摘要
利用二阶 Ditzian- Totik模考虑一类算子的强逆不等式 .这类不等式曾经被许多学者用不同的方法研究过 .本文将采用一种统一的方法来处理一大类算子的强逆不等式 ,得到了它们的 Ditzian- Ivanov结果 .本方法适用于更广的算子 .
The converse inequalities a re proved for a family of operators that state the equivalence of two terms of e rror in approximation to the revelant Ditzian-Totik modulus of smoothness.Such inequalities have been studied by many authors with different methods.The emphas is of this paper is that these strong converse inequalities follow from a united method;hence the Ditzian-Ivanov result is extened to a large family of operato rs.The method of this paper is suitable for vast numbers of operators.
出处
《纯粹数学与应用数学》
CSCD
2002年第4期317-321,共5页
Pure and Applied Mathematics
基金
河北省自然科学基金资助项目 (10 10 90 )
