Translating OWL and Semantic Web Rules into Prolog: Moving Toward Description Logic Programs

arXiv.org Artificial Intelligence

To appear in Theory and Practice of Logic Programming (TPLP), 2008. We are researching the interaction between the rule and the ontology layers of the Semantic Web, by comparing two options: 1) using OWL and its rule extension SWRL to develop an integrated ontology/rule language, and 2) layering rules on top of an ontology with RuleML and OWL. Toward this end, we are developing the SWORIER system, which enables efficient automated reasoning on ontologies and rules, by translating all of them into Prolog and adding a set of general rules that properly capture the semantics of OWL. We have also enabled the user to make dynamic changes on the fly, at run time. This work addresses several of the concerns expressed in previous work, such as negation, complementary classes, disjunctive heads, and cardinality, and it discusses alternative approaches for dealing with inconsistencies in the knowledge base. In addition, for efficiency, we implemented techniques called extensionalization, avoiding reanalysis, and code minimization.


Context and Ontologies: Contextual Indexing of Ontological Expressions

AAAI Conferences

This paper discusses aspects of context as applied to ontologies. In particular, we note some formalizations of context that have been applied to ontologies such as Menzel (1999) and Akman & Surov (1996, 1997), that have largely been framed in terms of theories such as Situation Theory (Barwise & Perry, 1983) which originated in natural language semantics. We also mention the notion of labeled deduction (Gabbay, 1996) and speculate on its prospective use in the contextualizing of ontologies. The latter can be viewed as a mechanism for annotating ontological assertions and proofs with contextual information about provenance, security, strength/confidence of assertion, and aspects of policy.


Ontologies for Corporate Web Applications

AI Magazine

In this article, we discuss some issues that arise when ontologies are used to support corporate application domains such as electronic commerce (ecommerce) and some technical problems in deploying ontologies for real-world use. In particular, we focus on issues of ontology integration and the related problem of semantic mapping, that is, the mapping of ontologies and taxonomies to reference ontologies to preserve semantics. Along the way, we discuss what typically constitutes an ontology architecture. We situate the discussion in the domain of business-to-business (B2B) e-commerce. By its very nature, B2B e-commerce must try to interlink buyers and sellers from multiple companies with disparate product-description terminologies and meanings, thus serving as a paradigmatic case for the use of ontologies to support corporate applications.


Ontologies for Corporate Web Applications

AI Magazine

In particular, we focus on issues of ontology integration and the related problem of semantic mapping, that is, the mapping of ontologies and taxonomies to reference ontologies to preserve semantics. Along the way, we discuss what typically constitutes an ontology architecture. By its very nature, B2B e-commerce must try to interlink buyers and sellers from multiple companies with disparate product-description terminologies and meanings, thus serving as a paradigmatic case for the use of ontologies to support corporate applications. Commercial organizations are seeking to codify web services using such formalizations as the universal description, discovery, and integration (UDDI) specification. There are efforts to standardize intelligent agent technology, such as the Foundation for Intelligent Physical Agents (FIPA). These efforts at standardization must use ontologies if emerging internet applications are to be powered by semantics, the meaning behind advanced applications and their enterprise-level and community-level transactions. In this article, we discuss some issues that arise when ontologies are used to support corporate application domains such as electronic commerce (e-commerce) and some technical problems in deploying ontologies for realworld use. In particular, we focus on issues of ontology integration and the related problem of semantic mapping, that is, the mapping of ontologies and taxonomies to reference ontologies to preserve semantics. Along the way, we discuss what typically constitutes an ontology architecture and provide a short summary of ontology development tools. By its very nature, B2B e-commerce must try to interlink buyers and sellers from multiple companies with disparate product-description terminologies and meanings, thus serving as a paradigmatic case for the use of ontologies to support corporate applications. The "vocabularies" for ontologies, as discussed in the introduction to this special issue, are distinct at different levels.


DR-Prolog: A System for Reasoning with Rules and Ontologies on the Semantic Web

AAAI Conferences

At present, the highest layer that has reached sufficient maturity is the ontology layer in the form of the description logic based languages, DAML OIL and OWL. The next step in the development of the Semantic Web will be the logic and proof layers. Rule systems can play a twofold role in the Semantic Web initiative: (a) they can serve as extensions of, or alternatives to, description logic based ontology languages; and (b) they can be used to develop declarative systems on top (using) ontologies. Defeasible reasoning is a simple rule-based approach to reasoning with incomplete and inconsistent information. It can represent facts, rules, and priorities among rules. Its main advantage is the combination of enhanced representational capabilities allowing one to reason with incomplete and contradictory information, coupled with low computational complexity compared to mainstream nonmonotonic reasoning. In this paper we report on the implementation of a defeasible reasoning system for reasoning on the Web.