• Journal of the Korean Geographical Society
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• v.41 no.3 s.114
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• pp.361-372
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• 2006

The purpose of this paper is to analyze temporal trends and spatial distribution of frost occurrence days using 54 weather stations under the Korea Meteorological Administration during the recent 30years ($1971{\sim}2000$). The frost occurrence days in the middle inland area was more than in the coastal area, but the period of free-frost days in the coastal area was longer than that in the middle inland. In the southern and eastern coastal areas, the frost day was more than in the western coastal area. The distribution of the first frost day was similar to that of the last frost day. The first frost day in the coastal area appeared a month later than that in the middle inland. The last frost day in the coastal area appeared $20{\sim}25$ days later than that in the middle inland. At most of stations which the first frost day was getting delayed and the last frost day earlier, the frost occurrence days showed a decreasing trend. However, in some stations, the frost occurrence day was increasing. As the frost days in October, March and April at some stations showed an increasing trend, the damage due to the frost might be increased in some areas in South Korea.

• Proceedings of the Korean Society of Grassland Science Conference
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• 1999.06a
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• pp.85.2-86
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• 1999

본 시험은 '96-'98년 3년 간 고랭지역에 적합한 사료작물 생산성 및 이용성 향상을 위하여 수행한 결과 얻어진 성적은 아래와 같았다. 1. 비교적 무상일수가 짧은 대관령(해발 800m)지역에서 최대의 옥수수 생산성을 올리기 위해서는 끝서리 오는 시기인 5월 중순에서 첫서리 오는 시기인 9월 하순 사이인 약 135일 안에 파종과 비배관리 및 수확을 끝내야 한다.(중략)

• Current Research on Agriculture and Life Sciences
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• v.19
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• pp.23-29
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• 2001

This study was carried out to develop a seedling raising method without nursery soils in automatic raising facility of rice seedlings for machine transplanting. Pre-germinated seeds were sowed on the seed trays with three different seats such as paper seat, corrugated board, and polyethylene film instead of nursery soils. The growth characteristics of the seedlings for 20 days after sowing were compared with that of a conventional standard raising method with nursery soils. There was no difference in plant height of 10-day old seedlings among the different nursery methods, but the plant height of seedlings grown for 15 days after sowing in the trays with fivefold newspaper and nursery soils was significantly taller than those on other nursery conditions. Dry weight of seedlings grown in the tray with fivefold newspaper bottom was heavier than those in nursery trays with a corrugated board and a piece of polyethylene film. The seedlings grown in a nursery tray with fivefold newspaper showed better seedling quality and root-mat formation compared with the other nursery trays. This result suggests that the healthy seedlings for machine transplanting can be raised in the paper-sheet tray without nursery soils. The labour hours and cost required for the soil-free method using paper was reduced by about 49.3% and 26.6%, respectively, compared with the semi-adult seedling on nursery soils.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.62 no.2
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• pp.149-155
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• 2017

To establish cultivation areas for the stable production of yacon, this study investigated the productivity and functional component contents of yacon in eight regions of Korea from 2011 to 2013. The results of principal component analysis using these data were as follows. A survey of 16 agricultural traits and meteorological data in the eight yacon cultivation areas showed that five factors (average temperature, maximum temperature, minimum temperature, frost-free days, and fructooligosaccharide content) were highly significant at the p < 0.001 level. Among the 16 agricultural traits and meteorological data used in the main component analysis of yacon cultivation areas, approximately eight contributed to the first principal component, and approximately four contributed to each of the second and third principal components. In particular, factors related to productivity, fructooligosaccharide content, and temperature change were considered important criteria for the classification of cultivation areas. The cultivation areas were divided into three groups by principal component analysis. In Group I, containing the Jinbu and Bonghwa areas in the mid-highland region at 500-560 m above sea level, the product yield was the highest at 2,622-3,196 kg/10a, the fructooligosaccharide content was also the highest at 9.04-9.62%, and the mean temperature was $17.3-18.5^{\circ}C$. In Group II, the areas Suncheon, Okcheon, Yeoju, and Gangneung, at 20-180 m above sea level, had the lowest yield, relatively lower fructooligosaccharide content, and the highest temperature. The areas in Group III showed values intermediate between those of Group I and Group II. For the different yacon cultivation areas, the product quantity and fructooligosaccharide content differed according to the environmental temperature, and the temperature conditions and number of frost-free days are considered important indicators for cultivation sites. Therefore, in terms of producing yacon with high quality, cultivation at 500-560 m is considered to give a higher yield and functional fructooligosaccharide content.

