基于视觉图像与激光点云融合的交通标志快速识别方法

交通标志对车辆交通起到重要作用和意义,而智能交通中交通标志识别由于标志特征提取效果差,导致识别率低、识别时间长,因此,提出一种新的基于视觉图像与激光点云融合的交通标志快速识别方法。采用双边滤波方法预处理原始激光点云数据;通过归一化处理得到视觉图像激光点云融合的目标空间激光点云位置测距数值。通过测距值获取目标图像位置,归一化处理交通标志视觉图像,引入k均值聚类算法(k-means clustering algorithm)二聚类处理图像,采用制作的切割模板切割图像感兴趣区域(ROI),提取交通标志图像的深度特征,结合卷积神经网络二次过滤特征,重新标定二次过滤后的特征,最终利用卷积神经网络模型实现交通标志快速识别。经实验对比证明,采用所提方法的提取各个类型交通标志特征的提取效果较好,并且识别率达到89.74%,识别时间仅为13.1s,干扰下识别时间最高仅为15.1s,验证了该方法可以快速且准确识别各个类型的交通标志。     

机器视觉测量系统在工业在线检测中的应用

机器视觉测量用视觉传感器采集目标图像,通过对图像各种特征量的分析处理,获取被测曲面信息.设计了一机器视觉测量系统,识别一幅图像中是否存在确定大小和形状子图像,若有则识别出它的位置.介绍如何利用“模板匹配”法对目标图像进行识别,并举例如何利用系统检测药片的包装是否合格（有无漏装）.     

梯度与视觉显著度下的图像灰度重叠区域识别

采用目前方法识别图像中存在的灰度重叠区域时,没有构建图像的显著性图,存在识别精度低、查全率低和识别效率低的问题.提出梯度与视觉显著度下的图像灰度重叠区域识别方法,根据Gestalt前背景分离原则对图像中存在的梯度通道和颜色通道进行随机阈值化处理,获得对应的二进制布尔图,采用线性平均融合方法融合利用上述获取的二进制布尔图生成视觉注意图.通过分块区域分割技术识别显著性图中存在的空间位置信息,为图像灰度重叠区域的识别提供点云数据,在云计算模式中结合局部空间降噪方法消除噪声,定位去噪处理后显著性图空置区域中存在的特征点,提取灰度重叠区域的动态特征,建立对应的灰度直方图,最后利用云检测技术识别图像中存在的灰度重叠区域.仿真结果表明,所提方法的识别精度高、查全率高、识别效率高.     

基于机器视觉高空飞机螺栓松动监测仿真

高空飞机受到自身振动、气流冲击和温度瞬变等干扰时,导致飞机螺栓结构松动、断裂或者脱落等问题.飞机螺栓结构具有复杂的动态性,传统的飞机螺丝辅助视觉松动检测方法在处理飞机螺栓复杂结构时,获取的螺丝帽和螺丝杆的相对位置过程中,受到采集环境的影响,很难得到稳定特征,导致图像监测误差,无法获取准确的螺栓松动监测结果.提出聚类RBF神经网络算法的高空飞机螺栓紧固方法.根采集检测部分螺丝视觉图像序列,并对上述图像进行离散变换处理,提取高空飞机螺栓图像的可识别分离特征.针对螺栓机器视觉图像特征误差较大的缺陷,构建特征分离目标函数,并建立聚类RBF神经网络模型,对特征进行多次校验计算,完成判断.实验结果表明,利用改进算法进行机器视觉的高空飞机螺栓松动监测,能够极大的提高监测的准确性.     

实验室火灾风险智能视觉预警仿真研究

当前的火灾风险视觉预警方法忽略了对火焰图像的增强处理，导致上述方法下火焰特征识别精度偏低。为此研究新的实验室火灾风险智能视觉预警方法。通过监控摄像装置实时采集图像，采用离散小波变换将采集图像分解成低通子带和高通子带图像，阈值去噪处理小尺度高通子带图像降低图像的噪声，增强图像对比度，获取增强后图像的火焰动态、静态特征。利用协方时空差融合火焰特征，经支持向量机分类器识别火焰图像后，通过实验室监控设备将识别的到火焰结果传输至微信APP完成视觉可视化预警。仿真结果表明，所提方法可有效降低图像噪声，提高火焰图像对比度，且静、动态特征融合后的图像特征识别率高达90%。所提方法可通过微信APP将预警信息实时传输给实验室负责人，实现实验室火灾风险的智能视觉预警。     

RoboCup标准组机器人队员识别仿真

在RoboCup标准组机器人比赛中,由于NAO机器人对其它队员的视觉识别容易受到场外背景和场内各队员之间的遮挡等干扰因素的影响,使得识别结果存在许多错误和遗漏.通过多特征融合目标识别方法,分别从机器人视觉图像中提取出尺度不变(SIFT)特征与颜色直方图,分别对两种特征进行匹配,通过匹配成功的SIFT特征点来获取机器人在视觉图像中的形体范围,再通过与颜色特征相结合来获取机器人的具体区域,避免了只采用单一特征进行识别所受到的干扰因素的影响.仿真结果分析显示了改进方法相比传统方法具有更好的识别准确度和抗干扰能力.     

