• Proceedings of the KSR Conference
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• 2008.11b
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• pp.50-55
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• 2008

The comparative analysis of fire-driven flow simulation for Dae-Gu subway station was performed using FDS and Fluent. The boundary condition was obtained from analyzed data for Dae-Gu subway fire accident which had been outbreaked in 2003 year. The smoke flow in the second and third basement has been analyzed. The CO and temperature distribution in the train units and station platform have been obtained with FDS and FLUENT and compared with each other. Total simulation time is 600s and the results are compared of each 10sec The analyzed data will be applied to the passenger evacuation simulation for Dae-Gu subway station and used to optimal design method.

• Journal of the Korean Institute of Gas
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• v.27 no.4
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• pp.70-77
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• 2023

In response to climate change, each country is proposing a goal to reduce greenhouse gases in its energy supply and demand plan, and the use of hydrogen gas is a topic that is always prioritized as an energy resource for implementation. A popular way to use this hydrogen gas is the use of hydrogen fuel cell vehicles, and expansion of hydrogen charging stations is essential for using these hydrogen fuel cell vehicles. However, there are several limitations to the expansion of hydrogen refueling stations, the most representative of which is resident acceptance. Most of the hydrogen charging stations currently built in Korea are located in the outskirts with low population density, so the inconvenience to hydrogen fuel cell vehicle users has not been resolved, and as a result, there has been no progress in the spread of hydrogen fuel cell vehicles. In this paper, we analyzed the consequences of accident damage to determine the risks of constructing a hydrogen charging station on a railroad site frequently used by citizens. The target hydrogen charging station site was a railroad depot in Busan, and there are trains, national highways, and commercial facilities around this site. Assuming the worst-case scenario, we would like to consider the safety of the hydrogen refueling station site by analyzing the area affected by the accident and its consequence.

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.658-670
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• 2007

Most railroad accidents are due to human errors. In particular, most of the causes of these accidents are faults of an engine driver, such as lack of signal confirmation, insecure braking, driving by guess or force of habit. This paper identifies a problem(s) by analyzing accidents for the past 10 years and also seeks a solution to train good engine drivers in order to prevent railroad accidents. In summary, what is needed are: 1) proper placement of various manpower, 2) proper training of engine drivers, 3) proper legislation for a 2-man on board system, and 4) proper reformation of personnel management.

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.1354-1361
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• 2007

The evacuation simulation study was performed with the boundary condition of a fire simulator, referring to Dae-gu Subway Fire Accident which was a real station fire. The subway station was modelled from B3F station building to B2F waiting room in fire simulation. Also, a fire simulation were performed with CFAST and FLUENT. In CFAST, the total 29 zones were divided into 18 station buildings in B3F and 11 station buildings in B2F. In FLUENT, the simulated space had the same establishment as zone of CFAST. The study focused on possibility for application of fire simulation in underground station by comparing the resulted values from two simulators. For application of fire effect, the fire data were loaded directly to EXODUS in the case of CFAST and performed a passenger evacuation simulation. In the case of FLUENT, Out Data values of a fire simulation were difficult to be compatible with EXODUS. Two resulted values of passenger evacuation simulation by fire simulation were compared with the Dae-gu Subway Fire Accident in reality.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.4
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• pp.12-19
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• 2016

The monitoring system in railway is under study to forecast any derailment and accident by defect of train. Because the monitoring system is composed of wireless sensor network based on ZigBee-communication between inside and outside of train, the study for wireless channel analysis is required. Especially, if multipath delay profile exist in the channel, the equalizer and channel estimator can be required for preventing receiver performance degradation. Therefore, we analyzed the wireless channel in train environment using measured data and, proposed the channel estimation method through the characterisitic of chip code, under the consideration of the channel characteristics in train. To show the performance of proposed method, we demonstrate the performance by mean square error(MSE), computational complexity and bit error rate(BER).

