• Proceedings of the Korean Information Science Society Conference
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• 2004.10c
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• pp.217-219
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• 2004

이동 Ad-hoc 네트워크(MANET) 환경은 기존의 서버/클라이언트 구조인 유선 네트워크와 달리 이동 노드만으로 구성된 네트워크로서, 노드들의 이동이 빈번하게 발생하는 매우 동적인 특성을 가지고 있다. 따라서 서버의 도움 없이 노드들 스스로 네트워크 토폴로지를 효과적으로 구성하고 이를 적절히 유지하는 기법이 요구된다. 본 논문에서는 메모리, 프로세싱, 베터리와 같은 노드 정보와 가용 대역폭, 서비스중인 노드의 수와 같은 네트워크 정보를 이용하어 적응적으로 네트워크 토폴로지를 구성하는 기법을 제시한다. 이 기법은 새로운 노드의 네트워크 참여 여부를 결정하는 토폴로지 디스커버리와 기존 노드의 탈퇴 및 위지 이동 등과 같은 상황에 적응적으로 대처하는 토폴로지 유지 기법으로 구성된다. 또한 기간망에 연결되지 않는 독립 Ad-hoc 네트워크와 기간망에 연결되는 통합 Ad-hoc 네트워크 간의 빠른 전환을 위한 네트워크 설정 자가 구성기법을 제시한다.

• Proceedings of the KIEE Conference
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• 2000.07b
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• pp.735-737
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• 2000

An axial-flux permanent-magnet machine(AFPM) topology with coreless winding is proposed. In the proposed AFPM configuration. the winding consists of a hexagon-shaped coils encapsulated in fiber-reinforced epoxy resin. Due to the lack of the iron core. the overall machine structure has high compactness and lightness. The simplified design calculation of the back emf was obtained. In this study, motor design was carried out using the software package Maxwell. This paper discusses the basic design of coil winding of AFPM motor. Experimental results were taken form a prototype machine rated 0.4 Nm, 2000 rpm.

• Structural Engineering and Mechanics
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• v.35 no.5
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• pp.539-554
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• 2010

Light weight superstructure is beneficial for bridges in remote areas and in emergency erection. In such weight sensitive applications, combination of fibre reinforced plastics (FRP) as material and box-girders as a structural system have great scope. This combination offers various options to tailor structure and its elements but this flexibility poses greater challenge in optimum design. In this paper a procedure is derived for a generalised optimum design of FRP box-girder bridges, using genetic algorithms (GA). The formulation of the optimum design problem in the form of objective function and constraints is presented. Size, configuration and topology optimization are done simultaneously. A few optimum design studies are carried out to check the performance of the developed procedure and to get trends in the optimum design which will be helpful to the new designers.

• Journal of Electrical Engineering and Technology
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• v.3 no.2
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• pp.235-242
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• 2008

In this paper, a 24-pulse AC-DC converter is designed, modeled, simulated, and developed to feed non-isolated varying loads. The proposed AC-DC converter configuration consists of an auto-transformer based on zigzag connection to overcome current harmonic problems in AC mains. It improves power quality at AC mains and it meets IEEE-519 standard requirements at varying loads. A set of power quality indices on input AC mains and on DC buses for a load fed from 6-pulse and 12-pulse AC-DC converters is also given to compare their performance. It is observed that input current total harmonic distortion(THD) of less than 8% is possible with the proposed topology of AC-DC converter at varying loads.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2011.10a
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• pp.63-65
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• 2011

Current general-purpose electromagnetic field simulator has been widespread and is being used to antenna design, EMC design, measurement, and microwave device design, etc. This paper is to solve various electromagnetic problems of X-band region for the purpose multi-core-based PC utilizing network resources more efficiently, and then the electromagnetic field simulator based on TCP / IP-based network topology, configuration, and its framework design is proposed.

• The Transactions of the Korean Institute of Power Electronics
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• v.8 no.6
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• pp.519-526
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• 2003

A singl-phase power factor corrected converter for switched reluctance motor hive is presented to achieve a sinusoidal and new unity power factor input currents. Because it combines a power factor corrected converter and a conventional asymmetric SRM driver into one power stage, the configuration has a simple structure resulted in low cost. A prototype to drive 6/6 poles SRM employing a parking magnet Is designed to evaluate the proposed topology. The characteristics and operational mode will be discussed in depth, and the validity of proposed driver will be verified through the experimental results.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.05a
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• pp.62-67
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• 2002

A single-phase power factor corrected converter for switched reluctance motor driving is presented to achieve sinusoidal, near unity power factor input currents. Because it combines a power factor corrected converter and a conventional asymmetric SRM driver into one power stage, the configuration has a simple structure resulted in low cost. A prototype to drive 6/6 poles SRM employing a parking magnet is designed to evaluate the proposed topology. The characteristics and operational mode will be discussed in depth, and the validity of proposed driver will be verified through the experimental results.

• Proceedings of the KIEE Conference
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• 2005.10c
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• pp.329-333
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• 2005

In this study paper, a 3[kW] Fuel Cell Generation (FCG)system with Fuel Cell(FC)simulator has been proposed. The developed FC simulator generates the actual voltage and current output characteristics of the Proton Exchange Membrane Fuel Cell (PEMFC), so that the overall performance and the dynamics of the proposed system could be effectively examined and tested. In this paper, at first, the system configuration and operational principle of the developed FC simulator has been investigated and the design process of the FCG system is explained in detail. In addition, the validity of the proposed system has been verified by the informative simulation and experimental results.

• 한국IT서비스학회:학술대회논문집
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• 2006.11a
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• pp.366-371
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• 2006

To compensate the loss of leased-line subscribers and the excessive increase of residential xDSL (Digital Subscriber Line) ones of KT (Korea Telecom), the paper proposes the service model by which it can reinstate the subscription ratio status through employing next generation OSS (Operations Support System) and highquality MPLS (Multiprotocol Label Switching) VPN (Virtual Private Network). It also describes diverse modules comprising NeOSS (New OSS) of KT, followed by detailed accounts regarding the service delivery process of KT VPN. Shortly visited are the primary constituents as well as configuration parameters of MPLS VPN. Finally the network topology along with a feasible service model case is presented.

• Journal of Institute of Convergence Technology
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• v.7 no.2
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• pp.1-5
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• 2017

The rotating electrodynamic wheel over a conductive plate produces thrust force as well as normal force. Specially, separating the conductive plate and spacing apart each part, the lateral stability of the rotating wheel is guaranteed due to the restoring force into neutral position. In this paper, the force characteristics of the electrodynamic wheel rotating over the conductive plate is analyzed using the finite element tool. First, the dominant parameters are identified considering the geometric configuration and the operating condition. And the sensitivity for the parameter deviation is quantified for the high force density. The above topology can be applied as an actuating principle for inter-city train as well as contact-free transfer device.