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ENTIRE SOLUTIONS OF HIGHER ORDER DIFFERENTIAL EQUATIONS WITH ENTIRE COEFFICIENTS HAVING THE SAME ORDER
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作者 冯子恒 黄志波 李叶舟 《Acta Mathematica Scientia》 SCIE CSCD 2024年第1期355-368,共14页
In this paper,we consider entire solutions of higher order homogeneous differential equations with the entire coefficients having the same order,and prove that the entire solutions are of infinite lower order.The prop... In this paper,we consider entire solutions of higher order homogeneous differential equations with the entire coefficients having the same order,and prove that the entire solutions are of infinite lower order.The properties on the radial distribution,the limit direction of the Julia set and the existence of a Baker wandering domain of the entire solutions are also discussed. 展开更多
关键词 entire solutions radial order Julia limiting direction Baker wandering domain transcendental direction
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SUBNORMAL SOLUTIONS OF DIFFERENTIAL EQUATIONS WITH PERIODIC COEFFICIENTS 被引量:2
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作者 陈宗煊 孙光镐 《Acta Mathematica Scientia》 SCIE CSCD 2010年第1期75-88,共14页
In this article, we apply the concept of hyper-order to higher order linear differential equations with periodic coefficients, investigate the existence and the form of its subnormal solution, and estimate the growth ... In this article, we apply the concept of hyper-order to higher order linear differential equations with periodic coefficients, investigate the existence and the form of its subnormal solution, and estimate the growth of all other solutions, and answer the question raised by Gundersen and Steinbart for more general periodic differential equations. 展开更多
关键词 periodic equation subnormal solution hyper order
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THE GROWTH OF SOLUTIONS TO HIGHER ORDER DIFFERENTIAL EQUATIONS WITH EXPONENTIAL POLYNOMIALS AS ITS COEFFICIENTS 被引量:1
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作者 黄志波 罗敏伟 陈宗煊 《Acta Mathematica Scientia》 SCIE CSCD 2023年第1期439-449,共11页
By looking at the situation when the coefficients Pj(z)(j=1,2,…,n-1)(or most of them) are exponential polynomials,we investigate the fact that all nontrivial solutions to higher order differential equations f((n))+Pn... By looking at the situation when the coefficients Pj(z)(j=1,2,…,n-1)(or most of them) are exponential polynomials,we investigate the fact that all nontrivial solutions to higher order differential equations f((n))+Pn-1(z)f((n-1))+…+P0(z)f=0 are of infinite order.An exponential polynomial coefficient plays a key role in these results. 展开更多
关键词 differential equations entire solution exponential polynomial GROWTH
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Research on Financial Distress Prediction with Adaptive Genetic Fuzzy Neural Networks on Listed Corporations of China
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作者 Zhibin XIONG 《International Journal of Communications, Network and System Sciences》 2009年第5期385-391,共7页
To design a multi-population adaptive genetic BP algorithm, crossover probability and mutation probability are self-adjusted according to the standard deviation of population fitness in this paper. Then a hybrid model... To design a multi-population adaptive genetic BP algorithm, crossover probability and mutation probability are self-adjusted according to the standard deviation of population fitness in this paper. Then a hybrid model combining Fuzzy Neural Network and multi-population adaptive genetic BP algorithm—Adaptive Genetic Fuzzy Neural Network (AGFNN) is proposed to overcome Neural Network’s drawbacks. Furthermore, the new model has been applied to financial distress prediction and the effectiveness of the proposed model is performed on the data collected from a set of Chinese listed corporations using cross validation approach. A comparative result indicates that the performance of AGFNN model is much better than the ones of other neural network models. 展开更多
关键词 MULTI-POPULATION ADAPTIVE GENETIC BP Algorithm Fuzzy NEURAL Network Cross Validation FINANCIAL DISTRESS
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The Mathematical Model of Short-Term Forest Fire Spread
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作者 Sunben Chiu Ying Li Jiayi Zhao 《Journal of Applied Mathematics and Physics》 2022年第5期1748-1761,共14页
