计算机辅助工时定额系统中的定额测算模型研究

针对国内现有的辅助工时定额系统大多“偏重时间研究,忽视方法研究”,提出了基元化的计算机辅助工时定额系统,构架了基元化定额测算模型的体系结构,建立了作业元模型和工艺基元模型。系统对时间研究与方法研究并重,有助于改变国内定额方法落后,定额水平低下的现状。     

点对点通信原语并行转换方法仿真研究

针对传统点对点通信原语并行转换方法无法集中分析内部数据结构,导致整体转换效果较差的问题,提出一种MPI程序下点对点通信原语并行转换方法。分析当前原语代码数据结构,完成对应结构化操作,基于并行解码的上行数据交换数据,根据数据理论分析获取数据节点冲突概率,引入高密度MDSCAN聚类算法实现符号的数据簇分类,利用Omega数据库的运算通信模式转换原语,实现通信原语转换为原语数据集。实验结果表明,研究方法的原语数据集抗压比和数据贴合度明显提高,数据显著性更好,转换效果更理想。     

高速以太网现场总线系统管理内核通信机制的研究

文章基于现场总线基金会提出的高速以太网现场总线这一大型系统,深入研究了该系统的系统管理内核与系统其他部分的通信。提出了一种可以对各条原语进行有效识别并进行可靠,快速,安全的传输的通信机制。     

基于几何元素的城市三维地理信息系统空间数据模型

空间数据模型是城市三维地理信息系统建立的核心问题。基于不同的城市空间对象划分方法,提出了城市三维地理信息系统的十八个空间数据模型:把空间现象抽象为六类对象:点对象、线对象、规则面对象、规则体对象、不规则对象和DTM,基于六种几何元素(点、直线段、多边形、函数构造面、TIN面片、规则体素)的不同组合,提出了城市三维地理信息系统的九个空间数据模型;把空间现象抽象为五类对象:0维空间对象(点对象)、一维空间对象(线对象)、二维空间对象(面对象)、三维空间对象(体对象)和DTM,基于六种几何元素的不同组合提出了八个空间数据模型;把空间现象抽象为0维对象(点对象)、一维对象(线对象)、二维对象(面对象)、三维对象(体对象)、DTM,基于点、直线段、TIN面片、多边形、规则面、不规则面六类几何元素提出了一个空间数据模型。通过对一个数据模型的实验验证和各模型的理论分析,表明了模型的特点及可行性。     

过程控制工业以太网通信模型探讨

提出了建立在交换式以太网和IEEE802.1Q/P技术基础上用于过程控制的以太网通信模型REPC,并进行了分析。     

基于多进程的测控系统软件设计及其数据通信

文章介绍了基于多进程的测控系统软件设计方法,将复杂测控系统的软件设计分割为若干相互联系的进程设计,并对多进程程序设计中的核心问题即进程间数据通信问题进行了详细的讨论。     

Stable trace automata vs. full trace automata

Trace automata provide a well-studied model for systems with concurrent behavior, which is usually given by associated domains of finite or infinite computation systems. Several authors in the literature have characterized order-theoretically these domains which are typically particular Scott domains. In most of these investigations, the question remain open when such a domain can be obtained from some finite automaton. In this paper it is shown that finite stable trace automata and finite full trace automata give rise to the same class of coherent dI-domains. The proof of this result involves combinatorial means from graph theory (colorings) and Ramsey's theorem.     

用PV操作原语实现进程的同步

首先建立“进程”的概念,理解进程的动态性以及进程间的相互作用——互斥与同步,接着分析了“互斥”与“同步”在概念上的差异,重点介绍多道程序系统中的同步互斥机制——PV操作原语,详细讨论了生产者-消费者典型问题,从而总结出PV操作应用的方法。     

On the expressiveness and decidability of higher-order process calculi

In higher-order process calculi, the values exchanged in communications may contain processes. A core calculus of higher-order concurrency is studied; it has only the operators necessary to express higher-order communications: input prefix, process output, and parallel composition. By exhibiting a deterministic encoding of Minsky machines, the calculus is shown to be Turing complete. Therefore its termination problem is undecidable. Strong bisimilarity, however, is shown to be decidable. Furthermore, the main forms of strong bisimilarity for higher-order processes (higher-order bisimilarity, context bisimilarity, normal bisimilarity, barbed congruence) coincide. They also coincide with their asynchronous versions. A sound and complete axiomatization of bisimilarity is given. Finally, bisimilarity is shown to become undecidable if at least four static (i.e., top-level) restrictions are added to the calculus.     

