Sökning: "gradient method"

Visar resultat 1 - 5 av 423 avhandlingar innehållade orden gradient method.

  1. 1. Shape Optimization for Acoustic Wave Propagation Problems

    Författare :Rajitha Udawalpola; Martin Berggren; Pekka Neittaanmäki; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; shape optimization; design optimization; acoustic wave propagation; Helmholtz equation; Boundary Element Method; Finite Element Method; inverse problems; adjoint method; gradient-based optimization; Scientific Computing; Beräkningsvetenskap;

    Sammanfattning : Boundary shape optimization is a technique to search for an optimal shape by modifying the boundary of a device with a pre-specified topology. We consider boundary shape optimization of acoustic horns in loudspeakers and brass wind instruments. LÄS MER

  3. 2. Gradient Methods for Large-Scale and Distributed Linear Quadratic Control

    Författare :Karl Mårtensson; Institutionen för reglerteknik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Large-Scale Control; Distributed Control; Linear Quadratic Gaussian Control; Gradient method; Controller Synthesis;

    Sammanfattning : This thesis considers methods for synthesis of linear quadratic controllers for large-scale, interconnected systems. Conventional methods that solve the linear quadratic control problem are only applicable to systems with moderate size, due to the rapid increase in both computational time and memory requirements as the system size increases. LÄS MER

  4. 3. Computational modeling of polycrystals using gradient crystal plasticity

    Författare :Mikkel Grymer; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; parallel algorithms; crystal plasticity; dual mixed finite element method; gradient hardening; grain modeling;

    Sammanfattning : This thesis treats the modeling of grain size dependence inmicrostructure models of metals. It is shown how gradient hardening, in a thermodynamically consistent fashion, can be included into a crystal plasticity model, which is used as the constitutive model in each grain of the polycrystal. LÄS MER

  5. 4. Some computational aspects of Markov processes

    Författare :Alexey Lindo; Göteborgs universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Galton-Watson process; embeddability; Gumbel distribution; Markov chain with a general state space; probability generating functional; infinitely divisible distribution; Levy process; gradient method; Chen-Stein s method; random matrix.; probability generating functional;

    Sammanfattning : .... LÄS MER

  7. 5. On Methods for Solving Symmetric Systems of Linear Equations Arising in Optimization

    Författare :Tove Odland; Anders Forsgren; William W. Hager; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; symmetric system of linear equations; method of conjugate gradients; quasi-Newton method; unconstrained optimization; unconstrained quadratic optimiza- tion; Krylov subspace method; unnormalized Lanczos vectors; minimum-residual method; symmetriska linjära ekvationssystem; konjugerade gradientmetoden; kvasi- Newtonmetoder; optimering utan bivillkor; kvadratisk optimering utan bivillkor; Kry- lovunderrumsmetoder; icke-normaliserade Lanczosvektorer; minimum-residualmetoden; Mathematics; Matematik;

    Sammanfattning : In this thesis we present research on mathematical properties of methods for solv- ing symmetric systems of linear equations that arise in various optimization problem formulations and in methods for solving such problems.In the first and third paper (Paper A and Paper C), we consider the connection be- tween the method of conjugate gradients and quasi-Newton methods on strictly convex quadratic optimization problems or equivalently on a symmetric system of linear equa- tions with a positive definite matrix. LÄS MER