基于动态拥挤距离的自适应变异演化算法

多目标演化算法的研究目标是使算法种群快速收敛并均匀分布于问题的非劣最优域。根据个体的非支配排序级数设计了一种自适应变异步长的柯西变异算子,对变异越界处理进行了改进;并定义和使用动态拥挤距离来保持群体中个体的均匀分布。最后通过对测试函数的实验,验证了算法的可行性和有效性。     

一种新的混合策略进化算法

进化计算已成功地运用到各种数值优化和组合优化问题中,而运用单一变异算子的进化算法总是存在着对某种函数优化问题性能良好,对另一些却不尽人意的问题。本文提出一种基于经典进化算法和单点变异算法的混合策略进化算法SPCEP。SPCEP算法利用两种变异算子各产生一个后代个体,并选择较好的一个作为唯一的后代。实验结果表明,在处理高维单模函数时,SPCEP的性能比CEP和SPMEP有显著的提高。     

Constrained optimization based on hybrid evolutionary algorithm and adaptive constraint-handling technique

A novel approach to deal with numerical and engineering constrained optimization problems, which incorporates a hybrid evolutionary algorithm and an adaptive constraint-handling technique, is presented in this paper. The hybrid evolutionary algorithm simultaneously uses simplex crossover and two mutation operators to generate the offspring population. Additionally, the adaptive constraint-handling technique consists of three main situations. In detail, at each situation, one constraint-handling mechanism is designed based on current population state. Experiments on 13 benchmark test functions and four well-known constrained design problems verify the effectiveness and efficiency of the proposed method. The experimental results show that integrating the hybrid evolutionary algorithm with the adaptive constraint-handling technique is beneficial, and the proposed method achieves competitive performance with respect to some other state-of-the-art approaches in constrained evolutionary optimization.     

一种改进的微分进化算法

相对于其他优化算法来说,微分进化算法具有控制参数少、易于使用以及鲁棒性强等特点,但在搜索过程中存在着局部搜索能力弱的缺点。针对微分进化算法局部搜索能力弱的缺点,提出了一种基于局部变异的微分进化算法,该算法使个体具有良好快速收敛能力。使用典型优化函数对比较算法进行了测试,算法分析和仿真结果表明,改进以后的算法具有寻优能力...     

带有遗传算子的烟花爆炸优化算法

受烟花爆炸现象的启发并结合遗传算法思想提出一种新的优化算法——带有遗传算子的烟花爆炸优化算法(GAFEO)。该算法主要模拟烟花爆炸的方式对解空间进行基本的并行弥漫式爆炸搜索,引入自适应局部搜索策略和遗传算法中的交叉变异策略以改善算法的优化性能。通过实验对12个常用高维测试函数进行优化计算,结果表明,与PSO算法以及其他新型算法相比,GAFEO算法在寻优能力、寻优精度等方面都具有较好的性能。     

基于分解和多策略变异的多目标差分进化算法*

差分进化是一种有效的优化技术,已成功用于多目标优化问题。但也存在Pareto最优集合的收敛慢和多样性差等问题。针对上述不足,本文提出了一种基于分解和多策略变异的多目标差分进化算法(MODE/DMSM)。该算法利用基于分解的方法将多目标优化问题分解为多个单目标优化问题;通过高效的非支配排序方法选择具有良好收敛性和多样性的解来指导差分进化过程;采用了多策略变异方法来平衡进化过程中收敛性和多样性。在ZDT和DTLZ的10个测试函数上的仿真结果表明,本文算法在Parato最优集合的收敛性和多样性优于其他六种代表性多目标优化算法。     

基于Q学习的适应性进化规划算法

进化规划中, 个体选择变异策略特别重要. 适应性变异策略因在进化过程中动态选择个体变异策略, 能够取得较好的性能. 传统适应性变异策略都依据个体一步进化效果考察个体适应性, 没有从多步进化效果上对变异策略进行评价. 本文提出一种新的基于 Q 学习的适应性进化规划算法QEP (Q learning based evolutionary programming), 该算法将变异策略看成行动, 考察个体多步进化效果, 并通过计算 Q 函数值, 学习个体最优变异策略. 实验表明, QEP 能够获得好的性能.     

