Sökning: "block iteration"

Visar resultat 1 - 5 av 16 avhandlingar innehållade orden block iteration.

  1. 1. On Numerical Solution Methods for Block-Structured Discrete Systems

    Författare :Petia Boyanova; Maya Neytcheva; Oleg Iliev; Uppsala universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; 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

  2. 2. Reinforcement learning for admission control and routing

    Författare :Jakob Carlström; Uppsala universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; routing; admission control; reinforcement learning; Markov decision processes; temporal-difference learning; policy iteration; gain scheduling; neural networks; self-similarity; asynchronous transfer mode; max-min fairness; Information technology; Informationsteknik; Computer Systems; Datorteknik;

    Sammanfattning : When a user requests. a connection to another user or a computer in a communications network, a routing algorithm selects a path for transferring the resulting data stream. If all suitable paths are busy, the user request cannot beserved, and is blocked. LÄS MER

  3. 3. Algebraic Reconstruction Methods

    Författare :Touraj Nikazad; Tommy Elfving; Constantin Popa; Linköpings universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; iterative methods; image reconstruction; ART; Cimmino; Kaczmarz; Landweber; sequential iteration; simultaneous iteration; block iteration; semi-convergence; relaxation parameters; stopping rules; discrepancy principle; 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 modeled using the Radon transform. After expanding the solution into a finite series of basis functions a large, sparse and ill-conditioned linear system occurs. LÄS MER

  4. 4. Robust preconditioned iterative solution methods for large-scale nonsymmetric problems

    Författare :Erik Bängtsson; Maya Neytcheva; Uppsala universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Scientific Computing; Beräkningsvetenskap;

    Sammanfattning : We study robust, preconditioned, iterative solution methods for large-scale linear systems of equations, arising from different applications in geophysics and geotechnics.The first type of linear systems studied here, which are dense, arise from a boundary element type of discretization of crack propagation in brittle material. LÄS MER

  5. 5. The Use of Landweber Algorithm in Image Reconstruction

    Författare :Touraj Nikazad; Tommy Elfving; George Baravdish; Linköpings universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; 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