused with pseudorandom generators (PRGs). The guarantee of a PRG is that a single output appears random if the input was chosen at random. On the other hand, the guarantee of a PRF is that all its outputs appear random, regardless of how the corresponding inputs were chosen, as long as the function was drawn at random from the PRF family.
A pseudorandom function family can be constructed from any pseudorandom generator, using, for example, the "GGM" construction given by Goldreich, Goldwasser, and Micali. While in practice, block ciphers are used in most instances where a pseudorandom function is needed, they do not, in general, constitute a pseudorandom function family, as block ciphers such as AES are defined for only limited numbers of input and key sizes.
Motivations from random functions
A PRF is an efficient (i.e. computable in polynomial time), deterministic function that maps two distinct sets (domain and range) and looks like a truly
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https://en.wikipedia.org/wiki/Nitrone
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In organic chemistry, a nitrone is a functional group consisting of an N-oxide of an imine. The general structure is , where R’ is not a hydrogen. A nitrone is a 1,3-dipole, and is used in 1,3-dipolar cycloadditions. Other reactions of nitrones are known, including formal [3+3] cycloadditions to form 6-membered rings, as well as formal [5+2] cycloadditions to form 7-membered rings.
Generation of nitrones
Nitrones are generated most often either by the oxidation of hydroxylamines or condensation of monosubstituted hydroxylamines with carbonyl compounds (ketones or aldehydes). The most general reagent used for the oxidation of hydroxylamines is mercury(II) oxide.
Carbonyl condensation methods avoid issues of site selectivity associated with the oxidation of hydroxylamines with two sets of (alpha) hydrogens.
A significant problem associated with many reactive nitrones is dimerization. This issue is alleviated experimentally by employing an excess of the nitrone or increasing the reaction temperature to exaggerate entropic factors.
Reactions
1,3-dipolar cycloadditions
As 1,3-dipoles, nitrones are useful in 1,3-dipolar cycloadditions. Upon reaction of a nitrone with an alkene dipolarophile, an isoxazolidine is formed:
See also
N-Oxoammonium salt
Nitronate
References
Functional groups
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https://en.wikipedia.org/wiki/E.%20B.%20Babcock
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Ernest Brown Babcock (July 10, 1877 – December 8, 1954) was an American plant geneticist who pioneered the under
standing of plant evolution in terms of genetics. He is particularly known for seeking to understand by field investigations and extensive experiments, the entire polyploid apomictic genus Crepis, in which he recognize 196 species. He published more than 100 articles and books explaining plant genetics, including the seminal textbook (with Roy Elwood Clausen) Genetics in Relation to Agriculture. He instructed Marion Elizabeth Stilwell Cave.
References
Publications
Carey, C.W. 2000. Babcock, Ernest Brown. American National Biography Online. Oxford University Press
External links
1877 births
1954 deaths
American geneticists
Modern synthesis (20th century)
University of California, Berkeley people
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https://en.wikipedia.org/wiki/Phosphonate
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In organic chemistry, phosphonates or phosphonic acids are organophosphorus compounds containing groups (where R = alkyl, aryl, or just hydrogen). Phosphonic acids, typically handled as salts, are generally nonvolatile solids that are poorly soluble in organic solvents, but soluble in water and common alcohols.
Many commercially important compounds are phosphonates, including glyphosate (the active molecule of the herbicide Roundup), and ethephon, a widely used plant growth regulator. Bisphosphonates are popular drugs for treatment of osteoporosis.
In biochemistry and medicinal chemistry, phosphonate groups are used as stable bioisosteres for phosphate, such as in the antiviral nucleotide analog, Tenofovir, one of the cornerstones of anti-HIV therapy. And there is an indication that phosphonate derivatives are "promising ligands for nuclear medicine."
Basic properties
Phosphonates feature tetrahedral phosphorus centers. They are structurally closely related to (and often prepared from) phosphorous acid.
Phosphonate salts are the result of deprotonation of phosphonic acids, which are diprotic acids:
RPO(OH)2 + NaOH → H2O + RPO(OH)(ONa) (monosodium phosphonate)
RPO(OH)(ONa) + NaOH → H2O + RPO(ONa)2 (disodium phosphonate)
Phosphonate esters are the result of condensation of phosphonic acids with alcohols.
Synthesis
Several methods exist for the preparation of phosphonic acids and their salts.
From phosphonic acid
Most processes begin with phosphorous acid (aka phospho
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https://en.wikipedia.org/wiki/Pole%E2%80%93zero%20plot
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In mathematics, signal processing and control theory, a pole–zero plot is a graphical representation of a rational transfer function in the complex plane which helps to convey certain properties of the system such as:
Stability
Causal system / anticausal system
Region of convergence (ROC)
Minimum phase / non minimum phase
A pole-zero plot shows the location in the complex plane of the poles and zeros of the transfer function of a dynamic system, such as a controller, compensator, sensor, equalizer, filter, or communications channel. By convention, the poles of the system are indicated in the plot by an X while the zeros are indicated by a circle or O.
A pole-zero plot is plotted in the plane of a complex frequency domain, which can represent either a continuous-time or a discrete-time system:
Continuous-time systems use the Laplace transform and are plotted in the s-plane:
Real frequency components are along its vertical axis (the imaginary line where )
Discrete-time systems use the Z-transform and are plotted in the z-plane:
Real frequency components are along its unit circle
Continuous-time systems
In general, a rational transfer function for a continuous-time LTI system has the form:
where
and are polynomials in ,
is the order of the numerator polynomial,
is the coefficient of the numerator polynomial,
is the order of the denominator polynomial, and
is the coefficient of the denominator polynomial.
Either or or both may be zero, but in rea
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https://en.wikipedia.org/wiki/Event%20generator
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Event generators are software libraries that generate simulated high-energy particle physics events.
They randomly generate events as those produced in particle accelerators, collider experiments or the early universe.
Events come in different types called processes as discussed in the Automatic calculation of particle interaction or decay article.
Despite the simple structure of the tree-level perturbative quantum field theory description of the collision and decay processes in an event, the observed high-energy process usually contains significant amount of modifications, like photon and gluon bremsstrahlung or loop diagram corrections, that usually are too complex to be easily evaluated in real calculations directly on the diagrammatic level. Furthermore, the non-perturbative nature of QCD bound states makes it necessary to include information that is well beyond the reach of perturbative quantum field theory, and also beyond present ability of computation in lattice QCD. And in collisional systems more complex than a few leptons and hadrons (e.g. heavy-ion collisions), the collective behavior of the system would involve a phenomenological description that also cannot be easily obtained from the fundamental field theory by a simple calculus.
Use in simulations
As said above, the experimental calibration involves processes that usually are too complicated to be easily evaluated in calculations directly, so any realistic test of the underlying physical process in a partic
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https://en.wikipedia.org/wiki/Lefschetz%20hyperplane%20theorem
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In mathematics, specifically in algebraic geometry and algebraic topology, the Lefschetz hyperplane theorem is a precise statement of certain relations between the shape of an algebraic variety and the shape of its subvarieties. More precisely, the theorem says that for a variety X embedded in projective space and a hyperplane section Y, the homology, cohomology, and homotopy groups of X determine those of Y. A result of this kind was first stated by Solomon Lefschetz for homology groups of complex algebraic varieties. Similar results have since been found for homotopy groups, in positive characteristic, and in other homology and cohomology theories.
A far-reaching generalization of the hard Lefschetz theorem is given by the decomposition theorem.
The Lefschetz hyperplane theorem for complex projective varieties
Let X be an n-dimensional complex projective algebraic variety in CPN, and let Y be a hyperplane section of X such that U = X ∖ Y is smooth. The Lefschetz theorem refers to any of the following statements:
The natural map Hk(Y, Z) → Hk(X, Z) in singular homology is an isomorphism for k < n − 1 and is surjective for k = n − 1.
The natural map Hk(X, Z) → Hk(Y, Z) in singular cohomology is an isomorphism for k < n − 1 and is injective for k = n − 1.
The natural map πk(Y, Z) → πk(X, Z) is an isomorphism for k < n − 1 and is surjective for k = n − 1.
Using a long exact sequence, one can show that each of these statements is equivalent to a vanishing theorem for certa
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https://en.wikipedia.org/wiki/Hyperplane%20section
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In mathematics, a hyperplane section of a subset X of projective space Pn is the intersection of X with some hyperplane H. In other words, we look at the subset XH of those elements x of X that satisfy the single linear condition L = 0 defining H as a linear subspace. Here L or H can range over the dual projective space of non-zero linear forms in the homogeneous coordinates, up to scalar multiplication.
From a geometrical point of view, the most interesting case is when X is an algebraic subvariety; for more general cases, in mathematical analysis, some analogue of the Radon transform applies. In algebraic geometry, assuming therefore that X is V, a subvariety not lying completely in any H, the hyperplane sections are algebraic sets with irreducible components all of dimension dim(V) − 1. What more can be said is addressed by a collection of results known collectively as Bertini's theorem. The topology of hyperplane sections is studied in the topic of the Lefschetz hyperplane theorem and its refinements. Because the dimension drops by one in taking hyperplane sections, the process is potentially an inductive method for understanding varieties of higher dimension. A basic tool for that is the Lefschetz pencil.
References
Algebraic geometry
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https://en.wikipedia.org/wiki/Saarland%20University
|
Saarland University (, ) is a public research university located in Saarbrücken, the capital of the German state of Saarland. It was founded in 1948 in Homburg in co-operation with France and is organized in six faculties that cover all major fields of science. In 2007, the university was recognized as an excellence center for computer science in Germany.
Thanks to bilingual German and French staff, the university has an international profile, which has been underlined by its proclamation as "European University" in 1950 and by establishment of Europa-Institut as its "crown and symbol" in 1951.
Nine academics have been honored with the highest German research prize, the Gottfried Wilhelm Leibniz Prize, while working at Saarland University.
History
Saarland University, the first to be established after World War II, was founded in November 1948 with the support of the French Government and under the auspices of the University of Nancy.
At the time the Saarland found itself in the special situation of being partly autonomous and linked to France by economic and monetary union. With its combination of the German and French educational traditions and the dual languages of instruction, the university had a European perspective right from the start. Prior to the foundation of the university, clinical training courses for medical students at the state hospital, Saarland University Hospital, in Homburg, Saarland, had been introduced in January 1946 and the "Centre Universitair
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https://en.wikipedia.org/wiki/Schauder%20basis
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In mathematics, a Schauder basis or countable basis is similar to the usual (Hamel) basis of a vector space; the difference is that Hamel bases use linear combinations that are finite sums, while for Schauder bases they may be infinite sums. This makes Schauder bases more suitable for the analysis of infinite-dimensional topological vector spaces including Banach spaces.
Schauder bases were described by Juliusz Schauder in 1927, although such bases were discussed earlier. For example, the Haar basis was given in 1909, and Georg Faber discussed in 1910 a basis for continuous functions on an interval, sometimes called a Faber–Schauder system.
