Resultados da pesquisa

Catálogo de Publicações - Todos

  • A mostrar 1 - 3 resultados de 3
Filtros
  1. 1

    Fitting mixtures of linear regressions

    Publicação
    por Faria, Susana
    Outros Autores: Soromenho, Gilda
    In most applications, the parameters of a mixture of linear regression models are estimated by maximum likelihood using the expectation maximization (EM) algorithm. In this article, we propose the comparison of three algorithms to compute maximum likelihood estimates of the parameters of these models: the EM algorithm, the classification EM algorithm and the stochastic EM algorithm. The comparison of the three procedures was done through a simulation study of the performance (computational effort, statistical properties of estimators and goodness of fit) of these approaches on simulated data sets. Simulation results show that the choice of the approach depends essentially on the configuration of the true regression lines and the initialization of the algorithms.
    2010 artigo Portugal acesso aberto
  2. 2

    Comparison of Mixture and Classification Maximum Likelihood Approaches in Poisson Regression Models

    Publicação
    por Faria, Susana
    Outros Autores: Soromenho, Gilda
    In this work, we propose to compare two algorithms to compute maximum likelihood estimators of the parameters of a mixture Poisson regression models. To estimate these parameters, we may use the EM algorithm in a mixture approach or the CEM algorithm in a classification approach. The comparison of the two procedures was done through a simulation study of the performance of these approaches on simulated data sets in a target number of iterations. Simulation results show that the CEM algorithm is a good alternative to the EM algorithm for fitting Poisson mixture regression models, having the advantage of converging more quickly.
    2008 documento de conferência Portugal acesso aberto
  3. 3

    Comparison of mixture and classification maximum likelihood approaches in poisson regression models

    Publicação
    por Faria, Susana
    Outros Autores: Soromenho, Gilda
    In this work, we propose to compare two algorithms to compute maximum likelihood estimators of the parameters of a mixture Poisson regression models. To estimate these parameters, we may use the EM algorithm in a mixture approach or the CEM algorithm in a classification approach. The comparison of the two procedures was done through a simulation study of the performance of these approaches on simulated data sets in a target number of iterations. Simulation results show that the CEM algorithm is a good alternative to the EM algorithm for fitting Poisson mixture regression models, having the advantage of converging more quickly.
    2008 comunicação em conferência Portugal acesso restrito