• Management Science and Financial Engineering
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• 제12권2호
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• pp.37-62
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• 2006

This paper considers the problem of designing logical tunnels in virtual private networks considering QoS guarantee which restricts the number of tunnel hops for each traffic routing. The previous researches focused on the design of logical tunnel itself and Steiner-tree based solution algorithms were proposed. However, we show that for some objective settings it is not sufficient and is necessary to consider both physical and logical connectivity at the same time. Thereupon, the concept of the layered network is applied to the logical tunnel design problem in virtual private networks. The layered network approach considers the design of logical tunnel as well as its physical routing and we propose a modified branch-and-price algorithm which is known to solve layered network design problems effectively. To show the performance of the proposed algorithm, computational experiments have been done and the results show that the proposed algorithm solves the given problem efficiently and effectively.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 ITC-CSCC -3
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• pp.1371-1374
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• 2002

This paper compares four network con-figurations for using as the logical topology in multi- hop wavelength division multiplexing (WDM) networks. The regular network configurations studied in this paper axe ShuffleNet, de Bruijn graph, hypercube, and Man-hattan street network. Instead of using the weight mean hop distance of node placement problem for comparing optimum logical topology, we introduce a new objective function that includes h and the network cost. It can be seen that the network cost strongly depends on the logical topology selected for the implementation of the network. The objective of this paper is to find an optimum logical topology for WDM networks that gives low as well as low network cost.

• 융합보안논문지
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• 제12권3호
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• pp.75-83
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• 2012

높은 네트워크 대역폭과 고품질을 요구하는 고에너지 물리, 기상 기후 등과 같은 특정 연구 그룹간의 논리 네트워크를 구축하여, 일종의 특정 그룹별 사설 네트워크 구축과 운용이 최근 많이 요구되고 있다. 지금까지 국내에서는 KREONET과 같은 국가연구망이 중심이 되어 이러한 대용량 사설 네트워크 서비스를 제공하고 있으나 이러한 사설 네트워크에 대한 체계적이고 표준화된 구축 및 관리 방법이 없어 이에 대한 체계적인 연구가 시급한 실정이다. 이를 위해 본 논문은 L2 기반에서 다양한 그룹별 논리 네트워크를 구성하는 핵심 서비스 요소와 표준 프로토콜을 제시하고, 구성된 논리 네트워크 정보를 관리 모니터링 할 수 있는 시스템 구조를 제시하였다. 또한 본 논문은 네트워크 인프라 자원과 관련된 망의 운영정보, 구성정보, 성능정보, 장애정보 등에 대한 정보를 통합적으로 관리할 수 있는 표준화된 명세시스템 구조를 제시하였다.

• 한국산업정보학회:학술대회논문집
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• 한국산업정보학회 2000년도 추계공동학술대회논문집
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• pp.375-389
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• 2000

Fuzzy logic ignores some information in the reasoning process. Neural networks are powerful tools for the pattern processing, but, not appropriate for the logical reasoning. To model human knowledge, besides pattern processing capability, the logical reasoning capability is equally important. Another new neural network called neural logic network is able to do the logical reasoning. Because the fuzzy inference is a fuzzy logical reasoning, we construct fuzzy inference network based on the neural logic network, extending the existing rule- inference. network. And the traditional propagation rule is modified. For the search strategies to find out the belief value of a conclusion in the fuzzy inference network, we conduct a simulation to evaluate the search costs for searching sequentially and searching by means of search priorities.

• 한국멀티미디어학회논문지
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• 제4권2호
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• pp.189-196
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• 2001

퍼지 논리의 추론과정에서 일부의 정보가 무시되어 적절하지 못한 추론 결과를 초래 할 수 있다. 한편 신경망은 패턴 처리에는 적합하지만 인간의 지식을 모델링하기 위해서 필요한 논리적인 추론에는 부적합하다. 그러나 신경망의 변형인 신경 논리망을 이용하면 논리적인 추론이 가능하다. 따라서 본 논문에서는 기존의 신경 논리망을 기반으로 하는 추론네트워크를 확장하여 퍼지 추론 네트워크를 구성한다. 그리고 기존의 추론 네트워크에서 사용되는 전파규칙을 보완하여 적용한다. 퍼지 추론 네트워크상에서 퍼지 규칙의 실행부에 해당하는 명제의 믿음 값을 결정하기 위해서는 추론하고자 하는 명제에 연결된 노드들을 탐색해야 한다.

