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浏览/检索结果: 共10条，第1-10条 帮助

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基于地震观测记录的地质灾害事件检测——以“23.7”北京山洪泥石流为例 期刊论文  OAI收割
地球与行星物理论评(中英文), 2025, 卷号: N/A, 期号: 0, 页码: 1-12
作者:  王烁帆;  崔一飞;  邓雄涛;  李尧;  张勇刚
  |  收藏  |  浏览/下载：57/0  |  提交时间：2025/07/04
A New Fire Detection Method Using a Multi-Expert System Based on Color Dispersion, Similarity and Centroid Motion in Indoor Environment 期刊论文  OAI收割
IEEE/CAA Journal of Automatica Sinica, 2020, 卷号: 7, 期号: 1, 页码: 263-275
作者:  Teng Wang;  Leping Bu;  Zhikai Yang;  Peng Yuan;  Jineng Ouyang
  |  收藏  |  浏览/下载：37/0  |  提交时间：2021/03/11
Distortion measurement of optical system using phase diffractive beam splitter 期刊论文  OAI收割
Optics Express, 2019, 卷号: 27, 期号: 21, 页码: 29803-29816
作者:  F.Wang;  Z.Y.Zhang;  R.Q.Wang;  X.F.Zeng;  X.Yang
  |  收藏  |  浏览/下载：42/0  |  提交时间：2020/08/24
Extracting the centroid of the light spot by two-dimensional sigmoid fitting 期刊论文  OAI收割
Optical Engineering, 2018, 卷号: 57, 期号: 10, 页码: 104113（1-7）
作者:  Hui Zhang;  Guoping Li;  Yong Zhang;  Shouwei Hu
  |  收藏  |  浏览/下载：142/0  |  提交时间：2019/02/03
ZigBee indoor positioning system precision parameter study based on BP neural network 会议论文  OAI收割
International Conference on Computer, Networks and Communication Engineering (ICCNCE), Beijing, PEOPLES R CHINA, MAY 23-24, 2013
Zeng Wenxiao; Wang Yanen; Wang Meng; Guo Ye
收藏  |  浏览/下载：67/0  |  提交时间：2014/11/10
Research on infrared dim-point target detection and tracking under sea-sky-line complex background (EI CONFERENCE) 会议论文  OAI收割
International Symposium on Photoelectronic Detection and Imaging 2011: Advances in Infrared Imaging and Applications, May 24, 2011 - May 24, 2011, Beijing, China
作者:  Dong Y.-X.;  Zhang H.-B.;  Li Y.;  Li Y.;  Li Y.
收藏  |  浏览/下载：136/0  |  提交时间：2013/03/25
Target detection and tracking technology in infrared image is an important part of modern military defense system. Infrared dim-point targets detection and recognition under complex background is a difficulty and important strategic value and challenging research topic. The main objects that carrier-borne infrared vigilance system detected are sea-skimming aircrafts and missiles. Due to the characteristics of wide field of view of vigilance system  the target is usually under the sea clutter. Detection and recognition of the target will be taken great difficulties.There are some traditional point target detection algorithms  such as adaptive background prediction detecting method. When background has dispersion-decreasing structure  the traditional target detection algorithms would be more useful. But when the background has large gray gradient  such as sea-sky-line  sea waves etc.The bigger false-alarm rate will be taken in these local area.It could not obtain satisfactory results. Because dim-point target itself does not have obvious geometry or texture feature  in our opinion  from the perspective of mathematics  the detection of dim-point targets in image is about singular function analysis.And from the perspective image processing analysis  the judgment of isolated singularity in the image is key problem. The foregoing points for dim-point targets detection  its essence is a separation of target and background of different singularity characteristics.The image from infrared sensor usually accompanied by different kinds of noise. These external noises could be caused by the complicated background or from the sensor itself. The noise might affect target detection and tracking. Therefore  the purpose of the image preprocessing is to reduce the effects from noise  also to raise the SNR of image  and to increase the contrast of target and background. According to the low sea-skimming infrared flying small target characteristics  the median filter is used to eliminate noise  improve signal-to-noise ratio  then the multi-point multi-storey vertical Sobel algorithm will be used to detect the sea-sky-line  so that we can segment sea and sky in the image. Finally using centroid tracking method to capture and trace target. This method has been successfully used to trace target under the sea-sky complex background. 2011 Copyright Society of Photo-Optical Instrumentation Engineers (SPIE).  
