样条函数

Algebraic curve is commonly used in CAGD. Traditional curve interpolation is in various forms of spline fuction. Although better result can be obtained by spline curve, the former two of elliptic, hyperbolic and parabolic shapes can not be represented by spline curve. An exploring research in this aspect is made in this thesis.

代数曲线是CAGD中经常用到的曲线，以往的曲线插值基本上是采用样条函数的形式，采用这种形式虽然能够获得很好的效果，但样条函数所能表达的形状都是抛物线型，对椭圆型与双曲线型曲线的表示是无能为力的。

Though comparing Canny operator and center B spline dyadic wavelet, the following conclusion is proven in this dissertation: a Center B spline function has tight support and Canny operator hasn't. b Center B spline function asymptotic convergence to Gaussian function and the derivative of Center B spline function asymptotic convergence to Canny operator. c The derivative of fourth order center spline B function is more suitable as a optimal edge detector than Canny operator. d Center B spline function can balance the smoothing and approximation of original data, and the fourth center B spline function is the only optimal solution of two order smoothing problem. e The error between the valve of time-frequency uncertainty of the fourth center B spline function and the lower bound of time-frequency uncertainty does not exceed 0.143% of the lower bound. f The derivative of center spline B function can construct a stability dyadic wavelet and can give a fast algorithm for multiscale edge detection, but Canny operator can do neither.

作者给出了Canny算子与中心B样条二进小波严格的比较证明，得出如下结论：a中心B样条函数具有紧支集，Canny算子不具有紧支集。b中心B样条函数的极限收敛于高斯函数，中心B样条函数的导数收敛于Canny算子。c四阶中心B样条函数的导数比Canny算子更接近最佳边缘检测滤波器。d中心B样条函数比高斯函数更能兼顾对原函数平滑和逼近的折中要求，并且四阶中心B样条函数是二阶逼近问题的唯一最优解。e四阶中心B样条函数的时频测不准关系值与时频测不准关系下界的逼近误差不超过0.143％。f中心B样条函数的导数可以构成稳定的二进小波，存在快速的多尺度算法；而Canny算子不构成稳定的二进小波，无法给出快速的多尺度算法。

The present paper applies the quadratic splines to the Chemical Engigeering calculations for integration, interpolation and differentiation with good precision.

在样条函数的研究和应用日益广泛的今天，作者将人们所忽视的二次多项式样条函数引用到化工计算中的插值，求积和求导等方面，取得良好的结果。

The properties of the new method are that (1) the equations that the quartic Bézier curve has to satisfy for being C 2 continuous are strictly row diagonally dominant;(2) the discontinuous points of the curve are at the given data points;(3) the curve is locally adjustable;(4) if the given data points are convex, the constructed quartic Bézier curve is convex.

用样条函数方法构造插值样条曲线曲面，曲线曲面的精度和形状是由给定的数据点和端点条件唯一确定的。在有些情况下，例如，对文献 [7～ 9]中的数据点集，由样条函数方法构造的C2 插值曲线是不可接受的，但由于没有额外自由度，无法调整曲线的形状。

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。

Lastly,we present an algorithm to isolate real roots of a univariate spline, i.e., computing asequence of disjoint intervals such that each of them contains exactly one real root of agiven spline function, which is primarily based on the use of Descartes\' rule of signs withits B-spline coefficients and de Casteljau algorithm of B?

最后，基于B-样条系数的Descartes符号准则和Bézier曲线的de Casteljau算法，我们给出了一元样条实根分离算法，也就是计算出一列不相交区间，使得每个区间恰好只包含此样条函数的一个实根。

Bring forward a kind of learning algorithm fitting on the base of spline function, because the spline function has good flexibility and quadratic smoothing property, the search problem of network weight functions training can be converted into the resoluting extreme value problem of the plurality function through using spline function to represent network input and link weight functions, thus the PNN can be trained with the help of the existing neural network learning algorithms;④build a kind of learning algorithm base on the alternate of Walsh function, the complexity of network computing can be decreased through using the complete orthogonality of Walsh function corollary.

应用结果表明该算法收敛速度快，稳定性好；③提出了一种基于样条函数拟和的学习算法，由于样条函数具有很好的柔韧性和二次光滑性，将网络输入函数和连接权函数用样条函数的形式表示，可把网络权函数训练的函数寻优问题转换为多元函数求极值的问题，从而可借助于现有的神经网络学习算法训练过程神经元网络；④建立了一种基于Walsh函数变换的学习算法，利用Walsh函数系的完备正交性，可大大降低网络计算的复杂度。

Then, have stressed kinds of technology cubic Hermite function and cubic spline function, step by step, expand dual-cubic Hermite and dual-cubic spline function to progressively, sum up in the point that trinary cubic Hermite and trinary cublic spline finally.

讨论时重点突出了三次埃尔米特函数和三次样条函数，表达方式由浅入深，逐步扩展到双三次埃尔米特函数和双三次样条函数，最后归结到三三次埃尔米特函数和三三次样条函数。

Using the quartic rational spline function, we can construct a net of feature curves passing through the four corner points P_ which situate at the rows (U-direction) and columns (V-direction) of a m×n rectangular control mesh.

本文构造了3／1型插值有理样条即分子、分母分别为三次、一次多项式的插值函数，该样条函数不仅可通过导数参数的选取，使得插值函数保单调，还可使得插值函数保凸。

The new methodof defining spline function will generalize the concept to the more universal Hilbert space. Hence, we take into consideration the interpolation spline function, general linear differential operater in semi- open interval and the Green function defined accordingly, and the reproducing kernel to produce the Green function and prove the existence of the reproducing kernel.

采用了一种新的样条函数的定义方法，把样条函数的概念推广到更一般的Hilbert空间上，再考虑半开闭区间a，+∞上的插值样条函数，一般线性微分算子及其定义的Green函数和再生核，构造出Green函数并且证明了再生核的存在性。

Chrysanthemum of 10 thousand birthday is lax to edaphic requirement, with the arenaceous qualitative loam with fecund, good drainage had better.

万寿菊对土壤要求不严，以肥沃。排水良好的砂质壤土为好。

He unstepped the mast and furled the sail and tied it.

他拔下桅杆，把帆卷起，系住。