• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.231-232
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• 2008

The proposed cavity-backed slot antenna is comprised of baffles, reflectors and thick ground plane. The baffles and reflectors are used to increase an antenna gain, thus reducing the coupling among slots on a thick ground plane. The height of the baffle and reflector were altered and the characteristics of corresponding $2{\times}2$ cavity-backed slot array antennas were measured separately. Themeasured antenna gains were above 15dBi, at f=42GHz and a wide impedance bandwidth over 27% at a center frequency of 42GHz.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.11a
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• pp.400.2-400
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• 2002

Recently rotating machines have became high speed and high Power and light weight. Bearings are one of the main components which influence power loss and stability of rotating machines. Appropriate bearing should be selected with considering characteristics of rotating machine. Floating ring journal bearing(FIB) consists of an inner film and outer film, and possess high damping and stability. FJB has been for adopted into turbocharger for the high stability at high operating speed. (omitted)

• Journal of the Korean Institute of Telematics and Electronics A
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• v.31A no.2
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• pp.53-59
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• 1994

The characteristics of the shielded suspended substrate strip transmission line(SSSL) are analyzed by the point matching method and the variational method in Quasi-TEM mode. The accuracy of this solution is confirmed by analyzing and comparing this solution with the empirical solution obtained from the same dimension. The characteristic impedance and the effective dielectric constant are also studied by increasing the air-layer height of SSSL.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.34D no.7
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• pp.71-78
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• 1997

In this paper, we analyzed the crosstalk characteristics of LD array modules for WDM and improved the crosstalk levels using a screening line between access lines. From the calculation resutls, we have found that inductive crosstalk of access lines is dominant for the low impedance LD arrays with short bondwire interconnections. The proposed array interconnecton with the screening line and ouble bondwires, rduces the crosstalk level about 10dB compared to conventional interconnections using simple access lines and a single bondwire. This proposed structure also can be easily imlemented with transmission reliability.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 1999.11a
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• pp.172-174
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• 1999

In this paper the approximated analysis method of industrial distribution system using PTW(Power Tools for Windows). System input data, cable impedance and transformer data etc., were calculated by the approximated method using EMTP(Electro Magnetic Transient Program). The effectiveness of this method was improved by electrical characteristics analysis of real factory.

• Journal of the Korean Institute of Navigation
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• v.20 no.3
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• pp.97-105
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• 1996

Authors have studied characteristics evalution on semianechoic chamber. And authors also find that in case of low frequencies like from 30MHz to 100MHz there are big differencies between the calculated and the measured site attenuation in semianechoic chamber made with ferrite grid. This is on account of not being considered the mutual coupling effects between two antennas. Accordingly Authors calculated site attenuation due to mutual coupling effects and compared the measured site attenuation with the calculated site attenuation with mutual coupling correction. As a result good agreement between site attenuation, measured or calculated is obtained.

• Proceedings of the KIPE Conference
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• 1998.07a
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• pp.123-128
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• 1998

This paper describes the evaluation of a force-reflecting interface with ultrasonic motors(USMs). The force-reflecting interface allows a human to feel object within virtual environment. To effectively display the mechanical impedance of the human hand we need a haptic device with specific characteristics, such as low inertia, almost zero friction and very high stiffness. USMs have attracted considerable attention as the actuator satisfied these conditions. USMs combine features such as high driving torque at low rotational speed, high holding torque and fast response therefore we studied two degree of freedom force-reflecting haptic system.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1997.04a
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• pp.681-686
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• 1997

Foamed aluminum is well known metallic porous sound absorption material which has excellent properties of light weight and high absorbing performance. For the purpose of finding out the sound field characteristics within a simple closed cubic enclosure with foamed aluminum, analytic and experimental studies are performed. For the first time, the standing wave apparatus is used to measure absorption coefficient and impedance of the foamed aluminum. Next, the sound effects of absorption material in acoustically loaded rectangular enclosure are identified according as the foamed aluminim is to be or not.

• Proceedings of the KIEE Conference
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• 2001.11b
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• pp.130-132
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• 2001

This paper discusses the operation zone of distance relay on transmission line connected unified power flow controller(UPFC). Depending on operating conditions of UPFC, the trip characteristics of distance relay is influenced by the prefault conditions. In this paper, apparent impedance of distance relay influenced by the UPFC control of distance is calculated.

• Proceedings of the Membrane Society of Korea Conference
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• 1998.04a
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• pp.49-52
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• 1998

1. 서론 : 화약이나 고체 충진제, 고체로\ulcorner 추진제의 산화제, slurry blasting agent 및 동물사료의 식품첨가제로 사용되고 있는 과염소산은 발화나 폭발성이 매우 강한 산화제로 정확한 순도를 측정하는 것은 중요하다. 용량분석법과 중량분석법에 비교하여 조작이 간단하고 편리한 과염소산이온의 농도를 직접 측정할 수 있는 PVC막 전극에 대한 많은 연구가 진행되고 있다. (생략)