• Journal of Radiation Protection and Research
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• v.41 no.2
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• pp.117-121
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• 2016

Background: Definition and grouping of initiating events (IEs) are important basics for probabilistic safety assessment (PSA). An IE in a spent fuel reprocessing plant (SFRP) is an event that probably leads to the release of dangerous material to jeopardize workers, public and environment. The main difference between SFRPs and nuclear power plants (NPPs) is that hazard materials spread diffusely in a SFRP and radioactive material is just one kind of hazard material. Materials and Methods: Since the research on IEs for NPPs is in-depth around the world, there are several general methods to identify IEs: reference of lists in existence, review of experience feedback, qualitative analysis method, and deductive analysis method. While failure mode and effect analysis (FMEA) is an important qualitative analysis method, master logic diagram (MLD) method is the deductive analysis method. IE identification in SFRPs should be consulted with the experience of NPPs, however the differences between SFRPs and NPPs should be considered seriously. Results and Discussion: The plutonium uranium reduction extraction (Purex) process is adopted by the technics in a model reprocessing plant. The first extraction cycle (FEC) is the pivotal process in the Purex process. Whether the FEC can function safely and steadily would directly influence the production process of the whole plant-production quality. Important facilities of the FEC are installed in the equipment cells (ECs). In this work, IEs in the FEC process were identified and categorized by FMEA and MLD two methods, based on the fact that ECs are containments in the plant. Conclusion: The results show that only two ECs in the FEC do not need to be concerned particularly with safety problems, and criticality, fire and red oil explosion are IEs which should be emphatically analyzed. The results are accordant with the references.

• Journal of the Korean Society for Precision Engineering
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• v.27 no.5
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• pp.36-47
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• 2010

The Korean Railroad Research Institute (KRRI) has developed the rubber tired AGT system (Model: K-AGT) between 1999 and 2005. The K-AGT is a light rail transit system does not require a driver and generally operates on an elevated railroad for transporting passengers. Accidents caused by driverless vehicles can severely affect social confidence, safety and economy therefore, it is very important to minimize the occurrences of such faults, and to accurately perform detailed maintenance tasks and thoroughly investigate the cause of any repeated failures. This research develops the web-based Preventive Maintenance (PM) system for the KAGT train system. The framework of the PM system is based on performing a reliability analysis and a failure mode effects analyses (FMEA) procedure on all the sub-systems in the K-AGT system. Out of the devices that have a low reliability, the high failure ranked devices are included high in the list for performing the overall maintenance plans. Through registration of historical failure data, the reliability indexes can be updated. Such a process is repeated continuously and can achieve very accurate predictions for device operational life times and failure rates. Therefore, this research describes the development of the overall PM system consists of a reliability analysis module, a failure mode effect analysis module, and maintenance request module.

• Proceedings of the KIEE Conference
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• 2004.05a
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• pp.29-32
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• 2004

Reliability is an important issue on the digital reactor protection system. This paper presents a Quantitative reliability evaluation method to find out an improvement effect of availability for the digital control module with a fault detection function. It is a reliability evaluation model which considers only the electronics parts ocurring a spurious reactor trip by the FMEA(Failure Mode Effect Analysis). Applying the previous and present methods to the reactor protection system, the availability factors are evaluated and compared.

• Journal of the Korean Society for Railway
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• v.9 no.4 s.35
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• pp.412-418
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• 2006

In this paper we deal with the APARP theory which has been applied for UK railway system and risk assessment method which has been using in the domestic railway system for the safety demonstration. Both techniques are applied to the ATP wayside equipment for interface. Also, fur the applications of each techniques a analysis of the safety activity and a possibility of the application of ALARP theory are evaluated. Finally, we generate requirements of the safety demonstration for the future domestic railway system by way of the analysis of some assumptions and requirement data which can be applied to the risk assessment of ALARP.

• Journal of the Korea Institute of Building Construction
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• v.21 no.6
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• pp.629-640
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• 2021

According to statistics from the Ministry of Land, Infrastructure and Transport in 2018, approximately 37% of residential buildings in Korea need to be reconstructed. Due to the rapid growth of the demolition industry, many side effects such as environmental destruction and safety accidents are becoming a problem in the demolition of existing buildings. This study proposes a decision-making process for selecting the most suitable dismantling method for field application by comprehensively considering safety, economic feasibility, and environmental characteristics. In particular, field applicability is evaluated by evaluating risk factors for the selected method. To this end, this study proposes the TOPSIS method for the selection of the dismantling method using the QFD development concept, and the FMEA method as a continuous development process of the selected method.

