编码与同义词替换结合的可逆文本水印算法

从通信编码的角度,该文探讨一种利用编码方法和同义词替换相结合的可逆文本篡改检测水印算法。以可替换同义词为标志对文本进行分组,提取分组文本特征生成认证水印信息;利用霍夫曼编码和纠错编码对同义词库各词进行编码,利用同义词替换技术完成水印的嵌入。在接收端,利用分组文本特征和霍夫曼编码,实现水印文本的篡改定位,利用纠错码实现可替换同义词的还原恢复。仿真实验表明,算法嵌入的水印具有良好的不可见性和较强的鲁棒性,在实现对文本篡改定位的同时,较好地实现了可替换同义词无损还原。     

基于汉明码的文本可逆数字水印研究

提出了一种新颖的文本可逆数字水印算法。对载体文本进行预处理,将原始可替换同义词的编码值分组作为信息位进行汉明编码,将获得的监督码元比特流利用矩阵编码的方式通过插入空格嵌入到文本中。水印信息则分组利用同义词修改位置编码的方式选定同义词进行替换来实现嵌入。在提取时利用汉明码的译码原理与可替换同义词分组位置编码规则,提取出水印信息并对原始文本进行无损恢复,即实现了文本可逆数字水印。该算法不仅能有效恢复出原始文本,且具有良好的隐蔽性,增强了水印方案的实际应用能力。     

可逆文本水印算法研究

提出一种可逆文本水印算法.该算法对文本特征进行分析,以确定待嵌入文本句子集,根据文本句子的奇偶性,利用同义词替换评价模型将水印不可感知地嵌入到原始文本中,通过调整算法参数,满足不同的鲁棒性和不可见性需求.仿真实验结果表明,该算法具有较好的不可见性,并能在提取水印后无损地恢复原始文本载体数据.     

基于Hopfield神经网络的文本认证与同义词替换的可恢复水印算法

针对水印文本的篡改检测和恢复问题,利用Hopfield网络的联想记忆功能,提出一种Hopfield神经网络与同义词替换技术相结合的文本认证与同义词替换的可恢复水印算法.算法首先将文本分为可替换同义词和非替换词语,利用可替换同义词在其同义词库中的位置及汉字笔画和结构特征,分别提取文本可替换同义词的特征信息和非替换词语的特征信息.然后通过同义词替换实现水印嵌入,并将水印信息和非替换词语的特征信息输入Hopfield神经网络进行训练,实现篡改检测与可替换同义词的恢复功能.实验仿真表明,该算法具有较好的鲁棒性、篡改检测性和恢复能力,能篡改检测和定位可替换同义词、非替换词语,实现认证功能,且能恢复被替换的同义词,实现恢复功能.     

具有纠错编码特性的指令统计特征水印算法

提出一种具有纠错编码特性的水印算法,将纠错编码的概念与改变指令统计特征方式相结合,通过替换等价指令改变程序指令统计特征,利用特征与水印信息的映射关系嵌入水印信息,提取程序的指令统计特征即可提取水印.运用纠错编码,增强了水印的鲁棒性.通过理论分析和实验证明,新方案对程序性能的影响非常小,并能抵御增加、混淆、反编译等攻击.     

鲁棒可逆文本水印算法

针对法律或军事领域在使用文本文件时必须要求真实性的要求,提出一种鲁棒可逆文本水印算法.根据0/1水印序列和同义词替换评价模型,将水印有选择地嵌入到原始文本中.投票原则的使用提高了水印的鲁棒性并降低了误检率,拥有密钥和其他秘密参数的用户才可以完全恢复原始数据.理论分析和仿真结果表明,采用文中算法嵌入的水印具有较好的不可见性和较强的鲁棒性.     

