Sökning: "variational"

Visar resultat 1 - 5 av 156 avhandlingar innehållade ordet variational.

  1. 1. Variational Methods in Combinatorial Optimization and Phylogeny Reconstruction

    Författare :Henrik Jönsson; Beräkningsbiologi och biologisk fysik - Genomgår omorganisation; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; statistical physics; gravitation; relativity; annealing; variational; mean-field; phylogeny; constraint satisfaction; combinatorial optimization; maximum likelihood; Physics; Fysik; Mathematical and general theoretical physics; quantum mechanics; classical mechanics; klassisk mekanik; kvantmekanik; relativitet; statistisk fysik; termodynamik; Fysicumarkivet A:2001:Jönsson; Matematisk och allmän teoretisk fysik; thermodynamics;

    Sammanfattning : Algorithms based on the variational approach, as used in statistical physics, are developed. For constraint satisfaction problems a novel cost function, based on information-theoretic arguments, is introduced, and an algorithm similar to the mean-field annealing algorithm is proposed. LÄS MER

  3. 2. Adaptive variational multiscale methods

    Författare :Axel Målqvist; Göteborgs universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; finite element method; Galerkin; duality; a posteriori error estimation; adaptivity; variational multiscale method; mixed formulation; multi-physics; oil reservoir simulation; finite element method;

    Sammanfattning : In this thesis we present a new adaptive multiscale method for solving elliptic partial differential equations. The method is based on numerical solution of decoupled local fine scale problems on patches. LÄS MER

  4. 3. Variational Inference of Dynamic Factor Models

    Författare :Erik Spånberg; Pär Stockhammar; Gebrenegus Ghilagaber; Sune Karlsson; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; dynamic factor models; variational inference; missing data; nowcasting; expectation maximization; statistik; Statistics;

    Sammanfattning : When we make difficult and crucial decisions, forecasts are powerful and important tools. For that purpose, statistical models can be our most effective aid. Ideally, these models can incorporate large sets of multifaceted data. LÄS MER

  5. 4. Variational methods for phylogeny and single-cell genomics

    Författare :Hazal Koptagel; Jens Lagergren; Alexandre Bouchard-Côté; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Variational inference; single-cell DNA sequencing; cell lineage tree; Bayesian phylogenetic tree inference; Variationsinferens; encellig DNA-sekvensering; cellhärkomstträd; Bayesiansk fylogenetisk trädinferens; Varyasyonel çıkarım; tek hücre DNA dizilimi; hücre soy ağacı; Bayesçi filogenetik ağaç çıkarımı; Datalogi; Computer Science;

    Sammanfattning : The investigation of the evolutionary history of organisms, both at the cellular level and at the species level, is a relevant research topic in computational biology. These investigations lead to a deeper understanding of developmental history, cancer progression, the genetic similarity of species, and more. LÄS MER

  7. 5. Class of Accurate Low Order Finite Elements

    Författare :Magnus Fredriksson; Hållfasthetslära; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; quadrilateral ; variational ; finite element ; element technology ; HuWashizu ; hexahedral ; Technological sciences; Teknik;

    Sammanfattning : High accuracy and low computational costs are essential properties for efficient finite element codes. Improvements of the finite element method in order to satisfy these qualities have been the subject for extensive research activities ever since its introduction. LÄS MER