• Journal of agriculture & life science
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• v.50 no.2
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• pp.187-194
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• 2016

The purpose of this study was to analyze temperature distribution characteristics using a model swine housing for temperature sensor adjustable positioning and developed a sensor and controller embedded exhaust fans utilizing ICT fusion technology for windowless swine housing. Temperature measured by the sensor attached on the exhaust fan was also determined that there is no problem, the temperature is located in the upper fan given the measured errors shown in the 1℃ temperature difference between the lower temperature than the other positions in the model swine housing. The performance of the exhaust fan at maximum output was found to be 1920rpm, air flow rate 125㎥/min. When the open area ratio of 70% one proper air volume of the exhaust fan was found to be 75㎥/min, 60pa. Maximum efficiency in all of the output of the exhaust fan is exhibited at about 70% open area ratio of the damper. The number of revolution of the exhaust fan was 1920rpm when the output was a maximum of 100%. AC output phase of the pulse duty ratio change of the controller was shown to change without delay. It was determined that the instant fan speed control is possible.

• Fire Science and Engineering
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• v.22 no.1
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• pp.61-67
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• 2008

This study is focused on the numerical predictions of heat and smoke exhaust characteristics in an underground subway station stopping a fire train. Various ventilation operating modes with the fan equipped the platform and tunnels are considered. Distributions of temperature, carbon monoxide and visibility at a height of 1.7 m(breath height) above the platform are analysed for different ventilation fan operation mode. The numerical results show that smoke and heat is rapidly removed through tunnel by operating the tunnels fans. We suggested that during evacuation of passengers is not completed, the ventilation system in the platform is activated. After completion of passenger evacuation tunnel fans are activated but the fans in the platform are stopped.

• Korean Journal of Organic Agriculture
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• v.22 no.1
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• pp.147-154
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• 2014

Spinach downy mildew caused by Peronospora spinaciae is the main reason of yield reduction in Korea as well as in worldwide. After forced ventilation or horizontal air circulation fans were installed to control growth conditions in green house, the changes of temperature, relative humidity (RH), growth and yield, and occurrence of downy mildew were examined. Althought here was no significant difference of temperature between the treatments, RH as 9.2% lower at nighttime by forced ventilation. In addition, final fresh weight was increased to 17.8g compared to control (10.1g), which as 7.7g enhancement. Downy mildew s tarted to show 20 days after sowing (DAS) and increased to 34.7% at 60 DAS on harvest time in control. In contrast downy mildew was occurred 40 DAS with 0.7% incidence rate and 4% at harvest by forced ventilation. The results indicated that reduction of only 9.2% of RH at nighttime by forced ventilation in greenhouse spinach growth was dramatically thrived over 76.2%. Additionally spinach downy mildew occurred 20 days later with extremely lower incident rate, which meant 88.5% reduction of downy mildew.

• Journal of Bio-Environment Control
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• v.12 no.3
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• pp.127-131
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• 2003

This study was conducted to establish the ventilation fan operation schedule to be able to provide satisfactory environment for colonies in thc wintering honey bee house. The simulation and practical measuring test were conducted to verify the applicability of an existing simulation program to thc calculation of inside thermal environment condition of the house, and the environment control performance was compared between the two types of fan operation schedule to find the proper schedule. It was concluded that the program could be used to design thc materials of the enclosure and the fan operation schedule and decide the number of accommodation hives. Inside temperature of bee house controlled by the fan operation schedule B was lower than the schedule A under the similar high outside temperature condition. In the presence of the high outside temperature condition, inside air temperature of bee house could be decreased by changing fan operation schedule A to schedule B. The humidity variation in bee house controlled by the tan operation of schedule B was smaller than that by schedule A. These results indicated that the schedule B was superior in the aspect of the environment control performance.

• Journal of Bio-Environment Control
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• v.25 no.4
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• pp.334-342
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• 2016

In order to evaluate the modified installation methods of roof ventilation devices, derived from the previous experiment ('investigation into the optimum capacity of roof ventilation devices and their deployment'), the conventional and modified (improved) roof ventilation systems were installed in the single-span plastic greenhouse for growing oriental melons. The roof vents ($60{\varphi}$) and roof fans (maximum air capacity of $38m^3/min$) were installed in the spacing of 15m (FT, modified 'side vent+roof fan' ventilation) and 6m (TT, modified 'side vent+roof vent' ventilation) respectively on the roof of greenhouses for the modified roof ventilation treatments, and 20m (FC, conventional 'side vent+roof fan' ventilation) and 8m (TC, conventional 'side vent+roof vent' ventilation) for the conventional ones. The stem diameter, leaf blade lengh, petiole length, and leaf width were lower in the FT and TT treatments than those in the conventional treatments, FC and TC. Although the fruit weight and total yields were slightly lower in the FT and TT treatments, the marketable fruit ratio (%) were higher, as a result of increased fruiting ratio (%) in these treatments, than those of FC and TC. The marketable yields (kg/10a) in the FT and TT treatments were 8,391 kg/10a and 7,283 kg/10a, which were respectively 661 kg/10a and 487 kg/10a higher than those in the treatments of FC and TC. The modified installation methods of roof fan resulted in production of more female flowers and lower fruit drop ratio (%) compared to conventional meathods. In the treatment of the conventional ventilation with roof vent, the fruit weight, fruit length & width, and flesh thickness were higher than in other treatments, but there were no significant differences in the fruit width and flesh thickness among the treatments.