Definitions
Let V denote a topological vector space over the field F. A Schauder basis is a sequence {bn} of elements of V such that for every element there exists a unique sequence {αn} of scalars in F so that The convergence of the infinite sum is implicitly that of the ambient topology, i.e., but can be reduced to only weak convergence in a normed vector space (such as a Banach space). Unlike a Hamel basis, the elements of the basis must be ordered since the series may not converge unconditionally.
Note that some authors define Schauder bases to be countable (as above), while others use the term to include uncountable bases. In either case, the sums themselves always are countable. An uncountable Schauder basis is a linearly ordered set rather than a sequence, and each sum inherits the order of its terms from this linear ord
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https://en.wikipedia.org/wiki/Raman%20Sundrum
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Raman Sundrum (born 1964) is an Indian-American theoretical particle physicist. He contributed to the field with a class of models called the Randall–Sundrum models, first published in 1999 with Lisa Randall.
Sundrum is a Distinguished University Professor at the University of Maryland and the director of Maryland Center for Fundamental Physics.
Biography
Sundrum did his undergraduate studies at University of Sydney in Australia and received his Ph.D. from Yale University in 1990. He was one of two Alumni Centennial Professors in the Department of Physics and Astronomy of the Johns Hopkins University. He was elected a Fellow of the American Physical Society in 2003 "for his discoveries in supergravity and in theories of extra dimensions, and for applications to testable models of fundamental physics".
In 2010, Sundrum left Johns Hopkins and moved to the University of Maryland. His research is in theoretical particle physics and focuses on theoretical mechanisms and observable implications of extra spacetime dimensions, supersymmetry, and strongly coupled dynamics.
According to Scientific American, he was considering leaving physics for finance, when he called collaborator Lisa Randall to propose working together on membranes, or "branes" as they are known. Branes are domains or swaths of several spatial dimensions within a higher-dimensional space. The fruits of that collaboration were papers known as RS-1 and RS-2.
Honors and awards
2019: J. J. Sakurai Prize for Theoret
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https://en.wikipedia.org/wiki/Leroy%20Dubeck
|
Leroy William Dubeck (born March 1, 1939) is an American chess master and retired professor of physics. He was president of the United States Chess Federation (USCF) from 1969 to 1972. Dubeck also writes science fiction.
Career
Academic
Dubeck is on the Faculty Committee of Temple University. He holds a PhD in physics from Rutgers University. He joined the Temple faculty in 1965, and retired in December 2012. He has served on dozens of senate, college and departmental committees including 15 years on the Faculty Senate Budget Review Committee, three years on the former Faculty Senate Research and Study Leaves Committee and served on the University Study Leaves Committee. He is the recipient of the Stauffer Award for service to Temple University.
He has been twice acting chair of the physics department and former chair of the Collegial Assembly of Temple's college of science and technology. he is the author/co-author of six college textbooks and has been active in curricular improvements in science courses. He developed and teaches the only completely online course offered by the physics department. He has been the recipient of more than 20 grants, mostly from the National Science Foundation.
Chess
Dubeck was president of the United States Chess Federation from 1969 to 1972. He was instrumental in getting Bobby Fischer to play his match for the 1972 World Chess Championship against Boris Spassky, although the match took place after his term of office was over. A life membe
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https://en.wikipedia.org/wiki/Local%20system
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In mathematics, a local system (or a system of local coefficients) on a topological space X is a tool from algebraic topology which interpolates between cohomology with coefficients in a fixed abelian group A, and general sheaf cohomology in which coefficients vary from point to point. Local coefficient systems were introduced by Norman Steenrod in 1943.
Local systems are the building blocks of more general tools, such as constructible and perverse sheaves.
Definition
Let X be a topological space. A local system (of abelian groups/modules/...) on X is a locally constant sheaf (of abelian groups/modules...) on X. In other words, a sheaf is a local system if every point has an open neighborhood such that the restricted sheaf is isomorphic to the sheafification of some constant presheaf.
Equivalent definitions
Path-connected spaces
If X is path-connected, a local system of abelian groups has the same stalk L at every point. There is a bijective correspondence between local systems on X and group homomorphisms
and similarly for local systems of modules. The map giving the local system is called the monodromy representation of .
This shows that (for X path-connected) a local system is precisely a sheaf whose pullback to the universal cover of X is a constant sheaf.
This correspondence can be upgraded to an equivalence of categories between the category of local systems of abelian groups on X and the category of abelian groups endowed with an action of (equivalently
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https://en.wikipedia.org/wiki/Array-access%20analysis
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In computer science, array-access analysis is a compiler analysis approach used to decide the read and write access patterns to elements or portions of arrays.
The major data type manipulated in scientific programs is the array. The define/use analysis on a whole array is insufficient for aggressive compiler optimizations such as auto parallelization and array privatization. Array access analysis aims to obtain the knowledge of which portions or even which elements of the array are accessed by a given code segment (basic block, loop, or even at the procedure level).
Array-access analysis can be largely categorized into exact (or reference-list-based) and summary methods for different tradeoffs of accuracy and complexity. Exact methods are precise but very costly in terms of computation and space storage, while summary methods are approximate but can be computed quickly and economically.
Typical exact array-access analysis include linearization and atom images. Summary methods can be further divided into array sections, bounded regular sections using triplet notation, linear-constraint methods such as data-access descriptors and array-region analysis.
References
Compiler construction
Static program analysis
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https://en.wikipedia.org/wiki/Ethyl%20isopropyl%20ketone
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Ethyl isopropyl ketone (2-methyl-3-pentanone) is an aliphatic ketone with used as a reagent in organic chemistry and as a solvent.
Its fully fluorinated analog is known as Novec 1230 and is used in gaseous fire suppression.
References
Hexanones
Ketone solvents
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https://en.wikipedia.org/wiki/L%C3%A1szl%C3%B3%20Babai
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László "Laci" Babai (born July 20, 1950, in Budapest) is a Hungarian professor of computer science and mathematics at the University of Chicago. His research focuses on computational complexity theory, algorithms, combinatorics, and finite groups, with an emphasis on the interactions between these fields.
Life
In 1968, Babai won a gold medal at the International Mathematical Olympiad. Babai studied mathematics at Faculty of Science of the Eötvös Loránd University from 1968 to 1973, received a PhD from the Hungarian Academy of Sciences in 1975, and received a DSc from the Hungarian Academy of Sciences in 1984. He held a teaching position at Eötvös Loránd University since 1971; in 1987 he took joint positions as a professor in algebra at Eötvös Loránd and in computer science at the University of Chicago. In 1995, he began a joint appointment in the mathematics department at Chicago and gave up his position at Eötvös Loránd.
Work
He is the author of over 180 academic papers.
His notable accomplishments include the introduction of interactive proof systems, the introduction of the term Las Vegas algorithm, and the introduction of group theoretic methods in graph isomorphism testing. In November 2015, he announced a quasipolynomial time algorithm for the graph isomorphism problem.
He is editor-in-chief of the refereed online journal Theory of Computing. Babai was also involved in the creation of the Budapest Semesters in Mathematics program and first coined the name.
Graph iso
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https://en.wikipedia.org/wiki/Arenium%20ion
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An arenium ion in organic chemistry is a cyclohexadienyl cation that appears as a reactive intermediate in electrophilic aromatic substitution.
For historic reasons this complex is also called a Wheland intermediate, after American chemist George Willard Wheland (1907–1976). They are also called sigma complexes. The smallest arenium ion is the benzenium ion (), which is protonated benzene.
Two hydrogen atoms bonded to one carbon lie in a plane perpendicular to the benzene ring. The arenium ion is no longer an aromatic species; however it is relatively stable due to delocalization: the positive charge is delocalized over 3 carbon atoms by the pi system, as depicted on the following resonance structures:
A complexed electrophile can contribute to the stability of arenium ions.
Salts of benzenium ion can be isolated when benzene is protonated by the carborane superacid H(CB11H(CH3)5Br6). The benzenium salt is crystalline with thermal stability up to 150 °C. Bond lengths deduced from X-ray crystallography are consistent with a cyclohexadienyl cation structure.
In one study a methylene arenium ion is stabilized by metal complexation:
In this reaction sequence the R–Pd(II)–Br starting complex 1 stabilized by TMEDA is converted through dppe to metal complex 2. Electrophilic attack of methyl triflate forms methylene arenium ion 3 with (based on X-ray crystallography) positive charge located in aromatic para position and with the methylene group 6° out of the plane of the ring.
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https://en.wikipedia.org/wiki/Subderivative
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In mathematics, the subderivative, subgradient, and subdifferential generalize the derivative to convex functions which are not necessarily differentiable. Subderivatives arise in convex analysis, the study of convex functions, often in connection to convex optimization.
Let be a real-valued convex function defined on an open interval of the real line. Such a function need not be differentiable at all points: For example, the absolute value function is non-differentiable when . However, as seen in the graph on the right (where in blue has non-differentiable kinks similar to the absolute value function), for any in the domain of the function one can draw a line which goes through the point and which is everywhere either touching or below the graph of f. The slope of such a line is called a subderivative.
Definition
Rigorously, a subderivative of a convex function at a point in the open interval is a real number such that
for all . By the converse of the mean value theorem, the set of subderivatives at for a convex function is a nonempty closed interval , where and are the one-sided limits
The set of all subderivatives is called the subdifferential of the function at , denoted by . If is convex, then its subdifferential at any point is non-empty. Moreover, if its subdifferential at contains exactly one subderivative, then and is differentiable at .
Example
Consider the function which is convex. Then, the subdifferential at the origin is the interval
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https://en.wikipedia.org/wiki/International%20Colloquium%20on%20Group%20Theoretical%20Methods%20in%20Physics
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The International Colloquium on Group Theoretical Methods in Physics (ICGTMP) is an academic conference devoted to applications of group theory to physics. It was founded in 1972 by Henri Bacry and Aloysio Janner. It hosts a colloquium every two years. The ICGTMP is led by a Standing Committee, which helps select winners for the three major awards presented at the conference: the Wigner Medal (19782018), the Hermann Weyl Prize (since 2002) and the Weyl-Wigner Award (since 2022).
Wigner Medal
The Wigner Medal was an award designed "to recognize outstanding contributions to the understanding of physics through Group Theory". It was administered by The Group Theory and Fundamental Physics Foundation, a publicly supported organization. The first award was given in 1978 to Eugene Wigner at the Integrative Conference on Group Theory and Mathematical Physics.
The collaboration between the Standing Committee of the ICGTMP and the Foundation ended in 2020. In 2023 a new process for awarding the Wigner Medal was created by the Foundation. The new Wigner Medal can be granted in any field of theoretical physics. The new Wigner Medals for 2020 and 2022 were granted retrospectively in 2023. The first winners of the new prize were Yvette Kosmann-Schwarzbach, and Daniel Greenberger.
The Standing Committee does not recognize the post-2018 Wigner Medals awarded by the Foundation as the continuation of the prize from 1978 through 2018.
