基于混沌理论的免疫量子进化算法

提出了基于混沌理论的免疫量子进化算法,该算法应用混沌理论并依据小生境机制将初始个体划分为实数编码染色体的子群,各子群应用免疫特性的局域搜索能力找出优化解。混沌优化搜索机制能有效避免早熟收敛。为解决2进制算法所不能避免的精度与效率的冲突,采用10进制编码染色体。算法综合了量子计算的天然并行性、免疫算法的充分自适应性和混沌系统的遍历性,它比传统的进化算法具有更好的种群多样性,更快的收敛速度,更有效的全局和局域寻优能力。仿真实验也表明了该算法的优越性。     

基于自适应算子的混合进化算法及其应用

提出了一种求解多目标优化最短路径问题的混合进化算法。算法中依据小生境机制生成若干个实数编码染色体的子群,各子群分别利用自适应算子的局域搜索能力找出优化解。协同进化机制能更好地保证进化的方向性和种群的多样性,基于路径表示的染色体十进制编码方法以及染色体的交叉和变异具有新颖性。该算法用于解决智能交通系统的公共交通线路换乘问题,实验结果表明了其优越性。还运用Markov随机过程理论证明了算法的收敛性。     

Optimisation With Real-Coded Genetic Algorithms Based On Mathematical Morphology

The goal of this work is to propose a novel approach to function optimisation by evolutionary techniques, in particular, real-coded genetic algorithms. A new genetic crossover operator, suitable for real codification, has been designed. This operator is called morphological crossover as it is based on mathematical morphology theory. The morphological crossover includes a new genetic diversity measure that has low computational cost. This operator is presented along with the resolution of a set of optimisation problems, including neural network training. The results are compared to other optimisation approaches as gradient descent methods or binary and real-coded genetic algorithms using different crossover operators. These tests show that the properties exhibited by the proposed operator when using real-coded genetic algorithms give higher convergence speed and less probability of being trapped in a local optimum.     

一种求解全局优化问题的新混合遗传算法

把简化的二次插值法融入实数编码遗传算法,构成适于求解全局优化问题的混合遗传算法,该混合算法可以较好解决遗传算法的早熟收敛问题,提高了收敛速度,改善了解的质量,并减少了计算量.由于该混合遗传算法对目标函数的性质没有要求,适合求解大规模问题和工程实际问题.通过对23个标准测试函数的仿真实验,并和已有算法的比较,结果表明本文提出的混合遗传算法是非常有效的.     

具有年龄结构的遗传算法

该文提出了一种基于年龄结构的遗传算法。标准遗传算法(SGA)已经被成功地应用到很多进化优化问题上，但是对于复杂的多模态函数寻优时，会出现早熟收敛现象。为了解决这个问题，该文结合自然规律和遗传算法的特点，提出了具有年龄结构的遗传算法的框架以及实现。通过对不同年龄个体的不同操作，克服了早熟收敛问题且保持了群体的多样性，使算法能顺利地收敛到全局最优值。     

具有年龄结构的遗传算法

结合自然规律以及遗传算法的特点,提出了具有年龄结构的遗传算法的框架以及实现。该算法能够通过对个体基因不同年龄的不同操作,克服遗传算法中存在的主要问题即过早收敛问题。该算法有效地保持群体的多样性,使遗传算法顺利地收敛到全局最优值。通过实际的例子说明,这种方法克服过早收敛问题并且相对于简单遗传算法提高了收敛速度。     

并行混合免疫遗传算法及其应用

以并行遗传算法(PGA)为基础,对其早熟、收敛慢等缺陷加以改进,提出一种并行混合免疫遗传算法(PHIGA)。该算法将免疫原理引入到遗传算法中,提高了算法的整体性能。这主要表现在一方面免疫选择可有效地防止早熟,另一方面基于免疫记忆的子群体信息交换策略可加速收敛。算法采用混沌初始化和基于自适应交叉、变异的多种群搜索,与单纯形法的混合可更好地改善其局部搜索性能。文中布局问题的算例验证了该算法的可行性和有效性。     

