• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.2
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• pp.739-748
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• 2013

In this study, analytical works for the induced winds due to traveling vehicles on highway have been conducted by Computation Fluid Dynamics (CFD). The traveling condition was considered in two cases: (a) single direction and (b) bi-direction. The analysis was focused on the effects of the induced winds on the upper part of a median strip while the aerodynamic characteristics of the vehicles were directly analyzed in the previous studies. From the analysis results, it has been found that the maximum magnitude of the induced winds was 2.2 m/s when the vehicles travel with the speed of 50 km/h. Additionally, 4.0 m/s and 5.3 m/s were obtained with the speed of 90 km/h and 120 km/h, respectively. Especially, the induced winds was generated about 84% of the vehicle speed at 1.0 m above from the median strip when the vehicles travel with the speed of 120 km/h. The induced winds was maintained during the very short period while the traveling. conclusively, it is noted that the wind power generation can be possible by using the small-sized wind power generators installed on median strips throughout the analytical results in this study.

• Economic and Environmental Geology
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• v.47 no.6
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• pp.589-599
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• 2014

This study selected optimal sites in Myeongsasimni located in west coast of Korea for stratigraphic research containing extreme climate event during quaternary period by spatio-temporal analyses of changes in sedimentary environment and land use employing 1918 topographic map, 2000 digital terrain map, 1976 and 2012 air photographies. The study area shows no significant changes in topographic characteristics that hilly areas with relatively large variations in elevation are distributed over north and south part of the study area, and sand dues are developed along the coast line. Moreover, flat low lying areas are located at the back side of the sand dues. The movement of surface run off and sediment loads shows two major trends of inland direction flow from back sides of sand dunes and outland direction flow from high terrains inland, and the two flows merge into the stream located in the center of the study area. Two sink with individual area of $0.2km^2$ are observed in Yongjeong-ri and Jaryong-ri which are located in south central part and south part of the study area, respectively. In addition, sea level change simulation reveals that $3.4km^2$ and $3.64km^2$ are inundated with 3 m of sea level rise in 1918 and 2000, respectively, and it would contribute to chase sea level change records preserved in stratigraphy. The inundated areas overlaps well with sink areas where it indicates the low lying areas located in south cental and south part of the study area are identical for sediment accumulation. The areas with minimal human impact on sediment records over last 100 years are $3.51km^2$ distributed over central and south part of the study area with the land use changes of mud and rice field in 1918 to rice field in 2012. The candidate sites of $0.15km^2$ in central part and $0.09km^2$ in south part are identified for preferable locations of geologic record of extreme climate events during quaternary period based on the overlay analysis of optimal sedimentary environment and land use changes.

• Proceedings of the Korea Water Resources Association Conference
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• 2007.05a
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• pp.178-182
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• 2007

In this study, we evaluated current raingauge network of Soyanggang dam region applying spatial-correlation analysis and Entropy theory to recommend an optimized raingauge network. In the process of analysis, correlation distance of raingauge stations is estimated and evaluated via spatial-correlation method and entropy method. From this correlation distances, respective influencing radii of each dataset and each methods is assessed. The result of correlation and entropy analysis has estimated correlation distance of 25.546km and influence radius of 7.206km, deducing a decrease of network density from $224.53km^2$ to $122.47km^2$ which satisfy the recommended minimum densities of $250km^2$ in mountainous regions(WMO, 1994) and an increase of basin coverage from 59.3% to 86.8%. As for the elevation analysis the relative evaluation ratio increased from 0.59(current) to 0.92(optimized) resulting an obvious improvement.

• Korean Journal of Environment and Ecology
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• v.22 no.3
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• pp.230-240
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• 2008

The primary aim of this study is to estimate the home range of a pair of raccoon dogs(Nyctereutes procyonoides koreensis) and to compare with the previous study of raccoon dogs in a rural area of Gurye, the southern part of South Korea. Radiotracking was regularly carried out on 2 raccoon dogs for 2 days every 2 months(in June, August, October and December, 2006). During the 2 days, radiotracking was usually conducted every $1{\sim}3$ hours through day and night. The analysis of tracking data with a total of $46{\sim}64$ bearings showed that the total home range size of the pair was $0.41km^2$, and mean home range size was $0.32km^2$ by 95% minimum convex polygons(MCP) estimate. The home ranges of the male and female were largely overlapping(about $70{\sim}95%$), and the sizes were not very much different from each other. However, there was a big difference between day $(0.01km^2)$ and night-time $(0.35km^2)$ home ranges, and it was largest in summer$(0.56km^2)$ and smallest in winter $(<0.01km^2)$. In addition, the home range of the pair included 1 core area and 4 different feeding areas. In conclusion, our raccoon dog home range data using the same individuals but with more frequent bearings per day and more extended tracking intervals still showed very similar results to the previous study with less frequent bearings per day and more extensive tracking days.

