查询词典 approximate derivative

In this paper, a region approximation idea that means using a "fat curve" with a width to approximate the offset curve is proposed, and a complete set of algorithms to approximate offset curve using disk Bézier curve are given and implemented. In the algorithms, the optimal and uniform approximate curve of the offset curve as the central curve of the Disk Bézier curve is found by using Remez method, and then the upper optimal and uniform approximation principle is proposed to compute the error radius function of the Disk Bézier curve. Thus, the whole Disk Bézier curve can be obtained. In the end of this paper, the approximate effect of the Disk Bézier curve is not only analyzed and assessed, but also some specific examples are provided.

提出用一条带宽度的"胖曲线"来逼近上述等距曲线的区域逼近思想，并建立与实现了圆域Bézier曲线等距逼近的整套算法，包括应用Remez方法求出等距曲线的最佳一致逼近曲线作为圆域Bézier曲线的中心曲线，提出上控最佳一致逼近的原理求出圆域Bézier曲线的误差半径函数，以及确定整条圆域Bézier曲线，最后还对该圆域Bézier逼近的效果做了分析和考核，并给出了一些具体实例。

And the direction query efficiency based on multi-approximate index is compared with that based on taditional external approximation index. 2 The algorithms of nearest neighbor and reverse nearest neighbor about point, line and ploygen based on multi-approximate index are proposed after the virous methods of distance measure are discussed in detail. And the query efficiency of NN and RNN based on multi-approximate index is compared with that based on taditional external approximation index. 3 The basic concept of semi-join and the strategy of distance-direction semi-join are introduced. And the model of distance relationship, direction relationship and the bounding for spatial object are discussed. Then the method is presented about how to implement the query of distance-direction semi-join, and the efficiency of the algorithm based on multi-approximate index is compared with that based on taditional external approximation index.

即：1在方向关系矩阵模型、开域方向模型基础上，讨论了基于多重近似索引下的定性与定量方向检索方法，并通过实验对基于多重近似索引与外部近似索引下的方向检索效率进行了对比分析；2详细讨论了各种距离度量方法，提出了基于多重近似索引下的点、线、面的最邻近查询和反最邻近查询算法，并通过实验对基于多重近似索引与外部近似索引下的最邻近查询和反最邻近查询效率进行比较分析；3介绍了半连接的基本概念，探讨了距离关系、方向关系以及空间对象数量的约束模型，给出了基于多重近似索引下的距离方向半连接实现方法，并通过实验对基于多重近似索引与外部近似索引下的距离方向半连接的效率进行了比较分析。

The average relativeerror was 3.63%, less much than mostly used group-contribution methods for alkyne, chlorine derivative, iodine derivative, especially for alkane, bromine derivative, aromatic hydrocarbon, alicyclic hydrocarbon and sulfur-containing organic compounds.

对4068种有机物的正常沸点进行了估算，其平均相对误差为3.63%，总体估算精度明显优于相比较的基团贡献法，对炔烃、氯衍生物、碘衍生物，尤其是对烷烃类、溴衍生物、芳烃、脂环烃和含硫化合物的估算误差明显减小。

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。

On the fuzzy number valued mapping F:〓→〓, we put forward the definitions ofdirectional derivative, differential, gradient and subdifferential, and with the "cut method" byusing respectively the directional derivative and differential of two crisp functions that aredetermined by F, characterize the directional derivative and differential of F.

对于模糊映射F：〓→〓，提出了方向导数，微分，梯度及次微分的概念，并通过取截集，用由F所完全确定的通常函数的方向导数和微分分别刻划F的方向导数和微分。

The dissertation begins with the further discussion attributions of the economic contract , and comparing the economic contract with the ordinary economic contract and financial instruments, I think that the derivative financial instrument is an economic contract essentially, and has all the common characters owned by the economic contract, so we should establish the accounting for derivative financial instrument on the executory contract, otherwise the accounting for the derivative financial instrument will lose the basis of the accounting theory.

本文共分四部分：本文首先对衍生金融工具的经济属性进行了较为深入的探讨，并将其与一般经济合约和基本金融工具进行了比较分析，认为衍生金融工具本质上是一项经济合约，具有所有经济合约所具有的共性，衍生金融工具的会计处理应建立在对履行中合约的会计处理基础之上，否则对衍生金融工具的会计处理就会缺乏理论基础。

Its concept is between nowhere Frechet derivative and uniformly non-Frechet derivative in derivative.

在可微性概念上介于无处Frechet可微和一致不Frechet可微之间。

The domain derivative of the Navier-Stokes equations is given in the same manner as the Stokes equatons' domain derivative by reducing to homogeneous equations and proving continuous character and existence of Frechet derivative .

同样利用对非齐次方程的齐次化、证明目标函数对区域的连续性和其导数的存在性，同时给出了定常Navier-Stokes方程的区域导数完整的理论证明。

By making use of the definition of derivative ,one can calculate the derivative of demarcation point ,the derioative of the special elementary function,the derivative of parametric equation.

利用导数的定义可求分界点的导数，特殊初等函数的导数和某些参数方程的导

The subjects include :(1) Limits and continuity,(2) The derivative,(3) The applications of derivative,(4) Partial derivative,(5) Infinite series,(6) Integration,(7) The technique of integral,(8) The applications of integration,(9) Multiple integrals.

主要课程包含有：(1)极限与连续，(2)导函数，(3)导函数的应用，(4)偏导函数，(5)无穷级数，(6)积分，(7)积分的技巧，(8)积分的应用，(9)重积分。

"Yes, now you can give yourself airs," she said, you have got what you wanted.

"对了，您现在高兴了，"她说道，这是您所期待的。

Then the LORD said to me: Rebel Israel is inwardly more just than traitorous Judah.

上主于是对我说：＂失节的以色列比失信的犹大，更显得正义。