Sökning: "Lanczos algorithm"
Visar resultat 1 - 5 av 10 avhandlingar innehållade orden Lanczos algorithm.
1. Adaptive Solvers for High-Dimensional PDE Problems on Clusters of Multicore Processors
Sammanfattning : 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. LÄS MER
2. A Richardson Leja Lanczos algorithm to compute interior eigenvalues of very large matrices
Sammanfattning : .... LÄS MER
3. Subspace Computations via Matrix Decompositions and Geometric Optimization
Sammanfattning : This thesis is concerned with the computation of certain subspaces connected to a given matrix, where the closely related problem of approximating the matrix with one of lower rank is given special attention. To determine the rank and obtain bases for fundamental subspaces such as the range and null space of a matrix, computing the singular value decomposition (SVD) is the standard method. LÄS MER
4. Singular Value Computations for Toeplitz Matrices and Subspace Tracking
Sammanfattning : This thesis addresses the problem of computing the largest singular values and corresponding singular vectors of a Toeplitz matrix. These are often requested in signal processing and system identification to extract the signal from the noise. LÄS MER
5. Experimental Studies of the Neutron Deficient Atomic Nuclei 88Ru and 87Tc, and the Diagonalization of the General Pairing Hamiltonian
Sammanfattning : This doctoral thesis consists of two parts: the experimental study of the neutron-deficient atomic nuclei 88Ru and 87Tc, and the computational study on the diagonalization of general pairing Hamiltonian. In the first part, which constitutes the main content of the thesis, the low-lying excited states in the N = Z nucleus 88Ru and N = Z + 1 nucleus 87Tc were studied via fusion-evaporation reactions induced by 115 MeV 36 Ar ions bombarding6 mg/cm 2 thick metallic 54 Fe target foils at the Grand Accélérateur Nationald’Ions Lourds (GANIL), Caen, France. LÄS MER