Weyl-Wigner Award
In 202021, the ICGTMP Standing Comm
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https://en.wikipedia.org/wiki/Foton%20%28satellite%29
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Foton (or Photon) is the project name of two series of Russian science satellite and reentry vehicle programs. Although uncrewed, the design was adapted from the crewed Vostok spacecraft capsule. The primary focus of the Foton project is materials science research, but some missions have also carried experiments for other fields of research including biology. The original Foton series included 12 launches from the Plesetsk Cosmodrome from 1985 to 1999.
The second series, under the name Foton-M, incorporates many design improvements over the original Foton, and is still in use. So far, there have been four launch attempts of the Foton-M. The first was in 2002 from the Plesetsk Cosmodrome, which ended in failure due to a problem in the launch vehicle. The last three were from the Baikonur Cosmodrome, in 2005, 2007, and 2014; all were successful. Both the Foton and Foton-M series used Soyuz-U (11A511U and 11A511U2) rockets as launch vehicles. Starting with the Foton-7 mission, the European Space Agency has been a partner in the Foton program.
Foton-M
Foton-M is a new generation of Russian robotic spacecraft for research conducted in the microgravity environment of Earth orbit. The Foton-M design is based on the design of the Foton, with several improvements including a new telemetry and telecommand unit for increased data flow rate, increased battery capacity, and a better thermal control system. It is produced by TsSKB-Progress in Samara.
The launch of Foton-M1 failed becau
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https://en.wikipedia.org/wiki/Medical%20genetics
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Medical genetics is the branch of medicine that involves the diagnosis and management of hereditary disorders. Medical genetics differs from human genetics in that human genetics is a field of scientific research that may or may not apply to medicine, while medical genetics refers to the application of genetics to medical care. For example, research on the causes and inheritance of genetic disorders would be considered within both human genetics and medical genetics, while the diagnosis, management, and counselling people with genetic disorders would be considered part of medical genetics.
In contrast, the study of typically non-medical phenotypes such as the genetics of eye color would be considered part of human genetics, but not necessarily relevant to medical genetics (except in situations such as albinism). Genetic medicine is a newer term for medical genetics and incorporates areas such as gene therapy, personalized medicine, and the rapidly emerging new medical specialty, predictive medicine.
Scope
Medical genetics encompasses many different areas, including clinical practice of physicians, genetic counselors, and nutritionists, clinical diagnostic laboratory activities, and research into the causes and inheritance of genetic disorders. Examples of conditions that fall within the scope of medical genetics include birth defects and dysmorphology, intellectual disabilities, autism, mitochondrial disorders, skeletal dysplasia, connective tissue disorders, cancer geneti
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https://en.wikipedia.org/wiki/INDO
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INDO stands for Intermediate Neglect of Differential Overlap. It is a semi-empirical quantum chemistry method that is a development of the complete neglect of differential overlap (CNDO/2) method introduced by John Pople. Like CNDO/2 it uses zero-differential overlap for the two-electron integrals but not for integrals that are over orbitals centered on the same atom.
The method is now rarely used in its original form with some exceptions but it is the basis for several other methods, such as MINDO, ZINDO and SINDO.
See also
Computational chemistry
References
Semiempirical quantum chemistry methods
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https://en.wikipedia.org/wiki/ZINDO
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ZINDO is a semi-empirical quantum chemistry method used in computational chemistry. It is a development of the INDO method. It stands for Zerner's Intermediate Neglect of Differential Overlap, as it was developed by Michael Zerner and his coworkers in the 1970s. Unlike INDO, which was really restricted to organic molecules and those containing the atoms B to F, ZINDO covers a wide range of the periodic table, even including the rare-earth elements. There are two distinct versions of the method:
ZINDO/1 – for calculating ground-state properties such as bond lengths and bond angles. It refers to a SCF (RHF or ROHF) calculation with the INDO/1 level as suggested by Pople, which provides the reference state MO coefficients. Ground-state dipole moments and ionization potentials are in general very accurate. Geometry optimizations are erratic, what prompted Zerner's group to improve the performance of the code in the late 1990s
ZINDO/S (sometimes just called INDO/S) – use the INDO/1 molecular orbitals for calculating excited states and hence electronic spectra. It consists of a CI calculation including only the reference state plus a small set of single-electron excitations within a selected active space, typically five HOMOs and five LUMOs.
The original BIGSPEC program from the Zerner group is not widely available, but the method is implemented in ORCA, in part, in Gaussian, and in SCIGRESS.
To obtain good results, it is frequently necessary to fit the parameters to a given mo
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https://en.wikipedia.org/wiki/SINDO
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SINDO, is one of many semi-empirical quantum chemistry methods. It stands for symmetric orthogonalised INDO and was developed by K. Jug and coworkers. Like MINDO, it is a development of the INDO method. The main development is the inclusion of d orbitals for atoms of the second row of the periodic table. It performs better for hypervalent compounds than other semiempirical methods.
References
Semiempirical quantum chemistry methods
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https://en.wikipedia.org/wiki/V%20particle
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In particle physics, V was a generic name for heavy, unstable subatomic particles that decay into a pair of particles, thereby producing a characteristic letter V in a bubble chamber or other particle detector. Such particles were first detected in cosmic ray interactions in the atmosphere in the late 1940s and were first produced using the Cosmotron particle accelerator at Brookhaven National Laboratory in the 1950s. Since all such particles have now been identified and given specific names, for instance Kaons or Sigma baryons, this term has fallen into disuse.
V0 is still used on occasion to refer generally to neutral particles that may confuse the B-tagging algorithms in a modern particle detector, as is used in Section 7 of
this ATLAS conference note.
References
Subatomic particles
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https://en.wikipedia.org/wiki/NDDO
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In computational chemistry, NDDO (neglect of diatomic differential overlap) is a formalism that was first introduced by John Pople and it is now the basis of most successful semiempirical methods. While INDO added all one-centre two electron integrals to the CNDO/2 formalism, NDDO adds all two centre integrals for repulsion between a charge distribution on one centre and a charge distribution on another centre. Otherwise the zero-differential overlap approximation is used.
A common software program is MOPAC (Molecular Orbital PACkage).
In the Neglect of Diatomic Differential Overlap (NDDO) method the overlap matrix S is replaced by the unit matrix. This allows one to replace the Hartree–Fock secular equation |H–ES| = 0 with a simpler equation |H–E|=0. The two-electron integrals from the NDDO approximation can either be one-, two-, three- or four-centered.
The one-and two-centered integrals are evaluated approximately or parameterized based on the experimental data while the three- and four-centered integrals vanish. Usually, only the valence electrons are treated quantum mechanically while the role of core electrons is to reduce the nuclear charge. Semiempirical calculations are usually carried out in a minimal basis set.
See also
MNDO
AM1
PM3
SAM1
RM1
MOPAC
References
Semiempirical quantum chemistry methods
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https://en.wikipedia.org/wiki/Fred%20L.%20Smith%20%28political%20writer%29
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Fred L. Smith Jr. is founder and former president of the Competitive Enterprise Institute, a Washington, D.C.-based nonprofit libertarian think tank. He has written on topics such as antitrust law, environmental regulation, and the economic impacts of global warming.
Education
Smith holds a B.S. degree in Theoretical Mathematics and Political Science from Tulane University where he earned the Arts and Sciences Medal (Tulane’s highest academic award) and was elected to Phi Beta Kappa.
Career
Smith served as Director of Government Relations for the Council for a Competitive Economy, as a senior economist for the Association of American Railroads, and for five years as a Senior Policy Analyst at the Environmental Protection Agency. Currently, he sits on the Institute Turgot in Belgium.
Smith founded the Competitive Enterprise Institute in 1984. In 2003, Smith lobbied the Secretary of the Treasury against a proposal that would require banks to report interest earned by non-resident aliens. Smith argued that foreign investors' willingness to invest in the United States depends on how they are treated by financial regulators.
Smith appeared on Crossfire in 2006 and stated: "We know that there are these elaborate computer models that have never been right before, may be right this time, that suggest climate changes, possibly good, possibly bad. Most of the indications right now are it looks pretty good. Warmer winters, warmer nights, no effects during the day because of cloudin
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https://en.wikipedia.org/wiki/Carl%20B.%20Allendoerfer
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Carl Barnett Allendoerfer (April 4, 1911 – September 29, 1974) was an American mathematician in the mid-twentieth century, known for his work in topology and mathematics education.
Background
Allendoerfer was born in Kansas City, the son of a prominent banker. He graduated from Haverford College in 1932 and attended New College, Oxford as a Rhodes Scholar, 1932-1934. He received his Ph.D. in mathematics from Princeton University in 1937.
Research & Teaching
Allendoerfer taught at Haverford College in the mid-1940s where he became known for work with André Weil on the Gauss–Bonnet theorem, an important theorem in differential geometry. He continued his studies of differential geometry at the Institute for Advanced Study (1948-1949).
In 1951, he became professor and later chair of the Mathematics Department at the University of Washington, where he is known for establishing the Summer Mathematics Institute for High School Teachers. Allendoerfer was president of the Mathematical Association of America (1959–60) and editor of its monthly journal. In 1966 he won a Lester R. Ford Award. In 1972, he received the MAA's Award for Distinguished Service to Mathematics. After his death, the MAA established the Carl B. Allendoerfer Award, which is given each year for "expository excellence published in Mathematics Magazine."
Allendoerfer is also known as a proponent of the New Math movement in the 1950s and 1960s, which sought to improve American primary and secondary mathemati
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https://en.wikipedia.org/wiki/Banach%20bundle
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In mathematics, a Banach bundle is a vector bundle each of whose fibres is a Banach space, i.e. a complete normed vector space, possibly of infinite dimension.
Definition of a Banach bundle
Let M be a Banach manifold of class Cp with p ≥ 0, called the base space; let E be a topological space, called the total space; let π : E → M be a surjective continuous map. Suppose that for each point x ∈ M, the fibre Ex = π−1(x) has been given the structure of a Banach space. Let
be an open cover of M. Suppose also that for each i ∈ I, there is a Banach space Xi and a map τi
such that
the map τi is a homeomorphism commuting with the projection onto Ui, i.e. the following diagram commutes:
and for each x ∈ Ui the induced map τix on the fibre Ex
is an invertible continuous linear map, i.e. an isomorphism in the category of topological vector spaces;
if Ui and Uj are two members of the open cover, then the map
is a morphism (a differentiable map of class Cp), where Lin(X; Y) denotes the space of all continuous linear maps from a topological vector space X to another topological vector space Y.
The collection {(Ui, τi)|i∈I} is called a trivialising covering for π : E → M, and the maps τi are called trivialising maps. Two trivialising coverings are said to be equivalent if their union again satisfies the two conditions above. An equivalence class of such trivialising coverings is said to determine the structure of a Banach bundle on π : E → M.
