一种基于差异演化的协同粒子群优化算法

提出一种协同进化PSO算法,用于保持粒子种群的多样性并避免发生“早熟”的问题．该方法采用两个不同的分群;其中分群一的粒子采用标准PSO算法进行搜索寻优,分群二的粒子采用差异演化算法进行搜索和寻找最优解．在搜索过程中,如果标准PSO算法的适应度变化率低于一个阈值,则按照黄金分割率用分群二中的若干优势粒子取代分群一中的劣势粒子．用所提出的PSO算法和标准PSO算法对4种常用函数进行优化．结果表明,该粒子群优化算法比标准粒子群优化算法更容易找到最优解,而且优化效率和优化性能明显提高．     

Parameter optimization of improved fuzzy c-means clustering algorithm for brain MR image segmentation

A traditional approach to segmentation of magnetic resonance (MR) images is the fuzzy c-means (FCM) clustering algorithm. The efficacy of FCM algorithm considerably reduces in the case of noisy data. In order to improve the performance of FCM algorithm, researchers have introduced a neighborhood attraction, which is dependent on the relative location and features of neighboring pixels. However, determination of degree of attraction is a challenging task which can considerably affect the segmentation results.This paper presents a study investigating the potential of genetic algorithms (GAs) and particle swarm optimization (PSO) to determine the optimum value of degree of attraction. The GAs are best at reaching a near optimal solution but have trouble finding an exact solution, while PSO’s-group interactions enhances the search for an optimal solution. Therefore, significant improvements are expected using a hybrid method combining the strengths of PSO with GAs, simultaneously. In this context, a hybrid GAs/PSO (breeding swarms) method is employed for determination of optimum degree of attraction. The quantitative and qualitative comparisons performed on simulated and real brain MR images with different noise levels demonstrate unprecedented improvements in segmentation results compared to other FCM-based methods.     

多阈值图像分割的模糊粒子群优化算法

把粒子群算法应用到多阈值图像分割中,结合已有的模糊C-均值聚类法提出了一种基于模糊技术的粒子群优化多阈值图像分割算法。FCM聚类算法是一种局部搜索算法,对初始值较为敏感,容易陷入局部极小值而不能得到全局最优解。PSO算法是一种基于群体的具有全局寻优能力的优化方法。将FCM聚类算法和PSO算法结合起来,将FCM聚类算法的聚类准则函数作为PSO算法中的粒子适应度函数。仿真实验表明新算法在最大熵评判准则下能够得到最优阈值。     

An improved FCM algorithm with adaptive weights based on SA-PSO

Fuzzy c-means clustering algorithm (FCM) often used in pattern recognition is an important method that has been successfully used in large amounts of practical applications. The FCM algorithm assumes that the significance of each data point is equal, which is obviously inappropriate from the viewpoint of adaptively adjusting the importance of each data point. In this paper, considering the different importance of each data point, a new clustering algorithm based on FCM is proposed, in which an adaptive weight vector W and an adaptive exponent p are introduced and the optimal values of the fuzziness parameter m and adaptive exponent p are determined by SA-PSO when the objective function reaches its minimum value. In this method, the particle swarm optimization (PSO) is integrated with simulated annealing (SA), which can improve the global search ability of PSO. Experimental results have demonstrated that the proposed algorithm can avoid local optima and significantly improve the clustering performance.

     

一种自适应柯西变异的反向学习粒子群优化算法

针对传统粒子群优化算法易出现早熟的问题,提出了一种自适应变异的反向学习粒子群优化算法。该算法在一般性反向学习方法的基础上,提出了自适应柯西变异策略(ACM)。采用一般性反向学习策略生成反向解,可扩大搜索空间,增强算法的全局勘探能力。为避免粒子陷入局部最优解而导致搜索停滞现象的发生,采用ACM策略对当前最优粒子进行扰动,自适应地获取变异点,在有效提高算法局部开采能力的同时,使算法能更加平稳快速地收敛到全局最优解。为进一步平衡算法的全局搜索与局部探测能力,采用非线性的自适应惯性权值。将算法在14个测试函数上与多种基于反向学习策略的PSO算法进行对比,实验结果表明提出的算法在解的精度以及收敛速度上得到了大幅度的提高。     

Dynamic Multiple Swarms in Multiobjective Particle Swarm Optimization

A multiple-swarm multiobjective particle swarm optimization (PSO) algorithm, named dynamic multiple swarms in multiobjective PSO, is proposed in which the number of swarms is adaptively adjusted throughout the search process via the proposed dynamic swarm strategy. The strategy allocates an appropriate number of swarms as required to support convergence and diversity criteria among the swarms. Additional novel designs include a PSO updating mechanism to better manage the communication within a swarm and among swarms and an objective space compression and expansion strategy to progressively exploit the objective space during the search process. Comparative study shows that the performance of the proposed algorithm is competitive in comparison to the selected algorithms on standard benchmark problems. In particular, when dealing with test problems with multiple local Pareto fronts, the proposed algorithm is much less computationally demanding. Sensitivity analysis indicates that the proposed algorithm is insensitive to most of the user-specified design parameters.     

