C3 - Artigos Publicados em Periódicos
URI permanente para esta coleçãohttps://rihomolog.furg.br/handle/1/486
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15 resultados
Resultados da Pesquisa
- ItemThe stochastic geometric machine model(2004) Reiser, Renata Hax Sander; Dimuro, Graçaliz Pereira; Costa, Antonio Carlos da RochaThis paper introduces the stochastic version of the Geometric Machine Model for the modelling of sequential, alternative, parallel (synchronous) and nondeterministic computations with stochastic numbers stored in a (possibly infinite) shared memory. The programming language L(D! 1), induced by the Coherence Space of Processes D! 1, can be applied to sequential and parallel products in order to provide recursive definitions for such processes, together with a domain-theoretic semantics of the Stochastic Arithmetic. We analyze both the spacial (ordinal) recursion, related to spacial modelling of the stochastic memory, and the temporal (structural) recursion, given by the inclusion relation modelling partial objects in the ordered structure of process construction.
- ItemO modelo de máquina geométrica intervalar(2003) Reiser, Renata Hax Sander; Costa, Antonio Carlos da Rocha; Dimuro, Graçaliz PereiraMostra-se neste trabalho que a linguagem e a correspondente semântica associada às interpretações obtidas na estrutura ordenada da Máquina Geométrica Intervalar, fundamentada nos espaços coerentes, são ferramentas importantes para construção, desenvolvimento e análise semântica de algoritmos da matemática intervalar, envolvendo paralelismo e não-determinismo, definidos por estruturas matriciais e operando de forma sincronizada.
- ItemThe stochastic geometric machine model(2004) Reiser, Renata Hax Sander; Dimuro, Graçaliz Pereira; Costa, Antonio Carlos da RochaThis paper introduces the stochastic version of the Geometric Machine Model for the modelling of sequential, alternative, parallel (synchronous) and nondeterministic computations with stochastic numbers stored in a (possibly infinite) shared memory. The programming language L(D! 1), induced by the Coherence Space of Processes D! 1, can be applied to sequential and parallel products in order to provide recursive definitions for such processes, together with a domain-theoretic semantics of the Stochastic Arithmetic. We analyze both the spacial (ordinal) recursion, related to spacial modelling of the stochastic memory, and the temporal (structural) recursion, given by the inclusion relation modelling partial objects in the ordered structure of process
- ItemPower flow with load uncertainty(2004) Barboza, Luciano Vitória; Dimuro, Graçaliz Pereira; Reiser, Renata Hax SanderThis paper presents a methodology to solve load flow problems in which the load data are uncertain due to measurement errors. In order to deal with those uncertainties we apply techniques of Interval Mathematics. The algorithm uses the Interval Newton’s method to solve the nonlinear system of equations generated by the problem. The implementation was performed in theMatlabr environment using the Intlab toolbox. In order to assess the performance of the proposed algorithm, the method was applied to hypothetical electric systems. In this paper, we present results for a three-bus network.
- ItemAnálise intervalar de circuitos elétricos(2006) Grigoletti, Pablo Souza; Dimuro, Graçaliz Pereira; Barboza, Luciano Vitória; Reiser, Renata Hax SanderEste trabalho apresenta uma aplicação da Matemática Intervalar à análise de circuitos elétricos, onde consideram-se as incertezas nos dados de entrada devido às tolerâncias existentes nos resistores. Sendo assim, os valores correspondentes às resistências dos resistores são modelados como dados intervalares cujos pontos médios respresentam as resistências nominais e os raios são especificados pelas tolerâncias percentuais dos resistores. O problema é modelado com a utiliza ção da técnica de análise nodal para circuitos elétricos, que gera um sistema de equações lineares intervalares, nas quais as tensões nodais intervalares do circuito são as incógnitas. A metodologia foi implementada na linguagem Python produzindo uma ferramenta denominada Free Interval Circuit Analyser (FINCA). São apresentados resultados para circuitos-teste com algumas topologias, comparando-os com os obtidos através da utilização de um software comercial que executa a análise de circuitos elétricos de forma convencional.
