Sökning: "likelihood ratio"

Visar resultat 6 - 10 av 126 avhandlingar innehållade orden likelihood ratio.

1. 6. Searching for Gamma Rays from Galaxy Clusters with the Fermi Large Area Telescope : Cosmic Rays and Dark Matter

   Författare :Stephan Zimmer; Jan Conrad; Christophe Clement; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; galaxy clusters; gamma rays; cosmic rays; dark matter; fermi-lat; likelihood analysis; joint likelihood;

   Sammanfattning : In this licentiate thesis, I report a search for GeV γ rays towards the location of Galaxy clusters. I mainly discuss the results of a search for cosmic-ray (CR) induced γ-ray emission but also briefly elaborate on a related study, searching for Dark Matter (DM)-induced γ-ray emission from Galaxy clusters. LÄS MER

3. 7. 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

4. 8. 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

5. 9. Methods for handling model misspecification in pharmacometric model-based approaches for the analysis of longitudinal clinical trial data

   Författare :Estelle Chasseloup; Mats Karlsson; Andrew Hooker; Karl Brendel; Uppsala universitet; []
   Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; pharmacometrics; nonlinear mixed-effects models; misspecification; type I error; power; accuracy; placebo; individual model averaging; IMA; likelihood ratio test; LRT; model averaging; covariate selection; mixture models; visual predictive checks; VPC; avatars; digital twins; virtual individual; Farmaceutisk vetenskap; Pharmaceutical Science;

   Sammanfattning : Pharmacometrics model-based analyses proved to be increasingly useful in drug discovery and development. This usefulness was made evident by the formalisation of the model-integrated drug discovery and development framework (MID3). LÄS MER

7. 10. Model-Based Optimization of Clinical Trial Designs

   Författare :Camille Vong; Mats O. Karlsson; Andrew C. Hooker; Lena E. Friberg; Marylore Chenel; Oliver Sander; Uppsala universitet; []
   Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; nonlinear mixed-effects models; pharmacometrics; likelihood ratio test; NONMEM; power; sample size; study design; proof-of-concept; dose-finding; population optimal design; LOQ; BQL data; neutropenia; docetaxel; myelosuppression; thrombocytopenia; MTD; Bayesian methods; 3 3 algorithm; dose escalation study; Pharmaceutical Science; Farmaceutisk vetenskap;

   Sammanfattning : General attrition rates in drug development pipeline have been recognized as a necessity to shift gears towards new methodologies that allow earlier and correct decisions, and the optimal use of all information accrued throughout the process. The quantitative science of pharmacometrics using pharmacokinetic-pharmacodynamic models was identified as one of the strategies core to this renaissance. LÄS MER