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Unimodality of Independence Polynomials of Rooted Products of a Kind of Tree
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作者 XIE Yuan ZHANG Xiaoqian 《数学理论与应用》 2025年第2期53-75,共23页
In 1987,Alavi,Malde,Schwenk and Erdős conjectured that the independence polynomial of any tree or forest is unimodal.Although many researchers have been attracted by it,it is still open.Inspired by this conjecture,in ... In 1987,Alavi,Malde,Schwenk and Erdős conjectured that the independence polynomial of any tree or forest is unimodal.Although many researchers have been attracted by it,it is still open.Inspired by this conjecture,in this paper,we prove that rooted products of some trees preserve real-rootedness of independence polynomials.In particular,we can obtain that their independence polynomials are unimodal and log-concave. 展开更多
关键词 Independence polynomial UNIMODALITY Claw-free graph
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Uniqueness Results for Meromorphic Functions Involving Differential-Difference Polynomials and Shared Values
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作者 Hongyan XU Rana MONDAL Imrul KAISH 《Journal of Mathematical Research with Applications》 2025年第3期304-328,共25页
Throughout this work,we explore the uniqueness properties of meromorphic functions concerning their interactions with complex differential-difference polynomial.Under the condition of finite order,we establish three d... Throughout this work,we explore the uniqueness properties of meromorphic functions concerning their interactions with complex differential-difference polynomial.Under the condition of finite order,we establish three distinct uniqueness results for a meromorphic function f associated with the differential-difference polynomial L_(η)^(n)f=Σ_(k=0)^(n)a_(k)f (z+k_(η))+a_(-1)f′.These results lead to a refined characterization of f (z)≡L_(η)^(n)f (z).Several illustrative examples are provided to demonstrate the sharpness and precision of the results obtained in this study. 展开更多
关键词 meromorphic function differential-difference polynomials Nevanlinna theory UNIQUENESS value sharing
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Robust Stability Analysis of Edge Polynomials with Variable Length 被引量:1
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作者 伍清河 《Journal of Beijing Institute of Technology》 EI CAS 2002年第1期24-28,共5页
The concept of edge polynomials with variable length is introduced. Stability of such polynomials is analyzed. Under the condition that one extreme of the edge is stable, the stability radius of edge polynomials with ... The concept of edge polynomials with variable length is introduced. Stability of such polynomials is analyzed. Under the condition that one extreme of the edge is stable, the stability radius of edge polynomials with variable length is characterized in terms of the real spectral radius of the matrix H -1 ( f 0) H (g) , where both H (f 0) and H (g) are Hurwitz like matrices. Based on this result, stability radius of control systems with interval type plants and first order controllers are determined. 展开更多
关键词 robust stability edge polynomial Hurwitz matrix
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Coefficient Multipliers for Polynomials
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作者 申大维 《Journal of Beijing Institute of Technology》 EI CAS 2001年第2期113-118,共6页
Let Q n denote the class of all polynomials p(z) nonvanishing in the unit disk with deg p≤n and p (0)=1, and let W n denote the class of all polynomials s(z) satisfying deg s≤n and for all... Let Q n denote the class of all polynomials p(z) nonvanishing in the unit disk with deg p≤n and p (0)=1, and let W n denote the class of all polynomials s(z) satisfying deg s≤n and for all p∈Q n, s*p∈Q n , where * denotes the Hadamard product. Some properties for W n and Q n are obtained. 展开更多
关键词 polynomials COEFFICIENTS MULTIPLIERS
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On the Coefficients of Polynomials with Positive Real Part in the Unit Disk
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作者 申大维 《Journal of Beijing Institute of Technology》 EI CAS 1995年第2期110+106-110,共6页
Let Q be the class of real coefficient polynomials of degree 2 with positive real part in the unit disk and constant term equal to 1. aam coefficient region of polynomials in Q is found and some sharp coefficient esti... Let Q be the class of real coefficient polynomials of degree 2 with positive real part in the unit disk and constant term equal to 1. aam coefficient region of polynomials in Q is found and some sharp coefficient estimates for the polynomials with positive real part in the unit disk are established in this paper. 展开更多
关键词 polynomials coefficients/positive real part SUBORDINATION
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A comparison of piecewise cubic Hermite interpolating polynomials,cubic splines and piecewise linear functions for the approximation of projectile aerodynamics 被引量:5
