42 resultados para nonclassical logic

em Biblioteca Digital da Produção Intelectual da Universidade de São Paulo (BDPI/USP)


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The existence of quantum correlation (as revealed by quantum discord), other than entanglement and its role in quantum-information processing (QIP), is a current subject for discussion. In particular, it has been suggested that this nonclassical correlation may provide computational speedup for some quantum algorithms. In this regard, bulk nuclear magnetic resonance (NMR) has been successfully used as a test bench for many QIP implementations, although it has also been continuously criticized for not presenting entanglement in most of the systems used so far. In this paper, we report a theoretical and experimental study on the dynamics of quantum and classical correlations in an NMR quadrupolar system. We present a method for computing the correlations from experimental NMR deviation-density matrices and show that, given the action of the nuclear-spin environment, the relaxation produces a monotonic time decay in the correlations. Although the experimental realizations were performed in a specific quadrupolar system, the main results presented here can be applied to whichever system uses a deviation-density matrix formalism.

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Despite modern weed control practices, weeds continue to be a threat to agricultural production. Considering the variability of weeds, a classification methodology for the risk of infestation in agricultural zones using fuzzy logic is proposed. The inputs for the classification are attributes extracted from estimated maps for weed seed production and weed coverage using kriging and map analysis and from the percentage of surface infested by grass weeds, in order to account for the presence of weed species with a high rate of development and proliferation. The output for the classification predicts the risk of infestation of regions of the field for the next crop. The risk classification methodology described in this paper integrates analysis techniques which may help to reduce costs and improve weed control practices. Results for the risk classification of the infestation in a maize crop field are presented. To illustrate the effectiveness of the proposed system, the risk of infestation over the entire field is checked against the yield loss map estimated by kriging and also with the average yield loss estimated from a hyperbolic model.

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A large number of initiatives in cities in Brazil - including slum clearance and upgrading - have been undertaken over the years in an effort to ameliorate the problems arising from informal occupation; unfortunately, however, little is known about the related performance outcomes. Careful appraisal of the results of such initiatives is thus called for, covering evaluations of dwellers` perceptions of the upgraded environments. Among the available evaluation methods, post-occupancy evaluation (POE) is commonly employed, although it fails adequately to reflect prevailing subjective concepts of quality. The present paper contains the partial findings of a research exercise aimed at developing an original method, using fuzzy logic, for urban environmental quality evaluation in informally occupied areas on the basis of combining quantitative indicators and dweller perception. It combines POE with fuzzy logic in order to develop tools that can better model the uncertain information that emerges from that kind of study. This paper aims to introduce an uncertainty measure used in order to identify the strengths and weaknesses of slum upgrading projects. The results show that it is possible to quantify certainty degrees in the findings and to define if additional information is needed.

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An efficient expert system for the power transformer condition assessment is presented in this paper. Through the application of Duval`s triangle and the method of the gas ratios a first assessment of the transformer condition is obtained in the form of a dissolved gas analysis (DGA) diagnosis according IEC 60599. As a second step, a knowledge mining procedure is performed, by conducting surveys whose results are fed into a first Type-2 Fuzzy Logic System (T2-FLS), in order to initially evaluate the condition of the equipment taking only the results of dissolved gas analysis into account. The output of this first T2-FLS is used as the input of a second T2-FLS, which additionally weighs up the condition of the paper-oil system. The output of this last T2-FLS is given in terms of words easily understandable by the maintenance personnel. The proposed assessing methodology has been validated for several cases of transformers in service. (C) 2010 Elsevier Ltd. All rights reserved.

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We examine the representation of judgements of stochastic independence in probabilistic logics. We focus on a relational logic where (i) judgements of stochastic independence are encoded by directed acyclic graphs, and (ii) probabilistic assessments are flexible in the sense that they are not required to specify a single probability measure. We discuss issues of knowledge representation and inference that arise from our particular combination of graphs, stochastic independence, logical formulas and probabilistic assessments. (C) 2007 Elsevier B.V. All rights reserved.

