• Journal of the Korean Geotechnical Society
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• v.29 no.6
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• pp.63-75
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• 2013

Inclined Earth Retaining Structure Method (IER Method), was developed in order to improve the mechanical properties of the existing earth retaining method. IER consists of two supports, which are front and back supports. In the IER method, back support is very effective for the reduction of the earth pressure acting on the front support. In this study, the effects of back support and fixing conditions of lower ends of supports are analysed by laboratory model tests in clay. The test results show that back support reduces the Leteral displacement of IER effectively, and according to the results the effect of interval and fixing condition of back support was analysed.

• 한국지구물리탐사학회:학술대회논문집
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• 2007.06a
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• pp.267-272
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• 2007

Uiseong subbasin belonging to Kyungsang basin resulted from volcanic activity in the late Cretaceous. In this study, we carry out MT and gravity survey at the Hwasan caldera, which was formed of volcanic and abyssal rocks complex, then analyze and identify geological substructure. Potential survey such as gravity and magnetic survey has been mainly carried out in former studies, so depth information for understanding substructure was not enough. To complement a potential survey, we use MT method, which has high vertical resolution. Moreover we make a simple 2D model comparing with former study. The result of MT and gravity 2D modeling shows that this area is roughly composed of 3 layers; The bottom layer is a basement. In the second layer, intrusive rocks having high resistivity is placed along the ring faults and the sedimentary layer of low resistivity is inside caldera. The highest layer is alluvium. To comprehend the 3D structure of the Hwasan caldera, we perform 3D gravity inversion, and construct the 3D model from the result of 3D gravity inversion. MT responses are calculated by using the constructed 3D model and the 3D model of the Hwasan caldera's structure is suggested after comparing the calculated values with the observed values at MT line.

• Geomechanics and Engineering
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• v.34 no.1
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• pp.17-27
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• 2023

Taking a subway shield tunnel in a certain section of Zhengzhou Metro Line 5 as an example, the field tests of shield cutting cement-soil monopile composite foundation were carried out. The load and internal force of the tunnel lining under the action of composite foundation were tested on-site and the distribution characteristics and variation laws of earth pressure around the tunnel under the load holding state of the composite foundation were analyzed. Five different load combinations (i.e., overburden load theory + q₀, Terzaghi's theory + q₀, Bierbaumer's theory + q₀, Xie's theory + q₀, and the proposed method (the combination of compound weight method and Terzaghi's theory) + q₀) were used to calculate the internal force of the tunnel structure and the obtained results were compared with the measured internal force results. The action mode of earth pressure on the tunnel lining structure was evaluated. Research results show that the earth pressure obtained by the calculation method proposed in this paper was more consistent with the measured value and the deviation between the two was within 5%. The distribution of the calculated internal force of the tunnel structure was more in line with the distribution law of field test data and the deviation between the calculated and measured values was small. This effectively verified the rationality and applicability of the proposed calculation method. Research results provided references for the design and evaluation of shield tunnels under the action of composite foundations.

• Journal of the Korean Vacuum Society
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• v.5 no.4
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• pp.315-326
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• 1996

The electronic structures of 3d and 4d core-levels of rare-earth atoms in the insulating rare-earth (Sm, Eu, Gd, and Tb) compounds were studied with x-ray photoelectron spectroscopy(XPS). It is shown that the intrinsic satellite structure due to the hybridization disappears for chemically stable-earth trivalent heavy rare-earth insulating compounds as the hybridization between f electrons of rare-earth atoms and p electrons of anion atoms decreases due to the lanthanide contraction. Eu atoms at the surface of the stable insulating trivalent Eu compounds are found to be divalent. The satellite peak of Eu 3d core-level spectra at about 10eV higher binding energy side relative the main peak comes from the multiplet structures of $\underline{3d}4f^6$ configuration. The satellite structure appearing at about 15 eV higher binding energy side relative to the main peak in all insulating rare-earth compounds is due to an energy loss process of creating a plasmon.

• Journal of Korean Elementary Science Education
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• v.27 no.4
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• pp.356-370
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• 2008

The study aims to explore sequence of earth science content in elementary school science curriculum in Korea and the U.S.. The analysis is focused on a) general content structure of earth science part; b) concept relationship between grades in the specific field of 'geology'; c) longitudinal connection of concepts and content in 'geology.' The findings are as follows. First, earth science curriculum content in Korea is structured according to sub-scientific disciplines centering on not science concepts but topics or inquiry activities whereas the U.S. curricular content is organized through integrative earth science topics with basic concepts and sub-concepts. Second, it is a common feature that basic concepts are interrelated to sub-concepts in all grades in both countries. However, basic concepts are scattered all over the grades, presented in a linear pattern in Korea while those are provided together in 3rd grade and repeated with extended concepts in a spiral structure in the U.S.. Last, it is not clear how concepts and content are longitudinally connected between grades in Korean curriculum. On the contrary, concepts and content in the U.S. curriculum have a strong longitudinal connection between grades with conceptual hierarchy. Such results indicate that Korean elementary school science curriculum would limit students' comprehensive understanding of science concepts through grades. The study suggests Korean science content should strengthen interrelationship among concepts as well as longitudinal connection between grades, in order to achieve the ultimate goal of science education, 'scientific literacy'.

