Research Article Time-Frequency Analysis of Horizontal Vibration for Vehicle-Track System Based on Hilbert-Huang Transform
|
|
- Lisa Oliver
- 8 years ago
- Views:
Transcription
1 Hindawi Publishing Corporation Advances in Mechanical Engineering Volume 3, Article ID 954, 5 pages Research Article Time-Frequency Analysis of Horizontal Vibration for Vehicle-Track System Based on Hilbert-Huang Transform Zaiwei Li,, Songliang Lian, 3 and Yuelei He College of Urban Rail Transportation, Shanghai University of Engineering Science, Shanghai 6, China Engineering Research Center of Railway Environmental Vibration and Noise of Ministry of Education, East China Jiaotong University, Nanchang 333, China 3 Key Laboratory of Road and Traffic Engineering of the Ministry of Education, Tongji University, Shanghai 4, China Correspondence should be addressed to Zaiwei Li; lzw 5964@63.com Received 5 July 3; Accepted 8 November 3 Academic Editor: Robert L. Reuben Copyright 3 Zaiwei Li et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Relationship between track alignment irregularity and car body horizontal vibration acceleration is analyzed by using Hilbert- Huang Transform (HHT). Actual measured alignment irregularity and car body horizontal vibration acceleration are decomposed by empirical mode decomposition (EMD) to obtain intrinsic mode function (IMF). By comparing IMF waveform and energy spectrum of the irregularity and vibration acceleration, there is the definitive correspondence of IMFs, and the adverse section of irregularity can be identified from car body horizontal vibration acceleration. Finally, regression analysis is taken for measured sample of track inspection car on Beijing-Guangzhou line; the quantitative relationship between track alignment irregularity and car body horizontal vibration acceleration is established with a wavelength between.5 m and 5 m.. Introduction Railroad tracks support weights of trains and help trains to run smoothly. However, operations of trains cause gradual track irregularities. Track irregularity is well known to be an important source of vibration of vehicle-track systems, where the track consists of a pair of rails supported by sleepers and ballast []. Therefore, it is necessary to study the vibration characteristics of such systems. Recently, a few studies have concentrated on vibration analysis of vehicle-track systems. Lian and Huang [] used the power spectra density and coherence functions to analyze the detrimental wavelengths of the track irregularities that induce large vibration responses to passenger and freight cars. Li et al. [3] developed a real-time technique relating track geometry to vehicle performance based on the neural network approach. Weston et al. [4] described the theory and practical results of using a bogie-mounted pitchrate gyro to obtain mean track alignment. A computational model for random vibration analysis of vehicle-track systems is proposed and solutions use the pseudoexcitation method and the symplistic method by Lu et al. []. Luber [5] proposeda method for track geometry assessment that calculates a vehicle response prediction based on system identifications. Gao et al. [6] proposed the vehicle-track coupled dynamics theory to analysis the sensitive wavelength of track irregularity in high-speed operation. However, these studies are used spectrum analysis to dynamic response characteristics based on coupled vehicle-track systems theory, which could not quantitatively analyse relationship between track alignment irregularity and car body horizontal vibration acceleration. In this paper, we proposed Hilbert-Huang Transform (HHT) to study the time-frequency characteristic of horizontal vibration for vehicle-track system. Firstly, the mathematical theory of Hilbert-Huang Transform is overviewed. And then, the relationship between track alignment irregularity and car body horizontal vibration acceleration based on intrinsic mode function of them is presented. Regression analysis is given to quantitative analysis relationship between track alignment irregularity and car body horizontal vibration acceleration. Finally, conclusions are drawn and future work is discussed.
2 Advances in Mechanical Engineering. Hilbert-Huang Transform The HHT, a National Aeronautics and Space Administration s designated name, is a combination of two methods, which arebothintroducedbyhuangetal.[7, 8], that is, the empirical mode decomposition (EMD) and the Hilbert spectral analysis (HSA). The principles and procedures are briefly summarized below. EMD decomposes a signal to a finite number of oscillatory modes called intrinsic mode functions (IMFs) that guaranteeawell-behavedhilberttransform.bydefinition,animf is any function that satisfies two conditions: (a) in the whole data set, the number of extrema and the number of zero crossingsmusteitherequalordifferatmostbyoneand(b) atanydatasample,themeanvalueoftheenvelopedefined by the local maxima and the envelope defined by the local minima is zero [7]. The process of the EMD decomposition of the original signal x(t) can be separated into several finite computational steps, which are briefly described below. First, identify all the local extrema and connect all the local maxima by a cubic spline line (upper envelope) and similarly all the local minima (lower envelope). The first proto-imf can be computed from the mean of the upper and lower envelope m (t) as follows: h (t) =x(t) m (t), () where h (t) is labeled proto-imf because it does not necessarily satisfy the rigorous constraints that define an IMF. Therefore, in the second round of sifting, h (t) is treated as data, and if the new mean is m (t),then h (t) =h (t) m (t), () where m (t) isthemeanoftheupperandlowerenvelopes of h (t). This process is generally reiterated k times until eventually h k (t) is obtained as h k (t) =h (k ) (t) m k (t) (3) is an IMF (c (t) = h k (t)). k is the number of iterations that allows h k (t) to satisfy the stoppage criterion of the sifting process. Theoretically, c (t) should contain the shortest period component of the data. Then, the residue is computed as r (t) =x(t) c (t). (4) The residue r (t) canbetreatedasthenewtimeseriestobe sifted as described above, in order to obtain a slower IMF. The whole process has to be reiterated n times until the residue r n (t) is an amonotonic function or a function with only one extremum. Finally, original data x(t) can be obtained from the sum of the IMFs components and residue r n (t) as follows: x (t) = n i= c i (t) +r n (t). (5) As a data-driven method, in the EMD process, when the endpoints are not extrema, there exist wild swings which are not limited to the neighborhoods of the ends and propagate into the interior of the data, leading to distorted components [8]. Therefore, a method combining the mirror extension with the gray neural network is proposed to extend the data, which can solve the end effects problem more efficiently and effectively [9]. However, the EMD output is prone to mode-mixing which mainly occurs due to the overlapping of the IMF spectra [7], and the aliasing caused by sub-nyquist extrema sampling. To overcome these issues, the ensemble EMD method was recently developed []. Essentially, it repeatedly decomposes the signal into IMFs by using the EMD method. During each trial of the decomposition process, white noise of finite amplitudeisaddedtotheoriginalsignal.tohelpovercome