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De Menezes Filho J.B.,Instituto Federal Of Educacao Ciencia E Tecnologia Da Paraiba Ifpb | Da Silva S.A.,Federal University of Paraiba | De Araujo C.S.,Federal University of Paraiba | Filho A.F.X.,Federal University of Paraiba
Controle y Automacao | Year: 2010

The proposal of this research is to present a new strategy of drive, called of Neural Vectorial Control, using a Multilayer Neural Network acting as a direct adaptive controller, that is based on the minimization of the error between the actual position vector and the vector of reference position. Two strategies of control are shown. The first strategy is based on the use of position neural controllers of independent axes. The second strategy, presented as the main contribution of this paper, is based on the use of the vectorial neural controller. The strategy proposal in this research is differentiated of the well known tracking controllers for not possessing individual closed loops of control for each axis. The XY table used for validation is a structure of two degrees of freedom, that it is considered as a manipulator with detached axes. Experimental and simulated results show the superior performance of the vectorial neural control. A lesser time of processing in the use of an only Neural Nework is an additional advantage of the use of the vectorial neural controller in relation to the independent controllers. Source


Camargo M.,Instituto Federal Of Educacao Ciencia E Tecnologia Da Paraiba Ifpb | Giarrizzo T.,Federal University of Para | Jesus A.J.S.,Federal University of Para
Brazilian Journal of Biology | Year: 2015

The assumption for this study was that litterfall in floodplain environments of the middle Xingu river follows a pattern of seasonal variation. According to this view, litterfall production (total and fractions) was estimated in four alluvial rainforest sites on the middle Xingu River over an annual cycle, and examined the effect of seasonal flooding cycle. The sites included two marginal flooded forests of insular lakes (Ilha Grande and Pimentel) and two flooded forests on the banks of the Xingu itself (Boa Esperança and Arroz Cru). Total litterfall correlated with rainfall and river levels, but whereas the leaf and fruit fractions followed this general pattern, the flower fraction presented an inverse pattern, peaking in the dry season. The litterfall patterns recorded in the present study were consistent with those recorded at other Amazonian sites, and in some other tropical ecosystems. © 2015, Instituto Internacional de Ecologia. All rights reserved. Source


Camargo M.,Instituto Federal Of Educacao Ciencia E Tecnologia Da Paraiba Ifpb | Giarrizzo T.,Federal University of Para | Isaac V.J.,Federal University of Para
Brazilian Journal of Biology | Year: 2015

This study estimates the main biological parameters, including growth rates, asymptotic length, mortality, consumption by biomass, biological yield, and biomass, for the most abundant fish species found on the middle Xingu River, prior to the construction of the Belo Monte Dam. The specimens collected in experimental catches were analysed with empirical equations and length-based FISAT methods. For the 63 fish species studied, high growth rates (K) and high natural mortality (M) were related to early sexual maturation and low longevity. The predominance of species with short life cycles and a reduced number of age classes, determines high rates of stock turnover, which indicates high productivity for fisheries, and a low risk of overfishing. © 2015, Instituto Internacional de Ecologia. All rights reserved. Source


De Andrade F.G.,Instituto Federal Of Educacao Ciencia E Tecnologia Da Paraiba Ifpb | De Souza Baptista C.,Federal University of Campina Grande
Proceedings of the Brazilian Symposium on GeoInformatics | Year: 2010

In the recent years, several works have been proposed with an approach to the use of semantics to improve the process of discovering geographic resources offered by spatial data infrastructures. However, semantic queries may return a large number of results, what causes the necessity for efficient ways to evaluate the relevance of each result retrieved. This paper proposes a framework that uses ontologies and thematic relevance to suggest a measurement that allows evaluating how relevant is each resource offered by the infrastructure to the user's query. This feature allows the results retrieved in a query to be organized through a ranking, in such a way that the most relevant resources are presented to the user first. Source


Brito S.A.C.,Governo do Para | Camargo M.,Instituto Federal Of Educacao Ciencia E Tecnologia Da Paraiba Ifpb | Melo N.F.A.C.,Federal Rural University of Amazonia | Estupinan R.A.,Instituto Federal Of Educacao Ciencia E Tecnologia Da Paraiba Ifpb
Brazilian Journal of Biology | Year: 2015

A zooplankton checklist is presented for the Middle Xingu River, based on surveys conducted at four sites in the main channel and two fluvial lakes. A total of 175 taxa are listed, including 141 rotifers, 20 cladocerans, and five copepods. Rapids presented the greatest species richness, with up to 124 taxa, while Ilha Grande lake had 70 taxa, the lowest number. Non-planktonic benthic larvae were recorded frequently in the samples. © 2015, Instituto Internacional de Ecologia. All Rights Reserved. Source

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