Research on automatic Hartmann test of membrane mirror (EI CONFERENCE) 会议论文  OAI收割
5th International Symposium on Advanced Optical Manufacturing and Testing Technologies: Optical Test and Measurement Technology and Equipment, April 26, 2010 - April 29, 2010, Dalian, China
作者:  Zhang P.
收藏  |  浏览/下载：66/0  |  提交时间：2013/03/25
Electrostatic membrane mirror is ultra-lightweight and easy to acquire a large diameter comparing with traditional optical elements  so its development and usage is the trend of future large mirrors. In order to research the control method of the static stretching membrane mirror  the surface configuration must be tested. However  membrane mirror's shape is always changed by variable voltages on the electrodes  and the optical properties of membrane materials using in our experiment are poor  so it is difficult to test membrane mirror by interferometer and null compensator method. To solve this problem  an automatic optical test procedure for membrane mirror is designed based on Hartmann screen method. The optical path includes point light source  CCD camera  splitter and diffuse transmittance screen. The spots' positions on the diffuse transmittance screen are pictured by CCD camera connected with computer  and image segmentation and centroid solving is auto processed. The CCD camera's lens distortion is measured  and fixing coefficients are given to eliminate the spots' positions recording error caused by lens distortion. To process the low sampling Hartmann test results  Zernike polynomial fitting method is applied to smooth the wave front. So low frequency error of the membrane mirror can be measured then. Errors affecting the test accuracy are also analyzed in this paper. The method proposed in this paper provides a reference for surface shape detection in membrane mirror research. 2010 Copyright SPIE - The International Society for Optical Engineering.  
Numerical study of centroid detection accuracy for Shack-Hartmann wavefront sensor 期刊论文  OAI收割
OPTICS AND LASER TECHNOLOGY, 2006, 卷号: 38, 期号: 8, 页码: 614-619
作者:  Jiang, ZL;  Gong, SS;  Dai, Y
收藏  |  浏览/下载：30/0  |  提交时间：2015/07/22
Research on tracking approach to low-flying weak small target near the sea (EI CONFERENCE) 会议论文  OAI收割
ICO20: Optical Information Processing, August 21, 2005 - August 26, 2005, Changchun, China
作者:  Xue X.-C.
收藏  |  浏览/下载：62/0  |  提交时间：2013/03/25
Automatic target detection is very difficult in complicate background of sea and sky because of the clutter caused by waves and clouds nearby the sea-level line. In this paper  in view of the low-flying target near the sea is always above the sea-level line  we can first locate the sea-level line  and neglect the image data beneath the sea-level line. Thus the noise under the sea-level line can be suppressed  and the executive time of target segmentation is also much reduced. A new method is proposed  which first uses neighborhood averaging method to suppress background and enhance targets so as to increase SNR  and then uses the multi-point multi-layer vertical Sobel operator combined with linear least squares fitting to locate the sea-level line  lastly uses the centroid tracking algorithm to detect and track the target. In the experiment  high frame rate and high-resolution digital CCD camera and high performance DSP are applied. Experimental results show that this method can efficiently locate the sea-level line on various conditions of lower contrast  and eliminate the negative impact of the clutter caused by waves and clouds  and capture and track target real-timely and accurately.  
Monte-Carlo analysis of centroid detected accuracy for wavefront sensor 期刊论文  OAI收割
OPTICS AND LASER TECHNOLOGY, 2005, 卷号: 37, 期号: 7, 页码: 541-546
作者:  Jiang, ZL;  Gong, SS;  Dai, Y
收藏  |  浏览/下载：25/0  |  提交时间：2015/07/17