共查询到20条相似文献,搜索用时 625 毫秒
1.
We deal with the application of ant colony optimization to group shop scheduling, which is a general shop scheduling problem that includes, among others, the open shop scheduling problem and the job shop scheduling problem as special cases. The contributions of this paper are twofold. First, we propose a neighborhood structure for this problem by extending the well-known neighborhood structure derived by Nowicki and Smutnicki for the job shop scheduling problem. Then, we develop an ant colony optimization approach, which uses a strong non-delay guidance for constructing solutions and which employs black-box local search procedures to improve the constructed solutions. We compare this algorithm to an adaptation of the tabu search by Nowicki and Smutnicki to group shop scheduling. Despite its general nature, our algorithm works particularly well when applied to open shop scheduling instances, where it improves the best known solutions for 15 of the 28 tested instances. Moreover, our algorithm is the first competitive ant colony optimization approach for job shop scheduling instances. 相似文献
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We consider general properties of isomorphic scheduling problems that constitute a new class of pairs of mutually related scheduling problems. Any such a pair is composed of a scheduling problem with fixed job processing times and its time-dependent counterpart with processing times that are proportional-linear functions of the job starting times. In order to introduce the class formally, first we formulate a generic scheduling problem with fixed job processing times and define isomorphic problems by a one-to-one transformation of instances of the generic problem into instances of time-dependent scheduling problems with proportional-linear job processing times. Next, we prove basic properties of isomorphic scheduling problems and show how to convert polynomial algorithms for scheduling problems with fixed job processing times into polynomial algorithms for proportional-linear counterparts of the original problems. Finally, we show how are related approximation algorithms for isomorphic problems. Applying the results, we establish new worst-case results for time-dependent parallel-machine scheduling problems and prove that many single- and dedicated-machine time-dependent scheduling problems with proportional-linear job processing times are polynomially solvable. 相似文献
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自私调度问题是一类应用于互联网和云计算的特殊调度问题.不同于传统调度问题,它的每个工件是一个自私的参与者,可以自主地选择一台机器加工以谋求自身加工费用最小化.针对机器可以自由选择WSPT机制或PS机制的混合协调分配机制自私调度问题,通过设计一个该问题的松弛线性规划,然后写出该线性规划的对偶规划.比较上述两个规划的最优目标值,以及该自私调度问题的最优社会费用和混合Nash均衡解的最差社会费用这四个数值,分析出该自私调度问题的混合社会无序代价为4. 相似文献
4.
We introduce constraint-based scheduling and discuss its main principles. An approximation algorithm based on tree search is developed for the job shop scheduling problem using ILOG SCHEDULER. A new way of calculating lower bounds on the makespan of the job shop scheduling problem is presented and we show how such results can be used within a constraint-based approach. An empirical performance analysis shows that the algorithm we developed performs well. Finally, taking the job shop scheduling problem as a start point, we discuss how constraint-based scheduling can be used to solve more general scheduling problems. 相似文献
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二机系统调度在一类线性摄动下具有鲁棒性的一个充要条件 总被引:3,自引:0,他引:3
用实数集R上一个含幺Abelian半群的性质研究了n/2/F/Cmax调度在一类线性摄动下具有鲁棒性的条件.由最优鲁棒调动的定义,证明了标称系统的最优鲁棒调度与标称系统的越-韩最优调度是等价的. 相似文献
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The transportation industry problem of scheduling vehicles combines the spatial characteristics of routing with time domain considerations of activity schedules. The problem is complex because of the numerous interacting constraints in the spatial and time domains. Further, some of the constraints are flexible and some arise in real-time. The scheduling problem is often presented with multiple objectives that are not all economic in nature and which can be contradictory to one another. In response to these needs, this paper describes an analogical reasoning model management system, called ARMMS, designed in the domain of vehicle scheduling. ARMMS consists of knowledge bases and data bases, a truth maintenance system, a user interface, an inference engine, a learning mechanism, and a model library. Given a scheduling problem, ARMMS searches its memory for solutions. If no solution is available, ARMMS falls back on an analogical problem solving approach in which similar experience can be recalled, and solutions to new, but similar, problems can be constructed. If no similar experience exists, ARMMS intelligently selects an appropriate algorithmic model from its model library, based on the input parameters and problem type, to solve the given problem. By combining experts' knowledge, analogical problem-solving approaches, and algorithmic methods, ARMMS provides an efficient problem-solving approach for vehicle scheduling and routing. ARMMS is also a feasible base for the development of intelligent model management systems. 相似文献
9.