If all the spaces Xi are isomorph
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https://en.wikipedia.org/wiki/The%20Heights%20School%20%28Maryland%29
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The Heights School is a preparatory school for boys in grades 3–13 in Potomac, Maryland, United States. Its mission is to assist parents in the intellectual, spiritual, and physical education of their sons. The Heights School offers a liberal arts curriculum in English, mathematics, classics, history, religion, science, Spanish, art, computers, and music.
As of 2017–2018, the school had an enrollment of 538 kids and 62.1 classroom teachers (on an FTE basis), for a student-teacher ratio of 8.7. Opus Dei, a personal prelature of the Catholic Church, supervises the school's religious orientation and spiritual formation. The local church authority, the Roman Catholic Archdiocese of Washington, however, does not include the Heights in their list of Catholic schools. Still, the faculty for the Catholic doctrine program as well as the curriculum are reviewed and approved by the Archdiocese of Washington.
Athletics
The Heights School currently has 12 different sports teams : cross country, golf, soccer, basketball, squash, swimming, wrestling, baseball, lacrosse, tennis, track and field, and rugby.
The Heights School is known for fielding especially strong soccer teams. Products of The Heights program include former national team and professional player Freddy Adu. Players from The Heights are often recruited by top programs.
In the fall of 2018 – the first year of membership in the WCAC – The Heights varsity soccer team won the Washington Catholic Athletic Conference championsh
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https://en.wikipedia.org/wiki/Cogenerator
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Cogenerator may refer to:
Cogeneration, simultaneous generation of heat and electricity
Injective cogenerator, in mathematics
More generally, cogenerator is the dual of a generator of a category.
An operator in the dilation theorem for contraction semigroups
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https://en.wikipedia.org/wiki/Schlieren
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Schlieren ( ; , ) are optical inhomogeneities in transparent media that are not necessarily visible to the human eye. Schlieren physics developed out of the need to produce high-quality lenses devoid of such inhomogeneities. These inhomogeneities are localized differences in optical path length that cause deviations of light rays, especially by refraction. This light deviation can produce localized brightening, darkening, or even color changes in an image, depending on the directions the rays deviate.
History
Schlieren were first observed by Robert Hooke in 1665 using a large concave lens and two candles. One candle served as a light source. The warm air rising from the second candle provided the schliere.
The conventional schlieren system is credited mostly to German physicist August Toepler, though Jean Bernard Léon Foucault invented the method in 1859 that Toepler improved upon. Toepler's original system was designed to detect schlieren in glass used to make lenses. In the conventional schlieren system, a point source is used to illuminate the test section containing the schliere. An image of this light is formed using a converging lens (also called a schlieren lens). This image is located at the conjugate distance to the lens according to the thin lens equation:
where is the focal length of the lens, is the distance from the object to the lens and is the distance from the image of the object to the lens. A knife edge at the point source-image location is pos
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https://en.wikipedia.org/wiki/Association%20for%20the%20Scientific%20Study%20of%20Consciousness
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The Association for the Scientific Study of Consciousness (ASSC) is a non-profit organization for professional membership that aims to encourage research on consciousness in cognitive science, neuroscience, philosophy, and other relevant disciplines. The association aims to advance research about the nature, function, and underlying mechanisms of consciousness.
History
The organization was created in 1994 in Berkeley. The original aim of the organization was to act as a framework by which the international academic community could generate meetings devoted to the academic study of consciousness. The original founding members included Bernard Baars, William Banks, George Buckner, David Chalmers, Stanley Klein, Bruce Mangan, Thomas Metzinger, David Rosenthal, and Patrick Wilken. Since 1994, the organization has put on eleven meetings and assumed many other activities, including an e-print archive and an online journal Psyche. The Psyche journal is no longer active.
Activities
Since 1997, the ASSC has organized annual conferences to promote interaction and spread knowledge of scientific and philosophical advances in the field of consciousness research.
In addition to organizing annual meetings, the association promotes the academic study of consciousness in a number of other ways:
The official journal of the society is the open-access journal Neuroscience of Consciousness.
The association published the open-access journal Psyche until 2010.
The association provides a free
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https://en.wikipedia.org/wiki/Recrystallization%20%28metallurgy%29
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In materials science, recrystallization is a process by which deformed grains are replaced by a new set of defect-free grains that nucleate and grow until the original grains have been entirely consumed. Recrystallization is usually accompanied by a reduction in the strength and hardness of a material and a simultaneous increase in the ductility. Thus, the process may be introduced as a deliberate step in metals processing or may be an undesirable byproduct of another processing step. The most important industrial uses are softening of metals previously hardened or rendered brittle by cold work, and control of the grain structure in the final product. Recrystallization temperature is typically 0.3–0.4 times the melting point for pure metals and 0.5 times for alloys.
Definition
Recrystallization is defined as the process in which grains of a crystal structure come in a new structure or new crystal shape.
A precise definition of recrystallization is difficult to state as the process is strongly related to several other processes, most notably recovery and grain growth. In some cases it is difficult to precisely define the point at which one process begins and another ends. Doherty et al. (1997) defined recrystallization as:
"... the formation of a new grain structure in a deformed material by the formation and migration of high angle grain boundaries driven by the stored energy of deformation. High angle boundaries are those with greater than a 10-15° misorientation"
Thus t
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https://en.wikipedia.org/wiki/William%20Hallock
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William Hallock, Ph. D., D.Pharm. (1857–1913) was an American physicist, born at Milton, New York.
He graduated from Columbia College in 1879, and received the degree of Ph.D. from Würzburg, German Empire in 1881.
He served as professor of chemistry and toxicology at the National College of Pharmacy in 1889–92, and as physicist of the United States Geological Survey from 1882 to 1891, then returned to Columbia as adjunct professor of physics in 1892.
He became full professor in 1902 and was dean of the faculty of pure science (1906–09).
Professor Hallock wrote Outlines of the Evolution of Weights and Measures and the Metric System (1906).
References
1857 births
1913 deaths
American chemists
American physicists
American science writers
Columbia College (New York) alumni
Columbia University faculty
People from Ulster County, New York
Scientists from New York (state)
Expatriates in the German Empire
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https://en.wikipedia.org/wiki/Gerald%20Schatten
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Gerald Schatten (born 1949) is an American stem cell researcher with interests in cell, developmental, and reproductive biology. He is Professor and vice-chair of Obstetrics, Gynecology and Reproductive Sciences and Professor of Cell Biology and of Bioengineering in the Schools of Medicine and Engineering at the University of Pittsburgh, where he is also Director of the Division of Developmental and Regenerative Medicine at the university's School of Medicine. Additionally, he is deputy director of the Magee-Women's Research Institute and Director of the Pittsburgh Development Center.. He is a member of the NCI-designated University of Pittsburgh Cancer Center and the McGowan Institute for Regenerative Medicine.
Early life and education
Schatten was born in 1949 in New York City and was educated in the public school system, including at Stuyvesant High School. He graduated with an A.B. in Zoology from the University of California, Berkeley in 1971, where he also obtained his Ph.D. in Cell and Developmental Biology.
Academic career
Schatten was awarded a Rockefeller Foundation Postdoctoral Fellowship for 1976–1977 to conduct mentored research under the direction of Daniel Mazia at UC Berkeley. He was also awarded a postdoctoral fellowship at the German Cancer Research Center.
1976-1985 he was assistant professor, associate professor, Full Professor of Biological Sciences and Molecular Biophysics at Florida State University; while there, he received a National Institutes
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https://en.wikipedia.org/wiki/Carbonate%20ester
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In organic chemistry, a carbonate ester (organic carbonate or organocarbonate) is an ester of carbonic acid. This functional group consists of a carbonyl group flanked by two alkoxy groups. The general structure of these carbonates is and they are related to esters (), ethers () and also to the inorganic carbonates.
Monomers of polycarbonate (e.g. Makrolon or Lexan) are linked by carbonate groups. These polycarbonates are used in eyeglass lenses, compact discs, and bulletproof glass. Small carbonate esters like dimethyl carbonate, ethylene carbonate, propylene carbonate are used as solvents, dimethyl carbonate is also a mild methylating agent.
Structures
Carbonate esters have planar OC(OC)2 cores, which confers rigidity. The unique O=C bond is short (1.173 Å in the depicted example), while the C-O bonds are more ether-like (the bond distances of 1.326 Å for the example depicted).
Carbonate esters can be divided into three structural classes: acyclic, cyclic, and polymeric. The first and general case is the acyclic carbonate group. Organic substituents can be identical or not. Both aliphatic or aromatic substituents are known, they are called dialkyl or diaryl carbonates, respectively. The simplest members of these classes are dimethyl carbonate and diphenyl carbonate.
Alternatively, the carbonate groups can be linked by a 2- or 3-carbon bridge, forming cyclic compounds such as ethylene carbonate and trimethylene carbonate. The bridging compound can also have substit
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https://en.wikipedia.org/wiki/Phosphoranes
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A phosphorane (IUPAC name: λ5-phosphane) is a functional group in organophosphorus chemistry with pentavalent phosphorus. Phosphoranes have the general formula PR5.
Phosphoranes of the type PX5 adopt a trigonal bipyramidal molecular geometry with the two apical bonds longer than the three equatorial bonds. Hypervalent bonding is described by inclusion of non-bonding MOs, as also invoked for the closely related molecule phosphorus pentafluoride.
Examples
The parent hydride compound is the hypothetical molecule PH5.
Pentaphenylphosphorane (Ph5P) is stable.
Pentaalkoxyphosphoranes are more common with electronegative substituents. Examples of P(OR)5 (R = alkyl), have however been prepared by reaction of phosphites with benzene alkyl sulfenates:
Wittig reagents
Phosphoranes of the type R3P=CR2 are more common and more important. Phosphoranes are also considered to be one of the resonance structures of ylides, these compounds feature a tetrahedral phosphorus center including a phosphorus–carbon double bond. These compounds are used as reagents in the Wittig reaction, for instance methylenetriphenylphosphorane or Ph3P=CH2.
See also
Organophosphorus chemistry
Phosphane
References
Organophosphanes
Functional groups
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https://en.wikipedia.org/wiki/Charles%20Thaxton
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Charles B. Thaxton (born 1939) is a proponent of special creation who went on to become one of the first intelligent design authors.
He was a Fellow of the Discovery Institute's Center for Science and Culture, and is currently a Fellow of the Discovery Institute.
Biography
Thaxton earned a doctorate in physical chemistry from Iowa State University. He went on to complete post-doctorate programs in the history of science at Harvard University and the molecular biology laboratories of Brandeis University.
Thaxton has co-authored several books, including The Mystery of Life's Origin and The Soul of Science. In The Mystery of Life's Origin, Thaxton argues for "Special Creation by a creator beyond the cosmos", and asserts that Special Creation holds "that the source that produced life was intelligent".
He was the editor of the first edition of the intelligent design textbook, Of Pandas and People. The book was featured prominently in Kitzmiller v. Dover Area School District and the sequence of drafts that show the transition between the terms "creation" and "creator" to "design", "designer", and "intelligent design", proved important in the judge's decision.
