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Variational Mode Decomposition-Informed Empirical Wavelet Transform for Electric Vibrator Noise Analysis
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作者 Zhenyu Xu Zhangwei Chen 《Journal of Applied Mathematics and Physics》 2024年第6期2320-2332,共13页
Electric vibrators find wide applications in reliability testing, waveform generation, and vibration simulation, making their noise characteristics a topic of significant interest. While Variational Mode Decomposition... Electric vibrators find wide applications in reliability testing, waveform generation, and vibration simulation, making their noise characteristics a topic of significant interest. While Variational Mode Decomposition (VMD) and Empirical Wavelet Transform (EWT) offer valuable support for studying signal components, they also present certain limitations. This article integrates the strengths of both methods and proposes an enhanced approach that integrates VMD into the frequency band division principle of EWT. Initially, the method decomposes the signal using VMD, determining the mode count based on residuals, and subsequently employs EWT decomposition based on this information. This addresses mode aliasing issues in the original method while capitalizing on VMD’s adaptability. Feasibility was confirmed through simulation signals and ultimately applied to noise signals from vibrators. Experimental results demonstrate that the improved method not only resolves EWT frequency band division challenges but also effectively decomposes signal components compared to the VMD method. 展开更多
关键词 Electric Vibrator noise Analysis Signal Decomposing Variational Mode Decomposition Empirical wavelet transform
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ELECTROCHEMICAL NOISE ANALYSIS OF PURE ALUMINUM IN SODIUM CHLORIDE SOLUTION WITH WAVELET TRANSFORM TECHNIQUE 被引量:7
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作者 Z. Zhang, Q.D. Zhong, J.Q. Zhang, Y.L. Cheng, F.H. Cao, J.M. and C.N. CaoDepartment of Chemistry, Zhejiang University, Hangzhou 310027, ChinaElectrochemical Research Group, Shanghai University of Electric Power, Shanghai 200090, ChinaState Key Laboratory 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 2002年第3期272-278,共7页
Wavelet transforms (WT) are proposed as an alternative tool to overcome the limitations of Fourier transforms (FFT) in the analysis of electrochemical noise (EN) data. The most relevant feature of this method of analy... Wavelet transforms (WT) are proposed as an alternative tool to overcome the limitations of Fourier transforms (FFT) in the analysis of electrochemical noise (EN) data. The most relevant feature of this method of analysis is its capability of decomposing electrochemical noise records into different sets of wavelet coefficients, which contain information about the time scale characteristic of the associated corrosion event. In this context, the potential noise fluctuations during the free corrosion of pure aluminum in sodium chloride solution was recorded and analyzed with wavelet transform technique. The typical results showed that the EN signal is composed of distinct type of events, which can be classified according to their scales, i.e. their time constants. Meanwhile, the energy distribution plot (EDP) can be used as 'fingerprints' of EN signals and can be very useful for analyzing EN data in the future. 展开更多
关键词 electrochemical noise wavelet analysis Fourier transforms CORROSION pure aluminum
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THE WAVELET TRANSFORM BASED PROCESSING MEANS FOR 1/f NOISE IN MILLIMETER WAVE FOCAL PLANE ARRAY
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作者 Zhang Yong Li Xingguo(Institute of Millimeter-Wave & Light-Wave Near Sensing Technology, Nanjing University of Science & Technology, Nanjing 210094) 《Journal of Electronics(China)》 1999年第4期343-349,共7页
After briefly introducing the characteristics of 1/f noise in millimeter wave focalplane array detectors, the paper analyses the relation of wavelet transform and 1/f noise in detail, suggests the fashion of decorrela... After briefly introducing the characteristics of 1/f noise in millimeter wave focalplane array detectors, the paper analyses the relation of wavelet transform and 1/f noise in detail, suggests the fashion of decorrelating 1/f noise using the wavelet transform and deduces the relative expressions. The results of computer simulation show good effectiveness. 展开更多
关键词 MILLIMETER wave FOCAL PLANE array 1/f noise wavelet transform Decorrelate
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Improving the Autoregressive Modeling Method in Random Noise Suppression of GPR Data Using Undecimated Discrete Wavelet Transform
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作者 Behrooz Oskooi Amin Ebrahimi Bardar Alireza Goodarzi 《Journal of Signal and Information Processing》 2018年第1期24-35,共12页
