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Cesare Arzelà
Cesare Arzelà (6 March 1847 – 15 March 1912) was an Italian mathematician who taught at the University of Bologna and is recognized for his contributions in the theory of functions, particularly for his characterization of sequences of continuous functions, generalizing the one given earlier by Giulio Ascoli in the Arzelà–Ascoli theorem. Life He was a pupil of the Scuola Normale Superiore of Pisa where he graduated in 1869. Arzelà came from a poor household; therefore he could not start his study until 1871, when he studied in Pisa under Enrico Betti and Ulisse Dini. He was working in Florence (from 1875) and in 1878 obtained the Chair of Algebra at the University of Palermo. After that he became a professor in 1880 at the University of Bologna at the department of analysis. He conducted research in the field of theory of functions. His most famous student was Leonida Tonelli. In 1889 he generalized the Ascoli theorem to Arzelà–Ascoli theorem, an important theorem in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Relief
Relief is a sculptural method in which the sculpted pieces are bonded to a solid background of the same material. The term ''relief'' is from the Latin verb ''relevo'', to raise. To create a sculpture in relief is to give the impression that the sculpted material has been raised above the background plane. When a relief is carved into a flat surface of stone (relief sculpture) or wood (relief carving), the field is actually lowered, leaving the unsculpted areas seeming higher. The approach requires a lot of chiselling away of the background, which takes a long time. On the other hand, a relief saves forming the rear of a subject, and is less fragile and more securely fixed than a sculpture in the round, especially one of a standing figure where the ankles are a potential weak point, particularly in stone. In other materials such as metal, clay, plaster stucco, ceramics or papier-mâché the form can be simply added to or raised up from the background. Monumental bronze reliefs a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sequence (mathematics)
In mathematics, a sequence is an enumerated collection of objects in which repetitions are allowed and order matters. Like a set, it contains members (also called ''elements'', or ''terms''). The number of elements (possibly infinite) is called the ''length'' of the sequence. Unlike a set, the same elements can appear multiple times at different positions in a sequence, and unlike a set, the order does matter. Formally, a sequence can be defined as a function from natural numbers (the positions of elements in the sequence) to the elements at each position. The notion of a sequence can be generalized to an indexed family, defined as a function from an ''arbitrary'' index set. For example, (M, A, R, Y) is a sequence of letters with the letter 'M' first and 'Y' last. This sequence differs from (A, R, M, Y). Also, the sequence (1, 1, 2, 3, 5, 8), which contains the number 1 at two different positions, is a valid sequence. Sequences can be ''finite'', as in these examples, or ''infinit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1912 Deaths
Year 191 ( CXCI) was a common year starting on Friday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year of the Consulship of Apronianus and Bradua (or, less frequently, year 944 ''Ab urbe condita''). The denomination 191 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years. Events By place Parthia * King Vologases IV of Parthia dies after a 44-year reign, and is succeeded by his son Vologases V. China * A coalition of Chinese warlords from the east of Hangu Pass launches a punitive campaign against the warlord Dong Zhuo, who seized control of the central government in 189, and held the figurehead Emperor Xian hostage. After suffering some defeats against the coalition forces, Dong Zhuo forcefully relocates the imperial capital from Luoyang to Chang'an. Before leaving, Dong Zhuo orders his troops to loot the tombs of the H ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1847 Births
Events January–March * January 4 – Samuel Colt sells his first revolver pistol to the U.S. government. * January 13 – The Treaty of Cahuenga ends fighting in the Mexican–American War in California. * January 16 – John C. Frémont is appointed Governor of the new California Territory. * January 17 – St. Anthony Hall fraternity is founded at Columbia University, New York City. * January 30 – Yerba Buena, California, is renamed San Francisco. * February 5 – A rescue effort, called the First Relief, leaves Johnson's Ranch to save the ill-fated Donner Party (California-bound emigrants who became snowbound in the Sierra Nevada earlier this winter; some have resorted to survival by cannibalism). * February 22 – Mexican–American War: Battle of Buena Vista – 5,000 American troops under General Zachary Taylor use their superiority in artillery to drive off 15,000 Mexican troops under Antonio López de Santa Anna, defeating the Mexicans the next da ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Total Variation
In mathematics, the total variation identifies several slightly different concepts, related to the (local or global) structure of the codomain of a function or a measure. For a real-valued continuous function ''f'', defined on an interval 'a'', ''b''⊂ R, its total variation on the interval of definition is a measure of the one-dimensional arclength of the curve with parametric equation ''x'' ↦ ''f''(''x''), for ''x'' ∈ 'a'', ''b'' Functions whose total variation is finite are called functions of bounded variation. Historical note The concept of total variation for functions of one real variable was first introduced by Camille Jordan in the paper . He used the new concept in order to prove a convergence theorem for Fourier series of discontinuous periodic functions whose variation is bounded. The extension of the concept to functions of more than one variable however is not simple for various reasons. Definitions Total variation for functions of one real variable Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Accademia Nazionale Dei Lincei
