Parallel discrete lion swarm optimization algorithm for solving traveling salesman problem

As a typical representative of the NP-complete problem, the traveling salesman problem(TSP) is widely utilized in computer networks, logistics distribution, and other fields. In this paper, a discrete lion swarm optimization(DLSO) algorithm is proposed to solve the TSP. Firstly, we introduce discrete coding and order crossover operators in DLSO. Secondly, we use the complete 2-opt(C2-opt) algorithm to enhance the local search ability.Then in order to enhance the efficiency of the algorithm, a parallel discrete lion swarm optimization(PDLSO) algorithm is proposed.The PDLSO has multiple populations, and each sub-population independently runs the DLSO algorithm in parallel. We use the ring topology to transfer information between sub-populations. Experiments on some benchmarks TSP problems show that the DLSO algorithm has a better accuracy than other algorithms, and the PDLSO algorithm can effectively shorten the running time.

Traveling Salesman Problem Using an Enhanced Hybrid Swarm Optimization Algorithm

The traveling salesman problem( TSP) is a well-known combinatorial optimization problem as well as an NP-complete problem. A dynamic multi-swarm particle swarm optimization and ant colony optimization( DMPSO-ACO) was presented for TSP.The DMPSO-ACO combined the exploration capabilities of the dynamic multi-swarm particle swarm optimizer( DMPSO) and the stochastic exploitation of the ant colony optimization( ACO) for solving the traveling salesman problem. In the proposed hybrid algorithm,firstly,the dynamic swarms,rapidity of the PSO was used to obtain a series of sub-optimal solutions through certain iterative times for adjusting the initial allocation of pheromone in ACO. Secondly,the positive feedback and high accuracy of the ACO were employed to solving whole problem. Finally,to verify the effectiveness and efficiency of the proposed hybrid algorithm,various scale benchmark problems were tested to demonstrate the potential of the proposed DMPSO-ACO algorithm. The results show that DMPSO-ACO is better in the search precision,convergence property and has strong ability to escape from the local sub-optima when compared with several other peer algorithms.

Application of the edge of chaos in combinatorial optimization

Many problems in science,engineering and real life are related to the combinatorial optimization.However,many combinatorial optimization problems belong to a class of the NP-hard problems,and their globally optimal solutions are usually difficult to solve.Therefore,great attention has been attracted to the algorithms of searching the globally optimal solution or near-optimal solution for the combinatorial optimization problems.As a typical combinatorial optimization problem,the traveling salesman problem(TSP)often serves as a touchstone for novel approaches.It has been found that natural systems,particularly brain nervous systems,work at the critical region between order and disorder,namely,on the edge of chaos.In this work,an algorithm for the combinatorial optimization problems is proposed based on the neural networks on the edge of chaos(ECNN).The algorithm is then applied to TSPs of 10 cities,21 cities,48 cities and 70 cities.The results show that ECNN algorithm has strong ability to drive the networks away from local minimums.Compared with the transiently chaotic neural network(TCNN),the stochastic chaotic neural network(SCNN)algorithms and other optimization algorithms,much higher rates of globally optimal solutions and near-optimal solutions are obtained with ECNN algorithm.To conclude,our algorithm provides an effective way for solving the combinatorial optimization problems.

ISPO: A New Way to Solve Traveling Salesman Problem

This paper first introduces the concepts of mobile operators and mobile sequence, with which it redefines the rate of particle swarm optimization algorithm and the formula of position updating. Combining this discrete PSO algorithm with neighbors, the paper puts forward Hybrd Particle Swarm Optimization Algorithm, whose effectiveness is verified at the end of this paper.

Algorithm for Solving Traveling Salesman Problem Based on Self-Organizing Mapping Network

Traveling salesman problem(TSP)is a classic non-deterministic polynomial-hard optimization prob-lem.Based on the characteristics of self-organizing mapping(SOM)network,this paper proposes an improved SOM network from the perspectives of network update strategy,initialization method,and parameter selection.This paper compares the performance of the proposed algorithms with the performance of existing SOM network algorithms on the TSP and compares them with several heuristic algorithms.Simulations show that compared with existing SOM networks,the improved SOM network proposed in this paper improves the convergence rate and algorithm accuracy.Compared with iterated local search and heuristic algorithms,the improved SOM net-work algorithms proposed in this paper have the advantage of fast calculation speed on medium-scale TSP.

A Binary Particle Swarm Optimization for the Minimum Weight Dominating Set Problem

The minimum weight dominating set problem （MWDSP） is an NP-hard problem with a lot of real-world applications. Several heuristic algorithms have been presented to produce good quality solutions. However, the solution time of them grows very quickly as the size of the instance increases. In this paper, we propose a binary particle swarm optimization （FBPSO） for solving the MWDSP approximately. Based on the characteristic of MWDSP, this approach designs a new position updating rule to guide the search to a promising area. An iterated greedy tabu search is used to enhance the solution quality quickly. In addition, several stochastic strategies are employed to diversify the search and prevent premature convergence. These methods maintain a good balance between the exploration and the exploitation. Experimental studies on 106 groups of 1 060 instances show that FBPSO is able to identify near optimal solutions in a short running time. The average deviation between the solutions obtained by FBPSO and the best known solutions is 0.441%. Moreover, the average solution time of FBPSO is much less than that of other existing algorithms. In particular, with the increasing of instance size, the solution time of FBPSO grows much more slowly than that of other existing algorithms.

