查询词典 surfaces

The surface of conventional engineering part is composed of simple analytical surfaces and four-boundary ruled surface primarily. Therefore a point cloud segmentation method based on those feature surfaces is proposed. Several algorithms to identify the simple analytical surface feature are investigated and discussed. The theory of fitting scattered point to B－Spline and Bézier surfaces is introduced and a fitting method based on four boundary and point set is also discussed. Moreover, anew method to recover the fix-radius rolling ball blend is proposed and discussed in detail.

常规工程零件的外表面中包含了大量的特征曲面，如简单解析曲面和四边直纹面，因此，本文提出基于特征曲面的的点云分割方法，研究几种识别简单解析曲面的算法；研究由点云拟合B－Spline和Bézier曲线的理论基础，总结曲面拟合的几种方法，提出一种反求定半径滚球圆角的方法。

It is sea-level rising and falling of high-amplitude and low-frequency that caused sequence boundary signs of distinct characteristics and stable distributing, which included paleokarst surfaces, which included paleokarst surfaces, erosive boundary, exposure surfaces and regional freshwater diagenetic facies tracts.

对层序界面而言，由于克拉通上高幅低频的海平面升降变化，容易造成特征明显、分布稳定的层序界面标志，包括古岩溶面、冲刷侵蚀面、暴露面、区域性淡水成岩相带等。

It seems natural to use this idea into the parameterization of the blending surfaces of three pipe surfaces, however, the blending surface of three pipe surfaces is very complicated and the inappropriate choice of parameters can lead to singular blending surface.

将这一思想应用于三管拼接曲面的参数化是自然的，但是由于三向管道曲面的拼接曲面是是复杂的，并且由于参数选取不当可能出现三个管道曲面分别拼接于混合拼接曲面的不同分支等奇异情况，从而这一思想的实现具有现实难度。

Two merging methods of Bézier curves are generalized to tensor product Bé zier surfaces, we propose two methods to approximate two pieces of adjacent tensor product Bézier surfaces by a piece of tensor product Bézier surface. We offer the explicit formulas of the merged tensor product Bézier surfaces with all kinds of merging conditions.

同样，Bézier曲线的两种合并方法也被成功的推广到张量积Bézier曲面上，得到把两片相邻张量积Bézier曲面合并成一片张量积Bézier曲面的两种合并方法，并给出在各种合并条件下的合并曲面控制顶点的显示表示式。

ABSTRACT This paper summarizes our researches on two key techniques in curve and surface modeling-the geometric approximation techniques and the geometric interpolation techniques. The former includes three types of geometric approximation techniques: Hybrid polynomial approximation to rational curves and surfaces, offset curves and surfaces approximation, interval Bézier curves and surfaces approximation. The latter includes a series of algorithms for shape blending modeling: the MSI algorithm for shape blending between space polylines or trees, the MSI algorithm for shape blending between triangular meshes, and skeleton-based shape blending algorithms using triangular decomposition and star-shape decomposition.

本文是作者对曲线曲面造型中两类核心技术几何逼近技术和几何插值技术的研究成果的总结，其中前者包括有理曲线曲面的Hybrid多项式逼近、等距曲线曲面逼近和区间曲线曲面逼近等三类几何逼近方法；后者包括用于形状混合造型的几何插值方法的一系列算法：空间多边形形状混合的MSI插值算法、三角网格形状混合的MSI插值算法、树的形状混合的MSI插值算法以及基于骨架树形状混合的三角剖分算法和星形剖分算法。

On the basis of study on two projects:"10-DOF ultrasonic detection system for complex surfaces part" and "Ultrasonic water-logging automatic survey system for rods", this thesis studies the technologies of ultrasonic measurement, kinematic and dynamic modeling of 10-DOF ultrasonic system, real-time sensitivity auto-adjusting, integrated technology of ultrasonic measurement, surface construction and ultrasonic detection for complex surface parts and rods, thus improving the accuracy and efficiency of ultrasonic detection for parts of complex surfaces. Meanwhile, an auto-detection system for metal rods with rough surfaces and bad columniform accuracy is presented for the first time.

本文结合&10自由度复杂曲面超声检测系统&和&棒材水浸超声自动检测系统&两个项目的研究，主要开展了超声测量、检测机器人运动学和动力学建模、误差补偿、灵敏度自动补偿和曲面构件超声检测一体化技术和轴棒类构件超声检测一体化技术的研究工作，进一步提高了复杂型面构件超声检测的效率和精度，并首次针对表面粗糙、圆柱度较差的金属轴棒类构件开发出了高效率的自动化检测设备。

The method connects the exponentially attenuating dividable auto-correlation function which is often used in the study of the lubricating behaviors of rough surfaces, to the theoretical model for studying the contact behaviors of rough surfaces and it will be a foundation for studying the lubrication and failure problems of sliding frictional pairs with anisotropic surfaces.

第三章对Onions-Archard的理论接触模型进行扩展，给出了计算各向异性粗糙表面接触性能的简便方法，并将粗糙表面润滑效应研究中常用的表征粗糙表面的指数衰减可分自相关函数和粗糙表面接触性能研究的理论模型联系了起来，为研究混合润滑工况下各向异性粗糙表面摩擦副的润滑和失效问题提供了基础。

According to this idea we study two types of surfaces, i.e., helicoidal surfaces and pseudo-umbilical surfaces, in Minkowski 3-space.

基于这种思想，本文讨论了三维Minkowski空间中的两类曲面，即螺旋面和伪全脐曲面。

The 3D topography of fractured surfaces was reconstructed and quantified by the means of SEM stereo pairs, image processing and analysis, and computer vision. It was shown that measured 3D roughness indexes Rs, Rq and Rmax have good positive relations to the crack propagation part of absorbed impact energy. Although fractal behavior had been checked out on the fractured surfaces, the fractal dimension was found nonsensitive to the fracture mode and mechanical properties. The geometric characteristics of fractal fractured surfaces should be quantified in fractal dimension together with absolute parameters.

利用扫描电镜立体对技术、图像处理与分析和计算机视觉方法对示波冲击断口形貌进行了三维重建和定量分析结果表明，断口三维粗糙度指数Rs，Rq和Rmax与示波冲击裂纹扩展功有很好的对应关系，显示了它们良好的应用前景断面虽然表现出分形行为，但分形维数是一个对断裂模式和性能不敏感参量对分形断口的几何特征描述应将分维和绝对尺度结合起来

And comparison of their most stable surfaces with the body-centered cubic Fe shows that these carbide surfaces have lower surface energies than the most stable (110) surface of body-centered cubic Fe, indicating that the surface thermodynamics favor carburization at Fe surfaces.

另外，与面心立方铁最稳定表面(110)相比，Fe2C、Fe3C及Fe4C晶体最稳定表面具有较低的表面能，表明铁表面碳化在热力学上是有利的。

Neither the killing of Mr Zarqawi nor any breakthrough on the political front will stop the insurgency and the fratricidal murders in their tracks.

在对危险的南部地区访问时，他斥责什叶派民兵领导人对中央集权的挑衅行为。

In fact,I've got him on the satellite mobile right now.

实际上 我们已接通卫星可视电话了