Thaxton stated that he preferred intelligent design to creationism because he "wasn’t comfortable with the typical vocabulary that for the most part creationists were using because it didn’t express what I was trying to do. They were wanting to bring God into the discussion, and I was wanting to stay within the empirical
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https://en.wikipedia.org/wiki/AMPAC
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AMPAC is a general-purpose semiempirical quantum chemistry program. It is marketed by Semichem, Inc. and was developed originally by Michael Dewar and his group.
The first version of AMPAC (2.1) was made available in 1985 through the Quantum Chemistry Program Exchange (QCPE). Subsequent versions were released through the same source, representing minor updates and optimized versions for other platforms.
In 1992, Semichem, Inc. was formed at Professor Dewar's urging to maintain and market the program. AMPAC 4.0 with Graphical User Interface was released in August of that year. Semichem's current version of AMPAC is 10.
AMPAC current implements the SAM1, AM1, MNDO, MNDO/d, PM3, MNDOC MINDO/3, RM1 and PM6 semi-empirical methods and AMSOL and COSMO salvation models. See this page for a detailed description of AMPAC's current capabilities.
See also
Quantum chemistry computer programs
References
Computational chemistry software
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https://en.wikipedia.org/wiki/Wheeler%27s%20delayed-choice%20experiment
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Wheeler's delayed-choice experiment describes a family of thought experiments in quantum physics proposed by John Archibald Wheeler, with the most prominent among them appearing in 1978 and 1984. These experiments are attempts to decide whether light somehow "senses" the experimental apparatus in the double-slit experiment it travels through, adjusting its behavior to fit by assuming an appropriate determinate state, or whether light remains in an indeterminate state, exhibiting both wave-like and particle-like behavior until measured.
The common intention of these several types of experiments is to first do something that, according to some hidden-variable models, would make each photon "decide" whether it was going to behave as a particle or behave as a wave, and then, before the photon had time to reach the detection device, create another change in the system that would make it seem that the photon had "chosen" to behave in the opposite way. Some interpreters of these experiments contend that a photon either is a wave or is a particle, and that it cannot be both at the same time. Wheeler's intent was to investigate the time-related conditions under which a photon makes this transition between alleged states of being. His work has been productive of many revealing experiments.
This line of experimentation proved very difficult to carry out when it was first conceived. Nevertheless, it has proven very valuable over the years since it has led researchers to provide "incre
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https://en.wikipedia.org/wiki/For
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For or FOR may refer to:
English language
For, a preposition
For, a complementizer
For, a grammatical conjunction
Science and technology
Fornax, a constellation
for loop, a programming language statement
Frame of reference, in physics
Field of regard, in optoelectronics
Forced outage rate, in reliability engineering
Other uses
Fellowship of Reconciliation, a number of religious nonviolent organizations
Pinto Martins International Airport (IATA airport code), an airport in Brazil
Revolutionary Workers Ferment (Fomento Obrero Revolucionario), a small left communist international
Fast oil recovery, systems to remove an oil spill from a wrecked ship
Field of Research, a component of the Australian and New Zealand Standard Research Classification
FOR, free on rail, an historic form of international commercial term or Incoterm
See also
Four (disambiguation)
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https://en.wikipedia.org/wiki/Timeline%20of%20information%20theory
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A timeline of events related to information theory, quantum information theory and statistical physics, data compression, error correcting codes and related subjects.
1872 – Ludwig Boltzmann presents his H-theorem, and with it the formula Σpi log pi for the entropy of a single gas particle
1878 – J. Willard Gibbs defines the Gibbs entropy: the probabilities in the entropy formula are now taken as probabilities of the state of the whole system
1924 – Harry Nyquist discusses quantifying "intelligence" and the speed at which it can be transmitted by a communication system
1927 – John von Neumann defines the von Neumann entropy, extending the Gibbs entropy to quantum mechanics
1928 – Ralph Hartley introduces Hartley information as the logarithm of the number of possible messages, with information being communicated when the receiver can distinguish one sequence of symbols from any other (regardless of any associated meaning)
1929 – Leó Szilárd analyses Maxwell's Demon, showing how a Szilard engine can sometimes transform information into the extraction of useful work
1940 – Alan Turing introduces the deciban as a measure of information inferred about the German Enigma machine cypher settings by the Banburismus process
1944 – Claude Shannon's theory of information is substantially complete
1947 – Richard W. Hamming invents Hamming codes for error detection and correction (to protect patent rights, the result is not published until 1950)
1948 – Claude E. Sh
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https://en.wikipedia.org/wiki/Fernando%20de%20Buen%20y%20Lozano
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Fernando de Buen y Lozano (10 October 1895 – 6 May 1962) was a Spanish ichthyologist and oceanographer. He lived in Mexico, Uruguay, and Chile. In Uruguay, he was the director of the Department of Science at the Oceanography and Fisheries Service as well as Professor of Hydrobiology and Protozoology in the Faculty of Arts and Sciences. He was an honorary foreign member of the American Society of Ichthyologists and Herpetologists.
See also
:Category:Taxa named by Fernando de Buen y Lozano
References
External links
1895 births
1962 deaths
Spanish ichthyologists
20th-century Spanish zoologists
Exiles of the Spanish Civil War in Mexico
Exiles of the Spanish Civil War in Uruguay
Exiles of the Spanish Civil War in Chile
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https://en.wikipedia.org/wiki/Born%E2%80%93von%20Karman%20boundary%20condition
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Born–von Karman boundary conditions are periodic boundary conditions which impose the restriction that a wave function must be periodic on a certain Bravais lattice. Named after Max Born and Theodore von Kármán, this condition is often applied in solid state physics to model an ideal crystal. Born and von Karman published a series of articles in 1912 and 1913 that presented one of the first theories of specific heat of solids based on the crystalline hypothesis and included these boundary conditions.
The condition can be stated as
where i runs over the dimensions of the Bravais lattice, the ai are the primitive vectors of the lattice, and the Ni are integers (assuming the lattice has N cells where N=N1N2N3). This definition can be used to show that
for any lattice translation vector T such that:
Note, however, the Born–von Karman boundary conditions are useful when Ni are large (infinite).
The Born–von Karman boundary condition is important in solid state physics for analyzing many features of crystals, such as diffraction and the band gap. Modeling the potential of a crystal as a periodic function with the Born–von Karman boundary condition and plugging in Schrödinger's equation results in a proof of Bloch's theorem, which is particularly important in understanding the band structure of crystals.
However, since any real crystal always has a finite size, the electronic states in the crystal do not satisfy the Born–von Karman boundary condition. Consequent
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https://en.wikipedia.org/wiki/Zero%20element
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In mathematics, a zero element is one of several generalizations of the number zero to other algebraic structures. These alternate meanings may or may not reduce to the same thing, depending on the context.
Additive identities
An additive identity is the identity element in an additive group. It corresponds to the element 0 such that for all x in the group, . Some examples of additive identity include:
The zero vector under vector addition: the vector of length 0 and whose components are all 0. Often denoted as or .
The zero function or zero map defined by , under pointwise addition
The empty set under set union
An empty sum or empty coproduct
An initial object in a category (an empty coproduct, and so an identity under coproducts)
Absorbing elements
An absorbing element in a multiplicative semigroup or semiring generalises the property . Examples include:
The empty set, which is an absorbing element under Cartesian product of sets, since
The zero function or zero map defined by under pointwise multiplication
Many absorbing elements are also additive identities, including the empty set and the zero function. Another important example is the distinguished element 0 in a field or ring, which is both the additive identity and the multiplicative absorbing element, and whose principal ideal is the smallest ideal.
Zero objects
A zero object in a category is both an initial and terminal object (and so an identity under both coproducts and products). For example, the tri
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https://en.wikipedia.org/wiki/Thouless
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Thouless may refer to:
People
David J. Thouless (1934–2019), British-American physicist, member of the U.S. National Academy of Sciences and 2016 recipient of the Nobel Prize in Physics
Robert H. Thouless (1894–1984), British psychologist and parapsychologist, author of Straight and Crooked Thinking
Other uses
Thouless energy
Kosterlitz-Thouless transition
See also
Thewlis
Thewliss
David Thewlis
Alison Thewliss
Michael Thewlis
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https://en.wikipedia.org/wiki/Rencontres%20numbers
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In combinatorial mathematics, the rencontres numbers are a triangular array of integers that enumerate permutations of the set { 1, ..., n } with specified numbers of fixed points: in other words, partial derangements. (Rencontre is French for encounter. By some accounts, the problem is named after a solitaire game.) For n ≥ 0 and 0 ≤ k ≤ n, the rencontres number Dn, k is the number of permutations of { 1, ..., n } that have exactly k fixed points.
For example, if seven presents are given to seven different people, but only two are destined to get the right present, there are D7, 2 = 924 ways this could happen. Another often cited example is that of a dance school with 7 couples, where, after tea-break the participants are told to randomly find a partner to continue, then once more there are D7, 2 = 924 possibilities that 2 previous couples meet again by chance.
Numerical values
Here is the beginning of this array :
Formulas
The numbers in the k = 0 column enumerate derangements. Thus
for non-negative n. It turns out that
where the ratio is rounded up for even n and rounded down for odd n. For n ≥ 1, this gives the nearest integer.
More generally, for any , we have
The proof is easy after one knows how to enumerate derangements: choose the k fixed points out of n; then choose the derangement of the other n − k points.
The numbers are generated by the power series ; accordingly,
an explicit formula for Dn, m can be derived as follows:
This immediately impl
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https://en.wikipedia.org/wiki/Neurospora
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Neurospora is a genus of Ascomycete fungi. The genus name, meaning "nerve spore" refers to the characteristic striations on the spores that resemble axons.
The best known species in this genus is Neurospora crassa, a common model organism in biology. Neurospora intermedia var. oncomensis is believed to be the only mold belonging to Neurospora which is used in food production (to make oncom).
Characteristics
Neurospora species are molds with broadly spreading colonies, with abundant production of ascomata. Ascomata are superficial or immersed, perithecial and ostiolate or cleistothecial and non-ostiolate, hairy or glabrous, dark coloured. Peridium membranaceous, asci cylindrical, clavate or subspherical, with a persistent or evanescent wall, usually with a thickened and non-amyloid annular structure at the apex, usually 8-spored. Ascospores broadly fusiform, ellipsoidal, or nearly spherical, unicellular, hyaline to yellowish brown or olive-brown, becoming dark and opaque at maturity, ascospore wall with longitudinal ribs or pitted, occasionally nearly smooth, 1–2 (but rarely up to 12) germ pores disposed at the ends of the ascospores, gelatinous sheaths or appendages are absent. Anamorphs are known in only a relatively small number of species, which belong to the fungi imperfecti genus Chrysonilia. The type species of the genus is Neurospora sitophila Shear.
