• Journal of the Society of Disaster Information
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• v.17 no.2
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• pp.236-244
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• 2021

Purpose: The purpose of this study is to develop IoT multi-fire detectors combined smoke/carbon monoxide/heat and wireless IoT communication and to confirm the detect performance by smoke generator fire test and cotton wicks fire test. Method: The IoT multi-fire detector combined smoke and CO and combined smoke and heat were experimented the detect performance by smoke generator test and fire test of cotton wicks. And the case of fire alarm was checked. Result: The IoT multi-fire detector combined smoke and CO rung the alarm at the fire test of cotton wicks, did not ring the alarm at the smoke generator test. In comparison, the IoT multi-fire detector combined smoke and heat did not ring the alarm both at the smoke generator test and the fire test of cotton wicks. Conclusion: The IoT multi-fire detector combined smoke and CO detected the only smoke including the carbon monoxide and the IoT multi-fire detector combined smoke and heat did not ring the alarm for lack of heat. As a result, when the developed IoT multi-fire detector was detected the signal more than the set point, the fire alarm was sounded through cotton wicks fire test and smoke generator.

• Journal of Oral Medicine and Pain
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• v.20 no.2
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• pp.283-289
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• 1995

레이저가 의학영역에서 사용된 후 구강내 연조직과 경조직 병소에 대한 임상적 적용에 관한 관심이 커져왔다. 레이저가 조사되는 부위에서는 대부분 연기가 발생한다. 이 경우 병원체가 존재하는 병소에 대한 레이저치료시 발생되는 연기속에 병원체가 포함되어 이Tekas 환자와 술자는 이의 흡입가능성이 크므로 균혈증 및 상기도나 호흡계의 의원성 감염이 유발될 수 있다. 저자는 레이저치료시 발생되는 연기속에 병원체가 포함되어 있는지의 여부를 규명하기위해 각각 10개의 실험군에 통기성 미생물인 Escherichia coli(E.coli)가 배양된 brain geart infusion (BHI) 배지와 E.coli 가 존재하는 치근단 병소를 실험적으로 만든 후 각각 pulsed Nd:YAG 레이저를 조사해 연기를 채취, 배양, 분석하여 다음과 같은 결과를 얻었다. 1. Pulsed Nd:YAG 레이저를 E. colir 배양된 agar substrate 와 실험적으로 만들어진 치근단부위의 E.coli 현탁액에 조사시 발생된 연기에서 처음 접종된 것과 같은 E.coli가 검출되었다. 2. 감염병소에 pulsed Nd:YAG 레이저를 조사시 발생되는 연기의 유해효과로부터 환자와 술자 및 보조자의 보호를 위해 효과적인 흡입기를 사용이 권장된다.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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• v.9 no.9
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• pp.721-736
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• 2019

In this paper, the behavior of the fire smoke due to the operation of the ventilation systems when the fire occurred in the underground station (6 basement floors) and the tunnel at the great depth was measured. Fire smoke was generated by using a smoke generator which realized heat buoyancy effect by using hot air blower. The two locations of the fire were selected on the platform and on the platform of the tunnel located outside the screen door. A ventilation mode is generally used in which smoke is exhausted through a vent hole provided in a platform when a platform fire occurs. The tests were performed by operating the exhaust through the ventilation holes of the tunnel part located at both ends of the platform. The smoke density and the wind speed/velocity were measured at various positions, and the videos were taken to analyze the movement and smoke of the smoke. In both cases for fire inside the platform and in the railway tunnel, due to the ventilation mode operation of the fan for the platform and the exhaust of the fans in the tunnel smoke were well exhausted and the smoke propagation to the area near the smoke zone was suppressed. The smoke-control mode, which is applied to both fans for the platform and fans for in the tunnel at both ends of the platform, can provide a safer evacuation environment to the passengers from the fire smoke when the platform fire or fire train stops.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2011.04a
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• pp.453-456
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• 2011

본 연구에서는 건축외장용 접착제의 발연특성을 알아보기 위해 접착제를 용도별로 구분하여 연기밀도시험기를 이용해 최대연기밀도와 초기발생연기밀도를 알아보았다. 실험 결과 창호전용 접착제가 586초에 509.64로 가장 많은 연기밀도를 발생하였으며, 석재용 275.63, 목공용 232.25의 순으로 많은 양의 연기가 발생하였고, 타일용 18.65, 스티로폼용 6.44로 최대연기밀도를 나타내었다. 창호전용과 스티로폼용의 경우 최대연기밀도를 나타낸 시간은 비슷한 범위에 나타났으나 연기밀도 값은 스티로폼용에 비해 창호전용 접착제가 80배 가까이 연기가 더 발생하는 것을 알 수 있었다.

• Journal of the Korean Society of Marine Environment & Safety
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• v.25 no.1
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• pp.111-116
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• 2019

The fire detectors used in the engine rooms of ships offer only a slow response to emergencies because smoke or heat must reach detectors installed on ceilings, but the air flow in engine rooms can be very fluid depending on the use of equipment. In order to overcome these disadvantages, much research on video-based fire detection has been conducted in recent years. Video-based fire detection is effective for initial detection of fire because it is not affected by air flow and transmission speed is fast. In this paper, experiments were performed using images of smoke from a smoke generator in an engine room. Data generated using LBP and GLCM operators that extract the textural features of smoke was classified using SVM, which is a machine learning classifier. Even if smoke did not rise to the ceiling, where detectors were installed, smoke detection was confirmed using the image-based technique.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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• v.8 no.7
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• pp.485-496
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• 2018

