|
Lothar Collatz
Lothar Collatz (; July 6, 1910 – September 26, 1990) was a German mathematician, born in Arnsberg, Westphalia. The "3''x'' + 1" problem is also known as the Collatz conjecture, named after him and still unsolved. The Collatz–Wielandt formula for the Perron–Frobenius eigenvalue of a positive square matrix was also named after him. Collatz's 1957 paper with Ulrich Sinogowitz, who had been killed in the bombing of Darmstadt in World War II, founded the field of spectral graph theory. Biography Collatz studied at universities in Germany including University of Greifswald and the University of Berlin, where he was supervised by Alfred Klose, receiving his doctorate in 1935 for a dissertation entitled ''Das Differenzenverfahren mit höherer Approximation für lineare Differentialgleichungen'' (The finite difference method with higher approximation for linear differential equations). He then worked as an assistant at the University of Berlin, before moving to the Technical Unive ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arnsberg
Arnsberg (; wep, Arensperg) is a town in the Hochsauerland county, in the German state of North Rhine-Westphalia. It is the location of the Regierungsbezirk Arnsberg administration and one of the three local administration offices of the Hochsauerlandkreis district. Geography Location Arnsberg is located in the north-east of the Sauerland in the Ruhr river valley. The river Ruhr meanders around the south of the old town of Arnsberg. The town is nearly completely encircled by forest, and the nature park ''Arnsberger Wald'' lies to the north". Arnsberg is connected by Federal Motorway 46 (Autobahn 46) Brilon in the east and (using the Federal Motorway 445) Werl in the west. It is also connected by several railroad stations, which provide a connection to the major city Dortmund and the Ruhrgebiet. There is also a regional airport, located in the city district of Vosswinkel, which is exclusively used for small private aircraft. The municipal territory spans a distance of up t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frank Natterer
Frank Natterer (20 July 1941) is a German mathematician. He was born in Wangen im Allgäu, Germany. Natterer pioneered and shaped the field of mathematical methods in imaging including computed tomography (CT), magnetic resonance imaging (MRI) and ultrasonic imaging. Career After studies at the Universities of Freiburg and Hamburg Frank Natterer in 1968 earned his PhD with a thesis "Einschließungen für die großen Eigenwerte gewöhnlicher Differentialgleichungen zweiter und vierter Ordnung" under the supervision of Prof. Lothar Collatz. In 1971, he made the habilitation "Verallgemeinerte Splines und singuläre Rand-Eigenwertaufgaben gewöhnlicher Differentialgleichungen". Following a visiting assistant professorship at Indiana University Bloomington, Indiana (USA) he was full professor at the Universität des Saarlandes, Saarbrücken (Germany), from 1973-1981. He was Director of the "Institut für Numerische und instrumentelle Mathematik" of the Westfälische Wilhelms Uni ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Technical University Of Vienna
TU Wien (TUW; german: Technische Universität Wien; still known in English as the Vienna University of Technology from 1975–2014) is one of the major universities in Vienna, Austria. The university finds high international and domestic recognition in teaching as well as in research, and it is a highly esteemed partner of innovation-oriented enterprises. It currently has about 28,100 students (29% women), eight faculties and about 5,000 staff members (3,800 academics). The university's teaching and research is focused on engineering, computer science, and natural sciences. History The institution was founded in 1815 by Emperor Francis I of Austria as the '' k.k. Polytechnische Institut'' (Imperial-Royal Polytechnic Institute). The first rector was Johann Joseph von Prechtl. It was renamed the ''Technische Hochschule'' (College of Technology) in 1872. When it began granting doctoral and higher degrees in 1975, it was renamed the ''Technische Universität Wien'' (Vienna Univers ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of São Paulo
The University of São Paulo ( pt, Universidade de São Paulo, USP) is a public university in the Brazilian state of São Paulo. It is the largest Brazilian public university and the country's most prestigious educational institution, the best university in Ibero-America, and holds a high reputation among world universities, being ranked 100 worldwide in reputation by the Times Higher Education World University Rankings. The USP is involved in teaching, research and university extension in all areas of knowledge, offering a broad range of courses. The university was founded in 1934, regrouping already existing schools in the state of São Paulo, such as the Faculdade de Direito do Largo de São Francisco (Faculty of Law), the Escola Politécnica (Engineering School) and the Escola Superior de Agricultura Luiz de Queiroz (College of Agriculture). The university's foundation is marked by the creation in 1934 of the Faculdade de Filosofia, Ciências e Letras (Faculty of Philoso ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hamburg Mathematical Society
The Hamburg Mathematical Society (german: Mathematische Gesellschaft in Hamburg) is a learned society concerned with mathematics and located in the German city of Hamburg. It was founded in 1690 by Heinrich Meissner as the "Kunstrechnungsübende Societät". It is the oldest still-active mathematical society in the world, and the second-oldest scientific society in Germany after the Academy of Sciences Leopoldina, which was founded in 1652. Two asteroids, 449 Hamburga Hamburga (minor planet designation: 449 Hamburga) is a carbonaceous asteroid from the background population of the intermediate asteroid belt, approximately 75 kilometers in diameter. It was discovered by German astronomers Max Wolf and Friedric ... and 454 Mathesis, were given their names at an anniversary celebration of the society in 1901. Its journal is the ''Mitteilungen der Mathematischen Gesellschaft in Hamburg''. It began publications in 1881, succeeding a listing of society talks which had been sent out t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Academy Of Sciences Of The Institute Of Bologna
