• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.1A
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• pp.67-73
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• 2008

Our research is aimed at developing an architectural frame-work of USN sensor network discovery service systems. The research is fo-cused on the four areas a survey of USN technology, development of a USN software model, development of the design space of the USN sensor network discovery service, and finally the architectural framework of the USN sensor network dicovery service. The survey of the USN technology is conducted on four technological visions that contain USN system technology, USN networking technology, and USN middleware along with the service platform, With respect to each technological division, domestic and worldwide leading research projects are primarily explored with their technical features and research projects are primarily explored with their technical features and research output To provide a means to analyze sensor network discovery services, we devel-oped the design space of the sensor network discovery services by exploring the scalability with respect to query scope, lookup performance, and resolution network.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.10a
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• pp.471-474
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• 2016

This standard defines global service discovery structure for argo-livestock products. The purpose of the standard is providing agro-livestock service list to users by discovering namer servers hierarchically with a class level argo-livestock identifier.

• Journal of Digital Contents Society
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• v.8 no.3
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• pp.269-277
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• 2007

Web service is an important technology to develop business to business e-commerce application. From a business perspective of time to market, dynamic evolution offers flexibility that software can adapt to unforeseen and fluctuating business requirements. OWL-S, based on OWL, is a service ontology language. The semantics provided by OWL support automation of service discovery, invocation, and service composition. In this paper we propose a framework to support dynamic evolution of service-oriented applications. We extend use-case analysis method to derive service description by defining requirements concept and mapping from requirement concept to activity diagram. A prototype is provided to show the validity of this framework.

• Journal of KIISE:Information Networking
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• v.31 no.6
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• pp.643-658
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• 2004

Mobile ad hoc networks(MANET) have recently attrarted a lot of attention in the research community as well as in industry. Although the previous research mainly focused on the various problems of MANET in data link and network layers, we consider, in this paper, how to efficiently support applications such as service discovery on top of MANET. Peer-to-Peer(P2P) overlay network can be adopted to service discovery mechanism because P2P and MANET share certain similarities, primarily the fact that both arc instances of self-organizing decentralized systems. Especially, distributed hash table(DHT) systems used for r2r overlay network can be effective in reducing the communication overhead in service discovery. However, since overlay network is independent of physical network topology and existing topology-aware mechanisms are based on the wired network, they are inefficient in MANET. We propose a proximity-based overlay network routing to overcome the inefficiency of routing in overlay network. In the proximity-based overlay network routing, each node collects information of physically close nodes by using one hop broadcast and routes messages to the logically closest node to destination. In a detailed ns-2 simulation study, we show that the proximity-based overlay network routing reduces the number of physical hops comparable to the flooding-based mechanism with low communication overhead. We also find that the proposed scheme works well in the mobile environment.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.41 no.12
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• pp.33-40
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• 2004

IPv6 defines relation between surrounding node using Neighbor Discovery protocol. Used Neighbor Discovery messages, grasp surrounding node, include important informations about network. These network information outcrops can give rise in network attack and also service that use network will paralysis. Various kinds of security limitation was found in Present Neighbor Discovery protocol therefore security function to supplement this problem was required. In this thesis, Secure Neighbor Discovery protocol that add with suity function was design and embody by CGA module and SEND module.

• Proceedings of the Korean Society of Crop Science Conference
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• 2019.04a
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• pp.143-143
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• 2019

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38C no.12
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• pp.1134-1149
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• 2013

Pub/sub system enables data users to access any necessary data without knowledge of the data producer and synchronization with the data producer. It is widely used as the middleware technology for the data-centric services. DDS (Data Distribution Service) is a standard middleware supported by the OMG (Object Management Group), one of global standardization organizations. It is considered quite useful as a standard middleware for US military services. However, it is well-known that it takes considerably long time in searching the Participants and Endpoints in the system, especially when the system is booting up. In this paper, we propose a discovery scheme to reduce the latency when the participants and Endpoints are densely distributed in a small area. We propose to modify the standard DDS discovery process in three folds. First, we integrate the Endpoint discovery process with the Participant discovery process. Second, we reduce the number of connections per participant during the discovery process by adopting the concept of successors in Distributed Hashing scheme. Third, instead of UDP, the participants are connected through TCP to exploit the reliable delivery feature of TCP. We evaluated the performance of our scheme by comparing with the standard DDS discovery process. The evaluation results show that our scheme achieves quite lower discovery latency in case that the Participants and the Endpoints are densely distributed in a local network.

