• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.2072-2073
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• 2007

This paper describes the analysis of potential distribution and leakage current magnitude around the electrical fittings submerged in an underground shopping street. In the experiment, a couple of electrical utilities(outlet, fluorescent lamp) were submerged in a concrete water bath. The experimental results are expected to be utilized for the risk assessment and the safety countermeasure against the electric shock.

• Journal of the Korea Safety Management & Science
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• v.17 no.4
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• pp.297-304
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• 2015

This study concerns the integrated gas sensor system of wire and wireless communication by using IoT(Internet of Things) technology. First, communication part is that it delivers the detection information, which transferred by wire or wireless communication and required control procedure based on a wireless module that receives the gas leakage information from wired or wireless detector, to administrator or user's terminal. Second, receiver part is that it shows the location and information, which received from the wired detector formed by a detecting sensor's node as linking with the communication part, and transfers these to the communication part. Third, wireless detector formed as a communication module of a detecting sensor node is that it detects gas leakage and transfers the information through wireless as a packet.Fourth, wired detector communicated with the receiver part and formed as a communication module of a detecting sensor node is that it detects gas leakage, transfers and shows the information as a packet. Fifth, administrator's terminal is that it receives gas leakage information by the communication part, transfers the signal by remote-control, and shut off a gas valve as responding the information. Sixth, database is that it is connected with the communication part; it sets and stores the default values for detecting smoke, CO., and temperature; it transfers this information to the communication part or sends a gas detecting signal to user's terminal. Seventh, user's terminal is that it receives each location's default value which stored and set at the database; it manages emergency situation as shutting off a gas valve through remote control by corresponding each location's gas leakage information, which transferred from the detector to the communication part by wireless.It is possible to process a high quality data regarding flammable or toxic gas by transferring the data, which measured by a sensor module of detector, to the communication part through wire and wireless. And, it allows a user to find the location by a smart phone where gas leaks. Eventually, it minimizes human life or property loss by having stability on gas leakage as well as corresponding each location's information quickly.

• Journal of Korean Tunnelling and Underground Space Association
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• v.24 no.4
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• pp.305-316
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• 2022

Hydrogen energy is emerging as an alternative to the depletion of fossil fuels and environmental problems, and the use of hydrogen vehicles is increasing in the automobile industry as well. However, since hydrogen has a wide flammability limit of 4 to 75%, there is a high concern about safety in case of a hydrogen car accident. In particular, in semi-enclosed spaces such as tunnels and underground parking lots, a fire or explosion accompanied by hydrogen leakage is highly likely to cause a major accident. Therefore, it is necessary to review hydrogen safety through analysis of flammability areas caused by hydrogen leakage. Therefore, in this study, the effect of the air velocity in the tunnel on the flammability area was investigated by analyzing the hydrogen concentration according to the hydrogen leakage conditions of hydrogen vehicles and the air velocity in the tunnel in a road tunnel with standard section. Hydrogen leakage conditions were set as one tank leaking and three tanks leaking through the TPRD at the same time and a condition in which a large crack occurred and leaked. And the air velocity in the tunnel were considered 0, 1, 2.5, and 4.0 m/s. As a result of the analysis of the flammability area, it is shown that when the air velocity of 1 m/s or more exists, it is reduced by up to 25% compared to the case of air velocity of 0 m/s. But there is little effect of reducing the flammability area according to the increase of the wind speed. In particular, when a large crack occurs and completely leaks in about 2.5 seconds, the flammability area slightly increases as the air velocity increases. It was found that in the case of downward ejection, hydrogen gas remains under the vehicle for a considerably long time.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 2008.04a
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• pp.217-222
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• 2008

In the last five years, 45 people died and 104 were wounded because of carbon monoxide poisoning accident. CO poisoning accident is higher than any other gas accident in the rate of deaths/incidents. Most of these CO poisoning accidents were caused by defective exhaust tube in the old gas boiler and multi-use facility. In this study, the spread of CO gas released from leakage hole of exhaust tube was analyzed by concentration measuring test. CO gas leaked form exhaust tube in a building was highest concentrated near the ceiling. Through these experiments, the reasonable installation location of CO alarm was made certain and suggested.

• International Journal of Safety
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• v.9 no.2
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• pp.1-5
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• 2010

In order to analyze the potential rise of ground surface of grounding grid installed in buildings, the grounding simulator has been designed and fabricated as substantial and economical measures. This paper describes the study of touch and step voltages with grounding grid where earth leakage current is injected. To assess risk voltage of grounding grid, the grounding simulator and CDEGS program were used to obtain measured data and theoretical results of this study. The grounding simulator was composed of an electrolytic tank, AC power supply, a movable potentiometer, and test grounding electrodes. The potential rise was measured by grounding simulator, and the touch and step voltages were computed by CDEGS program. As a consequence, the touch voltage and step voltage above the grounding grid were very low, but were significantly increased near the edge of grounding grid.