these issues, the sifting processes of EEMD algorithm are shown as follows. Add to the signal x(t) an ensemble of n groups of white Gaussian noise w(t), of which the mean value is zero and standard deviation of amplitude is a constant. If s n (t) indicates the nth group of noise-added signal, and w n (t) the nth group of white Gaussian noise signals is added, their relation is shown as follows: s n (t) =x(t) +w n (t). (6) Decompose the ensemble s n (t) by applying standard EMD to each realization s n (t) separately, obtaining M n IMFs for s n (t), denoted by {c n m (t)}m n m=. Average the corresponding IMFs from the whole ensembletoobtaintheaveraged(ensembled)imfs;forinstance, mth IMF can be obtained by using c m (t) = N m n= c n m (t), (7) where N is the total number of the ensemble members used in the process. As soon as the process of EEMD is completed, the Hilbert transform is applied to each IMF in order to compute instantaneous frequencies and instantaneous amplitudes. For every IMF component, that is, c i (t), its Hilbert transform y i (t) is defined as y j (t) = π P c i (τ) dτ, (8) t τ where P indicates the Cauchy principal value. The IMF, that is, c i (t),anditshilberttransform,thatis,y i (t),formananalytical signal z i (t) defined as where z i (t) =x i (t) +jy i (t) =A i (t) e jθ i(t), (9) A i (t) = ci (t) +yi (t), θ i (t) = arctan [ y i (t) ]. () c i (t) The instantaneous frequency is defined as ω i (t) =πf j (t) = dθ j (t). () dt
3 Advances in Mechanical Engineering 3 Taking into account the previous equations, each IMF component c i (t) canberepresentedas c i (t) = R (A i (t) e j πf i(t)dt ), () where R istherealpartofthevalue.andthus,theoriginal data x(t) canberecoveredas x (t) = R ( n i= A i (t) e j πf i(t)dt ). (3) Similar to the Fourier amplitude spectrum, the Hilbert amplitude spectrum H(ω, t) is the time-frequency distribution of theamplitude.themarginalspectrumh(ω, t) is a measure of the total amplitude (or energy) contribution from each frequency value. It represents the cumulative amplitude over theentiredataspaninaprobabilisticsense.themarginal spectrum is obtained by integrating the Hilbert spectrum over the time duration T as follows: T h (ω) = H (ω, t) dt. (4) Amplitude (mm) Amplitude (m s ) Hilbert-Huang Transform Analysis of Horizontal Vibration for Vehicle-Track System 3.. Waveform Analysis of Intrinsic Mode Functions. Track alignment irregularity of the railway line is the main horizontal vibration source to vehicle system, and there is correspondence between peaks of track alignment irregularity and response of car body horizontal vibration [3]. However, one of the underlying problems is that the current track horizontal irregularities may not be capable of identifying some track geometry conditions, which can cause undesirable vehicle response; conversely, many locations that do not meet the current standards may not cause poor vehicle performance. Track irregularities are usually measured in displacement by a track geometry measurement system that using bogie mounted noncontacting inertial sensors complemented by an optional image based subsystem. Furthermore, the waveband of track irregularities is from.5 to 7 m. The vibration acceleration of vehicle is normally measured at the vehicle floor, using servo accelerometer which presents a good sensitivity ( mv/g) and measure triaxial accelerations in a frequency range of 5 Hz. So that, the car body horizontal vibration acceleration in this paper is the vibration acceleration of the vehicle floor. Figure shows the original waveforms of track alignment irregularity and car body horizontal vibration acceleration which are sampled from the Beijing-Guangzhou Railway in China. This is the inspection result for traveling a straight line of ballasted track at a constant speed of 6 km/h. The peak number of track alignment irregularity waveform is relatively small, while car body horizontal vibration acceleration is large. There is poor one-to-one correlation which is an obvious difference from the results of theoretical model calculation.thereasonofthisisgreat,butthemainisimprecise Figure : Actual wave form of track alignment irregularity and car body horizontal acceleration. expressions of nonlinear characteristics of air spring and hydraulic shock absorber in the theoretical model. In Figure, decomposition results of the two signals using Empirical mode decomposition are plotted. As it is mentioned above, IMFs represent the intrinsic oscillation modes embedded in the signal. The IMF c covers the highest frequency band of the signal, and then the frequency components of the IMF c c6 become lower. Meanwhile, there are different amplitude characteristics of IMFs, which mean that the IMFs of track alignment irregularity and car body horizontal acceleration can have a variable amplitude and frequency. It is seen in Figure that the peak number of track alignment irregularity IMFs and car body horizontal acceleration IMFs are obviously different, while the number of car body horizontal vibration acceleration is larger. However, there is better correspondence between the positions of large values of track alignment irregularity IMFs and car body horizontal acceleration IMFs which means a high acceleration response mayindicatethatthereistrackgeometrydefect. 3.. Hilbert Spectra Analysis. The Hilbert spectra obtained by using HHT method is demonstrated in Figure 3. Itreflects well the time-frequency character, and from which the timefrequency distribution of signal is made up of many components with different frequencies and amplitudes that can be obviously analyzed. There are small amplitudes of short wavelength irregularities such as rail corrugation, and welded joint, while the amplitudes of long wavelength irregularities are relatively larger which reflect the waveform amplitude of track irregularities of the whole line in time domain.
4 4 Advances in Mechanical Engineering c (mm) c (mm) c 3 (mm) c 4 (mm) c 6 (mm) c 5 (mm) c c c c c (m s (m s 3 (m s 4 (m s 5 (m s ) ) ) ) ) c 6 (m s ) Figure : Empirical mode decomposition of track alignment irregularity and car body horizontal acceleration. Amplitude (mm) Spacial frequency (/m) Amplitude (m s ) Spacial frequency (/m) Figure 3: Hilbert time-frequency spectrum of track alignment irregularity and car body horizontal acceleration. Notice that the two spectrums show better correspondence among track alignment irregularity and car body horizontal acceleration, while there exist phase shift. Throughthetimedomainwaveformandenergyspectrum analysis above, we can conclude that there is good correspondence among track alignment irregularity and car body horizontal acceleration. Furthermore, calculation using dynamic simulation [] produces similar results. Therefore, it is a deterministic relationship between the IMFs of track alignment irregularity and car body horizontal acceleration, which means that the IMF of track geometry defect can cause a high IMF of acceleration response Regression Analysis of Intrinsic Mode Functions. The method of regression analysis is used to calculate the quantitative relationship between IMFs of track alignment irregularity and car body horizontal acceleration. At present, regress formula is based on linear regression theory, and it usually is regardless of vehicle travel speed which has significant effect on vibration of the vehicle in fact.
