Sökning: "Variational method"

Visar resultat 11 - 15 av 84 avhandlingar innehållade orden Variational method.

  1. 11. Variational Problems and Level Set Methods in Computer Vision - Theory and Applications

    Författare :Jan Erik Solem; Matematik LTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Mathematics; level set methods; computer vision; variational problems; Matematik;

    Sammanfattning : Current state of the art suggests the use of variational formulations for solving a variety of computer vision problems. This thesis deals with such variational problems which often include the optimization of curves and surfaces. LÄS MER

  3. 12. Four-Body Treatment of the Hydrogen-Antihydrogen System

    Författare :Henrik Stegeby; Piotr Froelich; Alejandro Saenz; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Antimatter; antihydrogen; four-body system; Adiabatic approximation; Born-Oppenheimer; elastic scattering; stabilization method; resonance states; coupled arrangement channels; coupled rearrangement channels; Gaussian Expansion Method; Antimateria; antiväte; fyrkroppars system; adiabatisk approximation; stabilisationsmetoden; resonanstillstånd; spridningstillstånd; kopplade arrangemangskanaler; Quantum Chemistry; Kvantkemi;

    Sammanfattning : This thesis presents a nonadiabatic (4-body) description of the hydrogen-antihydrogen system at a nonrelativistic level. The properties of the system, the rearrangement processes and the possible existence of resonance states are investigated by using a variational method for coupled arrangement channels, the Gaussian Expansion Method, and the stabilization method. LÄS MER

  4. 13. On the Impact of Phase Noise in Communication Systems –- Performance Analysis and Algorithms

    Författare :Rajet Krishnan; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Oscillator; phase noise; sum-product algorithm SPA ; random matrix theory; variational Bayesian method; massive MIMO; symbol error probability; maximum a posteriori MAP detection; constellations; extended Kalman filter EKF ; maximum likelihood ML detection; mutual information; multiple-input multiple-output MIMO ; factor graph; free probability.;

    Sammanfattning : The mobile industry is preparing to scale up the network capacity by a factor of 1000x in order to cope with the staggering growth in mobile traffic. As a consequence, there is a tremendous pressure on the network infrastructure, where more cost-effective, flexible, high speed connectivity solutions are being sought for. LÄS MER

  5. 14. Numerical Analysis of Evolution Problems in Multiphysics

    Författare :Anna Persson; Göteborgs universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; regularity; generalized finite element; localized orthogonal decomposition; multiscale; finite element method; Thermoelasticity; Riccati equations; thermistor; linear elasticity; Joule heating; parabolic equations; Regularity; generalized finite element; localized orthogonal decomposition; multiscale finite element method; Thermoelasticity; Riccati equations; thermistor; linear elasticity; Joule heating; parabolic equations;

    Sammanfattning : In this thesis we study numerical methods for evolution problems in multiphysics. The term multiphysics is commonly used to describe physical phenomena that involve several interacting models. Typically, such problems result in coupled systems of partial differential equations. LÄS MER

  7. 15. Some special problems in elliptic and parabolic variational inequalities

    Författare :Gulchehra Kulieva; Luleå tekniska universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Matematik; Mathematics;

    Sammanfattning : This Licentiate Thesis is devoted above all to the investigation of variational inequalities. Chapter 1 deals with linear elliptic variational inequalities, where the operator is degenerated or singular, which involves the use of some weighted Sobolev spaces. LÄS MER