• The Transactions of the Korean Institute of Electrical Engineers
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• v.45 no.2
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• pp.301-309
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• 1996

This paper estimates the electric field effect near 765[kV] AC double transmission line with numerical data. The induced voltage and current of a human and car under who kinds of phase arrangement are calculated when each of two objects is insulated or grounded. When the calculated results of the low-reactance and superposition phase arrangement are compared, it is proved that the induced voltage and current of the former are about 30 [%] smaller than that of the latter. The induced current of a human and car are less than 0.5[mA] which is about 10[%] less than that of the American National Standard Code. Also the induced voltage and current of dead lines by other live lines are calculated. Finally the effective number and position of shield wires to reduce the field in ground level are considered. charge simulation method and surface charge method are used to simulate the 2 or 3 dimensional transmission line model respectively.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.10
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• pp.7189-7195
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• 2015

The method of moments (MoM) is implemented to simulate scattering from a PEC (perfectly electric conductor) cylinder in the TE(transversw electric) EFIE (Electric Field Integral Equation) approach. The procedure expresses the singularity integral and the hypersingularity integral in terms of an analytic function and employs a singularity isolation process coupled with numerical technique along the discretized segment to evaluate the self terms. It is known that, in the MoM technique, the choice of base functions and test functions is very important for the accuracy and convergence of the numerical analysis. Thus, in this paper, three conditions, obtained from the combination of basis functions and test functions, are adopted to get the induced currents on the PEC surface. These currents are compared to the analytical one in the relative rms current error to get the condition that shows fast convergence rate. The fast order of convergence of the current error, 2.528, is obtained under the combination of pulse basis function/delta test function.

• Journal of the Korean Ceramic Society
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• v.24 no.5
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• pp.477-483
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• 1987

Cr2O3 doped Pb(Zr0.525 Ti0.475)O3 piezoelectric ceramics were prepared from reagent grade oxide mixture, PbO, ZrO2, TiO2 and Cr2O3. Piezoelectric and aging properties of specimens were measured for various additions of Cr2O3. Generally, it has been known that aging rate decreased with Cr2O3 addition by stabilizing the domain wall. But hysteresis loops showed that the domain destabilization was occurred at high electric field (larger than 10KV/cm). In smaller additions of Cr2O3 (0-0.2mol%), aging rate increased and microcracks were created with increasing poling filed due to increasing internal stress. In larger additions of Cr2O3(0.4∼0.6mol%), aging rate decreased with increasing poling field.

• Journal of the Korean Vacuum Society
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• v.8 no.3B
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• pp.368-375
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• 1999

The Maxwell equation and the transformer equivalent-circuit model are applied to a radio frequency planar inductively coupled plasma. The spatial distribution of the vector potential, the magnetic field, and the electric field are obtained analytically. As a result, the plasma current, the mutual inductance between the coil and the plasma, and the self inductance of plasma are found to increase with increasing skin depth. The spatial distribution of absorbed power has maximum where the antenna coil exists, and has a similar profile to that of the induced electric field. The power transfer efficiency is found to increase with increasing gas pressure before a saturation around p+ 20mTorr, while it shows an increase with the plasma density before a slight decrease around a density of $5\times10^{11}/\textrm{cm}^3$.

• Proceedings of the KIEE Conference
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• 1987.11a
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• pp.33-36
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• 1987

Is this study it is proposed a method which is able to compute preciously using time-difference method to the air-gap magnetic field in electric machines take into account of eddy current induced. The air-gap magnetic field has slot harmonics which are due to the structure of machines and the shape of slot harmonics varies with the related positions of slots when the rotor moves. Accordingly, considering the influence of slot-harmonics, we coupled macro-air-gap element with first-order triangular elements in domain and used direct-convergence method for magnetic saturation.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.4
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• pp.26-32
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• 2013

The earth reflection effect on the induced voltage by line source such as power line occurring induction inteference is analyzed to scrutinize how much it would reduce the induced voltage. Using hankel transformation including bessel function, directly calculation formulae for extracting a refelction coefficient is a most important technical application in this paper since the reflection coefficient on the earth cannot be deduced by a general coefficient calculation formulae according to a plain wave. The electric field is utilized to transform the electromagnetic field into an induced voltage. The composed efficiency to a source induction voltage by an earth reflection is about a range of 60~70% for the axis constellation of each object like observation point, source position and other material parameters.

