Robert M. MacGregor

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This paper presents a symbol level account of some of the representation and reasoning structures within the LOOM knowledge representation system. Reasoning in LOOM centers around a classifier whose primary function is to construct a taxonomy of all descriptions that have been entered into the system. The LOOM classifier is unique in that it constructs a(More)
This paper describes the design of a pattern matcher for a knowledge representation system called LOOM. The pattern matcher has a very rich pattern-forming language, and is logic-based, with a deductive mechanism which includes a truth-maintenance component as an integral part of the pattern-matching logic. The technology behind the LOOM matcher uses an(More)
A description classifier organizes concepts and relations into a taxonomy based on the results of subsumption computations applied to pairs of relation definitions. Until now, description classifiers have only been designed to operate over definitions phrased in highly restricted subsets of the predicate calculus. This paper describes a classifier able to(More)
In this paper, we present a scalable peer-to-peer RDF repository, named RDFPeers, which stores each triple in a multiattribute addressable network by applying globally known hash functions. Queries can be efficiently routed to the nodes that store matching triples. RDFPeers also enables users to selectively subscribe to RDF content. In RDFPeers, both the(More)
| Rules and frames are two knowledge representation schemes whose strengths and weakness are complementary to each other. Although several previous systems have attempted to integrate the two, few e orts have been made to incorporate the terminological knowledge of the frame-based systems into the rule-based paradigm. To achieve a deep integration of the(More)
This paper describes the practical application of ontologies in designing knowledge-based systems. We built a common ontology to allow knowledge sharing among several applications in the domain of air campaign planning. In trying to reuse this shared ontology, we confirmed previous findings in the knowledge acquisition literature: it is difficult to(More)