증기발생기 수실 노즐댐 설치 및 제거작업의 피폭선량 저감에 영향을 주는 관리요인에 관한 연구

이동하,Lee, Dhong Ha 대한인간공학회 2017 大韓人間工學會誌 Vol.36 No.5

Objective: The aim of this study is to investigate the effective managerial factors influencing dose reduction of the nozzle dam installation and removal tasks ranking within top 3 in viewpoint of average collective dose of nuclear power plant maintenance job. Background: International Commission on Radiation Protection (ICRP) recommended to reduce unnecessary dose and to minimize the necessary dose on the participants of maintenance job in radiation fields. Method: Seven sessions of nozzle dam installation and removal task logs yielded a multiple regression model with collective dose as a dependent variable and work time, number of participants, space doses before and after shield as independent variables. From the sessions in which a significant reduction in collective dose occurred, the effective managerial factors were elicited. Results: Work time was the most important factor contributing to collective dose reduction of nozzle dam installation and removal task. Introduction of new technology in nozzle dam design or maintenance job is the most important factor for work time reduction. Conclusion: With extended task logs and big data processing technique, the more accurate prediction model illustrating the relationship between collective dose reduction and effective managerial factors would be developed. Application: The effective managerial factors will be useful to reduce collective dose of decommissioning tasks as well as regular preventive maintenance tasks for a nuclear power plant.

인간공학표준을 활용한 적합성평가절차

이동하(Dhong Ha Lee) 대한인간공학회 2010 대한인간공학회 학술대회논문집 Vol.2010 No.10

본 논문은 의자의 인간공학적 편의성에 대한 국제표준 적합성 평가를 받기 위한 절차를 연구하였다. KSAISO 9241-5 영상디스플레이 사용을 위한 인간공학요건-제5부: 작업장배치 및 자세요건 표준에는 의자에 대한 인간공학적 적합성 평가를 수행해야 할 항목을 포함하고 있다. ISO 20282-3 Ease of operation(사용용이성) of everyday product-Part3: Test method for consumer product 표준에는 일상 생활에서 간편하게 사용하는 소비자 제품에 대한 적합성 평가 절차를 규정하고 있다. 이상의 두개의 표준을 조합하면 설계, 제조 또는 판매 대상이 되는 의자가 국제표준에 적합한지의 여부를 판정할 수 있다. 국제표준에 대한 적합성 평가를 통한 인증은 인간공학전문가가 수행할 수 있는 고유 업무영역으로서 널리 활용될 수 있을 것이다.

2008년도 ISO TC 159의 FDIS 개발 현황

이동하(Dhong Ha Lee) 대한인간공학회 2009 대한인간공학회 학술대회논문집 Vol.2009 No.11

This study surveyed final draft international standard publishing activities of the International Standard Organization (ISO) Technical Committee 159 (TC 159) (ergonomics) in the year 2008. The subcommittee 4 (SC 4) dealing with ergonomics of human system interaction issued 11 final draft international standards. The subcommittee 5 (SC 5) dealing with ergonomics of the physical environment issued one FDIS. This paper summarized the major features of the FDIS approved by each subcommittee of TC 159 for publication in the year 2008.

원전 노즐댐 설치 및 제거 작업의 지연요인 및 지연시간에 대한 전문가 예측 성능 평가

이동하(Dhong Ha Lee) 대한인간공학회 2018 大韓人間工學會誌 Vol.37 No.2

Objective: The aim of this study is to investigate the effectiveness of the expert prediction method for estimating the delay factors and the delay time of the nozzle dam installation and removal tasks. Background: The radiation managers of nuclear power plants have tried to find the delay factors to reduce the delay time of the nozzle dam installation and removal tasks, one of the highest radiation dose tasks performed during the scheduled preventive overhaul period of nuclear power plants. Method: Five experts on nozzle dam installation and removal tasks estimated relative weights for delay factors and the delay time of the task using the analytic hierarchy process (AHP) method. In the experiment using the steam generator water chamber mockup simulator the maximum delay time was measured from the difference between the longest and the shortest performance time of the tasks repeated by the three skilled workers. Results: Some unexpected events during the simulation trial lead to a low statistical correlation between the estimated delay time and the measured delay time of the nozzle dam installation and removal tasks. Expert estimations using the AHP method could not reflect the accidental event such as an unexpected excessively tightening of the bolts on the nozzle dam making the performance time prolonged. Conclusion: The estimates on the delay time using the AHP method were limited in usefulness but the debriefing results showed that the estimates of the delay factors predicted well the real situation of the nozzle dam installation and removals tasks. Application: The AHP method for delay factor estimation might be usefully applied to the other high radiation dose overhaul tasks of nuclear power plants such as refueling, reactor water clean-up, works for decommissioning and so on.

