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随着计算机和Internet的快速发展,语义网和描述逻辑在人工智能等领域扮演着越来越重要的角色。但在日常生活中,越来越多不确定的、不完整的知识需要解决,而现存的OWL只能表述确定的完整的概念和关系。为了能够表示和推理模糊知识,给出了一个基于描述逻辑SHIQ的全新的模糊描述逻辑公理体系——F-SHIQ公理体系,并以此公理体系为基础,扩展了OWL本体语言,能够描述和推理模糊知识。该文首先给出了系统详细的定义、公理、定理以及定理的证明;然后详述了如何用FSRL,即基于F-SHIQ的OWL扩展,来表示和推理模糊信息;最后通过一个例子来检验扩展语言的应用效果。 相似文献
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张建安 《网络安全技术与应用》2003,(4):55-58
规则检测方法是入侵检测系统中应用最为广泛的一种检测方法,现有的规则检测方法存在着规则不能扩充或规则扩充不够灵活、不够方便、用户不易掌握等问题。为此,本文提出了基于逻辑描述的开放式规则检测方法,并给出了概略的实现。 相似文献
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公理定位能够挖掘描述逻辑中可解释的缺陷,并为逻辑蕴含结果寻找隐藏的理由,因此在描述逻辑研究中引起了广泛的关注.平衡描述逻辑表达能力和推理机求解效率问题一直是公理定位研究的重点内容.本文基于一种后继式判定算法,从白盒和黑盒两个角度将其用于公理定位.白盒方法利用修正的后继式规则(即定位规则)来追踪推理的具体过程,并引入定位公式的概念建立子句的布尔公式标签与逻辑蕴含的所有极小公理集之间的对应关系.黑盒方法则直接调用基于未修正的后继式规则的推理机,并进一步利用碰集树方法求得逻辑蕴含的所有理由.最后,基于这样的两种面向强表达描述逻辑本体的公理定位算法设计推理工具,从理论和实验两方面验证其可行性,并与已有的推理工具比较求解性能. 相似文献
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现有的访问控制规则描述方式不易表达一类主体、客体间具有包含关系的访问控制规则.针对此问题,提出一种基于逻辑中合一思想的算法.算法首先将访问控制请求转换为逻辑提问,同时根据逻辑回答给出相应的访问控制请求应答;然后使用事实描述访问控制规则中的各个要素,并通过在系统运行过程中对非ground事实的变量的动态例化实现灵活的访问... 相似文献
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为了能够将哲学逻辑中的公理系统运用到行为时序逻辑的研究中。对行为时序逻辑公式的语义进行形式化定义.从语义和语法两方面研究行为时序逻辑公理系统和具有自反性质的线性时序逻辑公理系统之间的联系.提出并证明行为时序逻辑公式转换为自反线性时序逻辑公式的定理。按照集合论和模型论的思想,定义行为时序逻辑中项和行为时序逻辑原子公式的概念。定义Lesilie Lamport所提出的行为时序逻辑公式的语义。证明自反线性时序逻辑公理系统适用于行为时序逻辑公理系统.以此为基础证明行为时序逻辑的简单规则、基本规则和附加规则。 相似文献
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间断区间时态逻辑的语义 总被引:1,自引:0,他引:1
区间逻辑不能模拟自然语言中与,或,非时态关系,其公理系统的完备性不易保证。我们建立的间断区间时态知脚注可以克服区间逻辑的上述缺点,本文给出了间断区间逻辑的语法,语义及公理,即描述了间断区间时态逻辑的语义。 相似文献
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The paper researches Horn logic programs with grammatical view. The correspondence between Horn logic programs and grammars is found. The method by which type-0 grammars generate the least Herbrand models of logic programs is found. The method by which Horn logic programs generate the languages of type-0 grammars is found.The characterization of Horn Logic programs that are semantically equavanent to type-2 grammars and type-3 grammars is found. 相似文献
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Matthew Huntbach 《Formal Aspects of Computing》1989,1(1):193-211
Since logic programs are executable specifications, the main concern of logic programming, producing efficient programs, is tangential to the mainstream of formal methods. A fashionable automatic transformation technique for producing efficient programs, partial evaluation, applied to the concurrent logic programming language Parlog is discussed. 相似文献
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Alexander Tuzhilin 《Acta Informatica》1993,30(7):679-700
Temporal logic queries on Datalog and negated Datalog programs are studied, and their relationship to Datalog queries on these programs is explored. It is shown that, in general, temporal logic queries have more expressive power than Datalog queries on Datalog and negated Datalog programs. It is also shown that anexistential domain-independent fragment of temporal logic queries has the same expressive power as Datalog queries on negated Datalog programs with inflationary semantics. This means that for finite structures this class of queries has the power of the fixpoint logic. 相似文献
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Classical negation in logic programs and disjunctive databases 总被引:2,自引:0,他引:2
