Distributed Luby Transform （DLT） codes have been proposed to improve the robustness and system throughputs for multisource single-sink networks by exploiting the benefits of Network Coding （NC） at a single relay. ...Distributed Luby Transform （DLT） codes have been proposed to improve the robustness and system throughputs for multisource single-sink networks by exploiting the benefits of Network Coding （NC） at a single relay. All the proposed schemes such as the DLT and Soliton-Like Rateless Coding （SLRC） have attempted to maintain Robust Soliton Distribution （RSD） or Soliton-Like Distribution （SLD） for the output data at the relay. This rzsult in some source symbols to be discarded, thereby degrading the throughput. In this paper, we have proposed a novel method called the Full DLT （FDLT） coding scheme to be applied in the InterPlaNetary （IPN） Internet scenario comprising two sources and one relay The aim of the proposed scheme is to fully utilise the source symbols so as to reduce the overheads and improve energy efficiencies at the sources while maintaining low overhead at the relay. In addition, almost no buffer is needed in the proposed scheme so the relay can have limited storage space, and the proposed scheme is resilient to the churn rates of the nodes. The simulation results have shown that the proposed scheme outperforms the aforementioned schemes with respect to source overheads and total overhead in addition to preserving the benefits of NC and LT codes.展开更多
Coordinated scheduling of multimode plays a pivotal role in the rapid gathering and dissipating of passengers in transport hubs. Based on the survey data, the whole-day reaching time distribution at transfer points of...Coordinated scheduling of multimode plays a pivotal role in the rapid gathering and dissipating of passengers in transport hubs. Based on the survey data, the whole-day reaching time distribution at transfer points of passengers from the dominant mode to the connecting mode was achieved. A GI/M K/1 bulk service queuing system was constituted by putting the passengers' reaching time distribution as the input and the connecting mode as the service institution. Through queuing theory, the relationship between average queuing length under steady-state and headway of the connecting mode was achieved. By putting the minimum total cost of system as optimization objective, the headway as decision variable, a coordinated scheduling model of multimode in intermodal transit hubs was established. At last, a dynamic scheduling strategy was generated to cope with the unexpected changes of the dominant mode. The instance analysis indicates that this model can significantly reduce passengers' queuing time by approximately 17% with no apparently increase in departure frequency, which provides a useful solution for the coordinated scheduling of different transport modes in hubs.展开更多
基金supported by the National Natural Science Foundation of China under Grant No.61032004the National High Technology Research and Development Program of China (863 Program) under Grants No.2012AA121605,No.2012AA01A503,No.2012AA01A510
文摘Distributed Luby Transform （DLT） codes have been proposed to improve the robustness and system throughputs for multisource single-sink networks by exploiting the benefits of Network Coding （NC） at a single relay. All the proposed schemes such as the DLT and Soliton-Like Rateless Coding （SLRC） have attempted to maintain Robust Soliton Distribution （RSD） or Soliton-Like Distribution （SLD） for the output data at the relay. This rzsult in some source symbols to be discarded, thereby degrading the throughput. In this paper, we have proposed a novel method called the Full DLT （FDLT） coding scheme to be applied in the InterPlaNetary （IPN） Internet scenario comprising two sources and one relay The aim of the proposed scheme is to fully utilise the source symbols so as to reduce the overheads and improve energy efficiencies at the sources while maintaining low overhead at the relay. In addition, almost no buffer is needed in the proposed scheme so the relay can have limited storage space, and the proposed scheme is resilient to the churn rates of the nodes. The simulation results have shown that the proposed scheme outperforms the aforementioned schemes with respect to source overheads and total overhead in addition to preserving the benefits of NC and LT codes.
基金Projects(51278221,51378076)supported by the National Natural Science Foundation of China
文摘Coordinated scheduling of multimode plays a pivotal role in the rapid gathering and dissipating of passengers in transport hubs. Based on the survey data, the whole-day reaching time distribution at transfer points of passengers from the dominant mode to the connecting mode was achieved. A GI/M K/1 bulk service queuing system was constituted by putting the passengers' reaching time distribution as the input and the connecting mode as the service institution. Through queuing theory, the relationship between average queuing length under steady-state and headway of the connecting mode was achieved. By putting the minimum total cost of system as optimization objective, the headway as decision variable, a coordinated scheduling model of multimode in intermodal transit hubs was established. At last, a dynamic scheduling strategy was generated to cope with the unexpected changes of the dominant mode. The instance analysis indicates that this model can significantly reduce passengers' queuing time by approximately 17% with no apparently increase in departure frequency, which provides a useful solution for the coordinated scheduling of different transport modes in hubs.
