• KOREAN JOURNAL OF CROP SCIENCE
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• v.38 no.3
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• pp.208-212
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• 1993

Since ramie suckers distribute soil surface layer within 10cm depth, some of them are dead from low soil temperature in winter. An experiment was conducted to investigate the effects of various mulching methods on safe overwintering of sucker at three or four years old, fully-grown ramie plots. The sprouting dates of ramie was March 28 in transparent vinyl mulching(TPEF), April 1 in transparent vinyl mulching over cover of straw, manure or rice hull at the amount of 500kg /10a (CM), and April 6 in black vinyl mulching(BDEF). These treatments showed earlier sprouting date from 9 to 18 days than the conventional mulching with 1000 kg straw /10a the sprouting date of which was April 15. TPEF treatment showed the earliest but ununiform sprouting. In contrast, sprouts in CM treatment was uniform but emerged somewhat later compared with the treatment of TPEF. The number of stems per unit area increased 50 percent more in TPEF, and 35 to 39 percent more in CM than the treatment of conventional mulching.

• Journal of The Korean Society of Grassland and Forage Science
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• v.24 no.4
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• pp.309-316
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• 2004

This experiment was carried out to assess the growth and development of five rye(Secale cereale L.) cultivars based on the Feekes scale in relation to sowing date at the Experimental Livestock Farm, Seoul National University(SNU), Suwon from 30 September 2001 to 4 May 2002. The experiment was conducted in split plot design with three replications. The main plots consisted of two sowing date such as early(30 September) and late(15 October). The subplots consisted of rye cultivars of five different maturity groups such as 'Kodiak', 'Koolgrazer', 'Danko', 'Homil22' and 'Olhomil'. The plant height of early sowing rye cultivars was higher than that of late one. Among the rye cultivars tested, plant heights of early maturing cultivars were higher than those of the other cultivars. The tiller number at early sowing(48.0) was higher than that of late(24.3), however, late maturing cultivars were higher than those of the other cultivars among the rye cultivars tested. Growth and development in the early sowing were generally three days earlier than those of late sowing cultivars. Growth and development in 'Olhomil' rye cultivars was earlier than 'Danko' rye cultivars when sown in early, but 'Olhomil' and 'Koolgrazer' rye cultivars showed an early maturity than 'Danko' rye when sown in late. Therefore, the developmental stages of winter rye cultivars could be categorised the following maturity; 'Olhomil' and 'Koolgrazer' are early in maturity, 'Homil22' is medium, and 'Kodiak' and 'Danko' are late in maturity.

• Korean Journal of Breeding Science
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• v.41 no.1
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• pp.56-60
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• 2009

A new naked oat cultivar Daeyang (Avena sativa L.) was developed by Department of Rice and Winter Cereal Crop, NICS, RDA in 2007. It was derived from a cross between 'FLX446-1-84-Q1'. and 'SO92004-B-3-3-5-7'. The FLX446-1-84-Q1, a naked oat cultivar from USA, is early heading and has good seed quality, while the SO92004-B-3-3-5-7, a covered oat breeding line, has a high yield with large grain. Subsequent generations were handled in a bulk method and pedigree selection program, and the SO97013-B-16-4 was selected based on agronomic performance in 2001. The line showed both high yield and good husking rate of seed in the yield trial tested at Suwon from 2002 to 2003, being designated as Gwiri51. The Gwiri51 was subsequently evaluated for winter hardiness, earliness, and yield in four locations, Gimje, Iksan, Jeongeup, and Jinju, from 2004 to 2007 and was designated as "Daeyang" and released. Its heading date was May 8 and maturing time was June 14 in a paddy field condition. The new cultivar Daeyang had 97 cm of culm length and 25.2 cm of spike length, 644 spikes per $m^2$, 65 grains per spike, 30.3 g of 1,000-grain weight, and 635 g of test weight. Daeyang showed better winter hardiness than that of the check cultivar 'Sunyang', and similar seed quality to the check cultivar in respect to percent content crude protein and $\beta$-glucan. However, it showed higher husking rate than the check cultivar. Grain yield of Daeyang in the regional yield trial for 4 years were averaged 4.18 MT $ha^{-1}$, which was 20% higher than that of the check cultivar Sunyang. Fall sowing cropping is recommended only in a south area where daily minimum mean temperatures are averaged higher than $-4^{\circ}C$ in January, and should be excluded in mountain area where frost damage is presumable.

