• Journal of the Korean Society of International Agriculture
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• v.31 no.1
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• pp.76-81
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• 2019

'Asemi' is a rice variety derived from a cross between 'Jinmibyeo' which has translucent milled rice and medium maturity and 'Cheolwon46', an elite line with high yield and early maturity by the rice breeding team at NICS, RDA in 2013. The heading date of 'Asemi' is August 1, six days earlier than the check variety 'Hwaseong'. It has 82 cm culm length and 109 spikelets per panicle. 'Asemi' is resistant to blast disease, stripe virus and tungro virus, but susceptible to other viruses and planthoppers. The milled rice of this variety exhibits translucent, clear non-glutinous endosperm and short grain shape. It has protein content (6.7%) higher than 'Hwaseong', and amylose content (19.5%) similar to 'Hwaseong'. The milled rice recovery rate of 'Asemi' is similar to that of 'Hwaseong'. However, the head rice rate of 'Asemi' is higher than that of 'Hwaseong'. Milled rice yield of 'Asemi' is 5.23 MT/ha in ordinary cultivation. ' Asemi' could be adaptable to the wide region of tropical Asia (Registration No. 5639).

• Journal of Environmental Impact Assessment
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• v.32 no.6
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• pp.437-449
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• 2023

This study measured PM₁₀ concentrations and wind speeds in buffer green spaces and neighborhood parks located along the road, and compared them with roadside measurementresults to understand the effect of mitigating PM₁₀ concentrations by type of green space and the influence of wind speeds on it. As a result of the analysis, the effect of mitigating PM₁₀ concentration was different depending on the type of roadside green space, and an increase in wind speed had a significant effect on reducing PM₁₀ concentration. In buffer green areas with high planting density, wind speed was low and PM₁₀ stagnated inside, resulting in the highest concentration. On the other hand, green areas in neighborhood parks with relatively low planting density had high wind speeds and the lowest PM₁₀ concentration. The non-green area within the neighborhood park recorded the highest wind speed, which was advantageous for the spread of PM₁₀, but the concentration was higherthan that of the green area. Therefore, in orderto reduce PM₁₀ concentration in roadside green space, it is necessary to create green space with good ventilation, and the combined effect of green space and wind speed seems to be more advantageous in reducing PM₁₀ concentration. Green spaces capture and remove PM inside, contributing to reducing the concentration of PM outside. In order to manage PM in the entire city and on roads, it is necessary to increase planting density and leaf area in roadside green spaces, such as buffer green spaces, so that PM can be removed within the green spaces. However, in green spaces such as neighborhood parks that are actively used by city residents, in orderto minimize damage to users due to PM, it is desirable to create green spaces with a structure that allows PM to spread to the outside rather than stagnate inside.

• 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.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.29 no.1
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• pp.14-27
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• 2024

Unlike the shelf sand ridges moribund in motion, nearshore sand ridges are highly mobile, sensitive to changes in ocean environments, thereby becoming of particular interest with respect to morphological changes. About 5 km off the Daesan port, the Jangan Sand Ridge has been undergoing severe subsea morphological change over the past two decades. Understanding the nature of sand ridges is critical to elucidate the causes of morphological changes. In this context, this study aims at understanding the characteristics and distribution patterns of surface sediments of the ridge and its vicinity. For this purpose, 227 sediment samples were acquired using a grab-sampler, the grain sizes being analysed by the sieve-pipette method. In addition, comparison of grain sizes in sediments between 1997 and 2021 was made in order to investigate the 25-years change in sediment composition. Surface sediments along the ridge axis are fine to medium sands with 2-3 phi in mean grain size, whereas, in the trough of ridge, the sediments are composed of gravels and muddy sandy gravels with mean sizes of -2 to -6 phi. Sediments in the crest of the ridge are well-sorted with normal distribution, on the other hand, the basal sediments are poorly-sorted and positively skewed. Along the ridge crest, the sediments are negatively skewed. From 1997 to 2021, the ridge sediments became largely coarser about 0.5 phi. Such coarsening trend in mean grain size can be explained either by elimination of fine sediments during high waves in winter or elimination of fines suspended during sand mining activities in the past. Spatial distribution pattern of surface sediments shows that ca. 30 m thick of the sand ridge itself overlies the thin relict gravels. The strong asymmetry of sand ridge, the exposure of ridge base, and reworked gravel lags suggest that Jangan sand ridge is probably sediment-deficit and hence erosive in nature at present.

