A memetic algorithm （MA） for a multi-mode resourceconstrained project scheduling problem （MRCPSP） is proposed. We use a new fitness function and two very effective local search procedures in the proposed MA. The f...A memetic algorithm （MA） for a multi-mode resourceconstrained project scheduling problem （MRCPSP） is proposed. We use a new fitness function and two very effective local search procedures in the proposed MA. The fitness function makes use of a mechanism called ＂strategic oscillation＂ to make the search process have a higher probability to visit solutions around a ＂feasible boundary＂. One of the local search procedures aims at improving the lower bound of project makespan to be less than a known upper bound, and another aims at improving a solution of an MRCPSP instance accepting infeasible solutions based on the new fitness function in the search process. A detailed computational experiment is set up using instances from the problem instance library PSPLIB. Computational results show that the proposed MA is very competitive with the state-of-the-art algorithms. The MA obtains improved solutions for one instance of set J30.展开更多
Using a relaying system to provide spatial diversity and improve the system performance is a tendency in the wireless cooperative communications. Amplify-and-forward （AF） mode with a low complexity is easy to be imp...Using a relaying system to provide spatial diversity and improve the system performance is a tendency in the wireless cooperative communications. Amplify-and-forward （AF） mode with a low complexity is easy to be implemented. Under the consideration of cooperative communication systems, the scenario includes one information source, M relay stations and N destinations. This work proposes a relay selection algorithm in the Raleigh fading channel. Based on the exhaustive search method, easily to realize, the optimal selection scheme can be found with a highly complicated calculation. In order to reduce the computational complexity, an approximate optimal solution with a greedy algorithm applied for the relay station selection is proposed. With different situations of the communication systems, the performance evaluation obtained by both the proposed algorithm and the exhaustive search algorithm are given for comparison. It shows the proposed algorithm could provide a solution approach to the optimal one.展开更多
为了研究地面车辆与无人机在巡检过程中的最佳任务分配策略及路径规划问题,提出一种两阶段混合式启发算法——改进自适应大邻域搜索(improved adaptive large neighborhood search,IALNS)算法。第一阶段根据待巡检节点的不同需求等级及...为了研究地面车辆与无人机在巡检过程中的最佳任务分配策略及路径规划问题,提出一种两阶段混合式启发算法——改进自适应大邻域搜索(improved adaptive large neighborhood search,IALNS)算法。第一阶段根据待巡检节点的不同需求等级及距离等因素,利用聚类算法对目标节点进行划分;第二阶段采用一种混合式启发算法解决路线调度问题,增加6种新的局部优化算子,引入节点重分配策略,经过迭代得到成本最小的车辆与无人机协同混合路线。对所提算法解和其他算法解进行测试和比较分析,试验数据表明,IALNS算法在解决车辆与无人机协同巡检问题时具有显著优势。展开更多
基金supported by the National Natural Science Foundation of China(71171038)
文摘A memetic algorithm （MA） for a multi-mode resourceconstrained project scheduling problem （MRCPSP） is proposed. We use a new fitness function and two very effective local search procedures in the proposed MA. The fitness function makes use of a mechanism called ＂strategic oscillation＂ to make the search process have a higher probability to visit solutions around a ＂feasible boundary＂. One of the local search procedures aims at improving the lower bound of project makespan to be less than a known upper bound, and another aims at improving a solution of an MRCPSP instance accepting infeasible solutions based on the new fitness function in the search process. A detailed computational experiment is set up using instances from the problem instance library PSPLIB. Computational results show that the proposed MA is very competitive with the state-of-the-art algorithms. The MA obtains improved solutions for one instance of set J30.
基金supported by National Science Council under Grant No.101-2221-E-029-020-MY3
文摘Using a relaying system to provide spatial diversity and improve the system performance is a tendency in the wireless cooperative communications. Amplify-and-forward （AF） mode with a low complexity is easy to be implemented. Under the consideration of cooperative communication systems, the scenario includes one information source, M relay stations and N destinations. This work proposes a relay selection algorithm in the Raleigh fading channel. Based on the exhaustive search method, easily to realize, the optimal selection scheme can be found with a highly complicated calculation. In order to reduce the computational complexity, an approximate optimal solution with a greedy algorithm applied for the relay station selection is proposed. With different situations of the communication systems, the performance evaluation obtained by both the proposed algorithm and the exhaustive search algorithm are given for comparison. It shows the proposed algorithm could provide a solution approach to the optimal one.
文摘为了研究地面车辆与无人机在巡检过程中的最佳任务分配策略及路径规划问题,提出一种两阶段混合式启发算法——改进自适应大邻域搜索(improved adaptive large neighborhood search,IALNS)算法。第一阶段根据待巡检节点的不同需求等级及距离等因素,利用聚类算法对目标节点进行划分;第二阶段采用一种混合式启发算法解决路线调度问题,增加6种新的局部优化算子,引入节点重分配策略,经过迭代得到成本最小的车辆与无人机协同混合路线。对所提算法解和其他算法解进行测试和比较分析,试验数据表明,IALNS算法在解决车辆与无人机协同巡检问题时具有显著优势。
