Sökning: "Model approximation"

Visar resultat 1 - 5 av 523 avhandlingar innehållade orden Model approximation.

  1. 1. Modelling animal populations

    Författare :Åke Brännström; Umeå universitet; []
    Nyckelord :population model; stochastic population model; population dynamics; discrete time model; Beverton-Holt model; Skellam model; Hassell model; Ricker model; first principles; coupled map lattice; CML; area integral; square function; Mathematics; matematik;

    Sammanfattning : This thesis consists of four papers, three papers about modelling animal populations and one paper about an area integral estimate for solutions of partial differential equations on non-smooth domains. The papers are: I. Å. Brännström, Single species population models from first principles. LÄS MER

  3. 2. Analytical Approximation of Contingent Claims

    Författare :Karl Larsson; Claus Munk; Nationalekonomiska institutionen; []
    Nyckelord :SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Option pricing; approximation; stochastic volatility; implied volatility; perturbation; Malliavin calculus; commodities; swaption; swap; HJM model;

    Sammanfattning : This PhD thesis consists of three separate papers. The common theme is methods to calculate analytical approximations for prices of different contingent claims under various model assumptions. The first two papers deals with approximations of standard European options in stochastic volatility models. LÄS MER

  4. 3. Few is Just Enough! : Small Model Theorem for Parameterized Verification and Shape Analysis

    Författare :Frédéric Haziza; Parosh Aziz Abdulla; Tomáš Vojnar; Uppsala universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; program verification; model checking; parameterized systems; infinite-state systems; reachability; approximation; safety; tree systems; shape analysis; small model properties; view abstraction; monotonic abstraction; Computer Science; Datavetenskap;

    Sammanfattning : This doctoral thesis considers the automatic verification of parameterized systems, i.e. systems with an arbitrary number of communicating components, such as mutual exclusion protocols, cache coherence protocols or heap manipulating programs. The components may be organized in various topologies such as words, multisets, rings, or trees. LÄS MER

  5. 4. Model Vertices Beyond the GW Approximation

    Författare :Mikael Hindgren; Matematisk fysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Matematisk och allmän teoretisk fysik; thermodynamics; statistical physics; gravitation; GW approximation; Electron self energy; Green s function; consistency; local-field corrections; vertex function; conserving approximations; variational energies; Mathematical and general theoretical physics; classical mechanics; relativity; quantum mechanics; klassisk mekanik; kvantmekanik; relativitet; statistisk fysik; termodynamik; Fysicumarkivet A:1997:Hindgren;

    Sammanfattning : We study the effects of local vertex corrections to the self energy of the electron gas. We find that a vertex derived from time-dependent density-functional theory can give accurate self energies without including the explicit time dependence of the exchange-correlation potential provided, however, that a proper decay at large momentum transfer (large q) is built into the vertex function. LÄS MER

  7. 5. Approximation problems and weights

    Författare :Adem Limani; Matematik (naturvetenskapliga fakulteten); []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; approximation problems; weights; Spaces of analytic functions;

    Sammanfattning : This thesis is mainly concerned with investigations of approximation problems on spaces of analytic functions on the unit disc in the complex plane, which naturally arise in connection to spectral problems of certain classes of linear operators acting on the spaces in question. For instance, quasi-nilpotency of certain analytic paraproducts on the Hardy spaces and on the Bergman spaces are investigated. LÄS MER