• The Bulletin of The Korean Astronomical Society
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• v.41 no.1
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• pp.53.2-53.2
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• 2016

We present surface photometry results of the dwarf galaxies in the nearby NGC 2784 galaxy group. We newly detected about 30 dwarf galaxy candidates at about 30 square degree area around the nearby NGC 2784 galaxy (D~10 Mpc and MV=-20.5) applying a visual inspection technique on the wide-field optical images taken by the KMTNet Supernova Program (KSP). Surface brightnesses of the objects estimated from the stacked-images with total exposure time of about 6 hours reach approximately ${\mu}V$ ~28.5 mag/arcsec2 around $3{\sigma}$ above sky background. The central surface brightness and the total absolute magnitude for the faintest candidate dwarf galaxy among about 40 galaxies including the previously known ones is ${\mu}0$, V~26.1 mag/arcsec2 and MV~-9.5 mag, respectively. The effective radii of the candidates are larger than ~200 pc. The radial number density of the dwarf galaxy candidates from the center of NGC 2784 is decreasing. The mean color (<(B-V)0>~0.7) and $S{\acute{e}}rsic$ structure parameters of the dwarfs, assuming them to be located in the NGC 2784 group, are well consistent with those of the dwarf galaxies in other groups (e.g. M83 group and the Local Group (LG)). The faint-end slope of the cumulative luminosity function (CLF) of the galaxies in NGC 2784 group is about ${\alpha}=-1.2$, which is steeper than that of the LG galaxies, but is much flatter than that of the CLF expected by a ${\Lambda}CDM$ model.

• Proceedings of the Korea Water Resources Association Conference
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• 2015.05a
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• pp.106-106
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• 2015

The information of flow regimes continues to be norm in water resource and watershed management, in that stream flow regime is a crucial factor influencing water quality, geomorphology, and the community structure of stream biota. The objectives of this study were to estimate Korean stream flows from landscape variables, classify stream flow gages using hydraulic characteristics, and then apply these methods to ungaged biological monitoring sites for effective ecological assessment. Here I used a linear modeling approach (MLR, PCA, and PCR) to describe and predict seasonal flow statistics from landscape variables. MLR models were successfully built for a range of exceedance discharges and time frames (annual, January, May, July, and October), and these models explained a high degree of the observed variation with r squares ranging from 0.555 (Q95 in January) to 0.899 (Q05 in July). In validation testing, predicted and observed exceedance discharges were all significantly correlated (p<0.01) and for most models no significant difference was found between predicted and observed values (Paired samples T-test; p>0.05). I classified Korean stream flow regimes with respect to hydraulic and hydrologic regime into four categories: flashier and higher-powered (F-HP), flashier and lower-powered (F-LP), more stable and higher-powered (S-HP), and more stable and lower-powered (S-LP). These four categories of Korean streams were related to with the characteristics of environmental variables, such as catchment size, site slope, stream order, and land use patterns. I then applied the models at 684 ungaged biological sampling sites used in the National Aquatic Ecological Monitoring Program in order to classify them with respect to basic hydrologic characteristics and similarity to the government's array of hydrologic gauging stations. Flashier-lower powered sites appeared to be relatively over-represented and more stable-higher powered sites under-represented in the bioassessment data sets.

• Geotechnical Engineering
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• v.12 no.6
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• pp.115-126
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• 1996

The purpose of 1,his study is to analyze the compression and strength charactefistics of the decomposed -weathered soil originating from biotite gneiss or fine grained gneiss sampled from Poidong, Seoul : to figure out the behavioural characteristics of the decomposed -weathered soil in accordance with mineral composition and origin by comparing experimental results of residual soils. originating from granites and sampled from Bulam, Andong and Kimchun area. A series of CIU, CID CKoV, CKoD tests were car lied out. Although weathered soils have different origin and mineral composition, the slope of the NCL A was similar. It was also shown that plastic strain ratio was about 85% mainly due to the particle crushing effect during compression. The Poidong soil showed strain softening phenomenon unlike the Kimchun and Andong soils. this implies that the behavioural characteristics are affected by the origin and the mineral composition of the soil particles. Moreover, it was found that the angle of the shear resistance$(\phi')$ was dependent on the mineral composition. On the oher hand, measured Af values of decomposed weathered soils were more than one regardless of the origin and the mineral composition.

