• Fire Science and Engineering
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• v.28 no.6
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• pp.62-68
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• 2014

The high predictive performance of fire detector models is essentially required for the reliable design of evacuation safety using the fire modeling. The main objective of the present study is to measure input information in order to predict the accurate activation time of photoelectric smoke detector adopted in fire dynamics simulator (FDS) recognized a representative fire model. To end this, the fire detector evaluator (FDE) which could be measured the device properties of detector was used, and the input information of Heskestad and Cleary's models was obtained for a spot-type photoelectric smoke detector. In addition, the activation times of smoke detector predicted using default values into FDS and measured values in the present study were quantitatively compared. As a result, the Heskestad model could result in an inaccurate the activation time of photoelectric smoke detector compared to the Cleary model. In addition, there was a distinct difference between the default values used into FDS and the measured values in terms of device properties of smoke detector, and thus the activation time also showed a significant difference.

• Fire Science and Engineering
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• v.17 no.4
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• pp.86-91
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• 2003

Since the air stream in the room controlled by HVAC system affects on he expected response of conventional detectors which are designed in accordance with normal characteristics of air stream in the fire incident, unexpected operation time delay may occur in fire. In order to solve this problem and to improve sensitivity so that to initiate fire in its early stages for minimizing damage and protecting people, we studied and developed Air Sampling Smoke Detector. The Air Sampling Smoke Detector is a kind of active-type fire detection system. it draws air continuously from the protected area through an air sampling pipe network to the smoke density analyzer. This study presents smoke density analysing technique and air intake balancing technique through an air sampling pipe network. As a result of evaluating, Air Sampling Smoke Detector was much more sensitive than conventional smoke detectors that passively wait for smoke to reach them and was not affected by ambient airflow in the room by means of balanced air intake through the sampling holes.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.1
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• pp.533-538
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• 2014

This study examines the performance of and searches for improvements to the existing automatic fire detection systems installed at domestic apartment buildings as a basic study for development of intelligent fire detection systems specifically for apartments. Thus, this study aims to find out the problems in performance and maintenance of the existing fire detectors installed at apartment buildings which is the prerequisite process for development of intelligent fire detection system for that specific application. It is also found impossible to check whether or not the detectors installed at each apartment are in an operational state at normal times. This study finds that it is desirable to replace the slow-sensing heat detectors by a smoke and single smoke detectors which can detect a fire at its early stage in an effort to improve the problems of fire detectors installed at apartment buildings presently. Because we need to the independence fire detection system of apartment building.

• Fire Science and Engineering
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• v.27 no.4
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• pp.27-34
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• 2013

The high prediction performance of fire detector models is essentially needed to assure the reliability of fire and evacuation modeling in the process of PBD (Performance Based fire safety Design). The main objective of the present study is to measure input information in order to predict the accurate activation time of smoke detector into a Large Eddy Simulation (LES) fire model such as FDS (Fire Dynamics Simulator). To end this, FDE (Fire Detector Evaluator) which can measure the device properties of detector was developed, and the input information of Heskestad and Cleary's models was measured for a ionization smoke detector. In addition, the activation times of smoke detectors predicted using default values into FDS and measured values in the present study were systematically compared. As a result, the device properties of smoke detector examined in the present study showed a significant difference compared to the default values used into FDS, which resulted in the considerable difference of up to 15 minutes or more in terms of the activation time of smoke detector. The database (DB) on device properties of various smoke and heat detectors will be built to improve the reliability of PBD in future studies.

