• International journal of advanced smart convergence
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• 제8권1호
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• pp.35-43
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• 2019

A metro ring network using WDM technology requires many issues to be considered even though its transmission distance is shorter and its transmission capacity is lower than a long-haul WDM system. Unlike a long-haul WDM system, which is basically point-to-point configuration, a metro ring network usually equips with capabilty of wavelength reconfiguration. Therefore network performance considering crosstalk within OADM and the network behavior when the ring network is closed should be analyzed before implemented. We discussed some of results analyzed for the issues. Furthermore we proposed a novel method to design a dispersion map for a ring network, and demonstrated the methodology with an exemplary 8-node ring network of 399km circumference.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1999년도 하계종합학술대회 논문집
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• pp.17-20
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• 1999

In these days, wavelength division multiplexing(WDM) all-optical network are being deployed to support various multimedia communication services. In this paper, various WDM all-optical network are discussed, and a design of an all-optical backbone network has been proposed by using multiple self-healing ring technology. The proposed multiple self-healing ring network improves network expandability and efficiency of bandwidth, while it retains simplicity and ease of network control, which are from the nature self-healing ring. Using PDI traffic modeling technique, a well-balanced all-optical backbone network using multiple self-healing ring is designed for the 2010s in Korea.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권12호
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• pp.5442-5463
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• 2016

Designing efficient routing protocols for a wireless sensor network with mobile sinks (mWSN) is a challenging task since the network topology and data paths change frequently as sink nodes move. In this paper, we design a novel lightweight reactive ring based routing protocol called R3, which removes the need of proactively maintaining data paths to mobile sinks as they move in the network. To achieve high packet delivery ratio and low transmission cost, R3 combines ring based forwarding and trail based forwarding together. To support efficient ring based forwarding, we build a ring based structure for a network in a way such that each node in the network can easily obtain its ring ID and virtual angle information. For this purpose, we artificially create a virtual hole in the central area of the network and accordingly find a shortest cycled path enclosing the hole, which serves as base ring and is used for generating the remaining ring based structure. We accordingly present the detailed design description for R3, which only requires each node to keep very limited routing information. We derive the communication overhead by ring based forwarding. Extensive simulation results show that R3 can achieve high routing performance as compared with existing work.

• ETRI Journal
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• 제27권1호
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• pp.110-113
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• 2005

The resilient packet ring (RPR) is a data optimized ring network, where one of the key issues is on load balancing for competing streams of elastic traffic. This paper suggests three efficient traffic loading algorithms on the RPR. For the algorithms, we evaluate their efficiency via analysis or simulation.

• 한국경영과학회지
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• 제32권2호
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• pp.89-97
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• 2007

We study the maximum integer multiflow problem and the minimum multicut problem in a ring network. Both problems in a general network are known to be NP-hard. In this paper, we develop polynomial time algorithms to solve the problems. We also prove that even In a ring network, maximum multiflow is not always integral, which implies that the amount of maximum integer flow does not always reach the minimum capacity of multicut.

• 한국정보과학회논문지:시스템및이론
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• 제32권5호
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• pp.196-208
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• 2005

다중 프로세서 시스템에서 노드 간의 연결을 제공하는 상호 연결망이 전체 시스템의 성능에서 차지하는 비중은 매우 크다 상호 연결망의 형태는 여러 종류가 있을 수 있으나 Mesh, 링, 계층 링 등의 형태가 많이 사용된다. 이 논문에서는 기존의 계층 링을 수정,한 Torus Ring을 제안한다. Torus Ring은 계층 링과 완전히 동일한 복잡도를 가지면서도 지역 링 간의 연결 방법만을 변경한 형태의 상호 연결망이다. 이 연결망은 역방향 인접 링에 대한 요청에서 홉 수의 이득을 봄으로써 평균 흡수를 감소시킨다. 또한 접근의 지역성을 고려하지 않은 균등분포의 가정 하에서도 평균 홉수의 기대값에서 계층링과 동일한 값을 가지며, 실제 병렬 프로그램이 수행되는 환경에서는 인접링에 대한 통신 비율이 증가할 가능성이 크기 때문에 더 큰 흡수의 이익을 기대할 수 있다. 이에 따라 상호 연결망의 요청과 웅답의 지연 시간이 최대 19$\%$까지 감소하였으며, 이러한 웅답 지연 시간의 단축이 수행 시간을 최대 10$\%$ 정도까지 감소시키는 결과를 가져왔다.

