• The Transactions of the Korean Institute of Electrical Engineers C
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• v.55 no.6
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• pp.328-333
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• 2006

All the plants on earth live under an electric and magnetic field because the earth is a magnet and there is an electric field between the charged cloud and the ground. It has been reported that electromagnetic fields influence both the activation of ions and polarization of dipoles in living cells of seeds and plants, though the mechanism of these actions is still poorly understood. In this paper, the effects of the electric and magnetic fields and exposure times to the germination of several vegetable seeds and its early growth have been investigated experimentally to find out the feasibility of a plant factory for mass production of clean and unpolluted vegetables. The germination rate and the growth rate of some seeds under the fields exposed were analysed and compared with those of unexposed ones. It is found that the germination rate and its early growth rate of exposed seeds under the fields were accelerated about 1.1-1.4 and 1.7-2.2 times in maximum compared with those of unexposed ones. But, however, an inhibitory effect on germination and plant early growth were shown in the case of the higher electric and magnetic fields.

• JSTS:Journal of Semiconductor Technology and Science
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• v.16 no.6
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• pp.867-872
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• 2016

We have investigated the channel mobility of AlGaN/GaN-on-Si recessed-metal-oxide-semiconductor-heterojunction field-effect transistors (recessed-MOS-HFET) with $SiO_2$ gate oxide. Both field-effect mobility and effective mobility for the recessed-MOS channel region were extracted as a function of the effective transverse electric field. The maximum field effect mobility was $380cm^2/V{\cdot}s$ near the threshold voltage. The effective channel mobility at the on-state bias condition was $115cm^2/V{\cdot}s$ at which the effective transverse electric field was 340 kV/cm. The influence of the recessed-MOS region on the overall channel mobility of AlGaN/GaN recessed-MOS-HFETs was also investigated.

• Korean Journal of Optics and Photonics
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• v.10 no.6
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• pp.494-499
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• 1999

We report on the results of holographic transmission grating that can be controlled by the applied AC electric field. We have fabricated a polymer-dispersed liquid crystal material that composed of multifunctional acrylate monomer blended with the liquid crystal mixture E7. To investigate an electro-optic properties of fabricated HPDLC, diffraction efficienties (DE) are measured as a fuction of applied electric field and density of liquid crystal. Maximum DE of about 70% is obtained about 30 wt% of LC concentration at a zero field. We have also shown that optical image was recorded in the tllm, and then the reconstructive image was switchable with the applied electric fields. ields.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.39 no.5
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• pp.508-515
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• 1990

This paper describes the corona characteristics of conductor bundle for EHV transmission line. To reduce the corona noise, the asymmetric conductor bundle to minimize the electric field of the conductor surface is proposed. The charge simulation method is used to formulate the electric field of conductor surface and the optimal arrangement of subconductor to minimize it is selected to apply the nonlinear successive quadratic programming. Through the analytical comparison and the corona cage test, it is proved that the asymmetric conductor bundle proposed in this paper can reduce the average maximum electric field of the phase conductors and the corona noise more than the conventional symmetric conductor bundle and asymmetric conductor bundle by GE.

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.396-399
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• 2008

In this study, the electric field distributions have been investigated by simulation in accordance with the various shapes of ITO-electrodes. Also we have measured the density of excited Xe atoms in the 1s5 state in discharge cell, where the gap distance of 60 um, gas pressure of 400 Torr, Xe contents of 7%, and sustaining voltage of 200 V are kept in this experiment. The maximum density of excited Xe atoms in the 1s5 state in a discharge cell for the fish-boned, T shaped and squared ITO electrodes have been measured to be $3.01\;{\times}\;10^{13}\;cm^{-3}$, $2.66\;{\times}\;10^{13}\;cm^{-3}$ and $2.06\;{\times}\;10^{13}\;cm^{-3}$, respectively. It is shown that the electric field distribution with different ITO Electrodes is essential factor for these maximum density of excited Xe atoms in discharge cell.

