This paper presents a new method to reduce the distribution system loss by feeder reconfiguration.This new method combines self-adaptive particle swarm optimization(SAPSO) with shuffled frog-leaping algorithm(SFLA) in...This paper presents a new method to reduce the distribution system loss by feeder reconfiguration.This new method combines self-adaptive particle swarm optimization(SAPSO) with shuffled frog-leaping algorithm(SFLA) in an attempt to find the global optimal solutions for the distribution feeder reconfiguration(DFR).In PSO algorithm,appropriate adjustment of the parameters is cumbersome and usually requires a lot of time and effort.Thus,a self-adaptive framework is proposed to improve the robustness of PSO.In SAPSO the learning factors of PSO coevolve with the particles.SFLA is combined with the SAPSO algorithm to improve its performance.The proposed algorithm is tested on two distribution test networks.The results of simulation show that the proposed algorithm is very powerful and guarantees to obtain the global optimization in minimum time.展开更多
针对网络功能虚拟化(network function virtualization,NFV)环境下安全服务链(security service chain,SSC)故障问题,提出一种基于比例资源预留的备份恢复机制.该方法采用前摄性处理思想,预先在物理网络中按比例划分主备用资源并构造节...针对网络功能虚拟化(network function virtualization,NFV)环境下安全服务链(security service chain,SSC)故障问题,提出一种基于比例资源预留的备份恢复机制.该方法采用前摄性处理思想,预先在物理网络中按比例划分主备用资源并构造节点/链路候选集合;当发生节点故障时,从候选集合中选取重映射目标并为其分配预留的备用资源,利用改进的离散粒子群(discrete particle swarm optimization,DPSO)算法及时地解决节点故障重映射问题,在降低资源占用的同时提高故障修复率;当发生链路故障时,通过改变底层物理路径流量分割比例,将受影响流量迁移到候选集合的可用链路中,设计动态路径分割算法有效解决了链路故障重定向问题,实现底层物理网络资源剩余价值最大化.仿真实验验证了算法在不同物理网络环境下的适应性和不同故障模型下的有效性,此外,还初步探索了主用比例的取值对所提备份恢复机制的影响.展开更多
Attitude determination is a key technology in aerospace, sailing and land-navigation etc. In the method of double difference phase measurement, it is a crucial topic to solve the carrier phase integer ambiguity, which...Attitude determination is a key technology in aerospace, sailing and land-navigation etc. In the method of double difference phase measurement, it is a crucial topic to solve the carrier phase integer ambiguity, which is shown to be a combination optimization problem, and thus efficient heuristic algorithms are needed. In this paper, we propose a discrete particle swarm optimization (DPSO)-based solution which aims at searching for the optimal integer ambiguity directly without decorrelation of ambiguity, and computing the baseline vector consequently. A novel flat binary particle encoding approach and corresponding revision operation are presented. Furthermore, domain knowledge is incorporated to significantly improve the convergence rate. Through extensive experiments, we demonstrate that the proposed algorithm outperforms a classic algorithm by up to 80% in time efficiency with solution quality guaranteed. The experiment results show that this algorithm is efficient, robust, and suitable for dynamic attitude determination.展开更多
文摘This paper presents a new method to reduce the distribution system loss by feeder reconfiguration.This new method combines self-adaptive particle swarm optimization(SAPSO) with shuffled frog-leaping algorithm(SFLA) in an attempt to find the global optimal solutions for the distribution feeder reconfiguration(DFR).In PSO algorithm,appropriate adjustment of the parameters is cumbersome and usually requires a lot of time and effort.Thus,a self-adaptive framework is proposed to improve the robustness of PSO.In SAPSO the learning factors of PSO coevolve with the particles.SFLA is combined with the SAPSO algorithm to improve its performance.The proposed algorithm is tested on two distribution test networks.The results of simulation show that the proposed algorithm is very powerful and guarantees to obtain the global optimization in minimum time.
文摘针对网络功能虚拟化(network function virtualization,NFV)环境下安全服务链(security service chain,SSC)故障问题,提出一种基于比例资源预留的备份恢复机制.该方法采用前摄性处理思想,预先在物理网络中按比例划分主备用资源并构造节点/链路候选集合;当发生节点故障时,从候选集合中选取重映射目标并为其分配预留的备用资源,利用改进的离散粒子群(discrete particle swarm optimization,DPSO)算法及时地解决节点故障重映射问题,在降低资源占用的同时提高故障修复率;当发生链路故障时,通过改变底层物理路径流量分割比例,将受影响流量迁移到候选集合的可用链路中,设计动态路径分割算法有效解决了链路故障重定向问题,实现底层物理网络资源剩余价值最大化.仿真实验验证了算法在不同物理网络环境下的适应性和不同故障模型下的有效性,此外,还初步探索了主用比例的取值对所提备份恢复机制的影响.
基金supported by the National Research Foundation for the Doctoral Program of Higher Education New Teacher of China (Grant No. 20070359029)the Natural Science Foundation of Anhui Province of China (Grant No. 070412035)
文摘Attitude determination is a key technology in aerospace, sailing and land-navigation etc. In the method of double difference phase measurement, it is a crucial topic to solve the carrier phase integer ambiguity, which is shown to be a combination optimization problem, and thus efficient heuristic algorithms are needed. In this paper, we propose a discrete particle swarm optimization (DPSO)-based solution which aims at searching for the optimal integer ambiguity directly without decorrelation of ambiguity, and computing the baseline vector consequently. A novel flat binary particle encoding approach and corresponding revision operation are presented. Furthermore, domain knowledge is incorporated to significantly improve the convergence rate. Through extensive experiments, we demonstrate that the proposed algorithm outperforms a classic algorithm by up to 80% in time efficiency with solution quality guaranteed. The experiment results show that this algorithm is efficient, robust, and suitable for dynamic attitude determination.
