@inproceedings{PoveyHannemannBoulianneetal.2012, author = {Povey, Daniel and Hannemann, Mirko and Boulianne, Gilles and Burget, Luk{\´a}š and Ghoshal, Arnab and Janda, Miloš and Karafi{\´a}t, Martin and Kombrink, Stefan and Motl{\´i}ček, Petr and Qian, Yanmin and Riedhammer, Korbinian and Vesel{\´y}, Karel and Thang Vu, Ngoc}, title = {Generating Exact Lattices in the WFST Framework}, series = {2012 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP), Kyoto, Japan, May 2012.}, booktitle = {2012 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP), Kyoto, Japan, May 2012.}, pages = {4213 -- 4216}, year = {2012}, abstract = {We describe a lattice generation method that is exact, i.e. it satisfies all the natural properties we would want from a lattice of alternative transcriptions of an utterance. This method does not introduce substantial overhead above one-best decoding. Our method is most directly applicable when using WFST decoders where the WFST is "fully expanded", i.e. where the arcs correspond to HMM transitions. It outputs lattices that include HMM-state-level alignments as well as word labels. The general idea is to create a state-level lattice during decoding, and to do a special form of determinization that retains only the best-scoring path for each word sequence. This special determinization algorithm is a solution to the following problem: Given a WFST A, compute a WFST B that, for each input-symbol-sequence of A, contains just the lowest-cost path through A.}, language = {en} }