5 Advances in Mechanical Engineering 5 Table : Regression parameters of track alignment irregularity and car body horizontal acceleration. Wavelength/m Straight line Curve line A B A B e 6 6.4e e 6 6.4e e 6 6.7e 4.37e 6 6.e e e 4.55e 6 7.9e e 7 6.6e 4.3e 6 6.7e e 7 5.7e 4.8e e e 7 6.8e 4.8e 6 6.9e 4 Thus, the regress formula taking into account the speed factor is given as follows: a=a Q V x+b, (5) where a is car body horizontal acceleration, A and B are regression coefficients, V is vehicle traveling speed, x is the amplitude of track alignment irregularity, and Q is coefficient of curvature. The sample data is collected from one section of Beijing- Guangzhou Railway during the period from January, 8 to June 3, 9. The length of section is 35 km and the number of inspection is 36. Based on definition of the wavelength ranges of track irregularities, which the waveband from to 3.5 m is considered as short irregularity, the analysis wavelength uses wavebands m, 3.6 m,. m,. 3 m, 3. 4 m, and 4. 5 m. With the linear regression for the IMFs of track alignment irregularity and car body horizontal acceleration, the regression parameters are shown intable. 4. Conclusion In this paper, Hilbert-Huang Transform has been introduced for time-frequency analysis of horizontal vibration for vehicle-track system. Relationship between track alignment irregularity and car body horizontal acceleration is analyzed. Actual measured track alignment irregularity and car body horizontal acceleration are decomposed by empirical mode decomposition (EMD) to obtain intrinsic mode function (IMF). By comparing IMF waveform and Hilbert spectrum of track alignment irregularity and car body horizontal acceleration, there is the definitive correspondence of IMFs; and the section of track geometry defect can be identified from car body horizontal vibration acceleration. Regression analysis is taken for a measured sample of track inspection car on Beijing-Guangzhou line; the quantitative relationship between track alignment irregularity and car body horizontal acceleration is established with a wavelength between.5 m and 5 m. Acknowledgments This work was supported by the Key Subject Building Project of Shanghai Municipal Education Commission (J54), the Innovation Program of Shanghai Municipal Education Commission (4YZ37), the Natural Science Foundation of Shanghai (ZR43), and the Training Project of Youth College Teachers of Shanghai Municipal Education Commission (ZZGJD34). References []F.Lu,D.Kennedy,F.W.Williams,andJ.H.Lin, Symplectic analysis of vertical random vibration for coupled vehicle-track systems, Journal of Sound and Vibration, vol. 37, no. -, pp , 8. [] S. L. Lian and J. F. Huang, Study of the detrimental wavelengths of track irregularities for railways with passenger and freight traffic, JournaloftheChinaRailwaySociety,vol.6,no.,pp. 5, 4. [3] D.Li,A.Meddah,K.Hass,andS.Kalay, Relatingtrackgeometry to vehicle performance using neural network approach, JournalofRailandRapidTransit,vol.,no.3,pp.73 8, 6. [4] P.F.Weston,C.S.Ling,C.J.Goodman,C.Roberts,P.Li,and R. M. Goodall, Monitoring lateral track irregularity from inservice railway vehicles, Journal of Rail and Rapid Transit,vol.,no.,pp.89,7. [5] B. Luber, Railway track quality assessment method based on vehicle system identification, Elektrotechnik und Informationstechnik,vol.6,no.5,pp.8 85,9. [6] J.M.Gao,W.M.Zhai,andK.Y.Wang, Studyoilsensitivewavelengths of track irregularities in high-speed operation, Journal of the China Railway Society,vol.34,no.7,pp.83 88,. [7] N. E. Huang, Z. Shen, S. R. Long et al., The empirical mode decomposition and the Hubert spectrum for nonlinear and non-stationary time series analysis, Proceedings of the Royal Society A,vol.454,no.97,pp ,998. [8] N.E.Huang,Z.Shen,andS.R.Long, Anewviewofnonlinear water waves: the Hilbert spectrum, Annual Review of Fluid Mechanics, vol. 3, pp , 999. [9] Z.W.Li,S.L.Lian,andJ.L.Zhou, Time-frequencyanalysisof track irregularity based on improved empirical mode decomposition method, JournalofTongjiUniversity,vol.4,no.5,pp. 7 76,. []Z.WuandN.E.Huang, Ensembleempiricalmodedecomposition: a noise-assisted data analysis method, Advances in Adaptive Data Analysis,vol.,no.,pp. 4,9. [] H. C. Tsai, C. Y. Wang, and N. E. Huang, Fast inspection and identification techniques for track irregularities based on HHT analysis, Advances in Adaptive Data Analysis, vol. 4, no., pp. 6,. Conflict of Interests Alloftheauthorsdonothaveanydirectfinancialrelation with the commercial identities mentioned in this paper.
