Bibliographic pattern matching using the ICL Distributed Array Processor

Abstract

This article discusses the use of the ICL Distributed Array Processor (DAP), a highly parallel array processor containing 4096 processing elements, for pattern-matching operations in a bibliographic retrieval system. The hardware and software features of the DAP are described, together with a pattern-matching algorithm that makes full use of the DAP's parallelism. This algorithm can be used to search for exact patterns, right-hand or left-hand truncated patterns, embedded patterns, patterns containing fixed-length (FLDC) or variable-length (VLDC) don't care characters, and patterns that specify adjacent words. Experiments with a set of 898 query patterns and 2472 titles and abstracts from the INSPEC database show that right-hand truncation searches can be carried out on the DAP about ten times faster than searches using the Aho-Corasick pattern-matching algorithm on a Prime 550 minicomputer, the relative advantage of the DAP increasing linearly with a decrease in the number of query patterns. Simulated FLDC and VLDC searches on the DAP take about two and three times as long as right-hand truncation searches, respectively. © 1988 John Wiley & Sons, Inc.