• Proceedings of the KIEE Conference
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• 1992.07b
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• pp.922-924
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• 1992

This paper presents a CAE(Computer Aided Engineering)system for solving electrostatic field problems by means of a small size computer such as a personal computer. The system software operated on the personal computer is composed of a CAD(Computer aided Design), electric field analysis by using FEM(Finite Element Method)and DB(Data Base)of insulating materials. In addition, we discuss an application of the system to analyzing electric field such as parallel plate electrodes with an insulation spacer, which result suggests that the visualization of electric field distribution and tolerance for insulation strength enables us to assure a simplified evaluation of the insulating design.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.5
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• pp.1005-1010
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• 2011

The accidents caused by dielectric instability have been increasing in power grid. It is important to enhance the dielectric reliability of a high voltage apparatus to reduce the damage from electrical hazards. To develop an electrically reliable high voltage apparatus, the experimental study on the electrical breakdown field strength is indispensable, as well as theoretical approach. In this paper, the lightning impulse breakdown characteristics considering utilization factors are studied for the establishment of insulation design criteria of an high voltage apparatus. The utilization factors are represented as the ratio of mean electric field to maximum electric field. Dielectric experiments are performed by using several kinds of sphere-plane electrode systems made of stainless steel. As a result, it is found that dielectric characteristics are affected by not only maximum electric field intensity but also utilization factors of electrode systems. The results are expected to be applicable to designing the air-insulated high voltage apparatuses.

• Proceedings of the KIEE Conference
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• 1997.11a
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• pp.662-664
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• 1997

3-dimensional finite element method(FEM) electrical field analysis was performed to obtain electric fields on a field emission device tip in an array form. The simulation was performed by applying the Neumann boundary condition to the intermediate plane between tips. To verify our algorithm, comparison between simulation results and experimental data from another paper was made and the difference was discussed. Finally, analysis on triode structure was performed.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.67 no.3
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• pp.149-154
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• 2018

We consider the system is subject to the linearly polarized oscillatory external field. We study the optical quantum transition Line shapes(QTLS) which show the absorption power and the quantum transition line widths(QTLW) of electron-piezoelectric phonon interacting system. We analyze the magnetic field dependence of the QTLS and the QTLW in various cases. In order to analysis the quantum transition, we compare the magnetic field dependence of the QTLW and the QTLS of two transition process, the intra-Landau level transition process and the inter-Landau level transition process.

• Proceedings of the KIEE Conference
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• 1998.07e
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• pp.1650-1652
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• 1998

This paper describes characteristics of electric field waveforms associated with multiple-lightning discharges. The electric field measurment system. consists of hemi-sphere antenna 30 cm in diameter. integrator and data acquisition device. The frequency bandwidth is from 200 Hz to 1.56 MHz, and the sensitivity is 0.96 mV/V/m. The detected electric field signal is digitized every 500 ns with the resolution of 12-bit and the length of 2 kilowords and is registered at a personal computer. Also parameters of the electric fields associated with multiple-lightning discharges are ststistically analyzed.

• Proceedings of the KIEE Conference
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• summer
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• pp.926-928
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• 2004

For the permanent magnet synchronous motor(PMSM) drive to operate above the base speed in the constant horsepower region, field weakening control is applied. But field weakening control was not almost applied to sensorless control of the permanent magnet synchronous motor. In this paper, field weakening control is applied to the sensorless control of PMSM based on an instantaneos reactive power. And the effectiveness of the proposed system is verified by the experimental results.

• Proceedings of the KIEE Conference
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• 2002.06a
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• pp.142-145
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• 2002

This paper presents the electromagnetic field water treater system with the high performance for a good quality of water. The electromagnetic field water treater consists of a solion, a solion body. and a high voltage converter. The high voltage converter is controlled by PWM current controller. The high voltage converter of 13W is designed for an isolation operation ramp. an isolation current detector, and an over current protector. Using the high voltage PWM converter, the system with the proposed electromagnetic field water treater can be controlled easily. Simulation and experimental results show the effectiveness of the system strategy proposed for the scale rejection.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.4
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• pp.583-588
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• 2014

In this study, there are examined to the grounding of lightning protection system and electrical continuity tests in the field. The standard for lightning protection system is different design or construction according to the characteristics of the structure. Ground is measured and compared at least four locations. According to the measured results in the field, the sampled values of the ground resistance are measured $5{\Omega}$ or less and the difference between each value is suitable as $0.2{\Omega}$ or less. The values of the electrical continuity test between ground and metal bodies are measured 3 groups such as isolated portion, the mechanical contacted portion, and the electrical continuity portion measuring $0.2{\Omega}$ or less. It is measured to be less than $0.2{\Omega}$ at all in metal bodies of underground. A metal body installed inside the structure is not isolated, but the resistance values are higher than $0.2{\Omega}$. Therefore, It must be carried out the structure having lightning protection system confirm the LPL(lightning protection level) and design the strategy.

• Journal of Korean Vacuum Science & Technology
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• v.3 no.1
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• pp.38-42
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• 1999

Using the LOCOS process, we have fabricated the lateral type polysilicon field emission triodes with poly-Si/oxide/Si structure and investigated their current-voltage characteristics for three biasing modes of operation. The fabricated devices exhibit excellent electrical performances such as a relatively low turn-on anode voltage of 14 V at VGC = 0V, a stable and high emission current of 92${\mu}$A/triode over 90 hours, a small gate leakage current of 0.23 ${\mu}$A/triode and an outstanding transconductance of 57${\mu}$S/5triodes at VGC = 5V and VAC = 26V. these superior electrical operation is believed to be due to a large field enhancement effect, which is related to the sharp cathode tips produced by the LOCOS process as well as the high aspect ratio (height /radius ) of the cathode tip end.

• Journal of Electrical Engineering and Technology
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• v.13 no.1
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• pp.521-531
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• 2018

This paper presents a procedure for field measurements which provides a generalized Narrowband Power Line Communications (NB-PLC) channel model for low voltage (LV) access network in order to deploy advanced metering infrastructure (AMI) within Lahore, Pakistan. The measurements of allocated sites were performed in the residential (urban and rural), industrial and commercial electricity consumers for the NB-PLC channel modeling of overhead transmission lines (TLs). On the basis of extensive field measurement results, the average attenuation profile and transfer functions are presented. The results obtained from field measurements are validated by comparing them with a proposed Simulink model. A close agreement in the measured and simulated transfer function (TF) results is observed. The proposed Simulink model is an effort to model the NB-PLC channels in an effective way, especially in South Asian countries.