• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 제38회 하계학술대회
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• pp.384-385
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• 2007

The fault current through the earth originated from a power line ground fault might cause arcing through the soil to an adjacent pipeline, which might bring about not only a catastrophic accident such as gas explosion and oil leakage but also a hazard to the safety of workers responsible for the maintenance and repair of the pipeline. In this paper we experimented on the soil breakdown test using the fixture and outlined the standards for the separation distance of a buried pipeline adjacent to the power line tower.

• Advances in concrete construction
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• 제8권3호
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• pp.165-172
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• 2019

Progressive collapse is one of the factors which if not predicted at the time of structure plan; its occurrence will lead to catastrophic damages. Through having a glance over important structures chronicles in the world, we will notice that the reason of their collapse is a minor damage in structure caused by an accident like a terrorist attack, smashing a vehicle, fire, gas explosion, construction flaws and its expanding. Progressive collapse includes expanding rudimentary rupture from one part to another which leads to total collapse of a structure or a major part it. This study examines the progressive collapse of a 5-story concrete building with three column eliminating scenarios, including the removal of the corner, side and middle columns with the ABAQUS software. Then the beams and the bottom of the concrete slab were reinforced by (reinforcement of carbon fiber reinforced polymer) FRP and then the structure was re-analyzed. The results of the analysis show that the reinforcement of carbon fiber reinforced polymer sheets is one of the effective ways to rehabilitate and reduce the progressive collapse in concrete structures.

• Nuclear Engineering and Technology
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• 제54권6호
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• pp.2062-2066
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• 2022

Nuclear energy sources are indispensable in cost effectively achieving carbon neutral economy, where public opinion is critical to adoption as the consequences of nuclear accident can be catastrophic. In this context, discussion on spent nuclear fuel is a prerequisite to expanding nuclear energy, as it leads to the issue of radioactive waste disposal. Given the dearth of study on spent nuclear fuel public acceptance, we use text mining and big data analysis on the news article and public comments data on Naver news portal to identify the Korean public opinion on spent nuclear fuel. We identify that the Korean public is more interested in the nuclear energy policy than spent nuclear fuel itself and that the alternative energy sources affect the position towards spent nuclear fuel. We recommend relating spent nuclear fuel issue with nuclear energy policy and environmental issues of alternative energy sources to further promote spent nuclear fuel.

• 한국재난정보학회 논문집
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• 제16권1호
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• pp.44-59
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• 2020

이 논문에서는 2층 건물 지하층의 다방에서 가스냄새가 난다고 119신고가 되어 소방대원들이 출동하여 옥상에 있는 LPG 가스통들의 밸브를 직접 잠그고 지하층 다방의 중간밸브의 잠금 상태를 확인하고 현장에 도착한 가스공급 및 설치 업자에게 안전조치를 취하도록 요구하고 철수한 후 7분 만에 가스폭발사고가 발생하여 2명이 사망하고 21명이 부상을 입은 사례를 분석하고 있다. 법원은 가스폭발사고의 원인이 규명되지 아니하였으므로 가스공급 및 설치 업자와 한국가스안전공사에 배상 책임을 물을 수 없고 안전조치를 하지 않고 철수한 소방기관에게만 배상책임이 있다고 판결하였다. 그러므로 가스가 누설된다고 119신고가 되는 경우에 출동한 소방대는 가스 밸브를 잠그고 사람들을 대피시키거나 접근하지 못하게 하고 환기를 시키는 등 안전조치를 하고 화재나 폭발가능성이 없음을 확인한 후 철수해야 한다.

• 한국가스학회지
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• 제4권3호
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• pp.1-8
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• 2000

연료가스의 사용이 늘어나고 고압가스를 사용하는 공정이 날로 대형화$\cdot$복잡화됨에 따라 가스사고도 대형화되는 둥 이를 적절하게 관리할 필요성이 증대되고 있다. '95${\~}$'98년 동안 발생했던 사고를 체계적으로 분류$\cdot$분석하여서 사고 발생에 영향을 미치는 주된 요인을 찾아내었다. 그 결과 사고감소분야에 대해서는 기존의 사고관리정책을 견지하도록 하며 사고가 소폭 감소하거나 증가하는 분야에 대해서는 감소 대책을 제시하였다. '95${\~}$'98년 가스사고는 총 2,027건이며 띨6년 이후 연평균 $12\%$ 감소하는 것으로 나타났다. 가스종류별로는 LPG(Liquefied petroleum gas), 도시가스 등 연료가스사고가 $96\%$로서 대부분이며 사용처별로는 주택, 요식업소 등 사용시설에서 주로 사고가 발생했다. 원인별로는 가스의 종류 및 시설에 따라 그 특징이 다르나 시설미비, 제품불량, 및 사용자 취급부주의에 의한 사고가 대부분을 차지하였다. 연료가스에 의한 고의사고는 311건으로 전체가스사고 중 $15\%$를 차지하며 연평균 $38\%$ 증가하는 추세이나 그 발생 매커니즘이 다르므로 향후 좀더 체계적인 분석을 할 필요가 있으며 이번 분석에서 제외하였다.

