http://biblioteca.universia.net/vernivel.do?nivel=1201 Mostrando recursos 1 - 20 de 57,169 es http://biblioteca.universia.net/img/logotipo.jpg http://biblioteca.universia.net/ http://biblioteca.universia.net/ficha.do?id=3491 Edición digital a partir del texto original de la tesis doctoral. Ojeda Martínez de Castilla, Ignacio 2004-10-26T22:00:00Z http://biblioteca.universia.net/ficha.do?id=41466584 : Rough relation algebras were introduced by S. Comer as a generalisation of algebras of Pawlak 's rough sets and Tarski's relation algebras. In this paper, some algebraic and arithmetical properties of rough relation algebras are studied and the representable rough relation algebras are characterised. 1. Definitions and preliminary results We assume that the reader is familiar with the basic facts of relation algebras as presented e.g. in [4] or [8]. For Stone algebras the reader is invited ... Relation Algebras http://biblioteca.universia.net/ficha.do?id=41655517 : Rough relation algebras were introduced by S. Comer as a generalisation of algebras of Pawlak 's rough sets and Tarski's relation algebras. In this paper, some algebraic and arithmetical properties of rough relation algebras are studied and the representable rough relation algebras are characterised. 1. Definitions and preliminary results We assume that the reader is familiar with the basic facts of relation algebras as presented e.g. in [4] or [8]. For Stone algebras the reader is invited ... Rough Relation Algebras http://biblioteca.universia.net/ficha.do?id=41807021 : Rough relation algebras were introduced by S. Comer as a generalisation of algebras of Pawlak 's rough sets and Tarski's relation algebras. In this paper, some algebraic and arithmetical properties of rough relation algebras are studied and the representable rough relation algebras are characterised. 1. Definitions and preliminary results We assume that the reader is familiar with the basic facts of relation algebras as presented e.g. in [4] or [8]. For Stone algebras the reader is invited ... Relation Algebras,Ivo Dntsch http://biblioteca.universia.net/ficha.do?id=6711493 Apresentamos aqui os conceitos introdutórios à teoria de PI-álgebras, bem como apresentamos resultados que forneceram, ao longo da história, ferramentas poderosas para lidar com PI-álgebras sobre corpos de característica nula. Além disso, exibimos uma base para o conjunto de identidades polinomiais da álgebra de Grassmann, e por fim, mostramos que o teorema de Kemer sobre o produto de álgebras T-primas falha ao trabalharmos com corpos de característica positiva Ednei Aparecido Santulo Junior http://biblioteca.universia.net/ficha.do?id=44778834 In this paper we define maximal MV-algebras, a concept similar to the maximal rings and maximal distributive lattices. We prove that any maximal MV-algebra is semilocal, then we characterize a maximal MV-algebra as finite direct product of local maximal MV-algebras. Filipoiu, A.; Georgescu, George; Lettieri, Ada http://biblioteca.universia.net/ficha.do?id=44782636 A direct proof of Braun's characterization of Azumaya algebras is given. Dicks McLay, Warren http://biblioteca.universia.net/ficha.do?id=44782866 Entire functions operate in complete locally A-convex algebras but not continuously. Actually squaring is not always continuous. The counterexample we give is multiplier algebra. Oudadess, M. http://biblioteca.universia.net/ficha.do?id=41760967 intervals on them. Example 1. Consider the following specification in pseudo-OBJ syntax, where we distinguish between capital and small letters: obj NATS kind Nats sorts zero : -? Nats succ : Nats -? Nats sort-var X :: Nats ops 0 : -? zero s : X -? succ(X). In the initial algebra of this specification, which is unique up to isomorphism, succ n (zero) is interpreted as singleton fs n (0)g and Nats is the set of all such singletons. Now intervals on natural numbers can be specified as follows: ... Claus Hintermeier http://biblioteca.universia.net/ficha.do?id=38557589 We characterize the values of the stable rank for Leavitt path algebras, by giving concrete criteria in terms of properties of the underlying graph. Pardo, E.; Ara i Bertrán, Pere http://biblioteca.universia.net/ficha.do?id=46494369 The work reported here was part of research into the design of the Mathtalk program. This allows visually disabled people to read