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ON CONSERVATIVE APPROXIMATION BY LINEAR POLYNOMIAL OPERATORS AN EXTENSION OF THE BERNSTEIN'S OPERATOR
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作者 Francisco-Javier Munoz-Delgado Victoriano Ramirez-Gonzalez Paul Sablonniere 《Analysis in Theory and Applications》 1995年第1期62-71,共10页
In this work we slwly linear polynomial operators preserving some consecutive i-convexities and leaving in-verant the polynomtals up to a certain degree. First we study the existence of an incompatibility between the ... In this work we slwly linear polynomial operators preserving some consecutive i-convexities and leaving in-verant the polynomtals up to a certain degree. First we study the existence of an incompatibility between the conservation of cenain i-cotivexities and the invariance of a space of polynomials. Interpolation properties are obtained and a theorem by Berens and DcVore about the Bernstein's operator ts extended. Finally, from these results a genera'ized Bernstein's operator is obtained. 展开更多
关键词 LPO ON CONSERVATIVE approximation BY linear POLYNOMIAL operatorS AN EXTENSION OF THE BERNSTEIN’S operator
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DIRECT LOCAL AND GLOBAL APPROXIMATION THEOREMS FOR SOME LINEAR POSITIVE OPERATORS
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作者 Zoltán Finta 《Analysis in Theory and Applications》 2004年第4期307-322,共16页
In this paper we establish direct local and global approximation theorems for Baskakov type operators and Szasz - Mirakjan type operators, respectively.
关键词 direct approximation theorem Baskakov type operator Szasz-Mirakjan type operator
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On the Finite-dimensional Optimal Approximations to the Infinite dimensional Linear Operators
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作者 张秀玲 《Chinese Quarterly Journal of Mathematics》 CSCD 1999年第3期96-102, ,共7页
A method of approaching to the infinite dimensional linear operators by the finite dimensional operators is discussed. It is shown that,for every infinite dimensional operator A and every natural number n, there exist... A method of approaching to the infinite dimensional linear operators by the finite dimensional operators is discussed. It is shown that,for every infinite dimensional operator A and every natural number n, there exists an n dimensional optimal approximation to A. The norm error is found and the necessary and sufficient condition for such n dimensional optimal approximations to be unique is obtained. 展开更多
关键词 Hilbert space linear operator optimal approximation
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ON APPROXIMATION OF SMOOTH FUNCTIONS FROM NULL SPACES OF OPTIMAL LINEAR DIFFERENTIAL OPERATORS WITH CONSTANT COEFFICIENTS
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作者 Vesselin Vatchev 《Analysis in Theory and Applications》 2011年第2期187-200,共14页
For a real valued function f defined on a finite interval I we consider the problem of approximating f from null spaces of differential operators of the form Ln(ψ) =∑k=0^n akψ(k) where the constant coefficients... For a real valued function f defined on a finite interval I we consider the problem of approximating f from null spaces of differential operators of the form Ln(ψ) =∑k=0^n akψ(k) where the constant coefficients ak C R may be adapted to f. 展开更多
关键词 approximation of analytic function differential operator fundamental set of solutions
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A New Class of Generalized Landau Linear Positive Operator Sequence and Its Properties of Approximation
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作者 陈湛本 石济民 《Chinese Quarterly Journal of Mathematics》 CSCD 1998年第1期29-43, ,共15页
In this paper two sequences of generalized Landau linear positive operators are introduced. They can be applied in approximating continuous functions with arbitrary growth order, defined on a finite interval or the wh... In this paper two sequences of generalized Landau linear positive operators are introduced. They can be applied in approximating continuous functions with arbitrary growth order, defined on a finite interval or the whole real axis. The properties of approximation are studied and their asymptotic formulae are presented. These results show that their degrees of approximation are the best among existing operator sequences of Landau type, for example, their degrees of approximation for C 2[0, 1] are O(1/n 2) but corresponding degree of ordinary Landau operators are only O(1/n). 展开更多
关键词 generalized Landau linear positive operators degree of approximation asymptotic formula
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Simultaneous Approximation by Baskakov-Durrmeyer Operator
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作者 齐秋兰 郭顺生 《Chinese Quarterly Journal of Mathematics》 CSCD 2001年第1期38-45,共8页
In this paper, we investigate the degree of approximation by Baskakov_Durrmeyer operator for functions which derivatives have only discontinuity points of the first kind on [0,∞) with exponential growth.
