反曲线

To fulfill the need of the application of RP technique in medical domain, reverse CAD modeling from medical cross sections is systematically studied in this dissertation. Firstly, Some algorithms related to the research of this dissertation are studied. New algorithms for orientation and inclusion test for simple polygon, an error constrained automatic faring algorithm for B-spline curve and a theorem regarding the termination criterion for subdivision of triangular Bézier patch are proposed. Then based on similarity between contours of adjacent sections, a methodology for surface reconstruction from cross sections is presented. Finally, a virtual measuring method is proposed.

本文针对RP技术在医学领域应用的需要，系统研究了基于医学断层轮廓数据的反求CAD建模理论和方法：(1)在基础算法研究部分，提出了简单多边形方向及点在多边形内外判断的新方法、三角Bézier曲面片离散的误差控制定理和一种带误差约束的B样条曲线的自动光顺方法；(2)提出了一种基于相邻层轮廓相似性的医学断层轮廓数据曲面重构方法；(3)提出了一种称为"虚拟测量"的曲面模型处理方法。

This problem can be avoided by using three components which produce a skew symmetrical path curve.

使用三块能产生反对称形路径曲线的元件，即可避免上述问题。

In this paper, based on nonlinear FEA software ANSYS/LS-DYNA, 3D dynamic simulation models of eighteen-type tubes for backward spinning was established. This paper not only obtained spinning force of tube backward spinning but also obtained the spinning force curves varying with the different reducer ratio, feeds, fillet radius for spinning roller, forming angle and diameter of spinning roller, and diameter blank inner.

以大型非线性有限元软件ANSYS/LS-DYNA为分析平台，通过对18种几何尺寸和参数不同的筒形件三旋轮强力反旋旋压过程的三维动态模拟，得到了它们的旋压力以及旋压力随不同减薄率，旋轮进给量，旋轮圆角半径，旋轮成形角，旋轮直径和毛坯内径的变化曲线。

By means of the fractions of the equation of the non一ideal constrained motion of the particle along the plane curve on the tangential direction and normal direction,the motion speed expression of the particle under this condition is derived,the constrained counter force is further gained,thus some non一ideal constraint problems are solved from the given angle.

通过质点沿平面曲线的非理想约束运动方程在切线和法线方向上的分式，导出质点这一条件下的运动速度表示式，并进一步求出其约束反力，从一定角度解决一些非理想约束问

Based on frozen soil creep tests,yield stress limit is approximately determined by means of experimental tautochrone at first.

在大量冻土蠕变试验的基础上，用等时曲线近似方法确定了冻土的屈服极限，建立了多种粘弹性和粘弹塑性流变模型，采用非线性最小二乘法反演了冻土流变参数，并基于简单性和精确性原则，建立了冻土模糊优选模型。

This article analyses the application conditions of freezing method, current research status and the problems in this field. It points that it's necessary to study deep freezing temperature field deeply and discusses the factors which influence the freezing wall such as soil's nature, moisture content, geological conditions, etc. It introduces the theory, process of freezing method, the distribution of temperature field of freezing method and key thermotics parameters influencing freezing temperature field. It simplifies the deep freezing temperature field model. Through ANSYS, this article founds the deep freezing temperature field model, and simulates the field on vary heat conductivities. It analyzes the results of ANSYS simulation, gains the theoretical value of thermometric holes which is needed by back-analysis. Using the simulation temperature and actual value, it gets the equivalent heat conductivity. Then it solves the deep freezing temperature field by the equivalent value, simulates the freezing wall development process and temperature change curve. Against the actual project, the results are favorable.

文中分析了冻结法施工的应用条件，目前对冻结法施工的研究现状和在此领域内存在的问题，指出了对深土冻结温度场进行深入研究分析的必要性；对影响冻结壁形成发展的因素如冻土土性、含水量、地质条件及施工方法等因素进行了论述；对冻结法施工的原理、过程，冻结法温度场的分布情况，影响冻结温度场分布的主要热学参数进行了综述；对深土冻土温度场模型进行了合理的简化，通过ANSYS大型有限元分析软件，建立了深土冻结温度场的模型，对不同导热系数情况下的深土冻结温度场进行了模拟；对ANSYS的模拟结果进行了定性的分析，通过对ANSYS结果的后处理取得了反分析时需要用到的测温孔理论温度值；经过对测温孔模拟温度值和实测温度值的分析，得到了冻结温度场的等效导热系数；使用等效导热系数对深土冻结温度场进行了求解，模拟了冻结壁发展情况和温度场中的温度变化曲线，用所得结果对比工程实际情况，取得了较好的效果。

