How to predict the bus arrival time accurately is a crucial problem to be solved in Internet of Vehicle. Existed methods cannot solve the problem effectively for ignoring the traffic delay jitter. In this paper,a thre...How to predict the bus arrival time accurately is a crucial problem to be solved in Internet of Vehicle. Existed methods cannot solve the problem effectively for ignoring the traffic delay jitter. In this paper,a three-stage mixed model is proposed for bus arrival time prediction. The first stage is pattern training. In this stage,the traffic delay jitter patterns(TDJP)are mined by K nearest neighbor and K-means in the historical traffic time data. The second stage is the single-step prediction,which is based on real-time adjusted Kalman filter with a modification of historical TDJP. In the third stage,as the influence of historical law is increasing in long distance prediction,we combine the single-step prediction dynamically with Markov historical transfer model to conduct the multi-step prediction. The experimental results show that the proposed single-step prediction model performs better in accuracy and efficiency than short-term traffic flow prediction and dynamic Kalman filter. The multi-step prediction provides a higher level veracity and reliability in travel time forecasting than short-term traffic flow and historical traffic pattern prediction models.展开更多
Triggering characteristics of triggered vacuum switch （TVS）, including the discharge delay time, delay jitter, range of operational voltage and peak of pulsed current, are investigated. Both structure and experiment...Triggering characteristics of triggered vacuum switch （TVS）, including the discharge delay time, delay jitter, range of operational voltage and peak of pulsed current, are investigated. Both structure and experimental circuit of TVS are presented. The results indicate that TVS, as a surface flashover triggering device with high dielectric permittivity material, is with excellent triggering characteristics. When the hold-off voltage reaches 120 kV, the minimum operational voltage is 1.3 kV, and the minimum discharge delay time and jitter are 100 ns and ±10 ns, respectively. The peak current is up to 240 kA when the operational voltage reaches 100 kV. TVS can well satisfy the main demands of high voltage and current applications, and can also be used under a multi-crowbar circuit.展开更多
This paper studies statistical multiplexing performance by input of video traffic and data traffic. The inputs have different Qos requirements such as loss and delay jitter. By applying a modified FBM model, we presen...This paper studies statistical multiplexing performance by input of video traffic and data traffic. The inputs have different Qos requirements such as loss and delay jitter. By applying a modified FBM model, we present methods to estimate effective bandwidth of the aggregated traffic. Simulations were performed to evaluate effective bandwidth. The comparison between the estimation and the simulation shows that the estimations can give correct data for the effective bandwidths in terms of our interests. The analysis of gain by using priority multiplexing also addresses proper Qos configuration for the inputs in order to achieve positive gains.展开更多
A dynamic network Qo S control mechanism was proposed based on traffic prediction. It first predicts network traffic flow and then dynamically distributes network resources, which makes full use of network flow self-s...A dynamic network Qo S control mechanism was proposed based on traffic prediction. It first predicts network traffic flow and then dynamically distributes network resources, which makes full use of network flow self-similarity and chaos. So it can meet changing network needs very well. The simulation results show that the dynamic Qo S control mechanism based on prediction has better network performance than that based on measurement.展开更多
Motivated by 5th generation wireless systems(5G),a large number of emerging applications appear,which put forward higher requirements for the task’s transmission determinacy,which refers to the delay and jitter.To sa...Motivated by 5th generation wireless systems(5G),a large number of emerging applications appear,which put forward higher requirements for the task’s transmission determinacy,which refers to the delay and jitter.To satisfy the deterministic requirement,mobile edge computing(MEC)is envisioned as a promising technique for reducing the end-to-end delay significantly.In this paper,we consider delaysensitive task and jitter-sensitive task,and then formulate the joint communications and computing optimization problem under the latency,the total bandwidth,the total transmission power of base station(BS)and the computing ability of the MEC server constraints to minimize the delay and jitter in a multiuser MEC system.Because of the problems are nonconvex,we decouple them into some subproblems and propose the corresponding algorithms to obtain a suboptimal solution.Finally,numerical results show that the proposed algorithms have a significant performance gain over the traditional solution in terms of the delay and the jitter.展开更多