The Accademia dei Lincei (; literally the "Academy of the Lynx-Eyed", but anglicised as the Lincean Academy) is one of the oldest and most prestigious European scientific institutions, located at the Palazzo Corsini on the Via della Lungara in Rome, Italy. Founded in the Papal States in 1603 by Federico Cesi, the academy was named after the lynx, an animal whose sharp vision symbolizes the observational prowess that science requires. Galileo Galilei was the intellectual centre of the academy and adopted "Galileo Galilei Linceo" as his signature. "The Lincei did not long survive the death in 1630 of Cesi, its founder and patron", and "disappeared in 1651". During the nineteenth century, it was revived, first in the Vatican and later in the nation of Italy. Thus the Pontifical Academy of Science, founded in 1847, claims this heritage as the ''Accademia Pontificia dei Nuovi Lincei ("Pontifical Academy of the New Lynxes")'', descending from the first two incarnations of the Academy. S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Theorem
In mathematics, a theorem is a statement that has been proved, or can be proved. The ''proof'' of a theorem is a logical argument that uses the inference rules of a deductive system to establish that the theorem is a logical consequence of the axioms and previously proved theorems. In the mainstream of mathematics, the axioms and the inference rules are commonly left implicit, and, in this case, they are almost always those of Zermelo–Fraenkel set theory with the axiom of choice, or of a less powerful theory, such as Peano arithmetic. A notable exception is Wiles's proof of Fermat's Last Theorem, which involves the Grothendieck universes whose existence requires the addition of a new axiom to the set theory. Generally, an assertion that is explicitly called a theorem is a proved result that is not an immediate consequence of other known theorems. Moreover, many authors qualify as ''theorems'' only the most important results, and use the terms ''lemma'', ''proposition'' and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of Palermo
The University of Palermo ( it, Università degli Studi di Palermo) is a university located in Palermo, Italy, and founded in 1806. It is organized in 12 Faculties. History The University of Palermo was officially founded in 1806, although its earliest roots date back to 1498 when medicine and law were taught there. A little later in history, from the second half of the 16th century from their seat at the Collegio Massimo al Cassero, the Jesuit Fathers granted degrees in Theology and Philosophy - subjects in which they had been masters for over 200 years. In 1767 they were expelled from the kingdom by King Ferdinand I, until 37 years later, when they returned to take their seat - which in the meantime had been turned into the Regia Accademia. At this time, the same King Ferdinand decided to grant a good seat to the Accademia, moving its location to the Convent of the Teatini Fathers next to the Church of St. Giuseppe. After the unification of Italy in 1860, the University ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Florence
Florence ( ; it, Firenze ) is a city in Central Italy and the capital city of the Tuscany region. It is the most populated city in Tuscany, with 383,083 inhabitants in 2016, and over 1,520,000 in its metropolitan area.Bilancio demografico anno 2013, datISTAT/ref> Florence was a centre of medieval European trade and finance and one of the wealthiest cities of that era. It is considered by many academics to have been the birthplace of the Renaissance, becoming a major artistic, cultural, commercial, political, economic and financial center. During this time, Florence rose to a position of enormous influence in Italy, Europe, and beyond. Its turbulent political history includes periods of rule by the powerful Medici family and numerous religious and republican revolutions. From 1865 to 1871 the city served as the capital of the Kingdom of Italy (established in 1861). The Florentine dialect forms the base of Standard Italian and it became the language of culture throughout Ital ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ulisse Dini
Ulisse Dini (14 November 1845 – 28 October 1918) was an Italian mathematician and politician, born in Pisa. He is known for his contribution to real analysis, partly collected in his book "''Fondamenti per la teorica delle funzioni di variabili reali''". Life and academic career Dini attended the Scuola Normale Superiore in order to become a teacher. One of his professors was Enrico Betti. In 1865, a scholarship enabled him to visit Paris, where he studied under Charles Hermite as well as Joseph Bertrand, and published several papers. In 1866, he was appointed to the University of Pisa, where he taught algebra and geodesy. In 1871, he succeeded Betti as professor for analysis and geometry. From 1888 until 1890, Dini was ''rettore'' of the Pisa University, and of the ''Scuola Normale Superiore'' from 1908 until his death in 1918. He was also active as a politician: in 1871 he was voted into the Pisa city council, and in 1880, he became a member of the Italian parliament. Hono ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pisa
Pisa ( , or ) is a city and ''comune'' in Tuscany, central Italy, straddling the Arno just before it empties into the Ligurian Sea. It is the capital city of the Province of Pisa. Although Pisa is known worldwide for its leaning tower, the city contains more than twenty other historic churches, several medieval palaces, and bridges across the Arno. Much of the city's architecture was financed from its history as one of the Italian maritime republics. The city is also home to the University of Pisa, which has a history going back to the 12th century, the Scuola Normale Superiore di Pisa, founded by Napoleon in 1810, and its offshoot, the Sant'Anna School of Advanced Studies.Scuola Superiore Sant'Anna di Pisa Information statistics History ...
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