Aimed at the difficulties in accurately, comprehensively and systematically evaluating the reliability of industrial wireless sensor networks （WSNs）, a time-evolving state transition-Monte Carlo （TEST-MC） evaluati...Aimed at the difficulties in accurately, comprehensively and systematically evaluating the reliability of industrial wireless sensor networks （WSNs）, a time-evolving state transition-Monte Carlo （TEST-MC） evaluation method and a novel network function value representation method are proposed to evaluate the reliability of the IWSNs. First, the adjacency matrix method is used to characterize three typical topologies of WSNs including the mesh network, tree network and ribbon network. Secondly, the network function value method is used to evaluate the network connectivity, and the TEST-MC evaluation method is used to evaluate network reliability and availability. Finally, the variations in the reliability, connectivity and availability of these three topologies are presented. Simulation results show that the proposed method can quickly analyze the reliability of the networks containing typical WSN topologies, which provides an effective method for the comprehensive and accurate evaluation of the reliability of WSNs.展开更多
Fault tolerant ability is an important aspect for overall evaluation of distributed system(DS). This paper discusses three measures for the evaluation: node/edge connectivity, number of spanning trees and synthetic co...Fault tolerant ability is an important aspect for overall evaluation of distributed system(DS). This paper discusses three measures for the evaluation: node/edge connectivity, number of spanning trees and synthetic connectivity. A numerical example for illustration and analysis is given, and the synthetic connectivity measure presented by this paper is proved to be rational and satisfactory.展开更多
The traffic bottleneck plays a key role in most of the natural and artificial network. Here we present a simply model for bottleneck dynamical characteristics consideration the reliability on the complex network by ta...The traffic bottleneck plays a key role in most of the natural and artificial network. Here we present a simply model for bottleneck dynamical characteristics consideration the reliability on the complex network by taking into account the network topology characteristics and system size. We find that there is a critical rate of flow generation below which the network traffic is free but above which traffic congestion occurs. Also, it is found that random networks have larger critical flow generating rate than scale free ones. Analytical results may be practically useful for designing networks, especially for the urban traffic network.展开更多
This paper introduces an isolated reversible DC-DC converter with a particular topology, which benefits from both the NPC （neutral point clamped） structure and the series-parallel connection of converters. The key p...This paper introduces an isolated reversible DC-DC converter with a particular topology, which benefits from both the NPC （neutral point clamped） structure and the series-parallel connection of converters. The key property of the proposed topology is the output voltage elevation above the blocking capabilities of each switch, without taking to a delicate synchronization of series-connected semiconductors. The converter is composed by two identical cells, each containing a full bridge, a medium frequency transformer and an NPC converter, connected in parallel at the input and in series at the output. The operation principle of each cell, into which a trapezoidal modulation was implemented, is similar to a DAB （dual active bridge）. A new model improves the dynamic performance of the controller. Simulation and experimental results verify the proposed topology, its control and start-up strategy.展开更多
A mobile robot network is said to be easily scalable to any number of robots if its performance is kept almost fixed after these robots are added or some fail in the network. An interaction dynamics model based on mot...A mobile robot network is said to be easily scalable to any number of robots if its performance is kept almost fixed after these robots are added or some fail in the network. An interaction dynamics model based on motion synchronization is first established. Considering the mobility of mobile robot networks, we propose a relay switched, distributed topology control for the scalable network to drive neMy added robots to the most suitable positions with more neighbors as well as self-heal the blank positions of failed robots, and give a metric of the topology structure for evaluating the performance of network topologies. Then, we prove the stability of motion synchronization with the individual control based on Lyapunov exponent. Finally, the results of simulations have demonstrated the validity of the proposed modeling and control methods.展开更多
We introduce the generalized rumor spreading model and investigate some properties of this model on different complex social networks. Despite pervious rumor models that both the spreader-spreader (SS) and the spreade...We introduce the generalized rumor spreading model and investigate some properties of this model on different complex social networks. Despite pervious rumor models that both the spreader-spreader (SS) and the spreader-stifler (SR) interactions have the same rate α, we define α(1) and α(2) for SS and SR interactions, respectively. The effect of variation of α(1) and α(2) on the final density of stiflers is investigated. Furthermore, the influence of the topological structure of the network in rumor spreading is studied by analyzing the behavior of several global parameters such as reliability and efficiency. Our results show that while networks with homogeneous connectivity patterns reach a higher reliability, scale-free topologies need a less time to reach a steady state with respect the rumor.展开更多
基金The International S&T Cooperation Program of China(No.2015DFA10490)the National Natural Science Foundation of China(No.61571113,61240032)the Specialized Research Fund for the Doctoral Program of Higher Education(No.20130092110060)
文摘Aimed at the difficulties in accurately, comprehensively and systematically evaluating the reliability of industrial wireless sensor networks （WSNs）, a time-evolving state transition-Monte Carlo （TEST-MC） evaluation method and a novel network function value representation method are proposed to evaluate the reliability of the IWSNs. First, the adjacency matrix method is used to characterize three typical topologies of WSNs including the mesh network, tree network and ribbon network. Secondly, the network function value method is used to evaluate the network connectivity, and the TEST-MC evaluation method is used to evaluate network reliability and availability. Finally, the variations in the reliability, connectivity and availability of these three topologies are presented. Simulation results show that the proposed method can quickly analyze the reliability of the networks containing typical WSN topologies, which provides an effective method for the comprehensive and accurate evaluation of the reliability of WSNs.
