• 한국가시화정보학회:학술대회논문집
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• 2005.12a
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• pp.64-68
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• 2005

In this study, the smoke flows of the inner subway station were visualized through a numerical analysis and visualization experiment in the subway fire. A transparent acrylic model was designed and installed as 1:25th scale-down as the actual subway station by using geometrical similarity The properties of subway fire were reconstructed according to Densimetric Froude Similarity. The 47 to 53 ratio of the mixed air and Helium was inputted in the inner acrylic model to describe 1MW fire intensity with reference to the experiment paper. For the same time, the fire smoke from a smoke generator was inputted in the inner acrylic model with the mixture. At this time, the buoyancy effect of Helium gas went up the smoke to the acrylic model. When the sheet beam of Ar-lon laser was given out to the top and stair of subway model, the digital camcorder took the images of the scattered cluster of smoke particles when applying the smoke management system and PSD.

• Bulletin of the Korean Chemical Society
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• v.34 no.8
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• pp.2394-2398
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• 2013

Nicotine is the main component of environmental tobacco smoke, and its presence in indoor air is widely used as a secondhand-smoke indicator. Environmental tobacco smoke is a major source of indoor air pollution, but sufficient investigation of the uncertainty of its measurement, which mirrors the reliability of nicotine measurement, has not been performed. We calculated the uncertainty of measurement of indoor air nicotine concentration at low, medium, and high concentrations of 11.3798, 10.1977, $98.3768{\mu}g/m^3$, respectively, and we employed the Guide to the Expression of Uncertainty in Measurements (GUM), proposed by the International Organization for Standardization (ISO). The factors considered in determining the uncertainty were uncertainty of the calibration curve (calibration curve and repeated measurements), desorption efficiency, extraction volume, and sampling airflow (accuracy and acceptable limits of flowmeter). The measurement uncertainty was highest at low concentrations; the expanded measurement uncertainty is $0.9435{\mu}g/m^3$ and is represented as a relative uncertainty of 63.38%. At medium and high (concentrations, the relative uncertainty was 13.1% and 9.1%, respectively. The uncertainty of the calibration curve was largest for low indoor nicotine concentrations. To increase reliability of measurement in assessing the effect of secondhand smoke, measures such as increasing the sample injection rate ($1{\mu}L$ or more), increasing sampling volume to increase collected nicotine, and using gas chromatography-mass spectrometry (GC/MS) or GC/MS/MS, which has a lower quantitation threshold, rather than gas chromatography with nitrogen phosphorous detector, should be considered.

• Fire Science and Engineering
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• v.30 no.4
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• pp.82-87
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• 2016

The ventilation system for the efficient operation of the building services systems in the ventilation plan of super high-rise buildings is used to combine smoke control systems. This study evaluated models of super high-rise buildings with four basement levels and 59 stories and investigated the pressure distribution of each floor by the smoke driving forces by numerical analysis. The smoke driving forces on the building of analytical model was analyzed to determine the effects of the ventilation plan and smoke control plane. In addition, when a combination with ventilation and smoke control of the kitchen ventilation damper in the ventilation plan of analysis model building was designed based on the these results, the relationship between the opening and closing force of the damper and smoke driving combined forces to act on the design pressure of the damper by a motion analysis simulation. The driving units of the damper were selected from the analytical results.

• Journal of the Korea Society of Computer and Information
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• v.15 no.5
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• pp.57-65
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• 2010

In this paper, we propose a new real-time algorithm detecting the flame and smoke in digital CCTV images. Because the forest fire causes the enormous human life and damage of property, the early management according to the early sensing is very important. The proposed algorithm for monitoring forest fire is classified into the flame sensing and detection of smoke. The flame sensing algorithm detects a flame through the conditional test at YCbCr color model from the single frame. For the detection of smoke, firstly the background range is set by using differences between current picture and the average picture among the adjacent frames in the weighted value, and the pixels which get out of this range and have a gray-scale are detected in the smoke area. Because the proposed flame sensing algorithm is stronger than the existing algorithms in the change of the illuminance according to the quantity of sunshine, and the smoke detection algorithm senses the pixel of a gray-scale with the smoke considering the amount of change for unit time, the effective early forest fire detection is possible. The experimental results indicate that the proposed algorithm provides better performance than existing algorithms.

