Zero-order and twin images are a serious obstacle in achieving a high-quality output in in-line digital holography （DH）. They decrease the useful bandwidth of the off-axis DH. Over the years the twin image removal p...Zero-order and twin images are a serious obstacle in achieving a high-quality output in in-line digital holography （DH）. They decrease the useful bandwidth of the off-axis DH. Over the years the twin image removal problem was approached both by instrumental and numerical means. The paper provides an extended survey of the proposed solutions with their pros and cons as a guide for further advance in this field. Processing of a single spatial carrier fringe pattern involves spatial filtering in the frequency domain, spatial phase-shifting （PS） or wavelet transform. A point source digital holographic microscopy （DHM）, introduction of calibration measurements or various modifications of PS technique are instrumental solutions to the twin image problem for in-line DH. Numerical solutions to the same problem include iterative and non-iterative approaches, diffraction-based and inverse problem solutions, reconstruction of purely real or phase objects and of complex objects, reconstruction of plane and volume objects. Elimination only of the zero-order image relies on non-linear filtering or additional calibration measurements.展开更多
Herein we describe an approach to measure the volume and to characterize the volume distribution of large numbers of individual small regularly shaped seeds. The results of a preliminary investigation into the distrib...Herein we describe an approach to measure the volume and to characterize the volume distribution of large numbers of individual small regularly shaped seeds. The results of a preliminary investigation into the distribution of seed size of a multi-seeded sorghum mutant, as compared to the wild type from which it was developed are also reported, and are used as an example of the method’s utility.展开更多
In the last decade, X-ray fluorescence holography has been developed for the study of 3D atomic arrangements in solids. However, it encounters the twin image problem which may disturb the reconstructed atomic images. ...In the last decade, X-ray fluorescence holography has been developed for the study of 3D atomic arrangements in solids. However, it encounters the twin image problem which may disturb the reconstructed atomic images. In this paper, the formation of twin image is discussed and we propose a modified two-energy algorithm to remove the twin image. The simulation shows that the method is valid and more efficient than the multiple-energy algorithm proposed by Barton.展开更多
基于数字孪生技术,深入探讨建筑信息化模型(building information modeling,BIM)与智能图像识别技术在智能巡检领域的集成挑战及其对泵站设备异常等异常事件快速响应能力的提升方法。将BIM轻量化后与网络地理信息系统(Web geographic in...基于数字孪生技术,深入探讨建筑信息化模型(building information modeling,BIM)与智能图像识别技术在智能巡检领域的集成挑战及其对泵站设备异常等异常事件快速响应能力的提升方法。将BIM轻量化后与网络地理信息系统(Web geographic information system,WebGIS)相结合,为三维智能巡检搭建数字孪生场景。在此基础上,集成视频融合技术与智能识别算法,构建BIM技术耦合图像识别技术的三维智能巡检系统,实现BIM与视频监控虚实交互,快速直观地展示告警信息,辅助值班人员快速响应设备异常等事件。结果表明:BIM技术耦合图像识别技术在数字孪生泵站中具有巨大的潜力,可以有效提高巡检质量,为泵站智慧化管理作依托。展开更多
基金supported by the IT R&D programof MSIP(Fundamental technology development for digital holographic contents)
文摘Zero-order and twin images are a serious obstacle in achieving a high-quality output in in-line digital holography （DH）. They decrease the useful bandwidth of the off-axis DH. Over the years the twin image removal problem was approached both by instrumental and numerical means. The paper provides an extended survey of the proposed solutions with their pros and cons as a guide for further advance in this field. Processing of a single spatial carrier fringe pattern involves spatial filtering in the frequency domain, spatial phase-shifting （PS） or wavelet transform. A point source digital holographic microscopy （DHM）, introduction of calibration measurements or various modifications of PS technique are instrumental solutions to the twin image problem for in-line DH. Numerical solutions to the same problem include iterative and non-iterative approaches, diffraction-based and inverse problem solutions, reconstruction of purely real or phase objects and of complex objects, reconstruction of plane and volume objects. Elimination only of the zero-order image relies on non-linear filtering or additional calibration measurements.
文摘Herein we describe an approach to measure the volume and to characterize the volume distribution of large numbers of individual small regularly shaped seeds. The results of a preliminary investigation into the distribution of seed size of a multi-seeded sorghum mutant, as compared to the wild type from which it was developed are also reported, and are used as an example of the method’s utility.
文摘In the last decade, X-ray fluorescence holography has been developed for the study of 3D atomic arrangements in solids. However, it encounters the twin image problem which may disturb the reconstructed atomic images. In this paper, the formation of twin image is discussed and we propose a modified two-energy algorithm to remove the twin image. The simulation shows that the method is valid and more efficient than the multiple-energy algorithm proposed by Barton.
文摘利用PIV技术对气液两相流场与电场耦合作用下的外混式双流体雾化器荷电喷雾流场特性进行了测量研究,设计了一种带环形气幕的荷电感应装置,以控制喷雾射流在感应荷电过程中出现的液滴卷吸.结果表明:当水流量Q由20 L·h-1增加到36 L·h-1时,射流核心区速度增大,喷雾结构逐渐呈现非对称性,随着流量的增大非对称性越明显;扇形压力pR、雾化压力pB对喷雾流场的对称性及喷雾锥角的变化起重要作用;高压静电作用使得喷雾锥角略微增大,上卷吸现象明显并出现涡旋结构,长时间工作时电极环易积液;电极环气幕压力为100 k Pa时,其低压气流可以有效弱化细小液滴的上卷吸运动,解决电极环积液问题,荷电双流体雾化器运行稳定.
文摘基于数字孪生技术,深入探讨建筑信息化模型(building information modeling,BIM)与智能图像识别技术在智能巡检领域的集成挑战及其对泵站设备异常等异常事件快速响应能力的提升方法。将BIM轻量化后与网络地理信息系统(Web geographic information system,WebGIS)相结合,为三维智能巡检搭建数字孪生场景。在此基础上,集成视频融合技术与智能识别算法,构建BIM技术耦合图像识别技术的三维智能巡检系统,实现BIM与视频监控虚实交互,快速直观地展示告警信息,辅助值班人员快速响应设备异常等事件。结果表明:BIM技术耦合图像识别技术在数字孪生泵站中具有巨大的潜力,可以有效提高巡检质量,为泵站智慧化管理作依托。
