Search for dissertations about: "eigenvalue problems"

Showing result 21 - 25 of 50 swedish dissertations containing the words eigenvalue problems.

2. 21. Contributions to High–Dimensional Analysis under Kolmogorov Condition

   Author : Jolanta Maria Pielaszkiewicz; Dietrich von Rosen; Martin Singul; Thomas Holgersson; Linköpings universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Eigenvalue distribution; free moments; free Poisson law; Marchenko-Pastur law; random matrices; spectral distribution; Wishart matrix; Mathematics; Matematik;

   Abstract : This thesis is about high–dimensional problems considered under the so{called Kolmogorov condition. Hence, we consider research questions related to random matrices with p rows (corresponding to the parameters) and n columns (corresponding to the sample size), where p > n, assuming that the ratio  converges when the number of parameters and the sample size increase. READ MORE

4. 22. Eigenvalue analysis and convergence acceleration techniques for summation-by-parts approximations

   Author : Andrea Alessandro Ruggiu; Jan Nordström; Per Weinerfelt; Daniel Appelö; Linköpings universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES;

   Abstract : Many physical phenomena can be described mathematically by means of partial differential equations. These mathematical formulations are said to be well-posed if a unique solution, bounded by the given data, exists. READ MORE

5. 23. Adaptive Solvers for High-Dimensional PDE Problems on Clusters of Multicore Processors

   Author : Magnus Grandin; Sverker Holmgren; Michael Thuné; Michael Bader; Uppsala universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; adaptive mesh refinement; anisotropic refinement; exponential integrators; Lanczos algorithm; hybrid parallelization; time-dependent Schrödinger equation; Scientific Computing; Beräkningsvetenskap;

   Abstract : Accurate numerical solution of time-dependent, high-dimensional partial differential equations (PDEs) usually requires efficient numerical techniques and massive-scale parallel computing. In this thesis, we implement and evaluate discretization schemes suited for PDEs of higher dimensionality, focusing on high order of accuracy and low computational cost. READ MORE

6. 24. Parallel Algorithms and Library Software for the Generalized Eigenvalue Problem on Distributed Memory Computer Systems

   Author : Björn Adlerborn; Bo Kågström; Umeå universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; computer and systems sciences; data- och systemvetenskap;

   Abstract : We present and discuss algorithms and library software for solving the generalized non-symmetric eigenvalue problem (GNEP) on high performance computing (HPC) platforms with distributed memory. Such problems occur frequently in computational science and engineering, and our contributions make it possible to solve GNEPs fast and accurate in parallel using state-of-the-art HPC systems. READ MORE

7. 25. Distributed Detection in Cognitive Radio Networks

   Author : Ahti Ainomäe; Mats Bengtsson; Tõnu Trump; Olav Tirkkonen; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Cognitive Radio; distributed estimation; distributed detection; Diffusion LMS; Diffusion Networks; Adaptive Networks; Spectrum Sensing; Energy Detection; Random Matrix; Largest Eigenvalue Detection.; Electrical Engineering; Elektro- och systemteknik;

   Abstract : One of the problems with the modern radio communication is the lack of availableradio frequencies. Recent studies have shown that, while the available licensed radiospectrum becomes more occupied, the assigned spectrum is significantly underutilized. READ MORE