• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 1993.10a
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• pp.11-12
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• 1993

여름철 온실의 수경재배를 위해서는 양액의 냉각은 필수적이다. 이와 같은 양액냉각을 적절히 실행하기 위해서는 먼저 시설내의 환경예측에 의한 양액의 냉각부하 산정 및 냉각부하에 따른 설비용량 결정이 필요하다. 그동안 국내외적으로 온실의 환경예측을 위한 모델들은 많이 개발되어 있지만 대부분이 토경재배를 대상으로 온실의 변화나 난방효율의 예측을 목적으로 하고 있으며, 수경재배 온실 더우기 양액 냉각을 취급하는 경우는 찾아보기 힘들다. (중략)

• Horticultural Science & Technology
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• v.32 no.1
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• pp.46-52
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• 2014

This study was conducted to compare colony forming unit (CFU) of microorganisms in closed and open soilless culture systems for estimating the possibility for potential disease occurrence. Samples were collected at four different positions in four commercial greenhouses with closed or open soilless culture system using rock wool or coir as substrate, respectively. The distance between sampling positions was 3 cm starting from the substrate and the surface area of each position was $25cm^2$. The CFU of fungi was significantly higher in the open system, while that of bacteria was not significantly different but showed relatively lower in the closed system. Samples collected at the plastic surface of the substrates where little environmental effects occurred from drainage showed lower CFU than any other positions. The principal component analysis showed that samples collected on the drainage pathway highly affected the changes in microbial population in the greenhouse. These results indicated that greenhouses with closed soilless culture are expected to have more advantageous conditions for restraining the microbial growth, resulting in the lower potential of disease occurence in greenhouse ecosystem.

• Solar Energy
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• v.10 no.3
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• pp.27-34
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• 1990

The main objective of this study was to find the relationship between transpiration rate and environmental factors for crops in hydroponic culture within plastic greenhouse by using the computer model developed from the heat balance around leaves of a crop. A computer model was developed and verified through comparison with the experimental results for lettuce in hydroponic culture in a polyethylene film house. The model may be extensively used for the water management and thermal environment study of crops in protected culture, if the supplemented studies for some crops would be accomplished.

• Journal of Bio-Environment Control
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• v.2 no.2
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• pp.99-109
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• 1993

Cooling of nutrient solution is essential to improve the growth environment of crops in hydroponic culture during summer season in Korea. This study was carried out to provide fundamental data for development of the cooling system satisfying the required cooling load of nutrient solution in hydroponic greenhouse. A numerical model for prediction of the cooling load of nutrient solution in hydroponic greenhouse was developed, and the results by the model showed good agreements with those by experiments. Main factors effecting on cooling load were solar radiation and air temperature in weather data, and conductivity of planting board and area ratio of bed to floor in greenhouse parameters. Using the model developed, the design cooling load of nutrient solution in hydroponic greenhouse of 1,000$m^2$(300pyong) was predicted to be 95,000 kJ/hr in Suwon and the vicinity.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 1993.05a
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• pp.12-13
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• 1993

우리나라의 기상입지 특성상 여름철 온실 내에서 작물의 정상생육을 기대하는 것은 곤란하므로, 주년재배를 위한 여름철 온실내 환경의 호적화는 온실재배 당면의 연구과제라 할 것이다. 더우기 막대한 일사부하로 인하여 온실냉방은 경제적으로 불가능한 실정이므로 다른 방법을 강구해야 한다. 그런데 수경재배에 있어서는 비교적 근권부환경의 조절이 쉬우므로, 온실의 충분한 환기 및 차광과 더불어 양액의 냉각을 통하여 작물의 고온스트레스를 줄임으로써 안정생산을 가능하게 할 수 있을것으로 생각한다. (중략)

• Proceedings of the Korea Information Processing Society Conference
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• 2019.10a
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• pp.536-537
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• 2019

작물의 생육에 따라 적기에 필요한 양만큼의 양분을 공급해 최고의 생산성을 올릴 수 있는 수경재배는 정보통신기술(ICT)을 융·복합한 스마트 농업 형태로 전환되고 있으나, 기술 발전에도 불구하고 여전히 환경 및 경제성 문제 등 많은 개선점을 가지고 있다. 본 논문에서는 딸기 수경재배지의 환경 데이터 및 생육 데이터를 수집하고, 터치스크린과 스마트폰을 통하여 배양액의 배액량, pH, EC, 온도, 습도를 실시간 및 정한 기간에 따라 모니터링이 가능한 수경재배 소규모 온실을 위한 SBC기반의 모니터링 시스템을 제안한다.

