期刊文献+
共找到1,032篇文章
< 1 2 52 >
每页显示 20 50 100
Fuzzy Difference Equations in Diagnoses of Glaucoma from Retinal Images Using Deep Learning
1
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
下载PDF
A NOTE ON THE JULIA SETS OF ENTIRE SOLUTIONS TO DELAY DIFFERENTIAL EQUATIONS
2
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
下载PDF
LIMITING DIRECTIONS OF JULIA SETS OF ENTIRE SOLUTIONS TO COMPLEX DIFFERENTIAL EQUATIONS 被引量:1
3
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
下载PDF
Invariant Sets and Exact Solutions to Higher-Dimensional Wave Equations 被引量:11
4
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
不变的集合和准确答案(1+ 2 ) 维的波浪方程被讨论。在那里存在,这被显示出属于不变的集合 E <SUB>0</SUB>= 的方程的答案的一个类 { u:u <SUB > x </SUB>= v <SUB > x </SUB > F (u) , u <S... 不变的集合和准确答案(1+ 2 ) 维的波浪方程被讨论。在那里存在,这被显示出属于不变的集合 E <SUB>0</SUB>= 的方程的答案的一个类 { u:u <SUB > x </SUB>= v <SUB > x </SUB > F (u) , u <SUB > y </SUB>= v <SUB > y </SUB > F (u)} 。这条途径也被开发解决(1 + N ) 维的波浪方程。 展开更多
关键词 波动方程 不变集 精确解 解题方法
下载PDF
Differential characteristic set algorithm for the complete symmetry classification of partial differential equations
5
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
下载PDF
Analytical solution of basic equations set of atmospheric motion
6
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
下载PDF
Stability Criteria of Solutions for Stochastic Set Differential Equations
7
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
下载PDF
Invariant Sets and Exact Solutions to Nonlinear Diffusion Equations with x-Dependent Convection and Absorption
8
作者 JIA Hua-Bing XU Wei 《Communications in Theoretical Physics》 SCIE CAS CSCD 2008年第10期821-826,共6页
<正> In this paper,we introduce a new invariant set _0={u:u_x=f'(x)F(u)+ε[g'(x)-f'(x)g(x)]F(u)×exp(-i∫~u 1/F(z) dz)},where f and g are some smooth functions of x,ε is a constant,and F is a sm... <正> In this paper,we introduce a new invariant set _0={u:u_x=f'(x)F(u)+ε[g'(x)-f'(x)g(x)]F(u)×exp(-i∫~u 1/F(z) dz)},where f and g are some smooth functions of x,ε is a constant,and F is a smooth function to bedetermined.The invariant sets and exact solutions to nonlinear diffusion equation u_t=(D(u)u_x)_x+Q(x,u)u_x+P(x,u),are discussed.It is shown that there exist several classes of solutions to the equation that belong to the invariant set _0. 展开更多
关键词 不变量组 求解方法 非线性扩散方程式 数学
下载PDF
A SINGULAR VALUE DECOMPOSITION BASED TRUNCATION ALGORITHM IN SOLVING THE STRUCTURAL DAMAGE EQUATIONS 被引量:6
9
作者 RenWei-Xin 《Acta Mechanica Solida Sinica》 SCIE EI 2005年第2期181-188,共8页
The structural damage identification through modal data often leads to solving a set of linear equations. Special numerical treatment is sometimes required for an accurate and stable solution owing to the ill conditio... The structural damage identification through modal data often leads to solving a set of linear equations. Special numerical treatment is sometimes required for an accurate and stable solution owing to the ill conditioning of the equations. Based on the singular value decomposition (SVD) of the coefficient matrix, an error based truncation algorithm is proposed in this paper. By rejection of selected small singular values, the influence of noise can be reduced. A simply-supported beam is used as a simulation example to compare the results to other methods. Illustrative numerical examples demonstrate the good efficiency and stability of the algorithm in the nondestructive identification of structural damage through modal data. 展开更多
关键词 linear equation set single value decomposition least-square method finite element method modal analysis damage identification structural dynamics
下载PDF
Global attractor of 2D autonomous g-Navier-Stokes equations 被引量:4
10
作者 姜金平 王小霞 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2013年第3期385-394,共10页
In this paper, the existence of global attractors for the 2D autonomous g- Navier-Stokes equations on multi-connected bounded domains is investigated under the general assumptions of boundaries. The estimation of the ... In this paper, the existence of global attractors for the 2D autonomous g- Navier-Stokes equations on multi-connected bounded domains is investigated under the general assumptions of boundaries. The estimation of the Hausdorff dimensions for global attractors is given. 展开更多
关键词 global attractor g-Navier-Stokes equation bounded absorbing set semi-group multi-connected bounded domain Hausdorff dimension
下载PDF
THE EXISTENCE OF SOLUTIONS OF NONLINEARFREDHOLM INTEGRAL EQUATIONS IN BANACH SPACES 被引量:3
11
作者 闫宝强 史国良 《Acta Mathematica Scientia》 SCIE CSCD 1998年第S1期114-119,共6页
This paper improves Tychonov ford point theorem and discusses the existence of solutions of nonlinear Fredholm integral equations on [0,+∞] in Banach spaces with Frechet space theory.
