• Journal of the Korean Society of Safety
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• v.28 no.4
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• pp.1-7
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• 2013

Train accidents can be directly connected to fatal accidents-collision, derailment, Fire, railway crossing accidents-resulting in tremendous human casualties. First of all, the railway derailment is not only related to most of railway accidents but also it can lead to much more catastrophic accompanying train overtured than other factors. Therefore, it is most important factor to ensure railway safety. some foreign countries have applied to the detector machines(e.g., ultrasonic detector car, sleep mode, current detector, optical sensing, optical fiber). Since it was developed in order to prevent train from being derailed. In korea, the existing track method has been used to monitor rail condition using track circuit. However, we found out it impossible for Communication Based Train Control system(CBTC), recent technology to detect rail condition using balise(data transmission devices) without no track circuit. For this reason, it is needed instantly to develop real-time monitoring system used to detect broken rails. Firstly, this paper presents domestic and international statues analysis of rail breaks technology. Secondly, the composition and the characteristics of the real-time monitoring system. Finally, the evidence that this system could assumed the location and type of broken rails was proved by the experiment of prototype and operation line tests. We concluded that this system can detect rail break section in which error span exist within${\pm}1m$.

• Journal of Preventive Medicine and Public Health
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• v.35 no.1
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• pp.72-75
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• 2002

Objectives : To evaluate the health hazards in the underground storage facilities of ginger roots. Methods : The authors reviewed the emergency rescue records from the Seosan fire department over the period Jan 1, 1996 to Aug 31, 1999. The atmospheres in 3 different underground storage locations were analyzed for $O_2,\;CO_2,\;CO,\;H_2S\;and\;NH_4$. Results : From the emergency records, we were able to identify 20 individuals that had been exposed to occupational hazards in the underground storage facilities. Among these 20 cases, 13 were due to asphyxiation (resulting in f deaths) and 7 were due to falls. In the first atmospheric tests, peformed on Feb 25, 1998, the O2 level inside the underground storage facility, located about $5{\sim}6$ meters below the surface, was 20.6% and the $CO_2$ level was about 1,000 ppm. CO, $H_2S\;and\;NH_4$ were not detected. In the second tests on Jul 6, 1999, measurements of the $O_2$ level at 3 meters below the surface in two different storage locations were 15.3 and 15.1%. And the $O_2$ levels inside the storage facilities were 12.2 and 12.1%. The $CO_2$ level was above 5,000 ppm (beyond upper limits of measurement). CO, $H_2S\;and\;NH_4$ were not detected. Conclusions : We conclude that asphyxiation in the underground storage facilities for ginger roots was not due to the presence of toxic gases such as CO, $H_2S\;and\;NH_4$, but rather the exclusion of oxygen by carbon dioxide was responsible for causing casualties. For the development of a hazard free working environment, safety education as well as improvements in storage methods are needed.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.05a
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• pp.69-70
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• 2017

As the industry develops, the size of buildings and ships are getting bigger and more complicated. In such a complex space, emergency evacuation systems are required because of the possibility of casualties when an accident situation occurs. However, because present systems are composed of basic devices, such as alarms, emergency exit signs, and announcement regarding the situation and inform only the least information to evacuees, evacuees are not able to judge objectively. To solve these problems, various evacuation algorithms have been proposed. However, these studies aim to search evacuation routes based on specific risk factors or to model the effects of bottlenecks in evacuation situations. Therefore, there is a limit to apply to real systems. Therefore, we propose algorithms to search the optimal evacuation route considering various risk factors such as fire and bottleneck in evacuation situations and to be applicable in actual situation in this paper. Performance evaluation using computer simulations showed that the proposed scheme is effective.

• Journal of the Society of Disaster Information
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• v.13 no.4
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• pp.422-441
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• 2017

Notifying emergency evacuation methods, accurate disaster location and evacuation route guidance can be very active alternatives to quickly minimize evacuation and casualties in disaster situation in the development of subway disaster prevention detection system that detects the disaster signs at the subway station early on the basis of Internet of things and leads passengers to evacuate. It's not easy to ensure perfect functioning of fire fighting facilities and equipments due to underground space structure with narrow exits. Therefore, we developed disaster provision EL Display integrated board that can induce the most efficient evacuation and the field experiment was conducted to examine the practical application in this study. Especially the applicability was verified by field application test because there is no case in which EL panels are used to evacuate disasters.

