查询词典 wavelet

Tansformed the real part and imaginary part of interferogram to stationary wavelet domain, analyzed the PDF of signal and noise wavelet coefficients using Pearson distribution system, then evaluated the wavelet coefficients of signal in stationary wavelet domain by Maximum A Posterior criteria to reconstruct the interferogram.

2将干涉图的实部和虚部分解到静态小波域，用Pearson分布系作近似，分析了信号和噪声小波系数的概率密度函数，在静态小波域用MAP准则估计信号的小波系数用于干涉图的重建。

The results of quantitative coding to wavelet transform coefficient show that low-scale extreme wavelet coefficients can accurately localize the subaerial position of fractures.The shifting of extreme wavelet coefficients can be used to judge relative magnitude of dip angle and dip direction of fracture with scale increasing.The value of extreme wavelet coefficients can reflect density difference of formations on both sides of fracture and provide information of physical properties for fracture analysis.

小波变换系数量化编码结果表明，低尺度小波系数极值可以准确定位断裂在地表的位置；随着尺度的增加，小波系数极值会发生偏移，可以判断断裂的倾向和倾角的相对大小；小波系数极值可以反映断裂两侧地层的密度差异，为断裂分析提供物性信息。

A new approach for pattern recognition of ultra-high frequency signals of transformer partial discharge based on multi-scale analysis of wavelet packet and grid dimensionality is proposed, in which the multi-scale transform of wavelet packet is used to extract wavelet coefficients of UHF PD signals and by means of improving difference box-counting method the grid dimensionality of multi-scale wavelet coefficients is calculated and the multi-scale grid dimensionality is taken as the characteristic quantity that is used in the recognition of UHF PD signals.

提出了一种基于小波包多尺度分析和网格维数的变压器局部放电超高频信号模式识别的新方法，采用小波包多尺度变换提取局部放电超高频信号在多尺度上的小波系数，通过改进差盒计数法计算多尺度小波系数的网格维数，并将多尺度网格维数作为特征量用于局部放电超高频信号的识别。

The common methods of wavelet transform incudes the best wavelet packet-based method, embedded wavelet prediction coding ,wavelet zero-tree compression factor, and so on.

常见的基于小波变换的图像压缩方法有小波包最好基、嵌入式小波预测编码和小波系数零树压缩等。

The issues of present seismic wavelet frequency caused by different concepts, such as apparent frequency, dominant frequency, peak frequency and centroid frequency, etc., which are defined by different methods, and understanding deviation, definition of seismic wavelet frequency for time and frequency domain are concluded and summarized. On this basis, three kinds of seismic wavelets in common use such as Ricker and Zinc wavelets as well as sine wavelet with exponential attenuation characteristics are analyzed and a conclude is achieved that apparent frequency and dominant frequency are consistent in essence, but peak frequency and centroid frequency as well as apparent frequency or dominant frequency are not completely consistent with different seismic wavelets. For actual seismic data, peak frequency can approximately be used as dominant frequency, but it is not suitable when seismic wavelet is known for it can give out any wrong knowledge and results.

针对目前地震子波频率由于定义方式出现的各种概念（视频率、主频、峰值频率、中心频率等）以及理解上出现的偏差等问题，首先从时间域定义和频率域定义2个方面进行了归纳和总结，并在此基础上对3种常用地震子波（Ricker子波，Zinc子波，正弦指数衰减子波）进行了分析和研究，得出视频率与主频概念一致，但不同地震子波的峰值频率、中心频率和视频率之间并不完全一致的结论；而对于实际地震资料，将峰值频率近似看作地震子波的主频是可以的，但在地震子波已知的情形下这样做是不恰当的，甚至可能会得出错误的结论和认识。

The wavelet time-frequency properties of the uncracked rotor and the cracked rotor were discussed by the continuous wavelet time-frequency analysis algorithm. A new algorithm using the wavelet time-frequency analysis algorithm to detect the crack was proposed. The influence of the sampling frequency on the wavelet time-frequency analysis algorithm was analyzed through the numerical simulation research; the valid sampling frequency was presented.

