This paper focuses on some key problems in web community discovery and link analysis.Based on the topic-oriented technology,the characteristics of a bipartite graph are studied.An Х bipartite core set is introduced t...This paper focuses on some key problems in web community discovery and link analysis.Based on the topic-oriented technology,the characteristics of a bipartite graph are studied.An Х bipartite core set is introduced to more clearly define extracting ways.By scanning the topic subgraph to construct Х bipartite graph and then prune the graph with i and j ,an Х bipartite core set,which is also the minimum element of a community,can be found.Finally,a hierarchical clustering algorithm is applied to many Х bipartite core sets and the dendrogram of the community inner construction is obtained.The correctness of the constructing and pruning method is proved and the algorithm is designed.The typical datasets in the experiment are prepared according to the way in HITS（hyperlink-induced topic search）.Ten topics and four search engines are chosen and the returned results are integrated.The modularity,which is a measure of the strength of the community structure in the social network,is used to validate the efficiency of the proposed method.The experimental results show that the proposed algorithm is effective and efficient.展开更多
In the wireless sensor networks(WSN),the sensor nodes have limited battery life and are deployed in hostile environments.It is very difficult to recharging or replacement of the batteries after deployment for the sens...In the wireless sensor networks(WSN),the sensor nodes have limited battery life and are deployed in hostile environments.It is very difficult to recharging or replacement of the batteries after deployment for the sensor nodes in inaccessible areas.Therefore,how to increase the network lifetime of the WSN is deserved to be studied.In this study,a WSN routing algorithm was proposed based on block clustering and springboard nodes to increase the network lifetime of the WSN.Firstly,by analyzing the influence of communication transmission distance on network energy consumption,block clustering was introduced to control node transmission distance in order to reduce total network energy consumption.In addition,a network transmission model was proposed based on springboard nodes and the advantages of network energy consumption of this model against multi-hop between clusters were analyzed.The simulation results show that,compared with the LEACH algorithm,EECPK-means algorithm and energy centroid clustering algorithm,the proposed routing algorithm effectively prolongs the network lifetime of WSN.展开更多
文摘稀疏子空间聚类(Sparse subspace clustering,SSC)算法在处理高光谱遥感影像时,地物的划分精度较低,为了提高地物划分精度,本文提出了一种基于信息熵的加权块稀疏子空间聚类算法(Weighted block sparse subspace clustering algorithm based on information entropy,EBSSC)。信息熵权重与块对角约束的引入,可以在仿真实验前获得两像素属于同一类别的先验概率,从而正向干预模型求解出的解趋于块对角结构的最优近似解,使模型获得对抗噪声和异常值的性能,从而提高模型分类的判别能力,以获得更好的地物划分精度。在3个经典高光谱遥感数据集上的实验结果表明,本文算法聚类高光谱影像的效果优于现有的几个经典流行的子空间聚类算法。
基金The National Natural Science Foundation of China(No.60773216)the National High Technology Research and Development Program of China(863Program)(No.2006AA010109)+1 种基金the Natural Science Foundation of Renmin University of China(No.06XNB052)Free Exploration Project(985 Project of Renmin University of China)(No.21361231)
文摘This paper focuses on some key problems in web community discovery and link analysis.Based on the topic-oriented technology,the characteristics of a bipartite graph are studied.An Х bipartite core set is introduced to more clearly define extracting ways.By scanning the topic subgraph to construct Х bipartite graph and then prune the graph with i and j ,an Х bipartite core set,which is also the minimum element of a community,can be found.Finally,a hierarchical clustering algorithm is applied to many Х bipartite core sets and the dendrogram of the community inner construction is obtained.The correctness of the constructing and pruning method is proved and the algorithm is designed.The typical datasets in the experiment are prepared according to the way in HITS（hyperlink-induced topic search）.Ten topics and four search engines are chosen and the returned results are integrated.The modularity,which is a measure of the strength of the community structure in the social network,is used to validate the efficiency of the proposed method.The experimental results show that the proposed algorithm is effective and efficient.
基金National Natural Science Foundation of China(Nos.61661025,61661026)。
文摘In the wireless sensor networks(WSN),the sensor nodes have limited battery life and are deployed in hostile environments.It is very difficult to recharging or replacement of the batteries after deployment for the sensor nodes in inaccessible areas.Therefore,how to increase the network lifetime of the WSN is deserved to be studied.In this study,a WSN routing algorithm was proposed based on block clustering and springboard nodes to increase the network lifetime of the WSN.Firstly,by analyzing the influence of communication transmission distance on network energy consumption,block clustering was introduced to control node transmission distance in order to reduce total network energy consumption.In addition,a network transmission model was proposed based on springboard nodes and the advantages of network energy consumption of this model against multi-hop between clusters were analyzed.The simulation results show that,compared with the LEACH algorithm,EECPK-means algorithm and energy centroid clustering algorithm,the proposed routing algorithm effectively prolongs the network lifetime of WSN.
