• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2003.05a
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• pp.203-207
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• 2003

Mobile Ad Hoc Network is a kind of network technology, that mobile hosts can compose networks freely and temporarily where the base networks don't exist and where its establishment is difficult or as occasion demands. Ubiquitous computer network is prograssing in the forms of miniaturization, lightweight or portability. So far, MANET was studied in the point how to route it efficiently, but its power saving problems are been issuing nowadays. We try to not only compare and analyze power saving protocols in multi-hop Ad Hoc network but also present their efficiencies in this thesis.

• Proceedings of the Korean Information Science Society Conference
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• 2007.06d
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• pp.157-162
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• 2007

최근 홈 네트워크 및 유비쿼터스 컴퓨팅에 대한 일반인들의 관심이 크게 증가하면서, 10m 내외의 단거리에서 사용되는 개인 무선 네트워킹 솔루션인 무선 PAN 기술이 주목받고 있다. 본 논문에서는 이러한 무선 PAN 기술 중 저속, 저가, 저전력의 무선통신 기술인 ZigBee 이용해 당뇨병 환자들을 위한 실시간 모니터링 시스템을 구현하였다. 즉, 휴대용 인슐린 펌프에 ZigBee 통신이 가능한 모듈을 장착함으로써, 인슐린 펌프에 내장된 환자의 혈당치, 인슐린 투입량 등과 같은 중요 데이터를 별도의 조작 없이 유선 클라이언트에 실시간 전송할 수 있게 된 것이다. 한편, 유선 클라이언트에 저장된 환자의 정보는 서버에 즉시 전송되며, 담당 주치의의 모니터링이 가능하도록 웹 접근성을 부여하였다. 이를 통해 환자들이 보다 안전하고 편리하게 휴대용 인슐린 펌프를 사용할 수 있도록 하였다.

• The Journal of the Korea institute of electronic communication sciences
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• v.14 no.6
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• pp.1077-1082
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• 2019

The development of computing technology and networking has developed into a fundamental technology of the Fourth Industrial Revolution, which provides a ubiquitous environment. In the ubiquitous environment, the IoT environment has become an issue so that various devices and the things can be actively accessed and connected. Also, the RFID system using the wireless identification code attaches an RFID tag to the object, such as the production and distribution of products. It is applied to the management very efficiently. EPCglobal is conducting a research on RFID system standardization and various security studies. Since RFID systems use wireless environment technology, there are more security threats than wire problems. In particular, failure to provide confidentiality, indistinguishability, and forward safety could expose them to various threats in the Fourth Industrial Revolution. Therefore, this study analyzes the standard method of EPCgolbal and proposes RFID security method using hash code that can consider the amount of computation.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.44 no.10
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• pp.55-63
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• 2007

Multicast is an efficient transport mechanism for community communications and MANET is recently regarded as a promising solution for support ubiquitous computing as an underlying network technology. However, it is hard to deploy multicast mechanism into MANET owing to scarce resources in wireless networks and unpredictable changes in network topology. Several multicast mechanisms have been proposed in the literature to overcome the limitations. Especially, overlay multicasting schemes present several advantages over network based multicasting schemes. Yet, the overlay multicasting schemes still introduce redundant data transmissions that waste network bandwidth and battery of relay nodes. As a result the performance of the network is degraded. To reduce the redundancy, we propose an efficient way to construct an overlay structure as a multicast data delivery tree that utilizes a branch node which belongs to the tree. By using network simulation, we show that the proposed scheme presents higher packet delivery ratio and lower transmission cost than previously proposed schemes.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.12
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• pp.30-45
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• 2014

Recently, multimedia application users who demand for ubiquitous computing environment are rapidly increasing, and wireless mesh network is receiving attention as a cost-effective key technology for next generation wireless networking. When multiple flows are transmitting data at the same time in the network, routing for path selection of each flow and link resource allocation for data transmission of each flow are one of the key factors that influence to the effectiveness of the network directly. In this paper, we consider problems for path discovery and resource allocation of links at the same time and we propose an algorithm based on mathematical modeling using a technique for cross-layer optimization design in STDMA-based wireless mesh networks that can enhance transfer performance for each flow. We show by performance analysis that the proposed algorithm can enhance the throughput performance by maximally utilizing given bandwidth resources when the number of flows increase in multi-hop wireless mesh networks.