检索结果-南通市图书馆

Portable device for the local three-dimensional deformation measurement using a single camera

Science China(Technological Sciences) 2018年第1期61卷 51-60页

作者： MOHAMMED Mokhtar Eisa SHAO XinXing he xiaoyuan School of Civil Engineering Department of Engineering Mechanics Southeast University

The aim of this paper is to establish and validate a portable device for the local three dimensional deformation measurements using a single camera combined with a triangular prism mirror and two mirrors. The mirrors were utilized to convert a single camera into a stereo image system, which views a test object from two different directions and records the surface images of the test specimen on the two halves of the camera sensor in order to achieve a three-dimensional measurement. The proposed system consists of a single camera and the reflection system was integrated into a portable device to achieve a truly portable, low-cost, local three-dimensional deformation measurement, one-time calibration and easy implementation in situ. The optical design and measurement procedures to obtain the three-dimensional （3D） deformation measurements of the proposed system were described in detail. The efficiency and precision of the proposed system were verified by measuring the displacements of a translated fiat plate. As a practical application, the proposed system is used to measure the out-of-plane displacement of an aluminum circular plate with a central load. Moreover, the normal strain measurement of a plastic beam under symmetric four-point bending via an outer loading frame was also presented. The measurement results are in good accordance with the data obtained by strain gauges. The experimental results revealed that the proposed system was practicable and effective for the local three-dimensional deformation measurement. This system well-suited to both laboratory and field condition and will have significant application in the fields of engineering.

关键词： digital image correlation single camera strain analysis local 3D deformation

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Discovery of Kilometer-Scale Uplift and Exhumation Related to the Late Indosinian Movement in the Northern Ordos Basin, North China

引用

Acta Geologica Sinica(English Edition) 2019年第1期93卷 231-232页

作者： ZHANG Long LIU Chiyang he xiaoyuan School of Earth Sciences and Engineering Xi'an Shiyou University State Key Laboratory of Continental Dynamics Department of Geology Northwest University Aerial Photogrammetry and Remote Sensing Bureau China National Administration of Coal Geology

The tectonic response of the Ordos Basin to Indosinian movement mainly occurred in the southwestern part of the basin due to the Late Triassic collisional Qinling orogeny to the *** orogeny resulted in intense uplift and exhumation of the southwestern section of the Ordos Basin,where the upper and middle parts of the Upper Triassic Yanchang Formation were exhumated and the magnitude of exhumation progressively decreased to the northeast(Liu Chiyang et al.,2008).However,little attention has been paid to the influence of Indosinian movement to the northern Ordos *** this study,stratigraphic observations and new apatite fission track(AFT)data are integrated to characterize the effect of Indosinian movement in the northern Ordos Basin.

关键词： Late Triassic southwestern progressively

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

ON The UNIFORM STRONG APPROXIMATION OF MARCINKIEWICZ TYPE FOR MULTIVARIABLE CONTINUOUS FUNCTIONS

引用

Analysis in Theory and Applications 2005年第4期21卷 377-384页

作者： Yujun Zhang xiaoyuan he hebei North University China Beijing 101 Secondary School China

The rate of uniform strong approzimation of Marcinkiewicz type for multivariable continuous functions is obtained in this paper as follows：‖1/k＋1 ^k∑j=0 ｜Sj（f）-f｜^q‖≤C/k＋1^k∑j=0 Ej^q（f）,where Sj（f） denotes the square partial Fourier sum off and Ej（f） denotes the square best approximation of f by trigonometric polynomials of degree（j,j,…,j）,j=0,1,2.…

关键词： square partial Fourier sum strong approximation of Mareinkiewiecz type

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Optimization of the forearm angle for arm wrestling using multi-camera stereo digital image correlation: A preliminary study

