Revista de Matemáticas 6(1)

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  • Ítem
    On a variational principle for shape optimization and elliptic free boundary problems
    (2009-02-18 00:00:00) González De Paz, Raúl B.
    A variational principle for several free boundary value problems using a relaxation approach is presented. The relaxed Energy functional is concave and it is defined on a convex set, so that the minimizing points are characteristic functions of sets. As a consequence of the first order optimality conditions, it is shown that the corresponding sets are domains bounded by free boundaries, so that the equivalence of the solution of the relaxed problem with the solution of several free boundary value problem is proved.Keywords: Calculus of variations, optimization, free boundary problems.
  • Ítem
    Nuevas técnicas de particionamiento en clasificación automática
    (2009-02-18 00:00:00) Piza Volio, Eduardo; Murillo Fernández, Álex; Trejos Zelaya, Javier
    In this article there are exposed some new thechniques for hte search of global optima inthe partitioning problem in Cluster Analysis. With these thechniques the results are sensibly improved with respect to the traditional methods. The methods developed here are well known in Combinatorial Optimization: i)simulated annealing; ii) tabu search, iii)genetic algorithms. We use these three approaches in the partitioning problem for clustering, following a search xhee similar to that of Regnier's algorithm of transfers.Keywords: Clustering, stochastic optimization, combinatorial optimization, heuristics.
  • Ítem
    Casi-ortogonalidad y proximidad en L2 de martingalas pii en casi intervalos
    (2009-02-18 00:00:00) Lobo Segura, Jaime
    It was introduced in [2] the notion of prOcess with independent increments in near-intervals (PII), establishing the existence of a decomposition into components with certain regularity properties. In this work we deepen the study of such descomposition for a PII martingale, the components being one- parameter martingles with almost orthogonality and L2-proximity properties.Keywords: PII process, L2-regular martingales, totally discontinuous matingales, almost orthogonalit, L2-proximity.
  • Ítem
    Análisis discriminante descriptivo: teoría, algoritmo y software
    (2009-02-18 00:00:00) Castillo Elizondo, William; Rodríguez Rojas, Oldemar
    The objetive of this article is to present a computational implementation of the Descriptive Discriminant Analysis. We have developed some theoretical aspects in order to formulate an algorithm that was implemented using C+ +. Finally, the method and the software are illustrated an example.Keywords: Discrimination, algorithm, discriminant variable, a priori group, baricenter.
  • Ítem
    Estimación no paramétrica de la densidad y de la regresión - previsión no paramétrica
    (2009-02-18 00:00:00) Carbon, Michel; Francq, Christian
    We begin with a short wiew of non parametric estimation of density and regression; then we give details and interpretation of a forecasting method, called non parametric forecasting . We show different aspects, technical as well as practical, and we compare the method with the Box and Jenkings methodology, over some examples.Keywords: Non – parametric statistics, time series, forecasting, regression, Kernels.