• Korean Journal of Soil Science and Fertilizer
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• v.21 no.1
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• pp.11-14
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• 1988

Field study was conducted to evaluate the relationship between daytime net radiation (Drn) and global solar radiation (Rs) and to develop the empirical equation predicting daytime net radiation above corn canopy from observations of Rs and Ta (mean daily air temperature). The relationship between Drn and Rs under the cloudless day was Drn = 0.6659Rs and that under the cloudy (> 35% of possible sunshine) Drn = 0.729Rs. Thus, Drn/Rs Ratio under cloudless day was found to be lower than that under the cloudy day. Rs and Ta were used in the radiation balance equation to estimate Drn and the empirical model could be expressed as $Drn=[0.9Rs-(352-227{\times}10^{-10}{\times}Ta^4)]$ [1.11Rs/Rso - 0.05].

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 2003.04a
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• pp.195-198
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• 2003

자갈축열 태양열온실은 주간에 일사로 데워진 온실 내부공기를 온실하부에 설치된 자갈축열층사이로 강제순환시켜 자갈에 에너지를 축열한다. 이러한 축열과 방열과정을 통하여 겨울철 야간에 난방시스템으로 이용하고, 여름철에는 냉방효과를 꾀하게 된다. 온실내 공기가 축열층을 통과하는 동안의 열전달은 강제대류열전달이며, 이 경우 축열층내의 열이동은 축열층내 공기와 자갈표면온도가 초기에는 열적으로 평형상태로 존재하다가 순환공기의 온도상승에 따라 열전달이 일어나게 된다. (중략)

• Korean Journal Plant Pathology
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• v.12 no.2
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• pp.209-213
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• 1996

배나무잎 이상반점증상의 발병환경 조건을 조사하고자 실험한 결과 주간 23$^{\circ}C$, 야간 18$^{\circ}C$ 온도조건에서 병징발현이 가장 심하였고 이보다 높은 온도인 28/23$^{\circ}C$와 낮은 온도인 18/13$^{\circ}C$에서는 발병이 아주 적었다. 배나무잎에 봉지를 피복하면 발병이 전혀 없거나 극히 저조하였다. 이것은 봉지내의 온도가 최고 46.8$^{\circ}C$까지 올라가 고온에 의하여 발병이 억제된 것으로 생각된다. 이병주 토양과 건전주 토양의 화학성을 조사한 결과 이병주 토양에서는 건전주 토양보다 유효인산량이 많게 나타났다. 토양수분이 많거나 적었을 때는 병징발현이 다소 늦어지기는 하나 최종 조사시 발병정도는 큰 차이를 나타내지 않았다.

• Journal of Bio-Environment Control
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• v.22 no.4
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• pp.328-334
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• 2013

A greenhouse heating system to improve heat pump performance using inside and outside air of greenhouse as a heat source selectively and cut $CO_2$ enrichment costs by delay of greenhouse ventilation was developed. In this system, thermal storage modes divided into inside circulation mode using surplus solar energy and outside circulation mode using outside air heat. The thermal storage modes were designed to be switched mutually according to inside greenhouse temperature and six temperature values were input to control the heat pump operating, thermal storage mode switching and greenhouse heating automatically. Operating characteristics of this system were tested in a plastic greenhouse of non-ventilation condition. The results of test showed that the inside circulation mode began at about 11:00 and lasted for about 210 minutes and inside greenhouse temperature was maintained between $20{\sim}28^{\circ}C$ in spite of non-ventilation. System heating COP of the inside circulation mode in the daytime was 3.35, which was 36% and 25% higher than that of the outside circulation modes in the nighttime and daytime respectively.

• Korean Journal of Environmental Agriculture
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• v.33 no.4
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• pp.403-408
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• 2014

BACKGROUND: Kiwifruit is a warm-temperate, deciduous fruit tree. It is sensitive to frost or freeze damage during winter. Therefore, the farmers cover kiwifruit trunk with rice straw to preclude freeze injury. This study was conducted to evaluate trunk wraps for protection of freeze injury of kiwifruit (Actinidia deliciosa) vines. METHODS AND RESULTS: The experimental orchard was located in Sacheon (lat. $34^{\circ}56'N$, long. $128^{\circ}03'E$) of Gyeongsangnam-do, South Korea. The vines were 5-6-year-old 'Hayward'. Two wrap materials, rice straw and silver-cushioned mat (reflective foil-coated, plastic-foamed mat, Ganan Industry, Rep. of Korea) were evaluated for their heat-retaining ability. The trunks of kiwifruit vines were wrapped in late December, and the wraps were removed in mid-April the following year (2012/13 and 2013/14). Temperature inner wraps were recorded from January to March in 2013 and 2014 by WatchDog 2450 (Spectrum Technologies, Inc., USA). In 2013, the lowest ambient temperature of January and February was $-10.2^{\circ}C$, $-10.9^{\circ}C$, respectively. The lowest temperature of inner-wrap of silver -cushioned mat was $-6.3^{\circ}C$, $-2.6^{\circ}C$ in January and February, respectively. However, rice straw showed $-9.8^{\circ}C$ and $-9.9^{\circ}C$ in its lowest value of January and February. And also silver cushioned mat appeared to be superior to rice straw in its ability of heat-retaining during night time.

