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Ackermann Turning
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Ackermann may also refer to the following: *Ackermann (surname), for many people with this name *Several mathematical objects named after Wilhelm Ackermann **Ackermann function **Ackermann ordinal **Ackermann set theory *Ackermann steering geometry, in mechanical engineering *Ackermann's formula, in control engineering *''Der Ackermann aus Böhmen'', or "The Ploughman from Bohemia", a work of poetry in Early New High German by Johannes von Tepl, written around 1401 *''Ackermannviridae'', virus family named in honor of H.-W. Ackermann See also *Ackerman (other) *Ackermans (other) *Akkerman (other) *Åkerman Åkerman is a Swedish surname. Notable people with the surname include: *Gustaf Åkerman (1888–1959), Swedish economist *Gustav Åkerman (1901–1988), Swedish Army lieutenant general *Johan Åkerman (born 1972), Swedish ice hockey player *Lisbet ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ackermann (surname)
Ackermann is a surname. "Acker" comes from German or Old English, meaning "field", and is related to the word "acre". ''Ackermann'' means "farmer" (literally: "fieldman"). Notable people with the surname, also spelled Akkermann. include: * Annely Akkermann (born 1972) Estonian politician * Anton Ackermann (1905–1973), German foreign minister * Barbara Ackermann (1925–2020), American politician * Christian Ackermann (died 1710), Estonian sculptor * Colin Ackermann (born 1991), South African cricketer * Dorothea Ackermann (1752–1821), German actress * Else Ackermann (1933–2019), German physician and pharmacologist * Ernst Christian Wilhelm Ackermann (1761–1835), Bohemian public servant * Franz Ackermann (born 1963), German abstract artist * Georg Ackermann (other) * Gustav Adolph Ackermann (1791–1872), a German lawyer * Haider Ackermann (born 1971), French fashion designer * Hans Ackermann (16th century), German dramatist * Hans-Wofgang Ackermann (1936-2017), G ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wilhelm Ackermann
Wilhelm Friedrich Ackermann (; ; 29 March 1896 – 24 December 1962) was a German mathematician and logician best known for his work in mathematical logic and the Ackermann function, an important example in the theory of computation. Biography Ackermann was born in Herscheid, Germany, and was awarded a Ph.D. by the University of Göttingen in 1925 for his thesis ''Begründung des "tertium non datur" mittels der Hilbertschen Theorie der Widerspruchsfreiheit'', which was a consistency proof of arithmetic apparently without Peano induction (although it did use e.g. induction over the length of proofs). This was one of two major works in proof theory in the 1920s and the only one following Hilbert's school of thought. From 1929 until 1948, he taught at the Arnoldinum Gymnasium in Burgsteinfurt, and then at Lüdenscheid until 1961. He was also a corresponding member of the Akademie der Wissenschaften (''Academy of Sciences'') in Göttingen, and was an honorary professor at the Unive ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ackermann Function
In computability theory, the Ackermann function, named after Wilhelm Ackermann, is one of the simplest and earliest-discovered examples of a total computable function that is not primitive recursive. All primitive recursive functions are total and computable, but the Ackermann function illustrates that not all total computable functions are primitive recursive. After Ackermann's publication of his function (which had three non-negative integer arguments), many authors modified it to suit various purposes, so that today "the Ackermann function" may refer to any of numerous variants of the original function. One common version, the two-argument Ackermann–Péter function is defined as follows for nonnegative integers ''m'' and ''n'': : \begin \operatorname(0, n) & = & n + 1 \\ \operatorname(m+1, 0) & = & \operatorname(m, 1) \\ \operatorname(m+1, n+1) & = & \operatorname(m, \operatorname(m+1, n)) \end Its value grows rapidly, even for small inputs. For example, is an integer o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ackermann Ordinal
In mathematics, the Ackermann ordinal is a certain large countable ordinal, named after Wilhelm Ackermann. The term "Ackermann ordinal" is also occasionally used for the small Veblen ordinal, a somewhat larger ordinal. Unfortunately there is no standard notation for ordinals beyond the Feferman–Schütte ordinal Γ0. Most systems of notation use symbols such as ψ(α), θ(α), ψα(β), some of which are modifications of the Veblen function In mathematics, the Veblen functions are a hierarchy of normal functions ( continuous strictly increasing functions from ordinals to ordinals), introduced by Oswald Veblen in . If φ0 is any normal function, then for any non-zero ordinal α, φ ...s to produce countable ordinals even for uncountable arguments, and some of which are " collapsing functions". The last one is an extension of the Veblen functions for more than 2 arguments. The smaller Ackermann ordinal is the limit of a system of ordinal notations invented by , and is some ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ackermann Set Theory
In mathematics and logic, Ackermann set theory (AST) is an axiomatic set theory proposed by Wilhelm Ackermann in 1956. The language AST is formulated in first-order logic. The formal language, language L_ of AST contains one binary relation \in denoting set membership and one constant (mathematics), constant V denoting the Von Neumann universe, class of all sets (Ackermann used a predicate M instead). The axioms The axioms of AST are the following: # axiom of extensionality, extensionality # axiom of heredity, heredity: (x \in y \lor x \subseteq y) \land y \in V \to x \in V # axiom of comprehension, comprehension on V: for any formula \phi where x is not free variable, free, \exists x \forall y (y \in x \leftrightarrow y \in V \land \phi) # Ackermann's schema: for any formula \phi with free variables a_1, \ldots, a_n, x and no occurrences of V, a_1, \ldots, a_n \in V \land \forall x (\phi \to x \in V) \to \exists y V \forall x (x \in y \leftrightarrow \phi) An alternative axio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ackermann Steering Geometry
