Charles K. Nicholas

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The most prevalent experimental methodology for comparing the effectiveness of information retrieval systems requires a test collection, composed of a set of documents, a set of query topics, and a set of relevance judgments indicating which documents are relevant to which topics. It is well known that relevance judgments are not infallible, but recent(More)
Methods and tools for finding documents relevant to a user’s needs in document corpora can be found in the information retrieval, library science, and hypertext communities. Typically, these systems provide retrieval capabilities for fairly static corpora, their algorithms are dependent on the language for which they are written, e.g. English, and they do(More)
Information retrieval has become more and more important due to the rapid growth of all kinds of information. However, there are few suitable systems available. This paper presents a few approaches that enable large-scale information retrieval for the TELLTALE system. TELLTALE is a dynamic hypertext information retrieval environment. It provides full-text(More)
This paper describes aminimally immersive three-dimensional volumetric interactive information visualization system for management and analysis of document corpora. The system, SFA, uses glyph-based volume rendering, enabling more complex data relationships and information attributes to be visualized than traditional 2D and surface-based visualization(More)
The selection of indexing terms for representing documents is a key decision that limits how effective subsequent retrieval can be. Often stemming algorithms are used to normalize surface forms, and thereby address the problem of not finding documents that contain words related to query terms through infectional or derivational morphology. However,(More)
and application service frameworks). We believe that the Semantic Web markup language DAML+OIL (DARPA Agent Markup Language plus Ontology Inference Layer) will be central to this goal’s realization. The DAML Program aims to develop a Semantic Web markup language that provides sufficient rules for ontology development and that supports intelligent agents and(More)
We describe our efforts to analyze network intrusion detection data using information retrieval and visualization tools. By regarding Telnet sessions as documents, which may or may not include attacks, a session that contains a certain type of attack can be used as a query, allowing us to search the data for other instances of that same type of attack. The(More)
Collaborative filtering is a technique for recommending documents to users based on how similar their tastes are to other users. If two users tend to agree on what they like, the system will recommend the same documents to them. The generalized vector space model of information retrieval represents a document by a vector of its similarities to all other(More)
A new model of hypertext, in which text is augmented with a ne-grained semantic net representation of the text, solves several problems found in traditional hypertext models. In the new model, hypertext links are paths that originate in the text, move across to the semantic net, traverse a sub-path through the semantic net, then return to a diierent point(More)