基于多LCS和人工势场法的机器人行为控制

基于遗传算法的早熟收敛、局部最优解、占据较大的存储空间等缺陷,提出了一种基于多LCS和人工势场法的机器人行为控制方法,设计了特殊的适应度函数。不同算法的仿真实验结果表明多LCS和人工势场法相结合用于机器人行为控制是收敛的,很大程度上改善了遗传算法的早熟收敛和收敛速度慢等问题。     

基于迁移策略的分布式遗传算法多用户检测器

针对简单遗传算法多用户检测器的收敛速度慢和“早熟”问题,利用解相关算法的抗多址干扰能力和分布式遗传算法的快速全局寻优优势,提出了一种基于迁移策略的分布式遗传算法解相关多用户检测器。计算机仿真结果表明:该多用户检测器的检测性能明显优于简单遗传算法多用户检测器和解相关多用户检测器,更易于实现。     

A multi-crossover and adaptive island based population algorithm for solving routing problems

We propose a multi-crossover and adaptive island based population algorithm （MAIPA）. This technique divides the entire population into subpopulations, or demes, each with a different crossover function, which can be switched according to the efficiency. In addition, MAIPA reverses the philosophy of conventional genetic algorithms. It gives priority to the autonomous improvement of the individuals （at the mutation phase）, and introduces dynamism in the crossover probability. Each subpopulation begins with a very low value of crossover probability, and then varies with the change of the current generation number and the search performance on recent generations. This mechanism helps prevent premature convergence. In this research, the effec- tiveness of this technique is tested using three well-known routing problems, i.e., the traveling salesman problem （TSP）, capaci- tated vehicle routing problem （CVRP）, and vehicle routing problem with backhauls （VRPB）. MAIPA proves to be better than a traditional island based genetic algorithm for all these three problems.     

网格计算资源调度算法研究

如何将网格这个复杂环境中的资源进行有效调度，是一个NP问题。并行遗传算法被证明是解决这类问题的有效算法，同时并行遗传算法有“早熟”和慢速收敛等缺点。为了克服其缺点，该文引进蚁群算法思想，将两个算法结合起来，充分发挥各自的优势，该算法能更有效地解决网格计算资源分配的问题。     

混合模式搜索的分布式memetic差分进化算法

针对差分进化（DE）算法存在的早熟收敛与搜索停滞的问题,提出memetic分布式差分进化（DDE）算法。将memetic算法的思想融入到差分进化算法中,采用分布式的种群结构以及memetic算法中的混合策略,前者将初始种群分为多个子种群,子种群间根据冯·诺依曼拓扑结构周期性地实现信息交流,后者将差分进化算法作为进化的主要框架,模式搜索作为辅助手段,从而平衡算法的探索与开发能力。所提算法充分利用了模式搜索和差分进化算法的优势,建立了有效的搜索机制,增强了算法摆脱局部最优的能力,能够满足搜索过程对种群多样性及收敛速度的需求。将所提算法与几种先进的差分进化算法相比较,对标准测试函数进行优化的实验结果显示：所提算法在解的质量和收敛性能方面,均优于其他几种相比较的先进的差分进化算法。     

求解全局优化问题的混合智能算法

把序列二次规划作为遗传算法的一个局部搜索算子,嵌入到实数编码遗传算法中,构成一种基于序列二次规划和实数编码遗传算法的高效的混合智能算法。该方法充分利用序列二次规划法的强局部搜索能力和遗传算法的全局收敛性,使得混合算法的全局收敛性得到改善并且减少了计算量。数值实验结果表明,混合算法是高效可靠的。     

基于网格和Hamming距离的伪并行遗传算法

为了克服简单遗传算法“早熟”现象及慢速收敛性,提出基于网格和Hamming距离的伪并行遗传算法,即用随机选取的决策变量把整个搜索空间网格划分,在每个网格内用基于Hamming距离的随机化方法初始化子种群,同时引入多遗传算予和无约束移民策略和替换策略。该算法在一定程度上克服了引发算法早熟的“超级个体”和“封闭竞争”问题。测试实例说明,相比其他遗传算法,该算法更有效地抑制了“早熟”现象,其运行速度和精度也得到了相应的提高。     

