Sökning: "covariance function"

Visar resultat 11 - 15 av 76 avhandlingar innehållade orden covariance function.

1. 11. 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

3. 12. Network models with applications to genomic data: generalization, validation and uncertainty assessment

   Författare :José Sánchez; Göteborgs universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Inverse covariance matrix; precision matrix; graphical models; high-dimension; low-sample; networks; sparsity; fused lasso; elastic net; cancer; TCGA pan cancer analysis; online resource; discriminant analysis; classification; networks;

   Sammanfattning : The aim of this thesis is to provide a framework for the estimation and analysis of transcription networks in human cancer. The methods we develop are applied to data collected by The Cancer Genome Atlas (TCGA) and supporting simulations are based on derived models in order to reflect real data structure. LÄS MER

4. 13. Factors influencing emission fluxes and bacterial enrichment in sea spray aerosols : Insights from laboratory and field studies

   Författare :Julika Zinke; Matthew E. Salter; Paul Zieger; Rachel A. Foster; E. Douglas Nilsson; Patricia K. Quinn; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Sea spray aerosols; eddy covariance fluxes; air-sea-exchange; bacteria; primary biological airborne particles; laboratory studies; field studies; Baltic Sea; North-Eastern Atlantic; Environmental Sciences; miljövetenskap;

   Sammanfattning : Sea spray aerosol (SSA) is one of the major natural aerosol sources and is produced when wave breaking entrains air into ocean surface water, which subsequently breaks up into bubbles. These bubbles rise to the surface and can scavenge biogenic material. LÄS MER

5. 14. Modeling and Model Reduction by Analytic Interpolation and Optimization

   Författare :Giovanna Fanizza; Anders Lindquist; György Michaletzky; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Analytic Interpolation theory with a degree constraint; rational covariance extension problem; spectral estimation; model reduction; optimization; passive system; Optimization; systems theory; Optimeringslära; systemteori;

   Sammanfattning : This thesis consists of six papers. The main topic of all these papers is modeling a class of linear time-invariant systems. The system class is parameterized in the context of interpolation theory with a degree constraint. LÄS MER

7. 15. On some continuous-time modeling and estimation problems for control and communication

   Författare :Yasir Irshad; Magnus Mossberg; Magnus Jansson; Karlstads universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; System Identification; Parameter Estimation; Continuous-time Stochastic Systems; Networked Control Systems; Errors-in-variables Systems; Wireless Channel Modeling; Closed-loop Identification; Physics; Fysik;

   Sammanfattning : The scope of the thesis is to estimate the parameters of continuous-time models used within control and communication from sampled data with high accuracy and in a computationally efficient way.In the thesis, continuous-time models of systems controlled in a networked environment, errors-in-variables systems, stochastic closed-loop systems, and wireless channels are considered. LÄS MER