Reverse reachability analysis: A new technique for deadlock detection on communicating finite state machines

The communicating finite state machines can exchange messages over bounded FIFO channels. In this paper, a new technique, called reverse reachability analysis, is proposed to detect deadlocks on the communication between the communicating finite state machines. The technique is based on finding reverse reachable paths starting from possible deadlock states. If a reverse reachable path can reach the initial global state, then deadlock occurs. Otherwise the communication is deadlock-free. The effectiveness of the technique has been verified by some real protocols such as a specification of X.25 call establishment/clear protocol and Bartlet's alternating bit protocol.     

HVS：一个半现实全景图时空模型

利用实景图象组成具有空间感和时间感的虚拟空间，我们称之为半现实。这种具有空间“上下文”和时间“上下文”能力的半现实全景图可以应用于许多方面。文中描述了这种半现实ＨＶＳ的建模思想，给出了组成时空座标系的方法，并且讨论了实现中的若干问题。     

Knowledge extraction for production management

A procedure and underlying algorithm for extracting knowledge from production and inventory databases to support engineering management activities is described. The process searches for, detects and isolates behaviour patterns inherent in the data. It relates these patterns to production irregularities, suggests connections with specific causes and helps propose possible corrective or preventive actions. The approach is based on a four-phase procedure: (1) the decision-maker focuses on the subject or difficulty at issue, represented by a target concept; (2) the KEDB algorithm, based on a machine learning approach, processes the relevant database and provides knowledge characterizing and classifying the target concept; (3) the output is interpreted in Pareto fashion as a series of possible circumstances explaining the target concept behaviour; and (4) based on these causes, the decision-maker decides on possible corrective actions to improve the situation, or preventive actions to forestall unfavourable conditions. A case study based on an actual quality control database is detailed.     

交流探尺的控制及其在武钢新3^#高炉上的应用

本文论述了交流探尺的控制原理及到料面信号的检测方法。以其在武钢新３＃高炉上的应用为例，给出系统组态、控制框图及它在无料钟系统中所起的补偿倾动角度的作用。最后对交流、直流探尺系统进行了比较。     

准分子激光器异步感应密封传动技术

一种新型准分子激光器循环系统中的密封传动技术，具有可耐高气压，不失耦，不使用昂贵强磁材料，结构简单等优点，虽有涡流损失过大之不足，但能很好地适用于小功率下运行。     

造纸机集散控制系统

本文介绍了造纸机集散控制系统．讨论了其硬件的组成和软件结构．研究了ＤＤＳ过程级控制器的功能及对造纸机各分部速度的优化控制．系统投人运行后，取得较好的经济效益．     

Knowledge-based diagnosis of drill conditions

One major bottleneck in the automation of the drilling process by robots in the aerospace industry is drill condition monitoring. This paper describes a system approach to solve this problem through the advancement of new machine design, sensor instrumentation, metal-cutting research, and intelligent software development. All drill failures can be detected and distinguished: chisel edge wear, flank wear, crater wear, margin wear, corner wear, breakage, asymmetry, lip height difference, and chipping at lips. However, in the real manufacturing environment, different workpiece materials, drill size, drill geometry, drill material, cutting speed, feed rate, etc. will change the criteria for judging the drill condition. The knowledge base used for diagnosing the drill failures requires a huge data bank and prior exhaustive testing. A self-learning scheme is therefore introduced to the machine in order to acquire the threshold history needed for automatic diagnosis by using the same new tool under the same drilling conditions.     

锁相技术在电子束曝光机工件台稳速控制中的应用

采用锁相技术，对电子束曝光机工件台运动实现速度环的全数字控制。设计了数字差频积分回路和数字差频比例控制器，能有效消除速度的静态误差和改善系统的动态特性。     

着色型珠光颜料涂布纸的研制

本文论述了着色型珠光颜料涂布纸的研制工作，并对影响珠光涂料制备的几个因素进行探讨．优化结果表明，瓷土０～３０％，珠光颜料７０％～１００％，胶粘剂２５％～３０％，固含量２３％～２５％，涂布量１０～１５ｇ／ｍ２时，其纸面呈现强烈的珠光光泽，适用于胶印．     

微机控制托辊管筒加工机床的设计

介绍了一种生产效率高、加工质量稳定、利用单片机控制液压传动系列带式输送机托辊管筒自动加工机床的设计过程。