改进的量子遗传算法及应用

针对量子遗传算法在函数优化中迭代次数多,容易陷入局部最优解等缺点,提出新的量子遗传算法.该算法的核心是采用新的量子旋转门调整策略对种群进行更新操作,有效保证了种群的多样性,可以避免算法陷入局部最优解,提高了算法的全局寻优能力.同时能以更快的速度收敛于全局最优解.通过对典型复杂函数测试,计算结果表明,提出的算法优化质量和效率都要优于传统遗传算法和一般量子遗传算法.     

一种函数优化问题的混合遗传算法

将传统的局部搜索算法和遗传算法相结合,可以较好地解决遗传算法在达到全局最优解前收敛慢的问题.文章给出一种结合可变多面体法和正交遗传算法的混合算法.实验表明,它通过对问题的解空间交替进行全局和局部搜索,能更有效地求解函数优化问题.     

基于最大方差法和改进遗传算法的图像分割

针对应用标准遗传算法对一幅灰度图像寻找最优阈值时经常陷入局部寻优的问题,提出了一种利用最大方差法和新的改进遗传算法相结合对图像进行分割的方法.以灰度图像的最大方差作为适应度函数,把图像分割问题变成一个优化问题.利用遗传算法的寻优高效性,搜索到能使分割质量达到最优的分割阈值.实验结果表明,采用新的改进遗传算法和最大方差法相结合对图像搜索全局阈值时能收敛至全局最优解,并且大大缩短寻找最优阈值的时间.     

基于混沌“微变异”自适应遗传算法

遗传算法可以较好地解决复杂的组合优化问题,但也存在两方面不足:一是搜索效率比其他优化算法低;二是容易过早收敛,陷入局部最优.对此,提出一种混沌“微变异”遗传算法.利用混沌优化算法具有随机性和遍历性的特点,解决遗传算法容易陷入局部最优解的早熟问题,使得新算法同时具有较强的局部搜索能力和完成全局寻找最优解的能力.同时,对遗传算法的选择算子增加了混沌扰动,对交叉算子和变异算子进行自适应调整,对适应度函数进行改进,使遗传算法整体性能得到提高.最后,通过经典函数验证表明,混沌“微变异”遗传算法比一般的混沌遗传算法和经典遗传算法的进化速度更快,搜索精度更高.     

一种混合的GOA-GA优化算法

本文融合了网格算法(GOA)和遗传算法(GA),形成了一种混合GOA-GA算法进行函数优化问题的求解。网格算法作为一种定向的全局搜索算法,避免了大量的盲目搜索过程,同时不易陷入局部最优。遗传算法作为局部搜索能力较强的智能优化算法,在一些全局较好群体的基础上,采用随机优化技术能够较快地收敛到全局最优解。通过数值试验特别是对高维优化问题,算法体现出收敛速度快、精确性高、不宜陷入局部最优等优点。     

Pi-sigma神经网络混合学习算法及收敛性分析

将一种解决函数优化问题的混合遗传算法用于Pi-sigma神经网络的训练。这种混合算法充分利用遗传算法算法的全局搜索能力,又利用了单纯型法的局部搜索能力,因此该混合遗传算法可以使Pi-sigma神经网络更快的收敛到全局最优解,而且收敛速度比遗传算法更快。实验证明了这种算法的优越性。最后还证明了该算法可以以概率1收敛到全局最优解。     

基于遗传算法的物流配送路径优化问题研究

遗传算法是一种基于自然进化原理的全局搜索随机算法.遗传算法在选址问题、配送问题、调度问题、运输问题、布局问题方面意义重大.在建立物流配送路径优化问题数学模型的基础上,构造了求解该问题的遗传算法.该遗传算法采用常用的二进制编码,在个体选择上结合使用最优个体保留策略和轮盘赌法.最后以这种方法进行了实验计算,通过计算结果表明,用遗传算法进行物流配送路径优化,可以方便有效地求得问题的最优解或近似最优解.     