• Journal of the Korean Regional Science Association
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• v.40 no.2
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• pp.107-130
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• 2024

Urban land surface temperature (LST) change is a major environmental factor that affects the thermal comfort, energy consumption, and health of urban residents. Most studies that explored the relationship between LST and urban built-environment form analyzed only midday LST. This study explores the diurnal variation of summertime LST in Seoul using ECOSTRESS data, which observes LST at various times of the day and analyzes whether the LST variation differs by built environment type. Launched in 2018, ECOSTRESS operates in a non-sun-synchronous orbit, observing LST with a high resolution of 70 meters. This study collected data from early morning (6:25) to evening (17:26) from 2019 to 2022 to build time-series LST. Based on greenery, water bodies, and building form data, eight types of Seoul's built environment were derived by hierarchical clustering, and the LST fluctuation characteristics of each cluster were compared. The results showed that the spatial disparity in LST increased after dawn, peaked at noon, and decreased again, highlighting areas with rapid versus stable LST changes. Low-rise and high-rise compact districts experienced fast, high temperature increases and high variability, while low-density apartments experienced moderate LST increases and low variability. These results suggest urban forms that can mitigate rapid daytime heating.

• Horticultural Science & Technology
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• v.28 no.5
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• pp.783-789
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• 2010

The effective method for heating root-zone during winter season was studied in the aspects of growth, yield and economics for tomato ($Solanum$ $lycopersicum$) in perlite bag culture. There were four root-zone heating treatments: two hours heating from one hour before to one hour after sunrise, four hours from two hours before to two hours after sunrise, 15 hours after sunset, and no heating. The growth characteristics of the upper parts of plants were not significantly different among the treatments, but root volume increased with longer heating of the root zone. The Plant Development Index, using stem diameter and the length between growing tip and the upper flowering truss, showed relation between yield per cluster and growth pattern. The treatment heating for four hours was the most economic in terms of growth and yield of tomato.

• Life and Agrochemicals
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• s.250
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• pp.36-37
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• 2009

보통 $7\sim8$월에 수확하는 수박은 수분이 96%로 대부분이 당질이며 비타민은 극히 적으나 많은 양의 과당은 신장병에 좋다고 한다. 주과육 중에 있는 citrulline과 arginine은 이뇨효과는 껍질 쪽이 뛰어나다. 또한 씨에는 linoleic acid가 풍부하여 동맥경화 예방 효과가 있다. 저장은 보통 최적 온도 $2.2\sim4.4^{\circ}C$, 최적 습도 $80\sim85%$의 저온이며 $1\sim2$주간 저장 할 수 있다.

• Journal of Bio-Environment Control
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• v.6 no.1
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• pp.34-42
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• 1997

Effects of DIF on stem elongation in plug seedlings of mini tomato ‘Mini Carol’ and on the growth and flowering after transplanting were investigated. Stem elongation of seedlings was mainly influenced by day temperature rather than night temperature. When the effect of ＋DIF was compared to that of -DIF under the same average daily temperature(ADT), day temperature had greater impact on internode elongation than night temperature. On the other hand, leaf unfolding rate increased and compactness decreased as ADT in creased. Differences in internode length affected by DIF during seedlings stage DIF progressively diminished during growth period after transplanting. Node position at which first flower was initiated was lowered as ADT decreased. It was concluded that DIF treatment was an applicable tool for control of stem elongation, particularly to reduce stem length without a noticeably adverse effect on the growth and development of plant after transplanting.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 1998.05a
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• pp.77-82
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• 1998

현재 온실 난방에 주로 이용되고 있는 난방기는 대부분이 화석에너지를 연료로 사용하고 있다. 따라서 생산비의 가중이 불가피하며, 또한 연소 과정에서 발생하는 배기 가스로 인하여 환경 오염이 문제시되고 있다. 따라서 태양에너지를 보다 더 적극적으로 활용할 수 있는 기술의 개발이 요구된다. 태양에너지를 시설 농업에 적극적으로 이용하기 위해서는 주간에 밀도가 낮은 태양에너지를 고밀도로 축열하여 기온이 급강하하는 야간의 보온에 활용하여야 한다. 주간의 온실내 잉여 태양에너지를 축열할수 있는 상변화 온도 3$0^{\circ}C$ 수준의 잠열축열재를 개발하기 위하여 수행한 본 연구의 결과를 요약하면 다음과 같다. 1. SCD에 Borax를 0.0~5.0wt% 첨가하여 과냉도를 25.$0^{\circ}C$에서 $1.5^{\circ}C$ 이하로 조절하였으며, Borax의 적정 함량은 3.0wt%였다. 2. SCD에 Carbopol을 0.0~3.0wt% 첨가하여 상분리량을 70.0%에서 0.0%로 조절하였으며, Carbopol의 적정 함량은 1.5wt%였다.3. 축열재 내구성 검증을 위하여 0~1,500회의 상변화 사이클을 수행하였다. 이때 상변화 온도의 변화량이 $\pm$1.$0^{\circ}C$ 이하, 잠열량 변화가 $\pm$2.0 kacl/kg 이하로서 안정된 값을 보였다. 이상의 결과로 볼 때 축열재의 수명을 10년까지는 보장할 수 있는 것으로 판단되었다.