基于动态粒子数的微粒群优化算法

提出了基于动态粒子数的微粒群算法,并建立了粒子数变化函数．该函数包含粒子数衰减趋势项和周期振荡项．衰减趋势项能够在种群向最优解不断收敛的过程中逐渐减少粒子数,以提高粒子效率．周期振荡项中的递增阶段代表了新粒子的随机出现,以增加粒子群的多样性,而周期振荡项中的递减阶段代表了探索性能差的粒子逐渐消亡,以提高优化效率．对4个标准函数进行测试,仿真结果表明该算法能有效地减少计算量,并显著提高全局搜索性能．     

一种基于栅格的动态粒子数微粒群算法

微粒群算法的全局搜索性能容易受到局部极值点的影响.对此,提出一种基于栅格的动态粒子数微粒群算法(GB-DPPPSO).通过设计栅格信息更新策略,粒子产生策略和粒子消灭策略,可以根据种群搜索情况动态控制粒子数变化,以保持种群多样性,提高全局搜索性能.通过对4个典型数学验证函数的仿真实验,表明了该算法相对于DPPPSO在全局搜索成功率和搜索效率两方面均有明显改进.

     

一种基于距离行为模型的改进微粒群算法

提出一种基于距离行为模型的改进微粒群算法,根据微粒所处区域来调整其飞行的速度。在吸引区域微粒加速飞向群体最优位置,在排斥区域按正常速度飞行。为了研究算法的性能,对几种典型高维非线性函数进行了测试。研究结果表明,与基本微粒群算法相比,改进后的微粒群算法提高了算法的收敛速度和收敛精度,改善了算法的性能。     

一种多微粒群协同进化算法

受自然界共生现象的启发,将微粒群算法和协同进化相结合,提出了一种多微粒群协同进化算法。进化过程中,粒子不仅要与本子群的其他微粒交换信息,还要受其他子群体的影响。通过对三个标准函数优化的实验结果表明,此算法在一定程度上避免了陷入局部极值点并且提高了收敛精度。     

一种广义微粒群算法模型

在对标准微粒群算法模型及其机理进行分析的基础上,提出了一种广义微粒群算法模型(Generalized Particle Swarm Optimization,GPSO).该模型的微粒进化方程具有满足一定条件的抽象形式.文中给出了几种微粒进化方程的具体形式,并通过典型测试函数的仿真计算说明了GPSO的正确性和有效性.     

一种基于单纯形法的随机微粒群算法

以保证全局收敛的随机微粒群算法SPSO为基础,本文提出了一种改进的随机微粒群算法--SM-SPSO。该方法是在SPSO的进化过程中,以单纯形法所产生的最优个体来代替SPSO中停止的微粒,参与下一代的群体进化。这样既可以利用单纯形法的收敛快速性,又可以利用SPSO的全局收敛性。通过对两个多峰的测试函数进行仿真,其结果表明在搜索空间维数相同的情况下,SM-SPSO的收敛率及收敛速度均大大优于SPSO。     

多峰搜索的动态微粒群算法

对多峰搜索问题提出了一类动态微粒群算法。该算法通过变换函数将多峰问题中的所有峰变为等高峰,从而保证每个峰都有同等机会被找到;在搜索过程中采用群体规模动态可调的进化方式,使得初始群体可以任意指定,从而克服了标准微粒群算法由于无法事先知道多峰函数峰值点个数而很难确定合适群体大小的困难。实验表明了该算法可以尽可能多地找到峰值点。     

一种自适应的微粒群算法

研究发现,种群中个体间交换信息的方式对微粒群算法的性能影响很大。我们定义种群拓扑结构（population topology）为种群内部不同个体之间交流信息的网络。不同的种群拓扑结构有着各自的特点,有些利于加速收敛,有些利于扩展搜索空间。在分析种群拓扑结构变化特点的基础上,提出了一种新的自适应的微粒群算法。和通过调节惯性权重的自适应微粒群算法不同,本算法是通过改变种群拓扑结构来达到自适应优化目的的。     