关键词 operatorS simultaneous approximation moduli of smoothness
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On n-K Width of Certain Function Classes Defined by Linear Differential Operators in L_2 Space
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作者 吴嘎日迪 包那 《Chinese Quarterly Journal of Mathematics》 CSCD 1999年第4期27-31, ,共5页
Let M(u) be an N function, A=D r+∑r-1k=0a k(x)D k a linear differential operator and W M(A) the Sobolev Orlicz class defined by M(u) and A. In this paper we give the asymptotic estimates... Let M(u) be an N function, A=D r+∑r-1k=0a k(x)D k a linear differential operator and W M(A) the Sobolev Orlicz class defined by M(u) and A. In this paper we give the asymptotic estimates of the n K width d n(W M(A),L 2[0,1]) . 展开更多
关键词 linear operator smooth function class WIDTH
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On n-K Width of Certain Function Classes Defined by Linear Differential Operators in L2 Space 被引量:2
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作者 吴嘎日迪 包那 《Chinese Quarterly Journal of Mathematics》 CSCD 1999年第4期27-31,共页
Let M(u) be an N function, A=D r+∑r-1k=0a k(x)D k a linear differential operator and W M(A) the Sobolev Orlicz class defined by M(u) and A. In this paper we give the asymptotic estimates... Let M(u) be an N function, A=D r+∑r-1k=0a k(x)D k a linear differential operator and W M(A) the Sobolev Orlicz class defined by M(u) and A. In this paper we give the asymptotic estimates of the n K width d n(W M(A),L 2[0,1]) . 展开更多
关键词 linear operator smooth function class WIDTH
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Carlson iterating rational approximation and performance analysis of fractional operator with arbitrary order 被引量:9
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作者 何秋燕 余波 袁晓 《Chinese Physics B》 SCIE EI CAS CSCD 2017年第4期66-74,共9页
The performance analysis of the generalized Carlson iterating process,which can realize the rational approximation of fractional operator with arbitrary order,is presented in this paper.The reasons why the generalized... The performance analysis of the generalized Carlson iterating process,which can realize the rational approximation of fractional operator with arbitrary order,is presented in this paper.The reasons why the generalized Carlson iterating function possesses more excellent properties such as self-similarity and exponential symmetry are also explained.K-index,P-index,O-index,and complexity index are introduced to contribute to performance analysis.Considering nine different operational orders and choosing an appropriate rational initial impedance for a certain operational order,these rational approximation impedance functions calculated by the iterating function meet computational rationality,positive reality,and operational validity.Then they are capable of having the operational performance of fractional operators and being physical realization.The approximation performance of the impedance function to the ideal fractional operator and the circuit network complexity are also exhibited. 展开更多
关键词 fractional calculus fractional operator generalized Carlson iterating process approximation error
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Operators of Approximations and Approximate Power Set Spaces 被引量:5
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作者 张贤勇 莫智文 舒兰 《Journal of Electronic Science and Technology of China》 CAS 2004年第2期94-96,共3页
Boundary inner and outer operators are introduced, and union, intersection, complement operators of approximations are redefined. The approximation operators have a good property of maintaining union, intersection, co... Boundary inner and outer operators are introduced, and union, intersection, complement operators of approximations are redefined. The approximation operators have a good property of maintaining union, intersection, complement operators, so the rough set theory has been enriched from the operator-oriented and set-oriented views. Approximate power set spaces are defined, and it is proved that the approximation operators are epimorphisms from power set space to approximate power set spaces. Some basic properties of approximate power set space are got by epimorphisms in contrast to power set space. 展开更多
关键词 rough sets approximation operators operators of approximations power set space approximate power set spaces
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Weighted approximation of functions with singularities by Bernstein operators 被引量:8
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作者 Bao-rong WEI Yi ZHAO 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2008年第10期1451-1456,共6页
As an important type of polynomial approximation, approximation of functions by Bernstein operators is an important topic in approximation theory and computational theory. This paper gives global and pointwise estimat... As an important type of polynomial approximation, approximation of functions by Bernstein operators is an important topic in approximation theory and computational theory. This paper gives global and pointwise estimates for weighted approximation of functions with singularities by Bernstein operators. The main results are the Jackson's estimates of functions f∈ (Wwλ)2 andre Cw, which extends the result of (Della Vecchia et al., 2004). 展开更多
关键词 Bemstein operators Functions with singularities Weighted approximation Pointwise estimates
