Best approximation in Chebyshev subspaces of L(l1n,l1n)

Approximating weak Chebyshev subspaces by Chebyshev subspaces

We examine to what extent finite-dimensional spaces defined on locally compact subsets of the line and possessing various weak Chebyshev properties (involving sign changes, zeros, alternation of best approximations, and peak points) can be uniformly approximated by a sequence of spaces having related properties. r 2003 Elsevier Science (USA). All rights reserved.

Best Approximation in TVS

In this paper  we give newresults on the best approximation  in the Hausdorff topological vectorspace and  consider relationship  with orthogonality. Also we determined under  what conditions the map $P_{K,f}$ is upper semicontinous.

Variations on the Chebyshev and Lq Theories of Best Approximation

The classical Chebyshev theory of best uniform approximation to continuous functions by polynomials of degree <n was initiated by Chebyshev in [2]. This theory has a distinct advantage over the corresponding ones for L4-norms, 1 < q < co, in that the unique best approximant is characterized by a remarkable geometric property. Let f be a realvalued function, continuous on [0, 11, and, for n = 0,...

ε-weakly Chebyshev subspaces and quotient spaces

Contourlet Filter Design Based on Chebyshev Best Uniform Approximation

The contourlet transform can deal effectively with images which have directional information such as contour and texture. In contrast to wavelets for which there exists many good filters, the contourlet filter design for image processing applications is still an ongoing work. Therefore, this paper presents an approach for designing the contourlet filter based on the Chebyshev best uniform appro...