CESAS: Computerized event sequence abstracting system outlines and applications

For the purpose of efficient utilization of the safety-related event information on the nuclear power plants, a new computer software package CESAS has been under development. CESAS is to systematically abstract the event sequence, that is a series of sequential and causal relationships between occurrences, from the event description written in natural language of English. This system is designed to be based on the knowledge engineering technique utilized in the field of natural language processing. The analytical process in this system consists of morphemic, syntactic, semantic, and syntagmatic analyses. At this moment, the first version of CESAS has been developed and applied to several real event descriptions for studying its feasibility. This paper describes the outlines of CESAS and one of analytical results in comparison with a manually-extracted event sequence