Mobile ad hoc networks create additional challenges for implementing the group key establishment due to resource constraints on nodes and dynamic changes on topology. The nodes in mobile ad hoc networks are usually lo...Mobile ad hoc networks create additional challenges for implementing the group key establishment due to resource constraints on nodes and dynamic changes on topology. The nodes in mobile ad hoc networks are usually low power devices that run on battery power. As a result, the costs of the node resources should be minimized when constructing a group key agreement protocol so that the battery life could be prolonged. To achieve this goal, in this paper we propose a security efficient group key agreement protocol based on Burmester-Desmedt （BD） scheme and layer-cluster group model, referred to as LCKM-BD, which is appropriate for large mobile ad hoe networks. In the layer-cluster group model, BD scheme is employed to establish group key, which can not only meet security demands of mobile ad hoc networks but also improve executing performance. Finally, the proposed protocol LCKM-BD are compared with BD, TGDH （tree-based group Diffe-Hellman）, and GDH （group Diffie-Hellman） group key agreement protocols. The analysis results show that our protocol can significantly decrease both the computational overhead and communication costs with respect to these comparable protocols.展开更多
针对群组机器人系统在应急场景下移动频繁、能量有限的特点,提出了一种基于能量与速度的分簇自组织按需距离矢量协议(Clustered Ad hoc On-Demand Distance Vector Protocol Based on Energy and Speed,ESC-AODV),以延长群组机器人网络...针对群组机器人系统在应急场景下移动频繁、能量有限的特点,提出了一种基于能量与速度的分簇自组织按需距离矢量协议(Clustered Ad hoc On-Demand Distance Vector Protocol Based on Energy and Speed,ESC-AODV),以延长群组机器人网络运行时间,提高通信可靠性。用路由性能代替跳数作为路由判据,目的节点在重复接收到路由请求(Route Request,RREQ)数据包时,若路由性能更小,则回复路由应答(Routing Reply,RREP)数据包,以此选择更好的路由,引入分簇结构,通过簇头和网关组成的骨干网络减少广播洪泛次数。实验结果证明,节点数量多时,改进的ESC-AODV协议在延长网络生存时间的同时,平均端到端时延、数据包投递率、吞吐量和路由开销均优于AODV以及基于能量、负载和速度的AODV路由协议(AODV Routing Protocol Based on Energy,Load and Speed,ELS-AODV)。ESC-AODV协议能够节约网络能量,提高可靠性,获得更优的网络性能。展开更多
电力通信网跨层传输数据时,受到噪声数据影响,导致跨层数据传输耗时长、电流畸变率高。为了保证跨层通信安全,设计基于密度的聚类算法(Ordering Points To Identify the Clustering Structure,OPTICS)的电力通信网跨层保护系统。构建并...电力通信网跨层传输数据时,受到噪声数据影响,导致跨层数据传输耗时长、电流畸变率高。为了保证跨层通信安全,设计基于密度的聚类算法(Ordering Points To Identify the Clustering Structure,OPTICS)的电力通信网跨层保护系统。构建并联有源电力滤波器安全保护电路,保证三相四线制限幅后具有良好谐波补偿效果。通过跨层控制主动切换模块,实现目标通信链路下达指令的主动切换。对电力通信网跨层数据进行OPTICS聚类处理,结合Laplace机制添加对称指数分布噪声,将Laplace噪声添加到聚类簇中,输出添加噪声后结果存储在输出队列中,完成通信网跨层保护。由系统测试结果可知,该系统传输耗时少,且在10 s测试时间内跨层电流畸变率仅为21%,能够起到保护通信网跨层传输的作用。展开更多
