• Korean Journal of Agricultural and Forest Meteorology
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• v.15 no.2
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• pp.76-84
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• 2013

An adequate downscaling of the official forecasts of Korea Meteorological Administration (KMA) is a prerequisite to improving the value and utility of agrometeorological information in rural areas, where complex terrain and small farms constitute major features of the landscape. In this study, we suggest a simple correction scheme for scaling down the KMA temperature forecasts from mesoscale (5 km by 5 km) to the local scale (30 m by 30 m) across a rural catchment, especially under temperature inversion conditions. The study area is a rural catchment of $50km^2$ area with complex terrain and located on a southern slope of Mountain Jiri National Park. Temperature forecasts for 0600 LST on 62 days with temperature inversion were selected from the fall 2011-spring 2012 KMA data archive. A geospatial correction scheme which can simulate both cold air drainage and the so-called 'thermal belt' was used to derive the site-specific temperature deviation across the study area at a 30 m by 30 m resolution from the original 5 km by 5 km forecast grids. The observed temperature data at 12 validation sites within the study area showed a substantial reduction in forecast error: from ${\pm}2^{\circ}C$ to ${\pm}1^{\circ}C$ in the mean error range and from $1.9^{\circ}C$ to $1.6^{\circ}C$ in the root mean square error. Improvement was most remarkable at low lying locations showing frequent cold pooling events. Temperature prediction error was less than $2^{\circ}C$ for more than 80% of the observed inversion cases and less than $1^{\circ}C$ for half of the cases. Temperature forecasts corrected by this scheme may accelerate implementation of the freeze and frost early warning service for major fruits growing regions in Korea.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.11
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• pp.136-143
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• 2019

This study investigated the effects of environmental temperature and humidity on the physiological indicators such as respiratory rate, rectal temperature, and rumination time in cows. Twenty lactating Holstein cows were used for this study. The temperature/humidity index, which can be measured by the temperature and humidity of barns, was divided into three stages to distinguish the heat stress level of cows. The temperature and humidity indexes of each stage were classified into 70 ~ 75 for T1, 76 ~ 81 for T2, and 82 ~ 87 for T3, respectively. The respiratory rates per minute were 58.60 at T1, 66.12 at T2, and 84.05 at T3, respectively (P < 0.05), and the average rectal temperatures (℃) of the cows were 38.41 in T1, 38.69 in T2 and 39.05 in T3, respectively (P < 0.05). The body surface temperatures (℃) were 36.41 in T1, 36.51 in T2, and 37.39 in T3, respectively. The rumination times (minutes/day) were 473.10 in T1, 454.76 in T2, and 399.60 in T3, respectively (P < 0.05). As global warming continues to damage the dairy industry, further research is needed to improve the welfare of dairy cows and reduce their heat stress.

• Korean Chemical Engineering Research
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• v.50 no.6
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• pp.1002-1007
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• 2012

The considerable portion of energy demand has been satisfied by the combustion of fossil fuel and the consequent $CO_2$ emission was considered as a main cause of global warming. As a technology option for $CO_2$ emission mitigation, absorption process has been used in $CO_2$ capture from large scale emission sources. To set up optimal operating parameters in $CO_2$ absorption and solvent regeneration units are important for the better performance of the whole $CO_2$ absorption plant. Optimal operating parameters are usually selected through a lot of actual operation data. However theoretical approach are also useful because the arbitrary change of process parameters often limited for the stability of process operation. In this paper, a theoretical approach based on vapor-liquid equilibrium was proposed to estimate optimal operating conditions of $CO_2$ absorption process. Two $CO_2$ absorption processes using 12 wt% aqueous $NH_3$ solution and 20 wt% aqueous MEA solution were investigated in this theoretical estimation of optimal operating conditions. The results showed that $CO_2$ loading of rich absorbent should be kept below 0.4 in case of 12 wt% aqueous $NH_3$ solution for $CO_2$ absorption but there was no limitation of $CO_2$ loading in case of 20 wt% aqueous MEA solution for $CO_2$ absorption. The optimal regeneration temperature was determined by theoretical approach based on $CO_2$ loadings of rich and lean absorbent, which determined to satisfy the amount of absorbed $CO_2$. The amount of heating medium at optimal regeneration temperature is also determined to meet the difference of $CO_2$ loading between rich and lean absorbent. It could be confirmed that the theoretical approach, which accurately estimate the optimal regeneration conditions of lab scale $CO_2$ absorption using 12 wt% aqueous $NH_3$ solution could estimate those of 20 wt% aqueous MEA solution and could be used for the design and operation of $CO_2$ absorption process using chemical absorbent.

