• Journal of Advanced Marine Engineering and Technology
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• v.27 no.5
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• pp.565-574
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• 2003

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2000.04a
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• pp.21-21
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• 2000

• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.9B
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• pp.1601-1607
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• 1999

LMDS(Local Multipoint Distribution Service) is a broadband wireless transmission system in millimeter wave frequency. LMDS system is consisted with relay system to connect between head-end and hub and distribution system to connect between hub and subscribers. In this study, we develop point-to-point relay system to use back-bone system n LMDS network. We develop STM-1 transceiver over 27GHz and analyze the system performance. We can get the similar measurement results comparing the theoretical results and then prove that this system can fit LMDS back-bone network requirement. This is the first system in Korea and we expect this system can apply the various network.

• Journal of KIISE:Computer Systems and Theory
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• v.34 no.5_6
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• pp.202-213
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• 2007

A network is an important model widely used in natural and social science as well as engineering. To analyze these networks easily it is necessary that we should layout the features of networks visually. These Graph-Layout researches have been performed recently according to the development of the computer technology. Among them, the Scale-free Network that stands out in these days is widely used in analyzing and understanding the complicated situations in various fields. The Scale-free Network is featured in two points. The first, the number of link(Degree) shows the Power-function distribution. The second, the network has the hub that has multiple links. Consequently, it is important for us to represent the hub visually in Scale-free Network but the existing Graph-layout algorithms only represent clusters for the present. Therefor in this thesis we suggest Graph-layout algorithm that effectively presents the Scale-free network. The Hubity(hub+ity) repulsive force between hubs in suggested algorithm in this thesis is in inverse proportion to the distance, and if the degree of hubs increases in a times the Hubity repulsive force between hubs is ${\alpha}^{\gamma}$ times (${\gamma}$??is a connection line index). Also, if the algorithm has the counter that controls the force in proportion to the total node number and the total link number, The Hubity repulsive force is independent of the scale of a network. The proposed algorithm is compared with Graph-layout algorithm through an experiment. The experimental process is as follows: First of all, make out the hub that exists in the network or not. Check out the connection line index to recognize the existence of hub, and then if the value of connection line index is between 2 and 3, then conclude the Scale-free network that has a hub. And then use the suggested algorithm. In result, We validated that the proposed Graph-layout algorithm showed the Scale-free network more effectively than the existing cluster-centered algorithms[Noack, etc.].

• Proceedings of the Korean Information Science Society Conference
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• 2007.10c
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• pp.169-174
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• 2007

분산 데이터를 상호 운용하기 위해서는 공유되는 정보가 효율적으로 처리 및 관리되어야 한다. 특히 레거시 시스템과 같이 이질성을 내포하고 있는 환경에서 협업을 위한 상호 운용성의 확보가 효율적인 관건이다. 따라서 본 논문에서는 레거시 시스템간의 데이터 공유 및 교환에서 발생하는 의미적 상호 운용성의 문제점을 극복하는 XMDR 메시지 기반의 하이브리드 에이전트를 이용한 데이터 허브 시스템을 제안한다. 이 시스템은 데이터 협업 시 실시간으로 변화는 데이터론 일관성 있게 유지하기 위해서 질의 변환 방법인 메시지 사상 기법을 제시하여 이용한다. 이는 레거시 시스템들 간의 협업에 필요한 데이터를 공유 및 교환하는데 실시간으로 변화하는 데이터를 일관성 있게 유지한다. 그리고 통합 검색시 단일 인터페이스를 제공하여 각 시스템의 독립성을 유지하면서 데이터의 투명성과 가용성을 향상 시킬 수 있다.

• Journal of Appropriate Technology
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• v.6 no.2
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• pp.211-218
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• 2020

Since World Health Organization (WHO) declared Pandemic about COVID-19 at 11 March, 2020, 214 countries now have more than 5.8 million confirmed cases and 360 thousand deaths (29 March 2020). The pandemic of COVID-19 caused lockdown in numerous countries and cities. Strict social distancing also affects most of fields such as health, education, politics, religion, and economy. South Korea actively uses various digital technologies to fight against COVID-19, which is introduced internationally as a successful example. This article introduces the development background and functionalities of COVID-19 Epidemic Investigation Support System (EISS) as well as Smart City Datahub, the core technology that enables the rapid development and application of EISS. Moreover, based on this example, the role and importance of horizontal common platform, such as Datahub, are discussed in the view of future city.

• The monthly packaging world
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• s.156
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• pp.182-187
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• 2006

우크라이나,골판지 틈새 시장 유망/러시아, 수입물품 약 80% 모스크바 통해 유통/싱가포르,아시아 RFID 허브 육성/중,홍콩달러 7억5천만 투자/일,제지 업체 작년 경영실적 악화/영,FSA 식품 교통신호 시스템 권장/

• Journal of the KSME
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• v.54 no.7
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• pp.34-39
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• 2014

소형 풍력발전시스템(Small wind energy conversion systems)은 대형 풍력발전시스템과 더불어 급격한 성장세를 유지하고 있다. 풍력발전시스템은 다양한 기계적 하부시스템(로터, 허브 및 기어박스 등) 및 전기적 하부시스템(컨버터/인버터, 제어기 등)으로 구성되어 있다. 이와 같이 다양한 하부 시스템의 일부분이 파손될 경우, 이는 전체 시스템의 파손 또는 정지를 야기할 수 있고 막대한 경제적 손실을 발생시킬 수 있다. 이 글에서는 대형 풍력발전시스템과 더불어 급격한 성장세를 유지하고 있으며 인간의 생활 공간에 근접하게 설치되는 소형 풍력발전시스템의 기계적 신뢰성 평가 동향에 대하여 소개하고자 한다.

• Journal of the Economic Geographical Society of Korea
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• v.13 no.2
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• pp.219-233
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• 2010

In this study, the possibility of the application of knowledge management concept in a unit of regional industrial cluster is explored based on diverse case studies. For this purpose, a new framework for knowledge management strategies in an industrial cluster was developed and a model of Knowledge Hub was suggested for the support of integrated knowledge management in an industrial cluster. Additionally, characteristics of Knowledge Hub that should be considered in the design of the Hub are discussed. The concept of Knowledge Hub in this study could be particularly useful for the promotion of innovations in linking clusters and provincial industrial clusters.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.05a
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• pp.380-383
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• 2014

Hub BLDC (Brushless Direct Current) motor is a multi-pole outer rotor-type high-efficiency electric motors and the Direct Drive Motor having permanent magnet rotor to drive shaft of the wheel, also called wheel-in motor. In this study, we design a speed controller with vector control technique using the dsPIC30f2010 16 bit micro-controller to drive Hub BLDC motor. Especially, we propose vector control method which reduce complex operation time, and design directly MOSFET inverter directly which gain high economics.