查询词典 difference equation

Basing on the nonatationary linear mild-slope equation developed by Hong Guangwen in 1995, a complete wave model is built considering the bottom friction, nonlinear dispersion relation, and allied reflection and diffraction of several islands. Integrating with corresponding physical and imaginary boundaries, it is solved through Alternating Direction Implicit difference method.

本文以洪广文(1995)推导的非定常线性波缓坡方程为基础，建立考虑底摩阻项，非线性弥散关系，及多岛屿绕射反射作用的缓坡方程求解模式，采用经典的ADI法差分格式，结合物理和虚拟边界条件进行求解。

An extended hyperbolic mild-slope equation, which can take such terms as wind input, bottom friction and nonlinearity of wave into account, here has been deduced into a parabolic one in the form of a series of governing equations described with complex amplitude. It became a complete wave model when integrated with corresponding physical and imaginary boundaries, and can be solved through the improved Crank-Nicholson or the well known Alternating Direction Implicit difference method, both of which can accelerate the convergent speed , expand limitation of the mathematical method and improve the quality of the solution.

本文基于综合考虑底摩阻、风能输入及非线性影响的推广双曲型缓坡方程，将其进行转换，产生一个演变方程，其复振幅控制方程为抛物线性，并采用ADI差分格式、改进的Crank-Nicholson格式及相应的物理和虚拟边界条件进行求解，以提高数值模拟的适用性、数值计算的稳定性、收敛速度及精度。

To solve the B-Ss pricing formulas,there are many popular methods now,such as partial differential equation,analytical approximation,binomial tree methods,finite difference method and Monte-Carlo simulation.

对于Black-Scholes期权定价模型，如今比较流行的定价方法有偏微分方程、解析近似方法、二叉树方法、有限差分方法和Monte-Carlo模拟等。

This section presents two kinds of characteristic schemes, one is the natural use of the usual backward Euler characteristic difference scheme ( [60] ) onto the triangular mesh, the other replaces the backward Euler's method by modified Euler formula to approximate the characteristic differential equation, so that the discretization for characteristic curve can get up to second order accuracy.

本节给出了两种三角形网格上的特征差分格式，第一种是通常的向后Euler型特征差分格式（[60]）在三角形网格上的自然运用，第二种采用§3.3、§3.4的离散思想，使用改进的Euler公式代替向后Euler公式来近似特征微分方程，使其对特征线的离散达到了二阶精度。

Lastly, we study a model of the heat flow cryptosystem base on a linear pseudoparabolic equation. The C-N difference scheme arithmetic of the encryption and decryption problems is designed. Then the numerical simulation is done through computer programming. So by analysing the simulation data we deduce many regularly conclusions on the influence of the key functions to the encryption and decryption operations, which establish the theoretical base for the application of this cryptosystem.

最后，文章研究了一类基于线性伪抛物型方程的热流密码体制模型，设计了加、解密问题的C—N差分算法并通过计算机编程进行了数值模拟，得出了一些不同密钥函数对加、解密作业影响的规律性结论，为该密码体制的现实应用奠定了理论基础。

The implicit TDMA algorithm and first kind of firstorder upwind difference were employed to solve the conservation equation associated with appropriate boundary conditions.

通过分析离心力场作用下铝熔液在Al2O3短纤维多孔介质内的渗流传热现象，考虑离心惯性力对渗流传热过程的影响，建立了多孔介质渗流传热模型。

Derive recursive least squares method, recursive general least squares method, recursive augmented matrix method, recursive multiple-stage least squares method and recursive maximum likelihood method based on recursive Householder transformation by applying the three real-time solutions of overdetermined linear equation to difference model.

将线性矛盾方程组的三种实时解法应用于差分模型，导出了基于Househol-der变换的递推最小二乘法、递推广义最小二乘法、递推增广矩阵法、递推多级最小二乘法和递推极大似然法。

Finally, with help of a auxiliary equation,a set of sufficient conditions for the global stability of higher order rational difference equations were obtained.

同时，在每章的最后列举了一部分可以用本章所介绍的方法进行研究并可以证明其全局渐近稳定性的方程。

This paper gives an accurate inversion of matrix of coefficient which is derived fromsolving the boundary-value problem of biharmonic equation in rectangular region by meansof difference method.

将一个n阶电导矩阵实现为具有n+1节点的网络是一很重要的问题，并且引起了广泛的研究，本文扼要地介绍了有关电导矩阵的性质和一些己有的实现方法。

Result］Like most of C3 plants, the diurnal changes curve of NPR of Lonicera japonica Thunb. showed double peaks, but there were time difference in reaching the peak value between the study and previous ones. The responding mathematical model of NPR to photosynthetic valid radiation could be described by three mathematic functions , such as logarithm, linearity and binomial,but binomial function was more precise than the others. Light saturation point of Lonicera japonica Thunb. was figured out by binomial equation deduced in the study, and light saturation point was 1 086.3 μmol/(m2·s).

结果］与多数其他C3植物一样，金银花净光合速率日变化曲线呈双峰型，但在具体达到峰值的时间上与前人的结果有差异；金银花净光合速率对光合有效辐射的响应可用对数、线性、二项式3种数学函数来描述，但以二项式描述更确切；根据前面得到的二项式方程，计算出了金银花的光饱和点为1 086.3 μmol/(m2·s)。

On the other hand, the more important thing is because the urban housing is a kind of heterogeneity products.

另一方面，更重要的是由于城市住房是一种异质性产品。

Climate histogram is the fall that collects place measure calm value, cent serves as cross axle for a few equal interval, the area that the frequency that the value appears according to place is accumulated and becomes will be determined inside each interval, discharge the graph that rise with post, also be called histogram.

气候直方图是将所收集的降水量测定值，分为几个相等的区间作为横轴，并将各区间内所测定值依所出现的次数累积而成的面积，用柱子排起来的图形，也叫做柱状图。