Self-stabilizing depth-first token circulation on networks

Summary This paper proposes a self-stabilizing protocol which circulates a token on a connected network in nondeterministic depth-first-search order, rooted at a special node. Starting with any initial state in which the network may have no token at all or more than one token, the protocol eventually makes the system stabilize in states having exactly one circulating token. With a slight modification to the protocol —by removing nondeterminism in the search — a depth-first-search tree on the network can be constructed. The proposed protocol runs on systems that allow parallel operations. Shing-Tsaan Huang was born in Taiwan on September 4, 1949. He got his Ph.D. degree in 1985 from Department of Computer Science, University of Maryland at College Park. Before he pursued his Ph.D. degree, he had worked several years in the computer industry in Taiwan. Professor Huang is currently the chairman of the Department of Computer Science, Tsing Hua University, Taiwan, Republic of China. His research interests include interconnection networks, operating systems and distributed computing. He is a senior member of the IEEE Computer Society and a member of the Association for Computing Machinery. Nian-Shing Chen was born in Taiwan on October 21, 1961. He received his Ph.D. degree in computer science from National Tsing Hua University in 1990. Dr. Chen is currently an associate professor with the Department of Information Management at Sun Yat-Sen University of Taiwan. His research interests include distributed systems, computer networks, computer viruses and expert systems. He is a member of IEEE and Phi Tau Phi honorary society.This research is supported by National Science Council of the Republic of China under the contract NSC81-0408-E-007-05 and NSC82-0408-E-007-027     

接入网MAC层QoS系统的多业务令牌桶流量整形算法

以HFC网络核心设备双向CM(Cable Modem)为研究背景,首先对目前的流量整形算法进行了分析,在HFC网络QoS系统需求的基础之上,提出了一种动态支持多业务整形的令牌桶算法.以美国有线电视实验室的测试用例仿真分析了队列长度对丢包率以及延时的影响.通过性能分析可以看出,该算法满足了多种应用对延时和丢包率的要求,很好地调整了数据的突发速率,有效地进行了流量整形控制.     

基于DCS—MINICOM网络通信系统的在线实时优化控制

对进口集散控制系统(DCS)进行深开发，提高原有装置的控制水平，实现在线优化闭环实时控制是工业界普遍关注的研究课题。在美国ABB公司制造的MOD-300型DCS基础上，选用DEC公司制造的Alapha-3800小型机为控制与通信平台，通过PHENIX接口软件、Apclopt软件包及Setcim数据库构建了与DCS的网络信息交换系统，实现了装置的在线优化控制。以中石化某厂、阜海发电厂为例叙述了主要实施过程：优化目标函数的确定，变量的选取，数学模型的建立，优化算法与生产预报模型的形成过程。     

VBR流令牌桶流量整形的研究

对于可变比特率(VBR)令牌桶流量整形问题,示出令牌桶等待队列长度与丢包率的关系曲线,推导出在保证截止期条件下如何确定令牌桶参数的关系式.针对活动图像工作组(MPEG)视频流模型进行了仿真,仿真结果与理论结果吻合.     

Study of a simulated stream machine for dataflow computation

In this paper, a stream-based dataflow architecture is proposed, and its simulation model, which has helped to evaluate the effectiveness of the proposed architectural concept, is discussed. The machine integrates the conventional Von Neumann type of control flow subsystem with a dataflow processing element of token storage type. The control flow unit tackles the dynamic nature of the stream structure including input/output whereas the dataflow unit does the computation part in an applicative style. A pipelined version of the stream machine is also discussed. The effectiveness of the machine is studied by running a few example programs in the simulated machine. The machine is expected to be useful in real time signal processing applications.     

基于令牌总线的测试系统集散式控制

本文针对分布测试系统的特点,结合汽车车身视觉检测站的具体要求,对其数据通信进行了研究,建立了基于令牌环的数据通信网络,实现了对测试设备的多测点、远距离在线监控。实验表明,该通信网络具有通用性好、可靠性高、扩展能力强等优点。文中对该网络的拓扑结构、物理层接口、信息帧格式及软件设计进行了讨论,对其数据链路控制方法进行了研究,并介绍了它在仪器管理方面的应用。     

浅谈令牌环网络的发展方向

文章论述了令牌环网络的发展方向。并分析介绍了各类交换技术的特点。     

SELF-STABILIZING DEPTH-FIRST MULTI-TOKEN CIRCULATION IN TREE NETWORKS

Self stabilization is one of the new paradigms to investigate fault tolerance in distributed algorithm design. The multi-token or the l-exclusion problem is the logical generalization of standard mutual exclusion problem where l processes can enter their critical section at the same time. Self stabilizing single token circulation or the standard mutual exclusion problem has been investigated by a number of authors; recently authors in [16] have proposed a self stabilizing multi-token protocol for the ring networks. We propose a new self stabilizing algorithm (protocol) for depth first circulation of multiple tokens in a tree network. The algorithm uses only bounded integers and the correctness is proved by using induction.     

工控网络拓扑结构及其协议分析

随着信息技术的不断发展 ,FA(工业自动化 )网络在工厂控制领域得到了广泛的普及 ,并被广泛用于集散控制系统和监视监控系统。主要阐述了几种FA网络的结构及其互连 ,并对它们的协议进行了分析 ,同时针对实际情况给出了一种拓展方案