Sökning: "semiparametric"

Visar resultat 1 - 5 av 17 avhandlingar innehållade ordet semiparametric.

  1. 1. Semiparametric survival models for routine register data

    Författare :Frank Eriksson; Göteborgs universitet; Göteborgs universitet; Gothenburg University; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Survival; transformation; clustered; likelihood; random effects; case-cohort; routine register; semiparametric; clustered;

    Sammanfattning : Routine registers offer researchers opportunities to carry out studies of covariate effects on lifetimes of rare diseases otherwise infeasible because of the large cohorts required. Familial relationships necessary for analysis of environmental or genetic factors can be identified by record linking. LÄS MER

  2. 2. Monotonic and Semiparametric Regression for the Detection of Trends in Environmental Quality Data

    Författare :Mohamed Hussian; Anders Grimvall; Ali Hadi; Linköpings universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Normalisation; Monotonic; Semiparametric; Temporal trends; fluctuations; global; local; Matematisk statistik; Icke-parametriska metoder; Statistics; Statistik;

    Sammanfattning : Natural fluctuations in the state of the environment can long conceal or distort important trends in the human impact on our ecosystems. Accordingly, there is increasing interest in statistical normalisation techniques that can clarify the anthropogenic effects by removing meteorologically driven fluctuations and other natural variation in time series of environmental quality data. LÄS MER

  3. 3. Correlated random effects models for clustered survival data

    Författare :Frank Eriksson; Chalmers tekniska högskola; Göteborgs universitet; Gothenburg University; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; competing risks; case-cohort; semiparametric; Survival analysis; random effects; routine register; frailty model; Survival analysis; frailty model; competing risks; random effects; case-cohort; routine register; semiparametric;

    Sammanfattning : Frailty models are frequently used to analyse clustered survival data in medical contexts. The frailties, or random effects, are used to model the association between individual survival times within clusters. LÄS MER

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

    Författare :Johan Vegelius; Shaobo Jin; Fan Yang-Wallentin; Melanie Wall; Uppsala universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; 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

  5. 5. Improved pharmacometric model building techniques

    Författare :Radojka Savic; Mats Karlsson; Siv Jönsson; Matt Hutmacher; Uppsala universitet; []
    Nyckelord :Model building; Absorption model; Transit compartment model; Nonparametric method; Extended grid method; Semiparametric; Distribution transformation; Shrinkage; Model diagnostics;

    Sammanfattning : Pharmacometric modelling is an increasingly used method for analysing the outcome from clinical trials in drug development. The model building process is complex and involves testing, evaluating and diagnosing a range of plausible models aiming to make an adequate inference from the observed data and predictions for future studies and therapy. LÄS MER