混合粒子群和改进细菌觅食的不平衡数据分类

针对细菌觅食优化（Bacterial Foraging Optimization,BFO）算法易陷入局部最优的缺点,提出了混合粒子群优化（Particle Swarm Optimization,PSO）算法与改进的细菌觅食优化（Improved BFO）算法应用于不平衡数据的分类。使用三个数据集测试所提算法的性能,其一是卵巢癌微阵列真实数据,另两个来自UCI数据库的垃圾电子邮件数据最优集和动物园数据集。采用边界合成少数过采样技术（Borderline-SMOTE）和Tomek Link对不平衡数据进行预处理,利用所提算法对不平衡数据进行分类。在改进细菌觅食优化算法的过程中,对趋化过程进行改进,采用粒子群优化算法先进行搜索,将粒子作为细菌进行处理,提高了细菌觅食优化的全局搜索能力。改进复制操作过程,提高优胜劣汰的选择标准。改进迁徙操作过程,防止种群陷入局部最优,防止进化停滞。仿真结果表明,所提算法分类准确度优于现有方法。     

动态高斯变异和随机变异融合的自适应细菌觅食优化算法

针对细菌觅食优化(Bacterial Foraging Optimization,BFO)算法在高维函数优化上性能较差和普适性不强的问题,提出一种动态高斯变异和随机变异融合的自适应细菌觅食优化算法.首先,将原随机迁徙方案修改为动态高斯变异与随机变异融合的迁徙方法,即搜索前期利用随机迁徙有利于增加解的多样性,获得全局最优解,搜索后期改用动态的高斯变异来提高算法的收敛速度;然后,对趋化操作中的步长参数使用动态调整和自适应调整来增强算法的普适性;最后,构建全局极值感应机制使优化更有效,从而获得了一种高性能的自适应BFO算法,以便能够高效解决高维函数的优化问题.14个高维函数优化的仿真结果表明,提出的算法不仅优化效果好、普适性强,而且能以更快的速度找到全局最优解,性能优于SBFO、POLBBO、BFAVP和RABC算法.     

基于细菌觅食行为的多目标分布估计算法*

为增强多目标分布估计算法(MEDA)的局部搜索能力,将细菌的觅食(BF)行为引入到多目标分布估计算法中,提出一种基于细菌觅食行为的多目标分布估计算法(MEDA-BF)。数值实验选取四个常用测试函数,并与NSGA-II、MEDA两个多目标算法进行比较,结果表明MEDA-BF算法在收敛性和多样性两方面都有较好的性能。     

Development of bacteria foraging optimization algorithm for cell formation in cellular manufacturing system considering cell load variations

The cellular manufacturing system (CMS) is considered as an efficient production strategy for batch type production. The CMS relies on the principle of grouping machines into machine cells and grouping machine parts into part families on the basis of pertinent similarity measures. The bacteria foraging optimization (BFO) algorithm is a modern evolutionary computation technique derived from the social foraging behavior of Escherichia coli bacteria. Ever since Kevin M. Passino invented the BFO, one of the main challenges has been the employment of the algorithm to problem areas other than those of which the algorithm was proposed. This paper investigates the first applications of this emerging novel optimization algorithm to the cell formation (CF) problem. In addition, for this purpose matrix-based bacteria foraging optimization algorithm traced constraints handling (MBATCH) is developed. In this paper, an attempt is made to solve the cell formation problem while considering cell load variations and a number of exceptional elements. The BFO algorithm is used to create machine cells and part families. The performance of the proposed algorithm is compared with a number of algorithms that are most commonly used and reported in the corresponding scientific literature such as K-means clustering, the C-link clustering and genetic algorithm using a well-known performance measure that combined cell load variations and a number of exceptional elements. The results lie in favor of better performance of the proposed algorithm.     

