Sökning: "Yuli Liang"

Hittade 2 avhandlingar innehållade orden Yuli Liang.

  1. 1. A study of multilevel models with block circular  symmetric covariance structures

    Författare :Yuli Liang; Tatjana von Rosen; Dietrich von Rosen; Abdullah Almasri; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Block circular symmetry; Covariance matrix; Explicit solution; Maximum likelihood estimator; Multilevel model; Spectrum; statistik; Statistics; Matematik;

    Sammanfattning : This thesis concerns the study of multilevel models with specific patterned covariance structures and addresses the issues of maximum likelihoodestimation. In particular, circular symmetric hierarchical datastructures are considered. LÄS MER

  3. 2. Contributions to Estimation and Testing Block Covariance Structures in Multivariate Normal Models

    Författare :Yuli Liang; Tatjana von Rosen; Dietrich von Rosen; Ivan Žežula; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Block circular symmetry; covariance parameters; explicit maximum likelihood estimator; likelihood ratio test; restricted model; Toeplitz matrix; Statistics; statistik;

    Sammanfattning : This thesis concerns inference problems in balanced random effects models with a so-called block circular Toeplitz covariance structure. This class of covariance structures describes the dependency of some specific multivariate two-level data when both compound symmetry and circular symmetry appear simultaneously. LÄS MER