Even-aged restrictions with sub-graph adjacency

Restrictions on the size and proximity of clearcuts have led to the development of a variety of exact and heuristic methods to optimize the net present value of timber harvests, subject to adjacency constraints. Most treat harvest units as pre-defined, and impose adjacency constraints on any two units sharing a common border. By using graph theory notation to define sub-graph adjacency constraints, opening size can be considered variable, which may be more appropriate for landscape-level planning. A small example data set is used in this paper to demonstrate the difference between the two types of adjacency constraints for both integer programming and heuristic solution methods.     

服装供应商制造周期效能的提高及案例分析:订单排程与投料管控

以服装供应商——牛仔服加工厂改善制造周期效能为例,着重分析生产订单排程与合理投料的流程改进与优化.通过合理的订单排程、确定缓冲时间、根据缓冲状态管理优先顺序、管控投料等方法,为服装供应商实现缩短生产周期、准时交货以及增加有效产出提供可行性实施方案.     

异构网络中基于网络选择CPC广播内容研究

本文基于欧盟E2R项目已提出的异构网络中CPC（感知导频信道）广播信道,对CPC可以广播的内容进行了研究。通过CPC广播终端能够使用的无线接入技术的功能和性能参数,终端可以实时评估网络的负载情况和所能提供的QoS保证,选择合适的网络接入,以此来减少终端网络接入时间,提高接入的成功率和用户的满意度。     

FlOW Shop排序问题F3|s|Cmax的最优算法

讨论调整时间可分离的FlowShop排序问题F3|s|Cmax．对其一类特殊情况给出了最优算法．     

Scheduling Tasks on Unrelated Machines: Large Neighborhood Improvement Procedures

Two approximation algorithms are presented for minimizing the makespan of independant tasks assigned on unrelated machines. The first one is based upon a partial and heuristical exploration of a search tree, which is used not only to build a solution but also to improve it thanks to a post-optimization procedure. The second implements a new large neighborhood improvement procedure to an already existing algorithm. Computational experiments show that their efficiency is equivalent to the best local search heuristics.     

Integrated scheduling of handling equipment at automated container terminals

To improve the productivities of an automated container terminal, it is important to schedule different types of handling equipment in an integrated way. A mixed-integer programming model, which considers various constraints related to the integrated operations between different types of handling equipment, is formulated. A heuristic algorithm, called multi-layer genetic algorithm (MLGA) is developed with a view to overcome the computation difficulty for solving the mathematical model. A numerical experimentation is carried out in order to evaluate the performance of the algorithm.     

Competence-driven project portfolio selection,scheduling and staff assignment

This paper presents a new model for project portfolio selection, paying specific attention to competence development. The model seeks to maximize a weighted average of economic gains from projects and strategic gains from the increment of desirable competencies. As a sub-problem, scheduling and staff assignment for a candidate set of selected projects must also be optimized. We provide a nonlinear mixed-integer program formulation for the overall problem, and then propose heuristic solution techniques composed of (1) a greedy heuristic for the scheduling and staff assignment part, and (2) two (alternative) metaheuristics for the project selection part. The paper outlines experimental results on a real-world application provided by the E-Commerce Competence Center Austria and, for a slightly simplified instance, presents comparisons with the exact solution computed by CPLEX.     

基于动态优先权的进程调度算法的模拟实现

本文介绍了利用C语言模拟实现动态优先权的进程调度算法的方法,并给出相应的核心代码程序。在设计中,充分考虑了进程在执行过程中可能发生的多种情况,更好的体现了进程的就绪态、执行态、阻塞态三者之间的关系以及相互的转换。程序的运行过程清晰的体现了动态优先权的调度算法的执行过程,有利于加深对算法的理解和掌握。     

Comparison and hybridization of crossover operators for the nurse scheduling problem

In this paper, we present a hybrid genetic algorithm for the well-known nurse scheduling problem (NSP). The NSP involves the construction of roster schedules for nursing staff in order to maximize the quality of the roster schedule subject to various hard constraints. In the literature, several genetic algorithms have been proposed to solve the NSP under various assumptions. The contribution of this paper is twofold. First, we extensively compare the various crossover operators and test them on a standard dataset in a solitary approach. Second, we propose several options to hybridize the various crossover operators.     

Proactive heuristic procedures for robust project scheduling: An experimental analysis

Solution-robust project scheduling is a growing research field aiming at constructing proactive schedules to cope with multiple disruptions during project execution. When stochastic activity durations are considered, including time buffers between activities is a proven method to improve the stability of a baseline schedule.