鉴别逻辑与签名体制综述

鉴别逻辑与数字签名是认证系统的基础理论和基础技术。鉴别逻辑现有两种：相信逻辑（belief logic）和可信逻辑（trust logic）;签名体制也有两种：基于标识（identity）的签名体制和基于第三方（3rd party）的签名体制。     

基于时态逻辑的可信平台信任链建模

针对可信计算中信任链理论缺乏深入分析验证的现状,分析了信任链理论中,可信与信任的内涵及其隐含的动态特性,借助时态逻辑的时间推理能力,建立了可信平台中的信任链的形式化模型,依据该模型,观察信任传递的过程,从而从理论上验证了信任在信任链上的可传递性,并得出信任在信任链上传递的充分条件.     

基于主观逻辑的信任搜索算法

针对现有信任模型中信任搜索算法不能准确有效地对信任进行搜索与合成,利用主观逻辑理论对信任进行量化与计算,提出基于主观逻辑的信任搜索算法.算法由两个关键技术组成:信任路径提取算法与信任路径合成算法.仿真实例验证了该算法在信任合成时减少了信任网络中冗余信息对信任合成的影响,提高了信任搜索效率,使得合成结果更加准确.     

从ALC到SHOQ（D）：描述逻辑及其Tableau算法

描述逻辑是一类知识表示的形式系统，并成为语义Web的逻辑基础。Tableau是描述逻辑的基本证明论，基于Tableau的算法提供7描述逻辑的推理机。本文系统地阐述了对应于语义Web语言从基本的ALC到SHOQ(D)描述逻辑基础及其相应的Tableau算法。     

基于概率软逻辑模型的实体解析

在马尔科夫逻辑网(MLN)的实体解析算法中任意闭原子采用硬约束,导致推理及权重学习过程较难收敛到最优解,降低解析精度及执行效率。为此,提出一种将概率软逻辑(PSL)模型应用到实体解析中的方法,该模型中闭原子采用软约束,易于进行知识推理与权重学习。阐述PSL模型基本理论,通过实体关系、实体属性、本体约束构造PSL模型的逻辑规则,描述实体解析的匹配过程,根据PSL模型的推理机制实现实体解析的决策过程。实验结果表明,与基于MLN的实体解析算法相比,该方法可大幅提高实体解析的准确率、F1值及执行效率。     

基于A-ACDS信任协商机制的网格鉴别

网格用户身份鉴别是网格安全中的一个至关重要的环节.通过分析现有网格鉴别中存在的不足,将信任协商的思想引入至网格鉴别中,提出了适用于网格鉴别的A-ACDS信任协商机制,并给出了基于A-ACDS信任协商机制的新型网格鉴别模式.详细描述了基于此新型网格鉴别模式下网格鉴别的具体过程,并给出了其简要的形式化描述.通过与传统网格鉴别模式进行比较,分析其性能,得出该新型网格鉴别模式比传统的网格鉴别具有更好的安全性与功效性.     

基于模糊逻辑的主观信任管理模型研究

在开放网络中,信任管理是信息安全的重要前提与基础．通过考查主观信任的模糊性,首次将语言变量、模糊逻辑引入主观信任管理研究中,提出了信任的度量机制,运用模糊IF—THEN规则对人类信任推理的一般知识和经验进行了建模,提出了一种灵活直观,具有很强描述能力的形式化的信任推理机制,为主观信任管理研究提供了一种有价值的新思路．     

逻辑实体的行列模板的设计与实现

在现实中存在许多这样的实体,它需要关系数据库中多个相关的记录一起才能完整地表示其意义,且这些记录之间通常具有行和列上的计算关系,使用传统的方法不能很好地实现这样的实体.针对该情况,提出逻辑实体及其行列模板的概念,设计逻辑实体和行列模板的关系模式,给出行列模板的实现,并结合一个实例,详细说明了行列模板的具体应用.     

From Coalition Logic to STIT

STIT is a logic of agency that has been proposed in the nineties in the domain of philosophy of action. It is the logic of constructions of the form “agent a sees to it that φ”. We believe that STIT theory may contribute to the logical analysis of multiagent systems. To support this claim, in this paper we show that there is a close relationship with more recent logics for multiagent systems. We focus on Pauly's Coalition Logic and the logic of the cstit operator, as described by Horty. After a brief presentation of Coalition Logic and a discrete-time version (including a next operator) of the STIT framework, we introduce a translation from Coalition Logic to the discrete STIT logic, and prove that it is correct.     

基于认知反映的信念逻辑

Quine[9]提出了一类有关信念模态的难题,比如Cicero难题,这些难题的解读对模态逻辑语义具有重要的意义.目前的一阶模态逻辑普遍给予Quine难题以de re/de dicto解读.本文指出de re/de dicto解读存在缺陷,并且认为为了解读Quine难题,需要在一阶模态逻辑的模型中引入一个认知反映关系.在此观念下,本文提出了一个新的一阶模态逻辑系统--基于认知反映的信念逻辑.     

