Weak-restriction bi-objective optimization algorithm for scheduling with rejection on non-identical batch processing machines

We investigate the problem of scheduling a set of jobs with arbitrary sizes and unequal weights on a set of parallel batch machines with non-identical capacities. The objective is to minimize the makespan of the accepted jobs and the total rejection penalty of the rejected jobs, simultaneously. To address the studied problem, a Pareto-based ant colony optimization algorithm with the first job selection probability (FPACO) is proposed. A weak-restriction selection strategy is proposed to obtain the desirability of candidate jobs. Two objective-oriented heuristic information and pheromone matrices are designed, respectively, to record the experience in different search dimensions. Moreover, a local optimization algorithm is incorporated to improve the solution quality. Finally, the proposed algorithm is compared with four existing algorithms through extensive simulation experiments. The experimental results indicate that the proposed algorithm outperforms all of the compared algorithms within a reasonable time.     

不同容量平行机下差异工件尺寸的批调度算法

在容量不同的平行批处理机环境下, 针对工件带有不同尺寸和机器适用限制的最小化制造跨度的批调度问题, 提出一种有效的蚁群优化算法. 该算法基于解的浪费空间定义启发式信息, 针对机器容量约束提出两种用于构建解的候选集, 从而有效缩小搜索空间, 并引入局部优化方法提高解的质量. 仿真实验结果表明, 所提出算法具有较好的性能, 并且优于已有的其他算法.

     

A hybrid genetic heuristic for scheduling parallel batch processing machines with arbitrary job sizes

This paper investigates the scheduling problem of parallel identical batch processing machines in which each machine can process a group of jobs simultaneously as a batch. Each job is characterized by its size and processing time. The processing time of a batch is given by the longest processing time among all jobs in the batch. Based on developing heuristic approaches, we proposed a hybrid genetic heuristic (HGH) to minimize makespan objective. To verify the performance of our algorithm, comparisons are made through using a simulated annealing (SA) approach addressed in the literature as a comparator algorithm. Computational experiments reveal that affording the knowledge of problem through using heuristic procedures, gives HGH the ability of finding optimal or near optimal solutions in a reasonable time.     

Online batch scheduling on parallel machines with delivery times

We study the online batch scheduling problem on parallel machines with delivery times. Online algorithms are designed on m parallel batch machines to minimize the time by which all jobs have been delivered. When all jobs have identical processing times, we provide the optimal online algorithms for both bounded and unbounded versions of this problem. For the general case of processing time on unbounded batch machines, an online algorithm with a competitive ratio of 2 is given when the number of machines m=2 or m=3, respectively. When m≥4, we present an online algorithm with a competitive ratio of 1.5+o(1).     

A genetic algorithm application using fuzzy processing times in non-identical parallel machine scheduling problem

There are many scheduling problems which are NP-hard in the literature. Several heuristics and dispatching rules are proposed to solve such hard combinatorial optimization problems. Genetic algorithms (GA) have shown great advantages in solving the combinatorial optimization problems in view of its characteristic that has high efficiency and that is fit for practical application [1]. Two different scale numerical examples demonstrate the genetic algorithm proposed is efficient and fit for larger scale identical parallel machine scheduling problem for minimizing the makespan. But, even though it is a common problem in the industry, only a small number of studies deal with non-identical parallel machines. In this article, a kind of genetic algorithm based on machine code for minimizing the processing times in non-identical machine scheduling problem is presented. Also triangular fuzzy processing times are used in order to adapt the GA to non-identical parallel machine scheduling problem in the paper. Fuzzy systems are excellent tools for representing heuristic, commonsense rules. That is why we try to use fuzzy systems in this study.     

蚁群算法优化模糊规则

模糊控制器设计的关键是根据专家经验确定模糊规则。然而,在专家经验难以获取的情况下将无法进行设计,这就要求模糊规则能够自动优化。模糊规则的优化过程为前件选择后件的过程,是一个组合优化问题,本文应用蚁群算法对其进行优化。蚁群算法是一种新型的模拟进化算法,已被广泛且有效的应用到求解复杂的组合优化问题中。仿真结果显示了蚁群算法应用于优化模糊规则的可行性和有效性,扩大了蚁群算法的应用范围,也为模糊控制器的设计提供了新的思路。     

多目标蚁群优化网格调度算法

提出基于蚁群算法的网格调度算法,优化作业完成时间。同时局部升级和全局升级采用不同策略,解决资源负载均衡问题,满足网格的多目标优化。最后通过Gridsim仿真环境和其他算法进行比较分析。     

用于求解函数优化的蚁群算法设计

为了求解一般的函数优化,在对标准蚁群算法研究的基础上,将遗传算法的编码方式引入蚁群算法,对蚁群算法的信息素更新进行改进,并提出一种搜索矩阵表达方式,减少了搜索矩阵的规模,从而提高了搜索效率。通过对几个经典测试函数的求解,证明了算法的有效性。     

求解差异工件批调度问题的改进型蚁群算法

针对最小化制造跨度的差异工件尺寸单批处理机调度问题,通过将其转化为最小化浪费空间的问题,采用候选集策略构建分批以减少搜索空间,利用基于浪费空间的启发式更新信息素,提出一种改进的最大最小蚁群算法。此外,在算法中还引入了一种局部优化策略,以进一步提高算法的性能。仿真实验结果表明,所提出的算法优于其他几种已有算法,验证了所提出算法的有效性和鲁棒性。     