• Journal of the Korean Society of Safety
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• v.26 no.5
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• pp.33-40
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• 2011

In the hazardous areas where explosive liquids, vapors and gases exist, electrical apparatus/equipment should have explosion-proof construction. The consuming of liquefied natural gas(LNG) has markedly increased in the industrial field, especially in aspect of some thermoprocessing equipment, boiler, dryer, furnace, annealer, kiln, regenerative thermal oxidizer(RTO) and so on. Because it has many merits, clean fuel, safety, no transportation/storage facility and so on. It is strongly recommend that the classification of hazards has to be decided to prevent and protect explosion which may occur in thermoprocessing equipment. In this paper, the operated thermoprocessing equipments in industrial area investigated and explosion risk assessment about LNG leakage from its facilities was performed through numerical calculation and computer simulation. Finally, we suggest the systemic/technical approach for safety assessments of thermoprocessing equipments consumed LNG fuel which are specially subjected to classification of hazardous area.

• Journal of the Korean Institute of Gas
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• v.13 no.2
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• pp.36-40
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• 2009

In this study, we surveyed 544 drivers, who had taken the education course for autogas car drivers, to figure out their safety awareness status including the recognition of hazards of gas leaking from autogas cars and response attitude toward them. As a result of the survey, we found out that 63% of the responders recognized the hazards of gas leakage and 79% preferred parking in the aboveground areas. For the necessity of introducing restrictions on autogas cars parking in underground lots, 58% of all responders answered yes while 71% of the responders aged over fifties and 73% of them who responded to have known the hazards of parking in underground answered in the affirmative. Furthermore, we found out that responders who had recognized the hazards preferred aboveground parking areas, and the responders who had preferred the aboveground recognized the hazards of parking autogas cars underground and felt the necessity of restricting them from parking in underground relatively high. Through the analysis of these results, we can analyse that the drivers who are aware of the hazards of gas leakage have higher safety attitude for hazards than the other drivers who are not aware of them.

• Journal of the Korean Institute of Gas
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• v.18 no.5
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• pp.12-19
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• 2014

To minimize the risk of corrosion on buried pipeline and to maximize the efficiency of cathodic protection, various indirect inspection techniques have been used for decades. In the United States, 49 CFR has regulated the external corrosion direct assessment for buried pipelines. In Korea, there is no provision for external corrosion direct assessment but there is only, according to the KGS Code, provision that if the survey of the defects of buried pipeline and the leakage test for the pipe were conducted, it is deemed to leakage inspection. We, therefore, have suggested external corrosion direct assessment method appropriate to domestic status through the survey of the regulations and standards of UK and the USA and the investigation of domestic situation on coating damage detection method. The proposed external corrosion direct evaluation method was used as the basis when introducing the precision safety diagnosis regulation for the medium-pressure pipe in Korea.

• Journal of the Korean Institute of Gas
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• v.27 no.4
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• pp.1-11
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• 2023

The size of the OLED material market is expected to grow from $1.1 billion in 2019 to $2.3 billion in 2023, with an average annual sustainable growth of more than 19%. Among the facilities mainly used by OLED material manufacturers, accidents such as fire, explosion, and leakage frequently occur when using filtration equipment, so it is necessary to improve the risk when using filtration equipment. In this study, it was divided into four main processes, namely, assembly and disassembly process, filtration process, wet cake recovery process, and washing process in order to derive the risks associated with the use of filtration equipment. Hazard factors were derived by conducting accident case investigations, preliminary interviews, and surveys. For the analysis of questionnaire results, statistical analysis such as frequency analysis and Pearson chi-square test analysis was performed using SPSS 21, and risk improvement measures were suggested using the analyzed results. It is expected that this study will serve as a basis for dealing with safety and risk factors that may occur as the size of the OLED market expands.

• Proceedings of the KSR Conference
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• 2005.11a
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• pp.587-592
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• 2005

Explosions of dangerous goods such as accidents at Iri and Yongcheon Stations bring about a big damage and loss of assets. And leakage of toxic and dangerous materials may cause environmental pollution. Therefore, in developed countries, safety and operation codes for the carriage of dangerous goods were already established. In this study. we have searched. analyzed and summarized korean domestic codes concerning the carriage of dangerous goods for the drawing up of a korean safety standard code.