Sökning: "asymptotic behaviour"

Visar resultat 1 - 5 av 55 avhandlingar innehållade orden asymptotic behaviour.

  1. 1. Asymptotic analysis of solutions to elliptic and parabolic problems

    Författare :Peter Rand; Vladimir Kozlov; Mikael Langer; Vitali Liskevich; Linköpings universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Asymptotic behaviour; The Emden-Fowler equation; Parabolic system; Spectral splitting; Cylinder; Perturbation; MATHEMATICS; MATEMATIK;

    Sammanfattning : In the thesis we consider two types of problems. In Paper 1, we studysmall solutions to a time-independent nonlinear elliptic partial differential equation of Emden-Fowler type in a semi-infnite cylinder. The asymptotic behaviour of these solutions at infnity is determined. First, the equation under the Neumann boundary condition is studied. LÄS MER

  3. 2. Asymptotic Expansions for Perturbed Discrete Time Renewal Equations

    Författare :Mikael Petersson; Dmitrii Silvestrov; Ola Hössjer; Henrik Hult; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Renewal equation; Perturbation; Asymptotic expansion; Regenerative process; Quasi-stationary distribution; Risk process; Ruin probability;

    Sammanfattning : In this thesis we study the asymptotic behaviour of the solution of a discrete time renewal equation depending on a small perturbation parameter. In particular, we construct asymptotic expansions for the solution of the renewal equation and related quantities. LÄS MER

  4. 3. Asymptotic methods applied to some oceanography-related problems

    Författare :Moundheur Zarroug; Jonas Nycander; Kristofer Döös; Jan Erik Weber; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Asymptotic analysis; internal waves; geophysical fluid dynamics; thermal oscillator; Earth sciences; Geovetenskap; Oceanography; Oceanografi; atmosfärvetenskap och oceanografi; Atmospheric Sciences and Oceanography;

    Sammanfattning : In this thesis a number of issues related to oceanographic problems have been dealt with on the basis of applying asymptotic methods.  The first study focused on the tidal generation of internal waves, a process which is quantifed by the conversion rates. These have traditionally been calculated by using the WKB approximation. LÄS MER

  5. 4. Strong Cosmic Censorship and Cosmic No-Hair in spacetimes with symmetries

    Författare :Katharina Maria Radermacher; Hans Ringström; James Isenberg; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Cosmic Censorship; Cosmic No-Hair; Big Bang; symmetry; Bianchi; T2-symmetry; Gowdy; general relativity; cosmology; late time; initial time; asymptotic behaviour; perfect fluid; scalar field; Einstein equations; Mathematics; Matematik;

    Sammanfattning : This thesis consists of three articles investigating the asymptotic behaviour of cosmological spacetimes with symmetries arising in Mathematical General Relativity.In Paper A and B, we consider spacetimes with Bianchi symmetry and where the matter model is that of a perfect fluid. LÄS MER

  7. 5. Some asymptotic results in dependence modelling

    Författare :Jens Svensson; Boualem Djehiche; Allan Gut; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Mathematical statistics; Matematisk statistik;

    Sammanfattning : This thesis consists of two papers, both devoted to the study of asymptotics in dependence modelling. The first paper studies large deviation probabilities for a sum of dependent random variables, where the dependence stems from a few underlying random variables, so-called factors. LÄS MER