In order to improve the efficiency of operating rooms,reduce the costs for hospitals and improve the level of service qualities, a scheduling method was developed based on an estimation of distribution algorithm（ EDA...In order to improve the efficiency of operating rooms,reduce the costs for hospitals and improve the level of service qualities, a scheduling method was developed based on an estimation of distribution algorithm（ EDA）. First, a scheduling problem domain is described. Based on assignment constraints and resource capacity constraints, the mathematical programming models are set up with an objective function to minimize the system makespan. On the basis of the descriptions mentioned above, a solution policy of generating feasible scheduling solutions is established. Combined with the specific constraints of operating theatres, the EDA-based algorithm is put forward to solve scheduling problems. Finally, simulation experiments are designed to evaluate the scheduling method. The orthogonal table is chosen to determine the parameters in the proposed method. Then the genetic algorithm and the particle swarm optimization algorithm are chosen for comparison with the EDA-based algorithm, and the results indicate that the proposed method can decrease the makespan of the surgical system regardless of the size of operations. Moreover, the computation time of the EDA-based algorithm is only approximately 5 s when solving the large scale problems, which means that the proposed algorithm is suitable for carrying out an on-line scheduling optimization of the patients.展开更多
To fulfill the requirements for hybrid real-time system scheduling, a long-release-interval-first （LRIF） real-time scheduling algorithm is proposed. The algorithm adopts both the fixed priority and the dynamic prior...To fulfill the requirements for hybrid real-time system scheduling, a long-release-interval-first （LRIF） real-time scheduling algorithm is proposed. The algorithm adopts both the fixed priority and the dynamic priority to assign priorities for tasks. By assigning higher priorities to the aperiodic soft real-time jobs with longer release intervals, it guarantees the executions for periodic hard real-time tasks and further probabilistically guarantees the executions for aperiodic soft real-time tasks. The schedulability test approach for the LRIF algorithm is presented. The implementation issues of the LRIF algorithm are also discussed. Simulation result shows that LRIF obtains better schedulable performance than the maximum urgency first （MUF） algorithm, the earliest deadline first （EDF） algorithm and EDF for hybrid tasks. LRIF has great capability to schedule both periodic hard real-time and aperiodic soft real-time tasks.展开更多
In order to solve the no-wait flowshop scheduling problem to minimize the maximum lateness,three job-block-based neighborhoods are proposed,among which the block exchange neighborhood have a size of O（n4）while the b...In order to solve the no-wait flowshop scheduling problem to minimize the maximum lateness,three job-block-based neighborhoods are proposed,among which the block exchange neighborhood have a size of O（n4）while the block swap and the simplified block exchange neighborhoods have a size of O（n3）.With larger sizes than the existing neighborhoods,the proposed neighborhoods can enhance the solution quality of local search algorithms.Speedup properties for the neighborhoods are developed,which can evaluate a neighbor in constant time and explore the neighborhoods in time proportional to their proposed sizes. Unlike the dominance-rule-based speedup method,the proposed speedups are applicable to any machine number.Three neighborhoods and the union of block swap and the simplified block exchange neighborhoods are compared in the tabu search.Computational results on benchmark instances show that three tabu search algorithms with O（n3）neighborhoods outperform the existing algorithms and the tabu search algorithm with the union has the best performance among all the tested algorithms.展开更多
The dubas bug Ommatissus lybicus （Debergevin） （Homoptera： Tropiduchidae） was almost absent in AI-Anbar Province during the past years, however, field survey conducted in different regions of the province during f...The dubas bug Ommatissus lybicus （Debergevin） （Homoptera： Tropiduchidae） was almost absent in AI-Anbar Province during the past years, however, field survey conducted in different regions of the province during fall of 2007 indicated the presence of heavy infestation by this pest on date palm trees in some orchards toward the east of Hit city. Infestation was highly influencing in term of affected trees and accumulation of honey dew. Scattered infestations were also recorded in some orchards west of Hit city and near the cities of Haditha, Rawa and AI-Kaim near the Syrian border. However, a sharp decline of dubas population was observed during 2008 and subsequent years as a result of the influence of sever winter in 2008 and the continuous occurrence of dust storms which showed a detrimental effect on moving stages of dubas bug. Data showed that nymphs density reached to about 50 individuals/leaflet recorded during the last week of April and early May of 2008 and was reduced to less than 5 nymphs/leaflet by the end of the third week of May of the same year as a result of the indicated climatic factors. Farther samplings conducted in Spring and Fall seasons of 2009 and 2010 indicated that insects were mainly found on offshoots near the ground with a maximum density reached to 12 individuals/tree. Since the spread of the pest occurred in a discontinuous manner with no correlation to infestations in close by provinces indicating that the arrival or transportation of the pest was happened in a way other than the normal distribution, therefore, dubas bug may not persist in date palm orchards in A1- Anbar Province.展开更多
This paper is concerned with the fractional version of online hierarchical scheduling problem on uniform machines.In the problem,the jobs and machines have several different hierarchies and each job can be arbitrarily...This paper is concerned with the fractional version of online hierarchical scheduling problem on uniform machines.In the problem,the jobs and machines have several different hierarchies and each job can be arbitrarily split between the machines with hierarchies not above the hierarchy of the job.The objective is to minimize the makespan.The authors present an optimal algorithm for the problem with three hierarchies.展开更多
基金The National Natural Science Foundation of China(No.61273035,71471135)
文摘In order to improve the efficiency of operating rooms,reduce the costs for hospitals and improve the level of service qualities, a scheduling method was developed based on an estimation of distribution algorithm（ EDA）. First, a scheduling problem domain is described. Based on assignment constraints and resource capacity constraints, the mathematical programming models are set up with an objective function to minimize the system makespan. On the basis of the descriptions mentioned above, a solution policy of generating feasible scheduling solutions is established. Combined with the specific constraints of operating theatres, the EDA-based algorithm is put forward to solve scheduling problems. Finally, simulation experiments are designed to evaluate the scheduling method. The orthogonal table is chosen to determine the parameters in the proposed method. Then the genetic algorithm and the particle swarm optimization algorithm are chosen for comparison with the EDA-based algorithm, and the results indicate that the proposed method can decrease the makespan of the surgical system regardless of the size of operations. Moreover, the computation time of the EDA-based algorithm is only approximately 5 s when solving the large scale problems, which means that the proposed algorithm is suitable for carrying out an on-line scheduling optimization of the patients.
