• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.872-873
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• 2008

In this paper, a new type of switchgear, electro magnetic force driving actuator (EMFA), is developed and analyzed, applicable to high voltage gas circuit breaker (HGCB). Transient analysis is performed in order to obtain the dynamic characteristics of the EMFA. The distribution of static magnetic flux is obtained using the finite element method (FEM). The governing electric and kinematical equations are solved using the time difference method (TDM). Fabrication and experiments were performed in order to prove the applicability of HGCB for overall class. In comparing the experiment with simulated data, it is confirmed that analysis of the dynamic characteristics of EMFA is appropriate for design.

• Journal of Electrical Engineering and Technology
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• v.8 no.1
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• pp.130-136
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• 2013

This paper presents the magnetic equivalent circuit analysis of a double-excited, two-degree-of-freedom (DOF) motor. The double-excited, 2-DOF motor is a laminated structure, making it easy to manufacture and giving it simple operating principles. We explain the structure of the 2-DOF motor and analyze the static characteristics using a magnetic equivalent circuit (MEC) to reduce analysis time. The feasibility of MEC analysis was confirmed by experimental results of the tilting, panning motion. We also confirmed the occurrence of holding torque in every motion.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.33 no.3
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• pp.185-189
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• 2009

Focused ion beam system was designed, which includes LMIS, electrostatic lens and high voltage power supply. Control program is updated for high speed image processing. The details of vibration-free vacuum system and other important electrical parts were trouble-shooted for appropriately controlling high acceleration voltages.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.1289-1294
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• 2008

Electrostatic discharge(ESD) phenomenon is a serious reliability concern. It causes approximately most of all field failures of IC. To quality the ESD immunity of IC product, there are some test methods and standards developed. ESD events have been classified into 3 models, which are HBM, MM and CDM. All the test methods are designed to evaluate the ESD immunity of IC products. This study provides an overview among ESD test methods on ICs and an efficient ESD stress method. We have estimated on all pin combination about the positive and negative ESD stress. We make out the weakest stress mode. This mode called a worst-case mode. We proposed that positive supply voltage pin and I/O pin combination is efficient because it is a worst-case mode.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.352-352
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• 2000

ESR(ElectroSlag Remelting) Process is secondary fine process and melts steels by electric resistance heat and fines the melting steels by an appropriate solidification process parameters which affects the melting and solidification processes to get the high quality products. This paper describes a method to derive the mathematical model and analysis the dynamic characteristics for designing a controller of the ESR processes. The ESR process consists of a melting and solidificating processes and electrical system include the contact resistance mechanism. In this paper, we consider only the static relationship between inputs and outputs of the electric system because the dynamics of the electric system is so fast compared with the melting and solidificating processes which are analysed by using finite difference method. As the results, the fine processing in ESR is analysed and the process controller could be designed based on the process dynamic analysis.

• 한국신재생에너지학회:학술대회논문집
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• 2009.11a
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• pp.348-348
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• 2009

The conductive coating method is used for various industrial fields. For example, Sputtering process is used to coat ITO layer in LCD or OLED panel manufacture process and fabricate a base layer of substrate of an electric printing device. However, conventional coating processes (beam sputtering, spin coating etc.) has a problems in the industrial manufacturing process. These processes have a very high cost and critical manufacturing environment as a vacuum process. Recently, many researchers have proposed various printing process instead of conventional coating processes. In this paper, we propose an ESD printing process in ITO coating layer and apply to fabricate a conductive coating film. Furthermore, the effect of the nozzle and also the applied voltage on different configuration of the nozzle head was also studied for better understanding of the Electro Static deposition process.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.48 no.4
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• pp.219-225
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• 1999

This paper proposes a new reactive-power compensator composed of a thyristor current-source inverter. The compensator consists of a 6-pulse thyristor bridge, dc reactor, and a commutation circuit. The commutation circuit offers the thyristor bridge to have PWM operation with minimal switching losses. The operation of proposed system was analyzed by computer simulations with EMTP and experimental works with hardware scaled-model. The proposed system would have low cost and easy expansion of operation voltage due to using the conventional thyristors.

• Journal of the Korea Society of Computer and Information
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• v.20 no.12
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• pp.29-36
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• 2015

In this paper, we propose the horizontal line detection using the Haar-like features and linear regression in infrared images. In the marine environment horizon image is very useful information on a variety of systems. In the proposed method Haar-like features it was noted that the standard deviation be calculated in real time on a static area. Based on the pixel position, calculating the standard deviation of the around area in real time and, if the reaction is to filter out the largest pixel can get the energy map of the area containing the straight horizontal line. In order to select a horizontal line of pixels from the energy map, we applied the linear regression, calculating a linear fit to the transverse horizontal line across the image to select the candidate optimal horizontal. The proposed method was carried out in a horizontal line detecting real infrared image experiment for day and night, it was confirmed the excellent detection results than the legacy methods.

• The Transactions of the Korean Institute of Power Electronics
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• v.17 no.1
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• pp.41-47
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• 2012

This paper proposes a calculation of compensation current using phase shift to eliminate ripple components of instantaneous active power under unbalanced or non-linear loads condition. The proposed phase shift method instead of existing method(LPF; Low Pass Filter) to remove ripple components and this proposed method improves performances of transient and steady state response. To compare proposed method with existing method, experiments have been done for calculating an average active power at load side. Their results show that transient response and steady state response of proposed method is improved.

• Proceedings of the KSME Conference
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• 2001.06b
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• pp.121-126
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• 2001

In this study, the 4-way spool valve characteristics are clearly defined and proposed new type of spool valve. This paper presents governing equations of the flow through clearances between sleeve and spool as a model of orifice flow for null characteristic analysis, and programmed analysis software of it. This software is possible to basically analysis that not only which case of open center, closed center or critical center but +,- displacement of spool, lab position, boundary region and spool opening of the valve, and to estimate the pressure variation in the spool and external leak flow variation. We are convinced that the scale of load pressure difference is changed as lab condition of spool valve, and this scale is changed with boundary point on the annular clearance. It is vary useful to designer and user of spool valve with this design data and analysis software.