A novel hybrid adaptive collaborative approach based on particle swarm optimization and local search for dynamic optimization problems

This paper proposes a novel hybrid approach based on particle swarm optimization and local search, named PSOLS, for dynamic optimization problems. In the proposed approach, a swarm of particles with fuzzy social-only model is frequently applied to estimate the location of the peaks in the problem landscape. Upon convergence of the swarm to previously undetected positions in the search space, a local search agent (LSA) is created to exploit the respective region. Moreover, a density control mechanism is introduced to prevent too many LSAs crowding in the search space. Three adaptations to the basic approach are then proposed to manage the function evaluations in the way that are mostly allocated to the most promising areas of the search space. The first adapted algorithm, called HPSOLS, is aimed at improving PSOLS by stopping the local search in LSAs that are not contributing much to the search process. The second adapted, algorithm called CPSOLS, is a competitive algorithm which allocates extra function evaluations to the best performing LSA. The third adapted algorithm, called CHPSOLS, combines the fundamental ideas of HPSOLS and CPSOLS in a single algorithm. An extensive set of experiments is conducted on a variety of dynamic environments, generated by the moving peaks benchmark, to evaluate the performance of the proposed approach. Results are also compared with those of other state-of-the-art algorithms from the literature. The experimental results indicate the superiority of the proposed approach.     

一种新的求解动态连续优化的分层粒子群算法

为了高效求解动态连续优化问题,提出一种分层粒子群优化算法。该算法将动态函数定义域分成Q个子空间,每个空间用一个粒子群作为第一层进行独立搜索,Q个子空间的最优粒子再组成一个全局粒子群进行全局搜索,以达到全局牵引的作用,同时提出探测环境和响应环境的策略。利用经典的动态函数对算法进行测试,结果表明所提出算法能够迅速适应环境变化和跟踪最优解的变化,效果令人满意。     

Hybrid bare-bones PSO for dynamic economic dispatch with valve-point effects

This paper presents an efficient hybrid particle swarm optimization algorithm to solve dynamic economic dispatch problems with valve-point effects, by integrating an improved bare-bones particle swarm optimization (BBPSO) with a local searcher called directionally chaotic search (DCS). The improved BBPSO is designed as a basic level search, which can give a good direction to optimal regions, while DCS is used as a fine-tuning operator to locate optimal solution. And an adaptive disturbance factor and a new genetic operator are also incorporated into the improved BBPSO to enhance its search capability. Moreover, a heuristic handing mechanism for constraints is introduced to modify infeasible particles. Finally, the proposed algorithm is applied to the 5-, 10-, 30-unit-test power systems and several numerical functions, and a comparative study is carried out with other existing methods. Results clarify the significance of the proposed algorithm and verify its performance.     

A hybrid algorithm based on particle swarm and chemical reaction optimization

In this paper, a hybrid method for optimization is proposed, which combines the two local search operators in chemical reaction optimization with global search ability of for global optimum. This hybrid technique incorporates concepts from chemical reaction optimization and particle swarm optimization, it creates new molecules (particles) either operations as found in chemical reaction optimization or mechanisms of particle swarm optimization. Moreover, some technical bound constraint handling has combined when the particle update in particle swarm optimization. The effects of model parameters like InterRate, γ, Inertia weight and others parameters on performance are investigated in this paper. The experimental results tested on a set of twenty-three benchmark functions show that a hybrid algorithm based on particle swarm and chemical reaction optimization can outperform chemical reaction optimization algorithm in most of the experiments. Experimental results also indicate average improvement and deviate over chemical reaction optimization in the most of experiments.     

An interval space reducing method for constrained problems with particle swarm optimization

In this paper, we propose a method for solving constrained optimization problems using interval analysis combined with particle swarm optimization. A set inverter via interval analysis algorithm is used to handle constraints in order to reduce constrained optimization to quasi unconstrained one. The algorithm is useful in the detection of empty search spaces, preventing useless executions of the optimization process. To improve computational efficiency, a space cleaning algorithm is used to remove solutions that are certainly not optimal. As a result, the search space becomes smaller at each step of the optimization procedure. After completing pre-processing, a modified particle swarm optimization algorithm is applied to the reduced search space to find the global optimum. The efficiency of the proposed approach is demonstrated through comprehensive experimentation involving 100 000 runs on a set of well-known benchmark constrained engineering design problems. The computational efficiency of the new method is quantified by comparing its results with other PSO variants found in the literature.     

A stochastic local search algorithm for constrained continuous global optimization

This paper presents a new stochastic local search algorithm known as feasible–infeasible search procedure (FISP) for constrained continuous global optimization. The proposed procedure uses metaheuristic strategies for combinatorial optimization as well as combined strategies for exploring continuous spaces, which are applied to an efficient process in increasingly refined neighborhoods of current points. We show effectiveness and efficiency of the proposed procedure on a standard set of 13 well‐known test problems. Furthermore, we compare the performance of FISP with SNOPT (sparse nonlinear optimizer) and with few successful existing stochastic algorithms on the same set of test problems.     

