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Invariant Sets and Exact Solutions to Higher-Dimensional Wave Equations 被引量:11
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作者 QU Gai-Zhu ZHANG Shun-Li ZHU Chun-Rong 《Communications in Theoretical Physics》 SCIE CAS CSCD 2008年第5期1119-1124,共6页
The invariant sets and exact solutions of the (1 + 2)-dimensional wave equations are discussed. It is shown that there exist a class of solutions to the equations which belong to the invariant set E0 = {u : ux = ... The invariant sets and exact solutions of the (1 + 2)-dimensional wave equations are discussed. It is shown that there exist a class of solutions to the equations which belong to the invariant set E0 = {u : ux = vxF(u),uy = vyF(u) }. This approach is also developed to solve (1 + N)-dimensional wave equations. 展开更多
关键词 wave equation invariant set exact solution
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ON THE HOLOMORPHIC SOLUTION OF NON-LINEAR TOTALLY CHARACTERISTIC EQUATIONS WITH SEVERAL SPACE VARIABLES 被引量:5
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作者 陈化 罗壮初 《Acta Mathematica Scientia》 SCIE CSCD 2002年第3期393-403,共11页
In this paper the authors study a class of non-linear singular partial differential equation in complex domain C-t x C-x(n). Under certain assumptions, they prove the existence and uniqueness of holomorphic solution n... In this paper the authors study a class of non-linear singular partial differential equation in complex domain C-t x C-x(n). Under certain assumptions, they prove the existence and uniqueness of holomorphic solution near origin of C-t x C-x(n). 展开更多
关键词 non-linear singular partial differential equation holomorphic solution
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LIMITING DIRECTIONS OF JULIA SETS OF ENTIRE SOLUTIONS TO COMPLEX DIFFERENTIAL EQUATIONS 被引量:2
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作者 王珺 陈宗煊 《Acta Mathematica Scientia》 SCIE CSCD 2017年第1期97-107,共11页
In this paper,we mainly investigate the dynamical properties of entire solutions of complex differential equations.With some conditions on coefficients,we prove that the set of common limiting directions of Julia sets... In this paper,we mainly investigate the dynamical properties of entire solutions of complex differential equations.With some conditions on coefficients,we prove that the set of common limiting directions of Julia sets of solutions,their derivatives and their primitives must have a definite range of measure. 展开更多
关键词 limiting direction Julia set entire function linear differential equation defi-ciency
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A NOTE ON THE JULIA SETS OF ENTIRE SOLUTIONS TO DELAY DIFFERENTIAL EQUATIONS 被引量:2
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作者 李叶舟 孙合庆 《Acta Mathematica Scientia》 SCIE CSCD 2023年第1期143-155,共13页
Let f be an entire solution of the Tumura-Clunie type non-linear delay differential equation.We mainly investigate the dynamical properties of Julia sets of f,and the lower bound estimates of the measure of related li... Let f be an entire solution of the Tumura-Clunie type non-linear delay differential equation.We mainly investigate the dynamical properties of Julia sets of f,and the lower bound estimates of the measure of related limiting directions is verified. 展开更多
关键词 delay differential equation dynamical properties Julia sets limiting directions
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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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An explicit finite volume element method for solving characteristic level set equation on triangular grids 被引量:1
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作者 Sutthisak Phongthanapanich Pramote Dechaumphai 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2011年第6期911-921,共11页
Level set methods are widely used for predicting evolutions of complex free surface topologies,such as the crystal and crack growth,bubbles and droplets deformation,spilling and breaking waves,and two-phase flow pheno... Level set methods are widely used for predicting evolutions of complex free surface topologies,such as the crystal and crack growth,bubbles and droplets deformation,spilling and breaking waves,and two-phase flow phenomena.This paper presents a characteristic level set equation which is derived from the two-dimensional level set equation by using the characteristic-based scheme.An explicit finite volume element method is developed to discretize the equation on triangular grids.Several examples are presented to demonstrate the performance of the proposed method for calculating interface evolutions in time.The proposed level set method is also coupled with the Navier-Stokes equations for two-phase immiscible incompressible flow analysis with surface tension.The Rayleigh-Taylor instability problem is used to test and evaluate the effectiveness of the proposed scheme. 展开更多
关键词 Keywords Characteristic level set equation - Finite volume element method Explicit method Triangular grid Twophase incompressible flow
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Analytical Solutions of System of Non-Linear Differential Equations in the Single-Enzyme, Single-Substrate Reaction with Non-Mechanism-Based Enzyme Inactivation 被引量:2
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作者 Govindhan Varadharajan Lakshmanan Rajendran 《Applied Mathematics》 2011年第9期1140-1147,共8页
