• Transactions of the Korean Society of Pressure Vessels and Piping
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• v.7 no.2
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• pp.7-13
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• 2011

Turbine journal bearings are designed to support the weight of the rotors on a hydrodynamic oil film and to provide dynamic stability to the rotor system. The life time of journal bearings is infinite theoretically because the journal bearings are separated from the shaft journal by oil film. But poor design, assembly, operation and maintenance can cause problems to the journal bearings. The FMEA(Failure Mode and Effects Analysis) results of the journal bearings show that frequent maintenance of the journal bearings can cause failures and reduction of the bearing life. Therefore, the maintenance periods and history of the journal bearings with the bearing FMEA results are reviewed in order to establish the optimized maintenance period of the journal bearing for the nuclear power plants. Consequently it is necessary to maintain a best condition of lubrication system, reject time-based maintenance and perform the condition-based maintenance of journal bearings in order to maintain optimum condition of the journal bearing.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.10a
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• pp.495-497
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• 2012

Development of application risk management for medical device software test. First, Through questionnaires, Medical device manufacturers, Analysis of software validation and risk management status. Second, Analyzed by comparing the difference between black box testing and white box testing. Third, After analyzing the potential for software analysis tools using code derived factors were quantified, Finally, Medical device risk management process so that it can be applied to build the framework by FMEA(Failure Mode and Effect Analysis) technique. Through this Difficult to build software validation and risk management processes for manufacturers to take advantage of support in medical device GMP(Good Manufacture Practice).

• International Journal of Safety
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• v.9 no.2
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• pp.22-28
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• 2010

This paper describes a web-based design review system as a knowledge management system relating reliability and safety system design. Since people's consciousness for safety and security become sensitive and increases the need of establishing a proactive prevention method for internal failures and relating risks in products. It also means that prevailing tacit knowledge in retired workers, in order to transform them to be easily used to support new system development, become more important. When considering safety and reliability design, at least two data sheet are necessary; Failure Modes and Effects Analyses (FMEA) and Risk Assessment (RA). These two data are practically made separately. However, it includes the concerns that a risk by failures during long-term use may not be noticed. To overcome this insufficiency, a support tool for integrating reliability evaluation and risk assessment data simultaneously is expected to be revealed. The authors have then developed a web-based design review system for reliability and safety system design. The system include various profitable functions; making FMEA and RA sheet, retrieving past data sheet for engineering change management and new product development and web-based discussion to increase the efficiency of discussion. The system is applied to one practical development works in order to demonstrate its effectiveness that is to be made clear by interviewing user's qualitative comment.

• Journal of the Korean Society of Safety
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• v.35 no.5
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• pp.115-120
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• 2020

From 2009 when the CNS facility was installed, the number of reactor failures due to abnormal CNS facility system has increased significantly. Of the total of 19 nuclear reactor shutdowns over the six years from 2009 to 2019, there were 10 nuclear reactor shutdowns associated with the CNS facility, which are very numerous. Therefore, this report intends to analyze the history of nuclear reactor shutdowns due to CNS facility system failure in detail, and to present the root cause and solution to problems. As a result of FMEA implementation of CNS facility system, a total of 76 SPVs were selected. In addition, 10 cases of reactor shutdown history due to CNS facility system abnormalities were analyzed in detailed, and improvement plans for solving the root cause and problem were suggested for each trip history. The results of this study are expected to be able to operate the domestic research reactor and CNS facilities more stably by providing effective measures to prevent recurrence of CNS facilities and reactor trips.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.11
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• pp.78-87
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• 2017

Recently, the quality of a product or system has becoming increasingly important as it means customer satisfaction. The function, which is recognized as a nature of this quality, means how it functions well so it is the closest to the customer satisfaction. On the other hand, it is becoming more important as safety is closely related to destruction or human injury from accidents for engineers who handle large-scaled structures, such as ships. This study analyzed the function using quality function development (QFD) and considering the function and safety, which are being recognized as important in the structure. In addition, the safety and the quality analysis method based on the customers' needs was analyzed using failure mode and influence analysis (FMEA). In addition, the supplementary materials that are important in terms of the aspect of safety and function for the quality enhancement of a hatchway system were determined by applying a bulk carrier and hatchway. As a result, there are commonly understood items in important supplementary materials and parts, which are determined individually in terms of function and safety, because they can enhance both the function and safety simultaneously. This study shows that designers can improve the quality of products and systems by enhancing these supplementary materials and parts with greater interest.

