随着集中式电力市场规模的扩大,需要设置电力枢纽节点作为现货市场上可以进行统一交易的聚合节点,其同时也是电力金融市场发展与稳定运行的基石,对构建统一电力市场体系、完善市场功能具有十分重要的意义。枢纽节点设计的难点在于枢纽...随着集中式电力市场规模的扩大,需要设置电力枢纽节点作为现货市场上可以进行统一交易的聚合节点,其同时也是电力金融市场发展与稳定运行的基石,对构建统一电力市场体系、完善市场功能具有十分重要的意义。枢纽节点设计的难点在于枢纽节点数量的确定,需要通过合适的数量选取以保证对电力市场定价节点的准确覆盖,体现电力空间价值。针对枢纽节点数量选取这一枢纽节点设计的关键问题,提出了一种基于t-SNE(t-distributedstochasticneighbor embedding)降维和DBSCAN(density-based spatial clustering of applications with noise)分类的枢纽节点数量确定方法。首先,通过与KPCA(kernelprincipalcomponentanalysis)、UMAP(uniform manifold approximation and projection)等典型降维方法的对比实验,证明t-SNE对数据拥挤的高维节点电价集有更好的降维效果,其数据可视化效果符合通过降维使得定价节点分成尽可能独立的类的预期。其次,应用DBSCAN算法在基于密度的基础上去除异常点与偏离点并进行分类,通过交叉熵有效选取DBSCAN最佳域值,确定最优分类数。最后,通过一系列分类的内部有效性评价指标,证明了该方法的准确性与有效性,为进一步的枢纽区域划分提供合理依据。展开更多
In order to avoid internal attacks during data aggregation in wireless sensor networks, a grid-based network architecture fit for monitoring is designed and the algorithms for network division, initialization and grid...In order to avoid internal attacks during data aggregation in wireless sensor networks, a grid-based network architecture fit for monitoring is designed and the algorithms for network division, initialization and grid tree construction are presented. The characteristics of on-off attacks are first studied and monitoring mechanisms are then designed for sensor nodes. A Fast Detection and Slow Recovery (FDSR) algorithm is proposed to prevent on-off attacks by observing the behaviors of the nodes and computing reputations. A recovery mechanism is designed to isolate malicious nodes by identifying the new roles of nodes and updating the grid tree. In the experiments, some situations of on-off attacks are simulated and the results are compared with other approaches. The experimental results indicate that our approach can detect malicious nodes effectively and guarantee secure data aggregation with acceptable energy consumption.展开更多
Wireless sensor network is becoming more and more popular in recent years, but energy- constrained characteristic of sensor nodes is one of the critical issues that we must consider in system design. In this paper, a ...Wireless sensor network is becoming more and more popular in recent years, but energy- constrained characteristic of sensor nodes is one of the critical issues that we must consider in system design. In this paper, a cluster-based virtual VBLAST transmission scheme is proposed to achieve energy savings for energy-constrained wireless sensor networks. In the proposed scheme, instead of using cluster member as cooperative nodes, multiple cluster heads cooperate to form virtual antenna array so that V-BLAST based virtual MIMO transmission can be implemented. Based on the communication energy consumption model, a way to optimize the parameters for the scheme is given. In addition, detailed simulation is performed to evaluate the performance of the proposed scheme for both densely and sparsely deployed sensor networks. Theoretical analysis and simulation results verify the energy efficiency of the proposed scheme.展开更多
Wireless sensor networks(WSNs)consist of a great deal of sensor nodes with limited power,computation,storage,sensing and communication capabilities.Data aggregation is a very important technique,which is designed to s...Wireless sensor networks(WSNs)consist of a great deal of sensor nodes with limited power,computation,storage,sensing and communication capabilities.Data aggregation is a very important technique,which is designed to substantially reduce the communication overhead and energy expenditure of sensor node during the process of data collection in a WSNs.However,privacy-preservation is more challenging especially in data aggregation,where the aggregators need to perform some aggregation operations on sensing data it received.We present a state-of-the art survey of privacy-preserving data aggregation in WSNs.At first,we classify the existing privacy-preserving data aggregation schemes into different categories by the core privacy-preserving techniques used in each scheme.And then compare and contrast different algorithms on the basis of performance measures such as the privacy protection ability,communication consumption,power consumption and data accuracy etc.Furthermore,based on the existing work,we also discuss a number of open issues which may intrigue the interest of researchers for future work.展开更多
