Hopen多进程窗口系统模型研究及实现

Hopen原有单进程窗口系统稳定性较差、开发周期长且调试困难.针对这些问题,结合现有多款嵌入式窗口系统的特点和嵌入式系统的特殊需求,通过对传统客户端、服务器模型进行改造,设计专用的本地过程调用(LPC)通讯机制,并采用与WIN32兼容的调用接口,开发了Hopen多进程嵌入式窗口系统,提高了系统的稳定性,新产品调试、研发周期也大幅缩短,Hopen嵌入式软件平台的性能得到改善.     

Scheduling for stability in single-machine production systems

Robust scheduling aims at the construction of a schedule that is protected against uncertain events. A stable schedule is a robust schedule that changes only little when variations in the input parameters arise. This paper presents a model for single-machine scheduling with stability objective and a common deadline. We propose a branch-and-bound algorithm for solving an approximate formulation of the model. The algorithm is exact when exactly one job is disrupted during schedule execution.     

A CCS-based investigation of deadlock in a multi-process electronic mail system

The networking software for a VAX/VMS computer system had been implemented as a collection of communicating processes. One night, an unusually high load on the electronic mail component of the software caused deadlock to occur between two of the processes. This paper describes how the deadlock was analysed by modelling the software using the Calculus of Communicating Systems (CCS) and then by investigating the behaviour of the model using the Edinburgh Concurrency Workbench (CWB). The analysis suggested how the software should be restructured to prevent the problem recurring; the new set of processes was analysed, and shown to be deadlock-free.     

Scheduling a dynamic job shop production system with sequence-dependent setups: An experimental study

This paper presents the salient aspects of a simulation-based experimental study of scheduling rules for scheduling a dynamic job shop in which the setup times are sequence dependent. A discrete event simulation model of the job shop system is developed for the purpose of experimentation. Seven scheduling rules from the literature are incorporated in the simulation model. Five new setup-oriented scheduling rules are proposed and implemented. Simulation experiments have been conducted under various experimental conditions characterized by factors such as shop load, setup time ratios and due date tightness. The results indicate that setup-oriented rules provide better performance than ordinary rules. The difference in performance between these two groups of rules increases with increase in shop load and setup time ratio. One of the proposed rules performs better for mean flow time and mean tardiness measures.     

Scheduling a single mobile robot for part-feeding tasks of production lines

This study deals with the problem of sequencing feeding tasks of a single mobile robot which is able to provide parts for feeders of machines on production lines. The mobile robot has to be scheduled in order to stoppage from lack of parts in the production line. A method based on the characteristics of feeders and inspired by the ( \(s,Q\) ) inventory system, is thus applied to define time windows for the feeding tasks of the robot. The capacity of the robot is also taken into consideration. The performance criterion is to minimize total traveling time of the robot for a given planning horizon. A genetic algorithm-based heuristics is presented which results in a significant increase in the speed of finding near-optimal solutions. To evaluate the performance of the genetic algorithm-based heuristic, a mixed-integer programming model has been developed for the problem. A case study is implemented at an impeller production line in a real factory and computational experiments are also conducted to demonstrate the effectiveness of the proposed approach.     

一种多工序知识关联的纺纱质量智能控制模型

为解决单一工序的纺纱质量控制模型难以实现对纺纱质量的精准控制问题,构建了一种基于多工序知识关联的纺纱质量智能控制模型.首先,选取纱线断裂强度为主要控制指标,设计了基于纱线断裂强度的多工序质量控制点及质量损失函数,实现了棉纺生产过程中多工序质量控制点间知识的关联.进而,以质量损失函数为目标函数构建了纺纱质量控制模型,并借助自动过程控制技术实现了基于数据反馈的纺纱质量控制.然后,将惩罚函数引入到纺纱质量控制模型中,并利用多目标烟花算法对模型进行了求解.最后,通过对比验证表明,该模型与未考虑多工序间知识关联的质量控制模型以及控制前的结果相比,纱线断裂强度提升了1.27%和3.40%,纱线不合格率降低了23.48%和50.00%,从而有利于解单一工序的纺纱质量控制模型难以实现对纺纱质量的精准控制问题.     

