共查询到20条相似文献,搜索用时 109 毫秒
1.
本文主要讨论组合地图列举问题.刘的一部专著中提出了一个判定两个地图是否同构的算法.该算法的时间复杂度为O(m2),其中m为下图的规模.在此基础上,本文给出一个用于地图列举以及进而计算任意连通下图的地图亏格分布的通用算法.本文所得结果比之前文献中所给结果更优. 相似文献
2.
In this work,di erent kinds of traveling wave solutions and uncategorized soliton wave solutions are obtained in a three dimensional(3-D)nonlinear evolution equations(NEEs)through the implementation of the modi ed extended direct algebraic method.Bright-singular and dark-singular combo solitons,Jacobi's elliptic functions,Weierstrass elliptic functions,constant wave solutions and so on are attained beside their existing conditions.Physical interpretation of the solutions to the 3-D modi ed KdV-Zakharov-Kuznetsov equation are also given. 相似文献
3.
In this article, we introduce a robust sparse test statistic which is based on the maximum type statistic. Both the limiting null distribution of the test statistic and the power of the test are analysed. It is shown that the test is particularly powerful against sparse alternatives. Numerical studies are carried out to examine the numerical performance of the test and to compare it with other tests available in the literature. The numerical results show that the test proposed significantly outperforms those tests in a range of settings, especially for sparse alternatives. 相似文献
4.
In this paper,we consider the one dimensional third order p-Laplacian equation■u′′(0)=0.By using kernel functions and the Avery-Peterson fixed point theorem,we establish the existence of at least three positive solutions. 相似文献
5.
中国数学会第十次全国代表大会暨2007学术年会11月2日在北京航空航天大学开幕,这是中国数学会历史上规模最大的一次全国代表大会.教育部副部长吴启迪、中国科协书记处书记冯长根、北京航空航天大学校长李未及中科院、科技部等单位的相关领导、嘉宾出席开幕式. 相似文献
6.
This paper deals with an inverse problem for recovering the piecewise constant viscoelasticity of a living body from MRE(Magnetic Resonance Elastography)data.Based on a scalar partial differential equation whose solution can approximately simulate MRE data,our inverse coefficient problem is considered as a statistical inverse problem of reconstructing the posterior distribution of unknown viscoelastic modulus.For sampling this distribution,one usually can use the Metropolis-Hastings Markov chain Monte Carlo(MHMCMC)algorithm.However,without an appropriate"proposal"distribution given artificially,the MH-MCMC algorithm is hard to draw samples efficiently.To avoid this,a so-called slice sampling algorithm is introduced in this paper and applied for solving our problem.The performance of these statistical inversion algorithms is numerically tested basing on simulated data. 相似文献
7.
This paper is devoted to the study of the solitary wave solutions for the delayed coupled Higgs field equation{vtt-uxx-αu+βf*u|u|2-2uv-τu(|u|2)x=0 vtt+vxx-β(|u|x)xx=0.We first establish the existence of solitary wave solutions for the corresponding equation without delay and perturbation by using the Hamiltonian system method.Then we consider the persistence of solitary wave solutions of the delayed coupled Higgs field equation by using the method of dynamical system,especially the geometric singular perturbation theory,invariant manifold theory and Fredholm theory.According to the relationship between solitary wave and homoclinic orbit,the coupled Higgs field equation is transformed into the ordinary differential equations with fast variables by using the variable substitution.It is proved that the equations with perturbation also possess homoclinic orbit,and thus we obtain the existence of solitary wave solutions of the delayed coupled Higgs field equation. 相似文献
8.
马文秀 《数学物理学报(B辑英文版)》2022,(1):127-140
The paper aims at establishing Riemann-Hilbert problems and presenting soliton solutions for nonlocal reverse-time nonlinear Schrodinger(NLS) hierarchies associated with higher-order matrix spectral problems.The Sokhotski-Plemelj formula is used to transform the Riemann-Hilbert problems into Gelfand-Levitan-Marchenko type integral equations.A new formulation of solutions to special Riemann-Hilbert problems with the identity jump matrix,corresponding to the reflectionless inverse scattering transforms,is proposed and applied to construction of soliton solutions to each system in the considered nonlocal reversetime NLS hierarchies. 相似文献
9.
