圆函数

It is obviously that a planar point set has innumerable circumscribled circles. To get a minimum circumscribled circle, a mathematical model is built to transform the problem of getting a minimum circumscribled circle to the problem of optimizing function and to solve the function optimization with genetic algorithm.

为求得最小的包容圆，建立了求平面点列包容圆的数学模型，将求最小包容圆问题转化为函数优化问题，并用遗传算法解决了这个函数最优解的求解问题。

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

In recent years, Feng Kang has advanced a more natural and direct redu-ction, i. e. the reduction via Green's formula and Green's function.

近年来冯康又提出一种更自然而直接的归化，即从Green公式及Green函数出发将微分方程边值问题化为边界上的含有广义函数意义下发散积分有限部分的奇异积分方程，这种归化在各种边界归化中占有特殊地位，被称为正则边界归化，本文将这一理论应用于重调和椭圆边值问题，研究了其正则归化的性质，并通过利用Green函数、Fourier分析及复变函数论方法等不同途径求出了在上半平面、单位圆内部、单位圆外部三种区域的Poisson积分公式及正则积分方程，其离散化可用于实际计算。

So, in this paper, a circular cavity witha large radius is used to replace the straight boundary of thehalf space, then the half space problem can be changed tothe scattering problem of two circular cavities to the steadyincident P-wave . Having the aid of the mature cylinderfunction theory, the general solutions of the wave functionscan be given, and an infinite linear algebraic equations ofthe unknown coefficients in the wave functions can be gottenwith the boundary conditions and the Fourier complex seriesexpansion technology, the infinite linear algebraic equationscan be approximately solved by the finite trunction withsatisfying some definite precision, at the basis of thissolution of the equation, the variations and the lay-outs ofthe DSCF at the circular cavity boundary vs. the differentincident angles, the different embedded depths of thecircular cavity as well as the different dimensionless wavenumber of the incident P-wave.

为此，本文采用一个半径很大的圆孔来代替半空间的直边界，将该半空间问题转化为一无限大空间中两个圆孔对稳态P波的共同散射问题，借助于成熟的柱函数理论，通过写出问题波函数的一般形式解，利用问题的边界条件，并采用复数傅立叶级数展开技术将其化为一个仅包含问题波函数中未知系数的一无穷线性代数方程组，在满足一定计算精度的前提下，通过有限项截断进行近似求解，进而讨论了圆孔边界处的动应力集中系数随不同入射角、不同的圆孔掩埋深度、入射波的不同无量纲波数以及介质的泊松比变化和分布情况。

This paper establishes cubic spline function, analyzes subsection curve function and curve slope and curvature, at last decides to place the curve especial points which can be obtain easement curve length and other line parameters, such as the ZH point (end of line and beginning of transition curve), the HY point (end of transition curve and beginning of circular curve), the QZ point, the YH point (end of circular curve and beginning of transition curve), the HZ point (end of transition curve and beginning of line).

针对公路平面线形的8种组合类型，其线形元素特征则由最基本的直线、圆曲线、缓和曲线组成的特点，解析三次样条函数模型，得分段曲线函数、曲线斜率、曲率，从而确定曲线特征点（直缓ZH点、缓圆HY点、曲中QZ点、圆缓YH点、缓直HZ点）位置，进而得到曲线缓和曲线长度及其他线形参数。

As same as the above-mentioned reason, because theconditions at the inside straight boundary of the binarycomposite material can not be easily satisfied, here, anelastic circular inclusion with large radius is used to replacethe upper half space of the binary composite material, so the〓mary binary composite mater ial problem can be changed〓the scattering problem of a circular elastic inclusion andto the scattering problem of a circular eastic inclusion and〓circular cavity in an infinite space to the steady incident〓wave.

与前面两个问题的理由一样，同样，由于问题中双质复合材料的内部直边界上的边界条件不易解析满足，为此，本文采用了一个半径很大的弹性实夹杂来代替问题中双质复合材料的上半空间部分，而将原来的双质复合材料问题转化成了无限大空间中一圆形弹性夹杂和一圆孔对稳态P波的共同散射问题，根据该问题的特点写出了弹性夹杂内外波场中波函数的一般形式解，利用该问题中夹杂和圆孔处的位移和应力的连续条件，并采用复数傅立叶级数展开技术将其化为一个仅包含问题波函数中未知系数的无穷线性代数方程组，在满足一定计算精度的前提下，通过有限项截断进行近似求解，进而讨论了双质复合材料中圆孔边界处的动应力集中系数随不同入射角、圆孔的不同位置、以及入射波的不同无量纲波数的变化和分布情况。

Work pieces contour show that the shape of free forming area could be represented accurately by circular function.

通过对成形件外轮廓的测量分析知，固体颗粒介质板材成形过程中，自由变形区的形状可用圆函数非常精确的表示。

The relationship between head's relative displacement and sheet s maximum deformation is deduced by circular function forming model.

通过圆函数变形模型，推导出两种典型零件成形中压头压入行程与板料最大变形量的函数关系。

The paper adopts the RBF neural network to fit ship lines at the first time and puts forward the method determining the RBF center point sets suitable for fitting ship lines. It shows that the method is of much higher learning speed compared with BP neural network, and is both practical and feasible based on the examination of the fitting precision by using the power function and circular function.

采用RBF神经网络拟合船舶型线，提出了适合船舶型线拟合的RBF中心点集的选取方式，与BP网络相比大大提高了学习速度和精度，用幂函数和圆函数检验本方法拟合曲线的精度，充分证明本方法拟合船舶型线是实用可行的。

Themapping function sequences including circular cutouts and elliptical cutouts aregiven in this chapter.

然后为方便地满足圆柱壳大开孔的边界条件，通过复变函数方法中的用来求解多边形映射问题的Schwarz-Christoffel积分表达式，将圆柱壳展开面上的非圆非椭的开孔边界曲线保角映射成为单位圆，给出了在不同开孔率情况下的关于圆孔和椭圆孔的保角映射函数的具体形式。

I didn't watch TV last night, because it .

昨晚我没有看电视，因为电视机坏了。

Since this year, in a lot of villages of Beijing, TV of elevator liquid crystal was removed.

今年以来，在北京的很多小区里，电梯液晶电视被撤了下来。