基于HPN仿真的混杂系统分层调度方案

本文针对混杂系统中分段式生产的调度问题提出了一种分层调度的解决方案。在调度的上层将混杂系统中连续变量进行离散化处理,给出易于求解的静态调度方案：在下层利用HPN（bybrid Petrinet,混杂Petri网）仿真反馆调度信息,补偿上层调度中由于模型的离散化而丢失的动态信息。通过两层之间的通信达到整体调度方案的快速性、实时性和鲁棒性。     

基于ASP．Net技术实现网站新闻系统

本文以网站新闻系统的功能设计为例,详细介绍了ASP．NET技术的先进性,代码更易于编写,结构更清晰,程序的可靠性和稳定性有了很大的改善和提高。降低了系统的开发与维护的复杂度。     

基于.NET的Nx二次开发技术在标准件库中的应用

随着CAD技术的发展,CAD软件得到了广泛的应用,在这些平台上开发符合企业所需要的零件库的工作也取得了很大成果。但随着网络和信息技术的发展,这些零件库的缺点与不足也逐渐显露了出来,界面不够友好、重复开发现象严重、资源不能共享、移植性和扩展性较差等。基于现有的二次开发存在的问题,重点对CAD软件系统NX的NXOpenFor.Net的开发方式进行了研究,获取完整的开发过程,采用将交互式和批处理式相结合的二次开发模式,提出了一种新的基于UG的企业标准件数据库系统,实现了企业标准件数据库系统中的数据库和图形库同步管理。     

A generalized Petri net modeling approach for the control of re-entrant flow semiconductor wafer fabrication

Re-entrant flow manufacturing lines, such as occur in semiconductor wafer fabrication, are characterized by a product routing that consists of multiple visits to a workstation or group of workstations during the manufacturing process. In this paper, a modeling approach is based on the use of generalized Petri nets for a re-entrant flow manufacturing line is presented. Specifically, three Petri net models representing a re-entrant flow line with three work centers and six machines are modeled. How these models may be used to represent a variety of queuing disciplines and work release policies is discussed.     

Automatic Real-Time Analysis of Reactive Systems with the PARTS Toolset

Real-time systems are becoming increasingly widespread, often in safety-critical applications. It is therefore crucial that these systems be correct; however, there are few automated tools for analyzing concurrency and timing properties of these systems. The PARTS toolset uses a Petri-net-based reachability analysis to analyze program specifications written in an Ada-83 subset. Our simple time Petri nets are specifically aimed at facilitating real-time analysis. In order to control the state-explosion problem, PARTS employs several optimization techniques aimed at state-space reduction. In this paper we discuss our approach and we report on extensive experiments with several examples of real-time specifications based on Ada 83. When possible, we also compare our experimental results with results obtained by other approaches to real-time analysis.     

A multi-agent intelligent system for efficient ERP maintenance

The Enterprise Resource Planning (ERP) system is an enterprise-wide integrated software package designed to uphold the highest quality standards of business process. However, for the time being, when the business condition has been changed, the system may not guarantee that the process embedded in ERP is still best. Moreover, since the ERP system is very complex, maintaining the system by trial and error is very costly. Hence, this paper aims to construct a support system that adjusts ERP system to environmental changes. To do so, we adopt multi-agent intelligent technology that enables autonomous cooperation with one another to monitor ERP databases and to find any exceptional changes and then analyze how the changes will affect ERP performance. Moreover, Petri net is applied to manage the complexity and dynamics of agents’ behavior. To show the feasibility of the idea, a prototype agent system, ERP/PN, is proposed and an experiment is conducted.     

过程建模的Petri网模型

工作流管理的问题由于广泛存在于计算机应用的许多方面而迅速得到发展。本文介绍了一个以扩展的Petri网作为建模工具、以消息队列作为执行机制实现的过程管理的原型系统。该模型描述了活动的并发执行和依赖关系、活动激发的条件、事件顺序及文档管理等信息。执行该模型,在分布、异构、自治的环境中可自动监视、管理和调度工作任务,为业务过程重组、业务过程自动化提供了有力的支持。     

电力系统结线分析的有色Petri网方法

从离散事件动态系统角度考虑电力系统结线分析问题,提出了基本分析单元的有色Petri网模型以及基于该Petri网的结线分析算法,Petri网中的令牌代表结线分析中的结点,令牌的颜色表示连接在同一个结点上的元件,变迁将包含相同元件的结点连接在一起,论文对基于Petri网的结线分析算法及传统的算法进行了比较,并计算了一个模型系统各变电站的结点及网络的结线,表明了该方法的可行性及有效性。