Penalty guided bees search for redundancy allocation problems with a mix of components in series–parallel systems

This paper uses a penalty guided strategy based on an artificial bee colony algorithm (PGBC) to solve the redundancy allocation problem (RAP) in reliability series–parallel systems. The penalty strategy was designed to eliminate the equalities in constraints and formulate new objective operators which guarantee feasibility within a reasonable execution time. The PGBC is used to deal with two kinds of RAPs with a mix of components. In the first example, the RAPs are designed to find the appropriate mix of components and redundancies within a system in order to either minimize the cost in the context of a minimum level of reliability, or maximize reliability subject to a maximum cost and weight. The second example involves RAPs of multi-state series–parallel reliability structures, wherein each subsystem can consist of a maximum of two types of redundant components. The objective is to minimize the total investment cost of system design while satisfying system reliability constraints and the consumer load demands. There are five multi-state system design problems which have been solved for illustration in this example. The experimental results show that the PGBC can significantly outperform other existing methods in the literature with less cost, higher reliability, and a significantly shorter computational time.     

ACOA-RBF网络模型在短期负荷预测中的应用

为了进一步提高RBF神经网络的性能,实现准确、快速预测短期电力负荷的目的,将蚁群优化算法（ACOA）作为RBF神经网络的学习算法,建立了一种新的蚁群优化算法的RBF（ACOA-RBF）网络预测模型,利用山西某地区电网的历史数据进行短期负荷预测。仿真表明,这一算法与传统的RBF神经网络预测方法相比,能达到更好的预测效果。该优化算法改善了径向基神经网络的泛化能力,提高了山西电网短期负荷预测的精度,可有效用于电力系统的短期负荷预测。     

一种基于改进蚁群优化的QoS路由算法

蚁群优化（Ant Colony Optimization,AC0）是一种新型的分布式仿生优化算法,可有效地用来解决组合优化问题,而网络路由优化问题则正是组合优化问题当中的一种。因此,本文首先分析了常用路由算法与蚁群优化的基本原理,根据网络路由优化问题与蚁群优化算法的许多匹配特性,提出了一种基于改进蚁群优化的QoS路由算法（Route Algorithm based on Improved Ant Colony Optimlzation,RAIAC0）。最后,通过实验分析,对其可行性进行了证明。     

等级反馈蚁群算法求解成品油二次配送问题

针对成品油二次配送路径优化问题，提出了一种可变成本与动态载荷相关的评价指标。考虑蚁群算法求解路径优化问题的高效性，设计了一种等级反馈蚁群（HFAC）算法。采用局部距离等级策略代替基本蚁群算法的随机选取；利用较优（较差）个体对其所在路线进行正（负）反馈调整信息素浓度；对最优路线的子路线进行末端优化调整。通过15组不同类型算例进行仿真实验表明，HFAC算法在成品油二次配送路径优化中优于基本蚁群算法。     

A PSO algorithm for constrained redundancy allocation in multi-state systems with bridge topology

Bridge topology is a commonly used structure for load balancing and control in applications such as electric power generation and transmission, transportation and computer networks, and electronic circuits. The reliability performance of engineering systems with bridge topology can be characterized by multi-state models and enhanced by allocating redundant elements. The redundancy allocation problem, which aims at finding the optimal trade-off between system performance and investment costs, is proved difficult to solve and has received much attention in the literature. This paper advances a meta-heuristic approach called particle swarm optimization and applies it to effectively solve for near-optimal solutions to the redundancy allocation problem of multi-state systems with bridge topology. Two typical redundancy allocation problem formulations, i.e., minimizing the system cost while satisfying required system availability and maximizing the system availability with a limited budget, are studied. Heterogeneous redundancy, i.e., the mixture of redundant element types in each subsystem, is allowed in the formulations. The effectiveness and efficiency of the proposed approach are validated by the case studies of a bridge-structured coal conveyor multi-state system with extra constraints. The research results have practical meaning to the design and improvement of engineering systems with bridge topology.     