求解非线性约束问题的混合粒子群优化算法

将处理约束问题的乘子法与改进的粒子群算法相结合,提出了一种求解非线性约束问题的混合粒子群算法。此算法兼顾了粒子群优化算法和乘子法的优点,对迭代过程中出现的不可行粒子,利用乘子法处理后产生可行粒子,然后用改进的粒子群算法来搜索其最优解,这样不仅减小了粒子群算法在寻优过程中陷入局部极小的概率,而且提高了搜索精度。数值试验结果表明提出的新算法具有搜索精度更高、稳定性更强、鲁棒性更好等特点。     

Deterministic metaheuristic based on fractal decomposition for large-scale optimization

In this work a new method based on geometric fractal decomposition to solve large-scale continuous optimization problems is proposed. It consists of dividing the feasible search space into sub-regions with the same geometrical pattern. At each iteration, the most promising ones are selected and further decomposed. This approach tends to provide a dense set of samples and has interesting theoretical convergence properties. Under some assumptions, this approach covers all the search space only in case of small dimensionality problems. The aim of this work is to propose a new algorithm based on this approach with low complexity and which performs well in case of large-scale problems. To do so, a low complex method that profits from fractals properties is proposed. Then, a deterministic optimization procedure is proposed using a single solution-based metaheuristic which is exposed to illustrate the performance of this strategy. Obtained results on common test functions were compared to those of algorithms from the literature and proved the efficiency of the proposed algorithm.     

求解TSP问题的模糊自适应粒子群算法

由于惯性权值的设置对粒子群优化（PSO）算法性能起着关键的作用,本文通过引入模糊技术,给出了一种惯性权值的模糊自适应调整模型及其相应的粒子群优化算法,并用于求解旅行商（TSP）问题。实验结果表明了改进算法在求解组合优化问题中的有效性,同时提高了算法的性能,并具有更快的收敛速度。     

一种多粒子群协同进化算法

为进一步提高多粒子群协同进化算法的寻优精度, 并有效改善粒子群易陷入局部极值及收敛速度慢的问题, 结合遗传算法较强的全局搜索能力和极值优化算法的局部搜索能力, 提出了一种改进的多粒子群协同进化算法. 对粒子群优化算法提出改进策略, 并在种群进化过程中, 利用遗传算法增加粒子的多样性及优良性, 经过一定次数的迭代, 利用极值优化算法加快收敛速度. 实验结果表明该算法具有较好的性能, 能够摆脱陷入局部极值点的问题, 并具有较快的收敛速度.     

嵌入局部一维搜索技术的混合粒子群优化算法*

通过将粒子群优化算法(PSO)与经典局部一维搜索技术相结合,提出一种嵌入局部一维搜索技术的混合粒子群优化算法(LLS-PSO)。该算法在基本粒子群优化算法中引入一维搜索技术,选取最优粒子进行局部一维搜索,增强了在最优点附近的局部搜索能力,以加快算法的收敛速度。对三个经典复杂优化问题进行数值实验,并与基本PSO算法进行比较。实验分析和结果表明,LLS-PSO具有更好的优化性能。     

An evolutionary decoding method for HMM-based continuous speech recognition systems using particle swarm optimization

The main recognition procedure in modern HMM-based continuous speech recognition systems is Viterbi algorithm. Viterbi algorithm finds out the best acoustic sequence according to input speech in the search space using dynamic programming. In this paper, dynamic programming is replaced by a search method which is based on particle swarm optimization. The major idea is focused on generating initial population of particles as the speech segmentation vectors. The particles try to achieve the best segmentation by an updating method during iterations. In this paper, a new method of particles representation and recognition process is introduced which is consistent with the nature of continuous speech recognition. The idea was tested on bi-phone recognition and continuous speech recognition workbenches and the results show that the proposed search method reaches the performance of the Viterbi segmentation algorithm ; however, there is a slight degradation in the accuracy rate.     

一种基于单纯形搜索的粒子群优化算法

为了改善粒子群优化算法的求解性能,提出了一种基于单纯形搜索和粒子群优化的混合算法。该算法一方面自适应地确定惯性权重、认知以及社会参数来达到免参数目的,另一方面利用单纯形搜索来引导部分粒子的搜索方向,从而加速算法收敛。数值实验结果表明,与传统的粒子群算法和其他基于单纯形的粒子群算法相比,提出算法在评估次数、求解精度方面表现良好。     

连续区域改进蚁群算法的研究

为了解决蚁群算法难处理连续区域的问题,本文结合微粒群操作改进蚁群算法。采用平均分割定义域的方法,融入随机操作和微粒群操作的交叉应用,并加入了信息素的变异操作跳出停滞状态。该混合群算法同时具有全局寻优特性和较强的局部搜索能力,在确保全局收敛性的基础上,能够快速搜索到高质量的优化解。通过仿真算例分析了其可行性、优越性。     

