Sökning: "Computational efficiency"

Visar resultat 1 - 5 av 545 avhandlingar innehållade orden Computational efficiency.

1. 1. Computational Ice Sheet Dynamics : Error control and efficiency

   Författare :Josefin Ahlkrona; Per Lötstedt; Jesse Johnson; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; ice sheet modelling; stokes equations; shallow ice approximation; finite element method; perturbation expansions; non-newtonian fluids; free surface flow; Scientific Computing; Beräkningsvetenskap;

   Sammanfattning : Ice sheets, such as the Greenland Ice Sheet or Antarctic Ice Sheet, have a fundamental impact on landscape formation, the global climate system, and on sea level rise. The slow, creeping flow of ice can be represented by a non-linear version of the Stokes equations, which treat ice as a non-Newtonian, viscous fluid. LÄS MER

3. 2. Automated Computational Modeling

   Författare :Johan Jansson; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; multi-adaptivity; Galerkin; ODE; PDE; plasticity; elasticity; FEM; automated;

   Sammanfattning : This thesis is part of the FEniCS project of Automation of Computational Mathematical Modeling (ACMM) as the modern manifestation of the basic principle of science:formulating mathematical equations (modeling) and solving equations (computation). The vision of FEniCS is to set a new standard towards the goals of generality, efficiency, and simplicity, concerning mathematical methodology, implementation, and application. LÄS MER

4. 3. Computational Nonsmooth Mechanics

   Författare :Peter W. Christensen; J.A.C. Martins; Linköpings universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

   Sammanfattning : This thesis concerns the application of modern methods from the field of mathematical programming for solving certain problems of nonsmooth mechanics. Attention is given to contact problems with friction as well as plasticity problems. LÄS MER

5. 4. Voyage optimization algorithms for ship safety and energy-efficiency

   Författare :Helong Wang; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Energy efficiency; Dijkstra’s algorithm; Voyage optimization algorithms; Genetic algorithm; Ship safety; Expected time of arrival;

   Sammanfattning : Currently, over 90% of the world’s trade is transported by sea. The environmental impacts from shipping and societal challenges of human and property losses caused by ship accidents are pressuring the shipping industry for more energy efficiency and enhanced safety. LÄS MER

7. 5. Hybrid Methods for Unsteady Fluid Flow Problems in Complex Geometries

   Författare :Jing Gong; Jan Nordström; Gunilla Efraimsson; Mark H. Carpenter; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; hybrid methods; finite difference methods; finite volume methods; coupling procedure; stability; efficiency; artificial dissipation; Numerical analysis; Numerisk analys; Scientific Computing; Beräkningsvetenskap; Beräkningsvetenskap med inriktning mot numerisk analys;

   Sammanfattning : In this thesis, stable and efficient hybrid methods which combine high order finite difference methods and unstructured finite volume methods for time-dependent initial boundary value problems have been developed. The hybrid methods make it possible to combine the efficiency of the finite difference method and the flexibility of the finite volume method. LÄS MER