Hierarchical reduction and partition of hypergraph

In this paper, a hierarchical reduction method of hypergraphs is proposed. A macro-vertex in a reduced hypergraph corresponds to an edge of the original hypergraph, and thus a reduced hypergraph can provide a partition of a system. The reduction is realized by the iterations and the sequence of hierarchical reduction gives a sequence of hierarchical partitions. The proposed method allows to reduce and decompose the complexity of the system represented by hypergraphs.     

一种基于知识进化的多层次结构产品整体方案创新设计方法

研究并提出了一种基于知识进化的多层次结构产品整体方案创新设计系统模型,该模型根据机械产品都具有多层次结构的特点,通过把机械方案设计过程看作是一个状态空间的求解问题,用基因算法（DGA）从整体上控制其搜索过程,构建了新的多层次基因编码体系。为了适应新的编码体系重新构建了交叉和变异等基因操作,并利用复制、交换和变异等操作进行一次次迭代,最终自动生成一组最优的设计方案。该系统经过实例验证具有很高的有效性、准确性和实用性。     

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.     

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 hyper-heuristic approach to automated generation of mutation operators for evolutionary programming

Evolutionary programming can solve black-box function optimisation problems by evolving a population of numerical vectors. The variation component in the evolutionary process is supplied by a mutation operator, which is typically a Gaussian, Cauchy, or Lévy probability distribution. In this paper, we use genetic programming to automatically generate mutation operators for an evolutionary programming system, testing the proposed approach over a set of function classes, which represent a source of functions. The empirical results over a set of benchmark function classes illustrate that genetic programming can evolve mutation operators which generalise well from the training set to the test set on each function class. The proposed method is able to outperform existing human designed mutation operators with statistical significance in most cases, with competitive results observed for the rest.     

基于分级策略的演化算法

为了避免演化算法过早收敛,保持种群多样性,增加算法的搜索能力,本文提出基于分级策略的演化算法．即通过对种群进行分级,来度量种群的多样性,衡量算法是否陷入局部最优,协调种群多样性和精英策略之间的矛盾,再根据种群分布的多样性设计一种有效的半一致交叉算子与单重均匀变异算子。     

Wheel hub customization with an interactive artificial immune algorithm

With the transformation from traditional manufacturing to intelligent manufacturing, customer-oriented personalized customization has gradually become the main mode of production. Interactive algorithms determine the pros and cons of the solution via customers which can make customers better participants in the customization process. However, if the population size is expanded and the number of evolutionary iterations is too high, frequent interactions are likely to cause customer fatigue. This paper proposes an adaptive interactive artificial immune algorithm based on improved hierarchical clustering. This algorithm uses the improved hierarchical clustering algorithm to optimize generation of the initial antibodies and applies the affinity calculation method based on customer intention, adaptive crossover and mutation operators, and a multisolution reservation method based on hybrid selection strategy to the artificial immune algorithm. Via empirical research on the customized operational data of wheel hubs, the proposed method effectively solves the problem of customer fatigue, significantly improves the convergence speed of the algorithm and reduces the time cost.

     

Evolutionary programming using a mixed mutation strategy

Different mutation operators have been proposed in evolutionary programming, but for each operator there are some types of optimization problems that cannot be solved efficiently. A mixed strategy, integrating several mutation operators into a single algorithm, can overcome this problem. Inspired by evolutionary game theory, this paper presents a mixed strategy evolutionary programming algorithm that employs the Gaussian, Cauchy, Lévy, and single-point mutation operators. The novel algorithm is tested on a set of 22 benchmark problems. The results show that the mixed strategy performs equally well or better than the best of the four pure strategies does, for all of the benchmark problems.     

一种新的混合杂交方法及其在约束优化中的应用

为进一步提高基于混合杂交与间歇变异的约束优化演化算法的求解性能,提出了一种新的混合杂交方法。该方法主要是在混合算术杂交算子中引入离散均匀重组算子,并组成一个离散——算术混合杂交算子网,其中离散均匀重组算子起到协助调整子代分布、增强混合算术杂交算子局部搜索能力的作用。数值实验和比较表明所提的混合杂交方法可有效改善算法求解不等式约束优化问题的性能。     

New visual languages supporting design of multi-storey buildings

This paper deals with designing multi-storey buildings with the use of a knowledge-based visual design support system. In this system two visual languages for creating design solutions by the designer are proposed. The first one allows the designer to design 2D floor layouts, while the second one is dedicated to creating 3D building structures. The generated design solutions in the form of drawings are internally represented as hierarchical hypergraphs gathering design knowledge on which reasoning about designs can be based. The approach is illustrated by example of designing a three-storey house.     

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。     

A self-adaptive linear evolutionary algorithm for solving constrained optimization problems

In many real-world applications of evolutionary algorithms, the fitness of an individual requires a quantitative measure. This paper proposes a self-adaptive linear evolutionary algorithm (ALEA) in which we introduce a novel strategy for evaluating individual’s relative strengths and weaknesses. Based on this strategy, searching space of constrained optimization problems with high dimensions for design variables is compressed into two-dimensional performance space in which it is possible to quickly identify ‘good’ individuals of the performance for a multiobjective optimization application, regardless of original space complexity. This is considered as our main contribution. In addition, the proposed new evolutionary algorithm combines two basic operators with modification in reproduction phase, namely, crossover and mutation. Simulation results over a comprehensive set of benchmark functions show that the proposed strategy is feasible and effective, and provides good performance in terms of uniformity and diversity of solutions.     

