• Journal of Environmental Impact Assessment
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• v.13 no.1
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• pp.9-19
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• 2004

This study is performed to examine the relationship between air pollution exposure and mortality in Daejeon for the years of 1998 - 2001. Daily counts of death were analyzed by general additive Poisson model, with adjustment for effects of seasonal trend, air temperature, humidity, and day of the week as confounders in a nonparametric approach. Daily death counts were associated with CO(4 day before), $O_3$(current day), $PM_10$(4 day before), $NO_2$(6 day before), $SO_2$(2 day before). Increase of $31.07{\mu}g/m^3$(interquartile range) in $PM_10$ was associated with 2.0 % (95% CI = 0.5 % - 3.5 %)) increase in the daily number of death. This effect was greater in children(less than 15 aged) and elderly(more than 65 aged). We concluded that Daejeon had 2 - 4 % increase in mortality in association with IQR in air pollutants. Daily variations in air pollution within the range currently occurring in Daejeon might have an adverse effect on daily mortality. These findings also support the hypothesis that air pollution at levels below the current ambient air quality standards of Korea except PM10, is harmful to sensitive subjects, such as children or elderly.

• Tunnel and Underground Space
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• v.16 no.4 s.63
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• pp.296-306
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• 2006

It is difficult to solve problems regarding the adjustment on demand and supply of LNG due to seasonal variations of domestic demand of LNG, a discordance among import pattern and limits of storage facilities and so on. Also, there may be instability in LNG supply due to chances of accidents at LNG producing areas. Therefore, it is very important to secure large LNG storage facilities and to stabilize LNG supply management on a long term basis. The objective of this study is to examine the real-scale applicability of a lined underground rock storage system, which have been verified by a successful operation of the Daejeon LNG pilot plant. The new technology has many advantages of better economy, safety and environment protection, for above-ground and in-ground storage systems. The results of this study may promote the first ever real scale underground LNG storage system in a rock cavern.

• Journal of environmental and Sanitary engineering
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• v.18 no.3 s.49
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• pp.89-99
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• 2003

This study is peformed to examine the relationship between air pollution exposure and mortality in Incheon for the years of 1998 - 2001. Daily counts of death were analyzed by general additive Poisson model, with adjustment for effects of seasonal trend, air temperature, humidity, and day of the week as confounders in a nonparametric approach. Daily death counts were associated with CO(1 day before), O$_3$(2 day before), PM$_{10}$(1 day before), NO$_2$(1day before), SO$_2$(1 day before). Increase of 32.21 ${\mu}$g/m$^3$(interquartile range) in PM$_{10}$ was associated with 1.9 % (95% CI = 0.8 % - 2.9 %) increase in the daily number of death. This effect was greater in children(less than 15 aged) and elderly(more than 65 aged). We concluded that Incheon had 2 - 4 % increase in mortality in association with IQR in air pollutants. Daily variations in air pollution within the range currently occurring in Incheon might have an adverse effect on daily mortality. These findings also support the hypothesis that air pollution, at levels below the current ambient air quality standards of Korea, is harmful to sensitive subjects, such as children or elderly.

• Journal of Animal Science and Technology
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• v.61 no.6
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• pp.324-332
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• 2019

This study aimed to identify the causality between climatic and soil variables affecting the yield of Italian ryegrass (Lolium multiflorum Lam., IRG) in the paddy field by constructing the pathways via structure equation model. The IRG data (n = 133) was collected from the National Agricultural Cooperative Federation (1992-2013). The climatic variables were accumulated temperature, growing days and precipitation amount from the weather information system of Korea Meteorological Administration, and soil variables were effective soil depth, slope, gravel content and drainage class as soil physical properties from the soil information system of Rural Development Administration. In general, IRG cultivation by the rice-rotation system in paddy field is important and unique in East Asia because it contributes to the increase of income by cultivating IRG during agricultural off-season. As a result, the seasonal effects of accumulated temperature and growing days of autumn and next spring were evident, furthermore, autumnal temperature and spring precipitation indirectly influenced yield through spring temperature. The effect of autumnal temperature, spring temperature, spring precipitation and soil physics factors were 0.62, 0.36, 0.23, and 0.16 in order (p < 0.05). Even though the relationship between soil physical and precipitation was not significant, it does not mean there was no association. Because the soil physical variables were categorical, their effects were weakly reflected even with scale adjustment by jitter transformation. We expected that this study could contribute to increasing IRG yield by presenting the causality of climatic and soil factors and could be extended to various factors.

