点变换

In this paper, We firstly present a nonuniform sampling DCT method based on the relationship of Chebyshev polynomial interpolation and DCT, in which, the sampling points are chosen as zeros of Nth degree Chebyshev polynomials of the first kind.

文章首先利用Chebyshev多项式插值与DCT变换之间的相互关系，提出了基于第一类Chebyshev多项式的第N次多项式的零点作为非均匀取样点的DCT变换方法。

According to induced response method, the expression in frequency domain of pressure response at the end of pipeline is derived using impulse response method and convolution theorem. The expression indicates that that transfer function is only related to the characteristics of pipeline system and the Fourier transform of flow variable only depends on the operating characteristics, and the pressure response in frequency domain is linear with the Fourier transform of flow variable.

基于激励响应法，应用脉冲响应方法和卷积定理得出了管道末端压力响应在频域中的表达式，此式表明：传递函数只与系统的特性相关，流量变量的傅立叶变换只与操作特性相关，且压力频域响应与流量变量的傅立叶变换为线形关系，根据此式在理论上能够得到管道泄漏点的重要信息。

This dissertation addresses a practical data processing method of free-form surface for the coordinate measuring machine, including fitting algorithm, probe radius compensation and surface matching .

以坐标变换理论和最优化算法为基础，提出了应用单纯形法，对原始测量点进行坐标平移和旋转变换，将理论坐标与实际坐标统一起来，在此基础上进行误差处理，从而较好的解决了曲面匹配问题。

The variation transformation characteristics of three main joint methods (lap joint, butt joint and cornel joint) were analyzed.

通过建立基于多点约束的连接点模拟和装配面接触效应模拟的有限元模型，研究了三种典型装配接头结构对偏差变化的影响特征，揭示了偏差变换非线性的机理，并提出将Monte-Carlo方法与有限元法结合起来进行装配偏差变换的计算。

Fourier transformation image-processing technology was applied for determining the cross section fiber cell arrangement in hardwood. In this method, the disc-convoluted dot map from each cell radius with 10 pixels was transformed by Fourier transformation, and generated the angle distribution function in the power spectral pattern. The maximum value reflected the arrangement of the fiber cell.

利用傅立叶变换图象处理技术来测定阔叶材横切面纤维细胞排列，把表示每一个纤维细胞的半径为10个像素点的圈盘点图，进行傅立叶变换，再做能量光谱图的角度分布图，其最大值表示纤维细胞的排列。

After analyzing in the Gaussian point expansion function curve,there has several points of interest,and good showing in degraded image.These points of interest and spread function parameter have certain relations.

分析发现高斯型点扩展函数曲线中，存在着几个特征点，它们很好地表现在降质的图像傅里叶变换图像中，这几个点与扩展函数参数存在着一定的关系。

And the xyz-coordinates of the two point diffraction sources were calculated by the modified Newton method based on the Broyden-Fletcher-Goldfarb-Shanno alg.

基于傅里叶变换的点衍射干涉测量术是一种建立在点光源衍射干涉理论基础上的测量方法，它采用傅里叶条纹分析方法来求解干涉条纹的相位分布，运用基于BFGS的拟牛顿算法进行三坐标的迭代计算，确定点光源的三维空间坐标。

It is a measurement method following the diffraction and interference theory of the point light source. The phase message of interference pattern was obtained by the Fourier transform pattern analysis method. And the xyz-coordinates of the two point diffraction sources were calculated by the modified Newton method based on the Broyden-Fletcher-Goldfarb-Shanno algorithm.

基于傅里叶变换的点衍射干涉测量术是一种建立在点光源衍射干涉理论基础上的测量方法，它采用傅里叶条纹分析方法来求解干涉条纹的相位分布，运用基于BFGS的拟牛顿算法进行三坐标的迭代计算，确定点光源的三维空间坐标。

The accurate transformation matrix between two images can be estimated within the inliers subset.

点与外点，在内点域中精确计算图像之间的变换关系。

Then the fixed point of transformation can be found, among which those unstable ones are critical points of phase transition.

然后找出重整化变换的不动点，在所有不动点中那些不稳定不动点是发生相变的临界点。

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。