基于混合变异策略的动态差分演化算法

为提高差分演化算法的收敛速度和求解精度,提出了一种基于混合变异策略和参数自适应调整的动态差分演化算法,该算法首先选用3种变异策略作为候选池,通过记录各策略的历史效果来设置其候选概率,每个个体采用轮盘赌的机制从候选池中选取一个变异策略进行变异,在选择时采用动态机制让变异交叉产生的优秀试验个体直接替换目标个体来提高算法的收敛速度,算法的变异算子F、交叉算子CR根据进化中的反馈信息自适应动态调整。利用13个不同类型的经典测试函数进行实验,结果表明算法在收敛速度和求解精度上具有比较好的优势。     

基于混合变异策略的改进差分进化算法及函数优化

针对差分进化算法DE 传统变异策略不能有效平衡全局搜索和局部搜索,并且算 子固定,导致算法早收敛、搜索效率较低。基于DE 变异策略性能,提出一种混合变异策略, 力图平衡算法探索和开发能力,使得前期增强全局搜索,保持种群多样性; 后期偏重局部搜 索,尽快收敛到全局最优值。同时操作算子采用随机正态缩放因子F 和时变交叉概率因子CＲ, 进一步改善算法性能。几个典型Benchmarks 测试函数实验表明: 该改进型差分进化算法能有 效避免早收敛,较好地提高算法的全局收敛能力和搜索效率。     

差分进化算法的交叉概率因子递增策略研究

为了有效地控制差分进化算法的全局搜索和局部搜索,基于递增交叉概率因子的基本思想,在已有的自适应二次变异差分进化算法的基础上,提出了开口向下抛物线、开口向上抛物线和指数曲线3种非线性的交叉概率因子递增策略,并用4种经典函数对它进行测试。测试结果表明,对于多数连续优化问题,在初始参数相同的情况下,凹函数递增策略优于线性策略,而线性优于凸函数策略。凹函数递增策略能够在不影响收敛精度的情况下较大幅度地提高差分进化算法的收敛速度。     

基于t分布变异的自适应差分进化算法

为了更好地提高差分进化算法的全局探索和局部开发能力,提出了一种改进的差分进化算法。在该算法中,引入t分布变异算子将高斯变异和柯西变异的优点结合起来,根据以往的进化经验自适应地调整进化策略及交叉概率。通过四个典型的Benchmarks函数的测试结果表明算法具有良好的性能。     

基于锦标赛选择变异策略的改进差分进化算法及函数优化

针对差分进化算法传统变异策略在全局收敛鲁棒性和搜索效率上不能达到一个很好的折衷,并且算法的操作算子固定,导致搜索效率低、易早熟收敛等问题,文中在差分进化算法变异策略性能分析的基础上,提出了一种基于锦标赛选择的变异策略。该策略采用“锦标赛选择”对随机选取的变异向量排序选出基向量,差分向量选择有利于搜索的方向并对其 “强化”,以提高收敛速率和维持种群多样性;同时操作算子采用随机正态缩放因子F和时变交叉概率因子CR,以平衡局部搜索和全局搜索;最后,利用4个典型Benchmarks测试函数对改进算法进行测试。实验结果表明,该改进型差分进化算法能有效避免早熟收敛,较好地提高算法的全局收敛能力和搜索效率。     

改进差分进化PID参数优化及在凝絮中的应用

针对标准差分进化（DE）收敛速度慢和操作过程中参数为常数从而导致算法鲁棒性相对较差的缺点,采用以个体适应度值最优的个体为基矢量,沿次优个体方向搜索的变异策略来提高算法的搜索速度;提出根据差分矢量大小和个体收敛情况自适应调整变异参数F和交叉概率CR的自适应参数调整策略来确保搜索初期种群的多样性和后期算法的局部搜索能力。并将基于该改进差分进化算法（MDE）优化后的PID控制器用于水厂加药凝絮过程的控制,仿真结果表明该算法收敛速度快,基于该算法的MDE-PID控制器性能好,是PID控制器参数整定的有效搜索方法,也是实现水厂加药凝絮过程良好控制的有效途径。     

基于Laplace分布变异的改进差分进化算法

为了提高差分进化算法(DEA)的收敛速度和寻优精度,提出了一种改进的差分进化算法。在该算法中,引入了基于Laplace分布的变异算子,并且能根据以往的进化经验自适应地调整进化策略及交叉概率以适应不同阶段的进化。通过5个典型Benchmark函数的测试结果表明,该算法的收敛速度快、求解精度高、鲁棒性较强,适合求解高维复杂的全局优化问题。     

