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1.
系统聚类分析中应注意的两类问题   总被引:2,自引:0,他引:2  
给出了选用九种相似性度量,用最短距离法聚类,结果互不相同的一个有趣的例子。对该例,用欧氏距离求出距离矩阵后,除用最短距离法聚类结果唯一外,用最长距离法、重心法、类平均法、离差平方和法聚类,结果均不唯一。  相似文献   

2.
用Rosen投影梯度法构造搜索方向经常要两次汁算投影负梯度,对此本文提出一种改进的方法.  相似文献   

3.
In this paper, we develop a new, simple, and accurate scheme to obtain approximate solution for nonlinear differential equation in the sense of Caputo‐Fabrizio operator. To derive this new predictor‐corrector scheme, which suits on Caputo‐Fabrizio operator, firstly, we obtain the corresponding initial value problem for the differential equation in the Caputo‐Fabrizio sense. Hence, by fractional Euler method and fractional trapeziodal rule, we obtain the predictor formula as well as corrector formula. Error analysis for this new method is derived. To test the validity and simplicity of this method, some illustrative examples for nonlinear differential equations are solved.  相似文献   

4.
高阶波动方程的时空估计与低能量散射   总被引:2,自引:1,他引:1  
苗长兴 《数学学报》1995,38(5):708-717
本文研究了高阶波动方程的低能量散射理论,基本工具是高阶线性波动方程解的时空估计.与经典的二阶波动方程解的时空估计证明不同,我们采用泛函分析的方法与待定指标技巧,首次给出了高阶线性波动方程的时空估计,藉此与非线性函数在齐次Sobolev空间中的估计,获得了高阶波动方程的低能量散射结论.与此同时,也得到了具临界增长的高阶波动方程的柯西问题在低能量条件下的整体存在唯一性.  相似文献   

5.
In this paper, we make a full analysis of a family of Boussinesq equations which include nonlinear dispersion by using the classical Lie method of infinitesimals. We consider travelling wave reductions and we present some explicit solutions: solitons and compactons.For this family, we derive nonclassical and potential symmetries. We prove that the nonclassical method applied to these equations leads to new symmetries, which cannot be obtained by Lie classical method. We write the equations in a conserved form and we obtain a new class of nonlocal symmetries. We also obtain some Type-II hidden symmetries of a Boussinesq equation.  相似文献   

6.
In this paper, we introduce a new method of producing functionalrelations among multiple zeta-functions. This method can beregarded as a kind of multiple analogue of Hardy's one of provingthe functional equation for the Riemann zeta-function. Usingthis method, we give new functional relations for multiple zeta-functions.In particular, substituting positive integers into variablesof them, we obtain known relation formulas for the multiplezeta-values. Furthermore, applying our method to a certain seriesinvolving hyperbolic sine functions, we can obtain certain multipleanalogues of the known results given by Cauchy, Ramanujan, Berndtand so on.  相似文献   

7.
In this paper, we obtain the quantitative bound of the exponential convergence rates of Markov chains under a weaken minorization condition, using the coupling method and the analytic approach. And also, we obtain the convergence rates for continuous time Markov processes.  相似文献   

8.
In this paper we use some results on weighing matrices W (2 n ,9) constructed using two circulants to obtain infinite classes of orthogonal designs. We also present a method that is used to construct two directed sequences of length n and specific type. We apply this method to W (2 n , 9) and we obtain many new pairs of directed sequences of length n and type $(9 \cdot 2^m,9 \cdot 2^m), \ m=0,1,2,3.$ Using these directed sequences we can obtain many new infinite classes of weighing matrices W (2 n , k ), and orthogonal designs OD (2 n ; a,b) constructed from two circulants.  相似文献   

9.
In this paper, we introduce the concept of norm-to-weak continuous process in a Banach space, and obtain the existence of pullback attractors for this kind of process. Then we give a new method for proving the existence of the pullback attractors. As an application, we obtain the existence of pullback attractors for nonautonomous reaction–diffusion equation in with exponential growth of the external force.  相似文献   

