Modifizierte Restgliedabschätzungen für Quadraturformeln.
Moment computation in shift invariant spaces.
Nearly Coconvex Approximation
* Part of this work was done while the second author was on a visit at Tel Aviv University in March 2001Let f ∈ C[−1, 1] change its convexity finitely many times, in the interval. We are interested in estimating the degree of approximation of f by polynomials, and by piecewise polynomials, which are nearly coconvex with it, namely, polynomials and piecewise polynomials that preserve the convexity of f except perhaps in some small neighborhoods of the points where f changes its convexity. We obtain...
On a family of linear and positive operators in weighted spaces.
On a general class of linear and positive operators.
On a hybrid family of summation integral type operators.
On a new type of Meyer-Konig and Zeller operators.
On a subclass of functions for which the Lagrange interpolation yields the Jackson order of approximation.
On approximation by Chebyshevian box splines
Chebyshevian box splines were introduced in [5]. The purpose of this paper is to show some new properties of them in the case when the weight functions are of the form , where the functions are periodic functions of one variable. Then we consider the problem of approximation of continuous functions by Chebyshevian box splines.
On approximation of analytic functions and generalized orders
A characterization of a generalized order of analytic functions of several complex variables by means of polynomial approximation and interpolation is established.
On approximation of functions and their derivatives by quasi-Hermite interpolation.
On approximation of functions by certain operators preserving
In this paper we extend the Duman-King idea of approximation of functions by positive linear operators preserving , . Using a modification of certain operators preserving and , we introduce operators which preserve and and next we define operators for -times differentiable functions. We show that and have better approximation properties than and .
On approximation of functions by generalized Abel--Poisson operators.
On Bernstein type operators
On Best Error Bounds for Approximation by Piecewise Polynomial Functions.
On Certain Problems of Chebyshev, Zolotarev, Bernstein and Akhieser.
On convergence of derivatives of linear combinations of modified Lupas operators.
On convergence of -Chlodovsky-type MKZD operators
On counterexamples in multivariate approximation
On degrees of approximation of some classes by polynomials with respect to generalized Haar system.