查询词典 calculus of finite differences

It is usually that the solution for the Dirichlet problem can not be obtained actually. With the development of computers, people pay more and more attention to the numerical solution. Many ideas and methods have appeared. Among them the finite element method has become most popular. But the finite element method has some weaknesses and limitations too. First, it is not fit to higher-dimensional problems.

绝大多数Dirichlet问题的解析解往往难以得到，随着计算机技术的发展，Dirichlet问题的数值解法越来越受到人们的重视，新的思想和方法不断涌现，其中有限元法已经发展成为目前求解Dirichlet问题的最主要的数值方法，但是有限元法解决该问题时，存在着一些弱点和局限。

It is usually that the solution for the Dirichlet problem can not be obtained actually. With the development of computers, people pay more and more attention to the numerical solution. Many ideas and methods have appeared. Among them the finite element method has become most popular. But the finite element method has some weaknesses and limitations too.

绝大多数Dirichlet问题的解析解往往难以得到，随着计算机技术的发展，Dirichlet问题的数值解法越来越受到人们的重视，新的思想和方法不断涌现，其中有限元法已经发展成为目前求解Dirichlet问题的最主要的数值方法，但是有限元法解决该问题时，存在着一些弱点和局限。

By taking the advantages of SPH and standard finite element methods,a coupled method is proposed,in which the computational model is made up of finite elements in initial time and the large distortional elements are converted automatically into smoothed particles.

扼要讨论了光滑粒子法的离散思想，充分利用光滑粒子法和有限元方法各自的优点，提出了一种初始时刻用有限元建模，计算过程中大变形单元自动转换为光滑粒子的耦合算法。

Birkhoff, every finite distributive lattice is isomorphic to the lattice of all filters of a finite partially ordered set.

由G.Birkhoff的一个基本定理，每个有限分配格同构于一个有限偏序集所有滤子的格。

When the temperature distribution is analyzed, finite element reseaus are divided in space field and finite difference reseaus are divided in time field and then, the program is compiled.

截面温度场分析在空间域内采用有限元网格划分，在时间域内则用有限差分网格划分。

The use of ANSYS finite element software to establish a large-scale Decanters double cone angle of the two-dimensional finite element model of the drum to its normal working condition in the overall structure of static analysis, has been the drum of the radial, axial deformation and stress distribution and maximum stress points, results show that the double cone angle drum strength and stiffness to meet the requirements to verify the safety of the structure of double cone angle.

利用ANSYS有限元软件建立了大型卧螺离心机双锥角转鼓的二维有限元模型，对其在正常工作状态下的整体结构进行了静力分析，得到了转鼓的径向、轴向变形和应力分布及最大应力点，结果表明双锥角转鼓的强度和刚度均满足要求，验证了双锥角结构的安全性。

Then the fundamental equations for plate/shell bi-nonlinear finite element model were set up with layered finite method. the fundamental geometric nonlinearity equations for the unbonded prestressed tendon and double spring element were proposed, and the double spring element was used to simulate the interaction of unbonded prestressed tendon and deviator.

最后，针对配置体外CFRP预应力筋混凝土梁的受力特性，对各规范和规程中的裂缝计算公式进行了相应的修正，建立了适用于配置体外CFRP预应力筋混凝土箱梁和T梁短期和长期裂缝宽度的计算公式。

Based on the analyzing of finite field multiply operation, Matlab was used to simplify the sections which were complex and resource-consumed. As a result, a simple form of combinational logic was obtained. And bit-parallel multipliers under nature or dual basis were designed separately in finite-field with VHDL language.

在分析有限域乘法运算法则的基础上，用Matlab简化其复杂而消耗资源的部分，得到形式简单的组合逻辑，并用VHDL语言分别设计了有限域GF(2m)中自然基和对偶基下比特并行乘法器。

These kinds of analytical elements can describe the crack tip fields for the Dugdale model and can also be combined with the ordinate finite elements to form the semi-analytical finite element method.

该类超级单元能够准确地描述基于Dugdale模型的裂纹尖端场，可与普通有限单元相结合，构成半解析有限元法。

Within this context, four specific areas are addressed:(1) By means of finite integration technique, a new kind of the first order partial difference equation is derived from the original disperse transmission line equation of the uniform waveguide's. As it is the kind of one dimension Dirichlet's boundary problem, it is convenient for us to solve this equation from the leapfrog scheme. Because computation is carried out in one dimension, both high calculation efficiency and precision have been obtained in this method. Meanwhile, this method provide us a different selection to simulate the transient response of waveguide with non-simplical, for examples cylinder and elliptic waveguide, and avoid solving the second order equation, or using finite difference time domain to simulate a three dimension problem, sometimes the latter precision is not satisfied with the need, or low efficiency.

在这一研究内容下，主要研究四个方面的问题：(1)在完成金属波导传输线方程时域形式的基础之上，应用有限积分技术，把波导特征模式的色散传输线方程，化简为一组新的一阶偏微分方程组，该边值问题属一维Dirichlet边值问题，从而便于用蛙跳格式求解，由于是在一维中计算，该方法具有很高计算效率和精度，从而避免了以往为得到金属波导中特征模的时域响应特性，须要求解二阶方程，或用时域有限差分方法求解三维问题的方法，对于后者来说，计算有时是不准确的，或是很耗时的例如计算诸如圆波导、椭圆波导等其它复杂形状的波导。

You can snipe the second and third union leaders from this position.

您可以鹬第二和第三工会领袖从这一立场出发。

Aiming at the currently shortage of XML streams quality detecting, this paper proposes a new forecasting method of XML streams quality by least squares support vector machines, which is used the method of XML keys' vector matrix as windows, and vector product wavelet transform to multilevel decompose and refactor the XML streams series, that can fulfill real-time checking demand of XML quality, and ensure constraint, consist- ency and integrality. For even more adapting net load, it proposes a control strategy by weight and adaptive adjustment to ensure XML streams quality.

针对当前XML数据流质量检测存在的不足，提出构建XML键的矢量矩阵作为窗口，利用矢量积小波变换多级分解与重构XML数据流，再结合最小二乘支持向量机对XML数据流质量进行预测的一种方法，满足XML数据流质量重构时实时检测的要求，保证XML数据的约束性、一致性与完整性；为了更好的适应网络负载，采取加权与自适应窗口调整等调度策略充分保证XML数据流的质量检测。