Sökning: "Preconditioning techniques"

Visar resultat 1 - 5 av 22 avhandlingar innehållade orden Preconditioning techniques.

  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. Efficient Electromagnetic Induction Modelling : Adaptive mesh optimisation, advanced boundary methods and iterative solution techniques

    Författare :Laura M. Buntin; Thomas Kalscheuer; Gunilla Kreiss; Zhengyong Ren; Klaus Spitzer; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Applied geophysics; Electromagnetic theory; Numerical Modelling; Geo-Electromagnetics; Magnetotellurics; Controlled-source electromagnetics; Goal-oriented adaptive mesh refinement; Perfectly-matched layers; Iterative solution methods; Preconditioning; Geofysik med inriktning mot fasta jordens fysik; Geophysics with specialization in Solid Earth Physics;

    Sammanfattning : Forward modelling of electromagnetic induction data simulates the electric and magnetic fields within a computational domain for a given distribution of electromagnetic material properties and a given source of the electromagnetic field. The quantities of interest are the fields at receiver locations at the Earth's surface. LÄS MER

  4. 3. On surgical techniques to reduce morbidity after anterior cruciate ligament reconstruction. The significance of harvesting technique, preconditioning, graft choice and the course of bone mineral in the calcaneus

    Författare :Lars Ejerhed; Göteborgs universitet; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Anterior cruciate ligament reconstruction; patellar tendon autograft; semitendinosus tendon autograft; preconditioning; bone mineral areal mass;

    Sammanfattning : The aim of the study was to reduce undesired postoperative effects, such as anterior knee pain, loss of sensitivity in the knee region and problems with knee-walking after anterior cruciate ligament (ACL) reconstructive surgery. Furthermore, prospectively to evaluate the bone mineral in the calcanei before and after ACL reconstruction. LÄS MER

  5. 4. Implementation of the spectral element method and iterative solution techniques for 3D controlled-source electromagnetic modelling

    Författare :Michael Weiss; Thomas Kalscheuer; Michael Becken; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Controlled source electromagnetis; Electromagnetic theory; Numerical modelling; Applied geophysics; Geo-Electromagnetics; Spectral element method; Iterative solution methods; Preconditioning;

    Sammanfattning : Controlled-source electromagnetic methods are imaging techniques applied at/on the surface of the Earth which record the electromagnetic field in order to assess the electrical conductivity distribution of the Earth’s subsurface, along with anomalies in this material property, as well as to characterise and interpret structures in Earth’s crust. Extracting information from the recorded electromagnetic data requires inverse modelling algorithms. LÄS MER

  7. 5. 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