Systematics
The former genus Gelasinospora is closely related and not resolved as a distinct monophyletic group, thus
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https://en.wikipedia.org/wiki/Adel%20Sedra
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Adel S. Sedra is an Egyptian Canadian electrical engineer and professor.
Career
Born in Egypt in 1943, Sedra received his B.Sc. from Cairo University in 1964 and his M.A.Sc. and Ph.D. from the University of Toronto, in 1968 and 1969, respectively. All three of his degrees are in electrical engineering.
Sedra joined the faculty of the University of Toronto in 1969 and became associate professor in 1972 and professor in 1978. He served as chair of the Department of Electrical Engineering from 1986 to 1993, and was vice president, provost, and chief academic officer from July 1, 1993, to 2002. In his nine years as provost Sedra led the university through two major long-range planning cycles in 1994 and 1998.
On July 1, 2003, Sedra joined the University of Waterloo as dean of its Faculty of Engineering and as professor of electrical and computer engineering. In 2004 he initiated the University of Waterloo Engineering Planning Exercise, VISION 2010. He served as Dean of Engineering until June 2012.
A specialist in microelectronics, Sedra's research focuses on applications in communication and instrumentation systems, including theory and design of circuits. Sedra has co-authored three textbooks, including Microelectronic Circuits (with co-author K.C. Smith), now in its seventh edition (2014). The text is published in ten languages, has over one million copies in print, and is one of the most widely used texts on the subject to date. He is co-author with Gordon W. Roberts of t
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https://en.wikipedia.org/wiki/Bernard%20Davis%20%28biologist%29
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Bernard David Davis (January 7, 1916 – January 14, 1994) was an American biologist who made major contributions in microbial physiology and metabolism. Davis was a prominent figure at Harvard Medical School in microbiology and in national science policy. He was the 1989 recipient of the Selman A. Waksman Award in Microbiology from the National Academy of Sciences.
Education
Davis was born in Franklin, Massachusetts, where his parents, Jewish immigrants from Lithuania, had settled. He was valedictorian at his high school, then attended Harvard University, where he majored in biochemistry. After earning his Bachelor of Science degree, he enrolled at Harvard Medical School, graduating in 1940 with a rare M.D., summa cum laude. He was elected a Fellow of the American Academy of Arts and Sciences in 1958. In a front-note to a posthumously published commentary that appeared in 2000, the major contributions of Davis to microbial physiology has been noted as, "the use of penicillin for the selection of auxotrophic mutants and his U-tube experiment to prove that bacterial conjugation required direct contact between the two bacterial strains."
Moralistic fallacy
In a short article published in Nature in 1978, Davis coined the term "moralistic fallacy" after calls for ethical guidelines to control the study of what could allegedly become "dangerous knowledge." The term was intended as a converse to the naturalistic fallacy, a term coined by G.E. Moore in the early twentieth century b
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https://en.wikipedia.org/wiki/Quaternary%20%28disambiguation%29
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The Quaternary is a geologic period.
Quaternary (an adjective meaning "fourth in order" or "composed of four items") may also refer to:
Quaternary (chemistry) (see also Quaternary compound and Quaternary phase)
Quaternary structure of proteins
Quaternary sector of the economy, which encompasses knowledge-based services
Quaternary care, health care that includes highly specialized or experimental treatments
Quaternary numeral system (base-4) in mathematics
Quaternary counting system, as used in some human languages
Quaternary (EP), an album by Mötley Crüe
See also
Quinary, positional number system with base 5
Ternary (disambiguation)
Tertiary (disambiguation)
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https://en.wikipedia.org/wiki/Parton%20%28particle%20physics%29
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In particle physics, the parton model is a model of hadrons, such as protons and neutrons, proposed by Richard Feynman. It is useful for interpreting the cascades of radiation (a parton shower) produced from quantum chromodynamics (QCD) processes and interactions in high-energy particle collisions.
Model
Parton showers are simulated extensively in Monte Carlo event generators, in order to calibrate and interpret (and thus understand) processes in collider experiments. As such, the name is also used to refer to algorithms that approximate or simulate the process.
Motivation
The parton model was proposed by Richard Feynman in 1969 as a way to analyze high-energy hadron collisions. Any hadron (for example, a proton) can be considered as a composition of a number of point-like constituents, termed "partons". The parton model was immediately applied to electron-proton deep inelastic scattering by Bjorken and Paschos.
Component particles
A hadron is composed of a number of point-like constituents, termed "partons". Later, with the experimental observation of Bjorken scaling, the validation of the quark model, and the confirmation of asymptotic freedom in quantum chromodynamics, partons were matched to quarks and gluons. The parton model remains a justifiable approximation at high energies, and others have extended the theory over the years.
Just as accelerated electric charges emit QED radiation (photons), the accelerated coloured partons will emit QCD radiation in the form
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https://en.wikipedia.org/wiki/Neurath
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Neurath is a surname. Notable people with the surname include:
Alois Neurath (1886–1955), Sudeten German dissident communist activist
Carolina Neurath (born 1985), Swedish journalist and writer
Eva Neurath (1908–1999), British publisher
Hans Neurath (1909–2002), founding chairman of the Department of Biochemistry at the University of Washington in Seattle
Konstantin von Neurath (1873–1956), German diplomat, foreign minister of Germany between 1932 and 1938
Marie Neurath (1898–1986), member of the team that developed the Vienna Method of Pictorial Statistics, later renamed Isotype
Olga Hahn-Neurath (1882–1937), Austrian mathematician and philosopher
Otto Neurath (1882–1945), Austrian philosopher of science, sociologist, and political economist
Paul Neurath, creator of computer games
Walter Neurath, British publisher
Wilhelm Neurath, (1840–1901), Austrian political economist
See also
Neurath (Grevenbroich), a town in the Rhein-Kreis Neuss, in North Rhine-Westphalia, Germany
Neurath Power Station, lignite-fired power station at Neurath in Grevenbroich, North Rhine-Westphalia, Germany
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https://en.wikipedia.org/wiki/Charles%20Shattuck%20Hill
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Charles Shattuck Hill, C.E. (1868after 1909) was an American civil engineer, writer and editor, born at Fairfield, Vermont. He received his degree in civil engineering in 1888. He served on the editorial staff of the Engineering News until 1906; then he became editor of Engineering and Contracting.
Works
The Chicago Main Drainage Canal (1896)
Reinforced Concrete (1904)
Concrete Construction (1908)
Concrete Inspection (1909)
External links
1868 births
Year of death missing
People from Fairfield, Vermont
American male journalists
American non-fiction writers
Writers from Vermont
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https://en.wikipedia.org/wiki/Psyche%20%28consciousness%20journal%29
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Psyche was an online peer-reviewed academic journal covering studies on consciousness and its relation to the brain from perspectives provided by the disciplines of cognitive science, philosophy, psychology, physics, neuroscience, artificial intelligence, and anthropology. It was established in 1993. In 2008 it became the official journal of the Association for the Scientific Study of Consciousness. Psyche is no longer accepting articles, but the archive remains accessible.
External links
Psyche website and archive of issues 1994–2010
Official website of the ASSC
Biannual journals
Cognitive science journals
Works about consciousness
English-language journals
Publications disestablished in 2010
Academic journals established in 1994
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https://en.wikipedia.org/wiki/Zarankiewicz%20problem
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The Zarankiewicz problem, an unsolved problem in mathematics, asks for the largest possible number of edges in a bipartite graph that has a given number of vertices and has no complete bipartite subgraphs of a given size. It belongs to the field of extremal graph theory, a branch of combinatorics, and is named after the Polish mathematician Kazimierz Zarankiewicz, who proposed several special cases of the problem in 1951.
Problem statement
A bipartite graph consists of two disjoint sets of vertices and , and a set of edges each of which connects a vertex in to a vertex in . No two edges can both connect the same pair of vertices. A complete bipartite graph is a bipartite graph in which every pair of a vertex from and a vertex from is connected to each other. A complete bipartite graph in which has vertices and has vertices is denoted . If is a bipartite graph, and there exists a set of vertices of and vertices of that are all connected to each other, then these vertices induce a subgraph of the form . (In this formulation, the ordering of and is significant: the set of vertices must be from and the set of vertices must be from , not vice versa.)
The Zarankiewicz function denotes the maximum possible number of edges in a bipartite graph for which and , but which does not contain a subgraph of the form . As a shorthand for an important special case, is the same as . The Zarankiewicz problem asks for a formula for the Zarankiewicz function, or (failing t
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https://en.wikipedia.org/wiki/Coupling%20%28disambiguation%29
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Coupling is a connection or joint between two things.
Coupling may also refer to:
Coupling (physics), when two systems are interacting with each other
Rotational–vibrational coupling, occurring when rotation frequency of an object is close to or identical to a natural internal vibration frequency
Angular momentum coupling, the combining of quantized angular momentum (e.g., the interaction between two nuclei in nuclear magnetic resonance)
Quantum coupling, when quantum states in one of the systems will cause an instantaneous change in all of the bound systems
Coupling (computer programming), the degree to which each program module relies on each one of the other modules
Coupling (electronics), the transfer of a signal from one medium or circuit block to another
Coupling (genetics), a type of genetic linkage
Coupling (piping), a short length of pipe or tube to connect two pipes or tubes together
Coupling (probability), a proof technique in probability theory
Railway coupling, a mechanism for connecting railway rolling stock
Azo coupling, often called "coupling", an electrophilic substitution reaction
Coupling reaction, reactions between hydrocarbon fragments in organic chemistry
Hose coupling, a piece on the end of a hose to connect it to extra hoses or hose appliances
Coupling track, a term in music recording for a B-side track
Joint encoding, an audio compression technique in which the redundancy of information between audio channels is reduced; also commonly known as chann
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https://en.wikipedia.org/wiki/Building%20science
|
Building science is the science and technology-driven collection of knowledge in order to provide better indoor environmental quality (IEQ), energy-efficient built environments, and occupant comfort and satisfaction. Building physics, architectural science, and applied physics are terms used for the knowledge domain that overlaps with building science. In building science, the methods used in natural and hard sciences are widely applied, which may include controlled and quasi-experiments, randomized control, physical measurements, remote sensing, and simulations. On the other hand, methods from social and soft sciences, such as case study, interviews & focus group, observational method, surveys, and experience sampling, are also widely used in building science to understand occupant satisfaction, comfort, and experiences by acquiring qualitative data. One of the recent trends in building science is a combination of the two different methods. For instance, it is widely known that occupants’ thermal sensation and comfort may vary depending on their sex, age, emotion, experiences, etc. even in the same indoor environment. Despite the advancement in data extraction and collection technology in building science, objective measurements alone can hardly represent occupants' state of mind such as comfort and preference. Therefore, researchers are trying to measure both physical contexts and understand human responses to figure out complex interrelationships.
Building science tradi
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https://en.wikipedia.org/wiki/Hierarchical%20classification
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Hierarchical classification is a system of grouping things according to a hierarchy.
In the field of machine learning, hierarchical classification is sometimes referred to as instance space decomposition, which splits a complete multi-class problem into a set of smaller classification problems.
