A constraint-based specification of periodic patterns in time-oriented data

We use a constraint based language to specify periodic temporal patterns. The Constraint-based Pattern Specification Language (CAPSUL) is simple to use, but allows a wide variety of patterns to be expressed. CAPSUL solves problems such as: (1) how to use calendar based constraints to define repetition of a periodic event; (2) what temporal relations must exist between consecutive repeats of a pattern; and (3) how expressivity is limited if the same temporal relations must hold between each pair of intervals in the pattern. We implemented CAPSUL in a temporal-abstraction system called Resume, and used it in a graphical knowledge acquisition tool to acquire domain-specific knowledge from experts about patterns to be found in large databases. We summarize the results of preliminary experiments using the pattern specification and pattern detection tools on data about patients who have cancer and have been seen at the University of Chicago bone marrow transplantation center.