• Economic and Environmental Geology
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• v.28 no.5
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• pp.481-485
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• 1995

This paper presents a new approaching method to determine the velocity and geometry of shallow subsurface from seismic refraction events. After picking the first breaks from seismic refraction data, we assume that field refraction seismogram can be replaced by the unit delta function having time shift of first break. Time curves are generated by shooting ray tracing. The partial derivatives seismogram for a damped least squares method is computed analytically at each step of the forward ray tracing. The technique is successfully tested on synthetic and real data. It has the advantage of real full waveform inversion, which is robust at low frequency band even if the initial guess is far from the true model.

• The Journal of Engineering Geology
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• v.12 no.1
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• pp.35-51
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• 2002

This study aims to establish the methodology for design of an optimum water curtain system of the unlined underground oil storage cavern satisfying the requirements of hydrodynamic performance in a volcanic terrain of the south coastal area. For the optimum water curtain system in the storage facility, the general characteristics of groundwater flow system in the site are quantitatively described, i.e. distribution of hydraulic gradients, groundwater inflow rate into the storage caverns, and hydrogeologic influence area of the cavern. In this study, numerical models such as MODFLOW, FracMan/MAFIC and CONNECTFLOW are used for calculating the hydrogeological stability parameters. The design of a horizontal water curtain system requires considering the distance between water curtain and storage cavern, spacing of the water curtain boreholes, and injection pressure. From the numerical simulations at different scales, the optimum water curtain systems satisfying the containment criteria are obtained. The inflow rates into storage caverns estimated by a continuum model ranged from about 120 m$^3$/day during the operation stage to 130~140m$^3$/day during the construction stage, whereas the inflow rates by a fracture network model are 80~175m$^3$/day. The excavation works in the site will generate the excessive decline of groundwater level in a main fracture zone adjacent to the cavern. Therefore, the vertical water curtain system is necessary for sustaining the safe groundwater level in the fracture zone.

• Economic and Environmental Geology
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• v.50 no.3
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• pp.239-250
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• 2017

Physically based landslide susceptibility analysis has been recognized as an effective analysis method because it can consider the mechanism of landslide occurrence. The physically based analysis used the slope geometry and geotechnical properties of slope materials as input. However, when the physically based approach is adopted in regional scale area, the uncertainties were involved in the analysis procedure due to spatial variation and complex geological conditions, which causes inaccurate analysis results. Therefore, probabilistic method have been used to quantify these uncertainties. However, the uncertainties caused by lack of information are not dealt with the probabilistic analysis. Therefore, fuzzy set theory was adopted in this study because the fuzzy set theory is more effective to deal with uncertainties caused by lack of information. In addition, the vertex method and Monte Carlo simulation are coupled with the fuzzy approach. The proposed approach was used to evaluate the landslide susceptibility for a regional study area. In order to compare the analysis results of the proposed approach, Monte Carlo simulation as the probabilistic analysis and the deterministic analysis are used to analyze the landslide susceptibility for same study area. We found that Fuzzy Monte Carlo simulation showed the better prediction accuracy than the probabilistic analysis and the deterministic analysis.

• The Journal of Engineering Geology
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• v.24 no.1
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• pp.69-79
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• 2014

This study aims to elucidate the relative importance of geological characteristics, soil slope, and rainfall intensity in relation to soil erosion. To this end, indoor rainfall simulation experiments were carried out under different conditions of rainfall intensities, soil slope, and geological characteristics. The test results show that the factors affect soil erosion in the order of soil slope > rainfall intensity > organic content in the soil. Erosion rates were proportional to rainfall, and increase with increasing clay content. Therefore, the soil erosion rate increases strongly with increasing organic content and clay content. The results show that the soil erosion rate in areas of metamorphic rocks shows a marked increase compared with areas of steep slope and sedimentary rocks. These results indicate that the geological characteristics to produce soil are closely related to sedimentation before and after erosion, providing basic information for the development of models to predict soil erosion rates.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1994.04a
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• pp.291-291
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• 1994

Ibotonic acid와 FeCl$_3$ 투여군은 phosphate buffered saline을 투여한 대조군에 비해 흰쥐의 능동적 회피학습 습득율을 감소시켰고 해마영역의 과산화지질 형성도를 유의하게 증가시켰으며 acetylcholinesterase의 활성을 감소시켰으나 acetylcholine의 농도에는 별영향을 주지 못하였다. 이들 약물은 신경세포 지질막등에 작용하여 노인성 치매에서와 유사한 cholinergic신경계통에 neuronal degeneration을 유발하여 학습능력 감소를 유발한 것으로 보인다. 4,결론 중추 Cholinergic성 신경계활성의 변화와 뇌내 과산화지질의 과다 형성이 학습능력 감소 및 노인성치매의 원인이라고 말할수는 없지만 이러한 뇌내의 변화률이 치매과정과 연관성을 갖는 것으로 보여진다.

