• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• v.5B no.4
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• pp.324-330
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• 2005

The complex sensorless control scheme is not practical for use in the field of home appliance systems because it is not economical. Therefore, it is necessary to introduce a simplified sensorless control scheme that is composed of least calculation to estimate the rotor position. This paper presents the principle of the rotor position estimation with comparison of the estimated flux linkage and reference flux linkage. In order to verify the feasibility of the control scheme, ACSL is used for the simulation and TI DSP TMS320F240 is used for the experiment.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• v.2B no.3
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• pp.109-114
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• 2002

This paper analysis the transient performance of the modified excitation system using 4-quadrant chopper for a synchronous machine connected to HVDC system. Conventionally, capacitors are used to supply reactive power requirement at a strong converter bus. And the installation of a synchronous machine is essential in an isolated weak network to re-start after a shutdown of HVDC and to increase the system strength. However, a conventional static excitation system has some problems which are harmonic instability and the system stress due to overvoltage. To reduce these problems, the new excitation system, which has 4-quadrant chopper, is proposed. As the proposed system provides the capability to allow reverse current and isolate between AC network and excitation power, problems of overvoltage and harmonic instability can be solved. The investigation is performed and confirmed by the time domain digital simulation using PSCAD/EMTDC program.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• v.2B no.3
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• pp.90-94
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• 2002

The line start permanent magnet (LSPM) motor has been developed facilitate to the design of the synchronous motor. The rotor of this motor is composed of interior permanent magnets and aluminum bars instead of rotor windings. It is difficult to predict the performance characteristics accurately, because many characteristics are produced by the aluminum rotor bars and the permanent magnets. Therefore, in this paper the dynamic characteristics of the LSPM motor are described and compared via the time-stepped finite element method with those of the cage-type induction motor to find the characteristics of the permanent magnets and the rotor bars in the LSPM motor.

• Proceedings of the Korean Society of Computer Information Conference
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• 2018.07a
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• pp.73-75
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• 2018

디지털 콘텐츠의 영역을 확장하여 발달된 기술을 반영한 다양한 디지털 콘텐츠 기술이 발달하고 있다. 가상현실, 증강현실, 컴퓨터그래픽, 홀로그램, 오감 인터랙션, 지능형 스마트 미디어 유통기술이 그것인데 이 중 지능형 스마트 미디어 유통기술이란 IoT, 클라우드, 빅데이터 기반 개인 맞춤형 콘텐츠 유통기술, 영상정보를 검색하여 방송, 모바일 등 연관콘텐츠를 제공하는 유통기술(Visual Browsing) 등을 말한다. 이 논문에서는 디지털 콘텐츠 중 지능형 스마트 미디어 유통기술을 안전하게 개발하고 발전시키기 위하여 블록체인 방법을 활용한 스마트 미디어 유통기술에 대하여 연구하였다. 블록체인 기반 기술을 통하여 스마트 미디어 유통 시 해킹으로부터 데이터 원본 보호의 안전함을 제공하고 유통 시 필요한 저작권관리 및 유통 기록을 위 변조 없이 관리할 수 있다.

• International Commerce and Information Review
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• v.6 no.2
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• pp.147-168
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• 2004

Owing to the digital revolution, Internet Commerce and Electronic Commerce is having a profound influence on the global trade and internal commerce, revolutionizing the way of doing business. e-Trade have adopted in order to the reshape of the International Trade enterprise's competitiveness, and it is now being utilized as a major export marketing instrument to develop new customers, save export transaction costs ad facilitate new work processes. The purpose of this study is to provide a program for activation in e-Trade of the International Trade enterprise in Kangwon Do. However, at present, the environment of e-trade Infrastructure in Kangwon Do is very poor. Therefore, this study points out the problems of e-trade of the International Trade enterprise in Kangwon Do and provides many considerations for a program for activation of e-Trade.

