滚动接触疲劳缺陷检测的改进Otsu算法

针对滚动接触疲劳试验机高精度和高效率的检测要求,提出一种基于自动加权阈值的改进Otsu算法,将背景发生的概率作为Otsu分割阈值的权重,使分割阈值靠近直方图的左下缘.首先对试件图像进行区域定位,获得试件接触表面图像;然后比较不同滤波器的检测准确率、召回率、调和平均以及运行时间,选择运行时间短、调和平均大的快速导向滤波器对图像进行滤波;最后计算图像的错误分类误差来验证检测算法的有效性.实验结果表明,该算法对测试图像的错误分类误差接近于0,与Otsu、加权目标方差、谷值强调和邻域谷值强调阈值分割法相比,在滚动接触疲劳缺陷检测中有更好的分割结果.     

钢板表面低对比度微小缺陷图像增强和分割

目的 环境干扰及光学元件不稳定等因素往往会造成钢板表面图像照度不均,钢板表面的微小缺陷具有图像灰度不均、对比度低、形态微小等特点,给后续图像分析和缺陷识别带来因难。为此,提出一种钢板表面低对比度微小缺陷图像增强和分割算法,以消除照度不均并突出缺陷信息,从而有效分割缺陷目标。方法 采用小波-同态滤波算法进行图像增强处理,即先利用小波变换对图像进行分解,再基于同态滤波对小波低频系数进行图像灰度修正,同时对高频系数进行高通滤波,然后将处理后的小波低频系数和高频系数进行重构得到增强的图像,从而达到消除照度不均、增强缺陷细节信息的目的。最后利用最大类间方差法（Otsu法）确定自适应阈值提供给Canny算子进行边缘检测。结果 采用本文算法对钢板表面多类型低对比度表面微小缺陷进行研究,有效消除了光照不均;单一的Otsu阈值分割和Canny算子难以有效检测这些缺陷,而本文Otsu-Canny算法的正确检测率达96%。结论 采用小波-同态滤波进行图像增强处理后,再利用Otsu-Canny算法对钢板表面多类型、低对比度的微小缺陷进行边缘检测取得了良好效果。     

基于Otsu算法的木材缺陷图像分割

提出了基于Ostu算法的木材缺陷图像分割.该方法借助于二维中值滤波器对木材图像进行平滑处理,将平滑过的图像用Otsu算法确定图像分割阈值.实验结果表明,该方法可以有效地实现木材表面缺陷图像分割.     

基于广义调和均值距离的图像分割新算法

提出了基于广义调和均值距离的最小偏差图像阈值化分割新算法。Otsu阈值法是图像分割中最典型阈值法之一,因其计算简单、速度快和性能稳定等优点而在图像分割中得到广泛应用;但是,传统Otsu阈值法是基于欧式距离的最小偏差阈值法,由于欧式距离没有可调节参数而导致Otsu阈值法分割图像缺乏鲁棒性。首先将Otsu图像分割法中的欧式距离用广义调和均值距离代替并得到一种具有鲁棒性的图像分割新算法,其次给出该算法中参数选取办法。大量实验结果表明,新的图像分割算法相比Otsu法更有效。     

基于机器视觉的轴承防尘盖表面缺陷检测

为实现工业现场中轴承防尘盖表面缺陷的自动检测,提出一种基于机器视觉技术的检测方法。采用蓝色同轴光源作为检测系统所用光源,克服金属反光;采用最小二乘法拟合轴承外圆,根据轴承型号比例分割出防尘盖区域,利用Otsu阈值分割和Roberts边缘提取处理图像,每2°统计值为1的点的数目,与模板轴承此数据比较,求出相差角度,由此将防尘盖字符、非字符区域分离,两部分是否存在缺陷分开判别,互不干扰。实际测试表明：检测系统采集到的轴承图像清晰,缺陷检测算法正确率在96%以上,可实现轴承防尘盖表面缺陷的自动检测。     

产品表面图像中的缺陷自动检测方法研究

仔细设计产品表面缺陷检测的图像识别算法是基于图像处理的产品表面缺陷自动检测系统快速并正确地检测缺陷的关键。以E型磁环表面缺陷的自动检测为例,分析了产品表面图像的特征,用梯度直方图自适应阈值分割的方法对图像进行增强和分割;并提出了一种新的快速识别算法对分割后的目标图像进行检测,实验结果表明了该算法的有效性和实用性。     

基于狮群优化二维Otsu算法的输送带撕裂检测方法

基于传统二维Otsu分割算法的输送带撕裂检测方法采用穷尽搜索式的阈值选取方式,图像分割时间长、实时性差,不能同时满足撕裂检测精度与速度要求。针对上述问题,提出了一种基于狮群优化二维Otsu算法的输送带撕裂检测方法。首先通过输送带撕裂检测装置采集输送带图像,采用中值滤波和直方图均衡化对采集到的图像进行去噪和增强处理,突出撕裂部位;然后采用狮群优化二维Otsu算法对预处理过的图像求取接近实际的分割阈值,用该阈值对输送带图像进行分割处理;最后通过计算分割后图像中黑色像素点的数量进行撕裂诊断。仿真结果表明,该方法比基于传统二维Otsu算法的检测方法寻优能力更强,输送带分割效果更好,可以准确地从输送带图像中分割出裂痕,撕裂识别的正确率为98.2%,提高效率的同时缩短了运行时间,可以满足输送带撕裂检测的准确性和实时性要求。     

