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Equivalence of <i>K</i>-Functionals and Modulus of Smoothness Generated by a Generalized Dunkl Operator on the Real Line
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作者 Reem Fahad Al Subaie Mohamed Ali Mourou 《Advances in Pure Mathematics》 2015年第6期367-376,共10页
This paper is intended to establish the equivalence between K-functionals and modulus of smoothness tied to a Dunkl type operator on the real line.
关键词 Differential-Difference operator GENERALIZED Fourier Transform GENERALIZED Translation operators K-Functionals modulus of smoothness
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WEIGHTED L_p-APPROXIMATION OF DERIVATIVES BY THE METHOD OF BETA OPERATORS 被引量:1
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作者 宋儒瑛 《Acta Mathematica Scientia》 SCIE CSCD 1999年第S1期575-582,共8页
The author consides Beta operators βnf on suitable Sobolev type subspace of Lp[0, ∞) and characterizes the global rate of approximation of derivatives f(r) through corresponding derivatives (βnf)(r) in an appropria... The author consides Beta operators βnf on suitable Sobolev type subspace of Lp[0, ∞) and characterizes the global rate of approximation of derivatives f(r) through corresponding derivatives (βnf)(r) in an appropriate weighted Lp-metric by the rate of Ditzian and Totik's r-th order weighted modulus of Smoothness. 展开更多
关键词 Beta operators weighted modulus of smoothness weighted K-functional
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STRONG CONVERSE INEQUALITY FOR SZASZ-DURRMEYER OPERATORS 被引量:1
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作者 LI SONG(Department of Applied Mathematics,Zhejiang University, Hangzhou 310027.) 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 1996年第3期361-368,共8页
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.
关键词 Szasz-Durrmeyer operators strong converse inequality Ditzian-Totik modulus of smoothness.
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On the rate of convergence of two generalized Bernstein type operators 被引量:1
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作者 LIAN Bo-yong CAI Qing-bo 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2020年第3期321-331,共11页
In this paper,we introduce the Bézier variant of two new families of generalized Bernstein type operators.We establish a direct approximation by means of the Ditzian-Totik modulus of smoothness and a global appro... In this paper,we introduce the Bézier variant of two new families of generalized Bernstein type operators.We establish a direct approximation by means of the Ditzian-Totik modulus of smoothness and a global approximation theorem in terms of second order modulus of continuity.By means of construction of suitable functions and the method of Bojanic and Cheng,we give the rate of convergence for absolutely continuous functions having a derivative equivalent to a bounded variation function. 展开更多
关键词 Bernstein operators modulus of smoothness rate of convergence bounded variation
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Convergence of the q Analogue of Szász-Beta-Stancu Operators
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作者 Yang Xu Xiaomin Hu 《Analysis in Theory and Applications》 CSCD 2015年第1期45-57,共13页
In the present paper, we propose the q analogue of Szasz-Beta-Stancu operators. By estimate the moments, we establish direct results in terms of the modulus of smoothness. Investigate the rate of point-wise convergenc... In the present paper, we propose the q analogue of Szasz-Beta-Stancu operators. By estimate the moments, we establish direct results in terms of the modulus of smoothness. Investigate the rate of point-wise convergence and weighted approximation properties of the q operators. Voronovskaja type theorem is also obtained. Our results generalize and supplement some convergence results of the q-Szasz-Beta operators, thus they improve the existing results. 展开更多
关键词 q-Szasz-Beta operators q-analogues modulus of smoothness stancu weighted approximation.
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Weighted Approximation by Left Quasi-interpolants of Derivatives of Gamma Operators
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作者 JIANG HONG-BIAO 《Communications in Mathematical Research》 CSCD 2009年第4期289-298,共10页
In order to obtain much faster convergence, Miiller introduced the left Gamma quasi- interpolants and obtained an approximation equivalence theorem in terms of 2r wφ (f,t)p. Cuo extended the MiiUer's results to w... In order to obtain much faster convergence, Miiller introduced the left Gamma quasi- interpolants and obtained an approximation equivalence theorem in terms of 2r wφ (f,t)p. Cuo extended the MiiUer's results to wφ^24 (f, t)∞. In this paper we improve the previous results and give a weighted approximation equivalence theorem. 展开更多
关键词 Gamma operator quasi-interpolant weighted approximation modulus of smoothness derivative
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SIMULTANEOUS APPROXIMATION BY BERNSTEIN-SIKKEMA OPERATORS
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作者 Xuejiao Jiang Linsen Xie 《Analysis in Theory and Applications》 2008年第3期237-246,共10页
In this paper, we investigate the simultaneous approximation of Bernstein- Sikkema operators, and establish the direct and equivalent theorems by using the Ditzian-Totik modulus of smoothness.
