• Title/Summary/Keyword: Seoul Station

Search Result 1,224, Processing Time 0.026 seconds

Nitrogen Use and Yield of Silage Corn as Affected by Hairy Vetch(Vicia villosa Roth) Soil-incorporated at Different Time in Spring

  • Seo, Jong-Ho;Lee, Ho-Jin;Hur, Il-Bong;Kim, Si-Ju;Kim, Chung-Guk;Jo, Hyeon-Suk;Lee, Jung-Sam
    • KOREAN JOURNAL OF CROP SCIENCE
    • /
    • v.45 no.4
    • /
    • pp.272-275
    • /
    • 2000
  • Winter green manure crops including legume increase grain yield of subsequent crop and substitute N fertilizer requirement with organic-No Hairy vetch grows vigorously and can provide N-rich green manure for corn with its soil incorporation after wintering. But, grain yield of corn as succeeding crop would be reduced if its planting time is delayed until late spring. This experiment was carried out to find the proper incorporation time of hairy vetch green manure and planting time of subsequent corn in cropping system with winter hairy vetch(green manure)-summer corn. Hairy vetch was incorporated into soil at a ten-day interval between April 10 and May 10 and corn was planted at 5 days after each hairy vetch incorporation. Soil nitrate concentration on April 10 and 20 in hairy vetch plot was slightly lower than that at winter fallow. Above-ground dry matter and organic-N of hairy vetch increased linearly with delayed hairy vetch incorporation time from April 10 to May 10. Average dry matter and organic-N produced by hairy vetch were 5.7 ton/ha and 248 kgN/ha, respectively. Corn growth and yield decreased as delayed corn planting time after May in spite of increasing dry matter and N-yield of hairy vetch. Nitrogen concentration of corn grain, stalk and whole plant at harvest were the highest in May 5 planting, but total N-uptake of May 5 planting were not different from that of April 25 planting because of lower grain yield. It was concluded that the proper incorporation time of hairy vetch and corn planting time were April 20 and April 25, respectively, because grain yield was the highest and corn could use hairy vetch-N effectively to produce dry matter.

  • PDF

Analysis of Physical Characteristics Affecting the Usage of Public Bike in Seoul, Korea - Focused on the Different Influences of Factors by Distance to Bike Station- (서울시 공공자전거 이용에 영향을 미치는 물리적 환경 요인 분석 -대여소별 거리에 따른 요인의 영향력 차이를 중심으로-)

  • Sa, Kyungeun;Lee, Sugie
    • Journal of Korea Planning Association
    • /
    • v.53 no.6
    • /
    • pp.39-59
    • /
    • 2018
  • This study examines the relationship between the usage of public bike and physical environment factors around the public bike stations using the public bike rental history data from 2016 to 2017 in Seoul, Korea. Focusing on the different influences of determinant factors by distance to public bike station, this study identifies influential factors that affect the usage of public bike. The results of the analysis are as follows. First, both the land use and physical environmental variables of bike station areas show strong associations with the usage of public bike. Second, the usage of public bike is also associated with neighborhood living facilities, business facilities, land use mix, the distance to subway station, public facilities and universities. This finding indicates that public bike has played a role as a transportation mode for the short-distance travel and commuting purposes in everyday life. Third, this study shows that the usage of public bike is strongly associated with the average slope, traffic volume around public bike stations, distance to streams or rivers, and the types of bike lane. This finding also indicates that surrounding environmental factors play an important role in the usage of public bike. Finally, this study identifies the different influences of determinant factors on the usage of public bike by distance to public bike station. This study suggests policy implications for the potential locations of public bike stations in the future.

Statistical Analysis for Ozone Long-term Trend Stations in Seoul, Korea (통계적 기법을 적용한 서울의 오존 장기변동 대표측정소 선정)

  • Shin, Hyejung;Park, Jihoon;Son, Jungseok;Rho, Soona;Hong, Youdeong
    • Journal of Environmental Impact Assessment
    • /
    • v.24 no.2
    • /
    • pp.111-118
    • /
    • 2015
  • This study was conducted for the establishment of statistical method to determine the representative air quality monitoring station representing long-term ozone trends of Seoul. In this study, hourly ozone concentrations from 2002 to 2011 were used for further analysis. KZ-filter, correlation matrix, cluster analysis, and Kriging method were applied to select the representative station. The analysis based on correlation matrix found that long-term trend of ozone concentrations measured at Sinjung, Sadang, and Bun-dong showed a high correlation. The cluster analysis found that the former three stations belonged to the same cluster. The analysis based on Kriging method also showed that the former three stations were highly correlated with other stations in spatial distribution. Considering these results and the highest correlation coefficient of Sinjung station, the Sinjung station was the most suitable as the representative station used to understand the long-term ozone trend of Seoul. This result could be applied to understand long-term trend of other pollutants. Furthermore, this result can also be used to assess the appropriacy of spatial distribution of national air quality monitoring stations.