一种基于密度的局部搜索NSGA2算法

针对局部搜索类NSGA2算法计算量大的问题,提出一种基于密度的局部搜索NSGA2算法(NSGA2- DLS).使用解的密度衡量解的稀疏度,并将当前非支配解中稀疏度最小的解定义为稀疏解,每次遗传过程在稀疏解周围进行局部搜索.在局部搜索过程中,同时采用极限优化策略和随机搜索策略以提高解的质量和收敛速度.对ZDT系列函数和DTLZ系列函数进行仿真实验并与标准NSGA2算法、一种局部随机搜索算法和一种定向搜索算法进行比较,结果表明,NSGA2-DLS在消耗计算量和优化效果方面均优于对比方法.     

一种新的混沌差分进化算法

提出一种新的混沌差分进化(CDE)算法,在每一代中通过差分进化(DE)算法找到最佳个体,在最佳个体附近用混沌方法进行局部搜索,通过引入调节因子加强其搜索能力。6个基本测试函数的优化结果表明,当误差函数精度为10-14时,与DE相比,CDE的寻优能力更强、收敛速度较快。     

基于支配强度的NSGA2改进算法

NSGA2是一种简单、高效且被广泛使用的多目标进化算法(Multi-objective Evolutionary Algorithm,MoEA),但在求解实际工程领域中的高维、复杂非线性多目标优化问题(Multi-objective Optimization Problems,MOP)时,存在无法有效识别伪非支配解、计算效率低、解集收敛性和分布性较差等设计缺陷。对此,文中提出一种基于支配强度的NSGA2改进算法(INSGA2-DS)。新算法采用快速支配强度排序法构造非支配集,引入了考虑方差的拥挤距离公式,并通过自适应精英保留策略动态调整精英保留规模。基于标准测试函数的仿真实验表明,INSGA2-DS算法较好地改善了NSGA2算法的收敛性和分布性。     

一种改进搜索策略的人工蜂群算法

为克服人工蜂群算法原有搜索策略存在探索能力强而开采能力弱的缺点,受差分进化算法的启发,提出了一种新的搜索策略,在种群最优解的附近产生新的候选位置,有助于提高人工蜂群算法的开采能力.同时,为了平衡算法的探索和开采能力,将种群中的个体随机分成两组,每组采用不同的搜索策略同时寻优.对6个基准测试函数进行仿真的结果表明,改进的搜索算法相比基本人工蜂群算法能有效地改善寻优性能,增强算法摆脱局部最优的能力.     

具有局部搜索策略的差分进化算法

针对目前差分进化与局部搜索相结合仅局限于基于交叉的局部搜索的方法,提出了一种基于最佳个体局部搜索策略的差分进化算法(LSDE),并引入正态分布算子自动调整搜索步长和时变差分进化因子调整DE的两个参数。实验结果表明:除一个函数外,LSDE的寻优效果比DE和基于混沌搜索的微分进化算法(CDE)都要好,LSDE的收敛速度比DE快。     

一种带局部搜索功能的入侵杂草优化算法

为了改善入侵杂草优化算法解的质量,提出一种带局部搜索功能的入侵杂草优化算法。该算法按照一定概率对每代产生的最优个体执行球体局部搜索算子或Logistic映射搜索算子,在最优个体周围进行精细搜索,并用搜索到的较优个体代替最优个体,提高了算法的局部搜索能力和优化精度。并对7个测试函数进行了仿真实验,结果表明:该算法具有较高的优化性能。     

具有混沌局部搜索策略的差分进化全局优化算法

提出了一种具有混沌局部搜索策略的差分进化全局优化算法（CLSDE）,它是在每一代中通过DE/best/1/bin形式的差分进化算法找到最佳个体,然后在最佳个体的附近用混沌的方法进行局部搜索。8个基本的测试函数优化结果表明：若误差函数精度为10^-10,CLSDE寻优成功率比DE和SACDE都要高,而且收敛速度比DE和SACDE都要快。     

