Sökning: "latent-variable model"

Visar resultat 1 - 5 av 32 avhandlingar innehållade orden latent-variable model.

  1. 1. Latent variable models for longitudinal twin data

    Författare :Annica Dominicus; Juni Palmgren; Nancy L. Pedersen; Michael G. Kenward; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Latent variable models; twin models; variance components; change point models; non-ignorable nonresponse; likelihood ratio tests; Mathematical statistics; Matematisk statistik;

    Sammanfattning : Longitudinal twin data provide important information for exploring sources of variation in human traits. In statistical models for twin data, unobserved genetic and environmental factors influencing the trait are represented by latent variables. In this way, trait variation can be decomposed into genetic and environmental components. LÄS MER

  2. 2. Shared Gaussian Process Latent Variable Models

    Författare :Carl Henrik Ek; Oxford Brookes University; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : A fundamental task in machine learning is modeling the relationship between different observation spaces. Dimensionality reduction is the task of reducing thenumber of dimensions in a parameterization of a data-set. In this thesis we areinterested in the cross-road between these two tasks: shared dimensionality reduction. LÄS MER

  3. 3. Structured Representation Using Latent Variable Models

    Författare :Cheng Zhang; Hedvig Kjellström; Jordan Boyd-Graber; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Computer Science; Datalogi;

    Sammanfattning : Over the past two centuries the industrial revolution automated a great part of work that involved human muscles. Recently, since the beginning of the 21st century, the focus has shifted towards automating work that is involving our brain to further improve our lives. LÄS MER

  4. 4. Composite Likelihood Estimation for Latent Variable Models with Ordinal and Continuous, or Ranking Variables

    Författare :Myrsini Katsikatsou; Fan Yang-Wallentin; Irini Moustaki; Karl Gustav Jöreskog; Ruggero Bellio; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; latent variable models; factor analysis; structural equation models; Thurstonian model; item response theory; composite likelihood estimation; pairwise likelihood estimation; maximum likelihood; weighted least squares; ordinal variables; ranking variables; lavaan; Statistics; Statistik;

    Sammanfattning : The estimation of latent variable models with ordinal and continuous, or ranking variables is the research focus of this thesis. The existing estimation methods are discussed and a composite likelihood approach is developed. LÄS MER

  5. 5. Estimation of Nonlinear Latent Variable and Mixture Models

    Författare :Johan Vegelius; Shaobo Jin; Fan Yang-Wallentin; Melanie Wall; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; structural equation modeling; semiparametric; EM algorithm; adaptive Gauss-Hermite quadrature approximation; Laplace approximation; zero inflation; Statistics; Statistik;

    Sammanfattning : In this thesis methods are developed for estimation of latent variable models. In particular nonlinear structural equation models are estimated in the presence of ordinal data and mixture models for count data. LÄS MER