Now showing items 1-11 of 11

    • Analyis on the vascular epiphytes of tree ferns in a montane rain forest in Costa Rica 

      Bittner, Jens; Trejos Zelaya, Javier (2009-02-18)
      The relationships between epiphytes and host specifity are known. We investigated the relation between specific epiphytes and tree fern trunks. Only some epiphytes are frequent or very frequent on tree ferns. Most of the ...
    • Análisis de proximidades métrico usando búsqueda tabú 

      Villalobos Arias, Mario Alberto; Trejos Zelaya, Javier (2009-02-19)
      We apply tabu search (TS) in metric multidimensional scaling, obtaining good results comparable to those obtained with simulated annealing. A state in TS is a configuration of n points in a p dimensional space, and a ...
    • Aplicación de la búsqueda tabú en regresión no lineal 

      Villalobos Arias, Mario Alberto; Trejos Zelaya, Javier; de los Cobos Silva, Sergio Gerardo (2009-02-20)
      We implement the combinatorial optimization technique known as tabu search inthe parameter estimation problem in a given non linear model. For the generationof neighbors, the implementation is based on a discretization of ...
    • Definición de semiproductos escalares útiles en análisis de datos 

      Trejos Zelaya, Javier (2009-02-20)
      We develop the theory necessary for Data Analysis with inner semiproducts, extendingtha classical concepts of inner products usually employed. For this, we usethe basic algebraic definitions of non degenerated bilinear ...
    • El Número Equivalente como medida de la Información en Análisis de Datos 

      Trejos Zelaya, Javier (2012-03-28)
      Se recuerda la definición del número equivalente, propuesto para medir el número de unidades independientes de información y lo adaptamos al contexto del análisis multivariado de datos. Proponemos algunas propiedades en ...
    • Generación de métricas en análisis de datos 

      Bolaños Guerrero, Fabricio; Trejos Zelaya, Javier (2009-02-20)
      In this work we introduce primary generators of metrics, that consist of linearcombinations of known metrics. We establish some theoretical properties of these generators,related to the computation of principal components, ...
    • Generación de reglas estadísticas a partir de grandes bases de datos 

      Schektman, Yves; Trejos Zelaya, Javier; Troupé, Marylène (2009-02-18)
      Given a set of categorical variables, we want to predict one or more of them by the way rules. We propose an algorithm that (i) is guided by statistical results in a relational geometry where we use assymetrical association ...
    • Método heurístico para particionamiento óptimo 

      de los Cobos Silva, Sergio Gerardo; Trejos Zelaya, Javier; Pérez Salvador, Blanca Rosa; Gutiérrez Andrade, Miguel Ángel (2009-02-20)
      Many data analysis problems deal with non supervised partitioning of a data set,in non empty clusters well separated between them and homogeneous within the clusters.An ideal partitioning is obtained when any object can ...
    • Nuevas técnicas de particionamiento en clasificación automática 

      Piza Volio, Eduardo; Murillo Fernández, Álex; Trejos Zelaya, Javier (2009-02-18)
      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 ...
    • Propiedades de un enfoque difuso para particionamiento con datos bimodales 

      Castillo Elizondo, William; Trejos Zelaya, Javier (2010-04-09)
          It is presented a new fuzzy partitioning criterion for two-mode data and an algo-rithm is formulated for its optmization. We study the convergence properties of themethod. The method was tested on real data. It is ...
    • Proposición de índices difusos en la clasificación jerárquica ascendente 

      Murillo Fernández, Álex; Trejos Zelaya, Javier (2012-03-29)
      En el artículo se proponen índices para selecciónar las particiones de una clasificación automática jerárquica ascendente, para dirigir la interpretación de jerarquías a las particiones más relevantes en un cierto sentido. ...