查询词典 collocation of boundary

Next, the boundary value problem is changed into an integral equation by applying a Green function. Then, by establishing a normalized boundary equation, the irregularity of the kernel of integral equation is overcome.

弹性扭转问题可看成是Poisson方程的边值问题，R 函数理论保证了对于任何复杂的区域，总可以找到一个规范化方程，从而可以将弹性扭转问题化为一个无奇异性的第二类Fredholm积分方程。

Based on a chosen normalized boundary equation, a new normalized boundary equation can be established such that the irregularity of the kernel of integral equations is overcame. Finally, natural frequency is obtained by the existence condition of nontrivial solution of the discrete algebraic equations derived from the integral equations.

边界方程有多种选择，在选定一种边界方程的基础上，可以通过建立一个新的边界方程来表示问题的边界，以克服积分核的奇异性；最后由积分方程的离散化方程组有非平凡解的条件，求得固有频率。

The research achievement are acquired as follows: 1From mathematical models for inverse scattering in two dimensional homogenous media including Dirichlet, Neumann, Robin,all kinds of probable mixed boundaries and cracks, direct and inverse scattering are discussed, and ill-posed integral equation and indicator function method are formulated for the diverse of boundary identification. It is shown that the kernel of the integral equation characters the boundary of scatterer, which is determined by solving it by virtual of regularity method, meanwhile, some numerical tests are given.

本研究取得了如下研究成果： 1）在二维均匀介质逆散射各种边界识别的数学模型（包括Dirichlet，Neumann，Robin，各种可能的混合边界问题，裂纹问题）下，分别考虑了正散射问题和逆散射问题，推导了上述各种边界识别的不适定积分方程以及指示函数方法，由于积分方程的核充分表征了散射物的边界，由此说明只要利用正则化方法求解该积分方程，就可以确定散射物的边界，并给出了一些数值实验。

A boundary integral formulation describing constant-αforce-free field with finite energycontent in the semi-infinite space above the sun was proposed(Yan,1995), this formulationcontains boundary field and its normal gradient under integral sign.

颜毅华1995年在太阳物理杂志上发表一文，就太阳磁场提出了一个具有有限能量的线性无力场模型，并对磁场给出了一个边界积分表示公式，该公式用边界上的已知磁场值和未知的磁场法向导数值来确定空间任意点的磁场值。

Firstly, by using the vector integral theory and boundary conditions of the electromagnetic filed, the boundary problem of two electromagnetic fields in the upper half space and lower half space is transformed into two vector integral equations just related to the topography interface, i.e.

提出了一种用边界元法计算频率域人工源三维地形电磁场的数值模拟方法。

In the hybrid algorithm, we use FEM to model the EM field in the interior domain, and then use the integral equation to compute the field on the boundary (to provide an artificial boundary condition for FEM system), and the finite element approximation is also convenient for deriving discrete equations of the integral equation.

混合法的原理是引入一个包围非均匀目标体的虚构边界，在边界内部的场用有限元法模拟，在边界外部的场用积分方程表达，二者在边界上通过场的连续性耦合起来。

It has been solved to deal with the boundary when using interpolation function method to evaluate boundary value problem.

解决了插值函数法的边界（以及求解区域内不同介质间分界线）处理问题，其结果已得到实际计算的验证。

Starting from the concept of Measured Equation of Invariance and the local equivalent theorem, it regarded the determination of the truncation boundary condition as a question of field simulation in a small area near the grid boundary. The practical disposal in the 2D and 3D cases was discussed.

基于测度不变方程的概念和局部等效原理，将截断边界条件的确定归结为网格边界上一小区域的电位场模拟问题，并讨论了在二维、三维情况下的具体处理。

Special attention should be paid when we apply the decomposition method to two-point boundary value problems, it is necessary to solve a algebraic system;It should be noted that a modification of inverse operator should be made when dealing with singular boundary value problems;Laplace transform and Pade approximants can be coupled to enhance the efficiency of the decomposition method.

比如，在求解两点边值问题时就需要特别注意，这时需要采用待定系数法，最后会涉及到系数方程组的求解；在处理奇异边值问题时需要重新定义逆运算；不少研究人员还把分解方法与Laplace变换和Padé逼近相结合来进一步提高分解方法的精度。

In the present work,the existence and uniqueness results aboutperiodic boundary value problems for different kinds of the nonlin-ear periodically perturbed nonconservative systems are establishedthrough the discretization technique,under suitable assumptions,by using global inverse function theorem and result about the ex-istence and uniqueness of periodic solution for nonhomogeneouslyfirst order linear periodic boundary value problem.

本文的第一章概述了在讨论原问题解的存在唯一性过程中以及构造和分析相关的数值求解方法时将要用到的全局反函数定理、有关矩阵特征值的若干重要引理、线性常微分方程非齐次周期问题解的存在唯一性定理和单参数影射方法及有关结论，并简单回顾了已有的证明非线性微分方程周期边值问题解的存在唯一性的方法，其中包括谱理论、最大最小化形式方法、摄动技术和全局反函数理论方法，最后，介绍了两类数值求解非线性微分方程问题的方法。

Nowadays, most of research are to build a transmutative Petri Nets through adding controlling place sets, controlling arc sets and controlling policy to the basic Petri Nets, while the Controlled Petri Nets could be used to argue many controlling theory problems conveniently and to induce many logically and physically supervisory and solve the Event Feedback Controlling Problems and State Feedback Controlling Problem in DEDS supervisory theory.

目前大多数的研究表现为在变形后的受控Petri网基础上，利用各种方法求得各种逻辑型、结构型控制器，解决DEDS监控理论中的事件反馈控制问题与状态反馈控制问题。

On one hand, there are discussions with the works council and union about extension of short time working up to the end of September.

一方面，有讨论，工程理事会和联盟关于延长工作时间短至9月底。