Amedeo Cappelli

AI*IA 2003: Advances in Artificial Intelligence

Efficiency of the first-order logic proof procedure is a major issue when deduction systems are to be used in real environments, both on their own and as a component of larger systems (e.g., learning systems). Hence, the need of techniques that can perform such a process with reduced time/space requirements (specifically when performing resolution). This paper proposes a new algorithm that is able to return the whole set of solutions to θ-subsumption problems by compactly representing substitutions. It could be exploited when techniques available in the literature are not suitable. Experimental results on its performance are encouraging.

An integrated environment for lexical analyses

This article describes a project whose aim is to specify tools to be integrated in an environment for lexical analyses. As a result, a prototype of a workbench can be created which provides a user with several modules possessing different functions, in order to approach a text from different viewpoints. The prototype has been implemented on Macintosh. Every module can be used autonomously; once integrated in the environment they realize a sort of network of tools interacting with one another. Let us take a look at the single components of the system. Firstly, the user has at his disposal tools for the processing of a text in order to obtain indexes, concordances, lmnmatizations and various types of statistic analyses. The prototype also supplies the representational tools for structuring knowledge. A module containing an ontological reference scheme may be used to show a network of relationships between concepts or to suggest the description of single concepts. The user is also given a further possibility: access, starting from any node in the ontological network, to a lexical archive indicating all the terms that describe a specific conceptual field, with their relative definitions. In this way, the system helps in the interactive treatment of texts and nmkes it possible to mmlyze and to organize various types of information about a text. The front-end and certain modules have becu implemented by using HyperCard TM. This has certain cousequences on the interface to the global system, and on the structure add function of any single component. In a hypermedia framework, a text is no more a sequence of words or sentences, as phenomenologically it appears to a user, but it is a virtnal network of the associations implicit in it. In this way, the substance of a text coincides with the set of its possible readings: its informative content is a magma of fragments whose sense is re-created in the path of each reading. From a theoretical viewpoint, a hypertext denotes a non-linear writing whose structure is a set of nodes liuk~l by arcs. Nodes contain informative contents, while arcs represent the possible associations between different informative contents, in accordance with the logic of the hypertext itself. To sum up, the organization of the diflerent knowledge sources within the system facilitates the behaviour of a human operator working on a text from different viewpoints by using the computational metaphor of AN INTEGRATED ENVIRONMENT FOR LEXICAL ANALYSES I

Chunking mechanism for a knowledge representation system

A chunking mechanism to be used as a multipurpose device in a knowledge representation system is presented. The most relevant characteristics of this system are outlined in order to present the theoretical framework in which chunking has been developed. Uses of chunking as a learning mechanism and as a working memory are described.

Conceptual and linguistic constraints for the construction of a knowledge base in archaeology

This article describes a set of constraints for the construction of a knowledge base in archaeology, which satisfies explicit conceptual and linguistic assumptions. The model of organization has been specified by integrating a formalism, derived from structured inheritance networks and elements of conceptual dictionaries. Certain types of constraints have also been introduced to guarantee the coherence of the ontological modeling.