The paper presents a review of the ONIONS project. ONIONS is committed to developing a large­scale ontology library for medical terminology. The developed methodology exploits a description logic­based design for the modules in the library and makes extended use of generic theories, thus creating a stratification of the modules. Terminological knowledge is acquired by conceptual analysis and ontology integration over a set of authoritative sources. After addressing general issues about conceptual analysis and integration, the methodology is briefly described. The central part of the article presents the investigation we have made on the 476,000 medical concepts singled out by the National Library of Medicine as the Metathesaurus^TM in the UMLS project. This is followed by several case studies concerning lexical polysemy, the interface between ontologies and lexicon, and other special problems encountered in the specification of the ontologies. A section describing the current structure of the library and the generic theories reused is provided. Current results of our research include the integration of some top­level ontologies in the ON9.2 ontology library, and the formalization of the terminological knowledge in the UMLS Metathesaurus.

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In their framework for ontological analysis, Guarino and Welty provide a number of insights that are useful for guiding the design of taxonomic hierarchies. However, the formal statements of these insights as logical schemata are flawed in a number of ways, including inconsistent notation that makes the intended semantics of the logic unclear, false claims of logical consequence, and definitions that provably result in the triviality of some of their property features. This paper makes a negative contribution, by demonstrating these flaws in a rigorous way, but also makes a positive contribution wherever possible, by identifying the underlying intuitions that the faulty definitions were intended to capture, and attempting to formalize those intuitions in a more accurate way. Categories & Descriptors: I.2.4 [Knowledge Representation Formalisms and Methods]: Predicate logic Keywords: ontology, taxonomy 1.

this paper we present our library of ontologies and point out its role for integrating existing guideline models and defining standard representations.

Ontological Mediation: Finding Translations Across Dialects by Asking Questions by Alistair E. Campbell Major Professor: Stuart C. Shapiro, Ph.D.

The conceptual-modeling language ONTOFILE is introduced to cope with the ontological complexity of (distributed) file systems. On the basis of the functional-logic language Relfun and the metadata-element set Dublin Core, files are described by exterior and interior ontologies for the respective structuring of their manifest and underlying features. These declarative representations are subdivided into manifest file designators, attributes, and relations as well as underlying file entities and properties. Exterior designators are Relfun terms uniformly used to name local and global files by URLs of schemes "file" and "http", respectively. Exterior attributes and relations are refined by parameters; single-valued and multiple-valued attributes are represented, respectively, by deterministic and non-deterministic functions. Interior entites and properties are modeled by subsumption heterarchies; property-to-entity applications return the files in which they hold. An interior ontology can be empl...

this paper we investigate a subproblem thereof. Successful communication between two knowledge agents (or any agents for that matter) has a wide variety of prerequisites. One is that the agents use compatible communication protocols. The protocol aspect of communication encompasses establishing a communication channel, deciding on a content language, using the proper speech acts, e.g., assertion, query, etc., transmitting actual information, synchronization, error detection and recovery, etc. The Knowledge Query and Manipulation Language, KQML [Finin and others, 1992], is mainly concerned with that part of the communication between knowledge agents. Another important prerequisite of successful communication is that the exchanged content messages have the proper meaning so that they are understood correctly by the intended recipient. To achieve this, the language of one agent has to be translated into the language of the other. A form of translation --- perhaps better called explanation --- might be necessary even if the agents speak the same language, because they might have different expertise, use different terminology, etc. To facilitate that translation part of communication we are investigating the notion of an ontological mediator (OM), and the feasibility of implementing a computerized OM. An ontological mediator is an agent that enables communication among two or more intelligent agents who either speak different languages or use different ontologies. Unlike KQML mediators who treat the messages of the agents as uninterpreted strings, OMs are to involve themselves in the meanings of the messages being sent among agents. We need mediators because there is no common framework within which the community is developing knowledge agents. The interaction between spec...