Generating conceptual graphs from functional structures
Pierre Massicotte · Summit (Simon Fraser University) · 1988
Natural language analysis is the p x & s of extracting the infomation carrig by the variousCOIlStNctf of €he language.This information can be used for various p~rposes, and depending on a i pmicular purpose, c+ be appropriately npmmled by a specific formalism.Analysis systems can be divided inlo many spscialized tasks.This thesis is concerned with one of these tasks for natural language understanding.A semantic interpreter based upon a linguistica r ) is developed, wHch produces Conceptual Graph represcntati0n.s.Conceptual Graphs have been swxs$fully used for other language processing tasks.Since there exist systems LO generate language from this formalism [S, 4,231, our interpreter r could conaibute to a machine vanslation system.Thtougbout this work, emphasis has been given &guistic adequacy and implementation methodology rather than extensive language coverage: , ' * we have developed a methodology suitable to tbe tyo formalisms used.More possibilities offered d by these formalism3 could be add@'@ thig me&dology to augment language coverage.4' A r e p y o n for direded graphs in Logic programming is also introduced.Its advanvge lies in 7 the possibility of verifying node accessibility .veryefficiently.The scope of the ideas presented for this representation goes beyond the particular application wittiin which we exemplify it.For i n a w e , the techniques developed for this verification operation can be used in any artificial .inrefligence application that represents knowledge through graphs.P Tl-tis representation scheme contributes to the efficient implementation of an important semantic verification in our system.In a different framework, this representation sckme has been used to of c~llstraul * ts e x -in terms of node dominkon in a syntactic s m m .j This thesis would m t be mmplete ethout including the expression of my gratitude-towards many people who conuihted time and effort.First, I would like to thank my senior supervisor, Dr. V. w,' not only for her guidance and generow k l p she provided thloughoa this work but also for the responsibilities and opportunities she offered me during my entire degree.Her constant support and emuragemem have been an essential asset in bringing me to this point.i,wouid also like to w h ~l e d g e my o W r supervisor, Dr. R Hadley, for the useful comments and'suggestiom ' E he brought to my attention.In addition, the understanding and care he has shown me at all timcs are very much appreciated.Dr. N. Cercone, my exte al examiner, also -helped improving this ?' document co-iderably.His positive and w w a t e suggestions transformed the fear of the defcnsc inlo an instructive experience.Finally, Dr. P. Saint-Dizier contributed to this work through many conversations we had.It was he who inuoducgd me to Lexical Functional Grammar while hc was visiting Simon Frasr