基金The Natural Science Foundation of Jiangsu Province(NoBK2005408)
文摘To fulfill the requirements for hybrid real-time system scheduling, a long-release-interval-first （LRIF） real-time scheduling algorithm is proposed. The algorithm adopts both the fixed priority and the dynamic priority to assign priorities for tasks. By assigning higher priorities to the aperiodic soft real-time jobs with longer release intervals, it guarantees the executions for periodic hard real-time tasks and further probabilistically guarantees the executions for aperiodic soft real-time tasks. The schedulability test approach for the LRIF algorithm is presented. The implementation issues of the LRIF algorithm are also discussed. Simulation result shows that LRIF obtains better schedulable performance than the maximum urgency first （MUF） algorithm, the earliest deadline first （EDF） algorithm and EDF for hybrid tasks. LRIF has great capability to schedule both periodic hard real-time and aperiodic soft real-time tasks.
基金The National Natural Science Foundation of China(No.60672092,60504029,60873236)the National High Technology Researchand Development Program of China(863 Program)(No.2008AA04Z103)
文摘In order to solve the no-wait flowshop scheduling problem to minimize the maximum lateness,three job-block-based neighborhoods are proposed,among which the block exchange neighborhood have a size of O（n4）while the block swap and the simplified block exchange neighborhoods have a size of O（n3）.With larger sizes than the existing neighborhoods,the proposed neighborhoods can enhance the solution quality of local search algorithms.Speedup properties for the neighborhoods are developed,which can evaluate a neighbor in constant time and explore the neighborhoods in time proportional to their proposed sizes. Unlike the dominance-rule-based speedup method,the proposed speedups are applicable to any machine number.Three neighborhoods and the union of block swap and the simplified block exchange neighborhoods are compared in the tabu search.Computational results on benchmark instances show that three tabu search algorithms with O（n3）neighborhoods outperform the existing algorithms and the tabu search algorithm with the union has the best performance among all the tested algorithms.
文摘The dubas bug Ommatissus lybicus （Debergevin） （Homoptera： Tropiduchidae） was almost absent in AI-Anbar Province during the past years, however, field survey conducted in different regions of the province during fall of 2007 indicated the presence of heavy infestation by this pest on date palm trees in some orchards toward the east of Hit city. Infestation was highly influencing in term of affected trees and accumulation of honey dew. Scattered infestations were also recorded in some orchards west of Hit city and near the cities of Haditha, Rawa and AI-Kaim near the Syrian border. However, a sharp decline of dubas population was observed during 2008 and subsequent years as a result of the influence of sever winter in 2008 and the continuous occurrence of dust storms which showed a detrimental effect on moving stages of dubas bug. Data showed that nymphs density reached to about 50 individuals/leaflet recorded during the last week of April and early May of 2008 and was reduced to less than 5 nymphs/leaflet by the end of the third week of May of the same year as a result of the indicated climatic factors. Farther samplings conducted in Spring and Fall seasons of 2009 and 2010 indicated that insects were mainly found on offshoots near the ground with a maximum density reached to 12 individuals/tree. Since the spread of the pest occurred in a discontinuous manner with no correlation to infestations in close by provinces indicating that the arrival or transportation of the pest was happened in a way other than the normal distribution, therefore, dubas bug may not persist in date palm orchards in A1- Anbar Province.
基金supported by National Natural Science Foundation of China under Grant No.11171106
文摘This paper is concerned with the fractional version of online hierarchical scheduling problem on uniform machines.In the problem,the jobs and machines have several different hierarchies and each job can be arbitrarily split between the machines with hierarchies not above the hierarchy of the job.The objective is to minimize the makespan.The authors present an optimal algorithm for the problem with three hierarchies.