Real-coded memetic algorithms with crossover hill-climbing

This paper presents a real-coded memetic algorithm that applies a crossover hill-climbing to solutions produced by the genetic operators. On the one hand, the memetic algorithm provides global search (reliability) by means of the promotion of high levels of population diversity. On the other, the crossover hill-climbing exploits the self-adaptive capacity of real-parameter crossover operators with the aim of producing an effective local tuning on the solutions (accuracy). An important aspect of the memetic algorithm proposed is that it adaptively assigns different local search probabilities to individuals. It was observed that the algorithm adjusts the global/local search balance according to the particularities of each problem instance. Experimental results show that, for a wide range of problems, the method we propose here consistently outperforms other real-coded memetic algorithms which appeared in the literature.     

粒子群优化算法的改进研究

本文针对粒子群优化算法(PSO)存在早熟收敛的问题,提出了一系列改进措施,分别将混沌理论、遗传算法和免疫算法应用到PSO算法中。计算机仿真实验表明:改进算法基本保持了PSO算法简单、易实现的特点,且能够有效避免算法的早熟收敛问题,具有很强的全局搜索能力。     

Comparing performances of backpropagation and genetic algorithms in the data classification

Artificial neural networks (ANN) have a wide ranging usage area in the data classification problems. Backpropagation algorithm is classical technique used in the training of the artificial neural networks. Since this algorithm has many disadvantages, the training of the neural networks has been implemented with the binary and real-coded genetic algorithms. These algorithms can be used for the solutions of the classification problems. The real-coded genetic algorithm has been compared with other training methods in the few works. It is known that the comparison of the approaches is as important as proposing a new classification approach. For this reason, in this study, a large-scale comparison of performances of the neural network training methods is examined on the data classification datasets. The experimental comparison contains different real classification data taken from the literature and a simulation study. A comparative analysis on the real data sets and simulation data shows that the real-coded genetic algorithm may offer efficient alternative to traditional training methods for the classification problem.     

用改进的遗传算法设计交换式工业以太网拓扑

本文提出了使用改进的遗传算法来优化和设计工业控制网络的具体方法。针对交换式工业以太网的冗余拓扑结构和数据通信特点，将网络拓扑设计问题等价为一个多目标优化问题，即一方面要减少子网间通信量，同时需要平衡各个子网的通信负荷；此外，交换机物理条件的限制也为该优化问题设置了约束条件。在设计具体的遗传算法时，从编码
码方案、交叉概率和变异概率等三个方面进行改进，克服了基本遗传算法全局搜索能力较差、容易导致局部最优，以及收敛速度和全局收敛性存在矛盾等缺点。最后，仿真结果验证了该改进算法的有效性。     

改进算子的遗传算法在QoS多播路由优化上的应用

针对QoS多播路由问题提出了一种改进遗传算子的遗传算法,通过设计多样性维持机制的选择算子、与代数相关的交叉算子和与个体适应度相关的变异算子,有效地解决了传统遗传算法应用于多播路由优化时的早熟收敛问题。实验结果显示,在随机网络中,该算法所获得的解与最优解的相对误差不超过1．0％,算法的收敛速度和寻优能力明显优于传统遗传算法。     

Spin-flip symmetry and synchronization

In the context of optimization by evolutionary algorithms (EAs), epistasis, deception, and scaling are well-known examples of problem difficulty characteristics. The presence of one such characteristic in the representation of a search problem indicates a certain type of difficulty the EA is to encounter during its search for globally optimal configurations. In this paper, we claim that the occurrence of symmetry in the representation is another problem difficulty characteristic and discuss one particular form, spin-flip symmetry, characterized by fitness invariant permutations on the alphabet. Its usual effect on unspecialized EAs, premature convergence due to synchronization problems, is discussed in detail. We discuss five different ways to specialize EAs to cope with the symmetry: adapting the genetic operators, changing the fitness function, using a niching technique, using a distributed EA, and attaching a highly redundant genotype-phenotype mapping.