• 한국경영과학회지
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• 제36권1호
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• pp.39-55
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• 2011

Process monitoring has been emphasized for the monitoring of complex system such as chemical processing industries to achieve the efficiency enhancement, quality management, safety improvement. Recently, ICA (Independent Component Analysis) based MSPC (Multivariate Statistical Process Control) was widely used in process monitoring approaches. Moreover, DICA (Dynamic ICA) has been introduced to consider the system dynamics. However, the existing approaches show the limitation that their performances are strongly dependent on the statistical distributions of control variables. To improve the limitation, we propose a novel approach for process monitoring by integrating DICA and LOF (Local Outlier Factor). In this paper, we aim to improve the fault detection rate with the proposed method. LOF detects local outliers by using density of surrounding space so that its performance is regardless of data distribution. Therefore, the proposed method not only can consider the system dynamics but can also assure robust performance regardless of the statistical distributions of control variables. Comparison experiments were conducted on the widely used benchmark dataset, Tennessee Eastman process (TE process), and showed the improved performance than existing approaches.

• 대한교통학회지
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• 제7권1호
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• pp.43-55
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• 1989

This study is to review the road traffics and its process by the type of business in annual Statistical Yearbook of Transportation published under the supervision of Ministry of Transport, and the main purpose of this study is to find out an recommendations for the result of the review. For this purpose, this study surveyed and analyzed actual results and its output process in Statistical Yearbook by vehicle and business types. The local survey is performed for the nationwide 23 cities to produce passenger (ton) number and passenger (ton)-㎞ number by vehicle and business types. The result of the local survey is compared with the road traffics in Statistical Yearbook of Transpotation. The result of the survey analysis reveals that road traffic in Statistical Yearbook is produced formally and there is remarkable differences between road traffic in Statistical Yearbook and local survey output. Conclusively, statistical output process of road traffics must be improved to solve th se problems mentioned above in respect to system and technic. Also it is recommended to publish its own road traffic statistics (tentatively named Statistical Yearbook of Road Transportation) just like Statistical Yearbook of Railroad for user's expediency and practicality.

• 품질경영학회지
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• 제25권1호
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• pp.116-134
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• 1997

The present automated manufacturing environment is very different when the classical statistical process control method based on batch processing were used. Therefore these must be replaced by automated statistical process control method. In this point of view, this paper intends to develop the automated statistical process control method which can be implemented in the present automated manufacturing environment. Specially this study developed the rules to identify the special causes of the manufacturing process in the aspect of the 100 PPM management, and a numerical example is demonstrated to verify the usefulness of these rules.

• 품질경영학회지
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• 제24권2호
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• pp.172-178
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• 1996

In this study, we developed a software for statistical process control. This software presents $\bar{x}$, R, CUSUM, EWMA control chart and process capability index. In this system, statistical process control methods are integrated into the automated method on a real time base. It is available in process control of specified type and can be performed on personal computer with network system.

• 품질경영학회지
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• 제41권3호
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• pp.487-494
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• 2013

Purpose: In this study, we propose the precision guided munitions verification methodology using the statistical analysis method has been proposed. and it can be applied to the precision guided munitions quality assurance work. Methods: This modeling is based on Failure Mode and Effects Analysis, Statistical Process Control, Defense Quality Managerment System, Production Readiness Review, Manufacturing Readiness Assesment and so on. Results: The Process Control Modeling that has the following procedures ; searching the critical to quality, statistical analysis by process, verify process. Moreover, the effectiveness of the methodology is verified by applying to the precision guided munitions. Conclusion: To achieve a analysis methods of statistical process control and verify process for precision guided munitions.

