• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.10
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• pp.1790-1795
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• 2008

Energy scavenging is a technique that converts ambient energy, for example, vibration and light, to electrical energy in order to supply power to low power electronic devices such as ubiquitous sensors. In this paper, we propose an optimal operation condition of power delivery circuit and design strategy for energy scavenging system in which the generated power is order of microwatt and, consequently, efficient handling of power is critical. We also propose that high data transmission rate is more realistic optimal design objective rather than high energy efficiency. It is shown that disconnection of load from the storage capacitor right after data transmission reduces energy wasting and that optimal value of storage capacitor can be determined at this condition. The feasibility of our propose is proved by experiments and we believe that the proposed design strategy will promote the application of piezoelectric micropower generator to the ubiquitous sensor networks.

• Proceedings of the Korea Contents Association Conference
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• 2006.05a
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• pp.483-485
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• 2006

RFID 시스템은 물품 등의 관리할 사물에 태그를 부착하고 전파를 이용하여 사물의 정보(Identification) 및 주변 환경 정보를 인식하여 각 사물의 정보를 수집, 저장, 가공 및 추적함으로써 사물에 대한 측위, 원격처리 관리 및 개체 간에 정보교환 등 다양한 서비스를 제공하며, 칩, 태그, 리더, 미들웨어 및 응용서비스플랫폼으로 구성된다. 이러한 RFID 기술은 반도체 기술의 지속적인 발전에 의한 컴퓨팅 능력의 급성장과 통신망 인프라의 융합화를 기반으로 이제까지의 사람 중심 정보화에서 사물중심으로 정보화의 지평을 확대시킬 수 있는 핵심기수로서 부각되고 있다.[1][2][3] 본 연구는 실용화되어 운영되고 있는 RFID미들웨어의 형태를 조사하여 연구하고, RFID 기반 EPC 네트워크를 이용하여 병원 환경에서 RFID태그를 리더가 읽은 후 태그정보와 병원정보를 매칭하여 병원환경에서 통합적으로 운영할 수 있는 미들웨어(Middleware) 인터페이스 프로그램 개발에 관한 연구를 진행한다.

• Journal of Multimedia Information System
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• v.1 no.1
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• pp.23-43
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• 2014

With the rapidity of the development on electronic technology, various mobile devices are produced to make human life more convenient. The user is always in constant search of middle with ease of deployment. Therefore, the development of infrastructure and application with ubiquitous nature gets a growing keen interest. Recently, the number of pervasive network services is expanding into ubiquitous computing environment. To get desired services, user presents personal details about this identity, location and private information. The information transmitted and the services provided in pervasive computing environments (PCEs) are exposed to eavesdropping and various attacks. Therefore, the need to protect this environment from illegal accesses has become extremely urgent. In this paper, we propose an anonymous authentication and access control scheme to secure the interaction between mobile users and services in PCEs. The proposed scheme integrates a biometric authentication in PKI model. The proposed authentication aims to secure access remote in PCE for guaranteeing reliability and availability. Our authentication concept can offer pervasive network service users convenience and security.

• 한국HCI학회:학술대회논문집
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• 2007.02a
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• pp.796-801
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• 2007

유비쿼터스 지능 공간(Ubiquitous Smart Space)에서 동적으로 발생하는 다양한 문제를 협업을 통하여 해결할 수 있는 방법론으로 제안된 커뮤니티 컴퓨팅 (Community Computing) 모델을 기반으로 하는 개발 도구(Community Computing Development Tool Kit : CDTK)를 사용하면 특정 문제를 해결할 수 있는 커뮤니티 컴퓨팅 어플리케이션이 생성된다. 이 커뮤니티 컴퓨팅 어플리케이션이 실제로 유비쿼터스 지능 공간에 존재하는 uT-entity에 이식되어 동작하기 위해서 uT-entity의 종류에 상관없이 커뮤니티 컴퓨팅 어플리케이션이 배포될 수 있는 환경을 필요로 한다. 본 연구에서는 CDTK를 이용하여 생성된 커뮤니티 컴퓨팅 어플리케이션이 uT-entity에 배포(Deployment)되어 각 uT-entity가 커뮤니티의 멤버로 참여하여 멤버간의 협업을 통해 목적(Goal)을 달성할 수 있도록 지원하는 어플리케이션 프레임워크인 멤버 프레임워크(Member Framework)를 제안하고, 이를 이클립스 리치클라이언트 플랫폼(Rich Client Platform) 기반의 플러그인(Plug-In)으로 설계하고자 한다.

