曲面

The comparison of the derivative form of fixed aberration correction surface has been made with that of integral form surface as well as that of spherical surface in concentrating the solar ray.

同时，我们对以上两种不同表达式的曲面做了固定相差修正，并将这两种曲面，以及圆球面，分别做了聚光效果的模拟和比较。

We show that these two metrics are intrinsic to the geometry of a surface. They can be applied to compute the fingerprints of surfaces for the purposes of shape identification and comparison.

曲面的平坦度量和一致度量传递了曲面的共形结构信息，利用这两个度量，我们可以非常直观地进行曲面的识别和比较。

Based on the source investigation and the comparative approach of history of mathematics,a historical background of Gauss' competition essay and its contribution to intrinsic differential geometry are discussed.

高斯(C.F.Gauss，1777-1855)研究微分几何的出发点是"我们是否可以从曲面本身的度量出发决定曲面在空间的形状"[1]，这就是所谓的内蕴微分几何。

Based on the new method, the paper discusses an inverse mapping of rational parameter surface, also, the implicit equation of the parametric equation is obtained.

文中用该方法对基于有理参数曲面的逆映射进行了一些探讨，并得到参数曲面的隐式方程。

Based on the summarizing of the exiting algorithms of the texture mapping and antialiasing, this paper goes deeply into the basic theory and processing of texture mapping. The texture compress algorithm which can satisfy the need of the memory and time is given for the stochastic sampling in the inverse texture mapping; the geometry transformation in the texture mapping are discussed and the concepts of the unitary parametrization and the patch parametrization is proposed, some kinds of the unitary parametrization methods of parametric surfaces and the geometry transformation in the patch parametrization are also presented; in order to solve the aliasing in the parametrization of intermediate surface-sphere in two-part texture mapping, an area-preserving transformation is presented also; to improve the quality of the graph the aliasing in the texture mapping is analyzed from the aspect of signal process, and the modified summed-area tables algorithms is proposed; the distortion of the scanline conversion algorithms under perspective transformation is analyzed and the proper interpolation algorithm is presented so the aliasing problem of the polyhedral object after the unitary parametrization is efficiently solved.

本文在总结现有的纹理映射和反走样算法的基础上，深入研究了纹理映射的基本原理与过程，根据反向纹理映射对纹理随机采样的特殊要求，提出了一种可满足存储空间和寻址时间的纹理压缩存储算法；通过对纹理映射中几何变换理论的进一步深入探讨，提出了整体参数化和面片参数化的概念，并给出了参数化曲面的各种整体参数化方法和面片参数化的几何变换形式；针对现有的两步映射算法所存在的中间曲面—球面的参数化问题，提出一种等积映射方法，较好地实现了由非参数化面片拼接而成的多面体表面的纹理映射；从信号采样的角度深入分析了纹理映射中走样产生的原因，提出了改进的区域求和表算法，使图形生成的效果有所提高；还分析了一般的扫描线算法在透视变换中所存在的问题，提出了一种正确的插值算法，从而解决了整体参数化后多面体表面纹理映射的几何变形问题。

Aimed at the characteristic of multiple types of faults possibly happened in nuclear power plant, large scale of training sample, and requirement of quick and accurate diagnosing, after the analysis of large sample number generated by large fault type exceeds limitation of 64K paragraph in DOS and large number of local minmum in error surface, measurements of same format of data file, Win95/NT operating system platform, resetting weight learning rate, dynamic training set in quick learning algorithm and improvement on quick learning algorithm using homotopy method which can avoid local minmum points in error surface have been adopted to ensure quickly and effective process of the course of neural network's training and testing.

针对核动力装置可能发生的故障种类多，训练样本规模大，故障诊断需要快速准确的特点等，分析了样本多和故障种类多产生的训练样本量超出DOS段大小和网络误差曲面上局部极小值多的情况，采取了使用相同格式数据文件、Win95/NT操作系统平台，对快速学习算法采用重置神经网络权值学习率和动态训练集、并采用能够有效克服网络误差曲面上局部极小点的同伦方法对学习算法进行改进等措施保证神经网络训练测试过程的快速、有效地进行；针对装置发生的故障须快速、准确诊断的需要，分析了故障的产生对装置参数变化的影响及操纵员对故障诊断的基础，在核动力装置发生故障时参数曲线的变化量与正常运行时参数曲线的变化量存在明显差异的基础上，提出采用参数曲线的变化量作为神经网络的输入，并围绕参数变化量的方法采用二次曲线拟合滤波求变化量和阈值技术来保证神经网络得到精确的装置参数变化量，从而得到准确的诊断结果。

Three-dimensional reconstruction is realized by three-dimensional morphological characteristic of cucumber leaf ,cubic Bezier curve of leafstalk,pentagon leafstalk section,jointing quadrangle leafstalk surface,leafstalk shags built by random and joint sequential C0 cubic NURBS surface in cucumber.

根据黄瓜叶的三维形态特征，利用3次Bezier曲线描述黄瓜叶柄曲线，采用五边形作为叶柄截面，用四边形面片进行叶柄表面拼接，并用随机方法生成叶柄的粗毛；利用C0连续的3次NURBS曲面拼接生成了黄瓜叶片曲面，实现了黄瓜叶的三维重建。

By using the Lie group theory of differential geometry and Pontryagin's maximum principle, it is pointed out that the mobile CRS robot on surface is controllable, and the necessary conditions and the structure equations of extremal trajectories are proposed.

为了解决曲面上移动CRS机器人的路径规划问题，在曲面上建立了机器人的动态模型，利用微分几何的李群理论和庞特里亚金最大值原理，证明了曲面上CRS机器人是可控的，并给出了机器人的最小时间控制的必要条件和结构方程。

To be specific,by means of changing inside dimension of concave,enlarging working volume of crushing cavity,shortening length of parallel zone of crushing cavity ,and limiting engage angle and radius of curv.

通过轧臼壁内侧尺寸的变化，扩大破碎腔的工作容积、缩短平行区长度、限定曲面啮角和曲面半径等，从而提高了破碎机的破碎效率，延长了衬板的使用寿命，改善了产品的粒度分布。

This paper researches the part third-order contact condition of tool and the surfaces by the contact principle of deferential geometry in to the 5-axis NC machining and analyzes the contact degree of the intersection line of the cutter and the surfaces.

运用微分几何中的切触原理，研究了在多轴数控机床中铣刀铣削圆与零件曲面的切触条件和局部坐标系下的局部三阶切触条件，并用截形对铣刀铣削圆与曲面的贴近程度进行了分析。

However, as the name（read－only memory）implies, CD disks cannot be written onorchanged in any way.

然而，正如其名字所指出的那样，CD盘不能写，也不能用任何方式改变其内容。

Galvanizes steel pallet is mainly export which suits standard packing of European Union, the North America. galvanizes steel pallet is suitable to heavy rack. Pallet surface can design plate type, corrugated and the gap form, satisfies the different requirements.

镀锌钢托盘多用于出口，替代木托盘，免薰蒸，符合欧盟、北美各国对出口货物包装材料的法令要求；喷涂钢托盘适用于重载上货架之用，托盘表面根据需要制作成平板状、波纹状及间隔形式，满足不同的使用要求。