899 resultados para Almost always propositional logic


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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Os experimentos foram conduzidos em culturas comerciais de algodoeiros na região de Dourados no Estado de Mato Grosso do Sul, durante a safra 1996/97. Observaram-se os seguintes aspectos do parasitismo natural em ovos de Alabama argillacea Hübner e Heliothis virescens Fabricius por Trichogramma pretiosum Riley: índice de parasitismo, razão sexual e número de adultos emergidos por ovo. Realizou-se coleta semanal de ovos dos lepidópteros e sua incubação em laboratório. Aos 31 dias após a emergência das plantas (DAE), não se observou parasitismo nos ovos de A. argillacea. Porém, a partir de 58 dias (DAE), acima de 60% dos ovos estavam parasitados por T. pretiosum, atingindo em algumas avaliações quase 100%. Apesar da baixa ocorrência de ovos de H. virescens, esses também apresentaram elevado índice de parasitismo por T. pretiosum. O número de fêmeas emergidas dos ovos parasitados geralmente foi maior do que o de machos. Fêmeas representaram em torno de 60% do total de adultos emergidos na maioria das coletas efetuadas. O número de adultos emergidos por ovo de A. argillacea e H. virescens foi ao redor de dois. Na região de Dourados, portanto, o parasitismo natural em ovos de A. argillacea e H. virescens por T. pretiosum é elevado, mesmo com as freqüentes aplicações de inseticidas.

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The crossflow filtration process differs of the conventional filtration by presenting the circulation flow tangentially to the filtration surface. The conventional mathematical models used to represent the process have some limitations in relation to the identification and generalization of the system behavior. In this paper, a system based on fuzzy logic systems is developed to overcome the problems usually found in the conventional mathematical models. Imprecisions and uncertainties associated with the measurements made on the system are automatically incorporated in the fuzzy approach. Simulation results are presented to justify the validity of the proposed approach.

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It can be observed that the number and the complexity of the application's domains, where the Paraconsistent Annotated Logic has been used, have grown a lot in the last decade. This increase in the complexity of the application's domain is an extra challenge for the designers of such systems, once there are not suitable computer hardware to run paraconsistent systems. This work proposes a new hardware architecture for the building Paraconsistent system.

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Biochemical computing is an emerging field of unconventional computing that attempts to process information with biomolecules and biological objects using digital logic. In this work we survey filtering in general, in biochemical computing, and summarize the experimental realization of an and logic gate with sigmoid response in one of the inputs. The logic gate is realized with electrode-immobilized glucose-6-phosphate dehydrogenase enzyme that catalyzes a reaction corresponding to the Boolean and functions. A kinetic model is also developed and used to evaluate the extent to which the performance of the experimentally realized logic gate is close to optimal.

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Although the bipolar disorder (BD) occurs almost with the same frequency in both genders, the phenomenology and the outcome of the illness differ between them. Nevertheless, there is evidence that women with BD show, more than men, delayed beginning, especially in their fifth decade, more rapid cycling outcome, more depressive episodes, more dysphoric mania, more mixed states and more BD type II. Even so, the findings are not always consistent. Although the risk of comorbidities in BD includes, for both the sorts, excessive alcoholic consumption and drugs, bipolar men would have greater probability of being alcohol dependent, of not seeking treatment and of committing suicide. Suggested hypotheses to explain such differences vary from those centered in cultural or psychological aspects to those that focus on the steroids hormones, and other hormones such as cortisol, thyroid hormones and even on the cerebral anatomy. The reproductive cycle (menstrual cycle, pregnancy and menopause) influences on the BD phenomenology and its relevance to the therapeutical options in the treatment of the BD in women are presented in the last part of this review. Further investigations must to be done in order to clarify this controversy. However, up to now the data indicate that estrogen therapy is not to be primarily indicated to prevent depression, Alzheimer disease or cognition impairment.

