一类Stancu型的Szász-Mirakjan-Durrmeyer算子的逼近性质研究

该文介绍了一类Stancu型的Szász-Mirakjan-Durrmeyer算子,计算了该算子的一阶到四阶矩.然后用连续模和K-泛函等工具,讨论了该算子的逼近性质,还研究了算子对Lipschitz函数类的估计.最后建立了该算子的Voronvskaya型渐近展开式.所得定理扩展了Aslan(2022)的结果.

STRONG CONVERSE INEQUALITY FOR SZASZ-DURRMEYER OPERATORS

For Szasz-Durrmeyer operators L.(f,x),1<p ∞ we prove that, forsome m,where(x)2=x,M>0,is Ditzian-Totik modulus of smoothness.

ON THE RATE OF CONVERGENCE OF BEZIER VARIANT OF SZASZ-DURRMEYER OPERATORS

In the present paper, we introduce Szasz-Durrmeyer-Bezier operators M.,.(f,x) , which generalize the Szasz-Durrmeyer operators. Here we obtain an estimate on the rate of convergence of Mn,a(f,x) for functions of bounded variation. Our result extends and improves that of Sahai and Prasad and Gupta and Pant.

AN APPLICATION OF BERNSTEIN-DURRMEYER OPERATORS

In the present paper, we find that the Bernstein-Durrmeyer operators, besides their better applications in approximation theory and some other fields, are good tools in constructing translation network. With the help of the de la Vallée properties of the Bernstein-Durrmeyer operators a sequence of translation network operators is constructed and its degree of approximation is dealt.

APPROXIMATION BY COMPLEX SZSZ-DURRMEYER OPERATORS IN COMPACT DISKS

In the present paper, we deal with the complex Szasz-Durrmeyer operators and study Voronovskaja type results with quantitative estimates for these operators attached to analytic functions of exponential growth on compact disks. Also, the exact order of approximation is found.

APPROXIMATION OF A KIND OF NEVAI-DURRMEYER OPERATORS IN L_w^p SPACES

The present paper introduces a kind of Nevai-Durrmeyer operators which can be used to approximate functions in Lω^p, spaces with the weight ω（x）=1/√（1-x^2） and the approximate rate is also estimated.

APPLICATIONS OF THE BERNSTEIN-DURRMEYER OPERATORS IN ESTIMATING THE NORM OF MERCER KERNEL MATRICES

The paper is related to the norm estimate of Mercer kernel matrices. The lower and upper bound estimates of Rayleigh entropy numbers for some Mercer kernel matrices on [0, 1] × [0, 1] based on the Bernstein-Durrmeyer operator kernel are obtained, with which and the approximation property of the Bernstein-Durrmeyer operator the lower and upper bounds of the Rayleigh entropy number and the l2 -norm for general Mercer kernel matrices on [0, 1] x [0, 1] are provided.

On Weighted L^p-Approximation by Weighted Bernstein-Durrmeyer Operators

In the present paper, we establish direct and converse theorems for weight-ed Bernstein-Durrmeyer operators under weighted L^p-norm with Jacobi weight w（x）=x^a（1-x）β.All the results involved have no restriction a,β〈1-1/p,which indicates that the weighted Bemstein-Durrmeyer operators have some better approxi- mation properties than the usual Bernstein-Durrmeyer operators.

APPLICATIONS OF BERNSTEIN-DURRMEYER OPERATORS IN ESTIMATING THE COVERING NUMBER

The paper deals with estimates of the covering number for some Mercer kernel Hilbert space with Bernstein-Durrmeyer operators. We first give estimates of l2- norm of Mercer kernel matrices reproducing by the kernelsK（α,β）（x,y）：=∑∞k=0 Ck（α,β）（x）Qk（α,β）（y）,where Qk（α,β） （x） are the Jacobi polynomials of order k on （0, 1 ）, Ck（α,β） 〉 0 are real numbers, and from which give the lower and upper bounds of the covering number for some particular reproducing kernel Hilbert space reproduced by Kα,β （x, y）.

L^p APPROXIMATION BY GENERAL BERNSTEIN-DURRMEYER OPERATOR DEFINED ON SIMPLEX

As a generalization of the Bernstein-Durrmeyer operatora defined on the simplex, a class of general Bernstein-Durrmeyer operators is introduced. With the weighted moduli of smoothness as a metric, we prove a strong direct theorem and an inverse theorem of weak type for these operators by using a decom-position way. From the theorems the characterization of Lp approximation behavior is derived.