Advanced Signal Analysis Method to Evaluate the Laser Welding Quality
Advanced Signal Analysis Method to Evaluate the Laser Welding Quality Giuseppe D Angelo FIAT Research Center Process Research Dept. - 10043 Orbassano, Italy giuseppe.dangelo@crf.it 20 Novembre, 2010 General
More informationA VARIANT OF THE EMD METHOD FOR MULTI-SCALE DATA
Advances in Adaptive Data Analysis Vol. 1, No. 4 (2009) 483 516 c World Scientific Publishing Company A VARIANT OF THE EMD METHOD FOR MULTI-SCALE DATA THOMAS Y. HOU and MIKE P. YAN Applied and Computational
More informationA Flexible Method for Envelope Estimation in Empirical Mode Decomposition
A Flexible Method for Envelope Estimation in Empirical Mode Decomposition Yoshikazu Washizawa 1, Toshihisa Tanaka 2,1, Danilo P. Mandic 3, and Andrzej Cichocki 1 1 Brain Science Institute, RIKEN, 2-1,
More informationTime Domain and Frequency Domain Techniques For Multi Shaker Time Waveform Replication
Time Domain and Frequency Domain Techniques For Multi Shaker Time Waveform Replication Thomas Reilly Data Physics Corporation 1741 Technology Drive, Suite 260 San Jose, CA 95110 (408) 216-8440 This paper
More informationA New Wheel/Rail Spatially Dynamic Coupling Model and its Verification
Vehicle System Dynamics 2004, Vol. 41, No. 4, pp. 301 322 A New Wheel/Rail Spatially Dynamic Coupling Model and its Verification G. CHEN 1 AND W.M. ZHAI 2 SUMMARY Based on the theory of vehicle-track coupling
More informationTime series analysis of data from stress ECG
Communications to SIMAI Congress, ISSN 827-905, Vol. 3 (2009) DOI: 0.685/CSC09XXX Time series analysis of data from stress ECG Camillo Cammarota Dipartimento di Matematica La Sapienza Università di Roma,
More informationOpen Access A Facial Expression Recognition Algorithm Based on Local Binary Pattern and Empirical Mode Decomposition
Send Orders for Reprints to reprints@benthamscience.ae The Open Electrical & Electronic Engineering Journal, 2014, 8, 599-604 599 Open Access A Facial Expression Recognition Algorithm Based on Local Binary
More informationCombining Artificial Intelligence with Non-linear Data Processing Techniques for Forecasting Exchange Rate Time Series
Combining Artificial Intelligence with Non-linear Data Processing Techniques for Forecasting Exchange Rate Time Series Heng-Li Yang, 2 Han-Chou Lin, First Author Department of Management Information systems,
More informationSOFTWARE FOR GENERATION OF SPECTRUM COMPATIBLE TIME HISTORY
3 th World Conference on Earthquake Engineering Vancouver, B.C., Canada August -6, 24 Paper No. 296 SOFTWARE FOR GENERATION OF SPECTRUM COMPATIBLE TIME HISTORY ASHOK KUMAR SUMMARY One of the important
More informationResearch Article Forecasting Computer Products Sales by Integrating Ensemble Empirical Mode Decomposition and Extreme Learning Machine
Mathematical Problems in Engineering Volume 212, Article ID 83121, 15 pages doi:1.1155/212/83121 Research Article Forecasting Computer Products Sales by Integrating Ensemble Empirical Mode Decomposition
More informationNonlinear Signal Analysis: Time-Frequency Perspectives
TECHNICAL NOTES Nonlinear Signal Analysis: Time-Frequency Perspectives T. Kijewski-Correa 1 and A. Kareem 2 Abstract: Recently, there has been growing utilization of time-frequency transformations for
More informationA new approach for event study of private placement announcement effect: Evidence from China Yuling Zhao 1,a*
International Conference on Education, Management and Computing Technology (ICEMCT 21) A new approach for event study of private placement announcement effect: Evidence from China Yuling Zhao 1,a* 1 Experiment
More informationDYNAMIC RESPONSE OF VEHICLE-TRACK COUPLING SYSTEM WITH AN INSULATED RAIL JOINT
11 th International Conference on Vibration Problems Z. Dimitrovová et al. (eds.) Lisbon, Portugal, 9-12 September 2013 DYNAMIC RESPONSE OF VEHICLE-TRACK COUPLING SYSTEM WITH AN INSULATED RAIL JOINT Ilaria
More informationIntegration of PTC and Ride Quality Data. Presented by: Wabtec Railway Electronics, I-ETMS PTC Supplier. and
Integration of PTC and Ride Quality Data Presented by: Wabtec Railway Electronics, I-ETMS PTC Supplier and dfuzion, Inc., rmetrix Ride Performance Assessment System Supplier The FRA mandate to implement
More informationCHAPTER 5 PREDICTIVE MODELING STUDIES TO DETERMINE THE CONVEYING VELOCITY OF PARTS ON VIBRATORY FEEDER
93 CHAPTER 5 PREDICTIVE MODELING STUDIES TO DETERMINE THE CONVEYING VELOCITY OF PARTS ON VIBRATORY FEEDER 5.1 INTRODUCTION The development of an active trap based feeder for handling brakeliners was discussed
More informationThe Calculation of G rms
The Calculation of G rms QualMark Corp. Neill Doertenbach The metric of G rms is typically used to specify and compare the energy in repetitive shock vibration systems. However, the method of arriving
More informationINTERACTION BETWEEN MOVING VEHICLES AND RAILWAY TRACK AT HIGH SPEED
INTERACTION BETWEEN MOVING VEHICLES AND RAILWAY TRACK AT HIGH SPEED Prof.Dr.Ir. C. Esveld Professor of Railway Engineering TU Delft, The Netherlands Dr.Ir. A.W.M. Kok Associate Professor of Railway Engineering
More informationOPEN LOOP CONTROL OF FLEXIBLE BEAM PERIODIC MOTION VIA FREQUENCY RESPONSE ANALYSIS
ABCM Symposium Series in Mechatronics - Vol. 4 - pp.7-78 Copyright Proceedings 2 of COBEM by ABCM 29 Copyright c 29 by ABCM 2th International Congress of Mechanical Engineering November 5-2, 29, Gramado,
More informationA Sound Analysis and Synthesis System for Generating an Instrumental Piri Song
, pp.347-354 http://dx.doi.org/10.14257/ijmue.2014.9.8.32 A Sound Analysis and Synthesis System for Generating an Instrumental Piri Song Myeongsu Kang and Jong-Myon Kim School of Electrical Engineering,
More informationTime-frequency segmentation : statistical and local phase analysis
Time-frequency segmentation : statistical and local phase analysis Florian DADOUCHI 1, Cornel IOANA 1, Julien HUILLERY 2, Cédric GERVAISE 1,3, Jérôme I. MARS 1 1 GIPSA-Lab, University of Grenoble 2 Ampère
More informationRANDOM VIBRATION AN OVERVIEW by Barry Controls, Hopkinton, MA
RANDOM VIBRATION AN OVERVIEW by Barry Controls, Hopkinton, MA ABSTRACT Random vibration is becoming increasingly recognized as the most realistic method of simulating the dynamic environment of military
