• Journal of Korean Society for Atmospheric Environment
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• v.22 no.5
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• pp.661-678
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• 2006

Products developed in this research is a software which can transfer the type of shape(.shp) into the type of ascii using the land cover data and the topography data in the metropolitan area of Seoul. In addition, it can calculate the $CO_2$ flux according to distribution of plants within the land cover data. The $CO_2$ flux is calculated by the experimental equation which is compose of the meteorological parameters such as the solar radiation and the air temperature. The net flux was shown in about $-19ton/km^2$ by removing $CO_2$ through the photosynthesis during daytime, and in 2 ton/km2 by producing it through the respiration during nighttime on 10 August 2004, the maximum day of air temperature during the period of 3yr(2001 to 2004), in the metropolitan area of Seoul. Spatial distribution of the air temperature and the wind field is simulated by substituting the middle classification of the land cover map data, upgraded by the Korean Ministry of Environment(KME), for the land-use data of the United States Geological Survey(USGS) within the Meteorological Mesoscale Model Version 5(MM5) on 10 August 2006 in the metropolitan area of Seoul. Difference of the air temperature between both data was shown in the maximum range of $-2^{\circ}C\;to\;2.9^{\circ}C$, and the air temperature due to the land use data of KME was higher than that of USGS in average $0.4^{\circ}C$. Also, those of wind vectors were meanly lower than that of USGS in daytime and nighttime. Furthermore, the hourly time series of Volatile Organic Components(VOCs) is calculated by using the Biosphere Emission and Interaction System Version 2(BEIS2) including the new land cover data and the meteorological parameters such as the air temperature and so]ar insolation. It is possible to calculate the concentration of ozone due to the biogenic emission of VOCs.

• Journal of Environmental Impact Assessment
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• v.24 no.2
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• pp.111-118
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• 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.

• Horticultural Science & Technology
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• v.29 no.3
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• pp.181-186
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• 2011

To predict the bud bursting date of 'Campbell Early' grapevines, the bud developmental rate (DVR) models were constructed. The DVRs for bud bursting were calculated from the demanded times at controlled air temperatures. The DVRs were examined on the 'Campbell Early' grapevines incubated in three different temperatures at 4.6, 11.8, and $16.6^{\circ}C$. The DVR increased exponentially or linearly on the air temperature with a slope of about 0.0019. The DVR equations were computed as $DVR=0.0249+0.0020e^{0.1654x}$ or DVR = 0.0019x + 0.0187. These DVR equations offered developmental indices and predicted dates for bud bursting with air temperature data. The DVR equations were validated to the bud bursting data observed in the field. When bud bursting dates were calculated with daily temperature data, the root mean squared error (RMSE) between the observed and the predicted dates was less than 4 days. When those were calculated with hourly temperature data, on the other hand, the RMSE was less than 3 days. These results suggest that the DVR models are useful to predict bud bursting date of 'Campbell Early' grapevines.

• Journal of the Korean GEO-environmental Society
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• v.14 no.7
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• pp.51-56
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• 2013

Recently, a top record of hourly-based rainfall has been changed annually and flood damages of road have increased. To solve this problem, pavements for drainage were developed and practically constructed but there was no considerations on sub-base. In this research, we proposed standard for distribution of particle size of sub-base to consider strength characteristic and drainage property. We focused to compare coefficients strength and permeability by laboratory tests. Prior to tests, 4 samples were selected under the consideration on the international or domestic design guideline. In the tests, strength characteristics were compared with resilient modulus. Also, permeability characteristics were compared with coefficient of upward and downward permeability. Resilient modulus was determined with MR test using cyclic triaxial testing system. Two permeability tests were carried out. One is variable head permeability test for downward drainage and the other is Rowe Cell test for upward drainage. In the case of Rowe Cell test, middle-sized sampler with 150mm diameter was used for this study. Consequentially, we tried to find the optimum distribution of particle size to satisfy both of strength and permeability characteristics for sub-base.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.29 no.1
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• pp.105-117
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• 1999

