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CV主动轮廓模型在管道焊缝缺陷检测中的应用 总被引：2，自引：0，他引：2
焊接是钢结构生产的主要方法。射线检测方法是检查焊接缺陷的几种主要方法之一。射线检测结果的评定方法有两种：人工评定和计算机辅助评定。人工评定检测结果时,评定人员工作量大,评定结果易受评定人员主观因素影响。采用计算机对X射线检测结果进行分析和识别,可以大大提高工作效率。分析识别的基础是图像的分割。本文分析Mumford—Shah模型和主动轮廓的CV模型,并将其首次应用到焊缝缺陷的分割之中。目前多数文献选择单个初始圆为曲线演化的初始轮廓,本文将初始轮廓选择为多个初始圆,此方法极大加快了曲线演化的速度。 相似文献
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阵列式超声波混凝土结构检测图像中的异常特征识别往往依赖人工经验,具有效率低下以及准确率难以保证等问题.本文将人工智能深度学习中经典网络模型ResNet50与代表性的目标检测网络模型YOLOv2进行融合,搭建了一套适用于超声检测图像智能判译的网络模型.选择将超声检测图像中钢筋和界面反射信号作为模型的自动识别目标体,并制作了包含此两类目标体标注的实测数据集.测试结果显示,搭建的网络模型在小样本超声检测图像数据集的识别上取得了显著的效果,网络模型识别钢筋和界面两类信号特征的平均准确率分别达到91.21％和80.24％,表明人工智能深度学习技术在地球物理图像解译方面具有强大的表征能力,能有效降低对人工经验的依赖,提升资料解译的可靠性和工作效率,应用前景广阔. 相似文献
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图像分辨率测试卡的结构与标准 总被引：3，自引：1，他引：2
曾祥照 《CT理论与应用研究》2005,14(3):29-34
分辨率测试卡是客观描述射线实时成像检测系统分辨率和实时成像检测图像分辨率(包括射线照相底片分辨率)质量指标的重要器具,本文概述了图像分辨率测试卡的结构和正在制订的<射线透视检测用分辨率测试卡>行业标准进展情况. 相似文献
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断层识别是地震解释的一项重要任务.相对传统的基于人工或半人工的断层检测方法，基于深度学习的断层检测方法具有自动化程度高等特点，近年来已经吸引了业界广泛兴趣.目前，大多数利用深度学习的断层识别方法都是基于语义分割或图像分类，但基于语义分割或图像分类的方法预测出的断层噪声较多.而边缘检测网络可以通过学习断层在地震剖面中不连续的特征，从而提高网络的抗噪能力.为了利用边缘检测网络的抗噪优点并提升其性能，本文采用基于像素差分的卷积运算构建出像素差分网络模型(Pixel Difference Networks, Pidinet).相较于传统的边缘检测网络，Pidinet将传统的边缘检测算子与深度学习网络结合，有效地提升了边缘检测的效果.为了使Pidinet网络更好地预测断层，本文对原始Pidinet网络进行了优化，去掉了相对断层识别任务而言多余的分支结构和卷积层.相对于传统的卷积运算，基于像素差分的卷积运算可以让神经网络更好地学习断层信息.为了让网络充分学习数据中的断层特征，本文将真实地震样本与合成地震样本混合得到训练所用数据集.实验证明Pidinet在交并比(Intersection over ... 相似文献
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当前航空安全形势紧张,所有国家都正在加强其安全检测系统.鉴于危险物品的特殊性,对含有危险物品的行李包的X射线图像进行模拟是一种有效培训安检人员的方式.这种模拟方式可以增强安检人员对不同背景环境下危险物品X射线特征的敏感度.在本文中,首先对X射线图像融合的物理过程进行了分析并且介绍了当前此领域中普遍使用的融合算法,随后采... 相似文献
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为快速对地震现场损坏房屋裂缝宽度进行测量，本文提出运用图像处理技术与单个人工正方形标志的方法对裂缝宽度进行测量。基于数字图像处理技术，并利用MATLAB软件的图像处理功能，对拍摄的真实房屋裂缝图像进行灰度化、二值化、图像去噪、目标区域分割标记和像素标定等处理，计算得到图像中裂缝宽度的最大值。通过与实测数据对比，利用本方法获得房屋裂缝检测数据的识别精度为98.11%。结果表明，本文提出的方法可以有效检测房屋裂缝宽度，且获取图像的分辨率越高，裂缝宽度识别的误差越小。本方法可为地震灾害现场调查中的房屋破坏等级评价工作提供依据。 相似文献
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数字图像处理在汽车轮胎X射线检测中的应用 总被引：1，自引：1，他引：0
将数字图像处理与X射线检测的相关理论应用于轮胎子午线检测图像中质量问题的研究,在轮胎子午线图像与模板图像进行匹配时,对匹配算法进行了深入的研究,提出一种"先全局扫描,后小范围区域扫描"的搜索策略. 相似文献
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X射线在轮胎边缘检测中的应用 总被引：1，自引：1，他引：0
利用X射线对子午线轮胎进行质量检测是一个重要的课题,通过图像处理和匹配进行轮胎质量检测是一个复杂的系统,其中边缘检测是图像分割、纹理特征提取和形状特征提取等图像分析的重要基础。通过Matlab实验比较几种不同的边缘检测方法,找到了适合子午线轮胎质量检测的边缘检测方法。 相似文献
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数字射线技术正获得越来越广泛的应用,并成为射线检测技术的发展趋势。但目前有关数字射线技术的标准对于图像质量控制方面的规定还相对简单,难于进行有效的质量控制,因而在实际检测中可能出现较大的随意性而影响检测结果评判。使用互补金属氧化物半导体(CMOS)线阵列射线探测器与阶梯试块进行射线检测实验,得到了不同厚度所对应的灰度图像,测试了影像对比度,同时分析了图像的信噪比和检测灵敏度。通过对实验结果的综合对比分析,提出了数字化射线检测图像质量控制措施。 相似文献
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《中国科学:地球科学(英文版)》2014,(3)
正SCIENCE CHINA Earth Sciences,an academic journal cosponsored by the Chinese Academy of Sciences and the National Natural Science Foundation of China,and published by Science China Press and Springer,is committed to publishing high-quality,original results in both basic and applied research. 相似文献
