• ETRI Journal
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• v.31 no.5
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• pp.622-624
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• 2009

This letter presents a compact 2.5 Gb/s burst-mode receiver using the first reported monolithic amplifier IC developed with 0.25 ${\mu}m$ SiGe BiCMOS technology. With optimum avalanche photodiode gain, the receiver module can obtain a fast response, high sensitivity and wide dynamic range, satisfying the overhead timing and various power specifications for a 2.5 Gb/s next-generation passive optical network (PON), as well as a legacy 1.25 Gb/s PON in the upstream.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.1
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• pp.65-69
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• 2010

Supercapacitors as novel energy storage devices between conventional capacitors and batteries, with more specific capacitance and energy densities than conventional capacitors and more power densities than batteries are to be used in many fields. And, social demand on fuel economy and reducing pollution needs equipment of new function such as energy storage system with good power performance, high cyclability and good energy efficiency. Supercapacitor is regarded as one of good alternatives for meeting the requirement of market with excellent power performance and high cyclability. This paper deals with the fundamental characteristics of supercapacitor unit and charge and discharge behavior of supercapacitor module for developing 42V hybrid energy storage system with lead acid battery and supercapacitor in order to adopt to 42V power net for vehicle.

• IE interfaces
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• v.16 no.4
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• pp.432-440
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• 2003

The inter-organizational business process is one of the hot issues in B2B e-commerce. In this paper, through the survey of the inter-organizational business process integration and the analysis of B2Bi related standards, e.g., BPML, WSDL, WSCI, and BPSS, we propose a method of linking BPML and BPSS specifications that can be used to integrate private processes with the public processes among enterprises. We also suggest an application example of the method by redefining a PIP of RosettaNet to the BPSS specification. The basic principle of the method is to maintain the independency of the existing BPML and BPSS applications and to construct an intermediary transformation module between the two applications.

• ETRI Journal
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• v.39 no.3
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• pp.383-389
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• 2017

A small dual-polarized base station antenna with a simple isolation patch is presented. A high isolation is achieved when using a shorted metallic isolation patch. The experimental results indicate that the measured impedance bandwidth of the proposed antenna is 1.72 GHz to 1.89 GHz for small cell systems and that the isolation is more than 30 dB. The proposed antenna exhibits good radiation patterns with a peak gain of 8 dBi.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2015.11a
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• pp.347-348
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• 2015

Ni 도금 및 표면 거칠기에 따른 열전모듈의 접합강도 특성을 알아보기 위해 Bi-Te 소재 위에 Sand-blasting 방법을 사용하여 표면 거칠기를 조절하고, Ni-P 무전해 도금을 수행하였다. 접합강도 측정 및 표면 성분을 분석하기 위해 전단응력 측정기, FE-SEM을 이용하였다. Sand-blasting과 Ni 도금을 실시한 시편이 sand-blasting과 도금을 미실시한 대조군보다 전단응력이 높았고, 큰 방 수의 sand로 sand-blasting 한 시편일수록 전단응력이 더 높은 경향성을 보였다.

• Journal of Sensor Science and Technology
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• v.20 no.2
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• pp.77-81
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• 2011

This paper presents a single-pole eight-throw(SP8T) switch based on proposed a radio-frequency(RF) microelectromechanical systems (MEMS) switches. The proposed switch was driven by a double stop(DS) comb drive, with a lateral resistive contact. Additionally, the proposed switch was designed to have tapered signal line and bi-directionally actuated. A forward actuation connects between signal lines and contact part, and the output becomes on-state. A reverse actuation connects between ground lines and contact part, and the output becomes off-state. The SP8T switch of 3-stage tree topology was developed based on an arrangement of the proposed RF MEMS switches. The developed SP8T switch had an actuation voltage of 12 V, an insertion loss of 1.3 dB, a return loss of 15.1 dB, and an isolation of 31.4 dB at 6 GHz.