S I Brown R G McGarvey J A Ventura 《The Journal of the Operational Research Society》2004,55(6):614-621
This paper addresses the m-machine no-wait flowshop problem where the set-up time of a job is separated from its processing time. The performance measures considered are the total flowtime and makespan. The scheduling problem for makespan reduces to the travelling salesman problem (TSP), and the scheduling problem for total flowtime reduces to the time-dependent travelling salesman problem (TDTSP). Non-polynomial time solution methods are presented, along with a polynomial heuristic. 相似文献
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This paper studies the single-machine scheduling problem with deteriorating jobs and learning considerations. The objective is to minimize the makespan. We first show that the schedule produced by the largest growth rate rule is unbounded for our model, although it is an optimal solution for the scheduling problem with deteriorating jobs and no learning. We then consider three special cases of the problem, each corresponding to a specific practical scheduling scenario. Based on the derived optimal properties, we develop an optimal algorithm for each of these cases. Finally, we consider a relaxed model of the second special case, and present a heuristic and analyze its worst-case performance bound. 相似文献
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本文考虑下述排序问题:有n个工件需在同一台机器上加工,对各工件有一宽容交货期,若一工件在其宽容期前完工则受加权超前惩罚,若在其宽容期后完工则受加权延误惩罚,要求适当安排一加工方式使最大惩罚最小,文中相应某指定工件需准时完工的上述问题证得了Np-hard性,给出了最优算法,并作了一些讨论。 相似文献
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A note on single-machine scheduling with decreasing time-dependent job processing times 总被引:1,自引:0,他引:1
In this note we consider some single-machine scheduling problems with decreasing time-dependent job processing times. Decreasing time-dependent job processing times means that its processing time is a non-increasing function of its execution start time. We present polynomial solutions for the sum of squared completion times minimization problem, and the sum of earliness penalties minimization problem subject to no tardy jobs, respectively. We also study two resource constrained scheduling problems under the same decreasing time-dependent job processing times model and present algorithms to find their optimal solutions. 相似文献
13.
The achievable-region approach, based on strong conservation laws, has most often been applied to stochastic scheduling and
other control problems in the context of performance measures that are steady-state expected quantities. For some problems,
however, strong conservation laws hold for performance measures at every time point on every sample path. We exploit this
property to study optimal control for certain scheduling problems on a sample-path basis. Examples include preemptive scheduling
to minimize a weighted sum of work in the system in each class, nonpreemptive scheduling to minimize a weighted sum of the
number of customers in each class (when all classes have the same service-time distribution), and scheduling the processing
of fluid in a multiclass fluid system operating in a random environment. The last problem is solved by considering the related
Skorohod problem and its minimal solution.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
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Michael J. Shaw 《Annals of Operations Research》1989,17(1):323-345
This paper describes an FMS scheduling method that treats an FMS as a group of problem-solving agents cooperating to perform manufacturing jobs. The main thrusts of such a method include the ability to handle the dynamically changing production conditions, its taking into account the communication method, the improved reliability, and the use of distributed control. The paper emphasizes research issues associated with various aspects of the cooperative problem-solving method, including: (1) dynamic task assignments, (2) the coordination mechanism, and (3) knowledge-based scheduling as problem solving. A simulation study which compares the performance of the cooperative problem solving approach with that of the more traditional scheduling approaches is also reported. 相似文献
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A scheduling problem associated with teaching practices at colleges of education is formulated as a 3-dimensional assignment problem. An efficient algorithm for its solution, based on Lagrangean relaxation, is described. 相似文献
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带约束的平行机排序的一个近似算法 总被引:3,自引:0,他引:3
何勇 《高校应用数学学报(A辑)》2001,16(1):114-118
讨论有资源约束和有机器准备时间的平行机排序问题,资源约束为每个机器至多可加工k个工件,在极小化makespan的上给出了一个匹配算法,证明其最坏情况最紧界是2-m^-1,并进一步给出了它的两个带参数的最坏情况界。 相似文献
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排课问题是NP完全问题,高校实训室排课需考虑实训设备配置及教学改革"走班制"专业选修课所增加的排课复杂度.将高校实训室排课问题建模为硬约束目标及软约束优化满足问题,提出了经过改进的智能水滴算法,改进算法在路径寻优过程中根据待排课程的属性与当前排课状态,结合优化目标,自动进行跳转或围绕核心点变更搜索区域,有效解决了标准智能水滴算法搜索范围固定不利于算法搜索效率提升的问题.提出了预排序策略,减轻算法后期运行的阻力,在排课资源紧张的情况下,更好地实现收敛.通过改进智能水滴算法、标准智能水滴算法、遗传算法进行排课实验对比,验证了改进智能水滴算法在排课系统中的优化效果和高效性。 相似文献
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研究了与总误工损失相关的两个代理的单机排序问题。第一个代理以工件的总误工损失为目标函数,第二个代理以工件的总完工时间或总误工工件数为目标函数。目标是寻找一个排序,使得在第二个代理的目标函数不超过给定的上界的条件下,第一个代理的目标函数值最小。对这两个与总误工损失相关的两个代理的单机排序问题,分别给出它们的拟多项式时间的动态规划算法。 相似文献
20.
《Operations Research Letters》2023,51(1):99-104
One of the oldest results in scheduling theory is that the Shortest Processing Time (SPT) rule finds an optimal solution to the problem of scheduling jobs on identical parallel machines to minimize average job completion times. We present a new proof of correctness of SPT based on linear programming (LP). Our proof relies on a generalization of a single-machine result that yields an equivalence between two scheduling problems. We first identify and solve an appropriate variant of our problem, then map its solutions to solutions for our original problem to establish SPT optimality. Geometric insights used therein may find further uses; we demonstrate two applications of the same principle in generalized settings. 相似文献