• Journal of the Korean earth science society
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• v.42 no.1
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• pp.39-54
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• 2021

Damyang Wetland, a riverine wetland, has been designated as the first wetland protection area in South Korea and is a candidate area for the Mudeungsan Area UNESCO Global Geopark. The Damyang Wetland area is the upstream part of the Yeongsan River and is now a relatively wide plain. To reconstruct the sedimentary environment around the Damyang Wetland, core samples were obtained, and sedimentary facies analysis, AMS and OSL age dataings, grain size, and geochemical analyses were carried out. In addition, comprehensive sedimentary environment changes were reconstructed using previous core data obtained from this wetland area. In the Yeongsan River upstream area, where the Damyang Wetland is located, fluvial terrace deposits formed during the late Pleistocene are distributed in an area relatively far from the river. As a gravel layer is widely distributed throughout the plains, Holocene sediments were likely deposited in a braided river environment when the sea level stabilized after the middle Holocene. Then, as the sedimentary environment changed from a braided river to a meandering river, the influx of sand-dominated sediments increased, and a floodplain environment was formed around the river. In addition, based on the pollen data, it is inferred that the climate was warm and humid around 6,000 years ago, with wetland deposits forming afterward. The the trench survey results of the river area around the Damyang Wetland show that a well-rounded gravel layer occurs in the lower part, covered by the sand layer. The Damyang Wetland was likely formed after the construction of Damyang Lake in the 1970s, as muddy sediments were deposited on the sand layer.

• Korean Journal of Agricultural and Forest Meteorology
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• v.25 no.3
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• pp.142-150
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• 2023

As global warming continues, the time of invasion of Spodoptera frugiperda has been advanced and the inflow rate has been increasing, leading to great increases in damage to crops. In this study, in order to minimize crop damage caused by S. frugiperda, the control period was set for corn fields through control thresholds, and the control effects according to the chemical spraying methods were investigated in forage corn filed. Even under the condition of 4% injury level during the corn silking stage, the damage rate of ear was 70%, showing an aspect of extensive damage. The economic injury level of S. frugiperda second instar larvae was shown to be 0.7 larvae per stalk, and the control threshold level was shown to be 0.6 larvae. The income was calculated by applying the corn wholesale unit price, and according to the result, even under the condition of injury level of 4%, there was a loss of KRW 895,221/10a, and the higher the injury level, the greater the decrease in income. To control S. frugiperda, the insecticidal effects of 10 single formulations registered for S. frugiperda were tested, and according to the results, four types(emamectin benzoate, chlorantraniliprole, indoxacarb, and spinetoram) showed high insecticidal activity not lower than 93.3%, and three types (chloran- traniliprole, spinetoram, and indoxacarb) were considered to be effective in controlling S. frugiperda as they showed high residual effects through insecticidal effect persistence tests. Therefore, conventional control and aerial control were conducted twice at 7-day intervals with indoxacarb SC and chlorantraniliprol WP, which show high activity against S. frugiperda, respectively, prior to the silking of forage corn. As a result, conventional control showed higher control values, 46.3%p in the case of indoxacarb SC and 21.7%p in the case of chlorantraniliprol WP, than aerial control through the primary control. In the secondary control too, higher control values of 26.7%p in the case of indoxacarb SC and 40.4%p in the case of chlorantraniliprol WP were found in conventional control than in aerial control. Therefore, it is considered necessary to prepare measures to improve the control effects in the recent situation where alternative methods for manpower control are widely used.

