中国科学院机构知识库网格系统: 检索

Application of Fibonacci heap to fast marching method 期刊论文 OAI收割
OPEN PHYSICS, 2021, 卷号: 19, 期号: 1, 页码: 281-284
作者: Meng, Fanchang; Liu, Mingchen; Zhang, Ping; Yang, Junjie; Li, Meng

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收藏 | 浏览/下载：24/0 | 提交时间：2021/10/21

fast marching method Fibonacci heap sort travel time calculation seismic wave propagation eikonal equation

Library-driven approach for fast implementation of the voxel spread function to correct magnetic field inhomogeneity artifacts for gradient-echo sequences 期刊论文 OAI收割
MEDICAL PHYSICS, 2021
作者: Liu, Ying; Ye, Qiong; Zeng, Feiyan; Jiang, Xiaohua; Cai, Bin

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收藏 | 浏览/下载：32/0 | 提交时间：2021/06/15

fast calculation gradient echo library R2* voxel spread function

Full-orbit simulation of fast ion loss under resonant magnetic perturbations in the EAST tokamak 期刊论文 OAI收割
Nuclear Fusion, 2020, 卷号: 61
作者: He,K.; Sun,Y.; Wan,B.N.; Gu,S.; Jia,M.

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收藏 | 浏览/下载：150/0 | 提交时间：2020/12/28

fast ion full orbit resonant magnetic perturbation orbit-following Monte Carlo calculation

Resonant effects on the loss of energetic trapped ions induced by low-n resonant magnetic perturbations 期刊论文 OAI收割
NUCLEAR FUSION, 2019
作者: He, K.; Wan, B. N.; Sun, Y.; Jia, M.; Shi, T.

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收藏 | 浏览/下载：19/0 | 提交时间：2020/10/26

fast ion orbit following Monte Carlo calculation RMP resonance

High-precision Joint 2D Traveltime Calculation for Seismic Processing 期刊论文 OAI收割
EARTH SCIENCES RESEARCH JOURNAL, 2018, 卷号: 22, 期号: 4, 页码: 327-334
作者: Sun, Hui; Meng, Fanchang; Gao, Cheng; Chang, Zhihou; Liu, Mingchen

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收藏 | 浏览/下载：47/0 | 提交时间：2019/04/22

Seismic Imaging Traveltime calculation Fast Marching Method Wavefront Construction Seismic Processing

A parallel algorithm for medical images registration based on B-splines (EI CONFERENCE) 会议论文 OAI收割
4th International Congress on Image and Signal Processing, CISP 2011, October 15, 2011 - October 17, 2011, Shanghai, China
作者: Zhang T.

收藏 | 浏览/下载：26/0 | 提交时间：2013/03/25

Cubic B-splines is widely applied in non-rigid registration because of its approximation performance and fast computational characteristics. However a small scale non-rigid deformation is needed to characterize by a large number of control points. Moreover an iterative optimization strategy of the non-rigid registration algorithm and the normalized mutual information (NMI) cost a great quantity calculation. So the process of the non-rigid registration is slowed by calculations of NMI in a iterative optimization strategy. In this paper a parallel optimization algorithm based on cubic B-splines functions is proposed to parallelize the optimization algorithm of the nonrigid registration and the calculations of normalize mutual information. In practice a fast algorithm of cubic B-splines is used and the control points are only distributed on the targets. Experiments show that the use of the fast algorithm and the parallel optimization strategy improves the non-rigid registration process of medical images. 2011 IEEE.

The Research of real time auto-recognition of the moire fringe (EI CONFERENCE) 会议论文 OAI收割
International Symposium on Photoelectronic Detection and Imaging 2011: Advances in Imaging Detectors and Applications, May 24, 2011 - May 26, 2011, Beijing, China
Wang M.-J.; Wu Z.-G.

