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Analysis of Extended Fisher-Kolmogorov Equation in 2D Utilizing the Generalized Finite Difference Method with Supplementary Nodes
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作者 Bingrui Ju Wenxiang Sun +1 位作者 Wenzhen Qu Yan Gu 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第10期267-280,共14页
In this study,we propose an efficient numerical framework to attain the solution of the extended Fisher-Kolmogorov(EFK)problem.The temporal derivative in the EFK equation is approximated by utilizing the Crank-Nicolso... In this study,we propose an efficient numerical framework to attain the solution of the extended Fisher-Kolmogorov(EFK)problem.The temporal derivative in the EFK equation is approximated by utilizing the Crank-Nicolson scheme.Following temporal discretization,the generalized finite difference method(GFDM)with supplementary nodes is utilized to address the nonlinear boundary value problems at each time node.These supplementary nodes are distributed along the boundary to match the number of boundary nodes.By incorporating supplementary nodes,the resulting nonlinear algebraic equations can effectively satisfy the governing equation and boundary conditions of the EFK equation.To demonstrate the efficacy of our approach,we present three numerical examples showcasing its performance in solving this nonlinear problem. 展开更多
关键词 Generalized finite difference method nonlinear extended Fisher-Kolmogorov equation Crank-Nicolson scheme
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Fuzzy Difference Equations in Diagnoses of Glaucoma from Retinal Images Using Deep Learning
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作者 D.Dorathy Prema Kavitha L.Francis Raj +3 位作者 Sandeep Kautish Abdulaziz S.Almazyad Karam M.Sallam Ali Wagdy Mohamed 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第4期801-816,共16页
The intuitive fuzzy set has found important application in decision-making and machine learning.To enrich and utilize the intuitive fuzzy set,this study designed and developed a deep neural network-based glaucoma eye ... The intuitive fuzzy set has found important application in decision-making and machine learning.To enrich and utilize the intuitive fuzzy set,this study designed and developed a deep neural network-based glaucoma eye detection using fuzzy difference equations in the domain where the retinal images converge.Retinal image detections are categorized as normal eye recognition,suspected glaucomatous eye recognition,and glaucomatous eye recognition.Fuzzy degrees associated with weighted values are calculated to determine the level of concentration between the fuzzy partition and the retinal images.The proposed model was used to diagnose glaucoma using retinal images and involved utilizing the Convolutional Neural Network(CNN)and deep learning to identify the fuzzy weighted regularization between images.This methodology was used to clarify the input images and make them adequate for the process of glaucoma detection.The objective of this study was to propose a novel approach to the early diagnosis of glaucoma using the Fuzzy Expert System(FES)and Fuzzy differential equation(FDE).The intensities of the different regions in the images and their respective peak levels were determined.Once the peak regions were identified,the recurrence relationships among those peaks were then measured.Image partitioning was done due to varying degrees of similar and dissimilar concentrations in the image.Similar and dissimilar concentration levels and spatial frequency generated a threshold image from the combined fuzzy matrix and FDE.This distinguished between a normal and abnormal eye condition,thus detecting patients with glaucomatous eyes. 展开更多
关键词 Convolutional Neural Network(CNN) glaucomatous eyes fuzzy difference equation intuitive fuzzy sets image segmentation retinal images
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A-high-order Accuraqcy Implicit Difference Scheme for Solving the Equation of Parabolic Type 被引量:7
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作者 马明书 王肖凤 《Chinese Quarterly Journal of Mathematics》 CSCD 2000年第2期94-97,共4页
In this paper,a implicit difference scheme is proposed for solving the equation of one_dimension parabolic type by undetermined paameters.The stability condition is r=αΔt/Δx 2 1/2 and the truncation error is o(... In this paper,a implicit difference scheme is proposed for solving the equation of one_dimension parabolic type by undetermined paameters.The stability condition is r=αΔt/Δx 2 1/2 and the truncation error is o(Δt 4+Δx 4) It can be easily solved by double sweeping method. 展开更多
关键词 equation of one_dimension parabolic type high_order accuracy implicit difference scheme
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CONSERVATIVE DIFFERENCE SCHEME BASED ON NUMERICAL ANALYSIS FOR NONLINEAR SCHRDINGER EQUATION WITH WAVE OPERATOR 被引量:2
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作者 王廷春 张鲁明 陈芳启 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2006年第2期87-93,共7页
