栅格化网络信任传递技术研究

栅格化网络对信息安全的要求愈加迫切,有必要对其信任传递技术进行研究和验证。构建面向服务的端到端业务访问的安全体系结构,提出栅格环境下跨域业务访问的安全防护等关键技术,形成基于业务属性为驱动的动态安全策略防护机制,实现不同类型业务的安全服务能力,有效地保证系统的可靠运转,为栅格化网络的建设保障提供有力支撑,并对后期的研究工作进行了展望。     

Topological entropy of continuous transitive maps on the real line

The topological entropy of a continuous transitive map f : ? → ? is studied. We find lower bounds for the topological entropy of f and prove that transitive real maps can have finite entropy.     

A Behavioral Choice Model When Computational Ability Matters

This paper presents a model of how humans choose between mutually exclusive alternatives. The model is based on the observation that human decision makers are unable or unwilling to compute the overall worth of the offered alternatives. This approach models much human choice behavior as a process in which people seek to equate a less significant difference between alternatives on one dimension, thus leaving the greater one-dimensional difference to be differentiated as the determinant of the final choice. These aspects of the equate-to-differentiate model are shown to be able to provide an alternative and seemingly better account of the prominence effect. The model is also able to provide an explanation and prediction regarding the empirical violation of independence and transitivity axioms. It is suggested that the model allows understanding perplexing decision phenomena better than alternative models.     

On the reachable set of inflated singularly perturbed differential equations

Singularly perturbed differential equations with slow and fast subsystems are under consideration. It is well-known that the invariant probability measures of the unperturbed fast subsystems produce a limiting system for the slow subsystem. Unfortunately, the limiting system is non-smooth in general and might be too big since it also generates trajectories that are not related to the singularly perturbed system. However, if the flows produced by the unperturbed fast subsystems are chain transitive an inflation of the singularly perturbed system can be used in order to approximate all trajectories of the limiting system. Moreover, it turns out that the reachable sets of the limiting system are contained in the reachable sets of the slightly inflated singularly perturbed system.     

Stability analysis for linear time-varying systems using bicoprime factorization

This paper presents a bicoprime factorization (BCF) approach to deal with various stability problems for linear discrete time-varying (LTV) systems within the framework of nest algebra. Based on the bicoprime factorization, we give necessary and sufficient conditions for (strongly) simultaneous stabilization of three systems, which generalize similar results for systems by coprime factorization (CF). Finally, when the bicoprime factorization for the plant and controller has additive perturbations, we derive sufficient conditions using the norm inequality for robust stability of the system.     

由传递性产生初值敏感及混沌的几个充分条件

给出由传递性产生初值敏感及混沌的几个充分条件。     

《葛底斯堡演说》的及物系统语篇分析

林肯的《葛底斯堡演说》是历史上著名的演说,很多学者从功能语法、结构修辞和主位结构分析等方面对其进行探讨.本文以功能语法的及物系统理论为基础,分析了这篇演说中的6个过程,旨在探讨及物系统在演讲语篇中的特点.     

一种面向社交网络的细粒度密文访问控制方案

针对社交网络的隐私保护问题,采用属性基加密算法,提出一种安全、高效、细粒度的社交网络访问控制方案,并建立社交网络体系结构。通过引入线性秘密共享方案构造访问控制策略,实现灵活的访问控制结构,利用重加密技术,将部分重加密工作转移给社交网络平台执行,在保证用户数据安全的前提下,降低用户的计算代价,通过分析非授权成员与授权成员之间的关系,判定非授权成员的访问权限,进而实现访问权限的传递,并分析方案的安全性和有效性。分析结果表明,与现有基于加密技术的隐私保护方案相比,该方案能提高访问结构的表达能力和解密效率。     

基于限界传递相似度图的FCA概念相似度计算方法

使用相似度图计算FCA概念相似度需要构造相似关系的传递闭包,对于复杂问题会导致相似度图规模过大,从而影响相似度评价的效率.为了降低相似度图规模,提出一种基于限界传递相似度图的FCA概念相似度计算方法.该方法首先通过限定传递相似关系的长度来避免构造相似关系的传递闭包,得到的限界传递相似度图中忽略了长度超过界限且对区分FCA概念无用的传递相似关系,能够有效压缩相似度图的规模;然后给出了动态传递相似度计算方法和由限界传递相似度图构建二部图的方法.实验结果表明,使用限界传递相似度图能够在不损失计算结果准确度的情况下有效提高FCA概念相似度计算的效率.     

Biswapped网络(BSN)的拓扑性质研究:点对称性和极大容错性

Biswapped网络(BSN)是一类两层结构的互连网络,它以任意图为模块且模块间采用一种完全两部图方式互连.BSN的互连形式与OTIS网络(即Swapped网络)类似但互连规则更一致,使得BSN展现出更好的性能.文中主要研究BSN的点传递性和容错性能.首先证明BSN能继承因子网络的点传递性质,为BSN上的分析和算法简单性找到理论依据.其次,通过直接构造网络中两点间最大数目的点不相交路径证明以任意连通图为因子网络的BSN是一致极大容错的.这些结果表明BSN既能继承因子网络的理想性能还展现某些好的新特性.最后,通过与OTIS网络、卡式积网络等层次类网络比较表明,BSN提供了一种构建可扩展性、模块化、容错性的大规模并行计算机系统的潜在有竞争力的体系结构形式.