Based on the algebraic graph theory, the networked multi-agent continuous systems are investigated. Firstly, the digraph （directed graph） represents the topology of a networked system, and then a consensus convergen...Based on the algebraic graph theory, the networked multi-agent continuous systems are investigated. Firstly, the digraph （directed graph） represents the topology of a networked system, and then a consensus convergence criterion of system is proposed. Secondly, the issue of stability of multi-agent systems and the consensus convergence problem of information states are all analysed. Furthermore, the consensus equilibrium point of system is proved to be global and asymptotically reach the convex combination of initial states. Finally, two examples are taken to show the effectiveness of the results obtained in this paper.展开更多
This paper deals with the consensus problem for heterogeneous multi-agent systems. Different from most existing consensus protocols, we consider the consensus seeking of two types of agents, namely, active agents and ...This paper deals with the consensus problem for heterogeneous multi-agent systems. Different from most existing consensus protocols, we consider the consensus seeking of two types of agents, namely, active agents and passive agents. The objective is to directly control the active agents such that the states of all the agents would achieve consensus. In order to obtain a computational approach, we subtly introduce an appropriate Markov chain to cast the heterogeneous systems into a unified framework. Such a framework is helpful for tackling the constraints from passive agents. Furthermore, a sufficient and necessary condition is established to guarantee the consensus in heterogeneous multi-agent systems. Finally, simulation results are provided to verify the theoretical analysis and the effectiveness of the proposed protocol.展开更多
Graphic processing units （GPUs） have been widely recognized as cost-efficient co-processors with acceptable size, weight, and power consumption. However, adopting GPUs in real-time systems is still challenging, due ...Graphic processing units （GPUs） have been widely recognized as cost-efficient co-processors with acceptable size, weight, and power consumption. However, adopting GPUs in real-time systems is still challenging, due to the lack in framework for real-time analysis. In order to guarantee real-time requirements while maintaining system utilization ~in modern heterogeneous systems, such as multicore multi-GPU systems, a novel suspension-based k-exclusion real-time locking protocol and the associated suspension-aware schedulability analysis are proposed. The proposed protocol provides a synchronization framework that enables multiple GPUs to be efficiently integrated in multicore real-time systems. Comparative evaluations show that the proposed methods improve upon the existing work in terms of schedulability.展开更多
This paper investigates the fnite-time consensus problem of multi-agent systems with single and double integrator dynamics,respectively.Some novel nonlinear protocols are constructed for frst-order and second-order le...This paper investigates the fnite-time consensus problem of multi-agent systems with single and double integrator dynamics,respectively.Some novel nonlinear protocols are constructed for frst-order and second-order leader-follower multi-agent systems,respectively.Based on the fnite-time control technique,the graph theory and Lyapunov direct method,some theoretical results are proposed to ensure that the states of all the follower agents can converge to its leader agent s state in fnite time.Finally,some simulation results are presented to illustrate the efectiveness of our theoretical results.展开更多
In consultative committee for space data systems（CCSDS） file delivery protocol（CFDP） recommendation of reliable transmission,there are no detail transmission procedure and delay calculation of prompted negative ac...In consultative committee for space data systems（CCSDS） file delivery protocol（CFDP） recommendation of reliable transmission,there are no detail transmission procedure and delay calculation of prompted negative acknowledge and asynchronous negative acknowledge models.CFDP is designed to provide data and storage management,story and forward,custody transfer and reliable end-to-end delivery over deep space characterized by huge latency,intermittent link,asymmetric bandwidth and big bit error rate（BER）.Four reliable transmission models are analyzed and an expected file-delivery time is calculated with different trans-mission rates,numbers and sizes of packet data units,BERs and frequencies of external events,etc.By comparison of four CFDP models,the requirement of BER for typical missions in deep space is obtained and rules of choosing CFDP models under different uplink state informations are given,which provides references for protocol models selection,utilization and modification.展开更多
