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Single particle macromolecular structure determination via electron microscopy

FEBS LETTERS 2001年第2期505卷 199-205页

作者： Thuman-Commike, PA QED Labs San Jose CA 95128 USA

Three-dimensional structure determination of macromolecules and macromolecular complexes is an integral part of understanding biological functions. For large protein and macromolecular complexes structure determination is often performed using electron cryomicroscopy where projection images of individual macromolecular complexes are combined to produce a three-dimensional reconstruction. Single particle methods have been devised to perform this structure determination for macromolecular complexes with little or no underlying symmetry. These computational methods generally involve an iterative process of aligning unique views of the macromolecular images followed by determination of the angular components that define those views. In this review, this structure determination process is described with the aim of clarifying a seemingly complex structural method. (C) 2001 Federation of European Biochemical Societies. Published by Elsevier Science B.V. All rights reserved.

关键词： computer image processing electron microscopy macromolecular complex single particle three-dimensional structure

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Synchronous observation of rising soluble bubble through quiescent solution

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中国高等学校学术文摘·能源与动力工程 2009年第3期3卷 307-312页

作者： Yifu ZHANG Shuai TIAN Weizhong LI Yongchen SONG Key Laboratory of Ocean Energy Utilization and Energy Conservation of Ministry of Education Dalian University of Technology Dalian 116024 China

An experimental method using computer image processing technology (CIPT) was proposed to observe and investigate the velocity, deformation, heat and mass transfer, etc. of a rising soluble gas (CO2) bubble through a quiescent hot water. A model was set up to describe the behavior of the bubble in a visual experi-mental system in which a high-speed camera rose instantaneously with the movement of the bubble. A series of trajectory videos about the bubble were recorded by a computer linked to the camera. The trajectory, volume changes and rate of mass transfer of the bubble were obtained by the CIPT. It is found that the single bubble follows a rolling trajectory at the initial stage when there is mass transfer. With the volume decreasing, the disturbed behavior of the bubble becomes tempered. When the rising velocity of the bubble reaches the maximum, the velocity is nearly at a constant. The experimental and analysis results show that this method is useful for the research on the mass transfer and the movement of rising bubbles in liquid.

关键词： soluble bubble mass transfer synchronous observation computer image processing

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State Recognition of Egg Embryo in Vaccines Production Based on SVM 5

State Recognition of Egg Embryo in Vaccines Production Based...

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5th International Conference on Mechanical, Automotive and Materials Engineering (CMAME)

作者： Xu, Yanwei Chen, Menghui Xie, Tancheng Henan Univ Sci & Technol Sch Mechatron Engn Luoyang 471023 Peoples R China

ISBN: (纸本)9781538604328

The method for state recognition of egg embryo in biological vaccines production based on computer image processing and support vector machine was researched. Firstly, the median filtering method was applied to eliminate noises in the images of egg embryo that were classified by the requirements of practical production, then the threshold segmentation method was used to segment the images, then the blood vessels and black blocks in the egg embryo images were selected as major characteristics to extract. The decision tree classification model with structure of binary tree was built on support vector machine, and the model was trained with the toolkit LIBSVM, the penalty factor C = 2, RBF kernel parameter gamma=3.0512e-05 and the precision of cross validation accuracy is 98.913% Finally, 100 egg embryos were randomly selected as the test samples to do pattern recognition, and compared with manual test result. The comparison result showed that the discriminant accuracy of SVM classifier on weak embryo, polluted embryo or dead embryo was 100%, and it of SVM classifier on live embryo was 94.62%.

关键词： egg embryo pattern recognition support vector machine computer image processing

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A Medical image Segmentation Methods Based on SOM and Wavelet Transforms 11

A Medical Image Segmentation Methods Based on SOM and Wavele...

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11th International Symposium on Multispectral image processing and Pattern Recognition (MIPPR) - Automatic Target Recognition and Navigation

作者： Zhang Liping Changjiang Polytech Sch Elect & Mech Automobile Wuhan 430074 Peoples R China

ISBN: (纸本)9781510636361

image segmentation plays a crucial role in many medical imaging applications and is an important but inherently difficult problem. The paper discuses the method that classify unsupervised image using a Kohonen self-organizing map neural network. This method exits two problems: training time of the network is too long and the classified result and quantity were bigger influenced by the noise of image. Two-dimensional Discrete Wavelet Transforms (DWT) decompose MRI image into the small size and denoise approximation images. Kohonen self-organizing map neural network is trained with approximation image, then trained neural network classify pixels of original image. Training time of the network was notability decrease and the classified quality influenced by the noise of image was notability reduce. The technique presented here has shown a very encouraging level of performance for the problem of segmentation in MRI image of the head.

