• Journal of Korean Academy of Nursing
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• v.38 no.5
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• pp.667-675
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• 2008

Purpose: The aim of this study was to compare the relation between differently measured sports activities (metabolic equivalent [MET] and peak strain score) and distal radius bone mineral density in college-aged women. Methods: lifetime sports activity was scored in two different ways: 1) a sports activity score by multiplying the intensity (METs) and duration and 2) a sports activity score by adding up physical strain scores based on the ground reaction force of each sports activities. Bone mineral density was measured using dual energy x-ray densitometry (DTX-200) in the distal radius site. Results: In stepwise multiple regression analysis, body weight and sports activities during the college period were significant positive predictors for distal radius bone mineral density. The explained variance of sports activity measured with a peak strain score (8.8%) for distal radius bone mineral density was higher than one measured with the MET score (3.3%). Conclusion: It can be concluded that sports activity scores based on MET and peak strain scores during college are very important for determining the bone mineral density in the distal radius site in women under 30.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.5
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• pp.984-989
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• 2011

Electrical insulation is one of the most important part in a high voltage apparatus. Recently, researchers are interested in the environmental friendly vegetable oil from environmental viewpoint. Accelerated aging transformer insulating material in vegetable oil was compared to that of mineral oil. Accelerated aging oil samples produced in the oven at $140^{\circ}C$ for 500, 1000, 1500, 2000hours. And Real transformer insulation oils samples of vegetable oil and mineral oil were aged by thermal cycles repeating from $30^{\circ}C$ to $120^{\circ}C$. Samples were analyzed at 42, 63, 93, 143, 190, 240, 300 cycles. The mineral and vegetable insulating oils were investigated for breakdown voltage, water content, total acid number, viscosity, volume resistivity, insulating paper and oil permittivity, and dissolved gas analyses. The breakdown voltage of the vegetable insulating oil is higher than that found for the mineral oil; the accelerated aging progress decreased the breakdown voltage. The vegetable oil had a higher water saturation than the mineral oil; the vegetable oil has the superior water characteristics and breakdown voltage. And high viscosity of vegetable oil, care has to be taken, especially when designing the cooling system for a large transformer.

• Proceedings of the Korean Geotechical Society Conference
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• 2005.03a
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• pp.491-498
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• 2005

Acid Rock Drainage(ARD) is the product formed by the atmospheric(i.e. by water, oxygen and carbon dioxide) oxidation of the relatively common iron-sulphur minerals pyrite($FeS_2$). ARD causes the acidification and heavy metal contamination of water and soil and the reduction of slope stability. In this study the generation characteristics and the prediction of ARD of various road cut slopes were studied. An attempt to classify the rocks into several groups according to their acid generation potentials was made. Acid Base Accounting(ABA) tests, commonly used as a screening tool in ARD predictions, were performed. Sixteen rock samples were classified into PAF(potentially acid forming) group and four rock samples into NAF(non-acid forming) group. The chemical analysis of water samples strongly suggested that ARD with high content of heavy metals and low pH could pollute the ground water and/or stream water.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2004.09a
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• pp.334-337
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• 2004

Groundwater chemistry in Namwon area, Korea, was investigated to understand the contribution of geochemical processes on groundwater chemistry. For this study, a total of 279 groundwater samples were collected from 93 wells distributed over the study area. Higher concentrations of major ions are generally encountered in the shallow alluvial wells, suggesting that these chemicals are originated from the surface contamination sources. Mass balance analysis based on reaction stoichiometry reveals that the water chemistry is regulated by three major chemical processes: weathering of silicate/ carbonate minerals, input of C1/SO$_4$ salts, and nitrate generating processes. The results show that mineral weathering is the most dominating factor regulating the groundwater chemistry. However, the groundwaters with the higher salt concentration indicate the larger mineral weathering effect, suggesting that some part of the mineral weathering effect is also associated with the anthropogenic activities such as limes applied to the cultivated lands, carbonates (CaCO$_3$) in the cement materials.

• Journal of Physiology & Pathology in Korean Medicine
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• v.23 no.6
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• pp.1508-1512
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• 2009

This study was designed to analyze the results of bone mineral density test in oriental medical examination. The subjects were workers in the automobile manufacturing industry. The subjects consisted of 3,206 industrial workers who had received oriental medical examination by oriental medicine and they submitted questionnaires about drinking history and smoking history, during 9 months from March to November. They were categorized by sex, age, job class, drinking history, smoking history and exercise history. The T-scores were measured by using OSTEOPRO(BMTECH, Seoul, Korea). We analyzed the relationship between sex, age, job class, drinking history, smoking history, exercise history and the results of bone mineral density using X2-test of the SPSS Ver. 14.0. There was a positive correlation between age and osteoporosis prevalence. In job class, sales personnel were apt to have a higher prevalence of osteoporosis than factory workers and office workers. Osteoporosis rates of the drinker group showed a higher level than the non-drinker group. Bone mineral densities of non-smoker group were higher than the Smoker group. And bone mineral densities of exerciser group were higher than the non-exerciser group. They have to encourage exercise and educate the workers to quit smoking for their health promotion. Furthermore, continuous health check up needs to be done connectedly.

