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 共查询到19条相似文献,搜索用时 109 毫秒
1.
郭蔚  彭立中 《中国科学:数学》2010,40(11):1115-1128
本文给出了多小波框架的sub-QMF条件,提出了多小波框架低通滤波器的参数化设计,由正交分解和矩阵的酉扩张得到其相应的高通滤波器表示的整套多小波框架设计的参数化方法,同时针对多描述编码的需求,构造了两个长折叠对称带参数的多小波紧框架.  相似文献   

2.
收稿考滤了一类多带正交对称小波滤波器对应多相矩阵分解结构,系统地构造了一类具有自由参数多带小波滤波器簇,以4带小波为例得到了用参数角表示的一类正交对称滤波器序列.  相似文献   

3.
a尺度正交的多小波   总被引:2,自引:0,他引:2  
给出一种构造 a尺度正交多小波的方法 .它是由任意 a尺度正交的单小波及一组滤波器构造出来的 .由于 a尺度单正交尺度函数选取的任意性和滤波器的选取有相当大的自由度 ,使得有可能构造出大量 a尺度正交的多小波 .  相似文献   

4.
一对拟双正交框架小波   总被引:1,自引:0,他引:1  
张之华 《数学学报》2008,51(1):81-90
对于一对对偶框架多尺度分析,借助于滤波器,我们构造一对对偶框架小波和一对拟双正交框架小波,并且指出一对对偶框架小波和一对拟双正交框架小波的滤波器所满足的充分必要条件.  相似文献   

5.
利用有限元插值和多尺度分析理论构造出了有限元多尺度小波.这些小波函数集许多优良性质于一身,如固定的短支集、高阶的消失矩、半正交性及正则性等.  相似文献   

6.
在多小波和单小波的基础上利用矩阵卷积构造出了一类多尺度函数与多小波,并通过实例对构造算法加以说明.  相似文献   

7.
王国秋  全宏跃 《计算数学》2009,31(1):99-110
我们提出了最优多进Haar小波的概念,证明了其存在性和唯一性,给出了最优多进Haar小波构造的通用方法,并证明了最优多进Haar小波具有线性相位,在消失矩意义下,我们所得到的最优多进Haar小波优于离散余弦变换.同时,我们用图像缩编码的方法验证了最优多进Haar小波的性能优于离散余弦变换的,新的变换可以化为精确的小整数运算,能非常廉价地用集成电路实现,该变换的实用意义在于给图像和视频压缩提供了一个更好的选择.  相似文献   

8.
张泽银  黄达人 《数学学报》1998,41(6):0-1224
本文研究了一类多进小波展开的Gibbs函数的渐近性质,特别地,包括了多进Daubechies型小波.  相似文献   

9.
1引言我们知道,一个可生成L2(R)中的多分辩分析的尺度函数(x)满足双尺度差分方程(1)式的Fourier变换为其中(ω)是函数(x)的Fourier变换,而叫做小波的共轭滤波器(简称滤波器),它满足若将滤波器H(ω)设成则条件(3)成为可形式地写出Daubechies[1]给出了(6)式无穷乘积收敛的条件.她还针对F(z)为多项式情形(此时称滤波器为多项式滤波器),给出了产生紧支小波的方法并给出了正则阶估计[2].在[3]中,作者给出了小波分式滤波器的定义(即(4)式中F(z))是实系数有理…  相似文献   

10.
本文研究L2(Rn)上伸缩矩阵A满足|detA|1的半正交多小波框架.本文得到半正交和严格半正交框架的一系列性质及刻画.本文证明半正交Parseval多小波框架与广义多分辨分析(GMRA)Parseval多小波框架是等价的.特别地,本文利用最小频率支撑(MSF)多小波框架和小波集,构造若干半正交多小波框架的例子.  相似文献   

11.
Start‐up demonstration tests were first discussed in the quality/reliability literature about three decades ago. Since then, many variations of these tests have been introduced, and the corresponding distributional characteristics and inferential methods have also been studied. All these developments, based on independent and identically distributed binary trials, have been further generalized to some other forms of trials such as Markov‐dependent trials, exchangeable trials and multistate trials. In this paper, we provide a comprehensive review of all these results and highlight some unifications of the results. We also describe a general estimation method and then present several numerical examples to illustrate some of the models and methods described here. Finally, a number of open issues in this area of research are pointed out. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   

