多亲遗传算法的理论分析及其应用研究

多亲遗传算法是在保持了传统遗传算法一些特性的基础上，对传统遗传算法的交叉算子进行了改进。在介绍了多亲遗传算法的基础上，对其进行了理论分析，证明了多亲遗传算法满足Holland的模式定理；提出了一种称为群体中心交叉的多亲交叉算子，最后将这种多亲交叉算子的多亲遗传算法应用到了数据聚类问题中，取得了良好的实验结果。     

一种新的应用于文本特征子集优化的GATS算法

针对文本分类中特征子集优化问题,将禁忌搜索算法引入到遗传算法中对遗传算法的核心算子——交叉算子进行改进形成禁忌交叉算子,改进后的算法称为GATS（遗传禁忌搜索算法）,并将其应用在文本分类中来实现空间降维。实验证明,应用此方法进行文本特征项的选取不仅能够保持GA和TS算法本身的优点,还能在一定程度上提高文本分类的准确率。     

带有约束优化的遗传算法求解TSP*

主要研究用遗传算法解决带有约束的TSP的方法。使用贪婪交叉算子、自适应变异算子和带有精英保留策略的选择算子相结合对基本遗传算法进行了改进,针对实际TSP中的约束条件讨论了罚方法在遗传算法中的应用,提出了自适应的惩罚函数,并将其与改进后的遗传算法相结合,解决了带有时间约束的TSP。通过对实验结果的比较分析,证明了该方法的可行性和有效性。     

基于改进遗传算法的PID参数寻优与控制器设计

相比传统的调节方法,遗传算法具有更好的鲁棒性、最优性,能较好的实现参数的自动化调节。对标准遗传算法（SGA）进行了分析、研究,并在SGA的基础上进行了改进。改进的遗传算法从提高全局搜索性能和加快收敛速度出发,提出了改进的选择算子、交叉算子和变异算子,仿真结果表明,改进的遗传算法的全局搜索性能和收敛速度远远优于标准遗传算法。     

改进遗传算法在自动组卷中的应用研究

为了避免遗传算法在自动组卷中存在的未成熟收敛和收敛速度慢等弱点,根据群体适应值的分布特点,采用了基于小生境的改进自适应遗传算法。该算法采用模拟小生境法选择算子进行种群选取,并对交叉算子和变异算子进行了优化,实现了交叉和变异概率的非线性自适应调整。改进后的算法明显提高了组卷的成功率和收敛速度,取得了满意的组卷效果。     

基于改进遗传算法的小波去噪的阈值优化

根据基因重组原理,定义了新的反向逻辑交叉算子和随机逻辑交叉算子对标准遗传算法进行改进.利用改进的遗传算法求解多尺度小波分解每层系数的最优阈值,通过软阈值法对小渡系数处理后进行小波重构.实验结果表明,利用改进的遗传算法进行小波去噪是可行的,且能够达到较高的信噪比.     

目标分配的遗传算法改进研究

介绍一种目标分配的遗传算法求解方案,在此算法的基础上进行了算法改进。新算法对遗传算法涉及的初始种群、选择算子、交叉算子等进行了优化并结合微粒群算法的思想对遗传算法进行了改进。最后,通过仿真结果验证了改进算法的可行性。     

基于改进的遗传算法的数独谜题求解

针对数独谜题的特点,对遗传算法的选择算子、交叉算子和变异算子进行了大胆的创新性改进,提出了一个能够有效求解数独谜题的改进的遗传算法.模拟实验结果表明,改进后的遗传算法使得数独谜题的求解具有更高的可靠性、更好的稳定性以及更快的收敛速度.     

改进遗传算法在智能组卷系统中的应用

本文将遗传算法加以改进应用于自动组卷：采用自适应性的交叉算子和变异算子;应用模拟小生境技术的选择算子。还设计了具体的实现方法,并进行了测试,结果表明改进的遗传算法具有较高的组卷效率和良好的效果。     

Web服务器集群的负载均衡中遗传算子的设计

应用遗传算法进行作业调度已被越来越多的学者关注。在Web服务器集群环境中,对于客户端的Web请求分配问题,采用常规的遗传算法进行负载均衡并不总是有效的,好的遗传算子对算法收敛性及收敛到最优解非常重要。基于集群环境中Web请求分配的特点,设计了有针对性的遗传算子,即改进的内外结合交叉算子和主动变异算子。模拟实验结果与分析表明这些算子对Web集群的请求分配是有效的。     

单亲遗传算法及其全局收敛性分析

序号编码的遗传算法(GA)不能在两条染色体的任意位置进行交叉,必须使用 PMX,CX和OX等特殊的交叉算子,而这些交叉算子实施起来都很麻烦.针对序号编码GA 的上述不足,提出一种单亲遗传算法(PGA).PGA采用序号编码,不使用交叉算子,而代之以 隐含序号编码GA交叉算子功能的基因换位等遗传算子,简化了遗传操作,并且不要求初始 群体具有多样性,也不存在"早熟收敛"问题.仿真结果验证了这种算法的有效性.     

