基于中国剩余定理的动态水印方案

针对动态图水印性能指标之间的制约关系,提出了从分解水印图变为分解水印数据以提高隐藏信息量的设计思想,分析了称为抽象水印的方案,并结合动态图水印的明显优势,给出了一种基于中国剩余定理的动态水印方案。通过分析提高了动态水印性能的策略,指出软件水印技术的进一步发展方向。     

基于循环冗余校验的动态图软件水印方案*

针对动态图编码时间复杂度较高的问题,提出一种四进制编码方案,利用空间换时间的思想,通过增加两个专门用来编码系数的指针域,在空间复杂度不变的情况下,降低构造水印图的时间复杂度。同时借鉴计算机网络和数据通信的差错检验原理,提出一种基于循环冗余校验的动态图软件水印防窜改技术,实现了水印图的动态验证。实验表明,该方案提高了水印数据率,增强了水印抗攻击性,并使之具有一定的纠错能力。     

基于m-n变进制规则的动态图软件水印算法?

针对软件水印分存算法恢复缓慢、数据扩张的缺点,提出一种基于m-n变进制规则的动态图软件水印算法,利用水印信息、m-n变进制数、排列数与置换图之间的对应关系,实现水印的分存和编码。当水印嵌入时,根据变进制规则将水印信息分存为一组变进制数,构造一个完美哈希函数将变进制数映射为对应的排列数,把得到的排列数编码为置换图结构嵌入到程序的执行代码中,水印提取是水印嵌入的逆过程。实验结果表明,该算法能减小程序的负载,降低水印嵌入和提取的时间复杂度,增强水印的隐蔽性和纠错能力。     

基于变量防篡改的动态图软件水印方案

为了提高动态图软件水印的隐藏容量和鲁棒性,本文提出了一种基于变量防篡改的动态图软件水印方案。该方案利用不同进制形式的数可以相互转化的思想将大的水印信息分割成多个小的水印信息,然后将这些小的水印信息编码成一组图结构,动态地嵌入目标程序中。在编码水印信息时,利用动态图结构中结点的父指针来编码,并使其叶结点与目标程序变量关联,起到防篡改的作用,从而可对水印进行有效的保护。实验结果表明,嵌入水印信息后,目标程序的运行速度和结果都没有明显的变化,但水印对溢出攻击、扭曲攻击和附加攻击等都有明显的抵抗效果,水印也能够准确、方便地被提取出来。该方案的性能明显优于PPCT算法和常量防篡改水印算法。     

基于多常量编码的动态图软件水印保护技术

动态图软件水印在抗攻击性方面较通常的静态水印有明显的优势,然而由于这类水印信息本身与宿主程序的功能性之间并无关联,所以攻击者可以找到水印结构并对其进行恶意破坏,从而使水印提取过程失败.为此,提出了一种通过建立多常量与水印的依赖关系来对动态图水印进行保护的方法,并设计了针对Radix、PPCT、IPPCT结构动态图水印的保护算法.该算法通过创建动态图水印与宿主程序中多常量的依赖关系,对水印起到了防篡改的保护作用,从而可对该类水印进行有效的保护.最后通过数据率、鲁棒性两个方面对此算法进行了评测.结论是:基于IPPCT结构的算法不但过载较小,而且具有较高的数据率,还可以防止共谋攻击,是一种相对较好的水印保护算法.     

