基于凝聚函数的和声搜索算法求解绝对值方程*

绝对值方程Ax-|x|=b是一个不可微的NP-hard问题。在假设矩阵A的奇异值大于1（这里矩阵A的奇异值定义为矩阵ATA特征值的非负平方根）时,给出了求解绝对值方程一个新的光滑化算法。通过引入一种凝聚函数对绝对值方程进行光滑化处理,得到一个非线性方程组;再引入适当的目标函数,进而把绝对值方程化为无约束优化问题,然后利用和声搜索算法对其进行求解。该算法模拟了音乐创作中乐师们凭借自己的记忆,通过反复调整乐队中各乐器的音调,最终达到一个美妙的和声状态的过程。数值结果表明,该算法收敛快,数值稳定性好,是求解绝对     

利用改进的和声搜索算法求解Van Genuchten方程参数

Van Genuchten方程是最常用的土壤水分特征曲线方程,运用该方程的关键是4个参数的取值精度。为了精确地求解这些参数,引入和声搜索(HS)算法进行求解,提出一种基于全局信息的和声搜索优化计算方法——IGHS。IGHS算法具有如下特点：利用当前和声记忆库中的全局最优解产生新解,改变了和声搜索算法新解的产生方式;通过对和声记忆库中当前最优解的扰动避免算法早熟,增强算法的全局搜索能力;IGHS算法结构简单,容易实现。实验结果表明IGHS算法求解Van Genuchten方程参数的精度与随机微粒群结果相似,但其收敛速快、计算量小,因此可以作为计算Van Genuchten方程参数的新方法。     

自适应反向竞争和声搜索算法及其优化

提出一种自适应反向竞争和声搜索算法.该算法简单分析和声搜索算法步长设置的盲目性,提出一种自适应步长调整操作.算法融合反向学习策略的优势,建立末位淘汰竞争选择机制,以进一步提高算法的全局搜索能力,防止算法陷入局部最优.为验证文中算法的有效性,优化经典测试函数,数值结果表明文中算法在精度和鲁棒性方面比和声搜索算法及目前较优的改进和声搜索算法更好.最后通过优化求解热交换器和减速器设计问题,证明文中算法求解结果优于其他算法.     

基于反向计算和高斯分布估计的动态自适应和声搜索算法

为了增强和声搜索算法在求解高维多模态问题时的空间全局探索能力和求解精度,通过定义的4种反向计算方法和高斯分布估计算法,提出一种动态自适应高维和声搜索算法.该算法采用正交试验初始化和声记忆库;利用多维动态自适应算法进行和声创作;采用动态反向选择算法更新和声记忆库,并改进和声音调微调调解步长,从而增强算法的空间探索能力,避免陷入局部搜索.通过6个标准的高维Benchmark函数测试表明,本文算法在全局搜索能力、收敛速度和求解精度等方面都有明显改进.     

一种改进的和声搜索算法

针对基本和声搜索算法的不足,提出一种改进的和声搜索算法.首先在和声搜索算法的记忆库中加入权重,减少搜索的随机性;其次让扰动方程中的带宽具有自适应性,从而提高原算法的鲁棒性和收敛速度.算法在计算机上予以实现,并通过一系列测试函数求解,验证了改进算法与基本和声搜索算法及其他智能算法相比,能得到更多的最优解和较小的方差.     

新颖的全局和声搜索算法在经济性调度中的应用

提出采用新颖的全局和声搜索算法来解决经济调度问题,并设计了一种新颖的处理系统约束的方法;介绍了经济调度问题数学模型、新颖的全局和声搜索算法实现过程及其应用方法。实验结果表明,采用新颖的全局和声搜索算法所获得的最优值要明显好于采用进化算法、粒子群算法所获得的最优值,新颖的全局和声搜索算法为解决经济性调度问题提供了一种新的解决方案。     

多样性保持的和声搜索算法及其TSP求解

为了改善和声记忆库群体多样性, 提高算法的全局寻优能力, 在度量群体多样性指标的基础上, 从参数动态调整方法、和声记忆库更新策略两个方面对基本和声搜索算法进行了改进, 提出了多样性保持的和声搜索算法, 并将该算法应用于TSP的求解。结合TSP问题特点, 设计了基于交换和插入算子的和声微调方法。实例优化结果表明, 改进后的算法不容易陷入局部最优, 优化性能显著提高。     

