• The Journal of Engineering Geology
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• v.8 no.3
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• pp.285-296
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• 1998

As a part of the study for understanding the deep geological structure of the Ogcheon Zone, both gravity and geomagnetic surveys are performed. A 70km survey line of which direction is nearly perpendicular to major faults in the southern tip of the Zone. The observed data are corrected and transformed into Bouguer and total magnetic intensity anomalies, respectively. Recent studies for petrology and geochemistry in the southwestern Ogcheon Zone in the vicinity of the survey line are reviewed for better interpretation. Both gravity and geomagnetic anomalies abruptly change around Janghung area, the southern boundary of the, Ogcheon Zone. This rapid increase of Bouguer anomaly around Janghung area can be explained by a deep seated normal fault with fairy large displacement between Precambrian gneisses and the denser intermediate plutonic rocks. It is believed that the fault acted an important role for the formation and evolution of the Ogcheon Zone. A pseudomagnetic intensity anomaly is calculated from the Bouguer anomaly assuming that the both anomalies are associated with the common source. From the origin of the survey line to the 50km point, the calculated anomaly coincides with observed magnetic anomaly. Whereas both anomalies show negative correlation in the outside 50km. From the residual Bouguer anomalies, the subterranean geological structure is provided through the iterative forward method. The initial model is obtained from informations about the surface geology as well as the results of the inverse method.

• Journal of the Korean Society of Earth Science Education
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• v.15 no.1
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• pp.47-61
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• 2022

In this study, We developed VR (Virtual Reality) geological resources based on the Geo Big Data of the Big Data platform that provided by the Korea Institute of Geoscience and Mineral Material (KIGAM). So students selected the theme of lessons by using these resources and we operated Remote classes using the materials that developed as to Virtual Reality. Therefore, the geological theme maps provided by the Geo Big Data Open Platform were reconstructed and produced materials were created for Study about Real Korean geological outcrops grounded in Virtual Reality. And Topographic information data was used to produce class materials for Remote classes. Twenty students were selected by Random sampling, and data were collected by conducting a survey including interviews to confirm the change in students' perception of remote classes in virtual reality geological data development and the effect of the classes, so data were analyzed through inductive categorization. The results of this study are as follows. First, students showed positive responses in terms of interest, utilization, and knowledge utilization as taking remote classes for developing geological data in virtual reality geological data. This is the result of showing the adaptability of diverse and flexible learning getting away from a fixed framework by motivating and encouraging students and inducing cooperation for communication. Second, students recognized distance education in the development of Virtual Reality geological data as 'Realistic hands-on learning process', 'Immersive learning process by motivation', and 'Learning process of acquiring knowledge in the field of earth science'.

• Geophysics and Geophysical Exploration
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• v.14 no.1
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• pp.121-122
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• 2011

• The Bulletin of The Korean Astronomical Society
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• v.34 no.1
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• pp.143-143
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• 2009

• 한국지구과학회:학술대회논문집
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• 2005.02a
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• pp.153-156
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• 2005

• Geophysics and Geophysical Exploration
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• v.5 no.2
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• pp.118-125
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• 2002

The hydrogeologic structure in the Chojung area was evaluated from a set of geological and geophysical investigations: detailed geological survey, vertical electric sounding (VES), borehole logging, and controlled-source magnetotelluric (CSMT) survey. Among these, CSMT soundings were taken for integrated interpretation to extend hydrogeologic structure with depth. The result of CSMT survey along with VES and borehole logging provides the vertical geologic boundary connected with hydrogeologic structure, and also indicates the depth of aquifer in granite basement. To interpret the geologic boundary and aquifer characteristics using CSMT data, we adopted the technique of 1-D inversion with smoothness-constrained method and 2-D continuous profiling with 1-D Bostick inversion and spatial filtering. The methodology tested and adopted in this study would be useful and required for providing a more information to the structure of fractured aquifer system.

