立靶测试系统中高精度角度测量研究

为弥补传统光电立靶中相机仰角角度值不能实时显示的不足,介绍了一种新型高精度立靶密集度测试系统角度测量电路的设计;该角度测量电路主要由高精度角度传感器、51单片机、多位LED显示部分构成,可以完成线阵CCD相机仰角的实时测量和显示,精度可达0.0027°,并且可以和上位机进行多路串口通信,方便对多台线阵CCD相机仰角进行监控,避免在测量过程中因相机仰角的变化而带来的测量误差.     

基于双线阵相机的全视角高精度三维测量系统

提出一种基于双线阵相机的全视角高精度三维测量系统,实现对空间大尺寸物体三维测量。首先,通过两台高速线阵相机结合高精度单轴回转平台、高速图像采集卡对空间物体扫描成像,然后利用空间前方交会原理以及空间三维测量系统定向解算出空间物体的实际空间三维坐标。该三维测量系统的优点是不必提前对线阵相机进行内参标定,且自动化程度高,测量速度快。实验结果表明,该三维测量系统精度高,可以广泛地运用到大尺寸空间测量领域,具有良好的实用价值。     

大气参数廓线测量系统的设计与实现

在激光工程以及天文台选址中,需要对大气湍流以及风、温度和气压等大气参数廓线作深入定量的研究.本文以激光大气传输理论的研究为背景,针对大气中的风、湍流廓线测量方面存在的测量精度问题,对大气参数廓线测量系统的工作原理以及大气湍流测量原理进行了研究并设计出这一系统的实现方案.实验结果表明该系统的可靠性高且易于控制,并且具有较高的灵敏度和测量精度,有较好的实用价值.     

基于激光三角法的同步扫描形貌测量传感器

为了克服传统的激光三角非同步物体形貌测量传感器,在深度方向的测量精度和横向测量视场相互制约的固有缺点,设计了一种新型的激光同步扫描物体形貌测量传感器.传感器以激光三角测量法为基本原理,通过所设计的光路系统,实现激光投射方向与相机成像方向的同步扫描.本文研制了基于高速旋转的十二面转镜和线阵CCD相机为主体的实验样机,实现了测量深度方向和横向视场的相互独立,并结合精密电控位移导轨和激光跟踪仪等搭建了实验系统平台.在传统非参数标定方法基础上,提出了一种适用于该传感器的映射标定方法,能够准确快速的标定该传感器.系统利用激光跟踪仪进行比对实验验证,结果表明:单点重复性小于0.07 mm,测量精度优于0.25 mm.测量传感器具有精度高、速率快、稳定性好等优点,对于物体表面形貌快速精密测量有着广泛的应用前景.     

逆向工程点云数据采集系统设计及应用

针对目前四轴激光测量机的不足,设计了一种五轴逆向工程点云数据采集系统;在四轴的基础上增加了激光测头的旋转轴,采用基于PCI总线的运动控制系统及USB总线的数据采集系统,并植入了图像采集系统,通过二次开发技术利用Windows的应用程序编程接口函数对扫描范围进行自动识别;软件系统使用了采集路径规划及测量数据优化处理算法;在原始数据测量及曲面反求建模两个方面进行了实例应用,零件大斜度面和垂直于工作台的表面均能覆盖测量,并且所有点云数据是一次测量完成,实验结果验证了本系统的可行性与稳定性。     

车辙系统安装方式研究

介绍了针对车辙采集与处理子系统采用大功率红外线结构激光器、智能线识别相机组成路面激光断面测量设备。车辙系统车辙相机和激光器安置以往安装方式覆盖宽度不够的问题提出以下解决方案进行了探讨。     

