查询词典 cubic 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。

This algorithm firstly translates arbitrary parameter curves into the piecewise cubic-degree Bezier curves, then using the properties of Bezier curve we can get the tangent vector and the normal vector of every point on the approximation curve, and calculate the approximating offset curve.

此算法先将任意形式的参数曲线转化成分段三次Bézier曲线，利用Bézier曲线的性质容易得到逼近曲线的切向量和法向量，从而计算出其等距逼近曲线。

This paper adopts the method of double cubic B-Spline curved surface modeling based on cubic B-Spline curve,and comes out its matrix expression.

自由曲面的数据一般是由各截面型线给出的，数据用离散点组成的列表数据表示，给定型值点的自由曲面型

Therefore at each time we get the roots of this cubic equation, we can decide if we keep or reject each root according to the continuity of the curved surface, the method is as follows: If , the relative cubic plane curve is just a circle, this circle can be gotten by solving .

因此在每次求得该一元三次方程的解时，我们根据曲面的连续性来判断这些根的取舍，方法如下：在处，所得的平面曲线就是圆截线，该圆截线可以由相截得到，即。

This is a detailed introduction cubic spline curve function of the thesis, dissertation the main speaker of the cubic spline function of the mathematical foundations and algorithm description.

详细说明：这是一篇详细介绍三次样条曲线函数的论文，论文主要讲了三次样条函数的数学基础及算法说明。

It's the first time that from the angle of computational mathematics combined with the structure model of parallel machine, the parallel degree of the relevant algorithms in orthopaedics clinic engineering modeling system, such as piecewise cubic Lagrange interpolation formula, piecewise cubic Hermite's interpolation formula, cubic spline, Chebyshev multinomial fitting algorithms, least square method and contour curve multinomial algorithms, were discussed.

论文首次从计算数学的角度并结合并行机的结构模式出发，讨论了在骨科临床工程造型系统中可能涉及的如分段三次拉格郎日插值公式、分段三次埃尔米特插值公式、三次样条函数、切比雪夫多项式拟合算法，最小二乘法以及轮廓曲线多项式求值算法的并行度。

Because of cubic B spline curve have several advantages such as local controllable, continuity etc, an active contour model based on cubic B spline curve is proposed in this dissertation.

针对以上问题，结合三次B样条曲线连续性及局部可控性的特点，本文提出了一种基于三次B样条曲线的主动轮廓模型。

In order to overcome these weaknesses, we use quartic B-spline structure the yield curve, which indicates the less node cubic B-spline model is better under the situation that do not use the forward rate curve, if need to make use of forward rate curve to carry on the economy analysis, the suggestion use quartic B-spline method.

为克服这些缺点，我们用四次B-样条构造收益率曲线，实证表明能克服三次B-样条曲线上述缺点。因此，在不使用远期利率曲线情况下较少节点的三次样条模型是较好选择，当需要利用远期利率曲线进行经济分析时，建议使用四次B-样条法。

Further, it is found that the limit curve is a uniform rational cubic B-spline curve or the curve's control polygon when its tension parameters tend to zero or infinity respectively.

Barsky[4 ] 将具有张力参数样条的双曲样条曲线引入CAGD ，称之为张力样条参数曲线，并证明了这种曲线是一类泛函问题的极小解。

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。

Do you know, i need you to come back

你知道吗，我需要你回来

Yang yinshu、Wang xiangsheng、Li decang,The first discovery of haemaphysalis conicinna.

1〕 杨银书，王祥生，李德昌。安徽省首次发现嗜群血蜱。