• Korean Journal of Construction Engineering and Management
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• v.10 no.1
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• pp.91-101
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• 2009

The factors of uncertainty such as work delay could cause many problems, for example, increase of construction cost and terms of work, and the deterioration of quality. Because of these, the uncertainty risk is regarded as an important management factor to obtain the success of construction project. So, the systematic management plan about the uncertainty factors is needed because it plays an important role in the completion of entire project. And also analysis of some factors which can cause the work delay can be one way of improving construction project's certainty and making it competitive. In this reason, we have to make an effort to set a priority based on analysis of quantitatively numerical value about work delay factors to manage them effectively. Thus, this study aims to suggest the basic data for the effective management and prevention of work delay in steel-frame work which is progressive actively now, along with increasing of demand of high-rise buildings by analyzing each reasons of work delay factors and also by suggesting important management factors that are coded according to each construction work using FMEA method which could give a data about the importance of work delay factors through quantitatively numerical value.

• Journal of the Korean Society of Safety
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• v.25 no.6
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• pp.34-39
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• 2010

The purpose of this study is to suggest objective evaluation model as a plan to utilize as opportunity in establishing judgment standard of mutual inspection criteria and to upgrade inspection ability by reviewing and analyzing level of danger and importance in advance based on inspection results of inspection institutions regarding tower cranes used in construction fields. Tower crane is a mechanical device transporting construction supplies and heavy materials to places over 20~150M high from the ground for the period ranging from a short time of 2~3 months to two years after being installed in construction sites in vicinity of buildings or structures and is an important facility indispensable for construction sites. However, since use period after installation is short and professional technical ability of technicians working on-site about of tower crane is poor, systematic and quantitative safety management is not carried out As a part of researches on procedure of RBI(Risk Based Inspection) possible to apply to Knowledge Based System based on knowledge and experiences of experts as well as to tower cranes for solving these problems, quantitative RPN(Risk Priority Number) was applied to RPN utilizing technique of FMEA(Failure Mode and Effect Analyses). When general RBI 80/20 Rule was applied parts with high level of risks were found out as wire rope, hoist up/down safety device, reduction gear, and etc. However, since there are still many insufficient parts as risk analyses of tower crane were not established, it is necessary for experts with sufficient experiences and knowledge to supplement active RBI techniques and continuous researches on tower cranes by sharing and setting up data base of important information with this study as a starting point.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.10
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• pp.68-78
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• 2016

Safety is the most important factor for train control systems. Model-based design and safety activities for way-side equipment in train control systems are important factors. Model-based architecture verification was carried out to develop an effective control system, which is represented by model-based failure mode and effects analysis (FMEA). An architecture verification method was created based on FMEA to take advantage of a design model and improve the train safety control system. Case studies were applied to architecture verification scenarios, and the results demonstrate the usability of the method. The improved method is expected to reduce the cost and time in the conceptual design for future development of model-based verification train control systems.

• Journal of the Society of Disaster Information
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• v.19 no.2
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• pp.313-325
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• 2023

Purpose: According to the recent occurrence statistics of ground accidents, ground subsidence and subsidence have become social problems as the frequency has increased centering around the downtown areas. This study tried to clarify risk of detailed factors which have an effect on subsidence. Method: For the study, detailed risk factors of 28 foundations were mainly drawn through the materials, precedent studies, and research reports shown by analyzing JIS' accident cases from 2016 to September 6, 2022 and by taking advice from an excavation expert. And risk was assessed by conducting a survey on 12 subsidence experts from the universities, research institutes, and industries and applying Fuzzy-FMEA to it. Result: It has found that damage of sewer pipes is 24.99% of overall risk, followed by excavation work (17.34%), water pipes (14.84%), and poor compaction (refill) (13.93%). And it has found that risk of damaging utilities (water pipes, sewer pipes, and other utilities) is highest, followed by poor construction works (excavation work, damage of sewer and water pipes, and other utility work) and poor compaction (refill). Conclusion: This shows that risk of subsidence factors judged by experts is similar with JIS' cases of ground subsidence.

• Journal of the Korea Institute of Building Construction
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• v.23 no.4
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• pp.417-428
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• 2023

The demolition of domestic infrastructures mirrors other significant construction initiatives in presenting a markedly high accident rate. A comprehensive investigation into the origins of such accidents is crucial for the prevention of future incidents. Upon detailed inspection, the causes of demolition construction accidents are multifarious, encompassing unsafe worker behavior, hazardous conditions, psychological and physical states, and site management deficiencies. While statistics relating to demolition construction accidents are consistently collated and reported, there exists an exigent need for a more foundational cause categorization system based on accident type. Drawing from Heinrich's Domino Theory, this study classifies the origins of accidents(unsafe behavior, unsafe conditions) and human errors(human factors) as per the type of accidents experienced during demolition construction. In this study, a three-step model of QFD-FMEA(Quality Function Deployment - Failure Mode Effect Analysis) is employed to systematically categorize accident causes according to the types of accidents that occur during demolition construction. The QFD-FMEA method offers a technique for cause classification at each stage of the demolition process, including direct causes(unsafe behavior, unsafe environment), and human errors(human factors) through a tri-stage process. The results of this accident cause classification can serve as safety knowledge and reference checklists for accident prevention efforts.