截面线

We decompose curvature signal with wavelet at first and then extract itslow frequency coefficients as new smooth curvature signal, which is used to constructa G~2 continuous piecewise rational cubic Bezier curve with GHI method subsequently.

本文首先对估算得到的离散曲率进行小波分解，提取其低频部分作为新的曲率，然后利用几何Hermite插值方法，重建出光顺的截面线。

However, this flexibility brings a great deal of inconvenience to shape design for typical demand of design is not only qualitative but also quantitative, such as a global smooth and fair surface approximating a group of scattered points and interpolating a section curve .

但这种灵活性也给形状设计带来许多不便：典型的设计要求既是定量的又是定性的，如"逼近一组散乱点且插值于一条截面线的整体光顺又美光的曲面"。

In this article, the stress inside a quantum-wire structure is studied. Based on the derived expression of the stress inside a quantum-wire structure with arbitrarily shaped cross section, the analytical solution of the stress inside a trigonal quantum-wire structure in an infinite matrix is obtained.

研究了晶格失配和热失配在半导体量子线结构中所产生的弹性场，在分析圆柱形量子线结构弹性场的基础上，推导得到了任意截面形状量子线结构解的一般形式，并给出无限大基体内横截面为三角形量子线结构的解析结果。

Direct difference is sensitive to noisy data, so a threshold limitation is given, which can not only filter the result from noisy data but also pick edge points up according men's desire. On the other hand, artificial intelligence is used for segmentation in reverse engineering. Because the essence of segmentation is clustering similar characteristics and self-organizing feature mapping is one function of neural network, SOFM network is used for segmentation in the thesis, coordinates and normal of data points is took as the characteristics vector.

第二种方法，基于双向角度微分的边点提取法，针对三维正交模型采用基于截面线的方式组织数据，此方法比基于曲率半径方法更简洁，不用进行曲面拟合，大大提高了计算速度；计算过程中由数据点的直接差分逼近微分，但直接差分对数据误差敏感，为此，本文提出了阈值过滤的方法，一方面过滤了数据误差在计算结果中引起的噪音，另一方面可以按照设计意图控制边点的提取；来决定是否提取光滑交接的边点。

A sequence of 3D parallel cross-section data from the surface object can mainly be obtained with ease by means of data acquisition techniques.

在第六章中，提出了一种截面线数据的B样条曲面生成方法，以提取测量数据的几何信息。

Plyfil composite yarns is similar to two-ply yarn structures.

纺纱方法决定着成纱结构，成纱结构与纱线组成原料又决定了纱线的性能。sirofil复合纱线纺纱时长丝与短纤纱须条的间距及长丝的张力，plyfil复合线加工时二组分间并线张力对成纱结构及纱线的性能有着重要影响。sirofil复合纱的成纱横截面呈近似圆形结构，长丝位于成纱的一侧；纵向呈有"股线螺纹"的单纱外观。plyfil复合线具有类似于传统双股线的横截面和纵向外观。

One line from inferior edge of anteroinferior iliac spine to the crossing point of posterior gluteal line and posterior iliac crest was defined as A line, which was parallel to the Chiotic line (the crossing point of Chiotic line and posterior iliac crest called CLIC point).

设定髂前下棘下缘向后经过臀后线与骼嵴后部交叉点的连线截面为A线截面，此线与Chiotic线平行（Chiotic线与髂嵴后部交叉点称为CLIC点）。

In order to make this project more practicable, the friendly interactive interface is adopted.

在冲压方向的确定、压料面的添加过程中，都是利用这些截面线来完成。

The region enclosed by a constrained surface is divided into some of constrained maximum empty-sphere convex polyhedrons,the triangulation is followed inside these polyhedrons.

而由空间物体的一组平行截面线重建物体的三维表面则在医学图像和地理信息系统等领域有着广泛的应用。

For the floating body with complex bow and stern, the molded line reconstruction method is adopted to generate the section lines on the bow and on the stern which are necessary to construct the wetted surface, and it can raise efficiency greatly that the intersection lines of intersection structures are obtained by the way of combining modeling tool and NURBS technology; then the patch representation method is adopted in generating the mesh of wetted surface and interior free surface, and the velocity potentials on them are expressed separately, on basis of which the irregular frequency effect is dealt with in the calculation of hydrodynamic coefficients.

对于有复杂首尾结构的浮体，用型线重构的方式在首尾生成曲面构成所需要的截面线，将通用建模工具和NURBS曲线拟合相结合，生成相贯结构的相交线；然后，用分片法生成浮体湿表面及内自由面网格，并独立表达各自的速度势以处理不规则频率现象，进而进行水动力系数计算。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。