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Volumn 50, Issue 2, 2011, Pages 287-302

Variance sensitive adaptive threshold-based PCA method for fault detection with experimental application

Author keywords

Adaptive threshold; Experimental application; Fault detection; Principal component analysis

Indexed keywords

ERRORS; FAULT DETECTION; MONITORING; PROCESS MONITORING; STATISTICAL PROCESS CONTROL;

EID: 79952448162     PISSN: 00190578     EISSN: None     Source Type: Journal    
DOI: 10.1016/j.isatra.2010.12.004     Document Type: Article
Times cited : (67)

References (60)
  • 5
    • 19044365246 scopus 로고    scopus 로고
    • Model-based fault-detection-status and applications
    • R. Isermann Model-based fault-detection-status and applications Annual Reviews in Control 29 2005 71 85
    • (2005) Annual Reviews in Control , vol.29 , pp. 71-85
    • Isermann, R.1
  • 6
    • 43249111240 scopus 로고    scopus 로고
    • Observer-based fault detection and moisture estimating in coal mills
    • DOI 10.1016/j.conengprac.2007.10.008, PII S0967066107001888
    • P.F. Odgaard, and B. Mataji Observer-based fault detection and moisture estimating in coal mills Control Engineering Practice 16 8 2008 909 921 (Pubitemid 351650256)
    • (2008) Control Engineering Practice , vol.16 , Issue.8 , pp. 909-921
    • Odgaard, P.F.1    Mataji, B.2
  • 7
    • 67349241660 scopus 로고    scopus 로고
    • Bispectrum of stator phase current for fault detection of induction motor
    • J. Treetrong, J.K. Sinha, F. Gub, and A. Ball Bispectrum of stator phase current for fault detection of induction motor ISA Transactions 48 2009 378 382
    • (2009) ISA Transactions , vol.48 , pp. 378-382
    • Treetrong, J.1    Sinha, J.K.2    Gub, F.3    Ball, A.4
  • 8
    • 77949261515 scopus 로고    scopus 로고
    • Detection of broken rotor bars in induction motors using nonlinear Kalman filters
    • F. Karami, J. Poshtan, and M. Poshtan Detection of broken rotor bars in induction motors using nonlinear Kalman filters ISA Transactions 49 2 2010 189 195
    • (2010) ISA Transactions , vol.49 , Issue.2 , pp. 189-195
    • Karami, F.1    Poshtan, J.2    Poshtan, M.3
  • 9
    • 72249120210 scopus 로고    scopus 로고
    • Adaptive backstepping fault-tolerant control for flexible spacecraft with unknown bounded disturbances and actuator failures
    • Y. Jiang, Q. Hu, and G. Ma Adaptive backstepping fault-tolerant control for flexible spacecraft with unknown bounded disturbances and actuator failures ISA Transactions 49 1 2010 57 69
    • (2010) ISA Transactions , vol.49 , Issue.1 , pp. 57-69
    • Jiang, Y.1    Hu, Q.2    Ma, G.3
  • 10
    • 77953128645 scopus 로고    scopus 로고
    • Gear fault detection using customized multiwavelet lifting schemes
    • J. Yuan, Z. He, and Y. Zi Gear fault detection using customized multiwavelet lifting schemes Mechanical Systems and Signal Processing 24 2010 1509 1528
    • (2010) Mechanical Systems and Signal Processing , vol.24 , pp. 1509-1528
    • Yuan, J.1    He, Z.2    Zi, Y.3
  • 11
    • 0037443770 scopus 로고    scopus 로고
    • A review of process fault detection and diagnosis part I: Quantitative model-based methods
    • DOI 10.1016/S0098-1354(02)00160-6, PII S0098135402001606
    • V.R. Venkatasubramanian, K.Y. Rengaswamy, and S.N. Kavuri A review of process fault detection and diagnosis, part I: quantitative modelbased methods Computers & Chemical Engineering 27 2003 293 311 (Pubitemid 36285962)
    • (2003) Computers and Chemical Engineering , vol.27 , Issue.3 , pp. 293-311
    • Venkatasubramanian, V.1    Rengaswamy, R.2    Yin, K.3    Kavuri, S.N.4
  • 12
    • 0037443771 scopus 로고    scopus 로고
    • A review of process fault detection and diagnosis part II: Qualitative models and search strategies