一种机器视觉的雨伞自助借还识别系统

针对目前公共场所自助雨伞借还的监管难度大、监管困难以及难以有效维护其原始使用功能等问题,提出了一种机器视觉的雨伞自助借还识别系统。通过VS与OpenCv开发的雨伞位置孔位特征识别定位算法,对获取到的雨伞位置图像进行灰度化处理、一系列的去噪处理,得到雨伞位置特征二值化图像,经过对雨伞位置特征的边缘检测,提取雨伞位置特征信息,完成对雨伞位置是否归还的识别检测。该系统成功的进行对雨伞自助借还的识别和检测,且识别准确性较好,识别速度较快,具有一定的学术研究价值和应用推广价值。     

基于不变矩和SVM分类的三维目标识别方法

在计算机视觉问题的研究中,针对三维目标识别,可综合应用图像的不变矩特征和支持向量机分类方法,为快速目标识别,减少计算量,提出了一种红外图像中多视点目标的识别方法.首先获取各类三维目标的若干二维视图,将视图放在一起进行标准化处理并提取它们的不变特征矩.然后对每组视图的Zernike矩进行聚类;将聚类中心对应的Zernik...     

机载雷达图像目标识别模型仿真研究

机载视觉雷达对目标准确标识别,关系到航空领域的安全.机载视觉雷达的目标识别多是高空作业,识别的目标图像信息易受到飞机倾斜角度、高空外部噪声干扰、机身异常抖动、被测物体的抖动和采样速度过低等因素的干扰,使得识别目标区域模糊,可识别特征发生严重衰减.传统机载视觉雷达的目标识别方法中,在运动状态下对高空目标的图像衰减特征分割一直很困难,分割过程会出现过分割和欠分割的问题,导致目标识别结果不理想.提出采用机载视觉雷达倾斜状态下的目标识别方法,得到图像中对地目标的运行速度,通过雷达视场距离的标定成像几何原理,将地面目标三维场景投射到二维象平面中,并采用数据链驱动无缝集成模式来运算识别地面目标的实际数量,获取准确的塔机目标识别检测结果.实验结果说明,所提机载视觉雷达倾斜状态下的目标识别模型获取的地面目标识别更加准确,并且具有较高的检测效率和精度.     

混合高斯模型和机器视频的火灾检测的实现

针对目前基于传感器技术的火灾探测器存在检测区域小、干扰大、误报率高等不足,提出了一种基于混合高斯模型与机器视觉相结合的火灾检测方法.该方法通过对摄像头获取的图像信息进行处理和分析,利用火灾早期产生的烟雾和火焰的颜色及形体变化特征来探测火灾.通过建立混合高斯模型对火灾进行识别,再对识别结果进行进一步的动态特征识别.试验证明,该方法克服了传感器检测方法的缺点,实时性好、识别率高.     

European Community policy and the market

Abstract This paper starts with some reflections on the policy considerations and priorities which are shaping European Commission (EC) research programmes. Then it attempts to position the current projects which seek to capitalise on information and communications technologies for learning in relation to these priorities and the apparent realities of the marketplace. It concludes that while there are grounds to be optimistic about the contribution EC programmes can make to the efficiency and standard of education and training, they are still too technology driven.     

一种自适应子融合集成多分类器方法

融合集成方法已经广泛应用在模式识别领域,然而一些基分类器实时性能稳定性较差,导致多分类器融合性能差,针对上述问题本文提出了一种新的基于多分类器的子融合集成分类器系统。该方法考虑在度量层融合层次之上通过对各类基多分类器进行动态选择,票数最多的类别作为融合系统中对特征向量识别的类别,构成一种新的自适应子融合集成分类器方法。实验表明,该方法比传统的分类器以及分类融合方法识别准确率明显更高,具有更好的鲁棒性。     

Explanation and prediction: an architecture for default and abductive reasoning

Although there are many arguments that logic is an appropriate tool for artificial intelligence, there has been a perceived problem with the monotonicity of classical logic. This paper elaborates on the idea that reasoning should be viewed as theory formation where logic tells us the consequences of our assumptions. The two activities of predicting what is expected to be true and explaining observations are considered in a simple theory formation framework. Properties of each activity are discussed, along with a number of proposals as to what should be predicted or accepted as reasonable explanations. An architecture is proposed to combine explanation and prediction into one coherent framework. Algorithms used to implement the system as well as examples from a running implementation are given.     

Three Process Perspectives: Organizations, Teams, and People

This paper provides the author's personal views and perspectives on software process improvement. Starting with his first work on technology assessment in IBM over 20 years ago, Watts Humphrey describes the process improvement work he has been directly involved in. This includes the development of the early process assessment methods, the original design of the CMM, and the introduction of the Personal Software Process (PSP)^SM and Team Software Process (TSP){^SM}. In addition to describing the original motivation for this work, the author also reviews many of the problems he and his associates encountered and why they solved them the way they did. He also comments on the outstanding issues and likely directions for future work. Finally, this work has built on the experiences and contributions of many people. Mr. Humphrey only describes work that he was personally involved in and he names many of the key contributors. However, so many people have been involved in this work that a full list of the important participants would be impractical.     