More information5 Signal Design for Bandlimited Channels
225 5 Signal Design for Bandlimited Channels So far, we have not imposed any bandwidth constraints on the transmitted passband signal, or equivalently, on the transmitted baseband signal s b (t) I[k]g
More informationQuarterly Progress and Status Report. Measuring inharmonicity through pitch extraction
Dept. for Speech, Music and Hearing Quarterly Progress and Status Report Measuring inharmonicity through pitch extraction Galembo, A. and Askenfelt, A. journal: STL-QPSR volume: 35 number: 1 year: 1994
More informationChapter 2 The Research on Fault Diagnosis of Building Electrical System Based on RBF Neural Network
Chapter 2 The Research on Fault Diagnosis of Building Electrical System Based on RBF Neural Network Qian Wu, Yahui Wang, Long Zhang and Li Shen Abstract Building electrical system fault diagnosis is the
More informationDispersion diagrams of a water-loaded cylindrical shell obtained from the structural and acoustic responses of the sensor array along the shell
Dispersion diagrams of a water-loaded cylindrical shell obtained from the structural and acoustic responses of the sensor array along the shell B.K. Jung ; J. Ryue ; C.S. Hong 3 ; W.B. Jeong ; K.K. Shin
More informationT = 1 f. Phase. Measure of relative position in time within a single period of a signal For a periodic signal f(t), phase is fractional part t p
Data Transmission Concepts and terminology Transmission terminology Transmission from transmitter to receiver goes over some transmission medium using electromagnetic waves Guided media. Waves are guided
More informationThe Hilbert Transform and Empirical Mode Decomposition as Tools for Data Analysis
The Hilbert Transform and Empirical Mode Decomposition as Tools for Data Analysis Susan Tolwinski First-Year RTG Project University of Arizona Program in Applied Mathematics Advisor: Professor Flaschka
More informationNRZ Bandwidth - HF Cutoff vs. SNR
Application Note: HFAN-09.0. Rev.2; 04/08 NRZ Bandwidth - HF Cutoff vs. SNR Functional Diagrams Pin Configurations appear at end of data sheet. Functional Diagrams continued at end of data sheet. UCSP
More informationFiltering method in wireless sensor network management based on EMD algorithm and multi scale wavelet analysis
Available online www.ocpr.com Journal of Chemical and Pharmaceutical Research, 2014, 6(6):912-918 Research Article ISSN : 0975-7384 CODEN(USA) : JCPRC5 Filtering method in wireless sensor network management
More informationWeighted Sliding Empirical Mode Decomposition and its Application to Neuromonitoring Data
Weighted Sliding Empirical Mode Decomposition and its Application to Neuromonitoring Data Dissertation zur Erlangung des Doktorgrades der Naturwissenschaften (Dr. rer. nat.) der Naturwissenschaftlichen
More informationFault Analysis in Software with the Data Interaction of Classes
, pp.189-196 http://dx.doi.org/10.14257/ijsia.2015.9.9.17 Fault Analysis in Software with the Data Interaction of Classes Yan Xiaobo 1 and Wang Yichen 2 1 Science & Technology on Reliability & Environmental
More informationThe Mergers & Acquisitions Market Trends and Stock Market of China
International Business and Management Vol. 8, No. 2, 204, pp. 2-9 DOI:0.3968/4587 ISSN 923-84X [Print] ISSN 923-8428 [Online] www.cscanada.net www.cscanada.org The Mergers & Acquisitions Market Trends
More informationAN INTRODUCTION TO RANDOM VIBRATION Revision B. By Tom Irvine Email: tomirvine@aol.com October 26, 2000
AN INTRODUCTION TO RANDOM VIBRATION Revision B By Tom Irvine Email: tomirvine@aol.com October 26, 2000 Introduction Random Forcing Function and Response Consider a turbulent airflow passing over an aircraft
More informationAdaptive noise reduction method for DSPI fringes based on bi-dimensional ensemble empirical mode decomposition
Adaptive noise reduction method for DSPI fringes based on bi-dimensional ensemble empirical mode decomposition Yi Zhou 1,* and Hongguang Li 1 State Key Laboratory of Mechanical System and Vibration, Shanghai
More informationAddis Ababa University Addis Ababa Institute of Technology (AAiT)
Addis Ababa University Addis Ababa Institute of Technology (AAiT) School of Mechanical & Industrial Engineering Railway Engineering Stream Effect of Track Stiffness Variation on the Dynamic Response of
More informationDETERMINATION OF INTERFACES IN SOIL LAYERS BY SOUND WAVE ANALYSIS WITH CONE PENETRATION TESTS
664 Journal of Marine Science and Technology, Vol. 8, No. 5, pp. 664-673 (2) DETERMINATION OF INTERFACES IN SOIL LAYERS BY SOUND WAVE ANALYSIS WITH CONE PENETRATION TESTS Huei-Wen Chang*, Tseng-Hung Chang*,
More informationTCOM 370 NOTES 99-4 BANDWIDTH, FREQUENCY RESPONSE, AND CAPACITY OF COMMUNICATION LINKS
TCOM 370 NOTES 99-4 BANDWIDTH, FREQUENCY RESPONSE, AND CAPACITY OF COMMUNICATION LINKS 1. Bandwidth: The bandwidth of a communication link, or in general any system, was loosely defined as the width of
More informationSound absorption and acoustic surface impedance
Sound absorption and acoustic surface impedance CHRISTER HEED SD2165 Stockholm October 2008 Marcus Wallenberg Laboratoriet för Ljud- och Vibrationsforskning Sound absorption and acoustic surface impedance
More informationSIGNAL PROCESSING & SIMULATION NEWSLETTER
1 of 10 1/25/2008 3:38 AM SIGNAL PROCESSING & SIMULATION NEWSLETTER Note: This is not a particularly interesting topic for anyone other than those who ar e involved in simulation. So if you have difficulty
More informationActive Vibration Isolation of an Unbalanced Machine Spindle
UCRL-CONF-206108 Active Vibration Isolation of an Unbalanced Machine Spindle D. J. Hopkins, P. Geraghty August 18, 2004 American Society of Precision Engineering Annual Conference Orlando, FL, United States
More informationPredictive Indicators for Effective Trading Strategies By John Ehlers
Predictive Indicators for Effective Trading Strategies By John Ehlers INTRODUCTION Technical traders understand that indicators need to smooth market data to be useful, and that smoothing introduces lag
More informationThe Combination Forecasting Model of Auto Sales Based on Seasonal Index and RBF Neural Network