A single-point mutation evolutionary programming

In this paper, we propose an improved evolutionary programming based on single-point mutation, which is named Single-Point Mutation Evolutionary Programming (SPMEP). The distinctions between SPMEP and the classical evolutionary programming (EP) are the single-point mutation for each solution in each iteration and the fixed mutation scheme for deviation η. Simulation results show that SPMEP is obviously superior to the classical EP, fast EP and generalized EP for multimodal and high-dimensional functions.     

基于交流的求解数值优化问题的混合演化算法

演化算法中有很多不同的演化算子,每一种算子对于不同的优化问题都有自己的优点和缺点。提出了一种基于交流模型的多算子混合演化算法。在该算法中,有两个种群,使用两种算子:多父体杂交算子和Cauchy变异算子。种群间的信息交换通过个体交流实现。对23个标准测试函数的数值仿真表明,该算法具有良好的全局收敛性和鲁棒性。     

基于进化个体适应值灰度的自适应交互式遗传算法

为将交互式遗传算法成功应用于复杂优化问题,有必要提高交互式遗传算法的性能。提出基于进化个体适应值灰度的交互式遗传算法,该算法采用灰度衡量进化个体的适应值评价不确定性;通过适应值区间的分析,提取反映进化种群分布的信息;基于此,给出了进化个体的交叉和变异概率。将该算法应用于服装进化设计系统,结果表明该算法在每代可以获取更多的满意解。     

Ensemble strategies with adaptive evolutionary programming

Mutation operators such as Gaussian, Lévy and Cauchy have been used with evolutionary programming (EP). According to the no free lunch theorem, it is impossible for EP with a single mutation operator to outperform always. For example, Classical EP (CEP) with Gaussian mutation is better at searching in a local neighborhood while the Fast EP (FEP) with the Cauchy mutation performs better over a larger neighborhood. Motivated by these observations, we propose an ensemble approach where each mutation operator has its associated population and every population benefits from every function call. This approach enables us to benefit from different mutation operators with different parameter values whenever they are effective during different stages of the search process. In addition, the recently proposed Adaptive EP (AEP) using Gaussian (ACEP) and Cauchy (AFEP) mutations is also evaluated. In the AEP, the strategy parameter values are adapted based on the search performance in the previous few generations. The performance of ensemble is compared with a mixed mutation strategy, which integrates several mutation operators into a single algorithm as well as against the AEP with a single mutation operator. Improved performance of the ensemble over the single mutation-based algorithms and mixed mutation algorithm is verified using statistical tests.     

非均匀演化算法及其应用

提出一种基于非均匀变异的演化算法模型;基于随机过程理论分析了该算法的自适应性,用该算法求解了实际的“油层结垢”问题;基于随机优化领域经典的高维多峰测试函数,同已有的同类算法做了对比.实验结果表明：在没有引入任何额外参数和计算的前提下,该算法具有更好的收敛性和稳定性.     

基于多点非均匀变异的多目标极值优化算法研究

多目标进化算法因其在解决含有多个矛盾目标函数的多目标优化问题中的强大处理能力,正受到越来越多的关注与研究。极值优化作为一种新型的进化算法,已在各种离散优化、连续优化测试函数以及工程优化问题中得到了较为成功的应用,但有关多目标EO算法的研究却十分有限。本文将采用Pareto优化的基本原理引入到极值优化算法中,提出一种求解连续多目标优化问题的基于多点非均匀变异的多目标极值优化算法。通过对六个国际公认的连续多目标优化测试函数的仿真实验结果表明：本文提出算法相比NSGA-II、 PAES、SPEA和SPEA2等经典多目标优化算法在收敛性和分布性方面均具有优势。     

Evolutionary programming using mutations based on the Levy probability distribution

Studies evolutionary programming with mutations based on the Levy probability distribution. The Levy probability distribution has an infinite second moment and is, therefore, more likely to generate an offspring that is farther away from its parent than the commonly employed Gaussian mutation. Such likelihood depends on a parameter /spl alpha/ in the Levy distribution. We propose an evolutionary programming algorithm using adaptive as well as nonadaptive Levy mutations. The proposed algorithm was applied to multivariate functional optimization. Empirical evidence shows that, in the case of functions having many local optima, the performance of the proposed algorithm was better than that of classical evolutionary programming using Gaussian mutation.     

