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基于馈线自动化的新型配电线路故障特征量自识别方法研究

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电工技术 2024年第16期 134-136,139页

作者：陈俊梁国网湖北省电力有限公司武汉供电公司湖北武汉430050

为了减少馈线自动化环境下新型配电线路单相断线故障引发的过电压、人员伤害、设备损坏等风险事故,提出一种基于负序电压电流相关系数的单相断线故障特征识别方法。通过研究馈线自动化背景下的配电网单相断线负序等效网络中负序电压与... 详细信息

为了减少馈线自动化环境下新型配电线路单相断线故障引发的过电压、人员伤害、设备损坏等风险事故,提出一种基于负序电压电流相关系数的单相断线故障特征识别方法。通过研究馈线自动化背景下的配电网单相断线负序等效网络中负序电压与电流的相位关系,采集故障特征点上游线路的负序电压和电流的相关系数。结果表明,在单相断线故障发生时,故障特征点上游的线路负序电压与电流的相关系数为负,而正常运行线路与故障线路分支的负序电压与电流的相关系数则为正。通过对这一特征量的采集和分析,能够有效识别基于馈线自动化的配电线路单相断线故障,并精确定位故障区域。

关键词：馈线自动化新型配电网故障量特征自识别系统单相断线

Cross-Layer QoS Enabled SDN-Like Publish/Subscribe Communication Infrastructure for IoT

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China Communications 2020年第3期17卷 149-167页

作者： Yulong Shi Yang Zhang junliang chen State Key Laboratory of Networking and Switching Technology Beijing University of Posts and TelecommunicationsBeijing 100876China

Publish/subscribe paradigm is often adopted to create the communication infrastructure of the Internet of Things(IoT)for many clients to access enormous real-time sensor ***,most current publish/subscribe middlewares are based on traditional ossified IP networks,which are difficult to enable Quality of Service(QoS).How to design the next generation publish/subscribe middleware has become an urgent *** emerging Software Defined Networking(SDN)provides new opportunities to improve the QoS of publish/subscribe facilities for delivering events in IoT owing to its customized programmability and centralized *** can encode event topics,priorities and security policies into flow entries of SDN-enabled switches to satisfy personalized QoS *** this paper,we propose a cross-layer QoS enabled SDN-like publish/subscribe communication infrastructure,aiming at building an IoT platform to seamlessly connect IoT services with SDN networks and improving the QoS of delivering *** first present an SDN-like topic-oriented publish/subscribe middleware architecture with a cross-layer QoS control *** we discuss prototype implementation,including topic management,topology maintenance,event routing and policy *** the end,we use differentiated services and cross-layer access control as cross-layer QoS scenarios to verify the *** results show that our middleware is effective.

关键词： IoT publish/subscribe software defined networking quality of service middleware

Design and Implementation of an Adaptive Feedback Queue Algorithm over Open Flow Networks

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China Communications 2018年第7期15卷 168-179页

作者： Jiawei Wu Xiuquan Qiao junliang chen Beijing University of Posts and Telecommunications Beijing 100876China

The concurrent presence of different types of traffic in multimedia applications might aggravate a burden on the underlying data network, which is bound to affect the transmission quality of the specified traffic. Recently, several proposals for fulfilling the quality of service(QoS) guarantees have been presented. However, they can only support coarse-grained QoS with no guarantee of throughput, jitter, delay or loss rate for different applications. To address these more challenging problems, an adaptive scheduling algorithm for Parallel data Processing with Multiple Feedback(PPMF) queues based on software defined networks(SDN) is proposed in this paper, which can guarantee the quality of service of high priority traffic in multimedia applications. PPMF combines the queue bandwidth feedback mechanism to realise the automatic adjustment of the queue bandwidth according to the priority of the packet and network conditions, which can effectively solve the problem of network congestion that has been experienced by some queues for a long time. Experimental results show PPMF significantly outperforms other existing scheduling approaches in achieving 35--80% improvement on average time delay by adjusting the bandwidth adaptively, thus ensuring the transmission quality of the specified traffic and avoiding effectively network congestion.

