• Journal of the Korea institute for structural maintenance and inspection
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• v.4 no.2
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• pp.167-174
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• 2000

Ground penetrating radar(GPR) was applied for measuring depths, sizes and intervals of rebars embedded in concrete. A concrete wall was constructed for this study and a sand pool and a concrete block were used for simulation. Result of this study shows that GPR can be used for measuring rebar depths and intervals, even though it is limitary, but that measuring sizes is almost impossible. Simulation with the sand pool was helpful for research on the versatile rebar arrays though signal was not clear as real concrete wall. A concrete block with many cylindrical holes for inserting different sized rebars could not be used for simulator due to many unknown reflective waves. Antenna orientation must be perpendicular to rebars for large reflection signal.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.24 no.1
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• pp.98-105
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• 2013

This paper presents a finite-difference time-domain(FDTD) simulation and a data processing technique for radar sensing of the internal structure of a wall using an ultra-wide band antenna. We first designed an ultra-wide band anti-podal vivaldi antenna with a frequency range of 0.3~7 GHz which is chosen to be relatively low after considering the characteristics of wave attenuation, wall penetration, and range resolution. In this study the two-dimensional FDTD technique was used to simulate a wall-penetration-radar experiment under practical conditions. The next, the measured radiation pattern of the practical antenna is considered as an equivalent source in the FDTD simulation, and the reflection data of a concrete wall and targets are obtained by using the simulation. Then, a data processing technique has been applied to the FDTD reflection data to get a radar image for remote sensing of the internal structure of the wall. We compared the two different source excitations in the FDTD simulation; (1) commonly-used isotropic point sources and (2) polynomial curve fitting sources of the measured radiation pattern. As a result, when we apply the measured antenna pattern into the FDTD simulation, we could obtain about 2.5 dB higher signal to noise level than using a plane wave incidence with isotropic sources.

• 한국지구물리탐사학회:학술대회논문집
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• 2004.08a
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• pp.180-189
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• 2004

The name of (Ban)wolseong thanks to its having a shape like a half-moon. Wolseong fortress is one of 'Gyeongju Historic Area', world heritage. The Silla kingdom's royal palace previously maintained its capital fortress at the locale of Wolseong. However its real face has been kept in mystery. This study grafts Geophysics on modern Archaeology and approaches with scientific and systematic methods to an excavation plan or archaeological study by means of GPR exploration which can complement archaeological curiosity without destroying Wolseong fortress. The exploration area is $12,000m^2$ in front of Seokbinggo(stone storage for ice). It is only $10\%$ area of Wolseong fortress. As a conclusion, GPR detected 7 of squared buildings($8{\times}8m^2$ size), stone wall, an entrance for the fortress, lots of foundation stones, road(presumptive), and a presumptive pond which size is 35${\~}$40m in diameter.