• 산업경영시스템학회지
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• 제21권45호
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• pp.265-277
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• 1998

The control chart has been used widely and importantly as a tool for statistical process control(SPC). Most companies are concerned with improving the quality and the productivity as well as reducing the cost, especially in today's highly competitive environment. Though SPC is known as a technique for consistent quality, it is not used properly due to lack of knowledge about it. It is required to develop a support system for control chart selection and interpretation that can be utilized by non-specialist without hard training or experiences. The support system was developed by applying the expert system tool to popular control charts. Though some researches on this area has been performed, the implemented results expose many problems in field applications due to the unsatisfactory explanation of the selected control chart and limited knowledge base for resolving the problems. This thesis presented an expert system for control chart as solution for these problems. The expert system for the control chart selection and interpretation is developed by using Turbo C and EXSYS which is an expert system development tool.

• International Journal of Control, Automation, and Systems
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• 제4권3호
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• pp.372-381
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• 2006

The purpose of this study was to develop a process management system to manage ingot fabrication and improve ingot quality. The ingot is the first manufactured material of wafers. Trace parameters were collected on-line but measurement parameters were measured by sampling inspection. The quality parameters were applied to evaluate the quality. Therefore, preprocessing was necessary to extract useful information from the quality data. First, statistical methods were used for data generation. Then, modeling was performed, using the generated data, to improve the performance of the models. The function of the models is to predict the quality corresponding to control parameters. Secondly, rule extraction was performed to find the relation between the production quality and control conditions. The extracted rules can give important information concerning how to handle the process correctly. The dynamic polynomial neural network (DPNN) and decision tree were applied for data modeling and rule extraction, respectively, from the ingot fabrication data.

• 한국의상디자인학회지
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• 제25권3호
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• pp.143-155
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• 2023

This study examined the effect of beauty service location characteristics and service quality on customer satisfaction and revisit intention, and analyzed the gender control effect of location characteristics and service quality in the relationship with customer satisfaction. The Statistical Package for the Social Sciences (SPSS) was employed and analysis was conducted to investigate how location characteristics and service quality in beauty service encounters effects customer satisfaction. The results of this study are as follows. First, visibility, which is a location characteristic, was found to have a significant effect on customer satisfaction. Second, professionalism and convenience, which are service qualities, were found to have a significant impact on customer satisfaction. Third, customer satisfaction was found to have a significant effect on the intention to revisit. Fourth, as a result of analyzing the gender control effect in the relationship between location characteristics and service quality with customer satisfaction, the gender control effect was found in all factors.

• 응용통계연구
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• 제35권6호
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• pp.725-737
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• 2022

통계적 공정 모니터링에서 관리 상태일 때 품질 특성치의 모수값은 하나의 값으로 지정하는 경우가 대부분이다. 그러나 관리 상태로부터 공정 모수의 작은 변화는 실제적으로 크게 중요하지 않은 경우, 품질 특성치의 모수 영역은 관리 상태, 무관심, 그리고 이상 상태의 세 영역으로 구성될 수 있다. 이 논문에서는 3개의 모수 영역이 있는 공정에 적용할 수 있는 두 가지 지수가중 이동평균(exponentially weighted moving average; EWMA) 관리도 절차를 제안하고, 제안된 절차의 성능을 Shewhart 관리도 및 누적합(cumulative sum; CUSUM) 관리도와 비교하여 그 효율을 평가하였다.

• 품질경영학회지
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• 제50권3호
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• pp.373-386
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• 2022