关键词 Bernstein-Sikkema operator modulus of smoothness simultaneous approximation
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Approximation Theorems of Bernstein-Durrmeyer Operators in L_M^(Ba) Spaces
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作者 SUN Zhi-ling 《Chinese Quarterly Journal of Mathematics》 CSCD 2011年第3期400-404,共5页
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... 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. 展开更多
关键词 LBa M spaces Bernstein-Durrmeyer operators smoothness modulus
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Pointwise Approximation for the Iterated Boolean Sums of Bernstein Operators
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作者 HUO Xiao-yan LI Cui-xiang YAO Qiu-mei 《Chinese Quarterly Journal of Mathematics》 CSCD 2013年第1期129-138,共10页
In this paper, with the help of modulus of smoothness ω2r(f,t), we discuss the pointwise approximation properties for the iterated Boolean sums of Bernstein operator B n and obtain direct and inverse theorems when ... In this paper, with the help of modulus of smoothness ω2r(f,t), we discuss the pointwise approximation properties for the iterated Boolean sums of Bernstein operator B n and obtain direct and inverse theorems when 1-1/r ≤λ≤ 1, r ∈N. 展开更多
关键词 Bernstein operators the iterated Boolean sums modulus of smoothness
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Stechkin-Marchaud Type Inequalities in Lp for Linear Combination of Bernstein-Durrmeyer Operators
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作者 Feng Guo Meiqin Ke 《Open Journal of Applied Sciences》 2012年第4期228-232,共5页
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 ob... 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. 展开更多
关键词 BERNSTEIN-DURRMEYER operators linear combination K-FUNCTIONAL Stechkin-Marchaud-type inequalities modulus of smoothness
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Bernstein-Kantorovich算子的迭代布尔和的逼近性质 被引量:4
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作者 李翠香 任孟霞 《数学杂志》 CSCD 北大核心 2007年第1期105-110,共6页
本文利用光滑模及最佳逼近多项式的性质,研究了Bernstein-Kantorovich算子的迭代布尔和对Lp[0,1]中的函数的逼近性质,得到了逼近正定理,弱逆不等式及等价定理.
关键词 bernstein-kantorovich算子 光滑模 迭代布尔和
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在C(S)空间中多元的Bernstein-Kantorovich算子的正逆定理 被引量:2
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作者 李松 《数学物理学报(A辑)》 CSCD 北大核心 1997年第3期285-293,共9页
在C(S)空间中,对定义在单形上的Bernstein-Kantorovich算子Kn(f),给出了一个积分型估计式及一个弱型逆定理,得到了当0<α<1时,其中为定义在C(S)空间中的Ditzian-Totick光滑模[1].
关键词 B-K算子 光滑模 C(S)空间 正逆定理
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一类推广的Bernstein-Kantorovich算子的点态逼近 被引量:3
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作者 刘国芬 《纯粹数学与应用数学》 CSCD 2014年第1期32-39,共8页
讨论Bernstein-Kantorovich算子的一种推广形式的逼近性质,运用插项的方法证明了逼近正定理,并证明了逆定理,得到了逼近等价定理.完善了算子在逼近性质方面的结果.
关键词 bernstein-kantorovich型算子 光滑模 K-泛函 逼近正逆定理
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Bernstein-Kantorovich算子导数与光滑性
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作者 蒋红标 《吉首大学学报(自然科学版)》 CAS 2003年第1期68-70,共3页
借助于r-阶古典光滑模ωr(f,t),研究了Bernstein-Kantorovich算子导数与它所逼近函数光滑性之间的关系,得到了Bernstein-Kantorovich算子导数与r-阶古典光滑模ωr(f,t)的等价定理.