带局部搜索的NSGA Ⅱ算法在负荷分配中的应用

为了改善NSGAⅡ算法的收敛性能,将局部搜索的思想融入到NSGAⅡ中,提出一种带局部搜索的NSGAⅡ算法(NSGAⅡ-LS).该算法采用基于惩罚的边界插入法(PBI)产生局部搜索的优化函数,并使用序列二次规划方法(SQP)进行求解.通过在3个多目标标准测试函数上的仿真实验,结果表明相对于NSGAⅡ,NSGAⅡ-LS具有更好的收敛性能.最后将NSGAⅡ-LS应用到带钢热连轧负荷分配优化计算中,给出了兼顾轧制力平衡、最低轧制功率和优良板形的目标函数表达式,对多目标进化算法在热轧负荷分配优化计算中的应用进行研究,指出了目标之间的冲突关系.     

一种高效粒子群优化算法

针对标准粒子群算法收敛速度慢和易出现早熟收敛等问题,提出一种高效粒子群优化算法．首先利用局部搜索算法的局部快速收敛性,对整个粒子群目前找到的最优位置进行局部搜索;然后,为了跳出局部最优,保持粒子的多样性,给出一个学习算子．该算法能增强算法的全局探索和局部开发能力．通过对10个标准测试函数的仿真实验并与其他算法相比较,结果表明了所提出的算法具有较快的收敛速度和很强的跳出局部最优的能力,优化性能得到显著提高．     

基于模拟退火的差分变异群搜索优化算法

标准群搜索优化算法易陷入局部最优。为此,引入模拟退火策略和差分进化算子,使算法跳出局部极值点,变异和迭代同时进 行,并保持前期搜索速度快的特性。测试结果证明,改进算法的全局收敛能力明显提高,个体具有良好的人工智能性,能够真实模拟群体行为。     

Parallel machine scheduling with splitting jobs by a hybrid differential evolution algorithm

The problem of parallel machine scheduling for minimizing the makespan is an open scheduling problem with extensive practical relevance. It has been proved to be non-deterministic polynomial hard. Considering a job’s batch size greater than one in the real manufacturing environment, this paper investigates into the parallel machine scheduling with splitting jobs. Differential evolution is employed as a solution approach due to its distinctive feature, and a new crossover method and a new mutation method are brought forward in the global search procedure, according to the job splitting constraint. A specific local search method is further designed to gain a better performance, based on the analytical result from the single product problem. Numerical experiments on the performance of the proposed hybrid DE on parallel machine scheduling problems with splitting jobs covering identical and unrelated machine kinds and a realistic problem are performed, and the results indicate that the algorithm is feasible and efficient.     

Flexible job shop scheduling using hybrid differential evolution algorithms

This paper proposes hybrid differential evolution (HDE) algorithms for solving the flexible job shop scheduling problem (FJSP) with the criterion to minimize the makespan. Firstly, a novel conversion mechanism is developed to make the differential evolution (DE) algorithm that works on the continuous domain adaptive to explore the problem space of the discrete FJSP. Secondly, a local search algorithm based on the critical path is embedded in the DE framework to balance the exploration and exploitation by enhancing the local searching ability. In addition, in the local search phase, the speed-up method to find an acceptable schedule within the neighborhood structure is presented to improve the efficiency of whole algorithms. Extensive computational results and comparisons show that the proposed algorithms are very competitive with the state of the art, some new best known solutions for well known benchmark instances have even been found.     

A hybrid discrete differential evolution algorithm for the no-idle permutation flow shop scheduling problem with makespan criterion

This paper presents a hybrid discrete differential evolution (HDDE) algorithm for the no-idle permutation flow shop scheduling problem with makespan criterion, which is not so well studied. The no-idle condition requires that each machine must process jobs without any interruption from the start of processing the first job to the completion of processing the last job. A novel speed-up method based on network representation is proposed to evaluate the whole insert neighborhood of a job permutation and employed in HDDE, and moreover, an insert neighborhood local search is modified effectively in HDDE to balance global exploration and local exploitation. Experimental results and a thorough statistical analysis show that HDDE is superior to the existing state-of-the-art algorithms by a significant margin.     

