There is a problem of unfairness in allocation of radio resources among heterogeneous mobile terminals in heterogeneous wireless networks. Low-capability mobile terminals (such as single-mode terminals) suffer high ca...There is a problem of unfairness in allocation of radio resources among heterogeneous mobile terminals in heterogeneous wireless networks. Low-capability mobile terminals (such as single-mode terminals) suffer high call blocking probability whereas high-capability mobile terminals (such as quad-mode terminals) experience very low call blocking probability, in the same heterogeneous wireless network. This paper proposes a Terminal-Modality-Based Joint Call Admission Control (TJCAC) algorithm to reduce this problem of unfairness. The proposed TJCAC algorithm makes call admission decisions based on mobile terminal modality (capability), network load, and radio access technology (RAT) terminal support index. The objectives of the proposed TJCAC algorithm are to reduce call blocking/dropping probability, and ensure fairness in allocation of radio resources among heterogeneous mobile terminals in heterogeneous networks. An analytical model is developed to evaluate the performance of the proposed TJCAC scheme in terms of call blocking/dropping probability in a heterogeneous wireless network. The performance of the proposed TJCAC algorithm is compared with that of other JCAC algorithms. Results show that the proposed algorithm reduces call blocking/dropping probability in the networks, and ensure fairness in allocation of radio resources among heterogeneous terminals.展开更多
In this paper,an active fault-tolerant control(FTC)strategy of aerial manipulators based on non-singular terminal sliding mode(NTSM)and extended state observer(ESO)is proposed.Firstly,back-stepping technology is adopt...In this paper,an active fault-tolerant control(FTC)strategy of aerial manipulators based on non-singular terminal sliding mode(NTSM)and extended state observer(ESO)is proposed.Firstly,back-stepping technology is adopted as the control framework to ensure the global asymptotic stability of the closed-loop system.Next,the NTSM with estimated parameters of actuator faults is used as main robustness controller to deal with actuator faults.Then,the ESO is utilized to estimate and compensate the complex coupling effects and external disturbances.The Lyapunov stability theory can guarantee the asymptotic stability of aerial manipulators system with actuator faults and external disturbances.The proposed FTC scheme considers both actuator fault and modelling errors,combined with the adaptive law of actuator fault,which has better performance than traditional FTC scheme,such as NTSM.Finally,several comparative simulations are conducted to illustrate the effectiveness of the proposed FTC scheme.展开更多
Based on the analysis of the covert channel＇s working mechanism of the internet control message protocol （ICMP） in internet protocol version 4 （IPv4） and Internet Protocol version 6 （IPv6）, the ICMP covert cha...Based on the analysis of the covert channel＇s working mechanism of the internet control message protocol （ICMP） in internet protocol version 4 （IPv4） and Internet Protocol version 6 （IPv6）, the ICMP covert channd＇s algorithms of the IPv4 and IPv6 are presented, which enable automatic channeling upon IPv4/v6 nodes with non-IPv4-compatible address, and the key transmission is achieved by using this channel in the embedded Internet terminal. The result shows that the covert channel＇s algorithm, which we implemented if, set correct, the messages of this covert channel might go through the gateway and enter the local area network.展开更多
[研究目的]从情报学和情报工作专业视角研究美国商务部工业与安全局(The Bureau of Industry and Secur-ity of U.S.Department of Commerce,BIS)的情报工作,为新时期中国情报学和情报工作创新发展提供参考。[研究方法]通过BIS官方网站...[研究目的]从情报学和情报工作专业视角研究美国商务部工业与安全局(The Bureau of Industry and Secur-ity of U.S.Department of Commerce,BIS)的情报工作,为新时期中国情报学和情报工作创新发展提供参考。[研究方法]通过BIS官方网站信息内容研究、官方网站重要文件研究、瓦森纳协定官方网站信息内容研究、BIS典型执法案例研究相结合的方法,研究BIS情报工作的全貌和精要。[研究结论]从情报学和情报工作专业视角对BIS的组织机构使命、组织网络、信息网络、人际网络、法律保障、典型情报工作、提升美国出口商情报能力的主要工作进行研究,揭示了BIS情报工作全貌、精要和最突出的关键成功因素。展开更多
