We are experimenting with the representation of a DTD and associated documents (i.e., documents conformant to the DTD) in a knowledge representation (KR) system, in order to provide more sophisticated query and retrieval from TEI documents than current systems provide. We are using CLASSIC, a frame-based representation system developed at AT&T Bell Laboratories. Like many KR systems, CLASSIC enables the definition of structured concepts/frames, their organization into taxonomies, the creation and manipulation of individual instances of such concepts, and inference such as inheritance, relation transitivity, inverses, etc. In addition, CLASSIC provides for the key inferences of subsumption and classification. By representing a document as an individual instance of a hierarchy of concepts derived from the DTD, and by allowing the creation of additional user-defined concepts and relations, sophisticated query and retrieval operations can be performed. This paper describes CLASSIC and the formalism of description logic that underlies it, and demonstrates how it can be used for enhanced retrieval from richly encoded documents. 1.

Subject-based classification is an important part of information retrieval, and has a long history in libraries, where a subject taxonomy was used to determine the location of books on the shelves. We have been studying the notion of subject itself, in order to determine a formal ontology of subjects for a large-scale digital library card catalog system. Deep analysis reveals a lot of ambiguity regarding the usage of subjects in existing systems and terminology, and we attempt to formalize these notions into a single framework for representing it.

It has long been realised that the web could benefit from having its content understandable and available in a machine processable form, and it is widely agreed that ontologies will play a key role in providing much enabling infrastructure to support this goal. In this chapter we review briefly a selected history of description logics in web-based information systems, and the more recent developments related to OIL, DAML+OIL and the semantic web. OIL and DAML+OIL are ontology languages specifically designed for use on the web; they exploit existing web standards (XML, RDF and RDFS), adding the formal rigor of a description logic and the ontological primitives of object oriented and frame based systems.

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Several significant problems exist when applying knowledge representation systems to real problems. In particular, the obscurity of LISP, the resource consumption, garbage collection, and the single user nature of most KR systems can prevent the technology from being accepted in many non-research environments. This paper briefly presents one way to address these problems with a web interface, and outlines some of the general principles that guided the implementation of a web interface for Classic. 1 Introduction Implemented Knowledge Representation systems have much to offer in solving serious problems in the real world. In pursuing this belief, we have gathered experience transferring KR technology to users outside traditional academic circles. Most of this work has been in the context of AI & Software Engineering [ Welty, 1995a; 1995b ] , but a recent project in building a card catalog system for the web [ Welty, 1996 ] has led to some new web-based solutions for the problems facin...

Introduction We are working on several aspects of using description logics for digital libraries. Our main goal is to enable robust retrieval of information stored in a digital library. We have found that the use of description logics has also served to assist in ensuring the integrity of the data. In addtion, the recent release of XML has made us aware of an enormous opportunity to leverage description logic technology, in reality against the widely recognized problems with web searching. The three main thrusts of the project are: 1. Developing an ontology for card catalog data, traditionally known as meta-data, including a browsable and queryable hierarchy of subject classifications, similar to, yet substatially deeper and more complex than, the taxonomies which exist today. [1] 2. Developing techniques for representing mark up elements (or tags) specified in an SGML or XML DTD, and instantiating those representations on fully marked-up texts.[2]

Abstract. Complex systems-of-systems are becoming more prevalent in the increasingly interconnected and ever shrinking world engendered by modern information technology. These may be of a commercial or military nature, thus, governments and commercial organisations, alike, confront the challenge of planning, establishing and maintaining them. The achievement of highquality solutions to systems-of-systems problems requires decision-making support from methods that can take account of the interests of multiple stakeholders, while at the same time dealing with involved constraints on the solution options. This paper examines some techniques which might be combined to form a suitable decision analysis method. 1.

The AXIOM project is a collaboration between researchers in knowledge representation (KR), markup languages such as XML, linguistic analysis, text encoding, databases, humanities

The paper presents on-going research towards generic tools and methods for fulfilling the combined needs of information producers and consumers. It presents the principles, framework and key issues of our research, and focuses on developments concerning INFO-PRESENTER. This is an interactive system that provides knowledge-based and layout-driven information presentations, intending to satisfy the idiosyncrasies of information consumers, supporting a great amount of tailoring information to their needs, interests, preferences and background knowledge. The paper focuses mostly on themes concerning knowledge representation and layout specifications. The representation framework provides a general model for the specification of information requirements in terms of media-independent information item categories and types of information views for realising information. Layout specifications provide generic rules for tailoring information delivery, in conjunction with the information specifica...

This paper focuses briefly on the work we have been doing in developing an ontology of modalities for libraries. This ontology is founded on a simple, yet profound, observation: many of the different entities within a library will be versions of the same thing. Some of these may simply be identical copies of the same book, journal, etc., but even in the present day the majority of these cases are different modalities of the same thing. The prototypical example was formulated in [Welty, 1994]. A paper in the library, which has attributes such as author, abstract, date, what it was published in, etc., may be available in several formats, such as HTML, Postscript, PDF, etc. The key here is that the postscript file, the HTML file, and the PDF file, are all the same paper. They have the same author, abstract, etc., yet there are attributes of the different formats that are distinct, and are meaningful in the role of those files as different views of the paper. Obviously each has a different location in the filesystem, in addition the HTML file may have an html-version attribute, the postscript file may have a "translated by" attribute, etc. Finally, the paper may well exist in paper form as well, and this is merely another view of the paper. The paper form would have attributes like location (such as it's library catalog number - perhaps inherited from the book or journal the paper was published in. This has important implications for the card catalog system. Many views of the same document can be stored in the catalog without requiring different entries. A search for the paper will have a single result, and then give the user the option of "delivery formats". In fact, part of the AXIOM project includes research into a query language that will allow users to construct new ...