面向多峰函数优化的Lamarck免疫网络算法*

为改善免疫网络算法在多峰函数优化方面存在局部收敛的不足,提出一种Lamarck免疫网络算法(LM-aiNet)。依据Lamarck进化理论思想,设计基于方向的局部搜索机制和自适应的网络抑制阈值,提高了算法对于不同类型多峰函数优化的适应能力。对算法的复杂度和收敛性进行分析,重点讨论了算法主要参数对求解性能的影响,确定合适的参数取值范围。实验结果表明,算法能够有效地解决经典算法的局部收敛问题,其求解能力优于被比较的其他算法。     

基于正交设计NSGA-II算法的制动器多目标优化*

针对汽车鼓式制动器,以制动效能因数最大、制动鼓体积最小和制动器温升最低为目标,建立了多目标优化模型。针对传统NSGA-II算法求解3目标优化问题的不足,引入正交设计策略,提出了改进的NSGA-II算法。将改进算法与目前三种经典的多目标优化算法在DTLZ系列测试函数上进行性能测试,结果表明改进算法在求解3目标优化问题上有更好的性能。用改进算法和NSGA-II两种算法同时求解制动器多目标优化设计实例,改进算法得到了分布更好的Pareto前端,表明改进算法对此类问题求解行之有效。     

一种基于冷链低碳物流路径的混合优化算法

冷链物流运输路径优化问题是国内外学者近几年研究的一个热点问题。首先分析了冷链物流运输的特点和需求,并且提出了考虑综合代价、带硬时间窗和容量约束的单物流中心车辆路径优化模型,其中综合代价包括固定代价、车辆运输代价、货损代价、制冷代价、时间惩罚代价和碳排放代价。车辆路径规划问题是一个NP问题,需要使用智能优化算法对解空间进行搜索。该文对遗传算法和模拟退火算法这两种经典的优化算法进行结合和参数优化,提出了一种模拟退火-遗传混合算法(GA-SA)。该算法在搜索范围和搜索精度上有较好的性能,能够在同数量级运算量的情况下求出更优的解。对上述模型进行参数设置形成仿真实验并使用混合算法和以上两种经典算法对仿真实验进行求解,通过求解结果的对比,验证了混合算法的有效性。     

离散粒子群优化算法求解旅行商问题

在优化领域,粒子群算法适用于求解连续优化问题,而在离散优化上的应用还相对较少。本文在介绍基本粒子群优化算法的基础上,分析了粒子群优化算法在经典旅行商问题 中的应用性能及粒子群算法求解旅行商问题的相关操作。使用Ulysses等标准TSP测试数据进行了相关实验,并通过不同的参数设置对实验结果进行了性能分析和比较。     

基于模拟退火的自适应粒子群优化算法的改进策略

针对PSO算法在求解问题的优化问题中易陷入局部收敛且收敛速度较慢等缺陷,引入一种初始化改进策略,并将模拟退火算法与PSO算法相结合,提出了一种全新的算法。该算法将寻优过程分为两个阶段:为了提高算法的执行速度,前期使用标准PSO算法进行寻优,后期运用模拟退火思想对PSO中的参数进行优化搜索最优解。最后将该算法应用于八个经典的单峰/多峰函数中。模拟结果表明,该算法有效地避免了早熟收敛现象,并提高了收敛速度,从而提高了PSO算法解决全局优化的性能。     

优化复杂函数的粒子群-鸽群混合优化算法

针对复杂函数优化问题,提出一种两阶段混合优化算法。对基本粒子群和鸽群算法进行改进,引入惯性因子和跳跃算子增强了粒子群算法的搜索能力,提出干扰算子增加了鸽群算法的种群多样性。将改进后的两种算法相结合,形成两阶段混合优化算法,同时定义了一种多样性函数对种群进行实时监测,以保证种群的多样性。采用两组经典测试函数,对算法性能进行测试。结果表明,算法适用于求解复杂函数优化问题,且具有较好的收敛速度和收敛精度。     

限制速度粒子群优化和自适应速度粒子群优化在无约束优化问题中的应用

限制速度粒子群优化(RVPSO)和自适应速度粒子群优化(SAVPSO)是近年来提出的专门求解约束优化问题(COP)的粒子群优化算法,但目前尚无两算法在无约束优化应用方面的研究。为此,研究上述算法在无约束优化中的有效性和性能特点,并针对算法保守性较强的特点,分别引入混沌因子和随机优化策略对算法进行改进,从而提高算法的全局搜索能力;另外,还研究了不同参数设置对算法性能的影响。在5个典型测试函数上的仿真实验结果表明:RVPSO改进算法的鲁棒性及全局搜索能力优于原算法,但在求解高维多峰函数时仍易于陷入局部最优; SAVPSO改进算法的全局搜索能力比RVPSO改进算法强,且在求解高维多峰函数时具有更快的收敛速度并能取得精度更高的解,表现出较好的全局优化能力,是一种切实有效的求解无约束优化问题的算法。     

