• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2008년도 하계종합학술대회
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• pp.239-240
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• 2008

A new frequency offset estimator using low cross-property of PN sequences is proposed in the orthogonal frequency division multiple access (OFDMA) uplink systems. Simulation results show that the proposed estimator improves the mean square error (MSE) performance compared to conventional estimator [2] where each user have both different timing offset and different frequency offset. In addition, the MSE performance is improved as the length of PN sequence increases.

• 한국식물생명공학회:학술대회논문집
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• 한국식물생명공학회 2005년도 추계학술대회 및 한일 식물생명공학 심포지엄
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• pp.144-144
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• 2005

• 제어로봇시스템학회논문지
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• 제13권8호
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• pp.804-809
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• 2007

Initialization problem is defined for indoor mobile robot as a whole process from arrival to normal operation in a new environment. The unstructured environment make the process much more difficult compared to industrial robot in structured environments. We propose a simple and efficient initialization process based on artificial stars on ceiling. Important task points and paths connecting task points are defined based on the corresponding artificial stars. This approach can be used for all kinds of indoor mobile robots with landmarks used for indoor localization.

• 한국환경농학회지
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• 제26권4호
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• pp.364-366
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• 2007

• 한국환경농학회지
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• 제26권3호
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• pp.267-273
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• 2007

• Journal of Magnetics
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• 제11권3호
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• pp.119-122
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• 2006

We electroplated copper-cobalt thin films on a silicon substrate, which had 150 nm thick copper seed layer. The adhesion between the two metallic layers could be increased by utilizing a proper organic additive, pulse plating technique, and high temperature annealing. The thin films exhibited columnar growth of the deposits and enhanced adhesion. This is attributed to the grain growth mechanism introduced by the additive and annealing.

• 디지털융복합연구
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• 제6권1호
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• pp.35-41
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• 2008

The digital economic environment of next generation, which digital high-technology industry appears to be the economic center of the high degree of industry structure, is expected to be developed as the existing traditional industry is merged with high tech digital one. The developing system of contents policy for digital industry means the policy and vision, and strategic structure which get the mechanism of contents industry structure to work. The promotion organization of digital contents policy is requested to secure the framework of digital contents industry based on cluster, the infra framework of digital infra culture, the infra framework of industry-academic cooperation, and the overall digital contents based on motive policy for the vitality of the youth. The application of digital contents policy may lead to establish the framework of the growth for the every unit of industry with the cluster oriented system.

• 디지털콘텐츠학회 논문지
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• 제5권1호
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• pp.41-47
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• 2004

본 논문은 요즘 급부상하고 있는 메신저 기능을 이용해서 학교 내에 구축된 교내 망의 인트라넷 환경에서 구축되어 있는 DB의 정보를 이용하는 학교의 구성원인 교수와 학생들이 좀더 쉽게 인트라넷에 구축되어 있는 정보를 확인하고 활용할 수 있는 메신저구현 및 활용에 관한 연구이다. 즉, 대학내의 구성원의 정보를 확인할 수 있도록 하고 자신이 소속된 그룹 안에서 사용자가 선택한 범위의 인원들을 자동으로 친구로 등록 하여 사용자가 일일이 친구를 추가하는 불편함을 줄여주고 인트라넷의 기능과 기타 추가 기능들을 통해 사용자의 인트라넷의 이용의 편의성을 제공하기 위한 연구이다.

• 디지털콘텐츠학회 논문지
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• 제4권2호
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• pp.203-210
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• 2003

본 논문에서는 무선 Ad Hoc 네트워크에서 실시간 트래픽에 대한 QoS를 보장하기위한 새로운 MAC 프로토콜을 제안한다. NMAC 프로토콜은 각 노드들에 대한 공정성과 실시간 트래픽에 대한 QoS를 보장하기 위하여 경쟁 구간 예약 방법과, 우선순위를 제어하는 우선순위 제어 경쟁 방법을 가진다. 본 논문에서는 제안된 NMAC 프로토콜과 기존의 CSMA 프로토콜을 시뮬레이션을 통하여 비교하고 NMAC 프로토콜의 성능향상을 보인다.

• Bulletin of the Korean Chemical Society
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• 제13권1호
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• pp.83-87
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• 1992

The ring expansion of 1,3-thiazolidines 4 derived from ${\beta}$-ketoacid derivatives to the corresponding dihydro-1,4-thiazines 1 by using the action of chlorine on 4 has been achieved. In the chlorinolysis unisolable sulfenyl chlorides 5 may be formed from chlorosulfonium ions 11 by ${\beta}$-elimination involving carbonyl activated methylene hydrogens. Addition of sulfenyl chloride to the internal double bond appears to form probable thiiranium ions 14, which in turn gave 1 with loss of acidic proton. Imminium ions 15 could be hydrolyzed easily to give enol 8. As a side reaction, dihydrothiazine that was formed was further chlorinated to produce dichlorides 16 which were rearranged readily to the chloromethyl compounds 10.