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Virtual network embedding in software-defined hybrid networks

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The Journal of China Universities of Posts and Telecommunications 2018年第4期25卷 75-85页

作者： Xu Ran Wang Wendong gong xiangyang Que Xirong State Key Laboratory of Networking and Switching Technology Beijing University of Posts and Telecommunication

Network virtualization provides a powerful way of sharing substrate networks. Efficient allocation of network resources for multiple virtual networks( VNs) has always been a challenging task. Especially under the everincreasing demand of customized VN requests,many problems arise as network conditions change *** with the emergance of resource conflict alongside the development of VNs,service provider( SP) needs to provide a faster and more effective solution. Recently,software defined network( SDN) has emerged as a new networking paradigm,SDN’s centralized control and customizable routing features present new opportunities for convenient and flexible embedding VNs in the network. However,due to the limitations of SDN,replacing all legacy devices in current operational networks by SDN-enabled switches in a short span of time is ***,in our study,we focus on the scenario of VN embedding( VNE) in software-defined hybrid networks. In this work,first of all,we propose partially deploying SDN nodes; and then,we use the characteristics of SDN to allocate resources for VN requests,and redirect the path for requests conflict in hybrid SDN network. We formulate the problems and provide simple algorithms to solve them. Simulation results show that our scheme has high ratio in responsiveness and acceptance.

关键词： SDN hybrid network VNE

On the feasibility and efficacy of control traffic protection in software-defined networks

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Science China(Information Sciences) 2015年第12期58卷 44-62页

作者： HU YanNan WANG WenDong gong xiangyang QUE XiRong CHENG ShiDuan State Key Laboratory of Networking and Switching Technology Beijing University of Posts and Telecommunications

Software Defined Networking(SDN) is an emerging networking paradigm that assumes a logically centralized control plane separated from the data plane. Despite all its advantages, separating the control and data planes introduces new challenges regarding resilient communications between the two. That is, disconnections between switches and their controllers could result in substantial packet loss and performance *** paper addresses this challenge by studying the issue of control traffic protection in SDNs with arbitrary numbers of controllers. Specifically, we propose a control traffic protection scheme that combines both local rerouting and constrained reverse path forwarding protections, through which switches can locally react to failures and redirect the control traffic using standby backup forwarding options. Our goal is then to find a set of primary routes for control traffic, called protected control network, where as many switches as possible can benefit from the proposed protection scheme. We formulate the protected control network problem, prove its NP-hardness, and develop an algorithm that reconciles protectability and performance(e.g., switch-to-control latency). Through extensive simulations based on real topologies, we show that our approach significantly improves protectability of control traffic. The results should help further the process of deploying SDN in real-world networks.

关键词： software-defined network protection control traffic resilience optimization

A Semi-Supervised Topic Model Incorporating Sentiment and Dynamic Characteristic

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China Communications 2016年第12期13卷 162-175页

作者： Lanshan Zhang Xi Ding Ye Tian xiangyang gong Wendong Wang Beijing Key Laboratory of Network System and Network Culture Beijing University of Posts and Telecommunications State Key Lab of Networking and Switching Technology Beijing University of Posts and Telecommunications

With the rapid popularization of social applications, various kinds of social media have developed into an important platform for publishing information and expressing opinion. Detecting hidden topics from the huge amount of user-generated contents is of great commerce value and social significance. However traditional text analysis approachesonly focus on the statistical correlation between words, but ignore the sentiment tendency and the temporal properties which may have great effects on topic detection results. This paper proposed a Dynamic Sentiment-Topic(DST) model which can not only detect and track the dynamic topics but also analyze the shift of public's sentiment tendency towards certain ***-Maximization algorithm was used in DST model to estimate the latent distribution, and we used Gibbs sampling method to sample new document set and update the hyper parameters and *** are conducted on a real dataset and the results show that DST model outperforms the existing algorithms in terms of topic detection and sentiment accuracy.

