• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2007년도 한국컴퓨터종합학술대회논문집 Vol.34 No.1 (D)
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• pp.183-188
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• 2007

Peer-to-Peer (P2P) overlay networks have drawn much research interest in the past few years because they provide a good substrate for large-scale applications in the Internet. In this paper, we introduce the use of anycast, a new "one-to-one-of-many" communication method in the Internet, to solve the following common problems of P2P overlay networks: load-balancing, topology-awareness, system partitioning, and multi-overlay interconnection. We also give an analysis of the features and limitations of the recently deployed anycast infrastructures in the Internet for supporting P2P overlay networks.

• Journal of Communications and Networks
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• 제8권4호
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• pp.378-390
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• 2006

Many distributed applications build overlays on top of the Internet. Several unsolved issues at the network layer can explain this trend to implement network services such as multicast, mobility, and security at the application layer. On one hand, overlays creating basic topologies are usually limited in flexibility and scalability. On the other hand, overlays creating complex topologies require some form of application level addressing, routing, and naming mechanisms. Our aim is to design an efficient and robust addressing, routing, and naming infrastructure for these complex overlays. Our only assumption is that they are deployed over the Internet topology. Applications that use our middleware will be relieved from managing their own overlay topologies. Our infrastructure is based on the separation of the naming and the addressing planes and provides a convergence plane for the current heterogeneous Internet environment. To implement this property, we have designed a scalable distributed k-resilient name to address binding system. This paper describes the design of our overlay infrastructure and presents performance results concerning its routing scalability, its path inflation efficiency and its resilience to network dynamics.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제11권9호
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• pp.4641-4657
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• 2017

Named Data Networking (NDN) has emerged and become one of the most promising architectures for future Internet. However, like traditional IP-based networking paradigm, NDN may not evade some typical network threats such as malicious data aggregates (MDA), which may lead to bandwidth exhaustion, traffic congestion and router overload. This paper firstly analyzes the damage effect of MDA using realistic simulations in large-scale network topology, showing that it is not just theoretical, and then designs a fine-grained MDA mitigation mechanism (MDAM) based on the cooperation between routers via alert messages. Simulations results show that MDAM can significantly reduce the Pending Interest Table overload in involved routers, and bring in normal data-returning rate and data-retrieval delay.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2011년도 한국컴퓨터종합학술대회논문집 Vol.38 No.1(D)
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• pp.315-318
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• 2011

In this work, a VN-based IPTV service delivery network containing a novel VNT was designed, This VN-based IPTV service delivery network utilizes current resources that can be easily obtained by IPTV providers and organizes these resources in a more efficient manner, We also developed a three-stage VN allocation scheme to reduce the complexity of topology design and allocation.

• 한국멀티미디어학회논문지
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• 제19권2호
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• pp.291-299
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• 2016

To enhance network efficiency, named-data networking (NDN) implements data caching functionality on intermediate network nodes, and then the nodes directly respond to request messages for cached data. Through the processing of request messages in intermediate node, NDN can efficiently reduce the amount of network traffic, also solve network congestion problems near data sources. Also, NDN provides a data authenticate mechanism so as to prevent various Internet accidents caused from the absence of an authentication mechanism. Hence, through applying NDN to various smart IT convergence services, it is expected to efficiently control the explosive growth of network traffic as well as to provide more secure services. Basically, it is important factors of NDN which data is cached and where nodes caching data is located in a network topology. This paper first analyzes previous works caching content based on the popularity of the content. Then ii investigates the hitting rate of caches in each node of a network topology, and then propose an improved caching scheme based on the result of the analyzation. Finally, it evaluates the performance of the proposal.

• International journal of advanced smart convergence
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• 제1권2호
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• pp.16-19
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• 2012

A modified 4-coil magnetic resonance wireless power transfer (MRWPT) system is proposed. Four coils based on 2-coil system with additional two matching coils were used in this topology. When Tx-Rx distance is changed, the input impedance is changed. However, it can be adjusted by coil parameters of matching coils to maintain impedance matching for maximum efficiency. The equivalent circuit of MRWPT system was analyzed for both transmission function and optimum coupling coefficient of the matching coils. By using four spiral resonant coils, these design considerations was experimentally verified. The measured data agreed well with the calculated data and the transmission function of the proposed system was more efficient than that of conventional 2-coil system.

• International journal of advanced smart convergence
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• 제7권2호
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• pp.22-32
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• 2018

In VANET, frequent movement of nodes causes dynamic changes of the network topology. Therefore the routing protocol, which is stable to effectively respond the changes of the network topology, is required. Moreover, the existing cluster-based routing protocol, that is the hybrid approach, has routing delay due to the frequent re-electing of the cluster header. In addition, the routing table of CBRP has only one hop distant neighbor nodes. PCBRP (Paired CBRP), proposed in this paper, ties two clusters in one pair of clusters to make longer radius. Then the pair of the cluster headers manages and operates corresponding member nodes. In the current CBRP, when the cluster header leaves the cluster the delay, due to the re-electing a header, should be occurred. However, in PCBRP, another cluster header of the paired cluster takes the role instead of the left cluster header. This means that this method reduces the routing delay. Concurrently, PCBRP reduces the delay when routing nodes in the paired cluster internally. Therefore PCBRP shows improved total delay of the network and improved performance due to the reduced routing overhead.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 심포지엄 논문집 정보 및 제어부문
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• pp.448-450
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• 2007

Peer-to-Peer system has emerged as a popular model aiming at further utilizing Internet information and resources, complementing the available client-server services. However, the mechanism of peers randomly choosing logical neighbors without any knowledge about underlying physical location aware topology can cause serious performance degradation. In this paper, we consider the network distance between peers so that it helps peers select neighbors located at the nearest when they exchange queries for sharing of resources. To reduce the unnecessary signaling traffic and delay of query exchange, we propose a location aware topology based Hybrid P2P system. This system calculates the network distance which combines the direct measurement such as RTT (Round Trip Time) with geographic space of peers using IP address

• 산업공학
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• 제16권spc호
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• pp.14-20
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• 2003

This paper presents a multi-criteria decision model and Multi-Criteria Generic Algorithm(MCGA) approach to improve backbone topology by leveraging the Virtual Link(VL) system in an hierarchical Link-State(LS) routing domain. Given that the sound backbone topology structure has a great impact on the overall routing performance in an hierarchical LS domain, the importance of this research is evident. The proposed decision model is to find an optimal configuration of VLs that properly meets two-pronged engineering goals in installing and maintaining VLs: i.e., operational costs and network reliability. The experiment results clearly indicates that it is essential to the effective operations of hierarchical LS routing domain to consider not only engineering aspects but also specific benefits from systematical layout of VLs, thereby presenting the validity of the decision model and MCGA.

• 산업경영시스템학회지
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• 제27권4호
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• pp.77-82
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• 2004

Being in an internet era, the rapid transmission of 3D mesh models is getting more important and efforts toward the compression of various aspects of mesh models have been provided. Even though a mesh model usually consists of coordinates of vertices and properties such as colors and normals, topology plays the most important part in the compression of other information in the models. Despite the extensive studies on Edgebreaker, the most frequently used and rigorously evaluated topology compressor, the probability distribution of its five op-codes, C, R, E, S, and L, has never been rigorously analyzed yet. In this paper, we present probability distribution of the op-codes which is useful for both the optimization of the compression performance and a priori estimation of compressed file size.