• Journal of Bio-Environment Control
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• v.16 no.2
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• pp.121-129
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• 2007

Responses of antioxidant enzymes on chilling and drought stress in tomato seedlings were investigated. Growing patterns of tomato based on fresh weight of tomato seedlings were severely affected by chilling and drought stress. Fresh weight of tomato seedlings were reduced by 69.5% in chilling stress and 50.6% in drought stress compared to those in the unstressed control seedlings after 12 days of stress. The specific and gel activity of SOD and POD in the leaves, shoots, and roots of tomato seedlings were significantly increased by chilling and drought stress. Activation of SOD and POD activity by chilling stress were higher in the roots than those of drought stress. However, activation of SOD and POD activity by drought stress were higher in the leaves and shoots than those of chilling stress. The specific and gel activity of GR in the leaves, shoots, and roots of tomato seedlings were also significantly increased by chilling and drought stress. When the seedlings were treated with chilling or drought stress, one GR isozyme band (GR-3) was newly expressed in the leaves of tomato seedlings. The specific and gel activity of PPO was significantly increased in the roots and shoots of tomato seedlings by chilling and drought stress, respectively. However, the specific and gel activity of PPO in the leaves is no difference between stressed and controlled tomato seedlings.

• Proceedings of the Korean Information Science Society Conference
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• 2012.06c
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• pp.172-174
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• 2012

농 수산업 등 많은 신선 물류 환경에서는 저온저장고에 저장되는 물품을 신선하게 유지해야 한다. 신선도를 유지하기 위해 저온저장고 환경 모니터링 시스템을 이용하며, 센서를 이용하여 환경정보를 수집한다. 센서 데이터 수집의 목표는 저장되는 물품이 위치한 공간의 환경 정보를 모니터링 하는 것이지만, 물품에 센서를 부착하는 작업의 비효율성 또는 부착 불가능 등의 문제가 발생한다. 이를 해결하기 위하여 본 논문에서는 물리적 센서를 가상 센서로 대체하여 가상 센서 데이터를 생성하는 것을 제안하며, 가상 센서 데이터 생성을 위한 기법 및 센서 데이터 처리 시스템으로 적용 방법을 기술한다.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2002.07a
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• pp.176-181
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• 2002

국내 저온저장고의 문제점은 재래식 제어방식과 냉각방식으로 인한 온도분포의 불균일과 시스템 성능 저해, 청과물의 생리적인 특성을 고려하지 알은 냉기의 유속과 습도제어, 청과물의 저온저장 중 발생되는 환경가스 제거기술의 미흡으로 인한 땀은 감모율 발생 그리고 청과물의 생리적인 특성을 고려하지 않은 저온저장고의 최적 설계기술 미흡 등을 들 수 있다. (중략)

• Korean Journal of Environmental Biology
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• v.39 no.4
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• pp.486-494
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• 2021

Watermelon (Citrullus lanatus (Thunb.) Matsum. & Nakai) is sensitive to low temperature and shows retarded growth under 10℃. Although early transplanting guarantees higher returns, it requires cost and labor to maintain the appropriate temperature for plant growth. Therefore, cultivars tolerant to chilling stress is necessary to reduce the cost and labor requirements. The purpose of this study is to analyze data on plant growth and fruit enlargement under continuous chilling night temperature to develop new cultivars tolerant to chilling temperature. Two cultivars expected to have chilling tolerance and another cultivar sensitive to chilling temperature were grown in greenhouses with chilling and optimal night temperature conditions. In the early growth stage after transplanting, the cultivars expected to have chilling tolerance showed better vine length, fresh weight and dry weight. However, one of the tolerant cultivars showed significantly lower vine length, leaf length and width, and petiole length than the sensitive cultivar during pollination period and later growth stage, showing genotype specific responses. The fruit length, width, and weight were also significantly lower in the tolerant cultivar. The fruit set ratio was significantly higher in the chilling sensitive cultivar than the two tolerant cultivars. These results suggest that the present chilling tolerant cultivars in watermelon were selected based on their performance in the early growth stage, and further studies on chilling tolerance in different growth and development stages are required to develop cultivars adapted to various forcing cultivation systems.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.38 no.2
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• pp.119-128
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• 2010