• Proceedings of the Safety Management and Science Conference
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• 2011.11a
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• pp.289-297
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• 2011

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.16 no.11
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• pp.3544-3564
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• 2022

With the development of the NB-IoT (Narrow band Internet of Things) and smart cities, coupled with the emergence of smart smoke sensors, new requirements and issues have been introduced to study on the deployment of sensors in large spaces. Previous research mainly focuses on the optimization of wireless sensors in some monitoring environments, including three-dimensional terrain or underwater space. There are relatively few studies on the optimization deployment problem of smart smoke sensors, and leaving large spaces with obstacles such as libraries out of consideration. This paper mainly studies the deployment issue of smart smoke sensors in large spaces by considering the fire probability of fire areas and the obstacles in a monitoring area. To cope with the problems of coverage blind areas and coverage redundancy when sensors are deployed randomly in large spaces, we proposed an optimized deployment strategy of smart smoke sensors based on the PSO (Particle Swarm Optimization) algorithm. The deployment problem is transformed into a multi-objective optimization problem with many constraints of fire probability and barriers, while minimizing the deployment cost and maximizing the coverage accuracy. In this regard, we describe the structure model in large space and a coverage model firstly, then a mathematical model containing two objective functions is established. Finally, a deployment strategy based on PSO algorithm is designed, and the performance of the deployment strategy is verified by a number of simulation experiments. The obtained experimental and numerical results demonstrates that our proposed strategy can obtain better performance than uniform deployment strategies in terms of all the objectives concerned, further demonstrates the effectiveness of our strategy. Additionally, the strategy we proposed also provides theoretical guidance and a practical basis for fire emergency management and other departments to better deploy smart smoke sensors in a large space.

• Journal of the Korea Safety Management & Science
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• v.25 no.4
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• pp.67-72
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• 2023

Human and material damage can be reduced if the risk is evaluated by engineering analysis of fire combustion products, smoke concentration, and smoke movement speed in the event of a fire in apartment houses and officetels. In this study, a lot of research on related safety evaluation in the basement needs to be studied and reflected in design, so experimental research was conducted to analyze the flow of smoke through computer simulation and provide analysis data through evacuation safety evaluation. First of all, the five-story underground parking lot subject to simulation has a large floor area, which is advantageous for improving evacuation safety performance, but it uses temperature detectors to increase detection time and fire spread speed. Second, it was analyzed that the evacuation time at all evacuation ports did not exceed the evacuation time, and as the time from the start of evacuation to the evacuation time was 216.9% compared to the travel time, it was evaluated that the safety performance of the evacuation was secured. Third, the above simulation results are a comprehensive safety evaluation based on the non-operation of fire extinguishing facilities in the fire room to increase safety, which means that smoother evacuation safety performance can be secured by linking fire extinguishing facilities.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2011.11a
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• pp.310-313
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• 2011

국내에서 고층건물의 제연시스템으로 급기가압 제연시스템이 일반적으로 사용되고 있는데, 기존의 급기가압 제연시스템의 설계방안과 같이 한개의 급기풍도를 통해 누설량과 보충량이 동시에 공급될 경우에는 부속실과 옥내간에 형성되는 차압이 설계기준에 미달하거나 과압이 될 가능성이 매우 높아져서 급기가압 제연시스템의 설치목적을 달성하지 못할 수 있다. 이에 대한 개선방안으로 본 연구에서는 누설량의 공급과 보충량의 공급을 각기 다른 유로를 통해 수행하는 방안 및 장치구성을 제시함으로서 고층건물에서 화재 발생시 안전한 피난환경을 제공하고자 한다.

• Proceedings of the SAREK Conference
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• 2008.06a
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• pp.459-462
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• 2008

The fact that the major cases of life casualties are from smoke in the fire accidents and the expected steep increase of skyscrapers, huge spaces, multiplexes and huge scaled underground spaces demand establishment of efficient smoke countermeasure. The architectural factors affecting the pressure field of building should be examined for the successful design and operation of smoke management system and the stack effect is one of the important factors. The field experiments on stack effect in stairwells of high-rise building with regard to open/close condition of door are carried out to evaluate the features of pressure applied to door between each compartments, i.e, stair, lobby and accommodation. The procedures and results of experiments are presented.

• Journal of the Korea Safety Management & Science
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• v.9 no.1
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• pp.197-211
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• 2007

The power of semiconductor, Korea is continuously constructing semiconductor production line for keeping a front-runner status. however, studies and data about potential risks in semiconductor factory are still short. If fire does not initially suppressed, the fire causes a great damage. To decrease fire risk factors, in addition to fire fighting safety equipment, more important thing is how to design and construct fire protection system. The current fire protection codes about semiconductor factory come under functional law, and this law is short of consideration about particularity of factory. The existing prescriptive fire codes depending on experience compose without evident engineering verifications, thus equipments which is created by the current prescriptive fire code may bring about a variety of problems. For example, the design under the current regulation can not cope with the excessive investments, low efficiencies, and the diversifying construction designs and be applied to the quick changes of new technologies. Ergo, an optimal design for fire protection is to equip fire protection arrangements with condition and environment of production field. Manufacturing factory of semiconductors is a windowless airtight space. And for cleanliness, there exists strong flow of cooperation. Therefore, there is a need for fire safety design that meets the characteristic of a clean room. Accordingly, we are to derive smoke flow according to cooperation process within a clean room and construction plan of an optimal sensor system. In this study, in order to confirm the performance of proposed smoke-exhaust equipment and suggest efficient smoke exhaust device when there is a fire of 1MW of methane in the clean room of company H, we have implemented fire simulation using fluid dynamics computation.