Multi-objective evolutionary algorithm using problem-specific genetic operators for community detection in networks

Automatic network clustering is an important method for mining the meaningful communities of complex networks. Uncovered communities help to understand the potential system structure and functionality. Many algorithms that use multiple optimization criteria and optimize a population of solutions are difficult to apply to real systems because they suffer a long optimization process. In this paper, in order to accelerate the optimization process and to uncover multiple significant community structures more effectively, a multi-objective evolutionary algorithm is proposed and evaluated using problem-specific genetic mutation and group crossover, and problem-specific initialization. Since crossover operators mainly contribute to performance of genetic algorithms, more problem-specific group crossover operators are introduced and evaluated for intelligent evolution of population. The experiments on both artificial and real-world networks demonstrate that the proposed evolutionary algorithm with problem-specific genetic operations has effective performance on discovering the community structure of networks.

     

A bit-masking oriented data structure for evolutionary operators implementation in genetic algorithms

 In the present paper a special bit-masking oriented data structure for an improved implementation of crossover and mutation operators in genetic algorithms is shown. The developed data structure performs evolutionary operators in two separate steps: crossover and mutation mask fill and a special boolean based function application. Both phases are optimized to reach a more efficient, fast and flexible genetic reproduction than standard implementations. The method has been powered adding a multi-layered, bit-masking oriented data structure and a boolean operation based control mixer, allowing special blended crossover operators obtained by superposition of the standard ones. Several examples of crossover schemes produced by these extended controls are presented. In addition, a special purpose crossover scheme, capable to process at the same time two distinct groups of design variables with separate crossover schemes is shown, in order to improve efficiency and convergence speed of some discrete/continuous optimization problems. Finally, to highlight further capabilities of the bit-masking approach, a special single-step version of an evolutionary direction operator is also illustrated.     

Adaptive evolutionary programming based on reinforcement learning

This paper studies evolutionary programming and adopts reinforcement learning theory to learn individual mutation operators. A novel algorithm named RLEP (Evolutionary Programming based on Reinforcement Learning) is proposed. In this algorithm, each individual learns its optimal mutation operator based on the immediate and delayed performance of mutation operators. Mutation operator selection is mapped into a reinforcement learning problem. Reinforcement learning methods are used to learn optimal policies by maximizing the accumulated rewards. According to the calculated Q function value of each candidate mutation operator, an optimal mutation operator can be selected to maximize the learned Q function value. Four different mutation operators have been employed as the basic candidate operators in RLEP and one is selected for each individual in different generations. Our simulation shows the performance of RLEP is the same as or better than the best of the four basic mutation operators.     

Evolving computer programs without subtree crossover

An evolutionary programming procedure is used for optimizing computer programs in the form of symbolic expressions. Six tree mutation operators are proposed. Recombination operators such as crossover are not included. The viability and efficiency of the method is extensively investigated on a set of well-studied problems. The evidence indicates that the technique is not only viable but is indeed capable of evolving good computer programs. The results compare well with other evolutionary methods that rely on crossover to solve the same problems     

一种改进的克隆函数优化算法*

为了提高免疫克隆算法的寻优能力,借鉴生物免疫系统的Baldwin效应及生物进化的周期性,提出了一种Baldwin效应的正向和反向学习机制,克服纯粹随机进化;利用生物进化的周期性,设计了周期变异算子,提高算法的收敛速度。在函数测试问题上的仿真实验表明,该算法求解精度较高、寻优能力较强。     

Combining genetic algorithms with BESO for topology optimization

This paper proposes a new algorithm for topology optimization by combining the features of genetic algorithms (GAs) and bi-directional evolutionary structural optimization (BESO). An efficient treatment of individuals and population for finite element models is presented which is different from traditional GAs application in structural design. GAs operators of crossover and mutation suitable for topology optimization problems are developed. The effects of various parameters used in the proposed GA on the optimization speed and performance are examined. Several 2D and 3D examples of compliance minimization problems are provided to demonstrate the efficiency of the proposed new approach and its capability of obtaining convergent solutions. Wherever possible, the numerical results of the proposed algorithm are compared with the solutions of other GA methods and the SIMP method.     

一种新的基于进化计算的聚类算法

聚类是数据挖掘领域的重要研究内容之一。针对遗传聚类算法较好的稳定性与粒子群优化算法较强的局部搜索能力,在交叉、变异算子后叠加粒子群优化算子的方法实现了二者的结合,提出了GAPSO聚类算法,既保持了遗传算法的稳定性与泛化性的优势,又发挥了PSO算法收敛效率高的特点。通过对10组二维空间上的聚类样本进行实验研究显示,GAPSO聚类算法在收敛效率上显著优于GA聚类算法,在稳定性上优于PSO聚类算法。     

基于改进遗传算法的船舶管路布局设计

针对船舶管路布局设计中的路径规划问题提出一种改进型遗传算法求解方法。建立船舶管路布局设计问题的模型空间、约束条件和优化目标;提出一种基于连接点网格的定长编码方法,结合该编码方法设计了适合改进遗传算法应用的适应度函数和交叉、变异算子,定长编码可降低遗传算子设计复杂度和非法个体修补代价;提出在进化流程中嵌入以“去折弯”和“改模式”两种改善型变异方法构建的爬山操作,以提升算法收敛性和寻优能力。通过仿真实验验证所提算法具有可行性和先进性。