Approximation Theorems of Bernstein-Durrmeyer Operators in L_M^（Ba） Spaces

With the weighted modulus of smoothness as a metric,we prove the direct and the inverse theorems of approximation by Bernstein-Durrmeyer operators in LBa M spaces. Especially an approximation equivalent theorem of the operators is also obtained.

Approximation Properties by q-Durrmeyer-Stancu Operators

In this paper, we are dealing with q-Bemstein-Durrmeyer-Stancu operators. Firstly, we have estimated moments of these operators. Then we have discussed some approximation properties and asymptotic formulas. We have obtained better estimations by using King type approach and given statistical convergence for the operators.

Simultaneous Approximation for Szsz-Mirakian-Stancu-Durrmeyer Operators

The aim of this work is to generalize Szasz-Mirakian operator in the sense of Stancu-Durrmeyer operators. We obtain approximation properties of these operators. Here we study asymptotic as well as rate of convergence results in simultaneous approximation for these modified operators.

Approximation by Complex Baskakov-Szsz-Durrmeyer Operators in Compact Disks

In this paper, we deal with the complex Baskakov-Szasz-Durrmeyer mixed operators and study Voronovskaja type results with quantitative estimates for these operators attached to analytic functions of exponential growth in DR = {z ∈ C; ｜z｜ 〈 R}. Also, the exact order of approximation is found. The method used allows to construct complex Szasz-type and Baskakov-type approximation operators without involving the values on [0,∞）.

Strong Converse Inequality for the Meyer-Knig and Zeller-Durrmeyer Operators

In this paper we give a strong converse inequality of type B in terms of unified K-functional Kλα （f, t2） （0 ≤λ≤ 1, 0 〈 α 〈 2） for the Meyer-Knig and Zeller-Durrmeyer type operators.

Stechkin-Marchaud Type Inequalities in Lp for Linear Combination of Bernstein-Durrmeyer Operators

In this paper, we use the equivalence relation between K-functional and modulus of smoothness, and give the Stechkin-Marchaud-type inequalities for linear combination of Bernstein-Durrmeyer operators . Moreover, we obtain the inverse result of approximation for linear combination of Bernstein-Durrmeyer operators with . Meanwhile we unify and extend some previous results.

Szasz-Durrmeyer算子的逼近

对于 Szasz-Durrmeyer算子 ,周定轩曾用光滑模ω2φ(f ,t)和ω1 (f ,t)讨论了λ=1的情况 ,Ditzian用光滑模 ω2 (f ,t)和ω1 (f ,t) 解决了 λ=0 的情况 ,然而对于原算子 ,Ditzian曾用统一光滑模ω2φλ(f ,t)给出了一个有趣的点态逼近等价定理 ,统一了有关古典连续模及 Ditzian-Totik模的逼近结果 .对于 Durrmeyer型的算子 ,由于一阶矩不为零 ,要想得到类似的结果 ,需要克服许多困难 .本文中引入一个新算子 ,利用光滑模ω2φλ(f ,t)和ω1 (f ,t)之间的关系 ,得到了一个完美的等价定理 。

Szasz-Durrmeyer算子逼近的强逆不等式

引入新的K-泛函K(f,t)β研究Szasz-Durrmeyer算子逼近的强逆不等式,从而得到了算子逼近的特征刻画.1)设f∈CB[0,∞),则存在常数R>1,当l≥Rn时,有K(f,1/n)β≤Cln.(‖Mnf-f‖β+‖Mlf-f‖β);2)设0<h<1/16,0<α≤2,0≤λ≤1,则对每个x∈[0,∞),存在n=n(x,h)及正整数m,满足△2hφλf(x)≤Chαnα/2(‖Mnf-f‖β+‖Mmnf-f‖β).

一类Szasz-Durrmeyer-Bezier算子在Orlicz空间内的逼近

引入广义Szasz-Durrmeyer-Bezier算子,研究其在Orlicz空间内的逼近问题.利用凸函数的Jensen不等式、K-泛函以及函数逼近论中的常用方法,获得了该算子在Orlicz空间内的逼近定理.

Szasz-Mirakjan-Durrmeyer算子线性组合的加权Orlicz逼近

讨论Szasz-Mirakjan-Durrmeyer算子的线性组合在Orlicz空间内的逼近问题,借助Hölder不等式、K-泛函、Hardy不等式、光滑模等工具,给出Szasz-Mirakjan-Durrmeyer算子的线性组合在Orlicz空间内Jacobi加权的逼近定理。