火力优化分配问题的小生境遗传蚂蚁算法

火力分配问题是NP难题,经典的求解算法存在指数级的时间复杂度。文中提出一种小生境遗传算法与蚁群优化算法相结合的小生境遗传蚂蚁算法,并针对具体问题提出蚂蚁搜索的禁忌规则。对该算法进行了实验,并将实验结果与其他算法进行比较分析,分析结果表明：新算法无论是在优化性能还是在时间性能都取得了非常好的效果。文中算法对其他的NP问题同样适用。     

斐波那契树优化算法求解多峰函数全局最优解的可达性分析

为分析和验证斐波那契树优化算法（Fibonacci tree optimization algorithm,FTO）求解多峰函数全局最优解的算法性能,对算法的可达性问题进行研究.本文基于斐波那契法构造一个斐波那契树结构,在搜索空间中进行全局、局部交替搜索,不易陷入局部最优解.对斐波那契树优化算法基于该结构的可达性进行分析和证明.通过跟踪算法求解过程中坐标点的累积分布仿真实验和到达率的对比实验,分析和验证了算法求解多峰函数全局最优解的可达性.     

基于DTC-MOPSO算法的焊接机器人路径规划

点焊机器人在汽车白车身焊接中的应用大大提高了企业的生产效率,本文从焊接路径长度和能量两方面进行焊接机器人多目标路径规划．为了很好地解决这个问题,本文对一种新型多目标粒子群算法（三态协调搜索多目标粒子群优化算法）进行改进,得到适合于求解离散多目标优化问题的离散化三态协调搜索多目标粒子群算法（DTC-MOPSO）．通过和两个经典的优化算法比较,DTC-MOPSO算法在分散性和收敛性方面都有很好的优化性能．最后运用Matlab机器人工具箱对机器人的运动学、逆运动学以及逆动力学进行分析以求解机器人的路径长度和能耗,并将改进的算法应用于焊接机器人路径规划中,结果显示规划后的路径明显优于另外两种算法.     

三种现代优化算法的比较研究

现代最优化算法比较常见的有遗传算法、蚁群算法、微粒群算法、人工鱼群算法等。本文主要对前三种算法优化性能进行比较研究。首先介绍了三种算法的基本原理,然后总结了各自的优缺点并从原理和参数两个方面对三种算法进行了对比分析,最后以经典TSP问题为例进行了仿真研究并得出了一些指导算法适用范围的结论。     

Comparison of particle swarm optimization and genetic algorithm for FACTS-based controller design

Recently, genetic algorithms (GA) and particle swarm optimization (PSO) technique have attracted considerable attention among various modern heuristic optimization techniques. The GA has been popular in academia and the industry mainly because of its intuitiveness, ease of implementation, and the ability to effectively solve highly non-linear, mixed integer optimization problems that are typical of complex engineering systems. PSO technique is a relatively recent heuristic search method whose mechanics are inspired by the swarming or collaborative behavior of biological populations. Since the two approaches are supposed to find a solution to a given objective function but employ different strategies and computational effort, it is appropriate to compare their performance. This paper presents the application and performance comparison of PSO and GA optimization techniques, for flexible ac transmission system (FACTS)-based controller design. The design objective is to enhance the power system stability. The design problem of the FACTS-based controller is formulated as an optimization problem and both PSO and GA optimization techniques are employed to search for optimal controller parameters. The performance of both optimization techniques in terms of computational effort, computational time and convergence rate is compared. Further, the optimized controllers are tested on a weakly connected power system subjected to different disturbances over a wide range of loading conditions and parameter variations and their performance is compared with the conventional power system stabilizer (CPSS). The eigenvalue analysis and non-linear simulation results are presented and compared to show the effectiveness of both the techniques in designing a FACTS-based controller, to enhance power system stability.     

基于个体状态的粒子群优化算法

针对标准粒子群算法的种群多样性丧失和算法早熟收敛问题,借鉴自然界中群居动物个体行为的独立性特征,提出粒子的个体状态概念,给出一种基于微粒个体状态和状态迁移的粒子群优化算法。对典型函数测试结果的比较表明,改进后算法的寻优能力明显高于标准粒子群算法。与其他改进算法相比,该算法的寻优能力也较强。     

求解作业车间调度问题的微粒群遗传退火算法

标准微粒群算法（PSO）通常被用于求解连续优化的问题,很少被用于离散问题的优化求解,如作业车间调度问题（JSP）。因此,针对PSO算法易早熟、收敛慢等缺点提出一种求解作业车间调度问题（JSP）的混合微粒群算法。算法将微粒群算法、遗传算法（GA）、模拟退火（SA）算法相结合,既增强了算法的局部搜索能力,降低了算法对参数的依赖,同时改善了PSO算法和GA算法易早熟的缺点。对经典JSP问题的仿真实验表明：与标准微粒群算法相比,该算法不仅能有效避免算法中的早熟问题,并且算法的全局收敛性得到了显著提高。     