一种新型混合遗传算法及其应用

针对遗传算法应用的局限性,引入新的种群择优交叉运算、变异运算、遗传边界算子和相互学习过程的思想,提出一种新型混合遗传算法,提高了算法的收敛速度和稳定性,数值算例验证了该算法的有效性和实用性。     

An improved genetic algorithm with conditional genetic operators and its application to set-covering problem

The genetic algorithm (GA) is a popular, biologically inspired optimization method. However, in the GA there is no rule of thumb to design the GA operators and select GA parameters. Instead, trial-and-error has to be applied. In this paper we present an improved genetic algorithm in which crossover and mutation are performed conditionally instead of probability. Because there are no crossover rate and mutation rate to be selected, the proposed improved GA can be more easily applied to a problem than the conventional genetic algorithms. The proposed improved genetic algorithm is applied to solve the set-covering problem. Experimental studies show that the improved GA produces better results over the conventional one and other methods.     

Evolution of Appropriate Crossover and Mutation Operators in a Genetic Process

Traditional genetic algorithms use only one crossover and one mutation operator to generate the next generation. The chosen crossover and mutation operators are critical to the success of genetic algorithms. Different crossover or mutation operators, however, are suitable for different problems, even for different stages of the genetic process in a problem. Determining which crossover and mutation operators should be used is quite difficult and is usually done by trial-and-error. In this paper, a new genetic algorithm, the dynamic genetic algorithm (DGA), is proposed to solve the problem. The dynamic genetic algorithm simultaneously uses more than one crossover and mutation operators to generate the next generation. The crossover and mutation ratios change along with the evaluation results of the respective offspring in the next generation. By this way, we expect that the really good operators will have an increasing effect in the genetic process. Experiments are also made, with results showing the proposed algorithm performs better than the algorithms with a single crossover and a single mutation operator.     

改进梯度算子的小生境遗传算法

为避免小生境遗传算法存在的早熟和收敛速度慢等问题,本文提出了一种改进的梯度算子,以保证进化朝最优解方向前进,提高计算峰值的精度。同时,利用进化代数和个体的适应度值,动态调整个体的交叉算子和变异算子,有效保证种群的多样性,改善全局搜索能力,加快收敛速度。将改进的梯度算子引入到基本小生境遗传算法和自适应小生境遗传算法,通过Shubert函数测试,证明本文改进后的算法与基本小生境遗传算法和自适应小生境遗传算法相比,不仅大大提高了收敛速度,并能搜索到所有全局最优解。     

A study on synergy of multiple crossover operators in a hierarchical genetic algorithm applied to structural optimisation

Development of crossover operators is based on three different mechanisms: mating selection mechanism, offspring generation mechanism and offspring selection mechanism. Most crossover operators are able to get exploration or exploitation of the domain depending on the way they handle the current diversity of the population. Each crossover operator directs the search towards a different region in the neighbourhood of the parents. The quality of the elements belonging to the visited region depends on the particular problem to be solved. This is confirmed by the well known No Free Lunch (NFL) theorems. The simultaneous use of diverse crossover operators on the population may induce more efficient algorithms. The aim of this paper is to analyse and to study complementary properties resulting from synergy effects using several crossover operators in particular for a hierarchical genetic algorithm. The reached improvements using multiple crossover operators will be analysed through some standard optimisation examples of hybrid composite structures.     

A bit-masking oriented data structure for evolutionary operators implementation in genetic algorithms

 In the present paper a special bit-masking oriented data structure for an improved implementation of crossover and mutation operators in genetic algorithms is shown. The developed data structure performs evolutionary operators in two separate steps: crossover and mutation mask fill and a special boolean based function application. Both phases are optimized to reach a more efficient, fast and flexible genetic reproduction than standard implementations. The method has been powered adding a multi-layered, bit-masking oriented data structure and a boolean operation based control mixer, allowing special blended crossover operators obtained by superposition of the standard ones. Several examples of crossover schemes produced by these extended controls are presented. In addition, a special purpose crossover scheme, capable to process at the same time two distinct groups of design variables with separate crossover schemes is shown, in order to improve efficiency and convergence speed of some discrete/continuous optimization problems. Finally, to highlight further capabilities of the bit-masking approach, a special single-step version of an evolutionary direction operator is also illustrated.     

旅行商问题的一种插入交叉算子

求解TSP问题是遗传算法应用的一个重要领域,其本质是TSP问题中巡回路径编码串的组合最优化问题。对于符号编码方式的遗传算法,通常需要设计特定的交叉算子以提高算法的运行效率和性能。该文针对自然数编码的方式,提出了一种较适合于大规模TSP问题求解的遗传交叉算子:插入交叉(InsertCrossover,简称IX)算子。该算子以优良的交叉策略,保证了算法的快速收敛和全局寻优。仿真实验结果证明,IX算子对于大规模TSP问题具有比较好的性能。     

求解TSP的交配算子设计策略

旅行商问题(TSP)是一类典型的NP完全问题,遗传算法(GA)是求解这类问题的常用方法之一.由于该问题的解是一种特殊的序列,一些典型的GA交配方法在求解该问题时的性能并不理想.通过多次对比两种常用的GA交配方法与3种专门为TSP作优化的交配方法,总结了一种对旅行商问题的交配算子的设计策略,即注重对双亲的边继承以及加入适当的贪心控制策略.通过对Gr17、Oliver30、Eil51、Eil76和Krob100等测试数据进行实验,证明了在该策略的指导下改进的两种交配算子具有更好的表现.     

易腐物品车辆路径问题的并行遗传算法

本文采用并行遗传算法研究了易腐物品的车辆路径问题。通过设计粗粒度并行遗传算法和交叉、变异等算子,提高了算法的计算效率和性能。最后,以计算示例验证了算法的有效性。