Quantitation Method to the Imperceptibility of ：-Iiding-Vector in Multi-dimensional Hiding Space

Currently, few general methods have been suggested to quantitate the imperceptibility among var- ious hiding algorithms. Especially, it is a challenge to quantitate the imperceptibility of the hiding-vector, which is consisted of orthogonal hiding algorithms in the multi- dimensional hiding space. In this paper, a novel model of general imperceptibility quantitation was proposed. Ac- cording to this model, a quantitation method based on the relative entropy was designed. It is proved under this quantitation method that there exists the global maximal imperceptibility for any specified hiding-vector capacity. An optimization algorithm was proposed to approach this maximum by adjusting the allocation of secret message into each components of the hiding-vector. Experiments with VoIP and bitmap multi-dimensional hiding space validated the effectiveness of the designed quantitation method and the proposed optimization algorithm.     

Characteristics and favorable area prediction of Ordovician buried-hill carbonate reservoirs in the Bozhong 21–2 tectonic belt,Bohai Bay Basin,China

Based on core data, thin section and logging, this study investigates the basic characteristics and occurrence regularities of the Ordovician buried-hill carbonate reservoir in the Bozhong 21-2 tectonic belt. Results show that the reservoir lithology is primarily limestone, followed by dolomite, dolomitic limestone or limey dolomite, and silty mudstone. The reservoir spaces are primarily composed of secondary porosity. These reservoirs can be divided vertically into weathered-crust karst reservoirs and inner dissolution-type reservoirs. The distribution of reservoirs is controlled chiefly by karstification. The high karst units in the study area are favorable for the development of the two reservoir types.     

C50引导功能的使用

Ｃ５０内部具有９Ｋ单指令周期访问的片内ＲＡＭ，在应用程序不太大的情况下，将程序在运行前由存取速度较慢的片外的ＥＰＲＯＭ读入片内ＲＡＭ，再在零等待状态下运行不失为一种方便快速的方法。本文就此进行了说明。     

北京平原地热资源与地热供暖

本文对北京平原地区地热资源条件和供暖现状进行了概述,分析了地热供暖技术的特点、优势以及当前制约其推广发展的“瓶颈”,针对北京平原地热资源的可持续发展提出了两点具体建议。     

DSP在交流异步电动机变频调速中的应用

以三相交流异步电动机为控制对象,以TMS320LF2407A处理器为控制部件,通过SVPWM控制方法对交流电机实现恒压频比控制。试验表明,该系统控制性能和精度良好。     

基于混沌理论的煤矿监控网络流量时间序列的预测

针对目前煤矿监控网络的流量增大趋势,为了改进和提高网络的QoS质量,提出了基于混沌时间序列预测网络流量的方法.从相空间重构,用互信息量法和虚假临近点法确定了延迟时间和嵌入维数,用小数据量法求解了最大Lyapunov指数,由此证明了网络流量时间序列的混沌特性,并且建立相应模型,成功地对其做出了预测.仿真结果表明,该方法具有较高的准确度.     

D≠0时状态观测器的设计及系统分析

针对计算机控制系统中状态空间表达式中d≠0的情况,探讨了d≠0存在的条件和其状态观测器的设计,给出了相应的控制器的计算机实现．并进行了相应的系统分析,对计算机控制系统或离散系统的分析和设计有一定的实际意义。     

一种新的自主导航技术-单相机视觉系统

文中提出了一种新的漫游车自主导航技术，将扫描激光器和摄像机相结合，以代替计算机视觉中配准的作用。这种方法可以大幅度节约探测时间，快速识别视场内的地形，从而可以显著提高深空探测中自主导航的速度。     

针对多方参与特征的地理空间信息网格结构设计

地理空间信息网格结构层次设计既考虑了多方参与特征，又参考了目前较为流行的五层沙漏结构和开放网格服务结构，还参考了我国学者从开发的角度提出的一般网格层次结构，以此为基础试设计并探讨地理空间信息网格的基本层次结构。     

大型空间遥感器动力学试验

大型空间遥感器结构复杂、重量大,在研制过程中,给地面动力学环境试验工装的设计带来很大的困难.振动工装是振动试验的传力部件,将振动台与遥感器连接起来,其性能直接影响到振动试验的真实程度和可靠程度.本文论述了遥感器振动工装研制及动力学试验过程.正弦振动和随机振动结果表明,振动台的振动输入条件与工装对遥感器的输入条件基本一致...