• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 A
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• pp.440-442
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• 2004

The ground resistance of middle scale ground pole was measured by using the 'fall of potential method' suggested by IEEE However, the measured resistance value was lower than the minimum value required To solve this problem. ground pole was set to be used commonly. In this research. ground resistance was measured using the newly suggested method and the results were analyzed to see if they satisfied the domestic regulation The results of this research will be applied to the management works as well as the establishment of new plan.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 전기설비
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• pp.55-57
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• 2005

Along with the development of the industrial society, as the transportation of water which is the indirect capital of society and petroleum, gas, etc used as energy sources is rapidly increased. the underground material is being expanded. Like this, the pipes laid under the ground not only bring the corrosion to the land circumstances to reduce the life of the pipes, but also raise the social problem of leakage accidents and the economic loss by Pin Hole. By reason of this, for the purpose of protecting the corrosion of the underground material, we are constructing and operating the electrolytic protection facilities. In case of a region of which specific resistance is high, however, we are not keeping proper protection potential(that is -850mV) to get protection effects. In this study, for the water pipes that under-voltage phenomena occur in the protection potential, we made a spot survey on the under-voltage section and normal-voltage section, compared, analyzed each of the contents and examined the under-voltage causes of the protection potential.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2005년도 Proceedings of ISRS 2005
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• pp.153-164
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• 2005

The paper presents time and cost effective remote sensing technology to estimate recharge potential of fresh water shallow aquifers for their sustainable management in arid ecosystem. Precipitation measurement of Raudatain Basin in Kuwait from TRMM data has been made and integrated with geological, geomorphological and hyrological data, to estimate the recharge potential of the basin. The total potential recharge to the area is estimated as 333.964 MCM annually. The initial losses are estimated at $60\%$ of the net precipitation .The net available quantity for recharge is 133.58 MCM. For sustainable management of the ground water resources, recharge wells have been proposed in the higher order streams to augment the Raudatain aquifer in Kuwait. If the available quantity of precipitation can be successfully utilized, it will reduce considerable pressure on desalination, which is leading to increased salinity off the coast in Arabian Gulf.

• 한국수자원학회논문집
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• 제40권8호
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• pp.665-675
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• 2007

해안 지역 지하수 최적 관리의 기본계획 수립 단계에 사용될 수 있는 간편한 개발가능량 산정식이 제안되었다. 산정식은 대수층 특성, 해수침투허용 거리, 지하수 해안유출량 그리고 양수정의 위치 등 주요 영향 변수들의 함수이므로 합리적이며, 보편적으로 사용되는 해석 해들과 Ghyben-Herzberg 법칙을 이용하여 유도되었다. 산정식은 관련 변수들의 양 함수로 표현될 수 있으므로 그 적용이 매우 간편하다. 또한 주로 주관적 경험에 의하여 그 값이 결정되어 온 양수정의 영향반경을 대수층의 수리특성과 양수량 등의 함수로 산정할 수 있는 식이 제안되었다. 가상 유역에 대한 적용과 수치 해와의 비교분석을 통하여 제안된 식들이 보수적인 결과를 산출한다는 것을 보였다. 제안된 식들을 기존 관정들이 존재하는 유역에 적용하면 추가 개발가능량을 평가할 수 있다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 C
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• pp.1188-1191
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• 1998

Detailed estimation of subsurface resistivity distribution and accurate estimation of actual fault current coming into the grounding system are indispensible to optimun grounding system design. Especially, it is essential for efficient grounding design to estimate subsurface resistivity distribution quantitatively and logically. Accurate estimation of subsurface resistivity distribution has an absolute influence on calculating touch voltage, step voltage and ground potential rise (GPR) which are related with grounding design standard for human safety. In this study, thirty-three electrical sounding surveys were made in Yongdam Power Station to obtain detailed subsurface resistivity distribution and the sounding data were interpreted quantitatively using multi-layered model. The results of the quantitative resistivity models were adopted practically to calculate grounding resistance values. Analytical asymptotic equations and CDEGS program were used in grounding resistance calculation and the results were compared and reviewed in the study.

