Combining Rules and Ontologies . A survey (original) (raw)

Rules and ontologies for the semantic Web

2008

Rules and ontologies play a key role in the layered architecture of the Semantic Web, as they are used to ascribe meaning to, and to reason about, data on the Web. While the Ontology Layer of the Semantic Web is quite developed, and the Web Ontology Language (OWL) is a W3C recommendation since a couple of years already, the rules layer is far less developed and an active area of research; a number of initiatives and proposals have been made so far, but no standard as been released yet. Many implementations of rule engines are around which deal with Semantic Web data in one or another way. This article gives a comprehensive, although not exhaustive, overview of such systems, describes their supported languages, and sets them in relation with theoretical approaches for combining rules and ontologies as foreseen in the Semantic Web architecture. In the course of this, we identify desired properties and common features of rule languages and evaluate existing systems against their support. Furthermore, we review technical problems underlying the integration of rules and ontologies, and classify representative proposals for theoretical integration approaches into different categories.

Reasoning with Rules and Ontologies

Lecture Notes in Computer Science, 2006

For realizing the Semantic Web vision, extensive work is underway for getting the layers of its conceived architecture ready. Given that the Ontology Layer has reached a certain level of maturity with W3C recommendations such as RDF and the OWL Web Ontology Language, current interest focuses on the Rules Layer and its integration with the Ontology Layer. Several proposals have been made for solving this problem, which does not have a straightforward solution due to various obstacles. One of them is the fact that evaluation principles like the closed-world assumption, which is common in rule languages, are usually not adopted in ontologies. Furthermore, naively adding rules to ontologies raises undecidability issues. In this paper, after giving a brief overview about the current state of the Semantic-Web stack and its components, we will discuss nonmonotonic logic programs under the answer-set semantics as a possible formalism of choice for realizing the Rules Layer. We will briefly discuss open issues in combining rules and ontologies, and survey some existing proposals to facilitate reasoning with rules and ontologies. We will then focus on description-logic programs (or dl-programs, for short), which realize a transparent integration of rules and ontologies supported by existing reasoning engines, based on the answer-set semantics. We will further discuss a generalization of dlprograms, viz. HEX-programs, which offer access to different ontologies as well as higher-order language constructs.

Rules and Queries With Ontologies: a Unifying Logical Framework

Description Logics, 2005

In this paper we present a common framework for investigating the problem of combining ontology and rule languages. The focus of this paper is in the context of Semantic Web (SW), but the approach can be applied in any Description Logics (DL) based system. In the last part, we will show how rules are strictly related to queries. We claim that any choice of rule language for the semantic web should clearly define its semantics.

Rules and Queries with Ontologies: A Unified Logical Framework

Lecture Notes in Computer Science, 2004

In this paper we present a common framework for investigating the problem of combining ontology and rule languages. The focus of this paper is in the context of Semantic Web (SW), but the approach can be applied in any Description Logics (DL) based system. In the last part, we will show how rules are strictly related to queries.

A Unified Logical Framework for Rules (and Queries) with Ontologies

W3c Workshops, 2005

In this position paper we briefly present a semantic framework for investigating the problem of combining ontology and rule languages. We also show how rules are strictly related to queries. We claim that any choice of rule language for the semantic web should clearly define its semantics.

Hybrid reasoning with rules and ontologies

2009

For realizing the Semantic Web vision, extensive work is underway for getting the layers of its conceived architecture ready. Given that the Ontology Layer has reached a certain level of maturity with W3C recommendations such as RDF and the OWL Web Ontology Language, current interest focuses on the Rules Layer and its integration with the Ontology Layer. Several proposals have been made for solving this problem, which does not have a straightforward solution due to various obstacles. One of them is the fact that evaluation principles like the closed-world assumption, which is common in rule languages, are usually not adopted in ontologies. Furthermore, naively adding rules to ontologies raises undecidability issues. In this paper, after giving a brief overview about the current state of the Semantic-Web stack and its components, we will discuss nonmonotonic logic programs under the answer-set semantics as a possible formalism of choice for realizing the Rules Layer. We will briefly discuss open issues in combining rules and ontologies, and survey some existing proposals to facilitate reasoning with rules and ontologies. We will then focus on description-logic programs (or dl-programs, for short), which realize a transparent integration of rules and ontologies supported by existing reasoning engines, based on the answer-set semantics. We will further discuss a generalization of dlprograms, viz. HEX-programs, which offer access to different ontologies as well as higher-order language constructs.

A Framework for Composition and Inter-operation of Rules in the Semantic Web

2006

Abstract Developments in the RuleML initiative have led to the design of several languages for representing rules. In this paper we describe a framework, based on the integration of different flavors of logic programming, aimed at facilitate reasoning with multiple sources of knowledge expressed in an heterogeneity of RuleML languages. The framework allows the derivation of logic programming modules from each rule base, and their inter-operation through a well-defined module interface.

A Novel Way of Integrating Rule-Based Knowledge into a Web Ontology Language Framework

Studies in health technology and informatics, 2013

Web ontology language (OWL), used in combination with the Protégé visual interface, is a modern standard for development and maintenance of ontologies and a powerful tool for knowledge presentation. In this work, we describe a novel possibility to use OWL also for the conceptualization of knowledge presented by a set of rules. In this approach, rules are represented as a hierarchy of actionable classes with necessary and sufficient conditions defined by the description logic formalism. The advantages are that: the set of the rules is not an unordered set anymore, the concepts defined in descriptive ontologies can be used directly in the bodies of rules, and Protégé presents an intuitive tool for editing the set of rules. Standard ontology reasoning processes are not applicable in this framework, but experiments conducted on the rule sets have demonstrated that the reasoning problems can be successfully solved.

A defeasible logic programming approach to the integration of rules and ontologies

Journal of Computer Science & Technology, 2010

The Semantic Web is a vision of the current Web where resources have exact meaning assigned in terms of ontologies, thus enabling agents to reason about them. As inconsistencies cannot be treated by standard reasoning approaches, we use Defeasible Logic Programming (DeLP) to reason with possibly inconsistent ontologies. In this article we show how to integrate rules and ontologies in the Semantic Web. We present an approach that can be used to suitably extend the SWRL standard by incorporating classical and ...