• Journal of the Korean Institute of Gas
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• v.20 no.3
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• pp.38-45
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• 2016

In this study, we found that the release and dispersion of ammonia can create hazardous atmospheres using FLACS software. In General, ventilation or gas detector installations are recommended as preventive measures to control explosion incidents. However, the ventilation installations cannot be applicable to the refrigeration facility that uses ammonia as refrigerating medium, because the freezing room should be sealed. From the accident investigation of the explosion case, we suggested that all electronic devices were needed to be switched by explosion proof devices, and communication facility was also needed to be installed to announce to all employees within a building in case alert condition like ammonia releases occurred.

• Journal of the Korean Institute of Gas
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• v.1 no.1
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• pp.73-80
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• 1997

This study was performed to develop the dispersion modeling methodology for quantitative prediction of the hazard distance or toxic buffer distance by comparing 10-min average, 30-min average, and 1-hr average maximum ground-level concentration with $Cl_2$ regultaion concentration, IDLH and ERPG-3 concentration for hazardous toxic gas, $Cl_2$ releases from the storage tank of the chemical plant facilities. For this dispersion modeling, the source term model, dispersion model, meteorological and topographical data are incorporated into the SuperChems model, and then the effects of the atmospheric stability, wind speed, and surface roughness length changes on the maxum ground-level concentration were estimated.

• Journal of the Korean Institute of Gas
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• v.7 no.4 s.21
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• pp.14-19
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• 2003

Generally the accident by gas explosion in the working place is occurred at the condition of non-uniform mixture rather than uniform one. This study could predict the explosion phenomenon of non-uniform mixture with model explosion chamber which realize various practical conditions As a result, the mixing level of gas in the chamber depends on discharge area and velocity when there is gas discharge in certain space. In addition, as non-uniform increases, explosion pressure and its increasing rate decrease. However, firing risk after the explosion flame by infrared heat increase due to the increase of residence time of flame.

• Journal of the Korean Society of Marine Environment & Safety
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• v.30 no.5
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• pp.490-498
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• 2024

Ammonia is an eco-friendly marine fuel that does not emit carbon dioxide and is a primary contributor to global warming. Despite its benefits, ammonia poses significant risks owing to its toxicity, explosiveness, and corrosiveness, thus necessitating robust safety measures to manage its potential leaks on ships. This study investigates the characteristics of ammonia leaks and ventilation dynamics in a ship fuel-preparation room, with emphasis on the ef ect of varying the positions of air supply and exhaust outlets. The leakage rate is set at 0.1 kg/s, with a ventilation rate of 30 ACH (air changes per hour). The scenario with air supply at Aft - Top - Stbd and exhaust at Fwd - Top - Stbd (Case 1) results in the highest average ammonia concentration after 100 s. Conversely, the scenario with air supply at Aft - Bottom - Stbd and exhaust at Fwd - Bottom - Port (Case 14) results in the lowest concentration. After 50 s, Case 1 indicate ammonia concentrations exceeding 1500 ppm toward Aft, whereas Case 14 indicate a consistent stagnation zone along the Fwd wall. The distribution of ammonia concentration and velocity varies by height owing to the positioning of the air supply and exhaust outlets as well as the equipment configuration, thus resulting in higher concentrations in areas with slower airflow. When a small amount of ammonia leaked at 0.1 kg/s for 10 s, explosive gas formed near the leak point at a height of approximately 1 m, thus indicating an extremely low risk of explosion from slight ammonia leaks. This study confirms that the optimal combination of air supply and exhaust-duct positions can effectively control ammonia concentration. This finding is expected to contribute to the establishment of design standards and ensure safety when using ammonia as marine fuel.