2008년도 국제표준화기구 인간공학 기술위원회 표준 개발 활동 현황

이동하(Dhong Ha Lee) 대한인간공학회 2009 大韓人間工學會誌 Vol.28 No.3

This study surveyed standardization activities of the International Standard Organization (ISO) Technical Committee 159 (TC 159) (ergonomics) in the year 2008. The subcommittee 1 (SC 1) dealing with general ergonomics principles produced one committee draft (CD). The subcommittee 3 (SC 3) dealing with anthropometry and biomechanics systematically reviewed two ISO standards issued in 2003 and 2004 respectively. The subcommittee 4 (SC 4) dealing with ergonomics of human system interaction issued 11 final draft international standards (FDIS), 3 draft international standards (DIS), 4 CDs, and 4 new work item proposals (NWIP). The SC 4 also systematically reviewed 10 international standards due on the year 2008. The subcommittee 5 (SC 5) dealing with ergonomics of the physical environment issued one FDIS, 3 CDs, and one NWIP. This paper summarized the major features of the FDIS approved by each subcommittee of TC 159 for publication in the year 2008.

제어실의 인적오류 예방에 적용 가능한 ISO 표준 검토

이동하(Dhong Ha Lee) 대한인간공학회 2011 大韓人間工學會誌 Vol.30 No.1

Objective: The aim of this study is to review the ISO(the International Organization for Standardization) standards recommendations on a human error tolerant control room design. Background: ISO TC(Technical Committee) 159 published a variety of international standards on design of mental and physical work, design of displays and controls, and workstation layout design. A proper edition of these standards can be a good resource for a human error tolerant control center design guidelines. Method: Recommendations of ISO TC 159 standards were grouped into arrangement of control suite, layout of control room, layout and dimensions of workstations, design of displays and controls, environmental design, alarm, automation, management system design, procedure and training. Results: It was found that some standards on the design of supervisory control and data acquisition(SCADA), alarm, automation, layout, workload management, and environment can be used for human error prevention guidelines in the control center design. Conclusion: ISO TC 159 standards were not sufficient to cover all the ergonomics area of control center design. Application: Designers can have technical aids from these ISO standards to improve ergonomic performance of their control center.

합성곱신경망을 이용한 안전문화 수준 분류

이동하(Dhong Ha Lee) 대한인간공학회 2019 大韓人間工學會誌 Vol.38 No.6

Objective: The aim of this study is to investigate whether an artificial intelligence technique can be successfully applied to safety culture survey data classification. Background: Without help of artificial intelligence technique, classifying safety culture level from safety culture scores collected from a large-scale survey would require a lot of experts" time and effort. Method: Two convolution layers and 1 pooling layer was used as the middle layer of the artificial neural network to design a classifier for safety culture level. 1045 safety culture survey data collected from power plant workers used to train and validate the classifier. Results: After 40 epochs" training the classifier approached near 95% precision in classifying "safe" and "need to be improved" classes of safety culture level. Precision, recall and F1-score for the test data set showed over 95% of accuracy performance. Conclusion: An artificial intelligence technique using such as convolution neural network can help classification of safety culture survey data. Application: The safety culture level classifier using deeper neural network and big survey data might improve the performance and might substitute expert interviewers for safety culture evaluation.

신뢰성 매뉴얼 개발 및 보급을 위한 수요조사

김명수 ( Myung Soo Kim ),오근태 ( Geun Tae Oh ),이동하 ( Dhong Ha Lee ),차상원 ( Sang Won Cha ),박창규 ( Chang Gyu Park ) 한국품질경영학회 2005 품질경영학회지 Vol.33 No.1

This paper presents the investigation on the demand of domestic companies for reliability. For persons undertaking reliability tasks of 224 companies, the questionnaire study is made to investigate the importance and necessity of reliability, needs and priorities of reliability manuals, and the appropriate scheme to propagate them by internet and telephone. By analyzing the responses according to fields of industry, types of manufacturing, numbers of employees, and total sales, we obtained the useful informations for developing and propagating reliability manuals.

무기체계획득단계에서의 RAM 달성을 위한 기술검토의 식별과 업무분장

김명수(Myung-soo Kim),오근태(Geun-tae Oh),이동하(Dhong-ha Lee) 한국신뢰성학회 2007 신뢰성응용연구 Vol.7 No.2

모델휴먼프로세서를 활용한 인지과정 시뮬레이터 구축에 관한 연구

이동하,나윤균 한국산업안전학회 1998 한국안전학회지 Vol.13 No.4

Though limited, Model Human Processor (MHP) has been used to explain the complex users' behaviors during human-computer interactions in a simplified manner. MHP consists of perceptual, cognitive and motor systems, each with processors and memories interacting with each other in serial or parallel mode. The important parameters of memory include the storage capacity, the decay time, and the code type of a memorized item. The important parameter of a processor is the cycle time. Using these features of the model, this study developed a computerized cognitive process simulator to predict the cognitive process time of a class match task process. An experimental validity test result showed that the mean prediction time for cognitive process of the class match task simulated 50 times by the simulator was consistent with the mean cognitive process time of the same task performed by 37 subjects. Animation of the data flow during the class match task simulation will help understand the invisible human cognitive process.