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This paper investigates probabilistic logics endowed with independence relations. We review propositional probabilistic languages without and with independence. We then consider graph-theoretic representations for propositional probabilistic logic with independence; complexity is analyzed, algorithms are derived, and examples are discussed. Finally, we examine a restricted first-order probabilistic logic that generalizes relational Bayesian networks. (c) 2007 Elsevier Inc. All rights reserved.

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Nursing diagnoses associated with alterations of urinary elimination require different interventions, Nurses, who are not specialists, require support to diagnose and manage patients with disturbances of urine elimination. The aim of this study was to present a model based on fuzzy logic for differential diagnosis of alterations in urinary elimination, considering nursing diagnosis approved by the North American Nursing Diagnosis Association, 2001-2002. Fuzzy relations and the maximum-minimum composition approach were used to develop the system. The model performance was evaluated with 195 cases from the database of a previous study, resulting in 79.0% of total concordance and 19.5% of partial concordance, when compared with the panel of experts. Total discordance was observed in only three cases (1.5%). The agreement between model and experts was excellent (kappa = 0.98, P < .0001) or substantial (kappa = 0.69, P < .0001) when considering the overestimative accordance (accordance was considered when at least one diagnosis was equal) and the underestimative discordance (discordance was considered when at least one diagnosis was different), respectively. The model herein presented showed good performance and a simple theoretical structure, therefore demanding few computational resources.

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The logic of proofs (lp) was proposed as Gdels missed link between Intuitionistic and S4-proofs, but so far the tableau-based methods proposed for lp have not explored this closeness with S4 and contain rules whose analycity is not immediately evident. We study possible formulations of analytic tableau proof methods for lp that preserve the subformula property. Two sound and complete tableau decision methods of increasing degree of analycity are proposed, KELP and preKELP. The latter is particularly inspired on S4-proofs. The crucial role of proof constants in the structure of lp-proofs methods is analysed. In particular, a method for the abduction of proof constant specifications in strongly analytic preKELP proofs is presented; abduction heuristics and the complexity of the method are discussed.

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Planning to reach a goal is an essential capability for rational agents. In general, a goal specifies a condition to be achieved at the end of the plan execution. In this article, we introduce nondeterministic planning for extended reachability goals (i.e., goals that also specify a condition to be preserved during the plan execution). We show that, when this kind of goal is considered, the temporal logic CTL turns out to be inadequate to formalize plan synthesis and plan validation algorithms. This is mainly due to the fact that the CTL`s semantics cannot discern among the various actions that produce state transitions. To overcome this limitation, we propose a new temporal logic called alpha-CTL. Then, based on this new logic, we implement a planner capable of synthesizing reliable plans for extended reachability goals, as a side effect of model checking.

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This article describes the integration of the LSD (Logic for Structure Determination) and SISTEMAT expert systems that were both designed for the computer-assisted structure elucidation of small organic molecules. A first step has been achieved towards the linking of the SISTEMAT database with the LSD structure generator. The skeletal descriptions found by the SISTEMAT programs are now easily transferred to LSD as substructural constraints. Examples of the synergy between these expert systems are given for recently reported natural products.

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Neste artigo visamos apontar, apoiadas em W. Benjamim e G. Agamben, a fragilização do registro da experiência e sua incidência na lógica do poder/violência. Analisamos, pretendendo desmistificar a eficácia dos discursos mortificadores da experiência, a figura do "mulçumano"; - nome que designava os mortos-vivos nos campos de concentração, conforme relato de Primo Levi e outros. Tal figura é emblemática do estado limite a que chegaram algumas pessoas e podem expressar o destino de alguns sujeitos na contemporaneidade. Pudemos identificar nessa posição tanto um movimento na direção da perda do laço identificatório com o semelhante, como uma forma de resistência à violência perpetrada pelo discurso social. Tal resistência consiste em operar uma mimese ao objeto resto, o que permite ao sujeito a manutenção da estrutura fantasmática. Indicamos que, apesar das estratégias do poder, o sujeito reinventa modos de se situar na relação ao Outro, nos quais se fazem importantes a presença e a palavra, incluindo aí a experiência psicanalítica.

