约束导数值域一致逼近中最佳逼近的特征

本文在一般情况下给出了多重约束导数值域广义多项式的最佳一致逼近的特征。这一结果的适用范围极广,Hermite-Birkhoff插值约束逼近、复合共单调逼近及代数多项式情况下系数有界限的逼近等都是它的特例。

Characterization of Best Uniform Approximation with Restricted Ranges of Derivatives

This paper gives a general characterization theorem of a best uniform approximation of generalized polynomial having multiple restricted ranges of its derivatives. This theorem is widely applicable. The results on characterization in many standard approximations, such as approximation with Hermite-Birkhoff interpolatory side conditions, multiple comonotone approximation, and approximation by algebraic polynomials having boun- ded coefficients, etc., are special cases of our result.