• Journal of Bio-Environment Control
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• v.8 no.2
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• pp.75-82
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• 1999

This study was carried out to examine the effect of day/nignt temperatures during seedling culture on the vegetative and reproductive growth of Lycopersicum esculentum ‘Seokwang’. The study was consisted of two culture stages, plug seedling production in the growth chamber and hydroponic culture of the plant in a glasshouse. Experiments were replicated over time. The germinated seedlings were raised for 33 days (experiment 1) and 35 days (experiment 2) in 4 growth chambers, each with day/night temperatures of either $25^{\circ}C$/$25^{\circ}C$, 16$^{\circ}C$/16$^{\circ}C$, 16$^{\circ}C$/$25^{\circ}C$ or $25^{\circ}C$/16$^{\circ}C$. Cool-white fluorescent lamps provided 140$\mu$mol.m$^{-2}$ .s$^{-1}$ light for 12h each day. In the second experiment, all chambers were supplied with 1000$\mu$mol.mol$^{-1}$ CO$_{2}$ during the photoperiod and had an air velocity of 0.3m.s$^{-1}$ and relative humidity of 80%. Plug seedlings raised were transplanted to rockwool slabs in a glasshouse and were grown hydroponically using the same nutrient solutions used for seedling culture for 37 days (experiment 1) and 35 days (experiment 2). Plant height was affected more by mean daily temperature than by interaction of day and night temperatures. Plant height was the highest in 16/16$^{\circ}C$ treatment. Leaf count was not affected by day and night temperatures, and the chlorophyll concentration was the highest in 16/$25^{\circ}C$ treatment. Fresh and dry weights of stem tended to be greater in treatments of constant day and night temperature. The number of node on which first and second flower clusters were set was significantly higher in 25/$25^{\circ}C$ treatment than in the other treatments. Days to flower of the first flower on the first flower cluster were the greatest in 25/$25^{\circ}C$ and the least in 16/$25^{\circ}C$ treatment. Vegetative and reproductive growth, such as height, fresh and dry weights, days to flower, and nodes of the 1st and 2nd flower cluster set were affected by day/night temperatures.

• Journal of Bio-Environment Control
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• v.32 no.1
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• pp.64-71
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• 2023

Crassulacean acid metabolism (CAM) plants use surplus CO₂ generated by cooling and heating at night when ventilation is not needed in a greenhouse. Schlumbergera truncata 'Pink Dew' is a multi-flowering cactus that needs more phylloclades for high-quality production. This study examined photosynthetic characteristics by the phylloclade levels of S. truncata in a growth chamber and a greenhouse for use of night CO₂ enrichment. The CO₂ uptake rate of the S. truncata's top phylloclade in a growth chamber exhibited a C₃ pattern, and the second phylloclade exhibited a C₃-CAM pattern. The CO₂ uptake rate of the top phylloclade in a greenhouse showed a negative value both day and night, but those of the second phylloclade exhibited a CAM pattern. The stomatal conductance and water-use efficiency (WUE) of S. truncata at both the top and second phylloclades were higher in a growth chamber than in a greenhouse. The WUE of S. truncata in a growth chamber and a greenhouse was higher at the second phylloclade, which is a CAM pattern compared with those of the top phylloclade. The daily total net CO₂ uptake of S. truncata was higher in a growth chamber than in a greenhouse. The daily total net CO₂ uptake of S. truncata at the second phylloclade had the highest value of 155 mmol·m^-2·d^-1 in a growth chamber. The night total CO₂ uptake of S. truncate at the second phylloclade was 3-fold higher in a growth chamber than in a greenhouse. S. truncata's second phylloclade exhibited a CAM pattern that uptake CO₂ at night, and the second phylloclade, was more mature than the top phylloclade. A multi-flowering cactus S. truncata 'Pink Dew' efficiently uptake night surplus CO₂ in the proper environmental condition with matured phylloclade.

• Horticultural Science & Technology
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• v.18 no.6
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• pp.783-786
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• 2000

This study was carried out to examine the effect of root-zone temperatures on seedling growth, mineral contents and antioxidative enzyme activities of grafted watermelon. The grafted watermelon seedlings were grown in greenhouse bed for 20 days at root-zone day temperatures of 10, 15, $25^{\circ}C$ while night temperature was maintained at $10^{\circ}C$. Growth such as shoot height, leaf length, leaf number, stem diameter, and fresh and dry weights increased as increasing root-zone temperatures, and leaf area with $25^{\circ}C$($52.79mm^2$) was two times that of control($21.50mm^2$). As increasing the root-zone temperatures, Mn, Ca, Fe contents increased, K, P, Mg were non significant, and Na decreased. The activities of ascorbate peroxidase(APX) and guaiacol peroxidase(GPX) known as antioxidative enzyme were higher at $10^{\circ}C$ than $25^{\circ}C$.