• Journal of Environmental Science International
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• v.20 no.6
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• pp.737-753
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• 2011

The typical characteristics of seasonal winds were studied around the Pohang using two-stage (average linkage then k-means) clustering technique based on u- and v-component wind at 850 hpa from 2004 to 2006 (obtained the Pohang station) and a high-resolution (0.5 km grid for the finest domain) WRF-UCM model along with an up-to-date detailed land use data during the most predominant pattern in each season. The clustering analysis identified statistically distinct wind patterns (7, 4, 5, and 3 clusters) representing each spring, summer, fall, and winter. During the spring, the prevailed pattern (80 days) showed weak upper northwesterly flow and late sea-breeze. Especially at night, land-breeze developed along the shoreline was converged around Yeongil Bay. The representative pattern (92 days) in summer was weak upper southerly flow and intensified sea-breeze combined with sea surface wind. In addition, convergence zone between the large scale background flow and well-developed land-breeze was transported around inland (industrial and residential areas). The predominant wind distribution (94 days) in fall was similar to that of spring showing weak upper-level flow and distinct sea-land breeze circulation. On the other hand, the wind pattern (117 days) of high frequency in winter showed upper northwesterly and surface westerly flows, which was no change in daily wind direction.

• Korean Journal of Remote Sensing
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• v.37 no.6_1
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• pp.1599-1610
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• 2021

The natural environment and local ecosystem change depending on various factors, but among them, the change in water temperature is one of the major factors affecting the surrounding environment in the river ecosystem. However, research on water temperature change have not been actively conducted to date compared to the effect of water temperature on the river environment. Therefore, this study intends to study the change in water temperature from 2015 to 2021 through the change in the area of winter ice in the Hongcheon River. Optical satellite images were classified by referring to the field survey results, and the SAR satellite imagestried to overcome the limitations of the input data by using the GLCM texture analysis method. After verifying the accuracy of all images used, the calculated monthly average ice area was compared with the temperature data of the adjacent AWS. It was found that there is a correlation between water temperature and ice area, and the results of this study can be used to study environmental changes in small-scale rivers that are difficult to access or do not have systems in place.

• Atmosphere
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• v.32 no.4
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• pp.367-379
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• 2022

In this paper, the evaluation of the performance of Korea Meteorological Administratio (KMA) Global Seasonal forecasting system version 6 (GloSea6) is presented by assessing the effects of larger ensemble size and carrying out the test using different initial conditions for hindcast in sub-seasonal to seasonal scales. The number of ensemble members increases from 3 to 7. The Ratio of Predictable Components (RPC) approaches the appropriate signal magnitude with increase of ensemble size. The improvement of annual variability is shown for all basic variables mainly in mid-high latitude. Over the East Asia region, there are enhancements especially in 500 hPa geopotential height and 850 hPa wind fields. It reveals possibility to improve the performance of East Asian monsoon. Also, the reliability tends to become better as the ensemble size increases in summer than winter. To assess the effects of using different initial conditions, the area-mean values of normalized bias and correlation coefficients are compared for each basic variable for hindcast according to the four initial dates. The results have better performance when the initial date closest to the forecasting time is used in summer. On the seasonal scale, it is better to use four initial dates, where the maximum size of the ensemble increases to 672, mainly in winter. As the use of larger ensemble size, therefore, it is most efficient to use two initial dates for 60-days prediction and four initial dates for 6-months prediction, similar to the current Time-Lagged ensemble method.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.24 no.2
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• pp.207-217
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• 2021

Purpose: This study aimed to investigate the seasonal changes in vitamin D levels in a healthy pediatric population living in mid-latitude East Asian urban areas. Methods: A pediatric population was selected from single secondary hospital visitors. Clinical data and serum vitamin D levels were collected retrospectively. Statistical analyses were performed based on the month of the blood sampling date, subject age, and vitamin D supplementation history. The data were categorized into three subgroups based on serum vitamin D levels-adequate (≥30 ng/mL), insufficient (20-29 ng/mL), and deficient (<20 ng/mL). Results: Of the 481 patients, 172 had vitamin D supplementation history. More than 70% of the total study population had inadequate vitamin D levels (<30 ng/mL). The non-supplemented group and the supplemented group showed significantly uneven monthly distribution of the adequate, insufficient, and deficient subgroups. Only the non-supplemented group showed significantly different average vitamin D levels in the summer months compared to the winter months. In the non-supplemented group, vitamin D levels were the lowest in March, the highest in August and September. Significant relevance was noted between vitamin D supplementation status and vitamin D serum level in February and March. There was no significant difference between different age groups in terms of the distribution of vitamin D levels. Conclusion: Currently-widespread vitamin D replacement methods seem to have some effect on increasing the overall serum vitamin D levels, specifically during late winter when natural serum vitamin D levels plunge. However, they are unable to fully compensate the seasonal fluctuation.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.28 no.2
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• pp.233-239
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• 1983