• Journal of Soil and Groundwater Environment
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• v.27 no.2
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• pp.1-23
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• 2022

For its essential importance as a resource, sustainable development of groundwater has been major research interests for many decades. Conventional characterization of aquifer and groundwater has relied on borehole data from observation well. Although borehole data provide useful information on yield and flow of groundwater, it is often difficult and sometimes costly to estimate the spatial distribution of groundwater in entire aquifer. Geophysical probing is an alternative techique that provides such information due to its capability to image subsurface structures as well as to delineate spatial distribution of hydraulic parameters. This study presents various technical information about geophysical probing to estimate main characteristics of aquifer for groundwater exploitation. Subsequently, we analyzed representative cases, in which geophysical methods were applied to identify the location of the groundwater, classify freshwater and brine, derive hydraulic constants, and monitor groundwater.

• Economic and Environmental Geology
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• v.39 no.6 s.181
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• pp.787-801
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• 2006

Focused in the characteristic of R&D on Geoscience and Mineral Resources as basic research area, we survey on methods of public works' economic impact analysis including cost-benefit analysis and resent technology evaluation methods and suggest apply-methods to conduct economic impact analysis on R&D of geoscience and mineral resources. To conduct economic impact analysis on the basic research area, it need to identification research's out-come not just output. In this perspective, we propose a method, Input-Output-Outcome Roadmapping to identify the outcome of R&D and show the relation of input, output, and outcome of R&D. Furthermore, noticing the different effects of R&D from public works, we directly evaluate the use-value of the academic theory or geological maps through Contingent Valuation Method(CVM) and others developed as evaluation methods on environmental goods. In indirect application methods, it can evaluate the partial of the pubic works' benefit with assuming R&D factors if R&D is a part of public works. If not, we evaluate the R&D's value as reductions of costs or additions of benefit with finding related public works.

• Tunnel and Underground Space
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• v.30 no.6
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• pp.509-518
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• 2020

This study constructed a new simulation platform, including mesh generation process, numerical simulation, and post-processing for results analysis based on exploration data to perform real-scale numerical analysis considering the actual geological structure efficiently. To build the simulation platform, we applied for open-source programs. The source code is open to be available for code modification according to the researcher's needs and compatibility with various numerical simulation programs. First, a three-dimensional model(3D) is acquired based on the exploration data obtained using a drone. Then, the domain's mesh density was adjusted to an interpretable level using Blender, the free and open-source 3D creation suite. The next step is to create a 3D numerical model by creating a tetrahedral volume mesh inside the domain using Gmsh, a finite element mesh generation program. To use the mesh information obtained through Gmsh in a numerical simulation program, a converting process to conform to the program's mesh creation protocol is required. We applied a Python code for the procedure. After we completed the stability analysis, we have created various visualization of the study using ParaView, another open-source visualization and data analysis program. We successfully performed a preliminary stability analysis on the full-scale Dokdo model based on drone-acquired data to confirm the usefulness of the proposed platform. The proposed simulation platform in this study can be of various analysis processes in future research.

• Journal of the Mineralogical Society of Korea
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• v.24 no.1
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• pp.1-17
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• 2011

Mineralogical study was carried out for heavy minerals in the sea sand near Ongjingun bay, Kyonggi-do separated using the gravity and magnetic separators. Ilmenite, zircon and minor monazite and garnet were valuable minerals with gangue minerals of quartz, K-feldspar, plagioclase, muscovite, hornblende, epidote and chlorite. Quantitative analysis with SIROQUANT program showed that the contents of ilmenite separated with the gravity separation (the shaking table separation), the 1st step magnetic separation (rare earth magnetic separation) and the 2nd step magnetic separation (the Eddy current magnetic separation) were increased into 0.8, 18.3, and 48.7%, respectively. The content of ilmenite, monazite and zircon were recalculated based on the chemical composition of the representative and heavy fraction products of raw sand, the 1 step and 2 step gravity separations, and the 1 step and 2 step magnetic separations. The content increased to 0.23, 0.55, 5.22, 16.17, and 44.99% in ilmenite, 0.11, 0.02, 0.16, 0.51, and 1.19% in monazite. Although the zircon content did not differ over the processes (0.13, 0.12, 0.11, 0.15, and 0.10%), the improved recovery of zircon is expected by applying sieving process because of its high content (27%) in the fine grain size fraction (< 140#) of the 2 step gravity separation.

• Resources Recycling
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• v.28 no.4
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• pp.59-64
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• 2019

This study suggests a conceptual strategy and methodology for the risk assessment of the domestic abandoned mine fillers with fly ash. The fillers are composed of coal fly ash and solidification materials, and contain little toxic substances such as carbonates but also some heavy metals; therefore, those requires a risk assessment. The risk assessment should primarily focus on estimation of the effects to human health both on carcinogen and non-carcinogen aspects. The significant data such as toxicity and partition coefficients can be obtained from the national soil or mine environmental risk assessment guidelines. Accurate risk assessment of heavy metal contamination in the fillers may consume lots of time and efforts through site survey and instrumental analyses, etc. Moreover, it is inefficient to explore all of the factors as concentrations and categories in every heavy metal in the fillers, due to a high variety and complexity. Therefore, implementation of a preliminary risk assessment is suggested by using the literature data and the basic characteristics of the filler samples prior to the detailed risk assessment. Certainly, this presumes a thorough understanding of reliable sample analysis methods, exposure pathways, and relevant physicochemical and biological mechanisms.