Sökning: "integral representations"

Visar resultat 21 - 25 av 40 avhandlingar innehållade orden integral representations.

  1. 21. Theoretical and computational advances in small-angle x-ray scattering tensor tomography

    Författare :Leonard Nielsen; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; tensor tomography; reciprocal space map; small-angle scattering;

    Sammanfattning : The relationships between microscopic and macroscopic structures is a central topic of materials physics. Small-angle x-ray scattering (SAXS) is a powerful experimental technique for probing and mapping variations in electron density, given by the reciprocal space map, down to the nanometer scale in two dimensions. LÄS MER

  3. 22. Exact Results in Five-Dimensional Gauge Theories : On Supersymmetry, Localization and Matrix Models

    Författare :Anton Nedelin; Joseph Minahan; Ivan Kostov; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Supersymmetric localization; Matrix Models; Chern-Simons theory; Supersymmetric Field Theories; 2; 0 theories; Theoretical Physics; Teoretisk fysik;

    Sammanfattning : Gauge theories are one of the corner stones of modern theoretical physics. They describe the nature of all fundamental interactions and have been applied in multiple branches of physics. The most challenging problem of gauge theories, which has not been solved yet, is their strong coupling dynamics. LÄS MER

  4. 23. On the Modelling of Fracture Using Strong Discontinuities

    Författare :Martin Fagerström; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; fracture; strong discontinuity; material forces; finite deformations; FEM;

    Sammanfattning : The major concern of this work is the constitutive and numerical modelling of fracture,based on strong discontinuity formulations. More particularly, an extended finiteelement approach is used, where the total displacement is separated in two mutuallyindependent fields, representing the continuous and discontinuous displacement respectively. LÄS MER

  5. 24. Model Reduction for Linear Time-Varying Systems

    Författare :Henrik Sandberg; Anders Rantzer; Sanjay Lall; Institutionen för reglerteknik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Automation; robotics; control engineering; Performance limitations; Convergence analysis; Frequency-domain analysis; Error bounds; Time-varying systems; Model reduction; Linear systems; Automatiska system; robotteknik; reglerteknik; Model reduction;

    Sammanfattning : The thesis treats model reduction for linear time-varying systems. Time-varying models appear in many fields, including power systems, chemical engineering, aeronautics, and computational science. They can also be used for approximation of time-invariant nonlinear models. Model reduction is a topic that deals with simplification of complex models. LÄS MER

  7. 25. Reordering in Noncommutative Algebras, Orthogonal Polynomials and Operators

    Författare :John Musonda; Sergei Silvestrov; Sten Kaijser; Johan Richter; Viktor Abramov; Mälardalens högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Mathematics Applied Mathematics; matematik tillämpad matematik;

    Sammanfattning : The main object studied in this thesis is the multi-parametric family of unital associative complex algebras generated by the element $Q$ and the finite or infinite set $\{S_j\}_{j\in J}$ of elements satisfying the commutation relations $S_jQ=\sigma_j(Q)S_j$, where $\sigma_j$ is a polynomial for all $j\in J$. A concrete representation is given by the operators $Q_x(f)(x)=xf(x)$ and $\alpha_{\sigma_j}(f)(x)=f(\sigma_j(x))$ acting on polynomials or other suitable functions. LÄS MER