徐 蕤, 舒志彪
(福州大學數(shù)學與計算機科學學院, 福建 福州 350116)
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有限維Hilbert空間中等模緊框架的一類構造方法
徐 蕤, 舒志彪
(福州大學數(shù)學與計算機科學學院, 福建 福州 350116)
利用Hn中已有的等模緊框架構造Hn+1中的等模緊框架; 并利用Hn中已有的緊框架來構造Hn+1中的Parseval框架. 最后給出了在這種方法下構造Rn中框架元素個數(shù)為n+1的比較稀疏的單位模緊框架的具體表達式.
等模緊框架; Parseval框架; 稀疏框架; Hilbert空間
首先簡要介紹有限維Hilbert空間中框架的一些基本理論[5-6].
在分析和重構信號時, 合成算子、 分析算子、 框架算子起著重要的作用, 定義如下.
框架的稀疏性是近幾年比較活躍的研究內容,它與目前的研究熱點壓縮感知具有密切的關系. 文獻[14]提出框架稀疏的定義.
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對于任意g∈Hn+1,由式(1)~(4)有:
上面證明中第4個等式到第5個等式的部分推導是利用式子(3)得到, 即
當i=1, 2, …, N時, 有
證明 由于定理3給出的框架與定理2給出的框架具有相同的性質, 那么定理2的證明中得到的式(1)~(4)這4個等式在這里也成立.
對于任意g∈Hn+1,由式(1)~(4)有:
對于任意的i=1, 2, …, N, 得到
對于任意g∈Hn+1,由式(5)~(6)式有:
對于任意g∈Hn+1,由式(7)~(8)式有:
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(責任編輯: 林曉)
A class of methods for constructing equal-norm tight frames in a finite dimensional Hilbert space
XU Rui,SHU Zhibiao
(College of Mathematics and Computer Science, Fuzhou University, Fuzhou, Fujian 350116, China)
We use the existing equal-norm tight frames forHnto construct equal-norm tight frames forHn+1. We also use the existing tight frames forHnto construct Parseval frames forHn+1. In addition, we give a detailed expression of sparse unit-norm tight frames withn+1 vectors forRnin this construction.
equal-norm tight frame; Parseval frame; sparse frame; Hilbert spaces
10.7631/issn.1000-2243.2017.03.0323
1000-2243(2017)03-0323-06
2015-06-02
舒志彪(1958-),副教授,主要從事小波分析、 圖像處理等方面研究, fzb@fzu.edu.cn
福建省自然科學基金資助項目(2014J01007 ); 福建省教育廳A類資助項目(JA14041); 福州大學科技發(fā)展基金資助項目(2012-XQ-29)
O177.1
A