地下管道检测移动机器人的发展现状

简要介绍了管道检测移动机器人的发展状况,并对管道检测移动机器人的发展趋势及关键技术进行了探讨。     

陶瓷刀具模糊可靠性及其与刀具材料力学性能的关系

基于模糊数学和可靠性数学的基本理论 ,阐述了刀具模糊可靠性的基本概念和评价方法 ,并进一步应用于陶瓷刀具研究领域 ,建立了陶瓷刀具模糊可靠性与刀具材料力学性能的关系 ,从而使得不做或少做切削实验就能评价陶瓷刀具可靠性的设想成为可能     

人机交互式公路路线设计系统研究

介绍人机交互式公路路线设计系统的总体设计和环境需求,并对系统的社会效益进行分析．     

电机三维温度场新的有限元计算模型

提出了一种新的适合于电机温度场计算的圆柱坐标系下的有限元模型。通过数值计算结果与解析计算结果的实例对比,证明了本方法的正确性与有效性。最后应用本文提出的模型,对ＳＦ１２５－９６／１５６０型发电机的定子铁芯三维温度场进行了计算,并与实测结果作了比较,计算精度满足工程计算的要求。     

A geometrical approach to computer-aided process planning for computer-controlled machine tools

This paper documents part of a research program which has been under way at the CIM Centre at Swinburne University of Technology since 1989. The purpose of the research program was to develop an open-architecture machine tool control system and then to see how that system could be used to change the distribution of traditional manufacturing design, planning and control functions. This paper examines one part of that research program and focuses on a methodology which could prove to be useful in the machine tool selection, cutter selection and cutter path generation phases of process planning for cutting operations on workpieces in computer-controlled machine tools.It is suggested that a configuration space transform be used for each cutter/machine tool combination to find the volume that the combination could remove from the uncut workpiece without removing any of the material that will form the final workpiece. A method of comparing these volumes from different combinations is then outlined. The output of this method is a reasonable sequence of machine tools and cutters. Path planning can then be carried out for each of the chosen combinations using a method similar to the one used to find the possible volume to be removed.Possible implementation techniques, and their limitations on existing computer hardware, are discussed and the most promising of these are identified, based upon some properties of configuration space transforms.     

On a class of optimal abstractions of finite-state machines

Anabstraction A of an fsmM consists in partitioning its states, inputs, and outputs into groups, thus turning it into a non-deterministic fsmM _A. For fixed sets of states, inputs, and outputs, and abstraction generally maps a number of machinesM defined on these sets into the sameM _A. We would like to find anoptimal abstractionA ^* which minimizes this number, while lumping the states, inputs, and outputs into a specified number of classes. We extend these ideas to an fsmM operating in a random environment, and show that the abstraction results in a probabilistic fsm . Thinking of changes inM's output map as resulting in machinesM≠MM, we want to find anA ^* that minimizes the number ofMM which are such that the transition probabilities of their abstracted version are identical to those of the specification machine . SuchMM arise from statistically-undetectable output faults inM. Abstractions are directly applicable to the monitoring of a complex system by an observer for deviations from correct behavior (faults). Complex systems are usually accessible through restricted interfaces, which do not allow the observer to distinguish among all states, inputs, and outputs, thus rendering some faulty transitions undetectable. An optimal interface design will minimize the number of such undetectable faults. Assuming that only single-transition output faults occur inM, we show that each of the classes into which the abstraction lumps the outputs contributes a number of undetectable output faults. We then show that the problem of partitioning the outputs into a given number of classes that minimizes the maximum of these numbers is NP-complete. However, we give (a) an approximate minimization algorithm, running in time linear in the number of classes and quadratic in the number ofM's outputs, and (b) a lower bound on the minimum, computable in the same amount of time. The concept of optimal abstractions is illustrated by numerical results on combinational logic circuits that perform arithmetical operations. The results shed light on the trade-off between model simplification and the ability to detect erroneous behaviors in complex systems.     

服务器虚拟化技术及安全研究

文章概述了x86平台服务器主流虚拟化技术分类及原理,比较分析了全虚拟化、半虚拟化和硬件辅助虚拟化技术的优势和缺点,同时分析了服务器虚拟化带来的新的安全风险与挑战,并讨论了在虚拟环境下的安全应对措施。     

支持向量机在煤炭营销风险评估中的应用研究

介绍了支持向量机统计学习方法;结合煤炭营销管理的特点,提出了支持向量机在煤炭营销风险管理方面的应用方法。实验表明,采用支持向量机统计学习方法能够评估购煤客户的信用风险,帮助煤炭企业挑选优质客户,为煤炭企业积极防范和规避营销风险提供决策依据。     

基于LS-SVM的陶瓷窑炉温度预测控制

针对陶瓷窑炉大热容量、大滞后、非线性等特点,提出了一种基于最小二乘支持向量机动态矩阵控制方法;首先,采用保证种群多样性微粒群算法优化的最小二乘支持向量机离线建立被控对象模型;然后在系统运行过程中,用动态矩阵预测算法实现对被控系统的预测控制;并以陶瓷窑炉温度为控制对象,与Smith预估控制以及内模控制算法进行了比较;仿真结果证明了所提控制方法具有很好的动、静态性能和强鲁棒性。     

基于机器视觉的高密度电路板缺陷检测系统

为减少高密度电路板的缺陷误报率,研究一种新型自动光学检测系统(AOI);系统采用自行研制的多色LED照明系统,利用机器视觉获取被测PCB的图像,通过图像处理软件系统快速准确地识别出各种缺陷;系统利用获取的彩色图像信息,根据各种缺陷的特征信息不同,采用OPENCV对各种缺陷的检测算法进行改进,使得系统性能有很大改进;对30块同类HDI型PCB的36300个检测点进行测试,测试结果证明,系统PCB缺陷的检出率高达99.87%,误报率只有0.32%。