• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.12 no.3
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• pp.89-98
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• 1998

Some analytic results for a solenoid eddy current coil to test nondestructive conducting materials are described in this paper. Normalized impedance of solenoid coil encircling cylindrical conducting tubes or tow-conductor rods is analyzed. Electrical and magnetic properties such as conductivity, permeability and exciting frequency as well as the geometric ones of fill factor or radius ratio of the conductor are also considered. Impedance characteristics of the models obtained by numerical analysis are examined. Validation of the model is carried out using several samples of non-ferromagnetic conducting tubes and 2-conductor rods.

• Progress in Superconductivity and Cryogenics
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• v.9 no.3
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• pp.1-4
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• 2007

The current profiles in a coated conductor with transport current were calculated using an iterative inversion method from the data of the magnetic flux density profiles measured. The applied current was increased from 0 to 60 A by 10A step and decreased down to -60A by 20A step. The magnetic flux profiles were measured at a distance of 400 mm above the surface of the coated conductor using a scanning hall probe method. The current profiles calculated were very different from the Bean model: current density profile is not a constant in the critical region. However the aspect of the change of the current and magnetic flux density profiles in the case of decreasing applied current are similar to the theoretical calculations in Brandt's paper.

• International Journal of Railway
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• v.3 no.2
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• pp.46-53
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• 2010

Electric railroad systems consist of rolling stock, track, signal and catenary system. In the catenary system, one of the most important factors is the impedance according to the design and characteristic. Before the catenary system is designed, the impedance should be precedently researched. The railroad catenary system is complex system which is composed by five conductors. The five conductors classify up and down feeders, up and down contact wire group, rail group. Therefore, we should compose the catenary system of the equivalent five-conductors model. In this paper, we suggest a geometrical model and a equivalent conductor model by using geometric mean radius of five conductors in the catenary system. Also, we calculate demanded parameter values in the model. By using those, line constants of five conductors are analyzed by applying the equivalent method called as the condensed joint matrix.

• Progress in Superconductivity and Cryogenics
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• v.20 no.1
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• pp.19-22
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• 2018

The thermal and electrical properties of the conductor are critical parametersfor the design and optimization of the superconducting magnet. This paper presents simulation code to analyze electrical and thermal stability characteristics of the second generation (2G) high-temperature superconductor (HTS) by varying copper stabilizer thickness. Two types of commercial 2G HTS coated conductor tapes, YBCO and GdBCO were used in this study. These samples were cooled by Liquid Nitrogen ($LN_2$) having boiling at 77.3 K and an equivalent electrical circuit model for them is choosen and analysed in details. Also, an over-current pulse test in which a current exceeding a critical current was performed. From the simulation results, the influences of the copper stabilizer thickness on the stability characteristics of these samples are presented.

• Journal of the Korean Society of Safety
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• v.13 no.3
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• pp.80-87
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• 1998

This paper presents a study on the development of discharge model and computer program for assessing the risk of electrostatic discharge(ESD) of charged human body This ESD event is modelled as a two-body problem using spherical conductors, simulating the approach of a charged conductor (human body) to a second conductor (electronic equipment). The charge/discharge process for the model is formulated as a matrix of equations by Maxwell's method. Body potentials, energies and the charge transfer during a discharge are calculated. The developed program, based on the suggested scheme in this paper, is applied to a sample system. The results provide a better understanding of ESD event and demonstrate the usefulness of two-body model in practical applications.

• 한국초전도학회:학술대회논문집
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• 2008.08a
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• pp.38-38
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• 2008

• Proceedings of the KIEE Conference
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• 1998.07a
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• pp.113-115
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• 1998

This paper presents the indirect boundary integral equation method(BIEM) to analyze 3D moving conductor problem. Instead of an artificial upwind algothm, the proposed method uses a fundamental Green's function which is a particular solution of diffusion equation. Therefore, this method yields a stable and accurate solution regardless of the Peclet number. The indirect BIEM is compared with 3D upwind FEM for a numerical model which has analytic solutions.

• Wind and Structures
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• v.3 no.4
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• pp.243-253
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• 2000

To develop galloping suppression devices, it is important to understand the effects of wind turbulence on galloping and to establish an evaluation method which takes 'large conductor deformations' into account. This paper introduces some findings on galloping in gusty wind obtained by numerical simulation using a model based on the Mogami Test Line of the Tokyo Electric Power Co. The equations of motion of the conductor are based on the Lagrangian formulations by Simpson, and they are made discrete in accordance with a finite element method.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.56 no.3
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• pp.148-154
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• 2007

In this paper, characteristics of ignition voltage and current by wire length of HID(High Intensity Discharge) lamp circuit are analyzed. In the construction field, decision of the wire thickness for HID lamp circuit has the problems, and these are presented. Through transmit parameters, equivalent model of the ballast and HID lamp circuit was derived. The graph of voltage reduction about length between the ballast and the lamp is shown. The simulation of proposed model and experimental results are presented in order to validate the proposed method. The proposed model and graph can use to choose the proper length of wire between the ballast and the lamp in the field.

• Journal of the Korea Society of Computer and Information
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• v.9 no.4 s.32
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• pp.93-97
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• 2004

This paper proposed that a small type conductor surface open-loop antenna model for the moisture sensor and its operating characteristics were analysed numerically by using the moment methods. The numerical analysis results from this antenna model showed that this antenna could match the input impedance to $50[{\Omega}]$ by changing parameters of the antenna in the frequency range from 300[MHz] to 500[MHz]. This model also showed that the open-loop radius. height and wire width give a tremendous influence on the antenna resonance variation. while the loaded inductance values affects the variation or the input impedance at the resonance frequencies.