• Journal of the Korean Institute of Landscape Architecture
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• v.34 no.3 s.116
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• pp.79-90
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• 2006

Tamarix chinenis blooms twice a you and its flowers, branches and leaves make the adjustment of tree shape. Propagation methods and growth characteristics of T. chinensis were studied in order to ascertain its potential use as one of vegetation resources for coast forestation and landscaping. The study results indicated that 1 or 2 you old hard wood cuttings showed higher rooting ratio than greenwood or semi hard wood cuttings. One to one mixture between vermiculite and pearlite appeared to be the best for bed soil, and sea sand and silt(loess) mixture was the next. Sea sand and granitic soil followed after. In terms of seasonal differences, spring cuttings showed the best rooting ratio, root number, and root length. Fall cuttings followed after spring cutting, and summer cuttings showed worst results regarding rooting ratio, root number, and root length. The best rooting promotion effects of growth regulators were observed with sea sand bed soils. There was no significant difference among growth regulators in terms of rooting and shoot growth. Low concentration below 100 ppm of growth regulators was enough for rooting promotion effect. In general, the number and mean length of roots and shoots were showed the excellent records in the sites with high rooting ratio. The study result strongly showed that T. chinensis can be considered as a suitable tree for coast forestation and landscaping because of its easy cutting propagation and rapid growth on saline lands.

• Journal of Korean Society of Transportation
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• v.33 no.1
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• pp.90-99
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• 2015

The climate of Korea has clear rainy and dry season due to seasonal wind. In general, The rainy season in Korea is from early summer through to early fall. And precipitation accounted for more than half of the total annual rainfall in this period. This study is aiming to analysis of variation in saturation flow rate at signalized intersection during rainfall. The range of spatial is urban signalized intersections in Seoul and temporal is rainfall or ideal condition in daylight. Traffic data are collected through CCTV of Seoul Metropolitan Police Agency, and on-site video recordings directly. Weather condition data are collected from the Korea Meteorological Administration. In addition, the value of saturation headway and saturation flow rate, in rainfall condition, are derived through video frame analysis. As a results of analysis, decrease of saturation flow rate and increase of saturation headway during rainfall were confirmed by comparison with non-rainfall. The higher rainfall rate is, the more decreased saturation flow rate at the intersections. Rainfall rate is divided three area by the results of statistical test, and saturation flow rate decrease 7%, 17%, 21%, respectively.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.2B
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• pp.93-101
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• 2012

HEC-ResSim, reservoir operation model, is applied to Seomjin river dam in order to establish a rational method for water supply and flood control by dam operation. In order to minimize downstream flood damage for Seomjin river basin and adjacent regions, reservoir routing is applied to several frequency flood events within the framework of rainy seasonal operation rule and then the characteristics change of hydrological behavior for the downstream of study area is investigated in depth. Its quantitative efficiency and estimation method is evaluated on the basis of the adjustment scheme of conservation water surface elevation for flood control and water secure; reservoir routing considering preliminary release and variable restricted water level; and its effect to water supply; and downstream flood-duration analysis.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.27 no.3
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• pp.375-384
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• 2009

