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Józef Schreier
Józef Schreier (; 18 February 1909, Drohobycz, Austria-Hungary – April 1943, Drohobycz, Occupied Poland) was a Polish mathematician of Jewish origin, known for his work in functional analysis, group theory and combinatorics. He was a member of the Lwów School of Mathematics and a victim of the Holocaust. Józef Schreier was born on 18 February 1909 in Drohobycz. His father was a rabbi and doctor of philosophy. His cousin was the musician Alfred Schreyer. From 1927-31 he studied at the Jan Kazimierz University in Lwów. In his first published paper, he defined what later came to be known as Schreier sets in order to show that not all Banach spaces possess the weak Banach-Saks property, disproving a conjecture of Stefan Banach and Stanisław Saks. Schreier sets were later discovered independently by researchers in Ramsey theory. Schreier completed his master's degree ''On tournament elimination systems'' in 1932 under the direction of Hugo Steinhaus. Schreier correctly c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Schreier Set
Schreier is a surname of German origin. Notable people with the surname include: *Christian Schreier (born 1959), German footballer *Dan Moses Schreier, American sound designer and composer *Jake Schreier (born 1981), American director *Józef Schreier (1909–1943), Polish mathematician *Otto Schreier (1901–1929), Austrian mathematician *Peter Schreier (1935–2019), German tenor and conductor *Richard Schreier, Canadian engineer * Sandy Schreier, American fashion historian and collector *Jason Schreier Jason Schreier (born May 10, 1987) is an American journalist and author who primarily covers the video game industry. He worked as a news reporter for ''Kotaku'' from 2011 to 2020 and was recognized for several Investigative journalism, investig ... (born 1987), American journalist and author See also * Schreyer * Shrayer * Shroyer, Pennsylvania German form * Shrier, Americanized version {{surname German-language surnames ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Semigroups
In mathematics, a semigroup is an algebraic structure consisting of a set together with an associative internal binary operation on it. The binary operation of a semigroup is most often denoted multiplicatively (just notation, not necessarily the elementary arithmetic multiplication): , or simply ''xy'', denotes the result of applying the semigroup operation to the ordered pair . Associativity is formally expressed as that for all ''x'', ''y'' and ''z'' in the semigroup. Semigroups may be considered a special case of magmas, where the operation is associative, or as a generalization of groups, without requiring the existence of an identity element or inverses. As in the case of groups or magmas, the semigroup operation need not be commutative, so is not necessarily equal to ; a well-known example of an operation that is associative but non-commutative is matrix multiplication. If the semigroup operation is commutative, then the semigroup is called a ''commutative semigroup'' o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scottish Book
The Scottish Book () was a thick notebook used by mathematicians of the Lwów School of Mathematics in Poland for jotting down problems meant to be solved. The notebook was named after the " Scottish Café" where it was kept. Originally, the mathematicians who gathered at the cafe would write down the problems and equations directly on the cafe's marble table tops, but these would be erased at the end of each day, and so the record of the preceding discussions would be lost. The idea for the book was most likely originally suggested by Stefan Banach's wife, Łucja Banach. Stefan or Łucja Banach purchased a large notebook and left it with the proprietor of the cafe. History The Scottish Café () was the café in Lwów (now ''Lviv'', Ukraine) where, in the 1930s and 1940s, mathematicians from the Lwów School collaboratively discussed research problems, particularly in functional analysis and topology. Stanislaw Ulam recounts that the tables of the café had marble tops, s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scottish Café
The Scottish Café () was a café in Lwów, Poland (now Lviv, Ukraine) where, in the 1930s and 1940s, mathematicians from the Lwów School of Mathematics collaboratively discussed research problems, particularly in functional analysis and topology. Stanisław Ulam recounts that the tables of the café had marble tops, so they could write in pencil, directly on the table, during their discussions. To keep the results from being lost, and after becoming annoyed with their writing directly on the table tops, Stefan Banach's wife provided the mathematicians with a large notebook, which was used for writing the problems and answers and eventually became known as the '' Scottish Book''. The book—a collection of solved, unsolved, and even probably unsolvable problems—could be borrowed by any of the guests of the café. Solving any of the problems was rewarded with prizes, with the most difficult and challenging problems having expensive prizes (during the Great Depression and on ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Federation Of American Scientists
