• Economic and Environmental Geology
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• v.28 no.5
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• pp.503-512
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• 1995

Groundwater flow in fracture networks is simulated using a discrete fracture (DF) model which assume that groundwater flows only through the fracture network. This assumption is available if the permeability of rock matrix is very low. It is almost impossible to describe fracture networks perfectly, so a stochastic approach is used. The stochastic approach assumes that the characteristic parameters in fracture network have special distribution patterns. The stochastic model generates fracture networks with some characteristic parameters. The finite element method is used to compute fracture flows. One-dimensional line element is the element type of the finite elements. The simulation results are shown by dominant flow paths in the fracture network. The dominant flow path can be found from the simulated groundwater flow field. The model developed in this study provides the tool to estimate the influences of characteristic parameters on groundwater flow in fracture networks. The influences of some characteristic parameters on the frcture flow are estimated by the Monte Carlo simulation based on 30 realizations.

• Journal of the Korean earth science society
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• v.43 no.6
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• pp.749-761
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• 2022

As the number of National and UNESCO Global Geoparks has increased, awareness of geological heritage and local government interests have also increased. In this study, data from the geological heritage sites in the Ulsan area were summarized, a practical use plan for geological heritage was prepared based on the assessment results, and the expected effects were also presented. The value for 33 of 112 geological heritage sites identified through literature surveys was evaluated. In terms of the geological heritage types in Ulsan, there were two geological, one geomorphological, and thirty mixed-heritage sites. In the context of the geological heritage of Ulsan, rivers and coastal topography were found to be dominant, and various geomorphological and geological features, such as fossils, folds, faults, shear zones, minerals, and ore deposits are included. Based on the assessment results, there were three, eighteen, nine, and three sites in Classes I, II, III, and IV, respectively. Considering the intrinsic and subsidiary values of geological heritage, the Gangdong Coast, Jujeon Coast, Taehwagang area, Daewangam area, the Daegokri-Cheonjeonri track sites, and Mujechineup are likely to be listed as potential geosites. When the endorsement of the geopark has been promoted alongside these geosites, it can contribute to the sustainable preservation and maintenance of the geosites, satisfy the demand for science education through geo-education, and support the sustainable development of the local economy following the detailed standards for geopark certification in the Natural Parks Act. This is expected to increase the brand value of Ulsan Metropolitan City.

• Journal of Science Education
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• v.46 no.2
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• pp.165-177
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• 2022

This study aims to develop a field trip program for the Hantan River geopark in Pocheon using Orion's field trip model. The selected learning sites were the Hwajeogyeon and Bidulginang Falls, famous geosites of the Hantan River geopark in Pocheon. The field trip program consisted of six preparatory units, two field trip units, and two summary units. The preparatory stage helped reduce the novelty space considering cognitive, psychological, and geographical factors. In the field trip stage, students acquire concepts linked to learning elements in the curriculum scientifically and encourage interest in science. In the summary stage, students organized the geological phenomena observed in the field and inferred the vicinity of the Pocheon Hantan River region. The field trip program was modified to give enough time for observation activities to increase students' interest in science and to connect concepts with learning elements in the curriculum in the outdoor learning phase to allow students' convergent thinking. Implementing the field trip program raises students' interest and attitude in science.

• Journal of the Korean Society of Groundwater Environment
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• v.4 no.4
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• pp.223-230
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• 1997

DRASTIC system developed by U.S.EPA, is widely used for assessing regional groundwater pollution susceptibility by using hydrogeological factors such as depth to water, net recharge, aquifer media, soil media, topography, vadose zone media, hydraulic conductivity. The system can be applied to site selection of well or waste disposal and landuse for groundwater protection. In this study, hydrogeological spatial database of Younggwang area about topography, drainage, well, geology, soil and landuse was constructed using GIS (Geographic Information System) and regional groundwater pollution susceptibility is analyzed using the spatial database and GIS overlay technique.

• The Journal of Engineering Geology
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• v.25 no.2
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• pp.201-213
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• 2015

Site effects resulting in the amplification of earthquake ground motion are strongly influenced not only by the subsurface soil conditions and structure, but also by the surface topography. Yet, over the last several decades, most studies of site-specific seismic responses in Korea have focused primarily on the seismic amplification associated with geologic and soil conditions. For example, the effects of local geology are now well established and have been incorporated into current Korean seismic design codes, whereas topographic effects have not been considered. To help address this shortcoming, two-dimensional (2D) seismic site response analyses, using finite element (FE) ground modeling with three different slope angles, were performed in order to assess the site effects of surface topography. We then compared our results, specifically peak ground acceleration (PGA) and acceleration response spectrum, to those of one-dimensional (1D) FE model analyses conducted alongside our study. Throughout much of the upper slope region, PGAs and spectral accelerations are larger in the 2D analyses than in the 1D analyses as a result of the topographic effect.