• Proceedings of the Korea Information Processing Society Conference
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• 2001.10b
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• pp.1399-1402
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• 2001

네트워크가 발전하면서 무선 환경에서 각종 장치들을 연결하고자 하는 요구가 늘어나고 있다. 무선 장치들은 전력소모를 줄여야하기 때문에 보다 많은 기능을 탑재하는 데에 어려움이 따른다. 특히, 실행중에 다른 장치를 인식하고 환경설정하며 실행상태를 관찰하는 것은 많은 에너지를 필요로 하는 복잡한 작업일 수 있다. Jini 기술은 장치들을 자동으로 인식하고 설정하는 데에 있어 강력하면서도 단순한 Service Discovery Protocol을 포함하고 있다. 그러나 Jini는 유선 네트워크를 기준으로 개발되어졌기 때문에 무선, 특히 Ad-hoc 네트워크 환경에 적응하기 위해서는 각 요소들이 어떠한 중계도 없이 독립적으로 서로를 인식한 수 있도록 개선되어야 한다. Lookup Server가 작동을 멈추거나 룩업서비스를 받을 수 없는 지역에 있다면, 클라이언트는 서비스를 찾을 수 없고 서비스들도 새롭게 등록될 수 없다. 특히 이동성을 지닌 Ad-hoc 네트워크에서 룩업서비스의 존재는 보장받기 어렵다. 본 논문은 Jini를 기반으로 Ad-hoc 네트워크를 구축한 때 룩업서비스의 일부 기능을 클라이언트에게 분산시키고 다른 클라이언트와 정보를 공유한 수 있도록 개선된 Jini Discovery를 제안한다.

• Proceedings of the Korean Society of Computer Information Conference
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• 2015.01a
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• pp.159-161
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• 2015

서비스 디스커버리는 대부분의 분산시스템 및 서비스 지향 아키텍처의 핵심 구성요소다. 실시간 시스템 기반에서 서비스 위치는 자주 변경될 수 있는데, 이 때 서비스 중단 문제가 발생할 수 있다. 이를 방지하기 위해서 동적인 서비스 등록과 서비스 디스커버리 기법이 매우 중요하다. 본 논문은 서비스 중단 문제를 해결할 수 있는 몇 가지 오픈 소스 솔루션들을 소개한다. 각 솔루션들은 레지스트리 타입에 따라 크게 범용 레지스트리와 단일 목적용 레지스트리로 나눌 수 있다. 각 솔루션들의 기능을 서로 비교함으로써 사용자로 하여금 자신의 요구사항에 적합한 솔루션을 선택하는데 도움이 되고자 한다.

• The Journal of the Korea Contents Association
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• v.10 no.9
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• pp.79-87
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• 2010

This paper proposes a L3 handover method to minimize packet loss for supporting service continuity to IMS Terminal which has a single WLAN interface. The existing IMS based handover solution is able to support handover between different access networks in case that a terminal has multiple interfaces. That is, WLAN terminals need multiple interfaces to connect with one or more access networks. This proposed method configures IP address for the terminal in target WLAN previously by using Candidate Access Router Discovery(CARD) mechanism. Also, in the proposed method, service continuity server performs L3 connection establishment in target WLAN and registration to IMS server instead of the terminal. And then session control mechanism based on SIP is performed to support service continuity. We analyzed handover latency and signaling cost in the proposed method and existing method to show the improved performance by the proposed method.