窜改认证与内容恢复分离的自嵌入脆弱水印算法

为了提高可恢复水印的认证精度和恢复质量,降低虚警率,提出了一种窜改认证与内容恢复分离的自嵌入水印算法。该算法以2×2的图像块为认证单位,将认证水印与恢复水印分别嵌入到自身图像块和偏移图像块中,使认证虚警率降为0;同时提出一种基于线性函数和混沌映射的偏移值选取方案,使图像的恢复质量得到提高。理论分析和实验结果表明,该算法能在抵抗拼贴和量化攻击的同时,准确定位图像窜改并以较高的质量进行恢复。     

基于Asmuth-Bloom门限方案的动态图软件水印保护技术

动态图软件水印在抗攻击性方面较通常的静态水印有明显的优势,然而通过透彻的分析和修改嵌入水印后的程序,攻击者仍然可以找到水印结构并对其进行恶意破坏,从而使水印提取过程失败.为此,本文提出一种基于Asmuth-Bloom门限方案的软件水印分存算法,该算法将密码学中的密钥共享思想引入到软件水印中,实现了基于部分内容提取水印;最后通过鲁棒性对此算法进行了评测.该算法具有较强的鲁棒性,但该算法的不足之处是将水印数据扩张,减小了数据率和隐蔽性.     

基于门限方案的动态图软件水印算法

针对动态图水印鲁棒性和恢复率较低的问题,提出基于门限方案的动态图水印算法——AB算法。在软件水印中引入密钥共享思想,实验结果证明,该算法能有效弥补CT算法的缺陷,阻止攻击者通过透彻分析运行时的堆栈获取原始水印。     

改进的动态图水印技术编码方案*

针对动态图水印性能评测指标之间相互制约的关系,寻找指标之间的平衡点,满足理想水印图的特征条件,结合现有的动态图水印技术编码方案,改进了一种编码方案。该改进方案利用二维PPCT编码纠错能力强、抗攻击性能好的特点以及K基数链表编码率高的优点,引入混合编码的思想,添加指针域,构造多个水印图,对真实水印起到混淆的作用。理论分析和实验结果表明,该改进方案提高了数据率、抗攻击能力和鲁棒性,是一种不错的水印编码方案。     

基于迷乱变换的动态路径水印实现方案

结合软件水印技术的最新研究成果,提出了一种基于迷乱变换的动态路径水印实现方案。该方案充分利用动态图别名分析难的特点为不透明分支的构造创造条件,通过构造低开销、高隐蔽性和高鲁棒性的不透明分支对程序实施控制流迷乱变换,并将水印数据嵌入迷乱变换后程序的特定执行轨迹中。分析了该方案在隐藏信息量、隐蔽性和鲁棒性等方面的性能。     

Only connect: teaching, technology and telesis

Abstract This paper describes an approach to the design of interactive multimedia materials being developed in a European Community project. The developmental process is seen as a dialogue between technologists and teachers. This dialogue is often problematic because of the differences in training, experience and culture between them. Conditions needed for fruitful dialogue are described and the generic model for learning design used in the project is explained.     

European Community policy and the market

Abstract This paper starts with some reflections on the policy considerations and priorities which are shaping European Commission (EC) research programmes. Then it attempts to position the current projects which seek to capitalise on information and communications technologies for learning in relation to these priorities and the apparent realities of the marketplace. It concludes that while there are grounds to be optimistic about the contribution EC programmes can make to the efficiency and standard of education and training, they are still too technology driven.     

一种自适应子融合集成多分类器方法

融合集成方法已经广泛应用在模式识别领域,然而一些基分类器实时性能稳定性较差,导致多分类器融合性能差,针对上述问题本文提出了一种新的基于多分类器的子融合集成分类器系统。该方法考虑在度量层融合层次之上通过对各类基多分类器进行动态选择,票数最多的类别作为融合系统中对特征向量识别的类别,构成一种新的自适应子融合集成分类器方法。实验表明,该方法比传统的分类器以及分类融合方法识别准确率明显更高,具有更好的鲁棒性。     

Avoiding semantic and temporal gaps in developing software intensive systems

Development of software intensive systems (systems) in practice involves a series of self-contained phases for the lifecycle of a system. Semantic and temporal gaps, which occur among phases and among developer disciplines within and across phases, hinder the ongoing development of a system because of the interdependencies among phases and among disciplines. Such gaps are magnified among systems that are developed at different times by different development teams, which may limit reuse of artifacts of systems development and interoperability among the systems. This article discusses such gaps and a systems development process for avoiding them.     

