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一种基于最小四叉树划分的矢量数据水印算法 被引量:3
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作者 王云飞 赵婧 +1 位作者 崔伟宏 吕水 《计算机工程》 CAS CSCD 2012年第22期111-113,118,共4页
数字水印在实际应用时可能受到数据裁剪、数据压缩、随机增点和地物加密等攻击。针对该问题,基于特征点图层和最小四叉树划分,提出一种适用于线数据和面数据的矢量图层水印算法。利用Douglas-Peucker压缩算法提取矢量数据的特征点图层,... 数字水印在实际应用时可能受到数据裁剪、数据压缩、随机增点和地物加密等攻击。针对该问题,基于特征点图层和最小四叉树划分,提出一种适用于线数据和面数据的矢量图层水印算法。利用Douglas-Peucker压缩算法提取矢量数据的特征点图层,通过最小四叉树划分将水印信息分区域嵌入到地物的特征点中。实验结果表明,该算法具有很好的不可感知性,相比MQUAD算法能更好地抵抗地图裁剪攻击。 展开更多
关键词 特征点图层 最小四叉树 数字水印算法 矢量数据 Douglas—Peucker压缩算法
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Research on Characteristics of Focal Rupture of the Zhangbei-Shangyi Earthquake by Means of Deformation Field Obtained by Spaceborne D-INSAR 被引量:3
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作者 ShanXinjian MaJin +3 位作者 SongXiaoyu WangChao LiuJiahang ZhangGuifang 《Earthquake Research in China》 2003年第2期113-121,共9页
In the last ten years, the D_InSAR (Differential Interferometric Synthetic Aperture Radar) technique has proved very useful; it has been a new space observation technique with great potential. Investigating seismic fo... In the last ten years, the D_InSAR (Differential Interferometric Synthetic Aperture Radar) technique has proved very useful; it has been a new space observation technique with great potential. Investigating seismic focus rupture information using D_InSAR is a scientific issue to which more attention is being paid. In this paper, the basic theory of seismic focus dislocation models is discussed briefly. Based on a map of the interferometric deformation field of the Zhangbei_Shangyi earthquake from Jan.10, 1998, and applying the seismic focus dislocation model within elastic half_space medium; some geometrical and kinematical characteristics of the main seismic fault are deduced. Results were as follows: the seismic break surface of the Zhangbei_Shangyi earthquake is left_slip and thrust fault, striking in SEE_NWW 272°with dip angle 46°; rupture direction is unilateral faulting from SEE to NWW; length of rupture zone is 9km, width is 8km, and depth is 8km, the displacement vector of three directions are 290mm, 560mm and 0mm. 展开更多
关键词 D-INSAR INTERFEROGRAM Focal dislocation Focal characteristics Zhangbei-Shangyi earthquake
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