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作者 C.A.Rabbath D.Corriveau 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2019年第5期741-757,共17页
Modelling and simulation of projectile flight is at the core of ballistic computer software and is essential to the study of performance of rifles and projectiles in various engagement conditions.An effective and repr... Modelling and simulation of projectile flight is at the core of ballistic computer software and is essential to the study of performance of rifles and projectiles in various engagement conditions.An effective and representative numerical model of projectile flight requires a relatively good approximation of the aerodynamics.The aerodynamic coefficients of the projectile model should be described as a series of piecewise polynomial functions of the Mach number that ideally meet the following conditions:they are continuous,differentiable at least once,and have a relatively low degree.The paper provides the steps needed to generate such piecewise polynomial functions using readily available tools,and then compares Piecewise Cubic Hermite Interpolating Polynomial(PCHIP),cubic splines,and piecewise linear functions,and their variant,as potential curve fitting methods to approximate the aerodynamics of a generic small arms projectile.A key contribution of the paper is the application of PCHIP to the approximation of projectile aerodynamics,and its evaluation against a set of criteria.Finally,the paper provides a baseline assessment of the impact of the polynomial functions on flight trajectory predictions obtained with 6-degree-of-freedom simulations of a generic projectile. 展开更多
关键词 Aerodynamic coefficients PIECEWISE polynomiAL FUNCTIONS CUBIC splines Curve fitting PIECEWISE linear FUNCTIONS PIECEWISE CUBIC HERMITE interpolating polynomiAL PROJECTILE modelling and simulation Fire control inputs Precision Ballistic computer software
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ON PROPERTIES OF DIFFERENCE POLYNOMIALS 被引量:6
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作者 陈宗煊 黄志波 郑秀敏 《Acta Mathematica Scientia》 SCIE CSCD 2011年第2期627-633,共7页
We study the value distribution of difference polynomials of meromorphic functions, and extend classical theorems of Tumura-Clunie type to difference polynomials. We also consider the value distribution of f(z)f(z ... We study the value distribution of difference polynomials of meromorphic functions, and extend classical theorems of Tumura-Clunie type to difference polynomials. We also consider the value distribution of f(z)f(z + c). 展开更多
关键词 Difference polynomial Tumura-Clunie theorem value distribution.
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The Factorization of Adjoint Polynomials of E^G(i)-class Graphs and Chromatically Equivalence Analysis 被引量:15
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作者 ZHANG Bing-ru YANG Ji-ming 《Chinese Quarterly Journal of Mathematics》 CSCD 北大核心 2008年第3期376-383,共8页
Let Sn be the star with n vertices, and let G be any connected graph with p vertices. We denote by Eτp+(r-1)^G(i) the graph obtained from Sr and rG by coinciding the i-th vertex of G with the vertex of degree r ... Let Sn be the star with n vertices, and let G be any connected graph with p vertices. We denote by Eτp+(r-1)^G(i) the graph obtained from Sr and rG by coinciding the i-th vertex of G with the vertex of degree r - 1 of S,, while the i-th vertex of each component of (r - 1)G be adjacented to r - 1 vertices of degree 1 of St, respectively. By applying the properties of adjoint polynomials, We prove that factorization theorem of adjoint polynomials of kinds of graphs Eτp+(r-1)^G(i)∪(r - 1)K1 (1 ≤i≤p). Furthermore, we obtain structure characteristics of chromatically equivalent graphs of their complements. 展开更多
关键词 chromatic polynomial adjoint polynomials FACTORIZATION chromatically equivalent graph structure characteristics
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Some Results Concerning Growth of Polynomials 被引量:3
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作者 Ahmad Zireh E.Khojastehnejhad S.R.Musawi 《Analysis in Theory and Applications》 2013年第1期37-46,共10页
Let P(z) be a polynomial of degree n having no zeros in |z|〈 1, then for every real or complex number β with |β|≤ 1, and |z| = 1, R ≥ 1, it is proved by Dewan et al. [4] that|P(Rz)+β(R+1/2)^nP(z... Let P(z) be a polynomial of degree n having no zeros in |z|〈 1, then for every real or complex number β with |β|≤ 1, and |z| = 1, R ≥ 1, it is proved by Dewan et al. [4] that|P(Rz)+β(R+1/2)^nP(z)|≤1/2{(|R^n+β(R+1/2)^n|+|1+β(R+1/2)^n|max|z|=1|P(z)| -(|R^n+β(R+1/2)^n|-|1+β(R+1/2)^n|max|z|=1|P(z)|}.In this paper we generalize the above inequality for polynomials having no zeros in }z} 〈 k, k ≤ 1. Our results generalize certain well-known polynomial inequalities. 展开更多
关键词 polynomiAL INEQUALITY maximum modulus growth of polynomial.
