848 resultados para Relevance feature
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Feature selection has been actively pursued in the last years, since to find the most discriminative set of features can enhance the recognition rates and also to make feature extraction faster. In this paper, the propose a new feature selection called Binary Cuckoo Search, which is based on the behavior of cuckoo birds. The experiments were carried out in the context of theft detection in power distribution systems in two datasets obtained from a Brazilian electrical power company, and have demonstrated the robustness of the proposed technique against with several others nature-inspired optimization techniques. © 2013 IEEE.
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Feature selection aims to find the most important information from a given set of features. As this task can be seen as an optimization problem, the combinatorial growth of the possible solutions may be inviable for a exhaustive search. In this paper we propose a new nature-inspired feature selection technique based on the Charged System Search (CSS), which has never been applied to this context so far. The wrapper approach combines the power of exploration of CSS together with the speed of the Optimum-Path Forest classifier to find the set of features that maximizes the accuracy in a validating set. Experiments conducted in four public datasets have demonstrated the validity of the proposed approach can outperform some well-known swarm-based techniques. © 2013 Springer-Verlag.
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Besides optimizing classifier predictive performance and addressing the curse of the dimensionality problem, feature selection techniques support a classification model as simple as possible. In this paper, we present a wrapper feature selection approach based on Bat Algorithm (BA) and Optimum-Path Forest (OPF), in which we model the problem of feature selection as an binary-based optimization technique, guided by BA using the OPF accuracy over a validating set as the fitness function to be maximized. Moreover, we present a methodology to better estimate the quality of the reduced feature set. Experiments conducted over six public datasets demonstrated that the proposed approach provides statistically significant more compact sets and, in some cases, it can indeed improve the classification effectiveness. © 2013 Elsevier Ltd. All rights reserved.
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Includes bibliography
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Includes bibliography
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Includes bibliography
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Includes bibliography
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Introdução: A motivação tem sido cada vez mais objeto de estudo no campo da Linguística Aplicada e seu papel no processo de ensino e aprendizagem de línguas estrangeiras tem adquirido significativa importância na literatura especializada. Dentre as diversas construções teóricas envolvendo interpretações do processo motivacional e as variáveis que nele atuam, pode-se apontar o Modelo Processual de Motivação de Dörnyei, que apresenta a sequência acional do aprendente e os diferentes aspectos motivacionais presentes em cada uma das fases por que passa: a pré-acional, a acional e a pós-acional. Objetivos: Identificar, com base no Modelo Processual de Motivação de Dörnyei, as influências motivacionais atuantes na fase acional do processo de aprendizagem dos sujeitos de pesquisa, verificar a natureza e as circunstâncias determinantes das flutuações observadas nos alunos e levantar quais estratégias motivacionais para manter ou recuperar o entusiasmo para permanecer no curso. Metodologia: Trata-se de uma pesquisa longitudinal predominantemente qualitativa, cujos dados foram coletados por meio de análise de uma narrativa, três questionários e uma entrevista de oito alunos do curso de Licenciatura em Língua Inglesa da Universidade Federal do Pará, de março de 2010 a junho de 2011. Resultados: Foram observados fatores motivadores e desmotivadores que influenciam o comportamento dos alunos durante a fase acional do processo de aprendizagem, bem como diferentes flutuações em sua resultante motivacional, de acordo com suas características pessoais e o conhecimento e adoção de estratégias de gerenciamento da motivação e automotivação. Conclusão: O Modelo de Motivação de Dörnyei (2011) provou ser bastante útil para amparar a análise dos dados colhidos nesta pesquisa. A motivação é vista como um fenômeno dinâmico, que pode oscilar positiva ou negativamente, dependendo das crenças e percepções de cada aluno e da capacidade de gerenciá-la. Essa característica dinâmica e variável com o tempo pode nortear os agentes da aprendizagem na escolha de estratégias que a fomentem e que impeçam a baixa da maré motivacional do aluno no desenrolar do processo da aprendizagem, levando-os a considerar as influências motivacionais variáveis não só em relação a cada aprendente, mas também em relação à fase do processo de aprendizagem em que cada indivíduo se encontra.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Introduction: In the Web environment, there is a need for greater care with regard to the processing of descriptive and thematic information. The concern with the recovery of information in computer systems precedes the development of the first personal computers. Models of information retrieval have been and are today widely used in databases specific to a field whose scope is known. Objectives: Verify how the issue of relevance is treated in the main computer models of information retrieval and, especially, as the issue is addressed in the future of the Web, the called Semantic Web. Methodology: Bibliographical research. Results: In the classical models studied here, it was realized that the main concern is retrieving documents whose description is closest to the search expression used by the user, which does not necessarily imply that this really needs. In semantic retrieval is the use of ontologies, feature that extends the user's search for a wider range of possible relevant options. Conclusions: The relevance is a subjective judgment and inherent to the user, it will depend on the interaction with the system and especially the fact that he expects to recover in your search. Systems that are based on a model of relevance are not popular, because it requires greater interaction and depend on the user's disposal. The Semantic Web is so far the initiative more efficient in the case of information retrieval in the digital environment.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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The theme approached relates contemporaneous organizational competitive scenario to draw parallels between the organizational structure, Knowledge Management and Public Relations. Many aspects are complementary and can be grouped, enabling the idea of verifying the possibility of a Public Relations work like a manager of Knowledge Management. The objective of this study focuses in analyzing the administration ways of the organizational environment to verify the best kind of structure for the competitive development pattern, then we sought the meaning of Knowledge Management and their results to draw a parallel between the image of the Knowledge Management process manager and the Public Relations professional. The methodology chosen was bibliographic research, by which we noticed the theme relevance, the proposal validity and build a convergence between the skills of a person responsible for managing processes in Knowledge Management and the capabilities of a Public Relations professional. This way adopts a human feature to the managing process, respecting the technical-informational scenario of this area