    • DOI 10.1016/S0098-1354(02)00161-8, PII S0098135402001618
    • V.R. Venkatasubramanian, K.Y. Rengaswamy, and S.N. Kavuri A review of process fault detection and diagnosis, part II: qualitative models and search strategies Computers & Chemical Engineering 2 2003 313 326 (Pubitemid 36285963)
    • (2003) Computers and Chemical Engineering , vol.27 , Issue.3 , pp. 313-326
    • Venkatasubramanian, V.1    Rengaswamy, R.2    Kavuri, S.N.3
  • 13
    • 0037443803 scopus 로고    scopus 로고
    • A review of process fault detection and diagnosis part III: Process history based methods
    • DOI 10.1016/S0098-1354(02)00162-X, PII S009813540200162X
    • V.R. Venkatasubramanian, K.Y. Rengaswamy, and S.N. Kavuri A review of process fault detection and diagnosis, part III: process history based methods Computers & Chemical Engineering 27 2003 327 346 (Pubitemid 36285964)
    • (2003) Computers and Chemical Engineering , vol.27 , Issue.3 , pp. 327-346
    • Venkatasubramanian, V.1    Rengaswamy, R.2    Kavuri, S.N.3    Yin, K.4
  • 14
    • 77957907006 scopus 로고    scopus 로고
    • Observer based on-line fault diagnosis of continuous systems modeled as Petri nets
    • K. Renganathan, and V. Bhaskar Observer based on-line fault diagnosis of continuous systems modeled as Petri nets ISA Transactions 49 4 2010 587 595
    • (2010) ISA Transactions , vol.49 , Issue.4 , pp. 587-595
    • Renganathan, K.1    Bhaskar, V.2
  • 15
    • 74249085740 scopus 로고    scopus 로고
    • Unknown input observer for state affine systems: A necessary and sufficient condition
    • H. Hammouri, and Z. Tmar Unknown input observer for state affine systems: a necessary and sufficient condition Automatica 46 2 2010 271 278
    • (2010) Automatica , vol.46 , Issue.2 , pp. 271-278
    • Hammouri, H.1    Tmar, Z.2
  • 16
    • 67651213849 scopus 로고    scopus 로고
    • Parity space-based fault detection for Markovian jump systems
    • M.Y. Zhong, Q. Ding, and P. Shi Parity space-based fault detection for Markovian jump systems International Journal of Systems Science 40 4 2009 421 428
    • (2009) International Journal of Systems Science , vol.40 , Issue.4 , pp. 421-428
    • Zhong, M.Y.1    Ding, Q.2    Shi, P.3
  • 17
    • 75449092436 scopus 로고    scopus 로고
    • Observer-based fault detection for networked control systems with network quality of services
    • C. Peng, D. Yue, and E.G. Tian Observer-based fault detection for networked control systems with network quality of services Applied Mathematical Modelling 34 6 2010 1653 1661
    • (2010) Applied Mathematical Modelling , vol.34 , Issue.6 , pp. 1653-1661
    • Peng, C.1    Yue, D.2    Tian, E.G.3
  • 18
    • 33751415312 scopus 로고    scopus 로고
    • Fault detection for lateral and vertical vehicle dynamics
    • DOI 10.1016/j.conengprac.2006.05.007, PII S0967066106000967
    • D. Fischer, M. Brner, J. Schmitt, and R. Isermann Fault detection for lateral and vertical vehicle dynamics Control Engineering Practice 15 3 2007 315 324 (Pubitemid 44817583)
    • (2007) Control Engineering Practice , vol.15 , Issue.3 SPEC. ISS. , pp. 315-324
    • Fischer, D.1    Borner, M.2    Schmitt, J.3    Isermann, R.4
  • 19
    • 70350116152 scopus 로고    scopus 로고
    • Two fault detection and isolation schemes for robot manipulators using soft computing techniques
    • T. Yüksel, and A. Sezgin Two fault detection and isolation schemes for robot manipulators using soft computing techniques Applied Soft Computing 10 2010 125 134
    • (2010) Applied Soft Computing , vol.10 , pp. 125-134
    • Yüksel, T.1    Sezgin, A.2
  • 20
    • 0031148456 scopus 로고    scopus 로고
    • Trends in the application of model-based fault detection and diagnosis of technical processes
    • DOI 10.1016/S0967-0661(97)00053-1, PII S0967066197000531
