复杂背景下的路面裂缝检测的关键技术

针对目前路面裂缝检测方法在复杂环境下识别率较低、鲁棒性较差的问题，提出一种改进网络CBAM-Res-GhostNet对路面裂缝实现有效分类。在卷积神经网络中引入Ghost模块和改进残差模块，加入卷积注意力，避免梯度消失和过拟合现象，实现对路面裂缝的准确判断；在此基础上，提出一种改进网络Self-Attention-UNet对路面裂缝区域进行高精度分割，引入自注意力机制增强模型裂缝特征提取能力，提高分割精度。在EdmCrack600数据集上，所提分类算法准确度达到99.13%,分割算法的精准率和F1值分别为86.85%和86.6%,相较原始方法具有更好的分类分割效果。     

基于PCNN和遗传算法相结合的新型混凝土桥梁裂缝检测方法

针对混凝土桥梁裂缝对比度低、裂缝图像噪声干扰强等难题,提出了基于脉冲耦合神经网络(PCNN)和遗传算法相结合的混凝土桥梁裂缝检测新算法(GA-PCNN)。该算法首先利用遗传算法优化裂缝PCNN模型参数,然后通过改进的最小对数误差适应度函数区分裂缝与背景,当适应度值大小几乎无变化时,停止分割图像,最后通过连通域去噪算法滤除残余噪声,实现裂缝的自动检测。比较GA-PCNN、PCNN和基于熵和动态阈值算法对裂缝图像的分割效果,并绘制PR曲线和ROC曲线评价分割质量,经计算GA-PCNN算法的PR和ROC曲线下面积为90.6%和91.6%,分别高于PCNN算法10.1%和6.8%、基于熵和动态阈值6.5%和6.7%。试验的结果表明：GA-PCNN新算法分割效果好且去噪能力强,该算法能准确地提取混凝土桥梁裂缝特征。     

基于DSP的沥青路面裂缝图像处理算法的实现

沥青路面裂缝是高速公路路面的主要患害之一。提出一种沥青路面裂缝图像处理算法，即采用改进的经典算法和形态学算法对沥青路面裂缝图像进行去噪平滑、边缘检测、图像分割、效果增强及边缘连接等处理。该算法通过DSP软件的检验，处理的效果相对于其它经典算法，有了显著的提高。对用谊算法处理后的沥青路面裂缝图像进行检测，检测的精度和检测效果都比较满意。     

融合高阶多尺度特征的路面裂缝图像分割算法

针对裂缝图像的光照不均匀、斑马线等复杂背景使得传统的裂缝图像分割算法容易丢失细微及末梢裂缝等问题,本文提出了一种基于泰勒级数和多尺度特征的裂缝图像分割算法.首先,采用瑞利和高斯分布构成的有限混合模型对裂缝背景和目标进行建模,并使用期望最大化算法求解混合模型的参数;然后,通过泰勒级数的展开式描述裂缝的梯度方向,利用尺度变换构造裂缝图像的高阶多尺度特征;最后,将灰度有限混合模型和裂缝高阶多尺度特征融合到马尔科夫随机场模型,通过条件迭代算法优化求解裂缝标号场最大后验概率来实现图像分割.性能测试和不同算法对比分析实验表明,本文算法在保证裂缝几何参数不变的前提下能够抑制非裂缝目标并保留低对比度、细微和末梢裂缝,分割准确率达到85.93%、灵敏度达63.87%,衡量指标优于其他算法.     

改进马尔可夫模型的SAR图像分割

针对基于固定权重MRF模型的SAR图像分割算法出现参数估计结果不能反映图像的真实特征数据、忽略图像空间关系或参数估计是局部最优而不是全局最优的问题,将MRF模型的权重参数设置为变化的,不但可以得到特征模型的全局参数,而且可以增加类标分布的空间均质性限制。利用模拟数据和真实SAR图像数据进行分割实验。结果显示,固定权重MRF模型SAR图像分割算法和变权重的SAR图像分割算法的误分割率分别为8.4%、10.1%和2.5%、3.7%,证明该算法能够得到更好的分割效果。     

