A hybrid cuckoo search and genetic algorithm for reliability–redundancy allocation problems

Solving reliability and redundancy allocation problems via meta-heuristic algorithms has attracted increasing attention in recent years. In this study, a recently developed meta-heuristic optimization algorithm cuckoo search (CS) is hybridized with well-known genetic algorithm (GA) called CS–GA is proposed to solve the reliability and redundancy allocation problem. By embedding the genetic operators in standard CS, the balance between the exploration and exploitation ability further improved and more search space are observed during the algorithms’ performance. The computational results carried out on four classical reliability–redundancy allocation problems taken from the literature confirm the validity of the proposed algorithm. Experimental results are presented and compared with the best known solutions. The comparison results with other evolutionary optimization methods demonstrate that the proposed CS–GA algorithm proves to be extremely effective and efficient at locating optimal solutions.     

A hybrid cuckoo search-genetic algorithm for hole-making sequence optimization

Biologically-inspired algorithms are stochastic search methods that emulate the behavior of natural biological evolution to produce better solutions and have been widely used to solve engineering optimization problems. In this paper, a new hybrid algorithm is proposed based on the breeding behavior of cuckoos and evolutionary strategies of genetic algorithm by combining the advantages of genetic algorithm into the cuckoo search algorithm. The proposed hybrid cuckoo search-genetic algorithm (CSGA) is used for the optimization of hole-making operations in which a hole may require various tools to machine its final size. The main objective considered here is to minimize the total non-cutting time of the machining process, including the tool positioning time and the tool switching time. The performance of CSGA is verified through solving a set of benchmark problems taken from the literature. The amount of improvement obtained for different problem sizes are reported and compared with those by ant colony optimization, particle swarm optimization, immune based algorithm and cuckoo search algorithm. The results of the tests show that CSGA is superior to the compared algorithms.     

基于骑手优化的动态布谷鸟搜索算法

针对传统布谷鸟搜索算法（cuckoo search,CS）对复杂问题收敛精度低、迭代步幅局限性大的特点,提出了基于骑手优化的动态布谷鸟搜索策略（rider optimization cuckoo search,ROCS）。结合骑手优化算法（rider optimization algorithm,ROA）思想,利用多种群在单周期内进行多策略寻优,动态使用最优策略进行加强搜索,提高算法对复杂问题的收敛效率;同时对Lévy飞行运动进行动态参数调节,改善算法搜索前期及末期表现。仿真测试结果显示,改进算法对复杂问题的优化表现优于比对算法,算法寻优效率得到显著改善。     

基于种群特征反馈的布谷鸟搜索算法

布谷鸟搜索(CS) 算法是一种新型的生物启发式算法. 为了提高算法对不同优化问题的适应能力, 根据反馈控制原理提出一种基于种群特征反馈的布谷鸟搜索(SFFCS) 算法, 将年龄结构、变异成功率等种群特征作为反馈信息引入算法框架, 动态调节算法参数, 同时引入双进化策略机制和策略选择概率, 加强算法对局部搜索和全局搜索的平衡能力. 对标准测试函数和电力系统最优潮流问题进行数值实验, 实验结果表明, SFFCS 算法具有较好的收敛性能和适应能力, 验证了所提出算法的有效性和工程应用价值.

     

基于绝对贪心和预期效率的0-1背包问题优化

With analysis and research the traditional theory of solving knapsack problem, and then to optimize enigmatical knapsack problems, this paper proposed a new algorithm based on the absolute greedy and expected efficiency strategy. Through the three sets of simulation experiments, it shows that the algorithm can solve a class of knapsack problems and it is superior to greedy algorithm, backtracking algorithm, dynamic programming algorithm, branch and bound algorithm. The convergence speed is ten times as the artificial glowworm swam algorithm by comparing with these two algorithms. Finally, it analyzed discrete degree of data and determined an adaptive scope of the algorithm.     

