Étienne Halphen
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Étienne Halphen
Étienne Halphen (27 May 1911, in Bordeaux – 11 August 1954, in Neuilly-sur-Marne) was a French mathematician. He was known for his work in geometry, on probability distributions and information theory. Biography He was born as son of Germaine (née Weill) and Louis Halphen, a professor of history at Sorbonne, and grandson of Georges Henri Halphen and Mathieu Weill, both renowned mathematicians. He did his studies at École Normale Supérieure, where he received his ''agrégation'' in 1933. He worked as a teacher at Lycée de Sens (Yonne), where he was granted an indefinite leave of absence after a year due to health issues. From 1936 to 1940 he was member of the Research Group on Calculus of Probabilities and Mathematical Statistics. During the German occupation of France, he was banned from public service, but reinstated in 1945. During that period he was invited by Pierre Massé to join a statistics research group on hydrology at ''Societe hydro-technique de France'' (SHF ...
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Mathematics
Mathematics is a field of study that discovers and organizes methods, Mathematical theory, theories and theorems that are developed and Mathematical proof, proved for the needs of empirical sciences and mathematics itself. There are many areas of mathematics, which include number theory (the study of numbers), algebra (the study of formulas and related structures), geometry (the study of shapes and spaces that contain them), Mathematical analysis, analysis (the study of continuous changes), and set theory (presently used as a foundation for all mathematics). Mathematics involves the description and manipulation of mathematical object, abstract objects that consist of either abstraction (mathematics), abstractions from nature orin modern mathematicspurely abstract entities that are stipulated to have certain properties, called axioms. Mathematics uses pure reason to proof (mathematics), prove properties of objects, a ''proof'' consisting of a succession of applications of in ...
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Électricité De France
Électricité de France SA (; ), commonly known as EDF, is a French multinational corporation, multinational electric utility company owned by the government of France. Headquartered in Paris, with €139.7 billion in sales in 2023, EDF operates a diverse portfolio of at least 120 gigawatts of generation capacity in Europe, South America, North America, Asia, the Middle East, and Africa. In 2009, EDF was the world's largest producer of electricity. Its 56 active nuclear reactors in France are spread out over 18 sites (18 nuclear power plants). They comprise 32 reactors of 900 MWe, MWe, 20 reactors of 1,300 MWe, MWe, and 4 reactors of 1,450 MWe, all Pressurized water reactor, PWRs. EDF was created on 8 April 1946 by the 1945 parliament, from the merging of various divided actors. EDF led France's post-war energy growth, with a unique focus on civil nuclear energy, through reconstruction and further industrialization within the ''Trente Glorieuses'', being a flagship of France ...
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1954 Suicides
Events January * January 3 – The Italian broadcaster RAI officially begins transmitting. * January 7 – Georgetown–IBM experiment: The first public demonstration of a machine translation system is held in New York, at the head office of IBM. * January 10 – BOAC Flight 781, a de Havilland Comet jet plane, disintegrates in mid-air due to metal fatigue, and crashes in the Mediterranean near Elba; all 35 people on board are killed. * January 12 – 1954 Blons avalanches, Avalanches in Austria kill more than 200. * January 15 – Mau Mau rebellion, Mau Mau leader Waruhiu Itote is captured in Kenya. * January 17 – In Socialist Federal Republic of Yugoslavia, Yugoslavia, Milovan Đilas, one of the leading members of the League of Communists of Yugoslavia, is relieved of his duties. * January 20 – The US-based National Negro Network is established, with 46 member radio stations. * January 21 – The first nuclear-powered submarine, the , is ...
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École Normale Supérieure Alumni
École or Ecole may refer to: * an elementary school in the French educational stages normally followed by secondary education establishments (collège and lycée) * École (river), a tributary of the Seine flowing in région Île-de-France * École, Savoie, a French commune * École-Valentin, a French commune in the Doubs département * Grandes écoles, higher education establishments in France * The École The École, formerly Ecole Internationale de New York, is an intimate and independent French-American school, which cultivates an internationally minded community of students from 2 to 14 years old in New York City’s vibrant Flatiron Distric ..., a French-American bilingual school in New York City * Ecole Software, a Japanese video-games developer/publisher {{disambiguation, geo ...
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1911 Births
Events January * January 1 – A decade after federation, the Northern Territory and the Australian Capital Territory are added to the Commonwealth of Australia. * January 3 ** 1911 Kebin earthquake: An earthquake of 7.7 Moment magnitude scale, moment magnitude strikes near Almaty in Russian Turkestan, killing 450 or more people. ** Siege of Sidney Street in London: Two Latvian people, Latvian anarchists die, after a seven-hour siege against a combined police and military force. Home Secretary Winston Churchill arrives to oversee events. * January 4 – Comparison of the Amundsen and Scott expeditions, Amundsen and Scott expeditions: Robert Falcon Scott's British Terra Nova Expedition, ''Terra Nova'' Expedition to the South Pole arrives in the Antarctic and establishes a base camp at Cape Evans on Ross Island. * January 5 – Egypt's Zamalek SC is founded as a general sports and Association football club by Belgian lawyer George Merzbach as Q ...
