采用跨层协同设计的思路和定向通信机制,对移动 Ad Hoc 网中的按需路由算法进行跨层优化,提出一种新的 Ad Hoc 按需定向路由算法:CAODR。通过定向天线的使用和网络、MAC 与物理三层之间的跨层协同,实现了定向单播和全向广播的发送方式,...采用跨层协同设计的思路和定向通信机制,对移动 Ad Hoc 网中的按需路由算法进行跨层优化,提出一种新的 Ad Hoc 按需定向路由算法:CAODR。通过定向天线的使用和网络、MAC 与物理三层之间的跨层协同,实现了定向单播和全向广播的发送方式,成功减少了隐藏终端造成的分组碰撞和暴露终端造成的不必要等待。数学推导证明了 CAODR 对隐藏/暴露终端问题的改善。性能分析和仿真结果也表明:它在端到端时延、吞吐率、成功率等性能上的表现优于经典的 AODV 路由算法。展开更多
The equation of two-dimensional fiber direction vector was solved theoretically to give the fiber orientation distri- bution in simple shear flow, flow with two direction shears, extensional flow and arbitrary planar ...The equation of two-dimensional fiber direction vector was solved theoretically to give the fiber orientation distri- bution in simple shear flow, flow with two direction shears, extensional flow and arbitrary planar incompressible flow. The Fok- ker-Planck equation was solved numerically to validify the theoretical solutions. The stable orientation and orientation period of fiber were obtained. The results showed that the fiber orientation distribution is dependent on the relative not absolute magnitude of the matrix rate-of-strain of flow. The effect of fiber aspect ratio on the orientation distribution of fiber is insignificant in most conditions except the simple shear case. It was proved that the results for a planar flow could be generalized to the case of 3-D fiber direction vector.展开更多
文摘采用跨层协同设计的思路和定向通信机制,对移动 Ad Hoc 网中的按需路由算法进行跨层优化,提出一种新的 Ad Hoc 按需定向路由算法:CAODR。通过定向天线的使用和网络、MAC 与物理三层之间的跨层协同,实现了定向单播和全向广播的发送方式,成功减少了隐藏终端造成的分组碰撞和暴露终端造成的不必要等待。数学推导证明了 CAODR 对隐藏/暴露终端问题的改善。性能分析和仿真结果也表明:它在端到端时延、吞吐率、成功率等性能上的表现优于经典的 AODV 路由算法。
基金Project (No. 10372090) supported by the National Natural Science Foundation of China
文摘The equation of two-dimensional fiber direction vector was solved theoretically to give the fiber orientation distri- bution in simple shear flow, flow with two direction shears, extensional flow and arbitrary planar incompressible flow. The Fok- ker-Planck equation was solved numerically to validify the theoretical solutions. The stable orientation and orientation period of fiber were obtained. The results showed that the fiber orientation distribution is dependent on the relative not absolute magnitude of the matrix rate-of-strain of flow. The effect of fiber aspect ratio on the orientation distribution of fiber is insignificant in most conditions except the simple shear case. It was proved that the results for a planar flow could be generalized to the case of 3-D fiber direction vector.