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Recovery of Transient Signals in Noise by OptimalThresholding in Wavelet Domain
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作者 梅文博 《Journal of Beijing Institute of Technology》 EI CAS 1997年第3期274-279,共6页
:研究用离散子波变换复原被加性高斯白噪声污染的瞬态信号.在子波域中提出了一种最佳门限方法,该方法涉及到对于波系数的假设检验,利用似然比、奈曼,皮尔逊准则和最小均方差设计该门限,计算机仿真证明,该方法在较低信噪比下复原... :研究用离散子波变换复原被加性高斯白噪声污染的瞬态信号.在子波域中提出了一种最佳门限方法,该方法涉及到对于波系数的假设检验,利用似然比、奈曼,皮尔逊准则和最小均方差设计该门限,计算机仿真证明,该方法在较低信噪比下复原信号的有效性. 展开更多
关键词 n (Department of Electrical and Electronic Enginhaerhg University of Central Lancashire Preston PR1 2HE England) Abstract: The recovery of transient signals corrupted by additive white Gaussian noise by means of the discrete wavelet transform was studi
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An improved noise reduction transformation for algorithm based on wavelet MEMS gyroscope 被引量:3
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作者 Jianguo YUAN Yantao YUAN +2 位作者 Feilong LIU Yu PANG Jinzhao LIN 《Frontiers of Optoelectronics》 CSCD 2015年第4期413-418,共6页
To solve the large noise problem for the low- precision gyroscopes in micro-electro mechanical systems (MEMS) of inertial navigation system, an improved noise reduction method, based on the analyses of the fast Four... To solve the large noise problem for the low- precision gyroscopes in micro-electro mechanical systems (MEMS) of inertial navigation system, an improved noise reduction method, based on the analyses of the fast Fourier transformation (FFT) noise reduction principle and the simple wavelet noise reduction principle, was proposed. Furthermore, the FFT noise reduction method, the simple wavelet noise reduction method and the improved noise reduction method were comparatively analyzed and experimentally verified in the case of the constant rate and dynamic rate. The experimental analysis results showed that the improved noise reduction method had a very good result in the noise reduction of the gyroscope data at different fi:equencies, and its performance was superior to those of the FFT noise reduction method and the simple wavelet noise reduction method. 展开更多
关键词 micro-electro mechanical systems (MEMS) gyroscopes fast Fourier transformation (FFT) noise reduc-tion wavelet noise reduction
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A maximum noise fraction transform with improved noise estimation for hyperspectral images 被引量:6
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作者 LIU Xiang ZHANG Bing +1 位作者 GAO LianRu CHEN DongMei 《Science in China(Series F)》 2009年第9期1578-1587,共10页
Feature extraction is often performed to reduce spectral dimension of hyperspectral images before image classification. The maximum noise fraction (MNF) transform is one of the most commonly used spectral feature ex... Feature extraction is often performed to reduce spectral dimension of hyperspectral images before image classification. The maximum noise fraction (MNF) transform is one of the most commonly used spectral feature extraction methods. The spectral features in several bands of hyperspectral images are submerged by the noise. The MNF transform is advantageous over the principle component (PC) transform because it takes the noise information in the spatial domain into consideration. However, the experiments described in this paper demonstrate that classification accuracy is greatly influenced by the MNF transform when the ground objects are mixed together. The underlying mechanism of it is revealed and analyzed by mathematical theory. In order to improve the performance of classification after feature extraction when ground objects are mixed in hyperspectral images, a new MNF transform, with an improved method of estimating hyperspectral image noise covariance matrix (NCM), is presented. This improved MNF transform is applied to both the simulated data and real data. The results show that compared with the classical MNF transform, this new method enhanced the ability of feature extraction and increased classification accuracy. 展开更多
关键词 principal component transform maximum noise fraction transform hyperspectral image noise estimation
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Accurate Identification of Mass Peaks for Tandem Mass Spectra Using MCMC Model
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作者 Hui Li Chunmei Liu +1 位作者 Mugizi Robert Rwebangira Legand Burge 《Tsinghua Science and Technology》 SCIE EI CAS CSCD 2015年第5期453-459,共7页
In proteomics, many methods for the identification of proteins have been developed. However, because of limited known genome sequences, noisy data, incomplete ion sequences, and the accuracy of protein identification,... In proteomics, many methods for the identification of proteins have been developed. However, because of limited known genome sequences, noisy data, incomplete ion sequences, and the accuracy of protein identification,it is challenging to identify peptides using tandem mass spectral data. Noise filtering and removing thus play a key role in accurate peptide identification from tandem mass spectra. In this paper, we employ a Bayesian model to identify proteins based on the prior information of bond cleavages. A Markov Chain Monte Carlo(MCMC)algorithm is used to simulate candidate peptides from the posterior distribution and to estimate the parameters for the Bayesian model. Our simulation and computational experimental results show that the model can identify peptide with a higher accuracy. 展开更多
关键词 mass spectrometry Fourier transform noise filtering Markov Chain Monte Carlo(MCMC)
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New Exact Solutions for the Wick-Type Stochastic Kudryashov–Sinelshchikov Equation
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作者 S.Saha Ray S.Singh 《Communications in Theoretical Physics》 SCIE CAS CSCD 2017年第2期197-206,共10页
In this article, exact solutions of Wick-type stochastic Kudryashov–Sinelshchikov equation have been obtained by using improved Sub-equation method. We have used Hermite transform for transforming the Wick-type stoch... In this article, exact solutions of Wick-type stochastic Kudryashov–Sinelshchikov equation have been obtained by using improved Sub-equation method. We have used Hermite transform for transforming the Wick-type stochastic Kudryashov–Sinelshchikov equation to deterministic partial differential equation. Also we have applied inverse Hermite transform for obtaining a set of stochastic solutions in the white noise space. 展开更多
关键词 Kudryashov–Sinelshchikov Wick-product White noise space improved Sub-equation method Hermite transform inverse Hermite transform
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