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Toward coordinated look-ahead reactive power optimisation for distribution networks with minimal control

IET GENERATION TRANSMISSION & DISTRIBUTION 2018年第11期12卷 2707-2717页

作者： Ding, Min Chiang, Hsiao-Dong Li, Peng Tianjin Univ Sch Elect & Informat Engn Tianjin Peoples R China Cornell Univ Sch ECE Ithaca NY USA China Southern Grid Co Elect Power Res Inst Guangzhou Guangdong Peoples R China

A coordinated look-ahead reactive power optimisation method is proposed to minimise the required number of operating control devices for a time horizon of 24h. The aim is to determine, via solving a mixed integer non-linear programming (MINLP) problem, optimum value settings of transformer taps, capacitor banks and reactive power output of distributed generators (DGs) based on the day-ahead load demand and active power output of DGs satisfying the engineering and operational constraints. The proposed method employs a three-stage method: assessment stage, time-period-partitioning stage, and coordinated reactive power optimisation stage. The first stage assesses the hourly voltage profile and available delivery capability margin of the system, while the time-period-partitioning stage uses clustering algorithm based on power-flow solution to partition time periods into coherent time durations. The MINLP problem is solved in the proposed coordinated optimisation stage. A modified IEEE13 case and IEEE123 case are used to verify the effectiveness of the proposed three-stage method.

关键词： power distribution control reactive power control integer programming nonlinear programming minimisation power transformers power capacitors distributed power generation pattern clustering load flow power generation control distribution network coordinated look-ahead reactive power optimisation method mixed integer nonlinear programming problem MINLP problem transformer tap capacitor bank reactive power output distributed generator DG day-ahead load demand active power output assessment stage method time-period-partitioning stage method coordinated reactive power optimisation stage method time-period-partitioning stage clustering algorithm power-flow solution modified IEEE13 case study IEEE123 case study time 24 h

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UHF partial discharge localisation method in substation based on dimension-reduced RSSI fingerprint

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IET GENERATION TRANSMISSION & DISTRIBUTION 2018年第2期12卷 398-405页

作者： Li, Zhen Luo, Lingen Sheng, Gehao Liu, Yadong Jiang, Xiuchen Shanghai Jiao Tong Univ Dept Elect Engn 800 Dongchuan Rd Shanghai Peoples R China

Ultra-high frequency (UHF) technique is chosen for partial discharge (PD) detection due to its excellent anti-interference and stability. The existing UHF PD localisation methods are mainly based on time-difference technique, that suffer high hardware cost due to the high sampling rate requirement. The wireless UHF sensors together with the scene analysis methods, i.e. received signal strength indicator (RSSI) fingerprint, provide us a low hardware cost and high environmental adaptability solution for PD localisation in substation. The proposed PD localisation method here is divided into two stages. In the offline stage, the RSSI fingerprint map is established by site survey. In the online stage, the position of PD source is estimated by a probabilistic approach. To reduce the influence of noise, the RSSI fingerprints are transformed to a low-dimensional subspace, while the most of redundant noise is discarded. Furthermore, the PD heterogeneity and interference in the offline stage are also discussed and solved by normalisation and clustering algorithm, respectively. A filed test is performed and the results indicate that the mean localisation error is 1.87m and 82.6% localisation errors are <3m. The workload in the offline stage is also reduced approximate to 50%.

关键词： partial discharge measurement substations interference suppression wireless sensor networks UHF detectors UHF measurement probability pattern clustering UHF partial discharge localisation method substation dimension-reduced RSSI fingerprint map ultrahigh frequency technique partial discharge detection PD detection antiinterference stability UHF PD localisation method time-difference technique wireless UHF sensor scene analysis method received signal strength indicator probabilistic approach clustering algorithm

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An Energy-efficient Competitive clustering algorithm for Wireless Sensor Networks using Mobile Sink

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INTERNATIONAL JOURNAL OF GRID AND DISTRIBUTED COMPUTING 2012年第4期5卷 79-92页

