近似计算

In view of the demand of computerized eye-glasses-wearing system, an approach to match two dimensional (2D) human head images with 3D glasses frame graphics in 3D space has been proposed. First, the operator points out three or six key points, which are used to locate 3D eye-glasses frame, on the human face image displayed on the computer screen interactively.

论文针对计算机化眼镜配戴系统的要求，提出了一种在三维空间匹配二维人头图象和三维眼镜图形的方法，即通过人机交互方法，由操作者在显示于计算机屏幕上的二维人头图象上，指出确定三维眼镜位置的三个或六个关键点的二维坐标及其三维对应点，从而可以近似求出人面朝向及视点坐标，再用相应位置上的三维通用人头图形替换二维人面图象，计算人面和眼镜间的遮挡关系并显示，从而完成二者的空间匹配。

Based on Collins integral formula and the expansion of the hard aperture function into a finite sum of complex Gaussian functions,the approximate analytical expression of the diffraction field of Gaussian beam by a circular disc is derived,and its characteristics are analyzed by the numerical calculation and numerical simulation.

基于圆孔光阑函数展开为复高斯函数和的方法，用Colins积分公式，导出了高斯光束照射下圆盘衍射的光场近似解析表达式，经计算机数值计算，对高斯光束照射下圆盘衍射的衍射特性进行了详细的分析

By applying the method of multiple scales to the reduced system,the first approximation solution for 1/3 subharmonic resonance of the system is obtained.

应用非线性振动的多尺度法求得系统满足1/3次亚谐共振情况时的一次近似解，并进行数值计算。

By applying the method of multiple scales to the reduced system,the first approximation solution for 1/3 subharmonic resonanc...

应用非线性振动的多尺度法求得系统满足1/3次亚谐共振情况时的一次近似解，并进行数值计算。

The approximations can be used as the initial guess and pre-conditioner in the stabilized biconjugate-gradient fast Fourier transform algorithm for computing integral equations, and hence a hybrid DTA-BCGS algorithm with higher efficiency is formed.

这两种近似可以作为计算积分方程稳定型双共轭梯度快速Fourier变换算法的初始猜测值和预条件因子，从而形成效率更高的混合DTA-BCGS算法。

For free oscillation of various nonlinear conservative systems, the analytical approximate periods and the corresponding periodic solutions were established and they are valid for small as well as large amplitude of oscillation.

提出了结构参数发生较大变化时，计算结构的静力响应，固有频率与固有振型的高效的、适用范围广的方法；对非线性保守系统的自由振动，建立了既适用于小振幅又适用于大振幅的近似解析解法。

Simulation results show that bubbles induce the circulation of particles in the fluidized bed in which the distribution of particle velocities can be expressed by the Gauss distribution.

计算结果表明床内气泡的形成造成床内颗粒的循环，使得流化床内颗粒具有不同的轴向和径向脉动速度，颗粒分速度分布近似服从高斯分布。

When up to 31th harmonics are analyzed, the calculation time is only 1/82 of theat by the classical Gaussian elimination method.

对于一个周期值事先不知道，在一个周期内有100个采样点的非整周期采样，这个近似方法可使谐波分析的准确度由一般的DFT的10〓量级提高到10〓量级；当分析至31次谐波时，计算时间约为经典高斯消去法的〓，将能满足实际的工程需要。

For a 3D system, formulae for a general polynomial controller applied to the normal form of a system and for the relvant stability index are derived. Thereby the amplitude approximation in terms of control gains of the controlled system is solved.

对于三维系统，研究了作用于标准型下系统的普适的多项式控制器设计以及相应的极限环稳定性指标的计算，建立了受控系统的极限环幅值与控制增益之间的近似解析关系。

The approximate fractional dimension of Fujian Province′s coastline is evaluated and then used to design a fractal simulation system of the coastline on the basis of quasi-koch generating element.

运用分形几何的概念，计算了福建省海岸线的近似分维数。

However, as the name（read－only memory）implies, CD disks cannot be written onorchanged in any way.

然而，正如其名字所指出的那样，CD盘不能写，也不能用任何方式改变其内容。

Galvanizes steel pallet is mainly export which suits standard packing of European Union, the North America. galvanizes steel pallet is suitable to heavy rack. Pallet surface can design plate type, corrugated and the gap form, satisfies the different requirements.

镀锌钢托盘多用于出口，替代木托盘，免薰蒸，符合欧盟、北美各国对出口货物包装材料的法令要求；喷涂钢托盘适用于重载上货架之用，托盘表面根据需要制作成平板状、波纹状及间隔形式，满足不同的使用要求。