• Journal of the Korean GEO-environmental Society
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• v.7 no.5
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• pp.49-55
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• 2006

Quick lime made from limestone that are deposited abundantly in Korea has excellent potentials for stabilization of clayey soils. If Korea is able to take advantage of its abundant supply, economical efficiency could be achieved through mass production as well as being able to take advantage of utilization of natural resources. For stabilizing of clayey soil with lime, it is necessary to determine the required quantities of lime firstly and to evaluate the degree of stabilization with lime content. In this test, the quantity of lime required for 2 clayey soils which located in Seunggok and Bugok province respectively, and for 2 clay minerals-kaolinite and montmorillonite-were determined by ASTM C 977-92 and were evaluated for solidification of each samples with changing lime contents by Atterberg limit test and pH test. It was also evaluated for the improvement of each sample with lime content and curing time. The sample which added lime content determined by ASTM C 977-92 increased plastic limit, unconfined compression strength, and decreased pH in increasing trend.

• Journal of Environmental Science International
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• v.26 no.7
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• pp.803-815
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• 2017

In this study of the oak wilt disease that has occurred in a large scale in a protected area located near South Korea's metropolitan region, a detailed analysis has been conducted on the terrain, species and Diameters at Breast Height (DBH) of infected trees to identify the distribution of infection properties in the affected area. Taking into consideration the distribution of oak tree vegetation, a total of 4,640 quadrats in a size of 10 m by 10 m, have been set; and oak tree species, the DBH and infection damage per quadrat have been investigated. Geological properties have been analyzed according to elevation, slope, aspect and micro topography while a weighted value has been given according to the degree of infection in order to calculate an infection index. Through correlation analysis, the infection ratio of seriously-damaged and withered trees and the infection index have been analyzed with regards to the geological properties, tree species and DBH. The analysis shows that the disease tends to affect an area with medium elevation rather than those in the highest or lowest areas and that serious damage has been observed at rugged spots with a steep gradient (more than $30^{\circ}$). Although there has been no distinct tendency with regards to aspect, the infection ratio is relatively high in areas facing the north while the seriously-damaged and withered ratio are high in areas facing the south. In terms of micro topography, more damage has been spotted in valley terrain. Quercus mongolica has sustained more damage than other species. When it comes to the DBH, as seen in previous studies, large trees have suffered severe damage, but the analysis has also revealed conspicuous damage to medium trees with a DBH of 15-20 cm, which had not previously been considered at high risk.

• Corrosion Science and Technology
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• v.7 no.6
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• pp.319-323
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• 2008

The polarization resistance of mild steel in 0.5M hydrochloric acid has been evaluated by using impedance (Z) and linear polarization (LPR) techniques and compared to the noise resistance obtained from electrochemical noise data. The degree of localization of this general corrosion has also been discussed by evaluating localization index and power spectral density. Polarization resistance obtained by LPR technique ($28\Omega$) was higher than that obtained by impedance technique ($15\Omega$). Noise resistance ($11\Omega$) was much lower than polarization resistance measured by both of above techniques. Higher polarization resistance obtained by LPR technique is generally caused by passivation effect in the presence of scales or deposits which can introduce an increased resistance as can low conductivity electrolytes. The reason why noise resistance is lower than polarization resistance is the effect of background noise detected by using three platinum electrodes cell in 0.5M hydrochloric acid. Slope($-\beta$) of power spectral density (PSD) obtained from analysis of noise data ($-\beta$ = 3.3) was much higher than 2 which indicates mild steel corroded uniformly. Localization index (LI) calculated from statistical analysis (LI=0.08) is much lower than 1 which indicates that mild steel did not corroded locally. However, LI value is still higher than $1x10^{-3}$ and this indicates that mild steel corroded locally in microscopic point of view.

• Journal of agriculture & life science
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• v.46 no.1
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• pp.17-27
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• 2012

The purpose of this study is to analyze the trail deterioration condition and to obtain the information for the desirable maintenance and restoration of trail in national parks. The results obtained from this study were summarized as follows; The physical characteristics of trail were surveyed at the total 778 point for 204.5 km in length. As a result, the average degree of trail was $14.6^{\circ}$, average trail width was 1.5m and average bared trail width was 1.1 m. Major deterioration types of trail were trail deepen (37%), root exposed, widen, diverged, rock exposed and slope erosion in order of frequency. Deterioration class of trail were that non-deterioration was 165.34 km (80.9%), heavy class was 9.08 km, middle class was 12.69 km and light class was 17.39 km and the deterioration rate was 19.1%.

