基于混合粒子群算法的动态鲁棒优化

动态鲁棒优化问题广泛存在于各个领域,且难以求解。动态鲁棒粒子群优化(PSO)算法是一种有效的求解方法。但是,现有算法存在全局搜索能力弱和无法对个体进行综合评价的问题。为有效求解动态鲁棒优化问题,在研究的基础上提出一种混合差分进化的动态鲁棒粒子群(DRPSO-DE)算法。该算法不仅使用差分进化(DE)算法的变异策略提升粒子群算法的全局搜索能力,还提出一种综合指标来对种群个体进行评价。此外,为提高动态鲁棒粒子群算法的搜索效率,采用一种基于排序的选择策略挑选最佳个体,并将它们用于指引种群进化。为验证DRPSO-DE的有效性,选取五个动态标准测试函数对其进行测试。从试验结果来看,所提出算法的整体性能要优于原有算法,能够有效求解动态鲁棒优化问题。     

求解高维多模优化问题的正交小生境自适应差分演化算法

针对传统优化算法在求解高维多模态优化问题时存在收敛速度慢、求解精度低的问题,提出一种基于正交设计与小生境精英策略的自适应差分进化算法ONDE。首先利用正交表产生初始种群,然后采用小生境精英策略来产生小生境种群(NP),并用小生境种群更新精英个体;接着应用拥挤裁剪避免种群陷入局部搜索,最后利用自适应差分变异算子改进了差分进化(DE)算法。通过对7个benchmark函数仿真验证,实验结果表明,算法在收敛速度、求解精度和稳定性方面都有较大优势。     

超启发式人工蜂群算法求解多场景鲁棒分布式置换流水车间调度问题

本文考虑现实中广泛存在的加工时间不确定的分布式置换流水车间调度问题(DPFSP),研究如何建立问题模型和设计求解算法,方可确保算法最终获得的解在多个典型DPFSP场景下,均具有能满足客户期望的较小优化目标值(即makespan值).在问题建模方面,首先,采用场景法构建多个不同典型场景以组成场景集(每个场景对应1个具有不同加工时间的DPFSP),并设定合适的makespan值作为场景阈值,用于在评价问题解时从场景集中动态筛选出“坏”场景子集;其次,在常规优化目标makespan的基础上,结合“坏”场景子集概念提出可实现鲁棒调度的新型优化目标,用于引导算法每代加强对当前“坏”场景子集中每个DPFSP场景对应解空间的搜索;然后,结合所提的新型优化目标,建立基于多场景的鲁棒DPFSP (MSRDPFSP).在算法设计方面,提出一种超启发式人工蜂群算法(HHABC)对MSRDPFSP进行求解. HHABC分为高、低两层结构,其中低层设计6种启发式操作(HO),高层采用人工蜂群算法控制和选择低层HOs来不断生成新的混合启发式算法,从而实现在不同场景对应解空间中的较深入搜索.在不同规模测试问题上的仿...     

基于群智能求解带约束问题的时域鲁棒优化算法

针对现有的时域鲁棒优化算法无法解决带约束的优化问题,基于群智能优化方法,提出一种求解带约束优化问题的时域鲁棒优化算法.首先,用约束条件构造罚函数,将带约束优化问题处理成为无约束优化问题;然后,采用一个分段函数作为粒子的适应度评价函数,通过竞争规则筛选粒子,设计带约束问题的时域鲁棒优化算法.以优化碳纤维原丝的性能为背景,将算法在多组参数下进行测试和对比分析,结果表明了所提出算法的有效性.进一步分析AR模型对算法性能的影响,指出预测模型的改进是提升算法性能的一个重要手段.     

