• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.20 no.2
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• pp.129-134
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• 2009

In this paper, we proposed a miniaturized Balun-BPF structure using semi-lumped line The conventional Ring Balun-BPF relatively has a big size structure because they consist of two ring resonators, wide line width ring-resonators for low loss and $\lambda/4$transmission line inverters. The ring resonators are miniaturized to 1/4 size by semi-lumped line and we added triangle patches in the ring resonator for compact Balun-BPF structure. The fabricated Balun-BPF is miniaturized to 1/4 size and contains symmetrical output characteristics of balance ports.

• Journal of Navigation and Port Research
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• v.32 no.5
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• pp.363-368
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• 2008

This paper presents a miniaturization design technique of radio frequency identification (RFID) tag antenna operated in 910 MHz band. Miniaturization structure design for a tag antenna is performed by structure application of the folded dipole and meander line. In order to realize the maximum power transmission, imaginary part of a chip impedance and a tag antenna impedance is matched by complex conjugate number. The optimized tag antenna size is $50\;nm\;{\times}\;40\;nm\;{\times}\;1.6\;nm$ and its size is reduced about 62 % comparison with antenna size of reference [4]. The measured results of fabricated tag antenna are confirmed the reasonable agreement with prediction. The read range of the tag antenna with chip observed about 5 m.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.14 no.6
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• pp.110-116
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• 2015

In this paper, a compact low-loss reflector-type phase shifter with harmonic suppression using meander T-shaped branch-line coupler is suggested. The compact coupler for the phase shifter has a size of $22.2{\times}14.9mm^2$ while a conventional branch coupler has a size of $32.6{\times}27.8mm^2$. The phase shifter shows insertion losses of 0.19-0.28 dB at the center frequency of 2.1 GHz, and a measured maximum phase shift of $137^{\circ}$.

• Journal of Advanced Marine Engineering and Technology
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• v.38 no.1
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• pp.70-77
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• 2014

In this work, we studied basic characteristics of transmission lines employing various PSS (periodic strip structure) on silicon substrate for application to a miniaturization of RF components. According to the results, the transmission lines employing various PSS showed wavelength shorter than conventional coplanar waveguide due to their strong wave characteristics. Especially, with-contact structure was most effective for a miniaturization of RF component. Concretely, the size of the transmission line employing with-contact was only 4.39 % of the conventional coplanar waveguide, According to the bandwidth extraction result, the bandwidth of the transmission lines employing various PSS structures were wider than 384 GHz. Above results indicate that the transmission lines employing various PSS can be effectively used for application to a broadband and miniature RF component, and especially, with-contact is most effective for a miniaturization of RF components.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.5 no.2
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• pp.109-112
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• 2007

The possibility and limitation of one dimensional nano scale electron shielder is briefly discussed. A Nano scale electron shielder will reduce the weight and size of shielding materials. However, practical application still requires further research. In this work, we discuss general problems related to nano scale electron shielder, by taking an arbitrary one dimensional potential barrier as an example.

• Proceedings of the KIEE Conference
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• 2006.07a
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• pp.302-303
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• 2006

최근 디지털기기의 개발 및 활발한 보급으로 전력산업에서도 운영시스템이나 설비들이 통합, 소형화되거나 다양한 기능을 보유하는 등 많은 변화가 진행되고 있다. 보호계전기 분야도 예외가 아니어서 우리나라의 많은 154kV배전변전소에는 기존의 유도원판형(Induction disc type) 보호계전기가 점차 철거되고 기계적인 동작시간을 고려하지 않아도 되는 디지털보호계전기의 설치비중이 급속히 확대되고 있는 중이다. 하지만 아직까지 우리회사의 배전선로 보호협조 운영기준은 아날로그 유도 원판형 보호계전기를 고려하여 제정되어 있기 때문에 합리적인 배전계통운영을 위하여 보호협조 운영기준도 디지털 환경에 알맞도록 개선되어야 할 것이다. 이 논문에서는 배전변전소에서 사용 중인 아날로그와 디지털보호계전기의 특성 및 차이를 비교 검토하고, 디지털 환경에 적합한 배전선로 보호협조 방안도출을 위해 "디지털계전기 기반의 배전선로 보호협조 최적운용방안"을 제시하여 보고자 한다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.10a
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• pp.609-611
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• 2013

There's little to obstacles obstructing communication in the sky. There are nearly fixed obstacles obstructing communication on the ground. But communication disruption can be occur frequently and unexpectedly on the sea surface. Especially, it is difficult for a small station which can be greatly affected by waves and low antenna height to secure the LOS for radio communication. In this paper, LOS and minimum antenna height is calculated due to changing wave height and Tx/Rx antenna height on the sea surface.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.39 no.2
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• pp.134-142
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• 2003

Most of the vibration and noise generating in small boats come from shipboard machinery such as main engine, generator and auxiliary machinery etc. In order to build up the comfortable environment for the crew and to reduce the ambient noise, and provide basic materials for reasoning selection application, the design under allowable vibration & noise conditions and the examination of vibration condition of the new ships, this paper researches the frequency spectrum and order analysis of vibration and noise. The obtained results are summarized as follows : Through comparing the small boat internal noise with the regulation of IMO and DNV, it revealed that the noise level of main engine room accords with the standard, and the noise of other places are beyond the values. In this paper, two boats are analyzed, which are same type, same size and power, but the main engines noise of them is different. In order to search the noise source, the noise of main engine room and relative parts are measured. The third order of measured points is dominant in frequency domain by the order analysis.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.05a
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• pp.279-280
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• 2010

• Proceedings of the Optical Society of Korea Conference
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• 2005.02a
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• pp.236-237
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• 2005