Sökning: "Block-matrices"

Hittade 5 avhandlingar innehållade ordet Block-matrices.

  1. 1. Preconditioning for block matrices with square blocks

    Författare :Ivo Dravins; Maya Neytcheva; Svetozar Margenov; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; preconditioning; block preconditioning; PDE-constrained optimization; Implicit Runge-Kutta methods; Beräkningsvetenskap med inriktning mot numerisk analys; Scientific Computing with specialization in Numerical Analysis;

    Sammanfattning : Linear systems of equations appear in one way or another in almost every scientific and engineering problem. They are so ubiquitous that, in addition to solving linear problems, also non-linear problems are typically reduced to a sequence of linear ones. LÄS MER

  3. 2. Algorithms for a Partially Regularized Least Squares Problem

    Författare :Ingegerd Skoglund; Tommy Elfving; Inge Söderkvist; Linköpings universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Least squares; Regularization; Block-matrices; Conjugate gradient; QR-factorization; Cross-validation; Numerical analysis; Numerisk analys;

    Sammanfattning : Vid analys av vattenprover tagna från t.ex. ett vattendrag betäms halten av olika ämnen. Dessa halter är ofta beroende av vattenföringen. LÄS MER

  4. 3. On Numerical Solution Methods for Block-Structured Discrete Systems

    Författare :Petia Boyanova; Maya Neytcheva; Oleg Iliev; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Preconditioning techniques; Finite element method; Two-by-two block matrices; Optimal order methods; AMLI method; Cahn-Hilliard equation; Multiphase flow; Inexact Newton method; Beräkningsvetenskap med inriktning mot numerisk analys; Scientific Computing with specialization in Numerical Analysis;

    Sammanfattning : The development, analysis, and implementation of efficient methods to solve algebraic systems of equations are main research directions in the field of numerical simulation and are the focus of this thesis. Due to their lesser demands for computer resources, iterative solution methods are the choice to make, when very large scale simulations have to be performed. LÄS MER

  5. 4. On some Numerical Methods and Solution Techniques for Incompressible Flow Problems

    Författare :Xin He; Maya Neytcheva; Zhong-Zhi Bai; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Beräkningsvetenskap med inriktning mot numerisk analys; Scientific Computing with specialization in Numerical Analysis;

    Sammanfattning : The focus of this work is on numerical solution methods for solving the incompressible Navier-Stokes equations, which consist of a set of coupled nonlinear partial differential equations.In general, after linearization and finite element discretization in space, the original nonlinear problem is converted into finding the solutions of a sequence of linear systems of equations. LÄS MER

  7. 5. Quadrature rules for boundary integral methods applied to Stokes flow

    Författare :Oana Marin; Anna-Karin Tornberg; Fritz Bark; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Computer science; Datavetenskap;

    Sammanfattning :   Fluid phenomena dominated by viscous effects can, in many cases, be modeled by the Stokes equations. The boundary integral form of the Stokes equations reduces the number of degrees of freedom in a numerical discretization by reformulating the threedimensional problem to two-dimensional integral equations to be discretized over the boundaries of the domain. LÄS MER