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Este artigo, que tem como referência a teoria crítica, relata o resultado de uma pesquisa sobre atitudes em relação à educação inclusiva, realizada com doze professoras do 5º ano do ensino fundamental; dentre elas, seis tinham experiência de ter em sala de aula alunos com deficiência, e seis não tinham. A análise qualitativa dos dados decorrentes do levantamento realizado em seis escolas da rede municipal de Campo Grande (MS) demonstrou que, de modo geral, as professoras foram favoráveis à educação inclusiva. Contudo, ficou evidente a expressão de atitudes preconceituosas veladas ou explícitas no âmbito escolar. A formação para experiência com quem é "diferente" ainda encontra barreiras por conta do preconceito e da discriminação presentes nesta sociedade que tem como lógica uma "inclusão marginal". Em suas manifestações, apontaram dificuldades de trabalhar com alunos com deficiência intelectual severa; assinalaram que a responsabilidade de trabalhar sob a predominância da educação centrada no desempenho, com foco na inserção das pessoas no mercado de trabalho, gerava um "sentimento de impotência". Diante das contradições existentes, a educação inclusiva não deixa de evidenciar a presença das injustiças que ainda se apresentam no processo educativo. Apesar disso, foram indicados vários elementos favoráveis a essa forma de educação, que não é dissociada de movimentos sociais mais amplos.

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Neste artigo tivemos a intenção de oferecer ao leitor o resumo de um dos aspectos mais importantes da análise estrutural que realizamos, durante décadas, do texto de Jean Piaget, sobretudo as estreitas relações entre a Biologia e a Lógica na construção e na explicação do conhecimento científico. Nesse sentido, procuramos demonstrar que, a partir dos conceitos de implicação significante e de imagem mental criados por Piaget, um novo campo de investigações se abre, a saber, aquele que denominamos como o dos sistemas de significação não lógica, campo de suma relevância e que vem preencher uma secular lacuna entre a razão e a emoção até hoje presente nas pesquisas sobre os fenômenos normais e patológicos do psiquismo.

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Este trabalho problematiza, a partir de uma perspectiva sócio-histórica, formas de enfrentamento à violência a que estão submetidos adolescentes e jovens de grupos populares urbanos no Brasil. Considera-se a violência como um fenômeno complexo de grande relevância para diversas instâncias sociais. A vulnerabilidade daqueles adolescentes e jovens, expressa por inúmeros índices relacionados à violência, tem alcançado patamares alarmantes no nosso país, num contexto de políticas públicas que são, em grande parte, insuficientes, fragmentadas e/ou inadequadas. Assim, apresenta-se o relato e a análise de uma intervenção social calcada na educação e na defesa dos direitos decorrentes da cidadania, para adolescentes e jovens vulneráveis socialmente, tomando-se como referência uma região composta por bairros pobres e carentes de infra-estrutura social numa cidade média do interior do estado de São Paulo. Trabalhou-se em diferentes projetos com ações pautadas na abordagem interdisciplinar, por meio de três eixos bases: Violência Escolar; Violência Urbana; e Violação de Direitos e Comunidade. Os resultados alcançados refletem elaborações coletivas acerca das ações destinadas aos jovens de grupos populares urbanos e suas alternativas, buscando produzir estratégias de enfrentamento dessas questões em espaços públicos, desde a instituição escolar historicamente constituída para essa população, assim como as instituições mais recentes que respondem à lógica contraditória e complexa da assistência ao direito. Cria-se, portanto, subsídios para políticas públicas cujo impacto se dê na direção de promover a diminuição da desigualdade, da discriminação e da violência a que está sujeita a maioria dos adolescentes e jovens no Brasil.

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In this paper, we present a fuzzy approach to the Reed-Frost model for epidemic spreading taking into account uncertainties in the diagnostic of the infection. The heterogeneities in the infected group is based on the clinical signals of the individuals (symptoms, laboratorial exams, medical findings, etc.), which are incorporated into the dynamic of the epidemic. The infectivity level is time-varying and the classification of the individuals is performed through fuzzy relations. Simulations considering a real problem with data of the viral epidemic in a children daycare are performed and the results are compared with a stochastic Reed-Frost generalization