程序代码中隐含数据与控制的Petri 网建模技术

应用一种Petri网扩展CNets,描述程序代码中所隐含着的数据与控制,分别给出了程序代码的数据视图和控制视图.在CNets规范的基础上,研究程序中的数据与控制流之间的交互以及程序中数据、操作和资源之间的关系,同时给出CNets规范向经典Petri网规范的转换规则.在不运行程序的前提下,根据这一映射机制,通过CNets规范,利用经典Petri网理论对程序的性质进行分析.     

Lotus Domino数据自动备份程序实现

Autolt是用来完成在Windows GUI中进行自动操作的一种BASIC风格的脚本编程软件,程序员可以通过Autolt编程来模拟键击、鼠标移动、窗口和控件操作等来自动完成平常工作中一组Windows窗口操作任务,文中详细介绍实现Domino数据的自动备份程序,从而使Domino管理员从繁琐的Domino数据备份中彻底解脱出来。     

TurboC／C＋＋编程技巧—执行外部进程

在程序设计过程中,经常会出现需要调用DOS内外部命令,现成的应用程序或商品化软件如FoxBase,Basic。这样做的好处是整个操作都在同一程序的控制下进行,即节省时间又容易实现各程序之间的数据传递。如何便利、有效地执行这些外部命令在程序设计中需要妥善处理,否则会出现许多麻烦,如死机等。     

支持数据绑定的用户界面自动生成模型

针对现有用户界面模型在界面自动生成时不能实现控件和数据自动绑定的问题,提出一种新的用户界面模型,包括界面数据对象、数据对象之间及数据对象与控件关系的描述规范。应用结果证明,该模型能在用户界面生成时自动绑定控件和数据,实现界面数据的联动,减少界面开发时间,提高软件开发效率及可维护能力。     

"工控软件互操作规范OPC技术"讲座 第10讲 基于OPC规范和Internet/Intranet的实时监控系统

0　引言ＯＰＣ(ＯＬＥｆｏｒｐｒｏｃｅｓｓｃｏｎｔｒｏｌ)规范基于微软的ＯＬＥ(现在称为ＡｃｔｉｖｅＸ) /ＣＯＭ和ＤＣＯＭ技术 ,是由ＯＰＣ基金组织制定的工业标准。ＯＰＣ规范致力于成为一个开放的、易实现的、即插即用的标准 ,在工业控制设备和控制软件之间建立统一的数据存取规范 ,它不但能够应用于单台计算机 ,而且可以支持网络上分布式应用程序之间以及不同平台上应用程序之间的通信 ,实现系统软件与设备之间无缝集成和真正开放的通信。这样 ,通过ＯＰＣ规范可以将基于Ｗｉｎｄｏｗｓ应用的企业办公管理应用软件和生产现场的自动…     

基于图形的水厂自控系统界面功能设计

本文详细介绍了水厂自动控制系统和界面的设计。通过自动控制系统，实现水厂的自动化运行。界面是自控系统程序的集成，是操作人员直接面对的地方，操作人员通过界面对系统进行操作，界面的好坏直接关系到工作效率，出错的几率等。     

利用基因表达式编程自动生成循环不变式

描述了利用基因表达式编程自动生成循环不变式的方法。该方法的基本思想是在每一次循环条件变化时记录下程序变量的值,产生相应的跟踪表,然后从跟踪表中获得程序变量之间的函数依赖关系,这种变量之间的依赖关系构成了循环不变式的主要部分。程序变量之间的函数依赖关系的获得是利用基因表达式编程对跟踪表中数据执行符号回归得到。利用VC＋＋实现了基因表达式编程的函数挖掘,并通过一个实例说明了该方法的有效性。     

通过鼠标自动控制实现程序的自动化操作

Windows系统本身是一个消息系统,消息传递是其核心。通过向窗口对象发送鼠标点击消息来实现鼠标的自动控制,从而实现程序的自动化操作。文章着重就鼠标自动的控制以及实现程序的自动化操作过程中需要解决的一些关键问题作深入的探讨。     

支持用户自定义谓词的自动定理证明的研究

在先前设计的一个出具证明编译器原型基础上,增加了可用来描述数据结构性质的自定义谓词,对断言语言表达能力方面做了提升.在出具证明编译器的框架内,借助自动定理证明技术,针对自定义谓词的特点,设计了专门的推理规则,由此实现自定义谓词专用的自动定理证明器原型,并将它并入系统原来的自动定理证明器中.该原型可以用来证明操作单链表、二叉树等共享数据结构的程序的性质,其程序规范中可以使用自定义谓词描述数据有序性、链表长度等性质.     