利用连续小波时频分析方法，讨论了裂纹转子与无裂纹转子的小波时频特性，提出了利用小波时频分析方法识别裂纹的新方法；数值仿真研究了采样频率对小波时频分析方法的准确性和有效性的影响，并给出了建议性的采样频率。

We also study on the coding performance of these wavelet. At last, we investigate the wavelet threshold denosing for image, and present a improved Bayes denosing for image. We also combine the wavelet image coding with image denosing based on wavelet threshold, the noising image is compressed, the noise is de-noised at the same time.

最后，在对小波阈值的图像降噪原理进行分析的基础上，提出了一种改进的贝叶斯图像降噪方法，并将小波图像压缩和图像降噪结合在一起，来实现对噪声图像进行压缩的同时对它进行降噪。

To increase the security of the watermark, a new binary image encryption algorithm based on TD-ERCS map is presented. The watermark is encrypted by a chaos sequence generated by TD-ERCS map; A novel color image watermarking algorithm is proposed based on discrete chaotic map and 2-dimensions discrete wavelet transform. The watermark is encrypted by the new binary image encryption algorithm, and the encrypted watermark is embed into four sub-bands of the most deep level of blue branch of host image by three-level wavelet transform, and the embedded positions are determined by general cat cha otic map; A novel color-image blind detection watermarking algorithm is proposed based on integer wavelet transform and subsampling. The scrambled watermark is encrypted and embed into the low sub-bands after four sub-images of the Y branch of host image is transformed by two-level wavelet transform, and the embedded positions are determined by Logistic chaotic map, this watermarking scheme can realize blind extraction.

为了提高水印图像的安全性，提出了一种基于TD-ERCS混沌映射的二值水印图像的加密算法，该算法利用TD-ERCS映射产生的混沌序列加密水印图像；将离散混沌映射和二维离散小波变换相结合，研究了彩色图像水印新算法，该算法先对混沌序列加密后的水印图像进行小波变换，再嵌入到宿主图像的蓝色分量的最深层的四个子带中，嵌入位置则由广义猫映射确定；将整数小波变换和图像子采样技术应用于数字水印，提出了一种彩色图像盲提取水印算法，水印嵌入时，先对宿主图像在YIQ色彩空间中的Y分量进行子采样，并对得到的四个子图像分别进行二级离散小波变换，然后将置乱并加密后的水印图像嵌入到小波变换后的低频子带中，其嵌入位置由Logistic混沌映射产生的混沌序列确定，实现了水印的盲提取。

The application of noise removal for EEG signals based on wavelet transform is discussed in the paper,And the influence on EEG noise removal using different wavelet basis is introduced,Furthermore the wavelet soft-thresholding method and 1-Dimensional wavelet single-branch reconstruction are used for removing noise in EEG.

摘 要 摘要本文探讨了小波变换在脑电去噪中的应用方法，介绍了不同小波基对脑电去噪的影响，比较了小波软门限法和一维小波单支重构去噪方法的去噪效果。

Firstly, the algorithm decomposes the original images with wavelet analysis and obtains the positions of wavelet coefficients that belong to the edges. Then, the algorithm interpolates intensities and positions of those wavelet coefficients between corresponding wavelet sub-images. So that the new image basically satisfies the requirements of medical image interpolation.

通过对原图进行小波变换，获得图像边缘对应小波系数的位置信息，在断层图像的相应小波系数之间进行强度和位置插值，使新的图像不仅在灰度上，而且在组织形状上，介于原来的断层图像之间，满足了医学图像插值的要求。

In the days of sailing vessels the crew were afraid they would be becalmed on the ocean.

在使用帆船的时代，船员们担心他们会因为无风而无法在海洋上航行。

As long as foreign donors pay the PA's salary bill, few expect a new intifada.

只要外国继续为巴权力机构的薪水买单，希望发动新暴动的人便寥寥无几。