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浏览/检索结果: 共8条,第1-8条 帮助

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Design a Suitable Test Scheme for Triggering Bypass Protection Test of ITER PF Converter Unit 期刊论文  OAI收割
IEEE TRANSACTIONS ON PLASMA SCIENCE, 2018, 卷号: 46, 期号: 5, 页码: 1318-1322
作者:  
Zhang, Xiuqing;  Gao, Ge;  Fu, Peng;  Song, Zhiquan;  Wang, Bo
  |  收藏  |  浏览/下载:20/0  |  提交时间:2019/06/10
Image coding using wavelet-based compressive sampling (EI CONFERENCE) 会议论文  OAI收割
2012 5th International Symposium on Computational Intelligence and Design, ISCID 2012, October 28, 2012 - October 29, 2012, Hangzhou, China
作者:  
Li J.;  Li J.;  Li J.
收藏  |  浏览/下载:46/0  |  提交时间:2013/03/25
In this paper  we proposed a novel coding scheme is proposed using wavelet-based CS framework for nature image. First  two-dimension discrete wavelet transform (DWT) is applied to a nature image for sparse representation. After multi-scale DWT  the low-frequency sub-band and high-frequency sub-bands are re-sampled separately. According to the statistical dependences among DWT coefficients  we allocate different measurements to low- and high-frequency component. Then  the measurements samples can be quantized. The quantize samples are entropy coded and forward correct coding (FEC). Finally  the compressed streams are transmitted. At the decoder  one can simply reconstruct the image via l1 minimization. Experimental results show that the proposed wavelet-based CS scheme achieves better compression performance against the relevant existing solutions.  
Research on satellite platform vibration compensation technology for space optical communication (EI CONFERENCE) 会议论文  OAI收割
2012 International Meeting on Opto-Electronics Engineering and Materials Research, OEMR 2012, July 27, 2012 - July 29, 2012, Shenyang, Liaoning, China
Han C.; Li X.
收藏  |  浏览/下载:23/0  |  提交时间:2013/03/25
The piezo-electric steering control system is used to compensate the vibration of satellite platform. The mathematical model of piezo-electric steering system is built. The adaptive controller based on improved LMS filter algorithm is designed according to this system characteristic. The adaptive delay filter is designed to solve slow convergence speed problem of traditional algorithm. Meanwhile  the adaptive delay filter can also compensate phase delay of control circuit. The adaptive deviation filter is introduced and it effectively compensates the vibration deviation which is low frequency and high amplitude. The experimental results show that the remained errors are rad  which meets space optical communication requirement and proves that this control scheme is valid and feasible. (2012) Trans Tech Publications  Switzerland.  
Theoretical study and experimental scheme for the generation of a 1064-nm continuous variable entangled light source with quasi-phase-matching PPKTP crystal 期刊论文  OAI收割
nuclear instruments & methods in physics research section a-accelerators spectrometers detectors and associated equipment, 2011, 卷号: 637, 页码: s153-s157
作者:  
Liu, W. Y.;  Bi, S. W.
收藏  |  浏览/下载:229/44  |  提交时间:2011/07/08
The application of the discrete sliding mode control based on state observer in aerial camera (EI CONFERENCE) 会议论文  OAI收割
2nd Annual Conference on Electrical and Control Engineering, ICECE 2011, September 16, 2011 - September 18, 2011, Yichang, China
作者:  
Zhang X.;  Zhang X.;  Zhang X.
收藏  |  浏览/下载:22/0  |  提交时间:2013/03/25
Fast color-transfer-based image fusion method for merging infrared and visible images (EI CONFERENCE) 会议论文  OAI收割
Multisensor, Multisource Information Fusion: Architectures, Algorithms, and Applications 2010, April 7, 2010 - April 8, 2010, Orlando, FL, United states
作者:  
Xu S.
收藏  |  浏览/下载:29/0  |  提交时间:2013/03/25
We present a computationally efficient color image fusion algorithm for merging infrared and visible images. At the core of the proposed method is the color transfer technique based on the linear YCBCR space. The method directly uses the grayscale fused image and the difference signals of the input images to construct the source YCBCR components  then uses the statistical color transfer technique to form a color fused image that takes the target image's color characteristics. Two different strategies  which respectively employ the pixel averaging fusion scheme and the multiresolution fusion scheme as the grayscale image fusion solution  are proposed to fulfill different user needs. The simple strategy using the pixel averaging fusion scheme answers to a need of easy implementation and speed of use. And the complex strategy using the multiresolution fusion scheme answers to the high quality need of the fused products. In addition  we also describe some useful theories about color-transfer-based image fusion. Experimental results show that the proposed color image fusion algorithm can effectively produce a natural appearing "daytime-like" color fused image  and even using the pixel averaging fusion scheme to implement the grayscale fusion can also provide a pleasing result. 2010 Copyright SPIE - The International Society for Optical Engineering.  
Lossless wavelet compression on medical image (EI CONFERENCE) 会议论文  OAI收割
4th International Conference on Photonics and Imaging in Biology and Medicine, September 3, 2005 - September 6, 2005, Tianjin, China
作者:  
Liu H.;  Liu H.;  Liu H.
收藏  |  浏览/下载:51/0  |  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.  
Image compression based on biorthogonal wavelet transform (EI CONFERENCE) 会议论文  OAI收割
ISCIT 2005 - International Symposium on Communications and Information Technologies 2005, October 12, 2005 - October 14, 2005, Beijing, China
作者:  
Gao Y.;  Liu H.;  Liu H.;  Liu H.
收藏  |  浏览/下载:35/0  |  提交时间:2013/03/25
A method for image compression of biorthogonal wavelet transform based on lifting scheme with SPIHT (Set Partitioning In Hierachical Trees) is proposed in this paper. Wavelet transform affords wide space for image coding algorithms because of its excellent space-frequency localization characterizations. The compact supported  symmetrical and biorthogonal wavelet has linear phase  so it is applied on image compression area widely. The lifting scheme is an efficient method for constructing the wavelet filter after multiresolution. Under the condition of biorthogonal  biorthogonal wavelet base can be constructed freely according to the wavelet performance. And it can quicken the implementation speed of the wavelet transform. Analyzing the algorithm of lifting scheme is applying for constructing biorthogonal wavelet. Experimental results indicate that the method of the biorthogonal wavelet that has good performances with SPIHT is applying for image compression  so as image synthesis performs well. 2005 IEEE.