clarke@utcsri.UUCP (Jim Clarke) (11/25/86)
(GB = Galbraith Building, 35 St. George Street) A.I. SEMINAR, Tuesday, December 2, 3 pm, GB 119 Professor Michael Leyton Computer Science, SUNY "A Process Grammar for Shape" A computational theory is offered of the way in which process-history is recovered from shape. It is claimed that curvature extrema are cru- cially used in the inference of processes from shape, and rules are developed that formalize the inference procedure. We then establish a process-grammar of only six types of operations to express the relationship between any two given shapes such that one shape is represented as a later stage in the development of the other; i.e. one shape is described as the extrapolation of processes inferred in the other under the above inference rules. More formally, a deformation is expressed as a transformation of process-records - a technique reminiscent of Chomsky's description of linguistic transformations in terms of transitions between phrase-structure trees. In the present case, our process-grammar has the psychological role of explaining the curvature extrema in terms of a sequence of psychologi- cally meaningful deformations. We find that the grammar thereby stratifies shape-space into several intersecting systems of strata, where each strata-system represents a particular process-history of successive modifi- cation. -- Jim Clarke -- Dept. of Computer Science, Univ. of Toronto, Canada M5S 1A4 (416) 978-4058 {allegra,cornell,decvax,linus,utzoo}!utcsri!clarke