• Proceedings of the Safety Management and Science Conference
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• 2009.04a
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• pp.35-43
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• 2009

The specific feature of trains as a means of transportation is that, on one side, at once they can carry big loads but, at the same time, if an accident occurs, it potentially leads to many human casualties or big material losses. Especially, train accidents caused by bad weather conditions result in many fatal losses of human lives and property. In Korea many railways run either in mountainous areas or along rivers thus making them especially susceptible to natural hazards. The types of damages inflicted by heavy rains resulting from rapidly changing meteorological conditions are diverse; and not only their scope is big but also they repeat regularly. Consequently, this study analyses the reasons why such effects of heavy rains on the railway conditions, damage to the railways caused by heavy rains or cases of stone fall as well as other types of accidents are not avoided. Study also, on the basis of laws related to movement in poor weather conditions and specifics of train braking, identifies systematic and technical problems and suggests and emphasizes new complex measures on their prevention.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.58-68
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• 2007

Thorough preparations and investigations must be done in order to prevent the hazards which will happen when workers work on the roof of the rolling stocks. Some industrial disasters can be prevented by solving the risks involved in the working of the work processes. Falling accidents tend to happen from the roof of the trains when workers work in the high position. So through the analysis of the 4M( Man. Machine, Media, Management), this paper analyzed the risk factors among the roof works and all problems of the maintenance. Also this paper suggests new devices or new methods to prevent falling disasters and to relieve the mental senses of uneasiness.

• Journal of the Korea Safety Management & Science
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• v.11 no.1
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• pp.1-6
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• 2009

The specific feature of trains as a means of transportation is that, on one side, at once they can carry big loads but, at the same time, if an accident occurs, it potentially leads to many human casualties or big material losses. Especially, train accidents caused by bad weather conditions result in many fatal losses of human lives and property. In Korea many railways run either in mountainous areas or along rivers thus making them especially susceptible to natural hazards. The types of damages inflicted by heavy rains resulting from rapidly changing meteorological conditions are diverse; and not only their scope is big but also they repeat regularly. Consequently, this study analyses the reasons why such effects of heavy rains on the railway conditions, damage to the railways caused by heavy rains or cases of stone fall as well as other types of accidents are not avoided. Study also, on the basis of laws related to movement in poor weather conditions and specifics of train braking, identifies systematic and technical problems and suggests and emphasizes new complex measures on their prevention.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.7
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• pp.4863-4870
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• 2015

Currently, as a priority to secure the safety of the railway signalling system, verification for satisfy of the safety integrity requirements(SIR) is required to the essential elements. Safety Integrity Requirements(SIR) verification is performed based on the system safety analysis. But the probability of securing basic data for system safety analysis significantly dropped because there is no experience yet performed in the country. Therefore we are had to rely on a qualitative analysis. There are methods such as qualitative risk analysis matrix, and risk graphs. The qualitative analysis is wide, the width of the accident. However, the reliability of the result is significantly less has a disadvantage. Therefore, it should be parallel quantitative safety analysis of the system/products in order to compensate for the disadvantages of the qualitative analysis. This paper presents a quantitative safety analysis method to overcome the disadvantages of the qualitative analysis. And through a result, highly reliable Safety Integrity Requirements(SIR) verification measures proposed. Verification results, the dangerous failure incidence for vital data processing device was calculated to be $1.172279{\times}10^{-9}$. The result was verified to exceed the required safety integrity targets more.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.1807-1813
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• 2007

The study aims at analyzing an underground station refuge model using EXODUS, one of the refuge simulation programs. The model for simulation is the Daegu Subway (Joongang-ro station). The details of the accident are referred to as the simulation condition the refuge time of traveling from the $3^{rd}$ basement platform to the $1^{st}$ basement is mainly calculated, with passengers numbering 1,000 including 329 at car 1079, 320 at car 1080, and 360 who are not on board. Reference data is used to set up the position of passengers. CFAST fire simulator is also used, and a fast curve among the $t^2$ growth curves, selected as fire growth scenario. The zone is divided into a total of 24 including 18 at the $3^{rd}$ basement platform and 6 at the $2^{nd}$ basement the $1^{st}$ basement is excluded in the fire simulation, however.