可回收火箭大气层内动力下降的多阶段鲁棒优化制导方法

针对大气层内可回收火箭的动力下降问题, 提出一种多阶段的鲁棒优化(Robust optimization, RO)方法. 由于大气层内存在未知风场, 如何在火箭下降段考虑这种不确定性具有十分重要的意义. 首先, 建立一个关于高度的不确定风场模型, 在该风场下给出火箭动力下降的鲁棒最优控制问题. 为了求解该问题, 使用一种对不等式约束采取一阶近似并将一阶项作为安全裕量加入约束的鲁棒优化方法, 得到一个可以求解的单阶段鲁棒优化算法. 其次, 定量给出安全裕量的上界, 基于该上界提出一种多阶段鲁棒优化算法, 避免单阶段鲁棒优化算法中安全裕量可能过大导致无法求解的问题. 最后, 通过仿真对比各个算法在多个实际风场下的性能, 结果表明所提出的多阶段鲁棒优化方法同时具有较高的落点精度和对于不同风场的鲁棒性.     

一种求解高维多模态复杂问题的差分文化算法

针对在求解高维多峰值复杂问题时种群容易陷入局部搜索、求解精度低的问题,提出了一种基于自适应差分进化算法和小生境高斯分布估计的文化算法。将差分进化算法用于种群空间的优化,利用动态小生境识别算法在种群空间中识别小生境群体。信度空间利用高斯分布估计算法在小生境内进行局部优化,并将小生境特征存入进化知识库,进化知识库进一步引导种群空间,有效地保证了种群的多样性,避免了局部的重复搜索。最后,通过仿真实验测试表明,算法具有收敛速度快、求解精度高、稳定性高和全局搜索能力强等优势。     

迭代粒子群算法及其在间歇过程鲁棒优化中的应用

针对无状态独立约束和终端约束的间歇过程鲁棒优化问题，将迭代方法与粒子群优化算法相结合，提出了迭代粒子群算法．对于该算法，首先将控制变量离散化，用标准粒子群优化算法搜索离散控制变量的最优解．然后在随后的迭代过程中将基准移到刚解得的最优值处，同时收缩控制变量的搜索域，使优化性能指标和控制轨线在迭代过程中不断趋于最优解．算法简洁、可行、高效，避免了求解大规模微分方程组的问题．对一个间歇过程的仿真结果证明了迭代粒子群算法可以有效地解决无状态独立约束和终端约束的间歇过程鲁棒优化问题．     

拟人智能控制及鲁棒LQ控制在倒立摆基准问题中的应用

分别应用拟人智能控制策略解决倒立摆标称系统的控制和鲁棒LQ方法解决其鲁棒控制问题.拟人智能控制模仿人解决问题的归约思路,从物理角度出发分析被控系统并设计定性控制律.利用遗传算法良好的全局搜索收敛特点,对定性控制律中的参数进行优化搜索.当模型只存在结构化型不确定性且不确定性有界时,可通过求解一个Riccati方程来设计鲁棒LQ控制器.仿真结果表明给定的控制指标均得到满足,且控制律算法简单,实现比较方便.     

新的鲁棒粒子群算法在电磁场逆问题中应用研究

提出了一种搜索鲁棒优化解的粒子群算法。为解决期望适值函数计算需要大量新采样点而导致的计算效率过低问题,提出了一种期望适值赋值的新机制。该机制只对每一代粒子中的个体最优解和整体最优解分配期望适值。此外,为便于算法搜索鲁棒优化解,重新定义了粒子的邻域关系。最后,通过两个实例计算证明了新算法求解电磁场逆问题鲁棒优化解的可行性和优点。     

基于DC规划的鲁棒模糊核聚类算法

对以径向基核函数和欧拉核函数为代表的鲁棒模糊核聚类算法进行非凸优化,以改善聚类算法目标函数非凸导致的局部解问题.采用凸差规划(DCP)将目标函数转化为2个凸函数之差的形式,减缓局部解的不良性,提高聚类性能.采用凸差算法(DCA)优化求解DCP问题,能快速搜索到相对更优的解,并保持聚类的鲁棒性.在UCI数据集上的实验验证基于DCP的鲁棒模糊核聚类算法对大规模数据集表现出相对更优的聚类性能.     