10.
The nonlinear complementarity problem can be reformulated as a nonlinear programming. For solving nonlinear programming, sequential quadratic programming (SQP) type method is very effective. But the QP subproblem may be inconsistent. In this paper, we propose a kind nonmonotone filter method in which the QP subproblem is consistent. By means of nonmonotone filter, this method has no demand on the penalty parameter which is difficult to obtain. Moreover, the restoration phase is not needed any more. Under reasonable conditions, we obtain the global convergence of the algorithm. Some numerical results are presented.  相似文献   

11.
In this paper we consider a special fifth-order KdV equation with constant coefficients and we obtain traveling wave solutions for it, using the projective Riccati equation method. By mean of a scaling, exact solutions to general Kaup-Kupershmidt (KK) equation are obtained. As a particular case, exact solutions to standard KK equation can be derived. Using the same method, we obtain exact solutions to standard Ito equation. By mean of scaling, new exact solutions to general Ito equation are formally derived.  相似文献   

12.
The purpose of this paper is to present a general method that allows us to study self-improving properties of generalized Poincaré inequalities. When measuring the oscillation in a given cube, we replace the average by an approximation of the identity or a semigroup scaled to that cube and whose kernel decays fast enough. We apply the method to obtain self-improvement in the scale of Lebesgue spaces of Poincaré type inequalities. In particular, we propose some expanded Poincaré estimates that take into account the lack of localization of the approximation of the identity or the semigroup. As a consequence of this method we are able to obtain global pseudo-Poincaré inequalities.  相似文献   

13.
14.
利用直接方法研究了非线性对流扩散方程的守恒律,得到了关于非线性对流扩散方程的守恒律乘子性质的一个定理.利用这个定理,可以简化守恒律乘子的确定方程.随后通过对确定方程中的变量函数进行分析,发现在四种情况下乘子的确定方程是可解的.最后解出这些守恒律乘子,利用积分公式法分别得到了四种情况下对应于各个守恒律乘子的守恒律.  相似文献   

15.
在Banach空间中研究非线性算子方程F(x)=0的近似求解问题.首先,把实函数数值积分的梯形公式推广到非线性泛函的Bochner积分中来,得到Bochner积分的梯形公式;然后,利用这一公式来构造牛顿迭代法的变形格式,从而得到梯形牛顿法,并在弱条件的α-判据下借助于优函数技巧证明了它的收敛性.  相似文献   

16.
In this article, the Exp‐function method is applied to nonlinear Burgers equation and special fifth‐order partial differential equation. Using this method, we obtain exact solutions for these equations. The method is straightforward and concise, and its applications are promising. This method can be used as an alternative to obtain analytical and approximate solutions of different types of nonlinear differential equations. © 2009 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 2010  相似文献   

17.
In this paper, we introduce a one-parametric class of smoothing functions, which enjoys some favourable properties and includes two famous smoothing functions as special cases. Based on this class of smoothing functions, we propose a regularization Newton method for solving the non-linear complementarity problem. The main feature of the proposed method is that it uses a perturbed Newton equation to obtain the direction. This not only allows our method to have global and local quadratic convergences without strict complementarity conditions, but also makes the regularization parameter converge to zero globally Q-linearly. In addition, we use a new non-monotone line search scheme to obtain the step size. Some numerical results are reported which confirm the good theoretical properties of the proposed method.  相似文献   

18.
关于多个子空间的交空间   总被引:2,自引:2,他引:0  
关于多个子空间的交空间 ,到目前为止还没有一个行之有效的直接求法 .本文首先证明了关于分块矩阵的两个重要结果 ,由此得到了一个求多个子空间的交空间的直接方法——初等变换法 .  相似文献   

19.
两个新的Bonnesen型不等式   总被引:1,自引:0,他引:1  
本文研究了Bonnesen型不等式.利用积分几何方法,得到了两个新的Bonnesen型不等式.  相似文献   

20.
ABSTRACT

In this paper, we consider the split common fixed point problem for new demimetric mappings in two Banach spaces. Using the hybrid method, we prove a strong convergence theorem for finding a solution of the split common fixed point problem in two Banach spaces. Furthermore, using the shrinking projection method, we obtain another strong convergence theorem for finding a solution of the problem in two Banach spaces. Using these results, we obtain well-known and new strong convergence theorems in Hilbert spaces and Banach spaces.  相似文献   

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