Solving reliability redundancy allocation problems using an artificial bee colony algorithm

This paper proposed a penalty guided artificial bee colony algorithm (ABC) to solve the reliability redundancy allocation problem (RAP). The redundancy allocation problem involves setting reliability objectives for components or subsystems in order to meet the resource consumption constraint, e.g. the total cost. RAP has been an active area of research for the past four decades. The difficulty that one is confronted with the RAP is the maintenance of feasibility with respect to three nonlinear constraints, namely, cost, weight and volume related constraints. In this paper nonlinearly mixed-integer reliability design problems are investigated where both the number of redundancy components and the corresponding component reliability in each subsystem are to be decided simultaneously so as to maximize the reliability of the system. The reliability design problems have been studied in the literature for decades, usually using mathematical programming or heuristic optimization approaches. To the best of our knowledge the ABC algorithm can search over promising feasible and infeasible regions to find the feasible optimal/near-optimal solution effectively and efficiently; numerical examples indicate that the proposed approach performs well with the reliability redundant allocation design problems considered in this paper and computational results compare favorably with previously-developed algorithms in the literature.     

利用蚁群算法生成覆盖表:探索与挖掘

覆盖表生成问题是组合测试的重要研究内容之一,目前已有许多数学方法、贪心算法、搜索算法用于求解这一问题.蚁群算法作为一种能够有效求解组合优化问题的演化搜索算法,已被应用到求解覆盖表生成问题中.已有的研究工作表明:蚁群算法适于求解一般覆盖表、变力度覆盖表生成以及覆盖表排序等问题,但算法结果与其他覆盖表生成方法相比并不具有优势.为了进一步探索与挖掘蚁群算法生成覆盖表的潜力,进行了如下4个层次的改进工作:(1)算法变种集成;(2)算法参数配置优化;(3)演化对象结构调整及演化策略改进;(4)利用并行计算优化算法时间开销.实验结果表明:通过以上4个层次的改进,蚁群算法生成覆盖表的性能有了显著提升.     

蜂群—蚁群自适应优化算法*

为了解决蚁群算法在求解连续函数优化问题时,存在局部搜索能力较差的缺陷,提出一种新颖的自适应蜂群—蚁群优化算法。新算法在蚁群优化算法的基础上,设计了一种参数q的自适应机制,进而减少了参数个数,提高了其鲁棒性;根据蜂群算法基本思想,利用雇佣蜂和观察蜂设计了高效的局部搜索算子,从而提升了算法的局部能力。针对五个标准测试函数的仿真实验结果表明:与蚁群优化算法相比,新算法的全局和局部寻优能力均得到了极大的提升。     

可靠性优化的蚁群算法

建立了可靠性冗余优化模型，分析了各种优化方法的优缺点。采用模拟退火算法、遗传算法和蚁群算法分别解决了此问题，并通过实例，结果表明蚁群算法比较有效。     

应急物资运输路径多目标优化模型及求解算法

针对应急前期运输商自有车辆不足的实际背景,采用自有车辆和第三方租用车辆共同配送的运输模式,对混合车辆路径的组合优化问题进行研究。首先,考虑需求点和运输商的不同利益诉求,以系统满意度最大、系统配送时间和总成本最小为优化目标,建立带软时间窗的多目标混合车辆路径优化模型。其次,考虑NSGA-Ⅱ算法在求解该类问题时收敛性差和Pareto前沿分布不均匀的缺点,将蚁群算法的启发式策略和信息素正反馈机制用于生成子代种群,非支配排序策略模型用于指导算法的多目标择优过程,并引入变邻域下降搜索以扩大搜索空间,提出求解多目标的非支配排序蚁群算法以突破原有算法瓶颈。算例表明：构建的模型可对决策者在不同的情境下依据不同的优化目标选择合理的路径提供参考,提出的算法在求解不同规模的问题和不同分布类型的问题中均表现出较好的性能。     