• 한국가시화정보학회:학술대회논문집
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• 2007.11a
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• pp.51-54
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• 2007

The induced-charge electroosmosis (ICEO) is a kind of electroosmotic flow which is generated by the electrical charge induced by an externally-applied electric field. That kind of electrokinetic phenomenon provides a nonmechanical technique to handle microscale flows and particles. In this work, we report that the ICEO-like flow is observed around two kinds of circular-cylindrical rod submerged in a dielectric liquid. The conductivity of the solution is varied by adding a surfactant. The flow field is visualized by the PIV method, and average flow speed shows a remarkable dependence on electrical input frequency. Interestingly, the characteristics of the flow are quite different from the conventional ICEO with respect to the flow direction and the locations of center of vortices.

• Journal of the Korean Ceramic Society
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• v.37 no.1
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• pp.12-20
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• 2000

Dielectric property of Ba-modified 0.65Pb(Mg1/3Nb2/3)O3-0.35PbTiO3 ceramics having compositions near the morphotropic phase boundary was investigated. For the specimens having Ba contents between 0 and 20 at%, the average transition temperature was decreased linearly with increasing Ba contents and the degree of hysteresis was also decreased with increasing Ba contents. The maximum dielectric constants (K), electric field induced polarization(P) and electrically-induced strain(S) were found to exihibit a maximum value at∼3 at% of Ba. The increase of S and the decrease of hysteresis by minor additions of Ba impurities indicated the development of new higher perfomance actuator materials. The composition of Ba-PMN-PT (10/65/35) may be appropriate for capacitor materials because of low hysteresis and high polarization.

• Korean Journal of Food Science and Technology
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• v.31 no.2
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• pp.410-415
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• 1999

Yakju was sterilized with high-voltage pulses of short time of a continuous pulsed electric field (PEF) system. The initial microbial counts of Yakju were $2.2{\times}10^{5}$ CFU/mL for total aerobes. The pH, acidity and electric conductivity of Yakju were 3.82, 0.37% and 1.24 mS/cm, respectively. Yakju was treated with exponential-wave formed electric pulses of 100 Hz for $0{\sim}4000{\mu}s$ under the field strength of $20{\sim}35\;kV/cm$. The lethal effect of electric fields on microorganisms was resulted from the breakdown of the cell membrane induced by the transmembrane electric potential. The critical values of the external field for the sterilization were 16.0 kV/cm for total aerobes. Logarithmic survival rates decreased linearly at low electric field strength, but curvilinearly at high electric field strength with treatment time. The sterilization of Yakju was more largely affected by the electric field strength than by the treatment time. Any changes in pH, acidity, and the growth of microorganisms were not found in the PEF treated Yakju during the storage at both $4^{\circ}C\;and\;30^{\circ}C$.

• Journal of the Korea Institute of Military Science and Technology
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• v.9 no.2 s.25
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• pp.11-19
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• 2006

The underwater electromagnetic signatures of a naval ship are mainly generated from three sources which are the permanent and induced magnetic field in the ship's hull and other ferrous components, the cathodic current electromagnetic field established by the Impressed Current Cathodic Protection(ICCP) system or the Sacrificial Anode and the stray electromagnetic fields generated by onboard equipment. These signatures can be minimized by certain design methods or installation of signature reduction equipment. In this paper, we represented the characteristic of the underwater electromagnetic signature and the signature reduction techniques for a naval ship. Also, we measured the electromagnetic field changes emitted from the real ship using the Electric and Magnetic field Measurement System(EMMS). We found that the underwater electromagnetic signature for a naval ship can be used as input or trigger signal in a surveillance system and an influence mine.