精英化岛屿种群引导的差分进化算法

针对差分进化算法常见的早熟收敛、搜索停滞和求解精度低的问题,研究一种精英化岛屿种群的差分进化算法（EIDE）。为了实现全局搜索与局部搜索能力并重,EIDE划分多个岛屿种群,根据迭代时的适应度情况,动态地将岛屿种群分类为精英岛屿和普通岛屿;针对精英岛屿,提出一种控制参数自适应方法,依据岛屿适应度情况,自适应地调整变异概率与交叉概率,同时算法利用增强局部搜索的变异策略,提高收敛速度与精度;针对普通岛屿,使用适合全局搜索的变异与交叉概率及变异策略,维护种群多样性。EIDE提出了一种可控的“移民”与“个体迁移”策略,控制优质基因流动,有效避免早熟收敛与搜索停滞问题。在9个benchmark函数上的测试结果表明,新算法具有较强的全局寻优能力与稳定性,且收敛速度较快。     

基于反射变异策略的自适应差分进化算法

针对差分进化算法易于陷入早熟收敛和局部搜索较慢的问题,提出了一种类似Nelder-Mead方法中的反射操作的变异策略,称为反射变异策略。不同于其他基本的差分策略,提出的变异策略具有明确的差分方向,具有更快的局部收敛速度。为了避免因差分方向的贪婪性而导致算法早熟的可能性增加,反射变异策略使用4个随机的个体完成一次变异操作。将基于反射变异策略的子代生成策略和自适应参数方法组合形成了基于反射变异策略的自适应差分进化算法（RMADE）。使用12个函数测试了RMADE的性能并与其他算法进行比较,结果表明RMADE具有较快的收敛速度和较好的全局探测能力,进而体现了反射变异策略的价值。     

采用差分进化策略的入侵杂草改进算法及函数优化应用

针对入侵杂草优化算法易出现早熟且收敛速度较慢的问题,提出一种具有差分进化策略的入侵杂草算法。利用差分进化策略较强的开发能力,对种子进行交叉变异选择操作以帮助算法跳出局部最优;同时,为了提高算法的收敛速度和种群多样性,提出对杂草进行初始化并采用基于混沌反向学习的初始化方法。对8个标准测试函数进行的仿真实验表明:与标准杂草优化、差分进化及混合杂草优化算法相比,提出的改进算法具有较快的收敛速度、较高的收敛精度及较强的搜索全局最优解的能力。     

一种自适应差分演化算法

差分演化算法是一类基于种群的启发式全局搜索技术,对于实值参数的优化具有很强的鲁棒性。为了提高差分演化算法的寻优速度、克服启发式算法常见的早熟收敛问题,提出了一种自适应的方法来调整控制参数。实验表明,算法的收敛速度和寻优能力得到很大的提高。     

求解函数优化的新型差异演化算法*

针对差异演化算法存在早熟收敛和后期求解效率低的缺点,提出一种新型差异演化算法。该算法基于单种群,在演化过程中直接对当前种群进行变异、交叉和选择操作,无须差异演化算法中的中间过渡种群。此外,新型差异演化算法的变异与交叉概率是时变的,其中变异概率随着迭代次数的增加而减小;交叉概率随着迭代次数的增加而增加。对几个典型的测试函数进行仿真实验表明,该算法能够有效避免早熟收敛,改善了差异演化算法的优化性能。     

基于交叉变异策略的双种群差分进化算法

为加强差分进化算法的全局搜索能力,提出了一种基于交叉变异策略的双种群差分进化算法（CMDPDE）。CMDPDE中,两个种群分别采用大小不同的缩放因子和交叉因子,在每代进化完毕后,对其中缩放因子和交叉因子较小的种群执行交叉或变异策略来寻找更优的个体,同时两个种群之间每10代进行一次信息交流。这种方式与单种群差分进化算法相比,可以通过双种群和交叉变异策略来增加解的多样性,使算法能在更大的范围内寻优。6个Benchmark函数的实验结果证明CMDPDE具有较好的寻优能力。     

Self-adapting control parameters modified differential evolution for trajectory planning of manipulators

Control parameters of original differential evolution （DE） are kept fixed throughout the entire evolutionary process. However, it is not an easy task to properly set control parameters in DE for different optiinization problems. According to the relative position of two different individual vectors selected to generate a difference vector in the searching place, a self-adapting strategy for the scale factor F of the difference vector is proposed. In terms of the convergence status of the target vector in the current population, a self-adapting crossover probability constant CR strategy is proposed. Therefore, good target vectors have a lower CFI while worse target vectors have a large CFI. At the same time, the mutation operator is modified to improve the convergence speed. The performance of these proposed approaches are studied with the use of some benchmark problems and applied to the trajectory planning of a three-joint redundant manipulator. Finally, the experiment results show that the proposed approaches can greatly improve robustness and convergence speed.     