• Economic and Environmental Geology
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• v.48 no.5
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• pp.421-429
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• 2015

Base researches in geoscience and mineral resources, such as geological and geo-thematic mapping, geological survey and observation, have long-term, continuity and time-leasing characteristics and they are difficult to present the particular research stages or progressions in the research span. The Technology Readiness Levels (TRLs), developed by the U.S. National Aeronautics and Space Administration (NASA), is effective for presenting research maturity levels and progression in the development of new technologies. This study suggests adjusted definitions for the Technology Readiness Levels to fit Geo-technology (Technology in Geoscience and Mineral Resources). Base geological researches, including mapping, surveys and observation, can be also presented in research levels from TRL 1 (R&D planning, literature survey) to TRL 9 (geological information construction and service in all target areas) in terms of the final product's coverage. Moreover, not only development and construction of commercial products, geological disasters and environmental researches can also be presented in field demonstrations through public pilot applications. The modified commercialization or cemonstration TRLs in Geo-technology are TRL 5 (starting pilot field application), TRL 6 (pilot field operation) and TRL 7 (pilot field operation for a larger scale, greater than ten percent of the actual environment).

• 한국지구물리탐사학회:학술대회논문집
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• 2003.11a
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• pp.390-397
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• 2003

A three-dimensional (3D) inversion technique has been developed for interpretation of magnetotelluric (MT) data. The inversion method is based on the linearized least-squares (Gauss-Newton) method with smoothness regularization. In addition to the underground 3D resistivity distribution, static shifts are also treated as unknown parameters in the inversion. The forward modeling is by the staggered-grid finite difference method. A Bayesian criterion ABle is applied to search the optimum trade-off among the minimization of the data misfit, model roughness and static shifts. The method has been applied to several MT datasets obtained at geothermal fields in Japan and other Asian countries. In this paper, two examples will be discussed: one is the data at the Ogiri geothermal area, southwestern Japan, and the other is at the Pohang low-enthalpy geothermal field, southeastern Korea. The inversion of the Ogiri data has been performed stably, resulting in a good fitting between the observed and computed apparent resistivities and phases. The recovered 3D resistivity structure is generally similar to the two-dimensional (2D) inversion models, although the deeper portion of the 3D model seems to be more realistic than that of the 2D model. The 3D model is also in a good agreement with the geological model of the geothermal reservoirs. 3D interpretation of the Pohang MT data is still preliminary. Although the fitting to the observed data is very good, the preliminary 3D model is not reliable enough because the station coverage is not sufficient for a 3D inversion.

• The Journal of Engineering Geology
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• v.16 no.3 s.49
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• pp.265-273
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• 2006

Face mapping during tunnel construction is useful and critical to predict the characteristics and stability condition of following tunneling sections and to select optimum support pattern. Therefore, a detailed geological survey of the tunnel faces, as important as a routine underground survey and a RMR evaluation, should provide critical information of the tunnel face condition in terms of the engineering geological condition and the safety of working environment for the following tunneling section. But the results of the face investigation have not been applied satisfactorily during tunneling due to limitation of technique, experience and time. This study analyze problems of face mapping in tunnel construction site by using statistical results of face mapping sheets obtained from completed tunnels, and suggest several opinions to improve face mapping during tunnel construction.

• Proceedings of the KSRS Conference
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• 2005.10a
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• pp.325-328
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• 2005

To estimate presumptive local ground subsidence area near Abandoned Under ground Coal Mine(AUCM) at Samcheok city in Korea, the geological properties of existing ground subsidence area and the geophysical prospecting data were analyzed using GIS. The electrical resistivity survey and seismic reflection survey database were constructed from investigation reports and factors which are related with ground subsidence such as geological map, topological map, land use map, lineament map, groundwater level, RMR (Rock Mass Rating), mining tunnel map and slope database were constructed also to make a comparative study of each parameters. As a result of the spatial analysis of existing ground subsidence area, 9 major factors causing ground subsidence were extracted and a connection between the structure of underground and the ground subsidence was determined from the analysis of geophysical prospecting data. The estimation of presumptive ground subsidence area was performed using the correlation between the result from neural network analysis of 9 factors and the scrutiny of geophysical prospecting data.