A closed form of an analytical expression of concentration in the single-enzyme, single-substrate system for the full range of enzyme activities has been derived. The time dependent analytical solution for substrate, ... A closed form of an analytical expression of concentration in the single-enzyme, single-substrate system for the full range of enzyme activities has been derived. The time dependent analytical solution for substrate, enzyme-substrate complex and product concentrations are presented by solving system of non-linear differential equation. We employ He’s Homotopy perturbation method to solve the coupled non-linear differential equations containing a non-linear term related to basic enzymatic reaction. The time dependent simple analytical expressions for substrate, enzyme-substrate and free enzyme concentrations have been derived in terms of dimensionless reaction diffusion parameters ε, λ1, λ2 and λ3 using perturbation method. The numerical solution of the problem is also reported using SCILAB software program. The analytical results are compared with our numerical results. An excellent agreement with simulation data is noted. The obtained results are valid for the whole solution domain. 展开更多
关键词 non-linear Reaction equations ENZYME INACTIVATION HOMOTOPY PERTURBATION Method Time Dependent Analytical Solution
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Computer Methodologies for the Comparison of Some Efficient Derivative FreeSimultaneous Iterative Methods for Finding Roots of Non-Linear Equations 被引量:1
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作者 Yuming Chu Naila Rafiq +3 位作者 Mudassir Shams Saima Akram Nazir Ahmad Mir Humaira Kalsoom 《Computers, Materials & Continua》 SCIE EI 2021年第1期275-290,共16页
In this article,we construct the most powerful family of simultaneous iterative method with global convergence behavior among all the existing methods in literature for finding all roots of non-linear equations.Conver... In this article,we construct the most powerful family of simultaneous iterative method with global convergence behavior among all the existing methods in literature for finding all roots of non-linear equations.Convergence analysis proved that the order of convergence of the family of derivative free simultaneous iterative method is nine.Our main aim is to check out the most regularly used simultaneous iterative methods for finding all roots of non-linear equations by studying their dynamical planes,numerical experiments and CPU time-methodology.Dynamical planes of iterative methods are drawn by using MATLAB for the comparison of global convergence properties of simultaneous iterative methods.Convergence behavior of the higher order simultaneous iterative methods are also illustrated by residual graph obtained from some numerical test examples.Numerical test examples,dynamical behavior and computational efficiency are provided to present the performance and dominant efficiency of the newly constructed derivative free family of simultaneous iterative method over existing higher order simultaneous methods in literature. 展开更多
关键词 non-linear equation iterative method simultaneous method basins of attractions computational efficiency
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Exact Solutions and Invariant Sets to General Reaction-Diffusion Equation 被引量:1
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作者 JIA Hua-Bing XU Wei 《Communications in Theoretical Physics》 SCIE CAS CSCD 2008年第6期1389-1392,共4页
In this paper, we introduce new invariant sets, and the invariant sets and exact solutions to general reactiondiffusion equation are discussed. It is shown that there exist a class of exact solutions to the equations ... In this paper, we introduce new invariant sets, and the invariant sets and exact solutions to general reactiondiffusion equation are discussed. It is shown that there exist a class of exact solutions to the equations that belong to the invariant sets. 展开更多
关键词 invariant set exact solution general reaction-diffusion equation rotation group scaling group
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Approximate Solution of Non-Linear Reaction Diffusion Equations in Homogeneous Processes Coupled to Electrode Reactions for CE Mechanism at a Spherical Electrode 被引量:2
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作者 A. Eswari S. Usha L. Rajendran 《American Journal of Analytical Chemistry》 2011年第2期93-103,共11页
A mathematical model of CE reaction schemes under first or pseudo-first order conditions with different diffusion coefficients at a spherical electrode under non-steady-state conditions is described. The model is base... A mathematical model of CE reaction schemes under first or pseudo-first order conditions with different diffusion coefficients at a spherical electrode under non-steady-state conditions is described. The model is based on non-stationary diffusion equation containing a non-linear reaction term. This paper presents the complex numerical method (Homotopy perturbation method) to solve the system of non-linear differential equation that describes the homogeneous processes coupled to electrode reaction. In this paper the approximate analytical expressions of the non-steady-state concentrations and current at spherical electrodes for homogeneous reactions mechanisms are derived for all values of the reaction diffusion parameters. These approximate results are compared with the available analytical results and are found to be in good agreement. 展开更多
关键词 non-linear Reaction/Diffusion equation HOMOTOPY PERTURBATION Method CE Mechanism Reduction of Order SPHERICAL ELECTRODES
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On Computer Implementation for Comparison of Inverse Numerical Schemes for Non-Linear Equations 被引量:1