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《国际泥沙研究》2014,(4)
正Director:Shangfu Kuang,China Vice-directors:Chunhong Hu,China Duihu Ning,China Guangquan Liu,China The International Research and Training Center on Erosion and Sedimentation(IRTCES)was jointly set up by the Government of China and UNESCO on July 21,1984.It aims at the promotion of international exchange of knowledge and cooperation in the studies of erosion and 相似文献
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Richard D. Hey 《地球表面变化过程与地形》1979,4(1):59-72
Feedback mechanisms, which operate upstream through drawdown and backwater effects and downstream through sediment discharge are responsible for channel evolution. By combining these mechanisms with channel processes it euables a dynamic process-response model to be developed to simulate the initial evolution of straight gravel-bed channels. When erosion commences on a land surface, sediment entrained in the headwater reach by hydraulic action is selectively transported, deposited and reworked. This produces a damped oscillation between degradation and aggradation as the channel and valley respond to spatial and temporal variations in sediment calibre and hydraulic conditions. The initial cut and fill phases are responsible for valley incision and floodplain development while secondary and subsequent activity can produce river terraces. Eventually sediment entrainment in the headwaters declines as slopes are reduced. Subsequent channel evolution is relatively insignificant because it is dependent on local weathering activity producing material that can be transported on declining slopes. Therefore landforms produced during the initial phase of development, when local weathering was non-limiting, dominate the landscape. 相似文献
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Based on relocating the Jiujiang-Ruichang earthquake sequence which occurred on November 26, 2005 in Jiangxi Province with the double-difference （DD） algorithm and master event technique, the paper discusses the focal mechanism of the main shock （MsS.7） and the probable seismo-tectonics. The precise relocation results indicate that the average horizontal error is 0.31kin in a EW direction and 0.40kin in a NS direction, and the average depth error is 0.48kin. The focal depths vary from 8kin to 14kin, with the predominant distribution at 10kin - 12kin. The epicenter of the main shock is relocated to be 29.69^oN, 115.74^oE and the focal depth is about 10.Skin. Combining the predominant distribution of the earthquake sequence, the focal mechanism of the main shock and the tectonic conditions of N-E- and NW-strike faults growth in the seismic region, we infer that the main shock of the earthquake sequence was caused by a NW striking buried fault in the Rnichang basin. The nature of seismic faults needs to be further explored. 相似文献
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《水文科学杂志》2013,58(6)
