China’s high-speed railway network has already achieved speeds of 350 km/h;however,this could be further increased to 400 km/h.After considering the development status and technical level of the high-speed railway sy...China’s high-speed railway network has already achieved speeds of 350 km/h;however,this could be further increased to 400 km/h.After considering the development status and technical level of the high-speed railway system in China,this study indicates that there are four key technologies involved in improving its operational speed:the track,the electrical moving unit,the control system and the traction power supply.Through an experimental analysis,an evaluation index for the high-speed railway is then constructed based on four aspects:safety,comfort,intelligence and environmental protection.Using this system,the rationality of the high-speed railway speed-improvement plan can be scientifically evaluated.The results are of practical significance to the Chinese railway administration,as they can be used to formulate specific plans to increase rail speeds,and therefore promote the rapid development of the high-speed railway network in China.展开更多
Implementing video applications on emerging multi-core processors is a promising technique for personal, real-time multi-media applications. However, when porting the legacy parallel video encoders developed for clust...Implementing video applications on emerging multi-core processors is a promising technique for personal, real-time multi-media applications. However, when porting the legacy parallel video encoders developed for clusters to shared-memory multi-cores, the existing parallel algorithms result in workload imbalances on different cores and communication inefficiencies. This paper describes a strip-wise parallel scheme to balance workloads and a hybrid communication mechanism to reduce communication overhead. The implementation of the H.264 parallel encoder on an eight CPU Intel Xeon system achieves 5x to 6x speed-up over a single thread encoder and achieves a 29% performance improvement over the commonly used master-slave schemes on clusters. The paper also gives further analysis on scalability, parallel efficiency, workload balance, and communication overhead as the number of cores varies.展开更多
文摘China’s high-speed railway network has already achieved speeds of 350 km/h;however,this could be further increased to 400 km/h.After considering the development status and technical level of the high-speed railway system in China,this study indicates that there are four key technologies involved in improving its operational speed:the track,the electrical moving unit,the control system and the traction power supply.Through an experimental analysis,an evaluation index for the high-speed railway is then constructed based on four aspects:safety,comfort,intelligence and environmental protection.Using this system,the rationality of the high-speed railway speed-improvement plan can be scientifically evaluated.The results are of practical significance to the Chinese railway administration,as they can be used to formulate specific plans to increase rail speeds,and therefore promote the rapid development of the high-speed railway network in China.
基金Supported by the National Natural Science Foundation of China(No. 60236020)
文摘Implementing video applications on emerging multi-core processors is a promising technique for personal, real-time multi-media applications. However, when porting the legacy parallel video encoders developed for clusters to shared-memory multi-cores, the existing parallel algorithms result in workload imbalances on different cores and communication inefficiencies. This paper describes a strip-wise parallel scheme to balance workloads and a hybrid communication mechanism to reduce communication overhead. The implementation of the H.264 parallel encoder on an eight CPU Intel Xeon system achieves 5x to 6x speed-up over a single thread encoder and achieves a 29% performance improvement over the commonly used master-slave schemes on clusters. The paper also gives further analysis on scalability, parallel efficiency, workload balance, and communication overhead as the number of cores varies.
