Researches on Methods and Applications of Production Scheduling in the Process Enterprise

流程工业包含很多重要的能源和原材料工业，是国民经济的支柱产业，其地位举足轻重。因此，用先进技术进行流程工业的改造，使其保持高效稳定发展，对国民经济的可持续发展和增强国家经济实力是非常关键的。而生产调度是流程企业生产运行的指挥中心，提高生产调度的质量和效率对于提高流程企业的经济效益和社会效益会起到重要作用。因此，开展流程企业生产调度领域的研究是非常必要的，这些研究也必将具有重要的理论和实际意义。本文即是对流程企业生产调度中的几个典型问题进行了研究，其中有理论探讨，也有应用研究，主要研究内容和创新成果有：（1）生产调度问题描述方法研究。分析了实际调度问题和经典调度理论之间的鸿沟；指出了实际生产调度问题涉及的诸多方面，提出了多视图的描述方法。（2）Flow-shop调度问题混合策略求解方法研究。总结了求解Flow-shop调度问题的常见算法；提出了一种基于启发式搜索算法、遗传算法和禁忌搜索算法的混合遗传算法，通过对大量置换Flow-shop Benchmark问题进行实验仿真，证明算法是有效的。（3）流程企业物料流调度优化研究。总结和定义了流程企业物料流调度优化中的相关概念；基于已有工作，建立并完善了物料流调度优化的数学模型；针对实际的瓦斯调度问题，利用这个数学模型，提出了一种新的遗传编码方法并进行了实验，实验结果有一定的参考价值。（4）基于OAA的实时多Agent生产调度系统体系结构和调度算法研究。总结了实时Agent调度的相关工作；提出了一种基于。从的实时多Agent生产调度系统体系结构，并对其组成部分进行了形式化描述；提出了一种新的基于优先级表的实时调度算法，并利用典型数据进行了实验仿真，证明算法是有效的。（5）流程企业生产调度支撑环境研究。提出了企业问题求解环境的概念；设计了流程企业企业问题求解环境的体系结构，描述了各个组成部分的功能和实现方法；介绍了开发过程中用到的一些关键技术。总之，本文的研究工作涉及了流程企业生产调度的几个重要方面，对于建立更加完善的生产调度问题框架、选取和混合使用各种调度算法以及流程企业物料流调度优化具有一定的指导作用，而且为建立基于多Agent的实时生产调度系统以及更加完善的企业问题求解环境理论和应用系统打下了基础。Process industry includes many important energy and raw material industries, and it's the backbone industry of national economy of one country, it holds the balance of national economy of the country. So, it is crucial for keeping national economy developing continually and raising competitive level of national economy to reconstruct the process industry with advanced technologies and keep it developing efficiently and stably. And that, production scheduling is the headquarters of production running in one process enterprise, and improving the quality and efficiency of production scheduling plays an important role in improving economic and social benefits of the process enterprise. Therefore, it's necessary to carry on researches on production scheduling in the process enterprise, and these researches will have important theoretical and practical significance. This dissertation addresses some typical problems of production scheduling in the process enterprise, and these problems include both theoretical and practical problems, major researching aspects and innovative achievements are listed as follows: (1) Researches on describing methods of production scheduling problem. Firstly, the gap between practical scheduling problems and classical scheduling theories is analyzed; secondly, various aspects of one practical production scheduling problem are pointed out, and a new describing method with multiple views is presented. (2) Researches on hybrid strategies of different type of algorithms for solving Flow-shop scheduling problem. Firstly, several familiar algorithms for solving Flow-shop scheduling problem are introduced; secondly, a new heuristic search algorithm, genetic algorithm and tabu search algorithm based hybrid algorithm is presented, and finally it is proved effective through making experiments with a lot of permutation Flow-shop Benchmark problems. (3) Researches on material flow scheduling and optimization in the process enterprise. Firstly, basic concepts of material flow scheduling and optimization in the process enterprise are summarized and defined; secondly, based on some related research work, the mathematical models of material flow scheduling and optimization are built and improved; finally, in order to solve practical problem of gas scheduling, based on these mathematical models, a new genetic coding method is proposed and some experiments are implemented with genetic algorithm, the results of these experiments can supply reference to practical problem of gas scheduling in some extent. (4) Researches on the architecture of an OAA based real-time Multi-Agent system for production scheduling and its scheduling algorithms. Firstly, some related research work are summarized; secondly, the architecture of an OAA based real-time Multi-Agent system for production scheduling is brought out, and its constituents are formalized respectively; finally, a new priority table based real-time scheduling algorithm is proposed, and it is validated to be effective through making experiments with some typical data. (5) Researches on the supporting environment for production scheduling in the process enterprise. Firstly, the concept of Enterprise Problem Solving Environment is proposed; secondly, the architecture of Enterprise Problem Solving Environment for the process enterprise is designed, and the functions and implementation methods of its constituents are described; finally, some key technologies used during the course of developing the system are introduced. In conclusion, the dissertation addresses several key aspects of production scheduling in the process enterprise, and it can guide researchers and enterprise engineers to construct one more improved framework of practical production scheduling problem, to choose and hybridize various scheduling algorithms, and to schedule and optimize material flow in the process enterprise. Furthermore, it provides a basis for developing Multi-Agent based real-time production scheduling system and creating more perfect theory and applied system of Enterprise Problem Solving Environment

