期刊文献+
共找到2篇文章
< 1 >
每页显示 20 50 100
双阈值热点区域提取的线材表面缺陷检测方法 被引量:4
1
作者 甘胜丰 王典洪 孙林 《机械设计与制造》 北大核心 2016年第7期127-129,134,共4页
机器视觉的表面质量检测方法已广泛应用于工业生产,但高速线材由于其外形和工况的特殊性,鲜有应用。研究设计了4维面阵CCD与双色环形光源为图像采集单元,组合对比度边界检测算法、梯度和彩色图像均值阈值热点区域提取和二维最大熵图像... 机器视觉的表面质量检测方法已广泛应用于工业生产,但高速线材由于其外形和工况的特殊性,鲜有应用。研究设计了4维面阵CCD与双色环形光源为图像采集单元,组合对比度边界检测算法、梯度和彩色图像均值阈值热点区域提取和二维最大熵图像分割算法成基于双阈值热点区域提取的线材表面缺陷检测方法。实验结果表明,该方法弥补了单色光源条件下采用单一阈值提取缺陷热点区域的劣势,耗时1.25s可实现多种类二维和三维线材缺陷的准确分割。 展开更多
关键词 线材缺陷 热点区域提取 图像梯度 彩色图像均值
下载PDF
Extraction and Dynamic Spatial-Temporal Changes of Grassland Deterioration Research Hot Regions in China 被引量:4
2
作者 胡云锋 韩月琪 +1 位作者 张云芝 庄园 《Journal of Resources and Ecology》 CSCD 2017年第4期352-358,共7页
The authors use a web crawler to retrieve all periodical articles from CNKI between the 1950 s and 2016 and then parse the abstracts of 293368 articles about grassland deterioration by word segmentation, location matc... The authors use a web crawler to retrieve all periodical articles from CNKI between the 1950 s and 2016 and then parse the abstracts of 293368 articles about grassland deterioration by word segmentation, location matching and other methods. The authors also construct a research hot regions extraction model of grassland deterioration in China based on a comprehensive research hot regions index of toponyms and then analyze the spatial pattern and dynamic change in research hot regions of grassland deterioration in China. The research shows the following:(1) The spatial heterogeneity of grassland deterioration in China can be effectively described by a model of grassland deterioration based on the comprehensive research hot regions index.(2) The research hot regions of grassland deterioration are mainly distributed in most regions of Inner Mongolia, Xinjiang, Qinghai, Tibet, Gansu and other provinces. The northeastern region of Inner Mongolia(such as Hulunbeier) and the eastern region of Inner Mongolia(such as Xilin Gol, Chifeng and Wulanchabu) are significant hot regions in the study of grassland deterioration.(3) The number of high research hot regions increases from 81 in the 1950 s to 99 in the 2000s; the area increases from 1.038 million km2 to 1.146 million km2. The degree of hot for grassland deterioration research in 197 counties showed an upward trend. This paper also discusses the relationship between the region of research hot regions and the region of grassland deterioration and then indicates the differences between them in time matching, space matching and concept matching. 展开更多
关键词 knowledge engine hot regions analysis grassland deterioration region extraction spatial distribution dynamic change
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部