Improved auto control ant colony optimization using lazy ant approach for grid scheduling problem

An auto controlled ant colony optimization algorithm controls the behavior of the ant colony algorithm automatically based on a priori heuristic. During the experimental study of auto controlled ACO algorithm on grid scheduling problem, it was observed that the induction of lazy ants not only reduces the time complexity of the algorithm but also produces better results on the given objectives. Lazy ants are basically a mutated version of active ants that remain alive till the fitter lazy ants are generated in the successive generations. This work presents an improved auto controlled ACO algorithm using the lazy ant concept. Performance study reveals the efficacy and the efficiency achieved by the proposed algorithm. A comparative study of the proposed method with some other recent meta-heuristics such as auto controlled ant colony optimization algorithm, genetic algorithm, quantum genetic algorithm, simulated annealing and particle swarm optimization for grid scheduling problem exhibits so.     

Makespan minimization on single batch-processing machine via ant colony optimization

This paper investigates the problem of minimizing makespan on a single batch-processing machine, and the machine can process multiple jobs simultaneously. Each job is characterized by release time, processing time, and job size. We established a mixed integer programming model and proposed a valid lower bound for this problem. By introducing a definition of waste and idle space (WIS), this problem is proven to be equivalent to minimizing the WIS for the schedule. Since the problem is NP-hard, we proposed a heuristic and an ant colony optimization (ACO) algorithm based on the theorems presented. A candidate list strategy and a new method to construct heuristic information were introduced for the ACO approach to achieve a satisfactory solution in a reasonable computational time. Through extensive computational experiments, appropriate ACO parameter values were chosen and the effectiveness of the proposed algorithms was evaluated by solution quality and run time. The results showed that the ACO algorithm combined with the candidate list was more robust and consistently outperformed genetic algorithm (GA), CPLEX, and the other two heuristics, especially for large job instances.     

一种用于网格的启发性智能调度策略

任务调度是计算网格系统中极其关键的一部分,一种好的调度方法可以极大地提高整个系统的性能。针对蚂蚁算法在网格调度中早期信息素匮乏和蚂蚁分工单一的缺陷,提出了一种新的启发性智能调度方法。在调度过程前期,采用遗传算法为各网格节点生成丰富的信息素,作为调度中心进行任务调度的依据,然后在多群蚂蚁算法中,各种群的蚂蚁根据分工的不同在属于自己的空间中寻找最优解,从而缩小了搜索规模,加快了收敛速度,优化了调度性能。     

Two-generation Pareto ant colony algorithm for multi-objective job shop scheduling problem with alternative process plans and unrelated parallel machines

The flexibilities of alternative process plans and unrelated parallel machines are benefit for the optimization of the job shop scheduling problem, but meanwhile increase the complexity of the problem. This paper constructs the mathematical model for the multi-objective job shop scheduling problem with alternative process plans and unrelated parallel machines, splits the problem into two sub-problems, namely flexible processing route decision and task sorting, and proposes a two-generation (father and children) Pareto ant colony algorithm to generate a feasible scheduling solution. The father ant colony system solves the flexible processing route decision problem, which selects the most appropriate process node set from the alternative process node set. The children ant colony system solves the sorting problem of the process task set generated by the father ant colony system. The Pareto ant colony system constructs the applicable pheromone matrixes and heuristic information with respect to the sub-problems and objectives. And NSGAII is used as comparison whose genetic operators are re-defined. The experiment confirms the validation of the proposed algorithm. By comparing the result of the algorithm to NSGAII, we can see the proposed algorithm has a better performance.     

