基于Sybase数据库批量数据加载的实现方法

随着当今数据库管理系统和操作系统平台的快速更新换代,数据库管理员经常需要在两个不同的数据库之间或在两种不同的系统平台之间进行批量数据加载。论文介绍了实现Sybase数据库之间批量数据加载的几种方法,并对它们的优缺点做了对比分析。     

基于小波和不变矩的图像copy-move篡改盲检测

针对数字图像取证中一类常见的复制粘贴图像伪造,本文提出了一种基于小波变换和不变矩提取的检测算法。该算法利用小波变换提取图像的低频分量,对低频分量分块进行不变矩特征提取,然后将特征矢量进行按行字典排序,并且配合图像块的偏移位置信息,进行图像复制伪造区域的检测和定位。实验表明该算法能够较精确地定位出复制和粘贴的图像伪造区域,并有效地减少了运算量,提高了检测效率。     

一种快速灾难恢复方法*

提出并实现了一种在异地容灾系统中的快速灾难恢复方法。通过快速数据恢复和数据更新两步完成数据恢复,其中快速数据恢复采用差异拷贝恢复技术实现;数据更新采用对基于磁盘块的增量备份进行写重放来实现。该方法的实现使得灾难恢复的速度快、网络负载小、系统服务的丢失少。     

基于分布式数据库的连锁超市物流管理系统

本文针对连锁超市地理位置分散的实际特点,设计和实现了连锁超市物流管理系统的分布式数据库结构,使不同区域的数据可以共享,同时提出了该系统的数据复制和数据库备份问题的解决方案。     

NASSN： a NAS-based storage network

With the digital information and application requirement on the Internet increasing fleetly nowadays,it is urgent to work out a network storage system with a large capacity,a high availability and scalability.To solve the above-mentioned issues,a NAS-based storage network(for short NASSN)has been designed.Firstly,the NASSN integrates multi-NAS,iNAS(an iSCSI-based NAS)and enterprise SAN with the help of storage virtualization,which can provide a greater capacity and better scalability.Secondly,the NASSN can provide high availability with the help of server and storage subsystem redundancy technologies.Thirdly,the NASSN simultaneously serves for both the file I/O and the block I/O with the help of an iSCSI module,which has the advantages of NAS and SAN.Finally,the NASSN can provide higher I/O speed by a high network-attached channel which implements the direct data transfer between the storage device and client.In the experiments,the NASSN has ultra-high-throughput for both of the file I/O requests and the block I/O requests.     

在Word文档中插入AutoCAD图形的应用技巧

通过对AutoCAD输出文件类型格式的分析,介绍了把AutoCAD中绘制的图形插入到WORD文档中的几种有效方法.     

Dominating direction based an efficient copy–move image tampering detection technique

Post-processing operations on a copy–move tampered image makes tampering detection a challenge. Most of the existing techniques are unable to address all the problems simultaneously. This paper presents a block-based technique, which addresses all these problems effectively. Here, at first, the approximate band coefficients are extracted using Contourlet Transform for further steps as it reduces the dimensionality as well as the effects of noise. Then Harris’ matrix is used to find the dominant direction of the block to counter the rotation. Finally, singular values of blocks are calculated using singular value decomposition, which works as a feature vector. The efficacy of the proposed algorithm has been verified through extensive simulations and comparisons with several other challenging copy–move image tampering detection techniques.     

计算机剪贴板特性及使用探讨

从计算机剪贴板的“剪制的一次性”和“大小可变性”,粘贴的整体性”和“多次性”,系统的“共享性”等特性入手,探讨了它的使用性能和使用方法。     

帧内微块复制的屏幕图像编码算法

针对现有的帧内块复制（IBC）算法不能很好地适应屏幕图像具有各种不同大小和形状样图的问题,为了进一步提高屏幕图像的编码效率,提出了一种帧内微块复制（IMBC）算法。该算法首先将当前编码单元（CU）划分成L个微块。然后以每个微块作为最小的匹配和复制单元,采用匹配微块组选择算法,在参考像素集合R中找到与当前微块最匹配的“参考微块”。用L个位移矢量（DV）来表示“参考微块”所在位置与当前CU所在位置的位移关系。最后,对L个位移矢量应用预测算法以消除位移矢量之间的相关性后进行熵编码。对于屏幕图像标准测试数据集合中的视频序列,IMBC算法与IBC算法相比,在编码复杂度增加较低的前提下,在全帧内（AI）、随机接入（RA）、低延迟（LB）三种编码配置中,有损BD-rate降低率分别达3.4%、2.9%、2.6%,无损Bit-rate降低率分别达9.5%、5.2%、5.1%,能有效提高屏幕图像的编码效率。     

基于ICA的抗拷贝攻击的数字水印方案

该文提出了一种基于独立分量分析(Independent Component Analysis,ICA)的能有效抵抗拷贝攻击的数字水印方案。该方案将能够唯一描述原始图像的图像签名与数字水印一同嵌入到原始图像中,并采用ICA技术进行检测。通过验证签名,可以判断待测图像是否合法,从而实现抗拷贝攻击的目的。计算机仿真结果证明了该方案的有效性和鲁棒性。