an overview of theories and methods of production scheduling

生产调度理论与方法研究是非常困难的课题 ,但是对企业或行业提高生产效率和效益是至关重要的 ,特别是在当前市场经济时代 生产调度理论和方法的研究已经有 5 0多年的历史 ,但是经典调度理论和实际调度问题之间仍然存在着鸿沟 针对这一特点 ,指出了当前实际生产调度存在的一些问题和需要考虑的各种因素 ,例举了主要的生产调度方法和典型应用 ,指出了各种方法的优缺点 最后 ,总结并提出了生产调度理论和方法的未来研究方向和今后工作的建

Characteristics of the horseshoe vortex at a cylindrical pile under a current and combined waves and current

The horseshoe vortex (HSV) plays a key role in initiating and promoting the scouring process around a pile. In this study, the characteristics of the HSV at the symmetry plane at a cylindrical pile were experimentally investigated using Particle Image Velocimetry (PIV) technique for pile Reynolds numbers ranging from 12000 to 76000. Both the time-averaged and instantaneous characteristics of the HSV under a current and combined waves and current were analyzed. The experimental results under a pure current indicate a generally unified curve for the distribution of the instantaneous maximum swirling strength normalized with the peak swirling strength under various current velocities. The instantaneous HSVs with the swirling strength much lower than Ωpeak are present for the largest percentage of time. Superimposition of waves significantly affects the characteristics of the HSV at the pile. For a fixed value of pile Reynolds number spanning the present flow conditions, the peak value of the swirling strength for combined waves and current is generally lower than the pure current. © 2019 by the International Society of Offshore and Polar Engineers (ISOPE)

锰离子控制掺杂二氧化钛薄膜光催化活性增强的机理探讨

采用溶胶-凝胶法通过工艺控制制备了锰离子以不同形式掺杂TiO2的光催化剂薄膜，并通过XPS和SEM对薄膜的结构进行表征．通过UV-Vis分光光度计及电化学工作站表征了薄膜的光吸收性能和光电化学性能，通过甲基橙溶液的光催化降解脱色率来表征催化剂薄膜的光催化活性．结果表明，以锰离子MT掺杂方式制备的TiO2薄膜可明显增强TiO2的光催化活性，而以MM掺杂方式制备的TiO2薄膜反而降低了TiO2的光催化活性；锰离子MT掺杂方式的最佳掺杂质量分数为0．8％．催化剂薄膜的电化学行为显示，薄膜具有p-n结的电容一电压特性，锰离子MT掺杂TiO2薄膜的开路电位和瞬时光电流信号较强，说明其光生载流子易于生成并且分离效果较好．依据半导体的p-n结原理探讨了锰离子控制掺杂TiO2的光催化活性机理

priority table based real-time scheduling algorithm

本文提出了一种新的基于优先级表的实时调度算法 ,称作截止期—价值密度优先 (Deadline ValueDen sityFirst)算法 ,简称DVDF算法 .DVDF算法综合考虑了实时任务的截止期和价值密度两个参数 ,能够更好地适应不同的负载情况 .通过使用正常负载和过载情况下的典型数据对算法进行仿真研究表明 ,这种算法比单纯考虑截止期的EDF(EarliestDeadlineFirst)算法在性能方面有明显的改进 ,特别是在系统过载的情况下 ,能够优雅地降