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OVERCONVERGENCE AND ZEROS OF SEQUENCES OF RATIONAL FUNCTIONS 被引量:1
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作者 M.Simkani 《Analysis in Theory and Applications》 1993年第4期9-20,共12页
In the present paper we consider sequences of rational functions with a bounded number or free poles con- verging uniformly with a maximum geometric rate to a holomorphic function on a regular set,and we examine the l... In the present paper we consider sequences of rational functions with a bounded number or free poles con- verging uniformly with a maximum geometric rate to a holomorphic function on a regular set,and we examine the limiting distribution of the Zeros and its relations with the phenomenon of overconvergence.Our results further extend the well known classical theory of overconvergence and the zeros of sections of Taylor series. 展开更多
关键词 OVERCONVERGENCE AND ZEROS OF SEQUENCES OF rational functions
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Copositive approximation by rational functions with prescribed numerator degree
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作者 YU Dan-sheng ZHOU Song-ping 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2009年第4期411-416,共6页
The paper proves that, if f(x) ∈ L^p[-1,1],1≤p〈∞ ,changes sign I times in (-1, 1),then there exists a real rational function r(x) ∈ Rn^(2μ-1)l which is eopositive with f(x), such that the following Ja... The paper proves that, if f(x) ∈ L^p[-1,1],1≤p〈∞ ,changes sign I times in (-1, 1),then there exists a real rational function r(x) ∈ Rn^(2μ-1)l which is eopositive with f(x), such that the following Jackson type estimate ||f-r||p≤Cδl^2μωφ(f,1/n)p holds, where μ is a natural number ≥3/2+1/p, and Cδ is a positive constant depending only on δ. 展开更多
关键词 copositive approximation rational functions approximation rate
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PADE APPROXIMANTS AS LIMITS OF RATIONAL FUNCTIONS OF BEST APPROXIMATION IN ORLICZ SPACE
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作者 Li Jialiang Central China Normal University, China Department of Mathematics Central Normal University 《Analysis in Theory and Applications》 1994年第2期74-82,共9页
In this paper, we prove that the best rational approximation of a given analytic function in Orlicz space L~*(G), where G = {|z|≤∈}, converges to the Pade approximants of the function as the measure of G approaches ... In this paper, we prove that the best rational approximation of a given analytic function in Orlicz space L~*(G), where G = {|z|≤∈}, converges to the Pade approximants of the function as the measure of G approaches zero. 展开更多
关键词 rational MATH PADE APPROXIMANTS AS LIMITS OF rational functions OF BEST APPROXIMATION IN ORLICZ SPACE AS
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APPROXIMATION BY FABER-LAURENT RATIONAL FUNCTIONS IN THE MEAN OF FUNCTIONS OF CLASS LP(T) WITH 1
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作者 A. Cavus D. M. Israfilov 《Analysis in Theory and Applications》 1995年第1期105-118,共14页
Let Γ be a regular curve and Lp (Γ), 1<p<+∞. be the class of all complex - valued functions f de-fined on Γ which are such that |f|p is mtegrabie in sense of Lebesgue. In this work, we define the k th p-Fabc... Let Γ be a regular curve and Lp (Γ), 1<p<+∞. be the class of all complex - valued functions f de-fined on Γ which are such that |f|p is mtegrabie in sense of Lebesgue. In this work, we define the k th p-Fabcrpolynomial F k,p (z),the kth p-Faber principle part F k.p (1/z) for Γ , and defined the nth p-Fcber- Laurent rational function Rn.p (f, z) and p- generalized modulus of continuity Ωp(f, t) of a function f of Lp(Γ) We inves-tigate some properties of Fk,p (z) and Fk.p (1/z). And then we prove a direct theorem characterizing the degree of approximation with respect to Ω (. , t) in the mean of functions of Lp(Γ) by the rational junctions Rn.p (. . z). 展开更多
关键词 APPROXIMATION BY FABER-LAURENT rational functions IN THE MEAN OF functions OF CLASS LP WITH 1 rational
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RATIONAL FUNCTIONS OF BEST UNIFORM APPROXIMATION AND HOLOMORPHIC CONTINUATION OF FUNCTIONS
