近似微分

Put the discrete algebraic equations of initial derivative conditions and algebraic equation system of governing differential equation together to form a new algebraic system.

采用重心Lagrange插值近似未知函数，推导了未知函数各阶导数微分矩阵的显式表达式，建立了求解二阶常微分方程初值问题的重心Lagrange插值配点法。

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。

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。

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。

Then using classical fractional differential G-L definition deduces fractional order differential difference function and constructs an approximate fractional order differential Tiansi module.

然后由经典的分数阶微分定义出发，推导出了分数阶差分方程，构建了近似的分数阶Tiansi微分模板。

The basic concept in these sections is replacing backward Euler's method by modified backward Eulers's method to approximate the characteristic differential equation and discretizing the convection-diffusion equation at the middle point of the approximate characteristic curve, which will make the convective term get up to second order accuracy.

这三节的基本离散方法是用改进的Euler公式代替向后Euler公式来近似特征微分方程，并且将近似特征线的中点作为离散节点，使得对流项的离散精度提高到二阶，对于扩散项，将其转移到待求时间层进行离散。

With the advancement of science and technology, some new theories and new ways emerged gradually, some of them merged with specific theoretical tools, this specific theoretical tools include mathematical morphology, fuzzy techniques, neural networks, wavelet and so on. Secondly, in this paper, it described and analyzed the segmentation method based on the edge in the domain of image segmentation in detail. It did experiments on several edge detection operators using MATLAB, it summarized the advantage and the shortcoming of traditional edge detection operators, and the operating environment. On the basis of the experimental analysis, it implemented an edge location more precise, more efficient operating speed edge extraction method——Template Vector. In this method, it optimized differential approximate calculation of first differential operators the paper mentioned. After experimented on this edge extraction method, contracted with the traditional methods, the edge outline is extracted more accurately and more exquisitely, furthermore, it retained the object outline furthest, and achieved more satisfied edge extraction result.

其次，对图像分割领域中常用的基于边缘的分割方法进行了详细的研究与分析，对各种边缘检测算子进行了MATLAB环境下的实验，分析总结了各种传统边缘检测算子的优缺点和适应环境，并针对传统边缘检测算子在处理显微图像时的缺陷，在实验分析的基础上研究并实现了一种边缘定位更加精确、运算速度更加快捷的边缘提取方法——模板向量算法，在该算法中，对文章提到的一阶微分算子中微分的近似计算作进一步优化，经过对该边缘提取方法进行实验，其结果与传统方法相比，轮廓提取更为精确细腻，且最大程度的保留了图像中物体(目标个体或者明显噪声点)的轮廓，得到了比较理想的边缘提取效果。

In Chapter 2, starting from the basic fractional ordinary differential equations,weapply a high order approximation of fractional derivative advanced by Lubich to frac-tional differential equation, construct a high numerical difference scheme to solve thefractional differential equation, present error analysis of the algorithms theoretically,and prove the consistency ,convergency and stability.

接下来的第二章中，首先从基本的分数阶常微分方程出发，对Lubich提出的一个关于分数阶导数的高阶近似，将其应用于分数阶微分方程，构造高阶数值差分格式来进行分数阶微分方程的数值求解，并在理论上给出这一算法的误差分析，证明了它的相容性，收敛性和稳定性。

Beginning with a general mean function, the model analyzes the distance between the arithmetic average and geometric average by Taylor's expanding.

第二章介绍了亚式期权定价研究中的市场结构、一般原理和若干重要的定价方法：PDE偏微分方程法；埃级沃斯级数展开近似定价；倒数分布近似定价；条件期望近似定价；执行价格调整近似定价，这些方法使亚式期权的定价得到了很大的发展。

Using PH linearization ,the nonlinear partial differential equation was transformed into linear partial differential equation,and then,by introducing a complex function,it was further transformed into a set of two linear differential equations.

应用 PH线性化方法，将非线性偏微分方程转化为线性偏微分方程，引入复函数将复常数偏微分方程变为两个线性实常数微分方程组，并采用小参数迭代法进行求解，近似求得了螺旋槽内气体动压分布的解析解。

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。