遗传-蚁群算法在智能交通中的应用

随着私家车的增多,城市交通问题越来越严重。为了解决这个问题,人们将计算机技术运用于城市智能交通系统(intelligent transportation systems,ITS)中。行车路径规划是城市智能交通体系中重要的一个环节。目前,有不少路径优化算法被提出用于解决行车路径规划问题,但各有不足。因此,提出了一种混合遗传蚁群算法(GACHA)。从基本蚁群算法入手,结合遗传和蚁群算法的各自优点,将两种算法的寻优过程循环多次结合。在蚁群算法的一次迭代循环后,将蚁群算法产生的较优解代替遗传算法中的部分个体,用以加快遗传算法的迭代速度。同时,将遗传算法算出的解设为较优路径来更新蚁群算法中的信息素分配,实现参数调整。多次相互指导能有效解决蚁群算法前期效率低和遗传算法后期冗余迭代的问题。实验结果表明,遗传-蚁群混合算法可以有效地避免陷入局部最优解,提高计算效率。它具有良好的优化和收敛性,能够准确地找到满足路网综合要求的最优路径。     

DEM中基于遗传与蚁群的混合路径规划算法

现有启发式算法在DEM路径规划中因数据量巨大,效率较低。针对该问题,提出一种基于遗传和蚁群的混合路径规划算法。该算法在遗传过程中,通过在初始群体生成阶段构建选择因子,使得在节点搜索时更加倾向于终点方向,提高初始群体生成效率;对变异过程中变异节点的变异区间进行限制,避免产生路径断点;在蚁群寻优过程中,根据遗传过程产生的路径信息,采用自适应信息素初始化与更新策略,提高算法搜索效率。测试结果表明,混合算法能够在规则网格DEM数据下搜索出符合条件的路径,并具有较好的效率。     

Maximizing availability for task scheduling in computational grid using genetic algorithm

Computational grid provides a wide distributed platform for high‐end compute intensive applications. Grid scheduling is often carried out to schedule the submitted jobs on the nodes of the grid so that some characteristic parameter is optimized. Availability of the computational nodes is one of the important characteristic parameters and measures the probability of the node availability for job execution. This paper addresses the availability of the grid computational nodes for the job execution and proposes a model to maximize it. As such, the task scheduling problem in grid is nondeterministic polynomial‐time hard, and often, metaheuristics techniques are applied to solve it. Genetic algorithm, a metaheuristic technique based on evolutionary computation, has been used to solve such complex optimization problem. This work proposes a technique for the grid scheduling problem using genetic algorithm with the objective to maximize availability. Simulation experiment, to evaluate the performance of the proposed algorithm, is conducted, and results reveal the effectiveness of the model. A comparative study has also been performed. Copyright © 2014 John Wiley & Sons, Ltd.     

Genetic algorithm with ant colony optimization (GA-ACO) for multiple sequence alignment

Multiple sequence alignment, known as NP-complete problem, is among the most important and challenging tasks in computational biology. For multiple sequence alignment, it is difficult to solve this type of problems directly and always results in exponential complexity. In this paper, we present a novel algorithm of genetic algorithm with ant colony optimization for multiple sequence alignment. The proposed GA-ACO algorithm is to enhance the performance of genetic algorithm (GA) by incorporating local search, ant colony optimization (ACO), for multiple sequence alignment. In the proposed GA-ACO algorithm, genetic algorithm is conducted to provide the diversity of alignments. Thereafter, ant colony optimization is performed to move out of local optima. From simulation results, it is shown that the proposed GA-ACO algorithm has superior performance when compared to other existing algorithms.     

基于改进信息素的蚁群算法在QoS 组播路由中的研究

针对传统的蚁群算法在求解大规模旅行商问题时容易导致搜索时间过长或陷入停滞的问题,提出了一种基于改进信息素的蚁群算法。通过蚁群算法的改进,使得每轮搜索之后的信息素都能更好地反映解的质量。实验仿真结果表明,改进后的蚁群算法能获得比传统的蚁群算法更优的解,同时具有更快的收敛速度和较好的稳定性。     

一种新型求解多序列比对问题的方法

多序列比对问题是生物信息科学中一个非常重要且具挑战性的课题,并已经被证明属于问题.为了克服以往算法中的求解速度慢的缺点,本文提出了一种基于遗传算法和蚁群算法的算法来求解的新方法,在单独使用遗传算法的基础上再使用蚁群算法来进行局部搜索以便更快速地求得解.实验结果表明,遗传-蚁群算法能有效地求解多序列比对问题.     

