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Visar resultat 1 - 5 av 24 avhandlingar som matchar ovanstående sökkriterier.

  1. 1. Construction of Adaptive Multistep Methods for Problems with Discontinuities, Invariants, and Constraints

    Författare :Fatemeh Mohammadi; Numerisk analys; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; multistep methods; Initialization; beta-blocking; Discontinuity; Time adaptivity; Strong stability preserving; Differential algebraic equations;

    Sammanfattning : Adaptive multistep methods have been widely used to solve initial value problems. These ordinary differential equations (ODEs) may arise from semi-discretization of time-dependent partial differential equations(PDEs) or may combine with some algebraic equations to represent a differential algebraic equations (DAEs). LÄS MER

  3. 2. Analysis of Computational Algorithms for Linear Multistep Methods

    Författare :Anders Sjö; Matematik LTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; linear multistep method; Initial value ODE; variable step method; Adams method; BDF; stepsize control; error analysis; Mathematics; Matematik;

    Sammanfattning : Linear multistep methods (LMMs) constitute a class of time-stepping methods for the solution of initial value ODEs; the most well-known methods of this class are the Adams methods (AMs) and the backward differentiation formulae (BDFs). For the fixed stepsize LMMs there exists an extensive error and stability analysis; in practical computations, however, one always uses a variable stepsize. LÄS MER

  4. 3. Stability and boundedness results for variable-step variable-formula methods

    Författare :Jørgen Sand; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : This work constitutes the author's Doctoral thesis, which includes an introduction to and a summary of the following two TRITA-NA-reports: 8112 and 8218.In many practical applications one is interested in step-wise simulation of the behaviour of a dynamic system described by ordinary differential equations. LÄS MER

  5. 4. Discretizations of nonlinear dissipative evolution equations. Order and convergence

    Författare :Eskil Hansen; Numerisk analys; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; kontroll; systems; numerisk analys; control; Datalogi; numerical analysis; Computer science; B-convergence; Dissipative maps; Logarithmic Lipschitz constants; Galerkin methods; Nonlinear evolution equations; Time discretizations; system;

    Sammanfattning : The theme of this thesis is to study discretizations of nonlinear dissipative evolution equations, which arise in e.g. advection-diffusion-reaction processes. LÄS MER

  7. 5. Methods and Tools for Co-Simulation of Dynamic Systems with the Functional Mock-up Interface

    Författare :Christian Andersson; Matematik LTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Coupled Systems; Co-Simulation; FMI; Functional Mock-up Interface; PyFMI; Assimulo; Stability; Master Algorithm;

    Sammanfattning : Simulation of coupled dynamical systems, where the subsystems are bundled with their own internal solver, is important in industry. This is due to that in many cases, with complex systems, this is the only viable option. LÄS MER