文摘There is a problem of unfairness in allocation of radio resources among heterogeneous mobile terminals in heterogeneous wireless networks. Low-capability mobile terminals (such as single-mode terminals) suffer high call blocking probability whereas high-capability mobile terminals (such as quad-mode terminals) experience very low call blocking probability, in the same heterogeneous wireless network. This paper proposes a Terminal-Modality-Based Joint Call Admission Control (TJCAC) algorithm to reduce this problem of unfairness. The proposed TJCAC algorithm makes call admission decisions based on mobile terminal modality (capability), network load, and radio access technology (RAT) terminal support index. The objectives of the proposed TJCAC algorithm are to reduce call blocking/dropping probability, and ensure fairness in allocation of radio resources among heterogeneous mobile terminals in heterogeneous networks. An analytical model is developed to evaluate the performance of the proposed TJCAC scheme in terms of call blocking/dropping probability in a heterogeneous wireless network. The performance of the proposed TJCAC algorithm is compared with that of other JCAC algorithms. Results show that the proposed algorithm reduces call blocking/dropping probability in the networks, and ensure fairness in allocation of radio resources among heterogeneous terminals.
基金Project(51705243)supported by National Natural Science Foundation of ChinaProject(NS2020052)supported by the Fundamental Research Funds for the Central Universities,ChinaProject(GZKF-201915)supported by the Open Foundation of the State Key Laboratory of Fluid Power and Mechatronic Systems,China。
文摘In this paper,an active fault-tolerant control(FTC)strategy of aerial manipulators based on non-singular terminal sliding mode(NTSM)and extended state observer(ESO)is proposed.Firstly,back-stepping technology is adopted as the control framework to ensure the global asymptotic stability of the closed-loop system.Next,the NTSM with estimated parameters of actuator faults is used as main robustness controller to deal with actuator faults.Then,the ESO is utilized to estimate and compensate the complex coupling effects and external disturbances.The Lyapunov stability theory can guarantee the asymptotic stability of aerial manipulators system with actuator faults and external disturbances.The proposed FTC scheme considers both actuator fault and modelling errors,combined with the adaptive law of actuator fault,which has better performance than traditional FTC scheme,such as NTSM.Finally,several comparative simulations are conducted to illustrate the effectiveness of the proposed FTC scheme.
基金Supported by the National Natural Science Foun-dation of China (90104005 ,66973034)
文摘Based on the analysis of the covert channel＇s working mechanism of the internet control message protocol （ICMP） in internet protocol version 4 （IPv4） and Internet Protocol version 6 （IPv6）, the ICMP covert channd＇s algorithms of the IPv4 and IPv6 are presented, which enable automatic channeling upon IPv4/v6 nodes with non-IPv4-compatible address, and the key transmission is achieved by using this channel in the embedded Internet terminal. The result shows that the covert channel＇s algorithm, which we implemented if, set correct, the messages of this covert channel might go through the gateway and enter the local area network.
文摘[研究目的]从情报学和情报工作专业视角研究美国商务部工业与安全局(The Bureau of Industry and Secur-ity of U.S.Department of Commerce,BIS)的情报工作,为新时期中国情报学和情报工作创新发展提供参考。[研究方法]通过BIS官方网站信息内容研究、官方网站重要文件研究、瓦森纳协定官方网站信息内容研究、BIS典型执法案例研究相结合的方法,研究BIS情报工作的全貌和精要。[研究结论]从情报学和情报工作专业视角对BIS的组织机构使命、组织网络、信息网络、人际网络、法律保障、典型情报工作、提升美国出口商情报能力的主要工作进行研究,揭示了BIS情报工作全貌、精要和最突出的关键成功因素。
