查询词典 approximate

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。

Using this method, we will get the approximate solution of the fractional differential equations.

第三章在第二章的基础上把这个方法推广到更加复杂的分数阶微分方程，同样通过数值例子表明了该方法的高精度性和有效性。

And the numerical solutions of difference equation are regarded as the approximate solutions for the differential equation.

文中首先对对称正则长波方程提出了一个两层和两个三层的有限差分格式。

CA method can provide better approximate results when the differential physical effect of Pi is considered.

当考虑到占有几率Pi的微分效应时，相干近似方法能够提供更好的近似结果。

If the system is stable and running, import and export pressure approximate to set the differential pressure ΔP.

若系统稳定运行，进、出口压差ΔP近似为设定压差。

Most photorealistic solutions use a form of raytracing and complex differential equations to approximate the optical behaviour and motion dynamics of a water body.

大多数解决方案使用光线跟踪和复杂的微分方程来近似水体的光学行为和运动动力学。

The great advantage of using these difference equations is that they can be solved on a digital computer to provide approximate solutions to the differential equations.

将这个近似的差分式子代入微分方程中就得到了微分方程的差分近似，这个差分方程可直接用计算机进行求解，使计算方便快捷。

If you are unfortunate enough to the lovelorn, please tell me, I will help you out, really, please contact me!

如果你不幸失恋了，请告诉我，我会帮助你摆脱困境，真的，请联系我啦！

China's plan to cut energy intensity by 20 percent and pollutant discharges by 10 percent between 2006 and 2010 is a case in point.

中国计划在2006年到2010间降低20%的能源强度和减少10%的主要污染物排放，就是一个这样的例子。