• Journal of the Society of Disaster Information
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• v.16 no.4
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• pp.734-746
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• 2020

Purpose: Increase in the size and number of underpasses rises occurrence of disasters such as fire and flooding inundation in underpasses. In the occurrence of disasters, the underpasses are more vulnerable to expose of crucial disasters than the general roads due to they are built underground. Therefore, The purpose of this paper is to derive system improvement items to prevent and control disasters in underpasses. Method: A hierarchical model of disaster impact factors and alternatives was developed based on prior researches and expert advices on disaster analyses and impact factors in the underpasses. The developed model was employed for surveys of pairwise comparison, and rankings of improvement were determined by applying the AHP method. Result: With a consistency of the surveys, results of relative weights of evaluation criteria(traffic accidents, fire, flooding inundation) and alternatives(law, system/planning, maintenance/human factor/environment) shows that improvement of laws and system related to the fire disaster is a top priority to prevent and control disaster of the underpasses. Conclusion: From experts' point of view, strengthening laws and systems related to disater prevention facilities such as water spray facilities, external(ground) exit in relation to fire in underpasses showed that it is an alternative to prevent disasters and minimize damage to underpasses.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.56 no.1
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• pp.45-50
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• 2007

In this paper, this paper discusses how to improve the power control system of cold and hot water purifiers, in particular, system protecting device against abnormal voltage. The existing power supply control system came with a protecting device composed of varistor device only for impulse-type surges. Even though the existing system senses surge other than impulse-type, the system can not be protected. Accordingly, a new type of power control system was designed to protect the system from surge and ultimately prevent electricity accidents. The power control system suggested in this paper will be designed to protect the system by sensing input voltage and discontinuing power supply by means of SSR if voltage exceeding set value is sensed. To test the designed system, surge was imposed on the existing system and processes of system failure were experimented before safety of the designed power control system was simulated via P-spice program developed by Orcad in order to examine safety and reliability of the system.

• Journal of Korean Tunnelling and Underground Space Association
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• v.24 no.4
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• pp.327-339
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• 2022

The purpose of this study is to present the effective smoke control flow rate and mode for securing safety through quantitative risk assessment according to the smoke control flow rate and mode (supply or exhaust) of the platform when a train fire occurs at the subway platform. To this end, a fire outbreak scenario was created using a side platform with a central staircase as a model and fire analysis was performed for each scenario to compare and analyze fire propagation characteristics and ASET, evacuation analysis was performed to predict the number of deaths. In addition, a fire accident rate (F)/number of deaths (N) diagram (F/N diagram) was prepared for each scenario to compare and evaluate the risk according to the smoke control flow rate and mode. In the ASET analysis of harmful factors, carbon monoxide, temperature, and visible distance determined by performance-oriented design methods and standards for firefighting facilities, the effect of visible distance is the largest, In the case where the delay in entering the platform of the fire train was not taken into account, the ASET was analyzed to be about 800 seconds when the air flow rate was 4 × 833 m³/min. The estimated number of deaths varies greatly depending on the location of the vehicle of fire train, In the case of a fire occurring in a vehicle adjacent to the stairs, it is shown that the increase is up to three times that of the vehicle in the lead. In addition, when the smoke control flow rate increases, the number of fatalities decreases, and the reduction rate of the air supply method rather than the exhaust method increases. When the supply flow rate is 4 × 833 m³/min, the expected number of deaths is reduced to 13% compared to the case where ventilation is not performed. As a result of the risk assessment, it is found that the current social risk assessment criteria are satisfied when smoke control is performed, and the number of deaths is the flow rate 4 × 833 m³/min when smoke control is performed at 29.9 people in 10,000 year, It was analyzed that it decreased to 4.36 people.

• Proceedings of the KSR Conference
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• 2000.11a
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• pp.586-593
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• 2000

This paper describes a safety program plan of the LRT(Light Rail Transit) project. The SPP is a management document that describes the system safety objectives and how they will achieved so it embodies principles, methods and 1)lattices commonly used in the transit industry. In a Preliminary Hazard Analysis phase, the hazard analysis of collision and derailment is carried out. In this paper we make a definition of hazard that hazard is consist of an inner part(means a reliability) and an outer part(means a fire, flood and earthquake). Also safety principles for infrastructure, stations, electric traction system, railway control of system and train are performed.

• Journal of the Korean Society of Safety
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• v.22 no.3 s.81
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• pp.22-27
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• 2007

The knowledge of the flash point of the various liquid substances is required because of process safety and control in industrial fire protection. The epoxy resin is one of versatile resins that has wide selection of using curing agents and additives to achieve various applications such as coatings, adhesives, interior materials, reinforced plastics and electrical insulation. In this study, the lower flash points for p-xylene+epoxy resin, o-xylene+epoxy resin and n-butanol+epoxy resin systems were measured by using Pensky-Martens closed cup tester. The lower flash points for p-xylene+epoxy resin, o-xylene+epoxy resin and n-butanol+epoxy resin systems rapidly increased 80wt%, 90wt% and 95wt% of epoxy resin concentration, respectively. This results serve as a guide to estimate flash point of any epoxy resin solution.