自上而下注意图分割的细粒度图像分类

目的 针对细粒度图像分类中的背景干扰问题,提出一种利用自上而下注意图分割的分类模型。方法 首先,利用卷积神经网络对细粒度图像库进行初分类,得到基本网络模型。再对网络模型进行可视化分析,发现仅有部分图像区域对目标类别有贡献,利用学习好的基本网络计算图像像素对相关类别的空间支持度,生成自上而下注意图,检测图像中的关键区域。再用注意图初始化GraphCut算法,分割出关键的目标区域,从而提高图像的判别性。最后,对分割图像提取CNN特征实现细粒度分类。结果 该模型仅使用图像的类别标注信息,在公开的细粒度图像库Cars196和Aircrafts100上进行实验验证,最后得到的平均分类正确率分别为86.74%和84.70%。这一结果表明,在GoogLeNet模型基础上引入注意信息能够进一步提高细粒度图像分类的正确率。结论 基于自上而下注意图的语义分割策略,提高了细粒度图像的分类性能。由于不需要目标窗口和部位的标注信息,所以该模型具有通用性和鲁棒性,适用于显著性目标检测、前景分割和细粒度图像分类应用。     

基于类自适应高斯-马尔可夫随机场模型和EM算法的MR图像分割

高斯-马尔可夫随机场模型既利用了图像像素的灰度信息,又通过像素类别标记的Gibbs光滑先验概率引入了图像的空间信息,是能较好地分割含有噪声图像的模型,然而,Gibbs惩罚因子β的确定却一直是个难点,为获得好的分割效果,通常用多个β值人工尝试。本文针对此问题,提出了一种新的、简单的、类自适应的惩罚因子β,其利用后验概率来自动计算,并具有各类各向异性。再将模型利用EM-MAP算法来迭代求解。最后,将该算法应用于MR图像的分割,实验结果表明,该算法能自适应地、有效地分割噪声图像,并具有较高的正确分类率和类正确分类率。     

基于局部区域能量最小化模型的图像分割

在马尔可夫随机场(MRF)和概率理论的基础上,提出局部区域能量最小化模型,将传统基于像素的分割转化为基于区域的分割,能减小均匀区域中的误分类率。在该模型和MRF模型下,使用ICM算法、Gibbs采样算法、Metropolis采样算法对图像进行分割,结果表明该模型能取得更精确的分割结果,可有效拟制图像噪音和纹理对分割的影响。     

基于深度学习的织物缺陷在线检测算法

织物缺陷在线检测是纺织行业面临的重大难题，针对当前织物缺陷检测中存在的误检率高、漏检率高、实时性不强等问题，提出了一种基于深度学习的织物缺陷在线检测算法。首先基于GoogLeNet网络架构，并参考其他分类模型的经典算法，搭建出适用于实际生产环境的织物缺陷分类模型；其次利用质检人员标注的不同种类织物图片组建织物缺陷数据库，并用该数据库对织物缺陷分类模型进行训练；最后对高清相机在织物验布机上采集的图片进行分割，并将分割后的小图以批量的方式传入训练好的分类模型，实现对每张小图的分类，以此来检测缺陷并确定其位置。对该模型在织物缺陷数据库上进行了验证。实验结果表明：织物缺陷分类模型平均每张小图的测试时间为0.37 ms，平均测试时间比GoogLeNet减少了67%，比ResNet-50减少了93%；同时模型在测试集上的正确率达到99.99%。说明其准确率与实时性均满足实际工业需求。     

基于遗传算法和简化PCNN神经网络的裂缝检测方法*

为能够在复杂背景下检测裂缝、分析裂缝图像特征,由脉冲耦合神经网络(pulse coupled neural networks, PCNN)的运行特征和神经元的状态变化分析简化PCNN模型,将简化PCNN模型用于裂缝图像的目标检测。针对PCNN无法确定裂缝图像的最优检测以及脉冲门限具有非线性因子的问题,提出了一种基于遗传算法(genetic algorithm, GA)和简化PCNN的裂缝图像检测方法。该方法采用最小误差准则作为遗传算法的适应度函数,并且根据遗传算法具有全局最优解的特点确定简化PCNN中各因子的值,实现了简化PCNN的裂缝图像自动分割。将本文方法与不同的分割方法对实际裂缝图像的处理结果进行比较,通过区域对比度、准确率和召回率等客观指标进行定量分析,表明了该方法对裂缝图像检测的有效性与通用性。     

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。     

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.     

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.     

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.