Sökning: "iteration"

Visar resultat 16 - 20 av 187 avhandlingar innehållade ordet iteration.

  1. 16. The Use of Landweber Algorithm in Image Reconstruction

    Författare :Touraj Nikazad; Tommy Elfving; George Baravdish; Linköpings universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; convex feasibility; projection methods; simultaneous algorithms; iterative methods; stopping rules; semi-convergence; Numerical analysis; Numerisk analys;

    Sammanfattning : Ill-posed sets of linear equations typically arise when discretizing certain types of integral transforms. A well known example is image reconstruction, which can be modelled using the Radon transform. After expanding the solution into a finite series of basis functions a large, sparse and ill-conditioned linear system arises. LÄS MER

  3. 17. Partitioned methods for time-dependent thermal fluid-structure interaction

    Författare :Azahar Monge; Numerisk analys; []
    Nyckelord :thermal FSI; Conjugate heat transfer; Domain decomposition; Time adaptivity; Coupled problems; multirate;

    Sammanfattning : The efficient simulation of thermal interaction between fluids and structures is crucial in the design of many industrial products, e.g. turbine blades or rocket nozzles. LÄS MER

  4. 18. Robust Formulations for Beam-to-Beam Contact

    Författare :Hamid Reza Motamedian; Artem Kulachenko; Anders Klarbring; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Structures; Finite Element Methods; Hållfasthetslära; Solid Mechanics;

    Sammanfattning : Contact between beam elements is a specific category of contact problems which was introduced by Wriggers and Zavarise in 1997 for normal contact and later extended by Zavarise and Wriggers to include tangential and frictional contact. In these works, beam elements are assumed to have rigid circular cross-sections and each pair of elements cannot have more than one contact point. LÄS MER

  5. 19. Solution of linear programming and non-linear regression problems using linear M-estimation methods

    Författare :Ove Edlund; Luleå tekniska universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Scientific Computing; Teknisk-vetenskapliga beräkningar;

    Sammanfattning : This thesis is devoted to algorithms for solving two optimization problems, using linear M-estimation methods, and their implementation. First, an algorithm for the non-linear M-estimation problem is considered. LÄS MER

  7. 20. A Fast Method for Solving the Helmholtz Equation Based on Wave Splitting

    Författare :Jelena Popovic; Olof Runborg; Elisabeth Larsson; KTH; []
    Nyckelord :Helmholtz equation; high fequency waves;

    Sammanfattning : In this thesis, we propose and analyze a fast method for computing the solution of the Helmholtz equation in a bounded domain with a variable wave speed function. The method is based on wave splitting. The Helmholtz equation is first split into one--way wave equations which are then solved iteratively for a given tolerance. LÄS MER