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51.
Elser V 《Ultramicroscopy》2011,111(7):788-792
The high intensity of free-electron X-ray light sources may enable structure determinations of viruses or even individual proteins without the encumbrance of first forming crystals. This note compares two schemes of non-crystalline diffraction data collection that have been proposed: serial single-shot data from individual particles, and averaged cross-correlation data from particle ensembles. The information content of these schemes is easily compared and we show that the single-shot approach, although experimentally more challenging, is always superior in this respect. In fact, for 3D structure determination a constraint counting argument shows that the cross-correlation scheme suffers from data deficiency. 相似文献
52.
张乐 《自动化与仪器仪表》2010,(4):131-133
介绍了利用激光器、CCD相机、图像采集卡和计算机组成的沙波测量成像系统。阐述了系统的工作原理和计算机图像处理的方法。 相似文献
53.
为解决折反射全景成像系统中的采样分辨率与帧速之间的矛盾,通过反馈控制图像传感器的参数配置,设计并实现了一个全局与局部双模式的全景成像处理系统.在全局模式下,为保证采集帧速率,使用行列跳跃模式采集完整的环状全向图,并将其展开为包含360°全局信息的柱面全景图像;在局部模式下,根据感兴趣区域的空间位置设置采样窗口大小及位置,以逐像素采样模式只采集全向图中相应的一块矩形区域,并将其展开为对应视线方向上高清晰度的局部透视图;最后给出了DSP+FPGA结构的系统硬件设计方案.实验结果表明了该系统设计的科学性及实用性. 相似文献
54.
55.
Todd Zickler Satya P. Mallick David J. Kriegman Peter N. Belhumeur 《International Journal of Computer Vision》2008,79(1):13-30
Complex reflectance phenomena such as specular reflections confound many vision problems since they produce image ‘features’
that do not correspond directly to intrinsic surface properties such as shape and spectral reflectance. A common approach
to mitigate these effects is to explore functions of an image that are invariant to these photometric events. In this paper
we describe a class of such invariants that result from exploiting color information in images of dichromatic surfaces. These
invariants are derived from illuminant-dependent ‘subspaces’ of RGB color space, and they enable the application of Lambertian-based
vision techniques to a broad class of specular, non-Lambertian scenes. Using implementations of recent algorithms taken from
the literature, we demonstrate the practical utility of these invariants for a wide variety of applications, including stereo,
shape from shading, photometric stereo, material-based segmentation, and motion estimation. 相似文献
56.
朱德葛 《数字社区&智能家居》2009,(32)
高校的计算机房所用的操作系统大多数是Windows,常用教学软件的安装和维护,需要有非常丰富的计算机知识和动手能力很强的计算机老师来担当,学校的教学机房的维护管理好坏,直接影响到计算机的正常教学工作,该作者从事过一段机房软件安装、维护、管理工作,在此把他的管理经验和技巧归纳了一下。 相似文献
57.
详细分析和论述了克希霍夫积分偏移原理及其在探地雷达成像中的应用,针对单目标和多目标做了仿真实验.实验结果证明:将克希霍夫积分偏移原理应用在探地雷达成像中具有精度和效率较高、算法简单等优势. 相似文献
58.
In this paper we present a novel methodology based on non-parametric deformable prototype templates for reconstructing the
outline of a shape from a degraded image. Our method is versatile and fast and has the potential to provide an automatic procedure
for classifying pathologies. We test our approach on synthetic and real data from a variety of medical and biological applications.
In these studies it is important to reconstruct accurately the shape of the object under investigation from very noisy data.
Here we assume that we have some prior knowledge about the object outline represented by a prototype shape. Our procedure
deforms this shape by means of non-affine transformations and the contour is reconstructed by minimizing a newly developed
objective function that depends on the transformation parameters. We introduce an iterative template deformation procedure
in which the scale of the deformation decreases as the algorithm proceeds. We compare our results with those from a Gaussian
Mixture Model segmentation and two state-of-the-art Level Set methods. This comparison shows that the proposed procedure performs
consistently well on both real and simulated data. As a by-product we develop a new filter that recovers the connectivity
of a shape.