关键词： multimedia streams software defined networks quality of service priority-based adaptive feedback queues

An SDN-Based Publish/Subscribe-Enabled Communication Platform for IoT Services

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China Communications 2018年第1期15卷 95-106页

作者： Yali Wang Yang Zhang junliang chen State Key Laboratory of Networking and Switching technology Beijing University of Posts and Telecommunications Beijing 100876 China College of Computer and Information Engineering Henan Normal University Xinxiang Henan 453007 China

Publish/subscribe paradigm paves a way to integrate and serve many scalable, inter-operable Internet of Things(IoT) applications. The increasing IoT applications require new properties of publish/subscribe communication model, for example, strict quality of service(Qo S) guarantees, supporting a large number of widely distributed devices, etc. Software Defined Networking(SDN) enables personalized programming and individualized QoS supports for different applications. The combination of the two will have a good prospect. In this paper, we present an IoT-oriented communication platform which combines the publish/subscribe paradigm with SDN, aiming at establishing an IoT ecosystem to facilitate IoT services/applications accessing internet. We design the interaction logic of topic-based publish/subscribe middleware, and describe the setup and maintenance of topology information as well as event routing in detail, considering the characteristics of SDN. Finally, we exemplify its practicability with a deployed District Heating Control and Information Service System(DHCISS) and validity the effectiveness with some experiments.

关键词： IoT publish/subscribe paradigm QoS guarantee software defined networking

Enhancing Collaborative Filtering via Topic Model Integrated Uniform Euclidean Distance

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China Communications 2017年第11期14卷 48-58页

作者： Tieliang Gao Bo cheng junliang chen Ming chen State Key Laboratory of Networking and Switching Technology Beijing University of Posts and Telecommunications School of Business Xinxiang University Software Engineering College Zhengzhou University of Light Industry

Recommendation system can greatly alleviate the "information overload" in the big data era. Existing recommendation methods, however, typically focus on predicting missing rating values via analyzing user-item dualistic relationship, which neglect an important fact that the latent interests of users can influence their rating behaviors. Moreover, traditional recommendation methods easily suffer from the high dimensional problem and cold-start problem. To address these challenges, in this paper, we propose a PBUED(PLSA-Based Uniform Euclidean Distance) scheme, which utilizes topic model and uniform Euclidean distance to recommend the suitable items for users. The solution first employs probabilistic latent semantic analysis(PLSA) to extract users' interests, users with different interests are divided into different subgroups. Then, the uniform Euclidean distance is adopted to compute the users' similarity in the same interest subset; finally, the missing rating values of data are predicted via aggregating similar neighbors' ratings. We evaluate PBUED on two datasets and experimental results show PBUED can lead to better predicting performance and ranking performance than other approaches.

关键词： recommendation system topic model user interest uniform euclidean distance

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电厂运行管理信息化实践

电力系统装备 2024年第5期 167-169页

作者：朱辉陈俊良孟凯国网河南省电力公司商丘供电公司河南商丘476000

为深入挖掘地方电厂发电潜力,提升负荷高峰时段河南电网供电能力,促进清洁能源消纳,推动地方电厂与统调电厂同质化管理,文章以商丘地区管理的垃圾和生物质电厂为例,分析了电厂运行管理中基于地调OMS系统、互联网大区及D5000EMS系统搭建... 详细信息

为深入挖掘地方电厂发电潜力,提升负荷高峰时段河南电网供电能力,促进清洁能源消纳,推动地方电厂与统调电厂同质化管理,文章以商丘地区管理的垃圾和生物质电厂为例,分析了电厂运行管理中基于地调OMS系统、互联网大区及D5000EMS系统搭建的地方电厂运行管理平台,以此加强地方电厂的基础信息管理,实现网源协同、数据共享、聚合挖潜供电能力等精益化管理。

关键词：电厂运行管理信息化数据分析

Modeling and Analysis of Data Dependencies in Business Process for Data-Intensive Services

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China Communications 2017年第10期14卷 151-163页

作者： yuze huang jiwei huang budan wu junliang chen State Key Laboratory of Networking and Switching Technology Beijing University of Posts and Telecommunications Beijing 100876 China