Tags for Multi-Protocol Authentication

Formal methods have been proved successful in analyzing different kinds of security protocols. They typically formalize and study the security guarantees provided by cryptographic protocols, when executed by a (possibly unbounded) number of different participants. A key problem in applying formal methods to cryptographic protocols, is the study of multi-protocol systems, where different protocols are concurrently executed. This scenario is particularly interesting in a global computing setting, where several different security services coexist and are possibly combined together. In this paper, we discuss how the tagging mechanism presented in [M. Bugliesi, R. Focardi, and M. Maffei. Compositional analysis of authentication protocols. In Proceedings of European Symposium on Programming (ESOP 2004), volume 2986 of Lecture Notes in Computer Science, pages 140–154. Springer-Verlag, 2004, M. Bugliesi, R.Focardi, and M.Maffei. A theory of types and effects for authentication. In ACM Proceedings of Formal Methods for Security Engineering: from Theory to Practice (FMSE 2004), pages 1–12. ACM Press, October 2004] addresses this issue.     

The Decidability of the Structural Congruence for Beta-binders

Beta-binders is a recent process algebra developed for modeling and simulating biological systems. As usual for process calculi, the semantic definition heavily relies on a structural congruence. The treatment of the structural congruence is essential for implementation. The proof of the decidability of this congruence, reported in this paper, is a first step towards implementations.     

Freelance 800F DCS系统的数据通信分析

本文主要介绍ABB的Freelance 800F DCS系统的数据通信,以该系统为例,重点阐述了DCS系统数据通信的硬件结构,分析了操作级与控制级两个不同网络层次的数据通信特点,并分别给出了相关网络结构图。最后,对上述通信网络结构图进行了重点剖析。     

A note on an expressiveness hierarchy for multi-exit iteration

Multi-exit iteration is a generalization of the standard binary Kleene star operation. The addition of this construct to Basic Process Algebra (BPA) yields a more expressive language than that obtained by augmenting BPA with the standard binary Kleene star. This note offers an expressiveness hierarchy, modulo bisimulation equivalence, for the family of multi-exit iteration operators proposed by Bergstra, Bethke and Ponse.     

Weak repetitions in Sturmian strings

In this paper, we analyze the weak repetitions in Sturmian strings and show that an optimally efficient algorithm to compute the weak repetitions in Sturmian strings according to the output encodings defined in the literature is quadratic in the string length. Finally, we present an encoding that leads to a linear-time algorithm.     

数据通信的发展综述

从电信发展的大趋势出发，讨论了数据通信的概念、现状及一些前沿问题，说明了数据通信的发展方向。     

数据通信的发展战略研究

该文从电信发展的大趋势出发,讨论了数据通信的概念、现状及前沿问题,说明了多媒体通信是数据通信的发展方向。     

Windows环境下计算机与高速数字信号处理系统实时通信

介绍了Windows应用程序访问计算机硬件的主要方法 ,结合实例描述了如何运用Windows虚拟设备驱动程序实现计算机应用程序与高速数字信号处理系统之间实时通信     

无线通信在石油测井中的应用

无线通信应用于石油测井能够极大的提高测井效率，是石油测井未来的发展方向。本文分析了石油测井远程监测的基本要求，提出了一套无线数据传输的系统方案。在通信协议的设计和实现上，采用了双发送队列、优先级调度以及全双工滑动窗口协议等方法，同时保证了测井数据的实时传输和文件资料的正常交互，很好的满足了石油测井数据传输的要求。