• Journal of the Korean GEO-environmental Society
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• v.12 no.1
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• pp.81-87
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• 2011

The characteristics of vertical to horizontal ratio of response spectrum from 20 recent earthquakes were analysed. Response spectrum of 260 horizontal and 130 vertical ground motions were normalized by peak ground acceleration at each resonance frequency from 0.1 to 50Hz. It has been identified that the ratio of vertical to horizontal response spectrum has strong dependancy on epicentral distance and resonance frequency. The ratio of vertical to horizontal response spectrum for the 0-50km epicentral distance group are larger than 2/3 values, which is a standard engineering rule-of-thumb V/H=2/3, at resonance frequency above 7-8Hz. All the 3 groups such as 50-100, 100-150- and 150-200km epicentral distance have shown larger values of vertical to horizontal ratio than 2/3 at resonance frequency above 15Hz and also are larger than 2/3 at resonance frequency below 8-10Hz. Even though there are differences in specific resonance frequency values which depend on the epicentral distance group, we should be careful of seismic design of vertical component of the structures winch are located within the range of about 200km distance. form the potentially seismic causative faults.

• Journal of Korean Society for Geospatial Information Science
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• v.10 no.4 s.22
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• pp.61-67
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• 2002

This study is aimed to suggest a practical use of GPS continuous stations by conducting the precision analysis using its data. Currently dozens of continuous stations have been installed and operated since the first GPS continuous station built by KAO(Korea Astronomy Observation) in 1985. The utilization of the surveyed information, however, has been under-developed regardless of a significant investment, which leads the necessity of utilization plan. The results of this study show that the mis-closures between the two points at University of Incheon and Suwon/Seoul stations of NGI(National Geography Institute), Seoul stat ion of KAO, and Incheon station of MOGAHA(Ministry Of Government Administration and Home Affairs) are 0.0206m, 0.0118m, 0.0129m and 0.0024m respectively. It indicates that the analyzed mis-closures were less than the allowed values ill the primary/secondary control point specification for GPS surveying, i.e. a mis-closure less than 30mm for the distance less than 30km and a mis-closure less than $IPPM{\times}D(km)$ for the distance greater than 30km.

• Korean Journal of Environment and Ecology
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• v.30 no.5
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• pp.857-864
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• 2016

To analyze the behavioral characteristics of Korea endangered species female gorals (n=6) during the period of birth, using GPS collar attached on their necks, we carried out this study in two areas (Seoraksan and Woraksan National park) from March 2007 to May 2014. According to our analysis there was a change in their home range during the period of birth. The home range of females (n=6) in MCP 95% was Spring ($1.00{\pm}1.00km^2$) > Autumn ($0.66{\pm}0.30km^2$) > Summer ($0.61{\pm}0.40km^2$) > Winter ($0.50{\pm}0.10km^2$) (F=4.198, p<0.05). In the monthly analysis, their home ranges were dramatically reduced in May, June and July. It showed a statistically significant difference (F=24.261, p<0.01). These gorals showing a drastic change in home ranges were identified as gorals having offspring individual and their home ranges were decreased. The average altitude was $615.77{\pm}173.508m$ and there was no significant difference in major change between parous and nonparous female gorals. Through this analysis, we expect that it can be applied to the goral management and restoration project considering the time of birth.

• The Journal of Korean Medicine
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• v.34 no.2
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• pp.51-58
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• 2013