12.
The concept of data depth leads to a center-outward ordering of multivariate data, and it has been effectively used for developing various data analytic tools. While different notions of depth were originally developed for finite dimensional data, there have been some recent attempts to develop depth functions for data in infinite dimensional spaces. In this paper, we consider some notions of depth in infinite dimensional spaces and study their properties under various stochastic models. Our analysis shows that some of the depth functions available in the literature have degenerate behaviour for some commonly used probability distributions in infinite dimensional spaces of sequences and functions. As a consequence, they are not very useful for the analysis of data satisfying such infinite dimensional probability models. However, some modified versions of those depth functions as well as an infinite dimensional extension of the spatial depth do not suffer from such degeneracy and can be conveniently used for analyzing infinite dimensional data.  相似文献   

13.
The tail measure of a regularly varying stationary time series has been recently introduced. It is used in this contribution to reconsider certain properties of the tail process and establish new ones. A new formulation of the time change formula is used to establish identities, some of which were indirectly known and some of which are new.  相似文献   

14.
研究了一类具有正负系数的二阶非线性中立型时滞差分方程的振动性,利用Banach空间的不动点原理,结合Riccati变换,获得了该类方程存在非振动解的一些新的准则,并同时得到了该类方程振动的判别准则,这些准则改善了对方程的条件限制,所得结论推广并改进了现有文献中的一系列结果.  相似文献   

15.
Detecting arrays were proposed by Colbourn and McClary in 2008, which are of interest in generating software test suites to cover all t-sets of component interactions and detect interaction faults in component-based systems. So far, optimality and constructions of detecting arrays have not been studied systematically. Indeed, no useful benchmark to measure the optimality of detecting arrays has previously been given, and only some sporadic examples of optimal detecting arrays have been found. This paper tries to take the first step by presenting a lower bound on the size of detecting arrays and some methods of constructing optimal detecting arrays. A number of infinite series of optimal detecting arrays are then obtained.  相似文献   

16.
The first involvement arose because sales were in serious decline. From a position of considerable strength 8 years before, with half the market and twice the sales of the nearest competitor, the company was now performing only marginally better than its rivals. Of course, the total market had declined as well, but within that market the proportion of the company's sales had suffered too. The contact with the company arose because there had been yet another change of management and many remedies had been tried before. It was time to review those ideas again, to challenge assumptions and prejudices and to initiate and investigate other avenues. As work progressed, there were some major changes in thinking and objectives. Some well established practices were seen to be no longer necessary or useful and were abandoned, whilst others remained until it became possible to supersede them. But perhaps the greatest gain from the study came from the new and fresh attitudes that management were taking, coupled with their willingness to consider a broader range of possibilities than had been considered before. They were able to lay some worn out ideas to rest, whilst developing others which brought forth worthwhile potential dividends.  相似文献   

17.
重叠函数是一类特殊的非结合的二元聚类函数.利用重叠函数可以诱导出不同形式的模糊蕴涵.文[7]介绍了由重叠函数O和模糊否定N诱导出的模糊蕴涵—(O,N)-蕴涵,并对(O,N)-蕴涵的基本性质进行了研究,但尚存一些重要性质尚未得到研究.主要基于自同构φ和模糊否定N的相关性质对(O,N)-蕴涵进行深入研究,给出(O,N)-蕴...  相似文献   

18.
Simple semitoric systems were classified about ten years ago in terms of a collection of invariants, essentially given by a convex polygon with some marked points corresponding to focus-focus singularities. Each marked point is endowed with labels which are symplectic invariants of the system. We will review the construction of these invariants, and explain how they have been generalized or applied in different contexts. One of these applications concerns quantum integrable systems and the corresponding inverse problem, which asks how much information of the associated classical system can be found in the spectrum. An approach to this problem has been to try to compute invariants in the spectrum. We will explain how this has been recently achieved for some of the invariants of semitoric systems, and discuss an open question in this direction.  相似文献   

19.
韩德广 《数学学报》2017,60(1):3-18
Gabor分析中几个著名的基本定理(如对偶原理和稠密性定理)与群表示和算子代数理论密切相连.尽管时频分析与算子代数之间的某些联系是Jon von Neumann于1930年代建立的,可是它们在近期得到广泛研究,这主要应归于小波/Gabor理论或更一般的框架理论近二十年的发展.本文将讨论过去几年得到的一些主要结果,同时也给出一些新的结果、解释和问题,我们主要考虑来源于时频分析并能反映与群表示理论存在内在联系的那些结果.特别地,针对群表示的时频分析,将详细说明抽象的对偶原理及其与算子代数理论中几个公开问题的联系.  相似文献   

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