you cannot use a negated character class to match a q not followed by a u. Negative lookahead provides the solution: q(?!u).
Positive lookahead works just the same. q(?=u) matches a q that is followed by a u
Y. Li, R. Krishnamurthy, S. Raghavan, S. Vaithyanathan, und H. Jagadish. Proceedings of the 2008 Conference on Empirical Methods in Natural Language Processing, Seite 21--30. Honolulu, Hawaii, Association for Computational Linguistics, (Oktober 2008)
P. Pantel, und M. Pennacchiotti. Ontology Learning and Population: Bridging the Gap between Text and Knowledge, Volume 167 von Frontiers in Artificial Intelligence and Applications, IOS Press, (2008)