• Journal of The Korean Society of Grassland and Forage Science
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• v.5 no.3
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• pp.180-186
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• 1985

Field and phytotron experiments were conducted to determine the effect of morphological growth stage and environmental temperature on Weender components and net energy lactation (NEL) in corn cv. Blizzard and sorghum cv. Pioneer 931 and Sioux at Munich Technical University from 1978 to 1981. Various growth stages of maize and sorghum were grown for 42 days at 4 temperature regimes (30/25, 25/20, 28/18 and 18/8 degree C) and mid-summer sunlight over 13 hour days. The results obtained are summarized as follows: 1. Accumulation of crude protein in maize and sorghum plants was associated with leaf weight ratio and leaf area ratio ($P{\leq}0.1%$). Crude protein in the plants were shown to have a greate synthesis rates at early growth stages. The highest concentration of crude protein were found at 3-leaf stage with 31.4% and 33.9% for maize and sorghum, respectively. 2. Synthesis of crude fiber was increased after growing point differentiation markedly and were shown the highest concentration at heading stage with 28.4% and 31.5% for maize and sorghum, respectively. During the maturities, the crude fiber contents in maize were, however decreased and shown a value of 19.5% at physiological maturity, while that of sorghum were increased continuously. 3. NEL value in maize and sorghum plants were declined as morphological development and shown the lowest at growing point differentiation with 5.82 MJ (maize) and 5.46 MJ/kg (sorghum). During the late maturity, the NEL value of maize were increased markedly and shown a value of 6.70 MJ and 6.94 MJ/kg for milkstage and maturity stage, respectively, while NEL value in sorghum were not increased markedly. 4. Net energy lactation in maize and sorghum plants were associated with synthesis rate of non-structural carbohydrates, especially mono- and disaccharose while cell-wall constituents and crude fiber lowerd NEL contents ($P{\leq}0.1%$). 5. NEL accumulation and starch value were decreased under temperature. The NEL concentration of 4-leaf sorghum under different environmental temperatures of 30/25, 25/20, and 18/8 degree C were 4.87 MJ, 5.46 MJ and 5.81 MJ/kg, respectively.

• Korean Journal of Agricultural and Forest Meteorology
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• v.20 no.1
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• pp.73-87
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• 2018

A variety of micro meteorological variables such as air temperature, wind, solar radiation and latent heat at Gwangneung forests (conifer and broadleaved forests) and AWS (Automated Weather Station) of Pocheon urban area were used to quantify the air temperature reduction effect of forests, which is considered to be an eco-friendly solution for reducing the urban heat island intensity during summer. In June, July and August of 2016 and 2017, the average maximum air temperature differences between above and below canopy of forests, and between the forests and urban areas were $-1.9^{\circ}C$ and $-3.4^{\circ}C$ respectively, and they occurred at 17:00. However, there was no difference between conifer and broadleaved forests. The effect of air temperature reduction by the forests was positively correlated with accumulated evapotranspiration and solar radiation from 14:00 to 17:00 and showed a negative correlation with wind speed. We have developed a model to quantify the effect of air temperature reduction by forests using these variables. The nighttime air temperature reduction effect by forests was due to the generation of cold air from radiative cooling and the air temperature inversion phenomenon that occurs when the generated cold air moves down the side of mountain. The model was evaluated in Seoul by using 28 AWSs. The evaluation shows that the air temperature of each district in Seoul was negatively correlated with the area and size of the surrounding tall vegetation that drives vegetation evapotranspiration during the day. During the night, however, the size of the surrounding tall vegetation and the elevations of nearby mountains were the main influencing factors on the air temperature. Our research emphasizes the importance of the establishment and management of urban forests and the composition of wind roads from mountains for urban air temperature reduction.

• Journal of Bio-Environment Control
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• v.27 no.4
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• pp.302-311
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• 2018

Using cylindrical paper pot nursery method, three kinds of commercial tomatoes 'Dafnis', 'DOTAERANG DIA' and 'Maescala' were grafted onto a commercial rootstock 'B blocking'. From 10 to 40 days after graft-take, growth traits of seedlings were investigated by 0.5, 1.0 and 2.0S treatments of standard nutrient solution(S) for seedling growth, and top to root ratio(TRR), compactness(CP) and Dickson Quality Index(DQI) were calculated. Two weeks after transplanting of the seedlings under three different night temperature targeting to 10, 15, and $25^{\circ}C$, which were not precisely controlled, the relative growth rate (RGR) was investigated. The quantitative growth traits of grafted seedlings increased with increasing fertilizer concentration, and various range of seedling size could be produced. Compactness and DQI were significantly regressed (Adj $R^2=0.9480$). Short-term RGR after transplanting was higher at 1.0S treatment of standard nutrient solution at the seedling age of 30 days and 40 days after graft-take(DAGT). DQI and RGR were significantly regressed linearly at respective fertigation strength. Specially the diminishing slope of RGR was lower at 1.0S fertigation strength with the increase of DQI than others. The results indicate that DQI could be applied as a quality index of grafted tomato seedlings and the relation analysis between DQI and short-term RGR also could be used to determine the good quality seedlings of grafted tomato grown in cylindrical paper pot.

