• Fire Science and Engineering
• /
• v.18 no.4
• /
• pp.42-51
• /
• 2004

This paper presents a study on the analysis of fire detection system using fuzzy logic with input variables of temperature and smoke density. The input variables for the fuzzy logic algorithm are measured by fire experiment of small scale with temperature detector and smoke detector. The antecedent part of fuzzy rules consists of temperature and smoke density, and the consequent part consists of fire possibility. Also the triangular fuzzy membership function is chosen for input variables and fuzzy rules to simplify computation. In order to calculate fuzzy values of such fuzzy system, a computer program is developed with Matlab based on graphics user interface. The experiment was conducted with paper and ethanol to simulate flaming fire and with plastic and sawdust to model smoldering fire. The results showed that the fire detection system presented here was able to diagnose fire very precisely. With the help of algorithms using fuzzy logic we could distinguish whether fire or not.

• Fire Science and Engineering
• /
• v.29 no.5
• /
• pp.14-22
• /
• 2015

This thesis is based on the study of necessity of an addressable emergency broadcasting system to improve evacuation performance in order to minimize human casualty by avoiding the initial evacuation after fires such as the multi-unit dwelling fire in Euijeongbu in 2015. To minimize the damage from fire generated in a complex internal structure such as modern buildings, introduction of adaptable emergency broadcasting system, could increase the efficiency of evacuation by preventing of initial mistaken evacuation directions by alerting the accurate location of fire to the occupants, is needed. As such, this study designed and fabricated the addressable emergency broadcasting system using the existing addressable system. Its performance was compared with a conventional emergency broadcasting system to confirm the necessity of the addressable emergency broadcasting system to improve evacuation performance. The test result showed that the addressable emergency broadcasting system decreased the evacuation time by up to 30.3% in a small-scale model evacuation performance experiment, up to 54.6% in a hallway evacuation performance experiment compared to the conventional emergency broadcasting system.

• Tunnel and Underground Space
• /
• v.12 no.1
• /
• pp.31-36
• /
• 2002

This paper concerns smoke propagation in tunnel fires with various size of fire source. Experiments carried out in model tunnel and those results were compared with numerical results. The Froude scaling law was used to scale model tests for comparison with larger scale tests. In order to validate for numerical analysis, temperature distribution of predicted data was compared with measured data. Examining the temperature distribution, we found that smoke layer does not come down under 50% of tunnel heights for a short tunnel heights for a short tunnel firs without ventilation. Front velocity of smoke layer is proportional to the cube root of heat release rate. And it is in good agreement with existing empirical expression and numerical prediction. In a short tunnel fire, horizontal propagation of smoke layer is more important than vertical smoke movement for evacuation plan.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.20 no.4
• /
• pp.516-521
• /
• 2010

In this paper, we propose a video-based intelligent unmanned fire surveillance system using fuzzy color models. In general, to detect heat or smoke, a separate device is required for a fire surveillance system, this system, however, can be implemented by using widely used CCTV, which does not need separate devices and extra cost. The systems called video-based fire surveillance systems use mainly a method extracting smoke or flame from an input image only. The smoke is difficult to extract at night because of its gray-scale color, and the flame color depends on the temperature, the inflammable, the size of flame, etc, which makes it hard to extract the flame region from the input image. This paper deals with a intelligent fire surveillance system which is robust against the variation of the flame color, especially at night. The proposed system extracts the moving object from the input image, makes a decision whether the object is the flame or not by means of the color obtained by fuzzy color model and the shape obtained by histogram, and issues a fire alarm when the flame is spread. Finally, we verify the efficiency of the proposed system through the experiment of the controlled real fire.

• Journal of the Korean Society of Safety
• /
• v.20 no.4 s.72
• /
• pp.171-179
• /
• 2005

It is essential to understand the role of wall lining materials when they are exposed to a fire from an ignition source. Full-scale test methods permit an assessment of the performance of a wall lining material. Fire growth models have been developed due to the costly expense associated with full-scale testing. The models require heat flux maps from the ignition burner flame as input data. Work to date was impeded by a lack of detailed spatial characterization of the heat flux maps due to the use of limited instrumentation. To increase the power of fire modeling, accurate and detailed heat flux maps from the ignition burner are essential. High level spatial resolution for surface temperature can be provided from an infrared camera. The objective of this study was to develop a heat flux mapping procedure for a room test burner flame to a wall configuration with surface temperature information taken from an infrared camera. A prototype experiment was performed using the ISO 9705 test burner to demonstrate the developed heat flux mapping procedure. The results of the experiment allow the heat flux and spatial resolutions of the method to be determined and compared to the methods currently available.

