高层建筑应急情况下电梯群控算法研究

高层建筑带来城市景观的同时也带来安全问题,高层建筑发生应急情况时可以利用电梯运输效率高的特点进行人员疏散.文章依据高层建筑应急疏散特点,提出群控系统正常工作与应急工作两种工作模式,分析研究了电梯在应急情况下的交通流的特点,结合疏散路线提出电梯的应急疏散交通模式,采用静态分区内以最小侯梯时间为优化目标的应急群控算法.通过MATLAB面向对象编程技术对算法进行仿真分析,仿真结果表明,采用电梯进行应急疏散是可行和有效的.     

机动通信力量派遣问题建模与优化

机动通信力量派遣问题的建模与优化,是实现机动通信力量运用科学决策的有效手段。考虑战地通信力量损伤,建立最佳派遣方案,按照多目标规划的原理和方法,给出了派遣问题建模的基本假设,系统分析了影响派遣的作战需求、实力编制等因素,提出了机动通信的保障效能和成本损失目标函数,构建了系统的机动通信力量派遣模型。在模型优化的过程中,引入了宽容完全分层序列算法,并结合算例演示了建模和优化的一般过程,仿真结果表明对于机动通信力量运用具有一定的辅助决策价值。     

Lot streaming for product assembly in job shop environment

Assembly job shop scheduling problem (AJSP) is an extension of classical job shop scheduling problem (JSP). AJSP starts with JSP and appends an assembly stage to the completed jobs. Lot streaming (LS) technique is a process of splitting jobs into smaller sub-jobs such that successive operations can be overlapped. This paper combines, for the first time, LS and AJSP, extending LS applicability to both machining and assembly. To solve this complex problem, an efficient algorithm is proposed using genetic algorithms and simple dispatching rules. Experimental results suggest that equal size LS outperforms varied size LS with respect to the objective function.     

远程渲染分发管理系统的设计与实现

介绍了结合渲染集群系统和网络化管理功能研制的一个数字媒体远程渲染管理系统,该系统可支持远程用户完成渲染任务提交、任务监控和结果回收等功能,通过互联网扩展现有集群渲染系统的服务范围,提高渲染企业的生产力。重点对该系统的构架设计、分发算法设计和系统实现进行了说明,并给出了应用示例。     

江西电网备用调度交换网组网研究

文章详细介绍了江西电网调度交换网的现状,论述了省级备调系统的建设方案及原则,提出了备用调度交换系统单独组网和合并组网两种方案的特点,并对建设中的注意事项进行阐述。同时对上述两种组网方案进行了可靠性计算。阐明了两种组网方式均大幅提高了整个调度通信网的可靠性,为目前省级备用调度交换系统建设提出了更可靠的冗余解决方案。     

Dispatching rule for non-identical parallel machines with sequence-dependent setups and quality restrictions

This paper proposes a dispatching rule that guarantees a predetermined minimum quality level for non-identical parallel machines with multiple product types. Manufacturers are focusing on improving the overall quality of their products, as the demand for top quality products is increasing. Such changes increase the possibility of neglecting another crucial factor in manufacturing schedules, namely due date. Traditionally, jobs are dispatched with the focus on meeting due dates. That is, jobs are assigned to machines without consideration of product quality. This approach opens the possibility of manufacturing poor quality products. Realizing the shortcomings of the existing dispatching rules, manufacturers are tempted to dispatch jobs with the objective of maximizing product quality. With such an attempt, jobs are likely to be assigned to high performance machines only. In turn, waiting times will increase and job delays are inevitable. This research proposes a dispatching rule that satisfies both criteria, reducing due date delays, while ensuring a predefined product quality level. A quality index is introduced to standardize various product qualities. The index is used to ensure a predetermined quality level, whilst minimizing product delays. Simulations compare various dispatch methods, evaluating them based on mean tardiness and product quality.     

