• Korean Journal of Breeding Science
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• v.41 no.4
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• pp.403-411
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• 2009

We inspected seed sizes of 353 genetic accessions of watermelon to diversify functional utility related to seed size and classified them into six representative groups based on their seed sizes. Each group was named as giant seed (GS), big seed (BS), medium size (NS), small size (SS), micro seed (MS) and tomato seed (TS) from the biggest. As the seed size was getting smaller, decreased seed length and seed width, increased seed number per fruit, and decreased seed weight per fruit were observed, but seed shape did not change significantly. In order to study the effect of seed size on fruit weight and seed germination, we developed three near isogenic lines (NILs) with three different seed sizes, SS, MS and TS, from crossing between two accessions 'NT' and 'TDR', and one NIL with seed size of TS from crossing between two accessions 'S55' and 'TDR'. In the study on the fruit weight of NILs with various seed sizes, NS, SS, MS, and TS NILs produced an average of 6.4, 6.3, 5.9, and 4.2 kg fruits, respectively. The bigger seed types showed the better germination rate. NS type showed the highest germination percentage, while TS showed very low germination percentage. Fermentation treatment for 48 hrs increased the germination percentage on TS type seed, but still remained at a low level. In NS, SS, and MS material, the ratio of embryo/whole seed weight was over 50%, meanwhile that of TS was only 44.4% of which low embryo percentage would be one of the reason of low germination percentage. From this study, we concluded that watermelon has very wide genetic diversity on seed size which is somehow related to fruit sizes and germination rate.

• Journal of The Korean Society of Grassland and Forage Science
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• v.39 no.1
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• pp.24-30
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• 2019

This study was conducted to investigate the effect of seeding dates on grassland productivity and botanical composition in oversown pasture located in Cheonan of South Korea. Four treatment groups were established based on the seeding dates: 18th August, 1st September, 15th September and 29th September. Evaluation of seasonal changes in botanical composition of pasture showed that the highest ratios of grass in 18th August and 1st September (pasture species 93% and weeds 7%) and the lowest in 15th September (pasture species 75% and weeds 25%). In the plant length, there is no significantly different in 5% probability level. In the total dry matter yield of grass, 18th August ($13,362kg\;ha^{-1}$) and 1st September ($13,988kg\;ha^{-1}$) were higher than 15th September ($11,883kg\;ha^{-1}$) and 29th September ($11,459kg\;ha^{-1}$). The findings of the this study suggest that seeding by early September the most desirable results for botanical composition and grassland productivity in oversown pasture, Cheonan of South Korea.

• Journal of Korean Society of Disaster and Security
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• v.12 no.2
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• pp.73-82
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• 2019

Recently, as the occurrence frequency of sudden floods due to climate change increased, the flood damage on riverside social infrastructures was extended so that there has been a threat of overflow. Therefore, a rapid prediction of potential flooding in riverside social infrastructure is necessary for administrators. However, most current flood forecasting models including hydraulic model have limitations which are the high accuracy of numerical results but longer simulation time. To alleviate such limitation, data driven models using artificial neural network have been widely used. However, there is a limitation that the existing models can not consider the time-series parameters. In this study the water surface elevation of the Hangang River bridge was predicted using the NARX model considering the time-series parameter. And the results of the ANN and RNN models are compared with the NARX model to determine the suitability of NARX model. Using the 10-year hydrological data from 2009 to 2018, 70% of the hydrological data were used for learning and 15% was used for testing and evaluation respectively. As a result of predicting the water surface elevation after 3 hours from the Hangang River bridge in 2018, the ANN, RNN and NARX models for RMSE were 0.20 m, 0.11 m, and 0.09 m, respectively, and 0.12 m, 0.06 m, and 0.05 m for MAE, and 1.56 m, 0.55 m and 0.10 m for peak errors respectively. By analyzing the error of the prediction results considering the time-series parameters, the NARX model is most suitable for predicting water surface elevation. This is because the NARX model can learn the trend of the time series data and also can derive the accurate prediction value even in the high water surface elevation prediction by using the hyperbolic tangent and Rectified Linear Unit function as an activation function. However, the NARX model has a limit to generate a vanishing gradient as the sequence length becomes longer. In the future, the accuracy of the water surface elevation prediction will be examined by using the LSTM model.