A hybrid ant colony optimization algorithm for optimal multiuser detection in DS-UWB system

A hybrid ant colony optimization algorithm is proposed by introducing extremal optimization local-search algorithm to the ant colony optimization (ACO) algorithm, and is applied to multiuser detection in direct sequence ultra wideband (DS-UWB) communication system in this paper. ACO algorithms have already successfully been applied to combinatorial optimization; however, as the pheromone accumulates, we may not get a global optimum because it can get stuck in a local minimum resulting in a bad steady state. Extremal optimization (EO) is a recently developed local-search heuristic method and has been successfully applied to a wide variety of optimization problems. Hence in this paper, a hybrid ACO algorithm, named ACO-EO algorithm, is proposed by introducing EO to ACO to improve the local-search ability of the algorithm. The ACO-EO algorithm is applied to multiuser detection in DS-UWB communication system, and via computer simulations it is shown that the proposed hybrid ACO algorithm has much better performance than other ACO algorithms and even equal to the optimal multiuser detector.     

Hybridizing ant colony optimization via genetic algorithm for mixed-model assembly line balancing problem with sequence dependent setup times between tasks

This paper presents a new hybrid algorithm, which executes ant colony optimization in combination with genetic algorithm (ACO-GA), for type I mixed-model assembly line balancing problem (MMALBP-I) with some particular features of real world problems such as parallel workstations, zoning constraints and sequence dependent setup times between tasks. The proposed ACO-GA algorithm aims at enhancing the performance of ant colony optimization by incorporating genetic algorithm as a local search strategy for MMALBP-I with setups. In the proposed hybrid algorithm ACO is conducted to provide diversification, while GA is conducted to provide intensification. The proposed algorithm is tested on 20 representatives MMALBP-I extended by adding low, medium and high variability of setup times. The results are compared with pure ACO pure GA and hGA in terms of solution quality and computational times. Computational results indicate that the proposed ACO-GA algorithm has superior performance.     

Heuristics for the two‐machine scheduling problem with a single server

In this paper, the NP‐hard two‐machine scheduling problem with a single server is addressed. The problem consists of a given set of jobs to be scheduled on two identical parallel machines, where each job must be processed on one of the machines, and prior to processing, the job is set up on its machine using one server; the latter is shared between the two machines. An ant colony optimization (ACO) algorithm is introduced for the problem and its performance was assessed by comparing with an exact solution (branch and bound [B&B]), a genetic algorithm (GA), and simulated annealing (SA). The computational results reflected the superiority of “ACO” in large problems, with a performance similar to SA and GA in smaller problems, while solving the tested problems within a reasonable computational time.     

基于遗传算法与蚁群算法动态融合的网格任务调度

深入分析遗传算法和蚁群算法的机理,并结合网格任务调度的研究,提出基于遗传算法和蚁群算法动态融合的网格任务调度策略.该策略通过不同迭代次数中种群相似度的差值实现两种算法的动态融合.仿真实验表明该策略是可行的,并且具有高效性.     

基于改进势场蚁群算法的机器人路径规划

提出一种全局静态环境下移动机器人路径规划的改进势场蚁群算法.该算法采用人工势场法求得的初始路径和机器人与下一个节点之间的距离综合构造启发信息,并引入启发信息递减系数,避免了传统蚁群算法由于启发信息误导所致的局部最优问题;依据零点定理, 提出初始信息素不均衡分配原则,不同的栅格位置赋予不同的初始信息素,降低蚁群搜索的盲目性,提高算法的搜索效率;设定迭代阈值,自适应调节信息素挥发系数,使得该算法具有较高的全局搜索能力,避免出现停滞现象.仿真结果验证了所提出算法的可行性和有效性.     