, pp.67-76 http://dx.doi.org/10.14257/ijdta.2016.9.1.06 The Combination Forecasting Model of Auto Sales Based on Seasonal Index and RBF Neural Network Lihua Yang and Baolin Li* School of Economics and
More informationCHAPTER 3 MODAL ANALYSIS OF A PRINTED CIRCUIT BOARD
45 CHAPTER 3 MODAL ANALYSIS OF A PRINTED CIRCUIT BOARD 3.1 INTRODUCTION This chapter describes the methodology for performing the modal analysis of a printed circuit board used in a hand held electronic
More informationBandwidth-dependent transformation of noise data from frequency into time domain and vice versa
Topic Bandwidth-dependent transformation of noise data from frequency into time domain and vice versa Authors Peter Bormann (formerly GeoForschungsZentrum Potsdam, Telegrafenberg, D-14473 Potsdam, Germany),
More informationPRACTICAL GUIDE TO DATA SMOOTHING AND FILTERING
PRACTICAL GUIDE TO DATA SMOOTHING AND FILTERING Ton van den Bogert October 3, 996 Summary: This guide presents an overview of filtering methods and the software which is available in the HPL.. What is
More informationPOTENTIAL OF STATE-FEEDBACK CONTROL FOR MACHINE TOOLS DRIVES
POTENTIAL OF STATE-FEEDBACK CONTROL FOR MACHINE TOOLS DRIVES L. Novotny 1, P. Strakos 1, J. Vesely 1, A. Dietmair 2 1 Research Center of Manufacturing Technology, CTU in Prague, Czech Republic 2 SW, Universität
More informationAn Analysis of the Telecommunications Business in China by Linear Regression
An Analysis of the Telecommunications Business in China by Linear Regression Authors: Ajmal Khan h09ajmkh@du.se Yang Han v09yanha@du.se Graduate Thesis Supervisor: Dao Li dal@du.se C-level in Statistics,
More informationHow to compute Random acceleration, velocity, and displacement values from a breakpoint table.
How to compute Random acceleration, velocity, and displacement values from a breakpoint table. A random spectrum is defined as a set of frequency and amplitude breakpoints, like these: 0.050 Acceleration
More informationFrequency domain application of the Hot-Spot method for the fatigue assessment of the weld seams
Frequency domain application of the Hot-Spot method for the fatigue assessment of the weld seams Dr. Ing. Sauro Vannicola 1 sauro.vannicola@ch.abb.com Dr. Ing. Luigi De Mercato 2 luigi.de-mercato@ch.abb.com
More informationVibrations can have an adverse effect on the accuracy of the end effector of a
EGR 315 Design Project - 1 - Executive Summary Vibrations can have an adverse effect on the accuracy of the end effector of a multiple-link robot. The ability of the machine to move to precise points scattered
More informationTHE CASE OF USING A VEHICLE-TRACK INTERACTION PARAMETERS AND IMPACT TEST TO MONITOR OF THE TRAMWAY
THE CASE OF USING A VEHICLE-TRACK INTERACTION PARAMETERS AND IMPACT TEST TO MONITOR OF THE TRAMWAY Bartosz Czechyra, Bartosz Firlik and Tomasz Nowakowski Poznan University of Technology, Institute of Combustion
More informationBandwidth analysis of multimode fiber passive optical networks (PONs)
Optica Applicata, Vol. XXXIX, No. 2, 2009 Bandwidth analysis of multimode fiber passive optical networks (PONs) GRZEGORZ STEPNIAK *, LUKASZ MAKSYMIUK, JERZY SIUZDAK Institute of Telecommunications, Warsaw
More informationAdding Sinusoids of the Same Frequency. Additive Synthesis. Spectrum. Music 270a: Modulation
Adding Sinusoids of the Same Frequency Music 7a: Modulation Tamara Smyth, trsmyth@ucsd.edu Department of Music, University of California, San Diego (UCSD) February 9, 5 Recall, that adding sinusoids of
More informationWAVEFORM DICTIONARIES AS APPLIED TO THE AUSTRALIAN EXCHANGE RATE
Sunway Academic Journal 3, 87 98 (26) WAVEFORM DICTIONARIES AS APPLIED TO THE AUSTRALIAN EXCHANGE RATE SHIRLEY WONG a RAY ANDERSON Victoria University, Footscray Park Campus, Australia ABSTRACT This paper
More informationImproved Fault Detection by Appropriate Control of Signal
Improved Fault Detection by Appropriate Control of Signal Bandwidth of the TSA Eric Bechhoefer 1, and Xinghui Zhang 2 1 GPMS Inc., President, Cornwall, VT, 05753, USA eric@gpms-vt.com 2 Mechanical Engineering
More informationANALYZER BASICS WHAT IS AN FFT SPECTRUM ANALYZER? 2-1
WHAT IS AN FFT SPECTRUM ANALYZER? ANALYZER BASICS The SR760 FFT Spectrum Analyzer takes a time varying input signal, like you would see on an oscilloscope trace, and computes its frequency spectrum. Fourier's
More informationSignal to Noise Instrumental Excel Assignment
Signal to Noise Instrumental Excel Assignment Instrumental methods, as all techniques involved in physical measurements, are limited by both the precision and accuracy. The precision and accuracy of a
More informationWAVELET ANALYSIS BASED ULTRASONIC NONDESTRUCTIVE TESTING OF POLYMER BONDED EXPLOSIVE
WAVELET ANALYSIS BASED ULTRASONIC NONDESTRUCTIVE TESTING OF POLYMER BONDED EXPLOSIVE Weibin Zhang, Yong Tian, Zhanfeng Yang, Liling Wang Institute of Chemical Materials, China Academy of Engineering Physics,
More informationUltrasonic Detection Algorithm Research on the Damage Depth of Concrete after Fire Jiangtao Yu 1,a, Yuan Liu 1,b, Zhoudao Lu 1,c, Peng Zhao 2,d
Advanced Materials Research Vols. 368-373 (2012) pp 2229-2234 Online available since 2011/Oct/24 at www.scientific.net (2012) Trans Tech Publications, Switzerland doi:10.4028/www.scientific.net/amr.368-373.2229
More informationResearch Article Determination of Pavement Rehabilitation Activities through a Permutation Algorithm
Applied Mathematics Volume 2013, Article ID 252808, 5 pages http://dxdoiorg/101155/2013/252808 Research Article Determination of Pavement Rehabilitation Activities through a Permutation Algorithm Sangyum
More informationAbaqus Technology Brief. Automobile Roof Crush Analysis with Abaqus
Abaqus Technology Brief Automobile Roof Crush Analysis with Abaqus TB-06-RCA-1 Revised: April 2007. Summary The National Highway Traffic Safety Administration (NHTSA) mandates the use of certain test procedures
More informationFXA 2008. UNIT G484 Module 2 4.2.3 Simple Harmonic Oscillations 11. frequency of the applied = natural frequency of the
11 FORCED OSCILLATIONS AND RESONANCE POINTER INSTRUMENTS Analogue ammeter and voltmeters, have CRITICAL DAMPING so as to allow the needle pointer to reach its correct position on the scale after a single
More informationProbability and Random Variables. Generation of random variables (r.v.)