A novel bacterial foraging optimization algorithm for feature selection

Bacterial foraging optimization (BFO) algorithm is a new swarming intelligent method, which has a satisfactory performance in solving the continuous optimization problem based on the chemotaxis, swarming, reproduction and elimination-dispersal steps. However, BFO algorithm is rarely used to deal with feature selection problem. In this paper, we propose two novel BFO algorithms, which are named as adaptive chemotaxis bacterial foraging optimization algorithm (ACBFO) and improved swarming and elimination-dispersal bacterial foraging optimization algorithm (ISEDBFO) respectively. Two improvements are presented in ACBFO. On the one hand, in order to solve the discrete problem, data structure of each bacterium is redefined to establish the mapping relationship between the bacterium and the feature subset. On the other hand, an adaptive method for evaluating the importance of features is designed. Therefore the primary features in feature subset are preserved. ISEDBFO is proposed based on ACBFO. ISEDBFO algorithm also includes two modifications. First, with the aim of describing the nature of cell to cell attraction-repulsion relationship more accurately, swarming representation is improved by means of introducing the hyperbolic tangent function. Second, in order to retain the primary features of eliminated bacteria, roulette technique is applied to the elimination-dispersal phase.In this study, ACBFO and ISEDBFO are tested with 10 public data sets of UCI. The performance of the proposed methods is compared with particle swarm optimization based, genetic algorithm based, simulated annealing based, ant lion optimization based, binary bat algorithm based and cuckoo search based approaches. The experimental results demonstrate that the average classification accuracy of the proposed algorithms is nearly 3 percentage points higher than other tested methods. Furthermore, the improved algorithms reduce the length of the feature subset by almost 3 in comparison to other methods. In addition, the modified methods achieve excellent performance on wilcoxon signed-rank test and sensitivity-specificity test. In conclusion, the novel BFO algorithms can provide important support for the expert and intelligent systems.     

基于旋转基技术的多目标粒子群优化算法

为了解决多目标优化求解的问题,提出一种基于旋转基技术的多目标粒子群优化算法（rtMOPSO）。改进了旋转基可视化技术,并将Pareto前沿映射到改进的旋转基扇形平面上,采用差熵指标监测种群进化状态。为平衡归档集的收敛性和多样性,提出了角度支配和角度支配力度两种新的概念,并设计归档集新的排序方法。在融合了旋转基角度和距离的概念的基础上,提出了一种改进的全局引导粒子的选择策略。改进算法采用两个类别的测试函数,与五种多目标优化算法进行了对比实验。实验结果表明,改进算法在收敛性和多样性方面优势明显。     

基于Levy飞行的改进菌群觅食算法

针对经典菌群觅食算法因固定趋化步长导致的求解精度不高、收敛性能差等缺陷,提出一种基于Levy飞行的菌群觅食算法,其特点是利用基于Levy分布的趋化步长改善算法的求解精度与收敛性能,借助Levy飞行随机游走策略改善细菌迁徙位置.多个基准测试函数的实验结果表明,该算法在求解质量和收敛性能上均取得了较好的改进效果.     

基于改进PSO算法的移动机器人路径规划

针对粒子群优化(PSO)算法收敛速度快但容易陷入局部极值和细菌觅食优化(BFO)算法全局搜索能力强但效率低的问题,提出了一种将BFO算法的趋化、迁徙和复制操作引入到粒子群搜索过程的具有全局搜索能力和快速收敛的混合算法.在BFO算法和PSO算法的原理、操作步骤基础上,分别使用了PSO算法、BFO法和混合算法对移动机器人进行全局路径规划仿真试验,并分别给出了各算法的迭代次数、适应值曲线.仿真结果表明:与PSO算法和BFO算法相比,所提出的混合算法具有搜索时间短、迭代次数少的优点,较好验证了混合算法在移动机器人路径规划方面的可行性和有效性.     

改进的菌群算法研究

为了提高菌群寻优算法（ Bacterial Foraging Optimization, BFO）的搜索能力和解决多峰值复杂适应度函数模型避免过早收敛的问题,文中对原始菌群算法进行改进,提出多峰值菌群算法。将寻优过程分成两个时期,前期和原始菌群算法相同,在菌群收敛的后期,加入峰值数目和区间的判断,将区间编号,保证区间内部单峰值;然后在区间内部迭代运行菌群搜索,独立寻优,在多峰值和较复杂模型的情况下进行研究和评估。实验表明,在收敛速度、收敛稳定性和寻找全局最优方面均优于原始菌群算法。     

基于多策略的多目标粒子群优化算法

针对目前多目标粒子群优化算法的收敛性能和非劣解的多样性不能同时得到满足等缺陷,提出一种基于多策略的多目标粒子群优化算法（Multi-Objective Particle Swarm Optimization algorithm for Multi-Strategy,MS-MOPSO）。采用非支配排序和拥挤距离排序相结合策略,重新划分外部种群和进化种群;采用小生境选择策略,在外部种群中选择最佳粒子作为领导粒子,用于领导进化种群中粒子的进化;在进化种群中利用多尺度高斯变异策略,平衡算法的全局搜索和局部精确搜索;采用邻域认知个体极值更新策略,不断更新个体极值。将该算法应用到典型的多目标测试函数,并与其他多目标优化算法进行对比分析,测试结果表明该算法中四个策略的有效性和互补性,同时验证了该算法不但具有较好的收敛性和收敛速度,而且该算法最优解的分布具有良好的均匀性和多样性。     