• 한국지하수토양환경학회지:지하수토양환경
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• 제16권2호
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• pp.61-76
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• 2011

This study was objected to provide suggestions for best management practices to restore the cultural and historical values of the wells in Palaces as well as their water qualities. Water resources in the five Palaces in Seoul Metropolitan, including Gyeongbokgung, Changdeokgung, Changgyeonggung, Jongmyo Shrine, and Deoksugung, were surveyed for their physical flows and chemical compositions from April to July in 2010. Ground waters in most wells were found at depths within 5 m from the ground surface, showing typical water-table aquifer systems. Hydraulic gradients indicate water resources in Gyeongbokgung, Changdeokgung, and Changgyeonggung flowing toward south, and toward east in Deoksugung area. Especially, water-level fluctuation data at S-10 in Deoksugung implied the influence of groundwater discharge facility. In Jongmyo Shrine, water was not detected in wells, indicating the water level was lower than the well depth. Based on the water chemistry and stable isotope analyses, water resources and their qualities appeared to be formed by the water-rock interaction along the groundwater paths. S-10 (Deoksugung) and S-14 (Changgyeonggung) samples were contaminated with nitrate ($NO_3$) in levels of higher than Korean drinking water standard, 10 mg/L as $NO_3$-N, but once in four sampling campaigns. In the situation that water resources in Palaces still maintain natural characteristics, the materials that will be used for the restoration and improvement of the Palace water supplies should be carefully selected not to disturb the natural integrity. In addition, because the wells are located in the center of metropolitan area, a systematic monitoring should be applied to detect and to manage the potential impacts of underground construction and various pollution sources.

• Geosciences Journal
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• 제22권6호
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• pp.871-880
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• 2018

During and shortly after the 2017 Pohang Earthquake ($M_w$ 5.4), sand blows were observed around the epicenter for the first time since the beginning of instrumental seismic recording in South Korea. We carried out field surveys plus satellite and drone imagery analyses, resulting in observation of approximately 600 sand blows on Quaternary sediment cover in this area. Most were observed within 3 km of the epicenter, with the farthest being 15 km away. In order to investigate the ground's susceptibility to liquefaction, we conducted a trench study of a 30 m-long sand blow in a rice field 1 km from the earthquake epicenter. The physical characteristics of the liquified sediments (grain size, impermeable barriers, saturation, and low overburden pressure) closely matched the optimum ground conditions for liquefaction. Additionally, we found a series of soft sediment deformation structures (SSDSs) within the trench walls, such as load structures and water-escaped structures. The latter were vertically connected to sand blows on the surface, reflecting seismogenic liquefaction involving subsurface deformation during sand blow formation. This genetic linkage suggests that SSDS research would be useful for identifying prehistoric damage-inducing earthquakes ($M_w$ > 5.0) in South Korea because SSDSs have a lower formation threshold and higher preservational potential than geomorphic markers formed by surface ruptures. Thus, future combined studies of Quaternary surface faults and SSDSs are required to provide reliable paleoseismological information in Korea.

• 한국지리정보학회지
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• 제8권4호
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• pp.1-13
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• 2005

