• 한국지구물리탐사학회:학술대회논문집
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• 2004.06a
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• pp.260-265
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• 2004

• Geophysics and Geophysical Exploration
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• v.18 no.3
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• pp.162-166
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• 2015

• Proceedings of the Korea Water Resources Association Conference
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• 1996.05a
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• pp.303-308
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• 1996

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2006.04a
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• pp.138-138
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• 2006

• Proceedings of the KSEEG Conference
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• 2001.04a
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• pp.344-345
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• 2001

• Proceedings of the Petrological Society of Korea Conference
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• 2009.05a
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• pp.56-56
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• 2009

• Journal of the Korean Mathematical Society
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• v.38 no.4
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• pp.711-722
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• 2001

We survey recent results on the inverse kinematic problem arising in geophysics. The question is whether one can determine the sound speed (index of refraction) of a medium by measuring the travel times of the corresponding ray paths. We emphasize the anisotrpic case.

• The Bulletin of The Korean Astronomical Society
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• v.25 no.1
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• pp.30-30
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• 2000

• Geophysics and Geophysical Exploration
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• v.7 no.4
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• pp.256-261
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• 2004

This study grafts geophysics on modem archaeology and approaches with scientific and systematic methods to an excavation plan or archaeological study by means of GPR exploration which can assist archaeologists to study Wolseong fortress without excavating it. We investigated the areas in front of Seokbinggo (ice storage facility built of stone) and in the eastern corner of the castle with GPR. As a result, we detected 7 large squared building foundations, stone walls, an entrance for the fortress, many other foundation stones, a road and a garden.

• Structural Engineering and Mechanics
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• v.73 no.6
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• pp.651-666
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• 2020

In this study, the spatial variation mechanisms of large far-field earthquakes at engineering scales are first investigated with data from the 2008 Ms 8.0 Wenchuan earthquake. And a novel 'coherency cut-off frequency' is proposed to distinguish the spatial variations in ground motions in the low-frequency and high-frequency ranges. Then, a practical piecewise coherency model is developed to estimate and characterize the spatial variation in earthquake ground motions, including the effects of source-to-site distances, site conditions and neighboring topography on these variations. Four particular earthquake records from dense seismograph arrays are used to investigate values of the coherency cut-off frequency for different source-to-site distances. On the basis of this analysis, the model is established to simulate the spatial variations, whose parameters are suitable for both near- and far-field earthquake conditions. Simulations are conducted to validate the proposed model and method. The results show that compared to the existing models, the proposed model provides an effective method for simulating the spatial correlations of ground motions at local sites with known source-to-site distances.