A new conservative finite difference scheme is presented based on the numerical analysis for an initialboundary value problem of a class of Schroedinger equation with the wave operator. The scheme can be linear and im... A new conservative finite difference scheme is presented based on the numerical analysis for an initialboundary value problem of a class of Schroedinger equation with the wave operator. The scheme can be linear and implicit or explicit based on the parameter choice. The initial value after discretization has second-order accuracy that is consistent with the scheme accuracy. The existence and the uniqueness of the difference solution are proved. Based on the priori estimates and an inequality about norms, the stability and the convergence of difference solutions with the second-order are proved in the energy norm. Experimental results demonstrate the efficiency of the new scheme. 展开更多
关键词 Schroedinger equation difference scheme CONSERVATION existence and uniqueness of solution CONVERGENCE
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An Explicit Difference Scheme with High Accuracy and Branching Stability for Solving Parabolic Partial Differential Equation 被引量:4
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作者 马明书 王肖凤 《Chinese Quarterly Journal of Mathematics》 CSCD 2000年第4期98-103,共6页
This paper presents an explicit difference scheme with accuracy and branching stability for solving onedimensional parabolic type equation by the method of undetermined parameters and its truncation error is O(△t4+△... This paper presents an explicit difference scheme with accuracy and branching stability for solving onedimensional parabolic type equation by the method of undetermined parameters and its truncation error is O(△t4+△x4). The stability condition is r=a△t/△x2<1/2. 展开更多
关键词 parabolic type equation explicit difference scheme high accuracy branching stability truncation er
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HIGH RESOLUTION POSITIVITY-PRESERVING DIFFERENCE SCHEMES FOR TWO DIMENSIONAL EULER EQUATIONS
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作者 赵宁 张虎 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2000年第2期163-168,共6页
A class of high resolution positivity preserving Boltzmann type difference schemes for one and two dimensional Euler equations is studied. First, the relation between Boltzmann and Euler equations is analyzed. By usi... A class of high resolution positivity preserving Boltzmann type difference schemes for one and two dimensional Euler equations is studied. First, the relation between Boltzmann and Euler equations is analyzed. By using a kind of special interpolation, the high resolution Boltzmann type difference scheme is constructed. Finally, numerical tests show that the schemes are effective and useful. 展开更多
关键词 Euler equation Boltzmann equation finite difference scheme positivity preserving
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Global Attractivity of a Kind of Delay Difference Equations
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作者 李先义 朱德明 金银来 《Chinese Quarterly Journal of Mathematics》 CSCD 2002年第1期9-18,共10页
Several new sufficient conditions are given for the global attractivity of solutions of a kind of delay difference equations. They either include or improve some known results and put the study of Ladas' conjectur... Several new sufficient conditions are given for the global attractivity of solutions of a kind of delay difference equations. They either include or improve some known results and put the study of Ladas' conjecture forward. 展开更多
关键词 delay difference equation global attractivity positive semicycle negative semicycle periodic point of prime period two
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Asymptotic Behavior and Nonexistence of Positive Solutions of Delay Difference Equations *L
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作者 彭名书 徐千里 《Journal of Beijing Institute of Technology》 EI CAS 1999年第1期25-30,共6页
Aim To obtain new criteria for asymptotic behavior and nonexistence of positive solutions of nonlinear neutral delay difference equations. Methods By means of Hlder inequality and a method of direct analysis, some i... Aim To obtain new criteria for asymptotic behavior and nonexistence of positive solutions of nonlinear neutral delay difference equations. Methods By means of Hlder inequality and a method of direct analysis, some interesting Lemmas were offered. Results and Conclusion New criteria for asymptotic behavior and nonexistence of positive solutions of nonlinear neutral delay difference equations are established, which extend and improve the results obtained in the literature. Some interesting examples illustrating the importance of our results are also included. 展开更多
关键词 OSCILLATION asymptotic behavior positive solution neutral delay difference equation NONLINEARITY
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New exact solutions to some difference differential equations 被引量:15
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作者 王振 张鸿庆 《Chinese Physics B》 SCIE EI CAS CSCD 2006年第10期2210-2215,共6页