New Meta-Heuristic for Combinatorial Optimization Problems：Intersection Based Scaling

Combinatorial optimization problems are found in many application fields such as computer science, engineering and economy. In this paper, a new efficient meta-heuristic, Intersection-Based Scaling (IBS for abbreviation), is proposed and it can be applied to the combinatorial optimization problems. The main idea of IBS is to scale the size of the instance based on the intersection of some local optima, and to simplify the search space by extracting the intersection from the instance, which makes the search more efficient. The combination of IBS with some local search heuristics of different combinatorial optimization problems such as Traveling Salesman Problem (TSP) and Graph Partitioning Problem (GPP) is studied, and comparisons are made with some of the best heuristic algorithms and meta-heuristic algorithms. It is found that it has significantly improved the performance of existing local search heuristics and significantly outperforms the known best algorithms. Keywords combinatorial optimization - TSP (Traveling Salesman Problem) - GPP (Graph Partitioning Problem) - IBS (Intersection-Based Scaling) - meta heuristic Regular PaperThis work is supported by the National Basic Research 973 Program of China (Grant No.TG1998030401).Peng Zou was born in 1979. He received the B.S. degree in computer software from University of Science and Technology of China (USTC) in 2000. Now he is a Ph.D. candidate in computer science of USTC. His current research interests include algorithms for NP-hard problems and parallel computing.Zhi Zhou was born in 1976. He received the B.S. degree in computer software from USTC in 1995. Now he is a Ph.D. candidate in computer science of USTC. His current research interests include combinatorial problem and parallel computing.Ying-Yu Wan was born in 1976. He received the B.S. degree in computer software from USTC in 1997, and the Ph.D. degree from USTC in 2002. His current research interests include parallel computing and combinatorial problem.Guo-Liang Chen was born in 1938. Now he is an Academician of CAS and Ph.D. supervisor in Department of Computer Science at USTC, director of the National High Performance Computing Center at Hefei. His current research interests include parallel computing, computer architecture and combinatorial optimization.Jun Gu was born in 1956. He received the B.S. degree in electronic engineering from USTC in 1982, and the Ph.D. degree in computer science from University of Utah. Now he is a professor and Ph.D. supervisor in computer science at USTC and Hong Kong University of Science and Technology. His main research interrests include algorithms for NP-hard problems.

Hybrid Optimization Algorithm Based on Wolf Pack Search and Local Search for Solving Traveling Salesman Problem

Traveling salesman problem(TSP) is one of the typical NP-hard problems, and it has been used in many engineering applications. However, the previous swarm intelligence(SI) based algorithms for TSP cannot coordinate with the exploration and exploitation abilities and are easily trapped into local optimum. In order to deal with this situation, a new hybrid optimization algorithm based on wolf pack search and local search(WPS-LS)is proposed for TSP. The new method firstly simulates the predatory process of wolf pack from the broad field to a specific place so that it allows for a search through all possible solution spaces and prevents wolf individuals from getting trapped into local optimum. Then, local search operation is used in the algorithm to improve the speed of solving and the accuracy of solution. The test of benchmarks selected from TSPLIB shows that the results obtained by this algorithm are better and closer to the theoretical optimal values with better robustness than those obtained by other methods.

A Simulated Annealing-Based Algorithm for Traveling Salesman Problem

This paper presents a simulated annealing based algorithm for traveling salesman problem (SATSP),which was applied to the symmetrical traveling salesman problem about 31 cities of China and proved to be the best of all the algorithms at present.

基于离散粒子群算法的管道保温结构优化研究

针对目前管道保温结构优化算法不稳定、结果优化程度不高的问题,建立以经济效益为目标函数,以满足国家散热损失标准等条件为约束函数的离散型数学模型。以BPSO算法为基础改变其位置更新规则,防止种群进化失效;采用自适应权重增加粒子的全局和局部搜索能力;充分利用模拟退火算法的思想避免出现早熟现象。应用改进的算法分别对普通蒸汽管道和核电站的蒸汽管道进行系统仿真实验。结果表明,该算法能够在满足国家散热损失标准等条件下取得最优解,可以为管道保温结构提供合理的优化方案。

带冲突图的着色旅行商问题模型与算法

着色旅行商问题是多旅行商问题的一个重要变种,它被广泛地应用于带有重叠区域的多机工程系统。现有的着色旅行商问题难以有效应对带冲突的场景,这种冲突通常表现为两个城市不允许被同一旅行商访问。受带冲突图的组合优化问题的启发,提出了带冲突图的着色旅行商问题,且给出了其形式化的表达。带冲突图的着色旅行商问题是一个NP难问题,精确算法求解器CPLEX仅能在小规模问题实例上获得问题的最优解。为了求解更大规模的实例,提出了一个有效的模因算法。该模因算法采用了自适应大规模邻域搜索算子。对比模因算法和精确算法,模因算法在20个小规模实例中的9个结果更好,在18个实例上展现了其远超精确算法的求解速度。而比较模因算法和其他启发式算法,模因算法在全部14个中等规模实例上均取得了更好结果。此外,消融实验结果验证了模因算法中自适应大规模领域搜索算子的有效性。

