Synchronization is an essential technology in the radio navigation system. The technique for improving the “Beidou” positioning ability is presented through constituting the terrestrial improvement system, and the b...Synchronization is an essential technology in the radio navigation system. The technique for improving the “Beidou” positioning ability is presented through constituting the terrestrial improvement system, and the beacon synchronization of the improvement system with the “Beidou” one-way time transfer model is realized.The direct digital synthesis (DDS) is adopted to generate the pseudo-random code clock having high precision and stability. Meanwhile, the CPLD device is used to design the synchronization pulse picking-up module, the spread spectrum PN code generator and the spread spectrum modulator. Measurement results indicate that the beacon synchronization has the high precision and the stability.展开更多
This paper studies a cold standby repairable system with working vacations and vacation interruption. The repairman's multiple vacations policy, the working vacations policy and the vacation interruption are consi...This paper studies a cold standby repairable system with working vacations and vacation interruption. The repairman's multiple vacations policy, the working vacations policy and the vacation interruption are considered simultaneously. The lifetime of components follows a phase-type(PH) distribution. The repair time in the regular repair period and the working vacation period follow other two PH distributions at different rates. For this system, the vector-valued Markov process governing the system is constructed. We obtain several important performance measures for the system in transient and stationary regimes applying matrixanalytic methods. Finally, a numerical example is given to illustrate the results obtained.展开更多
文摘Synchronization is an essential technology in the radio navigation system. The technique for improving the “Beidou” positioning ability is presented through constituting the terrestrial improvement system, and the beacon synchronization of the improvement system with the “Beidou” one-way time transfer model is realized.The direct digital synthesis (DDS) is adopted to generate the pseudo-random code clock having high precision and stability. Meanwhile, the CPLD device is used to design the synchronization pulse picking-up module, the spread spectrum PN code generator and the spread spectrum modulator. Measurement results indicate that the beacon synchronization has the high precision and the stability.
基金supported by the National Natural Science Foundation of China(71371031)
文摘This paper studies a cold standby repairable system with working vacations and vacation interruption. The repairman's multiple vacations policy, the working vacations policy and the vacation interruption are considered simultaneously. The lifetime of components follows a phase-type(PH) distribution. The repair time in the regular repair period and the working vacation period follow other two PH distributions at different rates. For this system, the vector-valued Markov process governing the system is constructed. We obtain several important performance measures for the system in transient and stationary regimes applying matrixanalytic methods. Finally, a numerical example is given to illustrate the results obtained.