关键词： computer image processing medical image classification Neural Network Discrete Wavelet Transforms

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A geometric basis for calculation of right ventricular volume in man

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Catheterization and Cardiovascular Diagnosis 1977年第3期3卷 217-230页

作者： Boak, J. Gordon Bove, Alfred A. Kreulen, Thomas Spann, James F. Temple University Health Sciences Center Philadelphia Pennsylvania United States Jesrsey Medical Center-Fitkin Hospital Neptune New Jersey 07753 1945 Corlies Avenue United States

A clinically applicable method for determining right ventricular volume was developed using a new hemielliptical model. The model was derived from a detailed study of right ventricular geometry. Silicone rubber casts were made from 7 adult human right ventricles at autopsy. Cast volumes measured by water displacement ranged from 30 to 144 ml. Serial sections were made of each cast, and the product of the long and short axis of all sections was found to be directly related to the cross‐sectional area and independent of the region or the volume of the ventricle from which the slice originated. Further, using a hemielliptical model, the volume V of each ventricle could be calculated from the equation: V = (π/4) Σ dwh where, d is the depth, w is the width parallel to the septum, and h is the thickness of the cross section. Calculated volume agreed closely with displacement volume throughout (r equals;0.99, slope equals;1.05 ± 0.04, intercept equals;−3.6 ± 4., SEE equals;4.27 ml). Using the same model, calculation of right ventricular surface area was found to agree closely with measured surface area (r equals;0.99, slope equals;0.94, intercept equals;−.6, SEE equals;3.9). This model can be used to calculate right ventricular volumes from biplane radiographs in man using the equation V equals;(π/4)(A_RAO·A_LAO)/Hsb_L where A_RAO equals;the area of the 30° right anterior oblique image, A, H_L equals;the area and height respectively of the 60° left anterior oblique image. For all 7 casts, radiographic volume agreed closely with directly measured volume (slope equals;0.97, intercept equals;−5.5, r equals;0.99, SEE equals;4.7). Evaluation of positional effects showed that radiographic volume was most accurate when the 30° RAO/60° LAO projections were used. This study provides a method of calculating right ventricular volume, based upon right ventricular geometry, that may be applied to evaluating the volume of the right ventr

关键词： computer image processing right ventricular volume ventricular function ventriculography

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Automatic detection method of stenotic lesions in coronary cineangiograms

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The International Journal of Cardiac Imaging 1989年第1期5卷 17-23页

作者： Sugahara, Tetsuo Maeda, Hirofumi Yanagihara, Yoshio Department of Radiology National Cardiovascular Center Research Institute Osaka 565 5-7-1 Fujishiro-dai Suita Japan Department of Radiology Oita Medical school Oita 879-56 1-1506 IdaigaokaHazama-chyo Oita-gun Japan

A new image processing procedure enabling the automatic detection of coronary artery stenoses by cineangiography was developed. Detection of stenoses was performed using computer image processing by the following procedure. The path of the arteries was extracted by a subtraction method. The thresholding image was obtained from the subtraction image, and converted to a 'thinning' image, which represented the center line of the artery. For measurement of the arterial diameter, the vessel edges were determined by unilateral Gaussian fit to profile curves in sections perpendicular to the center line. Stenoses could then be detected on the basis of the normal diameter of artery estimated by Hough transformation. This method facilitates the detection of stenotic lesions from coronary cineangiograms. © 1989 Kluwer Academic Publishers.

关键词： cineangiogram computer image processing coronary artery stenosis

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Research in video detection of lane curve and its application in speed alert system

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Research Journal of Applied Sciences, Engineering and Technology 2014年第5期7卷 957-962页

作者： Song, Maliang Liu, Xiaoyan Faculty of Information Engineering and Automation Kunming University of Science and Technology Yunnan Province 650500 China Yunnan Provincial Key Laboratory of Computer Application Technology Yunnan Province 650500 China

That vehicles travel on a curve with excessive speed tends to skid or roll over. This study presents research in video recognition technology of lane and its application in traffic early safety alert system, which improves traffic safety. In our study, we use a monocular camera to acquire the image of the road ahead. Techniques such as gray-scale transformation, filtering, edge detection and curve fitting are used for the recognition of the lane line and curve fitting. Then radius of curvature of the road ahead will be extracted and then the maximum safe speed, which is to be compared with the speed of the vehicle in safety alert system. Experiments show that this method can accurately calculate the radius of the curve ahead and timely give alert message when the vehicle's speed exceeds safe speed. © Maxwell Scientific Organization, 2014.

