主曲率方向

It is based on the discrete model of finite analysis to get curvature ,normal vector, direction and geodesic curve,then to analyze and design the structure.

基于有限元分析的离散模型，将离散微分几何领域的最新成果运用于膜结构设计，求解曲面曲率，法向量，主方向及测地线，进行结构分析设计。

The shape-form analysis and load analysis were done by nonlinear FEM. On the basis of surface FEM grid nodes, geometry property research of structure curved surface was progressed, including normal vector, GAUSS curvature, mean curvature and principal direction vector. In this process, the approximate expression of surface didn't need to he known.

采用非线性有限元法进行了膜结构的形态分析和荷载分析，得到了曲面有限元网格；通过离散微分几何方法，研究了薄膜结构曲面的几何性质，包括曲面的法线向量、高斯曲率、平均曲率和主方向矢量，避免了复杂的曲面拟合过程。

Aiming at the problem of coarse footmark surface with severe noises, based on the in-depth analyzing geometrical relationship and differential characteristics of the three-dimensional footmark impressing surface, we propose a principal curvature and principal direction based impressing surface segmentation algorithm and a multi-scale fusion algorithm to segment the stereo footmark.

针对立体赤足迹表面粗糙、噪声严重的特点，深入分析立体足迹三维表面的几何关系和微分特性，提出了基于曲面主曲率和主方向的立体足迹压力面分割算法和多尺度融合算法，分割结果理想并与领域知识吻合。4。

Formulae about curvatures and three dimensional principal directions of an implicit surface are deduced.

推导得出了任意隐式曲面曲率的计算公式和三维矢量形式的主方向。

On the basis of Prof. S. Knothe's expression for arbitrary point in subsidence trough, the equations are derived with probabilistic integration for calculation of slope, curvature, horizontal movement, horizontal deformation, torsion and form deformation at arbitrary direction and point in subsidence trough.

本文在克诺特建立的地表下沉盆地任意点表达式的基础上，导出用概率积分法计算下沉盆地任意点任意方向的倾斜、曲率、水平移动、水平变形、扭曲和形变公式，并得出主剖面计算公式是任意点任意方向移动与变形计算公式的特例。

With Death guitarist Schuldiner adopting vocal duties, the band made a major impact on the scene.

随着死亡的吉他手Schuldiner接受主唱的职务，乐队在现实中树立了重要的影响。

But he could still end up breakfasting on Swiss-government issue muesli because all six are accused of nicking around 45 million pounds they should have paid to FIFA.

不过他最后仍有可能沦为瑞士政府&议事餐桌&上的一道早餐，因为这所有六个人都被指控把本应支付给国际足联的大约4500万英镑骗了个精光。