Wireless sensor networks are characterized by multihop wireless links and resource constrained nodes. In terms of data collection and forwarding scheduling, this paper investigates the load balancing in sensor nodes a...Wireless sensor networks are characterized by multihop wireless links and resource constrained nodes. In terms of data collection and forwarding scheduling, this paper investigates the load balancing in sensor nodes and wireless link based on the performance of wireless sensor networks. Leveraging the property of dissimilarity distribution, a method to quantitatively evaluate the benefits of load balancing is presented, in order to access the profitability. Then a novel Dynamic Load Balancing of Overlay-based WSN (DLBO) algorithm has been put forward. In particular, the tradeoff between transferring ratio and the load imbalance among nodes is discussed. The load balancing method in this paper outperforms others based on balancing factor, different nodes number and data scales of applications. The proposed model and analytical results can be effectively applied for reliability analysis for other wireless applications (e.g., persistent data delivery is involved).展开更多
Infrastructure as a Service （laaS） has brought advantages to users because virtualization technology hides the details of the physical resources, but this leads to the problem of users being unable to perceive their...Infrastructure as a Service （laaS） has brought advantages to users because virtualization technology hides the details of the physical resources, but this leads to the problem of users being unable to perceive their security. This defect has obstructed cloud computing from wide-spread popularity and development. To solve this problem, a dynamic measurement protocol in laaS is presented in this paper. The protocol makes it possible for the user to get the real-time security status of the resources, thereby solving the problem of guaranteeing dynamic credibility. This changes the cloud service security provider from the operator to the users themselves. This study has verified the security of the protocol by means of Burrow-Abadi-Needham （BAN） logic, and the result shows that it can satisfy requirements for innovation, privacy, and integrity. Finally, based on different laaS platforms, this study has conducted a performance analysis to demonstrate that this protocol is reliable, secure, and efficient.展开更多
The evolution of networks in rural industrial clusters,in particular in the context of China has been paid more attention to in the world.Applying the theory and techniques of social network analysis (SNA),this study ...The evolution of networks in rural industrial clusters,in particular in the context of China has been paid more attention to in the world.Applying the theory and techniques of social network analysis (SNA),this study is with particular regard to the business network relationships and their evolutionary dynamics of steel measuring tape manufacturing clustered in Nanzhuang Village,Yucheng County of Henan Province,China,which is important for better understanding the industrial and regional development in less developed rural areas.From data collected by comprehensive questionnaire survey in 2002 and mass interviews with 60 enterprises and assembling families and several government authorities in 2002,2003,2004,2005 and 2008,four types of networks are identified: spin-off,consulting,communication and cooperative.The characteristic of these networks is outlined in detail.Compared with the high-tech clusters of typical developed areas,the networks that have evolved in traditional manufacturing clusters are more affected by emotive linkages.The cluster networks are shown to exhibit a polycentric hierarchical structure.The family relationships are the dominate spin-off channels of enterprises,while the supply and demand relationships and the mobility of the skilled workers are also important paths of network learning,and the cooperation relationships are comparatively stable.Besides the root enterprises,the middle-sized enterprises are comparatively more active than small-sized enterprises,and the intermediary agencies and the service institutions act as bridges of the inter-enterprises cooperation.By analysis of the structure of networks and the interactions between the networks,the four stages of network evolution are also identified.The four stages are dominated by the family networks,the internal division production networks,the local innovation networks and the global supply networks respectively,and they play different roles in cluster development.展开更多
A tiny fraction of influential individuals play a critical role in the dynamics on complex systems. Identifying the influential nodes in complex networks has theoretical and practical significance. Considering the unc...A tiny fraction of influential individuals play a critical role in the dynamics on complex systems. Identifying the influential nodes in complex networks has theoretical and practical significance. Considering the uncertainties of network scale and topology, and the timeliness of dynamic behaviors in real networks, we propose a rapid identifying method（RIM）to find the fraction of high-influential nodes. Instead of ranking all nodes, our method only aims at ranking a small number of nodes in network. We set the high-influential nodes as initial spreaders, and evaluate the performance of RIM by the susceptible-infected-recovered（SIR） model. The simulations show that in different networks, RIM performs well on rapid identifying high-influential nodes, which is verified by typical ranking methods, such as degree, closeness, betweenness,and eigenvector centrality methods.展开更多
针对中压配电网缺少实时量测、伪量测精度较低以及现有的动态状态估计(dynamic state estimation,DSE)方法均采用恒定系统处理状态过程噪声的问题,提出了一种基于改进自适应无迹卡尔曼滤波(unscented kalman filter,UKF)算法的中压配电...针对中压配电网缺少实时量测、伪量测精度较低以及现有的动态状态估计(dynamic state estimation,DSE)方法均采用恒定系统处理状态过程噪声的问题,提出了一种基于改进自适应无迹卡尔曼滤波(unscented kalman filter,UKF)算法的中压配电网鲁棒DSE方法。首先,利用中压配电网变压器低压侧的智能电表量测和变压器模型,推导出等效中压量测以增强中压配网量测冗余度;然后,借鉴信号处理技术对系统状态过程噪声的协方差矩阵实时更新并融入UKF算法,以减轻状态预测和量测滤波的不确定性;最后,基于15节点中压配电网进行仿真。仿真结果表明:所提方法能够有效地进行中压配电网的动态状态估计,获取更为精确的态势感知信息。展开更多
文摘Wireless sensor networks are characterized by multihop wireless links and resource constrained nodes. In terms of data collection and forwarding scheduling, this paper investigates the load balancing in sensor nodes and wireless link based on the performance of wireless sensor networks. Leveraging the property of dissimilarity distribution, a method to quantitatively evaluate the benefits of load balancing is presented, in order to access the profitability. Then a novel Dynamic Load Balancing of Overlay-based WSN (DLBO) algorithm has been put forward. In particular, the tradeoff between transferring ratio and the load imbalance among nodes is discussed. The load balancing method in this paper outperforms others based on balancing factor, different nodes number and data scales of applications. The proposed model and analytical results can be effectively applied for reliability analysis for other wireless applications (e.g., persistent data delivery is involved).