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作者 I.V.Ivanov R.K.Kovacheva J.Gilewicz 《Analysis in Theory and Applications》 1996年第1期1-9,共9页
Let f be a function, continuous and real valued on the segment △,△ (-∞,∞) and {Rn} be the sequence of the rational functions of best uniform approximation to fon △ of order (n,n). In the present work, the converg... Let f be a function, continuous and real valued on the segment △,△ (-∞,∞) and {Rn} be the sequence of the rational functions of best uniform approximation to fon △ of order (n,n). In the present work, the convergence of {Rn} in the complex plane is considered for the special caseswhen the poles (or the zeros, respectively) of {Rn} accumulate in the terms of weak convergence of measures to acompact set of zera capacity.As a consequence, sufficient conditions for the holomorphic and the meromorphic continuability of fare given. 展开更多
关键词 rational functions OF BEST UNIFORM APPROXIMATION AND HOLOMORPHIC CONTINUATION OF functions
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TETRAHEDRAL C^m INTERPOLATION BY RATIONAL FUNCTIONS
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作者 Guo-liang Xu Chuan I Chu Wei-min Xue 《Journal of Computational Mathematics》 SCIE EI CSCD 2001年第2期131-138,共8页
A general local C-m(m greater than or equal to 0) tetrahedral interpolation scheme by polynomials of degree 4m + 1 plus low order rational functions from the given data is proposed. The scheme can have either 4m + 1 o... A general local C-m(m greater than or equal to 0) tetrahedral interpolation scheme by polynomials of degree 4m + 1 plus low order rational functions from the given data is proposed. The scheme can have either 4m + 1 order algebraic precision if C-2m data at vertices and C-m data on faces are given or k + E[k/3] + 1 order algebraic precision if C-k (k less than or equal to 2m) data are given at vertices. The resulted interpolant and its partial derivatives of up to order m are polynomials on the boundaries of the tetrahedra. 展开更多
关键词 C-m interpolation rational functions TETRAHEDRA
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Determination of the limits for multivariate rational functions
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作者 XIAO ShuiJing ZENG GuangXing 《Science China Mathematics》 SCIE 2014年第2期397-416,共20页
The purpose of this paper is to solve the problem of determining the limits of multivariate rational functions.It is essential to decide whether or not limxˉ→0f g=0 for two non-zero polynomials f,g∈R[x1,...,xn]with... The purpose of this paper is to solve the problem of determining the limits of multivariate rational functions.It is essential to decide whether or not limxˉ→0f g=0 for two non-zero polynomials f,g∈R[x1,...,xn]with f(0,...,0)=g(0,...,0)=0.For two such polynomials f and g,we establish two necessary and sufcient conditions for the rational functionf g to have its limit 0 at the origin.Based on these theoretic results,we present an algorithm for deciding whether or not lim(x1,...,xn)→(0,...,0)f g=0,where f,g∈R[x1,...,xn]are two non-zero polynomials.The design of our algorithm involves two existing algorithms:one for computing the rational univariate representations of a complete chain of polynomials,another for catching strictly critical points in a real algebraic variety.The two algorithms are based on the well-known Wu’s method.With the aid of the computer algebraic system Maple,our algorithm has been made into a general program.In the final section of this paper,several examples are given to illustrate the efectiveness of our algorithm. 展开更多
关键词 rational function limit infinitesimal element strictly critical point rational univariate represen-tation (RUR) Wu's method transfer principle
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Approximation Properties of Newman Type Interpolation Rational Functions with Fewer Nodes
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作者 Laiyi Zhu Xingjun Zhao 《Analysis in Theory and Applications》 CSCD 2023年第4期378-384,共7页
In the present note,we consider the problem:how many interpolation nodes can be deleted from the Newman-type rational function such that the convergence rate still achieve.
