共查询到18条相似文献,搜索用时 713 毫秒
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研究具有若干固定工件和自由工件,其中固定工件必须在指定时间窗内加工,而自由工件具有不同交工的时间,并且其加工可以中断的单机排序问题,其目标是极小化工件的误工数.该问题可以表示为1|FB,rj,pmtn|∑j Uj.首先讨论了问题的几个重要性质,以此为基础建立了求解该问题的动态规划算法,其时间复杂度为O(n4+m log m),其中m和n分别是固定工件数和自由工件数. 相似文献
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单机排序中一个极小最大绝对迟后问题 总被引:1,自引:0,他引:1
本文考虑n个工件在单机上加工的排序问题,工作j的预期开始加工时间和所需加工时间分别为αj,pj,应交工时间为dj=αj kpj d,这里的k(≥0),d是待定的变量,目标函数为极小化最大绝对迟后。本文首先考虑了该问题一些特殊情况的研究结果,然后在强一致性条件下证得此问题O(nlogn)可解。 相似文献
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孙世杰 《应用数学与计算数学学报》1993,(1)
一组n个工件需在一台机器上加工,工件j所需的准备时间、加工时间分别为rj,pj,可压缩准备时间为x_j,0≤x_j≤r_j,其中rj,pj,xj均为非负整数。由同压缩向量x有关的某一目标函数F_1和压缩费用F_2=∑xj可构成文中的四个多目标排序问题(P1)-(P4),这种可控准备时间的多目标排序问题由引文[2]的作者在1990年提出并作 相似文献
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本文考虑下述n个工件在一台机器上加工的排序问题。其中d_i,C_i,w_i和h_i分别为工件i的应交工时间、完工时间、延误权因子和成本权因子。工件i所需的加工时间为p_i,所有工件在时间t=0时同时到达机器旁,机器不允许空转,工件被加工时不允许中断。本文用一O(n)快速方法给出(P)的一个下界。对问题(P),当取O≤u_i≤w_i,i=1,2,…,n时, 相似文献
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本文讨论了一类工件加工时间随加工顺序而变的单机排序问题,在目标函数sum from i=1 to nC_i与Lmax下,Smith法则与Jackson法则仍然成立。从而推广了Smith与Jackson的结果。一般所考虑的单机排序问题是:有n个工件需要在一台机器上加工,而该机器只能一次加工一个工件,且工件j在该机器上所需的加工时间为P_i,这里P_j为一常量,即与工件早加工或晚加工无关。现在需要确定工件加工的一个顺序,使得在不同的目标下最优。 相似文献
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闻振卫 《数学的实践与认识》2011,41(22)
在经典的两台机流水作业排序问题F_2‖C_(max)的基础上进行修改,将工件J_j在两台机上的加工时间由常数A_j和B_j改成A_j(x)=a_j+c_jx和B_j(x)=b_j-d_jx,其中x是某区间上的可控(决策)变量.排序的目标是,选择适当的x(对应相应的加工时间是A_j(x)、B_j(x))(j=1,2,…,n)及相应的工件的加工顺序σ=[σ(1),σ(2),…,σ(n)],使时间表长(即最后一个工件J_σ(n)在第二台机上的完工时间)G_(max达到最小.给出了解决问题的有效方法. 相似文献
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In this paper we consider the flow shop scheduling problems with the effects of learning and deterioration. In this model the processing times of a job is defined as a function of its starting time and position in a sequence. The scheduling objective functions are makespan and total completion time. We prove that even with the introduction of learning effect and deteriorating jobs to job processing times, some special flow shop scheduling problems remain polynomially solvable. 相似文献
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This paper studies the single machine scheduling problems with learning effect and deteriorating jobs simultaneously. In this model, the processing times of jobs are defined as functions of their starting times and positions in a sequence. It is shown that even with the introduction of learning effect and deteriorating jobs to job processing times, the makespan, the total completion time and the sum of the kth power of completion times minimization problems remain polynomially solvable, respectively. But for the following objective functions: the total weighted completion time and the maximum lateness, this paper proves that the shortest weighted processing time first (WSPT) rule and the earliest due-date first (EDD) rule can construct the optimal sequence under some special cases, respectively. 相似文献
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并行分批排序起源于半导体芯片制造过程。在并行分批排序中,工件可成批加工,批加工机器最多可同时加工B个工件,批的加工时间为批中所有工件的最大工时。首先根据传统的机器环境和目标函数对并行分批排序已有成果进行分类介绍,主要为单机和平行机的机器环境,以及极小化最大完工时间、极小化总完工时间、极小化最大延迟、极小化误工工件数、极小化总延误和极小化最大延误的目标函数;然后梳理了由基本问题所衍生出来的具有新特点的16类新型并行分批排序,包括差异尺寸工件、多目标、工件加工时间或顺序存在限制、考虑费用和具有特殊机制等情况;最后展望未来的研究方向。 相似文献
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This paper considers some scheduling problems with deteriorating jobs. The objectives are to minimize the makespan, the total completion time, the total absolute deviation of completion time, the earliness, tardiness, and due date penalty, the sum of earliness penalties subject to no tardy jobs, respectively. We also explore two resource constrained scheduling problems: how to minimize the resource consumption with makespan constraints and how to minimize the makespan with the total resource consumption constraints. Several polynomial time algorithms are proposed to optimally solve the problems with the above objective functions. 相似文献
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This paper investigates a new problem, called single machine scheduling with multiple job processing ability, which is derived from the production of the continuous walking beaming reheating furnace in iron and steel industry. In this problem, there is no batch and the jobs enter and leave the machine one by one and continuously, which is different from general single machine batch scheduling problem where the jobs in a batch share the same start and departure time. Therefore, the start time and the departure time of a job depend on not only the job sequence but also the machine capacity. This problem is also different from the single semi-continuous batching machine scheduling recently studied in the literature, where the jobs are processed in batch mode and a new batch cannot be started for processing until the processing of the previous batch is completed though jobs in the same batch enter and leave the machine one by one. The objective of this problem is to minimize the makespan. We formulate this problem as a mixed integer linear programming model and propose a particle swarm optimization (PSO) algorithm for this problem. Computational results on randomly generated instances show that the proposed PSO algorithm is effective. 相似文献
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In scheduling problems with two competing agents, each one of the agents has his own set of jobs and his own objective function, but both share the same processor. The goal is to minimize the value of the objective function of one agent, subject to an upper bound on the value of the objective function of the second agent. In this paper we study two-agent scheduling problems on a proportionate flowshop. Three objective functions of the first agent are considered: minimum maximum cost of all the jobs, minimum total completion time, and minimum number of tardy jobs. For the second agent, an upper bound on the maximum allowable cost is assumed. We introduce efficient polynomial time solution algorithms for all cases. 相似文献
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This paper studies single-machine scheduling problems with setup times which are proportionate to the length of the already scheduled jobs, that is, with past-sequence-dependent or p-s-d setup times. The following objective functions are considered: the maximum completion time (makespan), the total completion time, the total absolute differences in completion times and a bicriteria combination of the last two objective functions. It is shown that the standard single-machine scheduling problem with p-s-d setup times and any of the above objective functions can be solved in O(nlog n) time (where n is the number of jobs) by a sorting procedure. It is also shown that all of our results extend to a “learning” environment in which the p-s-d setup times are no longer linear functions of the already elapsed processing time due to learning effects. 相似文献