수문순환 과정에서 증발산 현상은 수자원 개발을 위한 계획의 수립과 수자원시스템의 운영면에서 대단히 중요한 요소로서 작용한다. 본 연구는 Landsat TM(ETM+) 자료와 DEM, Landcover 등의 공간정보를 이용하여 지표면의 에너지수지 요소를 고려한 유역의 일일 잠재증발산량을 분포형으로 산정하는 것을 목적으로 하였다. 연구대상유역은 한강수계 경안천 유역으로 하였으며, 잠재증발산량 산정은 식생이 전혀 없는 수역과 비수역 부분으로 구분하여 식생이 존재하는 지역에는 엽면적지수(LAI)를 고려한 Penman-Monteith식을 이용하였다. 그리고 비식생영역인 수역은 Penman의 에너지수지 질량수송 조합방법에 의해 산정하였다. 잠재증발산량 산정에 필요한 입력자료 중 NDVI와 SR 그리고 알베도는 1986년부터 2002년까지의 Landsat TM 및 ETM+ 영상자료로부터 분포형으로 생성하였다. NDVI 분포도를 이용하여 지중열전도량 분포도를 생성하였고, SR 분포도를 이용하여 엽면적지수 분포도를 작성하였다. 산정결과 유역전체 평균 잠재증발산량은 단위 셀당 1.8~3.2mm/day정도로 산정되었다. 각 토지피복별 잠재증발산량을 산정한 결과 수표면에서의 잠재증발산량은 3.6~4.9mm/day, 도시지역은 1.4~3.1mm/day, 나대지는 1.4~3.5mm/day, 초지는 1.7~3.7mm/day, 산림지역은 1.7~3.0mm/day 그리고 농경지에서는 1.8~3.6mm/day로 산정되었다. 증발접시 관측자료와 비교한 결과 잠재증발산량이 과소하게 산정되었으나 물리적인 타당성은 있는 것으로 판단된다.

• 방사성폐기물학회지
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• 제19권4호
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• pp.533-546
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• 2021

Large earthquakes with (M_W > ~ 6) result in ground shaking, surface ruptures, and permanent deformation with displacement. The earthquakes would damage important facilities and infrastructure such as large industrial establishments, nuclear power plants, and waste disposal sites. In particular, earthquake ruptures associated with large earthquakes can affect geological and engineered barriers such as deep geological repositories that are used for storing hazardous radioactive wastes. Earthquake-driven faults and surface ruptures exhibit various fault zone structural characteristics such as direction of earthquake propagation and rupture and asymmetric displacement patterns. Therefore, estimating the respect distances and hazardous areas has been challenging. We propose that considering multiple parameters, such as fault types, distribution, scale, activity, linkage patterns, damage zones, and respect distances, enable accurate identification of the sites for deep geological repositories and important facilities. This information would enable earthquake hazard assessment and lower earthquake-resulted hazards in potential earthquake-prone areas.

• 대한원격탐사학회지
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• 제30권5호
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• pp.587-596
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• 2014

토양수분의 시공간적 변동성은 유역의 수문학적인 반응과 지표 대기간의 상호작용에서 중요한 관심사로 특히, 강우유출 예측 시 유역의 강우사상에서 사전 토양수분 상태 즉, 선행습윤조건(antecedent wetness conditions, AWC)이 고려되어야 한다. 본 연구에서는 선행습윤조건을 알아보기 위한 지표로 토양 습윤지수(SWI), 5일 선행강우지수($API_5$), 위성토양수분($SM_{rs}$), 5일 지점토양수분($SM_{g5}$)을 선정하여 한반도 4개 지점에 대한 선행수분조건을 파악하였다. 토양수분 자료는 AMSR-E로 관측된 자료를 활용하였으며, 이에 따라 각 지역별로 2011년의 강우사상을 선택하여 Soil Conservation Service-Curve Number (SCS-CN)법과 강우량을 활용하여 직접유출고와 최대잠재보유량을 산정하였다. 이를 토양의 습윤상태를 나타내는 4개 지표와의 관계를 살펴본 결과 최대잠재보유량과 SWI가 평균 -0.73의 높은 상관계수를 보였다. 또한 토양수분의 시간적 변동성을 나타내는 time length를 산정한 결과 지역 별로 상이하게 나타났으며 이는 연구지역 및 토양 특성을 반영한 것으로 판단된다. 추후 관측된 토양수분이 지표의 습윤상태를 예측하는데 정량적인 정보를 제공할 수 있으므로 이에 대한 지속적인 모니터링 및 분석이 필요할 것으로 사료된다.