• Tunnel and Underground Space
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• v.19 no.1
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• pp.11-18
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• 2009

Use of nuclear energy inevitably brings the problem of radioactive waste disposal. Repositories for disposing radioactive waste use underground space that is unconnected with the outside and the diagonal system, which allows the waste to be deposited. Ventilation if necessary because high-level radioactive waste generates heat. In this study, the air velocity through diagonal branches with regulators of different sizes and in different locations, was measured. The air velocity is determined by the size of the first and last regulators, regardless of the size of other regulators. In the diagonal system. Consequently, once the desired total airflow rate has been achieved by installing the appropriate first and last regulators, the other regulators fan be evenly installed to maintain the minimum air velocity needed.

• Fire Science and Engineering
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• v.17 no.2
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• pp.62-69
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• 2003

The smoke control system in subway platform is not only using for smoke exhaust facility but also using ventilation system. For this reason, smoke vent effectiveness is depending on its position, ventilating volume capacity and the vent method. In this study, the passenger's evacuation time was calculated for the case of fire on sloped subway train vehicle in subway platform. In order to recommend the mechanical smoke exhaust operation mode, SES (Subway Environmental Simulation) was used to predict the airflow of the inlet and outlet tunnel for the subway station. Fire dynamics Simulator(FDS) was used the SES's velocity boundary conditions to calculate the smoke density and temperature under the condition of fire on stopped subway train vehicle at the platform. We compared smoke density and temperature distributions for each 6 types of smoke exhaust systems to clarify the characteristics of smoke and hot air exhaust effectiveness from the result of fire simulation.

• Fire Science and Engineering
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• v.20 no.4 s.64
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• pp.135-142
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• 2006

The experiment applied Positive Pressure Ventilation to rapidly exhaust heat and smoke inside the construction in the fire was done. Changes of heat discharge and smoke density were measured, with the various blowing condition like a fan tilting angle to find the effect of the parameter. Experimental apparatus were with PPV and water mist system for better efficiency, and investigate the effect of heat discharge and smoke removal. In the experiment, flame temperature has decreased when PPV was applied. Smoke density, generated from fire also decreased dramatically and the efficiency showed the highest rate at $0^{\circ}$ tilting angle. In addition, combination of PPV and water mist system highly improved the efficiency of evacuation on heat and smoke density, clearly was influenced by the tilting angle.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.66-72
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• 2008

In this study, transient 3D numerical simulations were performed to analyze the characteristics of fire driven flow for smoke ventilation system operating conditions in the deeply underground subway station. The smoke flow patterns were compared and discussed under smoke fan operating mode and off mode in the platform. Soongsil Univ. station(line number 7)was chosen for simulation which was the one of the deepest underground subway stations in the each lines of Seoul. The geometry for model is 365m in length include railway, 23.5m for width, 47m for depth. Therefore 10,000,000 structured grids were used for fire simulation. The parallel computational method for fast calculation was employed to compute the heat and mass transfer eqn's with 6 CPUs(Intel 3.0GHz Dual CPU, 12Cores) of the linux clustering machine. The fire driven flow was simulated with using FDS code in which LES method was applied. The Heat release rate was 10MW and The Ultrafast model was applied for the growing model of the fire source.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.31 no.4
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• pp.331-341
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• 2021

Objectives: The aim of this study was to evaluate the concentrations and relationships of coarse particles with a diameter of 10 ㎛ (PM₁₀) with endotoxins according to the time of measurement in windowless poultry houses. Methods: In this study, measurement was performed on ten windowless poultry houses with a vertically integrated system from July to November. PM₁₀ was measured using personal environmental monitors and polytetrafluoroethylene (PTFE) filters with a 4 L/min-calibrated pump in selected sampling locations (two near the door and two near an exhaust fan). The endotoxin on PTFE filter was analyzed by the LAL turbidimetric method. Results: The range of geometric mean concentrations of PM₁₀ and endotoxins for each of the 38 samples were 0.12-3.30 mg/m³ and 11.9-3553.66 EU/m³, respectively. PM₁₀ and endotoxin concentrations varied by farm, increasing with the decrease in ventilation. The range of the coefficient of determination between PM₁₀ and endotoxin was 0.0009-0.9249. As the atmospheric temperature decreased, it was confirmed that the concentrations of PM₁₀ and endotoxin increased because the volume of ventilation was decreased. Conclusions: Endotoxins were more affected by time of measurement and ventilation than PM₁₀, which means that endotoxins could be an important indicator for intervention programs for improvement of indoor environments.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.28 no.3
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• pp.211-215
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• 2022

