• KIEAE Journal
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• v.9 no.2
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• pp.53-58
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• 2009

There are increasing developments and uses of functional building materials are recently developed and introduced to the test method for the materials. Especially, moisture problem has a major role are also being established in indoor air quality problems. The purpose of this study is to evaluate the water vapour adsorption/desorption property of a ceiling material. The variation of the temperature and moisture were measured with the application materials by mock up test based on JIS 1470-1. The result shows that water vapour adsorption/desorption property of ceiling material is appeared in changes of moisture adsorption and desorption in comparison with that of a general ceiling material. Therefore, in case of decreasing and increasing in humidity, these materials can be used as an finishing material to sustain comfort condition.

• Journal of computational fluids engineering
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• v.17 no.3
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• pp.45-52
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• 2012

This paper is a study on the design of the solar lamp bank which is a very important part of the solar simulator with the commercial metal halide lamps and infrared lamps. Lamp Bank is designed by the lamp bank design program based on point light source theory. The reliability of the program for lamp bank design is verified through irradiance variation experiments of a kind of lamp according to horizontal distance. Solar lamp bank facilitates heat distribution and satisfies the irradiance in the three wave length which test guidelines require. The shape of the ceiling board next to the lamp bank to promote the lamp cooling efficiency and to reduce temperature deviation and air velocity deviation in the chamber is so creative. The ceiling board of partial closed type is the best among several types.

• Journal of Fisheries and Marine Sciences Education
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• v.17 no.2
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• pp.145-154
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• 2005

It is necessary to develop new air-conditioning method which can be satisfied individual separated space and request of occupants. The indoor thermal environment and flow field are investigated both experimentally and numerically. This study concentrated on analysis of indoor thermal environment by diffusion direction of ceiling type air conditioner of the classroom. The velocity and temperature distribution of air in the room calculated by 3-dimensional method, which include the effect of insulation of the building and outdoor state. This analysis shows that optimum diffusion direction is $30^{\circ}$ to increase thermal comfort in winter and optimum diffusion direction is $15^{\circ}$ to increase thermal comfort in summer.

• Proceedings of the SAREK Conference
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• 2006.06a
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• pp.866-871
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• 2006

Recently according to the fashion of well-being, the case study of under floor heating system type for residential space is increasing. Specially double slab floor system can make several roles as reducing the acoustic noises and also supplying fresh air through the gap. So in present study floor heating performance was examined with various location of the space in the case of floor supply air and ceiling supply air. In both cases return air went out through ceiling opening. As one of the result is that when using the heat pipe type floor heating system the temperature difference between supply and return water was $15.2^{\circ}C$, but in case of commercial type floor heating system the temperature difference was $5.3^{\circ}C$ when the supply water temperature was $50^{\circ}C$.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2000.04a
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• pp.80-85
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• 2000

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.20 no.4
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• pp.291-297
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• 1991

• Fire Science and Engineering
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• v.26 no.6
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• pp.7-14
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• 2012

This paper is to develop analytical techniques of flammable liquids which have been used for accelerating fire in accidental fires and arsons. We tested the temperature distribution of ceiling, fire patterns on the floor, and existence of flammable liquids and a check with GC/MS about flammable liquids comparing with papers, newspapers, and clothing. Research findings are as follows. The temperature of ceiling is influenced by flame. So gasoline and thinner was observed that combustible materials would be burned by flame. The fire patten on the floor was observed that flammable liquids had specialized pattern comparing combustible materials. When combustible materials on the PVC (Polyvinyl chloride) floor was burned, they didn't react to the gas detector. But flammable liquids had opposite results. After 7 days, we identified components of fire residues with the GC/MS (Gas Chromatography/Mass Spectrometry) about existence of flammable liquids and got components of flammable liquids. Fire investigation is a complicated processes. But we understand characteristics of materials, need detail investigations, and use the GC/MS to analyse flammable materials.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.30 no.1
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• pp.18-27
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• 2020

Objectives: For testing asbestos stabilizer products which are used for the maintenance and management of asbestos-containing materials, durability assessment should accompany the evaluation of basic properties and performance. Therefore, in this study we designed a testing method and constructed a database of durability performance, thereby providing basic data for reliability studies of asbestos stabilizer. Methods: Since the ceiling materials targeted in this study are interior materials, test conditions of 95% relative humidity and 60℃ temperature were designed in consideration of the effect of high relative humidity in summer and seasonal indoor temperatures. Plate-shaped specimens treated with asbestos stabilizers were maintained in a thermo-hygrostat for 5, 10, and 20 days, and then the asbestos scattering prevention rate was measured by air erosion testing. Results: The scattering concentration tended to increase with time under the single humidity condition, and exceeded the indoor air quality standard of 0.01 f/cc, during the 20 days of maintenance. On the other hand, there was little change according to the temperature condition. In the case of a complex condition with temperature and humidity, the results were similar to the humidity test, but the scattering concentration increased more sharply at 20 days. Conclusions: The main deterioration factor that affects the durability of asbestos stabilizer is humidity, and the deterioration is caused by a mechanism in which the stabilizer coated on the surface is re-dissolved by moisture and evaporates or the coating layer is peeled off, which is accelerated by high temperatures.

• Journal of Environmental Science International
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• v.22 no.11
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• pp.1443-1449
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• 2013

This was an experimental study to evaluate temperature reduction and evapotranspiration of extensive green roof. Three test cells with a dimension of $1.2(W){\times}1.2(D){\times}1.0(H)$ meters were built using 4-inch concrete blocks. Ten-centimeter concrete slab was installed on top of each cell. The first cell was control cell with no green roof installed. The second and third cells were covered with medium-leaf type Zoysiagrass (Zoysia japonica) above a layer of soil. Soil thickness on the second cell was 10cm and that on the third cell was 20cm. Air temperature, relative humidity and solar irradiance were measured using AWS (automatic weather system). Temperature on top surface and ceiling of the control cell and temperature on top surface, below soil and ceiling of green roof cells was measured. Evapotranspiration of the green roof cells were measured using weight changes. Compared with temperature difference on the control cell, temperature difference was greater on green roof cells. Between two green roof cells, the temperature difference was greater on the third cell with a thicker soil layer. Temperature differences below soil and on ceilings of green roof cells were found greater than those of the control cell. Between the green roof cells, there was no difference in the temperature reduction effects below soil and on ceilings based on substrate depth. In summary, green roof was found effective in temperature reduction due to evapotranspiration and shading effect.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.19 no.1
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• pp.56-62
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• 2020

The purpose of this study is to observe the visualization of the flow field for air flow distributed in the car from the ventilation fan installed in the ceiling of the passenger elevator car through the numerical analysis using computational fluid dynamics. STAR-CCM+, which is a code used for the numerical analysis, was used to predict the airflow distribution inside the elevator car. The numerical analysis of the distribution of the air current in the elevator was carried out. As a result, the analysis results for each point and the visualization of the air current distribution and the temperature distribution in the elevator car and were obtained. It was found that heat transfer was actively occurring inside the car due to the influence of the flow field discharged from the ventilation vent installed in the ceiling in the elevator car, and especially the convection heat transfer of Model-2 was more active than that of Model-1. As a result, the temperature distribution inside the car was found to be relatively low. In addition, the temperature distribution at a cross-section of 1700mm height in the elevator car shows that Model-2 is the location of the ventilation vent which makes people feel more comfortable.