The Ackermann steering geometry is a geometric arrangement of linkages in the steering of a car or other vehicle designed to solve the problem of wheels on the inside and outside of a turn needing to trace out circles of different radii. It was invented by the German carriage builder Georg Lankensperger in Munich in 1817, then patented by his agent in England, Rudolph Ackermann (1764–1834) in 1818 for horse-drawn carriages. Erasmus Darwin may have a prior claim as the inventor dating from 1758. He devised his steering system because he was injured when a carriage tipped over. Advantages The intention of Ackermann geometry is to avoid the need for tires to slip sideways when following the path around a curve. The geometrical solution to this is for all wheels to have their axles arranged as radii of circles with a common centre point. As the rear wheels are fixed, this centre point must be on a line extended from the rear axle. Intersecting the axes of the front wheels on th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ackermann's Formula
In control theory, Ackermann's formula is a control system design method for solving the pole allocation problem for invariant-time systems by Jürgen Ackermann. One of the primary problems in control system design is the creation of controllers that will change the dynamics of a system by changing the eigenvalues of the matrix representing the dynamics of the closed-loop system. This is equivalent to changing the poles of the associated transfer function in the case that there is no cancellation of poles and zeros. State feedback control Consider a linear continuous-time invariant system with a state-space representation : \dot(t)=Ax(t)+Bu(t) : y(t)=Cx(t) where ''x'' is the state vector, ''u'' is the input vector, and ''A'', ''B'' and ''C'' are matrices of compatible dimensions that represent the dynamics of the system. An input-output description of this system is given by the transfer function : G(s) = C(sI-A)^B=C\ \frac\ B. Since the denominator of the right equation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Der Ackermann Aus Böhmen
''Der Ackermann aus Böhmen'' (German for "The Ploughman from Bohemia"), also known as ''Der Ackermann und der Tod'' ("The Ploughman and Death"), is a work of prose in Early New High German by Johannes von Tepl, written around 1401. Sixteen manuscripts and seventeen early printed editions are preserved; the earliest printed version dates to 1460 and is one of the two earliest printed books in German. It is remarkable for the high level of its language and vocabulary and is considered one of the most important works of late medieval German literature. It is a spirited dialogue between the ploughman, whose wife Margaretha has recently died, and Death. Central themes of the book are their opposing views on life, mankind, and morality. The work also represents a concept of marriage as a communion of love, a notion not generally accepted at the time. The work consists of 34 short chapters. In odd-numbered chapters the ploughman accuses Death of robbing him of his beloved young wife. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ackermannviridae
''Ackermannviridae'' is a family of viruses in the order ''Caudovirales''. Gammaproteobacteria in the phylum Pseudomonadota serve as natural hosts. There are 2 subfamilies, 10 genera, and 63 species in the family. Etymology The family's name, ''Ackermann'' is in honor of Hans-Wolfgang Ackermann (1936-2017), a German microbiologist, the suffix ''-viridae'' is the standard suffix for virus families.Hans-W. AckermannLife in science Bacteriophage. 2012 Oct 1; 2(4): 207. doi: 10.4161/bact.23159 . . A curriculum vitae. Taxonomy The following taxa are recognized (-''virinae'' denotes subfamily and -''virus'' denotes genus): * '' Aglimvirinae'' ** '' Agtrevirus'' ** '' Limestonevirus'' * '' Cvivirinae'' ** ''Kuttervirus'' ''incertae sedis ' () or ''problematica'' is a term used for a taxonomic group where its broader relationships are unknown or undefined. Alternatively, such groups are frequently referred to as "enigmatic taxa". In the system of open nomenclature, uncertainty ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ackerman (other)
Ackerman may refer to: Surname *Ackerman (surname), people with the surname Ackerman *Ackerman is a family name for singer Barlin Ackerman Places *Ackerman, Mississippi, town in Choctaw County, Mississippi, US *Ackerman, West Virginia, former unincorporated community in Mineral County, West Virginia, US *Ackerman Island, sandbar in the Arkansas River near Wichita, Kansas, US *Ackerman Nunatak, ridge of the Pensacola Mountains, Antarctica *Ackerman Ridge, ridge of the Queen Maud Mountains, Antarctica * Akkerman Other uses *Ackerman House (other) *Ackerman syndrome, medical disease *Ackermann steering geometry See also *Ackerman McQueen *Ackermans (other) * Ackermann (other) *Akkerman (other) Akkerman may refer to: Places * Bilhorod-Dnistrovskyi, a city in Ukraine * Akkerman Oblast, a region in Ukraine *Akerman Fortress; see Tyras Other uses * Akkerman (surname) * Akkerman Inc., a construction equipment manufacturer in Brownsdale, ... * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ackermans (other)
Ackermans is a retail store based in South Africa. Ackermans may also refer to: * Stan Ackermans (1936–1995), Dutch mathematician *Ackermans & van Haaren, Belgian holding company See also * Ackerman (other) * Ackermann (other) *Akkerman (other) *Akerman Akerman is a surname. People with the name include: *Alexander Akerman (1869–1948), American lawyer and judge *Amos T. Akerman (1821–1880), US Attorney General *Chantal Akerman (1950-2015), Belgian film director, artist and professor *Clive Ak ... * Åkerman, a Swedish surname {{disambig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
