• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 C
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• pp.1987-1989
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• 2000

In this paper, electric field distribution of dielectric sphere considering surface or volume resistivity is analysed by the use of rotational symmetric charge simulation method. We applied three methods such as ${\alpha},{\beta}$ modified $\beta$ method to check electric field calculation error. We find f method and modified $\beta$ method are suitable to simulate volume and surface resistivity respectively.

• International journal of advanced smart convergence
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• 제9권3호
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• pp.97-104
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• 2020

In this paper, we propose a method to derive the kernel function directly from the measured apparent earth resistivity. At this time, the kernel function is obtained through the process of solving a nonlinear system. Nonlinear systems with many variables are difficult to solve. This paper also introduces a method for converting nonlinear derived systems to linear systems. The kernel function is a function of the depth and resistance of the Earth's layer. Being able to derive an accurate kernel function means that we can estimate the earth parameters i.e. layer depth and resistivity. We also use various Earth models as simulation examples to validate the proposed method.

• 한국지반공학회논문집
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• 제29권3호
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• pp.51-60
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• 2013

말뚝 시공 시 선단 부분에 쌓이는 슬라임은 현장타설말뚝의 선단지지력을 감소시켜 구조물의 안정성에 큰 영향을 미친다. 슬라임의 존재 유무는 주로 다짐추 혹은 철근을 낙하시켜 판정하고 있으며, 이와 같은 방법은 주관적인 판단결과로 신뢰성에 한계가 있다. 본 논문에서는 물리탐사기법 중 하나인 전기비저항 특성을 활용하여 슬라임층의 존재 여부와 두께를 과학적이고 객관적으로 평가하는 방법을 제시하고자 한다. 슬라임층의 전기비저항 특성을 평가하기 위하여 기존에 개발된 온도보상형 전기비저항 프로브(TRP)를 활용하였으며, TRP의 형상은 원뿔형태로 직경은 표준콘 관입실험 장비와 동일하게 35.7mm이다. 현장타설말뚝 공법 중 P.R.D(Percusion Rotary Drill) 방법을 적용하고 있는 현장에서 실험을 수행하였으며 전기비저항의 결과를 이용하여 슬라임층의 두께를 평가하였다. 신뢰성 높은 분석을 도모하고자 현장 슬라임층을 이용하여 케이싱 효과, 시간경과 그리고 상대밀도에 따른 실내 실험도 추가적으로 수행하였다. 본 연구에서는 전기비저항을 이용하여 슬라임층 두께를 산정하는 방법이 합리적임을 보여주며, 추후 다양한 지층과 말뚝 시공 공법에 적용성이 기대된다.

• Geomechanics and Engineering
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• 제8권5호
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• pp.675-685
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• 2015

Weathering is the breaking/cutting down process of rocks due to physical and chemical processes in natural as well as artificial environment including $CO_2$ injection for storage in the sediment, or natural resource recovery process. This study suggests an alternative method to estimate the degree of weathering for granites. A series of laboratory and field experiments are performed to measure electrical resistivities on various rock samples experienced different degrees of weathering and their residual soils under different saturation conditions. It is found that the normalized electrical resistivity increases with a decrease in water absorption and the saturation. Simple boundaries are suggested to identify the weathering degree of granites, based on limited data. Field test results for three sites confirm that the suggested method could be estimated well the degree of weathering of granites compared with the other methods suggested previously. Although further research is required, this study suggests that an electrical resistivity could be an effective approach to estimate the degree of weathering of granites compared with the other methods suggested previously.

• 지구물리와물리탐사
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• 제19권2호
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• pp.59-66
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• 2016

환경오염부지의 오염원은 대부분 전기비저항이란 고유물성과 상관관계를 보이기 때문에 전기비저항 탐사는 지중 환경오염조사에 매우 효과적인 방법이다. 이 연구에서는 폐기물 매립장 주변에서 전기비저항 탐사를 수행하여 매립장 주변 지역의 하부 지질구조를 규명하는 한편 침출수 존재 여부 및 영향 범위를 파악하였다. 또한, 주변 관측정의 수질분석 결과와 전기비저항 탐사의 연관성에 대해 분석하였다. 그 결과, 전기비저항 탐사는 수질분석 자료와 매우 높은 연관성을 보였으며, 시추조사 결과와도 상당히 일치하는 것을 확인하였다.