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APPROXIMATION BY COMPLEX SZSZ-DURRMEYER OPERATORS IN COMPACT DISKS 被引量:3
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作者 Sorin G.GAL Vijay GUPTA 《Acta Mathematica Scientia》 SCIE CSCD 2014年第4期1157-1165,共9页
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 comp... 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. 展开更多
关键词 complex Szasz-Durrmeyer operators Voronovksaja type result exact order of approximation in compact disks simultaneous approximation
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A NEW PERTURBATION THEOREM FOR MOORE-PENROSE METRIC GENERALIZED INVERSE OF BOUNDED LINEAR OPERATORS IN BANACH SPACES 被引量:3
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作者 王紫 王玉文 《Acta Mathematica Scientia》 SCIE CSCD 2017年第6期1619-1631,共13页
In this paper, we investigate a new perturbation theorem for the Moore-Penrose metric generalized inverses of a bounded linear operator in Banach space. The main tool in this paper is "the generalized Neumann lemma"... In this paper, we investigate a new perturbation theorem for the Moore-Penrose metric generalized inverses of a bounded linear operator in Banach space. The main tool in this paper is "the generalized Neumann lemma" which is quite different from the method in [12] where "the generalized Banach lemma" was used. By the method of the perturba- tion analysis of bounded linear operators, we obtain an explicit perturbation theorem and three inequalities about error estimates for the Moore-Penrose metric generalized inverse of bounded linear operator under the generalized Neumann lemma and the concept of stable perturbations in Banach spaces. 展开更多
关键词 Banach space bounded linear operator metric projection generalized inverse perturbation analysis Moore-Penrose quasi-additive
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The construction and approximation of some neural networks operators 被引量:2
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作者 CHEN Zhi-xiang CAO Fei-long ZHAO Jian-wei 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2012年第1期69-77,共9页
In this paper, the technique of approximate partition of unity is used to construct a class of neural networks operators with sigmoidal functions. Using the modulus of continuity of function as a metric, the errors of... In this paper, the technique of approximate partition of unity is used to construct a class of neural networks operators with sigmoidal functions. Using the modulus of continuity of function as a metric, the errors of the operators approximating continuous functions defined on a compact interval are estimated. Furthmore, Bochner-Riesz means operators of double Fourier series are used to construct networks operators for approximating bivariate functions, and the errors of approximation by the operators are estimated. 展开更多
关键词 approximation sigmoidal function neural network operator Bochner-Riesz mean.
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DEGREE OF APPROXIMATION ASSOCIATED WITH SOME ELLIPTIC OPERATORS AND ITS APPLICATIONS 被引量:8
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作者 Xinlong Zhou(University of Duisburg, Germany) 《Analysis in Theory and Applications》 1995年第2期9-29,共21页
The Jackson-type estimates by using some elliptic operators will be achieved. These results will be used to characterize the regularity of some elliptic operators by means of the approximation degree and the saturatio... The Jackson-type estimates by using some elliptic operators will be achieved. These results will be used to characterize the regularity of some elliptic operators by means of the approximation degree and the saturation class of the multivariate Bernstein operators as well. 展开更多
关键词 DEGREE OF approximation ASSOCIATED WITH SOME ELLIPTIC operatorS AND ITS APPLICATIONS II ITS
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Linear goal programming approach to obtaining the weights of intuitionistic fuzzy ordered weighted averaging operator 被引量:3
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作者 Yejun Xu Chao Huang +1 位作者 Qingli Da Xinwang Liu 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2010年第6期990-994,共5页
The multiple attribute decision making problems are studied, in which the information about attribute weights is partly known and the attribute values take the form of intuitionistic fuzzy numbers. The operational law... The multiple attribute decision making problems are studied, in which the information about attribute weights is partly known and the attribute values take the form of intuitionistic fuzzy numbers. The operational laws of intuitionistic fuzzy numbers are introduced, and the score function and accuracy function are presented to compare the intuitionistic fuzzy numbers. The intuitionistic fuzzy ordered weighted averaging (IFOWA) operator which is an extension of the well-known ordered weighted averaging (OWA) operator is investigated to aggregate the intuitionistic fuzzy information. In order to determine the weights of intuitionistic fuzzy ordered weighted averaging operator, a linear goal programming procedure is proposed for learning the weights from data. Finally, an example is illustrated to verify the effectiveness and practicability of the developed method. 展开更多
关键词 intuitionistic fuzzy set intuitionistic fuzzy ordered weighted averaging(IFOWA) operator linear goal programming WEIGHTS multiple attribute decision making(MADM).