基于离散沙猫群优化算法的焊接路径规划

为实现对焊点焊接的最优路径规划,减少焊接路径长度,提高焊接效率,提出离散沙猫群优化算法。以汽车后门饰板为例,建立焊接路径规划优化模型。将沙猫群优化算法初始化改为最近邻初始化,使用5个离散转换算子及其随机组合和交叉操作实现沙猫觅食、攻击阶段的离散化,增加全局记忆功能,嵌入模拟退火算法更新准则和改进的3-opt算法,使得算法不易陷入局部最优解,提高算法性能。在6个标准算例和一个汽车后门饰板实例上验证了所提算法的有效性,相对于其他几种算法所得的结果更优,且更稳定。

基于改进自适应遗传算法的旅行商问题研究

传统遗传算法因其强大的全局搜索能力成为了解决旅行商问题的优选之一,但它较差的局部搜索能力限制了该算法在寻求最优解时的效能。为解决此问题,笔者通过改良圈算法优化初始解,在进化过程中自适应调整进行各遗传操作的概率,结合模拟退火算法的关键步骤metropolis准则和加入逆转操作,基于随机模拟的策略对遗传算法进行改进并将其应用于求解旅行商问题。仿真结果表明,改进的遗传算法在算法收敛速度、收敛效果和解质量方面均优于传统遗传算法。

基于二分法和控制信息素量的改进蚁群算法

为弥补蚁群算法易陷入局部最优、收敛速度较慢等不足,提出一种基于二分法和控制信息素量的改进蚁群算法。在每次迭代结束时,利用二分法放弃行走路程较远的半数蚁群的信息素,使收敛速度得到提高;利用3-opt局部优化方法提高解的精度;通过控制信息素量动态调整蚁群选择路径的概率,避免算法早熟;将改进的算法应用于旅行商问题。实验结果表明,该算法在寻优能力、可靠性、收敛速度以及稳定性方面均表现出明显的优越性。

基于混合人工蜂群算法和A^(*)算法的求解旅行商问题算法

针对旅行商问题(travel salesman problem,TSP),基于群智能优化算法的人工蜂群算法(artificial bee colony,ABC)可以较为有效地解决并规划出一条合理的路线。ABC算法的优点在于将优化求解的过程转化为模仿蜂群采蜜的仿生行为,容易求得可行解。但是该算法依然存在着种群数量过多、速度较慢的缺点。分析了ABC算法的模型并对更新策略进行了改进,在ABC算法得到初始解的路径点后再使用A-star算法进行优化,通过将两种算法组合的方式进行改进。实验证明在解决TSP的路径规划中,整体的路径表现更优,且减少了冗杂的迭代更新,提升了算法的效果。

求解旅行商问题的改进k-opt遗传算法

为了增强遗传算法的局部搜索能力,加速算法运行效率,尽量避免算法陷入早熟问题,提出一种改进k-opt遗传算法求解旅行商问题。该算法利用改进的k-opt方法初始化获得较优种群,引入改进的交叉变异机制增强算法全局搜索能力,结合改进的k-opt方法强化算法局部搜索能力。实验结果表明,改进的k-opt遗传算法能有效平衡算法探索和开发能力,其求解的质量优且运行效率高。

基于改进粒子群算法的路径规划研究与应用

为解决应用于旅行商问题的基本粒子群算法存在的收敛精度不高且早熟等问题,提出一种改进自适应杂交退火粒子群(IAHAPSO)算法。该算法采用基于种群离散度的分种群式自适应调整惯性权重,引导种群的正确进化发展方向;采用模拟退火算法更新群体极值的策略,避免粒子搜索陷入局部最优解;并在种群发展过程中引入遗传杂交算子,增加种群的多样性。通过3种标准TSPLIB测试集验证所提IAHAPSO算法在求解精度及效率上的可行性和优越性。以四轴裁剪机试验系统进一步验证所提算法的有效性。

粒子群优化算法求解旅行商问题

首先介绍粒子群优化的搜索策略与基本算法 ,然后通过引入交换子和交换序的概念 ,构造一种特殊的粒子群优化算法 ,并用于求解旅行商问题 .实验表明了在求解组合优化问题中的有效性 .

基于蚂蚁算法的混合方法求解旅行商问题

通过介绍蚂蚁觅食过程中最短路径的搜索策略,给出蚂蚁算法在旅行商问题中的应用,并加入3-opt方法和去交叉策略对问题求解进行局部优化.实验结果证明了其有效性.

改进微粒群优化算法求解旅行商问题

对微粒群优化算法的速度位置算式进行了改进,提出一种改进的微粒群优化算法。该算法符合组合优化问题的特点,在求解旅行商问题上有较高的搜索效率。将改进的PSO算法分别应用于14点的TSP问题以及中国旅行商问题中,该算法在较短时间内获得了目前已知的最好解。