Sökning: "singular perturbation"

Visar resultat 1 - 5 av 12 avhandlingar innehållade orden singular perturbation.

  1. 1. Differential-algebraic equations and matrix-valued singular perturbation

    Författare :Henrik Tidefelt; Torkel Glad; Ulf Jönsson; Linköpings universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Differential-algebraic equations; uncertainty; singular perturbation; state estimation; Automatic control; Reglerteknik;

    Sammanfattning : With the arrival of modern component-based modeling tools for dynamic systems, the differential-algebraic equation form is increasing in popularity as it is general enough to handle the resulting models. However, if uncertainty is allowed in the equations — no matter how small — this thesis stresses that such equations generally become ill-posed. LÄS MER

  3. 2. Generalized Titchmarsh-Weyl functions and super singular perturbations

    Författare :Christoph Neuner; Annemarie Luger; Pavel Kurasov; B. Malcolm Brown; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Generalized Titchmarsh-Weyl function; Super singular perturbations; Strongly singular potentials;

    Sammanfattning : In this thesis we study certain singular Sturm-Liouville differential expressions from an operator theoretic point of view.In particular we are interested in expressions that involve strongly singular potentials as introduced by Gesztesy and Zinchenko. LÄS MER

  4. 3. Structural algorithms and perturbations in differential-algebraic equations

    Författare :Henrik Tidefelt; Torkel Glad; Mats Jirstrand; Linköpings universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; differential-algebraic equations; index reduction; singular perturbation; Automatic control; Reglerteknik;

    Sammanfattning : Den kvasilinjära formen av differential-algebraiska ekvationer är både en mycket allmängiltig generalisering av den linjära tidsinvarianta formen, och en form som visar sig lämpa sig väl för indexreduktionsmetoder som vi hoppas ska komma att bli både praktiskt tillämpbara och väl förstådda i framtiden.Kuperingsalgoritmen (engelska: the shuffle algorithm) användes ursprungligen för att bestämma konsistenta initialvillkor för linjära tidsinvarianta differential-algebraiska ekvationer, men har även andra tillämpningar, till exempel det grundläggande problemet numerisk integration. LÄS MER

  5. 4. Computation of Parameters in some Mathematical Models

    Författare :Gunilla Wikström; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; inverse problems; parameter estimation; systems of ordinary differential equations; short-cut methods; separable nonlinear least squares problems; Matlab toolbox for nonlinear least squares ; linear systems of equations; pseudoinverse solution; perturbation theory; singular value decomposition; experimental error analysis; Computer science; Datavetenskap;

    Sammanfattning : In computational science it is common to describe dynamic systems by mathematical models in forms of differential or integral equations. These models may contain parameters that have to be computed for the model to be complete. LÄS MER

  7. 5. Spectral properties of elliptic operators in singular settings and applications

    Författare :Medet Nursultanov; Göteborgs universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : The present thesis is focused on the investigation of the spectral properties of the linear elliptic operators in the presence of singularities. It is divided into three chapters. In the first chapter, we consider geometric singularities. LÄS MER