基于Tent混沌搜索的差分进化算法及其应用

针对差分进化算法求解函数优化问题存在过早收敛和不稳定等缺陷,提出一种利用Tent混沌搜索的差分进化算法(TCDE).用Tent映射初始化种群,并以种群搜索到的最优个体为基础产生Tent混沌序列,以提高种群多样性,增强算法跳出局部最优解的能力.几个典型测试函数的测试结果表明TCDE的搜索能力优于DE.将改进算法应用于近似计算导数,仿真结果表明,新算法不仅能近似求解一阶导数,还能近似计算较复杂的高阶导数.     

Chaotic differential evolution methods for dynamic economic dispatch with valve-point effects

The dynamic economic dispatch (DED), with the consideration of valve-point effects, is a complicated non-linear constrained optimization problem with non-smooth and non-convex characteristics. In this paper, three chaotic differential evolution (CDE) methods are proposed based on the Tent equation to solve DED problem with valve-point effects. In the proposed methods, chaotic sequences are applied to obtain the dynamic parameter settings in DE. Meanwhile, a chaotic local search (CLS) operation for solving DED problem is designed to help DE avoiding premature convergence effectively. Finally, in order to handle the complicated constraints with efficiency, new heuristic constraints handling methods and feasibility based selection strategy are embedded into the proposed CDE methods. The feasibility and effectiveness of the proposed CDE methods are demonstrated for two test systems. The simulation results reveal that, compared with DE and those other methods reported in literatures recently, the proposed CDE methods are capable of obtaining better quality solutions with higher efficiency.     

An effective hybrid DE-based algorithm for multi-objective flow shop scheduling with limited buffers

This paper proposes an effective hybrid algorithm based on differential evolution (DE), namely HDE, to solve multi-objective permutation flow shop scheduling problem (MPFSSP) with limited buffers between consecutive machines, which is a typical NP-hard combinatorial optimization problem with strong engineering background. Firstly, to make DE suitable for solving scheduling problems, a largest-order-value (LOV) rule is presented to convert the continuous values of individuals in DE to job permutations. Secondly, after the DE-based exploration, an efficient local search, which is designed based on the landscape of MPFSSP with limited buffers, is applied to emphasize exploitation. Thus, not only does the HDE apply the parallel evolution mechanism of DE to perform effective exploration (global search) in the whole solution space, but it also adopts problem-dependent local search to perform thorough exploitation (local search) in the promising sub-regions. In addition, the concept of Pareto dominance is used to handle the updating of solutions in sense of multi-objective optimization. Moreover, the convergence property of HDE is analyzed by using the theory of finite Markov chain. Finally, simulations and comparisons based on benchmarks demonstrate the effectiveness and efficiency of the proposed HDE.     

A coevolutionary differential evolution with harmony search for reliability-redundancy optimization

Solving reliability-redundancy optimization problems via meta-heuristic algorithms has attracted increasing attention in recent years. In this paper, an effective coevolutionary differential evolution with harmony search algorithm (CDEHS) is proposed to solve the reliability-redundancy optimization problem by dividing the problem into a continuous part and an integer part. In CDEHS, two populations evolve simultaneously and cooperatively, where one population for the continuous part evolves by means of differential evolution while another population for the integer part evolves by means of harmony search. After half of the whole evolving process, the integer part stops evolving and provides the best solution to the other part for further evolving with differential evolution. Simulations results based on three typical problems and comparisons with some existing algorithms show that the proposed CDEHS is effective, efficient and robust for solving the reliability-redundancy optimization problem.     

应用反向学习和差分进化的群搜索优化算法

针对标准群搜索优化算法在解决一些复杂优化问题时容易陷入局部最优且收敛速度较慢的问题,提出一种应用反向学习和差分进化的群搜索优化算法(Group Search Optimization with Opposition-based Learning and Diffe-rential Evolution,OBDGSO)。该算法利用一般动态反向学习机制产生反向种群,扩大算法的全局勘探范围;对种群中较优解个体实施差分进化的变异操作,实现在较优解附近的局部开采,以改善算法的求解精度和收敛速度。这两种策略在GSO算法中相互协同,以更好地平衡算法的全局搜索能力和局部开采能力。将OBDGSO算法和另外4种群智能算法在12个基准测试函数上进行实验,结果表明OBDGSO算法在求解精度和收敛速度上具有较显著的性能优势。