Designing economic np control charts: A programmed simulation approach

This paper presents control charts models and the necessary simulation software for the location of economic values of the control parameters. The simulation program is written in FORTRAN, requires only 10K of main storage, and can run on most mini and micro computers. Two models are presented - one describes the process when it is operating at full capacity and the other when the process is operating under capacity. The models allow the product quality to deteriorate to a further level before an existing out-of-control state is detected, and they can also be used in situations where no prior knowledge exists of the out-of-control causes and the resulting proportion defectives.     

The development of robot art

Going through a few examples of robot artists who are recognized worldwide, we try to analyze the deepest meaning of what is called “robot art” and the related art field definition. We also try to highlight its well-marked borders, such as kinetic sculptures, kinetic art, cyber art, and cyberpunk. A brief excursion into the importance of the context, the message, and its semiotics is also provided, case by case, together with a few hints on the history of this discipline in the light of an artistic perspective. Therefore, the aim of this article is to try to summarize the main characteristics that might classify robot art as a unique and innovative discipline, and to track down some of the principles by which a robotic artifact can or cannot be considered an art piece in terms of social, cultural, and strictly artistic interest. This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January 31–February 2, 2008     

Explanation and prediction: an architecture for default and abductive reasoning

Although there are many arguments that logic is an appropriate tool for artificial intelligence, there has been a perceived problem with the monotonicity of classical logic. This paper elaborates on the idea that reasoning should be viewed as theory formation where logic tells us the consequences of our assumptions. The two activities of predicting what is expected to be true and explaining observations are considered in a simple theory formation framework. Properties of each activity are discussed, along with a number of proposals as to what should be predicted or accepted as reasonable explanations. An architecture is proposed to combine explanation and prediction into one coherent framework. Algorithms used to implement the system as well as examples from a running implementation are given.     

Three Process Perspectives: Organizations, Teams, and People

This paper provides the author's personal views and perspectives on software process improvement. Starting with his first work on technology assessment in IBM over 20 years ago, Watts Humphrey describes the process improvement work he has been directly involved in. This includes the development of the early process assessment methods, the original design of the CMM, and the introduction of the Personal Software Process (PSP)^SM and Team Software Process (TSP){^SM}. In addition to describing the original motivation for this work, the author also reviews many of the problems he and his associates encountered and why they solved them the way they did. He also comments on the outstanding issues and likely directions for future work. Finally, this work has built on the experiences and contributions of many people. Mr. Humphrey only describes work that he was personally involved in and he names many of the key contributors. However, so many people have been involved in this work that a full list of the important participants would be impractical.     

基于复小波噪声方差显著修正的SAR图像去噪

提出了一种基于复小波域统计建模与噪声方差估计显著性修正相结合的合成孔径雷达(Synthetic Aperture Radar,SAR)图像斑点噪声滤波方法。该方法首先通过对数变换将乘性噪声模型转化为加性噪声模型,然后对变换后的图像进行双树复小波变换(Dualtree Complex Wavelet Transform,DCWT),并对复数小波系数的统计分布进行建模。在此先验分布的基础上,通过运用贝叶斯估计方法从含噪系数中恢复原始系数,达到滤除噪声的目的。实验结果表明该方法在去除噪声的同时保留了图像的细节信息,取得了很好的降噪效果。     

基于QTE的蒙古文显示机制研究与实现

蒙古语言是中国蒙古族使用的通用语言,由于蒙古文区别于其他文字的书写方式和其自身变形机制等特点,在很多通用的文字处理引擎中都不被支持。在嵌入式产品开发与应用领域中Linux加QTE已经成为流行方式。该文给出了一种在QTE环境上实现基于标准Unicode的蒙古文点阵显示和变形算法, 并自定义了支持蒙古文的QTE组件,扩展了QTE功能,为在Linux加QTE方式的嵌入式体系结构中处理蒙古文提供了一种解决方法。