• Korean Journal of Environment and Ecology
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• v.38 no.1
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• pp.55-66
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• 2024

This study conducted a survey to investigate the characteristics of fish communities and the inhabiting status of endangered species in the Byekgye Stream, Korea from April to September 2020. A total of 3,415 fish of 9 families and 31 species were collected from 7 survey stations during the survey period. The dominant species was Zacco koreanus (relative abundance of 31.2%), and the subdominant species was Z. platypus (15.0%), followed by Pungtungia herzi (11.7%), Acheilognathus yamatsutae (5.4%), A. lanceolata intermedia (4.8%), Rhinogobius brunneus (4.4%), and Pseudopungtungia tenuicorpa (4.3%). Among the fish species collected, 19 (61.3%) were identified as Korean endemic species, and two cold-water fish species sensitive to climate change (Rhynchocypris kumgangensis and Cottus koreanus) were collected. Four species were designated as class II endangered wildlife by the Ministry of Environment: A. signifer, P. tenuicorpa, Rhodeus pseudosericeus, and C. koreanus. A. signifer and P. tenuicorpa mainly inhabited the mid to lower streams, R. pseudosericeus in the midstream, and R. pseudosericeus in the upstream. P. tenuicorpa inhabited in large numbers, and estimating the age by total length-frequency distribution in July, the total length of the 26-35 mm group was estimated as 0 years old, the 54-75 mm group as 1 year old, 82-97 mm group as 2 years old, 104-109 mm group as 3 years or older. The cluster analysis showed that the dominance index decreased from upstream to downstream, but the diversity, evenness, and richness index increased. The water quality of Byekgye Stream was evaluated as good overall since the river health (fish assessment index, FAI) using fish was evaluated as excellent (5 stations) and good (2 stations). Byekgye Stream has relatively well-preserved habitats, but conservation measures are required as habitats are disturbed by river repair work in some parts of the midstream and downstream areas where many endangered species inhabit.

• Solar Energy
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• v.13 no.2_3
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• pp.65-78
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• 1993

An overdose of fossil fuel for greenhouse heating causes not only the high cost and low quality of agricultural products, but also the environmental pollution of farm village. To solve these problems it is desirable to maximize the solar energy utilization for the heating of greenhouse in winter season. In this study phase change materials were selected to store solar energy concentratively for heating the greenhouse and their characteristics of thermal energy storage were analyzed. The results were summarized as follows. The organic $C_{28}H_{58}$, and the inorganic $CH_3COONa{\cdot}3H_2O\;and\;Na_2SO_4{\cdot}10H_2O$ were selected as low temperature latent heat storage materials. The equation of critical radius was derived to define the generating mechanism of the maximum latent heat of phase change materials. The melting point of $C_{28}H_{58}$ was $62^{\circ}C$, and the latent heat was $50.0{\sim}52.0kcal/kg$. The specific heat of liquid and solid phase was $0.54{\sim}0.69kcal/kg^{\circ}C$ and $0.57{\sim}0.75kcal/kg^{\circ}C$ respectively. The melting point of $CH_3COONa{\cdot}3H_2O$ was $61{\sim}62^{\circ}C$, the latent heat was $64.9{\sim}65.8$ kcal/kg and the specific heat of liquid and solid phase was respectively $0.83kcal/kg^{\circ}C$ and $0.51{\sim}0.52kcal/kg^{\circ}C$. The melting point of $Na_2SO_4{\cdot}10H_2O$ was $30{\sim}30.9^{\circ}C$, the latent heat was 53.0 kcal/kg and the specific heat of liquid and solid phase was respectively $0.78{\sim}0.89kcal/kg^{\circ}C$ and $0.50{\sim}0.7kcal/kg^{\circ}C$ When the urea of 21.85% was added to control the melting point of $Na_2SO_4{\cdot}10H_2O$ and the phase change cycles were repeated from 0 to 600, the melting point was $16.7{\sim}16.0^{\circ}C$ and the latent heat was $36.0{\sim}28.0kcal/kg^{\circ}C$.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.2
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• pp.217-223
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• 2010

This study was conducted to reclassify Dongsong series based on the second edition of Soil Taxonomy and to discuss the formation of Dongsong series distributed on the lava plain at Cheolweon in Korea. Morphological properties of typifying pedon of Dongsong series were investigated, and physico-chemical properties were analyzed according to Soil Survey Laboratory Methods Manual. The typifying pedon of Dongsong series has brown (7.5YR 4/2) silty clay loam Ap horizon (0-16 cm), brown (7.5YR 4/2) silty clay loam BA horizon (16-22 cm), brown (7.5YR 4/2) silty clay Bt1 horizon (22-50 cm), reddish brown (5YR 5/4) silty clay Bt2 horizon (50-92 cm), and brown (7.5YR 4/3) silty clay loam Bt3 horizon (92-120 cm). It occurs on lava plain derived from baslt materials. The typifying pedon has higher bulk density than 0.90 Mg $m^{-3}$. That can not be classified as Andisol. But it has an argillic horizon from a depth of 22 to more than 120 cm, and a base saturation (sum of cations) of less than 35% at 125 cm below the upper boundary of the argillic horizon. It can be classified as Ultisol, not as Andisol or Alfisol. It has aquic conditions for some time in normal years in one or more horizons within 50 cm of the mineral soil surface, redoximorphic features between a depth of 25 cm, and a depth of 40 cm from the mineral soil surface, and redox concentrations, and 50%or more redox depletions with chroma of 2 or less in the matrix within the upper 12.5 cm of the argillic horizon. Therefore it can be classified as Aquult. It has episaturation, and keys out as Epiaquult. It has 50% or more chroma of 3 or more in one or more horizons between a depth of 25 cm from the mineral soil surface, and a depth of 75 cm. It can be classified as Aeric Aquult. Dongsong series have 35%or more clay at the particle-size control section, and have mesic soil temperature regime. Therefore they can be classified as fine, mesic family of Aeric Epiaquults, not as fine, mesic family of Typic Epiaqualfs. The Quarternary volcanic activities occurred in Jeju Island, Ulrung Island, Baekryeong Island, Cheolweon area, and Mt. Paekdu et al. in the Korean Penninsula. Most of them belong to the central eruption type, but Cheolweon area may be of the fissure eruption type. Dongsong series occur on Cheolweon lava plains derived from basaltic materials. Most soils distributed in Jeju Island, and derived from mainly pyroclastics are developed as Andisols. But Dongsong series distributed in Cheolweon lava plains which have a relatively dry climate and derived from basaltic materials are developed as Ultisols.