Cell production system for assembly

The recent diversification of market needs and shortened product life have necessitated frequent model changes which robot assembly lines can no longer accommodate.

This paper proposes automatic assembly by a cell production system as a possible solution to this problem. The system is a combination of intelligent assembly cells with a conveyor system or an automatic guided vehicle system. This not only requires very little start-up time but also has high dispersibility and expansibility, because each cell can function independently whereas a robot assembles several parts. A demonstration assembly cell proved to have high flexibility and capability for long unmanned operation.     

Scheduling support for concurrency and parallelism in the Machoperating system

The shared use of general-purpose uniprocessors is examined. Support for common uniform-memory-access architectures that have all memory equidistant from all processors in terms of access time is emphasized. This work is also applicable to non-uniform-memory-access machines, whose memory access times depend on the physical distance between the processor and the accessed memory, but it does not provide a complete solution to load-balancing problems for this class of machine. The discussion covers time-sharing scheduling, the Mach scheduler, programming models, scheduling concurrency support, processor allocation, and related work     

应用于实时控制系统的线程池调度策略设计

在进行多任务实时控制系统设计时,采用线程池技术是一种有效的解决方法,但必须首先避免超时的发生。为了降低线程完成的超时发生率,采用Half-Sync/Half-Async线程池架构建立实时控制系统的线程池,利用最小二乘支持向量回归机（LSSVR）对线程执行时间进行预测估计,再基于估计结果对线程池线程的分配调度优先级别算法进行设计。性能测试以无线图像传感器网络节点为对象对所设计的LSSVR线程池及其他线程池在不同状态下的超时发生率做了比较,结果表明在大多数应用情况下LSSVR线程池在抑制超时方面具有明显的优越性。     

基于Petri网的柔性制造系统调度控制模型

给出了自顶向下构造柔性制造系统(FMS)Petri网模型的方法,提出了随机创建指定数目满足指定条件的测试模型的算法,并给出程序仿真运行的演算规则。在此基础上实现了基于Petri网FMS分析与调度仿真软件平台,该平台可配置性强,容易维护,降低了柔性制造系统方针研究的复杂性。最后给出了该模型实现的模块结构。     

The resource allocation model for multi-process instances based on particle swarm optimization

Resource allocation in process management focuses on how to maximize process performance via proper resource allocation since the quality of resource allocation determines process outcome. In order to improve resource allocation, this paper proposes a resource allocation method, which is based on the improved hybrid particle swarm optimization (PSO) in the multi-process instance environment. Meanwhile, a new resource allocation model is put forward, which can optimize the resource allocation problem reasonably. Furthermore, some improvements are made to streamline the effectiveness of the method, so as to enhance resource scheduling results. In the end, experiments are conducted to demonstrate the effectiveness of the proposed method.     

一种铝线生产智能监控系统

鉴于某铝线生产车间已经实现了WiFi网络全覆盖的情况,设计了一种基于WiFi无线传输的生产智能监控系统。监控终端外围设备将采集到的现场数据以无线WiFi方式上传至上位机,企业管理者可通过上位机监控软件实时查看生产数据,了解第一手生产资料。上位机同时可以自动完成信息反馈,监控终端根据反馈数据能实时控制生产进程。该系统针对工业现场环境中布线难的问题提出了WiFi无线传输的设计方案,切实解决了铝线企业对现场生产的实时监控问题。     

CDMA2000 1xEV-DO系统前向链路调度算法

CDMA2000 1xEV-DO作为第三代移动通信技术CDMA2000的演进,主要用来提供高速数据传输服务。系统前向时分复用,并采用“机会主义”调度算法实现前向数据吞吐量的提高。在介绍了1xEV-DO系统的基本原理与前向调度模型的基础上,详细讨论了近年来提出的各种前向链路调度算法,并对算法的优缺点做了比较,指出了部分算法研究过程中的不足之处。最后概述了前向调度算法下一步的研究方向。     

