Sökning: "Krylov subspace method"

Visar resultat 1 - 5 av 10 avhandlingar innehållade orden Krylov subspace method.

1. 1. Krylov Subspace Methods for Linear Systems, Eigenvalues and Model Order Reduction

   Författare :Daniel Skoogh; Göteborgs universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; eigenvalues; eigenvectors; sparse; parallel; rational; Krylov; shift; invert; Arnoldi; linear systems; iterative; model; reduction; passive; 65F15; 65F50; 65Y05; 65F10; 93A30; 93B40; rational;

   Sammanfattning : New variants of Krylov subspace methods for numerical solution of linear systems, eigenvalue, and model order reduction problems are described. A new method to solve linear systems of equations with several right-hand sides is described. LÄS MER

3. 2. On Methods for Solving Symmetric Systems of Linear Equations Arising in Optimization

   Författare :Tove Odland; Anders Forsgren; William W. Hager; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; symmetric system of linear equations; method of conjugate gradients; quasi-Newton method; unconstrained optimization; unconstrained quadratic optimiza- tion; Krylov subspace method; unnormalized Lanczos vectors; minimum-residual method; symmetriska linjära ekvationssystem; konjugerade gradientmetoden; kvasi- Newtonmetoder; optimering utan bivillkor; kvadratisk optimering utan bivillkor; Kry- lovunderrumsmetoder; icke-normaliserade Lanczosvektorer; minimum-residualmetoden; Mathematics; Matematik;

   Sammanfattning : In this thesis we present research on mathematical properties of methods for solv- ing symmetric systems of linear equations that arise in various optimization problem formulations and in methods for solving such problems.In the first and third paper (Paper A and Paper C), we consider the connection be- tween the method of conjugate gradients and quasi-Newton methods on strictly convex quadratic optimization problems or equivalently on a symmetric system of linear equa- tions with a positive definite matrix. LÄS MER

4. 3. Information Retrieval Using Krylov Subspace Methods

   Författare :Katarina Blom; Göteborgs universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

   Sammanfattning : In this dissertation we discuss how simple Krylov subspace methods can be used for information retrieval (IR). The dissertation consists of two parts. The first part gives a background of IR and introduces the vector space model for IR and the Krylov subspace methods that we use. The second part consists of four articles. LÄS MER

5. 4. Numerical methods for parameterized linear systems

   Författare :Siobhán Correnty; Elias Jarlebring; Johan Karlsson; Kirk M. Soodhalter; Andrew J. Wathen; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Parameterized linear systems; Krylov subspace methods; preconditioning; tensor decompositions; shifted linear systems; parameterized partial differential equations; time-delay systems; transfer functions; parameter estimation problems; Parameteriserade linjära system; Krylov-metoder; förkonditionering; tensordekomposition; skiftade linjära system; parametriserade partiella differentialekvationer; tidsfördröjningssystem; överföringsfunktioner; parameteruppskattningsproblem; Numerical Analysis; Numerisk analys;

   Sammanfattning : Solving linear systems of equations is a fundamental problem in engineering. Moreover, applications involving the solution to linear systems arise in the social sciences, business, and economics. Specifically, the research conducted in this dissertation explores solutions to linear systems where the system matrix depends nonlinearly on a parameter. LÄS MER

7. 5. Numerical methods for Sylvester-type matrix equations and nonlinear eigenvalue problems

   Författare :Emil Ringh; Elias Jarlebring; Johan Karlsson; Per Enqvist; Daniel Kressner; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Matrix equations; Lyapunov equation; Sylvester equation; nonlinear eigenvalue problems; two-parameter eigenvalue problems; Krylov methods; iterative methods; preconditioning; projection methods; Matrisekvationer; Lyapunovekvationen; Sylvesterekvationen; ickelinjära egenvärdesproblem; två-parameters egenvärdesproblem; Krylovmetoder; iterativa metoder; förkonditionering; projektionsmetoder; Tillämpad matematik och beräkningsmatematik; Applied and Computational Mathematics; Optimization and Systems Theory; Optimeringslära och systemteori; Numerical Analysis; Numerisk analys;

   Sammanfattning : Linear matrix equations and nonlinear eigenvalue problems (NEP) appear in a wide variety of applications in science and engineering. Important special cases of the former are the Lyapunov equation, the Sylvester equation, and their respective generalizations. These appear, e.g. LÄS MER