    • R. Isermann, and P. Ball Trends in the application of model-based fault detection and diagnosis of technical processes Control Engineering Practice 5 1997 709 719 (Pubitemid 27414363)
    • (1997) Control Engineering Practice , vol.5 , Issue.5 , pp. 709-719
    • Isermann, R.1    Balle, P.2
  • 21
    • 0034282185 scopus 로고    scopus 로고
    • Statistical and causal model-based approaches to fault detection and isolation
    • S. Yoon, and J.F. MacGregor Statistical and causal model-based approaches to fault detection and isolation AIChE Journal 46 9 2000 1813 1824
    • (2000) AIChE Journal , vol.46 , Issue.9 , pp. 1813-1824
    • Yoon, S.1    MacGregor, J.F.2
  • 22
    • 78651417659 scopus 로고    scopus 로고
    • Finding a trade-off between observability and economics in the fault detection of chemical processes
    • 10.1016/j.compchemeng.2010.04.006
    • M.B. Shams, H. Budman, and T. Duever Finding a trade-off between observability and economics in the fault detection of chemical processes Computers and Chemical Engineering 2010 10.1016/j.compchemeng.2010.04.006
    • (2010) Computers and Chemical Engineering
    • Shams, M.B.1    Budman, H.2    Duever, T.3
  • 23
    • 65449169571 scopus 로고    scopus 로고
    • The best approaches in the on-line monitoring of batch processes based on PCA: Does the modeling structure matter?
    • J. Camacho, J. Pico, and A. Ferrer The best approaches in the on-line monitoring of batch processes based on PCA: does the modeling structure matter? Analytica Chimica Acta 642 2009 59 68
    • (2009) Analytica Chimica Acta , vol.642 , pp. 59-68
    • Camacho, J.1    Pico, J.2    Ferrer, A.3
  • 25
    • 10244238854 scopus 로고    scopus 로고
    • Fault identification for process monitoring using kernel principal component analysis
    • DOI 10.1016/j.ces.2004.08.007, PII S0009250904006013
    • J.H. Cho, J.M. Lee, S.W. Choi, D. Lee, and I.B. Lee Fault identification for process monitoring using kernel principal component analysis Chemical Engineering Science 60 1 2005 279 288 (Pubitemid 39622624)
    • (2005) Chemical Engineering Science , vol.60 , Issue.1 , pp. 279-288
    • Cho, J.-H.1    Lee, J.-M.2    Choi, S.W.3    Lee, D.4    Lee, I.-B.5
  • 26
    • 76849101069 scopus 로고    scopus 로고
    • Semiconductor manufacturing process monitoring based on adaptive substatistical PCA
    • G. Zhiqiang, and S. Zhihuan Semiconductor manufacturing process monitoring based on adaptive substatistical PCA IEEE Transactions on Semiconductor Manufacturing 23 1 2010 99 108
    • (2010) IEEE Transactions on Semiconductor Manufacturing , vol.23 , Issue.1 , pp. 99-108
    • Zhiqiang, G.1    Zhihuan, S.2
  • 27
    • 0034651054 scopus 로고    scopus 로고
    • Statistical monitoring and diagnosis of automatic controlled processes using dynamic PCA
    • DOI 10.1080/002075400189338
    • F. Tsung Statistical monitoring and diagnosis of automatic controlled processes using dynamic PCA International Journal of Production Research 38 3 2000 625 637 (Pubitemid 35395468)
    • (2000) International Journal of Production Research , vol.38 , Issue.3 , pp. 625-637
    • Tsung, F.1
  • 28
    • 0036209691 scopus 로고    scopus 로고
    • Adaptive multiscale principal components analysis for online monitoring of wastewater treatment
    • J. Lennox, and C. Rosen Adaptive multi scale principal components analysis for online monitoring of wastewater treatment Water Science and Technology 45 45 2002 227 235 (Pubitemid 34256544)
    • (2002) Water Science and Technology , vol.45 , Issue.4-5 , pp. 227-235
    • Lennox, J.1    Rosen, C.2
  • 29
    • 79952452512 scopus 로고    scopus 로고
    • An ensemble approach to sensor fault detection and signal reconstruction for nuclear system control
