Considering that the vehicle routing problem （VRP） with many extended features is widely used in actual life, such as multi-depot, heterogeneous types of vehicles, customer service priority and time windows etc., a ...Considering that the vehicle routing problem （VRP） with many extended features is widely used in actual life, such as multi-depot, heterogeneous types of vehicles, customer service priority and time windows etc., a mathematical model for multi-depot heterogeneous vehicle routing problem with soft time windows （MDHVRPSTW） is established. An improved ant colony optimization （IACO） is proposed for solving this model. First, MDHVRPSTW is transferred into different groups according to the nearest principle, and then the initial route is constructed by the scanning algorithm （SA）. Secondly, genetic operators are introduced, and crossover probability and mutation probability are adaptively adjusted in order to improve the global search ability of the algorithm. Moreover, the smooth mechanism is used to improve the performance of the ant colony optimization （ACO）. Finally, the 3-opt strategy is used to improve the local search ability. The proposed IACO was tested on three new instances that were generated randomly. The experimental results show that IACO is superior to the other three existing algorithms in terms of convergence speed and solution quality. Thus, the proposed method is effective and feasible, and the proposed model is meaningful.展开更多
提出了一种基于滑动窗口的资源预留SWRR(sliding window based resource reservation)算法,它将预留资源在整个资源池中所占的比例称为窗口。窗口的"滑动"包含2层含义:1)窗口大小动态变化;2)窗口中的资源动态刷新。SWRR已被...提出了一种基于滑动窗口的资源预留SWRR(sliding window based resource reservation)算法,它将预留资源在整个资源池中所占的比例称为窗口。窗口的"滑动"包含2层含义:1)窗口大小动态变化;2)窗口中的资源动态刷新。SWRR已被应用于一个大型的云计算应用平台。实验数据表明,SWRR通过合理资源预留,在兼顾所有任务调度的基础上,可为特定用户提供有效的服务可用性保障。展开更多
基金The National Natural Science Foundation of China(No.61074147)the Natural Science Foundation of Guangdong Province(No.S2011010005059)+2 种基金the Foundation of Enterprise-University-Research Institute Cooperation from Guangdong Province and Ministry of Education of China(No.2012B091000171,2011B090400460)the Science and Technology Program of Guangdong Province(No.2012B050600028)the Science and Technology Program of Huadu District,Guangzhou(No.HD14ZD001)
文摘Considering that the vehicle routing problem （VRP） with many extended features is widely used in actual life, such as multi-depot, heterogeneous types of vehicles, customer service priority and time windows etc., a mathematical model for multi-depot heterogeneous vehicle routing problem with soft time windows （MDHVRPSTW） is established. An improved ant colony optimization （IACO） is proposed for solving this model. First, MDHVRPSTW is transferred into different groups according to the nearest principle, and then the initial route is constructed by the scanning algorithm （SA）. Secondly, genetic operators are introduced, and crossover probability and mutation probability are adaptively adjusted in order to improve the global search ability of the algorithm. Moreover, the smooth mechanism is used to improve the performance of the ant colony optimization （ACO）. Finally, the 3-opt strategy is used to improve the local search ability. The proposed IACO was tested on three new instances that were generated randomly. The experimental results show that IACO is superior to the other three existing algorithms in terms of convergence speed and solution quality. Thus, the proposed method is effective and feasible, and the proposed model is meaningful.
文摘提出了一种基于滑动窗口的资源预留SWRR(sliding window based resource reservation)算法,它将预留资源在整个资源池中所占的比例称为窗口。窗口的"滑动"包含2层含义:1)窗口大小动态变化;2)窗口中的资源动态刷新。SWRR已被应用于一个大型的云计算应用平台。实验数据表明,SWRR通过合理资源预留,在兼顾所有任务调度的基础上,可为特定用户提供有效的服务可用性保障。
