• Journal of Energy Engineering
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• v.23 no.4
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• pp.223-229
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• 2014

This study investigated the explosion characteristics of HCNG fuel using a simulation tool. The damage caused by the storage container explosion and vapor cloud explosion in a gas station was predicted. In case of an vapor cloud explosion in the HCNG station, 50~200kPa explosion pressure was predicted inside the station. When the cylinder explosion was occurred, in case of hydrogen, the measured influential distance of overpressure was 59m and radiant heat was 75m. In case of CNG, influential distance of overpressure was 89m and radiant heat was 144m would be estimated. In case of 30% HCNG that was blended with hydrogen and CNG, influential distance of overpressure was 81m and radiant heat was 130m were measured. The damage distance that explosive overpressure and radiant heat influenced CNG was seen as the highest. HCNG that was placed between CNG and hydrogen tended to be seen as more similar with CNG.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.19 no.2
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• pp.99-105
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• 1983

In the Steering and Sailing Rules of International Regulations for Preventing Collicions at Sea, 1972, any relative distance between two vessels necessary for taking action to avoid collision in head-on situation is not referred. In this paper, the author analyzed the ship's collision avoiding actions from a viewpoint of ship motions and worked out mathematical formulas to calculate the relative distances necessary for collision avoiding actions. Figuring out the values of maneuvering indices through experiments of actual ships, the author applied these values to the calculationg formulas and calculated the minimum safe relative distances. On the assumption that two vessels same in size and condition are approaching each other in head-on situation, the minimum safe relative distance was calculated as 5.0 times, sufficient safe relative one as 10.0 times their own length.

• Information Systems Review
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• v.20 no.3
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• pp.51-71
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• 2018

Many studies in the field of information security reveal the need to increase awareness. However, although awareness of information security has been raised to a considerable extent, actual security behavior has been shown to fall short of that. Therefore, we wanted to identify the role of psychological factors in making information security decisions by conducting a experimental study. The results show that there are differences in perception of information security risks according to the probabilistic distance and the degree of relative optimism due to social distance. In relation to their relative optimism and intention of information security, they reduced the level of perceived risk compared to those close to them and found that their influence varied according to their probabilistic distance. This study has made valuable attempt in terms of methodology and it is meaningful that the psychological factor is taken into consideration for the information protection behavior, so that the range of relative optimism that actually affects the perception of risk is narrowed. It is expected to contribute to the improvement of information security level of information technology users and protection of information assets by empirically identifying necessity of various approaches to decision making process for information security.

• Journal of Energy Engineering
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• v.26 no.4
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• pp.7-13
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• 2017

As environmental problems become a problem of survival, interest in eco-friendly energy is increasing to improve the environment. So, demand for eco-friendly fuels such as hydrogen, LPG and CNG is increasing. In particular, Korea, which relies on imports of most fuels, is investing in the development of hydrogen energy, which is favorable in terms of high production volume and energy independence. However, As demand grows every year, a variety of accidents occur in various ways, ranging from small leak incidents to massive fires and explosion, thus research needs to be done. So, in this study, compared and analyzed cases of hydrogen, LPG, CNG accidents occurring at domestic and overseas refueling stations. and various programs were used for assessing risk, estimated the flame length due to gas leakage and evaluated the dangerous distance.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2021.10a
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• pp.332-334
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• 2021

As fatal accidents due to industrial accidents and deaths due to civil accidents were pointed out as social problems, the Act on Punishment of Serious Accidents Occurred in the Workplace was enacted to ensure the safety of citizens and to prevent serious accidents in advance. Effort is required. In this paper, we propose a distance prediction model in relation to the case where an operator is hit by heavy equipment such as a forklift. For the data, actual forklift trucks and workers roaming environments were directly captured by CCTV, and it was conducted based on the Euclidean distance. It is thought that it will be possible to learn YOLO-v4 by directly building a data-set at the industrial site, and then implement a model that predicts the distance and determines whether it is a dangerous situation, which can be used as basic data for a comprehensive risk situation judgment model.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2010.10a
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• pp.19-22
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• 2010

부표 및 등부표는 항로를 표시하거나 항해상을 위험물을 표시하는 중요한 해상교통안전시설이다. 현재 부표 및 등부표의 표체가 철재로 되어 있으므로 해중 생물에 의한 오손, 무게로 인한 설치, 이설, 보수 등의 어려움이 있으며 무엇보다도 선박과의 충돌에 의한 부체의 손상이 발생하지 않은 철재 표체에 비하여 보수유지가 거의 필요없는 폴리에텔렌폼과 폴리우레탄 소재의 표체의 개발을 제시한다. 이 연구에서는 프로토타입으로서 LL260 표준 표체를 개발하였다.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.1896-1897
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• 2011

본 논문에서는 동적환경의 잠재적 위험 정의와 안전한 전역경로 계획 알고리즘을 제안 하였다. 대부분의 전역경로계획 연구는 시간과 거리의 비용을 최적화 시키는데 집중하고 있다. 하지만 동적환경으로 우리 주변에 많은 위험요소가 작용하고 있다. 본 논문에서 안전한 자율주행을 위한 경로계획방법으로 위험지역에 의해 정의 된 반발력과 S*알고리즘을 이용하여 안전하고 빠른 최적의 경로계획을 이루었다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2012.10a
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• pp.407-410
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• 2012

부표(등부표)는 항로를 표시하거나 항해상의 위험물을 표시하는 중요한 해상교통안전시설이다. 현재 부표(등부표)의 표체가 철재로 되어 있어 해중생물에 의한 오손, 무게로 인한 설치 이설 보수 등의 어려움이 있다. 무엇보다도 철재 표체에 비하여 선박과의 충돌에 의한 부체의 손상이 발생하지 않으며, 보수유지가 거의 필요 없는 폴리에틸렌폼과 폴리우레탄 소재의 표체의 개발을 제시한다.

• Journal of the Korean Institute of Gas
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• v.28 no.1
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• pp.85-99
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• 2024

As the proliferation of hydrogen electric vehicles accelerates, there is observed diversification in hydrogen refueling station models. This diversification raises safety concerns for different types of stations. This study conducted a quantitative risk assessment of a multi-vehicle hydrogen station, capable of simultaneously refueling cars, buses, and trucks. Utilizing Gexcon's Effects&Riskcurves Software, scenarios of fire and explosion due to hydrogen leaks were assessed. The study calculated the impact distances from radiative heat and explosion overpressure, and measured risks to nearby buildings and populations. The largest impact distance was from fires and explosions at dispensers and high-pressure storage units. High-pressure storage contributes most significantly to personal and societal risk. The study suggests that conservative safety distances and proper protective measures for these facilities can minimize human and material damage in the event of a hydrogen leak.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.35 no.1
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• pp.9-14
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• 2022

In this study, a smart jack-up system was developed to prevent safety accidents by performing risk analysis when a structure is lifted for maintenance. A quantitative risk analysis program that can analyze the risk using the pairwise comparison matrix analysis method was developed. The risk was analyzed in real-time for the lifting structure by connecting the program with an automatic jack-up system. Displacements were measured by the IR sensor among the components of the automatic jack-up system, and the displacements were provided to the quantitative risk analysis program. To confirm the performance of the smart automatic jack-up system, experiments were conducted on bridge and risk analysis was performed when a superstructure was lifted. A linear variable differential transformer (LVDT) was also installed on the bridge to verify the performance of the smart automatic jack-up system. The maximum displacements were measured using the devices, and the declinations were compared. The performance of the simultaneous operation of the jack-up device was verified by the analysis of variance (ANOVA).