Results 221 to 230 of about 30,909 (252)

Advanced Monitoring of Complex Autocorrelated Processes

IFAC Proceedings Volumes, 2004
Abstract In this work, the integration of ARMA filters into the multivariate statistical process control (MSPC) framework is presented to improve the monitoring of large-scale industrial processes. As demonstrated in the paper, such filters can remove auto-correlation from the monitored variables to avoid the production of false alarms.
Uwe Kruger, Yiqi Zhou, George W. Irwin
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Statistical Process Control of Stationary Autocorrelated Process

2010 International Conference on Intelligent Computation Technology and Automation, 2010
When control charts are used to monitor a process, a standard assumption is that observations from the process at different times are independent random variables. However, the independence assumption is often not reasonable for processes of interest in many applications because the dynamics of the process product autocorrelation in the process ...
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Batch processing in autocorrelation function analysis

Review of Scientific Instruments, 1975
The effect of batch processing on signal recovery statistics, in the case of an exponential autocorrelation function, is investigated. It is shown that the loss of information and accuracy is small provided the interval between batches is less than the coherence time of the signal.
A. Knox, T. A. King
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Autocorrelation processing in convergence zones

The Journal of the Acoustical Society of America, 1985
The sensitivity of first and second convergence zone arrivals to small changes in source location has been examined using two simple analytic models and the NUSC Generic Sonar Model (GSM). All three models indicate that the number of arrivals and the interpath time differences vary greatly with the location of the source in a convergence zone.
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Analysis of Autocorrelations in Dynamic Processes

Technometrics, 1994
Data collected by process information and control systems are almost always correlated due to process dynamics combined with short sampling times. The traditional time series approach for dealing with autocorrelated data has been to model the autocorrelation. This modeling effort is substantially more difficult than simply treating the time series as a
Nien Fan Zhang, James F. Pollard
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MONITORING AUTOCORRELATED PROCESSES WITH WAVELETS

International Journal of Reliability, Quality and Safety Engineering, 2010
This paper develops a wavelet control chart for monitoring autocorrelated processes. The procedure uses the discrete wavelet transform of the original series, and traditional control charts are applied to the stream of wavelet coefficients. Unlike other control charts for monitoring autocorrelated processes found in the literature, the wavelet control ...
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SPC Procedures for Monitoring Autocorrelated Processes

Quality Technology & Quantitative Management, 2007
AbstractThe inference about the statistical properties of quality control methodologies is based on the assumptions of normality and independence. In real industrial environments though process data is often correlated or exhibits some serial dependence affecting the efficiency of Statistical Process Control (SPC) methodologies.
S. Psarakis, G. E. A. Papaleonida
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DISTRIBUTION OF RESIDUAL AUTOCORRELATIONS IN NONSTATIONARY AUTOREGRESSIVE PROCESSES

Journal of Time Series Analysis, 1996
Abstract.The residual autocorrelations in nonstationary autoregressive processes with autoregressive characteristic roots on the unit circle are considered. Limiting distributions of the residual autocovariances and the residual autocorrelations are shown to be the same as the limiting distributions when parameters are estimated with all roots on the ...
Shin, Dong Wan, Lee, Jong Hyup
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Control charts for autocorrelated processes

2001
Ο Στατιστικός Έλεγχος Διεργασιών ασχολείται κυρίως με την εφαρμογή διαγραμμάτων ελέγχου. Τα διαγράμματα ελέγχου χρησιμοποιούνται για την παρακολούθηση της ποιότητας και της σταθερότητας των διεργασιών. Η μεθοδολογία του ελέγχου ποιότητας κάνει υποθέσεις για τη δομή των δεδομένων. Μία από αυτές είναι η υπόθεση της ανεξαρτησίας.
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Phase I Analysis for Autocorrelated Processes

Journal of Quality Technology, 2000
There has been recent interest in statistical process control for autocorrelated processes. Previous researchers have not distinguished models of autocorrelated common-cause variation from the actu...
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