动态调整策略改进的和声搜索算法

为了得到高维复杂问题的全局高精度最优解,提出一种动态调整策略,并用该策略改进和声搜索算法。算法选取和声记忆库中最差和声向量作为优化调整目标,随着迭代的进行,逐步降低决策变量的调整概率,该方法能够使得算法在全局探索能力和局部高精度开发能力之间实现平衡,有效提高了新和声更新最差和声的成功率。通过6个高维Benchmark测试函数的仿真结果表明,提出的动态调整策略能够有效提高和声搜索算法求解高维复杂优化问题的能力。     

求解绝对值方程的捕鱼算法

提出一种求解绝对值方程的捕鱼算法。算法首先将绝对值问题转化为一个最小化问题,然后使用三种搜索模式对目标函数进行寻优。数值实验结果表明,与粒子群算法和人群搜索算法以及他们的改进算法相比,所提算法不仅获得了稳定的求解结果,而且在最小值、最大值、平均值和方差等指标上均明显优于其他对比算法。     

和声搜索-分布估计混合算法求解多目标优化问题

针对和声搜索算法不能很好地求解多目标优化问题的缺陷,提出一种多目标和声搜索—分布估计混合算法(MHS-EDA)。该算法一方面利用分布估计的采样操作对和声记忆库内进行搜索,拓宽了和声记忆库内空间;另一方面对和声记忆库外进行外部档案搜索,实现群体间信息交换,从而提高了多目标和声算法的全局搜索能力。数值实验选取六个常用测试函数,并与多目标遗传算法、多目标分布估计算法、多目标和声搜索算法进行比较,测试结果表明提出的混合算法能够有效地解决多目标优化问题。     

A novel global harmony search algorithm for task assignment problem

The objective of task assignment problem (TAP) is to minimize the sum of interprocessor communication and task processing costs for a distributed system which subjects to several resource constraints. We use a novel global harmony search algorithm (NGHS) to solve this problem, and the NGHS algorithm has demonstrated higher efficiency than the improved harmony search algorithm (IHS) on finding the near optimal task assignment. We also devise a new method called normalized penalty function method to tradeo^® the costs and the constraints. A large number of experiments show that our algorithm performs well on finding the near optimal task assignment, and it is a viable approach for the task assignment problem.     

Robust pole assignment for linear control systems in a circular region using novel global harmony search algorithm

This paper presents a new approach to the problem of robust pole assignment in a circular region using novel global harmony search (NGHS) algorithm. Based on geometric principles, the position information of poles in the circular region is depicted and the rules of dynamic selection of poles from the circular region are determined. This ensures the algorithm select poles dynamically from the circular region. In order to get a set of poles and the state feedback controller which allow the system to have a maximum allowable perturbation or uncertainty, the upper bound of perturbation or uncertainty is optimized by the NGHS algorithm for the poles in the circular region. In contrast to most existing methods, an optimization method using NGHS algorithm for the dynamic selection of poles, makes the closed-loop system show better robustness. Finally, the simulation results demonstrate the effectiveness of the proposed approach.     

A novel global harmony search algorithm for reliability problems

Inspired by the swarm intelligence of particle swarm, a novel global harmony search algorithm (NGHS) is proposed to solve reliability problems in this paper. The proposed algorithm includes two important operations: position updating and genetic mutation with a small probability. The former enables the worst harmony of harmony memory to move to the global best harmony rapidly in each iteration, and the latter can effectively prevent the NGHS from trapping into the local optimum. Based on a large number of experiments, the proposed algorithm has demonstrated stronger capacity of space exploration than most other approaches on solving reliability problems. The results show that the NGHS can be an efficient alternative for solving reliability problems.     

New identification method for Hammerstein models based on approximate least absolute deviation

Disorder and peak noises or large disturbances can deteriorate the identification effects of Hammerstein non-linear models when using the least-square (LS) method. The least absolute deviation technique can be used to resolve this problem; however, its absolute value cannot meet the need of differentiability required by most algorithms. To improve robustness and resolve the non-differentiable problem, an approximate least absolute deviation (ALAD) objective function is established by introducing a deterministic function that exhibits the characteristics of absolute value under certain situations. A new identification method for Hammerstein models based on ALAD is thus developed in this paper. The basic idea of this method is to apply the stochastic approximation theory in the process of deriving the recursive equations. After identifying the parameter matrix of the Hammerstein model via the new algorithm, the product terms in the matrix are separated by calculating the average values. Finally, algorithm convergence is proven by applying the ordinary differential equation method. The proposed algorithm has a better robustness as compared to other LS methods, particularly when abnormal points exist in the measured data. Furthermore, the proposed algorithm is easier to apply and converges faster. The simulation results demonstrate the efficacy of the proposed algorithm.     

