• Proceedings of the IEEK Conference
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• 2000.11a
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• pp.213-216
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• 2000

In this paper, we propose a new scheme which improves the IP address lookup time. The new scheme is composed of two core technologies, named the prefix alignment and the prefix distance ordering. Now, as the Internet is being used commonly by improving the data transmission capacity, the need for enlarging the bandwidth of the Internet is on the rise. IP address lookup performance problem is an important obstacle in the router executing high speed packet forwarding. This results from the fact that the prefixes routing table is composed of and the traffic being processed in unit time are largely on the increase. The proposed lookup scheme is divided into two parts in technology, the one is the algorithm forming a routing database(routing table), the other is the lookup procedure in the actual packet processing.

• Journal of Korean Institute of Industrial Engineers
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• v.35 no.1
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• pp.1-14
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• 2009

The efficiency of transportation requests fulfillment can be increased through extending the problem of vehicle routing and scheduling by the possibility of subcontracting a part of the requests to external carriers. This problem extension transforms the usual vehicle routing and scheduling problems to the more general integrated operational transportation problems. In this contribution, we analyze the motivation, the chances, the realization, and the challenges of the integrated operational planning and report on experiments for extending the plain Vehicle Routing Problem to a corresponding problem combining vehicle routing and request forwarding by means of different sub-contraction types. The extended problem is formalized as a mixed integer linear programming model and solved by a commercial mathematical programming solver. The computational results show tremendous costs savings even for small problem instances by allowing subcontracting. Additionally, the performed experiments for the operational transportation planning are used for an analysis of the decision on the optimal fleet size for own vehicles and regularly hired vehicles.

• Journal of Korea Society of Digital Industry and Information Management
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• v.11 no.3
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• pp.79-90
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• 2015

Multipath routing technique is recognized as one of the effective approaches to improve the reliability of data forwarding. However, the traditional multipath routing focuses only on how many paths are needed to ensure a desired reliability. For this purpose, the protocols construct additional paths and thus cause significant energy consumption. These problems have motivated the study for the energy-efficient and reliable data forwarding. Thus, this paper proposes an energy-efficient concurrent multipath routing protocol with a small number of paths based on interaction between paths. The interaction between paths helps to reinforce the multipath reliability by making efficient use of resources. The protocol selects several nodes located in the radio overlapped area between a pair of paths as bridge nodes for the path-interaction. In order to operate the bridge node efficiently, when the transmission failure has detected by overhearing at each path, it performs recovery transmission to recover the path failure. Simulation results show that proposed protocol is superior to the existing multipath protocols in terms of energy consumption and delivery reliability.

• Journal of Satellite, Information and Communications
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• v.7 no.3
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• pp.47-53
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• 2012

In this paper, we present an algorithm called redundant logical paths (RLP) for efficient HSR traffic reduction. It creates redundant logical paths between each HSR node and all the other nodes. Eventually, a logical full-meshed network or paths will be established among all HSR node types, except the Quadbox type, which is used only for interconnection. The logical full-meshed network will be used instead of using the standard HSR protocol that depends on the concepts of the duplication and forwarding of the received frame until it reaches the destination node. The RLP algorithm results in significantly less frame traffic because there is no random forwarding as in the standard HSR protocol. For the sample network in this paper simulation results showed a 61.5-80% reduction in network frame traffic compared to the standard HSR. Our algorithm will avoid latency issues in the network and even network congestion, thus improving network efficiency.

• Proceedings of the Korean Information Science Society Conference
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• 2007.06a
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• pp.183-187
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• 2007

움직이는 노드에게 정보를 전달하는 것은 이제 흔한 일이 되었다. 더 나아가서 움직이는 노드들로 독립적인 네트워크를 형성 할 수도 있다. 최근 이러한 VANET(Vehiclular Ad Hoc Networks) 환경 하에서의 정보의 전송에 관심이 커지고 있다. 이동 노드들이 무선 링크를 통하여 연결될 수 있을 때에는 별도의 ad-hoc 네트워크를 형성하지 않고도 정보 전송 네트워크로 사용할 수 있다. 이를 기회적 전송(opportunistic forwarding)이라 하며, 이 논문에서는 세 개의 서로 다른 기회적 정보 전송 방법을 비교한다. 각 방법 하에서의 전송 시간, 성공률, 그리고 오버헤드를 측정하고, 이를 바탕으로 기회적 전송 문제 해결을 위한 새로운 방법을 제안한다. 이 방법은 전송의 매개체인 다른 이동 노드를 만났을 때 기회적 전송을 할 것인가의 여부를 결정하기 위해 양측의 속도 정보를 사용한다. 우리는 제안된 방법이 기존의 방법보다 효과적임을 시뮬레이션을 통해 보인다.