• Journal of the Korea Institute of Building Construction
• /
• v.20 no.3
• /
• pp.261-267
• /
• 2020

This study used a real-scale model experiment to reproduce internal fires in residential buildings such as a multi-dwelling unit, in order to prevent damage caused by tens of thousands of fires witnessed each year and to take measures to cope with them. For experimental conditions, different opening sizes were applied to measure and analyze the heating temperature of the exterior wall. Results drawn are as following: when the experiment was conducted with opening sizes(horizontal length) each at 2,000mm, 1,600mm, and 1,400mm, the flashover occurred at 630 seconds, 505 seconds and 510 seconds, respectively. Also, the total heating time, in proportion to this, came to 815 seconds, 713 seconds and 721 seconds. The maximum heating temperature of the exterior wall by the opening size reached 282.4℃ at 2,000mm, 382.9℃ at 1,600mm, and 423.8℃ at 1,400mm. This represented that as the opening size gets smaller, the heating temperature of the exterior wall by fire spread becomes higher.

• Journal of the Korean Society for Railway
• /
• v.12 no.1
• /
• pp.9-15
• /
• 2009

In this study, the l/35 reduced-scale model experiment were conducted to investigate designed ventilation system performance at rescue station in tunnel fire. A model tunnel with 2 mm thick of steel, 10 m long, 0.19 m high and 0.26m was made by using Froude number scaling law. The cross-passages installing escape door at the center. were connected between accident tunnel and rescue tunnel. The n-heptane pool fire, $4cm\times4cm$, with heat release rate 698.97W were used as fire source. The fire source was located in the center and portal of accident tunnel as Worst case.. An operating ventilation system extracted smoke amount of 0.015 cms. The smoke temperature and carbon monoxide. concentration in cross-passage were measured to verify designed ventilation system. The results showed that, in center fire case without ventilation in accident tunnel, smoke did not propagated to rescue station. In portal tire case, smoke spreaded to rescue station without ventilation. But smoke did not propagated to rescue station with designed ventilation.

• Journal of the Korea Institute of Building Construction
• /
• v.20 no.4
• /
• pp.339-345
• /
• 2020

This study used a real-scale model experiment to reproduce internal fires in residential buildings such as a multi-dwelling unit, in order to prevent damage caused by tens of thousands of fires witnessed each year and to take measures to cope with them. For experimental conditions, different opening sizes were applied to measure and analyze the heating temperature of the exterior wall. Results drawn are as follow : On top of this, the experimental conditions had whether to install shading and put a shading length differently, before measuring and analyzing the heating temperature of the exterior wall. Subsequent results were drawn as shown below. Based on the maximum temperature, the temperature was lowered as much as around 90℃ at 150mm, around 150℃ or over at 300mm and over 175℃ at 450mm. It also turned out that the difference in maximum temperature dropped by around 180℃ or over. This indicated that the shading installation works well in lowering flame temperature generated by fire spread of the exterior wall.

• Journal of the Korean Society of Safety
• /
• v.20 no.3 s.71
• /
• pp.71-77
• /
• 2005

This study aims to find the safe vent area to prevent a destruction of building by gas explosion in a building. Explosion vessel which used in this experiment is 1/5 scale down model of simple livingroom and its dimension is 100cm in length 60cm in width and 45cm in height. Liquified petroleum gas(LPG) was injected to the vessel to the concentration of 4.5vol%, and injection rate were varied in 1L/min or 4L/min. Gas mixture was ignited by the 10kV electric spark. For analysis the characteristics of vented explosion pressure according to the vent size and vent shape, its size and shape were varied. From the experiment, it was found that explosion pressure in the vented explosion :in affected by the gas injection rate, vent area and vent shape. And the vent area to volume ratio(S/V) to prevent the building destruction by explosion pressure, it is recommended that the design of vent area happened by the explosion should be above 1/500cm in S/V. And if the vent area has complicate structure in same area, vented explosion pressure will be higher than a single vent, and possibility of building destruction will increase. Therefore to effectively vent the explosion pressure for protect a building and residents from the gas explosion hazards, the same vent area should have a singular and constant shape in the cross-sectional area of the vessel.

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.11 no.4
• /
• pp.411-417
• /
• 2009

The thermo-flow field in road tunnel is influenced by some facts such as piston effect of vehicle's move, operation of ventilation facilities, natural wind and buoyancy effect of fire plume. Among those, piston effect is one of primary causes for formation of air flow in road tunnel and has an effect on initial direction of smoke flow in tunnel fire. In this study to analyze the unsteady flow in the tunnel caused by the run of vehicle, the experimental study of vehicle-induced unsteady flow on a reduced-scale model tunnel is presented. While the three types of vehicle shape such as basic type of rectangular shape, diamond-head type and stair-tail type are changed, the pressure and air velocity variations with time are measured. The rising ratio of pressure and velocity are in order of "basic type of rectangular shape > stair-tail type > diamond-head type". The experimental results would be good data for development of a numerical method on the vehicle-induced unsteady tunnel flow.