高分辨率SAR子孔径图像相干性分析及其地物分类应用

针对相干性这一合成孔径雷达(SAR)图像分析常用的特征量进行分析,首先从理论上分析高分辨率SAR图像中人造目标和自然地物等典型目标的子孔径、子频带以及不同子孔径重轨干涉图像间的相干系数,然后利用高分辨率星载SAR实际数据开展上述相干系数的计算,验证分析的正确性。随后根据不同地物在不同维度相干系数上体现的不同特点,进行非监督地物分类,并给出不同类别所表征的地物特点。分析结果可为高分辨率SAR数据的优化应用提供支撑,并可加深对SAR不同地物目标特性的理解。     

Research on ultrasonic detection of complex surfaces

INTRODUCTION Parts of complex surfaces have found wide ap-plications today in airplane,ship,automobile industry,medical science,etc.How to detect the internal de-fects of parts of complex surfaces efficiently and ac-curately is an important issue.Due to its special ad-vantages of high sensitivity,good detection,strong penetration ability,and harmlessness to human body,ultrasonic detection has become a most important method of Nondestructive Test(NDT).However,at present in China,to detec…     

Liquid Flow Field on Evaporator of Wiped Short Path Distillation--Experimental Results and Computer Simulation

Short path distillation (SPD) is a kind of high vacuum distillation method, which is suitable for the separation of high boiling, heat sensitivity and viscidity products.In this paper,through measuring the phase-averaged velocity distributions with a conditional sampling method of the particle imaging velocimetry (PIV), the liquid flow field that affects the heat and mass transfer of evaporating thin-film in an SPD evaporator is investigated.Measured results show that the flow velocities decrease rapidly apart from the wiper at different wiper velocities, the maximum velocity appears before wipers, and the quicker the wiping, the larger the flow velocity. Meanwhile, the evaluation of numerical calculations is carried out.The measured velocity distributions indicate clearly the effect of the wiper both on the flow field along its moving direction and on the vortices behind the wiper.Simulation data show that the performance of liquid flow field on the heating surface not only agrees with the experimental results well,but also can give further more information, such as the distribution of turbulent kinetic energy.In this study,turbulent kinetic energy mainly distributes before wipers and laminar flow appears far away from the wipers.     

三叉神经与血管关系的核磁影像学研究

常规MRI加3D T1 SPGR序列行脑干薄层扫描70例TN患者,采用盲法确定三叉神经根部解剖改变,分别观察双侧三叉神经周围是否存在血管影,并测定三叉神经长轴与邻近血管的距离,两侧对照分析。结果表明,MRI加3D T1 SPGR序列为目前TN病因诊断的较好影像检查方法,TN的主要病因为患侧三叉神经根部受血管压迫。     

基于 PyRadiomics 的医疗影像纹理获取原型系统集成

针对计算机辅助诊断中医学影像纹理计算相对复杂、商业分析软件功能相对固定和成本较高等问题,以目前主流的 Python 语言为开发工具,将其对应的 PyRadiomics 模块、SimpleITK 模块与 Pydicom 模块相结合,给出了符合 Dicom 3.0 格式的医疗影像数据纹理分析软件设计流程,开发了纹理计算过程和数据可视化原型系统。系统集成为影像医师诊断提供了一种低成本、交互友好的纹理特征数据获取与分析手段,为医学影像中的人工智能、深度学习应用打下了基础。     

Coupled physical and digital cadaver dissection followed by a visual test protocol provides insights into the nature of anatomical knowledge and its evaluation

This research effort compared and contrasted two conceptually different methods for the exploration of human anatomy in the first‐year dissection laboratory by accomplished students: “physical” dissection using an embalmed cadaver and “digital” dissection using three‐dimensional volume modeling of whole‐body CT and MRI image sets acquired using the same cadaver. The goal was to understand the relative contributions each method makes toward student acquisition of intuitive sense of practical anatomical knowledge gained during “hands‐on” structural exploration tasks. The main instruments for measuring anatomical knowledge under this conceptual model were questions generated using a classification system designed to assess both visual presentation manner and the corresponding response information required. Students were randomly divided into groups based on exploration method (physical or digital dissection) and then anatomical region. The physical dissectors proceeded with their direct methods, whereas the digital dissectors generated and manipulated indirect 3D digital models. After 6 weeks, corresponding student anatomical assignment teams compared their results using photography and animated digital visualizations. Finally, to see whether each method provided unique advantages, a visual test protocol of new visualizations based on the classification schema was administered. Results indicated that all students, regardless of gender, dissection method, and anatomical region dissected performed significantly better on questions presented as rotating models requiring spatial ordering or viewpoint determination responses in contrast to requests for specific lexical feature identifications. Additional results provided evidence of trends showing significant differences in gender and dissection method scores. These trends will be explored with further trials with larger populations. Anat Sci Ed 1:27–40, 2008. © 2007 American Association of Anatomists.     

Transforming clinical imaging data for virtual reality learning objects

Advances in anatomical informatics, three‐dimensional (3D) modeling, and virtual reality (VR) methods have made computer‐based structural visualization a practical tool for education. In this article, the authors describe streamlined methods for producing VR “learning objects,” standardized interactive software modules for anatomical sciences education, from newer high‐resolution clinical imaging systems data. The key program is OsiriX, a free radiological image processing workstation software capable of directly reformatting and rendering volumetric 3D images. The transformed image arrays are then directly loaded into a commercial VR program to produce a variety of learning objects. Multiple types or “dimensions” of anatomical information can be embedded in these objects to provide different kinds of functions, including interactive atlases, examination questions, and complex, multistructure presentations. The use of clinical imaging data and workstation software speeds up the production of VR simulations, compared with reconstruction‐based modeling from segmented cadaver cross‐sections, while providing useful examples of normal structural variation and pathological anatomy. Anat Sci Ed 1:50–55, 2008. © 2008 American Association of Anatomists.     

In situ hyperspectral data analysis for pigment content estimation of rice leaves

INTRODUCTIONPigmentsarecloselyrelatedtothephysiolog icalfunctionofleaves.Chlorophyllsabsorblightenergyandtransferitintothephotosyntheticpro cess.Carotenoids (yellowpigments)canalsocontributeenergytothephotosyntheticsystem .Becauseoftheimportanceofpigments…     

传统文件的数字影像化管理方法

本文详细给出了利用计算机技术,图像处理技术对传统票据文件进行数字影像化处理和管理的实现方法,并介绍了在开发过程中应用的技术方案和基本原理,介绍了数字影像化管理方案的功能和特点.     

Confocal XRF depth profiling non-destructively reveals the original blue pigments in a Renaissance painting by Caroto

Recent restoration of The Rest on the Flight into Egypt by Giovanni Francesco Caroto, from the Louvre collections, included a technical examination of the Virgin's blue robe that aimed to characterize the original materials and later additions. The painting was examined using light microscopy and ultraviolet and infrared imaging, and one cross section was taken. None of these methods showed a clear distinction between the layers that were artist applied or modifications made by another hand. To gain information about the paint stratigraphy without taking additional samples, non-invasive confocal X-ray fluorescence (CXRF) analysis was carried out to examine several areas of the Virgin's robe. Using this technique, it was possible to identify the pigments and order of application of paint by the artist. All the pigments identified were considered to be artist applied, and on this basis no further cleaning was carried out and conservation proceeded with retouching of minor areas of loss or damage. This study highlights the advantages of CXRF analysis for the technical study of paintings, used in combination with classical methods for making informed conservation treatment decisions.