基于复小波噪声方差显著修正的SAR图像去噪

提出了一种基于复小波域统计建模与噪声方差估计显著性修正相结合的合成孔径雷达(Synthetic Aperture Radar,SAR)图像斑点噪声滤波方法。该方法首先通过对数变换将乘性噪声模型转化为加性噪声模型,然后对变换后的图像进行双树复小波变换(Dualtree Complex Wavelet Transform,DCWT),并对复数小波系数的统计分布进行建模。在此先验分布的基础上,通过运用贝叶斯估计方法从含噪系数中恢复原始系数,达到滤除噪声的目的。实验结果表明该方法在去除噪声的同时保留了图像的细节信息,取得了很好的降噪效果。     

How do children do mathematics with LOGO?

Abstract  This paper considers some results of a study designed to investigate the kinds of mathematical activity undertaken by children (aged between 8 and 11) as they learned to program in LOGO. A model of learning modes is proposed, which attempts to describe the ways in which children used and acquired understanding of the programming/mathematical concepts involved. The remainder of the paper is concerned with discussing the validity and limitations of the model, and its implications for further research and curriculum development.     

Editorial: Special issue on recent advances in hybrid control theory and applications

正The demands of a rapidly advancing technology for faster and more accurate controllers have always had a strong influence on the progress of automatic control theory.In recent years control problems have been arising with increasing frequency in widely different areas,which cannot be addressed using conventional control techniques.The principal reason for this is the fact that a highly competitive economy is forcing systems to operate in regimes where     

Information for Authors

正Aim The Journals of Zhejiang University-SCIENCE(A/B/C)areedited by the international board of distinguished Chinese andforeign scientists,and are aimed to present the latest devel-opments and achievements in scientific research in China andoverseas to the world’s scientific circles,especially to stimulateand promote academic exchange between Chinese and for-eign scientists everywhere.     

Enhancing a leaf radiative transfer model to estimate concentrations and in vivo specific absorption coefficients of total carotenoids and chlorophylls a and b from single-needle reflectance and transmittance

The relative concentrations of different pigments within a leaf have significant physiological and spectral consequences. Photosynthesis, light use efficiency, mass and energy exchange, and stress response are dependent on relationships among an ensemble of pigments. This ensemble also determines the visible characteristics of a leaf, which can be measured remotely and used to quantify leaf biochemistry and structure. But current remote sensing approaches are limited in their ability to resolve individual pigments. This paper focuses on the incorporation of three pigments—chlorophyll a, chlorophyll b, and total carotenoids—into the LIBERTY leaf radiative transfer model to better understand relationships between leaf biochemical, biophysical, and spectral properties.Pinus ponderosa and Pinus jeffreyi needles were collected from three sites in the California Sierra Nevada. Hemispheric single-leaf visible reflectance and transmittance and concentrations of chlorophylls a and b and total carotenoids of fresh needles were measured. These data were input to the enhanced LIBERTY model to estimate optical and biochemical properties of pine needles. The enhanced model successfully estimated reflectance (RMSE = 0.0255, BIAS = 0.00477, RMS%E = 16.7%), had variable success estimating transmittance (RMSE = 0.0442, BIAS = 0.0294, RMS%E = 181%), and generated very good estimates of carotenoid concentrations (RMSE = 2.48 µg/cm², BIAS = 0.143 µg/cm², RMS%E = 20.4%), good estimates of chlorophyll a concentrations (RMSE = 10.7 µg/cm², BIAS = − 0.992 µg/cm², RMS%E = 21.1%), and fair estimates of chlorophyll b concentrations (RMSE = 7.49 µg/cm², BIAS = − 2.12 µg/cm², RMS%E = 43.7%). Overall root mean squared errors of reflectance, transmittance, and pigment concentration estimates were lower for the three-pigment model than for the single-pigment model. The algorithm to estimate three in vivo specific absorption coefficients is robust, although estimated values are distorted by inconsistencies in model biophysics. The capacity to invert the model from single-leaf reflectance and transmittance was added to the model so it could be coupled with vegetation canopy models to estimate canopy biochemistry from remotely sensed data.     

Mr. Twinn’s bombes

This article discusses the history and design of the special versions of the bombe key-finding machines used by Britain’s Government Code & Cypher School (GC&CS) during World War II to attack the Enigma traffic of the Abwehr (the German military intelligence service). These special bombes were based on the design of their more numerous counterparts used against the traffic of the German armed services, but differed from them in important ways that highlight the adaptability of the British bombe design, and the power and flexibility of the diagonal board. Also discussed are the changes in the Abwehr indicating system that drove the development of these machines, the ingenious ways in which they were used, and some related developments involving the bombes used by the U.S. Navy’s cryptanalytic unit (OP-20-G).