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浏览/检索结果: 共5条，第1-5条 帮助 已选(0)清除 条数/页：5101520253035404550556065707580859095100   排序方式：请选择发表日期升序发表日期降序作者升序作者降序提交时间升序提交时间降序题名升序题名降序 A new criterion for defining the breakpoint of the wetted perimeter-discharge curve and its application to estimating minimum instream flow requirements SCI/SSCI论文 2012 Men B. H.; Liu C. M.; Lin C. K. 收藏  |  浏览/下载：22/0  |  提交时间：2014/12/24 wetted perimeter method  slope  curvature  the West Course of the First  Stage Project of South-North Water Transfer Project (WCFSPSNWTP)  Tennant method  ecological water requirement   The research of the accurate measure of static transfer function for the TDI CCD camera (EI CONFERENCE) 会议论文 3rd International Photonics and OptoElectronics Meetings, POEM 2010, November 2, 2010 - November 5, 2010, Wuhan, China Guo-Ning L.; Long-Xu J.; Jian-Yue R.; Wen-Hua W.; Shuang-Li H. 收藏  |  浏览/下载：18/0  |  提交时间：2013/03/25 In the test course of static transfer function of TDI CCD camera  because of the influence that gets environmental and artificial etc. factor  the value of static transfer function measured at any time is between unceasing fluctuation  so  make accuracy reduce. To solve this problem  a kind of accurate measurement technique of static transfer function is put forward. First  before carrying out the measure of static quiet of transfer function  the best test point of transfer function of the TDI CCD camera must be determined  it is parallel to guarantee the rectangle target surface of parallel optical pipe and camera focal plane maintenance parallel  and again guarantee target strip in rectangle target and TDI CCD in camera focal plane maintenance vertical. TDI CCD catches rectangle target image  per 1000 lines of target mark image as a measures sample of static transfer function  exclude because of atmosphere tremble twisted  vague rectangle target mark image  retain 500 distinct and steady target mark image as measure sample set. Then  calculate the static transfer function of each measure sample respectively  take the average of all static quiet transfer function in measure sample set as the static transfer function of camera. Finally  the measure of the static transfer function for TDI CCD camera makes error analysis. Experimental results indicate that the value of the static transfer function of TDI CCD camera measured with this kind of method is 0.2923  with before measurement technique comparison  the value of static transfer function has raised 0.02  makes the accuracy of the measure of static transfer function have gotten raising.   重新审视和设计中国高校会计第一门课 期刊论文 2010, 2010 赵晓东; 王竞达; ZHAO Xiao-dong; WANG Jing-da 收藏  |  浏览/下载：2/0 Lossless wavelet compression on medical image (EI CONFERENCE) 会议论文 4th International Conference on Photonics and Imaging in Biology and Medicine, September 3, 2005 - September 6, 2005, Tianjin, China Zhao X.; Wei J.; Zhai L.; Liu H. 收藏  |  浏览/下载：29/0  |  提交时间：2013/03/25 An increasing number of medical imagery is created directly in digital form. Such as Clinical image Archiving and Communication Systems (PACS). as well as telemedicine networks require the storage and transmission of this huge amount of medical image data. Efficient compression of these data is crucial. Several lossless and lossy techniques for the compression of the data have been proposed. Lossless techniques allow exact reconstruction of the original imagery while lossy techniques aim to achieve high compression ratios by allowing some acceptable degradation in the image. Lossless compression does not degrade the image  thus facilitating accurate diagnosis  of course at the expense of higher bit rates  i.e. lower compression ratios. Various methods both for lossy (irreversible) and lossless (reversible) image compression are proposed in the literature. The recent advances in the lossy compression techniques include different methods such as vector quantization  wavelet coding  neural networks  and fractal coding. Although these methods can achieve high compression ratios (of the order 50:1  or even more)  they do not allow reconstructing exactly the original version of the input data. Lossless compression techniques permit the perfect reconstruction of the original image  but the achievable compression ratios are only of the order 2:1  up to 4:1. In our paper  we use a kind of lifting scheme to generate truly loss-less non-linear integer-to-integer wavelet transforms. At the same time  we exploit the coding algorithm producing an embedded code has the property that the bits in the bit stream are generated in order of importance  so that all the low rate codes are included at the beginning of the bit stream. Typically  the encoding process stops when the target bit rate is met. Similarly  the decoder can interrupt the decoding process at any point in the bil stream  and still reconstruct the image. Therefore  a compression scheme generating an embedded code can start sending over the network the coarser version of the image first  and continues with the progressive transmission of the refinement details. Experimental results show that our method can get a perfect performance in compression ratio and reconstructive image.   Aerial image blurring caused by image motion and its restoration using wavelet transform (EI CONFERENCE) 会议论文 Electronic Imaging and Multimedia Technology IV, November 8, 2004 - November 11, 2004, Beijing, China Liu M.; Liu G.; Xiu J.; Kuang H.; Zhai L. 收藏  |  浏览/下载：24/0  |  提交时间：2013/03/25 A wavelet-based approach of aerial blurred image restoration is proposed in this article. Image motion is inevitable in photographing for aerospace camera. Though some Image Motion Compensation(IMC) schemes are applied in aerial imaging system  the ultimate image will be blurred in certain extent for the existence of IMC residual error  while the forward image motion is the key element among all image motions which lead to image blurring. First the course of blurring caused by forward image motion is expressed using wavelet transform  and a multiresolution sparse matrix representation of the degeneration model is obtained according to the wavelet transform. Subsequently a regularizing restoration algorithm is deduced from it  and which can smoothly restraint the processed result efficiently. In the end the proposed approach is tested in MATLAB. The blurred image is restored using above-mentioned wavelet algorithm  conventional contrary filter and Wiener filter algorithm separately. The conclusion that the wavelet-based restoration algorithm is superior to other two approaches is obtained by comparing the restored image's value of mean gradient. The calculating quantity of the wavelet-based blurred image restoration approach isn't large and it has good practicability in the field of image interpretation and aerial survey or drawing.