    • P. Baraldi, A. Cammi, F. Mangili, and E. Zio An ensemble approach to sensor fault detection and signal reconstruction for nuclear system control Annals of Nuclear Energy 37 2010 778 790
    • (2010) Annals of Nuclear Energy , vol.37 , pp. 778-790
    • Baraldi, P.1    Cammi, A.2    Mangili, F.3    Zio, E.4
  • 30
    • 77649238075 scopus 로고    scopus 로고
    • A system-level fault detection and diagnosis strategy for HVAC systems involving sensor faults
    • S. Wang, Q. Zhou, and F. Xiao A system-level fault detection and diagnosis strategy for HVAC systems involving sensor faults Energy and Buildings 42 2010 477 490
    • (2010) Energy and Buildings , vol.42 , pp. 477-490
    • Wang, S.1    Zhou, Q.2    Xiao, F.3
  • 31
    • 33744524057 scopus 로고    scopus 로고
    • A diagnostic tool for online sensor health monitoring in air-conditioning systems
    • DOI 10.1016/j.autcon.2005.06.001, PII S092658050500066X
    • F. Xiao, S.W. Wang, and J.P. Zhang A diagnostic tool for online sensor health monitoring in air-conditioning systems Automation in Construction 15 2006 489 503 (Pubitemid 43817502)
    • (2006) Automation in Construction , vol.15 , Issue.4 , pp. 489-503
    • Xiao, F.1    Wang, S.2    Zhang, J.3
  • 32
    • 0344980778 scopus 로고    scopus 로고
    • Sensor validation and reconstruction for building central chilling systems based on principal component analysis
    • S.W. Wang, and Y.M. Chen Sensor validation and reconstruction for building central chilling systems based on principal component analysis Energy Conservation and Management 45 2004 673 695
    • (2004) Energy Conservation and Management , vol.45 , pp. 673-695
    • Wang, S.W.1    Chen, Y.M.2
  • 33
    • 67349194402 scopus 로고    scopus 로고
    • A fault detection technique for air-source heat pump water chiller/heaters
    • C. Youming, and L. Lili A fault detection technique for air-source heat pump water chiller/heaters Energy and Buildings 41 2009 881 887
    • (2009) Energy and Buildings , vol.41 , pp. 881-887
    • Youming, C.1    Lili, L.2
  • 34
    • 76049102279 scopus 로고    scopus 로고
    • Fault detection, diagnosis and data recovery for a real building heating/cooling billing system
    • C. Youming, and L. Lili Fault detection, diagnosis and data recovery for a real building heating/cooling billing system Energy Conversion and Management 51 2010 1015 1024
    • (2010) Energy Conversion and Management , vol.51 , pp. 1015-1024
    • Youming, C.1    Lili, L.2
  • 35
    • 0000325341 scopus 로고
    • On lines and planes of closest fit to systems of points in space
    • K. Pearson On lines and planes of closest fit to systems of points in space Philosophical Magazine Series B 2 1901 559 572
    • (1901) Philosophical Magazine Series B , vol.2 , pp. 559-572
    • Pearson, K.1
  • 36
    • 0002199780 scopus 로고
    • Multivariate quality control illustrated by the testing of sample bombsights
    • H. Hotelling Multivariate quality control illustrated by the testing of sample bombsights C. Eisenhart, M.W. Hastay, W.A. Wallis, Selected techniques of statistical analysis 1947 McGraw-Hill New York
    • (1947) Selected Techniques of Statistical Analysis
    • Hotelling, H.1
  • 38
    • 18844397336 scopus 로고    scopus 로고
    • Application of latent variable methods to process control and multivariate statistical process control in industry
    • DOI 10.1002/acs.859
    • T. Kourti Application of latent variable methods to process control and multivariate statistical process control in industry Journal of Adaptive Control and Signal Processing 19 2005 213 246 (Pubitemid 40680649)
    • (2005) International Journal of Adaptive Control and Signal Processing , vol.19 , Issue.4 , pp. 213-246
    • Kourti, T.1
  • 39
    • 77949491282 scopus 로고    scopus 로고
    • Multivariate and multiscale monitoring of large-size low-speed bearings using ensemble empirical mode decomposition method combined with principal component analysis
