改进量子进化算法及其在物流配送路径优化问题中的应用

量子进化算法的性能直接受量子旋转门旋转角计算方法的影响.文中提出一种改进量子进化算法,核心是设计了基于量子比特概率幅比值自适应计算量子旋转门旋转角的新方法,算法具有收敛速度快和全局搜索能力强的特点.通过0/1背包问题分析了新方法中相关参数对算法性能的影响,并应用算法求解物流配送路径优化问题,仿真表明改进量子进化算法性能优于量子进化算法和传统进化算法.     

量子搜索和进化搜索算法的比较研究

该文以求解一些NP问题(如TSP问题和背包问题)为例,分析了运行在量子计算机上的量子搜索算法和运行在经典计算机上的进化搜索算法的本质区别,同时也论述了它们之间相互结合的方法,特别是运行在经典计算机上的量子驱动的进化算法。     

一种新的量子群进化算法研究

提出了一种基于量子进化的量子群进化算法，使用量子角表示量子比特的状态，并引入改进的粒子群优化策略，对量子群中各量子的量子角进行自适应动态调整．在对0-1背包问题的求解中，表现出很好的性能．     

Measuring instance difficulty for combinatorial optimization problems

Discovering the conditions under which an optimization algorithm or search heuristic will succeed or fail is critical for understanding the strengths and weaknesses of different algorithms, and for automated algorithm selection. Large scale experimental studies - studying the performance of a variety of optimization algorithms across a large collection of diverse problem instances - provide the resources to derive these conditions. Data mining techniques can be used to learn the relationships between the critical features of the instances and the performance of algorithms. This paper discusses how we can adequately characterize the features of a problem instance that have impact on difficulty in terms of algorithmic performance, and how such features can be defined and measured for various optimization problems. We provide a comprehensive survey of the research field with a focus on six combinatorial optimization problems: assignment, traveling salesman, and knapsack problems, bin-packing, graph coloring, and timetabling. For these problems - which are important abstractions of many real-world problems - we review hardness-revealing features as developed over decades of research, and we discuss the suitability of more problem-independent landscape metrics. We discuss how the features developed for one problem may be transferred to study related problems exhibiting similar structures.     

基于自适应继承策略的帝国竞争算法求解旅行商问题

针对帝国竞争算法在求解旅行商问题时局部搜索能力不强和容易陷入局部最优的缺陷,提出一种基于自适应继承策略的帝国竞争算法.该算法采用自适应继承策略的启发式交叉算子、单点局部插入策略和固定邻域的2-opt算子来增强算法的局部优化能力,并加入帝国精英解集以保持种群的多样性.通过标准实例测试,验证了所提出的改进策略的优越性,与基于启发式交叉算子和帝国主义算法为框架的其他算法进行对比,实验结果表明,该算法求解中小规模的解旅行商问题具有较高的求解精度和较快的收敛速度.     

Quantum-inspired evolutionary algorithm for a class of combinatorial optimization

This paper proposes a novel evolutionary algorithm inspired by quantum computing, called a quantum-inspired evolutionary algorithm (QEA), which is based on the concept and principles of quantum computing, such as a quantum bit and superposition of states. Like other evolutionary algorithms, QEA is also characterized by the representation of the individual, evaluation function, and population dynamics. However, instead of binary, numeric, or symbolic representation, QEA uses a Q-bit, defined as the smallest unit of information, for the probabilistic representation and a Q-bit individual as a string of Q-bits. A Q-gate is introduced as a variation operator to drive the individuals toward better solutions. To demonstrate its effectiveness and applicability, experiments were carried out on the knapsack problem, which is a well-known combinatorial optimization problem. The results show that QEA performs well, even with a small population, without premature convergence as compared to the conventional genetic algorithm.     

应用改进的遗传算法求解TSP问题

旅行商问题,也称货郎担问题,属于完全NP问题,而遗传算法在解决组合排列问题方面占有很重要的地位.针对TSP问题,提出了一种改进的遗传算法.利用交换启发交叉算子和可变交叉概率实现局部搜索,加快算法的收敛速度,利用变换变异算子和可变变异概率维持群体的多样性防止算法早熟收敛.Java仿真实验结果表明,改进后的算法明显优于传统的遗传算法,说明该算法具有良好的有效性和可行性.     

The period traveling salesman problem: a new heuristic algorithm

A new, simple and effective heuristic algorithm has been developed for the period traveling salesman problem. Computational results obtained from the test problems taken from the literature indicate that the algorithm compares well in terms of accuracy with other existing algorithms, finding a larger number of best solutions. Moreover, its average percentage error and its worst ratio of solution to the best-known solution are smaller than those of the other existing algorithms.Scope and purposeIn the period traveling salesman problem, a traveling salesman must visit each city a fixed number of times over a given m-day planning period. Each city specifies a set of sequences of visit days and the visit days are assigned to the city by selecting one of these sequences. Moreover, for each day of the planning period, a not empty tour must be generated by connecting the salesman home city and the cities that must be visited on that day. The salesman objective is to minimize the total distance traveled over the entire m-day period. For this problem, arising in various situations such as mail delivery or lawn-care services, the paper proposes a simple and effective heuristic algorithm where an improvement procedure is embedded within a tour construction type procedure.     