• 한국위성정보통신학회논문지
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• 제7권3호
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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.

• 한국통신학회논문지
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• 제28권6A호
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• pp.361-370
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• 2003

본 논문에서는 PNNI(Private Network to Network Interface) 기반의 무선 ATM 망에서 단말의 이동성을 보장하기 위해 기존의 위치 등록기 구조를 개선하고자 한다. 기존의 위치 등록기 구조는 위치 등록기를 물리적 계층으로 배치함으로 인해 다수의 데이터베이스가 요구되고, 데이터베이스 액세스 회수와 신호 트래픽 및 호 설정 지연 등이 증가하는 문제점을 갖고 있었다. 이 문제점을 보완하기 위해 본 논문에서는 논리적 계층 형태로 이루어진 위치 등록기 구조를 제시하고자 한다. 제안된 논리적 계층 구조에서는 위치 등록기를 논리적인 그룹으로 묶고, 이 그룹들을 다시 그룹으로 묶어서 위치 등록기의 논리적인 트리 형태로 만들어 상위 레벨의 위치 등록기의 역할을 하위 레벨의 위치 등록기 중 하나가 수행하도록 하고 있다. 기존의 위치 등록기 구조와 성능을 비교한 결과에서 제안된 논리적 계층 구조는 데이터베이스 수와 위치 관리비용 측면에서 우수한 성능을 보여주고 있다.

• Journal of the Optical Society of Korea
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• 제19권1호
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• pp.13-21
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• 2015

In recent years energy consumption has become a main concern for network development, due to the exponential increase of network traffic. Potential energy savings can be obtained from a load-adaptive scheme, in which a day can be divided into multiple time periods according to the variation of daily traffic patterns. The energy consumption of the network can be reduced by selectively turning off network components during the time periods with light traffic. However, the time segmentation of daily traffic patterns affects the energy savings when designing multiperiod logical topology in optical wavelength routed networks. In addition, turning network components on or off may increase the overhead of logical topology reconfiguration (LTR). In this paper, we propose two mixed integer linear programming (MILP) models to design the optimal logical topology for multiple periods in IP-over-WDM networks. First, we formulate the time-segmentation problem as an MILP model to optimally determine the boundaries for each period, with the objective to minimize total network energy consumption. Second, another MILP formulation is proposed to minimize both the overall power consumption (PC) and the reconfiguration overhead (RO). The proposed models are evaluated and compared to conventional schemes, in view of PC and RO, through case studies.

• 한국학교수학회논문집
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• 제1권1호
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• pp.29-34
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• 1998

We proposed the teaching method about the logical inference in highschool using Logic Network. This method that we proposed is better than Vendiagram method because that is able to represent the more conditions in plane. The contents of this paper explained the method that conclusion is drived from given conditions using Logic Network. And we gave some examples of the process of logical inference.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 ITC-CSCC -2
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• pp.1053-1056
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• 2000

In general, neural networks based modeling involves trying multiple networks with different architectures and/or training parameters in order to achieve the best accuracy. Only the single best-trained neural network is chosen, while the rest are discarded. However, using only the single best network may never give the best solution in every situation. Many researchers, therefore, propose methods to improve the accuracy of neural networks based modeling. In this paper, the idea of the logical combinations of neural networks is proposed and discussed in detail. The logical combination is constructed by combining the corresponding outputs of the neural networks with the logical “And” node. The experimental results based on simulated data show that the modeling accuracy is significantly improved when compared to using only the single best-trained neural network.