基于免疫量子遗传算法的多峰函数寻优

针对多峰函数优化中的全局及局部寻优问题,提出了一种结合免疫克隆算子的量子遗传算法,给出了实现流程。该算法集量子遗传算法的快速性和免疫克隆算法全局搜索性于一身。它不仅有效克服了量子遗传算法容易陷于局部最优的缺点,也避免了普通免疫克隆算法计算缓慢的缺点。用多峰值函数进行了全局寻优的仿真实验,并与基本遗传算法,量子遗传算法的计算结果进行了比较,结果表明所提算法能以较快的速度搜索到全局最优解,并且其鲁棒性远高于普通量子遗传算法和遗传算法。     

基于改进量子遗传算法的连续函数优化研究

针对一般量子遗传算法在求解连续函数优化问题时存在的困难,研究了一种改进的量子遗传算法.该算法采用一种新的量子旋转门--Hε门对种群进行更新操作,可有效避免算法陷入局部最优解,提高算法的全局寻优能力.将该算法应用于几个典型复杂函数的优化测试结果表明,改进的量子遗传算法在对连续函数进行求解时,综合性能明显优于传统遗传算法和一般量子遗传算法.     

一种基于云模型的改进型量子遗传算法*

针对量子遗传算法在函数优化中易陷入局部最优和早熟收敛等缺点,采用云模型对其进行改进,采用量子种群基因云对种群进化进行定性控制,采用基于云模型的量子旋转门自适应调整策略进行更新操作,使算法在定性知识的指导下能够自适应控制搜索空间范围,能在较大搜索空间条件下避开局部最优解。典型函数对比实验表明,该算法可以避免陷入局部最优解,能提高全局寻优能力,同时能以更快的速度收敛于全局最优解,优化质量和效率都要优于遗传算法和量子遗传算法。     

一种新的非线性回归模型参数估计算法

提出一种新的基于混合基因算法（HGA）的非线性回归模型参数估计算法,新算法通过对问题的解空间交替进行全局和局部搜索,达到快速收敛至全局最优解,较好地解决了传统算法通用性差、易陷入局部极小的问题,实验验证了算法的通用性和有效性。     

A flexible tolerance genetic algorithm for optimal problems with nonlinear equality constraints

A hybrid method called a flexible tolerance genetic algorithm (FTGA) is proposed in this paper to solve nonlinear, multimodal and multi-constraint optimization problems. This method provides a new hybrid strategy that organically merges a flexible tolerance method (FTM) into an adaptive genetic algorithm (AGA). AGA is to generate an initial population and locate the “best” individual. FTM, serving as one of the AGA operators, exploits the promising neighborhood individual by a search mechanism and minimizes a constraint violation of an objective function by a flexible tolerance criterion for near-feasible points. To evaluate the efficiency of the hybrid method, we apply FTGA to optimize four complex functions subject to nonlinear inequality and/or equality constraints, and compare these results with the results supplied by AGA. Numerical experiments indicate that FTGA can efficiently and reliably achieve more accurate global optima of complex, nonlinear, high-dimension and multimodal optimization problems subject to nonlinear constraints. Finally, FTGA is successfully implemented for the optimization design of a crank-toggle mechanism, which demonstrates that FTGA is applicable to solve real-world problems.     

A new class of hybrid global optimization algorithms for peptide structure prediction: integrated hybrids

A novel class of hybrid global optimization methods for application to the structure prediction in protein-folding problem is introduced. These optimization methods take the form of a hybrid between a deterministic global optimization algorithm, the αBB, and a stochastically based method, conformational space annealing (CSA), and attempt to combine the beneficial features of these two algorithms. The αBB method as previously extant exhibits consistency, as it guarantees convergence to the global minimum for twice-continuously differentiable constrained nonlinear programming problems, but can benefit from improvements in the computational front. Computational studies for met-enkephalin demonstrate the promise for the proposed hybrid global optimization method.     

求解一类凸优化问题的区间迭代算法

研究了一类非线性带约束的凸优化问题的求解.利用Kuhn-Tucker条件将凸优化问题等价地转化为多变元非线性方程组的求解问题.基于区间算术的包含原理及改进的Krawczyk区间迭代算法,提出一个求解凸优化问题的区间算法.对于目标函数和约束函数可微的凸优化,所提算法具有全局寻优的特性.在数值实验方面,与遗传算法、模式搜索法、模拟退火法及数学软件内置的求解器进行了比较,结果表明所提算法就此类凸优化问题能找到较多且误差较小的全局最优点.     