• Proceedings of the KSEG Conference
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• 2004.03a
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• pp.12001-12049
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• 2004

암석의 풍화과정은 화학적인 변질, 물리적인 분해 및 생물학적인 작용으로 나뉘어 진다. 풍화에 영향을 주는 요소는 기후, 조성광물의 종류 및 구조, 절리와 단층, 열수변질작용과 광화작용, 염기성 및 산성암맥과 지형 등이다. 또한 암석의 풍화는 성인에 따라 다양한 양상으로 진행되는데 이는 암석을 이루고 있는 각각 광물들이 열역학적인 반응경로가 서로 다르고, 이에 수반되는 물리적인 풍화진행속도가 차이가 있으며, 암석의 균질성, 투수성 등이 암종별로 다양하기 때문이다. 현장에서 암석의 풍화정도는 조성광물의 변질과 분해정도를 육안 등으로 정성적으로 판단하고 분류하는 것이 일반적이다. (중략)

• Proceedings of the KSEG Conference
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• 2001.03a
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• pp.3-14
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• 2001

암석은 외력하에서 탄성 및 점탄성적 변형거동을 보인다. 크리프 특성은 일정하중하에서 시간에 대한 암석의 변형으로 장기적인 지반거동을 예측할 수 있는 중요한 요소이며 암석의 점탄성적 성질을 반영한다. 포항지역에 분포하는 미고결 퇴적암인 이암을 대상으로 암석의 기본적인 물성, 역학적 특성 및 크리프 시험을 실시하였다. 일축압축강도의 40-70% 응력수준에서 순간탄성변형률은 하중의 증가에 대하여 선형적인 관계를 보였으며, 일차 크리프변형률은 시간경과에 대하여 로그함수로 적절히 설명되었다. 일차 크리프에서 이차 크리프로 진행하는 과정을 살피기 위하여 약 5일 이상의 시간이 필요하였으며 최종 크리프 변형에 의한 파괴시의 변형률은 약 0.01로 밝혀졌다.

• Journal of Korean Society of Archives and Records Management
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• v.2 no.2
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• pp.205-211
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• 2002

퇴변한 필적을 회복하고 보호하는 것에 관계되는 여러 학과를 설립하여, 각고의 연구 끝에 이 영역에서 일련의 중대한 돌파를 얻었다. 볼펜 복사지 푸른색 먹(黑) 연필 청사진 등의 필적 재료의 퇴색 확산 회복 고정기제 및 종이 노화와 보호기제 등 복잡한 요소를 연구 분석하여 일련의 퇴변한 당안 필적 회복과 보호제를 연구 제작하였다. 이 일련의 성과가 세상에 나온 이래 중국 30개성 자치구에서 정부기관 경찰 법원 도시규획과 건설 지질 수도 전기 철로 석유 조사 설계 군사 등의 일부분 당안에서 응용되었고, 심각하게 퇴변한 대량의 진귀한 문헌 문물로 하여금 원래 모습을 회복시켰으며, 영구 보존할 필요가 있는 문건을 내구적으로 고정시킬 수 있었다. 동시에 국제 당안계 및 지질문물 수장, 연구 부분에서 강렬한 영향을 불러일으켰다.

• Journal of the Korean earth science society
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• v.42 no.5
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• pp.571-587
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• 2021

This study aims to investigate the problem recognition and clue capture processes of the observation stage in a geological field trip using abductive inquiry. To this end, eight outdoor geological programs were developed in the order of diagnostic evaluation, outdoor geological fieldwork, and review. Six middle-school students participated in these programs The geological field trip was conducted twice, followed by data provision, observation, rule generation, hypothesis generation, and final hypothesis presentation. Outdoor geological fieldwork recordings and student activity sheets were collected and analyzed qualitatively. From these data, three aspects of student observations emerged during the geological fieldwork: The characteristics of each pattern were subdivided into the geological importance of the clues, attention, type of clues, observation characteristics (attention factor), clue utilization, and clue deletion. Here, by combining these results, we propose educational applications that correspond to each aspect.

• The Journal of Engineering Geology
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• v.5 no.3
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• pp.301-308
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• 1995

In this study, a stochastic finite element method is proposed with a view to consider rock property variations in the analysis of structural behavior on underground caverns. Here, the Monte carlo simulation technique, which has been widely used in probabilistic applications in many engineering fields, is applied for the analysis of the effect rock property distribution. Using the newly developed computer program based on the above - mentioned method, the underground opening in biaxial stress field is analyzed considering the effect of material property variation.