The hygrothermal effect on the strength of composite single-lap bonded joints were investigated. The specimens were manufactured in four different manufacturing methods and tested in three different environmental conditions. An interesting result is that the strengths of the joints in the elevated temperature and wet (ETW) conditions were found to be 11 ~ 23% higher than those in the room temperature and dry (RTD) environment. In contrast, the strengths of the joints in the cold temperature and dry (CTD) condition decrease by 8 ~ 21% compared to those in the RTD environment except for cobonded joint. The difference in the strength by testing environments is mainly attributed to the change of the material properties of adhesive by temperature and moisture.

• Journal of Climate Change Research
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• v.4 no.2
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• pp.189-199
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• 2013

Using meteorological data collected from 60 observation stations during the last 38 years from 1973 through 2010, we have analysed the occurrence frequencies of abnormally low or high temperature leading to agrometeorological disasters. The analysis was made for 20 agro-climatic zones that had already been divided by the Rural Development Administration before. Since 1973, there have been an average of 1.8 frequency of abnormal air temperature occurrence per year. The frequency of abnormally high temperature occurrence has increased from an average of 0.2 per year in 1970s to 1.0 in 2000s. However, the frequency of abnormally low temperature occurrence has decreased from an average of 2.06 per year in 1970s to 0.63 in 2000s, which might be able to explain a recent global warming. The highest frequency of abnormally high temperature occurrence appeared in Taebaek Alpine zone with an average of 0.76 frequency per year. Meanwhile, abnormally low temperature was the highest in Western Sobaek Inland zone with an average of 1.43 frequency per year.

• Environmental engineer
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• v.19 s.207
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• pp.92-95
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• 2003

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2008.11a
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• pp.153-156
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• 2008

Ignition and combustion performance of a gas-turbine engine were changed by various high-altitude condition. A goal of this study is to make the small test facility to simulate high-altitude condition. To perform the low pressure condition, a diffuser was used in various diffuser front of primary nozzle pressure. To perform the low temperature, heat exchanger was used in various mixture ratio of cryogenic air and ambient temperature air. The experimental result shows that high-altitude conditions can be controled by diffuser front of primary nozzle pressure and mixture ratio of cryogenic air and ambient temperature air.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2000.04a
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• pp.313-314
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• 2000

최근들어 유해한 작업환경의 대기나 공장의 배기 가스, 또는 주변 주거 지역의 대기에서 검출되는 인체 유해 물질들에 많은 관심이 모아지고 있다. 이들 물질 중 휘발성 유기오염물(VOC)은 대기 중에 매우 낮은 농도로 존재하기 때문에 이의 측정은 매우 중요시되고 있다. 휘발성 유기화합물(VOC)의 분석 방법에는 GC-MS 또는 GC-FID에서 정확하게 측정하기 위하여 저온 농축법을 이용한 분석방법이 있으며 이들 두 가지 방법은 각각의 저온 농축시스템은 조절이 어렵고 작동하기가 복잡하다. (중략)

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2002.04a
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• pp.241-242
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• 2002

최근 들어 지표면 오존농도의 증가에 기여하는 오존전구물질에 대한 관심이 증대되면서 오존전구물질에 대한 분석방법의 확립에 많은 노력을 기울이고 있는 실정이다. 지금까지는 비극성 column을 이용하여 저온 농축과정을 거쳐 분석을 수행하거나 극성 및 비극성 column을 병렬로 연결하여 환경대기 중의 오존전구물질을 측정한 연구사례가 대부분인 것으로 보고되고 있으나 이러한 저온농축과정 및 다수의 column을 사용할 경우 소요되는 장비 및 시간에 대한 비경제적인 측면을 고려하지 않을 수 없다. (중략)