关键词 Fredholm equation Kuratowski measure of noncompactness locally equicontinuous set
下载PDF
MAXIMAL ATTRACTORS FOR THE COMPRESSIBLE NAVIER-STOKES EQUATIONS OF VISCOUS AND HEAT CONDUCTIVE FLUID 被引量:3
12
作者 秦玉明 宋锦萍 《Acta Mathematica Scientia》 SCIE CSCD 2010年第1期289-311,共23页
This article is concerned with the existence of maximal attractors in Hi (i = 1, 2, 4) for the compressible Navier-Stokes equations for a polytropic viscous heat conductive ideal gas in bounded annular domains Ωn i... This article is concerned with the existence of maximal attractors in Hi (i = 1, 2, 4) for the compressible Navier-Stokes equations for a polytropic viscous heat conductive ideal gas in bounded annular domains Ωn in Rn(n = 2,3). One of the important features is that the metric spaces H(1), H(2), and H(4) we work with are three incomplete metric spaces, as can be seen from the constraints θ 〉 0 and u 〉 0, with θand u being absolute temperature and specific volume respectively. For any constants δ1, δ2……,δ8 verifying some conditions, a sequence of closed subspaces Hδ(4) H(i) (i = 1, 2, 4) is found, and the existence of maximal (universal) attractors in Hδ(i) (i = 1.2.4) is established. 展开更多
关键词 compressible Navier Stokes equations polytropic viscous ideal gas spheri-cally symmetric solutions absorbing set maximal attractor
下载PDF
ASYMPTOTIC PROPERTIES OF FUNCTIONAL DIFFERENTIAL EQUATIONS IN BANACH SPACES 被引量:1
13
作者 Niu Jianren Den Jin Xu DaoyiDept.of Math.,Sichuan Univ.,Chengdu 610064,China. 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2003年第4期431-441,共11页
The paper is devoted to the asymptotic properties of functional differential equations in Banach spaces.The criteria of the invariant and attracting sets are obtained.Particularly, the sufficient condition of asymptot... The paper is devoted to the asymptotic properties of functional differential equations in Banach spaces.The criteria of the invariant and attracting sets are obtained.Particularly, the sufficient condition of asymptotic stability of the equilibrium point is given as the system has an equilibrium point.Several examples are also worked out to demonstrate the validity of the results. 展开更多
关键词 functional differential equations reaction diffusion equations invariant sets attracting sets
下载PDF
A Kind of Diophantine Equations in Finite Simple Groups 被引量:3
14
作者 曹珍富 《Northeastern Mathematical Journal》 CSCD 2000年第4期391-397,共7页
In this paper, we prove that if p, q are distinct primes, (p,q)≡(1,7) (mod 12) and Legendres symbol pq=1 , then the equation 1+p a=2 bq c+2 dp eq f has only solutions of the form (a,b,c,d,e,f)=... In this paper, we prove that if p, q are distinct primes, (p,q)≡(1,7) (mod 12) and Legendres symbol pq=1 , then the equation 1+p a=2 bq c+2 dp eq f has only solutions of the form (a,b,c,d,e,f)=(t,0,0,0,t,0), where t is a non negative integer. We also give all solutions of a kind of generalized Ramanujan Nagell equations by using the theories of imaginary quadratic field and Pells equation. 展开更多
关键词 exponential Diophantine equation generalized Ramanujan Nagell equation finite simple group difference set
下载PDF
An explicit finite volume element method for solving characteristic level set equation on triangular grids 被引量:1
15
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
下载PDF
On the Exponential Decay of Solutions for Some Kirchhoff-Type Modelling Equations with Strong Dissipation 被引量:1
16
作者 Yaojun Ye 《Applied Mathematics》 2010年第6期529-533,共5页