一种自适应梯度幅值的边缘检测算法

提出了一种基于Otsu自适应梯度幅值的边缘检测算法。鉴于传统基于梯度幅值的自适应边缘检测算法中单阈值所带来的边缘断裂问题,分别使用传统Otsu算法和迭代Otsu算法进行自适应阈值,能保证图像梯度幅值的方差最大的情况下求得最优阈值,从而准确的检测边缘像素;针对梯度幅值边缘检测算法中边缘较宽的问题,在Otsu自适应梯度幅值检测算法检测到的边缘图基础上,使用经典的并行细化算法进行了边缘细化;最后,通过实验结果与对比分析,验证了算法能准确定位边缘和获得完整的边缘信息,实现了较好的边缘检测效果。     

改进的二维Otsu算法在SF6压力表盘图像分割中的研究

为了提高SF6压力表盘图像分割准确度,对比了传统二维Otsu和Otsu双阈值分割算法,给出了一种改进二维Otsu算法.针对二维Otsu算法选取最佳阈值时存在的缺陷,将整体阈值再区分并结合离差平方和作为适应度函数选取最佳阈值,提高了目标图像的阈值分割效果.实验结果表明:所提算法不仅满足对SF6压力表盘图像进行目标区域分割,同时具有更高的稳定性、快速性和分割精度.     

汽车精密零件外观缺陷视觉检测方法研究

针对汽车精密零件质量检测的需求,提出了基于机器视觉的精密零件外观缺陷检测方法,搭建了相应的检测平台。采用小波去噪进行图像预处理,基于Otsu算法改进了Canny算子中的双阈值的选取问题,较好地实现了图像的缺陷分割。利用Hu矩进行缺陷特征提取并通过样本特征训练SVM分类器,实现零件外观缺陷的识别与分类。以汽车转向器内部套筒为试验对象,搭建了检测系统,实验结果表明,该算法可有效实现了零件外观缺陷自动检测。     

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.     

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.     

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.     

The Distributed Time-Triggered Simulation Scheme: Core Principles and Supporting Execution Engine

Distributed real-time simulation is a young technology field but its practice is under increasing demands. In recent years the author and his collaborators have been establishing a new approach called the distributed time-triggered simulation (DTS) scheme which is conceptually simple and easy to use but widely applicable. The concept was initiated in the course of developing a new-generation object-oriented real-time programming scheme called the time-triggered message-triggered object (TMO) programming scheme. Some fundamental issues inherent in distributed real-time simulation that were learned during recent experimental studies are discussed along with some approaches for resolving the issues. An execution engine developed to support both the TMOs engaged in control computation and the TMOs engaged in DTS is also discussed along with its possible extensions that will enable significantly larger-scale DTSs.     

Software-Konfigurationsmanagement in großen Softwareprojekten

Zusammenfassung Mit zunehmender Größe der Softwaresysteme verschärfen sich die für die Software-Herstellung typischen Probleme: Beherrschen großer Objektmengen, Erhalten der Systemkonsistenz, Kontrolle der ständigen Änderungseinflüsse und Gewährleisten einer langen Lebensdauer. Die Disziplin Konfigurationsmanagement bildet den methodischen Ansatz, diese Probleme besser zu beherrschen. Software-Konfigurationsmanagement faßt die Herstellung von Softwaresystemen als eine Abfolge von kontrollierten Änderungen an gesicherten Zwischen- und Endergebnissen auf. Dargestellt werden die Objekte und Funktionen des Software-Konfigurationsmanagements sowie die hierfür in großen Software-Projekten benötigten Methoden, Instanzen und Hilfsmittel.     

Information for Authors

正http://www.zju.edu.cn/jzus http://www.springerlink.com Aim The Journals of Zhejiang University-SCIENCE(A/B/C)are edited by the international board of distinguished Chinese and foreign scientists,and are aimed to present the latest developments and achievements in scientific research in China and     

Editorial:Brain-machine interface(BMI) and cyborg intelligence

正Brain-machine interfaces(BMIs)aim at building a direct communication pathway between the brain and an external device,and represent an area of research where significant progress has been made during the past decade.Based on BMIs,mind information can be read out by neural signals to control     

Information for Authors

正http://www.zju.edu.cn/jzus http://www.springerlink.com Aim The Journals of Zhejiang University-SCIENCE(A/B/C)are edited by the international board of distinguished Chinese and foreign scientists,and are aimed to present the latest developments and achievements in scientific research in China and overseas to the world’s scientific circles,especially to stimulate     

SCIENCE CHINA Information Sciences SUBJECT INDEX TO VOLUME 57(2014)

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Information for Authors

正http://www.zju.edu.cn/jzus http://www.springerlink.com Aim The Journals of Zhejiang University-SCIENCE(A/B/C)are edited by the international board of distinguished Chinese and foreign scientists,and are aimed to present the latest developments and achievements in scientific research in China and overseas to the world’s scientific circles,especially to stimulate