• Journal of Wetlands Research
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• v.19 no.4
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• pp.375-382
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• 2017

In this study, general characteristics of dynamic behavior of stormwater runoff from a small impervious catchment was investigated from a series of simulations for a radial type surface runoff. Based on the simulation results, a better placement strategy for stormwater inlets to improve performance of a structural best management practice (BMP) was suggested. The degree of pollutant first flush from an ideal radial type impervious catchment was simulated using a 1-D diffusion wave equation coupled with a pollutant transport equation. The results showed that the first flush of the chemical oxygen demand was the strongest when the catchment length ranged 30-50m at a bed slope of 0.02. This result suggested that a required degree of the first flush can be intentionally obtained by just changing the locations and numbers of stormwater inlets, and thereby adjusting the catchment length. Particularly, the overall performance of a structural BMP in reducing pollutant load can be improved by placing the stormwater inlets at locations for obtaining a required first flush strength.

• The Korean Journal of Community Living Science
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• v.17 no.1
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• pp.11-21
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• 2006

This research is focused on not only cultivated land as an important factor which represented the agricultural district, but also details of the research in the landscape of cultivated land. Moreover, we also focused on the cultivated land operating environmental friendly agriculture which took a lot of interest among the landscape of the cultivated land. The reason is, we judged environmental friendly agriculture is not only the simple purpose only for manufacturing food but also the key role for preserving their environment and landscape, and making sustainable agriculture. For this reason, our research treats the analysis that operating environmental friendly landscape has what kinds of different factors in landscape characteristic compare with other general agricultural methods. Plus we selected evaluating both the degree of citizen's presence and the degree of rural residents's importance in those factors as a mainly research matter. We drew out the landscape of cultivated land and concerning factors by analyzing policies(ESA, CSS, CTE, MFSP, ACL, etc) concerned with overseas agricultural landscape to deduct landscape Character factors in internal cultivated land. Based on eleven items of landscape factors in cultivated land deducted by documents research, we started to conduct field studies during MAY. 7th. 2004 $\sim$ JUL. 8th, DEC. 1th $\sim$ 3th reaching 32 villages and concerned institutes to deduct the factors in landscape characteristic in agricultural cultivated land in detail. We analyzed degrees of importance and preference in citizen and rural residents classified by 5 province of the whole country to evaluate the landscape Character factors in environmental friendly agriculture deducted by field research and 21 documents including extra items such as a scene of duck grazing by the duck techniques which is very popular way among internal environmental friendly agriculture, gardening space composed around farm and furrow on slope ground formed by unique topology in hilly country. The research period was progressed for 20 days from MAY. 28th. 2005 $\sim$ JUN. 17th. This research is the result that cultivated land landscape as a detail item holding agricultural environment especially, it is also meaningful result in environmental friendly agriculture as a basic research, because it is not only a value of simple food producing but also very effective role in both landscape and environmental parts.

• Preventive Nutrition and Food Science
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• v.15 no.2
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• pp.88-91
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• 2010

This study examined the effects of Korean red ginseng (RG) on muscle injury induced by eccentric exercise. Eighteen college male students were randomly assigned to either the RG group or the placebo group (P). The RG group ingested RG extract at 20 g/day (mixed with 200 mL of water) for 7 days prior to performing a downhill treadmill exercise and for 3 days after performing the downhill treadmill exercise, while the P group ingested 200 mL of water containing Agastachis Herba for 7 days prior to and 3 days following a downhill treadmill exercise. All subjects performed 2 bouts of a downhill treadmill exercise (6 km, -14 degree slope, 12 km/hr speed) with a 5 minute resting interval between bouts. Blood samples were drawn immediately before and after exercise, and at 1 hr, 24 hr, 48 hr, and 72 hr. Two-way repeated ANOVA documented that creatine kinase (CK) levels in the RG group were significantly reduced at 48 hr after exercise, as compared with P group, and remained constant until 72 hr after exercise. Lactate levels in the RG group were also significantly lower at 24 hr and 72 hr after exercise as compared to the P group. We conclude that supplementation of RGreduces CK levels and may prevent muscle injury induced by eccentric exercise.