查询词典 approximate derivative

That do not require derivative information and approximate the objective function without recourse to Taylor expansions.

虽然是有益的，我们觉得基于泰勒展式的分类法脱离了基本的问题。正如[27]，我们更强调逼近的构建，而不是他们构建的机制。

An approximate nth derivative of an analytical signal can be obtained by applying n times of the wavelet transform to the signal.

用Haar小波对信号进行n次连续小波变换，可得到信号的近似n阶导数。

For another, reduced-space approaches allow to exploit problem-dependent structure and approximate second derivative information.

简约空间方法适合过程系统优化命题的高维、低自由度特征，并可利用问题结构和近似二阶信息求解，是该类优化命题的良好求解途径。

Two new functions based on the property of bubble wavelet are proposed. An approximate 2nd derivative of an analytical signal can be obtained by applying n times of the wavelet transform to the signal, the signal-to-noise ratio can be enhanced greatly.

根据小波的定义和墨西哥帽小波的一些特点提出了两种简单的窗口函数，利用它们对模拟高斯信号求2n阶近似导数的同时滤除了噪声，同时还可分离重叠峰，并讨论了尺度因子对变换结果的影响。

We investigate mainly solving the hyperbolic and parabolic equations by using the MQ quasi-interpolation. The underlying idea of our means is that: employing the derivative of the MQ quasi-interpolation to approximate the spatial derivative of the PDE, while the approach of the temporal derivative of the PDE is used a finite difference.

我们主要就MQ拟插值在双曲型方程和抛物型方程中的应用进行了研究，其基本思路是：利用MQ拟插值的导数逼近微分方程的空间导数，而微分方程的时间导数则采用有限差分逼近。

In this dissertation, the following critical theoretical problems on local La-grangian numerical differentiation are studied: explicit formulas, local estimate for the remainder, and the highest order of approximation in the case that the values of the function at these interpolation nodes have perturbationsLagrangian numerical differentiation is a method that the Lagrange interpolation polynomialis differentiated to approximate the derivative, where Tn ={t_0,t_1,......

本文主要研究有关局部Lagrange数值微分法的一些关键性的理论问题：公式的显式表示，余项的渐近估计，以及在插值数据有扰动的情况下，局部Lagrange数值微分法的最大逼近阶。

To resolve thismodel,one approximate liner first derivative equation is used.An simple caculatemodel is setted up for caculating the motive adjust,and a mathematical equation incaculating the range of pressure motion in the system.Experiment data showe thatthese models have high accurecy.

在此基础上，对分析模型采用一阶微分近似线性化处理，建立了计算动态调节过程的简化计算模型，并以此建立了计算系统压力动态变幅的计算式，试验表明简化模型具有较高的精度。

Combining the definition of CWT and the derivative property of convolution, we constructed a general method to calculate the approximate derivative of signal through CWT by using the first and second derivative of Gaussian function, Haar, and the first derivative of three-order-Spline function as wavelets. As compared with the other approaches of calculating derivative, which include the numerical differentiation, polynomial filters, Fourier transform, and the recently proposed DWT method, fast calculation and simple mathematical operation were remarkable advantages of CWT method. For the signal corrupted by severe noise (Signal-toNoise Ratio=5), the satisfactory results could also obtained via CWT method through appropriately adiusting the dilations.

在此基础上，(1)结合连续小波变换的特点和卷积的微分性质，提出了使用Gaussian函数的一阶和二阶导数，Haar和三次样条函数的一阶导数作为小波函数的连续小波变换计算信号近似导数的一般性方法，与其他导数计算方法(包括数字微分法，多项式滤波法，Fourier变换法和离散小波变换法)相比，本法简单便捷，计算速度快，对于噪声含量较高的信号(S/N为5)，只要适当调节尺度即可获得比较满意的结果。

They concluded that the derivative-free formula is not exact under the assumed conditions, but it is a very good approximate reconstruction formula.

黄朝志等发现在1993年发表的非圆轨迹不含导数的扇束重建公式推导中的一个错误他们的结论是：在假设的条件下，不含导数的重建公式不是精确的，但是一个很好的近似重建公式。

In Part I, the biharmonic equation are chosen, and the boundary peanlty finite method using piecewise cubic Hermite elements is used to seek their approximate solutions, in particular satisfying the derivative and periodical boundary conditions.

在第一部份里，选择使用片断三次 Hermite元素的边界惩型有限元素法来求解满足边界导数条件和边界周期条件的重调和方程式的近似解。

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。