一种新的求解函数优化问题的快速演化算法

提出一种新的求解函数优化的快速演化算法;新算法的特征是引入一种基于高斯变异和Cauchy变异的混合自适应变异算子,并作为算法的唯一遗传算子;提出多父体变异的群体爬山搜索策略;采用随机排序选择策略,克服了经典算法易于陷入局部最优解的常见弊病;新算法具有保持群体的多样性、全概率收敛、淘汰压力小、子空间搜索、快速收敛、评价次数少等特性;通过7个标准测试函数测试结果表明,新算法在所有的测试函数中体现出很好的性能,具有稳定、高效和快速等特点.     

Max-min surrogate-assisted evolutionary algorithm for robust design

Solving design optimization problems using evolutionary algorithms has always been perceived as finding the optimal solution over the entire search space. However, the global optima may not always be the most desirable solution in many real-world engineering design problems. In practice, if the global optimal solution is very sensitive to uncertainties, for example, small changes in design variables or operating conditions, then it may not be appropriate to use this highly sensitive solution. In this paper, we focus on combining evolutionary algorithms with function approximation techniques for robust design. In particular, we investigate the application of robust genetic algorithms to problems with high dimensions. Subsequently, we present a novel evolutionary algorithm based on the combination of a max-min optimization strategy with a Baldwinian trust-region framework employing local surrogate models for reducing the computational cost associated with robust design problems. Empirical results are presented for synthetic test functions and aerodynamic shape design problems to demonstrate that the proposed algorithm converges to robust optimum designs on a limited computational budget.     

Adaptive robust stabilisation of uncertain nonlinear dynamical systems: an improved backstepping approach

The main purpose of this paper is to propose a design approach by which some simple adaptive robust controllers can be synthesised for a class of uncertain nonlinear dynamical systems which can be transformed into uncertain strict-feedback nonlinear systems. In this paper, an improved backstepping design approach is presented to synthesising a class of continuous adaptive robust state-feedback controllers with a rather simple structure. The improved backstepping design approach can avoid the repeated differentiation problem which appears in using the conventional backstepping algorithm. In particular, it is not required to know the nonlinear upper bound functions of uncertainties. In the light of the presented approach, the state-feedback controllers can be constructed to be linear in the state, with the time-varying control gains which can be self-tuned by the adaptive laws. Similar to the conventional backstepping algorithm, the improved backstepping approach can be extended to a rather large class of uncertain nonlinear systems, and by combining the improved backstepping approach with other control methods, it may be expected to obtain a number of interesting results.     

一类自适应混沌文化算法

混沌变异进化算法忽略了混沌规律性,未充分利用知识来提高算法的局部收敛能力.为此,借鉴文化算法的双层进化结构,在文化算法的进化引导函数中引入自适应混沌变异策略,提出一种自适应混沌文化算法.利用进化过程隐含知识控制变异尺度,使知识引导个体能跳出局部较优解,在保证种群多样性的同时,实现进化后期的精细搜索.仿真结果表明,该算法可以有效提高进化收敛速度,具有较好的计算稳定性.     

Improved salp swarm algorithm based on weight factor and adaptive mutation

Salp Swarm Algorithm (SSA) is a novel swarm intelligent algorithm with good performance. However, like other swarm-based algorithms, it has insufficiencies of low convergence precision and slow convergence speed when dealing with high-dimensional complex optimisation problems. In response to this concerning issue, in this paper, we propose an improved SSA named as WASSA. First of all, dynamic weight factor is added to the update formula of population position, aiming to balance global exploration and local exploitation. In addition, in order to avoid premature convergence and evolution stagnation, an adaptive mutation strategy is introduced during the evolution process. Disturbance to the global extremum promotes the population to jump out of local extremum and continue to search for an optimal solution. The experiments conducted on a set of 28 benchmark functions show that the improved algorithm presented in this paper displays obvious superiority in convergence performance, robustness as well as the ability to escape local optimum when compared with SSA.     

基于混合杂交与间歇变异的演化算法

通过混合使用多种杂交算子并辅之以间歇变异,提出了一种求解高维复杂函数全局优化问题的新型演化算法。用该算法求解了维数为100到400不等的典型测试函数,获得了比其它算法更精确或更接近最优的解,表明了算法的有效性。