多产品批处理过程调度的MILP建模

基于时间间隙的概念和连续时间描述，将设备、产品分配给时间间隙分别表达为两类0-1变量。采用一个时间轴，建立了具有并行生产线的单阶段多产品批处理过程的调度数学模型。模型表达为一个混合整数规划（Mixed Integer Linear Programming,MILP)问题。相对于已有的基于时间间隙描述的调度模型，该模型0-1变量少，且能处理顺序相关建立时间。求解采用分支定界法（BAB）。计算表明，该模型求解速度快，松弛线性规划和MILP的最优解之差（Integraligy Gap)小，尤其对包含多个相同批次的调度问题求解效果更为显著。     

序列状生产系统最优生产计划的一些性质及启发式算法

探讨了序列状多级生产系统的生产－库存计划问题，以“再生点性质”和“成套按排性质”为基础，证明了这类问题所具有的另外一些特殊性质，并运用这些性质建立了一种有效的启发式算法。     

Preemptive scheduling of equal-length jobs to maximize weighted throughput

We study the problem of computing a preemptive schedule of equal-length jobs with given release times, deadlines and weights. Our goal is to maximize the weighted throughput. In Graham's notation this problem is described as . We provide an O(n⁴)-time algorithm, improving the previous bound of O(n¹⁰).     

A Tabu Search Heuristic for a Full-Load, Multi-Terminal, Vehicle Scheduling Problem with Backhauling and Time Windows

The problem considered is the full-load pickup and delivery problem with time windows (PDPTW), and heterogeneous products and vehicles, where the assignment of pickup points to requests is not predetermined. Elements associated with tabu search, such as diversification by reversion to junctions and the use of soft aspiration criteria, are embedded into our tabu search implementation. This metaheuristic is evaluated using random instances and selected data from a construction company in the U.K. The obtained results are compared against lower bounds from LP relaxation and also solutions from an existing multi-level heuristic.     

A “Logic-Constrained” Knapsack Formulation and a Tabu Algorithm for the Daily Photograph Scheduling of an Earth Observation Satellite

The daily photograph scheduling problem of earth observation satellites such as Spot 5 consists of scheduling a subset of mono or stereo photographs from a given set of candidates to different cameras. The scheduling must maximize a profit function while satisfying a large number of constraints. In this paper, we first present a formulation of the problem as a generalized version of the well-known knapsack model, which includes large numbers of binary and ternary logical constraints. We then develop a tabu search algorithm which integrates some important features including an efficient neighborhood, a dynamic tabu tenure mechanism, techniques for constraint handling, intensification and diversification. Extensive experiments on a set of large and realistic benchmark instances show the effectiveness of this approach.     

List scheduling algorithms to minimize the makespan on identical parallel machines

In this paper we present constructive algorithms for the classical deterministic scheduling problem of minimizing the makespan on identical machines. Since the problem is known to beNP-hard in the strong sense, the approximate algorithms play a relevant role when solving this problem. The proposed algorithms are based on list scheduling procedures, but the assignment rule is not the same for the full set of jobs. Computational results show that these algorithms perform very well. This research has been partially supported by the Research Project H015/2000, Universidad de Alcalá. The authors are indebted to Joaquín Pérez and the referees for their helpful remarks and comments. We also wish to thank Paul Alexander Ayres for his help in the correct use of English.     

有重叠的两抓钩周期性排序问题的启发式算法

抓钩排序问题不同于古典的排序问题,只有一个抓钩和一种产品,它仍然被证明为ＮＰ难题,对于有重叠区域的两抓钩周期性排序问题,迄今尚无法用数学模型直接求解。为了寻找出好的排序,提出了一种启发式算法以及求解有重叠两抓钩周期性排序问题。该方法把问题分解成相应序列的子问题,并对每个序列化建立和求解一个整体问题的线性规划模型,在序列空间中,通过寻找好的序列以得到最佳的排序。量化的示例表明所使用的方法是高效的。     

Minimizing Weighted Number of Early and Tardy Jobs with a Common Due Window Involving Location Penalty

This paper studies a single machine scheduling problem to minimize the weighted number of early and tardy jobs with a common due window. There are n non-preemptive and simultaneously available jobs. Each job will incur an early (tardy) penalty if it is early (tardy) with respect to the common due window under a given schedule. The window size is a given parameter but the window location is a decision variable. The objective of the problem is to find a schedule that minimizes the weighted number of early and tardy jobs and the location penalty. We show that the problem is NP-complete in the ordinary sense and develop a dynamic programming based pseudo-polynomial algorithm. We conduct computational experiments, the results of which show that the performance of the dynamic algorithm is very good in terms of memory requirement and CPU time. We also provide polynomial time algorithms for two special cases.     

并行多机成组工件调度的启发式算法

N个成组工件将在M台并行一致的机器上加工,当一个工件接在不同组的工件之后时需要装设,而接在同组工件之后时不需要重新装设,目标函数是使总的通过时间最小·利用最优解的必要条件,将单个工件组成基本运行,在研究基本运行组合规则的基础上,提出了一个基于基本运行的并行多机成组工件调度的启发式算法·在中、小规模水平问题上,将启发式算法的结果与最优解的结果进行了比较·效果令人满意·实验证明该启发式算法能够有效地解决成组工件调度的实际问题,具有解决中大规模实际问题的潜力·     

基于VC++工控组态软件实时数据库系统的设计

结合作者从事工控组态软件设计开发的实际经验,介绍了基于VC++ 6.0的实时数据库系统(RTDBS)的设计思想和设计方法,提出了利用动态连接库来建立实时数据库系统的方法,给出了数据模型和接口的实现方法.利用该方法建立的实时数据库系统具有全面的开放性.