• Journal of the Korean Society of Safety
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• v.37 no.2
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• pp.1-9
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• 2022

Most factories deal with toxic or flammable chemicals in their industrial processes. These hazardous substances pose a risk of leakage due to accidents, such as fire and explosion. In the event of chemical release, massive casualties and property damage can result; hence, quantitative risk prediction and assessment are necessary. Several methods are available for evaluating chemical dispersion in the atmosphere, and most analyses are considered neutral in dispersion models and under far-field wind condition. The foregoing assumption renders a model valid only after a considerable time has elapsed from the moment chemicals are released or dispersed from a source. Hence, an initial dispersion model is required to assess risk quantitatively and predict the extent of damage because the most dangerous locations are those near a leak source. In this study, the dispersion model for initial consequence analysis was developed with three-dimensional unsteady advective diffusion equation. In this expression, instantaneous leakage is assumed as a puff, and wind velocity is considered as a coordinate transform in the solution. To minimize the buoyant force, ethane is used as leaked fuel, and two different diffusion coefficients are introduced. The calculated concentration field with a molecular diffusion coefficient shows a moving circular iso-line in the horizontal plane. The maximum concentration decreases as time progresses and distance increases. In the case of using a coefficient for turbulent diffusion, the dispersion along the wind velocity direction is enhanced, and an elliptic iso-contour line is found. The result yielded by a widely used commercial program, ALOHA, was compared with the end point of the lower explosion limit. In the future, we plan to build a more accurate and general initial risk assessment model by considering the turbulence diffusion and buoyancy effect on dispersion.

• Wind and Structures
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• v.36 no.6
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• pp.405-421
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• 2023

Strong wind is the main factors of wind-damage of high-rise buildings, which often creates largely economical losses and casualties. Wind pressure plays a critical role in wind effects on buildings. To obtain the high-resolution wind pressure field, it often requires massive pressure taps. In this study, two traditional methods, including bilinear and bicubic interpolation, and two deep learning techniques including Residual Networks (ResNet) and Generative Adversarial Networks (GANs), are employed to reconstruct wind pressure filed from limited pressure taps on the surface of an ideal building from TPU database. It was found that the GANs model exhibits the best performance in reconstructing the wind pressure field. Meanwhile, it was confirmed that k-means clustering based retained pressure taps as model input can significantly improve the reconstruction ability of GANs model. Finally, the generalization ability of k-means clustering based GANs model in reconstructing wind pressure field is verified by an actual engineering structure. Importantly, the k-means clustering based GANs model can achieve satisfactory reconstruction in wind pressure field under the inputs processing by k-means clustering, even the 20% of pressure taps. Therefore, it is expected to save a huge number of pressure taps under the field reconstruction and achieve timely and accurately reconstruction of wind pressure field under k-means clustering based GANs model.

• Journal of the Korean Institute of Gas
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• v.27 no.3
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• pp.84-90
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• 2023

Oxygen, which is always present in the atmosphere among the three elements of combustion, can cause fires and explosions with only a very small amount of combustibles under high-pressure oxygen conditions. The burning rate is also significant, and can rise to temperatures that can have a direct impact, such as melting process equipment and piping in an instant. Therefore, accidents that occur under high pressure oxygen often cause more damage than other accidents. Recently, while operating a valve installed in an oxygen supply pipe, rapid combustion and rupture occurred inside, resulting in human casualties due to an explosion. In the case of an old carbon steel pipe, particles generated during operation become combustible and can cause accidents. . In particular, since oxygen facilities are facilities licensed under the High Pressure Gas Safety Management Actand there are no restrictions under the Occupational Safety and Health Act, accumulating these standards is of utmost importance. Therefore, in this study, based on accident cases and overseas standards, methods for improving safety when handling hyperbaric oxygen are reviewed.

