Approximation Theory: (v. 58 Colloquia Mathematica Societatis Janos Bolyai S.)

Most of the 53 papers in this volume deal with subjects of current interest in approximation theory, such as orthogonal polynomials, interpolation, Fourier series, splines, and polynomial approximations. Except for two survey papers, all of them represent original research with full proofs not published elsewhere in any form.

Table of Contents:
Retrieving a Periodic Function from its Fourier Finite Transform Corrupted by Error (U. Amato, C. Serio). Besov Spaces and Generalized Lipschitz Spaces on Vilenkin Groups are Identical (M. Avdispahic). Korovkin-type Theorems for Generalized Boolean Sum Operators (C. Badea, C. Cottin). New Classes of Local Lipschitz Constants for the Best Approximation Operator on Finite Sets (M.W. Bartelt, J.J. Swetits). Duality of the Burkholder-Davis-Gundy Inequality and the Generalized Fefferman-Garsia Inequality I (N.L. Bassily). Jentzsch Type Theorem for the Zeros of a Sequence of Best Rational Approximants (P. Bojadziev, V. Hadzijski). New Integrability and L 1 -Convergence Classes for even Trigonometric Series II (M. Buntinas, N. Tanovic-Miller). Central Factorial Numbers and their Role in Finite Difference Calculus and Approximation (P.L. Butzer, M. Schmidt). Approximation by Extended Hermite-Fejer and Hermite Interpolation (G. Criscuolo et al.). On Several Classes of Sets III (M. Crnjac, H.I. Miller). The Degeneracy of Bernstein-Bezier Polynomials over Simplices (B. Della Vecchia, Lj.M. Kocic'). Linear Combinations of Derivatives of Berstein Type Polynomials on a Simplex (M.M. Derriennic). Convergence of Pade Approximants for Wynn's Power Series II (K.A. Driver, D.S. Lubinsky). Interpolation between Spaces H p of Dyadic Martingales of Two Indices. The Complex Method (V. Echandia). Problems and Results on Polynomials and Interpolation (P. Erdos). On the Arithmetic Means of Lagrange Interpolation (P. Erdos, G. Halasz). Generalized Sampling Approximation of Multivariate Signals; Inverse Approximation Theorems (A. Fischer, R.L. Stens). Embedding Theorems involving Dyadic Hardy and VMO Spaces (S. Fridli). Ikehara's Theorem in Several Dimensions (T. Ganelius). Vilenkin-Fourier Series and Limit Periodic Arithmetic Functions (G. Gat). Approximation on the Whole Plane (J. Grof). Approximation of Higher Order Derivatives of a Real Function (A.K. Gupta, I. Vincze). The Flow Semigroup Approximation Problem (K. Gustafson, K. Halasi). On the Operator of Bleimann, Butzer and Hahn (T. Hermann). On Imbedding Theorems in Connection with Freud's Weight (N.Q. Hoa, N.X. Ky). Characterisation of Hermite-Fourier Series (A.P. Horvath). Characterization of Best Approximations from Below and from Above (V.H. Hristov, K.G. Ivanov). Power-type Generating Functions (L.C. Hsu). Inequalities for Moduli of Continuity and Rearrangements (H. Johansson et al.). On Simultaneous Approximation (T. Kilgore). Some Negative Results concerning a Pointwise Comparison of a Trigonometric Convolution Process with its Discrete Analogue (N. Kirchhoff, R.J. Nessel). On Hermite-Fejer Interpolation at the Zeros of Hermite Polynomials (H.-B. Knoop). On the Rate of Pointwise Strong (c,alpha)-Summability of Fourier Series (W. Lenski). Bernstein-Baskakov-Kantorovic Operators and Lipschitz-type Maximal Functions (B. Lenze). Matrix Transformations in some Spaces of Strongly Bounded Sequences (E. Malkowsky).