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Some results on zeros and uniqueness of difference-differential polynomials 被引量:5
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作者 LIU Kai LIU Xin-ling CAO Ting-bin 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2012年第1期94-104,共11页
We consider the zeros distributions of difference-differential polynomials which are the derivatives of difference products of entire functions. We also investigate the uniqueness problems of difference-differential p... We consider the zeros distributions of difference-differential polynomials which are the derivatives of difference products of entire functions. We also investigate the uniqueness problems of difference-differential polynomials of entire functions sharing a common value. 展开更多
关键词 ZERO sharing value UNIQUENESS difference-differential polynomial.
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ON APPROXIMATION BY RECIPROCALS OF POLYNOMIALS WITH POSITIVE COEFFICIENTS IN ORLICZ SPACES 被引量:5
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作者 Xiaoli Wang Ran Huo Garidi Wu 《Analysis in Theory and Applications》 2008年第4期364-376,共13页
This paper discusses the approximation by reciprocals of polynomials with positive coefficients in Orlicz spaces and proved that if f(x) ∈ L^*M[0, 1], changes its sign at most once in (0, 1), then there exists ... This paper discusses the approximation by reciprocals of polynomials with positive coefficients in Orlicz spaces and proved that if f(x) ∈ L^*M[0, 1], changes its sign at most once in (0, 1), then there exists x0 ∈ (0, 1) and a polynomial Pn∈ Fin(+) such that ||f(x)-x-x0/Pn(x)||M≤Cω(f,n-1/2)M, where Пn(+) indicates the set of all polynomials of degree n with positive coefficients 展开更多
关键词 Orlicz space reciprocal of polynomial Steklov function modified Jacksonkernel
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Analysis of Nonlinear Electrical Circuits Using Bernstein Polynomials 被引量:2
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作者 M. Arounassalame 《International Journal of Automation and computing》 EI 2012年第1期81-86,共6页
In electrical circuit analysis, it is often necessary to find the set of all direct current (d.c.) operating points (either voltages or currents) of nonlinear circuits. In general, these nonlinear equations are of... In electrical circuit analysis, it is often necessary to find the set of all direct current (d.c.) operating points (either voltages or currents) of nonlinear circuits. In general, these nonlinear equations are often represented as polynomial systems. In this paper, we address the problem of finding the solutions of nonlinear electrical circuits, which are modeled as systems of n polynomial equations contained in an n-dimensional box. Branch and Bound algorithms based on interval methods can give guaranteed enclosures for the solution. However, because of repeated evaluations of the function values, these methods tend to become slower. Branch and Bound algorithm based on Bernstein coefficients can be used to solve the systems of polynomial equations. This avoids the repeated evaluation of function values, but maintains more or less the same number of iterations as that of interval branch and bound methods. We propose an algorithm for obtaining the solution of polynomial systems, which includes a pruning step using Bernstein Krawczyk operator and a Bernstein Coefficient Contraction algorithm to obtain Bernstein coefficients of the new domain. We solved three circuit analysis problems using our proposed algorithm. We compared the performance of our proposed algorithm with INTLAB based solver and found that our proposed algorithm is more efficient and fast. 展开更多
关键词 Nonlinear circuit analysis Bernstein polynomials Krawczyk operator interval analysis polynomial system
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RIEMANN-HILBERT CHARACTERIZATION FOR MAIN BESSEL POLYNOMIALS WITH VARYING LARGE NEGATIVE PARAMETERS 被引量:2
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作者 段萍 杜金元 《Acta Mathematica Scientia》 SCIE CSCD 2014年第2期557-567,共11页
In this article, we establish the Bessel polynomials with varying large negative parameters and discuss their orthogonality based on the generalized Bessel polynomials. By using the Riemann-Hilbert boundary value prob... In this article, we establish the Bessel polynomials with varying large negative parameters and discuss their orthogonality based on the generalized Bessel polynomials. By using the Riemann-Hilbert boundary value problem on the positive real axis, we get the Riemann-Hilbert characterization of the main Bessel polynomials with varying large negative parameters. 展开更多