关键词： dynamic sentiment-topic model sentiment analysis topic detection

Recent advances in molecular fluorescent probes for organic phosphate biomolecules recognition

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Chinese Chemical Letters 2019年第10期30卷 1775-1790页

作者： Wei Li xiangyang gong Xiaopeng Fan Shulu Yin Dongdong Su Xiaobing Zhang Lin Yuan State Key Laboratory of Chemo/Biosensing and Chemometrics College of Chemistry and Chemical EngineeringHunan UniversityChangsha 410082China Department of Chemistry and Chemical Engineering Beijing University of TechnologyBeijing 100124China

Organic phosphate biomolecules(OPBs) are indispensable components of eukaryotes and prokaryotes,such as acting as the fundamental components of cell membranes and important substrates for nucleic acids. They play pivotal roles in various biological processes, such as energy conservation, metabolism,and signal modulation. Due to the difficulty of detection caused by variety OPBs, investigation of their respective physiological effects in organisms has been restrained by the lack of efficient tools. Many small fluorescent probes have been employed for selective detection and monitoring of OPBs in vitro or in vivo due to the advantages of tailored properties, biodegradability and in situ high temporal and spatial resolution imaging. In this review, we summarize the recent advances in fluorescent probes for OPBs,such as nucleotides, NAD(P)H, FAD/FMN and PS. Importantly, we describe their identification mechanisms in detail and discuss the general strategies for these OPBs probe designs, which provide new insights and ideas for the future probe designs.

关键词： Organic phosphate biomolecules (OPBs) Fluorescent probes Selective detection Fluorescent imaging Design strategies

Applications of Acrylate-based Polymer and Silicone Resin on LPFG-based Devices

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High Technology Letters 2002年第2期8卷 31-34页

作者：何万迅 Shi Wenkang gong xiangyang Ye Ailun GAO Kan Fang Zujie School of Electronics & Information Technology Shanghai Jiaotong University Shanghai 200030 P.R.China Shanghai Institute of Optics and Fineness Mechanics Shanghai 201800 P.R.China

Both acrylate based polymer and silicone resin are proposed as recoating materials surrounding LPFGs for purposes of different applications. For the LPFG recoated with a thin layer of acrylate based polymer, the range of wavelength shift as much as 60nm is expected when temperature changes from 0～100℃. As for that with surrounding material of silicone resin, the temperature stability is greatly improved depicted as the maximum wavelength shift of about 0.6nm with the same temperature variation. The former is potentially a broadband tunable band rejection filter or temperature sensor with enhanced sensitivity. And the latter could be applied as temperature insensitive filter, demultiplexer or strain sensor.

关键词： long period fiber grating resonance wavelength wavelength tuning temperature compensation

On the feasibility and efficacy of control traffic protection in software-defined networks

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Science China Chemistry 2015年第12期58卷 40-58页

作者： HU YanNan WANG WenDong gong xiangyang QUE XiRong CHENG ShiDuan State Key Laboratory of Networking and Switching Technology Beijing University of Posts and Telecommunications

Software Defined Networking （SDN） is an emerging networking paradigm that assumes a logically centralized control plane separated from the data plane. Despite all its advantages, separating the control and data planes introduces new challenges regarding resilient communications between the two. That is, disconnec- tions between switches and their controllers could result in substantial packet loss and performance degradation. This paper addresses this challenge by studying the issue of control traffic protection in SDNs with arbitrary numbers of controllers. Specifically, we propose a control traffic protection scheme that combines both local rerouting and constrained reverse path forwarding protections, through which switches can locally react to fail- ures and redirect the control traffic using standby backup forwarding options. Our goal is then to find a set of primary routes for control traffic, called protected control network, where as many switches as possible can benefit from the proposed protection scheme. We formulate the protected control network problem, prove its NP-hardness, and develop an algorithm that reconciles proteetability and performance （e.g., switch-to-control latency）. Through extensive simulations based on real topologies, we show that our approach significantly im- proves protectability of control traffic. The results should help further the process of deploying SDN in real-world networks.

