基于MPSO算法的云计算资源调度策略

针对云计算服务集群资源调度和负载平衡的优化问题,提出一种基于改进的粒子群优化算法的云计算资源调度策略。将动态多群体协作和变异粒子逆向飞行思想引入到粒子群优化算法中,从而控制全局搜索和局部搜索,尽量避免陷入局部最优。在CloudSim 平台进行模拟测试,结果表明,该调度策略有效且执行效率较高。     

基于自适应参数与混沌搜索的PSO算法求解柔性作业车间调度问题

针对传统粒子群优化(PSO)算法在求解柔性作业车间调度问题中的不足,提出了基于自适应参数与混沌搜索的粒子群优化算法。对粒子群算法中的惯性系数等参数采用基于迭代搜索而自适应调整的方式,使粒子在初期以较大惯性进行大范围搜索,后期逐渐减小惯性而转入精细搜索。这种方法改变了传统粒子群算法在求解过程中的盲目随机与求解精度不高的问题;同时,通过在局部搜索过程中引入混沌技术,扩大对最优解的寻找范围,以此避免算法陷入局部最优,有效提高算法的全局寻优能力。实验结果表明,基于自适应参数与混沌搜索的粒子群优化算法在求解柔性作业车间调度问题(FJSP)时能够获得更优粒子适应度平均值及更好的优化目标。所提算法对求解柔性作业车间调度问题可行,有效。     

分层粒子群优化算法

针对粒子群优化算法存在进化后期局部搜索能力不强、收敛速度变慢的问题,提出一种分层粒子群优化算法。利用标准粒子群优化算法在整个搜索空间内进行全局搜索,由全局搜索获得的较优个体产生局部搜索区域,在局部区域内进行进一步搜索。为避免陷入局部最优,采用动态调整局部搜索区域的策略,保持算法的全局收敛性。通过典型测试函数计算表明,该算法的收敛速度和局部搜索能力有明显改善。     

基于QPSO算法的作业车间调度问题的研究

针对现行的遗传算法存在进化速度过慢和过早收敛的局限,以及粒子群优化算法搜索空间有限、容易陷入局部最优点的缺陷,提出将一种基于量子行为的粒子群优化算法应用于作业车间调度问题.将该问题中的每个调度组成一个多维向量,以此向量作为量子粒子群优化算法中的粒子进行进化,由此在解空间内搜索最优解.实例仿真结果表明,该算法收敛速度快、全局收敛性能好,可以得到比遗传算法、粒子群优化算法更佳的调度效果,证明了算法的有效性.     

基于混合粒子群的航班着陆调度优化研究

研究终端区航班着陆调度优化控制问题,为对多目标着陆实现实时调度,克服粒子群算法易陷入局部最优的问题,提出了一种免疫思想和禁忌搜索的混合粒子群调度算法,在粒子群算法的基础上引入了免疫系统的抗体浓度调节机制,以保证群体多样性.针对算法后期进化速度慢的缺点,采用了具有自适应能力的禁忌搜索算法进一步优化性能.最后将混合粒子群调度算法在不同规模的实例上进行了测试,并与其它几种具有代表性的算法进行了比较.实验结果表明,改进算法不仅较好地避免了陷入局部最优,提高了收敛速度,还有效地减少了航班着陆调度中的延迟.     

基于禁忌搜索的动态粒子群算法

惯性权重线性递减的线性群粒子算法往往不能反映实际的优化搜索过程。动态粒子群算法虽然能较好地实现非线性的搜索,但是更容易陷入局部最优。提出了基于禁忌搜索的动态粒子群算法,引入了禁忌搜索的思想,来解决动态粒子群算法的容易陷入局部最优问题;并对禁忌公式进行了修改,使其不仅可以解决极小值最优问题,也可以解决极大值最优问题。根据实验结果,改进的算法不仅较好地避免了陷入局部最优,而且收敛速度也有提高。     

电力系统经济负荷分配的混合粒子群优化算法

为解决电力系统中的经济负荷分配问题,提出一种将约束优化与粒子群优化算法相结合的混合算法,同时引入直接搜索方法。使得混合后的粒子群优化算法不但具有高效的全局搜索能力,而且具有较强的局部搜索能力,避免陷入局部最优,提高求解精度。对两个实例进行测试,与其他智能算法的结果比较,证明提出的算法可以有效找到可行解,避免陷入局部最优,实现问题的快速求解。     

基于自适应驱散机制的粒子群优化算法

为克服粒子群优化算法（PSO）易陷入局部最优导致早熟收敛的问题,提出了一种新型的基于自适应驱散机制的粒子群优化（ADMPSO）算法。基本的粒子群优化算法易陷入局部最优,一般的改进算法在搜索过程之中对个体最优和全局最优结果进行调整,虽然避免了粒子群陷入局部最优,但会很大程度减慢收敛速度。提出的改进算法只有在种群快要陷入局部最优时,才会对粒子群进行有效驱散,这样不仅保证了收敛速度,又不会使粒子群陷入局部最优。对维度30的12个标准测试函数进行测试的结果表明ADMPSO算法相较于经典粒子群（General PSO,GPSO）算法、综合学习粒子群优化算法（Comprehensive Learning PSO,CLPSO）算法和动态多粒子群协调搜索优化算法（Dynamic Multi-Swarm PSO with sub-regional Harmony Search,DMS-PSO-HS）,可以更有效避免陷入局部最优,稳定地找到最优值,同时又能保证一定的收敛速度。ADMPSO算法不容易陷入局部最优和迭代次数更少的特点使得PSO算法更加实用化。     