基于多个自主水下航行器的分布式协同流场估计

本文考虑利用多个自主式水下航行器(AUV)实现流场估计, 提出了一种基于树型网络的分布式方法来估计 水下流场. 在本文中, 借助绝对运动积分误差和相对运动积分误差, 流场估计问题被描述为求解一个以未知流场为 变元的非线性方程组. 继而本文在多AUV系统内建立一个低通讯成本的树型网络, 并在该网络上运行一种分布式 算法以求解与流场估计相关的非线性方程组. 在该算法中, 每个AUV将当前的流场估计值连续地投影到自身拥有 的约束方程的解集中, 并通过扩散和池化两个步骤在树型网络间传递流场估计值. 本文证明了上述算法的收敛性, 并通过仿真实验验证了所述分布式协同流场估计方法的有效性.     

一种自适应全局和声搜索算法

针对新颖全局和声搜索(NGHS) 算法过早收敛的问题, 提出自适应全局和声搜索(AGHS) 算法. 引入差分向量范数定义和声记忆库多样性, 给出新的位置更新策略, 排除变异操作. 以和声记忆库多样性信息为指导动态产生新和声, 提高算法对解空间信息开发的能力, 避免算法因过早收敛、易陷入局部最优的不足. AGHS算法操作更简单,需要设置的参数更少, 将其与目前文献中较优的几种改进HS 算法、PSO 算法和GA算法进行性能测试, 测试结果表明AGHS算法具有较高的寻优精度和较快的收敛速度.

     

Performance evaluation of an improved harmony search algorithm for numerical optimization: Melody Search (MS)

Melody Search (MS) Algorithm as an innovative improved version of Harmony Search optimization method, with a novel Alternative Improvisation Procedure (AIP) is presented in this paper. MS algorithm mimics performance processes of the group improvisation for finding the best succession of pitches within a melody. Utilizing different player memories and their interactive process, enhances the algorithm efficiency compared to the basic HS, while the possible range of variables can be varied going through the algorithm iterations. Moreover, applying the new improvisation scheme (AIP) makes algorithm more capable in optimizing shifted and rotated unimodal and multimodal problems than the basic MS.In order to demonstrate the performance of the proposed algorithm, it is successfully applied to various benchmark optimization problems. Numerical results reveal that the proposed algorithm is capable of finding better solutions when compared with well-known HS, IHS, GHS, SGHS, NGHS and basic MS algorithms. The strength of the new meta-heuristic algorithm is that the superiority of the algorithm over other compared methods increases when the dimensionality of the problem or the entire feasible range of the solution space increases.     

基于改进的人工蜂群的独立分量分析方法

针对快速固定点独立分量分析方法容易陷入局部最优解的问题,提出了一种基于改进的蜂群优化的独立分量分析方法。该方法以信号的峭度作为代价函数,利用人工蜂群方法对其进行优化。在优化的过程中,一方面为了避免随机搜索造成的开采能力弱的问题,在跟随蜂搜索阶段采用当前迭代最优解引导的方式产生新的候选解,另一方面,为了避免产生更差的解,在侦查蜂阶段,利用当前迭代中的最优解与最差解的距离产生新的解,代替最差解,提高人工蜂群优化方法的寻优效果,进而提高独立分量分析的精度。实验仿真验证了算法的性能。     

基于差分进化—单纯形混合算法求解绝对值方程*

绝对值方程Ax-｜x｜=b是一个不可微的NP-hard问题。在假设矩阵A的奇异值大于1（这里矩阵A的奇异值定义为矩阵ATA特征值的非负平方根）时, 给出了一种求解绝对值方程的新方法：差分进化—单纯形混合算法。该混合算法充分发挥了差分进化算法的群体搜索性和单纯形算法的局部细致搜索性,同时也克服了差分进化算法后期搜索效率降低和单纯形算法对初始点敏感的缺陷。数值实验表明所设计的混合算法是有效的。