求解工程结构优化问题的改进布谷鸟搜索算法

针对布谷鸟搜索算法局部搜索能力不强的缺点, 提出一种基于随机局部搜索的改进布谷鸟搜索算法用于求解工程结构优化问题。引入惯性权重以平衡算法的勘探和开采能力; 利用随机局部搜索方法对当前最优解进行局部搜索, 以加快算法的收敛速度。两个工程结构优化问题的实验结果表明了该算法的可行性和有效性。     

Seeker optimisation (human group optimisation) algorithm with chaos

Seeker optimisation algorithm (SOA), also referred to as human group metaheuristic optimisation algorithms form a very hot area of research, is an emerging population-based and gradient-free optimisation tool. It is inspired by searching behaviour of human beings in finding an optimal solution. The principal shortcoming of SOA is that it is easily trapped in local optima and consequently fails to achieve near-global solutions in complex optimisation problems. In an attempt to relieve this problem, in this article, chaos-based strategies are embedded into SOA. Five various chaotic-based SOA strategies with four different chaotic map functions are examined and the best strategy is chosen as the suitable chaotic scheme for SOA. The results of applying the proposed chaotic SOA to miscellaneous benchmark functions confirm that it provides accurate solutions. It surpasses basic SOA, genetic algorithm, gravitational search algorithm variant, cuckoo search optimisation algorithm, firefly swarm optimisation and harmony search the proposed chaos-based SOA is expected successfully solve complex engineering optimisation problems.     

Non-parametric particle swarm optimization for global optimization

In recent years, particle swarm optimization (PSO) has extensively applied in various optimization problems because of its simple structure. Although the PSO may find local optima or exhibit slow convergence speed when solving complex multimodal problems. Also, the algorithm requires setting several parameters, and tuning the parameters is a challenging for some optimization problems. To address these issues, an improved PSO scheme is proposed in this study. The algorithm, called non-parametric particle swarm optimization (NP-PSO) enhances the global exploration and the local exploitation in PSO without tuning any algorithmic parameter. NP-PSO combines local and global topologies with two quadratic interpolation operations to increase the search ability. Nineteen (19) unimodal and multimodal nonlinear benchmark functions are selected to compare the performance of NP-PSO with several well-known PSO algorithms. The experimental results showed that the proposed method considerably enhances the efficiency of PSO algorithm in terms of solution accuracy, convergence speed, global optimality, and algorithm reliability.     

Modified cuckoo optimization algorithm (MCOA) to solve graph coloring problem

In recent years, various heuristic optimization methods have been developed. Many of these methods are inspired by swarm behaviors in nature, such as particle swarm optimization (PSO), firefly algorithm (FA) and cuckoo optimization algorithm (COA). Recently introduced COA, has proven its excellent capabilities, such as faster convergence and better global minimum achievement. In this paper a new approach for solving graph coloring problem based on COA was presented. Since COA at first was presented for solving continuous optimization problems, in this paper we use the COA for the graph coloring problem, we need a discrete COA. Hence, to apply COA to discrete search space, the standard arithmetic operators such as addition, subtraction and multiplication existent in COA migration operator based on the distance's theory needs to be redefined in the discrete space. Redefinition of the concept of the difference between the two habitats as the list of differential movements, COA is equipped with a means of solving the discrete nature of the non-permutation. A set of graph coloring benchmark problems are solved and its performance is compared with some well-known heuristic search methods. The obtained results confirm the high performance of the proposed method.     

