曲线

Finally it analyzes the feasibility that using hydromechanics to analyze traffic flow by contrasting various characters between traffic flow and fluid flow. It analyzes influence of road alignment to basic expressway segment capacity by hydromechanics, and obtains viscous resistance and viscous movement differential equation when the vehicle drives on circular curve segment of expressway. And it infers that viscous resistance is correlated with sideway force coefficient, slope of crown and radius of circular curve. Radius of circular curve, sideway force coefficient and slope of crown are bigger, viscous resistance is smaller, the influence to capacity is smaller when the vehicle is running on nearside lane of circular curve; but radius of circular curve and sideway force coefficient are bigger, slope of crown is smaller, viscous resistance is smaller, the influence to capacity is smaller when the vehicle is running on fast lane of circular curve.

最后通过对比交通流与流体流的相似性，运用流体力学分析了道路线形对快速路基本路段通行能力的影响，求出了车辆在曲线路段的粘性阻力，建立了车辆在曲线路段的粘性运动微分方程，并由此推知，粘性阻力与横向力系数、路拱横坡度和圆曲线半径都有关系，当车辆在圆曲线外侧车道上行驶时，圆曲线半径、横向力系数和路拱横坡度越大，粘性阻力就越小，对道路的通行能力影响就越小；而当车辆在圆曲线内侧车道上行驶时，圆曲线半径和横向力系数越大，路拱横坡度越小，粘性阻力就越小，对道路的通行能力影响就越小。

A manner is presented with which complex curves including polylines, conics or free curves can be precisely represented, and corresponding algorithm is designed. The curve can be C〓 or C〓 continuous. So all type of curves and their composites can be represented in NURBS. A deep research is paid to skinning surface. Different forms of the formation of knots vector are applied to different section forms.

对由多段直线、二次曲线、自由曲线进行任意组合的这类复杂曲线，提出了一种用一条NURBS曲线进行精确表示的方法，并设计了相应的算法，曲线段连接处根据需要可为一阶连续或形成尖点，从而使所有类型的曲线及由它们任意组合所生成的复杂曲线统一用NURBS表示。

In order to overcome shortcomings that the circular arc and ellipse could not be accurately represented by CE-Bézier curves, this method used the continuity condition of CE-Bézier curves and C-Bézier curves to resolve the representation of circular arc and ellipse in CE-Bézier curve modeling.

该方法首先构造了一种具有优良形状可调性和更好逼近性的带3个形状参数α，β，γ的三次扩展Bézier曲线(CE-Bézier曲线)；并针对CE-Bézier曲线无法精确表示圆弧和椭圆弧等二次曲线的缺点，利用CE-Bézier曲线与C-Bézier曲线间的拼接技术，解决了CE-Bézier曲线造型中圆弧和椭圆弧的表示问题。

Chaikin algorithm is the simplest discrete curve modeling method.In thepaper planar Chaikin algorithm is generalized into sphere,and the practicability ofthe algorithm as well as the continuous differentiable property of the generatingcurve is proved.It is shown that the curve generated by Chaikin algorithm is apiecewise spherical Bezier curve of second kind of order two.Furthermore,generalspherical corner-cutting algorithms are discussed,and it is pointed out that thecurve generated through corner-cutting has"Spherical Variation DiminishingProperty".3Curve interpolation method restricted on a smooth surface based ontransformation.

Chaikin算法是最简单的离散曲线造型方法，文中将Chaikin算法推广到球面，证明了算法的可行性和生成曲线的连续可微性，指出球面Chaikin算法得到的曲线是分段的二次第二类球面Bezier曲线，并给出了用球面Chaikin算法构造球面插值曲线的算法；进一步，文中讨论了一般的球面割角算法，指出由球面割角算法得到的曲线具有"球面变差缩减性质"。3基于变换的约束在光滑曲面上的曲线插值方法。

ECC system makes use of the finite group of elliptic curve on the finite field instead of finite cyclic group used in the discrete logarithm problem. The theory of ECC is being studied a lot and it is the focus of the cryptography and the industrial estate, especially the technique of the implementation of ECC.In this thesis, the meaning of the information technology is discussed firstly, then we analyze the classical cryptography algoritham. After that, the mathematics base of elliptic curve cryptosytems are introduced, especially the theory of the finite field. As for some algorithms, we also give out the program of reliazation.

