Sökning: "Numerical linear algebra"

Visar resultat 1 - 5 av 21 avhandlingar innehållade orden Numerical linear algebra.

  1. 1. Ghosts and machines : regularized variational methods for interactive simulations of multibodies with dry frictional contacts

    Författare :Claude Lacoursière; Bo Kåggström; Ander Klarbring; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Discrete mechanics; Variational method; Contact problems; Impacts; Least action principle; Saddle point problems; Lagrange Multipliers; Constrained systems; Multibody Systems; Numerical regularization; Constraint realization; Constraint stabilization; Dry friction; Differential Algebraic Equations; Nonsmooth problems; Linear Complementarity; Quaternion algebra; Numerical linear algebra; Physics modeling; Interactive simulation; Numerical stability; Rigid body dynamics; Dissipative systems; Computational physics; Beräkningsfysik;

    Sammanfattning : A time-discrete formulation of the variational principle of mechanics is used to provide a consistent theoretical framework for the construction and analysis of low order integration methods. These are applied to mechanical systems subject to mixed constraints and dry frictional contacts and impacts---machines. LÄS MER

  3. 2. 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

  4. 3. Matrix Algebra for Quantum Chemistry

    Författare :Emanuel H. Rubensson; Pawel Salek; Stefan Goedecker; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; linear scaling; reduced complexity; electronic structure; density functional theory; Hartree-Fock; density matrix purification; congruence transformation; inverse factorization; eigenvalues; eigenvectors; numerical linear algebra; occupied subspace; canonical angles; invariant subspace; Theoretical chemistry; Teoretisk kemi;

    Sammanfattning : This thesis concerns methods of reduced complexity for electronic structure calculations.  When quantum chemistry methods are applied to large systems, it is important to optimally use computer resources and only store data and perform operations that contribute to the overall accuracy. LÄS MER

  5. 4. Fast Numerical Techniques for Electromagnetic Problems in Frequency Domain

    Författare :Martin Nilsson; Per Lötstedt; Abderrahmane Bendali; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Fast Multipole Method; Minimal Residual Interpolation; Sparse Approximate Inverse preconditioning; Method of Moments; fast solvers; iterative methods; multiple right-hand sides; error analysis; Numerical Analysis; Numerisk analys;

    Sammanfattning : The Method of Moments is a numerical technique for solving electromagnetic problems with integral equations. The method discretizes a surface in three dimensions, which reduces the dimension of the problem with one. A drawback of the method is that it yields a dense system of linear equations. LÄS MER

  7. 5. Lefschetz properties and Jordan types of Artinian algebras

    Författare :Nasrin Altafi; Mats Boij; Martina Juhnke-Kubitzke; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Lefschetz properties; Jordan type; Hilbert function; Artinian algebra; Gorenstein algebra; Hessian;

    Sammanfattning : This thesis contains six papers concerned with studying the Lefschetz properties and Jordan types of linear forms for graded Artinian algebras. Lefschetz properties and Jordan types carry information about the ranks of multiplication maps by linear forms on graded Artinian algebras. LÄS MER