Airway networks are the basic carriers of air traffic.Characterizing airway networks will significantly improve the operating efficiency of aviation.This study is targeted at the airway network composed of 1479 waypoi...Airway networks are the basic carriers of air traffic.Characterizing airway networks will significantly improve the operating efficiency of aviation.This study is targeted at the airway network composed of 1479 waypoints in 2018 of China.Together with spatial structures,traffic flow characteristics,and the dominating traffic flow,four airway network models are constructed from the perspective of complex networks,including physical airway network,airway traffic network,directed airway traffic network,and dominance-based directed airway traffic network.Then the topological characteristics of different networks are statistically analyzed by using typical network measure indices,and the differences of these indices among different networks are investigated.Thereby,composite indices are proposed.Statistical results show that the airway network under the influence of traffic flows exhibits richer heterogeneity and asymmetrical between-node relationship,and the distributions of indices among different networks are significantly different.Comparative analysis of composite indices and traffic flows show that some waypoints yield great results in multiple composite indices and traffic volumes;some waypoints display large results in multiple composite indices but low traffic flows,and other waypoints only perform well in certain composite indices.The importance levels of waypoints are divided,by the K-means method based on degree composite index,betweenness composite index and closeness composite index,into three levels,and the reasonableness of clustering results is validated by the statistical results of traffic flows,airport number,and flight delay.展开更多
This paper discussed the necessity of establishing a computer network in a mining railway transport management system. The network structure and the system security design, associated with the real development conditi...This paper discussed the necessity of establishing a computer network in a mining railway transport management system. The network structure and the system security design, associated with the real development condition of a mining area, were brought forward, and the system evaluation was given.展开更多
Because the node of vehicular ad-hoc networks has the characteristics of high mobility and encounter temporary, a trust management between the nodes in the routing process becomes more difficult. To solve this problem...Because the node of vehicular ad-hoc networks has the characteristics of high mobility and encounter temporary, a trust management between the nodes in the routing process becomes more difficult. To solve this problem, this paper proposes a new trusted routing protocol in VANET based on GeoDTN＋Nav by using trust management model of Bayesian and the three opportunistic routing forwarding models, which includes four steps of the routing initialization, the routing discovery, the trusted routing establishment and the routing deletion. The proposed protocol not only improves the security of routing, but also has the lower time complexity. Besides, experimental results and analysis show that the protocol has achieved good performance in the removal ratio of malicious nodes, correct reception ratio of packet and the message payload.展开更多
With the rapid development of Internet of Things (IoT),the issue of trust in distributed routing systems has attracted more research attention.The existing trust management frameworks,however,suffer from some possible...With the rapid development of Internet of Things (IoT),the issue of trust in distributed routing systems has attracted more research attention.The existing trust management frameworks,however,suffer from some possible attacks in hostile environments,such as false accusation,collusion,on-off,and conflicting behavior.Therefore,more comprehensive models should be proposed to predict the trust level of nodes on potential routes more precisely,and to defeat several kinds of possible attacks.This paper makes an attempt to design an attack-resistant trust management model based on beta function for distributed routing strategy in IoT.Our model can evaluate and propagate reputation in distributed routing systems.We first describe possible attacks on existing systems.Our model is then proposed to establish reliable trust relations between self-organized nodes and defeat possible attacks in distributed routing systems.We also propose a theoretical basis and skeleton of our model.Finally,some performance evaluations and security analyses are provided to show the effectiveness and robustness of our model compared with the existing systems.展开更多
基金This work was supported by the National Natural Science Foundations of China(Nos.U1833103,71801215,and U1933103)。
文摘Airway networks are the basic carriers of air traffic.Characterizing airway networks will significantly improve the operating efficiency of aviation.This study is targeted at the airway network composed of 1479 waypoints in 2018 of China.Together with spatial structures,traffic flow characteristics,and the dominating traffic flow,four airway network models are constructed from the perspective of complex networks,including physical airway network,airway traffic network,directed airway traffic network,and dominance-based directed airway traffic network.Then the topological characteristics of different networks are statistically analyzed by using typical network measure indices,and the differences of these indices among different networks are investigated.Thereby,composite indices are proposed.Statistical results show that the airway network under the influence of traffic flows exhibits richer heterogeneity and asymmetrical between-node relationship,and the distributions of indices among different networks are significantly different.Comparative analysis of composite indices and traffic flows show that some waypoints yield great results in multiple composite indices and traffic volumes;some waypoints display large results in multiple composite indices but low traffic flows,and other waypoints only perform well in certain composite indices.The importance levels of waypoints are divided,by the K-means method based on degree composite index,betweenness composite index and closeness composite index,into three levels,and the reasonableness of clustering results is validated by the statistical results of traffic flows,airport number,and flight delay.
文摘This paper discussed the necessity of establishing a computer network in a mining railway transport management system. The network structure and the system security design, associated with the real development condition of a mining area, were brought forward, and the system evaluation was given.
文摘Because the node of vehicular ad-hoc networks has the characteristics of high mobility and encounter temporary, a trust management between the nodes in the routing process becomes more difficult. To solve this problem, this paper proposes a new trusted routing protocol in VANET based on GeoDTN＋Nav by using trust management model of Bayesian and the three opportunistic routing forwarding models, which includes four steps of the routing initialization, the routing discovery, the trusted routing establishment and the routing deletion. The proposed protocol not only improves the security of routing, but also has the lower time complexity. Besides, experimental results and analysis show that the protocol has achieved good performance in the removal ratio of malicious nodes, correct reception ratio of packet and the message payload.
基金supported by the National Natural Science Foundation of China under Grant No.61100219the Fundamental Research Funds for the Central Universities under Grant No.2012JBM010the Key Program of National Natural Science Foundation of China under Grant No.60833002
文摘With the rapid development of Internet of Things (IoT),the issue of trust in distributed routing systems has attracted more research attention.The existing trust management frameworks,however,suffer from some possible attacks in hostile environments,such as false accusation,collusion,on-off,and conflicting behavior.Therefore,more comprehensive models should be proposed to predict the trust level of nodes on potential routes more precisely,and to defeat several kinds of possible attacks.This paper makes an attempt to design an attack-resistant trust management model based on beta function for distributed routing strategy in IoT.Our model can evaluate and propagate reputation in distributed routing systems.We first describe possible attacks on existing systems.Our model is then proposed to establish reliable trust relations between self-organized nodes and defeat possible attacks in distributed routing systems.We also propose a theoretical basis and skeleton of our model.Finally,some performance evaluations and security analyses are provided to show the effectiveness and robustness of our model compared with the existing systems.
