The unbounded single machine parallel batch scheduling problem with family jobs and release dates to minimize makespan

In this paper we consider the unbounded single machine parallel batch scheduling problem with family jobs and release dates to minimize makespan. We show that this problem is strongly NP-hard, and give an O(n(n/m+1)^m) time dynamic programming algorithm and an O(mk^k+1P^2k−1) time dynamic programming algorithm, where n is the number of jobs, m is the number of families, k is the number of distinct release dates and P is the sum of the processing times of all families. We further give a heuristic with a performance ratio 2. We also give a polynomial-time approximation scheme for the problem.     

动态拣选系统下订单分批问题研究

对分区拣选系统研究在线订单分批策略.基于排队论角度,采用随机过程、随机服务系统的基本理论与方法,构建串行分区下订单不分批与订单固定时间窗分批拣选的随机服务系统模型,确定要研究对比的系统效率指标.在MAT-LAB R2019a软件环境下模拟在线订单到达情况,分析系统效率指标并找出分区拣选系统的最优分批策略.仿真验证结果表...     

网络视频服务的代理缓存策略

流媒体传输已经成为Internet通信中的重要组成部分之一，虽然它可以从代理缓存中受益，但传统的代理缓存策略不能满足媒体对象所特有的特征，必须提出新颖的缓存方法。该文讨论了代理对视频流的缓存，包括前缀、分块和部分视频对象的全部缓存的问题和挑战。同时研究了缓存视频流的代理网络结构，有分布式、层次式和覆盖式，对它们进行了描述和评论，还把缓存和代理网络同组播相结合进行了讨论。     

混匀配料自动控制系统及故障诊断

分析了原混匀配料系统不能实现全自动配料作业的原因,提出了有针对性的改进措施,介绍其组织实施的情况和取得的成效。     

20kt/a聚丙烯挤压造粒装置配料系统的设计

设计了年产20kt聚丙烯造粒装置上游配料及计量加料系统、PID控制方案以及关键设备的选型.     

汾河二库混凝土拌和站的规划设计

:本文详细介绍了汾河二库混凝土拌和站的规划与设计     

Vision-based optimization of the generalized predictive active disturbance rejection controller

The batching system of the integrated mixing and spreading equipment for MOH material is a nonlinear system with large uncertainty. It is difficult for conventional control strategies to meet the requirements for system performance. This research combines generalized predictive control and active disturbance rejection technique to propose a new generalized predictive active disturbance rejection controller (GPADRC) used in the batching system of MOH material. For the nonlinearity and uncertainty of the batching system, the extended state observer in the active disturbance rejection technique is used for estimation and compensation. The batching system model is converted into an integrator form, based on which the use of generalized predictive control can greatly reduce the impact of nonlinear models and uncertainties on the controller. Aiming at the problem that the parameters of the proposed new controller are numerous and difficult to tune, the adaptive genetic algorithm is used to realize the automatic tuning of the parameters. The simulation experiment shows that the designed GPADRC can well adapt to the working conditions of the batching system and can meet the requirements for various control indicators. At the same time, the adaptive genetic algorithm can realize the rapid tuning of the controller parameters, which reduce the difficulty and time consumption of the tuning process, and improve the applicability and achievability of the designed controller.     

Scheduling jobs on a single batch processing machine with incompatible job families and weighted number of tardy jobs objective

In this paper, we minimize the weighted and unweighted number of tardy jobs on a single batch processing machine with incompatible job families. We propose two different mixed integer linear programming (MILP) formulations based on positional variables. The second formulation does not contain a big-M coefficient. Two iterative schemes are discussed that are able to provide tighter linear programming bounds by reducing the number of positional variables. Furthermore, we also suggest a random key genetic algorithm (RKGA) to solve this scheduling problem. Results of computational experiments are shown. The second MILP formulation is more efficient with respect to lower bounds, while the first formulation provides better upper bounds. The iterative scheme is effective for the weighted case. The RKGA is able to find high-quality solutions in a reasonable amount of time.     

组态王数据库访问功能在PVC配料系统中的应用

以PVC配料系统为例,说明组态王软件SQL访问数据库的功能,给出了组态王访问Ms Access数据库的一般方法与步骤,实现了PVC配料系统中各原料的日使用量统计并生成相应报表以供查询。     

投料孔施工技术及其应用

 为了缩短麻家梁矿井建设周期，节约基建成本，满足矿井建设需要，采用钻铤孔底加压，泥浆护壁的工艺技术在地面施工投料孔。基于投料孔在矿井建设中实际应用的重要性，本文介绍了投料孔施工方法，研究了投料孔应用的经济效益、应用前景及局限性，结论表明，投料孔在矿井建设中经济效益明显，具有广阔的推广前景。