• Korean Journal of Agricultural and Forest Meteorology
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• v.14 no.4
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• pp.207-221
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• 2012

Air temperature in Korea has increased by $1.5^{\circ}C$ over the last 100 years, which is nearly twice the global average rate during the same period. Moreover, it is projected that such change in temperature will continue in the 21st century. The objective of this study was to evaluate the potential impacts of future climate change on the rice production and adaptation methods in Korea. Climate data for the baseline (1971~2000) and the three future climate (2011~2040, 2041~2070, and 2071~2100) at fifty six sites in South Korea under IPCC SRES A1B scenario were used as the input to the rice crop model ORYZA2000. Six experimental schemes were carried out to evaluate the combined effects of climatic warming, $CO_2$ fertilization, and cropping season on rice production. We found that the average production in 2071~2100 would decrease by 23%, 27%, and 29% for early, middle, and middle-late rice maturing type, respectively, when cropping seasons were fixed. In contrast, predicted yield reduction was ~0%, 6%, and 7%, for early, middle, and middle-late rice maturing type, respectively, when cropping seasons were changed. Analysis of variation suggested that climatic warming, $CO_2$ fertilization, cropping season, and rice maturing type contributed 60, 10, 12, and 2% of rice yield, respectively. In addition, regression analysis suggested 14~46 and 53~86% of variations in rice yield were explained by grain number and filled grain ratio, respectively, when cropping season was fixed. On the other hand, 46~78 and 22~53% of variations were explained respectively with changing cropping season. It was projected that sterility caused by high temperature would have no effect on rice yield. As a result, rice yield reduction in the future climate in Korea would resulted from low filled grain ratio due to high growing temperature during grain-filling period because the $CO_2$ fertilization was insufficient to negate the negative effect of climatic warming. However, adjusting cropping seasons to future climate change may alleviate the rice production reduction by minimizing negative effect of climatic warming without altering positive effect of $CO_2$ fertilization, which improves weather condition during the grain-filling period.

• The Korean Journal of Air & Space Law and Policy
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• v.26 no.1
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• pp.3-30
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• 2011

According to the Article 86 of the United Nations on the Law of the Sea(UNCLOS) the provisions of high seas apply to all parts of the sea that are not included in the exclusive economic zone, in the territorial sea or in the internal waters of a State, or in the archipelagic waters of an archipelagic State. Article 87 also stipulates the freedom of the high seas. International laws on the flight over the high seas are found as follows; Firstly, as far as the nationality of the aircraft is concerned, its legal status is quite different from the ship where the flags of convenience can be applied practically. There is no flags of convenience of the aircraft. Secondly, according to the Article 95 of UNCLOS warships on the high seas have complete immunity from the jurisdiction of any State other than the flag State. We can suppose that the military(or state) aircraft over the high seas have also complete immunity from the jurisdiction of any State other than the flag State. Thirdly, according to the Article 101 of UNCLOS piracy consists of any act of voluntary participation in the operation of a ship or of an aircraft with knowledge of facts making it a pirate ship or aircraft. We can conclude that piracy can de done by a pirate aircraft as well as a pirate ship. Fourthly, according to the Article 111 (5) of UNCLOS the right of hot pursuit may be exercised only by warships or military aircraft, or other ships or aircraft clearly marked and identifiable as being on government service and authorized to that effect. We can conclude that the right of hot pursuit may be exercised only military aircraft, or aircraft clearly marked and identifiable as being on government service and authorized to that effect. Fifthly, according to the Article 110 of UNCLOS a warship which encounters on the high seas a foreign ship, is not justified in boarding it unless there is reasonable ground for suspecting that: (a) the ship is engaged in piracy, (b) the ship is engaged in the slave trade, (c) the ship is engaged in an authorized broadcasting and the flag State of the warship has jurisdiction under article 109, (d) the ship is without nationality, or (e) though flying a foreign flag or refusing to show its flag, the ship is, in reality, of the same nationality as the warship. These provisions apply mutatis mutandis to military aircraft. Sixthly, according to the Article 1 (5)(dumping), 212(pollution from or through the atmosphere), 222(enforcement with respect to pollution from or through the atmosphere) of UNCLOS aircraft as well as ship is very much related to marine pollution. Seventhly, as far as the crime on board aircraft over the high seas is concerned 1963 Convention on the Offences and Certain Other Acts Committed on Board Aircraft(Tokyo Convention) will be applied, and as for the hijacking over the high seas 1970 Convention for the Suppression of Unlawful Seizure of Aircraft(Hague Convention) and as for the sabotage over the high seas 1971 Convention for the Suppression of Unlawful Acts Against the Safety of Civil Aviation(Montreal Convention) will be applied respectively. These three conventions recognize the flag state jurisdiction over the crimes on board aircraft over the high seas. Eightly, as far as reconnaissance by foreign aircraft in the high seas toward the coastal States is concerned it is not illegal in terms of international law because its act is done in the high seas. Ninthly as for Air Defence Identification Zone(ADIZ) there are no articles dealing with it in the 1944 Chicago Convention. The legal status of the foreign aircraft over this sea zone might be restricted to the regulations of the coastal states whether this zone is legitimate or illegal. Lastly, the Arctic Sea is the frozen ocean. So the flight over that ocean is the same over the high seas. Because of the climate change the Arctic Sea is getting melted. If the coastal states of the Arctic Sea will proclaim the Exclusive Economic Zone(EEZ) as the ocean is getting melted, the freedom of flight over that ocean will also be restricted to the regulations of the coastal states.