Geophysics has played a significant and efficient role in studying geological structures over the past decades as the goal of geophysical data acquisition is to investigate underground phenomena with the highest possi... Geophysics has played a significant and efficient role in studying geological structures over the past decades as the goal of geophysical data acquisition is to investigate underground phenomena with the highest possible level of accuracy. The ground penetrating radar (GPR) method is used as a nondestructive method to reveal shallow structures by beaming electromagnetic waves through the Earth and recording the received reflections, albeit inevitably, along with random noise. Various types of noise affect GPR data, among the most important of which are random noise resulting from arbitrary motions of particles during data acquisition. Random noise which exists always and at all frequencies, along with coherent noise, reduces the quality of GPR data and must be reduced as much as possible. Over the recent years, discrete wavelet transform has proved to be an efficient tool in signal processing, especially in image and signal compressing and noise suppression. It also allows for obtaining an accurate understanding of the signal properties. In this study, we have used the autoregression in both wavelet and f-x domains to suppress random noise in synthetic and real GPR data. Finally, we compare noise suppression in the two domains. Our results reveal that noise suppression is conducted more efficiently in the wavelet domain due to decomposing the signal into separate subbands and exclusively applying the method parameters in autoregression modeling for each subband. 展开更多
关键词 Ground PENETRATING Radar Random noise Undecimated Discrete wavelet transform AUTOREGRESSIVE Filter
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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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WAVELET TRANSFORM THRESHOLD NOISE REDUCTION METHODS IN THE OIL PIPELINE LEAKAGE MONITORING AND POSITIONING SYSTEM 被引量:3
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作者 Gao Chao Zhou Shanxue 《Journal of Electronics(China)》 2010年第3期405-411,共7页
This letter investigates the wavelet transform, as well as the principle and the method of the noise reduction based on wavelet transform, it chooses the threshold noise reduction, and discusses in detail the principl... This letter investigates the wavelet transform, as well as the principle and the method of the noise reduction based on wavelet transform, it chooses the threshold noise reduction, and discusses in detail the principles, features and design steps of the threshold method. Rigrsure, heursure, sqtwolog and minimization four kinds of threshold selection method are compared qualitatively, and quantitatively. The wavelet analysis toolbox of MATLAB helps to realize the computer simulation of the signal noise reduction. The graphics and calculated standard deviation of the various threshold noise reductions show that, when dealing with the actual pressure signal of the oil pipeline leakage, sqtwolog threshold selection method can effectively remove the noise. Aiming to the pressure signal of the oil pipeline leakage, the best choice is the wavelet threshold noise reduction with sqtwolog threshold. The leakage point is close to the actual position, with the relative error of less than 1%. 展开更多
关键词 wavelet transform Decreasing-noise THRESHOLD Oil pipeline leakage MATLAB
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Characteristics analysis of muzzle impulse noise based on wavelet energy spectrum
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作者 赖富文 张建宇 胡桂梅 《Journal of Measurement Science and Instrumentation》 CAS CSCD 2015年第2期142-146,共5页
Because muzzle impulse noise could cause damage to or have an intluence on the operator, tiae ettecnve protecnve measures should be taken. Therefore, correct analysis of impulse noise characteristics is very significa... Because muzzle impulse noise could cause damage to or have an intluence on the operator, tiae ettecnve protecnve measures should be taken. Therefore, correct analysis of impulse noise characteristics is very significant. Considering the shortcomings of fast Fourier transform method (FFT) in analysis of muzzle impulse noise frequency characteristics, wavelet energy spectrum method is put forward. Based on specific experiment data, the frequency characteristics and spectral energy dis tribution can be obtained. The experiment results show that wavelet energy spectrum method is applicable in muzzle impulse noise characteristic analysis. 展开更多
关键词 muzzle impulse noise wavelet transform energy spectrum signal processing
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Wavelet domain adaptive filtering algorithm for removing the seamless pipe noise contained in the magnetic flux leakage data 被引量:1
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作者 韩文花 Que Peiwen 《High Technology Letters》 EI CAS 2006年第2期170-174,共5页
With the widespread application and fast development of gas and oil pipeline network in China, the pipeline inspection technology has been used more extensively. The magnetic flux leakage (MFL) method has establishe... With the widespread application and fast development of gas and oil pipeline network in China, the pipeline inspection technology has been used more extensively. The magnetic flux leakage (MFL) method has established itself as the most widely used in-line inspection technique for the evaluation of gas and oil pipelines. The MFL data obtained from seamless pipeline inspection is usually contaminated by the seamless pipe noise (SPN). SPN can in some cases completely mask MFL signals from certain type of defects, and therefore considerably reduces the detectability of the defect signals. In this paper, a new de-noising algorithm called wavelet domain adaptive filtering is proposed for removing the SPN contained in the MFL data. The new algorithm results from combining the wavelet transform with the adaptive filtering technique. Results from application of the proposed algorithm to the MFL data from field tests show that the proposed algorithm has good performance and considerably improves the detectability of the defect signals in the MFL data. 展开更多