引用

Theoretical & Applied Mechanics Letters 2021年第6期11卷 336-342页

作者： Zixiang Tong Xinxing Shao Zhenning Chen xiaoyuan he Department of Engineering Mechanics School of Civil EngineeringSoutheast UniversityNanjing 211189China College of Aerospace Engineering Nanjing University of Aeronautics&AstronauticsNanjing 210016China

This study analyzes the function of different muscles during arm wrestling and proposes a method to analyze the optimal forearm angle for professional arm *** built a professional arm-wrestling platform to measure the shape and deformation of the skin at the biceps brachii of a volunteer in vivo during arm *** observed the banding phenomenon of arm skin strain during muscle contraction and developed a model to evaluate the moment provided by the biceps *** to this model,the strain field of the area of interest on the skin was measured,and the forearm angles most favorable and unfavorable to the work of the biceps brachii were *** study demonstrates the considerable potential of applying DIC and its extension method to the in vivo measurement of human skin and facilitates the use of the in vivo measurement of skin deformation in various sports in the future.

关键词： Arm wrestling Skin deformation measurement Multi-camera stereo digital image correlation Close-range photogrammetry Forearm angle

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Short-working-distance optical imaging system and method for surface detection of underwater structures

引用

Science China(Technological Sciences) 2018年第5期61卷 774-781页

作者： LIU Cong WANG ChengFei XU YingJun LI Xu LUO ChunHao DAI MeiLing SHAO XinXing he xiaoyuan School of Civil Engineering Southeast University School of Science Nanjing University of Science and Technology School of Instrument Science and Engineering Southeast University

In the surface imaging of underwater structures, long working distance will reduce image quality due to the turbidity of water. To acquire high definition and large field of view(FOV) images for surface detection, a short-working-distance underwater imaging system is proposed based on camera array. A multi-view calibration and rectification method is developed. A look-up table(LUT) method and a multi-resolution spline(MRS) method are applied to stitch array images real-time and *** both in the air and in the water are conducted. Strength and weakness of the LUT and MRS methods are *** on the results, the effectiveness in surface detection of underwater structures is verified.

关键词： surface detection camera array image stitching calibration

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

数字图像相关方法在土木测试领域中的实验研究

引用

南京航空航天大学学报 2009年第2期41卷 271-275页

作者：孙伟何小元南京航空航天大学航空宇航学院南京210016 东南大学工程力学系南京210096

针对传统接触式测试方法(如电测法等)在土木工程领域中的局限性,开展了数字图像相关(Digitalimage correlation,DIC)方法在该测试领域的应用研究。采用橡胶带的拉伸实验来验证DIC方法的测量精度,具体的实验测试内容包括:基于空域和频域... 详细信息

针对传统接触式测试方法(如电测法等)在土木工程领域中的局限性,开展了数字图像相关(Digitalimage correlation,DIC)方法在该测试领域的应用研究。采用橡胶带的拉伸实验来验证DIC方法的测量精度,具体的实验测试内容包括:基于空域和频域相结合的混合相关法,开展了建筑膜材的双轴拉伸实验,测量了膜材的力学参数;基于仿射变换的相关迭代法,开展了钢管混凝土框架梁柱连接模型的转角测量与分析实验,测量了加强环式连接的弯矩转角关系;基于时间序列DIC和高速摄影成像技术,开展了自由振动状态下拉索模型的动力学参数识别的实验研究。实验结果验证了这一新型检测手段用于测试建筑材料及结构的力学性能的可靠性与精度。

关键词：相关方法建筑膜材钢管混凝土框架梁柱连接拉索模型

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Data compression of displacement fields in digital image correlation by non-integer quantization

引用

Journal of Southeast University(English Edition) 2022年第1期38卷 42-48页

作者： Chen Wenwu Shao Xinxing he xiaoyuan School of Civil Engineering Southeast UniversityNanjing 211189China

To solve the real-time transmission problem of displacement fields in digital image correlation,two compression coding algorithms based on a discrete cosine transform(DCT)and discrete wavelet transform(DWT)are *** on the Joint Photographic Experts Group(JPEG)and JPEG 2000 standards,new non-integer and integer quantizations are proposed in the quantization procedure of compression *** fields from real experiments were used to evaluate the compression ratio and computational time of the *** results show that the compression ratios of the DCT-based algorithm are mostly below 10%,which are much less than that of the DWT-based algorithm,and the computational speed is also significantly higher than that of the *** findings prove the algorithm s effectiveness in real-time displacement field wireless transmission.

