• 설비공학논문집
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• 제16권2호
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• pp.135-141
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• 2004

The present paper concerns a smoke movement in a tunnel fire with a vertical shaft. The model tunnel measured 13.4m long, 0.4m wide and 0.4m high. The cross section is 1： 20 of a full scale tunnel. Ethanol was used as a fuel. The fire size in model tests varied from 1.35 kW to 13.37 kW, which corresponds to full scale fires of 2.41 to 23.91 MW. Smoke front velocity and temperatrue were decreased due to the vertical shaft install. Temperature was reduced maximum about 2$0^{\circ}C$ at ceiling and about 23$^{\circ}C$ at vertical position. CO concentration was reduced as the vent width widened. When vent width was more than 15 cm, CO concentration was not reached 100 ppm. Descent degree of the smoke layer was confirmed through the visualization.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 춘계학술대회
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• pp.1274-1279
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• 2004

We performed the numerical study on the comparison of thermal comport performance indices for cooling loads in the classroom when the 4-way cassette air-conditioner is mounted on the ceiling. We investigated the velocity and the temperature distribution of the classroom as with respect to the variation of the air diffusion angle of the air-conditioner. Air diffusion performance index and Predicted mean vote were used for analyzing the characteristics of the thermal comport in the classroom and comparing their values each other. From the numerical results, we knew that the thermal comport is largely affected by the air diffusion angle and velocity of the air-conditioner. And we also found out that the qualitative tendency of the distribution between Air diffusion performance index and Predicted mean vote is very similar in all occupied zone.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2007년도 동계학술발표대회 논문집
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• pp.76-81
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• 2007

The shopping center in underground passage increased for efficient space utilization in urban area. This study describes operation characteristics of all air type and hybrid type with local ventilation and fan coil unit fixed to ceiling. In order to compare energy saving, thermal environment and installation space, etc., integrated simulator with heat production and indoor distribution system is designed and constructed. Energy saving of the hybrid system is calculated as over 30% compared to conventional all air type. And also the results showed that humidity decreased about 6%, also indoor thermal distribution is improved as temperature variation of around $1^{\circ}C$.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2008년도 동계학술발표대회 논문집
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• pp.381-386
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• 2008

In this study, the energy characteristic of automatic thermostatic valves according to each heating method in floor radiant heating system were researched by computer simulation. For the analysis of unsteady heat transfer phenomena in household, the method of using electrical equivalent R-C circuit is applied, and radiation heat transfer between panel, ceiling and walls in household is calculated by enclosure analysis method. The parametric study on heating method, valve's control method, outdoor air condition, supply heating water temperature, supply flow rate are performed to compare energy characteristic, respectively.

• 한국화재소방학회논문지
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• 제12권3호
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• pp.11-20
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• 1998

천장아래에 형성된 연기흐름을 대상으로 Laser 평면광과 열전대를 이용하여 연기선단의 위치를 추적하였다. 새로운 실험방법을 이용하여 연기선단의 도착순간을 열전대의 온도신호로부터 판단하는 종래의 직관적 기준을 평가하였다. 이러한 실험방법에서 사용된 Laser 평면광은 연기를 가시화 하기 위한 종래의 여러방법에 비교하여 뚜렷한 장점들이 있음을 입증하였다.

• 대한설비공학회지:설비저널
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• 제10권3호
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• pp.185-219
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• 1981

To analyze two dimensional incompressible laminar natural convection in a rectangular enclosure heated from below and cooled by a horizontal ceiling and two vertical walls, he primitive Navier-Stokes equations and the energy equation were solved numerically in time dependent form by a marker and cell method. A successive over-relaxation method for the elliptic portion of the problem and an explicit method for the parabolic portion were applied for the range of Grashoff number of $5{\times}10^3\;to\;5{\times}10^4$ to get the transient and steady state dimensionless temperature and velocity profiles. For the range of aspect ratio $L/H{\leqq}2.4$ in which only a pair of convection rolls exists mean Nusselt number calculated are as follows : $$N_{NU}0.89\;N_{Gr}^{0.2}(H/L)^{0.45}$$ By path lines drawn by marker particle trajectories roll number of cellular motion were observed for various aspect ratio of the enclosure.

