排序方式: 共有13条查询结果,搜索用时 31 毫秒
1.
Xianbin Li Houqiang Li Fuquan Wang Jing Ding 《Communications in Nonlinear Science & Numerical Simulation》1997,2(4):240-243
The exact relationships between the length of scale sequences and wavelet sequences in the Mallat pyramidal algorithm for computing wavelet transform coefficients are obtained, and the maximum possible scale of arbitrary discrete signal is derived. 相似文献
2.
Since modern accelerators demand excellent stability to magnet power supply (PS), it is necessary to decrease harmonic currents passing magnets. Aiming at depressing the rappel current from the PS in the Beijing electron-positron collider Ⅱ, a wavelet-based active power filter (APF) is proposed in this paper. An APF is an effective device to improve the quality of currents. As a countermeasure to these harmonic currents, the APF circuit generates a harmonic current, countervailing harmonic current from PS. An active power filter based on wavelet transformation is proposed. Discrete wavelet transformation is used to analyze the harmonic components in the supply current, and an active power filter circuit works according to the analysis results. Our simulation and experiment results are given to prove the effect of the APF. 相似文献
3.
4.
5.
陀螺仪漂移特性的小波分析 总被引:13,自引:3,他引:10
在简述小波分析中Mallat算法的基础上,用其实现陀螺仪漂移特性的小波分析,并对有关的工程问题进行了讨论,给出了某型陀螺实测数据的应用实例,证明了此方法的有效性。对今后的应用提出了一些看法。 相似文献
6.
实时小波滤波方法在硅微陀螺仪中的应用研究 总被引:1,自引:5,他引:1
采用实时小波滤波技术构建硅微陀螺仪数字化平台,对快速的MaIfat算法选用何种小波基,是否采用软硬阈值处理以及选用何种尺度和采样点数进行深入分析。考虑到滤波效果即陀螺仪输出信号滤波前后A1lan方差改进情况和硬件处理的实时性,通过比较最终选择3尺度16点软闽值db2小波Mallat快速算法。仿真计算和实验结果表明该滤波方法对改善微机械陀螺仪的零偏稳定性有一定的实用价值。 相似文献
7.
Since modern accelerators demand excellent stability to magnet power supply(PS), it is necessary to decrease harmonic currents passing magnets. Aiming at depressing the rappel current from the PS in the Beijing electron-positron collider, a wavelet-based active power filter(APF) is proposed in this paper. An APF is an effective device to improve the quality of currents. As a countermeasure to these harmonic currents, the APF circuit generates a harmonic current, countervailing harmonic current from PS. An active power filter based on wavelet transformation is proposed. Discrete wavelet transformation is used to analyze the harmonic components in the supply current, and an active power filter circuit works according to the analysis results. Our simulation and experiment results are given to prove the effect of the APF. 相似文献
8.
王继成 《数学的实践与认识》2008,38(23)
小波分析是近年来发展起来的一种数学方法,在信号与图象处理中有重要的应用.中值滤波是信号处理中常用的一种非线性滤波器,它能够有效地消除瞬时脉冲干扰,并且能够很好地保持信号的边缘信息,在信号和图象处理中得到广泛应用.对中值滤波器与小波变换的结合进行了比较系统的研究.通过实例说明中值滤波器与小波变换相结合具有比单一滤波器更好的效果. 相似文献
9.
Performance analysis of multi-spectral and panchromatic image fusion techniques based on two wavelet discrete approaches 总被引:1,自引:0,他引:1
During the past few years, many fusion algorithms have been proposed to combine a high-resolution panchromatic image with a low-resolution multi-spectral image to generate a high-resolution multi-spectral image. Among them, the wavelet-based algorithm has gained its popularity due to its ability of multi-resolution decomposition. More specifically, the wavelet transform is first applied to images. The wavelet coefficients are then combined based on a certain rule to produce the fused image. In this paper, we evaluated the performances of both the wavelet transform discrete approaches and the coefficient combination methods when they are applied to fuse multi-spectral and panchromatic images. For the discrete approaches of the wavelet transform, Mallat and “à trous” algorithms are chosen. For the coefficient combination, the additive wavelet method, the additive wavelet intensity method and the additive wavelet principal component method are selected. To evaluate the spectral quality of the fused images, correlation coefficient and Qavg index are used as a local and global measure, respectively. Meanwhile, average gradient and standard deviation are used to evaluate the spatial quality. Our experiments show that keeping the combination method the same, the “à trous” algorithm works better than the Mallat algorithm for the fusion purpose. In addition, if keeping the wavelet discrete algorithm the same, the combination methods mentioned above are found to have different advantages between the spatial resolution improvement and the spectral quality preservation. 相似文献
10.
改进的静止图像小波零树编码 总被引:5,自引:0,他引:5
在深入研究尺度小波变换和嵌入式小波零树压缩编码算法的基础上,探讨了一种改进的小波零树编码算法。通过采用基于嵌入式零树预测扫描算法的改进小波变换编码方法,对小波分解的低频子带图像采用DPCM预测编码,高频子带图像采用了改进的取消重要系数排序的零树预测扫描算法进行压缩编码,使之既具有原零树算法良好的压缩品质,同时也简化了的压缩算法,提高了该算法 的适应性,与JPEG压缩相比,它消除了JPEG图像在高压缩比下的方块效应,取得了令人满意的实验效果。 相似文献