The Effect of Median Based Estimators on CUSUM Chart

Cumulative Sum (CUSUM) chart has been used extensively to monitor mean shifts.It is highly sought after by practitioners and researchers in many areas of quality control due to its sensitivity in detecting small to moderate shifts. Normality assumption governs its ability to monitor the process mean...

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Main Authors: Abdul Rahman, Ayu, Syed Yahaya, Sharipah Soaad, Atta, Abdu Mohammed Ali
Format: Article
Language:English
Published: Universiti Teknikal Malaysia Melaka 2018
Subjects:
Online Access:https://repo.uum.edu.my/id/eprint/24403/1/JTEC%2010%201-10%20%202018%2049%2052.pdf
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author Abdul Rahman, Ayu
Syed Yahaya, Sharipah Soaad
Atta, Abdu Mohammed Ali
author_facet Abdul Rahman, Ayu
Syed Yahaya, Sharipah Soaad
Atta, Abdu Mohammed Ali
author_sort Abdul Rahman, Ayu
collection UUM
description Cumulative Sum (CUSUM) chart has been used extensively to monitor mean shifts.It is highly sought after by practitioners and researchers in many areas of quality control due to its sensitivity in detecting small to moderate shifts. Normality assumption governs its ability to monitor the process mean. When the assumption is violated, CUSUM chart typically loses its practical use. As normality is hard to achieve in practice, the usual CUSUM chart is often substituted with robust charts.This is to provide more accurate results under slight deviation from normality. Thus, in this paper, we investigate the impact of using robust location estimators, namely, median and Hodges-Lehmann on CUSUM performance. By pairing the location estimators with a robust scale estimator known as median absolute deviation about the median (MADn), a duo median based CUSUM chart is attained.The performances of both charts are studied under normality and contaminated normal distribution and evaluated using the average run length (ARL). While demonstrating an average power to detect the out-of-control situations, the in-control performances of both charts remain unaffected in the presence of outliers. This could very well be advantageous when the proposed charts are tested on a real data set in the future. A case in point is when the statistical tool is used to monitor changes in clinical variables for the health care outcomes.By minimising the false positives, a sound judgement can be made for any clinical decision.
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spelling uum-244032018-07-10T02:09:47Z https://repo.uum.edu.my/id/eprint/24403/ The Effect of Median Based Estimators on CUSUM Chart Abdul Rahman, Ayu Syed Yahaya, Sharipah Soaad Atta, Abdu Mohammed Ali QA Mathematics Cumulative Sum (CUSUM) chart has been used extensively to monitor mean shifts.It is highly sought after by practitioners and researchers in many areas of quality control due to its sensitivity in detecting small to moderate shifts. Normality assumption governs its ability to monitor the process mean. When the assumption is violated, CUSUM chart typically loses its practical use. As normality is hard to achieve in practice, the usual CUSUM chart is often substituted with robust charts.This is to provide more accurate results under slight deviation from normality. Thus, in this paper, we investigate the impact of using robust location estimators, namely, median and Hodges-Lehmann on CUSUM performance. By pairing the location estimators with a robust scale estimator known as median absolute deviation about the median (MADn), a duo median based CUSUM chart is attained.The performances of both charts are studied under normality and contaminated normal distribution and evaluated using the average run length (ARL). While demonstrating an average power to detect the out-of-control situations, the in-control performances of both charts remain unaffected in the presence of outliers. This could very well be advantageous when the proposed charts are tested on a real data set in the future. A case in point is when the statistical tool is used to monitor changes in clinical variables for the health care outcomes.By minimising the false positives, a sound judgement can be made for any clinical decision. Universiti Teknikal Malaysia Melaka 2018 Article PeerReviewed application/pdf en cc_by https://repo.uum.edu.my/id/eprint/24403/1/JTEC%2010%201-10%20%202018%2049%2052.pdf Abdul Rahman, Ayu and Syed Yahaya, Sharipah Soaad and Atta, Abdu Mohammed Ali (2018) The Effect of Median Based Estimators on CUSUM Chart. Journal of Telecommunication, Electronic and Computer Engineering, 10 (1-10). pp. 49-52. ISSN 2180-1843 http://journal.utem.edu.my/index.php/jtec/article/view/3790
spellingShingle QA Mathematics
Abdul Rahman, Ayu
Syed Yahaya, Sharipah Soaad
Atta, Abdu Mohammed Ali
The Effect of Median Based Estimators on CUSUM Chart
title The Effect of Median Based Estimators on CUSUM Chart
title_full The Effect of Median Based Estimators on CUSUM Chart
title_fullStr The Effect of Median Based Estimators on CUSUM Chart
title_full_unstemmed The Effect of Median Based Estimators on CUSUM Chart
title_short The Effect of Median Based Estimators on CUSUM Chart
title_sort effect of median based estimators on cusum chart
topic QA Mathematics
url https://repo.uum.edu.my/id/eprint/24403/1/JTEC%2010%201-10%20%202018%2049%2052.pdf
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