• 한국산업융합학회 논문집
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• 제21권6호
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• pp.395-408
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• 2018

Even after the Fukushima nuclear accident in 2011, the rate of production of electric energy using nuclear energy is increasing, but there is a great danger such as the radioactive waste produced when using nuclear power, the catastrophic accident of nuclear power plant, and connection with nuclear weapons. In particular, Cs present in the ionic form of alkaline elements has a long half-life (30.17 years) because it is readily absorbed by the organism and emits intense gamma rays, thus presenting a serious radiation hazard. Therefore, it must be completely removed before it can be released into the natural ecosystem, because it can adversely affect not only humans but also natural ecosystems. Many adsorbents and ion exchangers which have high Cs removal efficiency have been used in recent years to completely separate and remove by self separation in water. Many adsorbents and ion exchangers which have high Cs removal efficiency have been used in recent years to completely separate and remove by self separation in water. In addition, researches have been doing to synthesize magnetic materials with adsorbents such as HCF and PB, and it shows a great effect in the removal rate of Cs present in wastewater or the maximum Cs adsorption amount. In particular, when a magnetic material was applied, excellent results were obtained in which only Cs was selectively removed from other cations. However, new problems such as applicability in the sea where Cs is directly released, applicability in various pH ranges, and failure to preserve the magnetizing force possessed by the magnetic body have been found. However, researches using ferromagnetic field with stronger magnetic properties than those of magnetic bodies is considered to be insufficient. Therefore, it is considered that if the researches combining the ferromagnetic field with the magnetization ability and functional adsorbents more actively, the radioactive material Cs which adversely affects the natural ecosystem can be effectively removed.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제14권2호
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• pp.113-121
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• 2014

A subsea oil production system must be safely operated for 20-30 years after being installed. Because of the severe conditions of the subsea environment, such as extreme high pressure, low visibility, the possibility of unexpected impact by any object, and corrosion by seawater, subsea oil production systems should be monitored by subsea data logger systems and remotely operated vehicles to check for abnormal vibration and leakage to prevent a catastrophic accident. Because of the severity of subsea environmental conditions and the dominance of a few companies in the market, many people have thought that it would be difficult to develop a subsea data logger system. The primary objectives of the study described in this paper were to analyze existing subsea data logger systems to establish the requirements for a subsea data logger system, implement a prototype subsea data logger system, and conduct a test of the prototype subsea data logger system.

• 대한기계학회논문집B
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• 제26권6호
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• pp.788-794
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• 2002

In liquid rocket engine, propellant feed rate is proportional to approximately square root of the pressure difference between injector head and combustion chamber. This ΔP depends on the engine design, but in general on the order of 50psi. However, during ignition period, especially for the pressurized feed system, combustion chamber pressure is almost atmospheric and large ΔP causes over flow of propellants which may lead to catastrophic accident due to hard start. Hard start may be prevented by applying cavitating venturi or/and two step ignition. In cavitating venturi, evaporated propellants near the venturi throat become chocked and flow rate depends on only upstream condition. In two step ignition propellants are supplied to the liquid engine in two different flow rate. First step, to avoid hard start, small amount of propellants are supplied to build up chamber pressure in safe zone, then full propellants to ensure design pressure. In this study, both cavitating venturi and two step ignition method were used for the hot test and hard start problem was completely solved.

• 한국가스학회지
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• 제11권1호
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• pp.18-22
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• 2007

전력선에 지락고장이 발생할 경우 대지로 유입된 고장전류에 의하여 인접한 배관에 아크 용융이 발생하면 가스폭발이나 기름유출과 같은 대형사고를 발생시킬 수 있으며, 배관의 유지 및 보수를 담당하는 작업자의 안전에도 위험을 초래할 수 있다. 본 논문에서는 대지를 통한 철탑과 배관 사이의 아크 발생에 대하여 알아보고, 국내외에서 사용되고 있는 철탑 인근에 매설된 배관의 이격거리 기준을 조사하였다.

• 한국CDE학회논문집
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• 제21권2호
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• pp.111-121
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• 2016

The plant equipment usually has a long life cycle. During its O&M (Operation & Maintenance) phase, since the occurrence of an accident of offshore plant equipment causes catastrophic damage, it is necessary to make more efforts for managing critical offshore equipment. Nowadays due to the emerging ICTs (Information Communication Technologies) and sensor technologies, it is possible to gather the health status data of important offshore equipment and their environment data, which leads to much concern on CBM (Condition-Based Maintenance). In this study, we will propose an approach to estimate the remaining lifetime of an offshore plant equipment (pump tower) based on gathered ocean environment data.