In networked control systems （NCS）,the control performance depends on not only the control algorithm but also the communication protocol stack.The performance degradation introduced by the heterogeneous and dynamic ...In networked control systems （NCS）,the control performance depends on not only the control algorithm but also the communication protocol stack.The performance degradation introduced by the heterogeneous and dynamic communication environment has intensified the need for the reconfigurable protocol stack.In this paper,a novel architecture for the reconfigurable protocol stack is proposed,which is a unified specification of the protocol components and service interfaces supporting both static and dynamic reconfiguration for existing industrial communication standards.Within the architecture,a triple-level self-organization structure is designed to manage the dynamic reconfiguration procedure based on information exchanges inside and outside the protocol stack.Especially,the protocol stack can be self-adaptive to various environment and system requirements through the reconfiguration of working mode,routing and scheduling table.Finally,the study on the protocol of dynamic address management is conducted for the system of controller area network （CAN）.The results show the efficiency of our self-organizing architecture for the implementation of a reconfigurable protocol stack.展开更多
Nonlinear consensus protocols for dynamic directed networks of multi-agent systems with fixed and switching topologies are investigated separately in this paper. Based on the centre manifold reduction technique, nonli...Nonlinear consensus protocols for dynamic directed networks of multi-agent systems with fixed and switching topologies are investigated separately in this paper. Based on the centre manifold reduction technique, nonlinear consensus protocols are presented. We prove that a group of agents can reach a β-consensus, the value of which is the group decision value varying from the minimum and the maximum values of the initial states of the agents. Moreover, we derive the conditions to guarantee that all the agents reach a β-consensus on a desired group decision value. Finally, a simulation study concerning the vertical alignment manoeuvere of a team of unmanned air vehicles is performed. Simulation results show that the nonlinear consensus protocols proposed are more effective than the linear protocols for the formation control of the agents and they are an improvement over existing protocols.展开更多
The recent growth of the World Wide Web has sparked new research into using the Internet for novel types of group communication, like multiparty videoconferencing and real-time streaming. Multicast has the potential t...The recent growth of the World Wide Web has sparked new research into using the Internet for novel types of group communication, like multiparty videoconferencing and real-time streaming. Multicast has the potential to be very useful, but it suffers from many problems like security. To achieve secure multicast communications with the dynamic aspect of group applications due to free membership joins and leaves in addition to member's mobility, key management is one of the most critical problems. So far, a lot of multicast key management schemes have been proposed and most of them are centralized, which have the problem of 'one point failure' and that the group controller is the bottleneck of the group. In order to solve these two problems, we propose a Key Management Scheme, using cluster-based End-System Multicast (ESM). The group management is between both 1) the main controller (MRP, Main Rendezvous Point) and the second controllers (CRP, Cluster RP), and 2) the second controllers (CRPs) and its members. So, ESM simplifies the implementation of group communication and is efficient ways to deliver a secure message to a group of recipients in a network as a practical alternative to overcome the difficulty of large scale deployment of traditional IP multicast. In this paper, we analyze different key management schemes and propose a new scheme, namely Advanced Transition/Cluster Key management Scheme (ATCKS) and find it has appropriate performance in security.展开更多
Nowadays, Health Care Training-based System (HCTS) is a vital component in the education and training of health care in 3D Virtual Environment (VE). The practice of HCTS continues to grow at rapid pace throughout all ...Nowadays, Health Care Training-based System (HCTS) is a vital component in the education and training of health care in 3D Virtual Environment (VE). The practice of HCTS continues to grow at rapid pace throughout all of the healthcare disciplines, however research in this field is still in its early stage. Increasingly, decision makers and developers look forward to offer more sophisticated, much larger, and more complex HCTS to serve the desired outcome and improve the quality and safety of patient care. Due to the rapidly increasing usage of personal mobile devices and the need of executing HCTS applications in environments that have no previous network infrastructure available, Mobile Health Care Training-based System (MHCTS) is an expected future trend. In such systems, medical staff will share and collaborate in a 3D virtual environment through their mobile devices in an ad-hoc network (MANET) in order to accomplish specific missions’ typically surgical emergency room. Users are organized into various groups (Radiologists, Maternity departments, and General surgery etc...), and need to be managed by a multicast scheme to save network bandwidth and offer immersive sense. MHCTS is sensitive to networking issues, since interactive 3D graphics requires additional load due to the use of mobile devices. Therefore, we need to emphasize on the importance and the improvement of multicast techniques for the effectiveness of MHCTS and the management of collaborative group interaction. Research so far has devoted little attention to the network communication protocols design of such systems which is crucial to preserve the sense of immersion for participating users. In this paper, we investigate the effect of multicast routing protocol in advancing the field of Health care Training-based System to the benefit of patient’s safety, and health care professional. Also, we address the issue of selecting a multicast protocol to provide the best performance for a particular e-health system at any time. Previous work has demonstrated that multicast operates at least as efficiently as traditional MAODV. A comprehensive analysis about various ad-hoc multicast routing protocols is proposed. The selection key factors for the right protocol for MHCTS applications were safety and robustness. To the best of our knowledge, this work will be the first initiative involving systematic literature reviews to identify a research gate for the use of multicast protocol in health care simulation learning community.展开更多
It is an effective method to broadcast the augmentation information of satellite navigation system using GEO technology.However,it becomes difficult to receive GEO signal in some special situation,for example in citie...It is an effective method to broadcast the augmentation information of satellite navigation system using GEO technology.However,it becomes difficult to receive GEO signal in some special situation,for example in cities or canyons,in which the signal will be sheltered by big buildings or mountains.In order to solve this problem,an Internet-based broadcast network has been proposed to utilize the infrastructure of the Internet to broadcast the augmentation information of satellite navigation system,which is based on application-layer multicast protocols.In this paper,a topology and position aware overlay network construction protocol is proposed to build the network for augmentation information of satellite navigation system.Simulation results show that the new algorithm is able to achieve better performance in terms of delay,depth and degree utilization.展开更多
RFID(Radio Frequency IDentification)系统射频标签结构简单,且与阅读器间采用无线方式传输数据,易产生隐私泄露和受到安全攻击。针对该问题,文中提出通过双向轻权认证协议来保护RFID系统的安全性和隐私。该协议通过随机化标签的秘密...RFID(Radio Frequency IDentification)系统射频标签结构简单,且与阅读器间采用无线方式传输数据,易产生隐私泄露和受到安全攻击。针对该问题,文中提出通过双向轻权认证协议来保护RFID系统的安全性和隐私。该协议通过随机化标签的秘密信息再哈希的方法生成会话消息,标签与阅读器间采用二次相互认证,提升了协议的安全性。该协议通过哈希运算确保认证过程中会话信息的保密传输和完整性,通过对标签端每次发出会话消息的随机化确保了消息的新鲜性,系统秘密信息的更新确保协议满足前向安全性。RFID认证协议不仅能抵抗窃听、追踪、重放、去同步化等攻击,还能满足RFID系统的安全性和隐私保护需要。展开更多
基金Project supported by the National Science Fund for distinguished Young Scholars of China (Grant No 60525303)the Specialized Research Fund for the Doctoral Program of High Education of China (Grant No 20050216001)
文摘Based on the algebraic graph theory, the networked multi-agent continuous systems are investigated. Firstly, the digraph （directed graph） represents the topology of a networked system, and then a consensus convergence criterion of system is proposed. Secondly, the issue of stability of multi-agent systems and the consensus convergence problem of information states are all analysed. Furthermore, the consensus equilibrium point of system is proved to be global and asymptotically reach the convex combination of initial states. Finally, two examples are taken to show the effectiveness of the results obtained in this paper.
基金Project supported by the National Basic Research Program of China (Grant No. 2010CB731803)the National Natural Science Foundation of China (Grant Nos. 60934003, 60974123, 61172064, and 61273181)+1 种基金the Science and Technology Commission of Shanghai Municipality, China (Grant No. 11511501202)the Chenguang Program, China (Grant No. 09CG06)
文摘This paper deals with the consensus problem for heterogeneous multi-agent systems. Different from most existing consensus protocols, we consider the consensus seeking of two types of agents, namely, active agents and passive agents. The objective is to directly control the active agents such that the states of all the agents would achieve consensus. In order to obtain a computational approach, we subtly introduce an appropriate Markov chain to cast the heterogeneous systems into a unified framework. Such a framework is helpful for tackling the constraints from passive agents. Furthermore, a sufficient and necessary condition is established to guarantee the consensus in heterogeneous multi-agent systems. Finally, simulation results are provided to verify the theoretical analysis and the effectiveness of the proposed protocol.
