Sökning: "latent variable analysis"

Visar resultat 1 - 5 av 38 avhandlingar innehållade orden latent variable analysis.

1. 1. Latent variable based computational methods for applications in life sciences : Analysis and integration of omics data sets

   Författare :Max Bylesjö; Johan Trygg; Tormod Naes; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Chemometrics; orthogonal projections to latent structures; OPLS; O2PLS; K-OPLS; kernel-based; non-linear; regression; classification; Populus; Chemistry; Kemi;

   Sammanfattning : With the increasing availability of high-throughput systems for parallel monitoring of multiple variables, e.g. levels of large numbers of transcripts in functional genomics experiments, massive amounts of data are being collected even from single experiments. LÄS MER

3. 2. 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

4. 3. 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

5. 4. Novel variable influence on projection (VIP) methods in OPLS, O2PLS, and OnPLS models for single- and multi-block variable selection : VIPOPLS, VIPO2PLS, and MB-VIOP methods

   Författare :Beatriz Galindo-Prieto; Johan Trygg; Lennart Eriksson; Paul Geladi; Olav M. Kvalheim; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Variable influence on projection; VIP; MB-VIOP; orthogonal projections to latent structures; OPLS; O2PLS; OnPLS; variable selection; variable importance in multiblock regression; Computer Science; datalogi;

   Sammanfattning : Multivariate and multiblock data analysis involves useful methodologies for analyzing large data sets in chemistry, biology, psychology, economics, sensory science, and industrial processes; among these methodologies, partial least squares (PLS) and orthogonal projections to latent structures (OPLS®) have become popular. Due to the increasingly computerized instrumentation, a data set can consist of thousands of input variables which contain latent information valuable for research and industrial purposes. LÄS MER

7. 5. Rough beginnings : Executive function in adolescents and young adults after preterm birth and repeat antenatal corticosteroid treatment

   Författare :Johanna Stålnacke; Ann-Charlotte Smedler; Hans Forssberg; Peter Anderson; Stockholms universitet; []
   Nyckelord :SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; cognitive flexibility; cluster analysis; development; latent variable analysis; longitudinal studies; parental education; perinatal medical complications; person-oriented approach; structural equation modeling; working memory; Psychology; psykologi;

   Sammanfattning : This thesis investigates long-term cognitive outcome in two cohorts of adolescents and young adults exposed to stressors during the perinatal period: one group born preterm (.... LÄS MER