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Robust Damage Detection and Localization Under Complex Environmental Conditions Using singular value decomposition-based Feature Extraction and One-dimensional Convolutional Neural Network

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Chinese Journal of Mechanical Engineering 2023年第3期36卷 252-261页

作者： Shengkang Zong Sheng Wang Zhitao Luo Xinkai Wu Hui Zhang Zhonghua Ni Jiangsu Key Laboratory for Design and Manufacture of Micro-Nano Biomedical Instruments School of Mechanical EngineeringSoutheast UniversityNanjing 211189China

Ultrasonic guided wave is an attractive monitoring technique for large-scale structures but is vulnerable to changes in environmental and operational conditions(EOC),which are inevitable in the normal inspection of civil and mechanical *** paper thus presents a robust guided wave-based method for damage detection and localization under complex environmental conditions by singular value decomposition-based feature extraction and one-dimensional convolutional neural network(1D-CNN).After singular value decomposition-based feature extraction processing,a temporal robust damage index(TRDI)is extracted,and the effect of EOCs is well ***,even for the signals with a very large temperature-varying range and low signal-to-noise ratios(SNRs),the final damage detection and localization accuracy retain perfect 100%.Verifications are conducted on two different experimental *** first dataset consists of guided wave signals collected from a thin aluminum plate with artificial noises,and the second is a publicly available experimental dataset of guided wave signals acquired on a composite plate with a temperature ranging from 20℃to 60℃.It is demonstrated that the proposed method can detect and localize the damage accurately and rapidly,showing great potential for application in complex and unknown EOC.

关键词： Ultrasonic guided waves singular value decomposition Damage detection and localization Environmental and operational conditions One-dimensional convolutional neural network

Identification of m = 2 competent mode of complex magneto-hydro-dynamics activities during internal soft disruption based on singular value decomposition and tomography of soft-X-ray emission on the HT-7 tokamak

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Chinese Physics B 2012年第5期21卷 422-427页

作者：徐立清胡立群李二众陈开云刘志远陈晔斌张继宗周瑞杰杨茂毛松涛段艳敏 Institute of Plasma Physics Chinese Academy of Sciences

In this paper,the singular value decomposition(SVD) method as a filter is applied before the tomographic inversion of soft-X-ray *** of ’filtered’ signals including specific chronos and topos are obtained.(Here,chronos and topos are the decomposed spatial vectors and the decomposed temporal vectors,respectively).Given specific magnetic flux function with coupling m = 1 and m = 2 modes,the line-integrated soft-X-ray signals at all chords have been *** m = 1 and m = 2 modes have been identified by tomography of simulated ’filtered’ signals extracted by the SVD ***,using the experimental line-integrated soft-X-ray signals,m = 2 competent mode of complex magnetohydrodynamics(MHD) activities during internal soft disruption is *** result demonstrates that m = 2 mode plays an important role in internal disruption(Here,m is the poloidal mode number).

关键词： singular value decomposition disruption soft-X-ray tomography tokamak

Super-resolution reconstruction of synthetic-aperture radar image using adaptive-threshold singular value decomposition technique

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Journal of Central South University 2011年第3期18卷 809-815页

作者：朱正为周建江 College of Information Science and Technology Nanjing University of Aeronautics and Astronautics School of Information Engineering Southwest University of Science and Technology

A super-resolution reconstruction approach of （SVD） technique was presented, and its performance was radar image using an adaptive-threshold singular value decomposition analyzed, compared and assessed detailedly. First, radar imaging model and super-resolution reconstruction mechanism were outlined. Then, the adaptive-threshold SVD super-resolution algorithm, and its two key aspects, namely the determination method of point spread function （PSF） matrix T and the selection scheme of singular value threshold, were presented. Finally, the super-resolution algorithm was demonstrated successfully using the measured synthetic-aperture radar （SAR） images, and a Monte Carlo assessment was carried out to evaluate the performance of the algorithm by using the input/output signal-to-noise ratio （SNR）. Five versions of SVD algorithms, namely 1 ） using all singular values, 2） using the top 80% singular values, 3） using the top 50% singular values, 4） using the top 20% singular values and 5） using singular values s such that S2≥/max（s2）/rinsNR were tested. The experimental results indicate that when the singular value threshold is set as Smax/（rinSNR）1/2, the super-resolution algorithm provides a good compromise between too much noise and too much bias and has good reconstruction results.

关键词： synthetic-aperture radar image reconstruction super-resolution singular value decomposition adaptive-threshold

A NOTE ON singular value decomposition FOR RADON TRANSFORM IN R^n

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Acta Mathematica Scientia 2002年第3期22卷 311-318页

作者：王金平杜金元 School of Mathematics and Statistics Wuhan University Wuhan 430072 China Department of Mathematics Hubei Normal University Huangshi 435002 China

The singular value decomposition is derived when the Radon transform is restricted to functions which are square integrable on the unit ball in R-n with respect to the weight W-lambda(x). It fulfilles mainly by means of the projection-slice theorem. The range of the Radon transform is spanned by products of Gegenbauer polynomials and spherical harmonics. The inverse transform of the those basis functions are given. This immediately leads to an inversion formula by series expansion and range characterizations.

