Sökning: "Lagrange method"

Visar resultat 1 - 5 av 34 avhandlingar innehållade orden Lagrange method.

  1. 1. Adaptive Finite Element Methods for Optimal Control Problems

    Författare :Karin Kraft; Göteborgs universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; finite element method; discontinuous Galerkin method; optimal control; a posteriori error estimate; dual weighted residual; adaptive; multilevel algorithm; Newton method; control constraint; variational inequality; vehicle dynamics.;

    Sammanfattning : In this thesis we study the numerical solution of optimal control problems. The problems considered consist of a system of differential equations, the state equations, which are governed by a control variable. The goal is to determine the states and controls which minimize a given cost functional. LÄS MER

  3. 2. Optimisation and control of boundary layer flows

    Författare :Antonios Monokrousos; Dan S. Henningson; Per Lötstedt; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; boundary layer; control; estimation; optimal disturbances; Lagrange method; Engineering mechanics; Teknisk mekanik;

    Sammanfattning : Both optimal disturbances and optimal control are studied by means of numerical simulations for the case of the flat-plate boundary-layer flow. The optimisation method is the Lagrange multiplier technique where the objective function is the kinetic energy of the flow perturbations and the constraints involve the linearised Navier–Stokes equations. LÄS MER

  4. 3. Optimisation and control of shear flows

    Författare :Antonios Monokrousos; Dan S. Henningson; Laurette Tuckerman; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; shear flows; flow control; optimal disturbances; Lagrange method; transition to turbulence; non-linear dynamics; Engineering mechanics; Teknisk mekanik;

    Sammanfattning : Transition to turbulence and flow control are studied by means of numerical simulations for different simple shear flows. Linear and non-linear optimisation methods using the Lagrange multiplier technique are employed. LÄS MER

  5. 4. 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

  7. 5. Likelihood-Based Panel Unit Root Tests for Factor Models

    Författare :Xingwu Zhou; Johan Lyhagen; Joakim Westerlund; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Panel unit root; Exact factor model; Dynamic factor model; Maximum likelihood; Principal components; Lagrange multiplier;

    Sammanfattning : The thesis consists of four papers that address likelihood-based unit root tests for panel data with cross-sectional dependence arising from common factors.In the first three papers, we derive Lagrange multiplier (LM)-type tests for common and idiosyncratic unit roots in the exact factor models based on the likelihood function of the differenced data. LÄS MER