• Journal of the Korean earth science society
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• v.27 no.4
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• pp.450-463
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• 2006

Seasonal threshold values for fog detection over the ten airport areas within the Korean Peninsula have been derived from the data of polar-orbit Aqua/Terra MODIS and geostationary GOES-9 during a two years. The values are obtained from reflectance at $0.65{\mu}m\;(R_{0.65})$ and the difference in brightness temperature between $3.7{\mu}m\;and\;11{\mu}m\;(T_{3.7-11})$. In order to examine the discrepancy between the threshold values of two kinds of satellites, the following four parameters have been analyzed under the condition of daytime/nighttime and fog/clear-sky, utilizing their simultaneous observations over the Seoul metropolitan area: brightness temperature at $3.7{\mu}m$, the temperature at $11{\mu}m,\;the\;T_{3.7-11}$ for day and night, and the $R_{0.65}$ for daytime. The parameters show significant correlations (r<0.5) in spatial distribution between the two kinds of satellites. The discrepancy between their infrared thresholds is mainly due to the disagreement in their spatial resolutions and spectral bands, particularly at $3.7{\mu}m$. Fog detection from GOES-9 over the nine airport areas except the Cheongju airport has revealed accuracy of 60% in the daytime and 70% in the nighttime, based on statistical verification. The accuracy decreases in foggy cases with twilight, precipitation, short persistence, or the higher cloud above fog. The sensitivity of radiance and reflectance with wavelength has been analyzed in numerical experiments with respect to various meteorological conditions to investigate optical characteristics of the three channels.

• Journal of The Korean Society of Grassland and Forage Science
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• v.5 no.2
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• pp.121-126
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• 1985

Phytotron and field experiments were conducted to determine the influence of morphological growth stage and environmental temperature on synthesis and accumulation pattern of cyanogenic glycosides in sorghum cv. Pioneer 931 and Sioux at Munich technical university from 1979 to 1980. Various growth stages of sorghum plants were grown in phytotron at 4 different temperature regimes of 30/25, 25/20, 28/18 and 18/8 degree C with 35,000 Lux over 13-h days. The results obtained are summarized as follows: 1. Cyanogenic glycosides in sorghum plants were shown to have a great synthetic rate at early growth stages. The highest concentrations of hydrocyanic acid (HCN) were found at 2-leaf stage with 2384 and 1800ppm (DM basis) for Pioneer 931 and Sioux respectively. The contents of HCN were, however, however decreased markedly as morphological development, which shows a value of 173ppm (Pioneer 931) and 70ppm (Sioux) at heading stages. 2. Changes of hydrocyanic acid in sorghum plants were positive correlated with leaf weight ratio and leaf area ratio ($P{\leqq}0.1%$), while plant height shows a negative correlation with HCN contents ($P{\leqq}0.1%$). 3. Cyanogenic glycosides were accumulated in young plants mainly in leaves. During the late maturities, the contents of HCN in leaves and stalks were shown, however, a similar distribution. 4. Synthesis rates of cyanogenic glycosides were increased under high temperature. Accumulated hydrocyanic acid in the plants was, however declined when temperature exceeded 30 degree C. 5. Synthesis rates of cyanogenic glycosides were affected by nitrogen reductase activity (NRA). The concentration of hydrocyanic acid in sorghum plants was associated with increasing of nitrate-N accumulation.

• Korean Journal of Agricultural and Forest Meteorology
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• v.16 no.1
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• pp.39-50
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• 2014

This paper reviews the results of recent observations in the Yeonsuri valley of Mt. Youngmun during springtime (March to May) in 2012. Automated weather stations were installed at twelve sites in the valley to measure temperature and 2, 3 dimensional wind. We examined temporal and spatial characteristics of temperatures and wind data. The Yeonsuri valley springtime average temperature lapse rate between the top and bottom of the entire period is $-0.44^{\circ}C/100$ m. It can be changed by the synoptic weather conditions, the lapse rates is greatest in order of clear days ($-0.48^{\circ}C/100$ m), rainy ($-0.41^{\circ}C/100$ m) and cloudy days ($-0.40^{\circ}C/100$ m). In the night, the temperature inversion layer (thermal belt) and the cold pool are formed within the valley. In addition, we measured temperature and wind distribution from the bottom to 3.5 m, the cold layers existed up to 1.5 m, which were affected by ground mixed layer. The results will provide useful guidance on agricultural practices as well as model simulations.

