坐标变换

Utilizing wave function expansion method, all of the potential functions of scattered waves are transformed into one coordinate system with the aid of Graff's addition theorem.

使用波函数展开法，利用一组圆柱坐标系统和Graff加法转换定理，将散射波势函数的表达式变换到同一个坐标系。

In this paper,a new method of measuring the resonant frequency of the RLC parallel resonance circuit was intro- duced,which makes the asymmetric amplitude-frequency curve symmetric.

介绍了用Origin变换坐标，将不对称的RLC并联电路的幅频特性曲线对称变换，从而精确求解其共振频率的方法。

The technique made full use of the characteristic of PR controller which can realize zero steady-state error in AC input signal in stationary frame. In the method, the active and reactive current component in the vector control strategy were transformed in the stationary frame to achieve the objective of keeping the DC-link voltage constant, adjusting the power factor and decoupling the active and reactive power. Compared with conventional double close-loop proportional integral controller, the PR technique is better in harmonic compensation without the complex rotating frame transformation and the couple or feedback voltage which is easily influenced by temperature and circuit parameters. The control algorithm is easy to be realized while the robustness and power quality is improved.

该方法充分利用了PR控制器能够在静止坐标系下对交流输入信号无静差控制的优势，将矢量控制策略下的有功电流和无功电流分量转换到静止坐标系下进行调节，实现网侧变换器维持直流电压稳定和调节功率因数的控制任务和双馈电机有功、无功功率的解耦控制，与传统的双闭环PI控制相比，该策略无需繁琐的坐标旋转变换，不存在受温度及电路参数影响的耦合项和前馈补偿项，且易于实现对系统低次谐波电流的补偿，减小了控制算法实现难度，提高了控制系统的鲁棒性和电网电能质量。

As a special example, we calculated global errors and reflective coefficient on the interface of quasi-PML in the Cassinian transformation cylindrical coordinates. Numerical results validated the effectiveness of absorbing in quasi-perfectly matched layers for the conformal mapping case.

本文还以Cassinian变换柱形坐标为例，计算了准PML的全局误差和准PML界面中点的反射系数，证实了保角变换柱形坐标系准PML的吸收作用。

By circumrotate transform, the author gets id and iq,called PARK transform.

通过静止坐标变化得到i和 i，称作CLARKE变换（3/2变换）。

The original video is spitted into a series of frame groups,for each frame in the group,the points of contour shape are described by MPEG-7,and taking advantage of hash function to calculate the keys between those points in the 1D- DFT transform domain and the watermark signals.

在该算法中，原始视频数据被分割成等帧数的视频组，利用MPEG-7的轮廓编码计算每个视频帧的主要物体轮廓坐标点集合；接着通过傅立叶变换得到该帧轮廓点形状不变量，利用哈希的方法计算水印信号并将这些不变量的有效值作为密钥之一；再对整个视频组的轮廓点进行傅立叶变换，得到其时间轴上的有效不变域，将水印信号嵌入在这个不变域的中频部分以确保了水印的鲁棒性。

In this method the initial values of perspective projective matrix; rotative matrix and translative matrix are calculated from the fundamental matrix, than these matrices are optimized based on the coordinate value of corresponding points.

该方法从基本矩阵计算初始透视投影、旋转和竖直平移变换矩阵，然后以对应点坐标为基础对这些变换矩阵进行优化计算，从而有效地避免了优化计算的局部最小值，而且不过分依赖基本矩阵的计算精度。

Firstly,by moving and circumrotating coordinate switching the complex model of tri－phase AC aosynchronism motor to Magnetization－Torque two axeses,The physical model of AC color Is transformed model of DC motor approximately,It is convenience to control the motor.

首先，经过坐标的平移和旋转变换，将原三相交流异步电机的复杂模型转换到M－T（Magnetization－Torque）两轴旋转坐标系上，将交流电机的物理型等效地变换成近似于直流电动机的模型，为控制带来方便。

First1y, by moving and circumrotating coordinate switching thecomp1ex model of tri--phase AC asynchronism motor to Magnetization-Torque two axeses, the physica1 mode1 of AC motor is transformedmode1 of DC motor approximate1y, it is convenience to contro1 the motor.

首先，经过坐标的平移和旋转变换，将原三相交流异步电机的复杂模型转换到M-T(Magnetization-Torque)两轴旋转坐标系上，将交流电机的物理模型等效地变换成近似于直流电动机的模型，为控制带来方便。

A new method of automatic segmentation is developed based on the extreme point properties of wavelet transform. The method consists of two main steps: 1. Using the multi-resolution properties of wavelet transform, we can get the information of shape variation with space coordination.

该方法包括两个主要步骤，一是利用小波变换的多分辨率特性得到测井曲线的形态特性随空间坐标的变化信息；二是利用小波变换过零点的特征在不同尺度上的反映，提取不同尺度下的奇异点作为分层的待参考点，结合实际情况最终确定分层点。

With Death guitarist Schuldiner adopting vocal duties, the band made a major impact on the scene.

随着死亡的吉他手Schuldiner接受主唱的职务，乐队在现实中树立了重要的影响。

But he could still end up breakfasting on Swiss-government issue muesli because all six are accused of nicking around 45 million pounds they should have paid to FIFA.

不过他最后仍有可能沦为瑞士政府&议事餐桌&上的一道早餐，因为这所有六个人都被指控把本应支付给国际足联的大约4500万英镑骗了个精光。