• Title/Summary/Keyword: statistical quality control

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Statistical Process Analysis of Medical Incidents

  • Suzuki, Norio;Kirihara, Sojiro;Ootaki, Atsushi;Kitajima, Masanori;Nakamura, Shinobu
    • International Journal of Quality Innovation
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    • v.2 no.2
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    • pp.127-135
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    • 2001
  • Personnel engaged in the medical field have implemented continual improvement by team activities in an effort to construct a system that reduces the risks involved in medical care. Knowledge in total quality management (TQM), especially statistical quality control (SQC) developed for industry, seems to be applicable to medical care. This paper describes the application of SQC to continual improvement in medical care.

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Copula modelling for multivariate statistical process control: a review

  • Busababodhin, Piyapatr;Amphanthong, Pimpan
    • Communications for Statistical Applications and Methods
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    • v.23 no.6
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    • pp.497-515
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    • 2016
  • Modern processes often monitor more than one quality characteristic that are referred to as multivariate statistical process control (MSPC) procedures. The MSPC is the most rapidly developing sector of statistical process control and increases interest in the simultaneous inspection of several related quality characteristics. Most multivariate detection procedures based on a multi-normality assumptions are independent, but there are many processes that assume non-normality and correlation. Many multivariate control charts have a lack of related joint distribution. Copulas are tool to construct multivariate modelling and formalizing the dependence structure between random variables and applied in several fields. From copula literature review, there are a few copula to apply in MSPC that have multivariate control charts, and represent a successful tool to identify an out-of-control process. This paper presents various types of copulas modelling for the multivariate control chart. The performance measures of the control chart are the average run length (ARL) and the average number of observations to signal (ANOS). Furthermore, a Monte Carlo simulation is shown when the observations were from an exponential distribution.

Statistical design of Shewhart control chart with runs rules (런 규칙이 혼합된 슈와르트 관리도의 통계적 설계)

  • Kim, Young-Bok;Hong, Jung-Sik;Lie, Chang-Hoon
    • Journal of Korean Society for Quality Management
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    • v.36 no.3
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    • pp.34-44
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    • 2008
  • This research proposes a design method based on the statistical characteristics of the Shewhart control chart incorporated with 2 of 2 and 2 of 3 runs rules respectively. A Markov chain approach is employed in order to calculate the in-control and out-of-control average run lengths(ARL). Two different control limit coefficients for the Shewhart scheme and the runs rule scheme are derived simultaneously to minimize the out-of-control average run length subject to the reasonable in-control average run length. Numerical examples show that the statistical performance of the hybrid control scheme are superior to that of the original Shewhart control chart.

An Economic-Statistical Design of Moving Average Control Charts

  • Yu, Fong-Jung;Chin, Hsiang;Huang, Hsiao Wei
    • International Journal of Quality Innovation
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    • v.7 no.3
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    • pp.107-115
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    • 2006
  • Control charts are important tools of statistical quality control. In 1956, Duncan first proposed the economic design of $\bar{x}-control$ charts to control normal process means and insure that the economic design control chart actually has a lower cost, compared with a Shewhart control chart. An moving average (MA) control chart is more effective than a Shewhart control chart in detecting small process shifts and is considered by some to be simpler to implement than the CUSUM. An economic design of MA control chart has also been proposed in 2005. The weaknesses to only the economic design are poor statistics because it dose not consider type I or type II errors and average time to signal when selecting design parameters for control chart. This paper provides a construction of an economic-statistical model to determine the optimal parameters of an MA control chart to improve economic design. A numerical example is employed to demonstrate the model's working and its sensitivity analysis is also provided.

Applications of python package for statistical engineering (통계공학을 위한 Python 패키지 응용)

  • Jang, Dae-Heung
    • The Korean Journal of Applied Statistics
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    • v.34 no.4
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    • pp.633-658
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    • 2021
  • Statistical engineering contains design of experiments, quality control/ management, and reliability engineering. Python is a free software environment for machine learning, data science, and graphics. Python package has many functions and libraries for statistical engineering. We can use Python package as a useful tool for statistical engineering. This paper shows applications of Python package for statistical engineering and suggests a total Python projects for statistical engineering.

Implementation of Statistical Process Control Software developed by Object Oriented Tools (객체지향언어를 이용한 통계적 공정관리 소프트웨어의 구현)

  • 신봉섭
    • Journal of Korean Society for Quality Management
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    • v.27 no.4
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    • pp.256-265
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    • 1999
  • In this paper, we Present the implementation of statistical process control software by using XLISP-STAT which is a kind of object oriented language under Windows environment. This software can be used to generate the graphic objects for various control charts, histogram and plots using the full-down menu system. This software can also be used to calculate control limits, process capability indices and test procedures for normality.

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The CV Control Chart

  • Kang, Chang-W;Lee, Man-S;Hawkins, Douglas M.
    • Proceedings of the Korean Society for Quality Management Conference
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    • 2006.11a
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    • pp.211-216
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    • 2006
  • Monitoring variability is a vital part of modem statistical process control. The conventional Shewhart Rand S charts address the setting where the in-control process readings have a constant variance. In some settings, however, it is the coefficient of variation, rather than the variance, that should be constant. This paper develops a chart, equivalent to the S chart, for monitoring the coefficient of variation using rational groups of observations.

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Comparison of the Unbiasing Constants in Connection with Variable Control Charts (계량형 관리도와 관련된 불편화 상수의 비교)

  • Ahn, Haeil
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.37 no.4
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    • pp.134-144
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    • 2014
  • With the advent of lean-six sigma era, an extensive use of analytic tools such as control charts is required in the field of manufacturing. In relation to statistical quality control (SQC) or process control (SPC), the Korean standards have undergone a meaningful change. In this study, the theoretic backgrounds for evaluating the control limits in connection with the variable control charts are examined in view of better understanding the related constants and coefficients. This paper is intended to help the quality control practitioners understand the mathematical backgrounds by comparing related quality control constants and also to encourage them to make use of and to take the advantage of the variable control charts which are very useful for implementing the concept of lean-six sigma in many industrial sites.

A Statistical Study on the Quality Control of Environment-friendly Agricultural Products in School Meal (학교급식의 친환경 농산물 품질관리에 관한 통계적 연구)

  • Yim, Dong-Bin
    • Journal of Integrative Natural Science
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    • v.4 no.2
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    • pp.137-142
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    • 2011
  • This study was performed in order to examine the statistical quality control of environmentally-friendly agricultural products(EF AP) and they using school meal service whether to be influences to EF AP recognition of it's parents. As a results of above research, we can make a conclusion the elementary and middle school meal service using the EF AP leads to the recognition change to parents affirmatively in Jeollanam-do.

QUALITY IMPROVEMENT FOR EXPERT BASE WITH CONTROL CHART TECHNIQUES

  • Liu Yumin;Xu Jichao
    • Proceedings of the Korean Society for Quality Management Conference
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    • 1998.11a
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    • pp.189-197
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    • 1998
  • The axiomatic hypothesis of the objective distribution of evaluation subjection will be proposed in this paper. On the basis of that, set up the random response model of the expert evaluation system and the quality control principle of expert base. Under this principle, develop the statistical quality control theory of expert base, further; provide the quality improvement technology for expert base.

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