Francesco de Pasquale received his Ph.D. in Applied Statistics from the University of Plymouth, United Kingdom in 2004 discussing a thesis on Bayesian and Template based methods for image analysis. Since his degree in Physics obtained at the University of Rome ‘La Sapienza’in 1999 his work has been focused on developing models and methods for Magnetic Resonance Imaging, in particular image registration, classification and segmentation in a Bayesian framework. After being appointed a 2-year contract as a Lecturer at the University of Plymouth from 2003 to 2004 he is now a post-Doc researcher at the ITAB, Institute for Advanced Biomedical Technologies, University of Chieti, Italy and he works on the analysis of fMRI and MEG data. Julian Stander was born in Plymouth, UK in 1964. He received a BA in Mathematics with first class honours from University of Oxford in 1987, a Diploma in Mathematical Statistics with distinction from University of Cambridge in 1988, and a PhD from University of Bath in 1992. He has been a lecturer at the School of Mathematics and Statistics, University of Plymouth, since 1993, and was promoted to Reader in 2006. His fields of interest are: applications of statistics including image analysis, spatial modelling and disclosure limitation. He has published over 20 refereed journal articles. 相似文献
Francesco de PasqualeEmail: |
Francesco de Pasquale received his Ph.D. in Applied Statistics from the University of Plymouth, United Kingdom in 2004 discussing a thesis on Bayesian and Template based methods for image analysis. Since his degree in Physics obtained at the University of Rome ‘La Sapienza’in 1999 his work has been focused on developing models and methods for Magnetic Resonance Imaging, in particular image registration, classification and segmentation in a Bayesian framework. After being appointed a 2-year contract as a Lecturer at the University of Plymouth from 2003 to 2004 he is now a post-Doc researcher at the ITAB, Institute for Advanced Biomedical Technologies, University of Chieti, Italy and he works on the analysis of fMRI and MEG data. Julian Stander was born in Plymouth, UK in 1964. He received a BA in Mathematics with first class honours from University of Oxford in 1987, a Diploma in Mathematical Statistics with distinction from University of Cambridge in 1988, and a PhD from University of Bath in 1992. He has been a lecturer at the School of Mathematics and Statistics, University of Plymouth, since 1993, and was promoted to Reader in 2006. His fields of interest are: applications of statistics including image analysis, spatial modelling and disclosure limitation. He has published over 20 refereed journal articles. 相似文献
59.
Lung-Ming Fu Jing-Hui Wang Wen-Bo Luo Che-Hsin Lin 《Microfluidics and nanofluidics》2009,6(4):499-507
This paper presents a detection scheme for analyzing the temperature distribution nearby the channel wall in a microfluidic
chip utilizing a temperature-dependent fluorescence dye. An advanced optical microscope system—total internal reflection fluorescence
microscope (TIRFM) is used for measuring the temperature distribution on the channel wall at the point of electroosmotic flow
in an electrokinetically driven microfluidic chip. In order to meet the short working distance of the objective type TIRFM
scheme, microscope cover glass slits are used to fabricate the microfluidic chips. The short fluorescence excitation depth
from a TIRFM system makes the intensity information obtained using TIRFM is not sensitive to the channel depth variation which
ususally biases the measured results while using a conventional Epi-fluorescence microscope (EPI-FM). Therefore, a TIRFM can
precisely describe the temperature profile of the distance within 100 nm of the channel wall where consists of the Stern layer
and the diffusion layer for an electrokinetic microfluidic system. Results indicate the proposed TIRFM provides higher measurement
sensitivity over the EPI-FM. Significant temperature gradient along the channel depth is experimentally observed. In addition,
the measured wall temperature distributions can be the boundary conditions for numerical investigation into the joule heating
effect. The proposed method gives a precise temperature profile of microfluidic channels and shows the substantial impact
on developing a numerical simulation model for precisely predicting the joule heating effect in microfluidic chips. 相似文献
60.
A new nertral complex,^99mTcCl(4-MCDO)3MEB,((Bis[4-methyl-1,2-cyclohex-anedionedioximato(1-)-O]-[4-methyl-1,2-cyclohexanedione-dioximato(2-)-O] methyl-borato(2-)-N,N‘,N″,N‘‘‘,N‘‘‘‘0-chlorotechnetium,generally called BATO(Boronic acid adducts of technitium dioximes),has been synthesized and evaluated for potential use in myocardial perfusion imaging,It has intrinsic affinity for the blood clearance.The uptake of heart.lung and blood in mice at 2min separately are 1.12,2.48 and 6.66%ID.The complex formation is rapid,simple and highly yielded(≥93%).This process is easy to kit formation. 相似文献