关键词 Generalized Bessel polynomials Bessel polynomials with varying large neg-ative parameters ORTHOGONALITY Riemann-Hilbert boundary value problem Riemann-Hilbert characterization
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THE ROOTS OF σ-POLYNOMIALS 被引量:2
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作者 ZhaoHaixing LiuRuying LiXueliang 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2003年第2期230-234,共5页
Let G be a connected graph. We denote by σ(G,x) and δ(G) respectively the σ-polynomial and the edge-density of G,where δ(G)=|E(G)||V(G)|2. If σ(G,x) has at least an unreal root,then G is said to be a σ-unreal gr... Let G be a connected graph. We denote by σ(G,x) and δ(G) respectively the σ-polynomial and the edge-density of G,where δ(G)=|E(G)||V(G)|2. If σ(G,x) has at least an unreal root,then G is said to be a σ-unreal graph.Let δ(n) be the minimum edge-density over all n vertices graphs with σ-unreal roots. In this paper,by using the theory of adjoint polynomials, a negative answer to a problem posed by Brenti et al. is given and the following results are obtained:For any positive integer a and rational number 0≤c≤1,there exists at least a graph sequence {G i} 1≤i≤a such that G i is σ-unreal and δ(G i)→c as n→∞ for all 1≤i≤a,and moreover, δ(n)→0 as n→∞. 展开更多
关键词 ROOTS σ-polynomial adjoint polynomial.
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Robust power amplifier predistorter by using memory polynomials 被引量:4
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作者 Li Bo Ge Jianhua Ai Bo 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2009年第4期700-705,共6页
In memory polynomial predistorter design, the coefficient estimation algorithm based on normalized least mean square is sensitive to initialization parameters. A predistorter based on generalized normalized gradient d... In memory polynomial predistorter design, the coefficient estimation algorithm based on normalized least mean square is sensitive to initialization parameters. A predistorter based on generalized normalized gradient descent algorithm is proposed. The merit of the GNGD algorithm is that its learning rate provides compensation for the independent assumptions in the derivation of NLMS, thus its stability is improved. Computer simulation shows that the proposed predistorter is very robust. It can overcome the sensitivity of initialization parameters and get a better linearization performance. 展开更多
关键词 power amplifier predistortion memory polynomial generalized normalized gradient descent orthogonal frequency division multiplexing.
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The Origin and Mathematical Characteristics of the Super-Universal Associated-Legendre Polynomials 被引量:1
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作者 陈昌远 尤源 +2 位作者 陆法林 孙东升 董世海 《Communications in Theoretical Physics》 SCIE CAS CSCD 2014年第9期331-337,共7页
We study the mathematical characteristics of the super-universal associated-Legendre polynomials arising from a kind of double ring-shaped potentials and obtain their polar angular wave functions with certain parity. ... We study the mathematical characteristics of the super-universal associated-Legendre polynomials arising from a kind of double ring-shaped potentials and obtain their polar angular wave functions with certain parity. We find that there exists the even or odd parity for the polar angular wave functions when the parameter η is taken to be positive integer, while there exist both even and odd parities when η is taken as positive non-integer real values. The relations among the super-universal associated-Legendre polynomials, the hypergeometric polynomials, and the Jacobi polynomials are also established. 展开更多
关键词 double ring-shaped potential super-universal ASSOCIATED LEGENDRE polynomials parity HYPERGEOMETRIC functions JACOBI polynomials
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ASYMPTOTICS OF ORTHOGONAL POLYNOMIALS VIA THE RIEMANN-HILBERT APPROACH 被引量:2
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作者 R.Wong 赵育求 《Acta Mathematica Scientia》 SCIE CSCD 2009年第4期1005-1034,共30页