A hybrid variable neighborhood search for solving the hybrid flow shop scheduling problem

This paper proposes a hybrid variable neighborhood search (HVNS) algorithm that combines the chemical-reaction optimization (CRO) and the estimation of distribution (EDA), for solving the hybrid flow shop (HFS) scheduling problems. The objective is to minimize the maximum completion time. In the proposed algorithm, a well-designed decoding mechanism is presented to schedule jobs with more flexibility. Meanwhile, considering the problem structure, eight neighborhood structures are developed. A kinetic energy sensitive neighborhood change approach is proposed to extract global information and avoid being stuck at the local optima. In addition, contrary to the fixed neighborhood set in traditional VNS, a dynamic neighborhood set update mechanism is utilized to exploit the potential search space. Finally, for the population of local optima solutions, an effective EDA-based global search approach is investigated to direct the search process to promising regions. The proposed algorithm is tested on sets of well-known benchmark instances. Through the analysis of experimental results, the high performance of the proposed HVNS algorithm is shown in comparison with four efficient algorithms from the literature.     

A hybrid shuffled complex evolution approach with pattern search for unconstrained optimization

The difficulties associated with using classical mathematical programming methods on complex optimization problems have contributed to the development of alternative and efficient numerical approaches. Recently, to overcome the limitations of classical optimization methods, researchers have proposed a wide variety of meta-heuristics for searching near-optimum solutions to problems. Among the existing meta-heuristic algorithms, a relatively new optimization paradigm is the Shuffled Complex Evolution at the University of Arizona (SCE-UA) which is a global optimization strategy that combines concepts of the competition evolution theory, downhill simplex procedure of Nelder-Mead, controlled random search and complex shuffling. In an attempt to reduce processing time and improve the quality of solutions, particularly to avoid being trapped in local optima, in this paper is proposed a hybrid SCE-UA approach. The proposed hybrid algorithm is the combination of SCE-UA (without Nelder-Mead downhill simplex procedure) and a pattern search approach, called SCE-PS, for unconstrained optimization. Pattern search methods are derivative-free, meaning that they do not use explicit or approximate derivatives. Moreover, pattern search algorithms are direct search methods well suitable for the global optimization of highly nonlinear, multiparameter, and multimodal objective functions. The proposed SCE-PS method is tested with six benchmark optimization problems. Simulation results show that the proposed SCE-PS improves the searching performance when compared with the classical SCE-UA and a genetic algorithm with floating-point representation for all the tested problems. As evidenced by the performance indices based on the mean performance of objective function in 30 runs and mean of computational time, the SCE-PS algorithm has demonstrated to be effective and efficient at locating best-practice optimal solutions for unconstrained optimization.     

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.     

Self-adaptive Bat Algorithm With Genetic Operations

Swarm intelligence in a bat algorithm (BA) provides social learning. Genetic operations for reproducing individuals in a genetic algorithm (GA) offer global search ability in solving complex optimization problems. Their integration provides an opportunity for improved search performance. However, existing studies adopt only one genetic operation of GA, or design hybrid algorithms that divide the overall population into multiple subpopulations that evolve in parallel with limited interactions only. Differing from them, this work proposes an improved self-adaptive bat algorithm with genetic operations (SBAGO) where GA and BA are combined in a highly integrated way. Specifically, SBAGO performs their genetic operations of GA on previous search information of BA solutions to produce new exemplars that are of high-diversity and high-quality. Guided by these exemplars, SBAGO improves both BA’s efficiency and global search capability. We evaluate this approach by using 29 widely-adopted problems from four test suites. SBAGO is also evaluated by a real-life optimization problem in mobile edge computing systems. Experimental results show that SBAGO outperforms its widely-used and recently proposed peers in terms of effectiveness, search accuracy, local optima avoidance, and robustness.      

非线性最小二乘全局解的混合计算智能算法

通过在遗传算法中嵌入牛顿算子，并定义适当的适应度和数据结构，从而得到可结合遗传算法和牛顿法两者长处，既有较快收敛性，又能以较大概率求得非线性最小二乘全局解的混合计算智能算法．数值结果表明了该方法显著优于遗传算法和牛顿法．