关键词 pipeline inspection magnetic flux leakage data discrete wavelet transform wavelet domain adaptive filtering seamless pipe noise
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Arrival time measurements of first arrival phases P and PKIKP using the method of fixed scale wavelet transformation ratio
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作者 何小波 周蕙兰 《Acta Seismologica Sinica(English Edition)》 EI CSCD 2005年第4期410-418,499,共10页
The arrival times of first teleseismic phases are difficult to be measured precisely because of slowly and gradually changed onsets and weak amplitudes. The arrival times measured manually are usually behind the real ... The arrival times of first teleseismic phases are difficult to be measured precisely because of slowly and gradually changed onsets and weak amplitudes. The arrival times measured manually are usually behind the real ones. In this paper, using the ratio method of fixed scale wavelet transformations improved by us, the arrival times for the first arrival phases (such as P and PKIKP) at the teleseismic and far-teleseismic distances were measured. The results are reasonable and reliable based on the analysis and discussion of the reliabilities and errors. 展开更多
关键词 Morlet wavelet wavelet transformation ratio first arrival phase first arrival time signal to noise ratio
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Analyses on normal background characteristics about deformation observation data on the basis of wavelet transform method
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作者 李杰 刘希强 +2 位作者 李红 毛玉华 郑树田 《Acta Seismologica Sinica(English Edition)》 EI CSCD 2005年第1期34-42,124,共10页
Wavelet transform method is applied to measure time-frequency distribution characteristics of digital deformation data and noise. Based on the characteristics of primary modulus and stochastic white noise discriminati... Wavelet transform method is applied to measure time-frequency distribution characteristics of digital deformation data and noise. Based on the characteristics of primary modulus and stochastic white noise discrimination factor of wavelet decomposition, we analyze the variation rule of normal background and noise data from Shandong digital deformation observation data. The research results indicate that: a) 1/4 daily wave, semi-diurnal tide wave, daily wave and half lunar wave and so on quasi-periodic signal exist in the detail decomposing signal of wavelet when scale are equal to 2, 3 and 4; b) The amplitude of detail decomposing signal is the biggest when scale is equal to 3; c) The detail decomposing signal contains mainly noise corresponding to scale 1 and 5, respectively; d) We may trace the abnormal precursory which is related to earthquake by analyzing non-earthquake wavelet decomposing signal whose scale is specified from digital deformation observation data. 展开更多
关键词 wavelet transform digital deformation observation data separation method between signal and noise discrimination of earthquake precursory
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Single Channel Speech Enhancement by De-noising Using Stationary Wavelet Transform 被引量:2
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作者 张德祥 高清维 陈军宁 《Journal of Electronic Science and Technology of China》 2006年第1期39-42,共4页
A method of single channel speech enhancement is proposed by de-noising using stationary wavelet transform. The approach developed herein processes multi-resolution wavelet coefficients individually and then recovery ... A method of single channel speech enhancement is proposed by de-noising using stationary wavelet transform. The approach developed herein processes multi-resolution wavelet coefficients individually and then recovery signal is reconstructed. The time invariant characteristics of stationary wavelet transform is particularly useful in speech de-noising. Experimental results show that the proposed speech enhancement by de-noising algorithm is possible to achieve an excellent balance between suppresses noise effectively and preserves as many target characteristics of original signal as possible. This de-noising algorithm offers a superior performance to speech signal noise suppress. 展开更多
关键词 stationary wavelet transform speech enhancement DE-NOISING SNR
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Coefficients de-noising with wavelet transform for magnetic flux leakage data obtained from oil pipeline
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作者 韩文花 Que Peiwen 《High Technology Letters》 EI CAS 2005年第4期406-409,共4页
