Semantic networks

AbstractA semantic network is a graph of the structure of meaning. This article introduces semantic network systems and their importance in Artificial Intelligence, followed by I. the early background; II. a summary of the basic ideas and issues including link types, frame systems, case relations, link valence, abstraction, inheritance hierarchies and logic extensions; and III. a survey of ‘world-structuring’ systems including ontologies, causal link models, continuous models, relevance, formal dictionaries, semantic primitives and intersecting inference hierarchies. Speed and practical implementation are briefly discussed. The conclusion argues for a synthesis of relational graph theory, graph-grammar theory and order theory based on semantic primitives and multiple intersecting inference hierarchies

A Compositional Treatment of Polysemous Arguments in Categorial Grammar

We discuss an extension of the standard logical rules (functional application and abstraction) in Categorial Grammar (CG), in order to deal with some specific cases of polysemy. We borrow from Generative Lexicon theory which proposes the mechanism of {\em coercion}, next to a rich nominal lexical semantic structure called {\em qualia structure}. In a previous paper we introduced coercion into the framework of {\em sign-based} Categorial Grammar and investigated its impact on traditional Fregean compositionality. In this paper we will elaborate on this idea, mostly working towards the introduction of a new semantic dimension. Where in current versions of sign-based Categorial Grammar only two representations are derived: a prosodic one (form) and a logical one (modelling), here we introduce also a more detaled representation of the lexical semantics. This extra knowledge will serve to account for linguistic phenomena like {\em metonymy\/}.Comment: LaTeX file, 19 pages, uses pubsmacs, pubsbib, pubsarticle, leqn

Robust Grammatical Analysis for Spoken Dialogue Systems

We argue that grammatical analysis is a viable alternative to concept spotting for processing spoken input in a practical spoken dialogue system. We discuss the structure of the grammar, and a model for robust parsing which combines linguistic sources of information and statistical sources of information. We discuss test results suggesting that grammatical processing allows fast and accurate processing of spoken input.Comment: Accepted for JNL

Physical Object Representation and Generalization: A Survey of Natural Language Processing Programs

This paper surveys a portion of the field of natural language processing. The main areas considered are those dealing with representation schemes, particularly work on physical object representation, and generalization processes driven by natural language understanding. Five programs serve as case studies for guiding the course of the paper. Within the framework of describing each of these programs, seven other programs, ideas and theories that are relevant to the program in focus are presented. Our current work which integrates representation and generalization is also discussed

Inheritance and complementation : a case study of easy adjectives and related nouns

Mechanisms for representing lexically the bulk of syntactic and semantic information for a language have been under active development, as is evident in the recent studies contained in this volume. Our study serves to highlight some of the most useful tools available for structured lexical representation, in particular, (multiple) inheritance, default specification, and lexical rules. It then illustrates the value of these mechanisms in illuminating one corner of the lexicon involving an unusual kind of complementation among a group of adjectives exemplified by easy. The virtures of the structured lexicon are its succinctness and its tendency to highlight significant clusters of linguistic properties. From its succinctness follow two practical advantages, namely its ease of maintenance and modifiability. In order to suggest how important these may be practically, we extend the analysis of adjectival complementation in several directions. These further illustrate how the use of inheritance in lexical representation permits exact and explicit characterizations of phenomena in the language under study. We demonstrate how the use of the mechanisms employed in the analysis of easy enable us to give a unified account of related phenomena featuring nouns like pleasure, and even the adverbs (adjectival specifiers) too and enough. Along the way we motivate some elaborations of the Head-Driven Phrase Structure Grammar (HPSG) framework in which we couch our analysis, and offer several avenues for further study of this part of the English lexicon

SEAFACT: Semantic Analysis for Animation of Cooking Tasks

SEAFACT is a natural language interface to a computer-generated animation system. SEAFACT operates in the domain of cooking tasks. The domain is limited to a mini-world consisting of a small set of verbs which were chosen because they involve rather complex arm movements which will be interesting to animate. A linguistic analysis of the language found in recipes, included here, was used to define the domain. SEAFACT allows the user to specify tasks in this domain, using a small subset of English. The system then analyzes the English input and produces a representation of the task which can drive lower level motion synthesis procedures. The output of the system contains sufficient non-geometric information needed to schedule task start and end times, describe concurrent actions, and provide reach, grasp, and motion goals