Sökning: "simultaneous equations"

Visar resultat 1 - 5 av 54 avhandlingar innehållade orden simultaneous equations.

  1. 1. Teaching systems of linear equations in Sweden and China: What is made possible to learn?

    Författare :Johan Häggström; Göteborgs universitet; []
    Nyckelord :SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; mathematics education; school algebra; systems of equations; simultaneous equations; variation theory; international comparison; mathematics teaching;

    Sammanfattning : .... LÄS MER

  3. 2. Spatial and Physical Splittings of Semilinear Parabolic Problems

    Författare :Erik Henningsson; Matematik LTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; splitting schemes; parabolic equations; semilinear; evolution equations; dissipative; convergence order; dimension splitting; domain decomposition; axonal growth;

    Sammanfattning : Splitting methods are widely used temporal approximation schemes for parabolic partial differential equations (PDEs). These schemes may be very efficient when a problem can be naturally decomposed into multiple parts. LÄS MER

  4. 3. 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

  5. 4. Perfectly Matched Layers and High Order Difference Methods for Wave Equations

    Författare :Kenneth Duru; Gunilla Kreiss; Jan Nordsröm; Ken Mattsson; Marcus Grote; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Elastic waves; Surface waves; Perfectly matched layers; High order difference methods; Stability; Summation-by-parts operators; Boundary treatments; Beräkningsvetenskap med inriktning mot numerisk analys; Scientific Computing with specialization in Numerical Analysis;

    Sammanfattning : The perfectly matched layer (PML) is a novel technique to simulate the absorption of waves in unbounded domains. The underlying equations are often a system of second order hyperbolic partial differential equations. In the numerical treatment, second order systems are often rewritten and solved as first order systems. LÄS MER

  7. 5. Finite Difference Methods for Time-Dependent Wave Propagation Problems

    Författare :Ylva Ljungberg Rydin; Ken Mattsson; Erik Sjöqvist; Magnus Svärd; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Finite differences; Wave propagation problems; Summation-by-parts; Simultaneous approximation term; High-order accuracy; Deforming domains; Point sources; Scientific Computing; Beräkningsvetenskap;

    Sammanfattning : Wave propagation models are essential in many fields of physics, such as acoustics, electromagnetics, and quantum mechanics. Mathematically, waves can be described by partial differential equations (PDEs).  In most cases, exact solutions to wave-dominated PDEs are nearly impossible to derive. LÄS MER