针对机会网络中由于节点移动、网络稀疏等各种原因通常导致网络拓扑动态变化大,消息源节点到汇聚节点之间往往不存在稳定的端到端的通信链路,提出了一种基于偏好顺序决策法(the technique for order preference by similarity to ideal ...针对机会网络中由于节点移动、网络稀疏等各种原因通常导致网络拓扑动态变化大,消息源节点到汇聚节点之间往往不存在稳定的端到端的通信链路,提出了一种基于偏好顺序决策法(the technique for order preference by similarity to ideal so-lution,TOPSIS)的数据收集策略(data gathering based on the TOPSIS,DGT)。DGT策略根据节点的剩余能量、感知节点到汇聚节点的距离以及传感器节点的连通变化,采用TOPSIS评估选择下一跳中继节点。仿真实验表明,与现有的几种典型转发控制机制相比,DGT策略在保证较低传输延迟和较高传输成功率的基础上,通过减少节点间的转发次数,降低了网络传输开销。展开更多
针对软件定义网络(SDN,software defined networking)中匹配域范围有限和缺乏有效的数据来源验证机制问题,提出基于密码标识的SDN安全控制转发方法。首先,根据用户身份、文件属性或业务内容等特征信息生成密码标识,为数据流打上密码标...针对软件定义网络(SDN,software defined networking)中匹配域范围有限和缺乏有效的数据来源验证机制问题,提出基于密码标识的SDN安全控制转发方法。首先,根据用户身份、文件属性或业务内容等特征信息生成密码标识,为数据流打上密码标识并用基于密码标识的私钥签名。其次,在其进出网络时验证签名,确保数据的真实性,同时将密码标识设计为转发设备能识别的匹配项,基于密码标识定义网络转发行为,形成基于人、物、业务流等细粒度网络控管能力。最后,通过实验分析验证该方法的有效性。展开更多
Matrix Converter(MC),a direct AC-ACconverter which is capable of bidirectional powerflow,unity input power factor control and efficiencyimprovement.Thus,it is more suitable for integrationof motor machine and power el...Matrix Converter(MC),a direct AC-ACconverter which is capable of bidirectional powerflow,unity input power factor control and efficiencyimprovement.Thus,it is more suitable for integrationof motor machine and power electronics systems.This paper investigated a novel generationsystem,which is composed of hybrid excitedsynchronous generator(HESG)and matrix converter(MC),as shown in Fig.1.Owing to the voltage clampcircuit,this structure waived an external DC sourcecommonly used for the excitation for HESG.Thevoltage clamp circuit shared a DC bus with afull-bridge converter and the excitation winding ofHESG is directly connected to the output of thefull-bridge converter achieving a bidirectional currentflow.展开更多
文摘针对机会网络中由于节点移动、网络稀疏等各种原因通常导致网络拓扑动态变化大,消息源节点到汇聚节点之间往往不存在稳定的端到端的通信链路,提出了一种基于偏好顺序决策法(the technique for order preference by similarity to ideal so-lution,TOPSIS)的数据收集策略(data gathering based on the TOPSIS,DGT)。DGT策略根据节点的剩余能量、感知节点到汇聚节点的距离以及传感器节点的连通变化,采用TOPSIS评估选择下一跳中继节点。仿真实验表明,与现有的几种典型转发控制机制相比,DGT策略在保证较低传输延迟和较高传输成功率的基础上,通过减少节点间的转发次数,降低了网络传输开销。
文摘针对软件定义网络(SDN,software defined networking)中匹配域范围有限和缺乏有效的数据来源验证机制问题,提出基于密码标识的SDN安全控制转发方法。首先,根据用户身份、文件属性或业务内容等特征信息生成密码标识,为数据流打上密码标识并用基于密码标识的私钥签名。其次,在其进出网络时验证签名,确保数据的真实性,同时将密码标识设计为转发设备能识别的匹配项,基于密码标识定义网络转发行为,形成基于人、物、业务流等细粒度网络控管能力。最后,通过实验分析验证该方法的有效性。
文摘Matrix Converter(MC),a direct AC-ACconverter which is capable of bidirectional powerflow,unity input power factor control and efficiencyimprovement.Thus,it is more suitable for integrationof motor machine and power electronics systems.This paper investigated a novel generationsystem,which is composed of hybrid excitedsynchronous generator(HESG)and matrix converter(MC),as shown in Fig.1.Owing to the voltage clampcircuit,this structure waived an external DC sourcecommonly used for the excitation for HESG.Thevoltage clamp circuit shared a DC bus with afull-bridge converter and the excitation winding ofHESG is directly connected to the output of thefull-bridge converter achieving a bidirectional currentflow.