基于时间负载均衡蚁群算法的云任务调度优化

针对云渲染系统中渲染节点与任务不匹配调度而带来的时间负载不均衡和耗时长的问题,提出一种基于时间负载均衡的任务调度方式来优化系统耗时的策略.该算法采用Min-min与Max-min相结合的思想,建立时间负载均衡模型进行前期迭代,将迭代结果作为蚁群算法的初始序列,并按照适应度规则计算出相应的初始信息素,同时通过单一变量法确定合理的参数,蚁群算法采用已有的初始资源和参数值进行后期迭代,根据标准量度自定义函数进行高效寻优,进而求得最终的任务调度序列.仿真结果表明,本策略既具有较高的搜索效率和较强的全局寻优能力,又能有效降低任务完成时间,且在时间负载均衡和寻优速度方面均显著优于蚁群算法和蚁群退火算法.     

Cooperation and profit allocation in two-echelon logistics joint distribution network optimization

Collaborative two-echelon logistics joint distribution network can be organized through a negotiation process via logistics service providers or participants existing in the logistics system, which can effectively reduce the crisscross transportation phenomenon and improve the efficiency of the urban freight transportation system. This study establishes a linear optimization model to minimize the total cost of two-echelon logistics joint distribution network. An improved ant colony optimization algorithm integrated with genetic algorithm is presented to serve customer clustering units and resolve the model formulation by assigning logistics facilities. A two-dimensional colony encoding method is adopted to generate the initial ant colonies. Improved ant colony optimization combines the merits of ant colony optimization algorithm and genetic algorithm with both global and local search capabilities. Finally, an improved Shapley value model based on cooperative game theory and a cooperative mechanism strategy are presented to obtain the optimal profit allocation scheme and sequential coalitions respectively in two-echelon logistics joint distribution network. An empirical study in Guiyang City, China, reveals that the improved ant colony optimization algorithm is superior to the other three methods in terms of the total cost. The improved Shapley value model and monotonic path selection strategy are applied to calculate the best sequential coalition selection strategy. The proposed cooperation and profit allocation approaches provide an effective paradigm for logistics companies to share benefit, achieve win–win situations through the horizontal cooperation, and improve the negotiation power for logistics network optimization.     

蚁群优化算法及其应用研究进展

综述了近年来蚁群算法及其在组合优化中的应用研究成果。首先简述了蚁群的觅食行为及蚂蚁的信息系统，其次介绍了人工蚁群算法的基本原理及其主要特点。然后概述了这种算法在组合优化问题中的多种应用，诸如旅行商问题(TSP)、二次分配问题(QAP)、任务调度问题(JSP)、车辆路线问题(VRP)、图着色问题(GCP)、有序排列问题(SOP)及网络由问题等。最后对蚁群算法仍需要解决的问题和未来的发展方向进行了探讨。     

串并联系统中支持实时替换的混合冗余策略优化

在需要长时间可靠运行的软件系统中,由于持续运行时间和任务响应速度的要求增加,工作组件在被探测到失效后将被冗余组件实时替换.但现有可靠性优化研究通常假设冷备份冗余在所有积极冗余组件失效后才使用.针对支持实时替换的混合冗余策略,对其冗余度优化分配进行研究.该策略不仅能够保障系统可靠性,而且能够保障系统性能,故选用实时可用性和任务完成效率两类约束条件,建立冗余配置代价最小化模型.基于马尔可夫链理论对可靠性及性能两类系统指标进行定量分析;采用数值计算方法对非线性的状态分析模型进行计算;改进二元组编码遗传算法对上述优化问题进行求解.采用实例对串并联系统中实时可用性及任务完成效率的分析进行了说明,并对优化冗余分配模型进行了验证.实验结果表明,在相同冗余度下,支持实时替换的混合冗余策略在任务完成效率方面优于传统的混合冗余策略.所以,在相同约束条件下不同混合冗余策略需要采用不同的冗余优化配置方案.     