This article analyses the application conditions of freezing method, current research status and the problems in thisiold. It, points that it" s necessary to study deep freezing temperature field deeply and discusses the factors which influence the freezing wall such as soil" s nature, moisture content, geological conditions, etc. It introduces the theory, process of freezing method, the distribution of temperature field of freezing method and key thermotics parameters influencing freezing temperature field, it simplifies the deep freezing temperature field model. Through ANSYS, this article founds the deep freezing temperature field model, and simulates the field on vary heat conductivities. It analyzes the results of ANSYS simulation, gains the theoretical value of thermometric holes which is needed by back analysis. Using the simulation temperature and actual value, it gets the equivalent heat conductivity. Then it solves the deep freezing temperature field by the equivalent value, simulates the freezing wall development process and temperature change curve. Against the actual project, the results are favorable.

文中分析了冻结法施工的应用条件，目前对冻结法施工的研究现状和在此领域内存在的问题，指出了对深土冻结温度场进行深入研究分析的必要性；对影响冻结壁形成发展的因素如冻土土性、含水量、地质条件及施工方法等因素进行了论述；对冻结法施工的原理、过程，冻结法温度场的分布情况，影响冻结温度场分布的主要热学参数进行了综述；对深土冻土温度场模型进行了合理的简化，通过ANSYS大型有限元分析软件，建立了深土冻结温度场的模型，对不同导热系数情况下的深土冻结温度场进行了模拟；对ANSYS的模拟结果进行了定性的分析，通过对ANSYS结果的后处理取得了反分析时需要用到的测温孔理论温度值；经过对测温孔模拟温度值和实测温度值的分析，得到了冻结温度场的等效导热系数；使用等效导热系数对深土冻结温度场进行了求解，模拟了冻结壁发展情况和温度场中的温度变化曲线，用所得结果对比工程实际情况，取得了较好的效果。

According to this process, the key technology which including the characteristic measurement of surface, the pretreatment of data getting by line scan, the character expression and fitting of curve and surface, the characteristic identify of surface and translation from the model of surface to CAD.

对实物反求过程中的各关键技术作了研究，包括：曲面的特征测量、逐行扫描测量数据的预处理、曲线曲面的特征表示及其拟合、曲面的特征识别以及曲面模型向CAD模型的转化。

Into the F0 contour. And based on the idea of optimization, this paper inversely extracts the parameters associated with optimization (namely the top-line, the bottom-line, the smoothness, the distortion, the stress) from the clustered F0 contour using the MMSE principle for the monosyllable, the disyllable, the trisyllable chunks.

基于这种优化思想，该文针对聚类后的单音节、二音节和三音节韵律块的基频曲线，利用最小均方误差准则通过反演提取了各个单元的优化相关参数(高音线、低音线、平滑因子、形状失真度、重音强度)。

The molecular weight and molecular weight distribution of polyethylene were determined by GPC and Viscometry.

对GPC曲线的高斯函数拟合分峰，计算在双组分茂金属催化体系中每种催化剂得到的聚乙烯的重量之比；根据各催化剂的催化活性和按所加的催化剂的摩尔比例假定进行独立反应时，可以计算在双组分催化体系中每种催化剂得到的聚乙烯的重量之比；根据两种重量之比的比较结果和对双组分茂金属催化体系得到的聚乙烯的平均分子量和平均分子量分布的分析结果，可以推测在催化体系CatZr〓/CatZr〓中两种催化剂基本上不存在相互作用；而在CatZr〓／CatZr〓体系中两种催化剂之间可能有相互作用存在。

He knows that he's one of the mostdominant players in the NBA right now.

我知道他现在是联盟里最有统治力的球员之一了。

Using analysis method of BCG , the dissertation analyzed the management of voluntary service organizations .

利用BCG分析方法对我国的志愿服务组织管理进行了分析。