改进的势场蚁群算法的移动机器人路径规划

针对蚁群算法路径规划初期信息素浓度差异较小,正反馈作用不明显,路径搜索存在着盲目性、收敛速度相对较慢、易陷入局部最优等情况,人工势场算法的势场力可引导机器人快速朝目标位置前进,提出势场蚁群算法,通过栅格法对机器人的工作环境进行建模,利用人工势场中的势场力、势场力启发信息影响系数及蚁群算法中机器人与目标位置的距离构造综合启发信息,并利用蚁群算法的搜索机制在未知环境中寻找一条最优路径。大量的仿真实验表明势场蚁群算法路径规划能找到更优路径和收敛速度更快。     

改进蚁群算法在AGV路径规划中的应用

针对传统蚁群算法在路径规划时,易陷入局部最优、前期路径有效性差等问题,对传统蚁群算法进行改进并应用到AGV（Automated Guided Vehicle）路径规划上。采用栅格地图建立小车工作空间模型,利用改进的头尾搜索机制,提高并加快了算法的全局搜索能力和前期收敛速度;引入奖惩因子与信息素最大最小阈值,对每代最优路径上的信息素进行奖励,最差路径上的进行惩罚,提高全局搜索能力;引入遗传算法变异因子,使算法跳出局部最优能力加强;采用遗传算法对改进的蚁群算法进行参数优化,减少参数对算法的影响。在VS2017和MATLAB软件平台上进行算法仿真。结果表明了该算法在避免局部最优和加快收敛速度方面有很大改进。     

基于16方向24邻域改进蚁群算法的移动机器人路径规划

为了提高蚁群算法的路径寻优效果和搜索效率,提出一种改进的蚁群算法,用于移动机器人在栅格环境下的路径规划.在标准蚁群算法中,蚂蚁的搜索方式一般是4方向4邻域或者8方向8邻域,在此基础上提出一种16方向24邻域的蚂蚁搜索方式,给出蚂蚁的移动规则;针对启发信息,结合向量夹角的思想设计2种启发信息的计算方法,通过实验分析两种计算方法的使用特点;在转移概率部分引入转移概率控制参数,通过调整转移概率控制参数可以调控算法的搜索范围.最后,在不同规模的栅格地图环境下,通过实验仿真验证所提算法的有效性.     

面向机器人全局路径规划的改进蚁群算法研究

针对基本蚁群算法在机器人路径规划过程中路径转弯角度过大、易陷入局部极小值、收敛速度慢等问题,对其进行改进。在分析机器人路径规划环境建模方法基础上,将转角启发函数引入至节点选择概率公式,以增强路径选择指向性,提高算法搜索速度;通过引入当前节点与下一节点之间的距离和下一节点与目标节点距离之和的二次方对启发函数进行改进,使得算法搜索过程更有针对性,并降低陷入局部极小值概率;提出信息素挥发因子自适应更新策略,扩大算法搜索范围,提高收敛速度;利用遗传算法的交叉操作对移动路径进行二次优化,以增强算法的寻优能力,进而以Floyd算法为基础引入路径平滑操作,减少移动路径节点。在MATLAB中与其他算法通过求解多个单模测试函数与多模测试函数进行对比,并在栅格法环境建模中进行机器人全局路径规划仿真对比实验,以验证改进算法在路径寻优速度和质量上更具优越性。仿真结果表明,改进后的蚁群算法具有一定的可行性和有效性。     

遗传融合蚁群算法的改进与仿真

原有的遗传融合蚁群算法虽然克服了基本蚁群算法的不足,优化效果得到了改善,能够克服收敛速度较慢,易出现停滞,以及全局搜索能力较低的缺陷。但是还不够,因此,在原有的遗传融合蚁群算法的基础上进行了许多改进以扩大解的搜索空间,更加提高其全局优化寻优速度。并将遗传融合蚁群算法和改进的遗传融合蚁群算法分别应用于TSPLIB中的Att532TSP问题进行了仿真实验。仿真研究表明,改进后的算法具有更优良的全局优化性能,效果令人满意。