视觉里程计中的相机姿态和高度实时测量方法

在视觉里程计的应用中,实时准确的获得相机姿态和高度数据有助于提高视觉定位的精度.而现有解决方案要么成本过高,要么精度无法满足要求,为此提出了基于路面激光扫描的相机外参数实时测量方法.该方法将两台二维激光扫描仪相互正交安装且向下扫描,对获得的沿着两个方向的路面扫描线使用RANSAC算法估计出直线方程,根据两直线方程求得道路平面方程,并以该平面为参考获得相机相对路面的姿态和高度数据.室内实验结果表明:静态条件下对姿态的测量误差最大约0.1°,高度测量误差最大6 mm;室外动态实验结果表明:与传统的惯性测量方法不同,相机外参数测量结果不受车辆加减速运动的影响,且其动态姿态测量精度明显高于精度为1°的惯性测量系统.由于该方法获得的姿态和高度数据是以道路平面为参考基准,尤其适用于单目视觉里程计中以辅助提高定位精度.     

基于激光干涉仪的角度测量技术

介绍了一种基于激光干涉技术的精密角度测量系统 ,该系统利用干涉仪在几何量测量中的干涉测量技术 ,以激光作为干涉光源 ,迈克尔逊干涉仪作为干涉测量装置 ,通过角度转换装置将角度量转换为可以反映干涉光路中光程差变化的线位移量 ,由此引起干涉条纹的变化 ,再通过相应电路对干涉条纹进行一系列处理 ,从而实现了对大转角的精密测量。与以往类似系统相比 ,该系统具有结构简单、误差恒定、测量精度高、测角范围大、易于数字化等特点     

基于线阵CCD的激光干涉条纹信号处理系统

激光干涉测量系统在非接触精密测量领域占有重要地位,其中对干涉条纹的测量是激光干涉测量的核心。针对这种情况,提出利用线阵CCD将激光垂直照射在劈尖表面时所产成的干涉条纹光学图像转换成电信号并转移输出,通过视频信号预处理电路,模数转换后得到关于干涉条纹宽度的方度信号,完成了对CCD输出干涉条纹信号的处理,实现了对等间距干涉条纹的自动检测。     

高灵敏度TDI线阵CCD图像系统研究

对于低照度、高速运动物体等的测量拍摄场合,往往需要高灵敏度的线阵CCD相机。本文介绍了一款高灵敏度的线阵相机的研制方案,相机的线阵CCD芯片采用DALSA公司的IT-F6,它具有96级TDI功能,动态范围3600:1,经试验,灵敏度比一般的线阵CCD相机提高了约20倍,大幅度提高了系统的整体响应水平。在靶场测试中,对距离5米外的7.2mm高速子弹弹丸可以清楚捕捉,在高灵敏度的探测场合具有广阔的应用前景。     

Call for Papers The 6^th International Conference on Grid and Cooperative Computing

Recent years have seen rapid advances in various grid-related technologies, middleware, and applications. The GCC conference has become one of the largest scientific events worldwide in grid and cooperative computing. The 6th international conference on grid and cooperative computing (GCC2007) Sponsored by China Computer Federation (CCF),Institute of Computing Technology, Chinese Academy of Sciences (ICT) and Xinjiang University ,and in Cooperation with IEEE Computer Soceity ,is to be held from August 16 to 18, 2007 in Urumchi, Xinjiang, China.     

煤矿井下安全监控分站的设计及其仿真实现

为了设计一种具有低成本、低功耗、易操作、功能强且可靠性高的煤矿井下安全分站,针对煤矿安全生产实际,文章提出了采用MCS-51系列单片机为核心、具有CAN总线通信接口的煤矿井下安全监控分站的设计方案;首先给出煤矿井下安全监控分站的整体构架设计,然后着重阐述模拟量输入信号处理系统的设计过程,最后说明单片机最小系统及其键盘、显示、报警、通信等各个组成部分的设计;为验证设计方案的可行性与有效性,使用Proteus软件对设计内容进行仿真验证,设计的煤矿井下安全监控分站具有瓦斯、温度等模拟量参数超标报警功能和电机开停、风门开闭等开关量指示功能;仿真结果表明:设计的煤矿井下安全监控分站具有一定的实际应用价值.     