• 한국수학교육학회지시리즈A:수학교육
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• 제50권2호
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• pp.185-212
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• 2011

The purpose of this study is to analyze whether spreadsheet-used instruction can improve statistical thinking ability and attitude and also to identify what characteristics of statistical thinking is constructed. For this study, a subject of 2 classes were randomly selected among the 12 classes of the 11th grader in D high school and designated one class as the experimental group and the other class as the control group. Eight hours of the spread sheet-used instruction and the traditional textbook-oriented instruction had been carried out in each class. The research findings are as follows. First, the spread sheet-used instruction is shown to be more effective in enhancing statistical thinking than the traditional textbook-oriented instruction. Second, the spread sheet-used instruction is shown to be more effective in improving statistical attitude than the traditional textbook-oriented instruction. Third, students have shown the various characteristics of statistical thinking in the data descriptive process, data arrange-summary process, data representing process, and data analying process through the spread sheet-used instructions. Hence, the spread sheet-used instruction is recommended in teaching statistics.

• Journal of the Korean Statistical Society
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• 제27권2호
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• pp.221-235
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• 1998

Suppose that an observed process can be written as the additive model of the signal process and the noise process with unknown parameters. In practice the signal process is not directly observed. We consider the problem of estimating parameter from the observation process using the quasi-likelihood method.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
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• pp.1516-1519
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• 1997

With disseminationof Distributed Control Systems(DCS), the huge amounts of process operation data could have been available and led to figure out process behaviors better on the statistical basis. Until now, the statistical modeling technology has been susally applied to process monitoring and fault diagnosis. however, it has been also thought that these process information, extracted from statistical analysis, might serve a great opportunity for process operation improvements and process improvements. This paper proposed a general methodolgy for process operation improvements including data analysis, backing up the result of analysis based on the methodology, and the mapping physical physical phenomena to the Principal Components(PC) which is the most distinguished feature in the methodology form traditional statistical analyses. The application of the proposed methodology to the Balst Furnace(BF) process has been presented for details. The BF process is one of the complicated processes, due to the highly nonlinear and correlated behaviors, and so the analysis for the process based on the mathematical modeling has been very difficult. So the statisitical analysis has come forward as a alternative way for the useful analysis. Using the proposed methodology, we could interpret the complicated process, the BF, better than any other mathematical methods and find the direction for process operation improvement. The direction of process operationimprovement, in the BF case, is to increase the fludization and the permeability, while decreasing the effect of tapping operation. These guide directions, with those physical meanings, could save fuel cost and process operator's pressure for proper actions, the better set point changes, in addition to the assistance with the better knowledge of the process. Open to set point change, the BF has a variety of steady state modes. In usual almost chemical processes are under the same situation with the BF in the point of multimode steady states. The proposed methodology focused on the application to the multimode steady state process such as the BF, consequently can be applied to any chemical processes set point changing whether operator intervened or not.

• Journal of the Korean Statistical Society
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• 제35권2호
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• pp.193-199
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• 2006

We consider a zero coupon bond that is at the risk of multitype multiple defaults. Assuming defaults occur according to k Cox processes, we find a price process for zero coupon bonds. To derive this process we follow the Lando (1998)'s method which uses conditional expectations instead of the traditional methods.

• 한국학교수학회논문집
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• 제24권2호
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• pp.191-216
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• 2021

본 연구는 2015 개정 수학과 교육과정에 따른 <확률과 통계> 교과서의 통계적 추정 단원에서, 통계적 문제해결과정과 함께 통계적 소양이 어떻게 구현되는가를 분석하였다. 문헌 연구를 통해 통계적 소양의 성장에 기여하는 요소로서 '맥락', '변이성', '수학적·통계적 지식', '공학 도구의 활용', '비판적 태도', '의사소통'을 도출하여 통계적 문제해결과정에 따른 분석 관점을 설정하고, 이를 코드화하여 개발한 분석틀을 토대로 교과서 분석을 실시하였다. 통계적 문제해결과정의 관점에서 분석결과 '자료 분석'에 해당하는 과제가 많이 제시되어 있었고 '결과 해석', '문제 설정'과 관련한 과제가 부족하였다. 통계적 소양의 요소별 반영에 관한 분석 결과 '수학적·통계적 지식'을 요구하는 과제가 가장 많았으며, '비판적 태도', '공학 도구 활용'은 거의 다루어지지 않고 있었다. 이러한 교과서 분석결과를 바탕으로 통계적 소양의 함양 교육을 위한 교육과정 개선 및 교과서 개발에 대한 시사점을 제시하였다.