Purpose: This study proposes the application of Six Sigma management innovation method for more systematically enhanced execution of Quality by Design (QbD) activities. QbD requires a deeper understanding of the product and process at the design and development stage of the drug, and it is very important to ensure that no fault is fundamentally generated through thorough process control. Methods: Analyzing the background and specific procedures of quality improvement based on the drug design basis, and analyzing the key contents of each step, we have differentated and common points from the 6 Sigma methodology. We propose a new model of Six Sigma management innovation method suitable for pharmaceutical industry. Results: Regulatory agencies are demanding results from statistical analysis as a scientific basis in developing medicines to treat human life through quality improvement activities based on drug design. By utilizing the education system to improve the statistical analysis capacity in the Six Sigma activities and operating the 6 Sigma Belt system in conjunction, it helped systematically strengthen the execution power of quality improvement activities based on pharmaceutical design based on the members of the pharmaceutical industry. Conclusion: By using QbD Six Sigma, which combines quality enhancement based on pharmaceutical design basis and Six Sigma methodology suitable for pharmaceutical industry, it is possible to obtain satisfactory results both by pharmaceutical companies and regulators by using appropriate statistical analysis methods for preparing scientific evidence data required by regulatory.

• 한국환경보건학회지
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• 제28권3호
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• pp.34-38
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• 2002

Statistical analysis between sewage plant operating parameters and the effluent quality was performed. We extracted two factors from principal component analysis of operating parameters and effluent quality from each plant. The total variance of 84.7%, 79.2% was explained by the two factors at SB plant and SC plant, respectively. The factors were identified at SB plant in the following order 1) the oxidation of organic material by aeration basin microbe,2) biomass in aeration basin and at SC plant 1) the oxidation of organic material by aeration basin microbe, 2) thickening of acti-vated sludge. These results suggested that the control of microbial composition might be critical on the improvement of the effluent quality and plant operating efficiency because most of the factors were related with microbes.

• 전기학회논문지
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• 제58권12호
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• pp.2505-2510
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• 2009

Semiconductor processes need measurement to confirm where there are problems in quality after progresses manufacturing process. This paper suggests equipment and automatic measure sampling method that control monitoring ratio according to change point occurrence availability of process that is not measure method by the existent simple ratio rate. This paper defines measure section as ailment section, metastable section and stability section by change point standard and create statistical model of each section and developed suitable measure rate model by section. As a result, we have accomplished maximum throughput and minimum sampling number that needs to maintain constant level of quality. Proposed method minimizes load of measure process by brings production quality sophistication and decrease of process badness and lowers measure rate in stable section making perception about problem occurrence quick heightening measure rate at change point occurrence.

• 제어로봇시스템학회논문지
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• 제11권6호
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• pp.550-557
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• 2005

The multivariate statistical analysis methods, using both multiple linear regression(MLR) and partial least square(PLS), have been applied to predict the reactor properties and the product quality of a direct esterification reactor for polyethylene terephthalate(PET) synthesis. On the basis of the set of data including the flow rate of water vapor, the flow rate of EG vapor, the concentration of acid end groups of a product and other operating conditions such as temperature, pressure, reaction times and feed monomer mole ratio, two multi-variable analysis methods have been applied. Their regression and prediction abilities also have been compared. The prediction results are critically compared with the actual plant data and the other mathematical model based results in reliability. This paper shows that PLS method approach can be used for the reasonably accurate prediction of a product quality of a direct esterification reactor in PET synthesis process.

• 응용통계연구
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• 제9권2호
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• pp.55-72
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• 1996

일반적으로 타이어 제조공학에 있어서 측정되는 자료는 여러개의 설계인자와 성능 특성치가 사용된 다변량 자료행렬로 주어지는데, 이러한 자료행렬의 중요한 특성중의 하나는 각 반응값들이 서로 다른 것들과 높은 상관관곌르 가질 수 있다는 것이다. 따라서 본 연구는 이러한 복잡한 성격을 갖는 자료행렬의 분석에 적합한 biplot 작성의 수학적 이론을 알아보고, 또한 각 변수들의 구조적 특성 및 내재한 상호 관련성을 다변량 분산분석 biplot과 다반응치 희귀모형 biplot을 이용하여 포괄적으로 고찰하였다.

• Journal of the Korean Data and Information Science Society
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• 제14권3호
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• pp.545-551
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• 2003

Robust design is to identify appropriate settings of control factors that make the system's performance robust to changes in the noise factors that represent the source of variation. In this paper we propose how to simultaneously optimize multiple quality characteristics using the principal component analysis of multivariate statistical analysis. An example is illustrated to compare it with already proposed method.