• 한국연초학회지
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• 제16권2호
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• pp.139-143
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• 1994

This study was carried out to control the stalk curing period in Burley Tobacco, for its period was longer than 40 days. The 5 methods were treated to shorten the stalk curing period. The curing period was shortened for 1~3 days by the harvesting methods and the amount of predehydration, but it was shortened for 8 days by the hanging methods(sloping and horizontal curing)and the hanging density(90 plants/3.3m2) without the decrease of quality. In the ventilating condition of the curing house, the curing period could be controlled for 5 dyes with the quality like the conventional cured leaves by closing the curing house from the late curing stage. But when the curing house was not ventilated earlier, however the curing period was shortened but its quality was decreased.

• 한국지능시스템학회논문지
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• 제15권1호
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• pp.36-41
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• 2005

스마트 스페이스 환경은 유무선 네트워크기반과 다중 센서 기반이며 많은 제어기를 필요로 한다. 이러한 환경을 위해서 본 논문에서는 멀티레이트 디지털 분산 제어 제어기를 제안한다. 제안된 제어기 설계 방법은 디지털 재 설계 기법을 적용하는 것이다. 구체적으로 제안된 기법은 delta-operator와 멀티레이트를 기반으로 하며 선형 행렬 부등식형태로 나타난다. 제안된 기법의 우수성을 검증하기 위해서 스마트 스페이스에서 널리 사용되는 Heating, ventilating, and alt conditioning (HVAC) 시스템에 대해서 모의실험을 하였다.

• 한국전산유체공학회지
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• 제11권4호
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• pp.20-25
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• 2006

In the present study, flow characteristics inside a road tunnel are simulated for the ventilation flows due to jet fan system and flows induces by the traffic. Traffic ventilation is numerically simulated by multiple reference frame. From the results of steady state simulation of tunnel ventilation, it is found that the proper ventilation is achieved by the designed jet fan system along with ventilating flow induced by the traffic. A transient simulation is also performed for the case of vehicle fire in the tunnel reversing the direction of rotation of some fans. The results suggest that the heat and smoke can be controlled by the proper changing of fan operation mode. The present results can be used to design proper ventilation system and effective smoke control system as well.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2000년도 추계학술대회 논문집
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• pp.521-526
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• 2000

Experimental study is conducted to clarify pressure variation of the passenger cabin of conventional train. These pressure variation may give rise to the ear-discomfort. Generally ear-discomfort has been considered as a problem related to high speed train. Because there is also a good progress to speed-up for conventional line, this isn't only a phenomena related to high speed train any longer. In this study, tile pressure variation of interior, gangway and exterior of saemaeul passenger car is measured using the atmospheric pressure sensors in Honam line. From the results of experiment, the pressure variation per second almost close in upon the limitation in the case of Noryong tunnel. Therefore, to accomplish speed-up for conventional train, it may be necessary to study a serial ventilating and the airtightness of carbody.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2000년도 추계학술대회 논문집
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• pp.514-520
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• 2000

Numerical simulation is conducted to clarify the heat transfer and fluid flow characteristics of HVAC(Heating, Ventilating and Air-Conditioning) for Mugunghwa passenger car. The HVAC system is installed under the floor of carbody. This new HVAC system has a lot of merits in respect of the center of gravity of carbody, flow induced noise and reduction of condensation water etc. The standard k-epsilon turbulent model and SIMPLEC algorithm based on finite volume method are used to solve the physical HVAC model. To assure convergence, QUICK scheme for momentum equation and the first order upwind scheme for turbulent equations are used. From the results of simulation, the temperature and velocity magnitude are also distributed uniformly in the interior of car.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 춘계학술대회 논문집
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• pp.1325-1329
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• 2007

Indoor air quality is an important determinant of human health and comfort. However, the complexity of pollution sources and the multitude of parties responsible for creating indoor exposures makes the improvement of air quality difficult. The HVAC(Heating, Ventilating and Air-Conditioning) system is important facility to provide comfortable environment passenger service. The Ministry of Environment is established "Indoor Air Quality Management guidelines in Public Facilities"in December 2006. Hereupon, the train and the subway are included. In this research air quality in the Subway compartment has been measured. As a result, the concentrations of PM10 and $CO_2$ were reached to 93% and 61% of the regulation values, respectively. Thus, the indoor air qualities of subway have been proved that they satisfy the recommended guidelines by the Ministry of Environment.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 춘계학술대회 논문집
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• pp.1293-1296
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• 2007

An amenity requirement of the passenger using public traffic is rising continuously, and also The Ministry of Environment established "Indoor air quality management guidelines in public facilities(Dec. 2006)". To satisfy such requirement, the photoplasma device to decrease VOCs(Volatile Organic Compounds) and suspended bacillus is applied to the underframe mounted HVAC(Heating, Ventilating and Air-Conditioning) system for train. Air purifying method of photoplasma device is optical and chemical reaction that UV-light(wavelength less than 280nm) react with catalyst material(TiO2). To analyze the efficiency of photoplasma in this study, we measured the requirement time for toluene to decease down to 0.3ppm after contaminating the passenger cabin for train to toluene 1ppm.

• International Journal of Air-Conditioning and Refrigeration
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• 제9권3호
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• pp.63-71
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• 2001

This paper presents a model-based method for detecting and diagnosing some faults in the cooling tower of healing, ventilating, and air-conditioning systems. A simple model for the cooling tower is employed. Faults in cooling tower operation are detected through the deviations in the values of system characteristic parameters such as the heat transfer coefficient-area product, the tower approach, the tower effectiveness, and fan power. Three distinct faults are considered: cooling tower inlet water temperature sensor fault, cooling tower pump fault, and cooling tower fan fault. As a result, most values of the system characteristics parameter variations due to a fault are much higher or lower than the values without faults. This allows the faults in a cooling tower to be detected easily using above methods. The diagnostic rules for the faults were also developed through investigating the changes in the different parameter due to each faults.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2009년도 하계학술발표대회 논문집
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• pp.471-477
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• 2009

This study investigated automatic malodor exhaust ventilating methods in a water closet system. Even though these days advanced equipment has been applied into the toilet in a building or house, the odor due to the evacuating the bowels should be carefully removed to maintain clean and pleasant toilet. Therefore, this study thoroughly considered the main causes of the malodor problems and suggested the best applicable methods to the closet system.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2000년도 춘계학술대회논문집
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• pp.1416-1422
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• 2000

The cross-flow fans have been widely used to constitute the air moving systems in many air-ventilating and air-conditioning devices. The cross-flow fan system has many design parameters which have crucial influence on the performance and the noise characteristics of the devices. As a result, there are many difficulties in the design stage of the devices and the general design guide has not been sufficiently established yet. This study presents the experimental results of the parametric investigation of some chosen design parameters, which are the shape of the stabilizer, the profile of the scroll casing, and the diffusion angle of the flow exit. The results are expressed as the fan performance and the specific sound pressure level characteristic. These parts have been found to have crucial effects on the system performance/noise characteristics and should be considered with care in the design stage.