作者： Wang, Jin Yang, Xiaoqin Ma, Tinghuai Wu, Menglin Kim, Jeong-Uk Nanjing Univ Informat Sci & Technol Sch Comp & Software Nanjing 210044 Jiangsu Peoples R China Nanjing Univ Technol Coll Elect & Informat Engn Nanjing 211816 Jiangsu Peoples R China Sangmyung Univ Dept Energy Grid Seoul 110743 South Korea

Wireless sensor networks commonly consist of a large number of tiny sensor nodes that are deployed either inside the target area or very close to it to cooperatively monitor the target area. Energy efficiency and network lifetime are two challenges that most of researchers deal with. In this paper, to improve the performance of sensor networks, we propose an energy efficient competitive clustering algorithm for wireless sensor networks using a controlled mobile sink. clustering algorithm can effectively organize sensor nodes and the use of a controlled mobile sink node can mitigate hot spot problem or energy holes. The selection of optimal moving trajectory for sink nodes is an NP-hard problem. In our algorithm, we firstly study an competitive clustering algorithm in which cluster heads are rotated in each round and selected mainly based on their competition range and their residual energy. Besides, we use mobile sink node instead of fixed sink node. The mobile sink node moves at a certain speed along a predefined path and sojourn at some park position to collect data packets. Simulation results validate that competitive clustering algorithm outperforms LEACH and the use of mobile sink node significantly improve the performance of the sensor network.

关键词： wireless sensor network clustering algorithm mobile sink node

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Fuzzy c-means based coincidental link filtering in support of inferring social networks from spatiotemporal data streams

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SOFT COMPUTING 2018年第21期22卷 7015-7025页

作者： Zhang, Pu Shen, Qiang Aberystwyth Univ Dept Comp Sci Inst Math Phys & Comp Sci Aberystwyth SY23 3DB Dyfed Wales

Social network modelling offers an important computational mechanism for analysis of complex system behaviour. Social networks can be established by linking individuals based on observations of certain activities like physical proximity, by exploiting spatiotemporal data streams that have been acquired. A potentially powerful approach to building such networks is to computationally imitate the real-world foraging process of great tits, where the data streams required consist of the times and locations each tit of a certain population has appeared at. The method works by clustering individuals within the population into groups representing different gathering events with respect to the time and location. It links up the individuals appearing in the same events and subsequently, filters out those links that are set up coincidentally. However, the original filtering technique faces significant challenges when considering issues such as time and space complexity and non-unique parameters that are required for removing coincidental links. This paper presents an improved approach by the use of the popular fuzzy c-means method to reinforce the clustering of coincidental links in an emerging social network derived from spatiotemporal data. In particular, all links are organised into two groups: strong links or weak links, prior to the running of the filtering process. The efficacy of the modified version is demonstrated via systematic experimental comparisons against the performance of the original method.

关键词： Social networks Coincidental links clustering algorithm Fuzzy c-means Spatiotemporal data

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Improved method for deinterleaving radar signals and estimating PRI values

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IET RADAR SONAR AND NAVIGATION 2018年第5期12卷 506-514页

作者： Liu, Yanchao Zhang, Qunying Univ Chinese Acad Sci 19 A Yuquan Rd Beijing 1000492 Peoples R China Chinese Acad Sci Inst Elect 19 North 4th Ring Rd West Beijing 100190 Peoples R China Chinese Acad Sci Key Lab Electromagnet Radiat & Sensing Technol Lab 10 Beijing 100190 Peoples R China

In the electronic countermeasure, the electronic support measure (ESM) receiver intercepts the interleaved radar pulse streams, which radiates from surrounding radar emitters. At present, deinterleaving algorithm based on time of arrival which is called pulse repetition interval (PRI) deinterleaving occupies an important part of the ESM. The sequential difference histogram (SDIF) is a well-known and effective PRI deinterleaving algorithm, but it has several disadvantages. When the PRI jitter and pulse missing exist in the pulse streams, the SDIF algorithm cannot estimate the real PRI value reliably, and then cannot separate the radar pulse trains corresponding to the real PRI value from the interleaved pulse streams. In order to overcome these disadvantages, an improved SDIF algorithm using clustering algorithm and PRI transform is proposed. Simulation results have proved that this improved algorithm has higher reliability and accuracy in the presence of PRI jitter and pulse missing.