Purpose: Ionizing radiations have been reported as an apoptosis initiating stimulus in various cells and it has established that sustained elevations in [Ca/sup 2+/] can lead to DNA fragmentation by Ca/sup 2+/-dependent endonucleases, ultimately resulting in apoptotic cell death. The previous experiments have been reported by using primarily thymocytes and lymphocytes and the change of [Ca/sup 2+/] was measured only by minutes or hours respectively. We need to evaluate [Ca/sup 2+/] in both several minutes and hours after irradiation of radiation of radiation therapy and verify the apoptotic cells. Materials and Methods: We have measured [Ca/sup 2+/] in human gingival epitheloid cancer cell with 10Gy irradiation, at minutely intervals and hourly intervals using digitized video-intensified fluorescence microscopy and the fluorescent Ca/sup 2+/ indicator dye, fura-2. In order to find out that the transient rise in [Ca/sup 2+/] could induced apoptosis, cells were incubated for 1 hour at 37℃ with TdT enzyme, rinsed and resuspended containing fluorescence and observed under a confocal fluorescence microscope. MTT assay was done to determine cell activity and LDH assay was done to determine the amount of necrotic cells. Results: After irradiation, the transient and temporal increasing of [Ca/sup 2+/] in the KB cells was founded. Though, there was no change in the intracellular [Ca/sup 2+/] at 30 minutes and 2 hours after irradiation. We could detect of DNA fragmented cells at 4 hours after 10Gy irradiated cells. There were no significant differences between 4 hour, 1 day, 3 day cells. There were no significant differences in MTT and LDH assay between the irradiated group and the control group after 4 hours and 1 day. Though after 3 days there were differences in MTT and LDH assay between the irradiated group was significantly decreased than the control group, in LDH assay the number of necrotic cell death of the irradiated was higher than the control group. Conclusion: In KB cells there were incipient and temporal increasing of the [Ca/sup 2+/] with 10Gy irradiation and the apoptosis was founded from 4 hours later which was earlier than seeing of the change of the amount of the cellular ability and necrosis.

• Food Science and Preservation
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• v.21 no.1
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• pp.91-96
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• 2014

Evidence suggests that dietary indole, particularly rich in cruciferous vegetables, may reduce the risk of cardiovascular diseases. Endosulfan is a residual organochlorine pesticide, which is detected in fruits, vegetables, and crops. In this study, we investigated the effect of luminal indole on endosulfan transport in the small intestine in mesenteric lymph duct-cannulated rats. The duodenum was also cannulated and a fasting phosphate buffered saline-glucose solution was infused overnight at 3 mL/hr. After recovery, a lipid emulsion containing [2,3-$^{14}C$] endosulfan ($^{14}C$-endosulfan) was infused into the duodenum for 8 hours. The tested rats were infused with the same lipid emulsion, but with indole. Samples from the lymph-fistula were collected hourly, and the luminal contents and mucosa were collected at the end of the infusion. The lymph flow in the mesenteric lymph did not differ between the two groups. However, the intestinal absorption of both endosulfan and cholesterol were significantly decreased by indole. The amount of radioactive endosulfan, which remained in the mucosa, was greater in the indole-infused rats due to the decreased transport of endosulfan into the lymph. This study indicates that the indole decreases the intestinal transport of endosulfan into the mesenteric lymph.

• Journal of Korean Society for Atmospheric Environment
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• v.34 no.4
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• pp.542-553
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• 2018

Since many previous studies reported the health effect of air pollution and indicated traffic as a major pollution source, significant policy efforts have been made to control traffic to reduce air pollution. However, there have been few studies that evaluated such policy implementation. In Seoul, Korea, the exclusive median bus lane system was implemented in 2004, and the metropolitan government applied air pollution reduction policies such as conversion of diesel buses to compressed natural gas buses and installation of emission control devices. This paper aimed to investigate the impact of the exclusive median bus lane system on air pollution reduction. Using hourly concentrations of particulate matter ($PM_{10}$) and nitrogen dioxide ($NO_2$) measured at 131 regulatory monitoring sites in Seoul and Gyeonggi-do for 2001-2014, we calculated annual and daily average concentrations at each site. We assessed the impact of the policy using differences-in-differences analysis by annual and daily average models after adjusting for geographic and/or meteorological variables. This method divides population into treatment and control groups with and without policy application, and compares the difference between the two time periods before and after the policy implementation in the treatment group with the difference in the control group. We classified all monitoring sites into treatment and control groups using two definitions: 1) Seoul vs. Gyeonggi-do; 2) within vs. outside 300 meters from the median bus lane. Pre- and post-policy periods were defined as 2001-2005 and 2006-2014, and 2004 and 2014 in the annual and daily models, respectively. The decrease in $PM_{10}$ concentrations between the two periods across monitoring sites in the treatment group was larger by $1.73-5.88{\mu}g/m^3$ than in the control group. $NO_2$ also showed the decrease without statistical significance. Our findings suggest that an efficient public transport policy combined with pollution abatement policies can contribute to reduction in air pollution.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.2
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• pp.209-218
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• 2010