关键词 算子逼近 bernstein-kantorovich算子 r-阶古典光滑模 函数逼近 算子导数 光滑性
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L_p approximation by Bernstein-Kantorovich quasi-interpolants 被引量:1
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作者 LIU Li-xia SHI Ling GUO Shun-sheng 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2009年第2期200-208,共9页
Bernstein-Kantorovich quasi-interpolants K^(2r-1)n(f, x) are considered and direct, inverse and equivalence theorems with Ditzian-Totik modulus of smoothness ω^2rφ(f, t)p (1 ≤ p ≤+∞) are obtained.
关键词 quasi-interpolant bernstein-kantorovich operator Ditzian-Totik modulus
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二元Bernstein-Kantorovich算子在Orlicz空间的逼近
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作者 王孝斌 《宝鸡文理学院学报(自然科学版)》 CAS 2005年第2期91-93,共3页
讨论了二元Bernstein Kantorovich算子在Orlicz空间关于Ditizian Totik的逼近等价定理,从而改善了已有的结果。
关键词 二元Bernstein—Kantorovich算子 Ditizian—Totik光滑模 ORLICZ空间 逼近
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一般Gamma型算子在Orlicz空间内的逼近
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作者 刘倩 吴嘎日迪 《内蒙古师范大学学报(自然科学汉文版)》 CAS 2023年第6期601-605,共5页
讨论一般Gamma型算子在Orlicz空间内的逼近问题,由于Orlicz空间比连续函数空间和Lp空间“大”,范数结构也比Lp空间复杂,所以在Orlicz空间内研究Gamma算子的逼近问题具有一定的拓展性。借助Cauchy⁃Schwarz不等式、Jensen不等式、光滑模和... 讨论一般Gamma型算子在Orlicz空间内的逼近问题,由于Orlicz空间比连续函数空间和Lp空间“大”,范数结构也比Lp空间复杂,所以在Orlicz空间内研究Gamma算子的逼近问题具有一定的拓展性。借助Cauchy⁃Schwarz不等式、Jensen不等式、光滑模和N函数的凸性等,证明一般Gamma型算子在Orlicz空间内的有界性,给出该算子在Orlicz空间内的逼近正定理。 展开更多
关键词 Gamma型算子 光滑模 K泛函 ORLICZ空间
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学习理论中核函数逼近的Jackson型不等式
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作者 田明党 盛宝怀 《应用数学》 北大核心 2023年第4期903-914,共12页
从微分算子角度理解核函数空间,借助经典Fourier变换研究核函数逼近问题.应用Fourier乘子算子和算子半群定义了一种光滑模,证明其与一种基于微分算子的K-泛函的等价性,由此给出了刻画核函数逼近收敛性的Jackson不等式.进一步证明,如果... 从微分算子角度理解核函数空间,借助经典Fourier变换研究核函数逼近问题.应用Fourier乘子算子和算子半群定义了一种光滑模,证明其与一种基于微分算子的K-泛函的等价性,由此给出了刻画核函数逼近收敛性的Jackson不等式.进一步证明,如果微分算子为Riesz势算子或Bessel势算子,逼近的收敛性可以转化为卷积算子逼近.特别地,给出了再生核Hilbert空间逼近的一种上界估计. 展开更多
关键词 Jackson不等式 K-泛函 光滑模 再生核HILBERT空间 Riesz势算子 POISSON核 学习理论
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一类基于Pólya分布的修正Durrmeyer型算子的逼近
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作者 任美英 《武夷学院学报》 2023年第6期1-5,共5页
引进一类基于Pólya分布的修正Durrmeyer型算子,该算子具有常数保持与线性保持的性质。利用连续模、光滑模及K-泛函,讨论该算子的某些逼近性质,最后得出该算子的Voronovskaya型渐近公式。
关键词 修正Durrmeyer型算子 K-泛函 光滑模 逼近性质 Voronovskaya型渐近公式
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Beta算子加权逼近的点态结果 被引量:4
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作者 刘丽霞 许景彦 李翠香 《西南大学学报(自然科学版)》 CAS CSCD 北大核心 2007年第10期18-24,共7页
引入一种改变的带权K-泛函,利用带权光滑模和带权主部光滑模的关系及带权光滑模与改变的带权K-泛函的等价性,讨论了Beta算子的点态带Jacobi权逼近正定理及等价定理.
关键词 BETA算子 JACOBI权 光滑模 加权逼近
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