83 research outputs found

    HABCO: A Robust Agent on Hybrid Ant-Bee Colony Optimization

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    The purpose of this research is to generate a robust agent by combining bee colony optimization (BCO) and ELU-Ants for solving traveling salesman problem (TSP), called HABCO. The robust agents, called ant-bees, firstly are grouped into three types scout, follower, recruiter at each stages. Then, the bad agents are high probably discarded, while the good agents are high probably duplicated in earlier steps. This first two steps mimic BCO algorithm. However, constructing tours such as choosing nodes, and updating pheromone are built by ELU-Ants method.To evaluate the performance of the proposed algorithm, HABCO is performed on several benchmark datasets and compared to ACS and BCO. The experimental results show that HABCO achieves the better solution, either with or without 2opt

    Design and Development of the Reactive BGP peering in Software-Defined Routing Exchanges

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    The Software-Defined Networking (SDN) is considered to be an improved solution for applying flexible control and operation recently in the network. Its characteristics include centralized management, global view, as well as fast adjustment and adaptation. Many experimental and research networks have already migrated to the SDN-enabled architecture. As the global network continues to grow in a fast pace, how to use SDN to improve the networking fields becomes a popular topic in research. One of the interesting topics is to enable routing exchanges among the SDN-enabled network and production networks. However, considering that many production networks are still operated on legacy architecture, the enabled SDN routing functionalities have to support hybrid mode in operation. In this paper, we propose a routing exchange mechanism by enabling reactive BGP peering actions among the SDN and legacy network components. The results of experiments show that our SDN controller is able to mask as an Autonomous System (AS) to exchange routing information with other BGP routers

    Design and Implementation of Monitoring Schemes for Software-Defined Routing over a Federated Multi-domain SDN Testbed

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    Emerging Software-Defined Networking (SDN) paradigm has been widely affecting most networking fields. However, the real-world SDN application for inter-domain routing management is still limited since the routing exchange among wide-area networks is quite complicate due to the extreme scale of global Internet connectivity. Several SDN-leveraged routing ideas are being proposed to improve the routing exchange among wide-area networks. Thus, in this paper, an on-going experience for experimenting and validating the inter-domain routing proposals over OF@TEIN federated testbed in Asia is shared. By focusing on the design and implementation of monitoring deployment for visibility support, we try to identify practical key points and provide improved monitoring for validating the performance and anomaly of the exchange. Other design considerations are also discussed together with possible future research directions

    A Flow-based Method to Measure Traffic Statistics in Software Defined Network

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    Since software defined network became a revolution of network, many new developments and deployments are put forward. Device operating in software defined network environment will need a controller to store control policy. As a result of flow is one of traffic presentation units in software defined network, hence, this paper proposed a prototype of flow-based method to measure traffic statistics which can be used in OpenFlow network. By analysis of flow table, active flows which managed by controller can be listed, and information of each flow can be presented with developed module on the controller. After gathered port statistics from OpenFlow switch and entries in flow table, information of each flow can be presented on a developed graphic interface. By using this method, Traffic statistics of each flow may be more adaptive and realizable for measurement for observation

    Planning and Implantation of NetFPGA Platform on Network Emulation Testbed

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    The concepts of cloud computing and Internet applications have expanded gradually and have become more and more important. Researchers need a new, high-speed network to build experimental environments for testing new network protocolswithout affecting existing traffic. In this paper, we describe a way to integrate NetFPGA platform, OpenFlow concept and NetFPGA reference designs into anetwork testbed to improve the packet processing speed and the dynamic adjustability for network emulation experiments. Furthermore, combined with Tunneling and VPLS, the proposed network testbed can be connected to distributed network, thus providing researchers a traffic-controllable and NIC-programmable experimental networking testbed in intra-communicating part

    Repairing the Inconsistent Fuzzy Preference Matrix Using Multiobjective PSO

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    This paper presents a method using multiobjective particle swarm optimization (PSO) approach to improve the consistency matrix in analytic hierarchy process (AHP), called PSOMOF. The purpose of this method is to optimize two objectives which conflict each other, while improving the consistency matrix. They are minimizing consistent ratio (CR) and deviation matrix. This study focuses on fuzzy preference matrix as one model comparison matrix in AHP. Some inconsistent matrices are repaired successfully to be consistent by this method. This proposed method offers some alternative consistent matrices as solutions

    Toward Inter-Connection on OpenFlow Research Networks

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    With the advance of Future Internet technologies, many research issues andideas are growing fast in recent years. In the field of network virtualization, softwaredefined network becomes a common topic on network research. In Taiwan, manyinstitutes and laboratories of universities already built their bench-scale testbed forresearch and educational use with OpenFlow protocol. As time goes by, stitchingexperimental networks is a growing trend to fulfill requirements for large scaleemulation. Hence, this paper revealed a progressing deployment which connectsdifferent experimental networks with centralized control policy. The objective is tobuild an integrated research network with a proposed solution which utilizesOpenFlow protocol to deal with the inter-connections. With a centralized controllerand implemented architecture, the deployment not only solves the limitation of VLANtag number in network but also improves the flexibility of configuration. This designcould be a solution for the realistic constraints of network environment in Taiwan, andit also supports the possibility of stitching regional experimental networks fornetworking research

    Association of exposure to air pollutants with gestational diabetes mellitus in Chiayi City, Taiwan

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    IntroductionWe investigated the associations of exposure to particulate matter with an aerodynamic diameter less than 2.5 μm (PM2.5) and several gaseous pollutants with risk of gestational diabetes mellitus (GDM) in Taiwan.MethodsWe retrospectively identified pregnant women who underwent a two-step approach to screen for GDM between 2006 and 2014. Information on concentrations of air pollutants (including PM2.5, sulfur dioxide [SO2], nitrogen oxides [NOx], and ozone [O3]) were collected from a single fixed-site monitoring station. We conducted logistic regression analyses to determine the associations between exposure to air pollutants and risk of GDM.ResultsA total of 11210 women were analyzed, and 705 were diagnosed with GDM. Exposure to PM2.5 during the second trimester was associated with a nearly 50% higher risk of GDM (odds ratio [OR] 1.47, 95% CI 0.96 to 2.24, p=0.077). The associations were consistent in the two-pollutant model (PM2.5 + SO2 [OR 1.73, p=0.038], PM2.5 + NOx [OR 1.52, p=0.064], PM2.5 + O3 [OR 1.96, p=0.015]), and were more prominent in women with age <30 years and body mass index <25 kg/m2 (interaction p values <0.01).DiscussionExposure to PM2.5 was associated with risk of GDM, especially in women who were younger or had a normal body mass index
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