切曲面

A curvature based method for controlling iteration step is further proposed by projecting the given point onto the curvature circle of the normal transversal at the initial point.

仿真结果表明，该算法具有良好的收敛性、鲁棒性以及精确性。正交投影的概念最早出现在文献[1]中。所谓正交，就是在曲面上找到一点，使得该点与空间某一给定点的连线与曲面在该点处的切平面是垂直的。

This paper develops methods for tangent direction continuous (G1) and both tangent direction and curvature continuous (G2) interpolation of a range of points on surface with specified tangent and either a curvature vector or a geodesic curvature at every point.

给出了数据点的切方向(切方向及曲率向量或测地曲率值)指定而G1连续(G2连续)插值曲面上任意点列的方法。

In this thesis, we mainly study the relations between compact minimal hypersurfaces of S~(n+1)(1) and the Clifford minimal hypersurface of S~(n+1)(1) by their spectrums, and the relations between unit tangent sphere bundle T_1 M and its base manifold M.

在本文中，我们主要通过谱研究了S~(n+1)(1)中的紧致极小超曲面和S~(n+1)(1)中的Clifford极小超曲面之间的关系，以及单位切球丛T_1M与它的底流形M之间的关系。

The overcutting on tool end is checked via comparing the tool radius with the circumradius or the radius of inscribed circle, and the touch interference of tool body based on the symbol of the vector distance from the triangle vertex to the tangent plane of tool body column.

在曲面加工的无干涉路径规划中，通过恰当选择刀具初始位置避免了接触点处的曲率干涉；通过比较刀具半径与曲面上三角片外接园半径的大小即可判断刀具底面干涉；而根据三角片顶点与刀杆切平面的有向距离的正负来判断刀杆碰撞干涉。

This paper proposes an algorithm to recognize and reconstruct the skewed quadric surfaces based on the analysis of their projection features.

在分析斜截切二次曲面在三视图中的投影特性的基础上，提出识别和重建这类曲面的算法。

Based on subdivision of surface, a tangent plane method of calculating distance from point to free surface is put forward.

在拟合曲面细分基础上，提出切平面法快速求解点到自由曲面距离。

Suppose that is a point on a surface S with equation F=O and that the partial derivativesand are continuous and not all equal to zero at M, then the tangent plane to surface S at point M is given by

假设是方程所确定的曲面S上的一点，F的偏导数在该点连续且不同时为零，则曲面S在点M的切平面的方程是

The pressure on vegetation front surface is larger than that on back surface. And the pressure difference decreases with the lying of vegetation, while viscous force increases.

作用在植被叶片迎水曲面上的压力都大于背水曲面上的压力，且其压力差随着植被俯卧程度的增大是依次减小，而切应力依次增大。

For this purpose, a new approach for computing feature points and analyzing shape features of section contours was developed. It dealt with the sharp changes between the adjacent sections via the transition loop and accessional region.

同时，针对曲面片的分段识别，提出了基于顶点法向距离符号量的判断准则及计算方法，利用表面顶点处的切平面与其周围邻域内的顶点之间的位置关系来判断凸凹性，完成对于具有单一凸凹性质的曲面区域内的三角形面片的聚类划分。

Second, a nonuniform bilateral filtering algorithm for point set surface and surface attributes is developed, in which the tangent shift of points is avoided. The algorithm can be applied when points are sampled nonuniformly.

其次提出了基于双边滤波对曲面和定义在曲面上的函数的非一致双边滤波算法，该算法不仅避免了滤波过程中点的切向漂移，而且考虑了点采样的密度使得算法可以适应非均匀采样。

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。