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Incluye Bibliografía

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One of the critical problems in implementing an intelligent grinding process is the automatic detection of workpiece surface burn. This work uses fuzzy logic as a tool to classify and predict burn levels in the grinding process. Based on acoustic emission signals, cutting power, and the mean-value deviance (MVD), linguistic rules were established for the various burn situations (slight, intermediate, severe) by applying fuzzy logic using the Matlab Toolbox. Three practical fuzzy system models were developed. The first model with two inputs resulted only in a simple analysis process. The second and third models have an additional MVD statistic input, associating information and precision. These two models differ from each other in terms of the rule base developed. The three developed models presented valid responses, proving effective, accurate, reliable and easy to use for the determination of ground workpiece burn. In this analysis, fuzzy logic translates the operator's human experience associated with powerful computational methods.

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Due to growing urbanization and industrialization, the environment is suffering from pollution of rivers, degradation of soils and deteriorated air quality. Quality indices appear to be useful to evaluate the conditions of these media. The aim of this study was the development of a water quality index using a fuzzy inference system, since such an approach has proved advantageous in addressing problems that are subjective by nature or for which the data are uncertain. The methodology employed was based on this inference system, and considered the nine water quality parameters employed by CETESB (Companhia de Tecnologia de Saneamento Ambiental, São Paulo, Brazil) to evaluate water quality. After assessment of the data using the index, a comparison was made with the WQI (Water Quality Index), which is used for the monitoring of various water bodies, including in the study region. The results obtained using the index developed on the basis of fuzzy inference were found to be more useful than those derived from the method currently used by CETESB, since losses and/or omissions concerning individual parameters were minimized. © 2010 IEEE.

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Incluye Bibliografía

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Includes bibliography

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Gymnotus (Gymnotiformes, Gymnotidae) is the most diverse known Neotropical electric knife fish genus. Cytogenetic studies in Gymnotus demonstrate a huge karyotypic diversity for this genus, with diploid numbers ranging from 34 to 54. The NOR are also variable in this genus, with both single and multiple NORs described. A common interpretation is that the single NOR pair is a primitive trait while multiple NORs are derivative. However this hypothesis has never been fully tested. In this report we checked if the NOR-bearing chromosome and the rDNA site are homeologous in different species of the genus Gymnotus: G. carapo (2n = 40, 42, 54), G. mamiraua (2n = 54), G. arapaima (2n = 44), G. sylvius (2n = 40), G. inaequilabiatus (2n = 54) and G. capanema (2n = 34), from the monophyletic group G. carapo (Gymnotidae-Gymnotiformes), as well as G. jonasi (2n = 52), belonging to the G1 group. They were analyzed with Fluorescence in situ hybridization (FISH) using 18S rDNA and whole chromosome probes of the NOR-bearing chromosome 20 (GCA20) of G. carapo (cytotype 2n = 42), obtained by Fluorescence Activated Cell Sorting. All species of the monophyletic G. carapo group show the NOR in the same single pair, confirmed by hybridization with CGA20 whole chromosome probe. In G. jonasi the NORs are multiple, and located on pairs 9, 10 and 11. In G. jonasi the GCA20 chromosome probe paints the distal half of the long arm of pair 7, which is not a NOR-bearing chromosome. Thus these rDNA sequences are not always in the homeologous chromosomes in different species thus giving no support to the hypothesis that single NOR pairs are primitive traits while multiple NORs are derived. The separation of groups of species in the genus Gymnotus proposed by phylogenies with morphologic and molecular data is supported by our cytogenetic data. © 2013 Milhomem et al.

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Includes bibliography

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The semiotics of C S. Peirce presents fundamental concepts to discover aspects of the indexing process, including representation and classes of signs. However, we still know little of its theoretical potential for subject indexing. We believe that the main difficulty in the proposals to understand the process of subject indexing based on Peircean semiotics stems from an incomplete interpretation of his semiotic system. This paper attempts to describe the contributions of Peircean semiotics to subject indexing. First, we analyze some of the concepts of the branches of semiotics, after which, we discuss strategies for conceptual approximation. Secondly, and aiming to raise the level of interlocution between the areas, we intend to argue that subject indexing is an inferential process, as explained by the second branch of semiotics. Thus, we seek to go beyond the level of speculative grammar, the first branch of semiotics, to forge a closer link with pure or critical logic, the second branch. We conclude that the indexer's work does not produce a mere reflection of what already exists in documents, but involves an instigating action to discover, through the inferential matrix, the meaning of a text in order to find the subject and the most appropriate subject added entry to the information system.