• 전기의세계
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• v.52 no.9
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• pp.33-40
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• 2003

원전 안전등급 계측제어계통이 디지털화 되고 있으나 안전계통을 소프트웨어로 구현하는 과정에는 소프트웨어 공통모드고장(Common Mode Failure)과 같은 위험 요소가 존재한다. 일반 산업체와는 달리 원전에서 발생하는 사고는 일반 공중에게 방사능 누출 가능성을 내재하고 있어 디지털 안전계통은 원자로를 안전하게 정지시키는 것을 보장하고, 방사능이 누출되는 사고에 대해서도 그 피해를 최소화시키거나 방지할 수 있는 기능을 확보해야 한다. 이와 같은 원전 안전계통 디지털화의 성공과 원전의 안전성을 확보하기 위해서는 소프트웨어 신뢰성과 안전성 확보가 관건이며 안전-필수 소프트웨어 검증 기술개발이 절실히 요구된다. 본 기고에서는 원전 디지털 안전-필수 소프트웨어에 대한 개발방법과 규제요건, 규제방법 및 규제대처방법 등에서 공통적으로 고려해야 할 안전-필수 소프트웨어 개발 및 검증의 기술적 측면과 안전-필수 소프트웨어의 개발 및 검증의 각 단계에 대해서 기술한다.

• Journal of the Korean Institute of Gas
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• v.19 no.2
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• pp.1-4
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• 2015

The study analyses secondary damage of surrounding facilities from the fire accident by Unloading of LPG Bulk Lorry. Potential risk and extent of damage from jet flame and radiation heat is estimated with PHAST-RISK v6.7 program of DNV. According to above study, supplies can predict the damage range from gas release by Unloading, and be able to respond quickly.

• Journal of the Korean Institute of Gas
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• v.18 no.5
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• pp.1-5
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• 2014

As high-tech science has developed, the need of semiconductor is required constantly. However, there are many processes which use a great deal of poisonous gas in the semiconductor process, so the dangerousness by a gas leak is latent in these processes. Especially, the accident of toxic gas is almost made by ammonia and chlorine. Therefore this report estimates the damage by the leak of ammonia and chlorine used in LPCVD system.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.14 no.2
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• pp.75-83
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• 2004

We present a realization of an LFSM that utilizes an LFSR. This is based on a well-known fact from linear algebra. This structure is used to show that a previous attempt at using a cellular automata in place of an LFSR in constructing a stream cipher did not necessarily increase its security. We also give a general method for checking whether or not a nonlinear filter generator based on an LFSM allows reduction to one that is based on an LFSR and which is vulnerable to Anderson information leakage.

• 한국IT서비스학회:학술대회논문집
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• 2003.05a
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• pp.399-407
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• 2003

인터넷을 이용한 거래가 활발해지면서 개인 정보 누출, 사기 피해 등 이와 관련한 문제점들도 크게 증가하고 있다. 이러한 문제를 예방하기 위한 연구와 연구 결과의 활용이 활발한 가운데 특정 거래에 참여하는 거래 당사자에 대한 신뢰도를 측정하는 방법도 거래 위험도를 줄이는 방안의 하나로 연구되고 있다. 특히, 다수의 판매자와 구매자가 동시에 수 많은 거래에 참여하게 되는 온라인 경매의 경우 거래에 참여하는 거래 상대방에 대한 신뢰도를 측정하고 이를 제공함으로써 경매와 관련한 사기 거래의 위험성을 어느 정도 줄일 수 있게 된다. 본 연구에서는 온라인 경매 시스템에서 활용할 수 있는 퍼지 기반의 신뢰 측정 시스템의 기본 구조를 설계하고 그 작동 원리를 소개하고자 한다. 이를 위해 인맥형 커뮤니티 시스템으로부터 새로운 신뢰 측정 변수들을 도입하게 되며 이러한 신뢰 변수를 이용한 신뢰도 측정 과정을 자세히 소개한다.

• Proceedings of the Korean Society of Disaster Information Conference
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• 2023.11a
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• pp.133-134
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• 2023

유해위험한 물질을 다루는 사업장 내에서는 폭발·화재·누출 등의 사고가 발생할 가능성이 상시 존재하므로 사고를 미리 예방하고 위험성을 파악하여 발생할 수 있는 사고를 예방하고 대처하는 안전관리가 필요하다. 우리나라는 1990년대 이후 중대산업사고 예방을 위해 유해 위험방지계획서 시행, 공정 안전관리 제도 시행 등 여러모로 노력해 오고 있으나 최근의 일련의 중대 산업사고는 그 한계를 보여주고 있다. 그래서 본 연구는 PSM 취급사업장의 안전관리 개선을 위한 대책을제시하게 되었고 PSM 취급사업장의 안전관리 개선을 위해 철저한 안전 수칙 준수를 통해 중대 재해 발생을 방지하는 안전관리 개선에 대한 방안을 도출하였다.