基于细菌觅食的改进蚁群算法

蚁群算法是模仿蚂蚁觅食行为的一种新的仿生学智能优化算法。针对其收敛速度慢和易陷入局部最优的不足,将细菌觅食算法和蚁群算法相结合,提出一种细菌觅食 蚁群算法。在蚁群算法迭代过程中,引入细菌觅食算法的复制操作,以加快算法的收敛速度;引入细菌觅食算法的趋向操作,以增强算法的全局搜索能力。通过经典的旅行商问题和函数优化问题测试表明,细菌觅食 蚁群算法在寻优能力、可靠性、收敛效率和稳定性方面均优于基本蚁群算法及两种改进蚁群算法。     

改进的重叠蚁群优化算法

针对蚁群优化算法在进行全局最优解搜索时容易陷入局部最优解和收敛速度缓慢等缺陷,提出了一种有效求解全局最优解搜索问题的重叠蚁群优化算法。该算法通过设置多个重叠的蚁群系统,并对每一个蚁群初始化不同的参数,之后在蚁群之间进行信息素的动态学习,增强了不同蚁群对最优解的开采能力,避免了算法出现早熟现象。仿真实验结果表明,重叠蚁群优化算法在避免陷入局部最优解方面具有良好的效果,是一种提高蚁群算法性能的有效的改进算法。     

无线传感网络数据转发最佳权重选取算法仿真

为了有效提高无线传感网络数据转发的有效性和可靠性,针对传统的数据转发算法存在的数据转发率低、延时长等问题,提出一种基于蚁群优化的无线传感网络数据转发最佳权重选取算法。选择无线传感网络数据节点负载、剩余能量以及数据转发时延作为网络服务性能评价指标,利用熵权系数法自适应地确定评价指标的权重。引入数据转发链路容量和链路距离等因素建立数据转发时延最小的优化模型,利用蚁群算法的节点概率函数机制找出能同时满足时延带宽和数据转发链路容量要求的评价值最高的邻居节点,通过上述节点选取数据转发最优权重,完成数据转发。实验结果表明,所提算法在节点能量消耗、转发延迟、数据转发率等方面都优于现有无线传感网络数据转发算法。     

基于文化的连续蚂蚁优化算法的研究*

针对蚂蚁优化算法在求解连续空间问题方面的缺陷,提出一种基于文化的连续蚂蚁优化算法。该算法将蚂蚁优化算法纳入文化算法的框架,组成基于蚂蚁优化算法的主群体和信念的两大空间。在知识和群体层面使用双重进化机制支持问题的求解和知识的提取,从而充分利用精英蚂蚁所携带的特征信息,在很大程度上提高了收敛速度,增强了搜索的多样性。实验结果表明,该算法求解速度快、寻优成功率高,是一种提高蚂蚁优化算法性能的有效算法。     

基于蚁群优化算法的单通道冗余VLSI阵列重构

通过冗余修复方法来解决超大规模集成电路(VLSI)制造过程中因缺陷而造成的成品率低的问题。根据物理阵列中缺陷单元的分布情况,构造相应的矛盾图模型,将阵列的重构问题转化为用蚁群优化算法求解矛盾图的最大独立集问题,使得所求独立集的顶点个数恰为缺陷单元的个数。实验表明,与标准遗传算法和神经网络算法相比,用蚁群优化算法来求解单通道冗余VLSI阵列重构问题是简单有效的。     

基于交互式的并行蚁群优化算法

传统蚁群优化算法研究已经取得了很多重要的成果,但是在解决大规模组合优化问题时仍存在早熟收敛,搜索时间长等缺点.为此,将邻域搜索技术与蚁群优化算法进行融合,提出一种新的并行蚁群优化算法,实验结果表明,在解决大规模TSP问题时,该算法求解质量和稳定性更好,在短时间内即可得到较高质量的解.