法律信息库系统

本文分析了法律数据库的结构和特点，介绍了采用面向对象设计方法和超文本数据库技术开发和实现法律信息库系统将作为重要网络资源之一为不同用户进行法律咨询服务。     

View-based model-driven architecture for enhancing maintainability of data access services

In modern service-oriented architectures, database access is done by a special type of services, the so-called data access services (DAS). Though, particularly in data-intensive applications, using and developing DAS are very common today, the link between the DAS and their implementation, e.g. a layer of data access objects (DAOs) encapsulating the database queries, still is not sufficiently elaborated, yet. As a result, as the number of DAS grows, finding the desired DAS for reuse and/or associated documentation can become an impossible task. In this paper we focus on bridging this gap between the DAS and their implementation by presenting a view-based, model-driven data access architecture (VMDA) managing models of the DAS, DAOs and database queries in a queryable manner. Our models support tailored views of different stakeholders and are scalable with all types of DAS implementations. In this paper we show that our view-based and model driven architecture approach can enhance software development productivity and maintainability by improving DAS documentation. Moreover, our VMDA opens a wide range of applications such as evaluating DAS usage for DAS performance optimization. Furthermore, we provide tool support and illustrate the applicability of our VMDA in a large-scale case study. Finally, we quantitatively prove that our approach performs with acceptable response times.     

International Journal of Automation and Computing Table of Contents

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Information for authors

正SCIENCE CHINA Information Sciences(Sci China Inf Sci),cosponsored by the Chinese Academy of Sciences and the National Natural Science Foundation of China,and published by Science China Press,is committed to publishing highquality,original results of both basic and applied research in all areas of information sciences,including computer science and technology;systems science,control science and engineering(published in Issues with odd numbers);information and communication engineering;electronic science and technology(published in Issues with even numbers).Sci China Inf Sci is published monthly in both print and electronic forms.It is indexed by Academic OneFile,Astrophysics Data System(ADS),CSA,Cabells,Current Contents/Engineering,Computing and Technology,DBLP,Digital Mathematics Registry,Earthquake Engineering Abstracts,Engineering Index,Engineered Materials Abstracts,Gale,Google,INSPEC,Journal Citation Reports/Science Edition,Mathematical Reviews,OCLC,ProQuest,SCOPUS,Science Citation Index Expanded,Summon by Serial Solutions,VINITI,Zentralblatt MATH.     

Erratum to: Fast global kernel fuzzy c-means clustering algorithm for consonant/vowel segmentation of speech signal

正Erratum to:J Zhejiang Univ-Sci C(ComputElectron)2014 15(7):551-563doi:10.1631/jzus.C1300320The original version of this article unfortunately contained mistakes.Algorithm 6 should be as follows:Algorithm 6 FGKFCM-F clustering Input:(1)X={x_1,x_2,…,x_N},,x_iR~d,i=1,2,…,N,the dataset;(2)C,1C≤N,the number of clusters;(3)ε0,the stopping criterion;     

Journal of Zhejiang University-SCIENCE C (Computers & Electronics) Total contents

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A pragmatic multi-method investigation of discrepant technological events: Coping,attributions, and ‘accidental’ learning

Discrepant technological events or situations that entail a problem, a misunderstanding or a difficulty with the Information Technology (IT) being employed, are common in the workplace, and can lead to frustration and avoidance behaviors. Little is known, however, about how individuals cope with these events. This paper examines these events by using a multi-method pragmatic approach informed by coping theory. The results of two studies – a critical incident study and an experiment – serve to build and test, respectively, a theoretical model that posits that individuals use a variety of strategies when dealing with these events: they experience negative emotions, make external attributions, and adopt engagement coping strategies directed at solving the event, eventually switching to a disengagement coping strategy when they feel they have no control over the situation. Furthermore, users’ efforts may result in ‘accidental’ learning as they try to overcome the discrepant IT events through engagement coping. The paper ends with a discussion of the results in light of existing literature, future opportunities for research, and implications for practice.