Crustal movement and incremental-movement data observed repeatedly at GPS stations during 1999-2009 were analyzed to study the effect of two earthquakes of Ms8.1 and Ms8.0 that occurred in 2001 and 2008, respectively,...Crustal movement and incremental-movement data observed repeatedly at GPS stations during 1999-2009 were analyzed to study the effect of two earthquakes of Ms8.1 and Ms8.0 that occurred in 2001 and 2008, respectively, in Qinghai-Tibet sub-plate and its eastern margin. The result revealed certain anomalous pre-earthquake deformation and some large co-seismic changes. Prior to the 2008 Wenchuan Ms8.0 earthquake, the seismogenic Kunlunshan fault zone became a geographic boundary between different regional movements. At the time of the earthquake, there was an average cross-fault crustal shortening of -1.04 m and an average right-lateral strike slip of 0.76 m along the ruptured segment, as well as a strain-energy release of -62.66×10.7.展开更多
针对传统人工测量板材尺寸精度较低、工作量大、易导致板材表面受损等局限,基于双目视觉技术设计了一种板材尺寸视觉测量系统;通过双目相机采集棋盘格图像,采用MATLAB进行相机标定和图像校正,拍摄左右图像并通过半全局立体匹配算法(SGM,...针对传统人工测量板材尺寸精度较低、工作量大、易导致板材表面受损等局限,基于双目视觉技术设计了一种板材尺寸视觉测量系统;通过双目相机采集棋盘格图像,采用MATLAB进行相机标定和图像校正,拍摄左右图像并通过半全局立体匹配算法(SGM,semi global matching)进行特征点立体匹配,重建出目标三维点云模型;为提高目标特征点坐标获取的准确性,提出基于HARRIS的亚像素检测方法;采用区域生长算法结合膨胀和腐蚀操作提取板材表面轮廓,根据三角测量原理计算出板材轮廓上各点的三维坐标从而实现板材的尺寸测量,并进行点云重建增强三维展示效果;实践结果表明亚像素检测方法在角点提取上存在优势,在实际板材测量应用中实现了高精度尺寸测量,满足了工业测量需求。展开更多
在钢结构工程中,为了满足钢材的韧性要求,一般都会对钢材的次等级有一定的要求。论文对新旧英国标准BS EN 1993-1-10(新)和BS 5950-1(旧)的钢材次等级的计算方面进行了比较分析并归纳了新旧标准的异同,同时给出了应用算例,可为从事国外...在钢结构工程中,为了满足钢材的韧性要求,一般都会对钢材的次等级有一定的要求。论文对新旧英国标准BS EN 1993-1-10(新)和BS 5950-1(旧)的钢材次等级的计算方面进行了比较分析并归纳了新旧标准的异同,同时给出了应用算例,可为从事国外钢结构工程的相关设计和施工人员提供参考。展开更多
基金supported by Basic Research Projects of Tianjin(08JCZDJC18900)National Seismic Hazard Maps Program Planning of China+1 种基金China Earthquake AdministrationNational Science and Technology Supporting Plan of the Eleventh Five-Year(2006BAC01B02-02-03)
文摘Crustal movement and incremental-movement data observed repeatedly at GPS stations during 1999-2009 were analyzed to study the effect of two earthquakes of Ms8.1 and Ms8.0 that occurred in 2001 and 2008, respectively, in Qinghai-Tibet sub-plate and its eastern margin. The result revealed certain anomalous pre-earthquake deformation and some large co-seismic changes. Prior to the 2008 Wenchuan Ms8.0 earthquake, the seismogenic Kunlunshan fault zone became a geographic boundary between different regional movements. At the time of the earthquake, there was an average cross-fault crustal shortening of -1.04 m and an average right-lateral strike slip of 0.76 m along the ruptured segment, as well as a strain-energy release of -62.66×10.7.
文摘针对传统人工测量板材尺寸精度较低、工作量大、易导致板材表面受损等局限,基于双目视觉技术设计了一种板材尺寸视觉测量系统;通过双目相机采集棋盘格图像,采用MATLAB进行相机标定和图像校正,拍摄左右图像并通过半全局立体匹配算法(SGM,semi global matching)进行特征点立体匹配,重建出目标三维点云模型;为提高目标特征点坐标获取的准确性,提出基于HARRIS的亚像素检测方法;采用区域生长算法结合膨胀和腐蚀操作提取板材表面轮廓,根据三角测量原理计算出板材轮廓上各点的三维坐标从而实现板材的尺寸测量,并进行点云重建增强三维展示效果;实践结果表明亚像素检测方法在角点提取上存在优势,在实际板材测量应用中实现了高精度尺寸测量,满足了工业测量需求。