Abstract The western reservoirs represent the principal groundwater system in Morocco. Demographic, industrial and agricultural developments during the last decade have markedly altered groundwater quality. The Mamora coastal aquifer system is among the Atlantic systems which are most heavily threatened by pollution. Agricultural and industrial activities, and rapid urban growth contribute to the pollution of the groundwater. Contamination transport is facilitated by a high permeability of the aquifer formations. In order to assess the actual groundwater quality of the Mamora aquifer and to understand the influence of the factors generating the pollution, an extensive multidisciplinary research programme is in progress, with hydrochemistry and microbiology playing essential roles. The present paper concerns the spatial distribution of physico-chemical parameters in the groundwater, subjected to domestic, industrial and agricultural pollution. Fifty-seven samples were analysed for several parameters (Ca2+, Mg2+, Na+, K+, Cl?, SO4 2?, HCO3 ?, NO3 ?, pH, electrical conductivity and temperature). The microbiological analysis of 143 samples reveals the presence of four kinds of indicator bacteria in the groundwater resources: faecal Streptococci, faecal coliform, Escherichia coli and Clostridium. The physico-chemical results and bacteriological monitoring show that the nitrate and bacteria concentrations exceed the maximum admissible levels, notably around pumping stations in the sectors of Sidi Taibi, Sidi Ahmed Taleb and Aïn Sbaâ. Contamination is generated by uncontrolled anthropogenic activities and accentuated by the high intrinsic vulnerability of the aquifer system. Several parameters appeared to exceed admissibility standards. Measures are recommended to prevent groundwater pollution in the region. 相似文献
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K.-G. Malle 《洁净——土壤、空气、水》1992,20(4):196-204
Zinc in the Environment. In 1990 the world production of zinc ammounted to 7 Mio. metric tons. The main areas of application were: galvanization, alloys like brass and zinc metal. The content in the earth crust varies between 10–300 ppm zinc with a mean of 70 ppm. Uncontaminated surface waters contain less than 10 mg/m3 zinc. Apart from civilization air contains 1–10 ng zinc per m3. These background concentrations are exceeded by orders of magnitude in zinc deposit areas and where anthropogenic influences predominate. Accumulation can occur in sediments and sewage sludge. Molluscs and Algae also accumulate zinc. Zinc is essential for live. With normal food the zinc supply of man is just sufficient. Bioaccumulation of zinc towards man or chronic oversupply of man is not known. Zinc has no teratogenic or mutagenic effects, a suspicion on a carcinogenic effect proved wrong. In stockbreeding and plant cultivation a minimum supply of zinc is necessary. Plants are relatively less sensitive against higher soil contents of zinc. Considering the toxicological and ecotoxicological effects of zinc in the environment, the critical organismens are marine invertebratae like tubifex, daphnia, gammarus and algae. But normally only a minor part of the total zinc contest is biologically available, depending on salt content and pH of the waters. 相似文献