关键词： software-defined network protection control traffic resilience optimization

Rapid resolution of subdural hematoma after targeted epidural blood patch treatment in patients with spontaneous intracranial hypotension

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Chinese Medical Journal 2014年第11期127卷 2063-2066页

作者： Wang Jin Zhang Dan gong xiangyang Ding Meiping Department of Neurology Sir Run Run Shaw Hospital Zhejiang University School of Medicine Sir Run Run Shaw Institute of Clinical Medicine of Zhejiang University Hangzhou Zhejiang 310016 China Department of Radiology Sir Run Run Shaw Hospital Zhejiang University School of Medicine Sir Run Run Shaw Institute of Clinical Medicine of Zhejiang University Hangzhou Zhejiang 310016 China Department of Neurology The Second Affiliated Hospital Zhejiang University School of Medicine Hangzhou Zhejiang 310009 China

Background Subdural hematoma （SDH） is a common complication of spontaneous intracranial hypotension （SIH）.To date,the management of SDH caused by SIH remains *** this paper,we reviewed the clinical course of SDH in patients with SIH,and discuss the underlying mechanism and attributing factors for rapid resolution of subdural hematomas after epidural blood patch （EBP） *** We retrospectively reviewed a cohort of seventy-eight SIH patients diagnosed and treated with targeted EBP in our neurology *** who received early CT/MRI follow-up after EBP operation were *** A series of four cases of SIH complicated with SDHs were *** follow-up neuroimages of these patients revealed that SDHs could be partially or totally absorbed just two to four days after targeted epidural blood patch *** Targeted epidural blood patch can result in rapid hematoma regression and good recovery in some patients with a combination of SDH and SIH.

关键词： cerebrospinal fluid leak spontaneous intracranial hypotension subdural hematoma epidural blood patch

Coverage Area Based Opportunistic Forwarding Algorithm in VANETs

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China Communications 2012年第12期9卷 56-67页

作者： Ding Yu Wang Wendong gong xiangyang Cui Yong Wang Bai State Key Laboratory of Networking and Switching Technology Beijing University of Posts and Telecommunications Beijing 100876 P. R. China Department of Computer Science and Technology Tsinghua University Beijing 100084 P. R. China School of Computer Science Beijing University of Posts and Telecommunications Beijing 100876 P. R. China

The highly mobility of vehicles, intermittent communication between the vehicles and the requirements of real time applications are some of the main challenges of multi-hop message delivery in Vehicular Ad Hoc Networks （ VANETs ）. There are also additional challenges, especially when the destination for the message delivery is a moving vehicle. In this paper, we propose a novel multihop message delivery method, called the Coverage Area-based oPportunistic message forwarding algorithm （CAP）. The main idea of CAP is to cover the potential area of a moving target vehicle as much as possible with the reachable area of the required delivery messages, so that the message can be delivered successfully. Because the success ratio and overhead of the multi-hop message delivery are two important but incompatible parameters in CAP, two tunings are discussed in the algorithm in order to maintain the balance of the two parameters. The simulation results show that compared with other reference approaches, CAP provides an efficient message delivery with a higher success ratio and a shorter message deNNy.

关键词： coverage area opportunistic forwarding message delivery routing VANETs

On Reliability-optimized Controller Placement for Software-Defined Networks

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China Communications 2014年第2期11卷 38-54页

作者： HU Yannan WANG Wendong gong xiangyang QUE Xirong CHENG Shiduan State Key Laboratory of Networking and Switching Technology Beijing University of Posts and Telecommunications Beijing 100876 PR.China

By decoupling control plane and data plane,Software-Defined Networking(SDN) approach simplifies network management and speeds up network *** benefits have led not only to prototypes,but also real SDN *** wide-area SDN deployments,multiple controllers are often required,and the placement of these controllers becomes a particularly important task in the SDN *** paper studies the problem of placing controllers in SDNs,so as to maximize the reliability of SDN control *** present a novel metric,called expected percentage of control path loss,to characterize the reliability of SDN control *** formulate the reliability-aware control placement problem,prove its NP-hardness,and examine several placement algorithms that can solve this *** extensive simulations using real topologies,we show how the number of controllers and their placement influence the reliability of SDN control ***,we also found that,through strategic controller placement,the reliability of SDN control networks can be significantly improved without introducing unacceptable switch-to-controller latencies.

关键词： Software-Defined Networking controller placement reliability networkoptimization