粒子群Memetic算法求解多峰函数优化

针对目前多峰函数优化问题较难找到全部局部最优解的情况,提出了一种粒子群Memetic算法。算法结合了粒子群优化的全局搜索能力和爬山法的局部搜索能力,增强了算法搜索最优解的能力。实验结果表明,该算法求解精度较高,且收敛速度较快。     

基于紧凑度和调度处理的粒子群优化算法

针对标准粒子群优化算法存在收敛速度慢和难以跳出局部最优等问题,提出了一种基于紧凑度和调度处理的粒子群优化算法。给出了粒子紧凑度和调度处理的概念和方法,通过动态评价粒子群中各粒子间的紧凑程度,从而确定调度的粒子,进而对其进行调度处理,避免粒子陷入局部最优。对11个常见的标准函数进行测试,并与标准粒子群算法和其他改进算法进行对比,实验结果表明,基于紧凑度和调度处理的粒子群优化算法具有较高的寻优精度和较快的收敛速度。     

一种新的混合优化算法及其在车间调度中的应用

提出了一种解决车间调度问题的新方法, 该方法将序优化思想融入巢分区算法框架, 采用"序比较"的方法进行算法的局部寻优. "序"的指数收敛性加快了巢分区算法的局部收敛速度, 从而提高了算法整体的优化效率. 最优计算量分配技术则依据在线数据对计算量进行合理的分配, 进一步提高算法的收敛速度和结果的可靠性. 混合算法继承了巢分区算法的全局搜索特性以及序优化的快速收敛性. 用该算法解决标准 Jobshop 调度问题, 并与序优化方法和模拟退火算法进行比较, 发现本文算法在收敛速度与优化质量方面均优于这些算法.     

An effective hybrid optimization approach for multi-objective flexible job-shop scheduling problems

Scheduling for the flexible job-shop is very important in both fields of production management and combinatorial optimization. However, it is quite difficult to achieve an optimal solution to this problem with traditional optimization approaches owing to the high computational complexity. The combining of several optimization criteria induces additional complexity and new problems. Particle swarm optimization is an evolutionary computation technique mimicking the behavior of flying birds and their means of information exchange. It combines local search (by self experience) and global search (by neighboring experience), possessing high search efficiency. Simulated annealing (SA) as a local search algorithm employs certain probability to avoid becoming trapped in a local optimum and has been proved to be effective for a variety of situations, including scheduling and sequencing. By reasonably hybridizing these two methodologies, we develop an easily implemented hybrid approach for the multi-objective flexible job-shop scheduling problem (FJSP). The results obtained from the computational study have shown that the proposed algorithm is a viable and effective approach for the multi-objective FJSP, especially for problems on a large scale.     

Multi-center variable-scale search algorithm for combinatorial optimization problems with the multimodal property

Combinatorial optimization problems (COPs) are discrete problems arising from aerospace, bioinformatics, manufacturing, and other fields. One of the classic COPs is the scheduling problem. Moreover, these problems are usually multimodal optimization problems with a quantity of global and local optima. As a result, many search algorithms can easily become trapped into local optima. In this article, we propose a multi-center variable-scale search algorithm for solving both single-objective and multi-objective COPs. The algorithm consists of two distinct points. First, the multi-center strategy chooses several individuals with better performance as the only parents of the next generation, which means that there are a number of separate searching areas around the searching center. Second, the next generation of the population is produced by a variable-scale strategy with an exponential equation based on the searching center. The equation is designed to control the neighborhood scale, and adaptively realize the large-scale and small-scale searches at different search stages to balance the maintenance of diversity and convergence speed. In addition, an approach of adjusting centers is proposed concerning the number and distribution of centers for solving multi-objective COPs. Finally, the proposed algorithm is applied to three COPs, including the well-known flexible job shop scheduling problem, the unrelated parallel machine scheduling problem, and the test task scheduling problem. Both the single-objective optimization algorithm and the multi-objective optimization algorithm demonstrate competitive performance compared with existing methods.     

