Constrained Optimization
Mostrando 25-36 de 71 artigos, teses e dissertações.
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25. Phase-adaptive superresolution of mammographic images using complex wavelets
This correspondence describes a new superresolution approach for enhancing the resolution of mammographic images using complex wavelet frequency information. This method allows regions of interest of a mammographic image to be viewed in enhanced resolution while reducing the patient exposure to radiation. The proposed method exploits the structural character
Publicado em: 2011
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26. Optimization of viscoelastic systems combining robust condensation and metamodeling
The effective design of viscoelastic dampers as applied to real-world complex engineering structures can be conveniently carried out by using modern multiobjective numerical optimization techniques. The large number of evaluations of the cost functions normally combined with the typically high dimensions of finite element models of industrial structures make
Journal of the Brazilian Society of Mechanical Sciences and Engineering. Publicado em: 2010-12
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27. Derivative-free nonlinear programming / Programação não linear sem derivadas
We propose in this work a derivative-free Augmented Lagrangian algorithm for the general problem of optimization. We consider the method due to Andreani, Birgin, Martínez and Schuverdt, eliminating the derivative computations in the algorithm by making suitable modifications on the stopping criterion. The good theoretical results of the method were mantaine
Publicado em: 2009
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28. A filter SQP algorithm without a feasibility restoration phase
In this paper we present a filter sequential quadratic programming (SQP) algorithm for solving constrained optimization problems. This algorithm is based on the modified quadratic programming (QP) subproblem proposed by Burke and Han, and it can avoid the infeasibility of the QP subproblem at each iteration. Compared with other filter SQP algorithms, our alg
Computational & Applied Mathematics. Publicado em: 2009
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29. On the use of the Spectral Projected Gradient method for Support Vector Machines
In this work we study how to solve the SVM optimization problem by using the Spectral Projected Gradient (SPG) method with three different strategies for computing the projection onto the constrained set. One of the strategies is based on Dykstra's alternating projection algorithm since there is not a mathematical equation for the projection onto the whole c
Computational & Applied Mathematics. Publicado em: 2009
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30. Sequential quadratic programming and constraint qualification / Programação quadratica sequencial e condições de qualificação
In the context of constrained optimization problems, we face the optimality conditions and also constraint qualification. Our aim is to study with details several constraint qualification, highlighting the constant positive linear dependence condition, and its influence in Sequential Quadratic Programming algorithms convergence. The relevance of this study i
Publicado em: 2009
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31. Vibration H-infinity control with constrained force signal / Controle H-infinito de vibrações com restrições no esforço de controle
In this work, the H8 control of vibrations problem taking into account the effects of saturation of actuators is studied. Two situations of interest were explored. The first one considers that saturation should be avoided and does not cause damage to the system, even if this situation leads to loss of performance. The second alternative seeks to modify the c
Publicado em: 2009
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32. Lagrange multipliers : geometrical and algebraic aspects and an application in chemical engineering in the methanol distillation / Multiplicadores de Lagrange : aspectos geometricos e algebricos e uma aplicação em engenharia quimica na destilação do metanol
This work begins with a brief historical overview of Fermat?s method to find maxima and minima without derivatives. In theoretical terms, the elements concerning maximum and minimum of functions of n variables are discussed, together with a detailed study of unconstrained optimization, focusing on the Fermat?s rule and the classification of critical points.
Publicado em: 2008
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33. Hibridização de algoritmos genéticos e sistemas imunológicos artificiais para problemas de otimizacão com restricões em engenharia / HYBRIDIZATION OF GENETIC ALGORITHMS AND ARTIFICIAL IMMUNE SYSTEMS FOR CONSTRAINED OPTIMIZATION PROBLEMS IN ENGINEERING
In this work some possibilities of hibridization of genetic algorithms and artificial immune systems are proposed, computationally implemented, and tested in order to solve constrained optimization problems. Such problems arise frequently in the computational modeling of relevant scientific and technological problems. After a brief formulation and solution c
Publicado em: 2008
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34. Algebraic formulation for modeling hop-by-hop multi-constrained routing algorithms. / Formulação algébrica para a modelagem de algoritmos de roteamento multi-restritivo hop-by-hop.
This work presents a new mathematical structure for paths algebra that allows the convergence analysis of hop-by-hop multi-constrained routing algorithms and, under the traffic engineering and quality of service perspectives in the Generalized Multiprotocol Label Switching (GMPLS) architecture, trustily ensures the aggregation of new routing metrics in a con
Publicado em: 2008
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35. Otimização de colunas de destilação : uma abordagem aplicada dos multiplicadores de Lagrange / Optimization of distillation comumns : an applied approach of the Lagrange multipliers
This work tackles the optimization of a distillation process of a binary mixture in a column with plates, which came from the methanol distillation in the production process of the biodiesel. More specifically, it considers the minimization of a cost objective function that encompass the heat rate supplied to the reboiler and the feed temperature, subject to
Publicado em: 2008
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36. Estimação não parametrica da trajetoria percorrrida por um veiculo autonomo / Non-parametric curve estimation of an autonomous vehicle trajectory
The objective of this study is to find a smooth function joining two points A and B with minimum length constrained to avoid fixed subsets. A penalized nonparametric method of finding the best path is proposed. The method is generalized to the situation where stochastic measurement errors are present. In this case, the proposed estimator is consistent, in th
Publicado em: 2008