• Journal of Advanced Research in Ocean Engineering
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• 제3권3호
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• pp.125-135
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• 2017

The paper considers the practical application of the FMEA(Failure Mode and Effect Analysis) method to assess the operational reliability of the LNG(Liquefied Natural Gas) transfer system, which is a potential problem for the connection between the LNG FPSO and LNG carrier. Hazard Identification (HAZID) and Hazard operability (HAZOP) are applied to identify the risks and hazards during the operation of LNG transfer system. The approach is performed for the FMEA to assess the reliability based on the detection of defects typical to LNG transfer system. FTA and FMEA associated with a probabilistic risk database to the operation scenarios are applied to assess the risk. After providing an outline of the safety assessment procedure for the operational problems of system, safety assessment example is presented, providing details on the fault tree of operational accident, safety assessment, and risk measures.

• 한국항행학회논문지
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• 제16권6호
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• pp.920-926
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• 2012

본 논문에서는 최근 5년 동안의 국내 및 일본에서 일어난 선박 해난사고, 특히 어선 등 소형 선박에 대한 분석을 통해 사고 특성을 파악하였다. 또한 선박에 설치해야할 무선설비와 선박위치 식별장치의 설치 및 운영에 관한 규정들을 종합적으로 분석하여 사용되는 전파의 전달특성 및 통신기의 운용특성을 고려한 새로운 형태의 해상안전 종합 통신망을 제안하였다.

• Nuclear Engineering and Technology
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• 제47권2호
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• pp.157-164
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• 2015

Nuclear power plants have logical loop structures in their system configuration. This paper explains the method to solve a loop structure in reliability analysis. As examples of loop structured systems, the reactor core isolation cooling system and high-pressure core injection system of a boiling water reactor are considered and analyzed under a station blackout accident condition. The analysis results show the important role of loop structures under severe accidents. For the evaluation of the safety of nuclear power plants, it is necessary to accurately evaluate a loop structure's reliability.

• International Journal of Ocean System Engineering
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• 제1권4호
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• pp.211-221
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• 2011

Tugboats are widely used near harbors to assist with various operations such as the berthing and deberthing of very large vessels and the towing of barges. Capsizing accidents involving tugboats occasionally take place when the tugboat makes rapid turns in harsh weather conditions. When there is little evidence suggesting how the accident occurred and when the crew members are missing, it is necessary to predict the time history of the towing vessel’s attitude and trajectory from its departure point to when and where it capsized, depending on various input parameters using a numerical simulation. In this paper, the dynamics of a tugboat and a towed barge in conjunction with the external force and moment were established, and the possible input parameters and operational scenarios which might influence the large roll motion of the tugboat were identified. As a result of analyzing the simulated time history of the excessive roll motion of the tugboat, it was found that roll motion can take place when the tugboat is situated on the crest of a wave and when it is pulled by a towed barge through a towing line. The main cause of the accident would be the parameters that primarily influence such situations. These are the wave parameters, course changing scenario, and the amount of tension.

• 대한교통학회지
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• 제23권7호
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• pp.77-86
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• 2005

현재 우리나라 간선도로의 서비스수준(LOS)은 차량의 평균통행속도를 기준으로 평가되어지고 있다. 이는 도로의 혼잡도 만을 기준으로 적용한 것으로 교통안전측면이 고려되지 않은 것이 현실이다. 합리적인 도로 설계와 운영을 위한 평가 지표라면 도로 이용자에게 영향을 미치는 제반 인자들을 보다 포괄적으로 포함할 수 있어야 한다. 교통안전과 소통측면을 총괄할 수 있는 변수로 사용자비용 개념을 적용하여 간선도로 평가방법을 모색하고자 한다. 사용자 비용을 효과척도로 하는 간선도로 평가도 가능하다는 것을 본 연구를 통해 알 수 있었다. 또한, 본 연구의 사용자 비용에 의해 평가된 간선도로 서비스 수준과 도로용량편람의 평균통행속도에 의해 평가된 간선도로 서비스 수준을 비교 분석하여 종합적인 서비스 수준 분석방법 여부를 가릴 수 있을 것이다. 이로서, 안전과 소통 측면을 모두 고려한 간선도로 평가가 가능함을 알 수 있었다.

• 자동차안전학회지
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• 제4권1호
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• pp.5-11
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• 2012

This paper discusses the evaluation of the safety impact of the Adaptive Cruise Control (ACC) system in Korea. To evaluate the safety impact, this paper suggests an analysis method by using the test scenario and field operational test data. The test scenario is composed to represent the main component factor of the ACC system and ACC related accident situation such as rear-end collision, lane-change, and road-curvature, etc. Also, from the field operation test data, the system's potential to increase the safety can be measured ideally. Besides, field operational testdata was used to revise the expected safety impact value as Korean road conditions. By using the proposed evaluation method, enhanced safety impact of the ACC system can be estimated scientifically.