Probability and Random Variables Method for generating random variables with a specified probability distribution function. Gaussian And Markov Processes Characterization of Stationary Random Process Linearly
More informationVehicle-Bridge Interaction Dynamics
Vehicle-Bridge Interaction Dynamics With Applications to High-Speed Railways Y. B. Yang National Taiwan University, Taiwan J. D. Yau Tamkang University, Taiwan Y. S. Wu Sinotech Engineering Consultants,
More informationResearch on the UHF RFID Channel Coding Technology based on Simulink
Vol. 6, No. 7, 015 Research on the UHF RFID Channel Coding Technology based on Simulink Changzhi Wang Shanghai 0160, China Zhicai Shi* Shanghai 0160, China Dai Jian Shanghai 0160, China Li Meng Shanghai
More informationINTER-NOISE 2007 28-31 AUGUST 2007 ISTANBUL, TURKEY
INTER-NOISE 2007 28-31 AUGUST 2007 ISTANBU, TURKEY Force estimation using vibration data Ahmet Ali Uslu a, Kenan Y. Sanliturk b, etin Gül Istanbul Technical University Faculty of echanical Engineering
More informationComparison of the Response of a Simple Structure to Single Axis and Multiple Axis Random Vibration Inputs
Comparison of the Response of a Simple Structure to Single Axis and Multiple Axis Random Vibration Inputs Dan Gregory Sandia National Laboratories Albuquerque NM 87185 (505) 844-9743 Fernando Bitsie Sandia
More informationAdvanced Signal Processing and Digital Noise Reduction
Advanced Signal Processing and Digital Noise Reduction Saeed V. Vaseghi Queen's University of Belfast UK WILEY HTEUBNER A Partnership between John Wiley & Sons and B. G. Teubner Publishers Chichester New
More informationWireless Sensor Networks Coverage Optimization based on Improved AFSA Algorithm
, pp. 99-108 http://dx.doi.org/10.1457/ijfgcn.015.8.1.11 Wireless Sensor Networks Coverage Optimization based on Improved AFSA Algorithm Wang DaWei and Wang Changliang Zhejiang Industry Polytechnic College
More informationElectronic Communications Committee (ECC) within the European Conference of Postal and Telecommunications Administrations (CEPT)
Page 1 Electronic Communications Committee (ECC) within the European Conference of Postal and Telecommunications Administrations (CEPT) ECC RECOMMENDATION (06)01 Bandwidth measurements using FFT techniques
More informationAgilent Creating Multi-tone Signals With the N7509A Waveform Generation Toolbox. Application Note
Agilent Creating Multi-tone Signals With the N7509A Waveform Generation Toolbox Application Note Introduction Of all the signal engines in the N7509A, the most complex is the multi-tone engine. This application
More informationTDS5000B, TDS6000B, TDS/CSA7000B Series Acquisition Modes
TDS5000B, TDS6000B, TDS/CSA7000B Series Acquisition Modes Tektronix oscilloscopes provide several different acquisition modes. While this gives the user great flexibility and choice, each mode is optimized
More informationThe accurate calibration of all detectors is crucial for the subsequent data
Chapter 4 Calibration The accurate calibration of all detectors is crucial for the subsequent data analysis. The stability of the gain and offset for energy and time calibration of all detectors involved
More informationPeakVue Analysis for Antifriction Bearing Fault Detection
August 2011 PeakVue Analysis for Antifriction Bearing Fault Detection Peak values (PeakVue) are observed over sequential discrete time intervals, captured, and analyzed. The analyses are the (a) peak values
More informationSynchronization of sampling in distributed signal processing systems
Synchronization of sampling in distributed signal processing systems Károly Molnár, László Sujbert, Gábor Péceli Department of Measurement and Information Systems, Budapest University of Technology and
More informationVEHICLE POSTMORTEM AND DATA ANALYSIS OF A PASSENGER RAIL CAR COLLISION TEST
Proceedings of: JRC2002 The 2002 ASME/IEEE Joint Rail Conference April 23-25, 2002, Washington D.C. VEHICLE POSTMORTEM AND DATA ANALYSIS OF A PASSENGER RAIL CAR COLLISION TEST Robert A. MacNeill and Steven
More informationChapter 10. Key Ideas Correlation, Correlation Coefficient (r),
Chapter 0 Key Ideas Correlation, Correlation Coefficient (r), Section 0-: Overview We have already explored the basics of describing single variable data sets. However, when two quantitative variables
More informationVIBRATION DATA COLLECTION: A ROAD WORTH TRAVELING?
VIBRATION DATA COLLECTION: A ROAD WORTH TRAVELING? L.A.B. Equipment, Inc. January, 2006 Introduction There s been a great deal of interest and activity in the last decade or so focused on measurement of
More informationAnalysis of Wing Leading Edge Data. Upender K. Kaul Intelligent Systems Division NASA Ames Research Center Moffett Field, CA 94035
Analysis of Wing Leading Edge Data Upender K. Kaul Intelligent Systems Division NASA Ames Research Center Moffett Field, CA 94035 Abstract Some selected segments of the STS114 ascent and on-orbit data
More informationAP1 Oscillations. 1. Which of the following statements about a spring-block oscillator in simple harmonic motion about its equilibrium point is false?
