查询词典 direct numerical method

Compared with traditional numerical methods, the LB method has several important features, including: simplicity in algorithm, easily programming, direct calculation of pressure from a state equation and amenability to simulate all kinds of flow field with complex boundaries, it also has many advantages in the respect of parallel computation because of its regional evolution.

与传统的计算方法相比较，LB方法具有算法简单、编程容易、压力可以通过状态方程直接求解、能够模拟各种复杂边界的流场等优点，并且计算的局域性使其在并行计算方面也具有很大的优势。

Compared with traditional numerical methods such as the FEM, FDM, etc, the LB method has several important features, including: simplicity in algorithm, easily programming, direct calculation of pressure from a state equation and amenability to simulate all kinds of flow field with complex boundaries, it also has much advantage in the respect of parallel computation because of its regional evolution.

与传统的计算方法如FEM、FDM等相比，LB方法具有算法简单、编程容易、压力可以通过状态方程直接求解、能够模拟各种复杂边界的流场等优点，并且计算的局域性使其在并行计算方面也具有很大的优势。

As a result, it shows thatthe static or dynamic subsystem optimum alone is not equal to the system optimum. Three initial value problems met in the optimal design of flying vehicle are studied andconclusions are derived that: orthogonal test method can be adopted to decide the initial valueof static optimization problem, some mathematical techniques can be used to deal with thecostate variables of Maximum Principle and decide the initial value of the costate variable,the indirect method can be used to get the analytical solution under ideal case to guide thechoice of the initial control curve in the direct method. With some numerical examples oftrajectory optimization, it shows that all these methods are useful not only in accelerating theconvergence but also in converging to the global optimum.

针对飞行器优化设计中的三种初始值问题进行了研究，以远程弹道导弹弹道的工程优化为例说明，对于静态优化问题，采用正交试验法选取初始值，不仅可以大大加快收敛的速度，而且更有可能收敛到全局最优解；以气动力辅助变轨问题为例说明，用共态变量的一阶泰勒级数展开可以解决极大值原理中共态变量初值难于确定的问题；以二级弹道导弹的主动段弹道优化为例说明，利用间接法在理想情况下得到的解析解来指导直接法初始控制曲线的选择，将大大有利于提高直接法的收敛速度。

The variation regularity of joint size and the shear strength of fractal rock joints with different fractal dimensions were subsequently studied by using the numerical direct shear test method.

为了研究岩石节理抗剪强度参数取值中的尺寸效应问题，采用随机分形方法，重构了岩石节理剖面线，在此基础上，应用数值直剪试验方法，研究了不同分维值岩石分形节理抗剪强度参数随节理尺寸的变化规律。

The inversion of particle size distribution from measured data of light scattering, as a typical inverse problem, has been studied by many reseachers and solved by several numerical methods. Among which, direct Tikhonov regularization method with Morozov discrepancy principle, is often used to overcome the ill-posedness linked with the Fredholm integral equation of the first kind, so the stability of inversion has been heightened. But there has much room for improvement of the inversion accuaracy, especially for the double-peak problems.

由测量得到的散射光强数据来反演颗粒粒径分布是一个典型的反问题，它已为许多的学者所研究，并用多种数值方法来求解，其中带Morozov偏差原理的直接Tikhonov正则化方法经常被采用，以便用来克服与上述反演相联系的第一类Fredholm积分方程的不适定性带来的困难，因而反演的精度得到了提高；然而仍有许多改进的余地，特别是对于所谓"双峰"问题更是如此。

Direct method of Gaussian elimination, Gaussian main-element elimination, and the iterative method of Jacobi iteration, Gauss - Seidel (Gauss - Seidel) iterative method is linear equations numerical solution of important ways.

直接法中的高斯消去法、高斯列主元消去法，以及迭代法中的雅可比迭代法、高斯-赛德尔（Gauss-Seidel）迭代法又是线性方程组数值求解的重要方法。

With the compare of research methods such as direct experiment, indirect method and numerical simulation method, and with the applied background of the Virtual Prototype technology, the paper puts forward a new strategy for the design of the testing device for dynamic response of road based on Pro/E、 ADAMS and ANSYS software. On the basis of the theory, this paper analyze the scheme and the important parts, and has proposed that actual modeling parameter, pattern and arrangement scheme, and structured the complete machine scheme of a testing device for testing road dynamic response based on dynamic load of vehicle-road.

本文在系统分析了各种车路系统动载荷研究方法的基础上，针对直接试验方法、间接试验方法和数字仿真方法的发展，并结合"虚拟样机"技术的应用背景，提出了一种基于Pro／E、ADAMS和ANSYS软件的基于车路动载荷的测试路面力学响应的试验装置的虚拟样机的实现策略，并在此基础上，对方案和重要部件进行了分析，提出了实际的建模参数、型式和布局方案，构建了一种基于车路系统动力学的测试路面动态力学响应的试验装置的整机方案。

Numerical calculation results are given and compared with those by the direct integral of the Collins formula and by using Wen's method.

给出了数值计算结果，并与直接积分Collins公式和使用Wen方法的结果作了比较。

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。

To study numerical solution of the linear equations,the article presents direct method ,Jacobi iterate method and Gauss-seidel iterate method to approximately calculate,and has given its process in MATLAB.

为研究线性方程组的数值解，文章用直接解法、雅可比迭代法、高斯-赛德尔迭代法进行了近似计算，并给出在MATLAB中计算的程序。

Singer Leona Lewis and former Led Zeppelin guitarist Jimmy Page emerged as the bus transformed into a grass-covered carnival float, and the pair combined for a rendition of "Whole Lotta Love".

歌手leona刘易斯和前率领的飞艇的吉他手吉米页出现巴士转化为基层所涵盖的嘉年华花车，和一双合并为一移交&整个lotta爱&。

This is Kate, and that's Erin.

这是凯特，那个是爱朗。