Sökning: "covariance analysis"

Visar resultat 21 - 25 av 118 avhandlingar innehållade orden covariance analysis.

1. 21. Correlated random effects models for clustered survival data

   Författare :Frank Eriksson; Göteborgs universitet; []
   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

3. 22. 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

4. 23. Contributions to High–Dimensional Analysis under Kolmogorov Condition

   Författare :Jolanta Maria Pielaszkiewicz; Dietrich von Rosen; Martin Singul; Thomas Holgersson; Linköpings universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Eigenvalue distribution; free moments; free Poisson law; Marchenko-Pastur law; random matrices; spectral distribution; Wishart matrix; Mathematics; Matematik;

   Sammanfattning : This thesis is about high–dimensional problems considered under the so{called Kolmogorov condition. Hence, we consider research questions related to random matrices with p rows (corresponding to the parameters) and n columns (corresponding to the sample size), where p > n, assuming that the ratio  converges when the number of parameters and the sample size increase. LÄS MER

5. 24. Characterization and analysis of the astrometric errors in the global astrometric solution for Gaia

   Författare :Berry Holl; Astronomi - Genomgår omorganisation; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Astrometry; Catalogs; Methods: data analysis; statistical; numerical; analytical; Space vehicles: instruments; Instrumentation: detectors;

   Sammanfattning : The space astrometry mission Gaia, planned for launch in 2013 by the European Space Agency (ESA), will provide the most comprehensive and accurate catalogue of astrometric data for galactic and astrophysical research in the coming decades. It will observe roughly one billion stars, quasars and other point like objects for which the five astrometric parameters (position, parallax and proper motion) will be determined. LÄS MER

7. 25. Comparative network analysis of human cancer: sparse graphical models with modular constraints and sample size correction

   Författare :José Sánchez; Göteborgs universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Inverse covariance matrix; precision matrix; graphical models; high-dimension; low-sample; networks; sparsity; fused lasso; elastic net; cancer.; fused lasso;

   Sammanfattning : In the study of transcriptional data for different groups (e.g. cancer types) it's reasonable to assume that some dependencies between genes on a transcriptional or genetic variants level are common across groups. Also, that this property is preserved locally, thus defining a modular structure in the model networks. LÄS MER