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Activity Number:
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102
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Type:
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Contributed
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Date/Time:
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Monday, August 4, 2008 : 8:30 AM to 10:20 AM
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Sponsor:
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Section on Quality and Productivity
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| Abstract - #301738 |
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Title:
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CUSUM Charts with Censored Ordinal Categorical Data
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Author(s):
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Denisa A. Olteanu*+
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Companies:
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Virginia Polytechnic Institute and State University
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Address:
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615 Washington ST SE, Apt 3, Blacksburg, VA, 24060,
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Keywords:
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Ordinal Categorical ; Censored ; quality control ; CUSUM
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Abstract:
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In many quality control applications the data collected fall into a finite set of ordered categories. In some cases the analyst only knows an upper or lower limit for the actual data point. This paper uses a latent continuous random variable that takes values in the intervals determined by the ordered categories to model the process. The proposed procedure uses samples of n data points and models the counts of data points falling in any specific interval by a multinomial distribution. This paper develops a cumulative sum (CUSUM) control chart based on the multinomial distribution to detect changes in the latent distribution. This paper illustrates the proposed procedure to one of Becton Dickinson's, the medical devices manufacturer, processes.
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