A hybrid estimation of distribution algorithm(EDA)with iterated greedy(IG) search(EDA-IG) is proposed for solving the unrelated parallel machine scheduling problem with sequence-dependent setup times(UPMSP-SDST). For ...A hybrid estimation of distribution algorithm(EDA)with iterated greedy(IG) search(EDA-IG) is proposed for solving the unrelated parallel machine scheduling problem with sequence-dependent setup times(UPMSP-SDST). For makespan criterion, some properties about neighborhood search operators to avoid invalid search are derived. A probability model based on neighbor relations of jobs is built in the EDA-based exploration phase to generate new solutions by sampling the promising search region. Two types of deconstruction and reconstruction as well as an IG search are designed in the IG-based exploitation phase.Computational complexity of the algorithm is analyzed, and the effect of parameters is investigated by using the Taguchi method of design-of-experiment. Numerical tests on 1640 benchmark instances are carried out. The results and comparisons demonstrate the effectiveness of the EDA-IG. Especially, the bestknown solutions of 531 instances are updated. In addition, the effectiveness of the properties is also demonstrated by numerical comparisons.展开更多
Stochastic dynamic job shop scheduling pro- blem with consideration of sequence-dependent setup times are among the most difficult classes of scheduling problems. This paper assesses the performance of nine dispatchin...Stochastic dynamic job shop scheduling pro- blem with consideration of sequence-dependent setup times are among the most difficult classes of scheduling problems. This paper assesses the performance of nine dispatching rules in such shop from makespan, mean flow time, maximum flow time, mean tardiness, maximum tardiness, number of tardy jobs, total setups and mean setup time performance measures viewpoint. A discrete event simulation model of a stochastic dynamic job shop manufacturing system is developed for investigation purpose. Nine dispatching rules identified from literature are incorporated in the simulation model. The simulation experiments are conducted under due date tightness factor of 3, shop utilization percentage of 90 % and setup times less than processing times. Results indicate that shortest setup time （SIMSET） rule provides the best performance for mean flow time and number of tardy jobs measures. The job with similar setup and modified earliest due date （JMEDD） rule provides the best performance for make- span, maximum flow time, mean tardiness, maximum tardiness, total setups and mean setup time measures.展开更多
Nucleosome positioning is critical for gene expression and of major biological interest. The high cost of experimentally mapping nucleosomal arrangement signifies the need for computational approaches to predict nucle...Nucleosome positioning is critical for gene expression and of major biological interest. The high cost of experimentally mapping nucleosomal arrangement signifies the need for computational approaches to predict nucleosome positions at high resolution. Here, we present a web-based application to fulfill this need by implementing two models, YR and W/S schemes, for the translational and rotational positioning of nucleosomes, respectively. Our methods are based on sequence-dependent anisotropic bending that dictates how DNA is wrapped around a histone octamer. This application allows users to specify a number of options such as schemes and param- eters for threading calculation and provides multiple layout formats. The nuMap is implemented in Java/Perl/MySQL and is freely available for public use at http：//numap.rit.edu. The user manual, implementation notes, description of the methodology and examples are available at the site.展开更多
A new scheduling model for the bulk ore blending process in iron-making industry is presented , by converting the process into an assembly flow shop scheduling problem with sequence-depended setup time and limited int...A new scheduling model for the bulk ore blending process in iron-making industry is presented , by converting the process into an assembly flow shop scheduling problem with sequence-depended setup time and limited intermediate buffer , and it facilitates the scheduling optimization for this process.To find out the optimal solution of the scheduling problem , an improved genetic algorithm hybridized with problem knowledge-based heuristics is also proposed , which provides high-quality initial solutions and fast searching speed.The efficiency of the algorithm is verified by the computational experiments.展开更多
基金supported by the National Science Fund for Distinguished Young Scholars of China(61525304)
文摘A hybrid estimation of distribution algorithm(EDA)with iterated greedy(IG) search(EDA-IG) is proposed for solving the unrelated parallel machine scheduling problem with sequence-dependent setup times(UPMSP-SDST). For makespan criterion, some properties about neighborhood search operators to avoid invalid search are derived. A probability model based on neighbor relations of jobs is built in the EDA-based exploration phase to generate new solutions by sampling the promising search region. Two types of deconstruction and reconstruction as well as an IG search are designed in the IG-based exploitation phase.Computational complexity of the algorithm is analyzed, and the effect of parameters is investigated by using the Taguchi method of design-of-experiment. Numerical tests on 1640 benchmark instances are carried out. The results and comparisons demonstrate the effectiveness of the EDA-IG. Especially, the bestknown solutions of 531 instances are updated. In addition, the effectiveness of the properties is also demonstrated by numerical comparisons.
文摘Stochastic dynamic job shop scheduling pro- blem with consideration of sequence-dependent setup times are among the most difficult classes of scheduling problems. This paper assesses the performance of nine dispatching rules in such shop from makespan, mean flow time, maximum flow time, mean tardiness, maximum tardiness, number of tardy jobs, total setups and mean setup time performance measures viewpoint. A discrete event simulation model of a stochastic dynamic job shop manufacturing system is developed for investigation purpose. Nine dispatching rules identified from literature are incorporated in the simulation model. The simulation experiments are conducted under due date tightness factor of 3, shop utilization percentage of 90 % and setup times less than processing times. Results indicate that shortest setup time （SIMSET） rule provides the best performance for mean flow time and number of tardy jobs measures. The job with similar setup and modified earliest due date （JMEDD） rule provides the best performance for make- span, maximum flow time, mean tardiness, maximum tardiness, total setups and mean setup time measures.
基金supported by the scholarship of the King Abdullah International Medical Research Center (KAIMRC) in Saudi Arabia to BAthe start-up fund, Faculty of Development (FEAD) fund+1 种基金Dean’s Research Initiation Grant (D-RIG) fund of Rochester Institute of Technology in the USA awarded to FC the Intramural Research Program of National Cancer Institute, NIH of the USA to VBZ
文摘Nucleosome positioning is critical for gene expression and of major biological interest. The high cost of experimentally mapping nucleosomal arrangement signifies the need for computational approaches to predict nucleosome positions at high resolution. Here, we present a web-based application to fulfill this need by implementing two models, YR and W/S schemes, for the translational and rotational positioning of nucleosomes, respectively. Our methods are based on sequence-dependent anisotropic bending that dictates how DNA is wrapped around a histone octamer. This application allows users to specify a number of options such as schemes and param- eters for threading calculation and provides multiple layout formats. The nuMap is implemented in Java/Perl/MySQL and is freely available for public use at http：//numap.rit.edu. The user manual, implementation notes, description of the methodology and examples are available at the site.
基金Item Sponsored by National Key Technology Research and Development Program in 11th Five-Year Plan of China ( 2006AA04Z184 )National Natural Science Foundation of China ( 60974023 )
文摘A new scheduling model for the bulk ore blending process in iron-making industry is presented , by converting the process into an assembly flow shop scheduling problem with sequence-depended setup time and limited intermediate buffer , and it facilitates the scheduling optimization for this process.To find out the optimal solution of the scheduling problem , an improved genetic algorithm hybridized with problem knowledge-based heuristics is also proposed , which provides high-quality initial solutions and fast searching speed.The efficiency of the algorithm is verified by the computational experiments.
