离散问题

In this thesis including six chapters,we presents a combinatorial stabilized/(first or-der equation)Galerkin least-square finite element method for viscous incompressible flowproblem to circumvent inf-sup condition necessary for the classic Galerkin mitred finiteelement method.

在由六章组成的论文中，我们为粘性不可压缩流动问题提出一种消除了经典混合元中离散inf-sup条件约束的组合稳定/最小平方有限元格式。

First, we introduce the linearly distributed stress tensors as the source and by means of two-dimensional finite-difference scheme to obtain the response of this source, then the point source response is generated by correcting both the wave forms and geometrical spreadings for the linear respons.

但在理论地震学，工程地震学和勘探地震学中横向不均匀介质中的波传播问题非常重要，此时使用有限差分法和有限元法等离散数值方法比较有效。鉴于目前计算工具的限制，三维模型的有限差分计算虽然在理论上是可行的，但很少能用于实际。

In Chapter 3, the prior estimates about the 3-D difference solution and its difference quotients on time space and geometry space are made by means of discrete functional analysis, so that the stability and the convergence of the 3-D difference solution are obtained.

在第三章中，运用离散泛函分析的手段，对三维中子输运方程的差分解及其时间、空间差商进行了先验估计，从而得到了差分解的稳定性和收敛性，也为三维问题的应用研究打下了初步的理论基础。

In this paper, firstly, the theory and the discretization schemes of LBIE and the concepts of MLS and GMLS are introduced; secondly, LBIE method is applied to solve the thin plate-bending problems and four typical examples are given to demonstrate the applicability and validity of the method. The results obtained from numerical examples agree well with the exact solutions and have an excellent rate of convergence.

本文首先介绍了无网格局部边界积分方程方法的理论基础和离散步骤，以及移动最小二乘近似法和广义移动最小二乘近似法等概念；其次将该方法初步应用于计算薄板的弯曲问题，建立了完整的积分公式，求解了四个典型算例，结果同精确解非常接近，且收敛快。

In recent years,a number of data structures for global geo-referenced data sets have been proposed based on regular,multi-resolution partitions of polyhedra and spherical discrete grid is the most promising of such systems.

球面离散网格模型是管理海量数据的有效途径，如何构建球面网格是这类模型的基础问题。

Aimed at the shaking problem at the moment of high speed paper feeding by paper separation suction nozzle of feeder of the press, a set of inverse seeking designing method for the suction nozzle of paper separation mechanism was provided.

针对印刷机飞达分纸吸嘴高速输纸时的抖动问题，提供了一套分纸吸嘴机构反求设计的方法。根据实测凸轮廓线离散坐标，利用样条插值法得到了实际廓线的解析方程；构建了分纸机构运动反求的数学模型，得到了从动件及分纸吸嘴的运动规律。

The following are main contents studied: A finite element method for Navier-Stokes equation with ALE formulation is considered and by combined with theNewmark method of numerical intergration a pressure correction scheme is obtained for the solution of the FE formulation of N-S equation. Because the incompressibility condition can be satisfied approximately in this scheme, the interpolation functions of elements can be equalorder for the velocity field and pressure field. In the ALE formulation the fluid-solid interaction analysis became a three-field coupling problem of the fluid field, the solid field and the fluid dynamic mesh. The properties and charactiristices of this three-field coupling problem are deeply discussed.

研究的主要内容有：主容器中流体大晃动是一种强非线性问题，文中研究了求解ALE描述的粘性流体N-S方程的有限元方法，以有利于大晃动自由液面的跟踪和流体大晃动中非线性现象的描述；并结合Newmark数值积分法推出了求解ALE型N-S方程的压力修正解法，由于这种解法可以近似满足不可压条件，因此可以采用速度场和压力场等阶插值的有限元离散格式，从而较好地解决了普遍采用的不等阶插值解法中，速度场和压力场数值精度不一致、程序编制不便等的不足。

The parameters of a car-engine were discreteness; nonlinear and uncertain characteristics, so a general average control model could not control accurately the excess air coefficient and the spark advance angle in dynamic procedure. A self-optimizing fuzzy control with an immune correction coefficient was proposed.

针对发动机参数具有离散性、非线性和不确定性，采用常规的平均值控制模型难以精确控制瞬态过程的过量空气系数和点火时刻的问题，提出了一种带免疫修正因子的自寻优模糊控制。

One new auto-optimized fuzzy control model of car-engines based on genetic arithmetic was introduced aiming at the problem that the parameters of car-engine are of the discreteness, the nonlinear and the uncertain characteristics, with which it is difficult to control accurately the excess air coefficient and the spark advance angle in dynamic procedure when using a conventional control model.

针对汽车发动机参数具有离散性、非线性和不确定性，采用传统控制模型难以精确控制瞬态过程的过量空气系数和点火时刻的问题，提出了一种基于遗传算法的发动机自寻优模糊控制模型。设计了实现该控制模型的嵌入式控制器，讨论了实时在线仿真基础上，采用遗传算法对模糊控制参数的自动寻优。

Its security is based on the security of Shamir's threshold scheme and the intractability of discrete logarithm problem.

方案的安全性基于Shamir门限机制和离散对数问题。

For a big chunk of credit-card losses; the number of filings (and thus charge-off rates) would be rising again, whether

年美国个人破产法的一个改动使得破产登记急速下降，而后引起了信用卡大规模的亏损。

Eph. 4:23 And that you be renewed in the spirit of your mind

弗四23 而在你们心思的灵里得以更新