逼近

Comparing with deterministic system, the point of bifurcation in stochastic Duffing-van der Pol system is moved as increasing the intensity of random parameter.

进一步的推广证实正交多项式逼近法在实际问题中有广阔的应用前景，它可以解决含有多个随机参数的非线性随机动力学系统的分岔问题。

Because the derivation of the extended system has a block lower triangular form, the method of splitting iteration is applied to compute simple bifurcation point, not only computational work is reduced, but also local quadratic convergence is achieved.

由于所构造的扩充系统的导数具有分块下三角形式，采用分块迭代的方法进行数值求解，不仅减少了计算量，而且是二次收敛的，从而为Navier-Stokes方程非退化简单分歧点的数值逼近提供了有效的算法。

In this paper we explore multiresolution approximation to the solution of the boundary value problems in intervals and rectangular fields for the biharmonic equation using wavelet-Galerkin methods.

本文主要用小波－伽辽金方法研究了区间以及矩形域上双调和方程边值问题的解的多尺度逼近。

We deal with the biharmonic equation and proved that under our assumptions, the week solution of the natural boundary value problem strongly converges (in H~2) to that of the first boundary value problem.

为克服这一困难，我们用具自然边界条件的边值问题(在二阶椭圆型方程情形为第三边值问题)去逼近相应的第一边值问题，并以重调和方程为例，证明了在一定条件下，其具自然边界条件的边值问题的弱解在H~2的意义下强收敛到相应的第一边值问题的弱解。

In this paper we study the method of interpolation by radial basis functions in H~k(k ≥ 1) and give some error estimates. By means of such interpolation with a special kind of radial basis function, we construct a basis in H~k(k ≥ 1). Combined with the Galerkin method, this theory can be applied to solve boundary value problems for elliptic partial differential equations (such as the third boundary value problem for Poisson equation and the corresponding problem for the biharmonic equation), and some numerical experiments are also given.

本文从求解偏微分方程的角度出发，在被逼近函数u属于一般的Sobolev空间H~k(k≥1)的情形，引入了一种径向基函数插值方法，并建立了相应的误差估计；再利用这种插值性质，从一类特殊径向基函数出发构造Sobolev空间的一组基，针对Poisson方程第三类边值问题和重调和方程类似边值问题，为用无网格算法求解偏微分方程边值问题建立了相应的理论，并通过算例来验证了这一算法。

The bilinear programming is converted into a max-min problem on the principle of duality, and a linear approximation algorithm for the max-min problem is presented, which proves to be convergent in finite steps.

利用对偶原理，将双线性规划问题转化为极大极小问题，研究了该极大极小问题的线性逼近算法，并证明了该算法在有限步内收敛。

The bilinear programming is converted into a max min problem on the principle of dual ity, and a linear approximation algorithm for the max min problem is presented, which proves to be convergent in finite steps.

利用对偶原理，将双线性规划问题转化为极大极小问题，研究了该极大极小问题的线性逼近算法，并证明了该算法在有限步内收敛。

In the rst two examples, the basic binary element mightbe a chemical compound, while in the last it might be the state of ring of a neuron.

在这些模型里，有N个动态元素，定义为布尔变量，一步一步逼近，时钟频率由时间变量。

A theoretical distribution that is a good approximation to the binomial distribution when the probability is small and the number of trials is large.

当概率小而试验次数大时逼近二项式分布的一个理论分布。

We use heat equation and binomial model to solve the function.

解方程式则用了热扩散方程法以及二项式模型；二项式模型用了Cox、Ross、Rubinstein所提出的CRR二元树的概念推导选择权期初价格，所得到的二项式模型极限值将逼近於布莱克-休斯模型。

We have no common name for a mime of Sophron or Xenarchus and a Socratic Conversation; and we should still be without one even if the imitation in the two instances were in trimeters or elegiacs or some other kind of verse--though it is the way with people to tack on 'poet' to the name of a metre, and talk of elegiac-poets and epic-poets, thinking that they call them poets not by reason of the imitative nature of their work, but indiscriminately by reason of the metre they write in.

索夫农 、森那库斯和苏格拉底式的对话采用的模仿没有一个公共的名称；三音步诗、挽歌体或其他类型的诗的模仿也没有——人们把&诗人&这一名词和格律名称结合到一起，称之为挽歌体诗人或者史诗诗人，他们被称为诗人，似乎只是因为遵守格律写作，而非他们作品的模仿本质。

The relationship between communicative competence and grammar teaching should be that of the ends and the means.

交际能力和语法的关系应该是目标与途径的关系。