结合文化算法的多种群协同变异PSO算法

粒子群算法是一种新的基于群体智能的启发式全局优化算法,其概念简单,易于实现,而且具有良好的优化性能,目前已在许多领域得到应用。但在求解高维多峰函数寻优问题时,算法易陷入局部最优。结合文化算法和高斯变异的思想,提出一种基于文化算法和高斯变异的多群协同粒子群算法。该算法可以摆脱局部最优解对微粒的吸引,基于典型高维复杂函数的仿真结果表明,与多种群粒子群优化算法相比,该混合算法具有更好的优化性能。     

Solving nonlinear optimal control problems using a hybrid IPSO-SQP algorithm

A hybrid algorithm by integrating an improved particle swarm optimization (IPSO) with successive quadratic programming (SQP), namely IPSO-SQP, is proposed for solving nonlinear optimal control problems. The particle swarm optimization (PSO) is showed to converge rapidly to a near optimum solution, but the search process will become very slow around global optimum. On the contrary, the ability of SQP is weak to escape local optimum but can achieve faster convergent speed around global optimum and the convergent accuracy can be higher. Hence, in the proposed method, at the beginning stage of search process, a PSO algorithm is employed to find a near optimum solution. In this case, an improved PSO (IPSO) algorithm is used to enhance global search ability and convergence speed of algorithm. When the change in fitness value is smaller than a predefined value, the searching process is switched to SQP to accelerate the search process and find an accurate solution. In this way, this hybrid algorithm may find an optimum solution more accurately. To validate the performance of the proposed IPSO-SQP approach, it is evaluated on two optimal control problems. Results show that the performance of the proposed algorithm is satisfactory.     

吸引子权重改变内嵌区域震荡搜索粒子群算法

针对粒子群算法搜索精度不高、搜索最优解较慢的问题,提出了一种改进的粒子群算法。该算法通过调整全局最优解和个体最优解,形成一个新的全局吸引子解指导粒子收敛,优化种群粒子来搜索解空间的最优值。再将优化方案融入到内嵌区域震荡搜索的粒子群算法（RSPSO）中,仿真结果表明,改进的粒子群算法在寻优能力及搜索精度方面都得到了进一步的提高。     

一种并行的自适应量子粒子群算法

针对粒子群算法存在易陷入局部最优解的问题,提出了一种并行的自适应量子粒子群算法。通过共享粒子的两个极值,将改进后的自适应粒子群算法和边界变异的量子粒子群算法并行搜索,有效地克服了标准粒子群算法的缺陷。测试结果表明,该算法在精度和全局最优解的找寻速度方面有了很大的提高。     

基于PSO的模糊聚类算法

提出了一种基于模糊C-均值算法和粒子群算法的混合聚类算法。该算法结合PSO的全局搜索和FCM局部搜索的特点,将PSO优化聚类结果作为后续FCM算法的初始值,有效地克服了FCM对初始值敏感、易陷入局部最优和PSO算法局部搜索较弱的问题,同时增强了跳出局部最优的能力。实验表明,新算法得到的目标函数值更小,并能减小分类错误率,聚类效果优于单一使用FCM或PSO。     

基于CPSO的无线传感器网络路由优化

研究无线传感器网络路由优化问题,由于无线传感器节点的能量受到限制,通信过程能量损耗,影响网络的性能。传统粒子群算法难以获得最优网络路由方案。为延长网络生存时间,结合粒子群的快速性和混沌的遍历性优点,提出了一种混沌粒子群(CPSO)的无线网络路由优化方法。通过粒子群算法的自组织、动态寻优能力,并通过混沌机制对粒子群进行混沌扰动,增加多样性,加快最优路由优化速度,使网络最优路由和能量消耗间尽量平衡。仿真结果表明,相对于传统优化算法,CPSO提高了无线传感器网络路由优化速度,减少网络能量消耗,有效延长了网络生存时间,为提高整个网络通信效率提供了参考。     

