The Experts below are selected from a list of 281613 Experts worldwide ranked by ideXlab platform
Binqiang Chen - One of the best experts on this subject based on the ideXlab platform.
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automatic fault feature extraction of mechanical anomaly on induction motor bearing using ensemble super wavelet transform
Mechanical Systems and Signal Processing, 2015Co-Authors: Binqiang ChenAbstract:Abstract Mechanical anomaly is a major failure type of induction motor. It is of great value to detect the resulting fault feature automatically. In this paper, an ensemble super-wavelet transform (ESW) is proposed for investigating vibration features of motor bearing faults. The ESW is put forward based on the combination of tunable Q-factor wavelet transform (TQWT) and Hilbert transform such that fault feature adaptability is enabled. Within ESW, a parametric optimization is performed on the Measured Signal to obtain a quality TQWT basis that best demonstrate the hidden fault feature. TQWT is introduced as it provides a vast wavelet dictionary with time-frequency localization ability. The parametric optimization is guided according to the maximization of fault feature ratio, which is a new quantitative measure of periodic fault signatures. The fault feature ratio is derived from the digital Hilbert demodulation analysis with an insightful quantitative interpretation. The output of ESW on the Measured Signal is a selected wavelet scale with indicated fault features. It is verified via numerical simulations that ESW can match the oscillatory behavior of Signals without artificially specified. The proposed method is applied to two engineering cases, Signals of which were collected from wind turbine and steel temper mill, to verify its effectiveness. The processed results demonstrate that the proposed method is more effective in extracting weak fault features of induction motor bearings compared with Fourier transform, direct Hilbert envelope spectrum, different wavelet transforms and spectral kurtosis.
Bratislav P. Marinković - One of the best experts on this subject based on the ideXlab platform.
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volume correction factor in electron indium atom scattering experiments
Facta Universitatis - Series: Physics Chemistry and Technology, 2008Co-Authors: M S Rabasovic, S D Tosic, V Pejcev, D M Filipovic, D. Sevic, Bratislav P. MarinkovićAbstract:In crossed electron beam - Indium atom beam scattering experiments the Measured Signal arises from a spatial region (the 'interaction volume') defined by the overlap of the electron and target atom beam and the view cone of the detector. The exchange of the interaction volume with the scattering angle, named a volume correction factor is discussed. The approach of R. T. Brinkmann and S. Trajmar (J. Phys. E 14, 245-254 (1981)) is adopted for our experimental conditions to determine the volume correction factor and accordingly to transfer angular distributions of scattered electrons to relative differential cross sections.
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volume correction factor in electron indium atom scattering experiments udc 539 171
2008Co-Authors: M S Rabasovic, S D Tosic, V Pejcev, D M Filipovic, D. Sevic, Bratislav P. MarinkovićAbstract:In crossed electron beam - Indium atom beam scattering experiments the Measured Signal arises from a spatial region (the 'interaction volume') defined by the overlap of the electron and target atom beam and the view cone of the detector. The exchange of the interaction volume with the scattering angle, named a volume correction factor is discussed. The approach of R. T. Brinkmann and S. Trajmar (J. Phys. E 14, 245-254 (1981)) is adopted for our experimental conditions to determine the volume correction factor and accordingly to transfer angular distributions of scattered electrons to relative differential cross sections.
Paolo Mercorelli - One of the best experts on this subject based on the ideXlab platform.