• Proceedings of the Korean Society of Computer Information Conference
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• 2013.07a
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• pp.51-54
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• 2013

센서 네트워크는 주변의 환경 정보를 수집하여 사용자에게 제공함으로써 지능적인 처리를 가능하게 하는 시스템이다. 센서 네트워크를 구성하는 센서 노드들은 메모리, 연산 능력, 에너지 등 자원 측면에서 제약을 갖고 있으며 무선 통신을 사용하므로 센서 네트워크 환경에서는 각종 보안 위협이 발생할 수 있다. 선택적 전달 공격에서 네트워크 내의 훼손 노드는 자신을 지나는 이벤트 보고서 중 전체 또는 일부를 제거함으로써 중요한 이벤트 정보가 싱크 노드까지 도달하지 못하도록 한다. 선택적 전달 공격을 방어하기 위한 기존 라우팅 기법은 많은 에너지 소비를 유발한다는 단점이 존재한다. 본 논문에서는 지형 기반의 라우팅 프로토콜인 Greedy Perimeter Stateless Routing (GPSR) 프로토콜을 기반으로 선택적 전달 공격 발생 지점을 우회할 수 있는 방법을 제안한다. 제안 기법은 선택적 전달 공격이 발생하는 환경에서 에너지 효율적으로 소스 노드에서 기지 노드까지 이벤트 보고서를 신뢰성 있게 전달하는데 활용될 수 있다.

• Journal of Communications and Networks
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• v.12 no.2
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• pp.181-190
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• 2010

A multitude of overlay network designs for resilient routing, multicasting, quality of service, content distribution, storage, and object location have been proposed. Overlay networks offer several attractive features, including ease of deployment, flexibility, adaptivity, and an infrastructure for collaboration among hosts. In this paper, we explore cooperation among co-existing, possibly heterogeneous, overlay networks. We discuss a spectrum of cooperative forwarding and information sharing services, and investigate the associated scalability, heterogeneity, and security problems. Motivated by these services, we design Synergy, a utility-based overlay internetworking architecture that fosters overlay cooperation. Our architecture promotes fair peering relationships to achieve synergism. Results from Internet experiments with cooperative forwarding overlays indicate that our Synergy prototype improves delay, throughput, and loss performance, while maintaining the autonomy and heterogeneity of individual overlay networks.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2003.10a
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• pp.673-676
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• 2003

Call Processing Language is a standards which support the PSTN like various additional services send-receive call forbidden, call forwarding. This standards developed by IETF iptel working group. we can apply to users demands that want to possibilities of call connection by relating RFC 3261. This paper describes the design and development of CPL proxy in detail. Designing and implementation is accomplished in Linux kerenl version 2.4.18 using C Language.

• Proceedings of the KSR Conference
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• 2009.05a
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• pp.1895-1905
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• 2009

Recently it is required to present a new goal and direction regarding a railroad industrial informatization in order to respond to external change of environment along sharp development technical information communication (ICT), establish a strategic plan for o establish a strategic plan for harmonious developments of private and public sector through harmonious developments of private and public sector and efficient investments on an railroad industrial informatization. Forwarding plans for informatization industrial the existing railroad have been proceeded mainly around informatization of related organization regarding railroads. Study to have read to this established informatization architecture industrial a railroad for establishing deliberate systematic forwarding regarding informatization industrial a railroad of the center functional service a railroad taking charge of. we selected a system sub-of 25 by each fields for this after classifying it to, eight fields such as construction, train driving control, environment, maintenance, logistics, a train, assets management, passenger service.

• Proceedings of the Korea Information Processing Society Conference
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• 2000.10b
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• pp.1025-1028
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• 2000

본 논문에서는 VoIP(Voice over IP)의 광대역 네트워크에서 QoS(Quality of Service)를 지원하기 위한 방안을 스케줄링을 중심으로 하여 연구하였다. 이를 위하여 라우터 중심의 포워딩(forwarding)에 있어서 재생손실(Play Out Loss)이 발생하는 버퍼에 대해서는 음성통신을 제외한 일반 데이터에 할당을 하고 들어오는 음성 데이터에 대해서는 토큰 할당 방식으로 자원을 할당하는 모델에 대해 제안하였다. 또한 음성 데이터에 대해서는 폐기에 대한 방법대신 거절 개념을 포함시켜 이를 EF(Expedited Forwarding)모델과 시뮬레이션을 통하여 분석을 하였다.