NKI中的本体、框架和逻辑理论

NKI(国家知识基础设施)是一个大规模知识库,它用框架来表示本体中的概念,用Hom逻辑程序作为自动推理.给出NKI中的本体、框架和逻辑理论的形式表示以及形式表示之间的转换,并证明如果将本体、框架和逻辑理论看作是3个范畴,则这些转换是这3个范畴之间的函子.这个结果保证了在NKI中,基于Horn逻辑程序的推理关于用本体和框架表示的知识库是正确的.     

基于多Agent系统的自动协商机制及通用协商框架

自动协商是多Agent系统实现协作的关键环节。目前,对协商模型的研究大部分是在特定的应用系统中针对具体协商背景进行研究,协商模型的通用性较差。本文分析了多Agent系统协商机制的三个方面:Agent通信语言、通信方式和交互协议。在此基础上,给出了基于多Agent的通用协商框架GNF,该协商框架包括抽象协商过程、协商规则分类和协商协议。最后,给出了一个基于通用协商框架GNF的原型系统——采用Jess规则引擎实现的多Agent的商品交易系统。     

一种基于XML的贸易协商协议

在商业贸易过程中，制定合同或者订单之前，贸易双方的协商是个很重要的环节。如果要在电子商务中实现这个过程，那么如何描述贸易双方的需求以及如何解决贸易双方需求之间的矛盾是关键所在。该文提出了一种基于XML的贸易协商协议和对应的系统框架以解决这个问题，从而在电子商务中实现了贸易协商过程的自动化和标准化。     

基于计算解语义的逻辑程序测试和调试框架

逻辑程序开发过程中需要花费大量的时间用以程序调试,原因之一是调试通常包含大量的用户交互.减少对调试过程不必要的调用能够提高软件开发的效率.程序测试中得到的由同一个错误引发的多个症状是引发对调试过程不必要调用的因素之一.给出了一种逻辑程序测试和调试框架,其中测试用例的生成、症状的发现和调试(包括诊断和改错)交叉进行,由同一个错误引发的症状只有一个可引发调试过程执行,并以此方式避免了对调试过程不必要的调用.然后,利用一种基于约束的Prolog计算解语义,该框架被实例化为一种Prolog程序的测试和调试算法,本实例表明了该算法的应用.     

地震预报专家系统ESEP/PC中的类框架与规则知识表示法

根据地震预报领域知识的特点,在地震预报专家系统ESEP/PC中设计了规则/框架、类框架和一般规则三种知识表示方法。本文着重论述了后两种知识表示方法。对于类框架知识表示法其结构与框架一致,但是对框架中的各属性之间还可以具有某些逻辑关系;在一股规则知识表示法中,规則的结论部分为地震预报的时间、空间和强度目标,由断言框架或框架的逻辑组合而成;而前提部分则由字符串构成,它可以是一个或多个可选择前提,前者可称为Y/N型规则,而后者称为选择型规则.系统还通过实例阐述了这两种知识表示法的应用。     

Linux进程语义安全性检测的稳定模型

现有进程检测方法,检测的目标是系统调用的序列的排列关联,忽略了语义中潜在的异常。稳定模型是逻辑程序的语义模型,可以用以发现并修改逻辑程序的异常问题。该文以系统调用为基本检测点,采用逻辑程序描述进程的基本语义逻辑,用稳定模型表达进程的检测语义。系统定义进程的一系列安全语义规则,在进程执行中,计算安全语义规则与进程逻辑之间的稳定模型,得到安全语义的可计算性结论。论文最后,给出了一个Linux系统中的进程语义安全性检测的基本框架。     

逻辑推理理论的定量发展

本文在一阶谓词逻辑的基础上,为每个定性的Horn子句规则赋予一个蕴涵强度f,从而得到定量的f-Horn子句规则及其Herbrand解释.最后,我们成功地给出了f-Horn子句规则的模糊过程解释,并由此引入了模糊逻辑程序系统.     

SPVT:一个有效的安全协议验证工具

描述了基于Objective Caml开发的一个安全协议验证工具SPVT(security protocol verifying tool).在SPVT中,以扩展附加项的类(演算作为安全协议描述语言,以扩展附加项的Horn逻辑规则描述协议攻击者的Dolev-Yao模型,通过一组抽象规则将安全协议的类(演算模型转换为逻辑程序模型,基于安全协议逻辑程序的不动点计算验证安全性质,从安全协议逻辑程序的不动点计算和安全性质的验证过程中构造不满足安全性质的安全协议反例.以简化的Needham-Schroeder公钥认证协议为例,描述了使用SPVT自动验证安全协议的过程,表明了SPVT用于安全协议验证的有效性.     

逻辑程序在关系数据库完整性约束中的应用

逻辑程序设计语言具有很强的逻辑推理能力,将逻辑程序规则与数据库耦合在一起,可以扩充原有的关系数据库完整性约束规则.本文初步探讨了用逻辑程序实现关系数据库完整性约束的实现方法,该方法可以解决语义上逻辑错误的约束.     