针对航空发动机滑油箱油量测量值易受多个参数影响导致滑油消耗率难以计算和预测的问题,提出了一种改进的滑油量数据提取规则和滑油消耗率预测方法。基于密度聚类算法(Density-based spatial clustering of applications with noise,DBS...针对航空发动机滑油箱油量测量值易受多个参数影响导致滑油消耗率难以计算和预测的问题,提出了一种改进的滑油量数据提取规则和滑油消耗率预测方法。基于密度聚类算法(Density-based spatial clustering of applications with noise,DBSCAN)等方法对发动机数据进行了清洗,获取平稳飞行状态下滑油量数据。使用最小二乘法对滑油量进行拟合,得到了滑油消耗率,平均拟合优度达到了0.86。在此基础上,利用多层感知器(Multi-layer perception,MLP)建立了滑油消耗率与飞行状态参数之间的关系,预测结果与实际值的平均绝对百分比误差为1.15%。本文提出的方法能够满足实际工程需求,为评估航空发动机滑油系统的健康状况提供了可靠参考。展开更多
基金The National Natural Science Foundation of China (No.60403027)the Research Foundation for Out-standing Young Teachers, China University of Geosciences(Wuhan) (No.CUGQNL0836)
文摘Mobile ad hoc networks create additional challenges for implementing the group key establishment due to resource constraints on nodes and dynamic changes on topology. The nodes in mobile ad hoc networks are usually low power devices that run on battery power. As a result, the costs of the node resources should be minimized when constructing a group key agreement protocol so that the battery life could be prolonged. To achieve this goal, in this paper we propose a security efficient group key agreement protocol based on Burmester-Desmedt （BD） scheme and layer-cluster group model, referred to as LCKM-BD, which is appropriate for large mobile ad hoe networks. In the layer-cluster group model, BD scheme is employed to establish group key, which can not only meet security demands of mobile ad hoc networks but also improve executing performance. Finally, the proposed protocol LCKM-BD are compared with BD, TGDH （tree-based group Diffe-Hellman）, and GDH （group Diffie-Hellman） group key agreement protocols. The analysis results show that our protocol can significantly decrease both the computational overhead and communication costs with respect to these comparable protocols.
文摘针对群组机器人系统在应急场景下移动频繁、能量有限的特点,提出了一种基于能量与速度的分簇自组织按需距离矢量协议(Clustered Ad hoc On-Demand Distance Vector Protocol Based on Energy and Speed,ESC-AODV),以延长群组机器人网络运行时间,提高通信可靠性。用路由性能代替跳数作为路由判据,目的节点在重复接收到路由请求(Route Request,RREQ)数据包时,若路由性能更小,则回复路由应答(Routing Reply,RREP)数据包,以此选择更好的路由,引入分簇结构,通过簇头和网关组成的骨干网络减少广播洪泛次数。实验结果证明,节点数量多时,改进的ESC-AODV协议在延长网络生存时间的同时,平均端到端时延、数据包投递率、吞吐量和路由开销均优于AODV以及基于能量、负载和速度的AODV路由协议(AODV Routing Protocol Based on Energy,Load and Speed,ELS-AODV)。ESC-AODV协议能够节约网络能量,提高可靠性,获得更优的网络性能。
文摘电力通信网跨层传输数据时,受到噪声数据影响,导致跨层数据传输耗时长、电流畸变率高。为了保证跨层通信安全,设计基于密度的聚类算法(Ordering Points To Identify the Clustering Structure,OPTICS)的电力通信网跨层保护系统。构建并联有源电力滤波器安全保护电路,保证三相四线制限幅后具有良好谐波补偿效果。通过跨层控制主动切换模块,实现目标通信链路下达指令的主动切换。对电力通信网跨层数据进行OPTICS聚类处理,结合Laplace机制添加对称指数分布噪声,将Laplace噪声添加到聚类簇中,输出添加噪声后结果存储在输出队列中,完成通信网跨层保护。由系统测试结果可知,该系统传输耗时少,且在10 s测试时间内跨层电流畸变率仅为21%,能够起到保护通信网跨层传输的作用。
文摘针对航空发动机滑油箱油量测量值易受多个参数影响导致滑油消耗率难以计算和预测的问题,提出了一种改进的滑油量数据提取规则和滑油消耗率预测方法。基于密度聚类算法(Density-based spatial clustering of applications with noise,DBSCAN)等方法对发动机数据进行了清洗,获取平稳飞行状态下滑油量数据。使用最小二乘法对滑油量进行拟合,得到了滑油消耗率,平均拟合优度达到了0.86。在此基础上,利用多层感知器(Multi-layer perception,MLP)建立了滑油消耗率与飞行状态参数之间的关系,预测结果与实际值的平均绝对百分比误差为1.15%。本文提出的方法能够满足实际工程需求,为评估航空发动机滑油系统的健康状况提供了可靠参考。
