To construct an expandable and adaptable dialog system which handles multiple tasks, we proposed a dialog system using a weighted finite-state transducer (WFST) in which users concept and system action tags are input and output of the transducer, respectively. To test the potential of the WFST-based dialog management (DM) platform using statistical DM models, we constructed a dialog system using a human-to-human spoken dialog corpus for hotel reservation, which is annotated with Interchange Format (IF). A scenario WFST and a spoken language understanding (SLU) WFST were obtained from the corpus and then composed together and optimized. We evaluated the detection accuracy of the system next actions. In this paper, we focus on how WFST optimization operations contribute to the performance of the system. In addition, we have constructed a full WFST-based dialog system by composing SLU, scenario and sentence generation (SG) WFSTs. We show an example of a hotel reservation dialog with the fully composed system and discuss future work.
Bibliographic reference. Hori, Chiori / Ohtake, Kiyonori / Misu, Teruhisa / Kashioka, Hideki / Nakamura, Satoshi (2009): "Recent advances in WFST-based dialog system", In INTERSPEECH-2009, 268-271.