一种基于Levy飞行的改进蝗虫优化算法

蝗虫优化算法是一种元启发式优化算法,能够用于解决任务调度问题。已有的改进蝗虫优化算法缺乏随机性,跳出局部最优的能力较弱,改进效果不够显著。针对这一问题,本文提出一种基于Levy飞行的改进蝗虫优化算法（LBGOA）。该算法引入基于Levy飞行的局部搜索机制增强算法的随机性,并采用基于线性递减参数的随机跳出策略来提高算法跳出局部最优的能力。CEC测试实验结果表明,所提出的算法拥有较强的搜索能力,在30个测试函数结果中能够获得17个最优解和6个次优解。将所提出的改进算法应用于边缘计算中的任务调度问题。任务调度仿真实验结果表明,所提出的算法能够有效提高搜索效果,相比GOA、OBLGOA、WOA、ALO、DA和PSO算法,LBGOA的搜索效果分别提升7.4%、7.5%、4.8%、27.7%、29.9%和20.7%。     

基于粒子群优化的异构多处理器任务调度算法

为提高异构多处理器任务调度的执行效率,充分发挥多处理器并行性能,提出一种基于粒子群优化的异构多处理器任务调度算法——FPSOTTS算法。该算法以求得任务最短完成时间为目标,首先通过建立新的编码方式和粒子更新公式实现粒子搜索空间到离散空间的映射,使连续的粒子群优化算法适用于离散的异构多处理器任务调度问题;同时通过引入禁忌算法进行局部搜索,克服粒子群算法的早熟收敛现象,避免陷入局部最优。实验结果表明,FPSOTTS算法的执行效率优于Min-min算法和遗传算法,有效地降低任务的执行时间。FP-SOTTS算法很好地解决了异构多处理器任务调度问题,并且适合于大规模并行任务调度。     

ACOCS:一种云环境下资源调度混合算法

蚁群算法在优化组合问题中有着重要的意义,传统的蚁群调度算法搜索速度慢、容易陷入局部最优。针对这种情况,结合布谷鸟搜索算法,提出一种基于蚁群算法与布谷鸟搜索算法的混合算法(ACOCS),用于云环境下的资源调度。该方法有效保留了蚁群算法求解精度高和鲁棒性的特性,并融入了布谷鸟搜索具有快速全局搜索能力的优势。仿真实验结果表明,提出的ACOCS调度算法有效减少了调度所需的响应时间,也在一定程度上提高了系统资源利用率。     

An effective hybrid particle swarm optimization algorithm for multi-objective flexible job-shop scheduling problem

Flexible job-shop scheduling problem (FJSP) is an extension of the classical job-shop scheduling problem. Although the traditional optimization algorithms could obtain preferable results in solving the mono-objective FJSP. However, they are very difficult to solve multi-objective FJSP very well. In this paper, a particle swarm optimization (PSO) algorithm and a tabu search (TS) algorithm are combined to solve the multi-objective FJSP with several conflicting and incommensurable objectives. PSO which integrates local search and global search scheme possesses high search efficiency. And, TS is a meta-heuristic which is designed for finding a near optimal solution of combinatorial optimization problems. Through reasonably hybridizing the two optimization algorithms, an effective hybrid approach for the multi-objective FJSP has been proposed. The computational results have proved that the proposed hybrid algorithm is an efficient and effective approach to solve the multi-objective FJSP, especially for the problems on a large scale.     

A hybrid meta-heuristic algorithm for optimization of crew scheduling

Crew scheduling problem is the problem of assigning crew members to the flights so that total cost is minimized while regulatory and legal restrictions are satisfied. The crew scheduling is an NP-hard constrained combinatorial optimization problem and hence, it cannot be exactly solved in a reasonable computational time. This paper presents a particle swarm optimization (PSO) algorithm synchronized with a local search heuristic for solving the crew scheduling problem. Recent studies use genetic algorithm (GA) or ant colony optimization (ACO) to solve large scale crew scheduling problems. Furthermore, two other hybrid algorithms based on GA and ACO algorithms have been developed to solve the problem. Computational results show the effectiveness and superiority of the proposed hybrid PSO algorithm over other algorithms.     

A discrete version of particle swarm optimization for flowshop scheduling problems

Particle swarm optimization (PSO) is a novel metaheuristic inspired by the flocking behavior of birds. The applications of PSO to scheduling problems are extremely few. In this paper, we present a PSO algorithm, extended from discrete PSO, for flowshop scheduling. In the proposed algorithm, the particle and the velocity are redefined, and an efficient approach is developed to move a particle to the new sequence. To verify the proposed PSO algorithm, comparisons with a continuous PSO algorithm and two genetic algorithms are made. Computational results show that the proposed PSO algorithm is very competitive. Furthermore, we incorporate a local search scheme into the proposed algorithm, called PSO-LS. Computational results show that the local search can be really guided by PSO in our approach. Also, PSO-LS performs well in flowshop scheduling with total flow time criterion, but it requires more computation times.     

一种求解作业车间调度的混合粒子群算法*

针对车间作业调度问题,提出了一种混合了知识进化算法和粒子群优化的算法。算法主要是结合知识进化算法的进化选择机制和粒子群优化的局部快速收敛性特性,首先让粒子替代知识进化算法中的进化个体,在群体空间中按粒子群优化规则寻找局部最优,然后根据知识进化算法的全局选择机制寻找全局最优,最后,将车间作业调度问题的特点融入到所提出的混合算法中求解问题。采用基准数据进行测试的仿真实验,并比对标准遗传算法,结果表明所提算法的有效性。