tailieunhanh - Báo cáo khoa học: "The Costs of Inheritance in Semantic Networks"

Questioning texts represented in semantic relations I requires the recognition that synonyms, instances, and hyponyms may all satisfy a questioned term. A basic procedure for accomplishing such loose matching using inheritance from a taxonomic organization of the dictionary is defined in analogy with the unification a!gorithm used for theorem proving, and the costs of its application are analyzed. It is concluded tl,at inherit,~nce logic can profitably be ixiclu.'ted in the basic questioning procedure. . | The Costs of Inheritance in Semantic Networks Rob t F. Simmons The University of Texas Austin Abstract Questioning texts represented in semantic relations1 requires the recognition that synonyms instances and hyponyms may all satisfy a questioned term. A basic procedure for accomplishing such loose matching using inheritance from a taxonomic organization of the dictionary is defined in analogy with the unification algorithm used for theorem proving and the costs of its application are analyzed. It is concluded that inheritance logic can profitably be included in the basic questioning procedure. AJ Handbook Study- In studying the of answering questions from fifty pages of the Al Handbook it is striking that such subsections as those describing problem representations are organized so as to define conceptual dictionary entries for the terms. First class definitions are offered and their terms defined then examples are given and the computational terms of the definitions are instantiated. Finally the technique described is applied to examples and redefined mathematically. Organizing these texts by hand into coherent hierarchic structures of discourse results in very usable conceptual dictionary definitions that are related by taxonomic and partitive relations leaving gaps only for non-technical terms. For example in give snapshots of the state of the problem at various stages in its solution terms such as state problem and solution are defined by the text while give snapshots and stages are not. Our first studies in representing and questioning this text have used semantic networks with a minima number of case arcs to represent the sentences and Superset Instance and Of Has arcs to represent respectively taxonomic and partitive relations between concepts. Equivalence arcs are also used to represent certain relations signified by uses of is and apposition Supported by NSF Grant 1ST 8200976 and AND and OR arcs represent conjunction. Since June 1982 eight .