The Federation of American Scientists (FAS) is an American nonprofit global policy think tank with the stated intent of using science and scientific analysis to attempt to make the world more secure. FAS was founded in 1945 by a group of scientists, some of whom had previously contributed to the development of nuclear weapons in the Manhattan Project. The Federation of American Scientists states that it aims to reduce the amount of nuclear weapons that are in use, and prevent nuclear and radiological terrorism. It says it aims to present high standards for nuclear energy's safety and security, illuminate government secrecy practices, as well as track and eliminate the global illicit trade of conventional, nuclear, biological and chemical weapons. With 100 sponsors, the Federation of American Scientists says that it promotes a safer and more secure world by developing and advancing solutions to important science and technology security policy problems by educating the public and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stanisław Ulam
Stanisław Marcin Ulam ( ; 13 April 1909 – 13 May 1984) was a Polish and American mathematician, nuclear physicist and computer scientist. He participated in the Manhattan Project, originated the History of the Teller–Ulam design, Teller–Ulam design of thermonuclear weapons, discovered the concept of the cellular automaton, invented the Monte Carlo method, Monte Carlo method of computation, and suggested nuclear pulse propulsion. In pure and applied mathematics, he proved a number of theorems and proposed several conjectures. Born into a wealthy Polish Jewish family in Lemberg, Austria-Hungary; Ulam studied mathematics at the Lviv Polytechnic#Second Polish Republic, Lwów Polytechnic Institute, where he earned his PhD in 1933 under the supervision of Kazimierz Kuratowski and Włodzimierz Stożek. In 1935, John von Neumann, whom Ulam had met in Warsaw, invited him to come to the Institute for Advanced Study in Princeton, New Jersey, for a few months. From 1936 to 1939, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blindfold Chess
Blindfold chess, also known as ''sans voir'', is a form of chess play wherein the players do not see the positions of the pieces and do not touch them. This forces players to maintain a mental model of the positions of the pieces. Moves are communicated via a recognized chess notation. Blindfold chess was considered miraculous for centuries but now there is greater recognition of people who can keep track of more than one simultaneous blindfolded game. In Simultaneous exhibition, simultaneous blindfold play, an intermediary usually relays the moves between the players. Early history Blindfold chess was first played quite early on in the history of chess. The earliest name to be associated with play without the use of a material board is that of Sa'id bin Jubair (665–714) in the Middle East. In Europe, playing chess blindfolded became popular as a means of handicapping a chess master when facing a weaker opponent, or of simply displaying one's superior abilities. H. J. R. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hugo Steinhaus
Hugo Dyonizy Steinhaus ( , ; 14 January 1887 – 25 February 1972) was a Polish mathematician and educator. Steinhaus obtained his PhD under David Hilbert at Göttingen University in 1911 and later became a professor at the Jan Kazimierz University in Lwów (now Lviv, Ukraine), where he helped establish what later became known as the Lwów School of Mathematics. He is credited with "discovering" mathematician Stefan Banach, with whom he gave a notable contribution to functional analysis through the Banach–Steinhaus theorem. After World War II Steinhaus played an important part in the establishment of the mathematics department at Wrocław University and in the revival of Polish mathematics from the destruction of the war. Author of around 170 scientific articles and books, Steinhaus has left his legacy and contribution in many branches of mathematics, such as functional analysis, geometry, mathematical logic, and trigonometry. Notably he is regarded as one of the early founde ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ramsey Theory
Ramsey theory, named after the British mathematician and philosopher Frank P. Ramsey, is a branch of the mathematical field of combinatorics that focuses on the appearance of order in a substructure given a structure of a known size. Problems in Ramsey theory typically ask a question of the form: "how big must some structure be to guarantee that a particular property holds?" Examples A typical result in Ramsey theory starts with some mathematical structure that is then cut into pieces. How big must the original structure be in order to ensure that at least one of the pieces has a given interesting property? This idea can be defined as partition regularity. For example, consider a complete graph of order ''n''; that is, there are ''n'' vertices and each vertex is connected to every other vertex by an edge. A complete graph of order 3 is called a triangle. Now colour each edge either red or blue. How large must ''n'' be in order to ensure that there is either a blue triangle or a re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