Air distribution occupies an important position in the smart unit load container design process for agricultural products. Inner air may be uncomfortable because of its temperature, speed, direction, and volume flow rate. It doesn't matter how efficient the ventilation equipment is if the air is not distributed well. The main aim of this study was to design the inlet and outlet fan locations of smart unit load container for agricultural products. A numerical study was performed on the effects of the location of inlet air and outlet air in relation to the container cooling sources on air distribution and thermal comfort. A concept of combining inner container cooling sources with the exhaust outlet was employed in this investigation. Also, in this research, the developed CFD (Computational Fluid Dynamics) models were thoroughly validated. This system was adopted for use in container spaces, where the exhaust outlet was located. In this study, the location of the inlet was derived through CFD for a container with a size of 1,100×1,100×1,700 mm, and it was derived that the inlet was located at the center of the lower part of the container for efficient air flow. It was efficient to position the outlet through the air inlet in the center of the lower part of the container at the top of the same side.

• Journal of Animal Environmental Science
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• v.10 no.2
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• pp.93-100
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• 2004

An experiment was conducted to establish comparison of ventilation efficiency in an enclosed and conventional growing-finishing pig house. The experimental pigs were in winter and summer. The main results of the experiment are as follows : Then the air from planar slot inlet the pig house flow out through the sidewall outlet operated by exhaust fan(Gl). The second structure has an air input through the circular duct inlet are plated side the juncture of the entering wall and the air into the pig house flow out through the chimney and pit outlet are operated by exhaust fan(G2). Through the air into relay fan the pig house flow out through the curtains in sidewall(G3). Similarly, air comes in through the circular duct inlet are placed the air into the pig house flow out through the curtains in sidewall (G4). Air flow rate on the floor level which is the low part of pen and the living area of pigs in the G2 and G4 system during winter was measured at 0.2 to 0.3 m/s at the 0.5 to 0.6 m/s at the maximum ventilation efficiency. As for the results of detrimental gas(ammonia) concentration ratio analysis, while G2 and G4 system sustained of summer 13.3 $\~$ 16.6 ppm, winter 14.0 $\~$ 14.6 ppm level, Gl and G3 system sustained of summer 14.6 $\~$ 20.3 ppm, winter 20.3 $\~$ 25.0 ppm, and the latter one is lower than that of the G1 and G3 system.

• Proceedings of the KIEE Conference
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• 2008.04b
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• pp.3-5
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• 2008

In this paper, a modified diffusion model integrated with the effects of rebate programs is developed. The greater part of motors is included to various systems such as pump systems, fan systems, ventilation systems, motor itself, and so on. Hence, the existing rebate program is not suitable for these systems and a generalized rebate model for these systems is necessary. In the pre-study, a new diffusion model for motor rebate Program was proposed and the adequacy of this model was evaluated in the case of Korea. This paper shows that the motor rebate model could be applied to the case of pumps.

• Proceedings of the KIPE Conference
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• 2004.07a
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• pp.172-176
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• 2004

In this paper, We are inclined to design automated mushroom-cultivation system technology grafting communication technology as CAN(Control Area Network). Mushroom cultivation automated system have a goal to construct stable crop cultivation system ,as we construct embedded-system that can make into one to advance current system. Its sensor part is composed of temperature , humidity and CO2 concentration sensor and of chilling, heating and unit humidity-controlling unit, ventilation fan. In particular, having saved analized temperature, humidity, CO2 concentration data in each sensor, CAN which can control realtime communication is used to analyze the next mushroom-cultivation.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 2000.10b
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• pp.109-112
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• 2000

느타리버섯은 맛, 향기 및 영양가가 일반 채소류나 일부 버섯류에 비하여 높고, 고혈압, 당뇨병에도 효과가 있으며, 특히 항암효과 등의 약리활성이 있어서 오래 전부터 한국과 일본에서 부식으로 이용되었다. 느타리버섯의 국내 재배면적 및 생산량은 1988년 832,346평에 29,386톤에서 1997년 에는 2,100,890 평에 83,606톤으로 증가되었다. 그러나 생산량의 증가추세에 부합하는 재배기술의 축적, 적정 재배환경 관리의 모델화가 미흡하기 때문에 그 생산량은 국민적인 소비욕구를 충족시키지 못하고 있다. (중략)