In order to obtain basic date for the cultivation and the breeding of double zero varieties of rapeseed, spring nature grade were investigated. Spring nature grade could be classified to 8 classes by the method of material maturity. The double zero varieties, Ⅶ group of spring adaptability has been developed from the cross "Oro" and "Midas" classified as summer type. A significant negative correlation was found between the spring adaptability and seed yield. On the other hand, a highly significant negative correlation was found between maturation and spring adaptability, cold resistnce and spring adaptability, plant from and spring adaptability. Ⅵ and Ⅶ group close to summer type showed spring growing adaptability, and 0, I and II group were appeared as winter type, autumn growing adaptability with cold tolerance.with cold tolerance.

• Journal of The Korean Society of Clinical Toxicology
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• v.20 no.2
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• pp.45-50
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• 2022

Purpose: This study utilizes the NEDIS (National Emergency Department Information System) database to suggest a predictive model for snakebite and envenomation in Korea by analyzing the geographical distribution and seasonal variation of snakebite patients visiting the ER. Methods: This was a retrospective study on snakebite patients visiting the ER using the NEDIS database from January 2014 to December 2019. The subjects include patients with the KCD (Korea Standard Classification of Disease) disease code T63.0 (Toxic effect of contact with snake venom). Geographical location, patient gender, patient age, date of ER visit, treatment during the ER stay, and disposition were recorded to analyze the geographical distribution and seasonal variation of snakebite patients in Korea. Results: A total of 12,521 patients were evaluated in this study (7,170 males, 54.9%; 5,351 females, 40.9%). The average age was 58.5±17.5 years. In all, 7,644 patients were admitted with an average admission time of 5.04±4.7 days, and 2 patients expired while admitted. The geographical distribution was Gyeongsang 3,370 (26.9%), Cheonra 2,692 (21.5%), Chungcheong 2,667 (21.3%), Seoul Capital area 1,999 (16.0%), Kangwon 1,457 (11.6%), and Jeju 336 (2.7%). The seasonal variation showed insignificant incidences in winter and higher severity in spring and summer than in fall: winter 27 (0.2%), spring 2,268 (18.1%), summer 6,847 (54.7%), and fall 3,380 (27.0%). Conclusion: Patients presenting with snakebites and envenomation in the emergency room were most common in the Gyeongsang area and during summer. The simple seasonal model predicted that 436 snakebites and 438 envenomation cases occurred in July and August. The results of this study can be applied to suitably distribute and stock antivenom. Appropriate policies can be formed to care for snakebite patients in Korea.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.15 no.5
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• pp.155-163
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• 2012

This study was carried out to monitor reproductive responses of great tits in 17 urban forests in Daegu metropolitan city. The reproductive perspectives of great tits were surveyed by using 106 artificial bird nests, of which five or seven nests were set up in every urban forest. A ratio of artificial nests used by great tits for their reproduction was 27.4%. It was showing that forests, where the reproductive response was higher, was located at the edge of the city, or was known as having a good vegetation structure in the urban area. The laying date of a great tit was a little earlier in forests in the middle of the city. It might be dependent on the density of artificial land uses including a residential area and an industrial complex, which are able to increase an urban micro-temperature. Otherwise, natural forests or forest patches nearby natural forests located at the edge of the city were showing that the laying date of great tits was relatively later than the oneee in the forest in the middle of the city. There was a big difference of reproduction perspectives of great tit between the 1st and 2nd reproduction. In the 1st reproduction, a clutch size was larger, while an egg volume was so low. Otherwise, the clutch size was shown so smaller in the 2nd reproduction than in the 1st reproduction, while the egg volume was larger in the 2nd reproduction. It might be due to the survival strategy of a great tit to prepare the winter season for a juvenile. Many variables, regarding to the problem of climate changes, have been linked to the environment of urban area and the bird habitats. Finally, Monitoring a bird reproduction is a valuable work for managing an urban forest as well as for conserving a natural forest.