The first part of this paper gives a complete description of local automorphism groups for Levi degenerate hypersurfaces of finite type in C2. It is also proved that, with the exception of hypersurfaces of the form v ...The first part of this paper gives a complete description of local automorphism groups for Levi degenerate hypersurfaces of finite type in C2. It is also proved that, with the exception of hypersurfaces of the form v = |z|k, local automorphisms are always determined by their 1-jets. Using this result, the second part describes special normal forms which by an additional normalization eliminate the nonlinear symmetries of the model and allows to decide effectively about local equivalence of two hypersurfaces given in this normal form.展开更多
针对城市环境的车联网VANETSs(vehicular ad hoc networks)的非安全应用,多数路由协议采用贪婪技术,旨在降低端到端传输时延。然而,贪婪技术易引发局部最大化问题以及数据拥塞,增加端到端传输时延。因此,提出基于稳定支配集路由协议S-CD...针对城市环境的车联网VANETSs(vehicular ad hoc networks)的非安全应用,多数路由协议采用贪婪技术,旨在降低端到端传输时延。然而,贪婪技术易引发局部最大化问题以及数据拥塞,增加端到端传输时延。因此,提出基于稳定支配集路由协议S-CDSR(stable CDS based routing)。S-CDSR协议属于分布式路由,在数据传输前,计算整条路由路径的端到端传输时延,在每条路段上建立稳定的主干节点,在十字路口,利用桥节点连接路段上的主干节点,桥节点依据路径时延信息计算路段的权值,具有最低权值的路段被选择为转发数据的路径。仿真结果表明,S-CDSR协议能够降低端到端传输时延,提高数据包传输率。与ICAR协议相比,S-CDSR协议的端到端传输时延下降了43%。展开更多
文摘The first part of this paper gives a complete description of local automorphism groups for Levi degenerate hypersurfaces of finite type in C2. It is also proved that, with the exception of hypersurfaces of the form v = |z|k, local automorphisms are always determined by their 1-jets. Using this result, the second part describes special normal forms which by an additional normalization eliminate the nonlinear symmetries of the model and allows to decide effectively about local equivalence of two hypersurfaces given in this normal form.
文摘针对城市环境的车联网VANETSs(vehicular ad hoc networks)的非安全应用,多数路由协议采用贪婪技术,旨在降低端到端传输时延。然而,贪婪技术易引发局部最大化问题以及数据拥塞,增加端到端传输时延。因此,提出基于稳定支配集路由协议S-CDSR(stable CDS based routing)。S-CDSR协议属于分布式路由,在数据传输前,计算整条路由路径的端到端传输时延,在每条路段上建立稳定的主干节点,在十字路口,利用桥节点连接路段上的主干节点,桥节点依据路径时延信息计算路段的权值,具有最低权值的路段被选择为转发数据的路径。仿真结果表明,S-CDSR协议能够降低端到端传输时延,提高数据包传输率。与ICAR协议相比,S-CDSR协议的端到端传输时延下降了43%。