This paper considers the problem of noise cancellation for the magnetic flux leakage (MFL) data obtained from the inspection of oil pipelines. MFL data is contaminated by various sources of noise, and the noise can co... This paper considers the problem of noise cancellation for the magnetic flux leakage (MFL) data obtained from the inspection of oil pipelines. MFL data is contaminated by various sources of noise, and the noise can considerably reduce the detectability of flaw signals in MFL data. This paper presents a new de-noising approach for removing the system noise contained in the MFL data by using the coefficients de-noising with wavelet transform. Experimental results are presented to demonstrate the advantages of this de-noising approach over the conventional wavelet de-noising method. 展开更多
关键词 magnetic flux leakage coefficients de-noising wavelet transform pipeline inspection system noise flaw signals
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Improved signal de-noising in underwater acoustic noise using S-transform: A performance evaluation and comparison with the wavelet transform 被引量:1
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作者 Yasin Yousif Al-Aboosi Ahmad Zuri Sha’ameri 《Journal of Ocean Engineering and Science》 SCIE 2017年第3期172-185,共14页
Sound waves propagate well underwater making it useful for target locating and communication.Underwater acoustic noise(UWAN)affects the reliability in applications where the noise comes from multiple sources.In this p... Sound waves propagate well underwater making it useful for target locating and communication.Underwater acoustic noise(UWAN)affects the reliability in applications where the noise comes from multiple sources.In this paper,a novel signal de-noising technique is proposed using S-transform.From the time-frequency representation,de-noising is performed using soft thresholding with universal threshold estimation which is then reconstructed.The UWAN used for the validation is sea truth data collected at Desaru beach on the eastern shore of Johor in Malaysia with the use of broadband hydrophones.The comparison is made with the more conventionally used wavelet transform de-noising method.Two types of signals are evaluated:fixed frequency signals and time-varying signals.The results demonstrate that the proposed method shows better signal to noise ratio(SNR)by 4 dB and lower root mean square error(RMSE)by 3 dB achieved at the Nyquist sampling frequency compared to the previously proposed de-noising method like wavelet transform. 展开更多
关键词 Underwater acoustic noise Time-frequency analysis wavelet transforms S-transforms Signal de-noising
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SIGNAL FEATURE EXTRACTION BASED UPON INDEPENDENT COMPONENT ANALYSIS AND WAVELET TRANSFORM 被引量:7
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作者 JiZhong JinTao QinShuren 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2005年第1期123-126,共4页
It is an important precondition for machine fault diagnosis that vibrationsignal can be extracted effectively. Based on the characteristic of noise interfused during thecourse of sampling vibration signal, independent... It is an important precondition for machine fault diagnosis that vibrationsignal can be extracted effectively. Based on the characteristic of noise interfused during thecourse of sampling vibration signal, independent component analysis (ICA) method is combined withwavelet to de-noise. Firstly, The sampled signal can be separated with ICA, then the function offrequency band chosen with multi-resolution wavelet transform can be used to judge whether thestochastic disturbance singular signal is interfused. By these ways, the vibration signals can beextracted effectively, which provides favorable condition for subsequent feature detection ofvibration signal and fault diagnosis. 展开更多
关键词 Independent component analysis (ICA) wavelet transform DE-NOISING FAULTDIAGNOSIS Feature extraction
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An Improved Singularity Computing Algorithm Based on Wavelet Transform Modulus Maxima Method 被引量:1
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作者 赵健 谢端 范训礼 《Journal of Shanghai Jiaotong university(Science)》 EI 2006年第3期317-320,327,共5页
In order to reduce the hidden danger of noise which can be charactered by singularity spectrum, a new algorithm based on wavelet transform modulus maxima method was proposed. Singularity analysis is one of the most pr... In order to reduce the hidden danger of noise which can be charactered by singularity spectrum, a new algorithm based on wavelet transform modulus maxima method was proposed. Singularity analysis is one of the most promising new approaches for extracting noise hidden information from noisy time series . Because of singularity strength is hard to calculate accurately, a wavelet transform modulus maxima method was used to get singularity spectrum. The singularity spectrum of white noise and aluminium interconnection electromigration noise was calculated and analyzed. The experimental results show that the new algorithm is more accurate than tradition estimating algorithm. The proposed method is feasible and efficient. 展开更多
关键词 noise signal analysis singularity spectrum wavelet transform modulus maxima FRACTAL
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Denoising of an Image Using Discrete Stationary Wavelet Transform and Various Thresholding Techniques 被引量:8
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作者 Abdullah Al Jumah 《Journal of Signal and Information Processing》 2013年第1期33-41,共9页