蚁群算法求解函数优化中的参数设置

蚁群算法的参数设置一直是依靠经验和实验来确定,造成实验工作量大且难以得到最优的参数组合,影响了算法的使用。从基本蚂蚁算法出发,结合实验结果,讨论了α、β及ρ的变化对实验结果的影响,提出了相应的参数改进方案。并将经此方案修正的蚂蚁算法与基本蚂蚁算法同时运用于经典函数优化问题中,对仿真结果进行了对比。     

基于局部优化策略求解TSP的蚁群算法*

为了克服基本蚁群算法收敛速度慢、易于停滞的缺陷,提出了一种基于局部优化策略的蚁群算法（LOACA）。该算法根据TSP的特点,采用了三种局部优化算子来交换搜索路径中城市的位置,以改进解的质量。以TSP为例进行的实验结果表明,该算法优于ACA和ACAGA。     

基于滚动变时间窗的重组批处理机调度研究

针对具有等待时间限制和工件动态到达的重组批处理机调度问题,以拖延时间和最小为目标,提出基于滚动变时间窗的三层混合调度算法。该调度算法是应用滚动时域策略,将重组批处理机调度问题分解为许多变时间窗的子问题;每个子问题调度分三层执行：即产生触发并传递参数、重组批及排序、派工并更新参数。通过实时调度仿真平台和CPLEX平台进行实例验证,结果表明基于滚动变时间窗的三层混合调度算法能够在较短计算时间内获得满意优化解。     

基于遗传算法的可变机器约束模糊作业调度

对同时考虑模糊加工时间和模糊交货期,以及工件的某道工序有多台机器可供选择的模糊作业车间调度问题进行了研究,在 Giffler & Thompson算法的基础上引入了基于优先规则的冲突处理方法,并且设计了相应的遗传算子,保证遗传操作后的染色体搜索空间仍然属于活动调度集,最后通过仿真实验,验证了该算法的有效性。     

基于蚁群算法的航班网络座位优化研究

座位优化是航空公司增加收益的有效方法,航班网络座位优化是目前主要的研究方向。针对起始地 目的地 舱位票价（ODF）和座位数组合的复杂性,传统的优化模型由于决策变量数多,难以用于实际计算;改进的线性规划方法在一定程度上改善了模型的实用性,但在求解大规模的网络问题时,计算时间长,复杂度高。采用蚁群算法求解网络座位优化问题能克服以上不足。实验结果表明,蚁群算法能快速得到令人满意的解;同时,蚁群算法简化了问题复杂度,思想简单,易于实现。     

变异蚁群优化算法在流水作业排序中的应用

在采用蚁群算法求解流水作业排序中,针对蚁群算法存在的时间过长及过早收敛问题,使用解锁素及信息素挥发率作为启发式信息并引入局部优化,对蚁群系统加以改进。计算机仿真结果表明,改进后的蚁群系统对流水作业优化调度有较好的效果。     

基于变异操作的蚁群算法用于连续函数优化

介绍了基本蚁群算法的数学模型,在一种新的连续空间分解方法的基础上,对信息素更新方式进行了改进,采用信息素局部更新和自适应的信息素全局更新相结合的方式,以提高算法的收敛速度。引入了进化算法中的变异操作,对寻优过程中每次迭代的最优解进行变异,增加了种群的多样性,避免算法的早熟,以提高改进后蚁群算法的全局收敛性能。实验结果表明,提出的基于变异操作的蚁群算法在连续函数寻优上有更好的收敛速度和收敛性能。     

基于局部禁忌搜索策略的连续空间蚁群算法

针对蚁群算法容易陷入局部最优解及搜索时间长等不足,引入一种基于连续空间的禁忌搜索算法,并将其与蚁群算法相结合,提出了一种引入禁忌搜索策略的蚁群算法,以求解连续对象优化问题。经测试验证了该算法不仅跳出局部最优解的能力更强,而且能较快地收敛到全局最优解,表明算法的有效性。     

Scheduling jobs with equal processing times and time windows on identical parallel machines

We present a linear programming approach to the problem of scheduling equal processing time jobs with release dates and deadlines on identical parallel machines. The known algorithm with complexity O(n ³log log n) of B. Simons schedules all the jobs while minimizing both the maximum completion time and the mean flow time. Our approach permits also to minimize the weighted sum of completion times and total tardiness in polynomial time for the problems without deadlines. The complexity status of these problems was open. Contract/grant sponsor: Alexander von Humboldt Foundation.     

Fuzzy due-date scheduling problem with fuzzy processing time

For most of scheduling problems, jobs' processing times and due-dates are treated as certain values, but that is not proper to all actual situations. Processing times are not constant because of measurement errors in the data sets for deciding them and/or human actions in the manufacturing process. However, we may be permitted to exceed due-dates slightly. In this paper, we propose a model dealing with uncertain processing times and flexible due-dates in consideration of real situations. Assuming the times and due-dates to be fuzzy numbers, and defining a fuzzy tardiness for a job's due-date, we design to minimize the number of tardy jobs in our problem formulation.