• 지구물리와물리탐사
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• 제5권3호
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• pp.199-205
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• 2002

전기비저항 탐사에서 측정되는 양은 두 전위전극 사이의 전위차이다. 이 전위차가 양일 경우에는 겉보기 비저항도 양의 값을 가지며, 음일 경우에는 겉보기 비저항도 음의 값을 나타낸다. 또한 측정되는 전위차의 부호는 전기장의 방향에 따라 좌우된다. 만약 측정방향과 전기장의 방향이 같다면, 전위차와 겉보기 비저항은 양의 값을 보이게 되며, 그 반대의 경우에는 음의 값을 나타낸다. 일반적으로 지표 전기비저항 탐사에는 측정방향과 1차 전기장의 방향이 같은 전극 배열을 사용하며, 이 방향의 1차 전기장은 2차 전기장에 비하여 항상 크다. 따라서 일반적인 전극배열을 사용하는 지표 전기비저항 탐사의 경우에는 지형이 평탄하고 잡음이 없다면 음의 겉보기 비저항은 나타나지 않는다. 그러나 시추공-시추공 전기비저항 탐사의 경우에는 1차 전기장의 방향과 측정방향이 일치하지 않으며, 경우에 따라서는 1차 전기장의 측정방향 성분이 2차 전기장의 측정방향 성분 보다 그 크기가 작을 수 있다. 이 경우 2차 전기장의 방향과 측정방향이 서로 반대일 경우에는 음의 겉보기 비저항이 나타날 수 있다. 따라서 음의 겉보기 비저항은 측정방향의 1차 전기장이 매우 작은 영역에서 발생할 가능성이 높다.

• 조명전기설비학회논문지
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• 제21권4호
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• pp.53-60
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• 2007

In this study, an experiment on the efficient construction method of plate electrodes, the influence of electric potential interference in plate electrodes, and building foundations were explored. The experimental result of the electric potential measurement was taken on the basis of the direction of movement and the condition in which the plate electrodes are laid underground in building foundations. It shows that the construction method of laying the plate electrodes vertically exhibits a more efficient reduction of electric potential in a diagonal direction and on an X axis than laying plates horizontally. For plate electrode construction in an area that has uniform conditions, the parallel joint construction method is more effective than a single construction to reduce earth electrical potential and ground resistance. In addition, a straight arrangement performs well in ground efficiency, compared to the parallel arrangement.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제51권8호
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• pp.347-353
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• 2002

This paper presents an accurate method for measuring the ground resistance in powered grounding system. Most of substations and electric power equipments are interconnected to an extensive grounding network of overhead ground wires, neutral conductors of transmission lines, cable shields, and etc. The parasitic effects due to circulating ground currents and ground potential rise make a significant error in measuring the ground resistance. The test current transition method was proposed to reduce the effects of stray ground currents, ground potential rise and harmonic components in measurements of the ground resistance for powered grounding systems. The instrumental error of the test current transition method is decreased as the ratio of the test current signal to noise(S/N) increases. It was found from the test results that the proposed measuring method of the ground resistance is more accurate than the conventional fall-of-potential method or low-pass filter method, and the measuring error was less than 3[%]when S/N is 10.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 추계학술대회 논문집
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• pp.196-201
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• 2008

In DC traction systems, a part of feedback current returning through rails becomes leakage current, illumination on a metal laid underground results from the leakage current to ground. To prevent the leakage current on rails, feedback rails almost have insulated with the ground. Insulation between rails and the ground causes that the earth method changes a isolated method in DC traction systems. the rail potential rise results in the isolated method. the rail potential rise causes an electric shock when a person touches the ground and rolling stock. To decrease the rail potential rise and leakage current, there are methods for reducing the feedback resistance and current of rails, increasing the leakage resistance, decreasing the distance between substations. But it are necessary to forecast and analyze the rail potential and amplitude of leakage current. In this paper, we modeled DC traction systems and feedback circuit to simulate the rail potential and amplitude of leakage current using PSCAD/EMTDC that is power analysis program, forecasted the rail potential and amplitude of leakage current about changing various parameters in the electric circuit. By using the simulation model, we easily will forecast the rail potential and amplitude of leakage current in case of a level of basic design and maintenance in electric railway systems, valuably use basic data in case of system selection.

• 한국한의학연구원논문집
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• 제6권1호
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• pp.69-80
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• 2000

Objectives : Assuming that the characteristic of meridian system has been similar to this of electric potentials in human body and that measurements of electric potential at well(井穴) and sea(合穴) points in branches of the twelves meridians will be representative of measurements of the twelve meridians, to measure the electric potentials in twenty healthy volunteers when they were sleeping or waking respectively, to do significance test for electric potential of meridian system between hand and foot meridian, yin and yang meridian, exterior and interior of the body, and among the five elements. Methods : When twenty healthy volunteers were sleeping, their electric potentials of well and sea points in branches of the twelve meridians were simultaneously measured by physiograph. After a minute we measured them again, totally 5 times. And then when they were waking, their electric potentials were measured 5 times by the above method. Results : Measurements were analyzed by statistical t-test, we obtained that the left side electric potential of hand or yin meridian was significantly different from that of foot or yang meridian both sleeping and waking. The right side of electric potential was the same result as the left side's. Most of the t-test was significant between exterior and interior of the body, and among the five elements. That meaned that it was partly possible to apply the ancient theory of meridians to the study of electric potential at well and sea points in branches of the twelves meridians.

