查询词典 wavelet

This paper researches the wavelet transform of discrete-time sequences basing on dendriform filer banks in the signal processing field, analyses the theory and design method of two channel conjugate quadrature mirror filter banks and fast implement of discrete orthogonal wavelet transform and generation of orthogonal wavelets, and points out the internal relationship between them.

笔者从信号处理的角度研究了离散时间序列的小波变换利用树状滤波器组实现的方法，分析了两通道共轭正交镜象滤波器组理论及滤波器设计，离散时间序列的正交小波变换的快速实现以及正交小波的构造，指出了其内在联系，最后举例说明了正交小波变换通过共轭正交镜象滤波器组来实现信号分解和重构的全过程。

The invention discloses a construction method of biorthogonal wavelet, which is based on Bernstein base and comprises the following steps that:(1) a lowpass filter at a discomposing and reconstructing end is expressed by Bernstein base;(2) numerical calculation of the lowpass filter is carried out;(3) the lowpass filter at the discomposing and reconstructing end is led to meet the conditions to reconstruct the lowpass filter entirely;(4) the parameter of obtained biorthogonal wavelet is calculated.

本发明公开了一种基于Bernstein基的双正交小波构造方法，包括如下步骤：(1)将分解与重构端的低通滤波器用Bernstein基来表示；(2)进行低通滤波器的数值计算；(3)使分解与重构端的滤波器满足完全重构滤波器的条件；(4)计算获得双正交小波的参数。

An algorithm of dyadic wavelet transform of image was given in order to apply the dyadic wavelet to signal and image processing.

讨论了信号和图像处理中所用的二进小波，并给出了一种图像的二进小波变换算法。

A feature extraction method for palmprint image is proposed,the implementation procedure of this method is as follows:firstly,the 2D Gabor wavelet transform coefficient amplitudes are computed at the equispaced discrete positions on the palmprint image,and they are used as original features of the palmprint image;then,the dimension of the Gabor wavelet feature is reduced by principal component analysis;lastly,the optimal discriminant features that are most advantageous for classification are extracted by linear discriminant analysis.

提出了一种提取掌纹图像特征的方法，该方法的实现过程如下：首先，计算掌纹图像上均布离散位置的二维Gabor小波变换系数的幅值，将其作为掌纹图像的原始特征；其次，利用主分量分析实现Gabor小波特征的降维；最后，通过线性判别分析提取最有利于分类的最佳鉴别特征。

In the Sixth Chapter, the Wavelet analysis method is introduced in discussing some acoustic imaging problems related to the physical background of the ultrasonic detection. In the light of the solution of some theoretical problem in the 2D Wavelet transmission of two components form, the enhancement and identification of the spotty and fibriform faults of the acoutic image, along with two acoustic image deblurring methods based respectively on the acoustic physical feature analysis and the acoustic image's spatial feature analysis of the object, are realized. Therefore the image degeneration problem resulting from the acoustic beam diffusion or the acoustic focus diffusion in the ultrasonic detection are effectively improved. The software for this purpose has also been developed.

第六章首次应用小波分析的方法，研究了与超声检测的物理背景有关的一些声象处理问题，在解决了二分量形式的二维小波变换中的一些理论问题的基础上，建立起了对声象中点状和线状缺陷目标的增强与分离方法，以及分别基于目标的声学物理特征分析和基于目标声象空间特征分析的二种声象弥散消除方法，实验分析结果表明，这种方法较好地解决了超声检测中由于声束截面或声焦点扩散所造成的成象退化问题。

According to the analysis of reasons of transformer mal-operation in Pingdingshan Electric Power Bureac for years , and according to the present situation of transformer protection studies and applications at home and abroad. This paper points out the shortcomings of discrimination between internal faults and magnetizing inrush, the problems existing in differentiating the slight faults of turn-to-turn in transformer are also advanced. On the base of the electromagnetic characteristics of transformer, the relations between fluxional differential current and voltage of source side analyzed, all the operating states of transformer simulated by EMTP/ATP, the criterion of magnetizing inrush in transformer is got. Through the wavelet analysis of current waveform, using the intense reaction of wavelet transform to the little change of signal, the internal faults of transformer are distinguished by testing local extremum.

本文根据平顶山市电业局历年来变压器保护误动的原因分析，并根据国内外变压器保护使用和研究的现状，指出了现有变压器保护在区分变压器励磁涌流和内部故障方面以及在判断变压器匝间轻微故障方面存在的问题和不足；从变压器电磁特性出发，分析了电源侧电压和电流微分之间的关系，利用电磁暂态仿真程序对变压器各种运行状态进行了仿真，并以此建立了判断变压器是否含有励磁涌流的判据；通过对电流波形的小波分析，利用小波变换对信号微小变化极强的反映能力，通过检测电流的局部极值点来区分变压器运行状态，并作为上述判据的补充。

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。

The method has some characteristics:(1) it adapts to medical images authentication due to the high Signal-to-Noise when the watermark was embedded into images.(2) It ensures the fragileness of watermark when it combines with the statistical information of wavelet coefficient to choose the embedding position.(3) It has a strong localization ability for tampering because of the characteristics of wavelet decomposition in the space-frequency domain.(4) It uses the secret key which can resist the malice attack even if opening the algorithm completely to protect the proposed method.

本算法具有以下几个特点：(1)图像嵌入水印后具有较高的信噪比，适用于医学图像的认证；(2)结合小波系数的统计信息来选择嵌入水印的位置，保证了水印的易碎性；(3)小波分解在空频域的特性使得算法对篡改具有很强的定位能力；(4)利用密钥对算法进行保护，即使公开算法，也能抵挡恶意攻击。

The pipeline pressure drop is adopted for signal processing and the Harr wavelet is selected as the mother wavelet.

本文提出了一种基于小波分析进行水平管气液两相流流型辨识的新方法。

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。

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。