A clustering-ranking method for many-objective optimization

In evolutionary multi-objective optimization, balancing convergence and diversity remains a challenge and especially for many-objective (three or more objectives) optimization problems (MaOPs). To improve convergence and diversity for MaOPs, we propose a new approach: clustering-ranking evolutionary algorithm (crEA), where the two procedures (clustering and ranking) are implemented sequentially. Clustering incorporates the recently proposed non-dominated sorting genetic algorithm III (NSGA-III), using a series of reference lines as the cluster centroid. The solutions are ranked according to the fitness value, which is considered to be the degree of closeness to the true Pareto front. An environmental selection operation is performed on every cluster to promote both convergence and diversity. The proposed algorithm has been tested extensively on nine widely used benchmark problems from the walking fish group (WFG) as well as combinatorial travelling salesman problem (TSP). An extensive comparison with six state-of-the-art algorithms indicates that the proposed crEA is capable of finding a better approximated and distributed solution set.     

目标空间映射策略的高维多目标粒子群优化算法

为了平衡优化算法在高维多目标优化问题中收敛性和多样性之间的关系,增加算法的选择压力,本文提出了一种基于目标空间映射策略的高维多目标粒子群优化算法(many-objective particle swarm optimization algorithm based on objective space mapping strategy,MOPSO-OSM)。在求解高维多目标优化问题时,Pareto准则难以从众多的非支配解中确定最优“折中”解,因此将高维多目标空间映射为以收敛性和多样性评价指标的2维空间,再将上述2维空间根据性能指标的优劣划分为4个不同区域。同时,使用反向学习策略提高算法跳出局部最优的能力。实验表明,MOPSO-OSM算法可以有效平衡收敛性和多样性之间的关系,达到求解复杂多目标优化问题的目的。     

双局部粒子群算法解决环境经济调度问题

提出一种基于双局部最优的多目标粒子群优化算法,与可行解为优的约束处理方法相结合,来求解决非线性带约束的多目标电力系统环境经济调度问题。该算法针对传统多目标粒子群算法多样性低的局限性,通过对搜索空间的分割归类来增加帕累托最优解的多样性;并采用一种新的双局部最优来引导粒子的搜索,从而增强了算法的全局搜索能力。算法加入了可行解为优的约束处理方法对IEEE30节点六发电机电力系统环境经济负荷分配模型分别在几个不同复杂性问题的情况进行仿真测试,并与文献中的其他算法进行了比较。结果表明,改进的算法能够在保持帕累托最优解多样性的同时具有良好的收敛性能,更有效地解决电力系统环境经济调度问题。     

Automated design space exploration of multi-cycle transient fault detectable datapath based on multi-objective user constraints for application specific computing

A novel automated design space exploration (DSE) approach of multi-cycle transient fault detectable datapath based on multi-objective user constraints (power and delay) for application specific computing is presented in this paper. To the best of the authors’ knowledge, this is the first work in the literature to solve this problem. The presented approach, driven by bacterial foraging optimization (BFO) algorithm provides easy flexibility to change direction in the design space through tumble/swim actions if a search path is found ineffective. The approach is highly capable of reaching true Pareto optimal curve indicated by the closeness of our non-dominated solutions to the true Pareto front and their uniform distribution over the Pareto curve (implying diversity). The contributions of this paper are as follows: (a) novel exploration approach for generating a high quality fault detectable structure based on user provided requirements of power-delay, which is capable of transient error detection in the datapath; (b) novel fault detectable algorithm for handling single and multi-cycle transient faults.The results of the proposed approach indicated an average improvement in Quality of Results (QoR) of >9% and reduction in hardware usage of >23% compared to recent approaches that are closer in solving a similar objective.     

基于进化聚类的动态网络社团发现

社团的数目和时间平滑性的平衡因子一直是基于进化聚类的动态网络社团发现算法的最大的问题.提出一种基于标签的多目标优化的动态网络社团发现算法（LDMGA）.借鉴多目标遗传算法思想,将进化聚类思想转换为多目标遗传算法优化问题,保证当前时刻的聚类质量的同时,又能使当前聚类结果与前一个时刻网络结构保持一致.该算法在初始化过程加入标签传播算法,增加初始个体的聚类质量.提出基于标签的变异算法,增强了算法的聚类效果和算法的收敛速度.同时,多目标遗传算法和标签算法的结合使算法可扩展性强,运行时间随着节点或者边数目增加呈线性增长.将该算法与目前优秀算法在仿真数据集和真实数据集上进行对比实验,结果表明,该算法既有良好的聚类效果,又有良好的扩展性.     

