差分法

On the aspect of error compensation, the system using the geometric average sound pressure instead of the arithmetic average sound pressure to get the sound pressure of the measurement point. This method not only reduces the high frequency error in the sound intensity measurement, which compensates the finite difference approximation error, but also greatly reduces the computation of the sound pressure spectrum.

误差补偿方面，课题采用几何平均声压代替通常的算术平均声压来计算双传声器法的声场声压值，这样不仅可以有效的减少声强测量中的高频误差，对有限差分误差起到了补偿作用，而且还大大减小了声压谱计算中的计算量。

Using matlab to achieve numerical method of electromagnetic field inside the finite difference and finite element method.

利用matlab实现电磁场数值方法里面的有限差分与有限元法。

The method uses an implicit iterative scheme with a hyperbolic sine transformation for the matrix potential, takes the advancing front self-adaptive grid, and resolves problem of too much account in calculation to dry earth's surface by fixed grid method. Results indicate that calculation speed is increased greatly and errors are less than by fixed grid method.

该方法使用了水土势双曲正弦变换的隐式差分格式，并采取了自动向下搜索的空间网格形式，解决了干燥地表固定网格计算量过大的问题，同时计算速度大大提高，计算误差小于固定网格法的误差值。

In this chapter, a two-dimensional implicit difference scheme of the linear IBVP is designed, and the stability of the homogeneous scheme is proved by the method of separation of variable. At last, some numerical examples are presented. And the results are consistent with the theoretical result.

在本章中，建立了相应初边值问题的二维隐式格式，并利用分离变量法讨论了其中的一类特殊情形——齐次情形差分格式的稳定性，最后给出了数值算例，得到的数值结果与理论结果一致。

In the paper, river and the downstream area of dike are regarded as a whole system, and hydraulic model of coupling 1-D river and gradual dike-break is established, therein the Preissmann implicit difference scheme is applied to Main River, and the FVM is applied to the breach and polder. On the basis of FVM and unstructured grids, TVD ?

本文将河道与堤坝下游区域视为一个整体，对于单一河道采用Preissmann四点隐式差分格式计算，对于溃口及圩区采用有限体积法，建立了一维河道与堤坝渐溃耦联的水力模型，也是一维、二维耦合的水流模型。

In the forward aspect, the advantages and disadvantages of such methods as finite difference, finite element and integral equation as well as their development trend are discussed. In the inversion aspect, mainly linear and nonlinear inversions are analyzed, with a detailed discussion on the linear inversion methods both in the time domain and in the frequency domain as well as a prediction of their future development trend.

正演方面主要讨论了有限差分、有限元和积分方程法，分析了各种方法的优缺点、适用范围，并指出了未来发展趋势；反演方面主要讨论了线性反演和非线性反演，根据井间电磁波成像的性质，对时间域和频率域线性反演方法分别做了详细论述，并给出了未来发展趋势。

Stokes problems of interior domain are discussed synchronously, and comparied with pure numerical method.

3采用自然边界积分与有限差分的耦合方法，求解了自然边界积分法无法直接求解的一般区域上的Stokes问题，探讨了内部区域Stokes流问题，并与纯数值方法的结论作了比较。

More than that, the use of conjugate gradient accelerated Jacobi method improves further the computational efficiency of the model.

同时，对离散后得到的五点差分方程，用共轭斜量加速Jacobi法进行求解，使计算效率进一步提高。

Third,a semi-numerical method that uses finite difference for time toreplace Laplace transform for time is presented.

第三，提出了分布参数系统的半数值解析方法，通过对时间导数项用配置法进行差分离散，避免了Laplace变换。

Chapter two gives mathematical methods of controlled objects: state space method,dispersing method of dynamic equation about controlled objects, and solution and propertiesof linear difference equation.

第二章：介绍了受控对象的数学描述方法状态空间法、受控对象动态方程的离散化方法、线性差分方程的解及其性质。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。