基于嵌入模版的抗几何攻击的数字水印改进算法

提出一种改进的基于嵌入模板的抗几何攻击的数字水印算法。算法中的嵌入模板既可以标识变换的参数,也可以标识移动的坐标,以便于评估几何失真程度和提高水印恢复的效率。本算法在水印的鲁棒性和不可察觉性之间寻找一个平衡点,并在水印检测时实现盲检测。实验结果表明,该算法可以从全局和局部或非线性几何攻击中恢复失真,是实用和有效的。

三维GIS数据融合的基本方法与进展

三维数据融合是计算机视觉与精细化测绘领域的研究热点,在精细测量、风险监测、数据展示等过程中起着重要的作用。目前,测绘领域对三维数据融合的研究集中在地形地物的三维模型融合。本文主要总结了近年来地形地物三维数据融合的基本方法,对三维模型的数据结构、建立方法做了分类,并对几种应用最为广泛的融合方法进行了分析和评述。讨论了相关研究中存在的问题和发展前景,希望能为今后的研究提供帮助。

Matrix-Geometric Method Based Unified Delay Analysis for Wireless Relay Networks

A lot of work has been focused on desig-ning and analyzing various cooperative diversity pro-tocols for wireless relay networks. To provide a uni-fied queuing analytic framework, we fonmlate an em-bedded Markov chain, which rams out to be a Quasi-Birth-and-Death （QBD） process. Using the Matrix-Ce-ometric method, we can analyze the average delay in a unified way. Theoretical analysis is validated by simu-lation results. We show that the delay performances of Amplify-and-Forward or Decode-and-Forwaxd （AF/ DF） and incremental AF/DF schemes can be analyzed in the unified way. Thus, we can always choose the best cooperative diversity scheme in different scenari-os for delay minimization.

A multiple watermarks algorithm for image content authentication

A novel multiple watermarks cooperative authentication algorithm was presented for image contents authentication.This algorithm is able to extract multiple features from the image wavelet domain,which is based on that the t watermarks are generated.Moreover,a new watermark embedding method,using the space geometric model,was proposed,in order to effectively tackle with the mutual influences problem among t watermarks.Specifically,the incidental tampering location,the classification of intentional content tampering and the incidental modification can be achieved via mutual cooperation of the t watermarks.Both the theoretical analysis and simulations results validate the feasibility and efficacy of the proposed algorithm.

DARBOUX EQUATIONS AND ISOMETRIC EMBEDDING OF RIEMANNIAN MANIFOLDS WITH NONNEGATIVE CURVATURE IN R

The present paper is concerned with the existence of golbal smooth solutions for the homogeneous Dirichlet boundary value problem of the Darboux equation and the case degenerate onthe boundary is contained As some applications the smooth isometric embeddings of positivelyand nonnegatively curved disks into R^3 are constructed.

Property A and Uniform Embeddability of Metric Spaces Under Decompositions of Finite Depth

Property A and uniform embeddability are notions of metric geometry which imply the coarse Baum-Connes conjecture and the Novikov conjecture.In this paper,the authors prove the permanence properties of property A and uniform embeddability of metric spaces under large scale decompositions of finite depth.