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an on line orthogonal wavelet denoising algorithm for high resolution surface scans
Journal of The Franklin Institute-engineering and Applied Mathematics, 2017Co-Authors: Manuel Schimmack, Paolo MercorelliAbstract:Abstract This paper deals with noise detection and threshold free on-line denoising procedure for discrete scanning probe microscopy (SPM) surface images using wavelets. In this sense, the proposed denoising procedure works without thresholds for the localisation of noise, as well for the stop criterium of the algorithm. In particular, a proposition which states a constructive structural property of the wavelets tree with respect to a defined seminorm has been proven for a special technical case. Using orthogonal wavelets, it is possible to obtain an efficient localisation of noise and as a consequence a denoising of the Measured Signal. An on-line denoising algorithm, which is based upon the discrete wavelet transform (DWT), is proposed to detect unavoidable Measured noise in the acquired data. With the help of a seminorm the noise of a Signal is defined as an incoherent part of a Measured Signal and it is possible to rearrange the wavelet basis which can illuminate the differences between its coherent and incoherent part. In effect, the procedure looks for the subspaces consisting of wavelet packets characterised either by small or opposing components in the wavelet domain. Taking real measurements the effectiveness of the proposed denoising algorithm is validated and compared with Gaussian FIR- and Median filter. The proposed method was built using the free wavelet toolboxes from the WaveLab 850 library of the Stanford University (USA).
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a denoising procedure using wavelet packets for instantaneous detection of pantograph oscillations
Mechanical Systems and Signal Processing, 2013Co-Authors: Paolo MercorelliAbstract:Abstract This paper presents a robust online denoising algorithm for use in the online, instantaneous detection of changing harmonic Signals. This algorithm uses a classical time correlation function (scalar product). For instantaneous frequency detection, a short window is considered. It is known that cleaned Signals are required to determine the correct correlation between short Signals. The Measured Signal is cleaned by the proposed noise removal algorithm, which uses wavelet packets. The proposed cleaning method avoids classical thresholding techniques. Computer simulations that validate the procedure are shown.
M S Rabasovic - One of the best experts on this subject based on the ideXlab platform.
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volume correction factor in electron indium atom scattering experiments
Facta Universitatis - Series: Physics Chemistry and Technology, 2008Co-Authors: M S Rabasovic, S D Tosic, V Pejcev, D M Filipovic, D. Sevic, Bratislav P. MarinkovićAbstract:In crossed electron beam - Indium atom beam scattering experiments the Measured Signal arises from a spatial region (the 'interaction volume') defined by the overlap of the electron and target atom beam and the view cone of the detector. The exchange of the interaction volume with the scattering angle, named a volume correction factor is discussed. The approach of R. T. Brinkmann and S. Trajmar (J. Phys. E 14, 245-254 (1981)) is adopted for our experimental conditions to determine the volume correction factor and accordingly to transfer angular distributions of scattered electrons to relative differential cross sections.
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volume correction factor in electron indium atom scattering experiments udc 539 171
2008Co-Authors: M S Rabasovic, S D Tosic, V Pejcev, D M Filipovic, D. Sevic, Bratislav P. MarinkovićAbstract:In crossed electron beam - Indium atom beam scattering experiments the Measured Signal arises from a spatial region (the 'interaction volume') defined by the overlap of the electron and target atom beam and the view cone of the detector. The exchange of the interaction volume with the scattering angle, named a volume correction factor is discussed. The approach of R. T. Brinkmann and S. Trajmar (J. Phys. E 14, 245-254 (1981)) is adopted for our experimental conditions to determine the volume correction factor and accordingly to transfer angular distributions of scattered electrons to relative differential cross sections.
Wlodek Tych - One of the best experts on this subject based on the ideXlab platform.
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a simple transfer function based approach for estimating material parameters from terahertz time domain data
IEEE Photonics Journal, 2014Co-Authors: Katarzyna M Tych, C D Wood, Wlodek TychAbstract:A novel parametrically efficient approach to estimating the spectra of short transient Signals is proposed and evaluated, with an application to estimating material properties, including complex refractive index and absorption coefficient, in the terahertz frequency range. This technique includes uncertainty analysis of the obtained spectral estimates, allowing rigorous statistical comparison between samples. In the proposed approach, a simple few-parameter continuous-time transfer function model explains over 99.9% of the Measured Signal. The problem, normally solved using poorly numerically defined Fourier transform deconvolution methods, is reformulated and cast as a time-domain dynamic-system estimation problem, thus providing a true time-domain spectroscopy tool.