- ItemProbabilidades intervalares em modelos ocultos de Markov(2006) Santos, André Vinícius dos; Dimuro, Graçaliz Pereira; Barboza, Luciano Vitória; Costa, Antonio Carlos da Rocha; Reiser, Renata Hax Sander; Campos, Marcilia AndradeEste trabalho apresenta um estudo sobre modelos ocultos de Markov onde as probabilidades consideradas são representadas por intervalos. Utilizando-se técnicas da Matemática Intervalar, foram desenvolvidos algoritmos intervalares para os problemas relacionados a esses modelos (Problema da Avaliação, Problema da Decodificação e Problema da Estimação de Parâmetros). Apresentam-se versões intervalares para os algoritmos Forward, Backward, Viterbi e Baum Welch. As implementações foram realizadas utilizando-se o toolbox Intlab para a Matemática Intervalar, no ambiente Matlab. Exemplos de aplicações são apresentados, mostrando-se a validade dos algoritmos desenvolvidos.
- ItemProperties of fuzzy implications obtained via the interval constructor(2007) Bedregal, Benjamín Callejas; Santiago, Regivan Hugo Nunes; Reiser, Renata Hax Sander; Dimuro, Graçaliz PereiraThis work considers an interval extension of fuzzy implication based on the best interval representation of continuous t-norms. Some related properties can be naturally extended and that extension preserves the behaviors of the implications in the interval endpoints.
- ItemS-Implications on complete lattices and the interval constructor(2008) Reiser, Renata Hax Sander; Dimuro, Graçaliz Pereira; Bedregal, Benjamín Callejas; Santos, Hélida Salles; Bedregal, Roberto CallejasThe aim of this work is to present an approach of interval fuzzy logic based on complete lattices. In particular, we study the extensions of the notions of t-conorms, fuzzy negations and S-implication, from the unit interval to arbitrary complete lattices. Some general properties of S-implications on complete lattices are analyzed. We show that the interval extensions of t-conorms, fuzzy negations and S-implications on complete lattices preserve the optimality property, being the best interval representations of these fuzzy connectives.
- ItemXor-Implications and E-implications: classes of fuzzy implications based on fuzzy Xor(2009) Bedregal, Benjamín Callejas; Reiser, Renata Hax Sander; Dimuro, Graçaliz PereiraThe main contribution of this paper is to introduce an autonomous definition of the connective “fuzzy exclusive or” (fuzzy Xor, for short), which is independent from others connectives. Also, two canonical definitions of the connective Xor are obtained from the composition of fuzzy connectives, and based on the commutative and associative properties related to the notions of triangular norms, triangular conorms and fuzzy negations. We show that the main properties of the classical connective Xor are preserved by the connective fuzzy Xor, and, therefore, this new definition of the connective fuzzy Xor extends the related classical approach. The definitions of fuzzy Xor-implications and fuzzy E-implications, induced by the fuzzy Xor connective, are also studied, and their main properties are analyzed. The relationships between the fuzzy Xor-implications and the fuzzy E-implications with automorphisms are explored.
- ItemFirst steps in the construction of the geometric machine model(2002) Reiser, Renata Hax Sander; Costa, Antonio Carlos da Rocha; Dimuro, Graçaliz PereiraThis work introduces the Geometric Machine (GM) – a computational model for the construction and representation of concurrent and non-deterministic processes, preformed in a synchronized way, with infinite memory whose positionsare labelled by the points of a geometric space. The ordered structure of the GM model is based on Girard’s Coherence Spaces. Starting with a coherence space of elementary processes, the inductive domain-theoretic structure of this model is step-wise and systematically constructed and the procedure completion ensures the existence of temporally and spatially infinite computations. A particular aim of our work is to apply this coherence-space-based interpretation to the semantic modelling parallelism and distributed computation over array structures.