algebra notation using synthetic speech and non-speech audio [7]. This paper describes an experiment that investigated the problems of reading algebra notation by listening. The two questions addressed in this paper are firstly, does using prosodic cues facilitate the process of reading by listening and secondly, what is the role of external memory. Keywords: Algeb... Robert Stevens Peter; Peter Wright; Alistair Edwards http://biblioteca.universia.net/ficha.do?id=45722791 We consider the problem of solving a system of polynomial equations over fixed algebra A which we call MPOLSAT(A). We restrict ourselves to unary algebras and give a partial characterization of complexity of MPOLSAT(A). We isolate a preorder P(A) to show that when A has at most 3 elements then MPOLSAT(A) is in P when width of P(A) is at most 2 and is NP-complete otherwise. We show also that if P � = NP then the class of unary algebras solvable in polynomial time is not closed under homomorphi... Przemyslaw Broniek http://biblioteca.universia.net/ficha.do?id=42058447 this paper in this relatively simple case again, so we can show how our method works. The notations are like in [BDR] Hopf Algebras,Daniel Didt http://biblioteca.universia.net/ficha.do?id=3279674 Many computer algebra systems have already been proposed and implemented. Most of them are implemented in or even implement languages without the referential transparency property, making it difficult, if not impractical, to reason about algebra programs. This dissertation presents a computer algebra system implemented as a library in the Haskell programming language, a modern functional language with the desired referential transparency property. The author presents the foundations and basic... Malaquias, José Romildo http://biblioteca.universia.net/ficha.do?id=46382658 Constraint relational databases use constraints to both model and query data. A constraint relation contains a finite set of generalized tuples. Each generalized tuple is represented by a conjunction of constraints on a given logical theory and, depending on the logical theory and the specific conjunction of constraints, it may possibly represent an infinite set of relational tuples. For their characteristics, constraint databases are well suited to model multidimensional and structured data,... Alberto Belussi; Elisa Bertino; Barbara Catania http://biblioteca.universia.net/ficha.do?id=46283055 We consider the boolean complexity of the decomposition of semi-simple algebras over finite fields and number fields. Wayne Eberly http://biblioteca.universia.net/ficha.do?id=80566 See: Real Normed Algebra Weisstein, Eric W. http://biblioteca.universia.net/ficha.do?id=46271871 It was a conjecture of the second author that the Cantor-Bendixson rank of the Ziegler spectrum of a nite-dimensional algebra is either less than or equal to 2 or is undened. Here we refute this conjecture by describing the Ziegler spectra of some domestic string algebras where arbitrary nite values greater than 2 are obtained. We give a complete description of the Ziegler and Gabriel-Zariski spectra of the simplest of these algebras. The conjecture has been independently refuted by Sc... Kevin Burke; Mike Prest http://biblioteca.universia.net/ficha.do?id=41425778 Os Sistemas de Informação Geográfica (SIG)oferecem procedimentos de manipulação de mapas para que o usuário possa expressar modelos de análise espacial. Estes procedimentos, denominados Álgebra de Mapas, usualmente são expressos em linguagens, que permitem ordenar seqüências de transformações do dados geográficos para gerar novos mapas a partir dos mapas existentes. O Sistema de Processamento de Informações Georeferenciadas (SPRING), desenvolvido pelo Instituto Nacional de Pesquisas Espaciais... Ivan Soares de Lucena http://biblioteca.universia.net/ficha.do?id=3271522 Os Sistemas de Informação Geográfica (SIG)oferecem procedimentos de manipulação de mapas para que o usuário possa expressar modelos de análise espacial. Estes procedimentos, denominados Álgebra de Mapas, usualmente são expressos em linguagens, que permitem ordenar seqüências de transformações do dados geográficos para gerar novos mapas a partir dos mapas existentes. O Sistema de Processamento de Informações Georeferenciadas (SPRING), desenvolvido pelo Instituto Nacional de Pesquisas Espaciais... Ivan Soares de Lucena