文摘Fault tolerant ability is an important aspect for overall evaluation of distributed system(DS). This paper discusses three measures for the evaluation: node/edge connectivity, number of spanning trees and synthetic connectivity. A numerical example for illustration and analysis is given, and the synthetic connectivity measure presented by this paper is proved to be rational and satisfactory.
基金Supported by National Natural Science Foundation of China under Grant Nos.70871009 and 70801005Beijing Natural Science Foundation under Grant No 8102029+1 种基金Program for New Century Excellent Talents in University under Grart No.NCET-09-0208the Foundation of State Key Laboratory of Rail Traffie Control,and Safety under Grant No.RCS2010ZT001
文摘The traffic bottleneck plays a key role in most of the natural and artificial network. Here we present a simply model for bottleneck dynamical characteristics consideration the reliability on the complex network by taking into account the network topology characteristics and system size. We find that there is a critical rate of flow generation below which the network traffic is free but above which traffic congestion occurs. Also, it is found that random networks have larger critical flow generating rate than scale free ones. Analytical results may be practically useful for designing networks, especially for the urban traffic network.
文摘This paper introduces an isolated reversible DC-DC converter with a particular topology, which benefits from both the NPC （neutral point clamped） structure and the series-parallel connection of converters. The key property of the proposed topology is the output voltage elevation above the blocking capabilities of each switch, without taking to a delicate synchronization of series-connected semiconductors. The converter is composed by two identical cells, each containing a full bridge, a medium frequency transformer and an NPC converter, connected in parallel at the input and in series at the output. The operation principle of each cell, into which a trapezoidal modulation was implemented, is similar to a DAB （dual active bridge）. A new model improves the dynamic performance of the controller. Simulation and experimental results verify the proposed topology, its control and start-up strategy.
基金Supported by the National High Technology Research and Development Programme of China ( No. 2006AA040203 )the National Natural Science Foundation of China (No. 60775062)the Program for New Century Excellent Talents in University (No. NCET-07-0538).
文摘A mobile robot network is said to be easily scalable to any number of robots if its performance is kept almost fixed after these robots are added or some fail in the network. An interaction dynamics model based on motion synchronization is first established. Considering the mobility of mobile robot networks, we propose a relay switched, distributed topology control for the scalable network to drive neMy added robots to the most suitable positions with more neighbors as well as self-heal the blank positions of failed robots, and give a metric of the topology structure for evaluating the performance of network topologies. Then, we prove the stability of motion synchronization with the individual control based on Lyapunov exponent. Finally, the results of simulations have demonstrated the validity of the proposed modeling and control methods.
文摘We introduce the generalized rumor spreading model and investigate some properties of this model on different complex social networks. Despite pervious rumor models that both the spreader-spreader (SS) and the spreader-stifler (SR) interactions have the same rate α, we define α(1) and α(2) for SS and SR interactions, respectively. The effect of variation of α(1) and α(2) on the final density of stiflers is investigated. Furthermore, the influence of the topological structure of the network in rumor spreading is studied by analyzing the behavior of several global parameters such as reliability and efficiency. Our results show that while networks with homogeneous connectivity patterns reach a higher reliability, scale-free topologies need a less time to reach a steady state with respect the rumor.