The GRACE satellite, Launched in March 2002, is applied to research on glacial melt of polar regions, glacial isostatic adjustment(GIA), sea level change, terrestrial water storage(TWS) variation of river basin and large-scale earthquake etc. In this research, the TWS variation of Yangtze river basin from August, 2002 to January, 2009 is analyzed using Level-2 GRACE monthly gravity field model. Particularly, gravity changes of the Three Gorges Dam during the impoundment process in 2003, 2006 and 2008 is observed by estimating equivalent water thickness(EWT). The research results show the distinct annual and seasonal changes of Yangtze river basin, and its amplitude of annual variation is 2.3cm. In addition, we compare the results with water resource statistics and hydrologic observation data to confirm the possibility of research of TWS variation of river basin using GRACE observation data, and also the satellite gravity data is of great help for the research on the movement and periodic changes of river basin.

• Journal of Preventive Medicine and Public Health
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• v.34 no.1
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• pp.61-72
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• 2001

Objectives : To evaluate the hypothesis that increasing ambient levels of ozone or particulate matter are associated with increased emergency room visits for asthma and to quantify the strength of association, if any, between these. Methods : Daily counts of emergency room visits for asthma, air quality, and weather data were collected from hospitals with over 200 beds and from monitoring Stations in Seoul, Korea from 1994 through 1997. Daily counts of emergency mom visits for asthma attack were analyzed using a general additive Poisson model, with adjustment for the effects of secular trend, seasonal variation, Sunday and holiday, temperature, and humidly, according to levels of ozone and particulate matter. Results : The association between daily counts of emergency room visits for asthma attack and ozone levels was statistically significant in summer(from June to August), and the RR by unit inclement of 100 ppb ozone was 1.30(95% CI = $1.11\sim1.52$) without lag time. With restriction of the period from April to September in 1996, the RR was 1.37(95% CI = $1.06\sim1.76$), and from June to August in 1995, the RR was 1.62(95% CI = $1.12\sim2.35$). In the data for children$(5\sim14yr)$, the RR was 2.57(95% CI = $1.31\sim5.05$) with restriction of the period from April to September in 1997. There was no Significant association between TSP levels and asthma attacks, but a slight association was seen between PM10 levels and asthma attacks in a very restricted period. Conclusion : There was a statistically significant association between ambient levels of ozone and daily counts of emergency room visits for asthma attack. Therefore, we must make efforts to effectively minimize air pollution, in order to protect public health.

• Journal of The Korean Society of Agricultural Engineers
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• v.59 no.6
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• pp.1-8
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• 2017

The purpose of this study was to provide basic data for development of environmental design technology for greenhouses constructed in reclaimed lands. We analyzed the climatic conditions around seven major reclaimed land areas in Korea, which have a plan to install advanced horticultural complexes. The characteristics of heating load through the thermal environment measurement of the greenhouse in Saemangeum were analyzed. The part to be applied to the environmental design of the greenhouses in reclaimed lands were reviewed. The overall heat transfer coefficient of the experimental greenhouse with the aluminum screen and multi-layer thermal curtain averaged $3.79W/m^2^{\circ}C$. It represents a 44 % heat savings rate compared with plastic greenhouses with a single covering, which was significantly lower than that of the common greenhouses with 2-layer thermal curtains. This is because the experimental greenhouse was installed on reclaimed land and wind was stronger than the inland area. Among the total heating load, the transmission heat loss accounted for 96.4~99.9 %, and the infiltration loss and the ground heat exchange were low. Therefore, it is necessary to take countermeasures to minimize the transmission heat loss for greenhouses constructed in reclaimed lands. As the reclaimed land is located on the seaside, the wind is stronger than the inland area, and the fog is frequent. Especially, Saemangeum area has 2.6 times stronger wind speed and 3.4 times longer fog duration than the inland area. In designing the heating systems for greenhouses in reclaimed lands, it is considered that the maximum heating load should be calculated by applying the wind coefficient larger than the inland area. It is reasonable to estimate the operation cost of the heating system by applying the adjustment factor 10 % larger than the average in calculating the seasonal heating load.