逼近

In this paper, a method of digital approximation is used to approach the function of crustal movement, px.y.

本文运用数值逼近法去逼近地壳运动函数p=f，进而分别导出了按条件观测平差和按间接观测平差的严密公式。

The stopband error of prototype filter is used to be the objective function for optimization. Instead of the method of least square approximation, this paper introduce the method of best uniformity approximation.

选择低通原型滤波器最大阻带衰减为优化的目标函数，通常的优化目标函数选用最小平方逼近的方法，本文提出了使用最佳一致逼近的方法。

At first, an approximated mathematical model is presented. Then, the system manager can compute the optimal control policy via the method of successive approximation. Based on the above-mentioned algorithm, we design an intelligent system with feedback control to regulate the allocation of limited channels of trunk circuit. This system will continuously detect the status of whole cellular network. Once the system parameters cross the predefined threshold, the recomputing mechanism will be activated.

首先针对系统的近似数学模型先將其定义出来，然后就可以用连续逼近法將最佳控管决策计算出来，这样的最佳决策演算法我们把它设计在一个有迴授机制的智慧型决策系统裹，此决策系统將不断地侦测行动通讯网路运作的情形，一旦网路参数变化超过某个预定的临界值时，整个最佳决策演算法將被启动，系统的近似数学模型將依新的参数重新定义，接下来同样地写出最佳方程式並用连续逼近法计算出新的最佳控管决策。

This paper begin with a review of curves and surfces modeling, then we discuss the parametric polynomial minimal surface. This is followed by a discussion of the representations of catenoids and helicoids. Next, we discuss the numeric approximations to the minimal surfaces with piecewise polygons and B-Spline surfaces.

全文安排如下首先，我们简要回顾曲面造型历史和发展现状在第二和第三章，讨论参数多项式极小曲面；在第四章讨论悬链面和螺旋面的表示；在第五章讨论极小曲面的分片线性逼近；在第六章讨论极小曲面的B-样条逼近；最后，我们对全文做简单的总结。

At first, the existence of extended form of approach to continuous selection for any set valued mapping without any continuity restriction in para-compact metric space is proved ;by the topologically separated mappings , the approximate selection theorem of sub-lower-semi-continuous mapping is established, furthermore , continuous selection problem in H-space is studied. Next, with W-correspondence, an improved variational inequality is obtained ; by the H-KKM mapping ,Ky Fan\'s minimax inequality is generalized to H-space . At last, with H-convexity instead of the linear topological structure, a new version of Browder fixed point theorem is established.Chapter 3 deals with set-valued mapping vector variational inequality and minimax problems.

第二章首先在仿紧的度量空间上对任意的集值映射建立了新的逼近连续选择定理，利用映射的拓扑可分性，在H-空间上建立了次下半连续映射的逼近连续选择定理和一个新的连续选择定理；然后利用W-对应，在H-空间上建立了广义的变分不等式；利用H-KKM映射，在H-空间上建立了广义的KyFan极小极大不等式；最后，利用H-凸性代替拓扑线性结构，在H-空间上建立了一个新型的Browder不动点定理。

To solve the problem numerically, a mollification method is considered. Error estimate between the exact solution and its approximation is given.

作者在文章中提出了一类正则化方法，通过巧妙地选取适当的参数及相应高斯核正则化子来构造逼近解，并给出了逼近解的近似程度估计。

By using the Tadmor's convergence criteria for the difference approximation of the hyperbolic conservative e2 quation and introducing some adjusting parameter in the nonvanishing viscosity , some convergence properties are obtained.

Descripción ：摘要：应用Tadmor 的关于双曲型守恒方程式差分逼近的收敛性判别法，对于若干差分逼近式，引入一些参数，只要在上机时适当调整此参数值，即可得到其收敛性。

The method of calculating the perturbed Chebyshev-Padé approximation is proposed for not only the general situation but also some special cases, i.e., an odd function and an even one.

提出了一种新的带有扰动的Chebyshev-Padé逼近，它依赖于一个扰动参数，其优点在于：它可以通过调整扰动参数来提高逼近的精度。

A method for improving the order of convergence by Richardson extrapolation for the Peaceman-Rachford scheme is also presented,which obtains the two order approximating accuracy.

提出一种修正的交替方向隐格式逼近均匀介质中的非连续渗流方程，以及修正Douglas格式逼近非均匀介质中的连续渗流方程。

By means of estimates for three-dimensional discrete derivative Green's function , the theory of the interpolation operator of projection type and the technique of cancellation of elements, for several usual elements in the three-dimensional setting, including rectangular parallelepiped elements, tetrahedr.

借助三维离散导数Green函数的估计，投影型插值算子理论和单元合并技术，本文详细讨论了几种常用三维单元(包括长方体元，四面体元和三棱柱元)的有限元解梯度的最大模超逼近，均获得了高精度的超逼近结果。

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。