• Korean Institute of Interior Design Journal
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• v.14 no.3 s.50
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• pp.234-242
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• 2005

Interface is a medium or channel to communicate between human and things, while interaction is the manner of communication between them. Interaction design is designing experience of user through the interaction process for human, thing, system, and space. Richard Buchanan suggests four kinds of interaction: interface (person to thing interaction), transaction (person to person interaction), human interaction (human and environment interaction) and participation (human to cosmos interaction). With digital technology, architecture and space design have made various experiments at form, function, and content of space. Space evolves from a physical container to a stage to provide narrative and create new experience to users. Since understanding users, creating experience, efficient space design, content planning, and applicable technology are required for interaction design in space, multi-disciplinary research and cooperation is needed.

• Proceedings of the Korea Information Processing Society Conference
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• 2003.05c
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• pp.1913-1916
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• 2003

전자상거래 일반적인 구조인 SET(Secure Electronic Transaction)프로토콜은 비밀키 알고리즘의 DES(Data Encryption Standard), 공개키 알고리즘의 RSA(Rivest, Shamir, Adleman), 메시지 다이제스트의 SHA-1를 사용하고 있다. 본 논문에서는 비밀키 알고리즘의 DES를 이용하여 수신측에 전송하는 과정을 3BC알고리즘으로 대체함으로서 생략하였고, 공개키 알고리즘의 요소를 ECC(Elliptic Curve Cryptosystem)알고리즘을 사용하였다. 또한 전자서명을 위한 방법은 Double Signature를 사용하여 SET프로토콜에서 DES의 전송을 위한 전자봉투를 삭제한 결과 수행시간의 단축과 보안의 강도를 강화시켰다.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• v.4B no.3
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• pp.103-107
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• 2004

Recently, greater attention has been paid to the high-speed generator for its many merits, such as ease of installation, high efficiency and high power density. However, due to their high fundamental frequency, careful consideration needs to be given to both electromagnetic and mechanical design issues. This paper deals with the comparison of two types of permanent magnet high-speed machines. Specifically, the effect of the permanent magnet magnetization pattern on the rotor losses is investigated. On the basis of analytical field analysis and the 2-D finite element method, this paper predicts the flux harmonics and rotor losses under the no-load condition. It is shown that the Halbach magnetization is superior to parallel magnetization in terms of producing rotor losses.

• Proceedings of the Korea Inteligent Information System Society Conference
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• 2005.11a
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• pp.157-162
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• 2005

Seamlessness is the Keyword of U-Commerce Which may be defined as the commercial interaction among providers, consumers, products, and services, enabled and supported especially by the real-world seamless communication of each entity and object's digital information. However, the possibility of the seamless transactions increases the privacy risk of the entities involved. Therefore, the core issue of U-Commerce is how to promote seamless transactions while protecting the privacy. for the seamlessness, the role of incentive-emphasized business model is important since the seamlessness makes clear which economic entities contribute to a commercial transaction. Economic entities will reject the seamless transactions unless the sufficient incentives are given to them. In order to consider the privacy issue, we suggest an alternative U-Commerce architecture based on Hybrid P2P Model and Personal Information Base.

• Proceedings of the Korean Society of Computer Information Conference
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• 2019.01a
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• pp.413-414
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• 2019

국내외 기관 및 기업 간 거래를 위하여 블록체인기술 적용이 활성화되고 있다. 특히 국내의 문화 콘텐츠의 다국적 기업대상 거래 시 블록체인을 통한 스마트 컨트랙트 기술로 거래의 투명성과 안정성을 높일 수 있다. 본 논문에서는 디지털 콘텐츠 거래를 위하여 블록체인 이더리움 기술을 활용한 스마트 컨트랙트 적용 방법을 제안한다. 구현된 기술을 통하여 다기업간 신뢰성 있는 디지털 콘텐츠의 거래를 가능하게 하고 국내외의 문화 콘텐츠 거래를 활성화 할 수 있다.