基于融合特征的行人再识别方法*

行人再识别过程中,由于姿势和光照等因素的变化使不同相机中所得行人的外形具有明显变化,较难提取不变性特征,导致识别率偏低.鉴于此种情况,文中提出基于融合特征的行人再识别方法,提取的特征包括HSV颜色特征、颜色直方图特征及梯度方向直方图特征,行人再识别过程分为训练阶段和识别阶段.在训练阶段,首先对训练图像集中每幅图像进行特征提取,然后利用典型相关分析获得2部相机拍摄同一行人的图像特征之间的相关性,生成相关性矩阵.在识别阶段,首先对参考图像集和测试图像集中每幅图像进行特征提取,然后将各自特征向量利用相关性矩阵进行变换,最后进行相似度度量,得到识别结果.在3个图像库上的实验表明,文中方法可以提高行人再识别的识别率.     

基于特征脸的主成分分析人脸识别

采用基于PCA（主成分分析）的特征脸人脸识别方法,判断一张给定的图像是否为人脸图像。该方法通过计算训练集的特征向量,得到一个由特征脸组成的子空间,并将训练集中的人脸图像投影到该子空间中。检测人脸时,将二维的人脸图像投影到脸空间,并计算该图像与脸空间之间的欧几里得距离,以距离是否小于某一设定的阀值来识别是否人脸图像,实验测试结果准确率为97.5%。     

驾驶员眼部状态检测研究

对拍摄得到的驾驶员视频帧图像,使用复合肤色模型检测人脸;通过自适应边缘检测、图像增强等方法处理得到特征图像,经特征区域筛选,依据人脸先验知识匹配得到最佳人眼对;提取眼部特征向量,结合LVQ神经网络进行模式识别检测眼部状态,为判断驾驶员是否处于疲劳状态提供判据。     

低层特征获取高层语义的图像检索

首先采用基于颜色聚类的方法将图像分割成区域,提取每个区域的Gabor小波纹理特征和灰度共生矩阵纹理特征,接着采用信息熵对特征进行选择,使用选择后的特征对图像区域进行聚类,得到每幅图像的语义特征向量;然后提出遗传模糊C均值算法对图像进行聚类。在图像检索时,查询图像和聚类中心比较,在距离最小的类中进行检索。实验表明,提出的方法可以明显提高检索效率,提高了检索的精度。     

姿态特征与深度特征在图像动作识别中的混合应用

人体姿态是动作识别的重要语义线索,而CNN能够从图像中提取有很强判别能力的深度特征,本文从图像局部区域提取姿态特征,从整体图像中提取深度特征,探索两者在动作识别中的互补作用.首先介绍了一种姿态表示方法,每个肢体部件的姿态由描述该部件姿态的一组Poselet检测得分表示.为了抑制检测错误,设计了基于部件的模型作为检测上下文.为了从数量有限的数据集中训练CNN网络,本文使用了预训练和精细调节的方法.在两个数据集中的实验表明,本文介绍的姿态特征与深度特征混合使用,动作识别性能得到了极大提升.     

基于火焰图像动态特征的火灾识别算法

提出了一种基于火焰图像动态特征的火灾识别算法.首先在HSI空间对捕捉的图像进行彩色分割,通过相邻两帧图像判断视频中是否存在可疑火焰.当有可疑火焰存在时,再连续捕捉多帧图像,进行火焰中心定位并提取火焰动态特征,最后判断是否发生火灾.实验结果表明,该算法具有比较好的鲁棒性,能够有效地提高火灾识别的准确率、降低误报漏报率.     

基于SURF和全局特征融合的图像分类研究

针对SURF对图像局部特征具有极好的描述能力,但对于全局特征描述能力不强的缺点,提出将SURF和全局颜色特征相融合的图像分类算法,提取图像的SURF特征向量集,并利用随机直方图算法将该向量集进行数据归约成单一高维特征向量;提取图像HSV颜色直方图;分别利用支持向量机（SVM）对这两种特征进行分类;将两个分类结果进行高层特征融合得到最终分类结果。实验结果表明,该算法显著提高了图像分类的准确率。     

基于距离限定优化的多姿态人脸图像智能识别

针对人脸角度、姿态和表情复杂多变,导致人脸面部表情识别准确率较低的问题,提出基于距离限定优化的多姿态人脸图像智能识别方法.根据人脸图像特征类别进行标号并调整图像角度等值,借助向量内积确定人脸图像特征相似程度,提取人脸图像特征;采用离散化处理人脸图像特征,构建特征矩阵,将人脸图像特征分量中维度作为条件属性,采用粗糙集近似约简法对所得特征向量降维处理;通过边界值和阈值优化特征向量距离,采集不同姿态特征向量,生成多种姿态人脸图像库,将待测人脸图像特征与人脸特征姿态库中图像相匹配,通过匹配结果相似程度判定二者是否为同一对象,完成人脸识别全过程.实验结果证明,采用所提识别方法对多姿态人脸图像识别的准确率较高,鲁棒性更好.     

高铁闸机智能监控系统中的行人检测算法研究

针对高铁闸机智能监控行人检测系统中较高的实时性要求,提出一种改进的基于梯度直方图(HOG)特征与AdaBoost分类的行人检测算法。首先对图像样本提取HOG特征,进行Gentle AdaBoost分类训练,得到高检测率的强分类器;然后对待测图像进行垂直边缘预处理,根据行人图像与非行人图像的边缘对称性特征,排除大量非行人窗口;最后对剩余窗口提取HOG特征,依据训练出的AdaBoost分类器检测HOG特征向量,判断窗口是否含有行人。实验结果表明:改进的行人检测算法比原算法计算量少,能够在保证原有准确率的基础上,对图像进行更快的检测,满足高铁闸机行人检测系统的实时性要求。     

基于目标区域的语义图像检索

提出了一种基于高层语义的图像检索方法,该方法首先将图像分割成区域,提取每个区域的颜色、形状、位置特征,然后使用这些特征对图像对象进行聚类,得到每幅图像的语义特征向量;采用模糊C均值算法对图像进行聚类,在图像检索时,查询图像和聚类中心比较,然后在距离最小的类中进行检索。实验表明,提出的方法可以明显提高检索效率,缩小低层特征和高层语义之间的“语义鸿沟”。     

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