关键词： digital image correlation wireless transmission displacement field compression encoding

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

连续振动悬臂梁的瞬时三维形貌测量

引用

光学学报 2006年第11期26卷 1647-1650页

作者：陈凡秀何小元东南大学工程力学系

提出一种连续振动悬臂梁瞬时三维形貌的测量方法。利用影栅云纹法在连续振动悬臂梁表面产生包含有三维形貌信息的云纹,采用准直双光源提高亮度,通过高速摄相机获取随时间变化的一系列变形条纹,利用傅里叶变换方法对序列图像进行处理,采... 详细信息

提出一种连续振动悬臂梁瞬时三维形貌的测量方法。利用影栅云纹法在连续振动悬臂梁表面产生包含有三维形貌信息的云纹,采用准直双光源提高亮度,通过高速摄相机获取随时间变化的一系列变形条纹,利用傅里叶变换方法对序列图像进行处理,采用补零延拓法对数据进行处理,以减小频谱泄漏所引起的相位计算误差。将相位解包裹方法用于动态过程瞬时三维相位场的相位展开中,重建了悬臂梁的瞬时三维形貌,再现了悬臂梁的连续振动过程。

关键词：光学测量傅里叶变换影栅云纹悬臂梁

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Fish maneuver analysis system based on sequence images

引用

Journal of Southeast University(English Edition) 2009年第2期25卷 228-231页

作者：蒋明何小元东南大学土木工程学院南京210096 苏州科技学院土木工程学院苏州215011

The aim is to establish an automatic system to analyze the maneuver performance of fish. A high speed camera （1 000 frame/s） is employed to record fast-start maneuver. Three steps are taken to analyze the kinematics： first, the midline in the first image is partitioned into equal interval lengths and the coordinates of all inter segmental points are saved. Secondly, these points coordinates are searched in the next frame with the digital image correlation （DIC） method, then these points are fitted with a spline curve function. Repeat this step until all the midlines are figured out frame by frame. Finally, according to the variety of midlines, the kinematics of the fast-start is calculated. Using this system to test carp C-start, the duration is divided into two stages： stage 1 is defined as the formation of the C shape and stage 2 as the return flip of the tail followed with forward motion. By tracing the middle line, the kinematic parameters of turning rate, centre of mass （CM） turning rate, CM turning radius, etc. are obtained.

关键词： carp maneuver kinematics digital image correlation

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

光测法在混凝土表面裂缝测量中的应用

引用

东南大学学报（自然科学版） 2005年第A01期35卷 19-22页

作者：王伟何小元尹兰东南大学土木工程学院南京210096

针对采集到的裂缝图像特征,提出一种裂缝定量分析法,即根据裂缝图像灰度。利用otsu提出的类判别法计算出图像分割的最佳阈值,进而提取图像的裂缝信息,然后通过编制的图像处理程序分析出研究区域的裂缝宽度及其方差.实验结果表明:该定量... 详细信息

针对采集到的裂缝图像特征,提出一种裂缝定量分析法,即根据裂缝图像灰度。利用otsu提出的类判别法计算出图像分割的最佳阈值,进而提取图像的裂缝信息,然后通过编制的图像处理程序分析出研究区域的裂缝宽度及其方差.实验结果表明:该定量分析法处理图像效果好,数据稳定,相关的计算结果可为实际工程的安全可靠性评估提供准确的基础数据.经实践验证,该方法简单易行.

关键词：表面裂缝光测法定量分析混凝土

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：