• 대한의용생체공학회:의공학회지
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• 제3권2호
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• pp.65-70
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• 1982

This paper presents a new method of solving the electric potential distribution using the finite element method. The thoracic region surrounded by the body surface and the heart is discretized into finite elements and the Continuous Laplace-equation is transformed into one of the finite degrees of freedom. The current source density, the conductivity, and the excitable range is obtained by the references. From the result of simulation, it was revealed that the potential pattern of in homogeneity was much different from that of homogeneity.

• 한국한의학연구원논문집
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• 제7권1호
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• pp.85-103
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• 2001

Objectives : Assuming that the characteristic of meridian system has been similar to this of electric potentials in human body and that measurements of electric potential at well(井穴) and sea(合穴) points in branches of the twelves meridians will be representative of measurements of the twelve meridians, to measure the electric potentials in twenty aged(TAG) and fifty aged(FAG) healthy volunteers groups when they were sleeping or awakening respectively, to do significance test for electric potential of meridian system among circadian rhythms(CR) and Sasang constitutions(SC). Methods : We selected who thirty healthy volunteers were diagnosed by a blood test, urine examination and differentiation of syndromes by five viscera among volunteers. When they were sleeping, their electric potentials of well and sea points in branches of the twelve meridians were simultaneously measured by physiograph. After a minute we measured them again, totally 5 times. And then when they were awakening, their electric potentials were measured 5 times by the above method. Results : Measurements were analyzed by statistical ANOVA test, we obtained that some of the electric potentials of TAG at sleeping significantly varied with CR, SC, and at awakening some of the electric potentials of FAG also significantly did with CR, SC.

• 한국재료학회지
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• 제23권2호
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• pp.149-153
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• 2013

Delamination crack detection is very important for improving the structural reliability of laminated composite structures. This requires real-time delamination detection technologies. For composite laminates that are reinforced with carbon fiber, an electrical potential method uses carbon fiber for reinforcements and sensors at the same time. The use of carbon fiber for sensors does not need to consider the strength reduction of smart structures induced by imbedding sensors into the structures. With carbon fiber reinforced (CF/) epoxy matrix composites, it had been proved that the delamination crack was detected experimentally. In the present study, therefore, similar experiments were conducted to prove the applicability of the method for delamination crack detection of CF/polyetherethereketone matrix composite laminates. Mode I and mode II delamination tests with artificial cracks were conducted, and three point bending tests without artificial cracks were conducted. This study experimentally proves the applicability of the method for detection of delamination cracks. CF/polyetherethereketone material has strong electric resistance anisotropy. For CF/polyetherethereketone matrix composites, a carbon fiber network is constructed, and the network is broken by propagation of delamination cracks. This causes a change in the electric resistance of CF/polyetherethereketone matrix composites. Using three point bending specimens, delamination cracks generated without artificial initial cracks is proved to be detectable using the electric potential method: This method successfully detected delamination cracks.

• Interaction and multiscale mechanics
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• 제3권2호
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• pp.157-171
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• 2010

In this paper, a theoretical method has been developed for the electric double layer interaction under condition of the variable dielectric permittivity of water. Using Poisson-Boltzmann equation (PBE), for one plate and two plates having similar or dissimilar constant charge or constant potential, we have investigated the electric double layer potential, its gradient and the disjoining pressure as well as the effect of variation of dielectric permittivity on these parameters. It has been assumed that plates are separated by a specific distance and contain a liquid solution in between. It is shown that reduction of the dielectric permittivity near the interfaces results in compression of electric double layers and affects the potential and its gradient which leads to a decreased electrostatic repulsion. In addition, it is shown that variation of dielectric permittivity in the case of higher electrolyte concentration, leads to a greater change in potential distribution between two plates.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제15권3호
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• pp.1030-1050
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• 2021

The edges with "bridge characteristic" play the role of connecting the communication between regions in power optical cable network. To solve the problem of mining edges with "bridge characteristic" in provincial power optical cable network, the complex power optical cable network model is constructed. Firstly, to measure the generated potential energy of all nodes in n-level neighborhood local structure for one edge, the n-level neighborhood local structure topological potential is designed. And the minimum connected chain attenuation is designed to measure the attenuation degree caused by substituted edges. On the basis of that, the minimum connected chain attenuation topological potential based measurement is designed. By using the designed measurement, a bridge-edges mining algorithm is proposed to mine edges with "bridge characteristic". The experiments are conducted on the physical topology of the power optical cable network in Jilin Province. Compared with that of other three typical methods, the network efficiency and connectivity of the proposed method are decreased by 3.58% and 28.79% on average respectively. And the proposed method can not only mine optical cable connection with typical "bridge characteristic" but also can mine optical cables without obvious characteristics of city or voltage, but it have "bridge characteristic" in the topology structure.