• Proceedings of the KIEE Conference
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• 2006.07c
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• pp.1492-1493
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• 2006

Wenner 4-probe arrangement is used most widely by the method to measure soil resistivity and the measured data with the Wenner method are apparent resistivities of the soil. Therefore, the soil structure can be analyzed easily from the measured apparent resistivity, but the real soil resistivity is difficult to know correctly at a particular depth or at a specific location on earth surface. This paper introduces a method that can be used to decide the suitable burial depth and the electrode scale of a grounding rod effectively using soil structure analysis equipment based on the dipole-dipole method.

• The Journal of Engineering Geology
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• v.6 no.3
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• pp.119-130
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• 1996

The theory and numerical technique using boundary elements method (BEM) are given to solve 2-dimensional resistivity problems. Potential distributions from homogeneous resistivity model and layered model are calculated by using BEM for a point source of current injection. The potential distributions of BEM are compared with those of finite difference method (FDM) and finite elements method (FEM). Among the three numerical methods to solve 2-dimensional resistivity problem, it is proved that BEM is more efficient tool than FDM and FEM in consideration of computing storage and time as weU as the accuracy of solutions.

• Computers and Concrete
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• v.15 no.3
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• pp.461-471
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• 2015

The permeability is the most direct indicator to reflect the durability of concrete, and the testing methods based on external electric field can be used to evaluate concrete permeability rapidly. This study aims to use an experiment method to accurately predict the permeability of concrete box beam during service. The ion migration experiments and concrete surface resistivity are measured to evaluate permeability of five concrete box beams, and the relations between these results in service concrete and electric flux after 6 hours by ASTM C1202 in the laboratory are analyzed. The chloride diffusion coefficient of concrete, concrete surface resistivity and concrete 6 hours charge have good correlation relationship, which denote that the chloride diffusion coefficient and the surface resistivity of concrete are effective for evaluating the durability of concrete structures. The chloride diffusion coefficient of concrete is directly evaluated permeability of concrete box beam in service and may be used to predict the service life, which is fit to engineering applications and the concrete box beam is non-destructive. The concrete surface resistivity is easier available than the chloride diffusion coefficient, but it is directly not used to calculate the service life. Therefore the mathematical relation of the concrete surface resistivity and the concrete chloride diffusion coefficient need to be found, which the service life of reinforced concrete is obtained by the concrete surface resistivity.

• Geophysics and Geophysical Exploration
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• v.18 no.1
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• pp.14-20
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• 2015

Three-dimensional (3D) resistivity method is an effective tool in the engineering site survey because it can provide a 3D resistivity distribution of the site. In this study, we tried to find out faults, fractures and coal seams that can cause the collapse of the tunnel. We carried out 2D resistivity survey along 5 parallel lines and 11 cross lines and merged all the apparent resistivity data for 3D inversion. Finally, from the 3D resistivity image and drilling data we presented the 3D distribution of faults, fractures and coal seams that are considered the main cause of the tunnel collapse.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.05b
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• pp.26-29
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• 2001

ZnO thin film had been deposited on the glass by Evaporation Ramped method. and electrical and resistivity were investigated. Evaporation gas($O_{2}$,) pressure was 10mTorr~100mTorr, chamber pressure was $2{\times}10^{-5}$, and then ZnO film were deposited. AI-doped ZnO thin film had the lowest resistivity ($1{\times}10^{4}\;{\Omega}{\cdot}cm$), and then carrier concentration and Hall mobility were$6.27{\times}10^{20}\;cm^{3}$ and $22.04 cm^{2}/V{\cdot}s$, respectively. When ZnO film had been deposited by Ramp6ed method compared with normal method and investigated resistivity.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.10a
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• pp.1318-1327
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• 2008

Geotechnical sites in urban areas may have embedded structures such as utility lines and underground concrete structures, which cause difficulties in site investigation. This study is a preliminary research to establish knowledge base for developing an optimal technique for site investigation in urban areas. Surface-wave method and resistivity survey, which are frequently adopted for non-destructive site-investigation for geotechnical sites, were investigated to characterize effects of adjacent structures. In case of surface wave method, patterns of wave propagation were investigated for typical sets of multi-layered geotechnical profiles by numerical simulation based on forward modeling theory and field experiments for small-size model tests and real-scale tests in the field. In case of resistivity survey, 3-D finite element analyses and field tests were performed to investigate effects of adjacent concrete structures. These theoretical and experimental researches for surface-wave method and resistivity survey resulted in establishing physical criteria to cause interference of adjacent structures in site investigation at urban areas.

• Geophysics and Geophysical Exploration
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• v.6 no.4
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• pp.207-214
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• 2003

To analyze soil properties with depth in rice field, we compared resistivity distributions obtained from soil analysis with one dimensional inversion of small loop electromagnetic (EM) data. Although it didn't show consistency exactly between the two resistivity distributions, low resistivity zones in soil analysis, appeared to agree with low resistivity zones in EM result. Therefore, small loop EM method can be applied to obtain rapidly the soil properties such as salt accumulation in a rice field. If research on soil property and EM responses of unsaturated zone would be conducted consistently, small loop EM method can be used effectively to detect salt accumulated zone in agricultural area.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.03a
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• pp.961-965
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• 2009

Using much electric resistivity survey to design or preservation administration of facilities. However, By survey method that electric resistivity survey grasps special quality in base by potential difference creating artificial current in underground, Is influenced in electric resistance propensitys of various underground utilities in base. This Study selects dam 1 place that could grasp well underground situation and studied electricity interference effect by effect of underground utilities. Grasp underground utilities of dam interior, and control and observed accuracy with survey wave because various pole space. Through this Study, wish to present survey method of electric resistivity survey at design or survey of preservation administration dimension after with drawn result.

• International journal of advanced smart convergence
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• v.9 no.3
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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.

• Proceedings of the KIEE Conference
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• 1997.11a
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• pp.203-205
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• 1997

In this paper, we present a useful method of estimating earth resistivity using BP algorithm in Neural-Networks. From this method, equivalent earth resistivity(EER) can be obtained directly using training data composed of field-measured apparent resistivity and probe distance. This approach can reduce errors which is conventionally raised from manual operation of calculating EER. To evaluate its accuracy and convenience, the result of proposed method is compared to that of conventional methods, graphical($\rho$-a graph) and numerical(CDEGS program), respectively.