Bottleneck-based heuristics to minimize total tardiness for the flexible flow line with unrelated parallel machines

This paper considers the flexible flow line problem with unrelated parallel machines at each stage and with a bottleneck stage on the line. The objective of the problem is to minimize the total tardiness. Two bottleneck-based heuristics with three machine selection rules are proposed to solve the problem. The heuristics first develop an indicator to identify a bottleneck stage in the flow line, and then separate the flow line into the upstream stages, the bottleneck stage, and the downstream stages. The upstream stages are the stages ahead of the bottleneck stage and the downstream stages are the stages behind the bottleneck stage. A new approach is developed to find the arrival times of the jobs at the bottleneck stage. Using the new approach, the bottleneck-based heuristics develop two decision rules to iteratively schedule the jobs at the bottleneck stage, the upstream stages, and the downstream stages. In order to evaluate the performance of the bottleneck-based heuristics, seven commonly used dispatching rules and a basic tabu search algorithm are investigated for comparison purposes. Seven experimental factors are used to design 128 production scenarios, and ten test problems are generated for each scenario. Computational results show that the bottleneck-based heuristics significantly outperform all the dispatching rules for the test problems. Although the effective performance of the bottleneck-based heuristics is inferior to the basic tabu search algorithm, the bottleneck-based heuristics are much more efficient than the tabu search algorithm. Also, a test of the effect of the experimental factors on the dispatching rules, the bottleneck-based heuristics, and the basic tabu search algorithm is performed, and some interesting insights are discovered.     

Exact and heuristic algorithms for the aerial refueling parallel machine scheduling problem with due date-to-deadline window and ready times

The Aerial Refueling Scheduling Problem (ARSP) can be defined as determining the refueling completion times for fighter aircrafts (jobs) on multiple tankers (machines) to minimize the total weighted tardiness. ARSP can be modeled as a parallel machine scheduling with ready times and due date-to-deadline window to minimize total weighted tardiness. ARSP assumes that the jobs have different ready times and a due date-to-deadline window between refueling due date and a deadline to return without refueling. In this paper, we first formulate the ARSP as a mixed integer programming model. The objective function is a piece-wise tardiness cost that takes into account due date-to-deadline windows and job priorities. Since ARSP is NP-hard, two heuristics are proposed to obtain solutions in reasonable computation times, namely (1) modified ATC rule (MATC), (2) a simulated annealing method (SA). The proposed heuristic algorithms are tested in terms of solution quality and CPU time through computational experiments with data randomly generated to represent aerial refueling operations of an in-theater air operation. Solutions provided by both algorithms were compared to optimal solutions for problems with up to 12 jobs and to each other for larger problems with up to 60 jobs. The results show that, MATC is more likely to outperform SA especially when the problem size increases, although it has significantly worse performance than SA in terms of deviation from optimal solution for small size problems. Moreover CPU time performance of MATC is significantly better than SA in both cases.     

弹性文件系统在电力信息系统的应用研究

信息技术和网络技术在电力工业中得到广泛应用的同时也带来了负面影响。文章介绍了电力信息系统安全的现状,在总结现有网络安全措施的基础上提出采用基于分片–冗余–分散(Fragmentation-Redundancy-Scattering,FRS)技术的弹性文件保护模型实现电力信息网络的容入侵,论述了相关技术及各个功能模块。最后将弹性文件模型应用于电力调度自动化系统中,并对该模型进行了分析和评价。     

NMS2000系列网络型智能控制调度模拟屏在县级调度中的应用

随着电网的不断发展和无人值守变电站的实现，调度工作日益重要，调度模拟控制系统作为调度员日常工作的重要工具尤为突出，三水供电分公司于2001年对原有调度模拟屏进行了改造，使用的是NMS—2000系列网络型智能控制调度模拟屏控制系统，为此，本文探讨了网络型智能控制调度模拟屏系统的原理．系统结构和功能特点。NMS—2000系统投入运行后，大大提高了佛山三水区电网调度的自动化水平。