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作者 Mudassir Shams Naila Rafiq +3 位作者 Nazir Ahmad Mir Babar Ahmad Saqib Abbasi Mutee-Ur-Rehman Kayani 《Computer Systems Science & Engineering》 SCIE EI 2021年第3期493-507,共15页
In this research article,we interrogate two new modifications in inverse Weierstrass iterative method for estimating all roots of non-linear equation simultaneously.These modifications enables us to accelerate the con... In this research article,we interrogate two new modifications in inverse Weierstrass iterative method for estimating all roots of non-linear equation simultaneously.These modifications enables us to accelerate the convergence order of inverse Weierstrass method from 2 to 3.Convergence analysis proves that the orders of convergence of the two newly constructed inverse methods are 3.Using computer algebra system Mathematica,we find the lower bound of the convergence order and verify it theoretically.Dynamical planes of the inverse simultaneous methods and classical iterative methods are generated using MATLAB(R2011b),to present the global convergence properties of inverse simultaneous iterative methods as compared to classical methods.Some non-linear models are taken from Physics,Chemistry and engineering to demonstrate the performance and efficiency of the newly constructed methods.Computational CPU time,and residual graphs of the methods are provided to present the dominance behavior of our newly constructed methods as compared to existing inverse and classical simultaneous iterative methods in the literature. 展开更多
关键词 non-linear equation inverse iterative method simultaneous method basins of attraction lower bound of convergence
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Double Elzaki Transform Decomposition Method for Solving Non-Linear Partial Differential Equations 被引量:1
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作者 Moh A. Hassan Tarig M. Elzaki 《Journal of Applied Mathematics and Physics》 2020年第8期1463-1471,共9页
In this paper, we discuss a new method employed to tackle non-linear partial differential equations, namely Double Elzaki Transform Decomposition Method (DETDM). This method is a combination of the Double ELzaki Trans... In this paper, we discuss a new method employed to tackle non-linear partial differential equations, namely Double Elzaki Transform Decomposition Method (DETDM). This method is a combination of the Double ELzaki Transform and Adomian Decomposition Method. This technique is hereafter provided and supported with necessary illustrations, together with some attached examples. The results reveal that the new method is very efficient, simple and can be applied to other non-linear problems. 展开更多
关键词 Double Elzaki Transform Adomian Decomposition Method non-linear Partial Differential equations
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Differential characteristic set algorithm for the complete symmetry classification of partial differential equations
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作者 特木尔朝鲁 白玉山 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2009年第5期595-606,共12页
In this paper, we present a differential polynomial characteristic set algorithm for the complete symmetry classification of partial differential equations (PDEs) with some parameters. It can make the solution to th... In this paper, we present a differential polynomial characteristic set algorithm for the complete symmetry classification of partial differential equations (PDEs) with some parameters. It can make the solution to the complete symmetry classification problem for PDEs become direct and systematic. As an illustrative example, the complete potential symmetry classifications of nonlinear and linear wave equations with an arbitrary function parameter are presented. This is a new application of the differential form characteristic set algorithm, i.e., Wu's method, in differential equations. 展开更多
关键词 partial differential equations SYMMETRY CLASSIFICATION differential characteristic set
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Existence and Uniqueness for a Solution on the Closed Subset to the Cauchy Problem of Fuzzy Differential Equation
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作者 吴从怠 宋士吉 齐宗豫 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 1997年第2期1-7,共7页
By using the concept of H differentiability due to Puri and Ralescu,we consider the Cauchy problem of fuzzy differential equation for the fuzzy set valued mappings of a real variable whose values are normal, convex,... By using the concept of H differentiability due to Puri and Ralescu,we consider the Cauchy problem of fuzzy differential equation for the fuzzy set valued mappings of a real variable whose values are normal, convex, upper semicontinuous and compact supporting fuzzy sets in R n , and obtain the existence and uniqueness theorem for a solution on the closed subset of ( E n,D ). 展开更多
关键词 FUZZY set valued mapping FUZZY derivative FUZZY DIFFERENTIAL equation
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ON RADII OF ABSORBING SETS FOR KURAMOTOSIVASHINSKY EQUATION
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作者 王冠香 刘曾荣 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 1999年第7期28-37,共10页
In this article sharper estimates on the radii of absorbing sets for the Kuramoto_Sivashinsky equation are given. It is proved that radii of absorbing sets will decay to zero as the coefficient of viscosity tends to a... In this article sharper estimates on the radii of absorbing sets for the Kuramoto_Sivashinsky equation are given. It is proved that radii of absorbing sets will decay to zero as the coefficient of viscosity tends to a certain critical value, which is more reasonable in the physical sence compared with classical results. 展开更多