• Proceedings of the KAIS Fall Conference
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• 2009.05a
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• pp.231-235
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• 2009

본 연구는 일개 시 유치원에 입소한 아동 중 5~6세아 부모들을 대상으로 카시트 착용현황과 관련요인에 관한 실태를 파악하여 어린이 안전의식을 위한 기초자료를 제공하기 위한 연구이다. 연구대상은 2008년 09월22~09월29일까지 일개 시 유치원 5개소 입소한 아동 중 5~6세아 부모 189명을 대상으로 구조화된 설문지를 이용하였다. 연구결과 유아 연령이 낮고(p=0.128), 남자이며(p=0.474), 어머니의 연령이 30대 이하(p=0.294)일수록 유아 보호용 장구의 착용률이 높은 것으로 나타났으며, 어머니의 학력이 고등학교 이하(p=0.009), 아버지 직업(p=0.010)이 사무, 서비스직에 종사자 집단에서 유아보호용 장구 착용이 유의하게 나타났다. 또한 유아 보호용 장구 무상 대여사업에 대한 인지율 조사에서 월 평균 소득 300만원 미만(p=0.009)인 자에게서 유의하게 나타났으며, 유아 보호장구 장착에 영향을 미치는 요인으로는 카시트 관련교육 유무와 부 직업에 따라 유의하게 나타났다.

• Korean Journal of Environment and Ecology
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• v.26 no.4
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• pp.512-527
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• 2012

Jangdo Island (area $1.54km^2$) located in the western end of Dadohae Haesang National Park has been recognized as an prominent ecoregion possessing high moor and national biodiversity hotspot. In terms of the Z$\ddot{u}$rich-Montpellier School's phytosociology, we investigate the diversity of plant communities on the island and reevaluate the Jangdo wetland designated as Ramsar site. Ten physiognomic types of the Jangdo's vegetation were classified into 22 syntaxa (3 associations, 15 communities and 4 subcommunities). Jangdo wetland was actually denominated as 'eutrophic wetland' by Pharagmitetea and Orizetea rather than 'high moor'. Nevertheless, existence value of the Jangdo wetland is evaluated very high as a stepping stone for migratory birds and even plant dispersions. A new site of the northernmost distribution of Arachniodo-Castanopsietum sieboldii, which is a kind of cold-resistant phytocoenosis among the Camellietea japonicae of the warm-temperate broad-leaved forests, was described. Hosta yingeri-Carpinus turczaninovii var. coreana community and Carex wahuensis var. robusta-Juniperus chinensis var. procumbens community were described specifically as an endemic and an edaphic vegetation type, respectively. The unique Jangdo's vegetation reflects regional environmental conditions such as much higher frequency of frost-free days and the highest number of annual average foggy days in Korea and a well-developed aquifer in the depressed basin formed by differential erosion. We identified that human interventions (pasture, logging, forest fire, cultivation, etc.) has been involved intensively on every vegetation types, even though a rugged and inaccessible topography of the island. Particularly the Jangdo wetland has been recently threatened by fundamental distortion on hydrological system. We request an immediate establishment of the conservation prescription manual.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.5
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• pp.1891-1896
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• 2010

This study aims at illuminating the state of car seat use and relevant factors and providing basic data to enhance the consciousness of children's safety with the target group of parents who have 5~6 year old kindergarten pupils in a specific city. The target group to study is 189 fathers and mothers who have 5~6 year old kindergarten pupils in five different kindergartens in a city. Structured questionnaires are used and the major research results are the followings: The use rate of children's car seat is the higher in the lower age (p=0.128), boys (p=0.474), mothers below the age of 30s(p=0.294). The use of children's car seat is significant in the mothers who graduated high school or lower (p=0.009), and fathers(p=0.010) who are working in offices or service occupations. The study on the recognition rate of the free lease of children's car seat conducted by Korea Children Safety Foundation shows parents who earned 3 million won or lower per month(p=0.009) significantly, and the major significant factors affecting the use of children's car seat are existence or nonexistence of car seat education and kinds of parent's occupation.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.57 no.2
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• pp.195-201
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• 2012

It is important to determine the optimum harvesting time that impact decisively on the quality of vegetable waxy corns. In general, it takes 20~25 days from silking to harvest according to ecotype when waxy corn hybrids were sown in April. We identified the optimum harvesting time by the ecotypes and seeding dates for the establishment of corn double cropping system of waxy corn. It takes 23~25 days from silking to harvest regardless of ecotype, when waxy corns were sown at early in April or late in June. It takes 28~31 days when Chalok1, early maturing type, was sown between in July 10, and in July 30. It takes 29~31 days when Ilmichal, medium late maturing type, was sown between in July 10 and in July 20, but 39 days were required when sown at in July 30. The cumulative temperature for harvesting was about $1700^{\circ}C{\sim}2100^{\circ}C$. The minimum cumulative temperature from seeding to harvest was approximately $600^{\circ}C$. These results will be helpful to the farmers for determining the optimum harvest time of vegetable waxy corns.