• Korean Journal of Construction Engineering and Management
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• v.23 no.6
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• pp.101-110
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• 2022

Recently, the global construction market is expected to grow at an annual average of 4.8% by 2025 and the risk of overseas construction is also expected to increase accordingly. In particular, domestic construction companies intensively participated in the EPC(Engineering, Procurement, Construction)/Turnkey project, but as a result of failing to respond to contractual risks, they have suffered losses of trillions of won in overseas business since 2013. Nevertheless, there have been not many studies on the derivation of EPC/Turnkey's contractual key risk sub-clauses. Therefore, in this study, the key risk sub-clauses were studied for the conditions of the 2017 Silver Book contract issued by the International Consulting Engineering Federation(FIDIC). To this end, 30 experts with more than 10 years of experience in international construction contracts were formed as a panel to conduct a Delphi survey on 170 sub-clauses of 21 clauses of FIDIC Silver Book to derive 62 main risk sub-clauses. In addition, the RPN(Risk Priority Number) was finally calculated using the FMEA(Failure Mode and Effect Analysis) technique, and 25 key risk sub-clauses within the Critical Risk range were derived. Through the results of this study, the practical point of view is able to refer to the contract provisions to be carefully reviewed at the bidding and contract signing stage in overseas construction projects. From an academic point of view, it provides direction and basic knowledge of how to study the contract fields used in overseas construction EPC/Turnkey projects.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.22 no.3
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• pp.343-348
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• 2013

In line with the advances in factory automation, various pieces of equipment are now operated in batch processes controlled by computers. However, many kinds of faults can occur in complicated and large systems, which can result in low productivity and economic loss. The reliability and safety of systems have been studied because of the difficulty of determining the severity and location of faults. Therefore, it is necessary to detect and diagnose such faults in order to guarantee the reliability and safety of the equipment. In this paper, a diagnosis method for the ball bearings of a hydraulic pump is applied using a vibration signal for the maintenance of injection molding equipment. The bearings' defects are selected as a main failure mode through a failure mode and effect analysis (FMEA). Usually, there are nonlinear and impulse components of vibration in a ball bearing with faults. For the effective fault diagnosis of a ball bearing, nonlinear diagnostic methods and time-frequency analysis are applied, in addition to the methods currently used, such as power spectrum, time series analysis, and statistical methods. As a result of this study, a failure diagnosis system is provided that is useful even for non-experts. This is a condition-based method that makes it possible to resolve problems in a timely and economical way, in contrast to the prior method, which required regular but wasteful maintenance based on the experience of expensive external experts.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2007.04a
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• pp.109-112
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• 2007

As buildings become higher, larger, and more complex, safety issues for construction workers working at such environments become more important. We analyzed 140 critical accident cases reported to the KOSHA(Korea Occupational Safety & Health Agency) for construction cranes and lifts by types of cranes and by patterns of accidents and causes. By finding out the accident's types and causes, we expect to develop an efficient measure for preventing similar accidents in the near future. The cases will be studied further and reexamined using the FMEA(Failure Mode and Effect Analysis) as a quantitative analysis method.

• Korean Journal of Construction Engineering and Management
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• v.18 no.4
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• pp.17-26
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• 2017

The sustainable growth of Construction Management(CM) market depends on clients'acceptance from positive project outcomes of CM services. Achieving the positive outcomes requires CM firms'competency and efforts. Equally, it is critical to understand and overcome barriers of CM performance, which cause inefficiencies and under-performance of CM services. The objective of the study is to identify and discuss the barriers of CM performance during pre-construction stages in private CM projects based on the FMEA technique. Major findings basically suggest that clients and CM firms have roles to play, individually and collaboratively, in order to improve CM performance by eliminating performance barriers.

• Proceedings of the IEEK Conference
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• 2003.07c
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• pp.2545-2548
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• 2003

Reliability is the very important issue for nuclear fields. In this paper, an analysis method is suggested to evaluate the level of availability improvement by adding the fault diagnosis function in the control system of Reactor Protection System. The Failure Mode Effect Analysis(FMEA), MIL-HDBK-217F, and Makov modelling techniques are used for availability assessment.