查询词典 numerical

Finally, the idea of using new numerical method such as Discontinuous Deformation Analysis and Numerical Manifold Method to simulate the joint of CFRD is proposed, which can make guidance on the design and calculation of CFRD built on thick alluvium deposits.

提出引进新的数值方法，如不连续变形分析方法和数值流形方法，来模拟和计算面板坝接缝变形的设想，对深覆盖层上面板堆石坝的设计和计算有指导意义。

To reduce the large numerical dispersion error for the alternating direction implicit finite-difference time-domain method, an isotropic ADI-FDTD method with low numerical dispersion error was presented.

针对交替方向隐式时域有限差分方法数值色散严重的缺点，提出了一种低数值色散的各向同性ADI-FDTD方法。

The numerical ex-periment has shown that the number of iterations depends significantly on the positiveparameterα,β. But, in general, it is di?cult to choose a proper parameterα,β. Thuswe propose new self-adaptive alternating direction method which adjusts the scale pa-rameter automatically per iteration based on the message of the iterates. We have provedthe convergence of the method under mild assumptions.Finally, we present some numerical results.

对于我们提出的新交替方向法，数值实验表明，迭代的步数与时间与所取的参数α，β有关，然而我们很难去选择一个合适的参数α，β，因此我们提出新自适应交替方向法，对其中的参数α，β进行自适应调整，这种自适应算法根据每步迭代信息自动地调整参数α，β，并证明了算法的收敛性。

The angular distribution of the bistaticscattering coefficient of HH polarization were obtained by numerical implementation. Influences of the permittivity and the mean layer thickness of intermediate medium, friction velocity and the frequency of the incident wave on the bistatic scattering coefficient were discussed. The basic characteristics, the zonal characteristics and the characteristics with varying of frequency of the scattering coefficient from stratified sea surface were obtained. The numerical results show that the scattering coefficient has approximate "quantization" characteristics.

通过数值计算得到了HH 极化双站散射系数随散射角的变化曲线，讨论了中间介质介电常数和厚度、摩擦风速和入射波频率对双站散射系数的影响，得到改进的一维分形分层海面散射系数的基本特征、分区特征和随频率变化的特征，结果表明散射系数近似具有"量子化"特征。

In this dissertation, the following critical theoretical problems on local La-grangian numerical differentiation are studied: explicit formulas, local estimate for the remainder, and the highest order of approximation in the case that the values of the function at these interpolation nodes have perturbationsLagrangian numerical differentiation is a method that the Lagrange interpolation polynomialis differentiated to approximate the derivative, where Tn ={t_0,t_1,......

本文主要研究有关局部Lagrange数值微分法的一些关键性的理论问题：公式的显式表示，余项的渐近估计，以及在插值数据有扰动的情况下，局部Lagrange数值微分法的最大逼近阶。

Firstly, the isotropic difference templates were introduced to approximate the differential in the ADI-FDTD method, and the weighting coefficients of difference terms were determined for implementing isotropic numerical dispersion; Then the permittivity and permeability were adjusted manually to reduce the numerical dispersion error in any directions. Therefore the simulation accuracy and efficiency can be improved effectively for time domain problems with some finite bandwidths.

该方法在ADI-FDTD方法的差分近似微分中引入各向同性差分模板，并通过确定各向同性差分的加权系数来近似实现各向同性，然后人为修正空间的介质参数来减少各个方向上的数值色散误差，因此在模拟一定带宽的时域问题时可有效提高计算精度和计算效率。

Some numerical examples are given to show that the numerical method presented is an approximation method with high efficiency and convergence.

数值计算表明本文数值方法是一种高效和收敛的近似方法。

In the paper, the researches and conclusions are:The basic theory and technique ofgeography information system, Introduce the history of the GIS technique developmentand it develops the trend, the GIS modernizes the meaning of the construction and thepurpose and the meaning of the topic researches to the our army artillery.The design ofartillerist numeric map, Make use of the soft strong graphics function of the SuperMapgeography information system, from how made the numerical map of artillery tocommence, carried on the processing and processed the piece to the artilleryappropriative paper quality diagram to manufacture the numerical map of artillery.Themold of choosing the position of artillerist and excavating the position of spacedata;Rules of space clustering analyzing and space relationship on the basis ofmathematics configuration;Choosing the path of positing convert;optimalpath arithmetic on the basis of chart theory and realize optimal path analyze.

论文研究内容有：地理信息系统的基本理论与技术，介绍GIS技术发展的历史及其发展趋势，GIS对我军炮兵现代化建设的意义和课题研究的目的及意义；炮兵地图数字化设计与制作，利用SuperMap地理信息系统软强大的制图功能，从如何制炮兵数字地图入手，对炮兵专用的纸质地图进行处理和加工件来制作炮兵数字地图；炮兵阵地选取分析模型、阵地空间数据挖掘模型的建立和挖掘过程，基于数学形态学的空间聚类分析法、空间关联规则法的挖掘模型；阵地转移的路径选择，对炮兵阵地转移路径进行分析，基于图论中的Dijkstra最优路径算法，实现转移最佳路径分析。

Chapter 9: We report a large quantity of numerical experiments of 13 different algebraic multigrid algorithms for solving the Poisson equation, anisotropic equation, equation with cross-derivative terms, general matrix problems with large off-diagonal positive entries, biharmonic equation, Toeplity matrix, elasticity systems, finite element discretization of the Laplacian and even 3D problems. Particular attention is focused on asymptotic convergence factors and CPU-time consumed. Numerical results for many different types of practical problems demonstrate the efficiency and robustness of the proposed algebraic multigrid methods.

第九章：在各种代数多重网格算法的基础上，进行了大量的数值试验，具体给出了十三种不同的代数多重网格方法求解泊松方程，各向异性方程，带混合导数项的方程，带有大的非对角正元素的一般矩阵问题，重调和方程，托普利兹矩阵，弹性力学方程组，拉普拉斯算子的有限元离散，甚至三维问题的较为丰富的数值结果，重点关注它们的渐近收敛因子和所需的CPU时间，来源于不同类型问题的计算结果既为代数多重网格理论分析和算法的改进提供了很实用的资料，同时也证实了本文给出的代数多重网格算法的效绩和稳健性。

The results of numerical simulation reveal that the resistance to liquefaction of sands increases as the angularity of particles increased, and the micro_mechanism is related to the average coordination number of sample. It also found that the numerical sand sample made from randomly mixing multiple shapes of sand can quantitatively reflect the regularity of fabric evolution of sands during liquefaction.

结果表明，颗粒棱角度越大，试样抗液化能力越强，其在细观机理上与初始平均接触数大小有关；随机混合仿真试样可以从定性角度反映实际砂土振动液化过程中的细观组构演化规律，为今后进一步的定量研究奠定了基础。

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。