In this paper, we establish a mathematical model of the forest fire spread process based on a partial differential equation. We describe the distribution of time field and velocity field in the whole two-dimensional s... In this paper, we establish a mathematical model of the forest fire spread process based on a partial differential equation. We describe the distribution of time field and velocity field in the whole two-dimensional space by vector field theory. And we obtain a continuous algorithm to predict the dynamic behavior of forest fire spread in a short time. We use the algorithm to interpolate the fire boundary by cubic non-uniform rational B-spline closed curve. The fire boundary curve at any time can be simulated by solving the Eikonal equation. The model is tested in theory and in practice. The results show that the model has good accuracy and stability, and it’s compatible with most of the existing models, such as the elliptic model and the cellular automata model. 展开更多
关键词 Forest Fire Spread Model Spatial Velocity Field Eikonal Equation Dynamic Simulation Non-Uniform Rational B-Spline
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Zero distribution of some difference polynomials
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作者 LI Qian LIU Dan HUANG Zhi-bo 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2023年第3期392-402,共11页
In this paper,suppose that a,c∈C{0},c_(j)∈C(j=1,2,···,n) are not all zeros and n≥2,and f (z) is a finite order transcendental entire function with Borel finite exceptional value or with infinitely ma... In this paper,suppose that a,c∈C{0},c_(j)∈C(j=1,2,···,n) are not all zeros and n≥2,and f (z) is a finite order transcendental entire function with Borel finite exceptional value or with infinitely many multiple zeros,the zero distribution of difference polynomials of f (z+c)-af^(n)(z) and f (z)f (z+c_1)···f (z+c_n) are investigated.A number of examples are also presented to show that our results are best possible in a certain sense. 展开更多
关键词 difference polynomial zero distribution Borel exceptional value
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GLOBAL SOLUTIONS TO 1D COMPRESSIBLE NAVIER-STOKES/ALLEN-CAHN SYSTEM WITH DENSITY-DEPENDENT VISCOSITY AND FREE-BOUNDARY 被引量:1
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作者 丁时进 李颖花 王喻 《Acta Mathematica Scientia》 SCIE CSCD 2024年第1期195-214,共20页
This paper is concerned with the Navier-Stokes/Allen-Cahn system,which is used to model the dynamics of immiscible two-phase flows.We consider a 1D free boundary problem and assume that the viscosity coefficient depen... This paper is concerned with the Navier-Stokes/Allen-Cahn system,which is used to model the dynamics of immiscible two-phase flows.We consider a 1D free boundary problem and assume that the viscosity coefficient depends on the density in the form ofη(ρ)=ρ^(α).The existence of unique global H^(2m)-solutions(m∈N)to the free boundary problem is proven for when 0<α<1/4.Furthermore,we obtain the global C^(∞)-solutions if the initial data is smooth. 展开更多
关键词 Navier-Stokes/Allen-Cahn system density-dependent viscosity free boundary global solutions
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ESTIMATE ON THE BLOCH CONSTANT FOR CERTAIN HARMONIC MAPPINGS UNDER A DIFFERENTIAL OPERATOR
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作者 陈洁玲 刘名生 《Acta Mathematica Scientia》 SCIE CSCD 2024年第1期295-310,共16页
In this paper,we first obtain the precise values of the univalent radius and the Bloch constant for harmonic mappings of the formL(f)=zfz-zfz,where f represents normalized harmonic mappings with bounded dilation.Then,... In this paper,we first obtain the precise values of the univalent radius and the Bloch constant for harmonic mappings of the formL(f)=zfz-zfz,where f represents normalized harmonic mappings with bounded dilation.Then,using these results,we present better estimations for the Bloch constants of certain harmonic mappings L(f),where f is a K-quasiregular harmonic or open harmonic.Finally,we establish three versions of BlochLandau type theorem for biharmonic mappings of the form L(f).These results are sharp in some given cases and improve the related results of earlier authors. 展开更多
关键词 Bloch-Landau type theorem Bloch constant linear complex operator harmonic mapping biharmonic mapping UNIVALENT
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ON THE GROWTH OF ZERO ORDER LAPLACE-STIELTJES TRANSFORM CONVERGENT IN THE RIGHT HALF-PLANE 被引量:15
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作者 孔荫莹 孙道椿 《Acta Mathematica Scientia》 SCIE CSCD 2008年第2期431-440,共10页
In this article, authors study the growth of Laplace-Stieltjes transform with zero order convergent in the right half-plane, define the exponential order and the exponential low order, and find the relations between t... In this article, authors study the growth of Laplace-Stieltjes transform with zero order convergent in the right half-plane, define the exponential order and the exponential low order, and find the relations between them. Some results similar to Dirichlet series are obtained. 展开更多
关键词 Laplace-Stieltjes transforms of zero order Newton polygon exponential order exponential low order
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ZEROS OF ENTIRE SOLUTIONS TO COMPLEX LINEAR DIFFERENCE EQUATIONS 被引量:7