关键词 rational function approximation Newman-type rational approximation interpolation nodes convergence rate
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Multivariate Rational Response Surface Approximation of Nodal Displacements of Truss Structures 被引量:1
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作者 Shan Chai Xiang-Fei Ji +1 位作者 Li-Jun Li Ming Guo 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2018年第1期100-113,共14页
Polynomial-basis response surface method has some shortcomings for truss structures in structural optimization,concluding the low fitting accuracy and the great computational effort. Based on the theory of approximati... Polynomial-basis response surface method has some shortcomings for truss structures in structural optimization,concluding the low fitting accuracy and the great computational effort. Based on the theory of approximation, a response surface method based on Multivariate Rational Function basis(MRRSM) is proposed. In order to further reduce the computational workload of MRRSM, focusing on the law between the cross-sectional area and the nodal displacements of truss structure, a conjecture that the determinant of the stiffness matrix and the corresponding elements of adjoint matrix involved in displacement determination are polynomials with the same order as their respective matrices, each term of which is the product of cross-sectional areas, is proposed. The conjecture is proved theoretically for statically determinate truss structure, and is shown corrected by a large number of statically indeterminate truss structures. The theoretical analysis and a large number of numerical examples show that MRRSM has a high fitting accuracy and less computational effort. Efficiency of the structural optimization of truss structures would be enhanced. 展开更多
关键词 Multivariate rational function Response surfaces method Truss structures Structure optimization
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Optimization for ASP flooding based on adaptive rationalized Haar function approximation
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作者 Yulei Ge Shurong Li Xiaodong Zhang 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2018年第8期1758-1765,共8页
This paper presents an adaptive rationalized Haar function approximation method to obtain the optimal injection strategy for alkali-surfactant-polymer(ASP) flooding. In this process, the non-uniform control vector par... This paper presents an adaptive rationalized Haar function approximation method to obtain the optimal injection strategy for alkali-surfactant-polymer(ASP) flooding. In this process, the non-uniform control vector parameterization is introduced to convert original problem into a multistage optimization problem, in which a new normalized time variable is adopted on the combination of the subinterval length. Then the rationalized Haar function approximation method, in which an auxiliary function is introduced to dispose path constraints, is used to transform the multistage problem into a nonlinear programming. Furthermore, an adaptive strategy proposed on the basis of errors is adopted to regulate the order of Haar function vectors. Finally, the nonlinear programming for ASP flooding is solved by sequential quadratic programming. To illustrate the performance of proposed method,the experimental comparison method and control vector parameterization(CVP) method are introduced to optimize the original problem directly. By contrastive analysis of results, the accuracy and efficiency of proposed method are confirmed. 展开更多
关键词 Alkali-surfactant-polymer flooding OPTIMIZATION Enhanced oil recovery Mathematical modeling rationalized Haar function approximation Adaptive strategy
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THE ASYMPTOTIC FORMULA OF THE ORTHOGONAL RATIONAL FUNCTION ON THE UNIT CIRCLE
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作者 Zhu Laiyi People’s Universityy of China, China 《Analysis in Theory and Applications》 1993年第2期24-36,共13页
In this paper we obtained the asymptotic formula of the orthogonal rational function on the unit circle with respect to the weight function μ(z) with preasigned poles, which are in the exterior of the unit disk.
关键词 PRO rational THE ASYMPTOTIC FORMULA OF THE ORTHOGONAL rational FUNCTION ON THE UNIT CIRCLE 六丁
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New Extended Jacobi Elliptic Function Rational Expansion Method and Its Application
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作者 ZHENG Ying ZHANG Yuan-Yuan ZHANG Hong-Qing 《Communications in Theoretical Physics》 SCIE CAS CSCD 2006年第1X期5-9,共5页
In this paper, an extended Jacobi elliptic function rational expansion method is proposed for constructing new forms of exact Jacobi elliptic function solutions to nonlinear partial differential equations by means of ... In this paper, an extended Jacobi elliptic function rational expansion method is proposed for constructing new forms of exact Jacobi elliptic function solutions to nonlinear partial differential equations by means of making a more general transformation. For illustration, we apply the method to the (2+1)-dimensional dispersive long wave equation and successfully obtain many new doubly periodic solutions, which degenerate as soliton solutions when the modulus m approximates 1. The method can also be applied to other nonlinear partial differential equations. 展开更多
