共查询到17条相似文献,搜索用时 156 毫秒
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摘要:研究伸缩因子为3紧支撑对称双正交小波的构造问题.任给一个插值对称的加细函数,本文提供 一个构造其对偶尺度函数的迭代算法,其对偶尺度函数的正则性可以达到任意水平,讨论了它的一些性 质,如对称性和衰减性.最后,给出构造算例. 相似文献
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小波变换及其工程应用(连载):第二讲 小波系数的性质及变换算法 总被引:1,自引:0,他引:1
小波变换及其工程应用(连载)第二讲小波系数的性质及变换算法朱继梅(华东工业大学)2.1小波系数的性质在第一讲中,我们已经介绍了小波变换的概念,它的特点以及如何从尺度函数出发构造小波函数。我们曾以D4小波为例写出生成元ψ(X)(即尺度函数)所满足的双尺... 相似文献
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本文应用提升框架在任意维空间中构造具有任意阶主消失矩和对偶消失矩的离散、紧支撑双正交小波和完全重构滤波器组,给出定理证明并结合具体例子进行了说明。 相似文献
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正交复滤波器与小波的数值构造 总被引:1,自引:1,他引:0
侯宇 《中国计量学院学报》2008,19(3):194-200
研究了参数化正交复滤波器与小波的数值构造方法.在以往研究成果的基础上,建立了构造正交复滤波器的蝶形算法,该算法便于计算任意长度紧支集复滤波器,便于优化参数设计所需的滤波器与小波.并且研究了参数变化与复滤波器性质的关系,给出相关定理并加以证明.最后给出不同参数下复滤波器、复尺度函数和复小波的计算实例,通过参数优化得到具有对称性和近似线性幅频特性的复小波函数. 相似文献
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紧支集正交小波基的构造 总被引:7,自引:3,他引:4
分析了小波变换及其多尺度分析方法的基本性质,揭示了有限长双尺度方程在紧支集小波基构造中的重要地位,并从正交共轭滤波器的构造入手,提出了一种紧支集正交小波基的构造方法,构造出一系列特性不同的紧支集正交小波基。文章给出了一组性质较好的共轭滤波器系数,并就N=4的情况对两种小波基的性质进行了对比分析。 相似文献
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Noise source visualisation represents an important tool for technical acoustics. Many techniques of noise source visualisation have been developed, based on a specific noise source in a specific type of acoustic environment. A new visualisation method of complex noise sources is presented, using an acoustic camera and a new algorithm. Different transient acoustical phenomena can be noted. Additionally, a new family of biorthogonal wavelets is applied to determine fault in gears. The new wavelets are a generalisation of biorthogonal wavelet systems. Smoothness is controlled independently in the analysis. For the optimisation of the synthesis bank, discrete finite variation is used. Differentiability is measured, for which a large number of vanishing wavelet moments is necessary, in favour of a smoothness measure based on the fact that a finite depth of the filter bank tree is in most case related to practical applications. 相似文献
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以提升的方法,对CDF型双正交小波之间的构造关系进行了讨论。应用文中提到的算法一,给出了Cohen文中原来三组CDF型小波中,每组内的小波顺次逐一提升的关系;再用算法一结合平面束理论得到与Cohen文中12个CDF型小波不同的8个小波;还给出了算法二,并讨论了寻求两个已知CDF型小波之间提升算子S(ω)的问题。 相似文献
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A new family of biorthogonal wavelets used to identify fault in gears is dealt with. The fault detection analyses and methods presented in this paper are based on signals created by a faultless gear and by a gear with a crack in the tooth root, caused through operating conditions. The new wavelets are a generalization of biorthogonal wavelet systems. In the analysis, smoothness is controlled independently and discrete finite variation is used to optimise the synthesis bank. The procedure measure dispenses with a measure of differentiability, requiring a large number of vanishing wavelet moments in favour of a smoothness measure that is based on the fact that, in most practical applications, only a finite depth of the filter bank tree is involved. 相似文献
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Yoon Young Kim Gang‐Won Jang 《International journal for numerical methods in engineering》2002,53(7):1575-1592
The objective of the present work is to propose a new adaptive wavelet‐Galerkin method based on the lowest‐order hat interpolation wavelets. The specific application of the present method is made on the one‐dimensional analysis of thin‐walled box beam problems exhibiting rapidly varying local end effects. Higher‐order interpolation wavelets have been used in the wavelet‐collocation setting, but the lowest‐order hat interpolation is applied here first and a hat interpolation wavelet‐based Galerkin method is newly formulated. Unlike existing orthogonal or biorthogonal wavelet‐based Galerkin methods, the present method does not require special treatment in dealing with general boundary conditions. Furthermore, the present method directly works with nodal values and does not require special formula for the evaluation of system matrices. Though interpolation wavelets do not have any vanishing moment, an adaptive scheme based on multi‐resolution approximations is possible and a preconditioned conjugate gradient method can be used to enhance numerical efficiency. Copyright © 2001 John Wiley & Sons, Ltd. 相似文献