• Proceedings of the KIPE Conference
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• 2015.11a
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• pp.50-51
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• 2015

본 논문에서는 다수의 PV-부스트 컨버터를 입력으로 하는 계통연계형 풀브리지 인버터의 DC링크 커패시터간 전압 균등화 방법을 제안한다. 다수의 PV가 입력으로 연결된 인버터의 경우 각 PV의 부분 그늘짐 현상과 같은 조건에 따라서 최대 전력점이 달라질 수 있다. 각각의 PV와 연결된 부스트 컨버터의 출력 은 인버터의 DC링크 커패시터로서 각각이 직렬로 연결되는데 각 전압 분배는 PV의 입력에 따라 결정되게 된다. PV의 발전조건이 바뀌어 부스트 출력전압 편차가 극심해져서 더 이상 부스트 컨버터로서의 역할을 할 수 없는 조건이 갖춰진다면 PV에서의 안정적인 발전을 기대할 수 없을 것이다. 또한 DC링크 커패시터 간 전압의 불균형은 시스템을 설계함에 있어서 소자의 더 넓은 범위에서의 동작조건을 만족시켜야 하기 때문에 효율 면에서 나쁜 영향을 미치게 된다. 시뮬레이션을 통해서 DC링크 커패시터 간 전압 균등화 방법을 검증하였다.

• Annual Conference of KIPS
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• 2012.04a
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• pp.522-524
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• 2012

IT 사회의 변천에 따라 더욱더 중요시 되는 것이 컴퓨터 시스템 보안이다. 이 보안에 대한 위협 요소를 줄이기 위해서 TCG(Trusted Computing Group)은 TPM(Trusted Platform Module)이라는 반도체 칩을 기반으로 한 신뢰성 플랫폼을 제안하였다. 본 논문은 네트워크 서비스의 기술발전에 따른 모바일 환경에서의 TPM 칩을 기반으로 동작하는 컴퓨팅 환경의 신뢰 상태 및 시스템 자원에 대한 상태 정보를 실시간 모니터링한다. 또한 모니터링 중인 컴퓨터 시스템의 프로세스에 대해 BiT Profiling 기법을 통한 분기 명령 추적을 모니터링하며, 이를 통해 사용자가 능동적인 대처가 가능하도록 한다.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.15 no.2
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• pp.111-118
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• 2016

This paper presents an X-band (9.375 GHz) $1{\times}2$ array microstrip antenna which is capable of active beam compensation for installation of an unmanned aerial vehicle (UAV). First of all, a basic $1{\times}2$ array microstrip antenna incorporated with wilkinson power divider was designed and performance of the array antenna was verified. Next, to verify beam steering performance of the designed array microstrip antenna, we fabricated a phase shifter, and the wilkinson power divider as module structure and measured characteristics of beam steering according to phase shifting. The main lobe is 0.6 dBi at $0^{\circ}$, and the side lobe decreased 18.8 dB. The reliable radiation pattern was achieved. Finally, an active beam steering microstrip array antenna attached with the phase shifter and the power divider on the back side of the antenna was designed and fabricated to install wing of UAV for compactness. The maximum gain is 0.1 dBi. Therefore, we obtained a basic antenna technology for compensating beam error according to wing deformation of an UAV installed array antennas.

• Journal of IKEEE
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• v.16 no.1
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• pp.62-68
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• 2012

The planar microstrip antenna for the safety communication of life at sea is designed and manufactured to effectively receive the emergency wireless signal from the transmitter on the life vest. The proposed microstrip antenna in this paper is easy to make, light weight and cheap compared to other antennas because of printed antenna fabrication. To overcome the narrow bandwidth, large size and low gain characteristics of microstrip antenna, we use the IDMA(Identical Dual Patch Microstrip Antenna with Air-Gap) structure. The proposed antenna was fabricated with the use of 1.6mm FR4 and measured with the 28.7MHz(6.6%) of bandwidth and 3.04dBi of gain at the frequency of 426MHz. To validate the proposed antenna, we experimented the possible distance range at sea using the commercial UHF transceiver module and obtained over 5km distance for stable communication. This antenna can be widely applied to application of the UHF wireless mobile communication.