An algorithm for production planning in a flexible production system

In this paper, we consider the problem of determining the production rate, production batch size, and production sequence when production rate, setup cost, and unit processing cost are sequence-dependent. Using a standard lot sizing model with backorder, a tabu search algorithm for solving this problem is proposed. The algorithm is tested on some random test problems and its performance is compared with random sequencing. Computational results show that the proposed algorithm is very efficient.     

基于数学模型的多进程守护病毒的分析

文章分析了多进程守护病毒的相关特征,通过对捕食系统模型的修改并利用其平面稳定性的相关理论,对多守护进程病毒在计算机内的行为进行模型建立和结果仿真,解释了多守护进程病毒在计算机中除自身破坏代码外额外消耗大量资源的原因,并讨论了杀毒程序在面对没有完全病毒定义的多进程守护病毒时的防护行为对系统起到的负面影响.提出了防病毒程序的改善方法和面对一些简单多守护病毒的解决方案并分析其可行性.仿真结果表明了分析的准确性.     

A robust hierarchical production planning for a capacitated two-stage production system

In this paper, we propose a robust hierarchical production planning approach for a two-stage real world capacitated production system operating in an uncertain environment. The first stage of the system produces a set of semi-finished products having relatively stable annual demands, and the second finishing stage produces finished products having highly variable weekly demands. The fixed production setup costs incurred at the first stage are considerably high. Fixed production setup costs incurred at the second stage are fairly small compared to those of the first stage. We propose an integrated hierarchical planning model, where semi-finished products from the first stage (i.e. the aggregate level) are disaggregated into finished products to be produced in the second stage (i.e. the operational level). As a result of the relatively stable demands and the high setup costs experienced at the first stage, a cyclical aggregate planning model is proposed for production planning at the upper level of the hierarchical plan. Based on this aggregate plan, a modified periodic review policy is then proposed for production planning at the lower level. Finally, a coupling plan, linking the two planning levels, is proposed to ensure the feasibility of the disaggregation process at every period.     

A production system for LSI chip anatomizing

A production system for the LSI chip image study is presented, which is a key portion of chip reverse engineering. This system uses inference techniques based on the geometrical and constructional knowledge of the chip to identify the invisible layers and the layers unable to be recognized by their gray values. Final results are also presented.     

Proplant: Multiagent system for production planning

The so-called ''tribase'' acquaintance model of the agent's behavior is presented in this paper. This represents an extension of the twin-base model (Cao et al., 1997). Based on practical experience, the new model tries to cope with parallel processing, precedence constraints, and sparse resources. The idea of substituting the interagent negotiation processes by the periodical internal planning activity of the agents is stressed. A multiagent system, ProPlanT, as an application of the tribase model for the project-oriented production planning developed for TESLA TV company is described in detail. Three types of agents production planning agent (PPA), production management agent (PMA), and production agent (PA) are distinguished. The corresponding tribase models and potential role of metaagents are discussed.     

Scheduling production for a sawmill: A comparison of a mathematical model versus a heuristic

Sawmill production scheduling is complex. It involves determining which logs to process taking into account the diameter, length, and grade of each log, on one hand, and the finished products that are needed to fulfill the orders, on the other. The cutting pattern determines which products are generated and also the yield, which is how much of the volume of the log ends as finished products. We used two approaches to solve the problem: a mathematical model, which calculates the volume and the schedule of various types of logs, and a heuristic that solves the problem by systematically applying the criteria used by a sawmill programmer in southern Chile. We compare the results of using both approaches under various scenarios in a 6 week planning horizon, with the mathematical model showing a superior performance in almost all instances except two, were both found the optimal solution. The proposed mathematical model can be solved in a relatively short time, which makes it a suitable basis of a practical optimization-based decision support system.