Aristomenis Thanopoulos


2008

pdf bib
Eksairesis: A Domain-Adaptable System for Ontology Building from Unstructured Text
Katia Lida Kermanidis | Aristomenis Thanopoulos | Manolis Maragoudakis | Nikos Fakotakis
Proceedings of the Sixth International Conference on Language Resources and Evaluation (LREC'08)

This paper describes Eksairesis, a system for learning economic domain knowledge automatically from Modern Greek text. The knowledge is in the form of economic terms and the semantic relations that govern them. The entire process in based on the use of minimal language-dependent tools, no external linguistic resources, and merely free, unstructured text. The methodology is thereby easily portable to other domains and other languages. The text is pre-processed with basic morphological annotation, and semantic (named and other) entities are identified using supervised learning techniques. Statistical filtering, i.e. corpora comparison is used to extract domain terms and supervised learning is again employed to detect the semantic relations between pairs of terms. Advanced classification schemata, ensemble learning, and one-sided sampling, are experimented with in order to deal with the noise in the data, which is unavoidable due to the low pre-processing level and the lack of sophisticated resources. An average 68.5% f-score over all the classes is achieved when learning semantic relations. Bearing in mind the use of minimal resources and the highly automated nature of the process, classification performance is very promising, compared to results reported in previous work.

2002

pdf bib
Comparative Evaluation of Collocation Extraction Metrics
Aristomenis Thanopoulos | Nikos Fakotakis | George Kokkinakis
Proceedings of the Third International Conference on Language Resources and Evaluation (LREC’02)

2000

pdf bib
Automatic Extraction of Semantic Similarity of Words from Raw Technical Texts
Aristomenis Thanopoulos | Nikos Fakotakis | George Kokkinakis
Proceedings of the Second International Conference on Language Resources and Evaluation (LREC’00)

pdf bib
Automatic Extraction of Semantic Relations from Specialized Corpora
Aristomenis Thanopoulos | Nikos Fakotakis | George Kokkinakis
COLING 2000 Volume 2: The 18th International Conference on Computational Linguistics