The fifty six components of volatile organic compounds(VOCs) were continuously measured by the hour to see the distributions their of its concentration and the ozone creating contribution of nitric oxides and VOCs in Gamjeon Odor and VOCs Monitoring Network from April to September, 2008. Aromatics occupied 51.3% of VOCs and paraffins, alkanes and olefins came in order. The monthly concentration of VOCs in Gamjeon was high in July and low in September. As for hourly concentration of ozone and nitric oxides, ozone started to increase since 10am having the highest in the daytime, and nitric oxides had the different trend from that of ozone, showing the lowest in the daytime. The photochemical ozone creating potentials(POCPs) of toluene, propane, m/p-xylene, ethylbenzene, and 1,2,4-trimethylbenzene were 30.6%, 10.2%, 9.4%, 7.4% and 5.2% respectively. These five components occupied 62.8% of total POCPs, which means they contributed to the ozone creation mainly. Related with the ozone creating contribution, the ratio of VOCs to NOx was generally under 6 occupied 72.0%, which came under the area coexisting the limit of VOCs. Therefore it is thought that the management of emission source of VOCs is very important for the reduction of ozone.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.34 no.6
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• pp.617-623
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• 2001

To predict the seasonal variation of dissolved oxygen (DO) in Hakata bay, Japan, possible 20 time-series of different hourly-solar-radiation intensities were generated based on stochastically changing solar radiation intensity, and a numerical simulation on dissolved oxygen (DO) was carried out for each time series by using the Sediment-Water Ecological Model (SWEM). The model, consisting of two sub-models with hydrodynamic and biological models, simulates the circulation process of nutrient between water column and sediment, such as nutrient regeneration from sediments as well as ecological structures on the growth of phytoplankton and zooplankton, The results of the model calibration followed the seasonal variation of observed water quality well, and generated cumulative-frequency-distribution (CFD) curves of daily solar radiation agreed well with observed ones, The simulation results indicated that the exchange of sea water would have a great influence on the DO concentration, and that the concentration could change more than 1 mg/L in a day. This prediction method seems to be an effective way to examine a solution to minimize fishery damage when DO is depleted.

• Proceedings of the Korean Society of Food Science and Nutrition Conference
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• 2001.12a
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• pp.74-87
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• 2001

Evidence shows that the serum level of cholesterol (CH) is decreased with increasing green tea (GT) consumption. This presentation summarizes our recent findings on the effect of GT extract on intestinal absorption of [$^{14}C$-labeled CH and phosphatidylcholine (PC). Ovariectomized (OX) adult rats were infused intraduodenally with lipid emulsions containing radiolabeled lipids [$^{14}C$-CH or $^{14}C$-phosphatidylcholine (PC)] in the presence of GT extract or catechins to determine the rates and amounts of CH absorption and the intestinal hydrolysis and lymphatic output of PC. During lipid infusion, lymph was collected hourly for 8 h. The lymphatic absorption of $^14C$-CH was drastically lowered by infusion of GT extract at two dosage levels (GTl =5.4 mg catechins/h and GT2 = 15.1mg catechins/h). The cumulative lymphatic absorptions of $^{14}C$-CH in rats infused with GT1 and GT2 were 20.7$\pm$4.3 and $4.8{\pm}4.1{\%}$ dose, respectively, whereas the absorption of $^{14}C$-CH in rats infused with no GT extract (GT0) was $36.3{\pm}1.1{\%}$ dose. GT extracts also significantly lowered the absorption of-tocopherol (TP) in a dose dependent manner ($29.6{\pm}4.9{\%}$ dose in GT0, $20.8{\pm}5.8{\%}$ dose in GTl, and $7.9{\pm}5.4{\%}$ dose in GT2 groups). Both (+)-catechin and EGCG significantly lowered the lymphatic outputs of $^{14}C$-radioactivity after intraduodenal $^{14}C$-PC infusion. A significantly higher amount of $^{14}C$-PC remained unhydrolyzed in the intestinal lumen of the EGCG rats ($22.8{\%}$) compared with the (+)-catechin ($15.8\%$) and control groups ($11.9\%$). GT extracts, (+)-catechin, and EGCG significantly reduced the absorption of TP. The inhibitory effect of GT extract and catechins on lipid absorption may be mediated in part through the inhibition of pancreatic PLAz. The findings provide the first direct evidence that green tea and catechins have a profound inhibitory effect on the intestinal absorption of CH in OX rats. Results suggest that green tea and catechins may be used as a dietary or pharmacological means of lowering cholesterol absorption.