DFANS: A highly efficient strategy for automated trust negotiation

Automated trust negotiation (ATN) is an approach establishing mutual trust between strangers wishing to share resources or conduct business by gradually requesting and disclosing digitally signed credentials. The digital credentials themselves are usually sensitive, so they have corresponding access control policies to control their disclosure. Therefore, an ATN strategy must be adopted to determine the search for a successful negotiation based on the access control policies. Previously proposed negotiation strategies are either not complete, disclosing irrelevant credentials, or not efficient enough. In this paper, we propose a novel ATN strategy, that is, Deterministic Finite Automaton Negotiation Strategy (DFANS). DFANS is complete and ensures that no irrelevant credentials are disclosed during the negotiation. Furthermore, DFANS is highly efficient. In the worst case, its communication complexity is O(n), where n is the total number of credentials requested, and its computational complexity is O(m) when not involving the cyclic dependencies, where m is the total size of the both sides' policies looked up during the negotiation. When cyclic dependencies exist, a reasonable additional cost of running OSBE protocol that is a provably secure and quite efficient scheme will be added to the computational cost of DFANS to guarantee the negotiation success whenever possible.     

基于感知规则集策略的约束空间RFID室内符号定位算法

随着普适计算的不断发展,室内定位技术的研究也成为当今研究的热点问题。室内定位技术的不断进步使得RFID也开始部署到各种各样的室内场景。为了提高室内空间中的定位精度,提出了一种基于感知规则集策略的约束空间RFID室内符号定位方法。算法基于室内空间中的符号,通过定义感知情况来确立定位规则,使得算法具有良好的室内空间适应性,且使用少量的阅读器即可实现较高精度的定位。为了提高定位精度,引入了感知规则集的概念,对场景中的情况抽象提取,进一步增加算法定位精度。最后,以约束空间中的室内场景作为实验环境对算法进行验证,分析结果表明,在室内空间中算法的定位精度及抗干扰能力优于现有算法。     

Extending metric multidimensional scaling with Bregman divergences

Sum of weighted square distance errors has been a popular way of defining stress function for metric multidimensional scaling (MMDS) like the Sammon mapping. In this paper we generalise this popular MMDS with Bregman divergences, as an example we show that the Sammon mapping can be thought of as a truncated Bregman MMDS (BMMDS) and we show that the full BMMDS improves upon the Sammon mapping on some standard data sets and investigate the reasons underlying this improvement. We then extend a well known family of MMDS, that deploy a strategy of focusing on small distances, with BMMDS and investigate limitations of the strategy empirically. Then an opposite strategy is introduced to create another family of BMMDS that gives increasing mapping quality. A data preprocessing method and a distance matrix preprocessing are introduced.     

流媒体视频传输拥塞控制研究

随着计算机网络的流媒体系统在日常工作和生活中应用越来越广泛,流媒体数据传输和网络带宽之间的矛盾也日益剧烈和明显。在两者都已经固定的情况下,就需要应用合适的网络传输策略,有效利用媒体流的特点和网络资源,传输流媒体数据流。本文重点研究了拥塞控制策略中的分层策略,针对现在的分层策略中各层之间有着优先级不同的限制、灵活性不高的缺陷,提出了一种先分层后编码传输的分层组播策略,并给出了较详细的试验方案和实现方法,最后对该策略的特点进行了讨论。     

校园网建设的实用策略

校园网是一种应用在学校的局域网,其建设策略要考虑到网络拓扑结构、布线系统和设备选型策略、网络维护管理策略、资源建设策略、人员培训策略、校园网应用策略等方面,以便更好地为学校服务。     

An approach to analyzing and planning post-merger IS integration: Insights from two field studies

Information systems (IS) integration is among the most challenging tasks in corporate mergers and acquisitions (M&As). In this paper we propose and illustrate the use of an approach to analyzing and planning post-merger IS integration that extends general theory for IS planning, considering the specific characteristics of the M&A context. We highlight that planning effectiveness is possible to achieve in fundamentally different ways, dependent on the characteristics of the merger or acquisition at hand.

磁碟机病毒破坏机制与防治策略研究

磁碟机病毒及其变种是近几年来病毒技术含量最高、破坏性最强的病毒,已感染数十万台计算机,造成的损失远远超过"熊猫烧香"。为了能有效地防御和查杀该病毒,该文特地对磁碟机病毒进行了深入的研究,分析了磁碟机的破坏机制,指出了磁碟机的种种危害,提出了防治磁碟机的几种技术方法,这对当前防御和清除磁碟机病毒具有一定的现实意义。     

基于混合优化策略的智能集装箱预翻箱系统*

讨论了一个智能集装箱预翻箱系统的设计与实现。在将集装箱预翻箱问题分解的基础上,采用混合优化策略来实现集装箱预翻箱方案。混合优化策略首先根据堆箱规则构造集装箱堆栈目标状态,然后运用改进广度优先算法搜索搬箱步骤。系统是运用分层设计思想来设计的,它是在生产调度领域应用人工智能理论和方法的有益尝试。     

面向ASP分布式服务模式的多级用户控制*

针对四川区域中小制造业用户群对ASP的需求特点,分析了ASP分布式服务模式的原理及其三级异构平台间的功能交互特性。对三级异构服务平台体系中的多级用户角色的要求和特点进行了研究。提出了基于Web Service的多级用户管理和控制策略,并进行了详细设计和实现,其结果在区域网络化制造ASP服务三级服务平台得到实际应用。     

PRBAC技术在移动Agent主机保护中应用的研究与设计

随着网络技术的发展,移动Agent技术获得了极大的应用,移动Agent拥有许多优点,具有很好的应用前景,但是移动Agent主机的安全是一个不容忽视的问题。针对移动Agent主机保护的特点,简要分析了现有的安全机制在移动Agent系统主机保护中的不足,提出了一种基于PRBAC技术的移动Agent主机保护方案,详细分析了它的技术要点及实现流程,并从具体工程应用中说明了该方案适用于移动Agent系统的主机保护,并优于其他的安全机制。