文摘随着集中式电力市场规模的扩大,需要设置电力枢纽节点作为现货市场上可以进行统一交易的聚合节点,其同时也是电力金融市场发展与稳定运行的基石,对构建统一电力市场体系、完善市场功能具有十分重要的意义。枢纽节点设计的难点在于枢纽节点数量的确定,需要通过合适的数量选取以保证对电力市场定价节点的准确覆盖,体现电力空间价值。针对枢纽节点数量选取这一枢纽节点设计的关键问题,提出了一种基于t-SNE(t-distributedstochasticneighbor embedding)降维和DBSCAN(density-based spatial clustering of applications with noise)分类的枢纽节点数量确定方法。首先,通过与KPCA(kernelprincipalcomponentanalysis)、UMAP(uniform manifold approximation and projection)等典型降维方法的对比实验,证明t-SNE对数据拥挤的高维节点电价集有更好的降维效果,其数据可视化效果符合通过降维使得定价节点分成尽可能独立的类的预期。其次,应用DBSCAN算法在基于密度的基础上去除异常点与偏离点并进行分类,通过交叉熵有效选取DBSCAN最佳域值,确定最优分类数。最后,通过一系列分类的内部有效性评价指标,证明了该方法的准确性与有效性,为进一步的枢纽区域划分提供合理依据。
基金National High Technology Research and Development Program of China (863 Program) (No.2001AA512042) national 985 (105203200400006) project of applying GIS and remote sensing innovating platform
基金This work was supported by the National Natural Science Foundation of China under Grant No. 60873199.
文摘In order to avoid internal attacks during data aggregation in wireless sensor networks, a grid-based network architecture fit for monitoring is designed and the algorithms for network division, initialization and grid tree construction are presented. The characteristics of on-off attacks are first studied and monitoring mechanisms are then designed for sensor nodes. A Fast Detection and Slow Recovery (FDSR) algorithm is proposed to prevent on-off attacks by observing the behaviors of the nodes and computing reputations. A recovery mechanism is designed to isolate malicious nodes by identifying the new roles of nodes and updating the grid tree. In the experiments, some situations of on-off attacks are simulated and the results are compared with other approaches. The experimental results indicate that our approach can detect malicious nodes effectively and guarantee secure data aggregation with acceptable energy consumption.
文摘Wireless sensor network is becoming more and more popular in recent years, but energy- constrained characteristic of sensor nodes is one of the critical issues that we must consider in system design. In this paper, a cluster-based virtual VBLAST transmission scheme is proposed to achieve energy savings for energy-constrained wireless sensor networks. In the proposed scheme, instead of using cluster member as cooperative nodes, multiple cluster heads cooperate to form virtual antenna array so that V-BLAST based virtual MIMO transmission can be implemented. Based on the communication energy consumption model, a way to optimize the parameters for the scheme is given. In addition, detailed simulation is performed to evaluate the performance of the proposed scheme for both densely and sparsely deployed sensor networks. Theoretical analysis and simulation results verify the energy efficiency of the proposed scheme.
基金supported in part by the National Natural Science Foundation of China(No.61272084,61202004)the Natural Science Foundation of Jiangsu Province(No.BK20130096)the Project of Natural Science Research of Jiangsu University(No.14KJB520031,No.11KJA520002)
文摘Wireless sensor networks(WSNs)consist of a great deal of sensor nodes with limited power,computation,storage,sensing and communication capabilities.Data aggregation is a very important technique,which is designed to substantially reduce the communication overhead and energy expenditure of sensor node during the process of data collection in a WSNs.However,privacy-preservation is more challenging especially in data aggregation,where the aggregators need to perform some aggregation operations on sensing data it received.We present a state-of-the art survey of privacy-preserving data aggregation in WSNs.At first,we classify the existing privacy-preserving data aggregation schemes into different categories by the core privacy-preserving techniques used in each scheme.And then compare and contrast different algorithms on the basis of performance measures such as the privacy protection ability,communication consumption,power consumption and data accuracy etc.Furthermore,based on the existing work,we also discuss a number of open issues which may intrigue the interest of researchers for future work.
