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1.
为π演算建立具有安全级别的简单类型系统,并证明该类型系统在规约语义下的类型可靠性.此类型系统使得π演算成为安全系统、安全协议分析与规范的普适形式化工具. 相似文献
2.
设计基于跨层机制的通信协议,以达到优化网络性能、有效分配网络资源的目的,是无线传感器网络研究中的一项关键技术.对现有的基于跨层设计的网络通信协议进行综述和分析,并以跨层通信协议设计的目的性为着眼点,对跨层通信协议划分为3类：提高互操作性和增强网络适应性为目的的跨层设计,提高某些性能标准为目的的跨层设计和无分层模型设计.该分类方式有助于网络设计人员进行更具有针对性和实用性跨层设计. 相似文献
3.
李婷 《洛阳工业高等专科学校学报》2015,(1)
不同VANET应用对网络属性的要求和各自的特性影响路由协议的选择和使用。选择合适的路由协议将实现更好的网络性能,提供更高效的服务。通过分析VANET的5类应用的特点和对网络的要求,结合不同种类路由协议的特性,主要针对单播和多播情况下路由协议选择原因进行阐述,并给出单播协议中GPSR＋AGF和CAR这两种路由协议的构造方式。 相似文献
4.
Kadriye Ercikan Rubab Arim Danielle Law Jose Domene France Gagnon Serge Lacroix 《Educational Measurement》2010,29(2):24-35
This paper demonstrates and discusses the use of think aloud protocols (TAPs) as an approach for examining and confirming sources of differential item functioning (DIF). The TAPs are used to investigate to what extent surface characteristics of the items that are identified by expert reviews as sources of DIF are supported by empirical evidence from examinee thinking processes in the English and French versions of a Canadian national assessment. In this research, the TAPs confirmed sources of DIF identified by expert reviews for 10 out of 20 DIF items. The moderate agreement between TAPs and expert reviews indicates that evidence from expert reviews cannot be considered sufficient in deciding whether DIF items are biased and such judgments need to include evidence from examinee thinking processes. 相似文献
5.
基于单向陷门函数的TMN协议的改进 总被引：1，自引：0，他引：1
提出了一种利用陷门单向函数的性质对TMN协议进行改进的一般形式,利用串空间理论证明了它的安全性,并给出了几个具体的实现形式. 相似文献
6.
阐述了安全电子商务协议的安全属性,介绍了重要的安全电子商务协议,总结了近年来安全电子商务协议形式化分析方法的研究进展情况。文章最后对该领域主要的研究方向进行了展望。 相似文献
7.
给出了应用于不同系统的不变式的概述,分析了彼此之间的关系,进行了分类,并探讨了其未来发展趋势.密码协议的形式化分析日渐引起人们的广泛关注.这导致了不变式生成与描述技术的发展.不变式是对入侵者可知和不可知消息的定义,可用于协议认证和秘密性的证明,从而成为许多协议形式化分析工具和技术的核心 相似文献
8.
Maaike J. van den Haak Menno D.T. de JongPeter Jan SchellensAuthor Vitae 《Government Information Quarterly》2009
Usability methods have received relatively little methodological attention within the field of E-Government. This paper aims to address this gap by reporting on a usability test of the municipal website of Deventer (the Netherlands), carried out by means of three variants of the think-aloud method (concurrent/retrospective think-aloud protocols and constructive interaction). These three methods had proved successful in a previous evaluation of a different municipal website, yet we decided to replicate our study in order to investigate whether the three methods would reveal different results when applied to another municipal website with a different information architecture. The results of our study showed that, as in the previous municipal website evaluation, the three evaluation methods were largely comparable in terms of output. Nevertheless, we did find a number of differences between the present and previous municipal website evaluation regarding the workings of the three methods—differences that could be explained by the different information architectures of the municipal websites tested. This suggests that the three evaluation methods might indeed work differently depending on the nature of the website that is being evaluated, and calls for more research into the effect of task type on the validity of evaluation methods. 相似文献
9.
In this study we examined the effectiveness of self-regulated learning (SRL) and externally regulated learning (ERL) on college
students’ learning about a science topic with hypermedia during a 40-min session. A total of 82 college students with little
knowledge of the topic were randomly assigned either to the SRL or ERL condition. Students in the SRL condition regulated
their own learning, while students in the ERL condition had access to a human tutor who facilitated their self-regulated learning.
We converged product (pretest–posttest declarative knowledge and qualitative shifts in participants’ mental models) with process
(think-aloud) data to examine the effectiveness of SRL versus ERL. Analysis of the declarative knowledge measures showed that
the ERL condition group mean was statistically significantly higher than the group mean for the SRL condition on the labeling
and flow diagram tasks. There were no statistically significant differences between groups on the matching task, but both
groups showed statistically significant increases in performance. Further analyses showed that the odds of being in a higher
mental model posttest group were decreased by 65% for the SRL group as compared to the ERL group. In terms of SRL behavior,
participants in the SRL condition engaged in more use of selecting new information sources, re-reading, summarizing, free
searching, and enacting control over the context of their learning. In comparison, the ERL participants engaged in more activation
of prior knowledge, utilization of feeling of knowing and judgment of learning, monitoring their progress toward goals, drawing,
hypothesizing, coordination of information sources, and expressing task difficulty.
An earlier version of this paper was presented at the international conference of Artificial Intelligence in Education (AI-Ed
2007), Los Angeles, LA (July, 2007). 相似文献
10.