Objectives: The aim of this study was to examine the antithrombotic effects of the four herbal ingredients (Mume Fructus, MF; Santali Albi Lignum, SAL; Amomi Tsao-Ko Fructus, ATF; and Amomi Fructus, AF) of modified Jeho-tang (MJHT) in a ferric chloride ($FeCl_3$)-induced carotid arterial thrombosis model. Methods: Thirty minutes prior to a 35% $FeCl_3$ application, Sprague-Dawley (SD) rats were injected with saline, MF, SAL, ATF or AF (100 mg/kg, intraperitoneal injection), respectively. The effect of the MJHT ingredients was examined for time to occlusion (TTO) and thrombus weight (TW) in a $FeCl_3$-induced thrombosis model. Histological analysis was performed to examine the effect of the MJHT ingredients on collagen fiber damage using hematoxylin & eosin and Masson's trichrome staining. Results: Compared with vehicle treatment, MF, SAL and ATF treatment delayed TTO (vehicle, $8.11{\pm}0.60$ min; MF, $16.67{\pm}1.03$ min; SAL, $17.50{\pm}1.52$ min and ATF, $13.33{\pm}1.21$ min; P < 0.001) and inhibited thrombus formation (vehicle, $0.79{\pm}0.03$ mg/mm; MF, $0.61{\pm}0.07$ mg/mm; SAL, $0.57{\pm}0.03$ mg/mm and ATF, $0.72{\pm}0.02$ mg/mm; P < 0.001). In addition, each herbal ingredient of MJHT except for AF prevented the collagen fiber damage induced by a 35% $FeCl_3$ application. These results indicate that the MJHT ingredients MF ${\geq}$ SAL ${\geq}$ ATF ${\geq}$ AF possess antithrombotic activity in a $FeCl_3$-induced carotid arterial thrombosis. Conclusions: Altogether, these results are the first evidence that the MJHT ingredients MF, SAL and ATF have the ability to prevent vascular damage and thrombus formation in $FeCl_3$-induced carotid arterial thrombosis.

• Korean Journal of Environment and Ecology
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• v.26 no.3
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• pp.322-332
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• 2012

The objectives of this paper were to investigate home range, habitat selection, and threat factors of leopard cats (Prionailurus bengalensis) living in rural area of Korea. The results based on radio tracking of three leopard cats (two males and one female) can be summarized as follows. First, the average home range of leopard cats were $2.64{\pm}1.99km^2$ (Kernel 95) and $3.69{\pm}1.34km^2$ (MCP 100), and the average size of core areas was $0.64{\pm}0.47km^2$ (Kernel 50). The home range of a male leopard cat that radio-tracked in winter was the largest ($5.19km^2$, MCP 100). Second, the Johnson's habitat selection model based on the Jacobs index showed that leopard cats preferred meadows and paddy fields avoiding forest covers at the second level, whereas they preferred meadows adjacent to streams and avoided paddy fields at the third level. Finally, roadkill could be prime threat factor for the cat population. Therefore, habitats dominated by paddy fields, stream corridors with paved roads, and human settlements with insufficient forest patches could threaten the long-term viability of leopard cat populations. Thus the habitat managements for the leopard cat conservation should focus on the prevention of road-kill and the installation of wildlife passages in rural highways adjacent to stream corridors.

• Journal of Environmental Science International
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• v.9 no.3
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• pp.253-259
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• 2000

The purpose of this study is to investigate the physicochemical characteristics of salinization of groundwater at the estern area of Cheju island. For this purpose, the major ions of groundwater, spring water are analyzed. The concentration of $Cl^-$ and Na^++K^+$/ contained in the groundwater at near the coastline are higher than those at inland area away from the coastline. The water quality components of groundwater observed at this area can be classified into 4 types such as Na-Cl, $HCO_3, Na-Cl-HCO_3$ and Ca-HCO$_3$. The concentration ratio of $SO_4^1 to Cl^- is 0.1354(R^2=0.972)$ at this area. This value is very similar with Dittomer's ratio of 0.13. For Na^+, K^+, and Mg^{2+}/ versus Cl^-$, their ratios also show a significant relationship between sea water and groundwater in this area. From the chloride-bicarbonate ratio, it can be estimated that the intrusion distance of seawater from coastline to inland area is 2.8km at Onpyung-Nansan, Sangdo and Pyungdae areas, and 5.4km at Kosung-Susan area. The mixing ratio between seawater and fresh water by the intrusion of seawater is decreased with the distance toward inland from coastline. This ratio(fresh water : seawater) is 80:20 in spring water adjacent the coastlines, Onpyung area and 99.8:0.2 in the well at No.3 of Susan located at inland away from the coastline. The concentration of $Na^+$ observed at field is 25~45% lower than that theoretically calculated by this mixing ratio. Based on the data of EC, the equipotential line of 500$\mu$mhos/cm is located at 4~5km poing at Kosung-Susan area and 2.5km point at the other area. The equation of correlation between $Cl^-$ concentration and EC values is $Cl^-$=0.1927EC-16.683 for the area lower than 500 $\mu$mhos/cm and $Cl^-$=0.2773EC for the area beyond 500 $\mu$mhos/cm.