Sökning: "COMPUTATIONS"

Visar resultat 1 - 5 av 548 avhandlingar innehållade ordet COMPUTATIONS.

  1. 1. The Origin-Destination Matrix Estimation Problem : Analysis and Computations

    Författare :Anders Peterson; Jan Lundgren; Torbjörn Larsson; Lars-Göran Mattsson; Linköpings universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Traffic modelling; Travel demand; Origin--Destination matrix; Traffic flow observation; Detector allocation; Estimation.; OD-matris; Trafikflödesobservation; Detektorallokering; Skattning; Trafikmodellering; Reseefterfrågan; Optimization; systems theory; Optimeringslära; systemteori;

    Sammanfattning : For most kind of analyses in the field of traffic planning, there is a need for origin--destination (OD) matrices, which specify the travel demands between the origin and destination nodes in the network. This thesis concerns the OD-matrix estimation problem, that is, the calculation of OD-matrices using observed link flows. LÄS MER

  3. 2. Tools for Structured Matrix Computations : Stratifications and Coupled Sylvester Equations

    Författare :Andrii Dmytryshyn; Bo Kågström; Volker Mehrmann; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : Developing theory, algorithms, and software tools for analyzing matrix pencils whose matrices have various structures are contemporary research problems. Such matrices are often coming from discretizations of systems of differential-algebraic equations. LÄS MER

  4. 3. Canonical Bases for Algebraic Computations

    Författare :Patrik Nordbeck; Algebra; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; gruppteori; algebra; algebraisk geometri; fältteori; Talteori; group theory; algebraic geometry; field theory; Matematik; Number Theory; regular languages; Mathematics; composition of polynomials; factor algebras; Gröbner bases; SAGBI bases;

    Sammanfattning : This thesis deals with computational methods in algebra, mainly focusing on the concept of Gröbner and SAGBI bases in non-commutative algebras. The material has a natural division into two parts. The first part is a rather extensive treatment of the basic theory of Gröbner bases and SAGBI bases in the non-commutative polynomial ring. LÄS MER

  5. 4. Some computations in Grothendieck rings

    Författare :Karl Rökaeus; Stockholms universitet; []
    Nyckelord :;

    Sammanfattning : .... LÄS MER

  7. 5. Numerical Computations with Fundamental Solutions

    Författare :Per Sundqvist; Henrik Brandén; Sverker Holmgren; Alison Ramage; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; fundamental solution; partial differential equation; partial difference equation; iterative method; preconditioner; boundary method; Numerical Analysis; Numerisk analys;

    Sammanfattning : Two solution strategies for large, sparse, and structured algebraic systems of equations are considered. The first strategy is to construct efficient preconditioners for iterative solvers. The second is to reduce the sparse algebraic system to a smaller, dense system of equations, which are called the boundary summation equations. LÄS MER