Sökning: "iterative solution methods"

Visar resultat 21 - 25 av 90 avhandlingar innehållade orden iterative solution methods.

  1. 21. Models and solution methods for large-scale industrial mixed integer programming problems

    Författare :David Bredström; Mikael Rönnqvist; Dag Wedelin; Linköpings universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Mathematic; linear programming MIP ; production-planning; MATHEMATICS; MATEMATIK;

    Sammanfattning : This thesis deals with large-scale industrial problems that can be formulated using mixed integer linear programming (MIP) models. Because of the large problem size, it is not often possible to apply standard solution methods. Therefore special techniques must be used. LÄS MER

  3. 22. Developments in preconditioned iterative methods with application to glacial isostatic adjustment models

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

    Sammanfattning : This study examines the block lower-triangular preconditioner with element-wise Schur complement as the lower diagonal block applied on matrices arising from an application in geophysics. The element-wise Schur complement is a special approximation of the exact Schur complement that can be constructed in the finite element framework. LÄS MER

  4. 23. Characterization and analysis of the astrometric errors in the global astrometric solution for Gaia

    Författare :Berry Holl; Astronomi - Genomgår omorganisation; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Astrometry; Catalogs; Methods: data analysis; statistical; numerical; analytical; Space vehicles: instruments; Instrumentation: detectors;

    Sammanfattning : The space astrometry mission Gaia, planned for launch in 2013 by the European Space Agency (ESA), will provide the most comprehensive and accurate catalogue of astrometric data for galactic and astrophysical research in the coming decades. It will observe roughly one billion stars, quasars and other point like objects for which the five astrometric parameters (position, parallax and proper motion) will be determined. LÄS MER

  5. 24. Robust Preconditioners Based on the Finite Element Framework

    Författare :Erik Bängtsson; Maya Neytcheva; Per Lötstedt; Svetozar Margenov; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; FEM; iterative solution method; algebraic multilevel preconditioner; sparse approximate inverse; block preconditioner; Schur complement approximation; nonsymmetric saddle point matrix; isostatic glacial adjustment; pre-stress advection; elasticity; viscoelasticity; in compressible solid; ABAQUS; BEM DDM; Scientific Computing; Beräkningsvetenskap;

    Sammanfattning : Robust preconditioners on block-triangular and block-factorized form for three types of linear systems of two-by-two block form are studied in this thesis. The first type of linear systems, which are dense, arise from a boundary element type of discretization of crack propagation problems. LÄS MER

  7. 25. Methods for Direct Optimal Control of Multibody Systems

    Författare :Staffan C Björkenstam; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; discrete mechanics; robotics; Optimal control; motion planning; multibody dynamics; digital human modeling;

    Sammanfattning : In this thesis we present practical tools and techniques to numerically solve optimal control problems involving multibody systems. The driving application for the thesis has been developing motion planning tools for industrial robots and digital humans. LÄS MER