Sökning: "equations of state"

Visar resultat 11 - 15 av 277 avhandlingar innehållade orden equations of state.

  1. 11. 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

  3. 12. Computational electromagnetics : software development and high frequency modeling of surface currents on perfect conductors

    Författare :Sandy Sefi; Jesper Oppelstrup; Francisco Saez de Adana; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; High frequency approximations; Maxwell’s equations; Method of Moments; Physical Optics; Geometrical Theory of Diffraction; Extraction Extrapolation; Numerical analysis; Numerisk analys;

    Sammanfattning : In high frequency computational electromagnetics, rigorous numerical methods be come unrealistic tools due to computational demand increasing with the frequency. Instead approximations to the solutions of the Maxwell equations can be employed to evaluate th electromagnetic fields. LÄS MER

  4. 13. Differential-algebraic equations and matrix-valued singular perturbation

    Författare :Henrik Tidefelt; Torkel Glad; Ulf Jönsson; Linköpings universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Differential-algebraic equations; uncertainty; singular perturbation; state estimation; Automatic control; Reglerteknik;

    Sammanfattning : With the arrival of modern component-based modeling tools for dynamic systems, the differential-algebraic equation form is increasing in popularity as it is general enough to handle the resulting models. However, if uncertainty is allowed in the equations — no matter how small — this thesis stresses that such equations generally become ill-posed. LÄS MER

  5. 14. Theoretical prediction of ionisation properties of proteins

    Författare :Assen Koumanov; Karolinska Institutet; Karolinska Institutet; []
    Nyckelord :;

    Sammanfattning : This work emphasises on elaboration of improved theoretical and computational methods for determination of protonation/deprotonation equilibria in proteins. It also aims to contribute for a better understanding on atomic level of ionisation properties of proteins and their role in structure-functional relationship. LÄS MER

  7. 15. Accuracy and Convergence Studies of the Numerical Solution of Compressible Flow Problems

    Författare :Erik Sterner; Per Lötstedt; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; computational fluid dynamics; Navier-Stokes equations; convergence acceleration; preconditioning; semi-implicit; multiblock; multigrid; finite volume method; Numerical Analysis; Numerisk analys;

    Sammanfattning : The numerical solution of compressible flow problems governed by the Navier-Stokes equations is considered. A finite volume method is used for the discretization in space. Different techniques to accelerate the convergence to a steady state are suggested, and the accuracy of the spatial difference operator is analyzed. LÄS MER