数值函数

Xie-Beni index decreases with the number of partitions increasing. It is difficult to choose the optimal partition of data when the number of clusters is large. From the point of view of the compactness and the separation of clustering, a novel clustering validity function is proposed, which is based on the improved Huber Г statistic combined with the separation of clustering.

针对此问题，分别考察改进的Hubert Г统计量和聚类分离度，导出一个新的基于数据几何结构的聚类有效性函数，使得它有惟一的最大值，函数值随聚类个数增大而递减的趋势并不影响最优聚类个数的判定。

With k-ε turbulent model and wall function presented by Launder and Spalding, numerical results of viscous resistance coefficient, isoplethic maps of velocity and stress contributions are obtained.

采用 紊流模式及Launder和Spalding提出的壁函数进行数值模拟，得到了该双尾船船体粘性阻力及速度、切应力的等值线分布等结果。

With k- e turbulent model and wall function presented by Launder and Spalding, numerical results of viscous resistance coefficient, isoplethic maps of velocity and stress contributions are obtained.

采用k-ε紊流模式及Launder和Spalding提出的壁函数进行数值模拟，得到了该双尾船船体粘性阻力及速度、切应力的等值线分布等结果。

The closed-form expressions are derived so that all required differentiations are obtained in closed form and numerical differentiation can be avoided.

特别是对微带和缝隙混合结构的空域MoM分析，旋度算子的微分在谱域进行，并可以给出它们的解析表达式，其对应的空域格林函数可通过高阶的Sommerfeld恒等式获得，从而避免了数值微分。

The target motion state filtering model and combined filtering-predicting model are constructed based on numerical differentiation, using s-function to implement Kalman filter algorithm.

建立了基于数值微分的目标运动状态滤波预测模型，用s-函数实现了卡尔曼滤波预测算法。

In the numerical differentiation matlab, useful midpoint formula, adaptive method, Richardson extrapolation methods such as France seek the derivative of the function, the algorithm of the program implementation in the document have been given.

详细说明： matlab中的数值微分，有用中点公式，自适应法，理查森外推算法等方法求函数的导数，算法的程序实现在文件中都已经给出了。

Numerical analysis function which will be used to achieve.

在数值分析、函数实现中都会用到。

These two algorithms have not only solved certain function numerical integration problem but also have the accuracy quickly.

这两种算法不仅解决了某些函数的数值积分问题，而且具有快捷性、精确性。

The comparison between numerical results and known wavefield function values shows that the method put forward in this paper is effective and useful.

通过对数值计算结果与已知波场函数对比，证明了该方法的有效性和实用性。

Numerical distributed transfer function method is applied to planar optical waveguides .

把数值传递函数方法应用于对平面光波导的分析。

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。