In this paper, the smoke behavior in an underground station on operation of the fans in the ventiliation of the station was measured by the experimental method when the fire occurred in the underground station platform where the platfrom screen door was installed. The ventilation characteristics were compared when the ventilation system was operated and when the ventilation system was not operated when a fire occurred at the platform where the clean door was closed. To simulate the fire smoke, the smoke generated from the smoke generator was heated using a hot air fan. The transmittance was measured using a smoke density meter to quantitatively measure fire smoke. If the screen door is closed and the ventilation system of the underground station does not work, it is confirmed that if a fire occurs in the platform, smoke accumulates inside the platform, evacuating passengers is very difficult and can lead to a very dangerous situation. On the other hand, under the condition that the ventilation facility of the subway station is operated, the smoke evacuates to the outside through the ventilation facility of the underground station, and airflow is formed in the direction from the waiting room to the waiting area, so that the passenger located on the platform can safely evacuate toward the concourse. In the following paper, we will discuss the concurrent effect of tunnel ventilation through tunnel vent near the platform.

• Fire Science and Engineering
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• v.31 no.5
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• pp.44-52
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• 2017

This paper is based on a study of the response characteristics of photoelectric type smoke detector chambers according to dust color. Due to an amendment to the Fire Safety Codes to automatic fire alarm systems and visual alarm device, the installation of indoor smoke detectors has become mandatory, but in Korea there is still insufficient research on the non-operation or false alarms that could arise in indoor environments by indoor dust and other environmental conditions etc. In light of this, for this study, research was conducted on the indoor adaptability of smoke detector under various colors of fiber dust that were judged to occur most frequently in among the common indoor dust, photoelectric smoke detector with the lattice-type smoke detection chamber that the smoke detector which is most popular in the country was used, and four colors of fiber dust (brown, white, gray and black) were used the test dusts for carrying out dust and sensitivity testing. Also, the voltage of the photocell part of the smoke chamber was measured, and the scattering phenomenon in the chamber was observed. The result of the testing showed that all four dust types were suitable for dust and sensitivity testing under conditions of pollution A. Yet, there were occasions, at pollution B or C, where the brown, white and gray dust would cause fail alarm during operation testing. And black dust was confirmed to cause non-operation during operation testing. In the case of brown and white dust, the voltage measurement result of the photocell part of the smoke chamber confirmed that the voltage increases as the pollution level increases, and in the case of gray and black dust, the voltage decreases.

• Journal of Korean Tunnelling and Underground Space Association
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• v.6 no.2
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• pp.141-149
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• 2004

In this study, smoke movement in tunnel fire with natural and longitudinal ventilation systems has been investigated. Reduced-scale experiments were carried out under the Froude scaling using 14.55kW fire source with a wick and experimental data is obtained with 1/18 model tunnel test. Temperature profiles were measured under the ceiling and vertical direction along the center of the tunnel and poisonous gas was measured at emergency exit point. The results show that refuge time for 225m intervals of emergency exit in case of natural ventilation systems is 256 seconds and critical velocity for sufficient back-layer prevention is 2.8m/s for fire strength of 20MW.

• Fire Science and Engineering
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• v.31 no.1
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• pp.50-57
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• 2017

The present article discusses the response characteristics of smoke detector chamber due to dust and wind velocity. Although situations have improved in terms of early sensing of fires as the smoke detectors are applied indoors, studies tend to place insufficient focus on the side effects and malfunction that can be caused by diversified life dust produced indoors and environmental requirements, etc. Therefore, in the present study, 4 types of photoelectric smoke detectors with different forms and structures of smoke chamber were selected as the experimental objects, and dust test was conducted with fly ash, talcum powder and fiber dust as experiment samples to study indoor applicability of the smoke detectors in terms of their response to diversified dust and wind velocity. Also, to observe response characteristics due to pollution level inside the smoke chamber, wind velocity for dust test were set additionally at 0.25 m/s, 0.5 m/s, and 1.0 m/s. Based to the experimental results, fly ash, talcum powder, and fiber dust (black hair powder) were found to be suitable at the dust test reference wind velocity conditions of 0.25 m/s for both operation test and non-operation test after dust application. On the other hand, under the harsh wind velocity conditions of 0.5 m/s and 1.0 m/s, malfunction of unwanted alarm was observed in non-operation tests in the case of fly ash and talcum powder, and non-operation was confirmed to occur in the case of fiber dust as the alarm failed to operate normally in operation tests.

• Fire Science and Engineering
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• v.24 no.2
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• pp.82-88
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• 2010

In this study, we have performed several tests for composite plastic materials to be applied on interior materials of a vehicle to identify their combustion characteristics using cone calorimeter, smoke density chamber and toxicity index chamber. We have prepared a total of 12 samples for 4 major parts of a vehicle wherein each major part has 3 different materials. The results of cone calorimeter test showed ignition time of PVC sheet and PVC leather were 2s. The 8 samples showed under less than 10s of ignition time. The sample comprising Nylon and PE had the biggest maximum heat release rate of 635 $kW/m^2$. The sample comprising Rubber showed the smallest maximum heat release rate but with the biggest total heat release. The results of smoke density chamber test showed the sample that is made up with Rubber had the biggest specific optical smoke density. The sample comprising PVC leather and PUR showed the biggest VOF4 which enables the initial smoke production. The results of toxicity index test showed that all samples contained carbon dioxide content exceeding its lethal concentration. The sample comprising PVC showed high content of hydrogen chloride and hydrogen bromide. The PVC sheet showed the biggest toxicity index calculated by using lethal concentration and test results. Toxicity index of all sample wes over 1.