• Current Optics and Photonics
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• 제3권3호
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• pp.193-198
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• 2019

We propose a novel method to design a dispersion map for a WDM (Wavelength Division Multiplexing) ring network with the capability of wavelength reconfiguration. The method is simple, but gives us an optimum set of DCMs (Dispersion Compensation Modules) which satisfies a given value of the tolerable residual dispersion. The proposed method does not depend on compensation method, fiber type, or modulation format. We also demonstrate numerically how it works with an example 10-node ring network.

• 한국통신학회논문지
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• 제22권1호
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• pp.139-150
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• 1997

For high-speed networks, a new ring protocal is proposed in this paper. A ring network combined with destination removal can achieve much higher network throughput than the channel transmission rate. However, such a network exhibits fairness problems. Over a past few years, global fairness algorithms such as ATMR and Metaring have been proposed to solve such problems. But the ring access time delay and fairness in such networks are sensitive to the network parameters such as network size and traffic distribution. In addition to guaranteeing fair ring access to all nodes, there are several other important performance aspects in such networks. The one is that fairness is enforced while node throughputs are kept as high as possible. And another performance measure is access delay and more specifically Head-Of-Line(HOL) delay, i.e., the amount of time the first cell in the transmission buffer of a node has to wait before it accesses the ring. HOL delay is a mijor component in the transmission jitter of the synchronous traffic transmission. A key idea of the proposed ring protocol is to find the nodes that have much more chances to access the ring than any other nodes in the independently distributed node architecture. Since destined by many cells need to share a part of the bandwidths with the next node for the fairness in as much as performance degradation does not become critical. To investigate the performance behavior of the proposed ring protocol for various network condition,s several performance parameters wuch as ring access time delay, and throughput are compared with those of the ATMR and Metaring protocols using simulation package, SIMAN.

• 산업경영시스템학회지
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• 제15권25호
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• pp.83-90
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• 1992

This paper aims at the problem that design the network of Rig-star type with the minimum cost, which the Ring is composed of the selected nodes(concentrators) among the several candidate nodes on the network and other nodes(terminals) is connected to the Ring by star subnetwork. Especially, we consider the terminal reliability in network design problem. We develop the heuristic algorithm for network design problem to obtain the near optimal(best) solution for problem. We use an add-heuristic method and 2-exchange method in developing the heuristic algorithm.

• 한국통신학회논문지
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• 제27권5C호
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• pp.422-434
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• 2002

본 논문에서는 대용량 트래픽의 효율적 전송을 위해 B-DCS(Broadband-Digital Cross-connect System)망, 간선링, 지선링의 3계위 구조 광섬유 기간전송망을 제안하며 각 계위에서 경제적으로 망의 생존도를 보장하는 설계방법을 연구한다. 링 구축비용을 혼합정수계획(MIP) 모델을 이용해 수리적으로 최적화할 경우 비다항식 완전 문제(NP-complete problem)가 되어 실시간 내에 해를 구하기가 어려워지므로 본 논문에서는 B-DCS망을 위한 운용회선 및 예비회선의 최적할당 문제, 간선링을 위한 다중링 부하최적화 문제, 지선링을 위한 중첩링 부하최적화 문제에 대한 휴리스틱 알고리즘을 각각 개발하여 사례분석을 통해 그 효용성을 보인다.