Improvement of harmony search algorithm by using statistical analysis

In this article, we suggest a new method to improve the harmony search meta-heuristic algorithm. Several approaches are presented for improving the harmony search algorithm. These approaches consider different values for initial parameters in each optimization problem. Differences between the proposed algorithm and the harmony search algorithm are as follows. First, we add a new step to create a new harmony vector, which increases the accuracy and convergence rate and reduces the impact of the initial parameters in achieving an optimal solution. Second, we set introduce a parameter called bandwidth (bw), which is an important factor with great influence on the convergence rate toward optimal solutions. To prove the efficiency and robustness of the proposed algorithm, we argument about statistical analysis of proposed algorithm and examine it through a variety of optimization problems, including constrained and unconstrained functions, mathematical problems with high dimensions and engineering and reliability problems. In all of these problems, the convergence rate and accuracy of the answer are equal to or better than other methods. In addition, in our proposed method, the effect of initial parameters has been reduced with respect to the optimal solution.     

求解连续函数优化问题的合作协同进化布谷鸟搜索算法

为改善布谷鸟搜索算法求解连续函数优化问题的性能,提出合作协同进化的布谷鸟搜索算法.改进算法通过应用合作协同进化框架,将种群的解向量分解成若干子向量,并构成相应子群体.利用标准布谷鸟算法更新各子群体的解向量.各子群体为其它子群体提供最优个体,组合成问题解向量并完成子群体评价.经10个测试函数实验仿真,结果说明改进算法能有效改善求解连续函数优化问题的性能.同时,针对连续函数优化问题,该算法与其它算法相比是有竞争力的优化算法.     

交互式学习的布谷鸟搜索算法

针对布谷鸟搜索算法在求解旅行商问题时,存在初期信息缺乏严重和收敛速度慢等问题,提出一种交互式学习的布谷鸟搜索算法（Interactive Learning Cuckoo Search Algorithm,ILCSA）。为提高布谷鸟搜索算法的搜索效率,结合蚁群优化算法构建双层交互学习模型,将蚁群作为底层种群,布谷鸟作为高层种群,双种群互相学习,合作寻优,提高搜索速度;此外,在布谷鸟搜索算法中引入强化学习策略,自适应更新步长,并对发现概率进行动态调整,深度优化最优解,进一步提高解的质量。最后采用多组不同规模的标准TSPLIB算例与其他优化算法进行对比,结果表明ILCSA算法在求解精度和稳定性方面表现更优。     

求解约束化工优化问题的混合布谷鸟搜索算法

针对布谷鸟搜索算法存在收敛速度慢和易陷入局部最优等缺陷,提出一种基于Rosenbrock搜索和柯西变异的混合布谷鸟搜索算法用于求解约束化工优化问题。该算法首先采用佳点集方法对鸟窝位置进行初始化,为全局搜索的多样性奠定基础;然后利用Rosenbrock搜索算法对当前最优位置进行局部搜索,以提高算法的收敛速度;最后对当前最优解进行柯西变异以避免算法陷入局部最优。两个约束化工优化问题的实验结果表明了该混合算法的有效性。     

Cuckoo search algorithm: a metaheuristic approach to solve structural optimization problems

In this study, a new metaheuristic optimization algorithm, called cuckoo search (CS), is introduced for solving structural optimization tasks. The new CS algorithm in combination with Lévy flights is first verified using a benchmark nonlinear constrained optimization problem. For the validation against structural engineering optimization problems, CS is subsequently applied to 13 design problems reported in the specialized literature. The performance of the CS algorithm is further compared with various algorithms representative of the state of the art in the area. The optimal solutions obtained by CS are mostly far better than the best solutions obtained by the existing methods. The unique search features used in CS and the implications for future research are finally discussed in detail.     

Enhancing the performance of cuckoo search algorithm using orthogonal learning method

The cuckoo search algorithm is a simple and effective global optimization algorithm. It has been successfully applied to solve a wide range of real-world optimization problem. In this paper, we use a new search strategy based on orthogonal learning strategy to enhance the exploitation ability of the basic cuckoo search algorithm. In order to verify the performance of our approach, 23 benchmark functions are employed. Experimental results indicate that the proposed algorithm performs better than or at least comparable to state-of-the-art approaches from literature when considering the quality of the solution obtained.     