• Tunnel and Underground Space
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• v.13 no.3
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• pp.235-243
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• 2003

Recent worldwide trends show that tunnel length is getting longer, and the demand for longitudinal ventilation system with jet-fans in highway tunnels has also increased mainly due to the economic reasons. Improvements in vehicle engine subsequently reduced required ventilation rate(Qreq) which is the decisive factor in choosing the optimal ventilation system. Qreq contour map is a graph that defines the relationship among tunnel length, grade and required ventilation rate. It is important to understand the variation of Qreq in order to evaluate the characteristics of ventilation system with jet fans. Therefore this study aims at studying a graphical method for determining the characteristics of jet-fm ventilation system using Qreq contour map. Also, this study focuses on traffic composition on local highways.

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.38 no.9
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• pp.10-16
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• 2009

하이브리드 환기설비 중 강제환기팬은 일반 강제환기방식처럼 팬의 용량은 [강 중 약]의 3단계로 운전이 가능하도록 규정하고 있다. 수동 및 자동환기를 위해 일부 환기업체를 중심으로 $CO_2$ 센서를 설치하여 공동주택의 실내환경 기준 농도인 1,000 ppm을 기준으로 자동으로 작동이 가능하도록 하고 있으며 $CO_2$ 센서는 controller에 내장하고 있다. 이때 환기팬이 자동으로 작동하기 위한 적절한 $CO_2$ 농도 및 $CO_2$ 센서의 적정위치에 대해 검토하고자 한다.

• 월간낙농육우
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• v.37 no.7
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• pp.114-117
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• 2017

하절기 목장의 축산시설 관리 포인트는 무엇일까? 우선 유우사는 개방식 축사이기 때문에 지붕의 재료에 따라 다르지만 햇빛과 바람 관리만 잘해도 우사환경은 개선되는데, 계절적으로 하절기로 접어들면서 소가 더위에 시달리며 산유량이 떨어지는 목장이 많아지고 있다. 따라서 농가에서 무조건 환기팬의 대수만 많이 설치하면 된다고 생각하여 환기팬을 추가적으로 많이 설치해주고 있는 실정이다. 그러나 환기는 지붕의 구조와 소의 사육단계 등을 근거로 환기량을 결정해야 한다. 특히 여름철은 우사내 습도 관리를 잘해주어야 소의 생산성과 사료효율을 최적화할 수 있다. 따라서 적절한 채광을 해주고 바람의 이용과 차단을 해준다면 소는 하절기에 시원함을 느끼고 청결을 유지하며 관리자의 노력도 최소화되는 환경을 만들 수 있다. 따라서 본고에서는 시설 및 환기개선을 통한 하절기 축사관리 방법에 대하여 알아보고자 한다.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2011.04a
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• pp.313-318
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• 2011

도로터널은 반지하 공간으로서 환기에 많은 설비와 구조에 대한 연구가 진행되고 있으며 특히 제트팬의 경우 평상시에는 환기를 담당하고 있다. 또한 화재시에는 화재연기의 유독가스를 효과적으로 차단하는 제연역할을 함으로서 피난에 대한 중요한 역할을 담당한다. 이러한 제트팬의 특성을 정량적으로 유추하고 공학적인 QRA의 수행을 위한 기초적 연구로서 터널내부의 제트팬의 환기특성을 알아보기 위하여 모형실험체의 내부측정을 2/3까지한 전보에 이어 이번 연구에서는 터널내부전체를 측정하여 제트팬이 모형터널내에 미치는 영향을 CFD와 비교한 연구이다.

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.30 no.7
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• pp.24-28
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• 2001

터널 환기 설비는 터널에서 발생하는 오염물질을 희석 배출하여 터널에서의 안전운행 및 쾌적한 환경을 유지함을 목적으로 한다. 이를 위해서 각종 환기설비가 필요하게 되며, 이에 대한 설계 검토가 요구되고 있다. 본 원고에서는 제트팬 방식의 터널에서 풍속 측정을 중심으로 하여 측정결과 및 분석결과를 소개하고자 한다.