• Journal of the Korean earth science society
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• v.30 no.2
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• pp.185-195
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• 2009

We investigated the change of several meteorological variables due to deforestation. We established two sets of automatic weather observation system: one on a hill where forest was destructed by lumbering (Point 1) and the other in a neighboring district (Point 2) of fairly preserved forest. The observations were continued for one year (2006. 12-2007. 12). In this study, we analysed the data observed for one week from the nea day after summertime rainfall. The results showed that the air temperatures of Point 1 were about $1.5^{\circ}C$ higher than those of Point 2 during the daytime. But there were small gaps between the two poults during the nighttime. The relative humidities also differed greatly between the two during the daytime. It was as high as about 10% at Point 2. The surface and underground (15 cm in depth) soil temperatures were also fealty different between the two points during the daytime. They were $3-10^{\circ}C$ higher at Point 2 than those of Point 1. And the gaps reduced drastically during the nighttime. The averaged soil moistures were 7.1% at Point 1 and 19.5% at Point 2 during the observation period, respectively. The differences of wind direction were small, but the wind speeds differed between the two points. The observed wind speeds during the observation period were roughly estimated to be about 0.5m/s at Point 1 and 0.3m/s at Point 2. The heat budget analysis was also performed based on the observation data.

• Journal of Bio-Environment Control
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• v.30 no.4
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• pp.271-277
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• 2021

In this study, experiments of local heating on crown and supplying warm nutrient for energy saving and improving growth of 'Seolhyang' strawberry were conducted. The temperature of inside and crown in greenhouses which were control (space heating 8℃) and test (space heating 5℃+crown heating) was measured. In the control greenhouse, the average of temperature and humidity in December was 7.1℃, 87.2%, respectively. In the test greenhouse, the average of temperature and humidity in December was 5.7℃, 88.7%. The temperature of crown and inside the bed were 7.9℃, 10.8℃ in control, 9.3℃, 12.7℃ in test. During the test period, the total 16,847×10³ kcal of energy was consumed in control greenhouse including space heating. In test greenhouse including space heating, crown heating and warm water supplying, total 9,475.7×10³ kcal of energy was consumed. So, energy consumption in test was 43.8% less than in the control. The total yields of strawberry during test period were 412.7g/plant for test greenhouse and 393.3g/plant for control greenhouse respectively.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.14
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• pp.47-51
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• 1973

In order to ascertain the effects of fluctuations and range of daily temperatures on the growth of rice, a pot(1/5, 000 are) experiment was conducted in the phytotron, Crop Experiment Station, in 1972. Seven treatment combinations of day-temperatures 25 and $30^{\circ}C$ with night-temperatures 10, 15, 20 and $25^{\circ}C$ were applied in three 10 days periods, in to which the tillering stage was split after rooting of the paddy, namely, early, middle and late. The results may be summarized as follows: 1. The number of tillers were maximum with the treatments of day-temperature $30^{\circ}C$ and night-temperatures 20 as well as $25^{\circ}C$ in the early and middle periods, while the effects were small in the late period. 2. Multiplying plant height and number of panicles resulted in a high figure by combining a day-temperature of $30^{\circ}C$ with night-temperatures 20 as well as $25^{\circ}C$ in the early and middle periods, and no differences in the late period. 3. The treatment in the early period yielded a high RGR(g/g/day), of which the treatment combinations of day-temperature $30^{\circ}C$ with night-temperatures 20 and $25^{\circ}C$ gave the highest figure. 4. High straw weight in ripening stage was obtained with the temperature treatments in the early period rather than those in the late period. 5. Accordingly, it seems that the effect of temperature on the emergence of tillers is the highest at the early stage of tillering.

• Korean Journal of Agricultural and Forest Meteorology
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• v.1 no.2
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• pp.119-126
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• 1999

A numerical model using soil surface energy balance and soil heat flow equations to estimate mulched soil temperature was developed. The required inputs data include weather data, such as global solar radiation, air temperature, wind speed, atmospheric water vapor pressure, the optical properties of mulching material, and soil physical properties. The observed average soil temperature at 50 cm depth was used as the initial value of soil temperature at each depth. Soil temperature was simulated starting at 0 hour at an interval of 10 minutes. The model reliably described the variation of soil temperature with time progress and soil depth. The correlation between the estimated and measured temperature yielded coefficient values of 0.961, 0.966 for 5cm and 10cm depth of the bare soil, respectively, 0.969, 0.965 for the paper mulched soil, and 0.915, 0.938 for the black polyethylene film mulched soil. The percentages of absolute differences less than 2$^{\circ}$C between soil temperatures measured and simulated at 10 minute interval were 97.4% and 98.5% for 5 cm and 10cm for the bare soil, respectively, and 95.8% and 97.4% for the paper mulched soil, and 70.1% and 92.5% for the polyethylene film mulched soil. The results indicated that the model was able to predict the soil temperature fairly well under mulched condition. However, in the night time, the model performance was a little poor as compared with day time due to the difficulty of accurate determination of the atmospheric long wave radiation.