关键词 extended Jacobi elliptic function rational expansion method rational formal Jacobi elliptic function solution (2+1)-dimensional dispersive long wave equation
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Extended Jacobi Elliptic Function Rational Expansion Method and Its Application to (2+1)-Dimensional Stochastic Dispersive Long Wave System
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作者 SONG Li-Na ZHANG Hong-Qing 《Communications in Theoretical Physics》 SCIE CAS CSCD 2007年第6期969-974,共6页
In this work, by means of a generalized method and symbolic computation, we extend the Jacobi elliptic function rational expansion method to uniformly construct a series of stochastic wave solutions for stochastic evo... In this work, by means of a generalized method and symbolic computation, we extend the Jacobi elliptic function rational expansion method to uniformly construct a series of stochastic wave solutions for stochastic evolution equations. To illustrate the effectiveness of our method, we take the (2+ 1)-dimensional stochastic dispersive long wave system as an example. We not only have obtained some known solutions, but also have constructed some new rational formal stochastic Jacobi elliptic function solutions. 展开更多
关键词 stochastic evolution equations (2+ 1)-dimensional stochastic dispersive long wave system rational formal stochastic Jacobi elliptic function solutions
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Polynomial Functions Composed of Terms with Non-Integer Powers
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作者 Serdar Beji 《Advances in Pure Mathematics》 2021年第10期791-806,共16页
Polynomial functions containing terms with non-integer powers are studied to disclose possible approaches for obtaining their roots as well as employing them for curve-fitting purposes. Several special cases represent... Polynomial functions containing terms with non-integer powers are studied to disclose possible approaches for obtaining their roots as well as employing them for curve-fitting purposes. Several special cases representing equations from different categories are investigated for their roots. Curve-fitting applications to physically meaningful data by the use of fractional functions are worked out in detail. Relevance of this rarely worked subject to solutions of fractional differential equations is pointed out and existing potential in related future work is emphasized. 展开更多
关键词 rational Irrational Imaginary and Transcendental Powers Roots of functions with Variables of Non-Integer Powers Curve-Fitting by functions Incorporating Terms with rational Powers Fractional Differential Equations
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MATCHING PURSUITS AMONG SHIFTED CAUCHY KERNELS IN HIGHER-DIMENSIONAL SPACES 被引量:2
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作者 钱涛 王晋勋 杨燕 《Acta Mathematica Scientia》 SCIE CSCD 2014年第3期660-672,共13页
Appealing to the Clifford analysis and matching pursuits, we study the adaptive decompositions of functions of several variables of finite energy under the dictionaries consisting of shifted Cauchy kernels. This is a ... Appealing to the Clifford analysis and matching pursuits, we study the adaptive decompositions of functions of several variables of finite energy under the dictionaries consisting of shifted Cauchy kernels. This is a realization of matching pursuits among shifted Cauchy kernels in higher-dimensional spaces. It offers a method to process signals in arbitrary dimensions. 展开更多
关键词 Hardy space MONOGENIC adaptive decomposition DICTIONARY matching pursuit optimal approximation by rational functions
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A Complete Field of Meromorphic Function
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作者 Elhadi E. E. Dalam Ahmed M. Ibrahim 《Advances in Pure Mathematics》 2021年第2期138-148,共11页
In any completely close complex field C, generalized transcendental meromorphic functions may have some new properties. It is well known that a meromorphic function of characteristic zero is a rational function. This ... In any completely close complex field C, generalized transcendental meromorphic functions may have some new properties. It is well known that a meromorphic function of characteristic zero is a rational function. This paper introduced some mathematical properties of the transcendental meromorphic function, which is generalized to the meromorphic function by multiplying and differentiating the generalized meromorphic function. The analysis shows that the difference between any non-zero constant and the derivative of the general meromorphic function has an infinite zero. In addition, for any natural number n, there are no practically exceptional values for the multiplication of the general meromorphic function and its derivative to the power of n. 展开更多
关键词 Meromorphic functions Unit Disk rational functions
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Abundant different types of exact soliton solution to the (4+1)-dimensional Fokas and (2+1)-dimensional breaking soliton equations 被引量:2
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作者 Sachin Kumar Monika Niwas +1 位作者 M S Osman M A Abdou 《Communications in Theoretical Physics》 SCIE CAS CSCD 2021年第10期64-80,共17页
