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1.
The interior Radon transform arises from a limited data problem in computerized tomography. The corresponding operator R is investigated as a mapping between wightedL 2-spaces. Our result is the explicit construction of a singular value decomposition for R. This immediately leads to an inversion formula by series expansion and range characterizations. Foundation item: Supported by the Foundation of the Ministry of Education of China and the Science Foundation of Wuhan University Biography: WANG Jin-ping (1963-), male, Ph.D candidate, Research interests are in numerical solution of singular integral equation and integral transformation.  相似文献   

2.
The iterative solution for a class of multivalued monotone operator equations just likeA(u)∈−B(u) is discussed, whereA is a positive definite linear single-valued operator,B is a bounded and monotone multivalued operator. The existence and convergence of approximate solutions are proved. The method of numerical realization is demonstrated in some examples. Foundation item: Supported by the National Natural Science foundation of China Biography: XIAO Jin-sheng (1975-), male, Ph.D. Candidate. Current research interest is in the approximate solution of differential equation.  相似文献   

3.
The principles of Gradient operator, Laplacian operator, LOG operator and Sobel operator are discussed. Certain features of breast can be extracted in different degrees and aspects from original images by applying four edge sharpening operators to the breast near-infrared imaging. A great number of cases prove that compared with the other three operators, the improved Sobel operator can effectively extract the structural features of the breast from an original image. It can be concluded that the improved Sobel operator can assist in diagnosing breast diseases. Foundation item: Supported by the Enterprise Innovation Foundation of Wuhan Biography: Xiang Yan (1979-), female, Master candidate, research direction: biomedical engineering and biophysics.  相似文献   

4.
This paper studies the initial value problem for the Liouville equation by using the operator semigroup theory and shows existence and uniqueness of the solution to this problem if initial data belong to some subset ofL 2. Supported by the National Natural Science Foundation of China Jiang Zhenglu: born in Dec. 1966, Post Ph. D  相似文献   

5.
In this paper, we have proved some special properties of singular integral operators which are transformed from the singular integral equation defined in the interval (−1, 1), i.e., the properties of singular intergral operators at the endpoints and in the inner of (−1, 1). Foundation item: Supported by the Science Foundation of SEC of China and Foundation of Wuhan University. Biography: GONG Ya-fang (1973-), male, Ph. D candidate. Current research interest is in numerical solution of singular integral equation.  相似文献   

6.
This paper investigates the competition diffusion model with delay. The existence and stability of nontrivial steady state are studied. Foundation item: Supported by the National Natural Science Foundation of China Biography: ZHOU Li (1939-), male, Professor, research interest is in partial differential equation.  相似文献   

7.
差分方程的不变子空间   总被引:1,自引:0,他引:1  
研究了差分方程的不变子空间,讨论了多项式形式的子空间及三角函数型的子空间,并将这两类不变子空间运用到了拟线性演化方程和方程组。得到了以下结果:若已有的微分算子允许某一类不变子空间,则对应的差分方程也允许相应的不变子空间,且其系数满足一样的动力系统。  相似文献   

8.
The flowshop scheduling problem is NP complete. To solve it by genetic algorithm, an efficient crossover operator is designed. Compared with another crossover operator, this one often finds a better solution within the same time. Supported by the National Natural Science Foundation of China and 863 High Technology Project of China Qi Yuesheng: born in 1967, Ph. D.  相似文献   

9.
The reflective function of differential system   总被引:1,自引:0,他引:1  
This article deals with the reflective function of the differential systems. The results are applied to discussion of the existence and stability of the periodic solutions of these systems. Foundation item: Supported by the National Natural Science Foundation of Jiangsu Educational Committee (02 KJB 110009) Biography: Zhou Zheng-xin(1962-), female, Ph. D, Associate professor, research interests: ordinary differential equation.  相似文献   

10.
结合算子理论的相关知识,将矩阵方程的某些结果推广到相应的算子方程上.讨论无限维Hilbert空间上算子方程X^s+A^eX^-tA—I(s〉0,t〉0)的正算子解及其解的范围.  相似文献   