Self-adapting control parameters modified differential evolution for trajectory planning of manipulators

Control parameters of original differential evolution (DE) are kept fixed throughout the entire evolutionary process. However, it is not an easy task to properly set control parameters in DE for different optimization problems. According to the relative position of two different individual vectors selected to generate a difference vector in the searching place, a self-adapting strategy for the scale factor F of the difference vector is proposed. In terms of the convergence status of the target vector in the current population, a self-adapting crossover probability constant strategy is proposed. Therefore, good target vectors have a lower while worse target vectors have a large . At the same time, the mutation operator is modified to improve the convergence speed. The performance of these proposed approaches are studied with the use of some benchmark problems and applied to the trajectory planning of a three-joint redundant manipulator. Finally, the experiment results show that the proposed approaches can greatly improve robustness and convergence speed.     

An enhanced artificial bee colony algorithm with adaptive differential operators

Artificial bee colony algorithm (ABC) has been shown to be very effective to solve global optimization problems (GOPs). However, ABC performs well in exploration but relatively poorly in exploitation resulting in a slow convergence when it is used to handle complex GOPs. Differential evolution (DE) benefits from its differential operators, namely mutation operator and crossover operator, which could perturb multiple variables simultaneously and has shown a fast convergence speed. In order to improve ABC’s exploitation ability and accelerate its convergence, in this paper, we propose an enhanced ABC algorithm named ABCADE, which remedy the limitation of ABC by exploiting the advantage of differential operators. Particularly, in ABCADE, the employed bees employ differential operators to produce candidate solutions with an increasing probability, and the two important parameters (scale factor F and crossover rate CR) of differential operators are adaptively adjusted through Gaussian distribution. Moreover, to significantly differentiate the good solutions and bad solutions in a population, and put more effort in the exploitation around the good solutions, we design a new selection probability method for onlooker bees. To verify the performance of ABCADE, we compare ABCADE with other representative state-of-the-art ABC and DE algorithms, the comparison results on a set of 22 benchmark functions with various dimension sizes demonstrate that ABCADE obtains superior or comparable performance to other algorithms.     

Variance-based differential evolution algorithm with an optional crossover for data clustering

The differential evolution optimization-based clustering techniques are powerful, robust and more sophisticated than the conventional clustering methods due to their stochastic and heuristic characteristics. Unfortunately, these algorithms suffer from several drawbacks such as the tendency to be trapped or stagnated into local optima and slow convergence rates. These drawbacks are consequences of the difficulty in balancing the exploitation and exploration processes which directly affects the final quality of the clustering solutions. Hence, a variance-based differential evolution algorithm with an optional crossover for data clustering is presented in this paper to further enhance the quality of the clustering solutions along with the convergence speed. The proposed algorithm considers the balance between the exploitation and exploration processes by introducing (i) a single-based solution representation, (ii) a switchable mutation scheme, (iii) a vector-based estimation of the mutation factor, and (iv) an optional crossover strategy. The performance of the proposed algorithm is compared with current state-of-the-art differential evolution-based clustering techniques on 15 benchmark datasets from the UCI repository. The experimental results are also thoroughly evaluated and verified via non-parametric statistical analysis. Based on the obtained experimental results, the proposed algorithm achieves an average enhancement up to 11.98% of classification accuracy and obtains a significant improvement in terms of cluster compactness over the competing algorithms. Moreover, the proposed algorithm outperforms its peers in terms of the convergence speed and provides repeatable clustering results over 50 independent runs.     

基于种群相异度的改进遗传算法及应用

提出了一种基于种群相异度的改进遗传算法。该算法采用了启发式交叉策略，并且能够根据种群的相异度自适应地调节种群的交叉规模、变异规模以及变异个体中各个基因的变异率，从而能够避免种群早熟收敛，加快进化速度。将其应用于PID控制器的参数优化中，并与传统的遗传算法相比较，仿真结果证明了其有效性。