独立自适应调整参数的粒子群优化算法

针对传统粒子群优化算法在求解复杂优化问题时易陷入局部最优和依赖参数的取值等问题,提出了一种独立自适应参数调整的粒子群优化算法。算法重新定义了粒子进化能力、种群进化能力以及进化率,在此基础上给出了粒子群惯性权重及学习因子的独立调整策略,更好地平衡了算法局部搜索与全局搜索的能力。为保持种群多样性,提高粒子向全局最优位置的收敛速度,在算法迭代过程中,采用粒子重构策略使种群中进化能力较弱的粒子向进化能力较强的粒子进行学习,重新构造生成新粒子。最后通过CEC2013中的10个基准测试函数与4种改进粒子群算法在不同维度下进行测试对比,实验结果验证了该算法在求解复杂函数时具有高效性,通过收敛性分析说明了算法的有效性。     

两群微粒群优化算法及其应用

针对微粒群优化算法容易陷入局部极值的缺陷,提出两群微粒群优化算法．通过对5种常用测试函数进行测试和比较,结果表明两群微粒群优化算法比基本微粒群优化算法更容易找到全局最优解,优化效率明显提高．然后将两群微粒群优化算法用于催化裂化装置主分馏塔轻柴油95%点软测量建模,通过与实际工业数据对比,表明该软测量模型具有高的精度、好的性能和广阔的应用前景．     

A Cooperative approach to particle swarm optimization

The particle swarm optimizer (PSO) is a stochastic, population-based optimization technique that can be applied to a wide range of problems, including neural network training. This paper presents a variation on the traditional PSO algorithm, called the cooperative particle swarm optimizer, or CPSO, employing cooperative behavior to significantly improve the performance of the original algorithm. This is achieved by using multiple swarms to optimize different components of the solution vector cooperatively. Application of the new PSO algorithm on several benchmark optimization problems shows a marked improvement in performance over the traditional PSO.     

改进的SAMPSO的软件测试数据自动生成

针对软件测试数据的自动生成提出了一种简化的自适应变异的粒子群算法（SAMPSO）。该算法在运行过程中根据群体适应度方差以及当前最优解的大小来确定当前最佳粒子的变异概率,变异操作增强了粒子群优化算法前期全局搜索能力,去掉了粒子群优化（PSO）算法中进化方程的粒子速度项,仅由粒子位置控制进化过程,避免了由粒子速度项引起的粒子发散而导致后期收敛变慢和精度低问题。实验结果表明该算法在测试数据的自动生成上优于基本的粒子群算法,提高了效率。     

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。     

多量子粒子群协同优化算法研究

针对标准粒子群优化（PSO）算法及其改进算法存在的局部收敛与收敛速度问题,提出了一种多量子粒子群协同优化（QPSCO）方法。该算法采用双层的多粒子群协同优化结构：用多个量子粒子群在底层独立地搜索解空间,同时引入参数变异策略,以扩大搜索范围;上层用1个量子粒子群追逐当前全局最优解,并对飞离搜索区域粒子的位置用新位置取代,以加快算法收敛。在此基础上,将该算法应用于实际控制系统低阶时滞对象的PID控制器设计中。仿真结果表明,QPSCO是一种有效的参数优化算法,与标准PSO、QPSO等算法相比具有更好的全局收敛性能。     

一种用于多目标优化的混合粒子群优化算法

将粒子群算法与局部优化方法相结合,提出了一种混合粒子群多目标优化算法（HMOPSO）。该算法针对粒子群局部优化性能较差的缺点,引入多目标线搜索与粒子群算法相结合的策略,以增强粒子群算法的局部搜索能力。HMOPSO首先运行PSO算法,得到近似的Pareto最优解;然后启动多目标线搜索,发挥传统数值优化算法的优势,对其进行进一步的优化。数值实验表明,HMOPSO具有良好的全局优化性能和较强的局部搜索能力,同时HMOPSO所得的非劣解集在分散性、错误率和逼近程度等量化指标上优于MOPSO。     

基于改进的粒子群优化的模糊C-均值聚类算法

利用粒子群优化（PSO）算法全局寻优的特点,很大程度上避免了模糊C-均值聚类（FCM）算法对初值敏感、易陷入局部收敛的缺陷.利用收敛速度快的K均值聚类法得到的聚类中心作为PSO算法初始聚类中心的参考,提出一种新的模糊C-均值聚类算法Improved PSO FCM.实验结果表明,论文算法提高了FCM的搜索能力,聚类更为准确,效率更高.