The prime objective of this paper is to explore the new exact soliton solutions to the higher-dimensional nonlinear Fokas equation and(2+1)-dimensional breaking soliton equations via a generalized exponential rational... The prime objective of this paper is to explore the new exact soliton solutions to the higher-dimensional nonlinear Fokas equation and(2+1)-dimensional breaking soliton equations via a generalized exponential rational function(GERF) method. Many different kinds of exact soliton solution are obtained, all of which are completely novel and have never been reported in the literature before. The dynamical behaviors of some obtained exact soliton solutions are also demonstrated by a choice of appropriate values of the free constants that aid in understanding the nonlinear complex phenomena of such equations. These exact soliton solutions are observed in the shapes of different dynamical structures of localized solitary wave solutions, singular-form solitons, single solitons,double solitons, triple solitons, bell-shaped solitons, combo singular solitons, breather-type solitons,elastic interactions between triple solitons and kink waves, and elastic interactions between diverse solitons and kink waves. Because of the reduction in symbolic computation work and the additional constructed closed-form solutions, it is observed that the suggested technique is effective, robust, and straightforward. Moreover, several other types of higher-dimensional nonlinear evolution equation can be solved using the powerful GERF technique. 展开更多
关键词 nonlinear evolution equations soliton solutions exact solutions generalized exponential rational function method solitary waves
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Accuracy improvement of geometric correction for CHRIS data
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作者 WANG Dian-zhong PANG Yong GUO Zhi-feng 《Journal of Forestry Research》 SCIE CAS CSCD 2008年第3期260-262,共3页
This paper deals with a new type of multi-angle remotely sensed data--CHRIS(the Compact High Resolution Imaging Spec-trometer),by using rational function models(RFM)and rigorous sensor models(RSM).For ortho-rectifying... This paper deals with a new type of multi-angle remotely sensed data--CHRIS(the Compact High Resolution Imaging Spec-trometer),by using rational function models(RFM)and rigorous sensor models(RSM).For ortho-rectifying an image set,a rigorous sen-sor model-Toutin's model was employed and a set of reported parameters including across track angle,along track angle,IFOV,altitude,period,eccentricity and orbit inclination were input,then,the orbit calculation was started and the track information was given to the raw data.The images were ortho-rectified with geocoded ASTER images and digital elevation(DEM)data.Results showed that with 16 ground control points(GCPs),the correction accuracy decreased with view zenith angle,and the RMSE value increased to be over one pixel at 36 degree off-nadir.When the GCPs were approximately chosen as in Toutin's model,a RFM with three coefficients produced the same accuracy trend versus view zenith angle while the RMSEs for all angles were improved and within about one pixel. 展开更多
关键词 CHRIS ortho-rectify rigorous sensor model rational function model
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On dynamical behavior for optical solitons sustained by the perturbed Chen–Lee–Liu model
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作者 Sibel Tarla Karmina K Ali +1 位作者 Resat Yilmazer M S Osman 《Communications in Theoretical Physics》 SCIE CAS CSCD 2022年第7期41-48,共8页
This study investigates the perturbed Chen–Lee–Liu model that represents the propagation of an optical pulse in plasma and optical fiber.The generalized exponential rational function method is used for this purpose.... This study investigates the perturbed Chen–Lee–Liu model that represents the propagation of an optical pulse in plasma and optical fiber.The generalized exponential rational function method is used for this purpose.As a result,we obtain some non-trivial solutions such as the optical singular,periodic,hyperbolic,exponential,trigonometric soliton solutions.We aim to express the pulse propagation of the generated solutions,by taking specific values for the free parameters existed in the obtained solutions.The obtained results show that the generalized exponential rational function technique is applicable,simple and effective to get the solutions of nonlinear engineering and physical problems.Moreover,the acquired solutions display rich dynamical evolutions that are important in practical applications. 展开更多
关键词 perturbed Chen-Lee-Liu model generalized exponential rational function method analytical solutions
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AN EDGE CRACK PROBLEM IN A SEMI-INFINITE PLANE SUBJECTED TO CONCENTRATED FORCES
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作者 CHEN Yi-zhou(陈宜周) +1 位作者 Norio Hasebe(长谷部宣男) 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2001年第11期1279-1290,共12页
An oblique edge crack problem in a semi-infinite plane is discussed. Re concentrated forces are applied on the edge crack face, or on the line boundary of the cracked semi-infinite plane. The rational mapping function... An oblique edge crack problem in a semi-infinite plane is discussed. Re concentrated forces are applied on the edge crack face, or on the line boundary of the cracked semi-infinite plane. The rational mapping function approach is suggested to solve the boundary value problem and a solution in a closed form is obtained. Finally, several numerical examples with the calculated results are given. 展开更多
关键词 rational mapping function approach edge crack problem stress intensity factor
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