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Visar resultat 1 - 5 av 7 avhandlingar som matchar ovanstående sökkriterier.

  1. 1. Software tools for matrix canonical computations and web-based software library environments

    Författare :Pedher Johansson; Bo Kågström; Erik. Elmroth; Alan Edelman; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Canonical structure; Jordan canonical form; controllability; StratiGraph; Matlab toolbox; Kronecker canonical form; matrix; matrix pencil; perturbation theory; closure hirerarchy; matrix stratification; control system; observability; Numerical analysis; Numerisk analys;

    Sammanfattning : This dissertation addresses the development and use of novel software tools and environments for the computation and visualization of canonical information as well as stratification hierarchies for matrices and matrix pencils. The simplest standard shape to which a matrix pencil with a given set of eigenvalues can be reduced is called the Kronecker canonical form (KCF). LÄS MER

  3. 2. Skew-symmetric matrix pencils : stratification theory and tools

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

    Sammanfattning : Investigating the properties, explaining, and predicting the behaviour of a physical system described by a system (matrix) pencil often require the understanding of how canonical structure information of the system pencil may change, e.g., how eigenvalues coalesce or split apart, due to perturbations in the matrix pencil elements. LÄS MER

  4. 3. 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

  5. 4. Tools for Control System Design : Stratification of Matrix Pairs and Periodic Riccati Differential Equation Solvers

    Författare :Stefan Johansson; Bo Kågström; Erik Elmroth; Paul Van Dooren; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; control system design; stratification; controllability; observability; matrix pair; canonical forms; linear quadratic regulator; periodic systems; periodic Riccati differential equation; Computer science; Datavetenskap; Numerical Analysis; numerisk analys;

    Sammanfattning : Modern control theory is today an interdisciplinary area of research. Just as much as this can be problematic, it also provides a rich research environment where practice and theory meet. This Thesis is conducted in the borderline between computing science (numerical analysis) and applied control theory. LÄS MER

  7. 5. Non-selfadjoint operator functions

    Författare :Axel Torshage; Christian Engström; Marco Marletta; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Non-linear spectral problem; numerical range; pseudospectrum; resolvent estimate; equivalence after extension; block operator matrices; operator functions; operator pencil; spectral divisor; joint numerical range; Mathematics; matematik;

    Sammanfattning : Spectral properties of linear operators and operator functions can be used to analyze models in nature. When dispersion and damping are taken into account, the dependence of the spectral parameter is in general non-linear and the operators are not selfadjoint. LÄS MER