Search for dissertations about: "Fredrik Hellman"

Found 4 swedish dissertations containing the words Fredrik Hellman.

  1. 1. Multiscale and multilevel methods for porous media flow problems

    Author : Fredrik Hellman; Axel Målqvist; Uppsala universitet; []
    Keywords : NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Beräkningsvetenskap med inriktning mot numerisk analys; Scientific Computing with specialization in Numerical Analysis;

    Abstract : We consider two problems encountered in simulation of fluid flow through porous media. In macroscopic models based on Darcy's law, the permeability field appears as data.The first problem is that the permeability field generally is not entirely known. READ MORE

  2. 2. Numerical Methods for Darcy Flow Problems with Rough and Uncertain Data

    Author : Fredrik Hellman; Axel Målqvist; Auli Niemi; Fritjof Fagerlund; Robert Scheichl; Uppsala universitet; []
    Keywords : NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; numerical homogenization; multiscale methods; rough coefficients; high contrast coefficients; mixed finite elements; cdf estimation; multilevel Monte Carlo methods; Darcy flow problems; Beräkningsvetenskap med inriktning mot numerisk analys; Scientific Computing with specialization in Numerical Analysis;

    Abstract : We address two computational challenges for numerical simulations of Darcy flow problems: rough and uncertain data. The rapidly varying and possibly high contrast permeability coefficient for the pressure equation in Darcy flow problems generally leads to irregular solutions, which in turn make standard solution techniques perform poorly. READ MORE

  3. 3. Precambrian and Caledonian history of Svalbard’s West Ny Friesland Terrane

    Author : Fredrik Hellman; Berggrundsgeologi; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Geologi; physical geography; Geology; Detrital; Zircon; Svalbard; Caledonides; Spitsbergen; fysisk geografi; Petrology; mineralogy; geochemistry; Petrologi; mineralogi; geokemi;

    Abstract : This thesis deals mainly with age-investigations of metasedimentary and magmatic rocks of Ny Friesland, located in the northeastern Svalbard. However, the provenance of quartz-porphyry clasts in a Devonian conglomerate have also been investigated in northwestern Svalbard. READ MORE

  4. 4. Three Subfamilies of KRAB Zinc Finger Proteins : A Structural, Functional and Evolutionary Analysis

    Author : Charlotta Mark; Lars Hellman; Fredrik Öberg; Uppsala universitet; []
    Keywords : NATURAL SCIENCES; NATURVETENSKAP; Biology; Krüppel zinc finger; KRAB; TIF1β; transcriptional repression; Biologi; Biology; Biologi; Molecular Immunology; molekylär immunologi;

    Abstract : Krüppel-related zinc finger proteins constitute the largest single class of transcription factors within the human genome. Members of this protein family have the ability to either activate or repress transcription depending on the presence of specific activator or repressor domains within the protein. READ MORE