| Presentation | 2007/12/13 Efficient estimation method of scaling factors among probabilistic models in speech recognition Tadashi EMORI, Yoshifumi ONISHI, Koichi SHINODA, |
|---|---|
| PDF Download Page | PDF download Page Link |
| Abstract(in Japanese) | (See Japanese page) |
| Abstract(in English) | We propose a new efficient method for estimating scaling factors among probabilistic models in speech recognition. Most speech recognition systems consist of more than one model, include an acoustic and a language model, and require scaling factors to balance probabilities among them. The scaling factors are conventionally optimized in preliminary recognition tests using data for development. In our proposed method, the scaling factors are regarded as parameters of a log-linear model, and they are estimated using a gradient-ascent method based on the maximum a posteriori probability criterion. Posterior probability is computed using word-lattices generated by a speech recognizer. We employ an iteration technique which repeats a word-lattice-generation/scaling-factor-estimation process, and the resulting scaling factor estimation is robust with respect to the changes in initial values. In an experimental evaluation of our method by LVCSR using Japanese dialogue speech data, estimated scaling factors were nearly identical to optimal values obtained in a greedy grid search. We have also confirmed that estimated scaling factors changed little with variations in initial values. |
| Keyword(in Japanese) | (See Japanese page) |
| Keyword(in English) | speech recognition / scaling factor / log-linear model / word lattice |
| Paper # | NLC2007-41,SP2007-104 |
| Date of Issue |
| Conference Information | |
| Committee | NLC |
|---|---|
| Conference Date | 2007/12/13(1days) |
| Place (in Japanese) | (See Japanese page) |
| Place (in English) | |
| Topics (in Japanese) | (See Japanese page) |
| Topics (in English) | |
| Chair | |
| Vice Chair | |
| Secretary | |
| Assistant | |
| Paper Information | |
| Registration To | Natural Language Understanding and Models of Communication (NLC) |
|---|---|
| Language | JPN |
| Title (in Japanese) | (See Japanese page) |
| Sub Title (in Japanese) | (See Japanese page) |
| Title (in English) | Efficient estimation method of scaling factors among probabilistic models in speech recognition |
| Sub Title (in English) | |
| Keyword(1) | speech recognition |
| Keyword(2) | scaling factor |
| Keyword(3) | log-linear model |
| Keyword(4) | word lattice |
| 1st Author's Name | Tadashi EMORI |
| 1st Author's Affiliation | NEC Corporation() |
| 2nd Author's Name | Yoshifumi ONISHI |
| 2nd Author's Affiliation | NEC Corporation |
| 3rd Author's Name | Koichi SHINODA |
| 3rd Author's Affiliation | Tokyo Institute of Technology |
| Date | 2007/12/13 |
| Paper # | NLC2007-41,SP2007-104 |
| Volume (vol) | vol.107 |
| Number (no) | 405 |
| Page | pp.pp.- |
| #Pages | 5 |
| Date of Issue | |