• The Korean Journal of Air & Space Law and Policy
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• v.33 no.2
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• pp.267-290
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• 2018

This paper reviews and criticizes the EU Case of C-452/13, Germanwings GmbH v. Ronny Henning. Under this case, Ronny Henning later sued Lufthansa's budget carrier Germanwings after it refused to pay him 250 euros compensation for a delay he said totalled more than three hours. Germanwings, however, maintained his flight had arrived only two hours and 58 minutes behind schedule. In those circumstances, the following question to the European Court of Justice (ECJ) for a preliminary ruling: What time is relevant for the term time of arrival used in Articles 2, 5 and 7 of Regulation [No 261/2004]: (a) the time that the aircraft lands on the runway (touchdown); (b) the time that the aircraft reaches its parking position and the parking brakes are engaged or the chocks have been applied (in-block time); (c) the time that the aircraft door is opened; (d) a time defined by the parties in the context of party autonomy? ECJ says that the situation of passengers on a flight does not change substantially when their aircraft touches down on the runway at the destination airport, when that aircraft reaches its parking position and the parking brakes are engaged or when the chocks are applied, as the passengers continue to be subject, in the enclosed space in which they are sitting, to various constraints. Therefore, it is only when the passengers are permitted to leave the aircraft and the order is given to that effect to open the doors of the aircraft that the passengers may in principle resume their normal activities without being subject to those constraints. ECJ rules that it is apparent that Articles 2, 5 and 7 of Regulation No 261/2004 must be interpreted as meaning that the concept of 'arrival time', which is used to determine the length of the delay to which passengers on a flight have been subject, corresponds to the time at which at least one of the doors of the aircraft is opened, the assumption being that, at that moment, the passengers are permitted to leave the aircraft.

• Korean Journal of Environment and Ecology
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• v.35 no.2
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• pp.135-153
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• 2021

The demilitarized zone (DMZ) is a border barrier with 248 kilometers in length and about 4 kilometers in width crossing east to west to divide the Korean Peninsula about in half. The boundary at 2 kilometers to the south is called the southern limit line. The DMZ has formed a unique ecosystem through a natural ecological succession after the Armistice Agreement and has high conservation value. However, the use of facilities for the military operation and the unchecked weeding often damage the areas in the vicinities of the southern limit line's iron-railing. This study aimed to prepare basic data for the restoration of damaged barren vegetation. As a result of classifying vegetation communities based on indicator species, 10 communities were identified as follows: Duchesnea indica Community, Hosta longipes Community, Sedum kamtschaticum-Sedum sarmentosum Community, Potentilla anemonefolia Community, Potentilla fragarioides var. major Community, Prunella vulgaris var. lilacina Community, Dendranthema zawadskii var. latilobum-Carex lanceolata Community, Dendranthema zawadskii Community, Plantago asiatica-Trifolium repens Community, and Ixeris stolonifera-Kummerowia striata Community. Highly adaptable species can characterize vegetation in barren areas to environment disturbances because artificial disturbances such as soil erosion, soil compaction, topography change, and forest fires caused by military activities frequently occur in the barren areas within the southern limit line. Most of the dominant species in the communities are composed of plants that are commonly found in the roads, roadsides, bare soil, damaged areas, and grasslands throughout South Korea. Currently, the vegetation in barren areas in the vicinities of the DMZ is in the early ecological succession form that develops from bare soil to herbaceous vegetation. Since dominant species distributed in barren land can grow naturally without special maintenance and management, the data can be useful for future restoration material development or species selection.