随后，介绍了研究椭圆曲线密码系统所需要的数学理论基础，特别是有限域中的椭圆曲线理论，并对相关的方法给出相应的实例及其程序实现；论文第三章讨论给出了椭圆曲线密码体制的研究现状，综述了椭圆曲线与现有一些密码算法的结合，介绍了椭圆曲线的离散对数问题以及椭圆曲线面临的攻击，详细描述了椭圆曲线密码系统的实现细节及各个部分的实验数据。

Secondly, in this part, we will introduce the notation of average geodesic curvature for curves in the hyperbolic plane, and investigate the relationship between the embeddedness of the curve and its average geodesic curvature. Finally, we will employ the Minkowskis support function to construct a new kind of non-circular smooth constant breadth curves in order to attack some open problems on the constant width curves for example, whether there is a non-circular polynomial curve of constant width, etc.

其次，对双曲平面上的曲线引入平均测地曲率的概念，并讨论双曲平面上凸曲线的嵌入性与它的平均测地曲率之间的关系，其目的是为了将双曲平面上曲线的性质与欧氏平面中曲线的性质作一些对比；最后，我们利用Minkowski支撑函数构造了一类新的非圆的光滑常宽曲线，其目的是想回答有关常宽曲线的一些未解决问题如是否存在非圆的多项式常宽曲线？

Here, we will give an independent proof of the existence for inequality (2.1.3), and by the way, give an estimate on the width of the bi-enclosing annulus of closed convex curves in the plane. Secondly, in this part, we will introduce the notation of average geodesic curvature for curves in the hyperbolic plane, and investigate the relationship between the embeddedness of the curve and its average geodesic curvature.

其次，对双曲平面上的曲线引入平均测地曲率的概念，并讨论双曲平面上凸曲线的嵌入性与它的平均测地曲率之间的关系，其目的是为了将双曲平(来源：ABC论84文网www.abclunwen.com)面上曲线的性质与欧氏平面中曲线的性质作一些对比；最后，我们利用Minkowski支撑函数构造了一类新的非圆的光滑常宽曲线，其目的是想回答有关常宽曲线的一些未解决问题如是否存在非圆的多项式常宽曲线？

The first rank derivative is a reflection of curve change and its rate, at certain range, if the sign of the first rank derivative has changed, the logging value of the correspondence depth point means maximum in this range; the second rank derivative is the knaggy property reflection of curve, at certain range, if the sign of the second rank derivative has changed, the correspondence depth point represent the inflexion of geophysical logging curve, it＇s also a turning point of the reflection of knaggy change property of the curve, it is the interface of stratum.

测井曲线的值是深度的函数，测井曲线的一阶导数表示了曲线变化的趋势和变化的快慢，在某一范围内，当一阶导数呈现符号转换时，相对应的深度点的测井值即为该范围内极大值；测井曲线的二阶导数则表示曲线的凹凸性，在某一范围内，当二阶导数呈现符号转换时，相对应的深度点代表了测井曲线的拐点，即反映曲线凹凸性变化的转折点，亦即地层的分界面。

In this paper,the rational approximation of the offset curve of Bézier curves is obtained when a polynomial of symmetric power basis is used to approximate the norm of parametric speed of Bézier curves.

等距曲线逼近技术的关键在于参数速度的逼近，文章用S幂基多项式逼近平面Bézier多项式曲线的参数速度模长，得到Bézier多项式曲线的等距曲线的有理逼近曲线，所得有理多项式逼近曲线与等距曲线在端点处能够达到高阶插值。

This paper establishes cubic spline function, analyzes subsection curve function and curve slope and curvature, at last decides to place the curve especial points which can be obtain easement curve length and other line parameters, such as the ZH point (end of line and beginning of transition curve), the HY point (end of transition curve and beginning of circular curve), the QZ point, the YH point (end of circular curve and beginning of transition curve), the HZ point (end of transition curve and beginning of line).

针对公路平面线形的8种组合类型，其线形元素特征则由最基本的直线、圆曲线、缓和曲线组成的特点，解析三次样条函数模型，得分段曲线函数、曲线斜率、曲率，从而确定曲线特征点（直缓ZH点、缓圆HY点、曲中QZ点、圆缓YH点、缓直HZ点）位置，进而得到曲线缓和曲线长度及其他线形参数。

On the other hand, the more important thing is because the urban housing is a kind of heterogeneity products.

另一方面，更重要的是由于城市住房是一种异质性产品。

Climate histogram is the fall that collects place measure calm value, cent serves as cross axle for a few equal interval, the area that the frequency that the value appears according to place is accumulated and becomes will be determined inside each interval, discharge the graph that rise with post, also be called histogram.

气候直方图是将所收集的降水量测定值，分为几个相等的区间作为横轴，并将各区间内所测定值依所出现的次数累积而成的面积，用柱子排起来的图形，也叫做柱状图。