基于混合生物地理学优化的聚类算法

聚类分析是数据挖掘的重要任务之一,而具有易早熟与收敛速度慢等缺陷的传统生物地理优化算法(Biogeography-Based Optimization, BBO)很难满足具有NP(Non-deterministic Polynomial)性质的复杂聚类问题需求,于是提出了一种基于混合生物地理学优化的聚类算法(Mixed Biogeography-Based Optimization, MBBO),该算法构造了一个基于梯度下降局部最优贪心搜索的新迁移算子,以聚类目标函数值作为个体适应度进行数据集内隐簇结构寻优。通过在4个标准数据集(Iris、Wine、Glass与Diabetes)的实验,结果表明MBBO算法相对于传统的优化算法具有更好的优化能力和收敛度,能发现更高质量的簇结构模式。     

Modified bacterial foraging algorithm based multilevel thresholding for image segmentation

Multilevel thresholding is one of the most popular image segmentation techniques. In order to determine the thresholds, most methods use the histogram of the image. This paper proposes multilevel thresholding for histogram-based image segmentation using modified bacterial foraging (MBF) algorithm. To improve the global searching ability and convergence speed of the bacterial foraging algorithm, the best bacteria among all the chemotactic steps are passed to the subsequent generations. The optimal thresholds are found by maximizing Kapur's (entropy criterion) and Otsu's (between-class variance) thresholding functions using MBF algorithm. The superiority of the proposed algorithm is demonstrated by considering fourteen benchmark images and compared with other existing approaches namely bacterial foraging (BF) algorithm, particle swarm optimization algorithm (PSO) and genetic algorithm (GA). The findings affirmed the robustness, fast convergence and proficiency of the proposed MBF over other existing techniques. Experimental results show that the Otsu based optimization method converges quickly as compared with Kapur's method.     

基于改进粒子群优化的无标记数据鲁棒聚类算法

已有的聚类算法大多仅考虑单一的目标,导致对某些形状的数据集性能较弱,对此提出一种基于改进粒子群优化的无标记数据鲁棒聚类算法。优化阶段:首先,采用多目标粒子群优化的经典形式生成聚类解集合;然后,使用K-means算法生成随机分布的初始化种群,并为其分配随机初始化的速度;最终,采用MaxiMin策略确定帕累托最优解。决策阶段：测量帕累托解集与理想解的距离,将距离最短的帕累托解作为最终聚类解。对比实验结果表明,本算法对不同形状的数据集均可获得较优的类簇数量,对目标问题的复杂度具有较好的鲁棒性。     

基于多层次信息交互的多目标粒子群优化算法

为提高多目标优化算法的收敛性和多样性,提出一种基于多层次信息交互的多目标粒子群优化算法.在该算法中,整个优化过程可分为标准粒子群优化层、粒子进化与学习层和档案信息交换层3个层次.粒子进化与学习层保证了每次迭代都能得到更好的粒子位置;档案信息交换层可以提供更好的全局最优.优化算法各个层次之间通过信息交互,共同提高算法的收敛性和多样性.与NSGA-Ⅱ和MOPSO算法的对比分析表明,所提出算法具有良好的性能,能够有效解决多目标优化问题.     

均衡分布性和收敛性的多目标粒子群优化方法

粒子群优化（PSO）算法是一种基于群体演化且非常有效的求解多目标优化问题的方法,但因经典算法中粒子进化存在趋同性导致算法易陷入局部Pareto最优前沿,使得解集收敛性和分布性不理想。为此提出了一种均衡分布性和收敛性的多目标粒子群优化（DWMOPSO）算法,算法中每个粒子根据自身在进化过程中记忆的个体最好适应度值构建进化速度,由进化速度的快慢动态调整各粒子惯性权重,增加粒子的多样性,从而提高粒子跳出局部最优解的概率。通过在5个标准测试函数上进行仿真实验,结果表明,与Coello的多目标粒子群优化(MOPSO)算法相比,DWMOPSO算法获得的解集在与真实解集的逼近性和解集的分布性两个方面都有了很大的提高。