基金supported by the National Natural Science Foundation of China under Grant No.61003032/F020207
文摘Graphic processing units （GPUs） have been widely recognized as cost-efficient co-processors with acceptable size, weight, and power consumption. However, adopting GPUs in real-time systems is still challenging, due to the lack in framework for real-time analysis. In order to guarantee real-time requirements while maintaining system utilization ~in modern heterogeneous systems, such as multicore multi-GPU systems, a novel suspension-based k-exclusion real-time locking protocol and the associated suspension-aware schedulability analysis are proposed. The proposed protocol provides a synchronization framework that enables multiple GPUs to be efficiently integrated in multicore real-time systems. Comparative evaluations show that the proposed methods improve upon the existing work in terms of schedulability.
基金supported by National Basic Research Program of China (973 Program) (No.2010CB731800)National Natural Science Foundation of China (Nos.60934003 and 61074065)Natural Science Foundation of Hebei Province (No.F2012203119)
文摘This paper investigates the fnite-time consensus problem of multi-agent systems with single and double integrator dynamics,respectively.Some novel nonlinear protocols are constructed for frst-order and second-order leader-follower multi-agent systems,respectively.Based on the fnite-time control technique,the graph theory and Lyapunov direct method,some theoretical results are proposed to ensure that the states of all the follower agents can converge to its leader agent s state in fnite time.Finally,some simulation results are presented to illustrate the efectiveness of our theoretical results.
基金supported by the National Natural Science Fandation of China (6067208960772075)
文摘In consultative committee for space data systems（CCSDS） file delivery protocol（CFDP） recommendation of reliable transmission,there are no detail transmission procedure and delay calculation of prompted negative acknowledge and asynchronous negative acknowledge models.CFDP is designed to provide data and storage management,story and forward,custody transfer and reliable end-to-end delivery over deep space characterized by huge latency,intermittent link,asymmetric bandwidth and big bit error rate（BER）.Four reliable transmission models are analyzed and an expected file-delivery time is calculated with different trans-mission rates,numbers and sizes of packet data units,BERs and frequencies of external events,etc.By comparison of four CFDP models,the requirement of BER for typical missions in deep space is obtained and rules of choosing CFDP models under different uplink state informations are given,which provides references for protocol models selection,utilization and modification.
基金supported by National Natural Science Foundation of China (No. 60674081,No. 60834002,No. 61074145)
文摘In networked control systems （NCS）,the control performance depends on not only the control algorithm but also the communication protocol stack.The performance degradation introduced by the heterogeneous and dynamic communication environment has intensified the need for the reconfigurable protocol stack.In this paper,a novel architecture for the reconfigurable protocol stack is proposed,which is a unified specification of the protocol components and service interfaces supporting both static and dynamic reconfiguration for existing industrial communication standards.Within the architecture,a triple-level self-organization structure is designed to manage the dynamic reconfiguration procedure based on information exchanges inside and outside the protocol stack.Especially,the protocol stack can be self-adaptive to various environment and system requirements through the reconfiguration of working mode,routing and scheduling table.Finally,the study on the protocol of dynamic address management is conducted for the system of controller area network （CAN）.The results show the efficiency of our self-organizing architecture for the implementation of a reconfigurable protocol stack.
基金supported by National Natural Science Foundation of China(61304263,61233007)the Cross-disciplinary Collaborative Teams Program for Science,Technology and Innovation of Chinese Academy of Sciences-Network and System Technologies for Security Monitoring and Information Interaction in Smart Arid
基金supported by the National Natural Science Foundation of China (Grant No 60525303)the Natural Science Foundation of Hebei Province,China (Grant No 2006000270)
文摘Nonlinear consensus protocols for dynamic directed networks of multi-agent systems with fixed and switching topologies are investigated separately in this paper. Based on the centre manifold reduction technique, nonlinear consensus protocols are presented. We prove that a group of agents can reach a β-consensus, the value of which is the group decision value varying from the minimum and the maximum values of the initial states of the agents. Moreover, we derive the conditions to guarantee that all the agents reach a β-consensus on a desired group decision value. Finally, a simulation study concerning the vertical alignment manoeuvere of a team of unmanned air vehicles is performed. Simulation results show that the nonlinear consensus protocols proposed are more effective than the linear protocols for the formation control of the agents and they are an improvement over existing protocols.