收藏 | 浏览/下载：19/0 | 提交时间：2013/03/25

Measuring the movement of raster by the method of moire fringe has the advantage of high sensitivity high resolution and non-contacted measurement. The characteristic of moire fringe is that the image is white alternate with black the angle of the stripes is uniform the width of the stripes is uniform the terminators of the stripes aren't clear. A fast method that can figure out the width and angle of the moire fringe precisely is put forward in this paper. It calculates the angle the stripes firstly. According to the principle of the minimum mean squared error (MMSE) the closer a series of data is the smaller the value of the MMSE will be. The method is described as follows: It takes the image's center as the origin 180 beelines pass through the origin with the same angle interval. it calculates the value of the minimum mean squared error of the 180 beelines and find out the least one among those then the angle of the moire fringe comes out primarily. In order to improving the calculating precision of moire fringe 60 equal angles are divided in the neighborhood of the angle then a precise angle of moire fringe is calculated according to the principle of the MMSE. After getting out the angle of the moire fringe we begin to calculate the width of moire fringe. A line vertical with the moire fringe is drawn and we can get the width of the moire fringe by the vertical line. In order to get over the influence of the noise an effective area with the shape of diamond is selected in the image. The data of area is accumulated and projected according to the direction of moire fringe and a sine curve come out. The width of moire fringe can be obtained by getting the position of the first wave crest the position of the last wave crest and the number of wave crest. Experiments prove that the precision of the method put forward in this paper is enhanced in comparison with the traditional frequency method the precision of width calculation achieves to 99.6% according to the evaluation indicators of width detection error. The computing speed is boosted largely compared with traditional method and it can achieve with 15 ms that satisfying the demand of real time. 2011 SPIE.

A new accurate and fast algorithm of sub-pixel image registration (EI CONFERENCE) 会议论文 OAI收割
2010 IEEE 10th International Conference on Signal Processing, ICSP2010, October 24, 2010 - October 28, 2010, Beijing, China
作者: He B.

收藏 | 浏览/下载：24/0 | 提交时间：2013/03/25

In terms of large field view and multi-channel TDICCD remote sensing images previous interpolation methods and curve fitting methods are not able to achieve the high accuracy and fast registration and their noise immunity and robustness is not high. For that this paper presents a more accurate and faster method iterative pixel interpolation and surface fitting method. Firstly the method uses the some overlapping pixels between multi-channel images. Secondly the proposed technique which is based on the maximization of the correlation coefficient function combines an efficient pixel-moving interpolation scheme with surface fitting which makes use of accurate interpolation calculation and fast surface fitting in the iterative process. Finally the accuracy and speed of the algorithm is evaluated by sub-pixel registration of multi-channel images and comparison with other sorts of efficient methods. The experiment results show that the accuracy of the method reaches 0.01 pixels and it is 3 times faster than the interpolation method. In the registration of large field view and multi-channel TDICCD images the method is accurate and fast with greatly high stability noise immunity and robustness. 2010 IEEE.

Real-time matching algorithm of navigation image based on corner detection (EI CONFERENCE) 会议论文 OAI收割
International Symposium on Photoelectronic Detection and Imaging 2009: Advances in Imaging Detectors and Applications, June 17, 2009 - June 19, 2009, Beijing, China
作者: Zhang T.

收藏 | 浏览/下载：45/0 | 提交时间：2013/03/25

In order to meet requirement of real-time and high accuracy in image matching aided navigation SSDA algorithm is used to match remote sensing image and template image coarsely a fast and effective algorithm of remote sensing image matching based on corner detection is put forward. With the combination of rough and fine match when the matching result is bigger than one to count absolute value sum of energy difference of characteristic point energy to realize fine match of remote sensing image and template image to locate the position of template image in remote sensing image accurately. Simulation experiment proves that the matching of a remote sensing image resolution of 1018*1530 and a template image resolution of 150*90 can be fulfilled within 2.392 second wavelet transform is used to acquire low frequency component to realize image compression to decrease calculation work and increase matching speed. Harris corner detection algorithm is used to detect corner of remote sensing image and template image and energy of every corner is calculated the algorithm is robust and effective real time image navigation can be achieved. 2009 SPIE.

Displacement estimation by the phase-shiftings of fourier transform in present white noise (EI CONFERENCE) 会议论文 OAI收割
ICO20: Optical Information Processing, August 21, 2005 - August 26, 2005, Changchun, China
作者: Wu Y.-H.

收藏 | 浏览/下载：29/0 | 提交时间：2013/03/25

Displacement estimation is a fundamental problem in Real-time video image processing. It can be typically approached by theories based on features in spatial domain. This paper presents an algorithm which improves the theory for estimating the moving object's displacement in spatial domain by its Fourier transform frequency spectrum. Because of the characters of Fourier transform the result is based on all the features in the image. Utilizing shift theorem of Fourier transform and auto-registration the algorithm employs the phase spectrum difference in polar coordinate of two frame images sequence with the moving target1 2. The method needn't transform frequency spectrum to spatial domain after calculation comparing with the traditional algorithm which has to search Direc peak and it reduces processing time. Since the technique proposed uses all the image information including all the white noise in the image especially and it's hard to overcome the aliasing from noises but the technique can be an effective way to analyze the result in little white noise by the different characters between high and low frequency bands. It can give the displacement of moving target within 1 pixel of accuracy. Experimental evidence of this performance is presented and the mathematical reasons behind these characteristics are explained in depth. It is proved that the algorithm is fast and simple and can be used in image tracking and video image processing.