    • M. Zvokelj, S. Zupan, and I. Prebil Multivariate and multiscale monitoring of large-size low-speed bearings using ensemble empirical mode decomposition method combined with principal component analysis Mechanical Systems and Signal Processing 24 2010 1049 1067
    • (2010) Mechanical Systems and Signal Processing , vol.24 , pp. 1049-1067
    • Zvokelj, M.1    Zupan, S.2    Prebil, I.3
  • 40
    • 33750708301 scopus 로고    scopus 로고
    • Dynamic PCA-based MSPC charts for nucleation prediction in batch cooling crystallization processes
    • DOI 10.1016/j.chemolab.2006.04.016, PII S0169743906001183
    • K. Pllnen, A. Hkkinen, S. Reinikainen, J. Rantanen, and P. Minkkinen Dynamic PCA-based MSPC charts for nucleation prediction in batch cooling crystallization processes Chemometrics and Intelligent Laboratory Systems 84 2006 126 133 (Pubitemid 44708403)
    • (2006) Chemometrics and Intelligent Laboratory Systems , vol.84 , Issue.1-2 SPEC. ISS. , pp. 126-133
    • Pollanen, K.1    Hakkinen, A.2    Reinikainen, S.-P.3    Rantanen, J.4    Minkkinen, P.5
  • 41
    • 77951090351 scopus 로고    scopus 로고
    • On-line batch process monitoring using batch dynamic kernel principal component analysis
    • M. Jia, F. Chu, F. Wang, and W. Wang On-line batch process monitoring using batch dynamic kernel principal component analysis Chemometrics and Intelligent Laboratory Systems 101 2010 110 122
    • (2010) Chemometrics and Intelligent Laboratory Systems , vol.101 , pp. 110-122
    • Jia, M.1    Chu, F.2    Wang, F.3    Wang, W.4
  • 42
    • 0000736392 scopus 로고    scopus 로고
    • Analysis of multiblock and hierarchical PCA and PLS models
    • J.A. Westerhuis, T. Kourti, and J.F. MacGregor Analysis of multi-block and hierarchical PCA and PLS models Journal of Chemometrics 12 1998 301 321 (Pubitemid 128480027)
    • (1998) Journal of Chemometrics , vol.12 , Issue.5 , pp. 301-321
    • Westerhuis, J.A.1    Kourti, T.2    Macgregor, J.F.3
  • 44
    • 0035882158 scopus 로고    scopus 로고
    • A new multivariate statistical process monitoring method using principal component analysis
    • DOI 10.1016/S0098-1354(01)00683-4, PII S0098135401006834
    • M. Kano, S. Hasebe, I. Hashimoto, and H. Ohno A new multivariate statistical process monitoring method using principal component analysis Computers & Chemical Engineering 25 2001 1103 1113 (Pubitemid 32772290)
    • (2001) Computers and Chemical Engineering , vol.25 , Issue.7-8 , pp. 1103-1113
    • Kano, M.1    Hasebe, S.2    Hashimoto, I.3    Ohno, H.4
  • 47
    • 12344295457 scopus 로고    scopus 로고
    • Adaptive multiscale principal component analysis for on-line monitoring of a sequencing batch reactor
    • DOI 10.1016/j.jbiotec.2004.10.012, PII S0168165604005231
    • D.S. Lee, J.M. Park, and A.P. Vanrolleghem Adaptive multiscale principal component analysis for on-line monitoring of a sequencing batch reactor Journal of Biotechnology 116 2 2005 195 210 (Pubitemid 40128569)
    • (2005) Journal of Biotechnology , vol.116 , Issue.2 , pp. 195-210
    • Lee, D.S.1    Park, J.M.2    Vanrolleghem, P.A.3
  • 48
    • 0034295917 scopus 로고    scopus 로고
    • Fault detection and diagnosis of permanent-magnet DC motor based on parameter estimation and neural network
    • X.Q. Liu, and H.Y. Zhang Fault detection and diagnosis of permanent-magnet DC motor based on parameter estimation and neural network IEEE Transactions on Industrial Electronics 47 5 2000 1021 1030
    • (2000) IEEE Transactions on Industrial Electronics , vol.47 , Issue.5 , pp. 1021-1030
    • Liu, X.Q.1    Zhang, H.Y.2
  • 50
    • 56049083538 scopus 로고    scopus 로고
    • An isolation enhanced PCA method with expert-based multivariate decoupling for sensor FDD in air-conditioning systems
