为实现命名数据网络(NDN,name data networking)域间内容互访,提出了一种NDN域间多路径路由机制——MIRNDN。该机制使任意自治系统(AS,autonomous system)仅维护自身及客户AS可达内容的路由信息并聚合路由信息以缓解域间路由的可扩展性...为实现命名数据网络(NDN,name data networking)域间内容互访,提出了一种NDN域间多路径路由机制——MIRNDN。该机制使任意自治系统(AS,autonomous system)仅维护自身及客户AS可达内容的路由信息并聚合路由信息以缓解域间路由的可扩展性问题;采用"无谷底"路由策略引导请求非自身和客户AS内容的Interest报文从多路径探索内容,且请求聚合、网络缓存和自适应转发能优化探索;维护多路径路由信息以支持Interest多路径转发。从理论上分析了MIRNDN机制下FIB大小、路由更新的收敛时间和通信开销,在实际因特网AS级别拓扑上的仿真实验表明MIRNDN缓解了域间路由的可扩展性问题,路由更新的收敛时间较短,通信开销适量,并有效地减少了Interest报文的不必要转发。展开更多
A local domain-free discretization-immersed boundary method(DFDIBM)is presented in this paper to solve incompressible Navier-Stokes equations in the primitive variable form.Like the conventional immersed boundary meth...A local domain-free discretization-immersed boundary method(DFDIBM)is presented in this paper to solve incompressible Navier-Stokes equations in the primitive variable form.Like the conventional immersed boundary method(IBM),the local DFD-IBM solves the governing equations in the whole domain including exterior and interior of the immersed object.The effect of immersed boundary to the surrounding fluids is through the evaluation of velocity at interior and exterior dependent points.To be specific,the velocity at interior dependent points is computed by approximate forms of solution and the velocity at exterior dependent points is set to the wall velocity.As compared to the conventional IBM,the present approach accurately implements the non-slip boundary condition.As a result,there is no flow penetration,which is often appeared in the conventional IBM results.The present approach is validated by its application to simulate incompressible viscous flows around a circular cylinder.The obtained numerical results agree very well with the data in the literature.展开更多
文摘为实现命名数据网络(NDN,name data networking)域间内容互访,提出了一种NDN域间多路径路由机制——MIRNDN。该机制使任意自治系统(AS,autonomous system)仅维护自身及客户AS可达内容的路由信息并聚合路由信息以缓解域间路由的可扩展性问题;采用"无谷底"路由策略引导请求非自身和客户AS内容的Interest报文从多路径探索内容,且请求聚合、网络缓存和自适应转发能优化探索;维护多路径路由信息以支持Interest多路径转发。从理论上分析了MIRNDN机制下FIB大小、路由更新的收敛时间和通信开销,在实际因特网AS级别拓扑上的仿真实验表明MIRNDN缓解了域间路由的可扩展性问题,路由更新的收敛时间较短,通信开销适量,并有效地减少了Interest报文的不必要转发。
文摘A local domain-free discretization-immersed boundary method(DFDIBM)is presented in this paper to solve incompressible Navier-Stokes equations in the primitive variable form.Like the conventional immersed boundary method(IBM),the local DFD-IBM solves the governing equations in the whole domain including exterior and interior of the immersed object.The effect of immersed boundary to the surrounding fluids is through the evaluation of velocity at interior and exterior dependent points.To be specific,the velocity at interior dependent points is computed by approximate forms of solution and the velocity at exterior dependent points is set to the wall velocity.As compared to the conventional IBM,the present approach accurately implements the non-slip boundary condition.As a result,there is no flow penetration,which is often appeared in the conventional IBM results.The present approach is validated by its application to simulate incompressible viscous flows around a circular cylinder.The obtained numerical results agree very well with the data in the literature.