关键词： radar signal processing electronic countermeasures jitter military radar deinterleaving radar signals PRI value estimation electronic countermeasure electronic support measure ESM receiver interleaved radar pulse streams surrounding radar emitters time-of-arrival sequential difference histogram effective PRI deinterleaving algorithm PRI jitter pulse missing pulse streams SDIF algorithm radar pulse trains interleaved pulse streams PRI transform clustering algorithm

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Towards Obtaining Upper Bound on Sensitivity Computation Process for Cluster Validity Measures

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FUNDAMENTA INFORMATICAE 2018年第4期163卷 351-374页

作者： Mishra, Sumit Mondal, Samrat Saha, Sriparna Indian Inst Technol Patna Dept Comp Sci & Engn Patna 801103 Bihar India Indian Inst Informat Technol Guwahati Dept Comp Sci & Engn Gauhati 781015 Assam India

Cluster validity indices are proposed in the literature to measure the goodness of a clustering result. The validity measure provides a value which shows how good or bad the obtained clustering result is, as compared to the actual clustering result. However, the validity measures are not arbitrarily generated. A validity measure should satisfy some of the important properties. However, there are cases when in-spite of satisfying these properties, a validity measure is not able to differentiate the two clustering results correctly. In this regard, sensitivity as a property of validity measure is introduced to capture the differences between the two clustering results. However, sensitivity computation is a computationally expensive task as it requires to explore all the possible combinations of clustering results which are very large in number and these are growing exponentially. So, it is required to compute the sensitivity efficiently. As the possible combinations of clustering results grow exponentially, so it is required to first obtain an upper bound on this possible number of combinations which will be sufficient to compute the value of the sensitivity. In this paper, we obtain an upper bound on the number of possible combinations of clustering results. For this purpose, a generic approach which is suitable for various validity measures and a specific approach which is applicable for two validity measures are proposed. It is also shown that this upper bound is sufficient to compute the sensitivity of various validity measures. This upper bound is very less as compared to the total number of possible combinations of clustering results.

关键词： clustering algorithm sensitivity cluster validity measure

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Cluster-based emergency message dissemination strategy for VANET using V2V communication

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INTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS 2019年第5期32卷 e3897-e3897页

作者： Benkerdagh, Saliha Duvallet, Claude Univ Abd El Hamid Ibn Badis UMAB Comp Sci Dept Mostaganem Algeria Normandie Univ Comp Sci Dept UNIHAVRE UNIROUENINSA RouenLITIS F-76600 Le Havre France

Data dissemination in vehicular ad hoc network (VANET) is emerging as a critical area of research. One of the challenges posed by this domain is the reliability of connection, which depends on many parameters, such as the bandwidth consumption, transmission delay, and data quality of service (QoS). Dissemination of emergency messages is very critical since the network topology is changing frequently and rapidly, which leads to data loss. So, it is necessary to develop new protocols and enhance dissemination schemes in VANET to avoid more emergencies and hazards cases. In this regard, we have proposed a new strategy, which consists of data handling before dissemination process as the first step of our scheme. In this phase, the original message is optimized in order to reduce the number of exchanged packets. The second part of this proposition consists of constructing fast and stable clusters to improve the message delivery time and to procure efficient bandwidth consumption. This approach is based on a Fitness function, which takes into account different parameters such as the transmission period, the connectivity degree, the relative velocity, and the link lifetime validity. Since exchanging data in VANET is an important process, routing phase is proposed to perform data exchange among clusters. It is based on a rapid and real-time heuristic (real-time adaptive A* [RTAA*]). To evaluate the reliability of the proposed approach, an urban scenario is used with different simulation parameters. The simulation results show that our proposed approach presents a better stability and efficiency performance compared with the discussed approaches. The proposed approach improves the performance of cluster duration (5% - 25%), delivery rate (2% - 8%), and the overhead (5% - 35%) on average compared with the discussed approaches.