    • F. Xiao, S. Wang, X. Xu, and G. Ge An isolation enhanced PCA method with expert-based multivariate decoupling for sensor FDD in air-conditioning systems Applied Thermal Engineering 29 2009 712 722
    • (2009) Applied Thermal Engineering , vol.29 , pp. 712-722
    • Xiao, F.1    Wang, S.2    Xu, X.3    Ge, G.4
  • 51
    • 0034621334 scopus 로고    scopus 로고
    • Fault detection in industrial processes using canonical variate analysis and dynamic principal component analysis
    • DOI 10.1016/S0169-7439(00)00058-7, PII S0169743900000587
    • E.L. Russell, L.H. Chiang, and D.B. Richard Fault detection in industrial processes using canonical variant analysis and dynamic principal component analysis Chemometrics and Intelligent Laboratory Systems 21 1 2000 81 93 (Pubitemid 30251932)
    • (2000) Chemometrics and Intelligent Laboratory Systems , vol.51 , Issue.1 , pp. 81-93
    • Russell, E.L.1    Chiang, L.H.2    Braatz, R.D.3
  • 52
    • 40449094552 scopus 로고    scopus 로고
    • From large chemical plant data to fault diagnosis integrated to decentralized fault-tolerant control: Pulp mill process application
    • DOI 10.1021/ie071064m
    • D. Zumoffen, and M. Basualdo From large chemical plant data to fault diagnosis integrated to decentralized fault tolerant control: pulp mill process application Industrial & Engineering Chemistry Research 47 2007 1201 1220 (Pubitemid 351345907)
    • (2008) Industrial and Engineering Chemistry Research , vol.47 , Issue.4 , pp. 1201-1220
    • Zumoffen, D.1    Basualdo, M.2
  • 53
    • 52649131888 scopus 로고    scopus 로고
    • Cross-validation methods in principal component analysis: A comparison
    • G. Diana, and C. Tommasi Cross-validation methods in principal component analysis: a comparison Statistical Methods & Applications 11 2002 71 82
    • (2002) Statistical Methods & Applications , vol.11 , pp. 71-82
    • Diana, G.1    Tommasi, C.2
  • 54
    • 33750523425 scopus 로고    scopus 로고
    • Application of a data-driven monitoring technique to diagnose air leaks in an automotive diesel engine: A case study
    • DOI 10.1016/j.ymssp.2005.11.005, PII S0888327005002141
    • D. Antory Application of a data-driven monitoring technique to diagnose air leaks in an automotive diesel engine: a case study Mechanical Systems and Signal Processing 21 2007 795 808 (Pubitemid 44667407)
    • (2007) Mechanical Systems and Signal Processing , vol.21 , Issue.2 , pp. 795-808
    • Antory, D.1
  • 55
    • 0018503842 scopus 로고
    • Control procedures for residuals associated with principal component analysis
    • J.E. Jackson, and G.S. Mudholkar Control procedures for residuals associated with principal component analysis Technometrics 21 3 1979 341 349 (Pubitemid 9472204)
    • (1979) Technometrics , vol.21 , Issue.3 , pp. 341-349
    • Jackson J.Edward1    Mudholkar Govind, S.2
  • 57
    • 21844450086 scopus 로고    scopus 로고
    • Xian Jiaotong University Press China
    • R. Wang Statistical theory 2003 Xian Jiaotong University Press China
    • (2003) Statistical Theory
    • Wang, R.1
  • 58
    • 77955659017 scopus 로고    scopus 로고
    • Second-order sliding mode control with experimental application
    • . Eker Second-order sliding mode control with experimental application ISA Transactions 49 2010 394 405
    • (2010) ISA Transactions , vol.49 , pp. 394-405
    • Eker, .1
  • 59
    • 0033990574 scopus 로고    scopus 로고
    • A parallel neuro-controller for DC motors containing nonlinear friction
    • J.O. Jang, and G.J. Jeon A parallel neuro-controller for DC motors containing nonlinear friction Neurocomputing 30 2000 233 248
    • (2000) Neurocomputing , vol.30 , pp. 233-248
    • Jang, J.O.1    Jeon, G.J.2


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