With the growing popularity of data-intensive services on the Internet, the traditional process-centric model for business process meets challenges due to the lack of abilities to describe data semantics and dependencies, resulting in the inflexibility of the design and implement for the processes. This paper proposes a novel data-aware business process model which is able to describe both explicit control flow and implicit data flow. Data model with dependencies which are formulated by Linear-time Temporal Logic(LTL) is presented, and their satisfiability is validated by an automaton-based model checking algorithm. Data dependencies are fully considered in modeling phase, which helps to improve the efficiency and reliability of programming during developing phase. Finally, a prototype system based on j BPM for data-aware workflow is designed using such model, and has been deployed to Beijing Kingfore heating management system to validate the flexibility, efficacy and convenience of our approach for massive coding and large-scale system management in reality.

关键词： data-aware business process data-intensive services data dependency linear-time temporal logic(LTL) services computing

Exploring Application Layer Protocol Relationships in SoftSwitch

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China Communications 2009年第4期6卷 155-167页

作者： Zhu Xiaomin Liao Jianxin chen junliang Li Tonghong State Key Lab of Networking and Switching Technology Beijing University of Posts and Telecommunications Beijing 100876 China EBUPT Information Technology Co. Ltd. Beijing 100191 China Technical University of Madrid 28660 Madrid Spain

Relationships between application layer protocols in softswitch are explored in this *** notions, *** relationship and protocol grouping, are proposed, which are not clearly defined and even not paid much attention to *** the basis of a well known protocol relationship named protocol conversion, three novel protocol relationships including protocol collaboration relationship, protocol cooperation relationship and protocol independent relationship are presented, so that protocol relationships are classified into four *** to the functionality and purpose of each protocol, main protocols related to softswitch are divided into five *** to protocol conversion in softswitch, information flow trail(IFT) is utilized to facilitate problem solving.A decision rule for protocol conversion mode is proposed to guide how to choose between direct conversion and indirect conversion.A property of protocol relationships in softswitch is induced from all kinds of service scenarios of *** property summarizes protocol relationships within each protocol group or between two specific protocol groups.A merit of protocol grouping together with classification of protocol relationship is also *** effort of this paper pushes the protocol engineering to go ahead.

关键词： protocol relationship protocol grouping softswitch information flow trail

Boron-iron nanochains for selective electrocatalytic reduction of nitrate

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Chinese Chemical Letters 2021年第6期32卷 2073-2078页

作者： Fanfan Ni Yuanyuan Ma junliang chen Wei Luo Jianping Yang State Key Laboratory for Modification of Chemical Fibers and Polymer Materials College of Materials Science and EngineeringDonghua UniversityShanghai 201620China Institute of Functional Materials Donghua UniversityShanghai 201620China

The electrocatalysis of nitrate reduction reaction(NRR)has been considered to be a promising nitrate removal *** a highly effective iron-based electrocatalyst is an essential challenge for ***,boron-iron nanochains(B-Fe NCs)as efficient NRR catalysts were prepared via a facile lowcost and scalable *** Fe/B ratio of the B-Fe NCs-x can be elaborately adjusted to optimize the NRR catalytic *** to the electron transfer from boron to metal,the metal-metal bonds are weakened and the electron density near the metal atom centers are rearranged,which are favor of the conversion from NO3-into ***,the well-crosslinked chain-like architectures benefit the mass/electron transport to boost the exposure of abundant catalytic active *** experiments demonstrated that the optimized B-Fe NCs catalyst exhibits superior intrinsic electrocatalytic NRR activity of high nitrate conversion(~80%),ultrahigh nitrogen selectivity(~99%)and excellent long-term reactivity in the mixed electrolyte system(0.02 mol/L NaCl and 0.02 mol/L Na_(2)SO_(4)mixed electrolyte),and the electrocatalytic activity of the material shows poor performance at low chloride ion concentration(Nitrate conversion of~61%and nitrogen selectivity of~57%in 0.005 mol/L NaCl and 0.035 mol/L Na_(2)SO_(4)mixed electrolyte).This study provides a broad application prospect for further exploring the highefficiency and low-cost iron-based functional nanostructures for electrocatalytic nitrate reduction.

关键词： Nanostructured iron Boron doping Nitrate reduction reaction Electrocatalysis