We study the single-machine scheduling with maintenance intervals under preemptive pattern and resumable pattern,respectively,to minimize the total weighted late work and the weighted number of tardy jobs,respectively...We study the single-machine scheduling with maintenance intervals under preemptive pattern and resumable pattern,respectively,to minimize the total weighted late work and the weighted number of tardy jobs,respectively,where each job has a release date and a due date.According to the different combinations of the two scheduling patterns and the two scheduling criteria,six scheduling problems(including two Pareto-scheduling problems)are studied in this paper.We show that by modifying the release dates and the due dates,the six problems can be reduced to their corresponding scheduling problems without maintenance intervals in quasi-linear time.As a consequence,complexity results of our problems can be directly obtained from the known results in the literature.In particular,for the problem under resumable pattern to minimize the total weighted late work with all the jobs being released at time O,an O(mn^(2)P)-time algorithm was presented in the literature,where m is the number of maintenance intervals,n is the number of jobs,and P is the total processing time of the jobs;and our research shows that the same problem is solvable in O(n^(2)p+m log m)time,improving this known result.展开更多
Conventional maintenance mode for the traction power supply system(TPSS)is to perform scheduled regular maintenance activities for power supply equipment,while such maintenance mode may result in undue maintenance tas...Conventional maintenance mode for the traction power supply system(TPSS)is to perform scheduled regular maintenance activities for power supply equipment,while such maintenance mode may result in undue maintenance tasks and low efficiency due to different degradation processes of different sorts of equipment.To address this problem,this paper introduces a preventive opportunistic maintenance(POM)method for TPSS based on equipment reliability.Firstly,a POM model is established by considering the equipment reliability degradation process based on Weibull distribution.Then,by considering the total power outage time in the planned operation cycle of TPSS as the optimization objective,the optimal maintenance scheme of TPSS is formulated by iterative method of maintenance strategies.The proposed method is verified by introducing practical maintenance strategies and fault record data of the traction transformer,circuit breaker and disconnector in an actual TPSS of a railway administration.Results show that the presented method can make full use of the existing fault data to develop a POM scheme for TPSS.It can improve maintenance efficiency and reduce power outage time,providing guidance to formulate scientific maintenance strategies for TPSS.展开更多
We study the single-machine preemptive scheduling problem with multiple maintenance activities to minimize the total late work,in which the jobs must be processed in the time space not occupied by the maintenance inte...We study the single-machine preemptive scheduling problem with multiple maintenance activities to minimize the total late work,in which the jobs must be processed in the time space not occupied by the maintenance intervals.For this problem,we present a polynomial algorithm to determine the optimal schedule and establish a formula expression to the optimal value.Moreover,our result is used to correct some minor errors in the literature related to the single-machine(preemptive or non-preemptive)scheduling with one maintenance activity to minimize the total late work.展开更多
基金supported by the National Natural Science Foundation of China(Nos.12071442 and 12201186).
文摘We study the single-machine scheduling with maintenance intervals under preemptive pattern and resumable pattern,respectively,to minimize the total weighted late work and the weighted number of tardy jobs,respectively,where each job has a release date and a due date.According to the different combinations of the two scheduling patterns and the two scheduling criteria,six scheduling problems(including two Pareto-scheduling problems)are studied in this paper.We show that by modifying the release dates and the due dates,the six problems can be reduced to their corresponding scheduling problems without maintenance intervals in quasi-linear time.As a consequence,complexity results of our problems can be directly obtained from the known results in the literature.In particular,for the problem under resumable pattern to minimize the total weighted late work with all the jobs being released at time O,an O(mn^(2)P)-time algorithm was presented in the literature,where m is the number of maintenance intervals,n is the number of jobs,and P is the total processing time of the jobs;and our research shows that the same problem is solvable in O(n^(2)p+m log m)time,improving this known result.
基金the National Natural Science Foundation of China under Grant(51907166)the Science and Technology Project of CHINA RAILWAY under Grant(2017J001-F&N2018G023)the Sichuan Science and Technology Program under Grant(2018GZ0020).
文摘Conventional maintenance mode for the traction power supply system(TPSS)is to perform scheduled regular maintenance activities for power supply equipment,while such maintenance mode may result in undue maintenance tasks and low efficiency due to different degradation processes of different sorts of equipment.To address this problem,this paper introduces a preventive opportunistic maintenance(POM)method for TPSS based on equipment reliability.Firstly,a POM model is established by considering the equipment reliability degradation process based on Weibull distribution.Then,by considering the total power outage time in the planned operation cycle of TPSS as the optimization objective,the optimal maintenance scheme of TPSS is formulated by iterative method of maintenance strategies.The proposed method is verified by introducing practical maintenance strategies and fault record data of the traction transformer,circuit breaker and disconnector in an actual TPSS of a railway administration.Results show that the presented method can make full use of the existing fault data to develop a POM scheme for TPSS.It can improve maintenance efficiency and reduce power outage time,providing guidance to formulate scientific maintenance strategies for TPSS.
基金Supported by National Natural Science Foundation of China(Grant Nos.12071442,12201186).
文摘We study the single-machine preemptive scheduling problem with multiple maintenance activities to minimize the total late work,in which the jobs must be processed in the time space not occupied by the maintenance intervals.For this problem,we present a polynomial algorithm to determine the optimal schedule and establish a formula expression to the optimal value.Moreover,our result is used to correct some minor errors in the literature related to the single-machine(preemptive or non-preemptive)scheduling with one maintenance activity to minimize the total late work.