In this survey we give a brief introduction to orthogonal polynomials, including a short review of classical asymptotic methods. Then we turn to a discussion of the Riemann-Hilbert formulation of orthogonal polynomial... In this survey we give a brief introduction to orthogonal polynomials, including a short review of classical asymptotic methods. Then we turn to a discussion of the Riemann-Hilbert formulation of orthogonal polynomials, and the Delft & Zhou method of steepest descent. We illustrate this new approach, and a modified version, with the Hermite polynomials. Other recent progress of this method is also mentioned, including applications to discrete orthogonal polynomials, orthogonal polynomials on curves, multiple orthogonal polynomials, and certain orthogonal polynomials with singular behavior. 展开更多
关键词 orthogonal polynomials asymptotic methods Riemann-Hilbert approach
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Regularity of (0,2)-interpolation on the Zeros of the Lascenov Polynomials
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作者 张秀英 薛明志 《Chinese Quarterly Journal of Mathematics》 CSCD 2000年第2期80-86,共7页
In is paper, a necessary and sufficient condition of regularity of (0,2)_interpolation on the zeros of the Lascenov Polynomials R (α,β) n(x)(α,β>-1) in a manageable form is estabished. Meanwhile, the exp... In is paper, a necessary and sufficient condition of regularity of (0,2)_interpolation on the zeros of the Lascenov Polynomials R (α,β) n(x)(α,β>-1) in a manageable form is estabished. Meanwhile, the explicit representation of the fundamental polynomials, when they exist, is given. 展开更多
关键词 Birkhoff interpolation REGULARITY Lascenov polynomial fundamental polynomials
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Some Properties of a Class of Refined Eulerian Polynomials 被引量:2
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作者 Yidong SUN Liting ZHAI 《Journal of Mathematical Research with Applications》 CSCD 2019年第6期593-602,共10页
Recently, Sun defined a new kind of refined Eulerian polynomials, namely,An(p,q)=∑π∈■np^odes(π)q^edes(π) for n ≥ 1, where Sn is the set of all permutations on {1, 2,..., n}, odes(π) and edes(π) enumerate the ... Recently, Sun defined a new kind of refined Eulerian polynomials, namely,An(p,q)=∑π∈■np^odes(π)q^edes(π) for n ≥ 1, where Sn is the set of all permutations on {1, 2,..., n}, odes(π) and edes(π) enumerate the number of descents of permutation π in odd and even positions, respectively. In this paper,we obtain an exponential generating function for An(p, q) and give an explicit formula for An(p, q)in terms of Eulerian polynomials An(q) and C(q), the generating function for Catalan numbers.In certain cases, we establish a connection between An(p, q) and An(p, 0) or An(0, q), and express the coefficients of An(0, q) by Eulerian numbers An,k. Consequently, this connection discovers a new relation between Euler numbers En and Eulerian numbers An,k. 展开更多
关键词 EULERIAN polynomial EULERIAN NUMBER Euler NUMBER DESCENT alternating PERMUTATION CATALAN NUMBER
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ON THE COEFFICIENTS OF DIFFERENTIATED EXPANSIONS AND DERIVATIVES OF CHEBYSHEV POLYNOMIALS OF THE THIRD AND FOURTH KINDS 被引量:3
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作者 Eid H.DOHA Waleed M.ABD-ELHAMEED Mahmoud A.BASSUONY 《Acta Mathematica Scientia》 SCIE CSCD 2015年第2期326-338,共13页
Two new analytical formulae expressing explicitly the derivatives of Chebyshev polynomials of the third and fourth kinds of any degree and of any order in terms of Chebyshev polynomials of the third and fourth kinds t... Two new analytical formulae expressing explicitly the derivatives of Chebyshev polynomials of the third and fourth kinds of any degree and of any order in terms of Chebyshev polynomials of the third and fourth kinds themselves are proved. Two other explicit formulae which express the third and fourth kinds Chebyshev expansion coefficients of a general-order derivative of an infinitely differentiable function in terms of their original expansion coefficients are also given. Two new reduction formulae for summing some terminating hypergeometric functions of unit argument are deduced. As an application of how to use Chebyshev polynomials of the third and fourth kinds for solving high-order boundary value problems, two spectral Galerkin numerical solutions of a special linear twelfth-order boundary value problem are given. 展开更多
关键词 Chebyshev polynomials of the third and fourth kinds expansion coefficients generalized hypergeometric functions boundary value problems
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