Sökning: "variable dimension"

Visar resultat 1 - 5 av 51 avhandlingar innehållade orden variable dimension.

1. 1. Robust inference of gene regulatory networks : System properties, variable selection, subnetworks, and design of experiments

   Författare :Torbjörn E. M. Nordling; Elling W Jacobsen; Rolf Findeisen; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; network inference; reverse engineering; variable selection; model selection; feature selection; subset selection; system identification; system theory; network theory; subnetworks; design of experiments; perturbation experiments; gene regulatory networks; biological networks;

   Sammanfattning : In this thesis, inference of biological networks from in vivo data generated by perturbation experiments is considered, i.e. deduction of causal interactions that exist among the observed variables. Knowledge of such regulatory influences is essential in biology. LÄS MER

3. 2. Valid causal inference in high-dimensional and complex settings

   Författare :Niloofar Moosavi; Xavier de Luna; Jenny Häggström; Edward Kennedy; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Causal inference; high dimension; sensitivity analysis; variable selection; convolutional neural network; semiparametric efficiency bound; Statistics; statistik;

   Sammanfattning : The objective of this thesis is to consider some challenges that arise when conducting causal inference based on observational data. High dimensionality can occur when it is necessary to adjust for many covariates, and flexible models must be used to meet convergence assumptions. The latter may require the use of a novel machine learning estimator. LÄS MER

4. 3. Coding Speech for Packet Networks

   Författare :Jonas Lindblom; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; packet loss concealment; voice over IP; speech coding; harmonic modeling; vector quantization; sinusoidal modeling; Gaussian mixture modeling; bounded support; frame erasure; variable dimension;

   Sammanfattning : The topic of this thesis is speech coding for packet networks. Problems related to the use of packet networks for voice communication are addressed. Real-time voice communication is for example very delay sensitive; if the total end-to-end delay in a telephone session grows large, it is perceived as annoying. LÄS MER

5. 4. Dynamics of ecological communities in variable environments : local and spatial processes

   Författare :Linda Kaneryd; Bo Ebenman; Peter Münger; Michael S. Fowler; Linköpings universitet; []
   Nyckelord :;

   Sammanfattning : The ecosystems of the world are currently facing a variety of anthropogenic perturbations, such as climate change, fragmentation and destruction of habitat, overexploitation of natural resources and invasions of alien species. How the ecosystems will be affected is not only dependent on the direct effects of the perturbations on individual species but also on the trophic structure and interaction patterns of the ecological community. LÄS MER

7. 5. Scaling effects and homogenization of reaction-diffusion problems with nonlinear drift

   Författare :Vishnu Raveendran; Adrian Muntean; Irina Pettersson; Karlstads universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; homogenization; asymptotic expansion with drift; two-scale convergence with drift; effective transmission condition; dimension reduction; two-scale system; nonlinear dispersion; Matematik; Mathematics;

   Sammanfattning : We study the periodic homogenization of reaction-diffusion problems with nonlinear drift describing the transport of interacting particles in composite materials. The microscopic model is derived as the hydrodynamic limit of a totally asymmetric simple exclusion process for a population of interacting particles crossing a domain with obstacles. LÄS MER