基金National Science and Technology Major Project(2016ZX03001025-003)Special Found for Beijing Common Construction Project
文摘How to predict the bus arrival time accurately is a crucial problem to be solved in Internet of Vehicle. Existed methods cannot solve the problem effectively for ignoring the traffic delay jitter. In this paper,a three-stage mixed model is proposed for bus arrival time prediction. The first stage is pattern training. In this stage,the traffic delay jitter patterns(TDJP)are mined by K nearest neighbor and K-means in the historical traffic time data. The second stage is the single-step prediction,which is based on real-time adjusted Kalman filter with a modification of historical TDJP. In the third stage,as the influence of historical law is increasing in long distance prediction,we combine the single-step prediction dynamically with Markov historical transfer model to conduct the multi-step prediction. The experimental results show that the proposed single-step prediction model performs better in accuracy and efficiency than short-term traffic flow prediction and dynamic Kalman filter. The multi-step prediction provides a higher level veracity and reliability in travel time forecasting than short-term traffic flow and historical traffic pattern prediction models.
基金supported by the New Century Talent Foundation of Ministry of Education of China (NCET-08-0438)
文摘Triggering characteristics of triggered vacuum switch （TVS）, including the discharge delay time, delay jitter, range of operational voltage and peak of pulsed current, are investigated. Both structure and experimental circuit of TVS are presented. The results indicate that TVS, as a surface flashover triggering device with high dielectric permittivity material, is with excellent triggering characteristics. When the hold-off voltage reaches 120 kV, the minimum operational voltage is 1.3 kV, and the minimum discharge delay time and jitter are 100 ns and ±10 ns, respectively. The peak current is up to 240 kA when the operational voltage reaches 100 kV. TVS can well satisfy the main demands of high voltage and current applications, and can also be used under a multi-crowbar circuit.
文摘This paper studies statistical multiplexing performance by input of video traffic and data traffic. The inputs have different Qos requirements such as loss and delay jitter. By applying a modified FBM model, we present methods to estimate effective bandwidth of the aggregated traffic. Simulations were performed to evaluate effective bandwidth. The comparison between the estimation and the simulation shows that the estimations can give correct data for the effective bandwidths in terms of our interests. The analysis of gain by using priority multiplexing also addresses proper Qos configuration for the inputs in order to achieve positive gains.
基金Funded by the National Natural Science Foundation of China(No.41301084)the Scientific Research Project of Hunan Province Education Department,China(No.13C713)the Natural Science Foundation of Hunan Province,China(No.13JJ6075)
文摘A dynamic network Qo S control mechanism was proposed based on traffic prediction. It first predicts network traffic flow and then dynamically distributes network resources, which makes full use of network flow self-similarity and chaos. So it can meet changing network needs very well. The simulation results show that the dynamic Qo S control mechanism based on prediction has better network performance than that based on measurement.
基金This work is supported by the Ministry of Education of China(MOE)-China Mobile Communication Corpo-ration(CMCC)Science Joint Foundation under grant MCM20180102.
文摘Motivated by 5th generation wireless systems(5G),a large number of emerging applications appear,which put forward higher requirements for the task’s transmission determinacy,which refers to the delay and jitter.To satisfy the deterministic requirement,mobile edge computing(MEC)is envisioned as a promising technique for reducing the end-to-end delay significantly.In this paper,we consider delaysensitive task and jitter-sensitive task,and then formulate the joint communications and computing optimization problem under the latency,the total bandwidth,the total transmission power of base station(BS)and the computing ability of the MEC server constraints to minimize the delay and jitter in a multiuser MEC system.Because of the problems are nonconvex,we decouple them into some subproblems and propose the corresponding algorithms to obtain a suboptimal solution.Finally,numerical results show that the proposed algorithms have a significant performance gain over the traditional solution in terms of the delay and the jitter.