11.
定义了两种子:(Ⅰ)型算子与(Ⅱ)型算子,证明了下列定理,若Banach空间X上线性连续算子T:X→X是(Ⅰ)型算子或(Ⅱ)型算子,则T满足Daugavet方程‖I+T‖=1+‖T‖的充要条件是算子T的范数‖T‖是T的特征值。另一方面,给出了该结果的应用。例如,由此断言,弱局部一致凸Banach空间X上紧算子T:X→X满足Daugavet方程的充要条件是范数‖T‖的T的特征值。  相似文献   

12.
文章研究了确定KdV方程的相应Hamilton算子序列显式表示的各种计算机符号运算问题.利用算子序列的显式表示和Mathematica软件计算得到Hamilton算子序列前六项的具体表达式,其结果可适用于一般情形,对进一步研究Hamilton算子序列及其相应水波方程具有指导作用.  相似文献   

13.
We mainly consider a class of two dimensional normal type singular integral equations, the solutions as well as the conditions of solvability of which are obtained. The methods used consist of transferring them to several one dimensional Riemann boundary value problems, and then solving the latter. Foundation item: Supported by the National Natural Science Foundation of China. Biography: ZHANG Zhong-xiang (1975-), male, Ph. D. Candidate. Current research interests are in singular integral equation and its application.  相似文献   

14.
提出了一种基于物种方程和Kriging算子的多种群遗传算法。该算法中,将物种方程中的参数作为设计变量进行实数编码,物种方程作为一种修正的算术交叉算子参与遗传操作;同时,加入Kriging算子和移民算子,增强算法寻优能力,加快收敛。数学算例表明,改进的算法在计算效率和精度上都有明显的提高。  相似文献   

15.
By using complex variable methods, the boundary value problem for biharmonic functions arisen from the theory of clamped elastic thin plate is shown to be equivalent to the first fundamental problem in plane elasticity which, as well-known, may be easily solved by reduction to a Fredholm integral equation. The case of circular plate is illustrated in detail, the solution of which is obtained in closed form. Foundation item: Supported by the National Natural Science Foundation of China (No. 19871064) Biography: LU Jian-ke(1922-), male, Professor. Research interests are in applications of complex variables.  相似文献   

16.
This paper discusses complete binary trees as chromosomes of Genetic Algorithm (GA), and proposes the concept of dominant and recessive genes. On the base of it, a new crossover operator with the selective ability was designed. Finally experimental results are presented. Supported by the National Natural Science Foundation of China and State Education Committee Doctoral Foundation Kang Lishan born in 1934, Professor  相似文献   

17.
This paper discusses complete binary trees as chromosomes of Genetic Algorithm (GA), and proposes the concept of dominant and recessive genes. On the base of it, a new crossover operator with the selective ability was designed. Finally experimental results are presented. Supported by the National Natural Science Foundation of China and State Education Committee Doctoral Foundation Kang Lishan born in 1934, Professor  相似文献   

18.
When acquaintances of a model are little or the model is too complicate to build by using traditional time series methods, it is convenient for us to take advantage of genetic programming (GP) to build the model. Considering the complexity of nonlinear dynamic systems, this paper proposes modeling dynamic systems by using the nonlinear difference equation based on GP technique. First it gives the method, criteria and evaluation of modeling. Then it describes the modeling algorithm using GP. Finally two typical examples of time series are used to perform the numerical experiments. The result shows that this algorithm can successfully establish the difference equation model of dynamic systems and its predictive result is also satisfactory. Foundation item: Supported by Foundation for University Key Teacher by the Ministry of Education of China Biography: Liu Min ( 1978-), female, Master candidate, research derection: application mathematics.  相似文献   

19.
On the approximation solvability of the abstract differential inclusion   总被引:1,自引:0,他引:1  
The approximation solvability of the abstract differential inclusion du/dtf(t,u) is presented. The convergence of the approximation solution and the existence of the solution for abstract evolution multivalued problem are discussed. Foundation item: Supported by the National Natural Science Foundation of China (No. 19771062) Biography: Xia Jin-sheng (1975-), Ph.D candidate, research interest: the approximate solution of differential equation.  相似文献   

20.
在任意实Bnach空间中,设T是Lipschitz的k-次增生算子,研究了Ishikawa迭代过程关于含有算子T的方程的T-稳定性,推广了一些已知的结果.  相似文献   

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