Image denoising has remained a fundamental problem in the field of image processing. With Wavelet transforms, various algorithms for denoising in wavelet domain were introduced. Wavelets gave a superior performance in... Image denoising has remained a fundamental problem in the field of image processing. With Wavelet transforms, various algorithms for denoising in wavelet domain were introduced. Wavelets gave a superior performance in image denoising due to its properties such as multi-resolution. The problem of estimating an image that is corrupted by Additive White Gaussian Noise has been of interest for practical and theoretical reasons. Non-linear methods especially those based on wavelets have become popular due to its advantages over linear methods. Here I applied non-linear thresholding techniques in wavelet domain such as hard and soft thresholding, wavelet shrinkages such as Visu-shrink (non-adaptive) and SURE, Bayes and Normal Shrink (adaptive), using Discrete Stationary Wavelet Transform (DSWT) for different wavelets, at different levels, to denoise an image and determine the best one out of them. Performance of denoising algorithm is measured using quantitative performance measures such as Signal-to-Noise Ratio (SNR) and Mean Square Error (MSE) for various thresholding techniques. 展开更多
关键词 wavelet Discrete wavelet transform wavelet Packet transform STATIONARY wavelet transform THRESHOLDING Visu Shrink SURE Shrink Normal Shrink Mean Square Error Peak SIGNAL-TO-noise Ratio
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Technology of signal de-noising and singularity elimination based on wavelet transform 被引量:1
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作者 赵国建 韩宝玲 +1 位作者 罗庆生 王鑫 《Journal of Beijing Institute of Technology》 EI CAS 2011年第4期509-513,共5页
Based on wavelet transform theory,a method for signal de-noising and singularity detection and elimination is proposed,which can reduce the noises and express local singularity.Each singularity can also be detected an... Based on wavelet transform theory,a method for signal de-noising and singularity detection and elimination is proposed,which can reduce the noises and express local singularity.Each singularity can also be detected and located through the local modulus maxima of wavelet transform.Simulation experiments are conducted with MATLAB software.The experimental results demonstrate that the method proposed in this paper is effective and feasible. 展开更多
关键词 industrial palletizing robot photoelectric sensor wavelet transform wavelet de-noising SINGULARITY
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Analysis of corrosion behavior of LY12 in sodium chloride solution with wavelet transform technique 被引量:1
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作者 张昭 曹发和 +3 位作者 程英亮 张鉴清 王建明 曹楚南 《中国有色金属学会会刊:英文版》 CSCD 2002年第6期1206-1209,共4页
Wavelet transforms(WT) are proposed as an alternative tool to overcome the limitations of fast Fourier transforms(FFT) in the analysis of electrochemical noise(EN) data. The most relevant feature of this method of ana... Wavelet transforms(WT) are proposed as an alternative tool to overcome the limitations of fast Fourier transforms(FFT) in the analysis of electrochemical noise(EN) data. The most relevant feature of this method of analysis is its capability of decomposing electrochemical noise records into different sets of wavelet coefficients(distinct type of events), which contains information about the time scale characteristic of the associated corrosion event. In this context, the potential noise fluctuations during the free corrosion of commercial aluminum alloy LY12 in sodium chloride solution was recorded and analyzed with wavelet transform technique. The typical results show that the EN signal is composed of distinct type of events, which can be classified according to their scales, i.e. their time constants. Meanwhile, the energy distribution plot(EDP) can be used as "fingerprints" of EN signals and can be very useful for analyzing EN data in the future. 展开更多
关键词 电化学噪声 小波分析 傅立叶变换 腐蚀 铝合金2024-T3
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Super-Resolution image Reconstruction Based on Iteration and Wavelet Transform 被引量:1
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作者 Wang Jing Aidi Wu 《通讯和计算机(中英文版)》 2014年第1期39-44,共6页
关键词 超分辨率图像 图像重建 小波变换 迭代方法 低频信息 图像融合 高频信息 迭代过程
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Partial Discharge Source Classification and De-Noising in Rotating Machines Using Discrete Wavelet Transform and Directional Coupling Capacitor 被引量:1
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作者 Mohammad Amin Kashiha Diman Zad Tootaghaj Dolat Jamshidi 《Journal of Electromagnetic Analysis and Applications》 2009年第2期92-96,共5页
This paper introduces a new method to separate PD1 from other disturbing signals present on the high voltage genera-tors and motors. The method is based on combination of a pattern classifier, the Discrete Wavelet Tra... This paper introduces a new method to separate PD1 from other disturbing signals present on the high voltage genera-tors and motors. The method is based on combination of a pattern classifier, the Discrete Wavelet Transform (DWT), to de-noise PD and Time-Of-Arrival method to separate PD sources. Furthermore, it will be shown that it can recognize PD sources including rotating machine’s internal and external discharge pulses (e.g. on the bus bar). 展开更多
关键词 Partial DISCHARGE Discrete wavelet transform TIME-OF-ARRIVAL ROTATING Machines DE-NOISING Coupling CAPACITOR
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