• 한국재료학회지
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• 제25권5호
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• pp.258-263
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• 2015

To fabricate porous SiC-Si composites for heating element applications, both SiC powders and Si powders were mixed and sintered together. The properties of the sintered SiC-Si body were investigated as a function of SiC particle size and/or Si particle contents from 10 wt% to 40 wt%, respectively. Porous SiC-Si composites were fabricated by Si bonded reaction at a sintering temperature of $1650^{\circ}C$ for 80 min. The microstructure and phase analysis of SiC-Si composites that depend on Si particle contents were characterized using scanning electron microscope and X-ray diffraction. The electrical resistivity of SiC-Si composites was also evaluated using a 4-point probe resistivity method. The electrical resistivity of the sintered SiC-Si body sharply decreased as the amount of Si addition increased. We found that the electrical resistivity of porous SiC-Si composites is closely related to the amount of Si added and at least 20 wt% Si are needed in order to apply the SiCSi composites to the heating element.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2010년도 추계 학술발표회
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• pp.1177-1181
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• 2010

Unsaturated soil can describe soil particles, air-water and contact face between air and water. The providing a simple method to predict water content in Geotechnical mechanics is very important. In this experiment, DIP (Digital Image Processing) and electrical resistivity techniques were used simultaneously to predict the saturation degree, and the results of two techniques will be compared each other to get conclusion. The experiment was carried out for Jumunjin standard sand. The picture of experimental column of soil and water was taken at different times, then using DIP technique to measure Color number-the height of capillary in soil column. At the same time, measure electrical resistivity of the soil.

• 전기학회논문지
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• 제61권10호
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• pp.1561-1564
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• 2012

In this work, we have fabricated the nanocrystalline carbon films by using unbalanced magnetron sputtering method with graphite and Ti targets for contact strip application of electrical railway. The power density of graphite target was fixed and the power density was increased for the increase of Ti concentration in TiC films. We investigated the hardness, surface roughness, contact angle, resistivity, HRTEM and XPS of TiC films with Ti concentration. The hardness and resistivity were improved with increasing Ti concentration. These results indicate that the improvement of hardness and resistivity is related to the increase of sp2 clusters in TiC films.

• 한국전기전자재료학회논문지
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• 제11권8호
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• pp.601-606
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• 1998

ZnO thin film had been deposited on the glass by sputtering method, and the electrical and structural properties were investigated. When the rf power was 180W and sputtering was 10 m Torr at room temperature, Al-doped ZnO thin film had the lowest resistivity(1$\times10^{-4}\Omega\cdot{cm}$) and then carrier concentration and Hall mobility were $6.27\times10^{20} cm^{-3} and 22.04 cm^2/V\cdot$s, respectively. The undoped ZnO thin film had about 10$\times10^{14}\Omega\cdot cm$ resistivity when oxygen content was 10% or more at room temperature. When the oxygen content was 50% and below and sputtering pressure was 1.0$\times$1.0 \ulcorner Torr, the surface morphology of thin film observed by SEM was overall uniform.

• 한국지반공학회논문집
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• 제29권5호
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• pp.53-64
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• 2013

전기비저항 모니터링 탐사법은 공극의 변화는 입자와 함수율의 변화에 기인한다는 사실에 근간을 두고 있다. 모든 댐에서 내부 침식은 시간이 지날수록 발생하며, 시간이 지남에 따라 누수가 집중되고 결국 댐의 파괴에 이르게 한다. 전기비저항은 제체내 공극의 변화에 매우 민감하게 변화하는 것으로 알려져 있어 전기비저항 모니터링 탐사법은 누수탐지에 효과적으로 적용되어 왔다. 그러나 전기비저항은 온도의 계절 변화와 총고용용존물, 운영수위 등의 변화에 큰 영향을 받는다. 본 논문에서 우리는 댐마루 중앙부에 영구적으로 전극을 설치하고 2011년 4월 3일부터 2012년 7월 31일까지 매 6시간 마다 전기비저항 모니터링 탐사 자료를 획득하였다. 모니터링 데이터의 해석을 위해 각 전기비저항 데이터의 2,950여개가 넘는 데이터를 분석하였다. 그 결과 전기비저항은 온도의 영향으로 계절변화에 따라 변화함을 확인할 수 있었으며, 전기비저항 모니터링탐사로부터 제체의 공극률을 산출하고 분석하였다. 댐체에서 전기비저항 모니터링 탐사의 적용성과 안정성을 확인하였으며, 신뢰할 만한 전기비저항 모니터링 데이터의 중요성을 강조할 수 있었다.