39 research outputs found
Fast algorithms for integral equations.
by Wing-Fai Ng.Thesis (M.Phil.)--Chinese University of Hong Kong, 1996.Includes bibliographical references (leaves 7-8).Abstract --- p.1-2Introduction --- p.3-6References --- p.7-8Paper I --- p.9-32Paper II --- p.33-6
Fast algorithm for ill-conditioned toeplitz and toeplitz-like systems.
by Hai-Wei Sun.Thesis (Ph.D.)--Chinese University of Hong Kong, 1996.Includes bibliographical references.Abstracts --- p.1Summary --- p.3Introduction --- p.3Summary of the papers A-C --- p.5Paper A --- p.19Paper B --- p.34Paper C --- p.6
A fast and well-conditioned spectral method for singular integral equations
We develop a spectral method for solving univariate singular integral
equations over unions of intervals by utilizing Chebyshev and ultraspherical
polynomials to reformulate the equations as almost-banded infinite-dimensional
systems. This is accomplished by utilizing low rank approximations for sparse
representations of the bivariate kernels. The resulting system can be solved in
operations using an adaptive QR factorization, where is
the bandwidth and is the optimal number of unknowns needed to resolve the
true solution. The complexity is reduced to operations by
pre-caching the QR factorization when the same operator is used for multiple
right-hand sides. Stability is proved by showing that the resulting linear
operator can be diagonally preconditioned to be a compact perturbation of the
identity. Applications considered include the Faraday cage, and acoustic
scattering for the Helmholtz and gravity Helmholtz equations, including
spectrally accurate numerical evaluation of the far- and near-field solution.
The Julia software package SingularIntegralEquations.jl implements our method
with a convenient, user-friendly interface
Fast Numerical Methods for Non-local Operators
[no abstract available
Numerical solution of integral equation of the second kind.
by Chi-Fai Chan.Thesis (M.Phil.)--Chinese University of Hong Kong, 1998.Includes bibliographical references (leaves 53-54).Abstract also in Chinese.Chapter Chapter 1 --- INTRODUCTION --- p.1Chapter §1.1 --- Polynomial Interpolation --- p.1Chapter §1.2 --- Conjugate Gradient Type Methods --- p.6Chapter §1.3 --- Outline of the Thesis --- p.10Chapter Chapter 2 --- INTEGRAL EQUATIONS --- p.11Chapter §2.1 --- Integral Equations --- p.11Chapter §2.2 --- Numerical Treatments of Second Kind Integral Equations --- p.15Chapter Chapter 3 --- FAST ALGORITHM FOR SECOND KIND INTEGRAL EQUATIONS --- p.20Chapter §3.1 --- Introduction --- p.20Chapter §3.2 --- The Approximation --- p.24Chapter §3.3 --- Error Analysis --- p.35Chapter §3.4 --- Numerical Examples --- p.40Chapter §3.5 --- Concluding Remarks --- p.51References --- p.5
Some fast algorithms in signal and image processing.
Kwok-po Ng.Thesis (Ph.D.)--Chinese University of Hong Kong, 1995.Includes bibliographical references (leaves 138-139).AbstractsSummaryIntroduction --- p.1Summary of the papers A-F --- p.2Paper A --- p.15Paper B --- p.36Paper C --- p.63Paper D --- p.87Paper E --- p.109Paper F --- p.12