• Journal of the Society of Disaster Information
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• v.19 no.3
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• pp.608-623
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• 2023

Purpose: Recently, the number of logistics warehouses has been on the rise. In addition, as the number of such logistics warehouses increases, number of fire accidents also increases every year, increasing the importance of preventing fires in large logistics warehouses. Method: investigated aspirating smoke detectors that are emerging as adaptive fire detectors in logistics warehouses. Then, through fire simulation (FDS), logistics warehouse modeling was conducted to compare and analyze the detection speed of general smoke detectors and aspirating smoke detectors according to four stages of fire growth and three locations of fire in the logistics warehouse. Result: Growth speed in Slow-class fires and Mediumclass fires, the detection speed of aspirating smoke detectors was faster regardless of the location of the fire. However, in Fast-class fires and Ultra-Fast-class fires, it was confirmed that the detection speed of general smoke detectors was faster depending on the location of the fire. Conclusion: It was confirmed that the detection performance of the aspirating smoke detector decreased as the fire growth speed increased and the location of the fire occurred further than the receiver of the aspirating smoke detector. Therefore, even if an aspirating smoke detector is installed in a warehouse that stores combustibles with high fire growth rates, it is judged that an additional smoke detector is attached far away from the receiver of the general smoke detector to increase fire safety.

• Journal of the Korea Society of Computer and Information
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• v.16 no.4
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• pp.43-52
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• 2011

With the rapid development of technology, skyscrapers are widely spread and they are tightly coupled. If fire occurs in a building, it is easily spread to neighboring buildings, resulting in the large number of victims and property damages. To remove fire disasters, the need for early fire detection techniques is increasing. To detect fire, detecting devices for heat, smoke, and flame have been used widely. However, this paper surveys and presents the latest research which focuses on early smoke and flame detection algorithms and systems with camera's input images. In addition, this paper implements and evaluates the performance of these flame and smoke detection algorithms with several types of movies.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2013.11a
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• pp.166-166
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• 2013

본 연구에서는 화재감지기 중 연기감지기로 가장 많이 사용되고 있는 광전식 연기감지기의 신뢰성에 대하여 분진을 이용하여 검증하는 방법과 감도성능변화에 대하여 분석한 연구이다. 여러번 분진을 이용하여 실험을 실시한 결과 분진의 농도가 높아질수록 감도성능이 저하되는 것을 실험적으로 확인하였고, 동작시간에 대한 실측데이터를 제시하였다.

• Fire Science and Engineering
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• v.32 no.5
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• pp.40-45
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• 2018

This paper is an analysis of the influence of ceiling air conditioner airflow on fire detector response. In order to analyze the response characteristics of fire detector while forming air flow of a ceiling-type air conditioner, fire tests were carried out in accordance with ISO standard. This experiment was carried out in a fire test site of 10 m (width) ${\times}$ 7 m (length) ${\times}$ 4 m (height). As a result of the experiment, the response of fire detector shows a normal pattern that is delayed as the distance from the fire source is increased in the absence of the air conditioner, but it is confirmed that the pattern is not maintained in the strong air flow. When the air flow of air conditioner was strong, the response time was increased by 121% in the smoke detector and by 39% in the heat detector. In the case of ceiling type air conditioners, it is considered that the number of fire detectors should be increased, or a detector with high sensitivity should be installed for early detection of fire.

• Fire Science and Engineering
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• v.23 no.3
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• pp.67-72
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• 2009

This paper is for response feature of fire detectors not only to analysis response feature of fire detector, but also to observe flame spread of inside-building and fire enlargement by using the row house which is supposed to be broken up. Many kinds of popular detectors such as heat type detector(differential type, fixed temperature type, Analogue type)and smoke type(light scattered type, Analogue type, single alarm type) were installed in the house in order to check for the change of temperature by installing of thermocouples. As a result, smoke detectors are better than heat detectors when it comes to making effective fire-detect system in the row house.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.11
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• pp.2759-2764
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• 2014

Smoke detector is commonly used to reduce fire detection time. However, technical problems regarding its inaccuracy of laser beam-receiving point on the surface of the sensor associated with incoming interference are identified when the laser transmitter and receiver are installed at a distance of about 100m. In this paper, we propose the auto focus alignment algorithm with high precision to adjust tilting angle of lasers caused by environmental interference so that solve existing issues using multi-level worm gear set.