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作者 陈宗煊 《Acta Mathematica Scientia》 SCIE CSCD 2012年第3期1141-1148,共8页
In this article, we study the complex oscillation problems of entire solutions to homogeneous and nonhomogeneous linear difference equations, and obtain some relations of the exponent of convergence of zeros and the o... In this article, we study the complex oscillation problems of entire solutions to homogeneous and nonhomogeneous linear difference equations, and obtain some relations of the exponent of convergence of zeros and the order of growth of entire solutions to complex linear difference equations. 展开更多
关键词 Linear difference equation complex oscillation ZERO order of growth
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CONVERGENCE ANALYSIS OF THE JACOBI SPECTRAL-COLLOCATION METHOD FOR FRACTIONAL INTEGRO-DIFFERENTIAL EQUATIONS 被引量:9
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作者 杨银 陈艳萍 黄云清 《Acta Mathematica Scientia》 SCIE CSCD 2014年第3期673-690,共18页
We propose and analyze a spectral Jacobi-collocation approximation for fractional order integro-differential equations of Volterra type. The fractional derivative is described in the Caputo sense. We provide a rigorou... We propose and analyze a spectral Jacobi-collocation approximation for fractional order integro-differential equations of Volterra type. The fractional derivative is described in the Caputo sense. We provide a rigorous error analysis for the collection method, which shows that the errors of the approximate solution decay exponentially in L^∞ norm and weighted L^2-norm. The numerical examples are given to illustrate the theoretical results. 展开更多
关键词 Spectral Jacobi-collocation method fractional order integro-differential equations Caputo derivative
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ON PROPERTIES OF DIFFERENCE POLYNOMIALS 被引量:5
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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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OPTIMAL CONVERGENCE RATES OF LANDAU EQUATION WITH EXTERNAL FORCING IN THE WHOLE SPACE 被引量:6
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作者 杨彤 喻洪俊 《Acta Mathematica Scientia》 SCIE CSCD 2009年第4期1035-1062,共28页
In this paper, we combine the method of constructing the compensating function introduced by Kawashima and the standard energy method for the study on the Landau equation with external forcing. Both the global existen... In this paper, we combine the method of constructing the compensating function introduced by Kawashima and the standard energy method for the study on the Landau equation with external forcing. Both the global existence of solutions near the time asymptotic states which are local Maxwellians and the optimal convergence rates are obtained. The method used here has its own advantage for this kind of studies because it does not involve the spectrum analysis of the corresponding linearized operator. 展开更多
关键词 compensating function energy method Landau equation optimal convergence rates
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CRITICAL EXPONENTS OF EVOLUTIONARY p-LAPLACIAN WITH INTERIOR AND BOUNDARY SOURCES 被引量:3
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作者 尹景学 金春花 杨莹 《Acta Mathematica Scientia》 SCIE CSCD 2011年第3期778-790,共13页
This paper is concerned with the evolutionary p-Laplacian with interior and boundary sources.The critical exponents for the nonlinear sources are determined.
关键词 critical exponent P-LAPLACIAN global existence BLOW-UP
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ON MEROMORPHIC SOLUTIONS OF RICCATI AND LINEAR DIFFERENCE EQUATIONS 被引量:4
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作者 张然然 陈宗煊 《Acta Mathematica Scientia》 SCIE CSCD 2013年第5期1243-1254,共12页
In this paper, meromorphic solutions of Riccati and linear difference equations are investigated. The growth and Borel exceptional values of these solutions are discussed, and the growth, zeros and poles of difference... In this paper, meromorphic solutions of Riccati and linear difference equations are investigated. The growth and Borel exceptional values of these solutions are discussed, and the growth, zeros and poles of differences of these solutions are also investigated. Furthermore, several examples are given showing that our results are best possible in certain senses. 展开更多
关键词 complex difference equation growth order Borel exceptional value
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NUMERICAL ANALYSIS FOR VOLTERRA INTEGRAL EQUATION WITH TWO KINDS OF DELAY 被引量:2
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作者 郑伟珊 陈艳萍 《Acta Mathematica Scientia》 SCIE CSCD 2019年第2期607-617,共11页
