查询词典 transform

Acorrding to the character that wavelet transform technique can localize thetime-domain and frequency-domain, it can focalize any detail of signals and can recognize theabrupt signal and nostationary signal. The characteristics of typical fault for the centrifugalcompressor rotor are extracted by wavelet transform, and the characteristics vector is foundedby using energy as element.

通过小波变换技术对时域和频域同时具有良好的局部化性质，可以聚焦到信号的任意细节，对突变信号和非平稳信号具有很强的识别能力，利用小波包变换对离心压缩机转子典型故障的振动信号进行特征提取，并以&能量&为元素，构造离心压缩机故障信号的特征向量，以便神经网络识别。

In fact, the multiplicity is caused by the reason that there are a lot of techniques to fractionalize the eigenvalues of Fourier transform in the procedure of constructing the fractional Fourier transform.

实际上，分数傅立叶变换的多样性主要是由傅立叶变换的特征值在构造分数傅立叶变换时可采取不同的分数化方法所决定的。

Fast Fourior Transform plays an important roll in digital signal processing,its the kernel algorithm in a lot of process for signal processing.this paper first summarizes many algorithm for Fast Fourior Transform that in common use and synthesizes many reasons to adopt the radix-2 Demation-in-Frequency algorithm,then it compares two ways of implementing digital signal processing,the two ways are in field-programmable gata array and in programmable digital signal processor respectively.it points out the advantage and disadvantage of two ways.

快速傅立叶变换是数字信号处理中的重要内容之一，是很多信号处理过程中的核心算法。本文先总结了快速傅立叶变换的一些常用算法，并综合种种因素，采用了基2按频率抽取算法作为实现算法，然后将以现场可编程门阵列和以DSP处理器这两种实现数字信号处理的方式进行了比较，指出了各自的优点和不足之处。

In model experiments, we find that the deviation of the first derivative calculated by Fourier transform is very large to comparing with the theoretical derivative, but the fitting effect of the derivative of anomalies calculated by cosine transform is very good. The calculation accuracy of data are all very high except that errors of several data on the boundary are large because of the residual Gibbus effect induced by finite truncation of gravity anomalies. Errors are -009%～5%.

模型实验中发现，用Fourier变换计算的一阶导数与理论导数偏差很大，而余弦变换计算的导数与理论异常导数拟合效果非常好，除边界几个数据因重力异常的有限截断产生的吉布斯效应残留使误差较大外，数据的计算精度均很高，误差为-009%～5%。

The horizontal and vertical first derivatives of magnetic anomalies of an infinite cylinder are calculated by the cosine transform method, in which the maximum errors are -0.28 nT/m and 0.47nT/m, respectively and the percent errors are generally within -3.57%~3.27% and -1.94%~1.88%, respectively except several data of the boundary and part are bigger because of remains of Gibbus effect. The calculating curve and theoretical curve are approximately coincident, and there is no influence by effective magnetic dip angle in computing. But the errors with the Fourier transform method are -10.62nT/m and 14.42nT/m, there is large departure between the calculating curve and theoretical curve and evident influence by effective magnetic dip angle in computing.

利用余弦变换法计算的无限长水平圆柱体磁异常水平和垂向一阶导数的最大误差分别为-0.28nT/m、0.47nT/m；水平一阶导数的误差一般在-3.57%~3.27%之间，垂向一阶导数的误差一般在-1.94%~1.88%之间；计算的磁异常一阶导数值与理论值大致重合，而且不受有效磁化倾角的影响而Fourier变换法计算的水平和垂向一阶导数最大误差分别为-10.62nT/m、14.42nT/m，计算曲线与理论曲线偏离大，受磁化倾角的影响也较大。

Computer simulation result proves that A. C. parameters measurement of static signals using Harr wavelet transform could get the accurate result by the ideal sampling situation, i. e. the synchronous error is zero. Compare with synchronous and quasi-synchronous sampling algorithm, A. C. parameters measurement of transient signals using Harr wavelet transform could get more accurate result.

对谐波相位测量方法进行了误差分析，通过仿真证明，在稳态信号情况下，如果采样过程不存在同步偏差，利用Harr小波变换的方法可以对交流电量参数进行准确的测量；在暂态信号情况下，该方法与同步、准同步算法相比，可以达到很高的测量准确度。

It shows that the lensless Fourier transform digital hologram can be reconstructed at any distance by Fresnel transform algorithm. For convolution algorithm,the whole reconstructed image with high resolution can be acquired in an optimal reconstruction range or a small area around it.

结果表明：利用菲涅耳变换算法对离轴无透镜傅里叶变换数字全息进行重建时，无重建距离的限制；采用卷积重建法只能在最佳再现距离附近一个非常小的范围内才能获得高分辨率再现像；而采用角谱重建法在略小于最佳再现距离及大于最佳再现距离较大范围内重建，均能获得高分辨率的再现像。

Every kind of wavelet transform including the newly developed mult -band wavelet and transform characteristic are analysed in detail, their virtues and defects are pointed out too.

详细分析了各种小波变换包括近几年刚刚发展的多进制小波的变换特征并指出各自的优缺点。

In investigation of wavelet transform, the author has systematically studied properties of wavelet transform and its application in oscillographic determination.

作者在这方面的新贡献是：首次将小波变换这一新的信号处理技术系统地应用于重叠峰解析、有用信息提取等研究。

In the nature of physics,it consists with human's cochlea filter properties;in the sense of mathematics,Bark wavelet transform is a kind of non orthonormal but overcomplete,reversible and self inverting wavelet transform.

在感知特性中，它与人耳的听觉系统是直接吻合的：在数学上，它是一种非正交的但却是超完备的，可逆且是自反演的子波变换。

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。