Sökning: "graphical Lasso"

Hittade 3 avhandlingar innehållade orden graphical Lasso.

1. 1. 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. 2. 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. 3. Classification models for high-dimensional data with sparsity patterns

   Författare :Annika Tillander; Tatjana Pavlenko; Daniel Thorburn; Patrik Ryden; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; High-dimensionality; supervised classification; classification accuracy; sparse; block-diagonal covariance structure; graphical Lasso; separation strength; discretization; Statistics; statistik;

   Sammanfattning : Today's high-throughput data collection devices, e.g. spectrometers and gene chips, create information in abundance. However, this poses serious statistical challenges, as the number of features is usually much larger than the number of observed units. LÄS MER