关键词： radon transform projection-slice theorem singular value decomposition

Estimation of fracture density and orientation from azimuthal elastic impedance difference through singular value decomposition

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Petroleum Science 2021年第6期18卷 1675-1688页

作者： Lin Li Guang-Zhi Zhang Jun-Zhou Liu Lei Han Jia-Jia Zhang School of Geosciences China University of Petroleum(East China)QingdaoShandong 266580China Sinopec Exploration and Production Research Institute Beijing100083China

Accurate estimation of fracture density and orientation is of great significance for seismic characterization of fractured ***,we propose a novel methodology to estimate fracture density and orientation from azimuthal elastic impedance(AEI)difference using singular value decomposition(SVD).Based on Hudson's model,we first derive the AEI equation containing fracture density in HTI media,and then obtain basis functions and singular values from the normalized AEI difference utilizing *** shows that the basis function changing with azimuth is related to fracture orientation,fracture density is the linearly weighted sum of singular values,and the first singular value contributes the most to fracture ***,we develop an SVD-based fracture density and orientation inversion approach constrained by smooth prior elastic *** example shows that fracture density and orientation can be stably estimated,and the correlation coefficient between the true value and the estimated fracture density is above 0.85 even when an S/N ratio of *** data example shows that the estimated fracture orientation is consistent with the interpretation of image log data,and the estimated fracture density reliably indicates fractured gas-bearing reservoir,which could help to guide the exploration and development of fractured reservoirs.

关键词： singular value decomposition HTI media Azimuthal elastic impedance inversion Fracture density Fracture orientation

Steering laws analysis of SGCMGs based on singular value decomposition theory

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Applied Mathematics and Mechanics(English Edition) 2008年第8期29卷 1013-1021页

作者：张景瑞 Beijing Institute of Technology School of Aerospace Science Engineering Beijing 100081P.R.China

The steering laws of single gimbal control moment gyros （SGCMGs） are analyzed and compared in this paper for a spacecraft attitude control system based on singular value decomposition （SVD） theory. The mechanism of steering laws escaping singularity, especially how the steering laws affect singularity of gimbal configuration and the output torque error, is studied using SVD theory. Performance of various steering laws are analyzed and compared quantitatively by simulation. The obtained results can be used as a reference for designers.

关键词： single gimbal control moment gyros singular value decomposition steering law singularity

IMPROVED singular value decomposition TECHNIQUE FOR DETECTING AND EXTRACTING PERIODIC IMPULSE COMPONENT IN A VIBRATION SIGNAL

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Chinese Journal of Mechanical Engineering 2004年第3期17卷 340-345页

作者： LiuHongxing LiJian ZhaoYing QuLiangsheng DepartmentofElectronicScienceandEngineering NanjingUniversityNanjing210093China MechanicalEngineeringCollege Xi＇anJiaotongUniversityXi＇an710049China

Vibration acceleration signals are often measured from case surface of arunning machine to monitor its condition. If the measured vibration signals display to have periodicimpulse components with a certain frequency, there may exist a corresponding local fault in themachine, and if further extracting the periodic impulse components from the vibration signals, theseverity of the local fault can be estimated and tracked. However, the signal-to-noise ratios (SNRs)of the vibration acceleration signals are often so small that the periodic impulse components aresubmersed in much background noises and other components, and it is difficult or inconvenient for usto detect and extract the periodic impulse components with the current common analyzing methods forvibration signals. Therefore, another technique, called singular value decomposition (SVD), istried to be introduced to solve the problem. First, the principle of detecting and extracting thesignal periodic components using singular value decomposition is summarized and discussed. Second,the infeasibility of the direct use of the existing SVD based detecting and extracting approach ispointed out. Third, the approach to construct the matrix for SVD from the signal series is improvedlargely, which is the key program to improve the SVD technique; Other associated improvement is alsoproposed. Finally, a simulating application example and a real-life application example ondetecting and extracting the periodic impulse components are given, which showed that the introducedand improved SVD technique is feasible.

关键词： Fault diagnosis Vibration Signal processing singular value decomposition

DIRECT PERTURBATION METHOD FOR REANALYSIS OF MATRIX singular value decomposition

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Applied Mathematics and Mechanics(English Edition) 1997年第5期18卷 471-477页

作者：吕振华 Qinghua University Beijing PR China

The perturbational reanalysis technique of matrix singular value decomposition is applicable to many theoretical and practical problems in mathematics, mechanics, control theory, engineering, etc.. An indirect perturbation method has previously been proposed by the author in this journal, and now the direct perturbation method has also been presented in this paper. The second-order perturbation results of non-repeated singular values and the corresponding left and right singular vectors are obtained. The results can meet the general needs of most problems of various practical applications. A numerical example is presented to demonstrate the effectiveness of the direct perturbation method.

关键词： matrix algebra singular value decomposition reanalysis perturbation method

PERTURBATION METHOD FOR REANALYSIS OF THE MATRIX singular value decomposition

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Applied Mathematics and Mechanics(English Edition) 1991年第7期12卷 705-715页

作者：吕振华冯振东 Jilin University of Technology Changchun

The perturbation method for the reanalysis of the singular value decomposition (SVD) of general real matrices is presented in this paper. This is a simple but efficient reanalysis technique for the SVD, which is of great worth to enhance computational efficiency of the iterative analysis problems that require matrix singular value decomposition repeatedly. The asymptotic estimate formulas for the singular values and the corresponding left and right singular vectors up to second-order perturbation components are derived. At the end of the paper the way to extend the perturbation method to the case of general complex matrices is advanced.

关键词： matrix algebra singular value decomposition reanalysis,perturbation method