基于纠错编码的矢量地图可逆水印算法*

针对当前矢量地图可逆水印算法中缺乏水印提取结果纠错方法研究的问题,提出了一种基于纠错编码的矢量地图可逆水印算法。首先采用二值数组表达版权信息并生成其纠错编码,然后将二者合并组成水印数据,最后将水印数据嵌入地图顶点极坐标以增强算法抵抗几何变换的能力。水印提取后,通过纠错编码对水印提取结果进行纠错,达到提升算法稳健性的目的。实验结果证明：该算法具有严格的可逆性、理想的隐蔽性以及较强的稳健性。     

基于文本重要内容的鲁棒水印算法

提出一种基于文本重要内容的鲁棒水印算法, 对文本的特征进行分析, 确定文本的重要内容. 根据水印序列和同义词替换评价模型, 将水印不可感知地嵌入到文本的重要内容中, 提高水印的鲁棒性. 投票原则的使用又进一步提高水印的鲁棒性并降低了误检率. 理论和实验分析表明, 采用文中算法嵌入的水印具有较好的鲁棒性、安全性和不可见性.     

基于BCH纠错码的数字水印算法

提出一种将BCH纠错码用于水印生成的数字水印算法。该算法利用了BCH纠错码的纠错特性增强了水印的鲁棒性;之后对水印的BCH纠错码进行交织,一方面可以利用交织提高纠正突发错误的能力,进一步提高水印的鲁棒性,另一方面可以利用预设的交织参数对水印进行加密。针对编码后数据量增大的问题,采用了可以嵌入较多数据的LSB算法嵌入水印。并利用图像的边缘检测信息选取水印嵌入的位置．既加强了LSB嵌入算法的鲁棒性,又使嵌入的水印不可见性更好。     

基于语义角色标注的文本水印算法

为保护数字文本的知识产权,提出一种利用语义角色嵌入水印信息的文本水印算法。采用Unicode编码和Huffman编码对水印进行预处理形成特定形式的水印信息串,借助自然语言处理技术标注文本中的语义角色,将水印信息映射为语义角色的位置,实现水印的嵌入与提取。算法对文本的格式和内容不做任何修改,具有很强的隐蔽性和鲁棒性,能有效抵抗常见的格式变换和攻击,同时能提供较大的水印容量,与其它文本水印算法相比具有一定的优越性。     

煤矿井下安全监控分站的设计及其仿真实现

为了设计一种具有低成本、低功耗、易操作、功能强且可靠性高的煤矿井下安全分站,针对煤矿安全生产实际,文章提出了采用MCS-51系列单片机为核心、具有CAN总线通信接口的煤矿井下安全监控分站的设计方案;首先给出煤矿井下安全监控分站的整体构架设计,然后着重阐述模拟量输入信号处理系统的设计过程,最后说明单片机最小系统及其键盘、显示、报警、通信等各个组成部分的设计;为验证设计方案的可行性与有效性,使用Proteus软件对设计内容进行仿真验证,设计的煤矿井下安全监控分站具有瓦斯、温度等模拟量参数超标报警功能和电机开停、风门开闭等开关量指示功能;仿真结果表明:设计的煤矿井下安全监控分站具有一定的实际应用价值.     

View-based model-driven architecture for enhancing maintainability of data access services

In modern service-oriented architectures, database access is done by a special type of services, the so-called data access services (DAS). Though, particularly in data-intensive applications, using and developing DAS are very common today, the link between the DAS and their implementation, e.g. a layer of data access objects (DAOs) encapsulating the database queries, still is not sufficiently elaborated, yet. As a result, as the number of DAS grows, finding the desired DAS for reuse and/or associated documentation can become an impossible task. In this paper we focus on bridging this gap between the DAS and their implementation by presenting a view-based, model-driven data access architecture (VMDA) managing models of the DAS, DAOs and database queries in a queryable manner. Our models support tailored views of different stakeholders and are scalable with all types of DAS implementations. In this paper we show that our view-based and model driven architecture approach can enhance software development productivity and maintainability by improving DAS documentation. Moreover, our VMDA opens a wide range of applications such as evaluating DAS usage for DAS performance optimization. Furthermore, we provide tool support and illustrate the applicability of our VMDA in a large-scale case study. Finally, we quantitatively prove that our approach performs with acceptable response times.     