• Journal of Bio-Environment Control
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• v.1 no.2
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• pp.123-134
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• 1992

In order to verify the usability of the greenhouse for aquaculture with nutrient culture synchronously and to obtain the fundamental data fir the establishment of efficient farming technology, the characteristics of microclimate and the growth of leafy vegetables were examined. Tilapia averaged 428.6 g grew to 784 g(1.83 times) for 147 days from May 29 to Oct. 21 and fingerlings averaged 12.9 g grew by 1.37 times for 61 days from Sep. 13 to Nov. 12. The growth of vegetables such as water dropwort, leaf lettuce, Chinese cabbage, and Welsh onion in the greenhouse was better for aquaculture with nutrient culture than for nutrient culture only. Between above two greenhouses, pH and EC of nutrient solution was same but the temperature different by about 2$^{\circ}C$. Average day temperature, relative humidity, and $CO_2$ concentration were higher by 2.9$^{\circ}C$, 6%, and 200 ppm in the greenhouse for aquaculture with nutrient culture, respectively. Net assimilation rate of vegetables in the greenhouse was a little higher for aquaculture with nutrient culture than for nutrient culture only. Therefore, provided aquaculture and nutrient culture are carried out in the same greenhouse, the saving effect of heating cost as well as the additional promotive effects of vegetable and tilapia growth can be obtained.

• Proceedings of the Korea Information Processing Society Conference
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• 2016.10a
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• pp.370-371
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• 2016

본 논문은 최근 증가하고 있는 딸기 고설수경재배 농가의 생산성 향상과 소득 증대를 위해 생장지표와 목표점을 기반으로 온실의 내/외부 환경 요소 및 시장정보 등의 외적 요소를 반영하여 효율적인 생장관리를 지원해주기 위한 복합환경제어 시스템에 대한 연구이다.

• Magazine of the Korean Society of Agricultural Engineers
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• v.36 no.3
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• pp.113-121
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• 1994

Since it is difficult to expect the normal production of plants in greenhouses during hot summer season in Korea, certain provisions on the control of extreme environmental factors in summer should be considered for the year-round cultivation in greenhouses. This study was carried out to find a method to suppress the temperature rising of nutrient solution by cooling, which is able to contribute to the improvement of the plant growth environment in hydroponic greenhouse during hot summer season. A mechanical cooling system using the counter flow type with double pipe was developed for cooling the nutrient solution efficiently. Also the heat transfer characteristics of the system was analysed experimentally and theoretically, and compared with the existing cooling systems of nutrient solution. The cooling capacities of three different Systems, which used polyethylene tube in solution tank, stainless tube in solution tank, and the counter flow type with double pipe, were evaluated. The performance of each cooling system was about 41 %, 70% and 81 % of design cooling load in hydroponic greenhouse of 1 ,000m$^2$ on the conditions that the flow rate of ground water was 2m$^3$/hr and the temperature difference between two liquids was 10 ˚C According to the results analysed as above, the cooling system was found to have a satisfactory cooling capability for regions where ground water supply is available. Fer the other regions where ground water supply is restricted, more efficient cooling System should be developed.

• Journal of Bio-Environment Control
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• v.5 no.2
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• pp.210-214
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• 1996

The measuring system was developed for automation of hydroponic culture. It runs in Windows 3.1 and 95. Main window contains greenhouse screen and menu bars such as system setting, sensor calibration, greenhouse status, actuator control, file management, view, and help. Users can use pop-up menu, tool bar and status bat as well as menu bar for manipulation. Especially it was designed to retain flexibility for researchers, who changed detecting sensors frequently. Users can change storage intervals of files, of which 3 types were prepared to use in other software like as statistical programs, graphic programs and/or spread sheets. This system was adopted to deep flow culture system and evaluated to be appropriate for any kind of hydroponic systems.