• Current Photovoltaic Research
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• 제7권2호
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• pp.38-45
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• 2019

In this paper, we analyzed the present status of the safety manager and safety assurance aspects through a complex analysis on the operational aspects, marketability and electrical safety aspects of photovoltaic power generation facilities. In the analysis of the equipment status, we analyzed the status and operated status of the installed PV system in Korea and the correlation between the safety manager and the accident. In addition, we analyzed the direction of the ESS through the analysis of the installation status of the ESS, and applied it to the interpretation part of the ESS associated with the solar power generation. The status of the electric safety manager can be used to analyze the data for selecting the electric safety manager by capacity by analyzing the accident status, the electric safety manager operation status, the safety management time by capacity, and the electric safety manager market.

• 한국안전학회지
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• 제34권1호
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• pp.76-81
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• 2019

In this study, the causes of human error were identified through the survey of the drivers of the three organizations: Seoul Metro, Seoul Metropolitan Rapid Transit Corporation, and Korail. It was started with the aim of finding and eliciting causes in various directions including human factors, job factors, and environmental factors. The Cronbach alpha value was 0.95 for the reliability significance of the stress-induced factors in the operational area. The significance probability for organisational factors was shown to be 0.82, and the significance of the sub-accident experience and the driving skill factors in operation was 0.81 In addition, the analysis results showed that stress-induced in the field of driving is higher than the human factors in the reliability analysis. The results of the analysis confirmed that the reliability of the organizational and operational stress-induced factors was higher than other causes. In order to reduce urban railroad accidents, this paper suggests a method for operating safe urban railroad through the minimization human errors.

• 시스템엔지니어링학술지
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• 제18권2호
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• pp.58-74
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• 2022

Deterministic accident analysis plays a central role in the nuclear power plant (NPP) safety evaluation and licensing process. Traditionally the conservative approach opted for the point kinetics model, expressing the reactor core parameters in the form of reactivity and power tables. However, with the current advances in computational power, high fidelity multi-physics simulations using real-time code coupling, can provide more detailed core behavior and hence more realistic plant's response. This is particularly relevant for transients where the core is undergoing reactivity anomalies and uneven power distributions with strong feedback mechanisms, such as reactivity initiated accidents (RIAs). This work addresses a RIA, specifically a control element assembly (CEA) withdrawal at power, using the multi-physics analysis tool RELAP5/MOD 3.4/3DKIN. The thermal-hydraulics (TH) code, RELAP5, is internally coupled with the nodal kinetics (NK) code, 3DKIN, and both codes exchange relevant data to model the nuclear power plant (NPP) response as the CEA is withdrawn from the core. The coupled model is more representative of the complex interactions between the thermal-hydraulics and neutronics; therefore the results obtained using a multi-physics simulation provide a larger safety margin and hence more operational flexibility compared to those of the point kinetics model reported in the safety analysis report for APR1400. The systems engineering approach is used to guide the development of the work ensuring a systematic and more efficient execution.

• 한국ITS학회 논문지
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• 제5권2호
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• pp.61-71
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• 2006

본 연구는 신호교차로에서의 교통사고 감소방안에 대한 연구로써 이를 위하여 좌회전 현시 순서를 중심으로 연구를 진행하였다. 현재 우리나라는 1985년부터 기존에 사용하던 후행 이중 좌회전 방식을 직진 이동류의 통과효율 및 교차로의 용량을 높이고 소통을 증진시키기 위한 목적으로 선행 이중좌회전 방식으로 바꾸어 사용하고 있다. 이는 그 당시에 도로교차로가 비교적 협소하여 전용좌회전 차로가 거의 없었기 때문으로 선행 이중좌회전 방식을 적용해온 현시점에서 어느 방식이 교통안전과 소통에 더 적합한지를 분석할 필요가 있다고 생각된다. 본 연구에서는 먼저, 선행 좌회전과 후행 좌회전의 안전성을 분석하기 위하여 교차로를 '교차로 내', '횡단보도', '접근부와 유출부'로 나누었다. 이렇게 구분되어진 교차로를 '유효페이스 간격(EIP)'과 '상충기법'을 적용하여 안전성을 분석하였다. 연구 결과 후행 좌회전이 선행 좌회전 보다 전체적인 안전성이 좋은 것으로 나타났으며, 연간 418억원의 사고비용을 절감할 수 있는 것으로 분석되었다.