• Journal of Korean Society of Forest Science
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• v.32 no.1
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• pp.64-72
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• 1976

A series of rooting experiments of P. radiata needle fascicles were carried out in test tubes using peat-pumice medium to see a possibility of rooting fascicles in test tubes and, if possible, to find out whether that method can improve the rooting. Typical rooting of clones from ortets aged 3, 7, 11. 18, and over 40, respectively, was 57%, 47%, 18%, 4%, and 2%. The effect of ortet ages upon rooting of fascicle cuttings was significantly exerted in these experiments. In the older ortets these results are not as good as those often obtained in a glasshouse. Hormones tested (indolebutyric acid and abscisic acid) had no significant effect on rooting and neither did a series of fungicides tested. Needle fascicles placed in an 18 hour day at $20^{\circ}/10^{\circ}C$ (day/night temperature) rooted signficantly better than those in a 10 hour day at the same temperature regime. The latter in turn rooted better than those set under a 10 hour day at $15^{\circ}/5^{\circ}C$. Clonal differences in rooting ability were also distinct in every trial of the present experiments with needle fascicles.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2005.11a
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• pp.23-28
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• 2005

청계천의 경관조명은 하천을 가로지르는 다리 22개를 비롯하여 다양한 경관요소에 대하여 주변경관에 알맞는 경관조명으로 청계천의 특성을 부각시키고 있다. 특히 수변공간의 경관에서 큰 비중을 차지하고 있는 교량의 경관조명이 야간 청계천 경관의 아름다움을 좌우한다고 할 수 있다. 다양한 구조형태 및 특징을 가진 22개의 교량은 특색에 맞는 조명연출로 인지도를 주어 보행자로 하여금 청계천에 대한 방향감 및 공간감을 제공한다. 따라서 본 연구의 목적은 청계천 교량의 경관조명 효과를 분석하는 것이다 이를 위하여 청계천 8개의 교량을 대상으로 휘도, 색온도, 색도분포를 측정하였으며 측정 결과는 다음과 같다. 오피스 지역에 위치해 있는 교량은 배경과 교량의 휘도대비가 시각적으로 명확성이 좋은 것으로 나타났으며 색온도는 차가운 느낌과 따뜻한 느낌의 조명이 조화를 이루며 교량의 온열감을 표현하는 것으로 나타났다. 상업지역에 위치해 있는 교량의 경우 오피스 지역의 교량보다는 휘도대비가 작게 나타났지만 시각적 측면에서는 효과가 있는 것으로 나타났다. 색온도는 안정감 있는 느낌을 주는 것으로 나타났다. 주거지역에 위치해 있는 교량의 경우 교량자체의 휘도평균은 낮게 나타나 주변 환경을 고려하여 밝지 않게 조명된 것으로 판단된다. 전체적으로 청계천 교량의 경관조명 특성은 교량의 주변 환경에 따라 다른 효과가 연출된 것으로 나타났다.

• Journal of the Korean Institute of Landscape Architecture
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• v.50 no.5
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• pp.80-89
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• 2022

In order to solve the limitations of horizontal thermal environment improvement, this study compared the thermal environment of the indoor and outdoor of a building in summer according to the presence or absence of a green curtain, a vertical greening method. In the summer of 2021, the air temperature, relative humidity, wind speed, and shortwave and longwave radiation were measured at a central point inside a building and the grass field outside of the building to determine the human thermal sensation index, PET and UTCI. As a result, the green curtain showed an average 1.6℃ cooler air temperature during the daytime, but it did not have an effect at night. For relative humidity, it showed higher humidity indoors by an average of 5.6% and 1.0% during the daytime and at night, respectively. Wind speed was 1.4-1.8 ms^-1 and 1.4-1.5 ms^-1 higher outdoors on average during the daytime and at night, respectively, showing a high value outdoors regardless of whether a green curtain was installed. The green curtain showed an average indoor mean radiant temperature reduction effect of 4.7℃ during the daytime, but it did not have an effect at night. In PET and UTCI, the green curtain reduced the indoor PET by about a 1/3 level, an average of 2.1℃, and the indoor UTCI by about a 1/6 level, an average of 1.1℃, during the daytime. However, no effects appeared in PET and UTCI at night. For landscape planning, a green curtain can effectively modify the thermal environment during the daytime in summer.