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Revue De Statistique Appliquée
A revue is a type of multi-act popular theatrical entertainment that combines music, dance, and sketches. The revue has its roots in 19th century popular entertainment and melodrama but grew into a substantial cultural presence of its own during its golden years from 1916 to 1932. Though most famous for their visual spectacle, revues frequently satirized contemporary figures, news or literature. Similar to the related subforms of operetta and musical theatre, the revue art form brings together music, dance and sketches to create a compelling show. In contrast to these, however, revue does not have an overarching storyline. Rather, a general theme serves as the motto for a loosely related series of acts that alternate between solo performances and dance ensembles. Owing to high ticket prices, ribald publicity campaigns and the occasional use of prurient material, the revue was typically patronized by audience members who earned more and felt even less restricted by middle-class s ...
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Vingtième Siècle
The ''vingtième'' (, ''twentieth'') was an income tax of the ''ancien régime'' in France. It was abolished during the French Revolution. First Proposition It was first proposed by the minister of finance, Jean-Baptiste de Machault, comte d'Arnouville, in 1749. The War of the Austrian Succession had just ended, with the French government at the point of bankruptcy. A temporary income tax, the '' dixième'' (levied by Louis XIV in 1710 at the rate of one-tenth of annual income), had been levied during the war, but Louis XV had promised that it would be removed with the end of the war. The comte d'Arnouville planned to introduce a new permanent tax modelled upon the ''dixième'', to create a sinking fund to repay the national debt. The ''vingtième'', introduced in 1749, was to be one-twentieth of annual income (5%), collected directly by the government, from all people regardless of their rank - although the First and Second Estates were largely exempt or could buy exemption thro ...
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Generalized Inverse Gaussian Distribution
In probability theory and statistics, the generalized inverse Gaussian distribution (GIG) is a three-parameter family of continuous probability distributions with probability density function :f(x) = \frac x^ e^,\qquad x>0, where ''Kp'' is a modified Bessel function of the second kind, ''a'' > 0, ''b'' > 0 and ''p'' a real parameter. It is used extensively in geostatistics, statistical linguistics, finance, etc. This distribution was first proposed by Étienne Halphen. It was rediscovered and popularised by Ole Barndorff-Nielsen, who called it the generalized inverse Gaussian distribution. Its statistical properties are discussed in Bent Jørgensen's lecture notes. Properties Alternative parametrization By setting \theta = \sqrt and \eta = \sqrt, we can alternatively express the GIG distribution as :f(x) = \frac \left(\frac\right)^ e^, where \theta is the concentration parameter while \eta is the scaling parameter. Summation Barndorff-Nielsen and Halg ...
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Académie Des Sciences (France)
An academy (Attic Greek: Ἀκαδήμεια; Koine Greek Ἀκαδημία) is an institution of tertiary education. The name traces back to Plato's school of philosophy, founded approximately 386 BC at Akademia, a sanctuary of Athena, the goddess of wisdom and Skills, skill, north of Ancient Athens, Athens, Greece. The Royal Spanish Academy defines academy as scientific, literary or artistic society established with public authority and as a teaching establishment, public or private, of a professional, artistic, technical or simply practical nature. Etymology The word comes from the ''Academy'' in ancient Greece, which derives from the Athenian hero, ''Akademos''. Outside the city walls of Athens, the Gymnasium (ancient Greece), gymnasium was made famous by Plato as a center of learning. The sacred space, dedicated to the goddess of wisdom, Athena, had formerly been an olive Grove (nature), grove, hence the expression "the groves of Academe". In these gardens, the philos ...
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Harmonic Distribution
In probability theory and statistics, the harmonic distribution is a continuous probability distribution. It was discovered by Étienne Halphen, who had become interested in the statistical modeling of natural events. His practical experience in data analysis motivated him to pioneer a new system of distributions that provided sufficient flexibility to fit a large variety of data sets. Halphen restricted his search to distributions whose parameters could be estimated using simple statistical approaches. Then, Halphen introduced for the first time what he called the harmonic distribution or harmonic law. The harmonic law is a special case of the generalized inverse Gaussian distribution family when \gamma=0. History One of Halphen's tasks, while working as statistician for Electricité de France, was the modeling of the monthly flow of water in hydroelectric stations. Halphen realized that the Pearson system of probability distributions could not be solved; it was inadequate for ...
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