In this paper, we use our method to solve the extended Lotka-Volterra equation and discrete KdV equation. With the help of Maple, we obtain a number of exact solutions to the two equations including soliton solutions ... In this paper, we use our method to solve the extended Lotka-Volterra equation and discrete KdV equation. With the help of Maple, we obtain a number of exact solutions to the two equations including soliton solutions presented by hyperbolic functions of sinh and cosh, periodic solutions presented by trigonometric functions of sin and cos, and rational solutions. This method can be used to solve some other nonlinear difference-differential equations. 展开更多
关键词 difference differential equation soliton solutions Lotka-Volterra equation discrete KdV equation
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THE GROWTH ORDER OF SOLUTIONS OF SYSTEMS OF COMPLEX DIFFERENCE EQUATIONS 被引量:17
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作者 高凌云 《Acta Mathematica Scientia》 SCIE CSCD 2013年第3期814-820,共7页
Using Nevanlinna theory of the value distribution of meromorphic functions and Wiman-Valiron theory of entire functions, we investigate the problem of growth order of solutions of a type of systems of difference equat... Using Nevanlinna theory of the value distribution of meromorphic functions and Wiman-Valiron theory of entire functions, we investigate the problem of growth order of solutions of a type of systems of difference equations, and extend some results of the growth order of solutions of systems of differential equations to systems of difference equations. 展开更多
关键词 Growth order difference equations entire function
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KAMENEV-TYPE OSCILLATION CRITERIA FOR DELAY DIFFERENCE EQUATIONS 被引量:6
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作者 程金发 《Acta Mathematica Scientia》 SCIE CSCD 2007年第3期574-580,共7页
Some oscillation criteria are established by Raccati transformation techniques for the following second-order nonlinear neutral difference equation △(pn(△(Xn + CnXn-τ))^γ) + qnX^Bn-σ = 0, n :0, 1, 2...wh... Some oscillation criteria are established by Raccati transformation techniques for the following second-order nonlinear neutral difference equation △(pn(△(Xn + CnXn-τ))^γ) + qnX^Bn-σ = 0, n :0, 1, 2...which extend and include several oscillation criteria in [11], and also correct a theorem and its proof in [10]. 展开更多
关键词 OSCILLATION SUPERLINEAR SUBLINEAR difference equations
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MEROMORPHIC SOLUTIONS OF A TYPE OF SYSTEM OF COMPLEX DIFFERENTIAL-DIFFERENCE EQUATIONS 被引量:5
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作者 李海绸 高凌云 《Acta Mathematica Scientia》 SCIE CSCD 2015年第1期195-206,共12页
Applying Nevanlinna theory of the value distribution of meromorphic functions, we mainly study the growth and some other properties of meromorphic solutions of the type of system of complex differential and difference... Applying Nevanlinna theory of the value distribution of meromorphic functions, we mainly study the growth and some other properties of meromorphic solutions of the type of system of complex differential and difference equations of the following form {j=1∑nαj(z)f1(λj1)(z+cj)=R2(z,f2(z)),j=1∑nβj(z)f2(λj2)(z+cj)=R1(z,f1(z)). where λij (j = 1, 2,…, n; i = 1, 2) are finite non-negative integers, and cj (j = 1, 2,… , n) are distinct, nonzero complex numbers, αj(z), βj(z) (j = 1,2,… ,n) are small functions relative to fi(z) (i =1, 2) respectively, Ri(z, f(z)) (i = 1, 2) are rational in fi(z) (i =1, 2) with coefficients which are small functions of fi(z) (i = 1, 2) respectively. 展开更多
关键词 growth order system of equations complex differential equations difference equations Nevanlinna theory value distribution
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ON DIFFERENCE EQUATIONS RELATING TO GAMMA FUNCTION 被引量:8
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作者 陈宗煊 黄志波 张然然 《Acta Mathematica Scientia》 SCIE CSCD 2011年第4期1281-1294,共14页
We consider the existence, the growth, poles, zeros, fixed points and the Borel exceptional value of solutions for the following difference equations relating to Gamma function y(z + 1) -y(z) = R(z) and y(z ... We consider the existence, the growth, poles, zeros, fixed points and the Borel exceptional value of solutions for the following difference equations relating to Gamma function y(z + 1) -y(z) = R(z) and y(z + 1) = P (z)y(z). 展开更多
关键词 difference equation meromorphic function Borel exceptional value
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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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ANALYTIC INVARIANT CURVES OF A NONLINEAR SECOND ORDER DIFFERENCE EQUATION 被引量:4
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作者 王五生 《Acta Mathematica Scientia》 SCIE CSCD 2009年第2期415-426,共12页