• Fire Science and Engineering
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• v.20 no.3 s.63
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• pp.1-8
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• 2006

The purpose of this work is to analyze quantitatively if the safety instrumented system(SIS) like the pressure safety valves(PSV) in the processes of ethyl benzene plant have been designed relevantly to the safety integrity level because overpressure in the benzene or ethyl benzene columns causes the explosive reactions, fires and reactor explosions. The safety integrity level(SIL) 3 has been adopted as a target level of SIS based on the general data of the Probability of Failure on Demand of PSV, $1.00E-4{\sim}1.00E-3$. The standard model of the reliability has been set up and then the fault tree analysis of it has been carried out to get the PFD of SIS, and the results show 8.97E-04, 5.37E-04, 5.37E-04 for benzene prefractionator column, benzene column and EB column, respectively. Thus, we conclude that the SIS is designed to fulfill the condition of SIL3, and when the partial stroke test for the control valve are carried out every sixth month, the SIS of each column is expected to increase its reliability up to $22{\sim}27%$.

• Transactions of the Korean Society of Automotive Engineers
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• v.8 no.3
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• pp.163-170
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• 2000

Accident statistics shows that the portion of fatal occupant injuries due to side impacts is considerably high. The side impact usually leads to a severe intrusion of side structure into the passenger compartment. Furthermore, the safety zone for the side impact is relatively small compared to the front impact. Those kinds of physics for side impact frequently result in a fatal injury for the occupant. Therefore, NHTSA and EEVC are trying to intensify the regulation for the occupant protection against side impact. Both the regulation and recent market trends are asking for an installation of side airbag. There are several types of system configuration for side impact sensing. In this paper, we adopt the acceleration-based remote sensing method for the side airbag control system. We mainly focus on the development of hardware and crash discrimination algorithm of remote sensing unit. The crash discrimination algorithm needs fast decision of airbag firing especially for high-speed side impact such as FMVSS 214 and EEVC tests. It is also required to distinguish between low-speed fire and no-fire events. The algorithm should have a sufficient safety margin against any misuse situation such as hammer blow, door slam, etc. This paper introduces several firing criteria such as acceleration. velocity and energy criteria that use physical value proportional to crash severity. We have made a simulation program by using Matlab/Simulink to implement the proposed algorithm. We have conducted an algorithm calibration by using real crash data for 2,500cc vehicle. The crash performance obtained by the simulation was verified through a pulse injection method. It turned out that the results satisfied the system requirements well.

• Journal of the Society of Disaster Information
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• v.18 no.1
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• pp.129-145
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• 2022

Purpose: This study aims at preparing an external evacuation system by setting up situation that may occur outside buildings in case of large-scale fire at buildings such as multiuse facilities and presenting appropriate response procedures and action instructions for evacuees and facility managers. Method: Major matters are summarized based on various situations which may occur outside in case of fire and the contents of fire manual. Necessary factors including risk alert standards in the event of fire and the role of building occupants are classified and then important issues are summarized. In addition, the definition of fire-related outside shelters and external evacuation routes are showed, and then the applicability to the shelters and the routes are reviewed for old apartments in Jung-gu among multi-dense facilities. Result: Four stages (attention, caution, alert, serious) for standards of fire risk warning are established with the results of the investigation and analysis, and guidelines for behavior for evacuees, facility owners, residents, managers are summarized and presented. In addition, the concept and role of external shelters are divided into primary to the third shelters, and matters related to the definition of each shelter and the establishment of evacuation routes are presented, and then considered them carefully. Conclusion: This study has highlighted the importance of suggesting a systematic plan to secure the safety for evacuees outside space of buildings with disorder and difficulty to control in the event of fire. Therefore, we are confident that it will be useful in making an integrated manual for inside and outside buildings.

• Journal of the Korean Society of Industry Convergence
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• v.18 no.1
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• pp.10-17
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• 2015

We describe a research about remote control of mobile robot based on voice command in this paper. Through real-time remote control and wireless network capabilities of an unmanned remote-control experiments and Home Security / exercise with an unmanned robot, remote control and voice recognition and voice transmission are possible to transmit on a PC using a microphone to control a robot to pinpoint of the source. Speech recognition can be controlled robot by using a remote control. In this research, speech recognition speed and direction of self-driving robot were controlled by a wireless remote control in order to verify the performance of mobile robot with two drives.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2008.05a
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• pp.173-176
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• 2008

There are researches are in progress on ensuring the safety of the high impact concrete in cases of fire which is a current rising social problem and this research institute also developed PFB technology, the explosion preventing technology. PFB technology is to apply POSCO E&C Fire Board, a fireproof board, with an adhesive agent on the construction site, and this technology passed 3-hour fireproof test and this technology was proven from a previous research that the temperature of main root is maintained under 200 ℃. Therefore, tests on basic contents to be examined before the actual construction in this research by with a wooden prototype of a full scale to apply PFB technology to actual construction sites and tests are being done on the workability of fireproof board, the adhesive power, the resistance against imprint of wooden nail, the heat conductivity and etc. As the results of those tests, PFB technology was proven to have an excellent workability at a construction site and to be easy for processing and also this technology was proven to have a great the resisting power against imprint of wooden nail, so this research has confirmed that PFB technology has no problem to be applied on a construction site.