Sökning: "Computational efficiency"

Visar resultat 21 - 25 av 545 avhandlingar innehållade orden Computational efficiency.

  1. 21. Topics in Analysis and Computation of Linear Wave Propagation

    Författare :Mohammad Motamed; Olof Runborg; Shi Jin; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Numerical analysis; Numerisk analys;

    Sammanfattning : This thesis concerns the analysis and numerical simulation of wave propagation problems described by systems of linear hyperbolic partial differential equations. A major challenge in wave propagation problems is numerical simulation of high frequency waves. LÄS MER

  3. 22. Efficient and Flexible First-Order Optimization Algorithms

    Författare :Hamed Sadeghi; Institutionen för reglerteknik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Monotone Inclusion; Convex Optimization; First-Order Methods; Fixed-Point Iterations; Forward–Backward Splitting; Primal–Dual Algorithm;

    Sammanfattning : Optimization problems occur in many areas in science and engineering. When the optimization problem at hand is of large-scale, the computational cost of the optimization algorithm is a main concern. LÄS MER

  4. 23. Parallelization of dynamic algorithms for electronic structure calculations

    Författare :Anton G. Artemov; Emanuel H. Rubensson; Maya Neytcheva; Bo Kågström; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; parallelization; task-based programming; matrix algorithms; sparse matrices; inverse factorization; localized computations; density matrix methods; electronic structure calculations; Scientific Computing; Beräkningsvetenskap;

    Sammanfattning : The aim of electronic structure calculations is to simulate behavior of complex materials by resolving interactions between electrons and nuclei in atoms at the level of quantum mechanics. Progress in the field allows to reduce the computational complexity of the solution methods to linear so that the computational time scales proportionally to the size of the physical system. LÄS MER

  5. 24. High-order finite element methods for incompressible variable density flow

    Författare :Lukas Lundgren; Murtazo Nazarov; Anders Logg; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Finite element method; artificial viscosity; Navier-Stokes equations; conservation properties; artificial compressibility; viscous regularization; variable density flow; Beräkningsvetenskap med inriktning mot numerisk analys; Scientific Computing with specialization in Numerical Analysis;

    Sammanfattning : The simulation of fluid flow is a challenging and important problem in science and engineering. This thesis primarily focuses on developing finite element methods for simulating subsonic two-phase flows with varying densities, described by the variable density incompressible Navier-Stokes equations. LÄS MER

  7. 25. Numerical analysis and simulation of stochastic partial differential equations with white noise dispersion

    Författare :André Berg; David Cohen; Per Åhag; Guillaume Dujardin; Ludovic Goudenège; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; stochastic partial differential equation; mathematics; numerical analysis; numerical scheme; time integrator; convergence analysis; blowup; critical exponent; nonlinear Schrödinger equation; Manakov equation; Benjamin-Bona-Mahony equation; BBM equation; stochastic; random; dispersion; white noise dispersion; finite difference; pseudospectral; code; matlab; exponential integrator; splitting integrator; convergence in probability; Mathematics; matematik; Numerical Analysis; numerisk analys;

    Sammanfattning : This doctoral thesis provides a comprehensive numerical analysis and exploration of several stochastic partial differential equations (SPDEs). More specifically, this thesis investigates time integrators for SPDEs with white noise dispersion. LÄS MER