A Fuzzy Dynamic Belief Logic System

In this paper, we develop a fuzzy dynamic belief revision logic system. In our system, propositions take truth values in a set of multiple fuzzy linguistic terms, which people use in everyday life. And we use a uninorm operator to aggregate the linguistic truth values of the same proposition but drawn from two different rules because uninorms can reflect well that the aggregated result of two somehow negative truth values of the same proposition should be more negative, the aggregated result of two somehow positive ones should be more positive, and the result of a negative one and a positive one is a compromise. In this system, the belief on a proposition is the linguistic truth of the proposition in the most possible world according to the current preference over all possible worlds. In the light of new information, the preference degrees of possible worlds will be updated. Accordingly, the most possible world will be changed to another and thus an old belief on a propositional formula will be changed to the linguistic truth of the proposition in the new most possible world. Moreover, we prove the soundness and completeness of our fuzzy dynamic belief revision system. In addition, we also prove that our belief revision method in fuzzy environment satisfies some relevant ones of standard AGM postulates (named after the names of their proponents, Alchourrón, Gärdenfors, and Makinson).     

Belief, Logic, and Partial Truth

Contrary to some interpretations of "impossibility theorems," belief models exist which are both truth-functional and give equal credibility to all equivalent formulas. This combination of features can be useful, e.g., in case-based reasoning. That such models exist casts doubt on theories which try to restrict the applications of belief calculi based upon the supposed incompatibility of the features. One prominent theory attempts to divorce partial truth, described as the province of fuzzy logic, from probabilistic reasoning. Nevertheless, ordinary logic and cumulative probability exactly restate the inferences of the usual fuzzy logic.     

一种可分析保密性与认证性的模态逻辑

提出了一种新的基于信念的模态逻辑——MBL逻辑,来分析由单向函数构造的对称钥认证交换协议的安全性。该逻辑有严格的证明体系,可证明推理规则在其语义模型下的正确性,说明该逻辑具有合理性。其推理规则不仅能对单向函数保护的消息进行有关认证性的推理,克服了以往逻辑系统使用不当的安全服务来分析协议认证性的缺陷,而且可分析消息的保密性,避免了其他逻辑分析协议时对可信中心的过分依赖,可发现敌手通过欺骗可信中心而造成的攻击。     

Interpreting Presuppositions Using Active Logic: From Contexts to Utterances

Presupposition is a pervasive feature of human language. It involves many interesting interactions between the utterances of a discourse and the context of the discourse. In this paper we focus on issues of logical form connected with the interaction of presupposition and discourse context, and illustrate our theory with some implementational work using the active logic framework. After reviewing some of the major issues in presupposition theory we turn to a largely successful unified approach of Heim. We show how the main principles of this theory can be implemented in active logic. But we also find two serious difficulties. These consist in (a) a straightforward counterexample and (b) a type of discourse that we call a garden‐path discourse. We maintain that both the counterexample and the garden‐path type of discourse can be handled by our active‐logic version of Heim's theory. This requires us to reformulate and extend Heim's theorey. Although this work is largely theoretical, both Heim's theory and ours have important things to say about the incremental processing of the utterances that make up discourse. And we present our theory as a specification of a processing device that takes logical form of a sentence along with current discourse context as input and delivers an updated discourse context as output. As an experiment, we have implemented portions of this device.     

描述任务逻辑及其应用

针对任务逻辑存在的两个缺点：（1）不可判定,无法保证推理过程都能在有限的时间内结束;（2）任务的定义局限于抽象的、逻辑的定义。无法描述任务的具体属性和任务之间的关系,将描述性结构引入任务逻辑,构造了一个可描述具体属性的、可判定的任务逻辑系统——描述任务逻辑．将所构造的逻辑系统应用于具有组织的多主体系统行为建模,建立了基于描述任务逻辑的多主体组织模型和建模框架,并且表明应用描述任务逻辑构造应用系统具有表达能力强、结构紧凑的特点．     

一种分析和设计认证协议的新逻辑

提出一种分析和设计认证协议的新逻辑,可以用来分析认证协议和设计认证协议。通过运用该逻辑,使认证协议的设计和分析可以在同一种逻辑中进行,也消除了用不同的方法来设计和分析认证协议的不一致性。在分析协议时,先用逻辑对协议进行形式化,再用推理规则对协议进行推理。如果不能推理出协议的最终目标,说明协议存在缺陷或者漏洞。在设计协议时,通过运用合成规则使协议设计者可用一种系统化的方法来构造满足需要的协议。用该逻辑对Needham-Schroeder私钥协议进行了分析,指出该协议不能满足协议目标,并重新设计了该协议。     

认证协议设计逻辑的语义

Levente Buttyan等人提出了一种认证协议设计的简单逻辑，协议设计者可以使用该逻辑，用一种系统的方法来构造认证协议。该文把简单逻辑和串空间（Strand Space）模型结合起来，给出了简单逻辑的串空间语义，然后运用该语义证明了简单逻辑的推理规则是正确的。