Subset Selection
Mostrando 1-12 de 173 artigos, teses e dissertações.
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1. K-RANK: AN EVOLUTION OF Y-RANK FOR MULTIPLE SOLUTIONS PROBLEM
ABSTRACT Y-rank can present faults when dealing with non-linear problems. A methodology is proposed to improve the selection of data in situations where y-rank is fragile. The proposed alternative, called k-rank, consists of splitting the data set into clusters using the k-means algorithm, and then apply y-rank to the generated clusters. Models were calibrat
Braz. J. Chem. Eng.. Publicado em: 15/07/2019
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2. Maximal Information Coefficient and Support Vector Regression Based Nonlinear Feature Selection and QSAR Modeling on Toxicity of Alcohol Compounds to Tadpoles of Rana temporaria
Efficient evaluation of biotoxicity of organics is of vital significance to resource utilization and environmental protection. In this study, toxicity of 110 alcohol compounds to tadpoles of Rana temporaria is adopted as the dependent variable and 1388 physiochemical parameters (features) calculated by PCLIENT are used for representing each compound. A featu
J. Braz. Chem. Soc.. Publicado em: 2019-02
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3. Classification of soil respiration in areas of sugarcane renewal using decision tree
ABSTRACT: The use of data mining is a promising alternative to predict soil respiration from correlated variables. Our objective was to build a model using variable selection and decision tree induction to predict different levels of soil respiration, taking into account physical, chemical and microbiological variables of soil as well as precipitation in ren
Sci. agric. (Piracicaba, Braz.). Publicado em: 2018-05
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4. Decision model to control water losses in distribution networks
Abstract The losses in the urban water supply networks have become a growing concern. There are several alternatives for the quantification, detection and monitoring of water losses. However, in general, water companies have budgetary and other constraints that hinder implementation. Therefore, this paper presents a model to aid the selection of a subset of
Prod.. Publicado em: 25/07/2016
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5. An Active Search Method for Finding Objects with Near-Optimal Property Values within a Given Set
This paper proposes an active search method aimed at finding objects with optimal or near-optimal y-property values, on the basis of x-variables obtained by indirect, less costly methods. The proposed method progresses in a sequential manner, starting from a small subset of objects with known y-values. At each iteration, the K-nearest neighbour regression te
J. Braz. Chem. Soc.. Publicado em: 2016-06
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6. Tópicos em seleção de modelos markovianos / Topics in selection of Markov models
This work related two statistical problems involving the selection of a Markovian model of finite order. Firstly, we propose a procedure to choose a context tree from independent samples, with more than half of them being realizations of the same finite memory Markovian processes with finite alphabet with law P. Our model selection strategy is based on estim
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 13/12/2011
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7. Selecting the system most likely to be the best in the presence of an infinite number of alternatives
Simulation Optimization (SO) belongs to a broader class of problems called Stochastic Optimization. Most of the proposed SO methodologies in the literature aim to optimize the expected value of the performance measure. This thesis focus is on another class of problems: Multinomial Selection Procedures (MSPs). These procedures select the best alternative, whe
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 02/12/2011
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8. Variable selection for survival models based on penalized likelihood / Seleção de covariáveis para modelos de sobrevivência via verossimilhança penalizada
Variable selection is an important step when setting a parsimonious model. However, the most popular variable selection techniques, such as the best subset variable selection and the stepwise method, do not take into account inherent stochastic errors in the variable selection step. This work presents a study of alternative procedures to more popular methods
Publicado em: 2009
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9. SeleÃÃo local de caracterÃsticas em agrupamento hierÃrquico de documentos
Hierarchical clustering of documents is used to provide interface for navigating through collections of documents, assisting in the activity of information retrieval. As the vectors representing the documents have a high dimensionality, the presence of irrelevant terms can harm the clustering algorithm. The use of feature selection in text clustering is able
Publicado em: 2009
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10. Analysis of the Clustering Algorithms for the Databases / Análise de Algoritmos de Agrupamento para Base de Dados Textuais
The increasing amount of digitally stored texts makes necessary the development of computational tools to allow the access of information and knowledge in an efficient and efficacious manner. This problem is extremely relevant in biomedicine research, since most of the generated knowledge is translated into scientific articles and it is necessary to have the
Publicado em: 2008
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11. Fatoração QR como ferramenta para a determinação de poços principais em redes de monitoramento de aqüíferos freáticos
Monitoring networks of piezometric motion are increasingly used for evaluation and management of aquifers. A pivoted version of the QR factorization was used in four networks, with the purpose of determining principal wells. One network is located at river Jardim watershed, at the east portion of Distrito Federal, Brazil, and the other three are located in s
Publicado em: 2008
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12. Uma nova metodologia para seleção de atributos no processo de extração de conhecimento de base de dados baseada na Teoria de Rough Sets
In this dissertation, a new Feature Selection Subsets methodology is proposed, to be used in the Knowledge Discover in Database process. The databases, dimensioned for specific purposes, own in its essence, the intrinsic knowledge to the system of its application. This knowledge is very valuable and important to take strategical decisions in this system. Thu
Publicado em: 2008