• Sleep Medicine and Psychophysiology
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• v.27 no.2
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• pp.67-76
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• 2020

Objectives: Brain maturation involves brain lateralization and asymmetry to achieve efficient information processing and cognitive controls. This study elucidates normal brain maturation change during the gap between ages 6-9 and age 14-17 using resting EEG. Methods: An EEG dataset was acquired from open source MIPDB (Multimodal Resource for Studying Information Processing in the Developing Brain). Ages 6-9 (n = 24) and ages 14-17 (n = 26) were selected for analysis, and subjects with psychiatric illness or EEG with severe noise were excluded. Finally, ages 6-9 (n = 14) and ages 14-17 (n = 11) were subjected to EEG analysis using EEGlab. A 120-sec length of resting EEG when eyes were closed was secured for analysis. Brain topography was compartmentalized into nine regions, best fitted with brain anatomical structure. Results: Absolute power of the delta band and theta band in ages 6-9 was greater than that of ages 14-17 in the whole brain, and, also is relative power of delta band in frontal compartment, which is same line with previous studies. The relative power of the beta band of ages 14-17 was greater than that of ages 6-9 in the whole brain. In asymmetry evaluation, relative power of the theta band in ages 14-17 showed greater power in the left than right frontal compartment; the opposite finding was noted in the parietal compartment. For the alpha band, a strong relative power distribution in the left parietal compartment was observed in ages 14-17. Absolute and relative power of the alpha band is distributed with hemispheric left lateralization in ages 14-17. Conclusion: During the gap period between ages 6-9 and ages 14-17, brain work becomes more complicated and sophisticated, and alpha band and beta band plays important roles in brain maturation in typically developing children.

• Journal of The Korean Society of Grassland and Forage Science
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• v.42 no.2
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• pp.89-95
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• 2022

This experiment was conducted to investigate the change in the productivity of Italian ryegrass seeds according to the inter-row spacing in the southern region of the Korean Peninsula. Italian ryegrass (Lolium multiflorum Lam.) 'Green Call' variety was sown in Jinju, Gyeongnam in the fall of 2020 with three inter-row spacings (20, 30 and 40 cm). The experiment was arranged a randomized block design with three replications. The ryegrass was sown on October 17, 2020, and the harvest was on May 31, about 60 days from the first heading stage. There was no difference among treatments with an average of April 27^th in heading stage. Plant height was significantly longer at 30 cm seeding interval and the shortest in 20 cm treatment. The length of the spike was the longest in the 40 cm seeding interval, and the number of seeds per spike was the highest in the 20cm seeding interval, but there was no significant difference among treatments. The seed yield was the highest at the 20 cm sowing interval (2,180 kg/ha), and decreased as the spacing increased. The dry matter content of seeds and straw was found to be 44.90% and 45.51% on average, and there was no significant difference among treatments. The amount of remaining straw after harvesting was found to be 7,506 kg/ha on average on DM basis, and was high at the 20 cm seeding interval. In view of the above results, it was found that it is most advantageous to sow at intervals of 20 cm when producing Italian ryegrass seeds through autumn sowing in the southern region.

• Journal of the Korean Burn Society
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• v.24 no.2
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• pp.21-29
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• 2021

Purpose: Frostbite is a hazard to people exposed to cold environments. With the progression of modern industrial development and change of leisure behavior encountering cold environments, frequent accidental exposure to frostbite injury during work and human behavior is increasing, and the predisposing factors of frostbite were greatly changed than before. The purpose of this study was to make epidemiological analysis, and to review the treatment outcomes of frostbite. Methods: From March 2010 to February 2021, this study has included 27 patients with second- to third-degree frostbite injuries in Advanced Burn Reconstruction Center, Bundang Jesaeng Hosptial. A retrospective study was made about the distribution of age, gender, predisposing factors, prevalent area, type of managements, and the length of treatment period. Results: In our institution, acute management of frostbite patients has included rewarming, anticoagulation therapy (acetylsalicylic acid), and agents to improve vascular perfusion (lipo-prostaglandin E1 [Eglandin^®]). The 25 frostbite patients with second-degree frostbite (92.6%) were successfully managed by the conservative treatment alone with a mean of 20.3 days healing time. Two patients with third-degree frostbite (7.4%) also showed good outcomes after surgical reconstruction with a mean of 59 days healing time. In our clinical experiences of third-degree frostbite, definitive surgical reconstruction should be recommended to wait for more than 4~6 weeks for identification of clear demarcation of necrotic tissue caused by frostbite. In this study, 43 frostbite injuries site in 27 frostbite patients occurred. Among them, 15 patients (55.6%) had multiple-site frostbite injury. The most common predisposing cause of frostbite was refrigerant gas accidents (44.4%), followed by outdoor activity in cold environments (40.8%), misapplying ice pack for treatment purposes (7.4%), barefoot walking on the cold ground (3.7%), and loss of consciousness in cold grounds (3.7%). The most prevalent sites of frostbite injuries revealed as the hand (58.1%), followed by the foot (32.6%), face (7.0%), and abdomen (2.3%). And in the winter season from the November to March, the incidence rate of frostbite injuries was high at 74.1%. Conclusion: This study included 27 frostbite patients with 43 frostbite sites since last decade in a single institution at the community hospital. The frostbite patients with second-degree frostbite (92.6%) were successfully healed by the conservative treatment alone with a mean of 20.3 days healing time. The most common predisposing cause of frostbite was refrigerant gas accidents (44.4%), followed by outdoor activity in cold environments, etc. The most prevalent site of frostbite injuries was the hand (58.1%). And the most prevalent seasonal incidence of frostbite was from November to March (74.1%).