• Journal of the Korean Geotechnical Society
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• v.28 no.12
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• pp.99-110
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• 2012

Inclined Earth Retaining Structure Method (IER method, briefly) is developed in order to improve the existing earth retaining method. In IER method, there are three main structures, front support, back support, and head binding. Especially, back support acts the role that reduces the earth pressure acting on the front support. In this study, the stability according to the installation angle and stiffness of front or back support is analysed by model tests. By the test results, it is known that inclined back support is very effective to reduce the earth pressure acting on the front support. Especially, the effect of the stiffness and installation angle of back support is analysed.

• THE INTERNATIONAL COMMERCE & LAW REVIEW
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• v.71
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• pp.297-324
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• 2016

China not only has the largest amount of rare earth reserves, but it also produces the most rare earth products. However, China lacks appropriate supervision and management systems of its rare earth industry. The Chinese government's inappropriate mechanisms have been cause for reckless development by national rare earth providers characterized by excessive competition, environmental pollution, and smuggling. In response to the problems, China implemented regulatory measures to restructure the rare earth industry. The Chinese central government intensifies its efforts to control the total quantity of rare earth products and tackle environmental pollution. Six leading conglomerates have been selected to promote the Chinese central government's policy. A new environmental guideline has been drawn up to reduce the discharging of wastewater and air pollution substance. Huge transition and a great influence of its policy changes are expected. These policy changes are bound to entail huge transitions, and the policy is expected to have a great influence in the future structure of the rare earth industry. In consideration of these changes, the Korean government, in collaboration with private enterprises needs to take appropriate measures, such as overseas resources development, R&D expansion, tactical stockpiling, professional manpower training and so on.

• Geophysics and Geophysical Exploration
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• v.20 no.3
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• pp.176-184
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• 2017

To interpret the seismic image precisely, random noises should be suppressed and the continuity of the image should be enhanced by using the appropriate smoothing techniques. Structure-Oriented Filter-Edge Preserving (SOF-EP) technique is one of the methods, that have been actively researched and used until now, to efficiently smooth seismic data while preserving the continuity of signal. This technique is based on the principle that diffusion occurs from large amplitude to small one. In a continuous structure such as a horizontal layer, diffusion or smoothing is operated along the layer, thereby increasing the continuity of layers and eliminating random noise. In addition, diffusion or smoothing across boundaries at discontinuous structures such as faults can be avoided by employing the continuity decision factor. Accordingly, the precision of the smoothing technique can be improved. However, in the case of the structure-oriented semblance technique, which has been used to calculate the continuity factor, it takes lots of time depending on the size of the filter and data. In this study, we first implemented the SOF-EP method and confirmed its effectiveness by applying it step by step to the field data. Next, we proposed and applied the corner response method which can efficiently calculate the continuity decision factor instead of structure-oriented semblance. As a result, we could confirm that the computation time can be reduced by about 6,000 times or more by applying the corner response method.

• 한국지구물리탐사학회:학술대회논문집
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• 2005.05a
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• pp.203-208
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• 2005

We have performed magnetotelluric (MT) surveys to investigate the deep crustal structure of Gyeongsang basin. The MT data were collected in the frequency range from 0.00042 to 320Hz along a profile across the Gyeongsang basin, and 2-D inversion was carried out to interpret the geoelectrical structure. We also extracted gravity data around the MT profile from KIGAM database and calculated the density inversion to compare with the geoelectrical structure. The results obtained are good agreement with geological distribution and indicate contrasts of physical properties of sedimentary rock, igneous rock and metamorphic rock.

• Journal of the Korean housing association
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• v.16 no.4
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• pp.91-100
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• 2005

This study aims to find the architectural concepts of Song-Sun and the spatial structure of the Myonangjong through kasa, sijo, and Chinese poems. He considered his place as a ideal place to dwell a secluded life which is surrounded by mountains, and opened to a field in front. That places is connected with geomancy or Feng Sui, and he attached great importance to placeness of the Myonangjong as a pavilion. As his place was called 'tyoro samgan', his place should be simple, and that was harmonized with nature. He regarded his place as a part of the outside space and its surrounding nature. As the pen name of Myonangjong shows that his way of life is very pure so he need not disgrace against the earth and the sky, he considered his building as a place of embodying the Confucian great law of heaven and earth. Myonangjong has a concentric circle structure of the scenery which is viewed panoramically along with the visual direction.