• Polymer(Korea)
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• v.30 no.6
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• pp.568-571
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• 2006

Poly(vinyl alcohol) (PVA)/gelatin(GEL) blend membranes were prepared under a high electric field, and their swelling and ion permeation behaviors were investigated. For alkali metal salts such as LiCl, NaCl and KCl, the permeability coefficients were increased until the electric field of 10 kV due to the decreased tortuosity, whereas they were decreased over 10 kV owing to the increase of the degree of crystallinity. The swelling ratios of the blend membranes showed the minimum values at pH 6, while the permeability coefficients exhibited the maximum values at the same condition. The minimum swelling ratios result from the repulsion effect between charged groups in acidic or basic regions, and the maximum permeabilities result from Donnan exclusion effect in the same regions. Especially, the per-meability coefficient for KCl of the membrane increased steeply to five times at $40^{\circ}C$ than below $35^{\circ}C$.

• Journal of the Korean Applied Science and Technology
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• v.35 no.4
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• pp.1206-1212
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• 2018

In this study, the polarization reversal characteristics of thin film capacitors with a thickness of 100 nm or less fabricated with ferroelectric polymer were measured and analyzed. For the fixed film thickness, polarization reversal occurred at higher coercive fields as the applied maximum electric field increased. For the fixed maximum electric field, polarization reversal occurred at the same coercive field irrespective of the thickness of the thin film. The proportional constant values between the logarithmic electric field and the logarithmic scale frequency were $0.12{\pm}0.01$ for all measurements. As a result, the ferroelectric polymer capacitors consistently exhibited polarization reversal characteristics without any size effects up to a thickness of 40 nm. This study shows the possibility of a polymer memory device that can operate at low voltage, which is useful for predicting the behavior of a low-voltage operating polymer memory device.

• Proceedings of the KIEE Conference
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• 1994.07b
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• pp.1639-1642
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• 1994

The severe conditions such as rated voltage of 800kV, gas pressure of $5kg/cm^2$ and rated lighting impulse withstand voltage of 2400kV were adopted for the design of spacers in the 800kV GIS to give a sufficient design margin. The design criteria on the maximum electric field strength of the center conductor and the insulator surface were established by considering the insulator surface characteristics, electrode area and surface effects in the unequal electric field strength of the given gap. The design parameters such as inter/outer envelope degree, thickness, inter/outer inserts, triple junction gap were determined by calculating the electric field using FLUX-2D program package and by referring to the published papers. The mechanical stress analysis was conducted on the feasible model spacers that showed good electric field distributions to confirm the sufficient mechanical design margin. The 800kV spacer designed as described above is now in the process of manufacturing.

• Journal of Magnetics
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• v.21 no.1
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• pp.102-109
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• 2016

In this paper, the theoretical and experimental characteristics of magnetic and electric fields in the vicinity of high voltage lines are investigated. To realize these measurements and calculations, we have developed some equations for two overhead power line configurations of 150 kV (single circuit, double circuit), based on Biot-savart law, image and Maxwell theories, in order to calculate the magnetic and electric fields. The measurements were done to a maximum distance from the tower of 50 m, at a height of 1m from the ground. These experiments take into consideration the real situations of the power lines and associated equipment. The experimental results obtained are near to that of the Biot-Savart theoretical results for a far distance from the tower; and for a distance close to the power line, the results from the image theory are in good agreement with the experimental results.

• Journal of the Korean Society of Safety
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• v.11 no.3
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• pp.75-80
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• 1996

This paper presents a study on characteristics and safety for human body in ELF electric and magnetic fields using statistical method. The magnetic fields from a power line can be computed given a knowledge of the currents, voltage and geometry of the line. In this paper, a statistical method for predicting the magnetic fields given the inherent indetermination of the currents is presented. But the electric field is calculated given a knowledge of the voltage and geometry of the line. The effect of unexpected fluctuations in current is modeled by the Monte Carlo simulation. The suggested method is applied to the 345kV and 765kV transmission line system, the result shows that the maximum electric and magnetic field intensity is 6.8627kV/m and 284mG in 345kV system, 2. 5590kV/m and 35mG in 765kV system, respectively.