In this article, we study the Volterra integral equations with two kinds of delay that are proportional delay and nonproportional delay. We mainly use Chebyshev spectral collocation method to analyze them. First, we u... In this article, we study the Volterra integral equations with two kinds of delay that are proportional delay and nonproportional delay. We mainly use Chebyshev spectral collocation method to analyze them. First, we use variable transformation to transform the equation into an new equation which is defined in [-1,1]. Then, with the help of Gronwall inequality and some other lemmas, we provide a rigorous error analysis for the proposed method, which shows that the numerical error decay exponentially in L~∞ and L_(ω~c)~2-norm. In the end, we give numerical test to confirm the conclusion. 展开更多
关键词 VOLTERRA integral equation proportional DELAY nonproportional DELAY linear transformation CHEBYSHEV spectral-collocation method GRONWALL INEQUALITY
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ON THE DIFFERENCE COUNTERPART OF BRCK'S CONJECTURE 被引量:3
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作者 陈宗煊 《Acta Mathematica Scientia》 SCIE CSCD 2014年第3期653-659,共7页
In this article, for a transcendental entire function f(z) of finite order which has a finite Borel exceptional value a, we utilize properties of complex difference equations to prove the difference counterpart of B... In this article, for a transcendental entire function f(z) of finite order which has a finite Borel exceptional value a, we utilize properties of complex difference equations to prove the difference counterpart of Bruck's conjecture, that is, if △f(z) = f(z + η) - f(z) and f(z) share one value a (≠α) CM, where η ∈ C is a constant such that f(z +η) ≠ f(z),then△f(z)-a/f(z)-a=a/a-α. 展开更多
关键词 Complex difference Borel exceptional value sharing value
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SHARP ESTIMATES OF QUASI-CONVEX MAPPINGS OF TYPE B AND ORDER α 被引量:2
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作者 刘名生 吴芬 杨燕 《Acta Mathematica Scientia》 SCIE CSCD 2019年第5期1265-1276,共12页
In this paper, we first establish several sharp inequalities of homogeneous expansion for biholomorphic quasi-convex mappings of type B and order α on the unit ball E in a complex Banach space X by applying the metho... In this paper, we first establish several sharp inequalities of homogeneous expansion for biholomorphic quasi-convex mappings of type B and order α on the unit ball E in a complex Banach space X by applying the method and technique of complex analysis. Then, as the application of these sharp inequalities, we derive the sharp estimate of third homogeneous expansions for the above mappings defined on the unit polydisk U^n in C^n. 展开更多
关键词 quasi-convex MAPPINGS of TYPE B and order α INEQUALITIES of HOMOGENEOUS EXPANSIONS the SHARP estimate of third HOMOGENEOUS EXPANSIONS
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PRECISE VALUES OF THE BLOCH CONSTANTS OF CERTAIN LOG-p-HARMONIC MAPPINGS 被引量:2
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作者 刘名生 骆莉芳 《Acta Mathematica Scientia》 SCIE CSCD 2021年第1期297-310,共14页
The aim of this article is twofold.One aim is to establish the precise forms of Landau-Bloch type theorems for certain polyharmonic mappings in the unit disk by applying a geometric method.The other is to obtain the p... The aim of this article is twofold.One aim is to establish the precise forms of Landau-Bloch type theorems for certain polyharmonic mappings in the unit disk by applying a geometric method.The other is to obtain the precise values of Bloch constants for certain log-p-harmonic mappings.These results improve upon the corresponding results given in Bai et al.(Complex Anal.Oper.Theory,13(2):321-340,2019). 展开更多
关键词 Bloch constant Landau theorem Bloch theorem biharmonic mappings polyharmonic mappings log-p-harmonic mappings UNIVALENT
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COMPLEXITY OF ASYMPTOTIC BEHAVIOR OF SOLUTIONS FOR THE POROUS MEDIUM EQUATION WITH ABSORPTION 被引量:3
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作者 尹景学 王良伟 黄锐 《Acta Mathematica Scientia》 SCIE CSCD 2010年第6期1865-1880,共16页
In this paper we analyze the large time behavior of nonnegative solutions of the Cauchy problem of the porous medium equation with absorption ut - △um + yup = 0,where γ≥0,m〉 1and P〉m+2/N We will show that if γ... In this paper we analyze the large time behavior of nonnegative solutions of the Cauchy problem of the porous medium equation with absorption ut - △um + yup = 0,where γ≥0,m〉 1and P〉m+2/N We will show that if γ=0 and 0〈μ〈 2N/n(m-1)+2 or γ 〉 0 and 1/p-1 〈 μ 〈 2N/N(m-1)+2 then for any nonnegative function φ in a nonnegative countable subset F of the Schwartz space S(RN), there exists an initial-value u0 ∈ C(RN) with limx→∞ uo(x)= 0 such that φ is an w-limit point of the rescaled solutions tμ/2u(tβ, t), Where β = 2-μ(m-1)/4. 展开更多
关键词 COMPLEXITY asymptotic behavior porous medium equation
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