数值算法

The nonlinear hyperbolic conservation laws of the transient flow of the media in gas pipeline are hard to he solved, so, the control conservation laws are constituted of mass, momentum arid energy conservation laws, TVD/Godunov hydrid algorithm is used to simulate the transient flow in gas pipeline, and the traditional splitting approach processing nonlinear convection in momentum equation is dismissed ,the convection tern; is directly processed, in the way, the stablization of the algorithm and emulating accuracy of the transient flow are greatly improved.

针对管道中介质瞬变流动的非线性偏微分方程组难以解析求解的问题，由质量、动量、能量三个偏微分方程构成的控制方程组，应用TVD/Godunov混合算法数值模拟天然气管道中气体的瞬变流动，摒弃了传统的差分方法时动量方程非线性时流项的线性化处理，而直接处理非线性对流项，从而大大提高了算法的稳定性和管道瞬变流动的仿真精度。

Based on the characteristics of numerical reconstruction for lensless Fourier transform hologram, a set of digital image processing algorithm is presented to eliminate zero diffraction component and "twin image".

针对无透镜傅里叶变换全息图数值再现过程的特点，提出了一套不同于以往的削弱或消除全息图 0级衍射和孪生像的数字图像处理算法。该算法分为三步。

The high frequency combustion instability in liquid rocket engine LRE is analyti cally studied by usin g CFD methods.The comprehensive model and governing equations for numerical simu lation of high frequency combustion instability are presented.The PISO and MacCo rmack algorithms are compared in this study.Both methods can successfully handle combustion instability analysis.

应用CFD方法对液体火箭发动机中的高频燃烧不稳定性进行了分析研究，建立了液体火箭发动机不稳定燃烧数值模拟的综合模型和控制方程，比较了PISO和Ma cCormack两种算法，得出了两种算法均能成功应用于不稳定燃烧分析的结论。

In chapter 2 and chapter 3,the nonoverlapping DDMand overlapping DDM based on natural boundary reduction for 2-D exteriorHelmholtz problem are studied respectively,the convergence and the conver-gence rate of these algorithm are discussed,some numerical results are given.

其次，分别研究二维Helmholtz方程外问题的基于自然边界归化的非重叠型和重叠型区域分解算法，分析了这些算法的收敛性和收敛速度，并给出了数值算例。

Some aspects of numerical computation algorithms, of which this is the use of Romberg integration method recalculate the realization algorithm.

详细说明：一些数值计算方面的算法，其中这是利用龙贝格积分法重新计算的实现算法。

The theoretical analysis of thismethod and the details realized it are given in thesis.Some examplesare illustrated to show the validness of this method.

本文给出了该算法的理论分析和实现细节说明，一些数值例子验证了这种算法的有效性。

In more detail, the article adduces credit card analysis and credit management system .In credit card analysis, use K means algorithm,one of the method in clustering algorithm, to find the minimal partition of DSS.

在信用卡信用评分系统中，运用基于划分的聚类方法K means算法，试图找出使DSS函数值最小的划分，该算法的准则函数与信用评分评级的&均方差&准则相吻合。

On one hand, the optimal set membership state estimation algorithm by ellipsoids for linear systems is improved, and two numerically stable suboptimal algorithms are proposed.

一方面，对线性系统最优椭球集员滤波算法进行了改进，给出了两种数值稳定性比较好的次优算法。

For numerical computation,we can construct the schemesfrom the two different formalisms,and in some cases,we can prove that the twoschemes based on the two different formalisms are equivalent.

进行数值计算时我们也可以从这两个角度出发去构造算法，在一些情形，我们也能证明从这两个方面构造的算法的等价性。

That is: According to the guide star flag, the number of stars identified and the cost-function of two attitude determination algorithm to carry on the final attitude determination, the better attitude are chose as the output.Through Monte-carol simulation, the error of four cases of attitude determination algorithms is studied.

对于实拍星图，基于导航星选取过程中赋予的恒星标识及星图识别结果给出了姿态确定算法的选取原则，即：根据导航星的恒星标识、识别出的恒星数目及不同定姿算法计算出的最小代价函数值的优劣进行最终姿态计算结果的选择输出。

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。