基于逻辑程序的安全协议验证

安全协议本质上是分布式并发程序，可以自然地描述为多个子进程的并发合成系统．将安全协议对应的并发合成系统抽象为逻辑程序进行消解，能够对安全协议无穷多个会话的交叠运行进行验证．该文提出了安全协议逻辑程序中逻辑规则的一个分类方法，基于该分类方法提出了安全协议逻辑程序不动点的迭代计算方法．逻辑规则的分类优化了安全协议逻辑程序不动点的迭代计算和安全性质验证过程中的计算．由于安全协议逻辑程序不动点迭代计算过程不一定终止，文中提出了每进行k≥1步安全协议逻辑程序不动点迭代计算验证一次安全性质的验证策略．     

A Logic-Program-Based Negotiation Mechanism

This paper presents a logic-program-based mechanism of negotiation between two agents.In this mechanism an extended logic program(ELP) is regarded as an agent.The negotiation process between two agents is then modelled as multiple encounters between two ELPs,each of which selects an answer set as its initial demand.Both agents mutually revise the original sets of demands through accepting part of the opponent's demand and/or giving up part of its own demand.The overall dynamics can be regarded as mutual ...     

Paraconsistent Declarative Semantics for Extended Logic Programs

We introduce a fixpoint semantics for logic programs with two kinds of negation: an explicit negation and a negation-by-failure. The programs may also be prioritized, that is, their clauses may be arranged in a partial order that reflects preferences among the corresponding rules. This yields a robust framework for representing knowledge in logic programs with a considerable expressive power. The declarative semantics for such programs is particularly suitable for reasoning with uncertainty, in the sense that it pinpoints the incomplete and inconsistent parts of the data, and regards the remaining information as classically consistent. As such, this semantics allows to draw conclusions in a non-trivial way, even in cases that the logic programs under consideration are not consistent. Finally, we show that this formalism may be regarded as a simple and flexible process for belief revision.     

Program-substitution and admissibility of rules in algorithmic logic

Summary The purpose of this work is to show a point of view upon the notions of program-substitution and admissibility of rules which are the tools for proving properties of programs of algorithmic logic and the so-called extended algorithmic logic with quantifiers and with non-deterministic programs. We prove that the set of theses of algorithmic logic is closed under each program-substitution. This substitution rule allows us to formulate a problem of algorithmic structural completeness as a question about derivability of all structural, finitary and admissible rules. We prove the incompleteness of algorithmic logic strengthened by the substitution rule and its algorithmically structural completeness. This work was supported by the Polish Academy of Sciences CPBP 08–15.     

Automated Negotiation from Declarative Contract Descriptions

Our approach for automating the negotiation of business contracts proceeds in three broad steps. First, determine the structure of the negotiation process by applying general knowledge about auctions and domain–specific knowledge about the contract subject along with preferences from potential buyers and sellers. Second, translate the determined negotiation structure into an operational specification for an auction platform. Third, after the negotiation has completed, map the negotiation results to a final contract. We have implemented a prototype which supports these steps by employing a declarative specification (in courteous logic programs) of (1) high–level knowledge about alternative negotiation structures, (2) general–case rules about auction parameters, (3) rules to map the auction parameters to a specific auction platform, and (4) special–case rules for subject domains. We demonstrate the flexibility of this approach by automatically generating several alternative negotiation structures for the domain of travel shopping in a trading agent competition.     

分布式环境下的访问控制

为适应分布式环境下的安全需求,提出了一种描述访问控制策略和判定访问请求的方法。采用类似于无函数的扩展逻辑程序的表示方法对安全访问策略进行描述,限定权限传播的深度,利用不同的优先次序定义了多种消解冲突的规则,并给出了类似扩展逻辑程序的回答集语义解释。结合确定性推理和可能性推理,描述了如何判定访问请求的算法。解决了3个问题：分布式授权、私有权限和冲突消解方法。     

一种用于指针程序验证的指针逻辑

本文改进并扩展先前为验证指针程序提出的指针逻辑,主要贡献是提出了合法访问路径集合的概念,极大地简化了访问路径上的基本运算,并使得指针逻辑推理规则变得易理解.另外,增加了局部推理规则和函数构造的推理规则,使得指针逻辑可以方便地用于有函数调用的场合.     

Autoepistemic logic programming

An autoepistemic logic programming language is derived from a subset of a three-valued autoepistemic logic, called 3AEL. Autoepistemic programs generalize several ideas underlying logic programming: stable, supported, and well-founded models, Fitting's semantics, Kunen's semantics, and abductive frameworks can all be captured through simple autoepistemic translations; moreover, SLDNF-resolution and a generate-and-test method for stable semantics are generalized to provide sound and complete proof methods for autoepistemic programs. These methods extend existing proof methods for 3AEL. Thus autoepistemic logic programming, besides contributing to the understanding of 3AEL, can be seen as a unifying framework for the theory of logic programs. It should also be regarded as a first step toward a flexible environment where different forms of inference can be formally integrated.This paper is an extended version of [8]. I am grateful to my advisor, Giorgio Levi, to Paolo Mancarella, who read the first version of the paper, and to the anonymous referees, whose comments led to sensible improvements.