• 보존과학연구
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• 통권26호
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• pp.57-75
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• 2005

The burial custom in the Youngsan river area was to build a jar-coffin and lay the body in state, however the methods in building and moulding the massive jar, as well as in which kiln it was made has not been examined precisely. Thus, this research not only investigates previous results related to the manufacturing methods of massive jar-coffins, but also examines samples that were excavated and collected. The clay used to produce jar-coffin consists a large portion of unglazed qualities, which was split-moulded from the bottom up to the mouth area. The interior was finished by applying water, whereas the exterior was decorated by regularly pasting or stamping in parallel with a lattice design. It can be presumed that the finished jar-coffin was not moved, but the ceiling and walls were built around it as a kiln, for the jar-coffin to be oxidized or to reduce the flame condition in a temperature approximately $700~1,200^{\circ}C$The results from the research, however, show limitations to exploit the exact manufacturing method, therefore there is a need for in-depth examinations: mineralogical investigation on a large amount of jar-coffin samples through a polarized light microscope; substance analysis using various equipments; speculation on the temperature in the place of production and the flame inside.

• 설비공학논문집
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• 제22권1호
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• pp.20-25
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• 2010

In this study, As a basic research for improving indoor thermal environment at tower type apartment houses, specifications of heat storage and heat emission in the structures of apartment houses were investigated, and the ratio of indoor and outdoor air velocity at tower type apartment house was examined, too. Indoor temperature at night time was higher than outdoor air temperature because heat emission from the structure of wall, ceiling and floor those are constructed by use of reinforced concrete which has large heat capacity. The ratio of indoor and outdoor air velocity was lower than 0.1 and this was caused by the plan of tower type apartment house. PMV was in the range of 0.3~1.9, and was about 1.0 (it means slightly warm) at 10 : 00 p.m.. To improve indoor thermal environment in summer season at tower type apartment houses, it needs more investigation on specifications of heat storage and heat emission in the structure including winter season, and on the improvement of the ratio of indoor and outdoor air velocity.

• 한국화재소방학회논문지
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• 제25권4호
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• pp.94-102
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• 2011

지하철 본선터널에서 고온 연기시험을 수행하였다. 고온의 화재연기를 모사하기 위하여 약 1.0MW의 알콜트레이 및 연기발생장치를 이용하였다. 화재발생후 9분 후에 터널내에 설치된 팬이 순차적으로 작동하여 화재 연기가 제어되는지를 확인하였다. 터널내의 주요 위치에서의 풍속, 풍향, 온도 및 연기농도 등을 측정하여 이를 화재안전 관점에서 분석하였다. 화재 인근의 천장부분의 풍속 측정값으로 연기의 속도를 구하였으며, 위치별 제연기류가 형성되는 시간이 상이한 것을 확인하였다. 본 연구에서 계측된 풍속분포를 이용하여 지하철 본선터널 제연설비 성능 평가를 위한 수치해석의 경계값 및 비교결과로 활용될 것이다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2014년도 추계학술대회 논문집
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• pp.791-795
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• 2014

In this paper, in order to impart the aging condition of the parts, by configuring the cycle of temperature from low temperature was performed by applying the aging conditions for vehicle cockpit module. The reason for the selected modules of the cockpit vehicle parts, because the joint occurrence typical components of the room component is a first module and ceiling cockpit module. After setting the excitation profile using the BSR exciter only that this is for the module degradation after the initial and grasp the change in the dynamic characteristics of the modules based on the before and after deterioration may be made in the module, grasp the noise generating position I measured the noise and proximity. Was also visualized on the position of the joint is generated using a sound camera to objective results occurring where the joint is selected through subjective evaluation.