Local and global approximation theorems for positive linear operators

被引：25

作者：

Felten, M ^{[1
]}

机构：

[1] Univ Dortmund, D-44221 Dortmund, Germany

来源：

JOURNAL OF APPROXIMATION THEORY | 1998年 / 94卷 / 03期

关键词：

D O I：

10.1006/jath.1998.3212

中图分类号：

O1 [数学];

学科分类号：

0701 ; 070101 ;

摘要：

In this paper we bridge local and global approximation theorems for positive linear operators via Ditzian-Totik moduli omega(phi)(2)(f, delta) of second order whereby the step-weights phi are functions whose squares are concave. Both direct and converse theorems are derived. In particular we investigate the situation for exponential-type and Bernstein-type operators. (C) 1998 Academic Press.

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收藏

页码：396 / 419

页数：24

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