Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 2 of 2
Full-Text Articles in Entire DC Network
Some New Methods For Image Compression, Muhammad Aslam
Some New Methods For Image Compression, Muhammad Aslam
Graduate Theses, Dissertations, and Problem Reports
The vanishing moment of wavelets and associated multi-resolution framework yield an efficient representation of smooth functions with wavelet approximation. However as pointed out in many papers, the similar result cannot be expected for the piecewise smooth functions with large jumps. In other words, wavelet approximation cannot achieve the same approximation order in the vicinity of jumps as in the smooth regions. Large wavelet coefficients associated with jumps are generated and consequently produce oscillations near discontinuities in the reconstructed signal. This is the so-called Gibbs phenomenon or a Ringing effect. In this thesis, we develop a technique which reduces the Gibbs …
Asymptotic Solutions Of Almost Diagonal Differential And Difference Systems, Fei Xue
Asymptotic Solutions Of Almost Diagonal Differential And Difference Systems, Fei Xue
Graduate Theses, Dissertations, and Problem Reports
New methods for both asymptotic integration of the linear differential systems Y'(t) = [D( t) + R(t)]Y( t) and asymptotic summation of the linear difference systems Y(t + 1) = [D(t)+ R(t)]Y(t) are derived. The fundamental solution Y(t) = phi( t)[I+P(t)] for differential and difference systems is constructed in terms of a product. The first matrix function phi(t) is decided by the diagonal matrix D(t) and the second matrix I + P(t) is a perturbation of the identity matrix I. Another fundamental solution Y( t) = [I + Q(t)]phi( t) is also constructed for difference systems. Conditions are given on …