量子群智能优化算法综述

随着科学技术的不断发展,最优化理论及其衍生出的算法已经广泛应用于人们的日常工作与生活当中,现实世界中的很多问题都可以被描述为组合优化问题。群智能优化算法这些年来被证明在解决组合优化问题方面效果显著,将当下处于研究热点的量子计算概念引入群智能优化算法形成的量子群智能优化算法,为更好地解决组合优化问题提出了一个新的研究方向。在过去的二十多年里,许多量子群智能优化算法被不断开发出来,同时在此基础上进行了大量改进与应用。综述了量子蚁群算法、量子粒子群算法、量子人工鱼群算法、量子人工蜂群算法、量子布谷鸟搜索算法、量子混合蛙跳算法、量子萤火虫算法、量子蝙蝠算法等量子群智能优化算法,并对量子群智能优化算法面临的问题以及未来研究方向进行了深入探讨。     

PSOSA混合优化策略

本文提出了一种微粒群算法与模拟退火算法相结合的混合优化方法，该方法在群体进化的每一代中，首先通过微粒群算法的进化方法来控制微粒的飞行方向，然后利用模拟退火算法来拓展其搜索领域。这样既可以利用微粒群算法的收敛快速性，又可以利用模拟退火算法的全局收敛性。本文还证明了该混合优化方法依概率1收敛于全局最优解。仿
真结果表明，在搜索空间维数增大时，该方法的全局收敛性明显优于基本微粒群算法。     

混合粒子群算法及在可靠性优化中的应用

针对粒子群算法搜索精度低和早熟收敛的缺陷,通过算法混合,提出了基于混沌与和声搜索算法思想的混合粒子群优化算法。该算法采用Tent映射,利用混沌特性提高种群的多样性和粒子搜索的遍历性,同时采用和声策略对解空间进行开发,引入了柯西变异,帮助粒子跳出局部陷阱,采用云模型的自适应策略来调整惯性权重。最后将该优化算法应用于可靠性优化设计中,仿真实验表明,改进后的混合粒子群优化算法较基本粒子群算法收敛速度加快,且不易陷入局部极值点。     

Sequential approximation optimization assisted particle swarm optimization for expensive problems

In this paper, an efficient sequential approximation optimization assisted particle swarm optimization algorithm is proposed for optimization of expensive problems. This algorithm makes a good balance between the search ability of particle swarm optimization and sequential approximation optimization. Specifically, the proposed algorithm uses the optima obtained by sequential approximation optimization in local regions to replace the personal historical best particles and then runs the basic particle swarm optimization procedures. Compared with particle swarm optimization, the proposed algorithm is more efficient because the optima provided by sequential approximation optimization can direct swarm particles to search in a more accurate way. In addition, a space partition strategy is proposed to constraint sequential approximation optimization in local regions. This strategy can enhance the swarm diversity and prevent the preconvergence of the proposed algorithm. In order to validate the proposed algorithm, a lot of numerical benchmark problems are tested. An overall comparison between the proposed algorithm and several other optimization algorithms has been made. Finally, the proposed algorithm is applied to an optimal design of bearings in an all-direction propeller. The results show that the proposed algorithm is efficient and promising for optimization of the expensive problems.     

A hybrid particle swarm optimization algorithm for the vehicle routing problem

This paper introduces a new hybrid algorithmic nature inspired approach based on particle swarm optimization, for successfully solving one of the most popular supply chain management problems, the vehicle routing problem. The vehicle routing problem is considered one of the most well studied problems in operations research. The proposed algorithm for the solution of the vehicle routing problem, the hybrid particle swarm optimization (HybPSO), combines a particle swarm optimization (PSO) algorithm, the multiple phase neighborhood search–greedy randomized adaptive search procedure (MPNS–GRASP) algorithm, the expanding neighborhood search (ENS) strategy and a path relinking (PR) strategy. The algorithm is suitable for solving very large-scale vehicle routing problems as well as other, more difficult combinatorial optimization problems, within short computational time. It is tested on a set of benchmark instances and produced very satisfactory results. The algorithm is ranked in the fifth place among the 39 most known and effective algorithms in the literature and in the first place among all nature inspired methods that have ever been used for this set of instances.     

A comparative study of the improvement of performance using a PSO modified by ACO applied to TSP

Swarm-inspired optimization has become very popular in recent years. Particle swarm optimization (PSO) and Ant colony optimization (ACO) algorithms have attracted the interest of researchers due to their simplicity, effectiveness and efficiency in solving complex optimization problems. Both ACO and PSO were successfully applied for solving the traveling salesman problem (TSP). Performance of the conventional PSO algorithm for small problems with moderate dimensions and search space is very satisfactory. As the search, space gets more complex, conventional approaches tend to offer poor solutions. This paper presents a novel approach by introducing a PSO, which is modified by the ACO algorithm to improve the performance. The new hybrid method (PSO–ACO) is validated using the TSP benchmarks and the empirical results considering the completion time and the best length, illustrate that the proposed method is efficient.