Nested region algebra extended with variables for tag-annotated text search
Katsuya Masuda, Jun’ichi Tsujii · 2008
This paper presents a framework for searching text regions with specifying annotated information in tag-annotated text by using Region Algebra. We extend the efficient algorithm for region algebra to handle both nested and crossed regions and introduce variables for attribute values to treat tag-annotations in which attributes indicate another tag regions. Our framework have been implemented in a text search engine for MEDLINE, which is a large textbase of abstracts in medical science. Experiments in tag-annotated MEDLINE abstracts demonstrate the effectiveness of specifying annotations and the efficiency of our framework.