See also
Deductive classifier
Cascading classifiers
Faceted classification
References
External links
Hierarchical Classification – a useful approach for predicting thousands of possible categories
Classification algorithms
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https://en.wikipedia.org/wiki/Helena%20Rasiowa
|
Helena Rasiowa (20 June 1917 – 9 August 1994) was a Polish mathematician. She worked in the foundations of mathematics and algebraic logic.
Early years
Rasiowa was born in Vienna on 20 June 1917 to Polish parents. As soon as Poland regained its independence in 1918, the family settled in Warsaw. Helena's father was a railway specialist. She exhibited many different skills and interests, from music to business management and the most important of her interests, mathematics.
In 1938, the time was not very opportune for entering a university. Rasiowa had to interrupt her studies, as no legal education was possible in Poland after 1939. Many people fled the country, or at least they fled the big towns, which were subject to German bombardment and terror. The Rasiowa family fled also, as most high-ranking administration officials and members of the government were being evacuated to Romania. The family spent a year in Lviv. After the Soviet invasion in September 1939, the town was taken over by the Soviet Union. The lives of many Poles became endangered, so Helena's father decided to return to Warsaw.
Academic development
Rasiowa became strongly influenced by Polish logicians. She wrote her Master's thesis under the supervision of Jan Łukasiewicz and Bolesław Sobociński. In 1944, the Warsaw Uprising broke out and consequently Warsaw was almost completely destroyed. This was not only due to the immediate fighting, but also because of the systematic destruction which followed th
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https://en.wikipedia.org/wiki/CIV
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Civ or CIV may refer to:
Arts and entertainment
CIV (band), a punk rock music band
Civ (imprint), an imprint of VDM Publishing devoted to the reproduction of Wikipedia content
Civilization (1980 board game)
Civilization (series) or Civ, a series of computer games
Physics
Corona inception voltage, see corona discharge
Critical ionization velocity, a plasma phenomenon in physics
Other uses
Civ., an abbreviation for 'civil'
Civilian
104 (number), or CIV in Roman numerals
CIV (rail travel), International Convention for the transportation of Passengers (French: Convention Internationale pour le transport des Voyageurs)
"Caritas in Veritate", Pope Benedict XVI's social encyclical
City of London Imperial Volunteers, a British corps of volunteers during the Second Boer War
Ivory Coast (officially Côte d'Ivoire), a country in West Africa
See also
C4 (disambiguation) -- i.e. C-IV
Civilization (disambiguation)
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https://en.wikipedia.org/wiki/Logic%20%28disambiguation%29
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Logic is the study of the principles and criteria of valid inference and demonstration.
Logic may also refer to:
Mathematical logic, a branch of mathematics that grew out of symbolic logic
Philosophical logic, the application of formal logic to philosophical problems
Art, entertainment, and the media
"Logic" (song), by Operator Please, 2010
Logic, a 1981 album by Hideki Matsutake's Logic System
Mr Logic, a character in a Viz magazine comic strip
Logic (poem) by Ringelnatz
The Logic, a Canadian news website
People
Logic (rapper) (born 1990), American rapper
Logic, member of hip hop group Y'all So Stupid
DJ Logic (born 1972), American turntablist
Lamont "Logic" Coleman, producer of two tracks on Jim Jones's 2011 album, Capo
Lora Logic (born 1960), British saxophonist and singer
Louis Logic, American underground hip-hop emcee
Samantha Logic (born 1992), American basketball player
Science and technology
Business logic, program portion encoding the rules determining data processing
Digital logic, a class of digital circuits characterized by the technology underlying its logic gates
LOGIC (electronic cigarette), an electronic cigarette owned by Logic Technology Development
Relocating logic, embedded information in programs for relocation
Logically, a startup known for its software, which utilizes artificial intelligence to label textual or visual media as real or fake.
Software
Dolby Pro Logic, also known as Pro Logic, a surround sound processing technology
Logic Pro, a MIDI
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https://en.wikipedia.org/wiki/Dean%E2%80%93Stark%20apparatus
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The Marcusson apparatus, Dean-Stark apparatus, Dean–Stark receiver, distilling trap, or Dean–Stark Head is a piece of laboratory glassware used in synthetic chemistry to collect water (or occasionally other liquid) from a reactor. It is used in combination with a reflux condenser and a distillation flask for the separation of water from liquids. This may be a continuous removal of the water that is produced during a chemical reaction performed at reflux temperature, such as in esterification reactions. The original setup by Julius Marcusson (invented in 1905) was refined by the American chemists Ernest Woodward Dean (1888–1959) and David Dewey Stark (1893–1979) in 1920 for determination of the water content in petroleum.
Function
Two types of Dean–Stark traps exist – one for use with solvents with a density less than that of water and another for use with solvents with a density greater than that of water.
The Dean–Stark apparatus typically consists of a vertical cylindrical glass tube, often with a volumetric graduation along its full length and a precision stopcock at its lower end, very much like a burette. Traps designed to remove or measure very small amounts of water may be closed, with no tap. The lower end of a reflux condenser fits into the top of the cylinder. Immediately below the joint between the condenser and the cylinder is a sloping side-arm that joins the cylinder to a reaction flask. The lower end of the side-arm turns sharply downward, so that the side
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https://en.wikipedia.org/wiki/Alternating%20factorial
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In mathematics, an alternating factorial is the absolute value of the alternating sum of the first n factorials of positive integers.
This is the same as their sum, with the odd-indexed factorials multiplied by −1 if n is even, and the even-indexed factorials multiplied by −1 if n is odd, resulting in an alternation of signs of the summands (or alternation of addition and subtraction operators, if preferred). To put it algebraically,
or with the recurrence relation
in which af(1) = 1.
The first few alternating factorials are
1, 1, 5, 19, 101, 619, 4421, 35899, 326981, 3301819, 36614981, 442386619, 5784634181, 81393657019
For example, the third alternating factorial is 1! – 2! + 3!. The fourth alternating factorial is −1! + 2! − 3! + 4! = 19. Regardless of the parity of n, the last (nth) summand, n!, is given a positive sign, the (n – 1)th summand is given a negative sign, and the signs of the lower-indexed summands are alternated accordingly.
This pattern of alternation ensures the resulting sums are all positive integers. Changing the rule so that either the odd- or even-indexed summands are given negative signs (regardless of the parity of n) changes the signs of the resulting sums but not their absolute values.
proved that there are only a finite number of alternating factorials that are also prime numbers, since 3612703 divides af(3612702) and therefore divides af(n) for all n ≥ 3612702. , the known primes and probable primes are af(n) for
n = 3, 4, 5, 6, 7, 8,
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https://en.wikipedia.org/wiki/Phylogenomics
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Phylogenomics is the intersection of the fields of evolution and genomics. The term has been used in multiple ways to refer to analysis that involves genome data and evolutionary reconstructions. It is a group of techniques within the larger fields of phylogenetics and genomics. Phylogenomics draws information by comparing entire genomes, or at least large portions of genomes. Phylogenetics compares and analyzes the sequences of single genes, or a small number of genes, as well as many other types of data. Four major areas fall under phylogenomics:
Prediction of gene function
Establishment and clarification of evolutionary relationships
Gene family evolution
Prediction and retracing lateral gene transfer.
The ultimate goal of phylogenomics is to reconstruct the evolutionary history of species through their genomes. This history is usually inferred from a series of genomes by using a genome evolution model and standard statistical inference methods (e.g. Bayesian inference or maximum likelihood estimation).
Prediction of gene function
When Jonathan Eisen originally coined phylogenomics, it applied to prediction of gene function. Before the use of phylogenomic techniques, predicting gene function was done primarily by comparing the gene sequence with the sequences of genes with known functions. When several genes with similar sequences but differing functions are involved, this method alone is ineffective in determining function. A specific example is presented in the pap
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https://en.wikipedia.org/wiki/Implementation%20of%20mathematics%20in%20set%20theory
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This article examines the implementation of mathematical concepts in set theory. The implementation of a number of basic mathematical concepts is carried out in parallel in ZFC (the dominant set theory) and in NFU, the version of Quine's New Foundations shown to be consistent by R. B. Jensen in 1969 (here understood to include at least axioms of Infinity and Choice).
What is said here applies also to two families of set theories: on the one hand, a range of theories including Zermelo set theory near the lower end of the scale and going up to ZFC extended with large cardinal hypotheses such as "there is a measurable cardinal"; and on the other hand a hierarchy of extensions of NFU which is surveyed in the New Foundations article. These correspond to different general views of what the set-theoretical universe is like, and it is the approaches to implementation of mathematical concepts under these two general views that are being compared and contrasted.
It is not the primary aim of this article to say anything about the relative merits of these theories as foundations for mathematics. The reason for the use of two different set theories is to illustrate that multiple approaches to the implementation of mathematics are feasible. Precisely because of this approach, this article is not a source of "official" definitions for any mathematical concept.
Preliminaries
The following sections carry out certain constructions in the two theories ZFC and NFU and compare the resulting i
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https://en.wikipedia.org/wiki/Zero%20differential%20overlap
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Zero differential overlap is an approximation in computational molecular orbital theory that is the central technique of semi-empirical methods in quantum chemistry. When computers were first used to calculate bonding in molecules, it was only possible to calculate diatomic molecules. As computers advanced, it became possible to study larger molecules, but the use of this approximation has always allowed the study of even larger molecules. Currently semi-empirical methods can be applied to molecules as large as whole proteins. The approximation involves ignoring certain integrals, usually two-electron repulsion integrals. If the number of orbitals used in the calculation is N, the number of two-electron repulsion integrals scales as N4. After the approximation is applied the number of such integrals scales as N2, a much smaller number, simplifying the calculation.
Details of approximation
If the molecular orbitals are expanded in terms of N basis functions, as:
where A is the atom the basis function is centred on, and are coefficients, the two-electron repulsion integrals are then defined as:
The zero differential overlap approximation ignores integrals that contain the product where μ is not equal to ν. This leads to:
where
The total number of such integrals is reduced to N(N + 1) / 2 (approximately N2 / 2) from [N(N + 1) / 2][N(N + 1) / 2 + 1] / 2 (approximately N4 / 8), all of which are included in ab initio Hartree–Fock and post-Hartree–Fock calculations.
Scope
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https://en.wikipedia.org/wiki/Bob%20O%27Rear
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Robert "Bob" O'Rear is a former employee of Microsoft, and is among the group of eleven early Microsoft employees who posed for a company photo taken in Albuquerque in 1978. A Texan, he has degrees in mathematics and physics. He left Microsoft in 1993, and reportedly owns a cattle ranch in Texas.
Early life
O'Rear, born in Wellington, Texas, was brought up in Perryton, a rural town of 3,500 people in the Texas Panhandle by his grandparents, who were sharecroppers on a cotton farm. O'Rear planned to be a physical education teacher, but later ended up graduating from the University of Texas at El Paso with a bachelor's degree in mathematics. He went on to graduate school at the University of Texas at Austin to study mathematics and astrophysics.
