基于XML的数字签名技术研究与实现

XML广泛应用于Web服务系统,选择XML数字签名技术对XML文档中的重要元素进行数字签名,可以确保网络传输数据的完整性,身份的可验证性和不可抵赖性.主要研究了基于XML的数字签名技术,首先阐述了XML数字签名的工作原理,分析了数字签名与验证签名的流程,接着叙述了W3C数字签名规范,给出了XML数字签名文档结构,最后提出了在C#.NET环境下如何编程实现XML数字签名与验证签名的过程,并列举了一个有关购物的XML数字签名文档.     

XML数字签名及其应用研究

介绍了数字签名的原理,探讨了XML数字签名的格式并通过一个实例给出了数字签名生成的实现,并阐述了XML数字签名的生成验证步骤,对XML数字签名的发展做了展望.指出XML数字签名是集安全性与灵活性于一体的电子文档验证机制,能够在Java平台上实现,这项技术的发展将会大大地推进网络的安全性和可靠性.     

基于XML安全技术的算法实现

XML作为一种数据交换格式在网络上得到越来越普遍的应用,与之而来的安全性问题也备受关注.文中分析了目前XML安全技术的两个最核心的技术:XML文档加密技术和XML数字签名技术,并给出文档加密和数字签名的原理及加密实现步骤.最后用文档加密算法实现XML文档加密,按数字签名算法把要加密元素进行加密.     

XML数字签名技术应用研究

随着XML技术的不断发展,其在各方面应用范围越来越广泛,同时XM&的数据的完整性、安全性和机密性越来越重要,通过各种技术方法来保证,其中数字签名与加密也成为研究重点并在实际上得到应用.针对XML数字签名技术进行研究,并使用JAVA实现XML数字签名.     

基于无可信第三方IBS的XML数字签名

传统XML数字签名基于公共密钥基础设施（PKI）体系和非对称算法,存在管理复杂、计算量大等缺陷。通过对XML数字签名规范和无可信第三方基于身份的签名(IBS)方案的研究,采用无可信第三方IBS的密钥管理机制和对应椭圆曲线双线性映射算法实现XML数字签名,按照XML数字签名规范的要求,对相应XML数字签名实现过程和XML数字签名文件结构进行了设计,并分析了具体实现方式。该XML数字签名方案在保证安全性的同时,克服了传统基于PKI的XML数字签名的缺陷,具有更高的效率。     

基于圆锥曲线的XML数字签名应用研究

为实现高校教务管理系统中对学生成绩的数字签名,将基于环Zn上的圆锥曲线ElGamal型数字签名方案应用于XML数字签名领域,设计和实现了一个学生成绩XML数字签名系统.介绍了系统的数据流程、功能模块、关键算法以及新的XML签名文档结构,并对系统的安全性和运行效率等性能进行了分析和对比.实验结果表明,该系统达到了预期的功能,安全性和效率得到了进一步提高,圆锥曲线密码体制能够应用于XML数字签名领域.     

一种对OWL进行数字签名的方法

普通的XML数字签名技术只能对基于XML的文档在XML语义层次上进行文档内容正规化并进行数字签名,无法在更高一层的语义层次上进行数字签名.对于基于OWL(Web本体语言)的文档,需要在更高的语义层次进行对其数字签名.提出了一个对OWL进行数字签名的方法,该方法主要针对OWL文档的RDF Triple(RDF三元组)进行正规化处理后,再进行数字签名,该RDF正规化算法的时间复杂度为O(N lg N),N为RDF Triple的数量.     

XML数字签名技术的研究与实现

通过XML Schema讨论了XML数字签名规范，说明了XML数字签名特点及其优越性，描述了利用XML对文档进行数字签名和对签名进行校验的过程，给出了一个在Microsoft．Net环境下的XML数字签名的具体实现。     

独立于现有系统的XML数字签名系统的研究

描述了一种在不修改已存在的基于XML的B2B系统只要引用一个Web服务即可对XML文档进行数字签名.在应用间的签名代理关注网络上XML消息的交换,外部的消息由签名服务自动对消息签名,内部的消息将会由代理和签名服务进行证实.已经存在的应用系统不用考虑数字签名的处理过程.该系统称为XML安全服务套件(XML Security Srvices Suite,XSSS),包括数字签名以及与安全相关的Web服务集合.     

XML签名技术研究与实现

XML数字签名是基于XML语言基础上的数字签名的新方法。本文对XML数字签名技术进行了研究,并分析了XML签名方式的应用场景,探讨了对XML文档进行XML签名与验证的过程,并给出了基于JAvA的XML数字签名生成和基于C＋＋的XML签名验证的实现。     

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。     

How do children do mathematics with LOGO?

Abstract  This paper considers some results of a study designed to investigate the kinds of mathematical activity undertaken by children (aged between 8 and 11) as they learned to program in LOGO. A model of learning modes is proposed, which attempts to describe the ways in which children used and acquired understanding of the programming/mathematical concepts involved. The remainder of the paper is concerned with discussing the validity and limitations of the model, and its implications for further research and curriculum development.