量子衍生布谷鸟搜索算法

为提高布谷鸟搜索算法的寻优能力,通过在经典布谷鸟搜索算法中引入量子计算机制,提出了一种量子衍生布谷鸟搜索算法.该算法采用量子比特编码个体,采用泡利矩阵确定旋转轴,采用Levy飞行原理确定旋转角度,采用量子比特在Bloch球面上的绕轴旋转实现个体更新.标准函数极值优化的实验结果表明,与传统布谷鸟搜索算法相比,该算法的搜索能力确有明显提升.     

汽车混流装配线的混合布谷鸟算法排序研究

为解决汽车混流装配线作业者工作负荷不均衡的问题,构建了最小化违背装配频率上限次数的优化模型,提出了布谷鸟算法与遗传算法相结合的混合算法。该方法将遗传算法的选择与交叉思想引入布谷鸟算法的迭代过程,以克服布谷鸟算法寻优过程中收敛速度慢和容易陷入局部最优的问题。测试函数的对比求解和合作汽车企业的优化实例表明该改进算法具有更高的求解精度和更快的收敛速度,能有效地解决大规模的汽车混流装配线排序优化问题。     

基于BACS算法的数据库查询优化

针对布谷鸟算法局部搜索能力弱、寻优精度低等缺陷,提出一种蝙蝠算法和布谷鸟算法相融合的数据库查询优化算法（BACS）。按照布谷鸟优化算法对鸟巢位置进行更新,利用蝙蝠算法的动态转换策略对鸟巢位置进一步更新,避免算法陷入局部最优;最后将BACS应用于数据库查询优化问题求解,并通过仿真实验对BACS的性能进行测试。实验结果表明,BACS加快了数据库查询优化求解的收敛速度,获得了质量更高的查询优化方案。     

Reliability-based design optimization for problems with interval distribution parameters

Traditional reliability-based design optimization (RBDO) generally describes uncertain variables using random distributions, while some crucial distribution parameters in practical engineering problems can only be given intervals rather than precise values due to the limited information. Then, an important probability-interval hybrid reliability problem emerged. For uncertain problems in which interval variables are included in probability distribution functions of the random parameters, this paper establishes a hybrid reliability optimization design model and the corresponding efficient decoupling algorithm, which aims to provide an effective computational tool for reliability design of many complex structures. The reliability of an inner constraint is an interval since the interval distribution parameters are involved; this paper thus establishes the probability constraint using the lower bound of the reliability degree which ensures a safety design of the structure. An approximate reliability analysis method is given to avoid the time-consuming multivariable optimization of the inner hybrid reliability analysis. By using an incremental shifting vector (ISV) technique, the nested optimization problem involved in RBDO is converted into an efficient sequential iterative process of the deterministic design optimization and the hybrid reliability analysis. Three numerical examples are presented to verify the proposed method, which include one simple problem with explicit expression and two complex practical applications.     

具有适应性突变和惯性权重的粒子群优化(PSO)算法及其在动态系统参数估计中的应用

An important problem in engineering is the unknown parameters estimation in nonlinear systems. In this paper, a novel adaptive particle swarm optimization (APSO) method is proposed to solve this problem. This work considers two new aspects, namely an adaptive mutation mechanism and a dynamic inertia weight into the conventional particle swarm optimization (PSO) method. These mechanisms are employed to enhance global search ability and to increase accuracy. First, three well-known benchmark functions namely Griewank, Rosenbrock and Rastrigrin are utilized to test the ability of a search algorithm for identifying the global optimum. The performance of the proposed APSO is compared with advanced algorithms such as a nonlinearly decreasing weight PSO (NDWPSO) and a real-coded genetic algorithm (GA), in terms of parameter accuracy and convergence speed. It is confirmed that the proposed APSO is more successful than other aforementioned algorithms. Finally, the feasibility of this algorithm is demonstrated through estimating the parameters of two kinds of highly nonlinear systems as the case studies.