This paper deals with the initial boundary value problem for a class of nonlinear Kirchhoff-type equations with strong dissipative and source terms in a bounded domain, where and are constants. We obtain the global ex... This paper deals with the initial boundary value problem for a class of nonlinear Kirchhoff-type equations with strong dissipative and source terms in a bounded domain, where and are constants. We obtain the global existence of solutions by constructing a stable set in and show the energy exponential decay estimate by applying a lemma of V. Komornik. 展开更多
关键词 Kirchhoff-type equation Initial Boundary Value Problem Stable set EXPONENTIAL DECAY ESTIMATE
下载PDF
JULIA LIMITING DIRECTIONS OF ENTIRE SOLUTIONS OF COMPLEX DIFFERENTIAL EQUATIONS 被引量:1
17
作者 王珺 姚潇 张诚纯 《Acta Mathematica Scientia》 SCIE CSCD 2021年第4期1275-1286,共12页
For entire or meromorphic function f,a value θ∈[0,2π)is called a Julia limiting direction if there is an unbounded sequence{z_(n)}in the Julia set satisfying limn→∞ arg z_(n)=θ.Our main result is on the entire s... For entire or meromorphic function f,a value θ∈[0,2π)is called a Julia limiting direction if there is an unbounded sequence{z_(n)}in the Julia set satisfying limn→∞ arg z_(n)=θ.Our main result is on the entire solution f of P(z,f)+F(z)f^(s)=0,where P(z,f)is a differential polynomial of f with entire coefficients of growth smaller than that of the entire transcendental F,with the integer s being no more than the minimum degree of all differential monomials in P(z,f). We observe that Julia limiting directions of f partly come from the directions in which F grows quickly. 展开更多
关键词 Julia set meromorphic function Julia limiting direction complex differential equations
下载PDF
Existence and Uniqueness for a Solution on the Closed Subset to the Cauchy Problem of Fuzzy Differential Equation
18
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
ExistenceandUniquenessforaSolutionontheClosedSubsettotheCauchyProblemofFuzzyDifferentialEquationWUCongxin(吴... ExistenceandUniquenessforaSolutionontheClosedSubsettotheCauchyProblemofFuzzyDifferentialEquationWUCongxin(吴从)SONGShiji(宋士吉)... 展开更多
关键词 FUZZY set valued mapping FUZZY derivative FUZZY DIFFERENTIAL equatION
下载PDF
ON RADII OF ABSORBING SETS FOR KURAMOTOSIVASHINSKY EQUATION
19
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
下载PDF
ANALYTIC SOLUTIONS OF SYSTEMS OF FUNCTIONAL EQUATIONS
20
作者 Liu XinheDept. of Math., Guangxi Univ., Nanning 530004,China. 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2003年第2期129-137,共9页
Let r be a given positive number. Denote by D=D r the closed disc in the complex plane C whose center is the origin and radius is r. For any subset K of C and any integer m≥1, write A(D m,K)={f|f∶D m→K is a cont... Let r be a given positive number. Denote by D=D r the closed disc in the complex plane C whose center is the origin and radius is r. For any subset K of C and any integer m≥1, write A(D m,K)={f|f∶D m→K is a continuous map, and f|(D m)° is analytic}. For H∈ A(D m,C)(m≥2), f∈A(D,D) and z∈D, write Ψ H(f)(z)=H(z,f(z),...,f m-1(z)). Suppose F,G∈A(D 2n+1,C), and H k,K k∈A(D k,C), k=2,...,n. In this paper, the system of functional equations F(z,f(z),f 2(Ψ H 2(f)(z)),...,f n(Ψ H n(f)(z)),g(z),g 2(Ψ K 2(g)(z)),..., g n(Ψ K n(g)(z)))=0 G(z,f(z),f 2(Ψ H 2(f)(z)),...,f n(Ψ H n(f)(z)),g(z),g 2(Ψ K 2(g)(z)),..., g n(Ψ K n(g)(z)))=0(z∈D) is studied and some conditions for the system of equations to have a solution or a unique solution in A(D,D)×A(D,D) are given. 展开更多
关键词 functional equation analytic solution difference quotient functional space compact convex set fixed point.
下载PDF
上一页 1 2 52 下一页 到第
使用帮助 返回顶部