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浏览/检索结果: 共4条，第1-4条 帮助 已选(0)清除 条数/页：5101520253035404550556065707580859095100   排序方式：请选择作者升序作者降序题名升序题名降序发表日期升序发表日期降序提交时间升序提交时间降序 分位数单位根检验的有限样本绩效及其应用 期刊论文 2014 吴亮; 邓明 收藏  |  浏览/下载：5/0  |  提交时间：2016/05/17 分位数单位根检验  数据产生过程  商品价格指数  quantile unit root test  data generating process  corporate goods price index   A local feature based simplification method for animated mesh sequence (EI CONFERENCE) 会议论文 2010 2nd International Conference on Computer Engineering and Technology, ICCET 2010, April 16, 2010 - April 18, 2010, Chengdu, China Zhang S.; Zhao J.; Wang B. 收藏  |  浏览/下载：20/0  |  提交时间：2013/03/25 Although animated meshes are frequently used in numerous domains  only few works have been proposed until now for simplifying such data. In this paper  we propose a new method for generating progressive animated models based on local feature analysis and deformation area preservation. We propose the use of solid angle and height value for a non-hyperbolic vertex to define the local feature parameter. This local factor is embedded to the vertex quadric error matrix when calculating the edge collapse cost. In order to preserve the areas with large deformation  we add deformation degree weight to the aggregated quadric errors when computing the unified edge contraction sequence. Finally  a mesh optimization process is proposed to further reduce the geometric distortion for each frame. Our approach is fast  easy to implement  and as a result good quality dynamic approximations with well-preserved fine details can be generated at any given frame. 2010 IEEE.   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：28/0  |  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.   Analysis on local railroad freight transportation's unit Root,Process of structural changes 会议论文 2007 IEEE INTERNATIONAL CONFERENCE ON AUTOMATION AND LOGISTICS, VOLS 1-6, 1095, 2007 作者:  Chen, HL;  Ma, CQ;  Qin, T 收藏  |  浏览/下载：1/0  |  提交时间：2020/01/13 data-generating process  local railroad freight transportation  structural changes  unit root process