• 한국HCI학회:학술대회논문집
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• 2007.02a
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• pp.802-807
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• 2007

유비쿼터스 컴퓨팅 환경에서 커뮤니티 메타포를 이용하여 유비쿼터스 서비스를 실현하는 커뮤니티 컴퓨팅에 대한 연구가 제안되었다. 제시된 커뮤니티 컴퓨팅 어플리케이션 개발과정은 MDA 개발방법을 적용하여 추상화된 고수준의 모델로부터 최종 플랫폼에 적합한 코드를 생산한다. 그러나 커뮤니티 컴퓨팅 시스템을 구현하기 위한 통합개발환경은 존재하지 않는다. 이에 본 연구에서는 최근 관심이 고조되고 있는 이클립스를 이용하여 커뮤니티 컴퓨팅에서 요구되는 기능들을 플러그인으로 통합하여 커뮤니티 컴퓨팅 어플리케이션 개발에 적합한 통합개발환경(CDTK : Community computing Development Tool Kit)을 제안한다.

• Proceedings of the IEEK Conference
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• 2009.05a
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• pp.16-18
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• 2009

VoIP(Voice over IP) is the technology to transport voice and video over IP networks such as Internet. Today, VoIP technology is viewed as the right choice for provide voice, video, and data communication over next generation network. We are sure that the multipoint VoIP will help enhancing the various application services in ubiquitous environment. The paper shows multipoint VoIP system implemented with end-point mixing model and introduces various embedded systems such as UFC(Ubiquitous Fashionable Computer), tourist guide terminal and industrial terminal which use the multipoint VoIP.

• Proceedings of the KIEE Conference
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• 2006.04a
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• pp.165-167
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• 2006

In this paper we present a new-generation sensor network processor which is not optimized in circuit level, but in system architecture level. The new design build on a conventional processor architecture, improving the design by focusing on application oriented specification, ISA, and micro-architectural optimization that reduce overall design size and advance energy-per-instruction. The design employs harvard architecture, 8-bit data paths, and an compact 19 bit wide RISC ISA. The design also features a unique interrupt handler which offloads periodical monitoring jobs from the main part of CPU. Our most efficient design is capable of running at 300 KHz (0.3 MIPS) while consuming only about few pJ/instruction.

• IE interfaces
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• v.21 no.2
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• pp.177-188
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• 2008

Recently, due to emerging technologies such as radio frequency identification(RFID), global positioning system(GPS), and wireless mobile communication technologies, it is possible to build up the infrastructure for tracking and tracing product logistics data at any place and at any time. However, for implementing the infrastructure, it is necessary to develop a suitable management method for product logistics data. To this end, this study deals with a resource description framework(RDF) based modeling and application method for product logistics data in the ubiquitous environment. It will give us the capability to control product logistics data, which leads to streamline logistics operations.

• International Commerce and Information Review
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• v.10 no.3
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• pp.101-116
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• 2008

Future e-Trade RFID/USN distribution should satisfy the new needs of reasonable customers such as efficient supply of goods, presentation of information, and communication by developing intermediate and long-term strategies through analysis of industrial conditions and customers' needs. Through preferential application of new technology, knowledge-based e-Trade RFID/USN distribution environment and DB of industrial portal sites should be developed, RFID/USN infra such as Supply Chain Management(SCM) should be expanded, future-oriented knowledge-based services should be developed to prepare specific and realistic plans for proper UT(Ubiquitous Technology). Such change in e-Trade distribution environment should have historical and environmental backgrounds to suggest specific tasks and directions as a conversion of structural concept of engineering and trade theory for new u-Trade. Accordingly, this study is to present all the problems available in RFID/USN distribution, develop an organized and technological estimate model and provide a foundation to apply it efficiently. This study aims to present an interpretational foundation of RFID/USN distribution, rather than technical directions.

• Journal of information and communication convergence engineering
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• v.7 no.3
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• pp.412-417
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• 2009

With ubiquitous computing aid, it can improve human being's life quality if all people have more convenient medical service under pervasive computing environment. In this paper, for a pervasive health care application for diabetes patient, we've implemented a health care system, which is composed of three parts. Various sensors monitor both outer and inner environment of human such as temperature, blood pressure, pulse, and glycemic index, etc. These sensors form zigbee-based sensor network. And as a backend, medical information server accumulates sensing data and performs back-end processing. To simply transfer these sensing values to a medical team may be a low level's medical service. So, we've designed a model with context awareness for more improved medical service which is based on ART(adaptive resonance theory) neural network. Our experiments show that a proposed healthcare system can provide improved medical service because it can recognize current context of patient more concretely.