Research Reports

2/1998 Dynamic choice of the leaving-face criterion in bound-constrained quadratic minimization
Maria A. Diniz-Ehrhardt, Márcia A. Gomes-Ruggiero, Sandra A. Santos

In this work we focus our attention on the quadratic subproblem of trust–region algorithms for bound–constrained minimization, proposing and testing dynamic choices for the parameter in charge of the decision of leaving or not the current face of the feasible set. The practical consequences of an appropriate decision of such parameter have shown to be crucial, particularly when dual degenerate and ill-conditioned problems are solved.


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1/1998 Generic one parameter families of reversible vector fields
Cláudio A. Buzzi, Marco A. Teixeira

In the present paper we study the dynamics of a class of reversible vector fields having eigenvalues (0 ; \alpha i; \alphai ) around their symmetric equilibria. We give a complete list of all normal forms for such vector fields, their versal unfoldings, and the corresponding bifurcation diagrams of codimensional one case. We also obtain some important conclusions on the existence of homoclinic and heteroclinic orbits, invariant tori and symmetric periodic orbits.


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95/1997 The beginning of the Fucik spectrum for the p-Laplacian
M. Cuesta, Djairo G. Figueiredo, J. P. Gossez
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94/1997 Análise de Estabilidade para Métodos de Diferenças Finitas: Equações Parabólicas Lineares
Saulo Pomponet Oliveira, Petrônio Pulino
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93/1997 Equivalence Classes of Quasi-Projective Transformations
Marcelo Firer
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92/1997 Nonmonotone Spectral Projected Gradient Methods on Convex Sets
Ernesto G. Birgin, José Mario Martínez, Marcos Raydan
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91/1997 Implementando Critérios Dinâmicos de Decisão Para Controlar a Estratégia de Globalização de ROUXINOL
Patrícia Nunes da Silva, Márcia A. Gomes-Ruggiero
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90/1997 Resolução de Problemas de Controle Ótimo Utilizando o Algoritmo BOX
Alberto Adami, Márcia A. Gomes-Ruggiero
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89/1997 An Error Estimates Uniform in Time for Spectral Galerkin Approximations of the Magneto-Micropolar Fluid Equations
Elva E. Ortega-Torres, Marko A. Rojas-Medar
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88/1997 Uma Metodologia de Dessazonalização de Índices de Preços ao Consumidor Via Método X11-Arima
Emanuel P. Barbosa, Wanderley Ramalho, Valéria de Aquino
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