A pragmatic multi-method investigation of discrepant technological events: Coping,attributions, and ‘accidental’ learning

Discrepant technological events or situations that entail a problem, a misunderstanding or a difficulty with the Information Technology (IT) being employed, are common in the workplace, and can lead to frustration and avoidance behaviors. Little is known, however, about how individuals cope with these events. This paper examines these events by using a multi-method pragmatic approach informed by coping theory. The results of two studies – a critical incident study and an experiment – serve to build and test, respectively, a theoretical model that posits that individuals use a variety of strategies when dealing with these events: they experience negative emotions, make external attributions, and adopt engagement coping strategies directed at solving the event, eventually switching to a disengagement coping strategy when they feel they have no control over the situation. Furthermore, users’ efforts may result in ‘accidental’ learning as they try to overcome the discrepant IT events through engagement coping. The paper ends with a discussion of the results in light of existing literature, future opportunities for research, and implications for practice.     

Call for Papers The 6^th International Conference on Grid and Cooperative Computing

Recent years have seen rapid advances in various grid-related technologies, middleware, and applications. The GCC conference has become one of the largest scientific events worldwide in grid and cooperative computing. The 6th international conference on grid and cooperative computing (GCC2007) Sponsored by China Computer Federation (CCF),Institute of Computing Technology, Chinese Academy of Sciences (ICT) and Xinjiang University ,and in Cooperation with IEEE Computer Soceity ,is to be held from August 16 to 18, 2007 in Urumchi, Xinjiang, China.     

The Distributed Time-Triggered Simulation Scheme: Core Principles and Supporting Execution Engine

Distributed real-time simulation is a young technology field but its practice is under increasing demands. In recent years the author and his collaborators have been establishing a new approach called the distributed time-triggered simulation (DTS) scheme which is conceptually simple and easy to use but widely applicable. The concept was initiated in the course of developing a new-generation object-oriented real-time programming scheme called the time-triggered message-triggered object (TMO) programming scheme. Some fundamental issues inherent in distributed real-time simulation that were learned during recent experimental studies are discussed along with some approaches for resolving the issues. An execution engine developed to support both the TMOs engaged in control computation and the TMOs engaged in DTS is also discussed along with its possible extensions that will enable significantly larger-scale DTSs.     

Software-Konfigurationsmanagement in großen Softwareprojekten

Zusammenfassung Mit zunehmender Größe der Softwaresysteme verschärfen sich die für die Software-Herstellung typischen Probleme: Beherrschen großer Objektmengen, Erhalten der Systemkonsistenz, Kontrolle der ständigen Änderungseinflüsse und Gewährleisten einer langen Lebensdauer. Die Disziplin Konfigurationsmanagement bildet den methodischen Ansatz, diese Probleme besser zu beherrschen. Software-Konfigurationsmanagement faßt die Herstellung von Softwaresystemen als eine Abfolge von kontrollierten Änderungen an gesicherten Zwischen- und Endergebnissen auf. Dargestellt werden die Objekte und Funktionen des Software-Konfigurationsmanagements sowie die hierfür in großen Software-Projekten benötigten Methoden, Instanzen und Hilfsmittel.     

Information for Authors

正http://www.zju.edu.cn/jzus http://www.springerlink.com Aim The Journals of Zhejiang University-SCIENCE(A/B/C)are edited by the international board of distinguished Chinese and foreign scientists,and are aimed to present the latest developments and achievements in scientific research in China and     

Editorial:Brain-machine interface(BMI) and cyborg intelligence

正Brain-machine interfaces(BMIs)aim at building a direct communication pathway between the brain and an external device,and represent an area of research where significant progress has been made during the past decade.Based on BMIs,mind information can be read out by neural signals to control     

Information for Authors

正http://www.zju.edu.cn/jzus http://www.springerlink.com Aim The Journals of Zhejiang University-SCIENCE(A/B/C)are edited by the international board of distinguished Chinese and foreign scientists,and are aimed to present the latest developments and achievements in scientific research in China and overseas to the world’s scientific circles,especially to stimulate     

SCIENCE CHINA Information Sciences SUBJECT INDEX TO VOLUME 57(2014)

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