基金supported by the National Basic Research Program of China (No. 2014CB340600)the National Natural Science Foundation of China (Nos. 61332019, 61173138, 6127245, and 91118003)the New Products and Technology Research and Development Projects of Hubei Province (No. 2012BAA03004)
文摘Infrastructure as a Service （laaS） has brought advantages to users because virtualization technology hides the details of the physical resources, but this leads to the problem of users being unable to perceive their security. This defect has obstructed cloud computing from wide-spread popularity and development. To solve this problem, a dynamic measurement protocol in laaS is presented in this paper. The protocol makes it possible for the user to get the real-time security status of the resources, thereby solving the problem of guaranteeing dynamic credibility. This changes the cloud service security provider from the operator to the users themselves. This study has verified the security of the protocol by means of Burrow-Abadi-Needham （BAN） logic, and the result shows that it can satisfy requirements for innovation, privacy, and integrity. Finally, based on different laaS platforms, this study has conducted a performance analysis to demonstrate that this protocol is reliable, secure, and efficient.
基金Under the auspices of National Natural Science Foundation of China (No.41071080,41071082)Key Bidding Project for Soft Science in Henan Province in 2010 (No.102400410002)Key Project of the Humanities and Social Sciences Research Base in Ministry of Education (No.YRCSD08A10)
文摘The evolution of networks in rural industrial clusters,in particular in the context of China has been paid more attention to in the world.Applying the theory and techniques of social network analysis (SNA),this study is with particular regard to the business network relationships and their evolutionary dynamics of steel measuring tape manufacturing clustered in Nanzhuang Village,Yucheng County of Henan Province,China,which is important for better understanding the industrial and regional development in less developed rural areas.From data collected by comprehensive questionnaire survey in 2002 and mass interviews with 60 enterprises and assembling families and several government authorities in 2002,2003,2004,2005 and 2008,four types of networks are identified: spin-off,consulting,communication and cooperative.The characteristic of these networks is outlined in detail.Compared with the high-tech clusters of typical developed areas,the networks that have evolved in traditional manufacturing clusters are more affected by emotive linkages.The cluster networks are shown to exhibit a polycentric hierarchical structure.The family relationships are the dominate spin-off channels of enterprises,while the supply and demand relationships and the mobility of the skilled workers are also important paths of network learning,and the cooperation relationships are comparatively stable.Besides the root enterprises,the middle-sized enterprises are comparatively more active than small-sized enterprises,and the intermediary agencies and the service institutions act as bridges of the inter-enterprises cooperation.By analysis of the structure of networks and the interactions between the networks,the four stages of network evolution are also identified.The four stages are dominated by the family networks,the internal division production networks,the local innovation networks and the global supply networks respectively,and they play different roles in cluster development.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61374180 and 61373136)the Ministry of Education Research in the Humanities and Social Sciences Planning Fund Project,China(Grant No.12YJAZH120)the Six Projects Sponsoring Talent Summits of Jiangsu Province,China(Grant No.RLD201212)
文摘A tiny fraction of influential individuals play a critical role in the dynamics on complex systems. Identifying the influential nodes in complex networks has theoretical and practical significance. Considering the uncertainties of network scale and topology, and the timeliness of dynamic behaviors in real networks, we propose a rapid identifying method（RIM）to find the fraction of high-influential nodes. Instead of ranking all nodes, our method only aims at ranking a small number of nodes in network. We set the high-influential nodes as initial spreaders, and evaluate the performance of RIM by the susceptible-infected-recovered（SIR） model. The simulations show that in different networks, RIM performs well on rapid identifying high-influential nodes, which is verified by typical ranking methods, such as degree, closeness, betweenness,and eigenvector centrality methods.
文摘针对中压配电网缺少实时量测、伪量测精度较低以及现有的动态状态估计(dynamic state estimation,DSE)方法均采用恒定系统处理状态过程噪声的问题,提出了一种基于改进自适应无迹卡尔曼滤波(unscented kalman filter,UKF)算法的中压配电网鲁棒DSE方法。首先,利用中压配电网变压器低压侧的智能电表量测和变压器模型,推导出等效中压量测以增强中压配网量测冗余度;然后,借鉴信号处理技术对系统状态过程噪声的协方差矩阵实时更新并融入UKF算法,以减轻状态预测和量测滤波的不确定性;最后,基于15节点中压配电网进行仿真。仿真结果表明:所提方法能够有效地进行中压配电网的动态状态估计,获取更为精确的态势感知信息。