The Academy of Sciences of the Institute of Bologna (''Accademia delle Scienze dell'Istituto di Bologna'') is an academic society in Bologna, Italy, that was founded in 1690 and prospered in the Age of Enlightenment. Today it is closely associated with the University of Bologna. Origins By the end of the seventeenth century the University of Bologna, one of the world's oldest and once a thriving center of artistic and scientific discovery, had entered a long period of decline. The ''Academy degli Inquieti'' was founded in Bologna around 1690 by Eustachio Manfredi as a place where mathematical topics could be discussed. At first, the academy held its meetings in Manfredi's house, where it began to attract scholars working in other disciplines such as anatomy and physiology, from Bologna and from nearby provinces. In 1694 the academy moved to the house of Jacopo Sandri, a professor of anatomy and medicine at the University of Bologna. In 1704 the academy acquired a more formal struct ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Academy Of Sciences Leopoldina
The German National Academy of Sciences Leopoldina (german: Deutsche Akademie der Naturforscher Leopoldina – Nationale Akademie der Wissenschaften), short Leopoldina, is the national academy of Germany, and is located in Halle (Saale). Founded on January 1, 1652, based on academic models in Italy, it was originally named the ''Academia Naturae Curiosorum'' until 1687 when Emperor Leopold I raised it to an academy and named it after himself. It was since known under the German name ''Deutsche Akademie der Naturforscher Leopoldina'' until 2007, when it was declared to be Germany's National Academy of Sciences. History ' The Leopoldina was founded in the imperial city of Schweinfurt on 1 January 1652 under the Latin name sometimes translated into English as "Academy of the Curious as to Nature." It was founded by four local physicians- Johann Laurentius Bausch, the first president of the society, Johann Michael Fehr, Georg Balthasar Metzger, and Georg Balthasar Wohlfarth; and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Emeritus
''Emeritus'' (; female: ''emerita'') is an adjective used to designate a retired chair, professor, pastor, bishop, pope, director, president, prime minister, rabbi, emperor, or other person who has been "permitted to retain as an honorary title the rank of the last office held". In some cases, the term is conferred automatically upon all persons who retire at a given rank, but in others, it remains a mark of distinguished service awarded selectively on retirement. It is also used when a person of distinction in a profession retires or hands over the position, enabling their former rank to be retained in their title, e.g., "professor emeritus". The term ''emeritus'' does not necessarily signify that a person has relinquished all the duties of their former position, and they may continue to exercise some of them. In the description of deceased professors emeritus listed at U.S. universities, the title ''emeritus'' is replaced by indicating the years of their appointmentsThe Protoc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Technical University Of Hannover
Gottfried Wilhelm Leibniz University Hannover (german: Gottfried Wilhelm Leibniz Universität), also known as the University of Hannover, is a public research university located in Hanover, Germany. Founded on 2 May 1831 as Higher Vocational School, the university has undergone six periods of renaming, its most recent in 2006. Leibniz University Hannover is a member of TU9, an association of the nine leading Institutes of Technology An institute of technology (also referred to as: technological university, technical university, university of technology, technological educational institute, technical college, polytechnic university or just polytechnic) is an institution of te ... in Germany. It is also a member of the Conference of European Schools for Advanced Engineering Education and Research, a non-profit association of leading engineering universities in Europe. The university sponsors the German National Library of Science and Technology, the largest science and technolo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alwin Walther
Alwin Oswald Walther (born 6 May 1898 in Reick; died 4 January 1967 in Darmstadt) was a German mathematician, engineer and professor. He is one of the pioneers of mechanical computing technology in Germany. Life Alwin Walther was born in May 1898 in Reick near Dresden. From 1916 to 1919 Walther served his military service. He was wounded twice and received the Iron Cross 1st Class. From 1919 to 1922 he studied mathematics at the Technical University of Dresden and the University of Göttingen. In 1922, he received his doctorate to Dr. rer. tech. (today according to Dr.-Ing.) from the University of Göttingen under the supervision of Gerhard Kowalewski and . From 1922 to 1928, he was assistant and senior Assistant to Richard Courant at the Mathematical Institute at the University of Göttingen. In 1924, he habilitated and became a Privatdozent. The year before, he stayed in Copenhagen for scientific purposes. From 1926 to 1927 he was a Rockefeller Fellow in Copenhagen and Stockho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Privatdozent
''Privatdozent'' (for men) or ''Privatdozentin'' (for women), abbreviated PD, P.D. or Priv.-Doz., is an academic title conferred at some European universities, especially in German-speaking countries, to someone who holds certain formal qualifications that denote an ability (''facultas docendi'') and permission to teach (''venia legendi'') a designated subject at the highest level. To be granted the title Priv.-Doz. by a university, a recipient has to fulfill the criteria set by the university which usually require excellence in research, teaching, and further education. In its current usage, the title indicates that the holder has completed their habilitation and is therefore granted permission to teach and examine students independently without having a professorship. Conferment and roles A university faculty can confer the title to an academic who has a higher doctoral degree - usually in the form of a habilitation. The title, ''Privatdozent'', as such does not imply a sala ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spectral Graph Theory
In mathematics, spectral graph theory is the study of the properties of a graph in relationship to the characteristic polynomial, eigenvalues, and eigenvectors of matrices associated with the graph, such as its adjacency matrix or Laplacian matrix. The adjacency matrix of a simple undirected graph is a real symmetric matrix and is therefore orthogonally diagonalizable; its eigenvalues are real algebraic integers. While the adjacency matrix depends on the vertex labeling, its spectrum is a graph invariant, although not a complete one. Spectral graph theory is also concerned with graph parameters that are defined via multiplicities of eigenvalues of matrices associated to the graph, such as the Colin de Verdière number. Cospectral graphs Two graphs are called cospectral or isospectral if the adjacency matrices of the graphs are isospectral, that is, if the adjacency matrices have equal multisets of eigenvalues. Cospectral graphs need not be isomorphic, but isomorphic graphs a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
