Search for dissertations about: "variational principle"

Showing result 1 - 5 of 16 swedish dissertations containing the words variational principle.

  2. 1. Statistical energy analysis and variational principles for the prediction of sound transmission in multilayered structures

    Author : Mathias Barbagallo; Svante Finnveden; Jean-Louis Guyader; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; statistical energy analysis; porous materials; biot theory; variational principles; hamilton principle; double walls; multilayered structures; Järnvägsgruppen - Ljud och vibrationer; Järnvägsgruppen - Ljud och vibrationer;

    Abstract : Multilayered structures have many application in industry and society: they have peculiar properties and serve a variety of purposes, like structural support, thermal insulation, vibrational and acoustic isolation. This thesis concerns the prediction of sound transmission in multilayered structures. READ MORE

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

    Author : Claude Lacoursière; Bo Kåggström; Ander Klarbring; Umeå universitet; []
    Keywords : 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;

    Abstract : 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. READ MORE

  5. 3. Class of Accurate Low Order Finite Elements

    Author : Magnus Fredriksson; Hållfasthetslära; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; quadrilateral ; variational ; finite element ; element technology ; HuWashizu ; hexahedral ; Technological sciences; Teknik;

    Abstract : High accuracy and low computational costs are essential properties for efficient finite element codes. Improvements of the finite element method in order to satisfy these qualities have been the subject for extensive research activities ever since its introduction. READ MORE

  6. 4. Foundation of Density Functionals in the Presence of Magnetic Field

    Author : Andre Laestadius; Michael Benedicks; Trygve Helgaker; KTH; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Current density functional theory; Hohenberg-Kohn theorems; paramagnetic current density functionals; Kohn-Sham theory; Levy-Lieb functional; variational principle; N-representable; degeneracy; Mathematics; Matematik;

    Abstract : This thesis contains four articles related to mathematical aspects of Density Functional Theory.In Paper A, the theoretical justification of density methods formulated with current densities is addressed. It is shown that the set of ground-states is determined by the ensemble-representable particle and paramagnetic current density. READ MORE

  7. 5. Optimal Switching Problems and Related Equations

    Author : Marcus Olofsson; Kaj Nyström; Saïd Hamadène; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; optimal switching; stochastic control; variational inequalities; backward stochastic differential equations; incomplete information; stochastic filtering; Mathematics; Matematik;

    Abstract : This thesis consists of five scientific papers dealing with equations related to the optimal switching problem, mainly backward stochastic differential equations and variational inequalities. Besides the scientific papers, the thesis contains an introduction to the optimal switching problem and a brief outline of possible topics for future research. READ MORE