一种新形式的微粒群算法

标准微粒群算法在优化多峰、多维的复杂函数时,其效果并不理想,容易早熟收敛。为了改进微粒群算法处理此类问题的性能,提出了一种新的微粒群算法。该算法将标准微粒群算法迭代公式中的群体最优位置用个体最优位置的中心代替,有利于增强群体的多样性,避免早熟收敛,同时保持了迭代公式的简洁形式。3个常用测试函数的数值模拟表明,新的微粒群算法较标准微粒群算法在寻优能力上有明显的提高。     

一种基于聚类的小生境微粒群算法

在小生境微粒群算法中引入一种简单的聚类算法，替换了原算法中依赖于圆形拓扑领域的小生境产生方法，构建出一种基于聚类的小生境微粒群算法．该算法在对主微粒群进行l best PSO寻优的同时对其中的微粒进行聚类，当聚类簇中的个体数目达到规定的子微粒群最小规模时形成一个小生境．用这种算法能够产生大小和形状不同的小生境，克服了NichePSO算法的不足．     

混沌动态种群数粒子群优化算法

针对粒子群优化算法在整个迭代过程中粒子极易陷于局部极值区域,提出一种混沌动态粒子数的粒子群优化算法,也即在判定全局最优值处于停滞时,以混沌策略对粒子进行位置初始化后加入种群,从而有效地保证了粒子群的多样性。用4个测试函数验证了该算法具有很好的寻优能力和较高的搜索精度。     

基于种群熵的多粒子群协同优化

提出了一种基于种群熵的多粒子群协同优化算法,通过引入熵对种群粒子的分布性进行度量,然后利用它来引导在多种群协同演化中粒子迁徙的时间和方向,从而保持粒子在寻优过程中的多样性和快速性。通过四个典型测试函数的仿真说明了该算法具有摆脱局部极值能力和较高的收敛速度。     

Multi-strategy ensemble particle swarm optimization for dynamic optimization

Optimization in dynamic environments is important in real-world applications, which requires the optimization algorithms to be able to find and track the changing optimum efficiently over time. Among various algorithms for dynamic optimization, particle swarm optimization algorithms (PSOs) are attracting more and more attentions in recent years, due to their ability of keeping good balance between convergence and diversity maintenance. To tackle the challenges of dynamic optimization, several strategies have been proposed to enhance the performance of PSO, and have gained success on various dynamic optimization problems. But there still exist some issues in dynamic optimization which need to be studied carefully, i.e. the robustness of the algorithm to problems of various dynamic features. In this paper, a new multi-strategy ensemble particle swarm optimization (MEPSO) for dynamic optimization is proposed. In MEPSO, all particles are divided into two parts, denoted as part I and part II, respectively. Two new strategies, Gaussian local search and differential mutation, are introduced into these two parts, respectively. Experimental analyses reveal that the mechanisms used in part I can enhance the convergence ability of the algorithm, while mechanisms used in part II can extend the searching area of the particle population to avoid being trapped into the local optimum, and can enhance the ability of catching up with the changing optimum in dynamic environments. The whole algorithm has few parameters that need to be tuned, and all of them are not sensitive to problems. We compared MEPSO with other PSOs, including MQSO, PHPSO and Standard PSO with re-initialization, on moving peaks Benchmark and dynamic Rastrigin function. The experimental results show that MEPSO has pretty good performance on almost all testing problems adopted in this paper, and outperforms other algorithms when the dynamic environment is unimodal and changes severely, or has a great number of local optima as dynamic Rastrigin function does.     

Unified particle swarm delivers high efficiency to particle swarm optimization

This paper suggests integrating a unification factor into particle swarm optimization (PSO) to balance the effects of cognitive and social terms. The resultant unified particle swarm (UPS) moves particles toward the center of its personal best and the global best. This improves on PSO, which moves particles far beyond the center. Widely used benchmark functions and four types of experiments demonstrate that the proposed UPS uses slightly more computational time than PSO to attain significantly higher efficiency and, usually, better solution effectiveness and consistency than PSO. Robust performance was further demonstrated by the significantly higher efficiency and better solution effectiveness and stability achieved by the UPS, as compared to the PSO and its variants. Outstandingly, convergence speeds for the proposed UPS were very good on the 13 benchmark functions examined in experiment 1, demonstrating the correct movement of UPS particles toward convergence.     