• Journal of Forest and Environmental Science
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• v.3 no.1
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• pp.1-9
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• 1983

The purpose of this study was to elucidate the ecophysiological habitat of natural Sorbus commixta forest at Mt. Seorak. The results obtained were as follows: 1. The Sorbus commixta trees mainly distributed from 900m to 1,500m altitude. In there, the warm index(WI) was about 42$3.2{\times}10^3$ to $9.2{\times}10^3$, cation exchange capacity(CEC) was 13.7 to 19.5mg/100g, N content 0.21 to 0.39%, $P_2O_5$ content was 22.6 to 38.7ppm, and pH value was 5.6 to 5.8 respectively. 4. The upper crown trees in Sorbus commixta communities were Abies nephrolepis, Taxus cuspidata, Betula platyphylla var. japonica, Quercus${\times}$grosseserrata, Acer mono, Prunus sargentii, Carpinus cordata, Tilia amurensis, and the under crown trees were Rhododendron brachycarpum, Acer pseudo-sieboldianum, Thuja olientalis, Corylus heterohpylla, Philadelphus schrenckii, Rhododendron schlippenbachii, Rhododendron mucronulatum, and Magnolia sieboldii. 5. The stand densities were 1,156 trees/ha at 1,160m and 3,600 trees/ha at 1,300m respectively. The coverages by the DBH basal area were 0.37 at 1,160m and 0.31 at 1,300m respectively, and the vegetation coverages by the crown projection area were 2.04 at 1,160m and 1.61 at 1,300m respectively. 6. The light extinction coefficient(k) in Beer-Lambert's law, showed the distance, F(z), from top canopy to aboveground, was 0.17. 7. The water relations parameters of Sorbus commixta shoot were obtained by the pressure chamber technique. The osmotic pressure, ${\pi}_o$, at maximum turgor was -16.2 bar, and VAT pressure was 14.5bar. The osmotic pressure, ${\pi}_p$, at incipient plasmolysis was -19.4bar. The relative water contents at incipient plasmolysis were 83.1% ($v_p/v_o$) and 87.1%($v_p/w_s$;$w_s$, total water at maximum turgor). 8. The bulk modulus of elasticity(E) of shoot was about 69.6. The total symplasmic water to total water in shoot was 67.7%, and the apoplastic water to total water was 32.3%.