A robust dynamic niching genetic algorithm with niche migration for automatic clustering problem

In this paper, a genetic clustering algorithm based on dynamic niching with niche migration (DNNM-clustering) is proposed. It is an effective and robust approach to clustering on the basis of a similarity function relating to the approximate density shape estimation. In the new algorithm, a dynamic identification of the niches with niche migration is performed at each generation to automatically evolve the optimal number of clusters as well as the cluster centers of the data set without invoking cluster validity functions. The niches can move slowly under the migration operator which makes the dynamic niching method independent of the radius of the niches. Compared to other existing methods, the proposed clustering method exhibits the following robust characteristics: (1) robust to the initialization, (2) robust to clusters volumes (ability to detect different volumes of clusters), and (3) robust to noise. Moreover, it is free of the radius of the niches and does not need to pre-specify the number of clusters. Several data sets with widely varying characteristics are used to demonstrate its superiority. An application of the DNNM-clustering algorithm in unsupervised classification of the multispectral remote sensing image is also provided.     

On the role of population size and niche radius in fitness sharing

We propose a characterization of the dynamic behavior of an evolutionary algorithm (EA) with fitness sharing as a function of both the niche radius and the population size. Such a characterization, given in terms of the mean and the standard deviation of the number of niches found during the evolution, can be applied to any EA employing a proportional selection mechanism and does not make any assumption on either the fitness landscape or the internal parameters of the EA itself. On the basis of the proposed characterization, a method for estimating the optimal values for the population size and the niche radius without any a priori information on the fitness landscape is presented and tested on a standard set of functions. The proposed method also provides the best solution for the problem at hand, i.e., the solution obtained in correspondence of such optimal values, at no additional cost.     

一种基于正交设计的快速差分演化算法及其应用研究

为了进一步加快差分演化算法的速度和增强算法的鲁棒性,提出了一种基于正交设计的快速差分演化算法,并把它应用于函数优化问题的求解中.新算法在保持传统差分演化算法的简单、有效等特性的同时,具有以下特征：1）采用基于正交设计的杂交算子,并结合直观统计法产生最优子个体;2）采用决策变量分块策略,以减少正交实验次数,加快算法收敛速度;3）提出一种基于非凸理论的多父体混合自适应杂交变异算子,以增强算法的非凸搜索能力和自适应能力;4）简化基本差分演化算法的缩放因子,尽量减少算法的控制参数,方便工程人员的使用.通过对12个标准测试函数进行实验,并与其他演化算法的结果相比较,其结果表明,新算法在解的精度、稳定性和收敛性上表现出很好的性能.     

Multi-modal function optimization with the ZEDS (zoomed evolutionary dual strategy) algorithmzoomed evolutionary algorithm

This article introduces a new evolutionary algorithm for multi-modal function optimization called ZEDS (zoomed evolutionary dual strategy). ZEDS employs a two-step, zoomed (global to local), evolutionary approach. In the first (global) step, an improved ‘GT algorithm’ is employed to perform a global recombinatory search that divides the search space into niches according to the positions of its approximate solutions. In the second (local) step, a ‘niche evolutionary strategy’ performs a local search in the niches obtained from the first step, which is repeated until acceptable solutions are found. The ZEDS algorithm was applied to some challenging problems with good results, as shown in this article.     

基于正交设计的多目标演化算法

提出一种基于正交设计的多目标演化算法以求解多目标优化问题(MOPs)．它的特点在于：(1)用基于正交数组的均匀搜索代替经典EA的随机性搜索,既保证了解分布的均匀性,又保证了收敛的快速性;(2)用统计优化方法繁殖后代,不仅提高了解的精度,而且加快了收敛速度;(3)实验结果表明,对于双目标的MOPs,新算法在解集分布的均匀性、多样性与解精确性及算法收敛速度等方面均优于SPEA;(4)用于求解一个带约束多目标优化工程设计问题,它得到了最好的结果——Pareto最优解,在此之前,此问题的Pareto最优解是未知的．     

Coevolution of multiple species through niche construction modifying shared environments