• Journal of the Korea Institute of Building Construction
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• v.9 no.4
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• pp.63-73
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• 2009

Recently, the use of lightweight panels in building structures has been increasing. Of the various lightweight panel types, styrofoam sandwich panels are inexpensive and are excellent in terms of their insulation capacity and their constructability. However, sandwich panels that include organic material are quite vulnerable to fire, and thus can numerous casualties in the event of a fire due to the lack of time to vacate and their emission of poisonous gas. On the other hand, lightweight foamed concrete is excellent, both in terms of its insulation ability and its fire resistance, due to its Inner pores. The properties of lightweight concrete is influenced by foaming agent type. Accordingly, this study investigates the insulation properties by foaming agent type, to evaluate the possibility of using light-weight foamed concrete instead of styrene foam. Our research found thatnon-heating zone temperature of lightweight foamed concrete using AP (Aluminum Powder) and FP (animal protein foaming agent) are lower than that of light-weight foamed concrete using AES (alkyl ether lactic acid ester). Lightweight foamed concrete using AES and FP satisfied fire performance requirements of two hours at a foam ratio 50, 100. Lightweight foamed concrete using AP satisfied fire performance requirements of two hours at AP ratio 0.1, 0.15. The insulation properties were better in closed pore foamed concrete by made AP, FP than with open pore foamed concrete made using AES.

• Fire Science and Engineering
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• v.32 no.5
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• pp.46-51
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• 2018

The purpose of this study was to assess the evacuation route in a disaster information map to evacuate people to a shelter quickly and precisely during a disaster situation. For this purpose, this study examined the current status of domestic and international disaster information maps and related laws and conducted experiments to derive effective types of intersecting routes. The problems of the disaster information map were obtained through the first preliminary experiment and a survey. Based on these problems, experiments for each type were conducted to provide effective indication information for a disaster information map. To investigate the gait characteristics according to the number of crossing paths, the reduction rate in the crossing path was derived for each type by comparing the previous speed and passing speed. This will enable suggestions to judge the route quickly and accurately when determining the intersecting route in the search for an evacuation route. In conclusion, the experiment of this paper aims to make rapid and accurate evacuations using the disaster information map in response to disasters, and provide guidelines to citizens to contribute to a reduction of casualties.

• Journal of the Korean Recycled Construction Resources Institute
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• v.9 no.4
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• pp.642-649
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• 2021

Energy saving standard for buildings are strengthened, the application of exterior insulation finishing system and thickness of insulation materials are increasing. Most buildings with exterior insulation finishing system is applied organic insulating material. Organic insulating material have workability, economic feasibility, reduction in construction cost, and excellent thermal insulation performance. However, Organic insulating material is very vulnerable to heat, so when a fire occurs, rapid fire spread and toxic gas are generated, causing many casualties. Inorganic insulating material can be non-combustible performance, but it is heavy and has low thermal insulation performance. Mineral wool has higher thermal insulation performance than other types of inorganic insulating material, but mineral wool is disadvantageous to workability and vulnerable to moisture. Glass bubble are highly resistant to water and chemically stable substances. In addition, the density of the glass bubble is very low and the particles are spherical, fluidity is improved by the ball bearing effect. Glass bubbles can be used with cement-based ino rganic insulating material to impro ve the weight and thermal insulatio n perfo rmance o f cement-based inorganic insulation. This study produced a inorganic insulating materials were manufactured using cement-based materials and glass bubble. In order to evaluate the insulation performance and flame retardant performance of cement-based super light-weight inorganic insulating materials using with glass bubble, insulation performance or flame retardant and non-combustible performance were evaluated after manufacturing insulating materials using micro cement and two types of glass bubbles. From the test result, Increasing the mixing ratio of glass bubbles improved the insulation performance of cement-based super light-weight inorganic insulating materials, and when the mixing ratio of glass bubbles was 10%, it sho wed sufficient flame retardant and no n-co mbustible perfo rmance.