关键词 K_S equation uniform estimate absorbing set
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THE INERTIAL SETS OF EQUATION FOR THE FLOW AND MAGNETIC FIELD WITHIN THE EARTH
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作者 戴正德 屈超纯 《Acta Mathematica Scientia》 SCIE CSCD 1996年第S1期143-152,共10页
In this paper we consider a class of equations for the flow and magnetic field within the earth, for initial-boundary value problem, we prove existence of inertial sets and it's fractal dimension has been given, t... In this paper we consider a class of equations for the flow and magnetic field within the earth, for initial-boundary value problem, we prove existence of inertial sets and it's fractal dimension has been given, the squeezing rate to inertial sets from trajectory of absorbing set has been estimated. 展开更多
关键词 Inertial fractal sets F-M equation fractal dimension
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Stability of Semi-implicit Finite Volume Scheme for Level Set Like Equation
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作者 Kim Kwang-il Son Yong-chol Ma Fu-ming 《Communications in Mathematical Research》 CSCD 2015年第4期351-361,共11页
We study numerical methods for level set like equations arising in image processing and curve evolution problems. Semi-implicit finite volume-element type schemes are constructed for the general level set like equati... We study numerical methods for level set like equations arising in image processing and curve evolution problems. Semi-implicit finite volume-element type schemes are constructed for the general level set like equation (image selective smoothing model) given by Alvarez et al. (Alvarez L, Lions P L, Morel J M. Image selective smoothing and edge detection by nonlinear diffusion II. SIAM J. Numer. Anal., 1992, 29: 845-866). Through the reasonable semi-implicit discretization in time and co-volume method for space approximation, we give finite volume schemes, unconditionally stable in L∞ and W1'2 (W1'1) sense in isotropic (anisotropic) diffu- sion domain. 展开更多
关键词 level set like equation SEMI-IMPLICIT finite volume scheme STABILITY
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VALUE DISTRIBUTION OF MEROMORPHIC SOLUTIONS OF CERTAIN NON-LINEAR DIFFERENCE EQUATIONS
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作者 Minfeng CHEN Zongsheng GAO Jilong ZHANG 《Acta Mathematica Scientia》 SCIE CSCD 2019年第4期1173-1184,共12页
In this article, we consider the non-linear difference equation(f(z + 1)f(z)-1)(f(z)f(z-1)-1) =P(z, f(z))/Q(z, f(z)),where P(z, f(z)) and Q(z, f(z)) are relatively prime polynomials in f(z) with rational coefficients.... In this article, we consider the non-linear difference equation(f(z + 1)f(z)-1)(f(z)f(z-1)-1) =P(z, f(z))/Q(z, f(z)),where P(z, f(z)) and Q(z, f(z)) are relatively prime polynomials in f(z) with rational coefficients. For the above equation, the order of growth, the exponents of convergence of zeros and poles of its transcendental meromorphic solution f(z), and the exponents of convergence of poles of difference △f(z) and divided difference △f(z)/f(z)are estimated. Furthermore, we study the forms of rational solutions of the above equation. 展开更多
关键词 non-linear DIFFERENCE equation MEROMORPHIC SOLUTION RATIONAL SOLUTION value dist ribution
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Analytical solution of basic equations set of atmospheric motion
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作者 施惟慧 沈春 王曰朋 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2007年第3期385-394,共10页
On condition that the basic equations set of atmospheric motion possesses the best stability in the smooth function classes, the structure of solution space for local analytical solution is discussed, by which the thi... On condition that the basic equations set of atmospheric motion possesses the best stability in the smooth function classes, the structure of solution space for local analytical solution is discussed, by which the third-class initial value problem with typ- icality and application is analyzed. The calculational method and concrete expressions of analytical solution about the well-posed initial value problem of the third-kind are given in the analytic function classes. Near an appointed point, the relevant theoretical and computational problems about analytical solution of initial value problem are solved completely in the meaning of local solution. Moreover, for other type ofproblems for determining solution, the computational method and process of their stable analytical solution can be obtained in a similar way given in this paper. 展开更多
关键词 basic equations set of atmospheric motion structure of solution space analytical solution
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Stability Criteria of Solutions for Stochastic Set Differential Equations
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作者 Ho Vu Nguyen Ngoc Phung +1 位作者 Ngo Van Hoa Nguyen Dinh Phu 《Applied Mathematics》 2012年第4期354-359,共6页
The existence and uniqueness results on solutions of set stochastic differential equation were studied in [1]. In this paper, we present the stability criteria for solutions of stochastic set differential equation.
关键词 STOCHASTIC set DIFFERENTIAL equation STABILITY EXPONENTIAL STABILITY
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