构建在进化技术上的动态价格优化研究

电子商务改变了企业的定价策略,产品由固定价格转向动态价格。用两种不同的进化算法-遗传算法（GA）和基于种群递增学习算法（PBIL）求解两种不同的动态价格模型,并对两种算法进行了比较。在提出的模型中,算法PBIL的结果及分析充分显示了模型在资源管理中的适用性,以及基于种群的优化技术在动态价格中的应用能力。     

A genetic algorithm and a particle swarm optimizer hybridized with Nelder–Mead simplex search

This paper integrates Nelder–Mead simplex search method (NM) with genetic algorithm (GA) and particle swarm optimization (PSO), respectively, in an attempt to locate the global optimal solutions for the nonlinear continuous variable functions mainly focusing on response surface methodology (RSM). Both the hybrid NM–GA and NM–PSO algorithms incorporate concepts from the NM, GA or PSO, which are readily to implement in practice and the computation of functional derivatives is not necessary. The hybrid methods were first illustrated through four test functions from the RSM literature and were compared with original NM, GA and PSO algorithms. In each test scheme, the effectiveness, efficiency and robustness of these methods were evaluated via associated performance statistics, and the proposed hybrid approaches prove to be very suitable for solving the optimization problems of RSM-type. The hybrid methods were then tested by ten difficult nonlinear continuous functions and were compared with the best known heuristics in the literature. The results show that both hybrid algorithms were able to reach the global optimum in all runs within a comparably computational expense.     

On the equivalences and differences of evolutionary algorithms

Evolutionary algorithms (EAs) are fast and robust computation methods for global optimization, and have been widely used in many real-world applications. We first conceptually discuss the equivalences of various popular EAs including genetic algorithm (GA), biogeography-based optimization (BBO), differential evolution (DE), evolution strategy (ES) and particle swarm optimization (PSO). We find that the basic versions of BBO, DE, ES and PSO are equal to the GA with global uniform recombination (GA/GUR) under certain conditions. Then we discuss their differences based on biological motivations and implementation details, and point out that their distinctions enhance the diversity of EA research and applications. To further study the characteristics of various EAs, we compare the basic versions and advanced versions of GA, BBO, DE, ES and PSO to explore their optimization ability on a set of real-world continuous optimization problems. Empirical results show that among the basic versions of the algorithms, BBO performs best on the benchmarks that we studied. Among the advanced versions of the algorithms, DE and ES perform best on the benchmarks that we studied. However, our main conclusion is that the conceptual equivalence of the algorithms is supported by the fact that algorithmic modifications result in very different performance levels.     

差分和扰动混合的多策略粒子群优化算法

通常的粒子群优化算法采取单一的学习策略,不利于搜索信息的有效保留,因此将改进的差分变异策略引入到粒子的速度更新中以增强算法的群体多样性;综合利用差分变异与扰动策略两种不同的产生新解的方式,提出了一种多策略交叉学习机制算法DPPSO（hybrid particle swarm optimization with differential and per-turbation）。每一个粒子通过引进的差分变异操作和扰动操作分别产生一个中间粒子,再选择较好的粒子作为当前粒子的新位置,从而实现所有粒子动态地选择更好的生成策略来更新自己的位置和速度,因此该交叉策略能够有效提高PSO算法的群体多样性和搜索路径的多样性,粒子可以获取更好的启发式信息,沿着不同的路径被引向更有潜力的搜索区域。实验结果表明了两种策略的有效性和互补性,DPPSO算法比其他三种算法有更好的综合表现,具有有效的全局收敛能力和准确定位能力。     

基于群体智能算法的粗糙集约简方法研究

随着粗糙集理论的应用越来越广泛,寻找一个适当的方法进行粗糙集约简已成为一个关键问题,同时这也成为研究粗糙集理论的瓶颈。粒子群优化算法（PSO）起源对简单社会系统的模拟,对解决这个问题具有特别的优势。同时该文用遗传算法（GA）来评价提出来的粒子群优化的成效,结果发现,在解决某些粗糙集约简问题上,PSO更具优势。     

Particle swarm optimization with crazy particles for nonconvex economic dispatch

The paper presents an effective evolutionary method for economic power dispatch. The idea is to allocate power demand to the on-line power generators in such a manner that the cost of operation is minimized. Conventional methods assume quadratic or piecewise quadratic cost curves of power generators but modern generating units have non-linearities which make this assumption inaccurate. Evolutionary optimization methods such as genetic algorithms (GA) and particle swarm optimization (PSO) are free from convexity assumptions and succeed in achieving near global solutions due to their excellent parallel search capability. But these methods usually tend to converge prematurely to a local minimum solution, particularly when the search space is irregular. To tackle this problem “crazy particles” are introduced and their velocities are randomized to maintain momentum in the search and avoid saturation. The performance of the PSO with crazy particles has been tested on two model test systems, compared with GA and classical PSO and found to be superior.