A study on a quantum-inspired evolutionary algorithm based on pair swap

A quantum-inspired evolutionary algorithm (QEA) is proposed as a stochastic algorithm to perform combinatorial optimization problems. The QEA is evolutionary computation that uses quantum bits and superposition states in quantum computation. Although the QEA is a coarse-grained parallel algorithm, it involves many parameters that must be adjusted manually. This paper proposes a new method, named pair swap, which exchanges each best solution information between two individuals instead of migration in the QEA. Experimental results show that our proposed method is a simpler algorithm and can find a high quality solution in the 0-1 knapsack problem. This work was presented in part at the 12th International Symposium on Artificial Life and Robotics, Oita, Japan, January 25–27, 2007     

Improving Combinatorial Optimization Algorithms through Record Keeping in Constructive Multistart Search

Constructive multistart search algorithms are commonly used to address combinatorial optimization problems; however, constructive multistart search algorithm performance is fundamentally affected by two factors: (i) The choice of construction algorithm utilized and (ii) the rate of state space search redundancy. Construction algorithms are typically specific to a particular combinatorial optimization problem; therefore, we first investigate construction algorithms for iterative hill climbing applied to the traveling salesman problem and experimentally determine the best performing algorithms. We then investigate the more general problem of utilizing record‐keeping mechanisms to mitigate state space search redundancy. Our research shows that a good choice of construction algorithm paired with effective record keeping significantly improves the quality of traveling salesmen problem solutions in a constant number of state explorations. Particularly, we show that Bloom filters considerably improve time performance and solution quality for iterative hill climbing approaches to the traveling salesman problem.     

基于交换策略的蚁群算法求解多维0-1背包问题

在项目决策与规划、资源分配、货物装载等工作中,提出了多维0-1背包问题,对这一问题,国内外学者提出了许多算法。本文推广了文献[7]中求解单维0-1背包问题的蚁群算法,并从结合2-opt等局部优化的蚁群算法求解旅行商问题中得到启示：通过交换策略可以加快算法的收敛速度和获取更高质量的解,因此提出了基于交换策略的蚁群算法。再把这种算法与AIAACA算法进行比较,实验结果显示该算法与AIAACA算法效果相当,用时更少,是求解多雏0-1背包问题的有效算法。     

高效软硬件划分算法及其提升技术

软硬件划分是软硬件协同设计的关键环节,它决定系统中哪些组件由软件实现,哪些由硬件实现。软硬件划分问题已被证明是NP完全问题。将一类软硬件划分问题看作变异的0-1背包问题,在求解背包问题的算法基础上构造出软硬件划分问题的优质启发解。此外,采用禁忌搜索(Tabu Search)算法对求得的启发解进行改进,在软件开销和通信开销满足一定约束的条件下,使得硬件开销尽可能小。实验结果证明,所提算法对当前最新算法的改进最大可达到28%。     

一种快速求解旅行商问题的蚁群算法

蚁群优化是一种元启发式的随机搜索技术,是目前解决组合优化问题最有效的工具之一.将信息素更新和随机搜索机制的改进相结合,提出一种快速求解旅行商问题的蚁群算法.首先给出了一种新的信息素增量模型,以体现蚂蚁在不同路径上行走时所产生的信息素差异;然后以蚂蚁经过的路径(直线段)作为信息素扩散浓度场的信源,改进了信息素扩散模型,强化了蚂蚁间的协作和交流;最后采用较低复杂度的变异策略对迭代的结果进行优化.在大量通用数据集上的实验表明,该算法不仅能获得更好的最优解,而且收敛速度有显著的提高.     

蚁群算法在求解旅行商问题中的应用综述

旅行商问题作为组合优化研究中最具挑战的问题之一, 自被提出以来就引起了学术界的广泛关注并提出了大量的方法来解决它. 蚁群算法是求解复杂组合优化问题的一种启发式仿生进化算法, 是求解旅行商问题的有效手段. 本文分别介绍蚁群算法中几个有代表性的算法, 综述了蚁群算法的改进、融合和应用的文献研究进展, 以评价近年来不同版本的蚁群算法为解决旅行商问题的发展和研究成果, 并针对改进蚁群算法结构框架、算法参数的设置及优化、信息素优化和混合算法等方面, 对现被提出的改进算法进行了分类综述. 对蚁群算法在未来对旅行商问题及其他不同领域的研究内容和研究热点的进一步发展提供了展望和依据.     