文摘The recent growth of the World Wide Web has sparked new research into using the Internet for novel types of group communication, like multiparty videoconferencing and real-time streaming. Multicast has the potential to be very useful, but it suffers from many problems like security. To achieve secure multicast communications with the dynamic aspect of group applications due to free membership joins and leaves in addition to member's mobility, key management is one of the most critical problems. So far, a lot of multicast key management schemes have been proposed and most of them are centralized, which have the problem of 'one point failure' and that the group controller is the bottleneck of the group. In order to solve these two problems, we propose a Key Management Scheme, using cluster-based End-System Multicast (ESM). The group management is between both 1) the main controller (MRP, Main Rendezvous Point) and the second controllers (CRP, Cluster RP), and 2) the second controllers (CRPs) and its members. So, ESM simplifies the implementation of group communication and is efficient ways to deliver a secure message to a group of recipients in a network as a practical alternative to overcome the difficulty of large scale deployment of traditional IP multicast. In this paper, we analyze different key management schemes and propose a new scheme, namely Advanced Transition/Cluster Key management Scheme (ATCKS) and find it has appropriate performance in security.
文摘Nowadays, Health Care Training-based System (HCTS) is a vital component in the education and training of health care in 3D Virtual Environment (VE). The practice of HCTS continues to grow at rapid pace throughout all of the healthcare disciplines, however research in this field is still in its early stage. Increasingly, decision makers and developers look forward to offer more sophisticated, much larger, and more complex HCTS to serve the desired outcome and improve the quality and safety of patient care. Due to the rapidly increasing usage of personal mobile devices and the need of executing HCTS applications in environments that have no previous network infrastructure available, Mobile Health Care Training-based System (MHCTS) is an expected future trend. In such systems, medical staff will share and collaborate in a 3D virtual environment through their mobile devices in an ad-hoc network (MANET) in order to accomplish specific missions’ typically surgical emergency room. Users are organized into various groups (Radiologists, Maternity departments, and General surgery etc...), and need to be managed by a multicast scheme to save network bandwidth and offer immersive sense. MHCTS is sensitive to networking issues, since interactive 3D graphics requires additional load due to the use of mobile devices. Therefore, we need to emphasize on the importance and the improvement of multicast techniques for the effectiveness of MHCTS and the management of collaborative group interaction. Research so far has devoted little attention to the network communication protocols design of such systems which is crucial to preserve the sense of immersion for participating users. In this paper, we investigate the effect of multicast routing protocol in advancing the field of Health care Training-based System to the benefit of patient’s safety, and health care professional. Also, we address the issue of selecting a multicast protocol to provide the best performance for a particular e-health system at any time. Previous work has demonstrated that multicast operates at least as efficiently as traditional MAODV. A comprehensive analysis about various ad-hoc multicast routing protocols is proposed. The selection key factors for the right protocol for MHCTS applications were safety and robustness. To the best of our knowledge, this work will be the first initiative involving systematic literature reviews to identify a research gate for the use of multicast protocol in health care simulation learning community.
基金supported by National High Technical Research and Development Program of China (863 Program) under Grant No. 2009AA12Z322
文摘It is an effective method to broadcast the augmentation information of satellite navigation system using GEO technology.However,it becomes difficult to receive GEO signal in some special situation,for example in cities or canyons,in which the signal will be sheltered by big buildings or mountains.In order to solve this problem,an Internet-based broadcast network has been proposed to utilize the infrastructure of the Internet to broadcast the augmentation information of satellite navigation system,which is based on application-layer multicast protocols.In this paper,a topology and position aware overlay network construction protocol is proposed to build the network for augmentation information of satellite navigation system.Simulation results show that the new algorithm is able to achieve better performance in terms of delay,depth and degree utilization.
文摘RFID(Radio Frequency IDentification)系统射频标签结构简单,且与阅读器间采用无线方式传输数据,易产生隐私泄露和受到安全攻击。针对该问题,文中提出通过双向轻权认证协议来保护RFID系统的安全性和隐私。该协议通过随机化标签的秘密信息再哈希的方法生成会话消息,标签与阅读器间采用二次相互认证,提升了协议的安全性。该协议通过哈希运算确保认证过程中会话信息的保密传输和完整性,通过对标签端每次发出会话消息的随机化确保了消息的新鲜性,系统秘密信息的更新确保协议满足前向安全性。RFID认证协议不仅能抵抗窃听、追踪、重放、去同步化等攻击,还能满足RFID系统的安全性和隐私保护需要。