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ONE LINEAR ANALYTIC APPROXIMATION FOR STOCHASTIC INTEGRODIFFERENTIAL EQUATIONS 被引量:1
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作者 Svetlana Jankovic Dejan Ilic 《Acta Mathematica Scientia》 SCIE CSCD 2010年第4期1073-1085,共13页
This article concerns the construction of approximate solutions for a general stochastic integrodifferential equation which is not explicitly solvable and whose coeffcients functionally depend on Lebesgue integrals an... This article concerns the construction of approximate solutions for a general stochastic integrodifferential equation which is not explicitly solvable and whose coeffcients functionally depend on Lebesgue integrals and stochastic integrals with respect to martingales. The approximate equations are linear ordinary stochastic differential equations, the solutions of which are defined on sub-intervals of an arbitrary partition of the time interval and connected at successive division points. The closeness of the initial and approximate solutions is measured in the L^p-th norm, uniformly on the time interval. The convergence with probability one is also given. 展开更多
关键词 Stochastic integrodifferential equation linear approximation approximate solution L^p-convergence convergence with probability one
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ASYMPTOTIC APPROXIMATION OF FUNCTIONS AND THEIR DERIVATIVES BY GENERALIZED BASKAKOV-SZAZS-DURRMEYER OPERATORS 被引量:1
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作者 Ulrich Abel Vijay Gupta Mircea Ivan 《Analysis in Theory and Applications》 2005年第1期15-26,共12页
We present the complete asymptotic expansion for a generalization of the Baskakov-Szasz-Durrmeyer operators and their derivatives.
关键词 approximation by positive operators rate of convergence degree of approximation asymptotic expansion Stirling numbers
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BEST APPROXIMATION FOR WEIERSTRASS TRANSFORM CONNECTED WITH SPHERICAL MEAN OPERATOR 被引量:1
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作者 L.T.Rachdi N.Msehli 《Acta Mathematica Scientia》 SCIE CSCD 2012年第2期455-470,共16页
Using reproducing kernels for Hilbert spaces, we give best approximation for Weierstrass transform associated with spherical mean operator. Also, estimates of extremal functions are checked.
关键词 Weierstrass transform spherical mean operator best approximation repro-ducing kernel extremal function
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EQUIVALENT THEOREMS ON SIMULTANEOUS APPROXIMATION BY COMBINATIONS OF BERNSTEIN OPERATORES 被引量:1
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作者 Li Cheng Linsen Xie 《Analysis in Theory and Applications》 2006年第3期246-253,共8页
In this paper we give equivalent theorems on simultaneous approximation for the combinations of Bernstein operators by r-th Ditzian- Totik modulus of smoothness w^rφλ (f, t)(0 ≤ λ≤ 1). We also investigate th... In this paper we give equivalent theorems on simultaneous approximation for the combinations of Bernstein operators by r-th Ditzian- Totik modulus of smoothness w^rφλ (f, t)(0 ≤ λ≤ 1). We also investigate the relation between the derivatives of the combinations of Bernstein operators and the smoothness of derivatives of functions. 展开更多
关键词 Bernstein operators COMBINATION simultaneous approximation moduli of smoothness
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