Niche construction is a process whereby organisms, through their metabolism, activities, and choices, modify their own and/or each other’s niches. Our purpose is to clarify the interactions between evolution and niche construction by focusing on non-linear interactions between genetic and environmental factors shared by interacting species. We constructed a new fitness landscape model termed the NKES model by introducing environmental factors and their interactions with genetic factors into Kauffman’s NKCS model. The evolutionary experiments were conducted using hill-climbing and niche-constructing processes on this landscape. The results have shown that the average fitness among species strongly depends on the ruggedness of the fitness landscape (K) and the degree of the effect of niche construction on genetic factors (E). Especially, we observed two different roles of niche construction: moderate perturbations on hill-climbing processes on the rugged landscapes, and the strong constraint which yields the convergence to a stable state. Also, we show that the difference in the structures of (direct or indirect) interactions among species drastically changes the coevolutionary process of the whole ecosystem by comparing the evolutionary dynamics of the NKES model with that of the NKCS model.     

基于小生境遗传算法的多媒体数据查询优化

提出一种基于增强遗传算法的对多媒体数据的查询优化算法.将查询种群组织成多个小生境,一个小生境用于查询文档空间的一个区域,设计相应的基于项权重和相似项的交叉算子、自适应变异算子,通过引入局部搜索机制来增强算法的搜索能力,最后依据相关性次序将查询结果进行合并,返回查询结果.实验结果表明,该算法在查询精度和查询速度上均能获得比较满意的效果.     

多模态函数优化的拥挤聚类遗传算法

对多模态函数优化问题，分析了各种小生境策略；将拥挤模型与聚类算法相结合，提出了一种拥挤聚类遗传算法．拥挤模型在适应值曲面上形成多个小生境，聚类算法消除了每个小生境内部的基因漂移现象．理论分析证明了算法的收敛性能．数值实例表明，拥挤聚类模型在多极值搜索的数量、质量和精度上都优于拥挤模型与确定性拥挤模型．将拥挤聚类遗传算法应用于国家同步辐射实验室变间距全息光栅的设计，取得了满意的效果．     

Large population size IGA with individuals’ fitness not assigned by user

User fatigue problem in traditional interactive genetic algorithms restricts the population size. It is necessary to maintain large population size in order to apply these algorithms to optimize complicated problems. We present a large population size interactive genetic algorithm with an individual’s fitness not assigned by the user in this paper. The algorithm divides a population into several clusters, and the maximum number of clusters is changeable with the evolution and the distribution of the population. A user only evaluates one representative individual in each cluster, and others’ fitness are estimated based on these representative ones. In addition, to assign a representative individual’s fitness, we record time when the user evaluates it satisfactory or unsatisfactory according to his/her sensibility, and its fitness is automatically calculated based on the time. Finally, we apply the proposed algorithm in a fashion evolutionary design system, and compare it with other two IGAs each of which has one aspect, including the population size and the evaluation method, the same as the proposed algorithm. The experimental results validate its efficiency.     

An orthogonal multi-objective evolutionary algorithm for multi-objective optimization problems with constraints

In this paper, an orthogonal multi-objective evolutionary algorithm (OMOEA) is proposed for multi-objective optimization problems (MOPs) with constraints. Firstly, these constraints are taken into account when determining Pareto dominance. As a result, a strict partial-ordered relation is obtained, and feasibility is not considered later in the selection process. Then, the orthogonal design and the statistical optimal method are generalized to MOPs, and a new type of multi-objective evolutionary algorithm (MOEA) is constructed. In this framework, an original niche evolves first, and splits into a group of sub-niches. Then every sub-niche repeats the above process. Due to the uniformity of the search, the optimality of the statistics, and the exponential increase of the splitting frequency of the niches, OMOEA uses a deterministic search without blindness or stochasticity. It can soon yield a large set of solutions which converges to the Pareto-optimal set with high precision and uniform distribution. We take six test problems designed by Deb, Zitzler et al., and an engineering problem (W) with constraints provided by Ray et al. to test the new technique. The numerical experiments show that our algorithm is superior to other MOGAS and MOEAs, such as FFGA, NSGAII, SPEA2, and so on, in terms of the precision, quantity and distribution of solutions. Notably, for the engineering problem W, it finds the Pareto-optimal set, which was previously unknown.