New Additive Watermark Detectors Based On A Hierarchical Spatially Adaptive Image Model

In this paper, we propose a new family of watermark detectors for additive watermarks in digital images. These detectors are based on a recently proposed hierarchical, two-level image model, which was found to be beneficial for image recovery problems. The top level of this model is defined to exploit the spatially varying local statistics of the image, while the bottom level is used to characterize the image variations along two principal directions. Based on this model, we derive a class of detectors for the additive watermark detection problem, which include a generalized likelihood ratio, Bayesian, and Rao test detectors. We also propose methods to estimate the necessary parameters for these detectors. Our numerical experiments demonstrate that these new detectors can lead to superior performance to several state-of-the-art detectors.     

柳钢混铁炉炉衬结构及运行管理的技改实践

针对混铁炉使用过程中出现的各种侵蚀状况，设计采用砖砌十浇注复合炉衬结构，特别对前墙拐角和后墙中段等侵蚀快的关键部位作了有针对性的技术改进；在运行管理上，制定推行全新的工艺操作规程，取得了显著的使用效果。     

日产1000t水泥熟料生产线的提产措施

通过对五级旋风筒下料管、回转窑转速、配料方案、物料稳定等四方面进行改进,达到提产目的。     

小生境遗传算法AVOA反演

采用具有水平对称轴的横向各向同性(HTI)模型研究裂缝性油气藏,P波振幅随炮检距和方位角变化(AVOA),表现出较强的方位各向异性特征。本文基于Ruger提出的HTI介质模型的P波反射系数公式,利用由基准测线和另外两条与之呈45°、90°测线的P波反射系数的相对差异估算裂缝方位;同时引入小生境遗传算法,对基准测线和与之呈90°测线的P波反射系数差进行反演,得到了较高精度的纵、横波波速比和Thomsen各向异性参数。     

城市堤防工程设计的体会与思考

在堤防建设中,城市堤防的新建和加固占有相当比例。建设城市堤防工程,不能与城市总体建设截然分开。山丘区城市的堤防设计中存在堤防建设与城市建设之间的矛盾,设计中应根据各堤防的实际情况,采用合理的设计方案,并结合采用适宜的景观设计,较好地解决这些矛盾。     

Verifiable Distributed Oblivious Transfer and Mobile Agent Security

The mobile agent is a fundamental building block of the mobile computing paradigm. In mobile agent security, oblivious transfer (OT) from a trusted party can be used to protect the agent’s privacy and the hosts’ privacy. In this paper, we introduce a new cryptographic primitive called Verifiable Distributed Oblivious Transfer (VDOT), which allows us to replace a single trusted party with a group of threshold trusted servers. The design of VDOT uses a novel technique called consistency verification of encrypted secret shares. VDOT protects the privacy of both the sender and the receiver against malicious attacks of the servers. We also show the design of a system to apply VDOT to protect the privacy of mobile agents. Our design partitions an agent into the general portion and the security-sensitive portion. We also implement the key components of our system. As far as we know, this is the first effort to implement a system that protects the privacy of mobile agents. Our preliminary evaluation shows that protecting mobile agents not only is possible, but also can be implemented efficiently. This work was supported in part by the DoD University Research Initiative (URI) program administered by the Office of Naval Research under grant N00014-01-1-0795. Sheng Zhong was supported by ONR grant N00014-01-1-0795 and NSF grants ANI-0207399 and CCR-TC-0208972. Yang Richard Yang was supported in part by NSF grant ANI-0207399. A preliminary version of this paper was presented at the DialM-POMC Joint Workshop on Foundations of Mobile Computing in 2003. Sheng Zhong received his Ph.D. in computer science from Yale University in the year of 2004. He holds an assistant professor position at SUNY Buffalo and is currently on leave for postdoctoral research at the Center for Discrete Mathematics and Theoretical Computer Science (DIMACS). His research interests, on the practical side, are security and incentives in data mining, databases, and wireless networks. On the theoretical side, he is interested in cryptography and game theory. Yang Richard Yang is an Assistant Professor of Computer Science at Yale University. His research interests include computer networks, mobile computing, wireless networking, sensor networks, and network security. He leads the LAboratory of Networked Systems (LANS) at Yale. His recent awards include a Schlumberger Fellowship and a CAREER Award from the National Science Foundation. He received his B.E. degree from Tsinghua University (1993), and his M.S. and Ph.D. degrees from the University of Texas at Austin (1998 and 2001).     

建筑意--中国雕版印刷博物馆及扬州博物馆设计

本文以中国雕版印刷博物馆及扬州博物馆设计为例，从空间意象、理水设计、造形元素等方面对特定历史条件、自然条件下的建筑创作进行了探讨。     

重庆嘉华大坪隧道变断面衬砌台车设计

本文介绍变断面衬砌台车设计,用以解决重庆嘉华大坪隧道变断面大跨度衬砌施工。     

基于MapInfo的西气东输管线地理信息系统的研究

讨论了西气东输管线空间数据库的建立过程，并以该空间数据库为后台利用MapInfo公司的GIS组件MapX进行二次开发，实现了全数字化的输气管道信息的存储与查询，使输气管线信息化管理更加现代化。