马文秀 《数学物理学报(B辑英文版)》2022,(1)
The paper aims at establishing Riemann-Hilbert problems and presenting soliton solutions for nonlocal reverse-time nonlinear Schrodinger(NLS) hierarchies associated with higher-order matrix spectral problems.The Sokhotski-Plemelj formula is used to transform the Riemann-Hilbert problems into Gelfand-Levitan-Marchenko type integral equations.A new formulation of solutions to special Riemann-Hilbert problems with the identity jump matrix,corresponding to the reflectionless inverse scattering transforms,is proposed and applied to construction of soliton solutions to each system in the considered nonlocal reversetime NLS hierarchies. 相似文献
10.
朱琳 《高等学校计算数学学报》2021,43(1):83-96
Based on the maximum principle,the difference formula defined on a non-integral node is given to approximate the fractional Riemann-Liouville derivative and the finite difference scheme for solving one-dimensional space fractional diffusion equations(FDEs) with variable coefficients is presented.Furthermore,using the maximum principle the scheme is proved unconditionally stable and secondorder accuracy in spatial grid size.Several numerical examples are given to verify the efficiency of the scheme. 相似文献
11.
自然数幂和公式的另一种计算机实现方法 总被引:1,自引:0,他引:1
龚飞兵 《数学的实践与认识》2006,36(8):364-366
自然数幂和问题,许多文献给出不同算法,借助M ATLAB系统,利用自然数幂和的矩阵算法,给出可计算所有小于任意指定自然数m的自然数幂和公式的计算机实现方法. 相似文献
12.
In problems of topology and analysis, well-known theorem on the preservation by any continuous homotopy of the property of a mapping to have a fixed point and the property of a pair of mappings to have a coincidence point are extensively applied. Thus, for contraction mappings and some of their generalizations, Frigon’s results on the preservation of the property to have a fixed point by a homotopy of a special type are known. This paper presents theorems on the preservation by order homotopy of the property of a pair of mappings to have a coincidence point. As a corollary, conditions under which such a homotopy preserves the property of a mapping to have a fixed point are obtained. 相似文献
13.
定义L上加细的半拓扑生成序在GOH下的象和逆象,研究L上加细的拓扑共生结构的象和逆象,得到一些重要性质。 相似文献
14.
Dr. Peter C. Fishburn 《International Journal of Game Theory》1971,1(1):65-71
Contrary to what appears to have become an accepted part of the folklore of game theory, a finite two-person zero-sum game with non-Archimedean utilities may have no equilibrium-point solution, and either one or both players may have no “minimax” strategy. Even when both players have “minimax” strategies, such a game may lack an equilibrium point. 相似文献
15.
对区间长度为定值均匀分布位置参数的点估计量进行了研究,得到位置参数点估计量的渐近分布.讨论了渐近分布的相关性质.给出了位置参数的区间估计及其假设检验方法. 相似文献
16.
本文研究了有三个种群相互作用的数学模式: 我们分别建立了系统(*)和(**)存在唯一的大范围渐近稳定的正周期解的充分条件. 相似文献
17.
The equations of motion governing the inrun and free-flight phases of a ski-jump have been set down. These equations have been used as the basis for a numerical scheme from which the in-flight trajectory and jump length have been calculated. The influence of such factors as the friction between the skis and snow, the jump technique at take-off, the angle of incidence of the airborne jumper and variations in air density have been investigated. Jump lengths consistent with those measured on the 90 m Sapporo ski-slope have been computed. Deductions are made concerning critical aspects of ski-jump technique. 相似文献
18.
S.R. Chakravorti 《Journal of multivariate analysis》1974,4(1):31-51
In this article, we have considered the problem of testing equality of several growth curves under Behrens-Fisher situation. In this context, the robustness of the existing test criteria have been studied. Also, some exact test procedures have been considered and the exact and asymptotic noncentral distribution problems have been studied. 相似文献
19.
《Communications in Nonlinear Science & Numerical Simulation》2010,15(3):629-636
We have studied the interaction of optical phonons with photons. So, we have calculated the coupled modes of photons and transverse optical phonons and likewise, the dielectric function. We have found an alternative relation of the splitting between the frequencies of the longitudinal optical (LO) and transverse optical (TO) phonons in crystals. Likewise, we have studied the plasmon resonance frequency. We have determined the phonon–photon and the plasmon–photon coupling constant in ionic crystals and in metals, respectively, which is very close to the elastic force constant, and we have evaluated the bulk modulus. Further we have applied these results to tetrahedrally bonded III–V semiconductors. 相似文献
20.
将文献[1]给出的由一维连续型随机变量的概率密度函数构造二维连续型随机变量的概率密度函数的方法,推广为由一维连续型随机变量的概率密度函数构造三维连续型随机变量的概率密度函数的情况,并作出了证明和举例说明.说明利用本文的方法构造多维概率密度函数,其方法简单易行. 相似文献