1. Which of the following statements about a spring-block oscillator in simple harmonic motion about its equilibrium point is false? (A) The displacement is directly related to the acceleration. (B) The
More informationCORRECTION OF DYNAMIC WHEEL FORCES MEASURED ON ROAD SIMULATORS
Pages 1 to 35 CORRECTION OF DYNAMIC WHEEL FORCES MEASURED ON ROAD SIMULATORS Bohdan T. Kulakowski and Zhijie Wang Pennsylvania Transportation Institute The Pennsylvania State University University Park,
More informationExperiment #1, Analyze Data using Excel, Calculator and Graphs.
Physics 182 - Fall 2014 - Experiment #1 1 Experiment #1, Analyze Data using Excel, Calculator and Graphs. 1 Purpose (5 Points, Including Title. Points apply to your lab report.) Before we start measuring
More informationUnivariate and Multivariate Methods PEARSON. Addison Wesley
Time Series Analysis Univariate and Multivariate Methods SECOND EDITION William W. S. Wei Department of Statistics The Fox School of Business and Management Temple University PEARSON Addison Wesley Boston
More informationRail Roughness Monitoring in the Netherlands
Rail Roughness Monitoring in the Netherlands A.H.W.M. Kuijpers M+P consulting engineers, P.O. Box 2094, 5260 CB, Vught, The Netherlands Tel.: +31 73 6589050; Fax: +31 73 6589051 ArdKuijpers@mp.nl Summary
More informationBuilding Design for Advanced Technology Instruments Sensitive to Acoustical Noise
Building Design for Advanced Technology Instruments Sensitive to Acoustic Noise Michael Gendreau Colin Gordon & Associates Presentation Outline! High technology research and manufacturing instruments respond
More informationMobile field balancing reduces vibrations in energy and power plants. Published in VGB PowerTech 07/2012
Mobile field balancing reduces vibrations in energy and power plants Published in VGB PowerTech 07/2012 Dr. Edwin Becker PRÜFTECHNIK Condition Monitoring PRÜFTECHNIK Condition Monitoring GmbH 85737 Ismaning
More informationJitter Measurements in Serial Data Signals
Jitter Measurements in Serial Data Signals Michael Schnecker, Product Manager LeCroy Corporation Introduction The increasing speed of serial data transmission systems places greater importance on measuring
More informationAN1200.04. Application Note: FCC Regulations for ISM Band Devices: 902-928 MHz. FCC Regulations for ISM Band Devices: 902-928 MHz
AN1200.04 Application Note: FCC Regulations for ISM Band Devices: Copyright Semtech 2006 1 of 15 www.semtech.com 1 Table of Contents 1 Table of Contents...2 1.1 Index of Figures...2 1.2 Index of Tables...2
More informationResearch Article Effect Analysis of Intermittent Release Measures in Heavy Fog Weather with an Improved CA Model
Discrete Dynamics in ature and Society Volume 213, Article ID 812562, 7 pages http://dx.doi.org/1.1155/213/812562 Research Article Effect Analysis of Intermittent Release Measures in Heavy Fog Weather
More informationOverview of Methods for Measurement of Track Irregularities Important for Ground-Borne Vibration. Deliverable D2.5
RIVAS Railway Induced Vibration Abatement Solutions Collaborative project Overview of Methods for Measurement of Track Irregularities Important for Ground-Borne Vibration Deliverable D2.5 Submission date:
More informationApplication Note Noise Frequently Asked Questions
: What is? is a random signal inherent in all physical components. It directly limits the detection and processing of all information. The common form of noise is white Gaussian due to the many random
More informationGPR Polarization Simulation with 3D HO FDTD
Progress In Electromagnetics Research Symposium Proceedings, Xi an, China, March 6, 00 999 GPR Polarization Simulation with 3D HO FDTD Jing Li, Zhao-Fa Zeng,, Ling Huang, and Fengshan Liu College of Geoexploration
More informationAppendix 1: Time series analysis of peak-rate years and synchrony testing.
Appendix 1: Time series analysis of peak-rate years and synchrony testing. Overview The raw data are accessible at Figshare ( Time series of global resources, DOI 10.6084/m9.figshare.929619), sources are
More informationPUMPED Nd:YAG LASER. Last Revision: August 21, 2007
PUMPED Nd:YAG LASER Last Revision: August 21, 2007 QUESTION TO BE INVESTIGATED: How can an efficient atomic transition laser be constructed and characterized? INTRODUCTION: This lab exercise will allow
More informationSome Recent Research Results on the use of Acoustic Methods to Detect Water Leaks in Buried Plastic water Pipes
Some Recent Research Results on the use of Acoustic Methods to Detect Water Leaks in Buried Plastic water Pipes M.J. Brennan*, P.F. Joseph, J.M. Muggleton and Y. Gao Institute of Sound and Vibration Research,
More informationSBB Infrastructure, Measurement and Diagnostic Technology.
SBB Infrastructure, Measurement and Diagnostic Technology. Your partner for testing railway technology. Contents. Measurement and Diagnostic Technology 4 3 Infrastructure diagnostics 6 Running gear technology
More informationSummary Nonstationary Time Series Multitude of Representations Possibilities from Applied Computational Harmonic Analysis Tests of Stationarity
Nonstationary Time Series, Priestley s Evolutionary Spectra and Wavelets Guy Nason, School of Mathematics, University of Bristol Summary Nonstationary Time Series Multitude of Representations Possibilities
More informationChapter 8 - Power Density Spectrum
EE385 Class Notes 8/8/03 John Stensby Chapter 8 - Power Density Spectrum Let X(t) be a WSS random process. X(t) has an average power, given in watts, of E[X(t) ], a constant. his total average power is
More informationStatistical Analysis of Non-stationary Waves off the Savannah Coast, Georgia, USA
1 Statistical Analysis of Non-stationary Waves off the Savannah Coast, Xiufeng Yang School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, GA, USA, 30332 (xfyang@gatech.edu)
More informationNonlinear Iterative Partial Least Squares Method
Numerical Methods for Determining Principal Component Analysis Abstract Factors Béchu, S., Richard-Plouet, M., Fernandez, V., Walton, J., and Fairley, N. (2016) Developments in numerical treatments for
More information