• Journal of agriculture & life science
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• v.44 no.4
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• pp.79-85
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• 2010

An analysis in heating effects of an electric radiator located in a 1-2W type chrysanthemum (3 cultivars) cultivation greenhouse installed in Gyeongsang National University drew the following conclusions. During the experiment period, the highest, average, and the lowest outside temperatures were in the ranges of $-3.8{\sim}21.3^{\circ}C$, $-5.2{\sim}16.1^{\circ}C$ and $-12.5{\sim}14.4^{\circ}C$, respectively, and the average relative humidity inside and outside the greenhouses were in the ranges of 43.5~98.6% and 35.2~100%, respectively. From mid-December to early February, the lowest outside temperature was recorded as approximately $-5.0{\sim}-10.0^{\circ}C$, which showed that it tended to be relatively lower than the temperatures recorded at the Jinju Meteorological Observatory. During the night, the leaf temperature measured directly under the radiator tended to be higher by $2{\sim}3^{\circ}C$ than that those at the middle point of the radiator, or higher by a negligible amount. In the case of root zone temperature, it was found that there was almost no difference between temperatures of the part directly under and the middle point, and the time when the highest temperature of root zone and other highest temperatures took place showed that there was about a 2-hour delay phenomenon. The total electricity consumption, energy supply and total heating cost during the experiment period were 2,800 kWh, 2,408,000 kcal and 112,000 won, respectively. When diesel, a kind of fossil fuel, was used as heating oil, the total heating cost was around 224,500 won. It was estimated that the total heating cost could be reduced by around 50% if a radiator was used.

• Ecology and Resilient Infrastructure
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• v.7 no.4
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• pp.227-237
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• 2020

Microclimatic data were measured, and the human thermal sensation was analyzed at 10 local climate zones based on the major land cover classification to investigate the thermal environment of urban areas during summer nighttime. From the results, the green infrastructure areas (GNIAs) showed an average air temperature of 1.6℃ and up to 2.4℃ lower air temperature than the gray infrastructure areas (GYIAs), and the GNIAs showed an average relative humidity of 9.0% and up to 15.0% higher relative humidity. The wind speed of the GNIAs and GYIAs had minimal difference and showed no significance at all locations, except for the forest location, which had the lowest wind speed owing to the influence of trees. The local winds and the surface roughness, which was determined based on the heights of buildings and trees, appeared to be the main factors that influenced wind speed. At the mean radiant temperature, the forest location showed the maximum value, owing to the influence of trees. Except at the forest location, the GNIAs showed an average decrease of 5.5℃ compared to GYIAs. The main factor that influenced the mean radiant temperature was the sky view factor. In the analysis of the human thermal sensation, the GNIAs showed a "neutral" thermal perception level that was neither hot nor cold, and the GYIAs showed a "slightly warm" level, which was a level higher than those of the GNIAs. The GNIAs showed a 3.2℃ decrease compared to the GYIAs, except at the highest forest location, which indicated a half-level improvement in the human thermal environment.

• Journal of the Korean Society of International Agriculture
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• v.23 no.5
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• pp.520-530
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• 2011

This study was carried out to evaluate the possibility of rice double cropping in Korea by assessing the growth and yield performance of rice cultivars transplanted at the extremely-early date. When the transplanted rice seedling was exposed to low temperature below 0℃, the survival rate decreased drastically. However, short exposure to below 0℃ one or two times did not damage transplanted rice seedling so severely. Thus, the earliest transplanting in spring would be possible when minimum temperature rises above 0℃. Compared with the conventional seedling nursery tray (CSNT), seedling rearing with the potted nursery tray was more effective for increasing leaf age and seedling dry weight during nursery period. In the first rice cropping, rice cultivation with seedlings reared in PSNT showed shorter growth duration and cumulative temperature from transplanting to heading than that with seedlings reared in CSNT. The earliest heading date on July 4 in Jinbuolbyeo was earlier by two to three days than that of Dunaebyeo. If rice has not exposed to cold damage, the earliest heading date of Jinbujolbyeo can advance to June 30 or July 1. In this case, rice harvest would be possible on August 5, enabling the rice transplanting of the second rice cropping before August 10. At transplanting time with low temperature damage rice yield were less than 400 kg/10a while rice yield exceeded 400 kg/10a at transplanting time without low temperature damage.

• Korean Journal of Plant Resources
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• v.2 no.2
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• pp.298-305
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• 1989

This study was carried out to understand the immigration period, climatic conditions for mass immigration and bionomical characters ofthe brown pLanthopper(BPH) in Hae NamThe results are as follows ; (1) The Periods of first immigraion and mass immigration of BPH , were from the late June to early JuLy and from earlyto mid JuLy in HaeNam, that were faster about 15-30days than in inland of ChonnanThe climatic factors that related closely to mass immigration wereas follows ; temp.: $20{\;}~{\;}25^{\circ}C$, humidity : 86 ~ 95 % , wind direcion : SW, wind velocity: 1.0 ~ 2.9gm/sec. (2)The population of immigranted BPH was in the field much more overthe mountain near coast than other places . Biotype composition showed that biotype I was on the decrease and biotype II, III were on the increase (3)The bionomical characters were variable, for climatic conditions,that egg stage, nymphal stage and adult stafe of immigranted BPHwere 9-12days, 13-16days and 12-36days respectively, that hatchability(%) and emergence rate ( % ) were higher than 80%. The adult Longevity in female and macropterous BPH showed Longerthan that of male and brachypterous respectively. (4) The distance of nymphs and brachypterous adults move by walking was within 16cm over the water surface, by hopping was within 20cm horizontally.