• Korean journal of applied entomology
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• v.61 no.3
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• pp.399-408
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• 2022

There has been much debate on the morphometric divergence between the recently identified Apis cerana koreana and Apis cerana honey bees. The aim of this study was to obtain phenotypic information that can be used to compare A. c. koreana data with other A. cerana subspecies data from open resources and determine breeding results on the basis of morphometric traits. To differentiate A. c. koreana, we investigated 22 classic morphological characteristics; royal jelly secretion; and the weight of workers, queens, and drones of A. c. koreana bred in Korea. To define the selection results, we used the geometric morphometric method. The artificially selected A. c. koreana secreted significantly more royal jelly (1.18 times) than the naturally selected A. c. koreana, which positively influenced the health of the colonies. These honey bees were identified more clearly with the geometric morphometric method than with the classic morphometric method, which is traditionally used to determine the subspecies. Large trends were noted for A. c. koreana on the basis of our results and literature from the 1980s regarding A. cerana sizes in Korea (tarsal index, length of forewing, and cubital index were measured). The cluster analysis revealed the proximity of A. c. koreana, A. cerana in China, and A. c. indica on the basis of eight classic characters, which, perhaps, relay the origin of the honey bees. The results of this study defined the morphometric responses of A. c. koreana honey bees to geographic isolation, climate change, and selection, which are important to identify, protect, and preserve honey bee stock in Korea.

• Journal of Practical Agriculture & Fisheries Research
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• v.4 no.1
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• pp.128-137
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• 2002

This study was conducted to develop the heat exchanger by utilizing the heat energy of underground water(15℃), which might be used for cooling and heating system of the agricultural facilities. We developed the heat exchanger by using the parallel type plat fin tube made of Aluminum(Al 6063), which was named Aloo-Heat(No. 0247164, offered by Korean Intellectual property Office). The trial manufactures were made from Aloo-heat which was 600mm, 700mm length respectively, and It were welded to the end "U" type in order to direct flow of the underground water. The performance test was carried out under the condition of open space and room temperature with the change of flow rate of the underground water and air. The results are as follows. 1. The trial manufactures had convection heat value from 33 to 156 W/m²℃, and It was coincided with design assumption. 2. The amount of energy transfer was increased with the increment of the area of heat transfer, the air flow, the gap of temperature inlet & outlet the underground water and the air. 3. The heat value was 6,825W when the air flow was 6,000m³/h and the gap of temperature between inlet and outlet of the underground water was 6℃, and It dropped from 25.8℃ to 23.2℃(-2.6℃ difference). The convection heat value was 88.5W/m²℃. 4. The heat value was 2.625W when the air flow was 4,000m³/h and the gap of temperature between inlet and outlet the underground water was 2℃, and It dropped from 27℃ to 22.5℃(-4.5℃ difference). The convection heat value was 33.6W/m²℃. 5. Correlation values(R²) of the testing heat values of the trial manufacture type I, II, and III were 0.9141, 0.8935, and 0.9323 respectively, and correlation values(R²) of the amount of the air flow 6,000m³/h, 5,000m³/h, 4,000m³/h were 0.9513, 0.9414, and 0.9003 respectively.