• Journal of Wetlands Research
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• v.20 no.2
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• pp.155-160
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• 2018

We investigated to know the growth patterns of Aedes albopictus larva at the four different temperature conditions. Each of 120 individuals was placed into a $20m{\ell}$ vial and 12 sets (a set of 10 vials) were separated into 12 water tanks ($17{\times}24{\times}18cm^3$). Each water tank was composed of 3 the $1^{st}$ instar, 3 the $2^{nd}$ instar, 2 the $3^{rd}$ instar, and 2 the $4^{th}$ instar. Three sets of water tanks were placed under the four different incubator temperatures ($17^{\circ}C$, $21^{\circ}C$, $24^{\circ}C$, $28^{\circ}C$). We found that the eclosion rates were $20.00{\pm}5.77%$ at $21^{\circ}C$ and $3.33{\pm}3.33%$ at other temperatures. For the mosquito larva mortality rate, $1^{st}$ instar was $19.24{\pm}3.65%$, $2^{nd}$ instar was $16.48{\pm}3.25%$, $3^{rd}$ instar was $23.54{\pm}5.06%$, and $4^{th}$ instar was $40.74{\pm}7.08%$. The lowest mortality rate in growth stages according to temperature was $13.33{\pm}6.67%$ at $17^{\circ}C$ in $1^{st}$ instar larva, $7.41{\pm}7.41%$ at $21^{\circ}C$ at $2^{nd}$ instar larva, $10.74{\pm}6.43%$ at $24^{\circ}C$ in $3^{rd}$ instar larva, and $20.37{\pm}5.46%$ at $28^{\circ}C$ in $4^{th}$ instar larva. The survival period of mosquitoes in underwater were $26.33{\pm}0.67days$ at $17^{\circ}C$, $23.33{\pm}1.33days$ at $21^{\circ}C$, $20.00{\pm}2.52days$ at $24^{\circ}C$, and $11.67{\pm}1.20days$ at $28^{\circ}C$. From our results the most effective temperature to the normal growth of mosquito larva was $21^{\circ}C$, and the highest mortality rate was shown at the $4^{th}$ instar stage of larva growth. Our results would provide the basic data for the mosquito larva's growth pattern.

• Journal of Food Hygiene and Safety
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• v.32 no.6
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• pp.470-476
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• 2017

The purpose of this study was to investigate and evaluate the safety of the grains, nut products, beans and oilseeds being sold in Gyeonggi province by analyzing mycotoxins. A multi-mycotoxins analysis method based on LC-MS/MS was validated and applied for the determination of eight mycotoxins, including aflatoxins ($B_1$, $B_2$, $G_1$ and $G_2$), fumonisins ($B_1$, $B_2$), zearalenone and ochratoxcin A in 134 samples. The limit of detection (LOD) and limit of quantitation (LOQ) for the eight mycotoxins ranged from 0.14 to $8.25{\mu}g/kg$ and from 1.08 to $7.21{\mu}g/kg$, respectively. Recovery rates of mycotoxins were determined in the range of 61.1 to 97.5% with RSD of 1.0~14.5% (n=3). Fumonisin $B_1$, $B_2$, zearalenone, and ochratoxin A were detected in 22 samples, indicating that 27% of grains, 12.5% of beans and 11.8% of oilseeds were contaminated. Fumonisin and zearalenone were detected simultaneously in 2 adlays and 3 sorghums. Fumonisin $B_1$ and $B_2$ were detected simultaneously in most samples whereas fumonisin $B_1$ was detected in 1 adlay, 1 millet and 1 sesame sample. The average detected amount of fumonisin was $49.3{\mu}g/kg$ and $10.1{\mu}g/kg$ for grains and oilseeds, respectively. The average detected amount of zearalenone was $1.9{\mu}g/kg$ and $1.5{\mu}g/kg$ for grains and beans, respectively. In addition, the average amount of ochratoxin A was $0.08{\mu}g/kg$ for grains. The calculated exposure amounts of fumonisin, zeralenone and ochratoxin A for grains, beans and oilseeds were below the PMTDI/PTWI.

• 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.