Sökning: "eigenvalue problem"

Visar resultat 21 - 25 av 62 avhandlingar innehållade orden eigenvalue problem.

  1. 21. Least squares rigid body fitting of point-sets with unknown correspondences

    Författare :Tapani Utriainen; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : The problem addressed here is: given points u_1,...,u_n and v_1,. LÄS MER

  3. 22. Response Matrix Reloaded : for Monte Carlo Simulations in Reactor Physics

    Författare :Mickus Ignas; Jan Dufek; Jaakko Leppänen; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Kärnenergiteknik; Nuclear Engineering;

    Sammanfattning : This thesis investigates Monte Carlo methods applied to criticality and time-dependent problems in reactor physics. Due to their accuracy and flexibility, Monte Carlo methods are considered as a “gold standard” in reactor physics calculations. However, the benefits come at a significant computing cost. LÄS MER

  4. 23. Shape and material optimization for antenna applications

    Författare :Per Jacobsson; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; explicit-implicit time stepping; sensitivity analysis; Nitsche s method; total scattering cross section; shape and material optimization; array antennas; finite element method;

    Sammanfattning : In this thesis, a gradient-based method for shape and material optimization fortwo antenna applications is presented: minimization of the active reflectioncoefficient for conformal array antennas; and minimization of the totalscattering cross section for cylindrical scatterers. The sensitivity of theobjective function with respect to changes of the shape and material of the geometry isexpressed in terms of the original field problem and an adjoint field problem. LÄS MER

  5. 24. Finite Element Analysis of Structure-acoustic Systems : Methods and Applications

    Författare :Peter Davidsson; Byggnadsmekanik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Sammanfattning : Paper 1The problem in which a flexible structure interacts with an acoustic fluid is analysed by use of the finite element method. With increasing complexity of the geometry and when increasing the frequency limit is of interest, the number of degrees of freedom needed to describe the system becomes very large. LÄS MER

  7. 25. Numerical Methods for Ports in Closed Waveguides

    Författare :Christer Johansson; KTH; []
    Nyckelord :waveguides fem ports edge elements;

    Sammanfattning : Waveguides are used to transmit electromagnetic signals.Their geometry is typically long and slender their particularshape can be used in the design of computational methods. Onlyspecial modes are transmitted and eigenvalue and eigenvectoranalysis becomes important.We develop a . LÄS MER