Sökning: "polynomial chaos"

Visar resultat 1 - 5 av 7 avhandlingar innehållade orden polynomial chaos.

  1. 1. Uncertainty Quantification and Numerical Methods for Conservation Laws

    Författare :Per Pettersson; Jan Nordström; Gianluca Iaccarino; Gunilla Kreiss; Rémi Abgrall; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; uncertainty quantification; polynomial chaos; stochastic Galerkin methods; conservation laws; hyperbolic problems; finite difference methods; finite volume methods; Beräkningsvetenskap med inriktning mot numerisk analys; Scientific Computing with specialization in Numerical Analysis;

    Sammanfattning : Conservation laws with uncertain initial and boundary conditions are approximated using a generalized polynomial chaos expansion approach where the solution is represented as a generalized Fourier series of stochastic basis functions, e.g. orthogonal polynomials or wavelets. LÄS MER

  3. 2. System identification of large-scale linear and nonlinear structural dynamicmodels

    Författare :Vahid Yaghoubi Nasrabadi; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Finite element model; Surrogate modeling; Bootstrapping; Polynomial chaos expansion; System identification; Exponential integration; Uncertainty quantification;

    Sammanfattning : System identification is a powerful technique to build a model from measurement data by using methods from different fields such as stochastic inference, optimization and linear algebra. It consists of three steps: collecting data, constructing a mathematical model and estimating its parameters. LÄS MER

  4. 3. Approximation of pluricomplex Green functions : A probabilistic approach

    Författare :Azza Alghamdi; Maciej Klimek; Kaj Nyström; Anna Zdunik; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; pluricomplex Green function; pluriregular sets; Bernstein-Markov property; Bergman function; nearly orthonormal polynomials; orthogonal polynomials; Monte Carlo simulation; composite Julia sets; Julia sets; iterated function systems; the chaos game.;

    Sammanfattning : This PhD thesis focuses on probabilistic methods of approximation of pluricomplex Green functions and is based on four papers.The thesis begins with a general introduction to the use of pluricomplex Green functions in multidimensional complex analysis and a review of their main properties. LÄS MER

  5. 4. Uncertainty quantification for wave propagation and flow problems with random data

    Författare :Markus Wahlsten; Jan Nordström; Per Pettersson; Rémi Abgrall; Linköpings universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : In this thesis we study partial differential equations with random inputs. The effects that different boundary conditions with random data and uncertain geometries have on the solution are analyzed. Further, comparisons and couplings between different uncertainty quantification methods are performed. LÄS MER

  7. 5. Application of Uncertainty Quantification Techniques to Studies of Wall-Bounded Turbulent Flows

    Författare :Saleh Rezaeiravesh; Mattias Liefvendahl; Gunilla Kreiss; Pierre Sagaut; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Uncertainty Quantification; Large Eddy Simulation; Wall-Bounded Turbulent Flows; Wall Modeling; OpenFOAM; Beräkningsvetenskap med inriktning mot numerisk analys; Scientific Computing with specialization in Numerical Analysis;

    Sammanfattning : Wall-bounded turbulent flows occur in many engineering applications. The quantities of interest (QoIs) of these flows can be accurately obtained through experimental measurements and scale-resolving numerical approaches, such as large eddy simulation (LES). LÄS MER