An important limitation of traditional logic programming as a knowledge representation tool, in comparison with classical logic, is that logic programming does not allow us to deal directly with incomplete information. In order to overcome this limitation, we extend the class of general logic programs by including classical negation, in addition to negation-as-failure. The semantics of such extended programs is based on the method of stable models. The concept of a disjunctive database can be extended in a similar way. We show that some facts of commonsense knowledge can be represented by logic programs and disjunctive databases more easily when classical negation is available. Computationally, classical negation can be eliminated from extended programs by a simple preprocessor. Extended programs are identical to a special case of default theories in the sense of Reiter. 相似文献
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Inductive logic programming combines both machine learning and logic programming techniques. ILP uses first-order predicate logic restricted to Horn clauses as an underlying language. Thus, programs induced by an ILP system inherit the classical limitations of PROLOG programs. Constraint logic programming avoids some of the limitations of logic programming, and so ILP aims to induce programs that employ this paradigm. Current ILP systems that induce constrained logic programs extend systems based on the normal semantics ofILP. In this article we introduce IC-Log, a new system that induces constrained logic programs and relies on an extension ofa nonmonotonic semantics-based system. We then present an application of IC-Log in the field ofcomputer-aided publishing. 相似文献
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一种用于指针程序安全性证明的指针逻辑 总被引:7,自引:3,他引:4
在高可信软件的各种性质中,安全性是被关注的重点,其中软件满足安全策略的证明方法是研究的热点之一.文中根据作者所设想的安全程序的设计和证明框架,为类C语言的一个子集设计了一个指针逻辑系统.该逻辑系统是Hoare逻辑系统的一种扩展,它用推理规则来表达每一种语句引起指针信息的变化情况.它可用来对指针程序进行精确的指针分析,所获得的信息用来证明指针程序是否满足定型规则的附加条件,以支持程序的安全性验证.该逻辑系统也可用来证明指针程序的其它性质. 相似文献
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John S. Schlipf 《Annals of Mathematics and Artificial Intelligence》1995,15(3-4):257-288
This paper surveys complexity, degree of uncomputability, and expressive power results for logic programming. Some major decision problem complexity results and other results for logic programming are also covered. It also proves several new results filling in previous gaps in the literature. The paper considers seven logic programming semantics: the van Emden-Kowalski semantics for definite (Horn) logic programs; the perfect model semantics for stratified and for locally stratified logic programs; and the two- and three-valued program completion semantics, the well-founded semantics, and the stable semantics, all for normal logic programs, under skeptical inference. The main results concern expressibility and query complexity/uncomputability in five contexts: for propositional logic programs, for first order logic programs with infinite Herbrand universes on their Herbrand universes (a closed domain assumption), for first order logic programs with infinite Herbrand universes on those universes extended with infinitely many new elements (an open domain assumption), and for logic programs without function or constant symbols evaluated over varying extensional databases (DATALOG-type results, data complexity results only) under both closed and open domain assumptions. Several of the open domain assumption results are new to this paper. Other results surveyed are (1) results about the family of all stable models of a program and (2) decision questions about when a logic program has nice properties with respect to a semantics (e.g., a unique stable model). One decision result, for well-founded semantics, is new to this paper.Work supported in part by NSF grant IRI-8905166. 相似文献