混合量子进化算法及其应用

文章将量子进化算法(QEA)和粒子群算法(PSO)互相结合,提出了两种混合量子进化算法。第一种算法叫做嵌入式粒子群量子进化算法,其主要思想是将简化的PSO进化方程嵌入QEA的进化操作中,简化了QEA算法的结构,增强了QEA跳出局部极值的能力。第二种算法叫做量子二进制粒子群算法,其主要思想是将QEA中的量子染色体的概念引入二进制粒子群算法(BPSO),提高了BPSO算法保持种群多样性的能力和运算速度。通过对0-1背包问题和多用户检测问题的求解表明,新的算法不仅操作更简单,而且全局搜索能力有了显著的提高。     

Premium-penalty ant colony optimization and its application in slope stability analysis

Ant colony optimization (ACO) is a very suitable path search algorithm, whose typical application is traveling salesman problem. However, as one heuristic algorithm, it has many shortcomings, such as slow convergent speed and low searching efficiency. To overcome these shortcomings, the premium-penalty strategy has been introduced, and the pheromone diversity of the good paths and the ordinary ones is increased to polarize pheromone density of all paths. Thus, premium-penalty ant colony optimization (PPACO) is proposed. And its good performance is verified by the applications to some typical traveling salesman problems. Its two important parameters are discussed too. Because location critical slip surface in slope stability analysis is a path search problem, it can be solved by the ACO very suitably. Therefore, based on PPACO and typical mature limit equilibrium analysis (Spencer method), a new method to analyze the slope stability is proposed. Through two typical examples, one simple slope and one complicated slope, the efficiency and effectiveness of the new algorithm are verified. The results show that, the new algorithm can always find the less safety factor and its critical slip surface in shorter time than many previous algorithms, and the new algorithm can be used in real engineering very well.     

Solving the traveling salesman problem with annealing-basedheuristics: a computational study

Recently, several general optimization algorithms based on the demon algorithm from statistical physics have been developed and tested on a few traveling salesman problems with encouraging results. In this paper, we conduct an extensive computational study of 11 annealing-based heuristics for the traveling salesman problem. We code versions of simulated annealing, threshold accepting, record-to-record travel and eight heuristics based on the demon algorithm. We apply each heuristic to 29 traveling salesman problems taken from a well-known online library, compare the results with respect to accuracy and running time and provide insights and suggestions for future work     

基于自适应机制的多宇宙并行量子衍生进化算法

进化参量的选取对量子衍生进化算法(QEA)的优化性能有极大的影响,传统QEA在选择进化参量时并未考虑种群中个体间的差异,种群中所有个体采用相同的进化参量完成更新,导致算法在解决组合优化问题中存在收敛速度慢、容易陷入局部最优解等问题。针对这一问题,采用自适应机制调整QEA的旋转角步长和量子变异概率,算法中任意一代的任一个体的进化参量均由该个体自身适应度确定,从而保证尽可能多的进化个体能够朝着最优解方向不断靠近。此外,由于自适应量子进化算法需要评估个体的适应度,导致运算时间较长,针对这一问题则采用多宇宙机制将算法分布于多个宇宙中并行实现,从而提高算法的执行效率。通过搜索多峰函数最优解和求解背包问题测试算法性能,结果表明,与传统QEA相比,所提出算法在收敛速度、搜索全局最优解及执行速度方面具有较好的表现。     

0/1背包问题的量子算法

近年来针对各种问题提出了许多量子算法,这些量子算法都利用了量子态的可迭加性(Superposition)和纠缠性(Entan-glement),本文在量子环境下对0/1背包问题进行求解,介绍了量子算法的基本思想及相关概念。然后分析并给出求解0/1背包问题的量子算法,在量子物理环境下它能在多项式时间内求出所需要的解。这个量子算法可以推广解决其它NPC问题,如旅行售货员问题等。     

混合量子差分进化算法及应用

量子进化算法基于量子旋转门更新量子比特状态影响了算法搜索性能．提出一种差分进化（DE）与和声搜索（Hs）相结合更新量子比特状态的混合量子差分进化算法（HQDE）．该方法采用实数量子角形式编码染色体,设计一种由差分进化计算更新量子位状态的量子差分进化算法（QDE）和一种由和声搜索更新量子位状态的量子和声搜索（QHS）,并相互机制融合,采用两种不同进化策略共同作用产生种群新量子个体以克服常规算法中早熟及收敛速度慢等缺陷;在此基础上,算法还引入量子非门算子对当前最劣个体以一定概率选中的量子比特位进行变异操作增强算法跳出局部最优解能力．理论分析证明该算法收敛于全局最优解．0／1背包问题及旅行商问题实例测试结果验证了该方法有效性．