Sökning: "Dissipative systems"

Visar resultat 1 - 5 av 36 avhandlingar innehållade orden Dissipative systems.

  1. 1. Discretizations of nonlinear dissipative evolution equations. Order and convergence

    Författare :Eskil Hansen; Numerisk analys; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; kontroll; systems; numerisk analys; control; Datalogi; numerical analysis; Computer science; B-convergence; Dissipative maps; Logarithmic Lipschitz constants; Galerkin methods; Nonlinear evolution equations; Time discretizations; system;

    Sammanfattning : The theme of this thesis is to study discretizations of nonlinear dissipative evolution equations, which arise in e.g. advection-diffusion-reaction processes. LÄS MER

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

    Författare :Claude Lacoursière; Bo Kåggström; Ander Klarbring; Umeå universitet; []
    Nyckelord :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;

    Sammanfattning : 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. LÄS MER

  4. 3. Prediction horizon requirement  in control and extreme load analyses for survivability : Advancements to improve the performance of wave energy technologies

    Författare :Zahra Shahroozi; Jens Engström; Malin Göteman; Uppsala universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; control; optimal velocity; non-causality; maximum power output; extreme waves; wave tank experiment; end-stop compression; wave breaking slamming; PTO damping; return level; return period; peak-over-threshold;

    Sammanfattning : The main objective of wave energy converters (WECs) is to ensure reliable electricity production at a competitive cost. Two challenges to achieving this are ensuring an efficient energy conversion and offshore survivability. LÄS MER

  5. 4. Linear response theory: from black holes to Weyl systems and back

    Författare :Jorge Laraña Aragón; Bo Sundborg; Lárus Thorlacius; Emil J. Bergholtz; Ulf Gran; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Linear response; Black holes; Thermalization; Holography; Weyl systems; Non-Hermitian systems; Theoretical Physics; teoretisk fysik;

    Sammanfattning : Linear response theory is a powerful calculation tool in quantum field theory. We apply this framework to a variety of models originating from distinct areas in theoretical physics and for different reasons. LÄS MER

  7. 5. Critical Scaling in Particle Systems and Random Graphs

    Författare :Vasilii Goriachkin; Matematisk statistik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; dissipative force; particles collisions; random graphs; random walks; martingales; geometric random graphs; neural networks; critical scaling; diffusion approximation;

    Sammanfattning : The purpose of this thesis is to study the behavior of macro-systems through their micro-parameters. In particular, we are interested in finding critical scaling in various models.Paper I investigates the influence of discrete-time collisions on particle dynamics. LÄS MER