关键词： computer image processing Coordinate transform Monocular vision Speed alert

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An Intelligent Peak Search Program for Digital Electron Diffraction images of 3D Nano-crystals

An Intelligent Peak Search Program for Digital Electron Diff...

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2nd International Congress on image and Signal processing

作者： Jiang, Linhua Georgieva, Dilyana IJspeert, Kim Abrahams, Jan Pieter Leiden Univ Dept Biophys Struct Chem LIC NL-2333 CC Leiden Netherlands

ISBN: (纸本)9781424441303

Electron diffractograms are lattice images of crystalline samples taken in transmission electron microscopy for molecular structure determination studies. Electron diffraction is a technique widely used in material science and recently it is gaining significance also in life science for studying 2D and 3D organic crystals. However, often the images suffer from strong background noise, masking the data points. Moreover, they suffer also from the strong center beam exposure or a big beam-stop which covers a lot of useful information. This paper presents a user-friendly peak search program in which an autocorrelation algorithm is utilized creatively to intensify the signal and to center the image in the particular regular lattice. An adaptive background removal algorithm is designed to remove the central beam and to reduce the background noise. The latter algorithm can be used for a wide range of applications, such as 2D spectral analysis in physics, NMR Analysis, stars recognition of aerospace photographs.

关键词： Peak search Background removal Electron diffraction 3D protein nano-crystals computer image processing

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Limitation of detection and evaluation of coronary arterial stenosis by densitometry

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The International Journal of Cardiac Imaging 1994年第1期10卷 35-43页

作者： Sugahara, Tetsuo Kimura, Koji Yanagihara, Yoshio Sugimoto, Naozou Azumi, Takayoshi Department of Radiology Aizembashi Hospital Osaka 556 3-1-11 Nihombashihigashi Naniwaku Osaka Japan Department of Radiology National Cardiovascular Center Osaka 565 5-7-1 Fujishirodai Suita Japan Department of Investigative Radiology National Cardiovascular Center Research Institute Japan Department of Medicine Mikishimin Hospital Hyougo 630 3-1 Kasa Miki Japan

In coronary cineangiography, both X-ray absorption and light scatter in the image intensifier tend to degrade image quality, and so affect the accuracy of densitometric measurement of vessel diameter. To investigate this problem, we compared the accuracy and precision of the densitometric method and the edge detection method in the automated detection of stenosis in both vessel phantom and clinical studies. In the phantom study, the X-ray penetration was varied by altering the thickness of the model, and the change in the measured diameter obtained by each of the two methods was evaluated simultaneously. A difference of 5 mm in the thickness of the model was found to alter significantly (P < 0.01) measurement of the diameter obtained using the densitometric method, but not that obtained by the edge detection method. In the clinical part of the study, the accuracy of each method in the automated detection of coronary stenosis was evaluated. With respect to the detection of stenosis, the level of disagreement between the assessment of the 3 observers and what was detected by densitometry (22.8%) was 2.9 times higher than the disagreement between the observers' assessment and what was detected using the edge detection method (7.9%). When the background density of the coronary cineangiogram along the axis of the vessel was uneven, many vessel segments which had been evaluated as normal when edge-detection was used were evaluated as stenosed when densitometry was used. This study, then, demonstrates that the Lambert-Beer law does not apply in cases where the thickness of the subject varies in different locations along the axis of the same vessel. We therefore conclude that densitometry is not a reliable means of assessing coronary stenosis in such cases, due to veiling-glare and scatter, and recommend that it not be routinely used in the automated detection of coronary arterial stenosis. © 1994 Kluwer Academic Publishers.

关键词： computer image processing coronary cineangiogram coronary stenosis densitometry edge detection

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Near-nucleus imaging of comet IRAS-Araki-Alcock 1983H1

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Earth, Moon and Planets 1996年第1期75卷 1-16页

作者： Kubáček, D. Pittichová, J. Astronomical Institute Slovak Academy of Sciences Dubravska cesta 9 842 28 Bratislava Slovakia

Several digital image processing techniques were used to improve the visibility of details, fans and jets, in the inner coma of the comet IRAS-Araki-Alcock 1983VII on the short CCD-exposures taken by R.E. Schild with the 61-cm telescope through three I, J, and F band filters, at the Whipple Observatory during the close approach from May 6 through May 12, 1983. About 140 CCD images with the pixel size of 0.73 give a resolution about 20 km, and selected CDD frames presented together with isophotes demonstrate the variation and interrelation of the coma morphology and the nucleus activities during the observing period. Results and processed images are compared with observations taken by other observers during the same period.

关键词： Comet IRAS-Araki-Alcock near nucleus imaging computer image processing coma morphology near-nucleus jets

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