Cellular particle swarm optimization

This paper proposes a cellular particle swarm optimization (CPSO), hybridizing cellular automata (CA) and particle swarm optimization (PSO) for function optimization. In the proposed CPSO, a mechanism of CA is integrated in the velocity update to modify the trajectories of particles to avoid being trapped in the local optimum. With two different ways of integration of CA and PSO, two versions of CPSO, i.e. CPSO-inner and CPSO-outer, have been discussed. For the former, we devised three typical lattice structures of CA used as neighborhood, enabling particles to interact inside the swarm; and for the latter, a novel CA strategy based on “smart-cell” is designed, and particles employ the information from outside the swarm. Theoretical studies are made to analyze the convergence of CPSO, and numerical experiments are conducted to compare the proposed algorithm with different variants of PSO. According to the experimental results, the proposed method performs better than other variants of PSO on benchmark test functions.     

一种基于引导策略的自适应粒子群算法

为解决粒子群算法前期搜索“盲目”,后期搜索速度慢且易陷入局部极值的问题,对算法中粒子更新方式和惯性权重进行了改进,提出了一种基于引导策略的自适应粒子群算法。该算法在种群中引入4种粒子,即主体粒子、双中心粒子、协同粒子和混沌粒子对粒子位置更新进行引导,克服算法的随机性,从而提高搜索效率;为进一步克服粒子群优化算法进化后期易陷入早熟收敛的缺点,引入聚焦距离变化率的概念,通过聚焦距离变化率的大小动态调整惯性权重,以提高算法的收敛速度和精度,两者结合极大地提高了搜索到全局最优解的有效性。对4个标准测试函数进行仿真,实验结果表明IPSO算法在收敛速度、收敛精度以及成功率上都明显优于LDWPSO和WPSO算法。     

基于种群分类粒子群算法的物流车辆调度优化

为了获得更加理想的配送车辆调度方案,提出一种基于种群分类粒子群算法的配送车辆调度优化方法。首先建立多约束配送车辆调度的数学模型,并以配送路径最短作为目标函数,然后采用粒子群算法对模型进行求解,并对每次迭代产生的粒子群进行分类,根据分类结果对粒子群进行不同的操作,加快了算法的搜索速度,以避免陷入局部最优,最后进行仿真对比实验。结果表明,种群分类粒子群算法获得比较理想的配送车辆调度方案,具有一定的实用价值。     

基于动态邻域的粒子群算法的研究

研究了邻域拓扑结构对粒子群算法性能的影响。设计了两种动态邻域生成策略,并基于一组具有代表性的测试函数,对两种典型的算法模型——标准的粒子群算法（CPSO）和充分联系的粒子群算法（FIPS）进行实验。实验结果表明,不同的邻域拓扑结构和不同的算法模型都能够影响粒子群算法的性能。     

基于动态粒子群优化的网格任务调度算法*

提出了一种基于动态粒子群优化的网格任务调度算法。设计了网格任务调度问题的数学模型,给出了自适应变异的动态粒子群优化算法的框架,引入了自适应学习因子和自适应变异策略,从而使算法具有动态自适应性,能够较容易地跳出局部最优。实验结果表明,本文算法能有效地解决异构网格任务调度问题,具有较好的应用价值。     

Non-parametric particle swarm optimization for global optimization

In recent years, particle swarm optimization (PSO) has extensively applied in various optimization problems because of its simple structure. Although the PSO may find local optima or exhibit slow convergence speed when solving complex multimodal problems. Also, the algorithm requires setting several parameters, and tuning the parameters is a challenging for some optimization problems. To address these issues, an improved PSO scheme is proposed in this study. The algorithm, called non-parametric particle swarm optimization (NP-PSO) enhances the global exploration and the local exploitation in PSO without tuning any algorithmic parameter. NP-PSO combines local and global topologies with two quadratic interpolation operations to increase the search ability. Nineteen (19) unimodal and multimodal nonlinear benchmark functions are selected to compare the performance of NP-PSO with several well-known PSO algorithms. The experimental results showed that the proposed method considerably enhances the efficiency of PSO algorithm in terms of solution accuracy, convergence speed, global optimality, and algorithm reliability.