查询词典 parametric curve

The cubic algebraic curves (the Bezier curve and B style curve, etc belong to the parameter curve) is apter to realize the curve transition and fitting to dispersed data than the cubic parametric curves.

比如参数曲面与平面的交线就是一条平面代数曲线；平面参数曲线的等距曲线也是一条代数曲线。

Regularity is an important algebraic property of parametric curve and surface, which depends on the parameterization of parametric curve and surface.

正则性是参数曲线曲面的重要代数性质，是由参数曲线曲面的参数化决定的。

However, no matter what free-form deformation based on extension factor for parametric curve or arbitrary partition will reduce smoothness of parametric curve.

然而，无论是基于伸缩因子的自由变形还是基于任意分割参数曲线的自由变形都会使参数曲线的光滑度降低。

In computer-aided manufacturing, the processed parametric curve and surface should be regular, so the parametric curve and surface generated by computer-aided design should be regular first.

在计算机辅助制造过程中，要求所处理的参数曲线曲面是正则的，前提是计算机辅助设计得到的参数曲线曲面是正则曲线曲面。

Parametric model of brake pad and parametric design of brake shoe have been accomplished on the base of parametric method, secondary development tools on UG, the method of setting environment variables about development system and establishing method of application program, and which can provide the foundation for the development platform of automotive brake system.

对鼓式制动器的组件进行了离散化处理，在介绍了参数化方法、UG二次开发工具、开发系统环境变量的设置以及应用程序创建方法的基础上，完成了鼓式制动器垫片参数化模型的建立以及制动蹄的参数化设计，为汽车制动器专用开发平台的建立奠定了基础。

On the basis of the parametric graphics representation, a new system architecture of product-oriented parametric design has been developed. Based on the research work, a series of software system have been developed, such as Parametric Design Program Generator .

在参数化图形建模的基础上，将产品设计选型系统、产品设计计算、产品设计尺寸推导和图纸输出集成，提出了支持系列化产品变型设计的产品参数化设计体系结构。

Using the amplification transfer function of type Ⅰ BBO crystal, the theoretical study of spatial properties of the optical parametric fluorescence generated by homochromatic signal and polychromatic signal in optical parametric amplification is investigated, The numerical simulation results demonstrate that when the homochromatic signal is injected into optical parametric amplifier, the fluorescence signal is first emitted in a cone and then in a ring while centering on the pump wave direction.

采用第Ⅰ类相位匹配BBO晶体的放大传递函数方法，分别对光参量放大过程中单波长信号光注入和多波长信号光注入出现的参量荧光的空间特性进行了详细的理论研究。

This article first introduces the math foundation required by ECC,including the addition rule for elliptic curve point defined over finite field.Then , the principle of ECC is discussed and its security and efficiency of ECC are analyzed.Third, a cryptosystem is designed through analyzing the security requiration, choosing the elliptic curve domain parameters,denoting field element,elliptic curve and elliptic curve point,choosing associate primitves and schemes andpartitioning functional module.Forth, how to develop a crytosystem based on elliptic curve encryption algorithm is investigated.Fifth, a cryptosystem we have developed by us and the testing result is described.

本文首先介绍了ECC的数学基础，对有限域上椭圆曲线点的运算规则进行了详细描述；其次探讨了ECC的原理，分析了ECC的安全性和有效性；第三，设计了一个基于ECC的加密系统，包括系统的安全需求分析，域参数选择，域元、椭圆曲线、点的表示，原语和方案的选择，及整个系统的模块功能划分；第四，在设计的基础上，研究如何开发一个基于椭圆曲线的加密系统；第五，描述了一个我们已经设计与开发的基于椭圆曲线的加密系统，并给出了相应的测试结果。

This dissertation investigates the construction of pseudo-random sequences (pseudo-random numbers) from elliptic curves and mainly analyzes their cryptographic properties by using exponential sums over rational points along elliptic curves. The main results are as follows:(1) The uniform distribution of the elliptic curve linear congruential generator is discussed and the lower bound of its nonlinear complexity is given.(2) Two large families of binary sequences are constructed from elliptic curves. The well distribution measure and the correlation measure of order k of the resulting sequences are studied. The results indicate that they are "good" binary sequences which give a positive answer to a conjecture proposed by Goubin et al.(3) A kind of binary sequences from an elliptic curve and its twisted curves over a prime field F_p. The length of the sequences is 4p. The "1" and "0" occur almost the same times. The linear complexity is at least one-fourth the period.(4) The exponential sums over rational points along elliptic curves over ring Z_ are estimated and are used to estimate the well distribution measure and the correlation measure of order k of a family of binary sequences from elliptic curves over ring Z_.(5) The correlation of the elliptic curve power number generator is given. It is proved that the sequences produced by the elliptic curve quadratic generator are asymptotically uniformly distributed.(6) The uniform distribution of the elliptic curve subset sum generator is considered.(7) We apply the linear feedback shift register over elliptic curves to produce sequences with long periods. The distribution and the linear complexity of the resulting sequences are also considered.

本文研究利用椭圆曲线构造的伪随机序列，主要利用有限域上椭圆曲线有理点群的指数和估计讨论椭圆曲线序列的密码性质——分布、相关性、线性复杂度等，得到如下主要结果：(1)系统讨论椭圆曲线-线性同余序列的一致分布性质，即该类序列是渐近一致分布的，并给出了它的非线性复杂度下界；(2)讨论两类由椭圆曲线构造的二元序列的"良性"分布与高阶相关性(correlation of order κ)，这两类序列具有"优"的密码性质，也正面回答了Goubin等提出的公开问题；(3)利用椭圆曲线及其挠曲线构造一类二元序列，其周期为4p(其中椭圆曲线定义在有限域F_p上)，0-1分布基本平衡，线性复杂度至少为周期的四分之一；(4)讨论了剩余类环Z_上的椭圆曲线的有理点的分布估计，并用于分析一类由剩余类环Z_上椭圆曲线构造的二元序列的伪随机性；(5)讨论椭圆曲线-幂生成器序列的相关性及椭圆曲线-二次生成器序列的一致分布；(6)讨论椭圆曲线-子集和序列的一致分布；(7)讨论椭圆曲线上的线性反馈移位寄存器序列的分布，线性复杂度等性质。

In curve fitting, the speed-flow rate curve shows that the curve of 16mm pitch wheel is a line and that of 12mm pitch wheel is a down-winding curve, the speed-pressure curves of two pitches both are up-winding curves and in the resistance-flow rate curves the curve of 12mm one has lower slope than that of the 16mm one.

曲线拟合结果显示，在转速-流量曲线中，16mm螺距叶轮为一直线，12mm螺距的叶轮为一向下弯曲的曲线；转速-压力曲线显示两者都是向上弯曲的曲线；阻力-流量曲线显示12mm螺距的叶轮斜率较小。

Objective:To explore the feasibility of laparoscopy in diagnosing and treating of abdominal diseases.

目的：探讨腹腔镜用以诊断腹部外科疾病及选择治疗方案的可行性。

The lifetime of nylon 1010 and nylon 1010/POSS composites decreased with increasing temperature.

热重-红外联用分析表明尼龙1010在氮气气氛下的降解产物主要为小分子的低聚物，POSS并不改变尼龙1010降解产物的组成。