Sökning: "Multilevel models Statistics"

Visar resultat 1 - 5 av 12 avhandlingar innehållade orden Multilevel models Statistics.

  1. 1. Intelligence and models for cognitive development

    Författare :Linda Wänström; Daniel Thorburn; Gösta Hägglund; Dag Sörbom; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; intelligence; cognitive development; sample size; multilevel models; latent growth curve models; Statistics; Statistik; statistik; Statistics;

    Sammanfattning : This dissertation focuses on cognitive development. In papers I and II, I study a special model, the second order latent growth curve model, that can be used to study cognitive development. Algebraic expressions for the variance of the estimation of slope differences are given. LÄS MER

  3. 2. 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

  4. 3. Spatial analysis and modeling of nerve fiber patterns

    Författare :Claes Andersson; Göteborgs universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; hierarchical models; Bayesian estimation; epidermal nerve fibers; cluster processes; spatial point processes; diabetic neuropathy; Bayesian field theory; Diabetic neuropathies; Multilevel models Statistics ; Institutionen för matematiska vetenskaper. Tillämpad matematik och statistik.; CTH;

    Sammanfattning : Diabetic neuropathy is a condition associated with diabetes affecting the epidermal nerve fibers (ENFs). This thesis presents analysis methods and models for ENF data, with two main puroposes: to find early signs of diabetic neuropathy and to characterize how this condition changes the nerve fiber structure. LÄS MER

  5. 4. Statistical modeling in international large-scale assessments

    Författare :Inga Laukaityte; Marie Wiberg; Kenny Bränberg; Ewa Rolfsman; Bernard Veldkamp; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; multilevel model; plausible values; sampling weights; missing information; multiple imputation; non-monotone missing pattern; TIMSS; PISA; Statistics; statistik; pedagogik; Education;

    Sammanfattning : This thesis contributes to the area of research based on large-scale educational assessments, focusing on the application of multilevel models. The role of sampling weights, plausible values (response variable imputed multiple times) and imputation methods are demonstrated by simulations and applications to TIMSS (Trends in International Mathematics and Science Study) and PISA (Programme for International Student Assessment) data. LÄS MER

  7. 5. Simulation and Estimation of Diffusion Processes : Applications in Finance

    Författare :Carl Åkerlindh; Finansiell matematik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Diffusion processes; Kalman filter; Uncented Kalman filter; EM algorithm; Kernel estimation; Bandwidth selection; Multilevel Monte Carlo; Simulated maximum likelihood estimation; Julia language;

    Sammanfattning : Diffusion processes are the most commonly used models in mathematical finance, and are used extensively not only by academics but also practitioners. Nowadays a wide range of models, that can capture many of the effects observed in financial markets, are available. LÄS MER