• Economic and Environmental Geology
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• v.45 no.5
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• pp.525-533
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• 2012

Snowmelt from seasonal snow covers can be significant in many environments of northern and alpine areas. Water flow and chemical transport resulting from snowmelt have been studied for an understanding of contributions to watersheds or catchments. A Mobile-Immobile water Model (MIM) was developed to describe the movement of ionic tracers through a snowpack by Lee et al. (2008a) and Lee et al. (2008b). To validate the model used in the studies, mass balance calculations of the model were conducted and comparisons were made between model results and analytical solutions in this work. Mass balance was calculated based on the fact that change in total mass within a snowpack with time is equal to sum of any change in the flux of water or ionic tracers into and out of the snowpack. Calculations of both water and ionic mass show almost perfect agreement between changes of two water and solute mass fluxes. Comparisons between model results and analytical solutions including wave velocity and effective saturation show almost perfect agreement.

• The Journal of Engineering Geology
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• v.28 no.4
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• pp.583-592
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• 2018

Recently, concern has arisen regarding the lowering of groundwater levels in the hinterland caused by the development of high-capacity radial collector wells in riverbank filtration areas. In this study, groundwater levels are estimated using Modflow software in relation to the water volume pumped by the radial collector well in Anseongcheon Stream. Using the water volume data, an artificial neural network (ANN) model is developed to determine the amount of water that can be withdrawn while minimizing the reduction of groundwater level. We estimate that increasing the pumping rate of the horizontal well HW-6, which is drilled parallel to the stream direction, is necessary to minimize the reduction of groundwater levels in wells OW-7 and OB-11. We also note that the number of input data and the classification of training and test data affect the results of the ANN model. This type of approach, which supplements ANN modeling with observed data, should contribute to the future groundwater management of hinterland areas.

• Economic and Environmental Geology
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• v.48 no.4
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• pp.325-335
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• 2015

This study examined the possibility to extract potential alteration zones and lithologic information based on ASTER band ratio techniques for mineralized area located in ${\ddot{O}}v{\ddot{o}}rkhangai$ province, Mongolia, and the effectiveness of remote sensing as a preliminary exploration tool for mineral exploration was tested. The results of ABRLO, PBRLO, and PrBRLO models indicated that the detection of argillic zone requires the verification of the samples to verify hydrothermal alteration minerals as clay minerals can formed by weathering process, whereas phyllic-propylitic zones were considerably related to the spatial distribution of the intrusive bodies, geological structures, and ore distribution. QI and MI results showed that QI is more useful for sedimentary rocks such as conglomerate and sandstone than meta-sedimentary like quartzite, and MI faced relatively uncertain in detection of felsic or mafic silicate rocks. QI and MI may require additional geologic information such as the characteristics of samples and geological survey data to improve extraction of lithologic information, and, if so, it is expected that remote sensing technique would contribute significantly as a preliminary geological survey method.

• Journal of the Korean Applied Science and Technology
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• v.36 no.4
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• pp.1198-1207
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• 2019

This study investigated action mechanism and biological effect of Jijang-kimch, including its anti-obesity effect and blood lipid-decreasing effect in a high-fat diet-induced obese model animals. There were four treatment groups: CD (chow diet as normal control), HFD (high fat diet as obesity control), HFDCK (HFD plus commercial kimchi extracts), and HFDJK (HFD plus Jijang-kimchi extract). Kimchi extracts were orally administered for 28 days. Body weight, liver, and adipose tissue weight declined in HFDJK compared to those in HFDCK(p<0.05). Blood triglyceride, total cholesterol, low density lipoprotein-cholesterol (LDL-C), and glucose level decreased in CD, HFDJK, and HFDCK compared to those in HFD(p<0.05). Those in HFDJK were lower than those in HFDCK(p<0.05). Sizes of liver and adipose cells increased in HFD, HFDCK, and HFDJ that those in CD(p<0.05). Those in HFDJK were greatly decreased than those in HFDCK(p<0.05). These results indicate that ingestion of Jijang-kimchi in obese model animals has anti-obesity effect by lowering blood lipid and glucose levels and decreasing adipocyte size compared to that of commercial-kimchi.

• Journal of the Korean Society of Food Science and Nutrition
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• v.24 no.2
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• pp.195-201
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• 1995

In this study we wanted to investigate the effect of taurine supplement on the lipid peroxide formation and the activities of glutathione(GSH) dependent enzyme in diabetic model mice. We induce type I diabetes mellitus with alloxan injeciton in ICR mice and type II with high calorie diet in genetically hyperglycemic KK mice. Taurine was given in drinking water at the level of 5%(w/v) for seven days. In type I diabetic model, the malondialdehyde(MDA) of liver and islet significantly increased compared to control group and they significantly decreased by taurine supplement. In type II diabetic model, the concentration of MDA was not changed by taurine supplement. The activities of GSH-peroxidase(GPX) of liver and islet increased in type I diabetic group while decreased in type II. GPX activities were not changed by taurine supplement in the liver of both types but increased in the islet of type II. Taurine supplement has no effect on the activities of GSH S-transferase(GST) in both types. From these results, we suggest that taurine supplement protect against lipid peroxide formation in diabetic model of type I.