This article studies the existence of analytic invariant curves for a nonlinear second order difference equation which was modeled from macroeconomics of the business cycle. The author not only discusses the case of t... This article studies the existence of analytic invariant curves for a nonlinear second order difference equation which was modeled from macroeconomics of the business cycle. The author not only discusses the case of the eigenvalue off the unit circle S^1 and the case on S^1 with the Diophantine condition but also considers the case of the eigenvalue at a root of the unity, which obviously violates the Diophantine condition. 展开更多
关键词 difference equation invariant curves functional equation ANALYTICITY diophantine condition majorant series
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Bounded Oscillation for Second-order Nonlinear Difference Equation with Variable Delay 被引量:9
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作者 杨甲山 孙文兵 《Chinese Quarterly Journal of Mathematics》 CSCD 2011年第4期516-520,共5页
In this paper, a class of second order nonlinear neutral difference equations with variable delays are studied. The criteria for existence of bounded eventually positive solution is obtained by using Banach contractio... In this paper, a class of second order nonlinear neutral difference equations with variable delays are studied. The criteria for existence of bounded eventually positive solution is obtained by using Banach contraction mapping principle and some necessary techniques. Moreover, some sufficient conditions for oscillation of the equations are given. Some results available in documents are extended in this paper. Illustrative examples are given. 展开更多
关键词 neutral difference equation NONLINEAR eventually positive solution OSCILLATION
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GLOBAL ASYMPTOTIC STABILITY FOR A NONLINEAR DELAY DIFFERENCE EQUATION 被引量:7
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作者 LiXianyi ZhuDeming 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2002年第2期183-188,共6页
In this paper,a sufficient condition for the global asymptotic stability of the solutions of the following nonlinear delay difference equation is obtained, xn+ 1=xn+xn- 1xn- 2 +a xnxn- 1+xn- 2 +a, n =0 ,1 ,..., ... In this paper,a sufficient condition for the global asymptotic stability of the solutions of the following nonlinear delay difference equation is obtained, xn+ 1=xn+xn- 1xn- 2 +a xnxn- 1+xn- 2 +a, n =0 ,1 ,..., where a∈ [0 ,∞ ) and the initial values x- 2 ,x- 1,x0 ∈ (0 ,∞ ) .As a special case,a conjecture by Ladas is confirmed. 展开更多
关键词 nonlinear delay difference equation global asymptotic stability SEMICYCLE
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Implicit finite difference method for fractional percolation equation with Dirichlet and fractional boundary conditions 被引量:5
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作者 Boling GUO Qiang XU Zhe YIN 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2016年第3期403-416,共14页
An implicit finite difference method is developed for a one-dimensional frac- tional percolation equation (FPE) with the Dirichlet and fractional boundary conditions. The stability and convergence are discussed for ... An implicit finite difference method is developed for a one-dimensional frac- tional percolation equation (FPE) with the Dirichlet and fractional boundary conditions. The stability and convergence are discussed for two special cases, i.e., a continued seep- age flow with a monotone percolation coefficient and a seepage flow with the fractional Neumann boundary condition. The accuracy and efficiency of the method are checked with two numerical examples. 展开更多
关键词 fractional percolation equation (FPE) Riemann-Liouville derivative frac-tional boundary condition finite difference method stability and convergence Toeplitzmatrix
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ON PROPERTIES OF MEROMORPHIC SOLUTIONS FOR COMPLEX DIFFERENCE EQUATION OF MALMQUIST TYPE 被引量:3
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作者 黄志波 陈宗煊 李倩 《Acta Mathematica Scientia》 SCIE CSCD 2013年第4期1141-1152,共12页
In this paper, we present the properties on zeros, fixed points, poles, Borel exceptional value of finite order transcendental meromorphic solutions of complex difference equation of Malmquist typewhere n(∈ N) 〉 2... In this paper, we present the properties on zeros, fixed points, poles, Borel exceptional value of finite order transcendental meromorphic solutions of complex difference equation of Malmquist typewhere n(∈ N) 〉 2, P(f(z)) and Q(f(z)) are relatively prime polynomials in f(z) with rational coefficients a8 (s = 0, 1,…,p) and bt (t = 0, 1,… ,q) such that aoapbq 7≠ O, and also consider the existence and the forms on rational solutions of this type of difference equations. Some examples are also listed to show that the assumptions of theorems, in certain senses, are the best possible. 展开更多
关键词 ZEROS POLES FIXED-POINTS Borel exceptional value difference equation
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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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