In 1966, TRW in Redondo Beach hired O'Rear to work on Air Force spy satellite programs. He also wrote programs that optimized the trajectory of Minuteman missiles during the Cold War. Later on, in the 1960s, he went to work for NASA. He helped write a program that determined the trajectory of the Apollo Command Module as it reentered the Earth's atmosphere, and was in the NASA Command Center when Neil Armstrong landed on the Moon.
Later in the 1970s, O'Rear and a friend from his TRW days founded a company called Texametrics that made automated machinery for the manufacturing of polyurethane bottle caps. O'Rear worked on a program that analyzed the patterns of correctly manufactured caps and caused the incorrectly manufactured parts
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https://en.wikipedia.org/wiki/Vasant%20Honavar
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Vasant G. Honavar is an Indian born American computer scientist, and artificial intelligence, machine learning, big data, data science, causal inference, knowledge representation, bioinformatics and health informatics researcher and professor.
Early life and education
Vasant Honavar was born at Poona, India to Bhavani G. and Gajanan N. Honavar. He received his early education at the Vidya Vardhaka Sangha High School and M.E.S. College in Bangalore, India. He received a B.E. in Electronics & Communications Engineering from the B.M.S. College of Engineering in Bangalore, India in 1982, when it was affiliated with Bangalore University, an M.S. in electrical and computer engineering in 1984 from Drexel University, and an M.S. in computer science in 1989, and a Ph.D. in 1990, respectively, from the University of Wisconsin–Madison, where he studied Artificial Intelligence and worked with Leonard Uhr.
Career
Honavar is on the faculty of Penn State College of Information Sciences and Technology at Pennsylvania State University where he currently holds the Dorothy Foehr Huck and J. Lloyd Huck Chair in Biomedical Data Sciences and Artificial Intelligence and previously held the Edward Frymoyer Endowed Chair in Information Sciences and Technology. He serves on the faculties of the graduate programs in Computer Science, Informatics, Bioinformatics and Genomics, Neuroscience, Operations Research, Public Health Sciences, and of an undergraduate program in Data Science. Honavar serves
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https://en.wikipedia.org/wiki/Davidson%20correction
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The Davidson correction is an energy correction often applied in calculations using the method of truncated configuration interaction, which is one of several post-Hartree–Fock ab initio quantum chemistry methods in the field of computational chemistry. It was introduced by Ernest R. Davidson.
It allows one to estimate the value of the full configuration interaction energy from a limited configuration interaction expansion result, although more precisely it estimates the energy of configuration interaction up to quadruple excitations (CISDTQ) from the energy of configuration interaction up to double excitations (CISD). It uses the formula
where a0 is the coefficient of the Hartree–Fock wavefunction in the CISD expansion, ECISD and EHF are the energies of the CISD and Hartree–Fock wavefunctions respectively, and ΔEQ is the correction to estimate ECISDTQ, the energy of the CISDTQ wavefunction. Such estimation is based on perturbation theory analysis. Therefore, CISD calculations with the Davidson correction included are frequently referred to as CISD(Q).
Application
The Davidson correction is very popular due to its low computational cost. The correction improves the contribution of electron correlation to the energy. The size-consistency and size-extensivity problems of truncated CI are alleviated but still exist. In small molecules, accuracy of the corrected energies can be similar to results from coupled cluster theory calculations.
The Davidson correction does not giv
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https://en.wikipedia.org/wiki/Real-time%20polymerase%20chain%20reaction
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A real-time polymerase chain reaction (real-time PCR, or qPCR when used quantitatively) is a laboratory technique of molecular biology based on the polymerase chain reaction (PCR). It monitors the amplification of a targeted DNA molecule during the PCR (i.e., in real time), not at its end, as in conventional PCR. Real-time PCR can be used quantitatively and semi-quantitatively (i.e., above/below a certain amount of DNA molecules).
Two common methods for the detection of PCR products in real-time PCR are (1) non-specific fluorescent dyes that intercalate with any double-stranded DNA and (2) sequence-specific DNA probes consisting of oligonucleotides that are labelled with a fluorescent reporter, which permits detection only after hybridization of the probe with its complementary sequence.
The Minimum Information for Publication of Quantitative Real-Time PCR Experiments (MIQE) guidelines propose that the abbreviation qPCR be used for quantitative real-time PCR and that RT-qPCR be used for reverse transcription–qPCR. The acronym "RT-PCR" commonly denotes reverse transcription polymerase chain reaction and not real-time PCR, but not all authors adhere to this convention.
Background
Cells in all organisms regulate gene expression by turnover of gene transcripts (single stranded RNA): The amount of an expressed gene in a cell can be measured by the number of copies of an RNA transcript of that gene present in a sample. In order to robustly detect and quantify gene expression f
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https://en.wikipedia.org/wiki/Leonard%20Uhr
|
Leonard Uhr (1927 – October 5, 2000) was an American computer scientist and a pioneer in computer vision, pattern recognition, machine learning and cognitive science. He was an expert in many aspects of human neurophysiology and perception, and a central theme of his research was to design artificial intelligence systems based on his understanding of how the human brain works. He was one of the early proponents of incorporation into artificial intelligence algorithms of methods for dealing with uncertainty.
Uhr published eight books (as author and/or editor) and nearly 150 journal and conference papers. His seminal work was an article written in 1963 with Charles Vossler, "A Pattern Recognition Program That Generates, Evaluates, and Adjusts Its Own Operators", reprinted in Computers and Thought — edited by Edward Feigenbaum and J. Feldman — which showcases the work of the scientists who defined the field of artificial intelligence. He was a Ph.D. major professor for 20 students, many of whom have gone on to become in their own right important contributors to artificial intelligence.
Uhr graduated from Princeton University in 1949 with a B.A. in psychology. He received master's degrees in philosophy from the University of Brussels and Johns Hopkins University in 1951 before obtaining his Ph.D. in psychology in 1957 from the University of Michigan. As a child, Uhr attended Oak Lane Country Day School outside Philadelphia.
Uhr was a professor of computer science and of neuro
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https://en.wikipedia.org/wiki/Fillet%20%28mechanics%29
|
In mechanical engineering, a fillet is a rounding of an interior or exterior corner of a part designed in CAD. An interior or exterior corner, with an angle or type of bevel, is called a "chamfer". Fillet geometry, when on an interior corner is a line of concave function, whereas a fillet on an exterior corner is a line of convex function (in these cases, fillets are typically referred to as rounds). Fillets commonly appear on welded, soldered, or brazed joints.
Depending on a geometric modelling kernel different CAD software products may provide different fillet functionality. Usually fillets can be quickly designed onto parts using 3D solid modeling engineering by picking edges of interest and invoking the function. Smooth edges connecting two simple flat features are generally simple for a computer to create and fast for a human user to specify. It is pronounced as "fill-et" similarly like the Fillet in picture framing. Once these features are included in the CAD design of a part, they are often manufactured automatically using computer-numerical control.
Applications
Stress concentration is a problem of load-bearing mechanical parts which is reduced by employing fillets on points and lines of expected high stress. The fillets distribute the stress over a broader area and effectively make the parts more durable and capable of bearing larger loads.
For considerations in aerodynamics, fillets are employed to reduce interference drag where aircraft components such as win
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https://en.wikipedia.org/wiki/Applied%20Physics%20Letters
|
Applied Physics Letters is a weekly peer-reviewed scientific journal that is published by the American Institute of Physics. Its focus is rapid publication and dissemination of new experimental and theoretical papers regarding applications of physics in all disciplines of science, engineering, and modern technology. Additionally, there is an emphasis on fundamental and new developments which lay the groundwork for fields that are rapidly evolving.
The journal was established in 1962. The editor-in-chief is physicist Lesley F. Cohen of the Imperial College London.
Abstracting and indexing
This journal is indexed in the following databases:
Chemical Abstracts Service
Current Contents/Physical, Chemical & Earth Sciences
Science Citation Index Expanded
According to the Journal Citation Reports, the journal has a 2021 impact factor of 4.0.
References
External links
Physics journals
Academic journals established in 1962
Weekly journals
English-language journals
American Institute of Physics academic journals
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https://en.wikipedia.org/wiki/William%20Andrew%20Goddard%20III
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William Andrew Goddard III (born March 29, 1937) is the Charles and Mary Ferkel Professor of Chemistry and Applied Physics, and director of the Materials and Process Simulation Center at the California Institute of Technology.
Early life and education
William A. Goddard III was born in El Centro California and lived his early years in farm towns across California (El Centro, Delano, Indio, Lodi, Oildale, MacFarland, Firebaugh, also Yuma AZ), where his dad made the wooden boxes used to ship agricultural products. He always dreamed of living in Los Angeles. Goddard earned a BS in engineering from the University of California at Los Angeles in 1960 and PhD in engineering science with a minor in physics from Caltech in 1964. He has four children (Bill, Suzy, Cecilia, Lisa) and has been married for 58 years.
Career
He joined the chemistry faculty at Caltech in November 1964 where he remains today as a professor and researcher.
After his Ph.D. he remained at the California Institute of Technology as Arthur Amos Noyes Research Fellow (1964–66), Professor of Theoretical Chemistry (1967–78) and Professor of Chemistry & Applied Physics (1978-).
Goddard has made many contributions to theoretical chemistry, such as the generalized valence bond (GVB) method for ab initio electronic structure calculations and the ReaxFF force field for classical molecular dynamics simulations.
He is a member of the International Academy of Quantum Molecular Science and the U.S. National Academy of Scie
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https://en.wikipedia.org/wiki/David%20P.%20Craig
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David Parker Craig (23 December 1919 – 1 July 2015), an Australian chemist, was the Foundation Professor of Physical and Theoretical Chemistry and later Emeritus Professor in the Research School of Chemistry at the Australian National University in Canberra.
Born in Sydney, Craig was educated at the University of Sydney, receiving a Bachelor of Science with Honours in 1940 and a Master of Science in 1941. He was awarded a Doctor of Philosophy degree from the University of London in 1949. He was a captain in the Second Australian Imperial Force from 1942 to 1944. Craig was a lecturer in physical chemistry, at the University of Sydney from 1944 to 1946, a Turner and Newall Research Fellow and Lecturer at University College, London from 1946 to 1952, Professor in physical chemistry at the University of Sydney from 1952 to 1956 and Professor in theoretical chemistry at University College, London from 1956 to 1967.
He was a Fellow of the Royal Society, the Royal Society of New South Wales, the Australian Academy of Science, a former President of AAS, and a Member of the International Academy of Quantum Molecular Science. In 1985 he was appointed an Officer of the Order of Australia (AO) "in recognition of service to the community, particularly in the field of physical chemistry", and was a recipient of the Centenary Medal "for service to Australian society and science in theoretical chemistry".
Family
David Craig married Veronica (Ronia) Bryden-Brown on 25 August 1948, in Cav
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