Michele Missikoff

Integrated approach to Web ontology learning and engineering

Developing the Semantic Web, seeking to improve the semantic awareness of computers connected via the Internet, requires a systematic, computer-oriented world representation. Researchers often refer to such a model as an ontology. Despite the work done on them in recent years, ontologies have yet to be widely applied and used. Research has devoted only limited attention to such practical issues as techniques and tools aimed at an ontologys actual construction and content. The authors have built a software environment, centered around the OntoLearn tool, which can build and assess a domain ontology for intelligent information integration within a virtual user community. OntoLearn has already been tested in two European projects, where it functioned as the basis for a semantic interoperability platform used by small- and medium-sized tourism enterprises. Further, developers can easily adapt OntoLearn to work with other general-purpose ontologies.

Text Mining Techniques to Automatically Enrich a Domain Ontology

Though the utility of domain ontologies is now widely acknowledged in the IT (Information Technology) community, several barriers must be overcome before ontologies become practical and useful tools. A critical issue is the ontology construction, i.e., the task of identifying, defining, and entering the concept definitions. In case of large and complex application domains this task can be lengthy, costly, and controversial (since different persons may have different points of view about the same concept). To reduce time, cost (and, sometimes, harsh discussions) it is highly advisable to refer, in constructing or updating an ontology, to the documents available in the field. Text mining tools may be of great help in this task. The work presented in this paper illustrates the guidelines of SymOntos, ontology management system, and the text mining approach adopted herein to support ontology building. The latter operates by extracting, from the related literature, the prominent domain concepts and the semantic relations among them.

Concept Similarity in SymOntos: An Enterprise Ontology Management Tool

playsan important role. It is constantly used whenever certain goods or services are not availablewith the required characteristics. Then a substitute may be accepted, as far as it is sufficientlyclose to what was originally required. In this paper we propose a method for evaluating conceptsimilarity. The work has been performed within the

SymOntoX: a Web-ontology tool for ebusiness domains

Ontologies are emerging as a key solution to allow different applications to exchange information in a cooperative business environment. From the technology point of view, the growth of the Internet and the Web has favoured the exchange of information and documents among people, but unfortunately the same is not true when information is exchanged among software applications. To tackle the latter problem, ontology-based approaches are among the most promising ones. This is one of the reasons of the momentum that ontologies, and consequently ontology management systems (OMSs), are witnessing. An OMS represents a powerful tool to create common and shareable knowledge repositories concerning a given application domain. The goal of this work is to present SymOntoX, a Web-based OMS conceived for the ebusiness domain. It is an open source software system supporting collaborative and distributed ontology authoring activities.

Correctness of ISA hierarchies in object-oriented database systems

In Object-Oriented databases, ISA hierarchy provides a powerful modeling tool that, through the inheritance mechanism, yields a coincise description of the world. In this paper, we tackle the problem of the correctness of ISA hierarchies in Object-Oriented database schemas. In general, the inheritance mechanisms proposed in literature do not preserve subtyping, i.e. they are not sound. Strict inheritance has been proposed in order to guarantee subtyping after inheritance. However, strict inheritance is sound but fails to cope with a significant class of schemas. The problem relies on refinement rules. In the paper, we characterize the schemas for which strict inheritance is sound and complete and we present a methodology aimed at identifying such schemas. The problem is addressed using the Object-Oriented data definition language TQL.

Semantic mediation for standard-based B2B interoperability

A semantic-mediation architecture advances traditional approaches for standard-based business-to-business interoperability. The architecture formally models a business domain in a reference ontology and annotates domain message schemas to define public and proprietary reconciliation rule sets. Enterprises can use the rule sets to implement standard-based message interfaces and to translate message content between their proprietary message forms. An implementation of the semantic-mediation architecture augments a general applications-integration toolset developed for the Athena European FP 6 project. The implementation demonstrates the architectures feasibility and suggests directions for future tool enhancements.

A proposal for a unified process for ontology building: UPON

Ontologies are the backbone of the Semantic Web, a semantic-aware version of the World Wide Web. To the end of making available large-scale, high quality domain ontologies, effective and usable methodologies are needed to facilitate the process of Ontology Building. Many of the methods proposed so far only partly refer to well-known and widely used standards from other areas, like software engineering and knowledge representation. In this paper we present UPON, a methodology for ontology building derived from the Unified Software Development Process. A comparative evaluation with other methodologies, as well as the results of its adoption in the context of the Athena Integrated Project, are also discussed.

Integrity Constraints Representation in Object-Oriented Databases

This paper presents a Data Definition Language (DDL), called TQL, based on an Object-Oriented data model characterized by the possibility of expressing integrity constraints in the schema of the database. This work originates from the need to enrich the amount of knowledge represented, declaratively, in the database schema and processed by the Database Management Systems (DBMS). The proposed approach allows the reduction of the amount of code in methods. However, by increasing the power of the DDL, the possibility of introducing errors in the schema also increases. Therefore, rich data models require enhanced checking facilities in order to support the design phase. In the paper, after having formally presented the language TQL, the notions of satisfiability and correctness of a TQL schema, which are strictly related to the notion of legal database state, are introduced. These issues are presented using a formal approach based on a denotational semantics which concerns both the structural part of the schema and the integrity constraints.

A lightweight methodology for rapid ontology engineering

UPON Lite focuses on users, typically domain experts without ontology expertise, minimizing the role of ontology engineers.

An Ontology-based Platform for Semantic Interoperability

In this chapter the main issues of an Ontology-based platform for semantic interoperability, with particular attention to the underlying methodology, are illustrated. The solutions presented here have been developed in the context of Harmonise, an IST project aimed at developing an interoperability platform for SMEs in the tourism sector. The illustrated platform is an advanced software solution, based on the use of computational ontologies, aiming at the reconciliation of conceptual, structural, and formatting differences that hamper information exchange. The proposed approach relies on the availability of a domain ontology, used as a semantic reference for cooperating systems. Then we elaborate on semantic clashes, arising when a conceptual local schema is contrasted with the ontology. Semantic clashes are taken into account when the elements of a conceptual local schema are semantically annotated. Semantic annotation is requested to reconcile existing differences of cooperating information systems. Having illustrated the underlying approach, we briefly report on the main phases required to an information system to enter in the Harmonise space (i.e., to acquire interoperability capability) and, finally, on the overall Harmonise platform.