关键词： clustering algorithm data dissemination Fitness function quality of service routing transmission delay

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Inclusion measures of probabilistic linguistic term sets and their application in classifying cities in the Economic Zone of Chengdu Plain

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APPLIED SOFT COMPUTING 2019年 82卷 105572-000页

作者： Tang, Ming Long, Yilu Liao, Huchang Xu, Zeshui Sichuan Univ Business Sch Chengdu 610064 Sichuan Peoples R China

The probabilistic linguistic term set is a powerful tool to express and characterize people's cognitive complex information and thus has obtained a great development in the last several years. To better use the probabilistic linguistic term sets in decision making, information measures such as the distance measure, similarity measure, entropy measure and correlation measure should be defined. However, as an important kind of information measure, the inclusion measure has not been defined by scholars. This study aims to propose the inclusion measure for probabilistic linguistic term sets. Formulas to calculate the inclusion degrees are put forward Then, we introduce the normalized axiomatic definitions of the distance, similarity and entropy measures of probabilistic linguistic term sets to construct a unified framework of information measures for probabilistic linguistic term sets. Based on these definitions, we present the relationships and transformation functions among the distance, similarity, entropy and inclusion measures. We believe that more formulas to calculate the distance, similarity, inclusion degree and entropy can be induced based on these transformation functions. Finally, we put forward an orthogonal clustering algorithm based on the inclusion measure and use it in classifying cities in the Economic Zone of Chengdu Plain, China. (C) 2019 Elsevier B.V. All rights reserved.

关键词： Probabilistic linguistic term set Information measure Relationships clustering algorithm Classifying cities

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Based on the fuzzy clustering algorithm of the classification of the cluster CDN users design

Based on the fuzzy clustering algorithm of the classificatio...

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2nd International Conference on Instrumentation and Measurement, Computer, Communication and Control (IMCCC)

作者： Liu, Xiaoguo Jing, Tian Jilin Agr Univ Changchun Peoples R China Changchun Vocat Inst Technol Informat Branch Changchun Peoples R China

ISBN: (纸本)9780769549354

the research to improve the performance of network problems, in order to improve the CDN network of user division to solve problems, and put forward a kind of fuzzy clustering algorithm to differentiate the user cluster load balance algorithm, using this algorithm CDN user cluster, can detect the results from the client, update maintenance global load balance of content routing table, the user request redirect to more precise edge servers, improve service percentage. Make the content of the users need timely release, alleviate network congestion problem, enhance the user access to the network response speed.

关键词： global load balanceing elient-side probe user clustering data mining clustering algorithm

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Water-efficient sensing method for soil profiling in the paddy field

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International Journal of Agricultural and Biological Engineering 2018年第4期11卷 207-216页

作者： Zhenran Gao Jun Ni Yan Zhu Qi Jiang Weixing Cao National Engineering and Technology Center for Information Agriculture Jiangsu Key Laboratory for Information AgricultureJiangsu Collaborative Innovation Center for Modern Crop ProductionJiangsu Collaborative Innovation Center for the Technology and Application of Internet of ThingsNanjing Agricultural UniversityNanjing 210095China

The comprehensive and reliable perception of moisture in a soil profile is essential to *** establish an efficient method for sensing soil moisture,field trials were conducted to analyze the spatial and temporal variations of moisture in a paddy soil profile by using coefficients of *** results showed that soil layers at shallow depths undergo more extensive changes in the coefficients of *** perception is most sensitive within a depth range of 0-60 cm in the vertical soil profile of a paddy *** using the clustering algorithm of Euclidean distance,the paddy soil profile was divided into three categories based on soil *** first category includes depths ranging from 10-20 cm,the second is from 30-40 cm,and the third is from 50-100 *** analysis indicated that the most sensitive depths for moisture sensing in a paddy soil profile were 20 cm,30 cm,and 50 cm,whereas the most sensitive depths for moisture sensing by time stability analysis were 20 cm,40 cm,and 60 *** on the multiple regression of sensitive depths,the results of quantitative inversion indicated that the time stability analysis results were 0.962 when the(y,y)Coryy of path analysis was 0.980,and the time stability analysis was 0.61 when the root mean square error(RMSE)of path analysis was *** relative error range between the measured and predicted values of path analysis was less than that of time stability *** findings suggest that it is feasible to effectively sense the moisture of the entire vertical soil profile based on the sensitive *** present study has also determined that path analysis is superior to time stability analysis.

关键词： paddy field profile soil moisture perception clustering algorithm path analysis

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