并发程序原子图挖掘技术

针对当前并发程序的不确定性和复杂性,以及程序原子性质获取困难的问题,提出一种并发程序原子性质提取方法。将并发程序中的同步区域转化为与并发操作相关的并发操作图后,采用频繁子图挖掘算法自动提取程序中的原子图,使其能刻画并发程序的原子性质,包括并发操作以及操作之间的控制依赖关系。实验结果证明,该方法能以较低的误测率有效提取并发程序的原子性质。     

Petri网模型代码映射研究

为了简化仿真系统的实现过程,分析总结了Petri网到程序代码的映射准则,从Petri网的基本元素和关系入手,根据逻辑关系建立映射的三类原子语句,并通过两种合成方式形成分子语句。以原型Petri网为例,遍历可达标识图的各种分支路径,提出循环路径到循环结构语句的代码映射方法。最后给出了带抑制弧的扩展Petri网和受控Petri网的代码映射方案,为Petri网向程序代码的转换提供了理论依据。     

Structuring Acyclic Petri Nets for Reachability Analysis and Control

The incidence matrices—from places to transitions and vice versa—of an acyclic Petri net can obtain a block-triangular structure by reordering their rows and columns. This allows the efficient solution of some reachability problems for acyclic Petri nets. This result is further used in supervisory control of Petri nets; supervisors for Petri nets with uncontrollable transitions are constructed by extending the method of Yamalidou et al. (1996) to Petri nets where transitions can be executed simultaneously. A large class of Petri nets with uncontrollable transitions is given for which the maximally permissive supervisor can be realized by a Petri net. The original specification is algorithmically transformed—by using the results for acyclic Petri nets—into a new specification to take the presence of uncontrollable transitions into account. The supervisor is obtained by simple matrix multiplications and no linear integer programs need to be solved. Furthermore, a class of Petri nets is given for which the supervisor can be realized by extending the enabling rule with OR-logic.     

自控网的S-不变的研究

自控网是一种自修正系统，主要用于并发系统中的程序规范以及工业控制中的数学建模等领域。自控纲的S-不变、T-不变的非线性，使得它无法直接套用Petri网中一些已有的分析方法。有关不变的讨论一般在具体系统中作具体分析，从而给出具体的解释。对于一般网中S-不变呈现的特性在自控网上是否有条件的成立却鲜有文献涉及，本文给出了一个相应的定理。     

A Visualization Modeling Framework for a CSP-Based System

In this paper, we draft a CSP-based language for our distributed software development system. A program model hierarchy, classified into three characteristic layer: specification layer, monitoring/debugging layer and code layer, is introduced to help users use appropriate modeling methods in the program development cycle. A hierarchical visualization interface—which contains our three-level visualization modeling framework with three different models: Petri nets, IPC Dataflow and Event Code View, transferred from the extended CSP—has been also designed and implemented. We could monitor a distributed application by using any coordinated combination of the constructs of the above models as a favorite view in a systematic manner. The transformation rules among the constructs of these visual models are also discussed.     

Design and Implementation of Discrete Event Control Systems: A Petri Net Based Hardware Approach

This paper presents a methodology for modeling and hardware implementation of discrete event control systems based on the formalism of Petri nets (PN). The control algorithm is initially specified as an executable PN specification which is subsequently compiled directly into a compact machine code and stored in commercially available programmable read only memory (PROM). As an implementation platform, a programmable Petri net based dedicated discrete event controller is proposed. The scalable architecture of the controller is optimized to process PN constructs of all possible classes. A remarkable feature of the proposed architecture is its ability to handle explicit concurrency. The controller exploits hardware-level parallelism to track multiple tokens (control threads) through the net. The performance of the architecture has been verified and benchmarked on the fabricated integrated circuit (IC) prototype of the controller.     

自动化仓库输送调度问题的建模与控制研究

基于面向对象着色Petri网模型和时态逻辑方法,对自动化仓库输送系统运行过程的调度问题进行研究。建立了系统的面向对象着色Petri网模型,讨论了该过程的死锁分析问题,给出了系统行为的时态逻辑规范和死锁避免的最大允许反馈控制策略。     

Automatic construction of systems of distributed components from nested Petri nets models

Multi-level multi-agent systems (MASs) with dynamic structure are widely used in solving important applied problems in telecommunication, transportation, social, and other systems. Therefore, ensuring correct behavior of such systems is an actual and important task. One of the most error-prone stages of system development in the framework of model-oriented approach is the implementation stage, in the course of which a program code is constructed based on the model developed. This paper presents an algorithm for automated translation of MAS models represented as nested Petri nets into systems of distributed components. Nested Petri nets are the extension of Petri nets in the framework of the nets-within-nets approach, which assumes that tokens in a Petri net may themselves be Petri nets, possess autonomous behavior, and interact with other tokens of the net. This makes it possible to model MASs with dynamic structure in a natural way. The translation presented in this paper preserves distribution level and important behavioral properties (safety, liveness, and conditional liveness) of the original model and ensures fairness of the target system execution. The use of such translation makes it possible to automate construction of distributed MASs by models of nested Petri nets. As a test example, translation of nested Petri nets into systems of distributed components was implemented on the basis of the EJB component technology.     

Generalized stochastic Petri nets: a definition at the net leveland its implications

The class of Petri nets obtained by eliminating timing from generalized stochastic Petri net (GSPN) models while preserving the qualitative behavior is identified. Structural results for those nets are derived, obtaining the first structural analysis of Petri nets with priority and inhibitor arcs. A revision of the GSPN definition based on the structural properties of the models is presented. It is shown that for a (wide) class of nets, the definition of firing probabilities of conflicting immediate transitions does not require the information on reachable markings. Identification of the class of models for which the net-level specification is possible is also based on the structural analysis results. The procedure for the model specification is illustrated by means of an example. It is also shown that a net-level specification of the model associated with efficient structural analysis techniques can have a substantial impact on model analysis