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IEEE International Conference on Acoustics, Speech, and Signal Processing

作者： Uto, T Ikehara, M Okuda, M Keio Univ Fac Sci & Technol Tokyo 108 Japan

ISBN: (纸本)0780374029

wavelet packets represent an elegant generalization of the wavelet transform, capable of providing arbitrary frequency resolution to meet a signal's spectral behaviors. Recent research advances have shown that wavelet-based image compression techniques offer several advantages over traditional techniques in terms of progressive transmission capability and compression efficiency. The embedded compression techniques - tree-structured coding techniques, such as embedded zerotree wavelet (EZW) and set partitioning in hierarchical trees (SPIHT), and quadtree-structured coding techniques, such as wavelet quadtree (WQT), multigrid embedded (MGE) and EZW based on intraband partitioning (EZW-IP), - demonstrate the competitive performance of wavelet based compression schemes. This paper describes the wavelet packet algorithm which makes it suited to subsequent quadtree-based embedded image coders, such as EZW-IP. In our technique, the hierarchical sums of maximum magnitude of each quadtree node role as the decomposition criterion. The simulation results for various images show that the proposed algorithm gives a better coding efficiency than the octave-band decomposition.

关键词： quadtrees image coding data compression wavelet transforms transform coding set theory wavelet packet algorithm quadtree-based embedded image coding wavelet transform frequency resolution wavelet-based image compression progressive transmission compression efficiency embedded compression techniques tree-structured coding embedded zerotree wavelet coding set partitioning in hierarchical trees SPIHT quadtree-structured coding multigrid embedded coding intraband partitioning EZW-IP simulation results coding efficiency octave-band decomposition

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Modeling and Simulation of Power Grid Voltage Harmonic Detection Method Based on the Improved wavelet packet Transform 40

Modeling and Simulation of Power Grid Voltage Harmonic Detec...

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40th Chinese Control Conference (CCC)

作者： Guo, Jian Jiang, Chao Guan, Chenxi Zhang, Tao Pu, Jiangkun Harbin Engn Univ Coll Mech & Elect Engn Harbin 150001 Peoples R China

ISBN: (纸本)9789881563804

In order to solve the existing problems of the grid voltage harmonic detection algorithms, such as low precision, complicated calculation, the harmonic detection algorithm based on wavelet packed transform is proposed in this paper. The filtering algorithm of an improved wavelet packet transform is also presented by combining the wavelet packet transform with two-stage method. That is to say, on the basic of wavelet packet transform, the standard waveform of the fundamental harmonic can be obtained by taking compound decomposition algorithm. And then the amplitude of the fundamental and each odd harmonic is also obtained through the effective value module. The modeling and simulation analysis of the proposed algorithm are performed. The simulation results show that the improved detection algorithm can effectively filter out the harmonics and obtain a complete fundamental wave. The obtained fundamental waveform meets the electricity requirements.

关键词： wavelet Transform wavelet packet algorithm Grid Voltage Harmonic Detection

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Detection of damage in aluminum plates by wavelet analysis

Detection of damage in aluminum plates by wavelet analysis

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Smart Structures and Materials 2002 Conference

作者： Xie, B Song, G Univ Akron Dept Mech Engn Smart Struct & Mat Lab Akron OH 44325 USA

ISBN: (纸本)0819444499

In this paper, structural health monitoring based on wavelet analysis is investigated to detect damages in thin aluminum plates. Conventional methods in health monitoring mainly focus on differences in the modal parameters such as natural frequency, but they require the existence of a large damage in order to detect the damage efficiently. In this paper the damage feature is extracted from the distribution energy metric by means of wavelet packet algorithms, which can demonstrate the large difference even when the damage is very small. Experimental research is carried out to validate the method used in our approach. Piezoceramic actuators and sensors are used to excite the plate and sense the induced vibrations. wavelet analysis is then conducted using the recorded data to obtain the distribution energy metric for each plate. As a result, it is shown that the health status of thin aluminum plates with small holes can be effectively identified through the distribution energy metric.

关键词： wavelet transform structural health monitoring wavelet packet algorithm

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Modeling and Simulation of Power Grid Voltage Harmonic Detection Method Based on the Improved wavelet packet Transform

Modeling and Simulation of Power Grid Voltage Harmonic Detec...

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第40届中国控制会议

作者： Jian Guo Chao Jiang Chenxi Guan Tao Zhang Jiangkun Pu College of Mechanical and Electrical Engineering Harbin Engineering University

In order to solve the existing problems of the grid voltage harmonic detection algorithms, such as low precision,complicated calculation, the harmonic detection algorithm based on wavelet packed transform is proposed in this paper. The filtering algorithm of an improved wavelet packet transform is also presented by combining the wavelet packet transform with two-stage method. That is to say, on the basic of wavelet packet transform, the standard waveform of the fundamental harmonic can be obtained by taking compound decomposition algorithm. And then the amplitude of the fundamental and each odd harmonic is also obtained through the effective value module. The modeling and simulation analysis of the proposed algorithm are performed. The simulation results show that the improved detection algorithm can effectively filter out the harmonics and obtain a complete fundamental wave. The obtained fundamental waveform meets the electricity requirements.

关键词： wavelet Transform wavelet packet algorithm Grid Voltage Harmonic Detection

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A New Method for Multipath Filtering in GPS Static High-Precision Positioning

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SENSORS 2019年第12期19卷 2704.-2704.页

作者： Han, Ke Tang, Canyang Deng, Zhongliang Beijing Univ Posts & Telecommun Sch Elect Engn 10 Xitucheng Rd Beijing 100876 Peoples R China

It is well known that multipath is one of the main sources of errors in GPS static high precision positioning of short baselines. Most algorithms for reducing multipath manipulate the GPS double difference (DD) observation residuals as input signal in GPS signal processing. In the traditional multipath mitigation methods, applying the wavelet transform (WT) to decompose the GPS DD observation residuals for identifying the multipath disturbance cannot effectively filter out the white noise of the high frequency part of the signal, and it is prone to edge effect. In this paper, for extracting multipath, a wavelet packet algorithm based on two-dimensional moving weighted average processing (WP-TD) is proposed. This algorithm can not only effectively filter out the white noise of the high frequency part of the signal, but also weaken the influence of the edge effect. Furthermore, considering the repeatability of multipath error in static positioning, we propose a method for determining the level of wavelet packet decomposition layers which make multipath extraction more effectively. The experimental results show that the corrected positioning accuracy is 14.14% higher than that of the traditional wavelet transform when applying the obtained multipath to DD coordinate sequences for position correction.

关键词： two-dimensional moving weighted average algorithm multipath wavelet packet algorithm GPS static high-precision positioning

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Target identification based on the optimal base number

Target identification based on the optimal base number

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1998 Fourth International Conference Signal Processing

作者： Du Yinggang Lu Jinhui Shi Xiangquan Gu Yalin Electronic Engineering & Photoelectron Technology School Nanjing University of Science & Technology

In the paper,a new method is introduced to identify the helicopter and the tank:the wavelet packet algorithm is applied to decompose the signal of an unknown target,and the optimal base number (OBN) of the signal is obtained by using the entropy function as the information cost function combined with wavelet packet theory,and then the fact that whether the OBN is in the predetermined threshold can give the judgment that whether the target is a helicopter or a *** method is proved to be very effective.

关键词： optimal base number wavelet packet algorithm threshold entropy helicopter tank

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