| Presentation | 1998/7/23 A Parameter Estimation of a Probabilistic Context Free Grammar on a Sparse Sample Yoichi TOMIURA, Takeshi NISHIDA, Toru HITAKA, |
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| PDF Download Page | PDF download Page Link |
| Abstract(in Japanese) | (See Japanese page) |
| Abstract(in English) | We can disambiguate syntactic structures of a sentence based on a Porbabilistic Context Free Grammar (PCFG), where syntactic categories are subdivided semantically so that dependency constraints are expressed in the production rules. But to describe dependency constraints in detail causes an explosion of the number of production reles, which makes it difficult to collect enough size of sample to get a reliable maximum likelihood estimate of parameters in the PCFG. This paper proposes a new estimator of parameters in the PCFG and show the result of an experiment in disambiguation of English prepositional phrase attachment. The mean error of proposed estimator is practically smaller than the one of the maximum likelihood estimator, and this tendency is more conspicuous on a small size of sample. |
| Keyword(in Japanese) | (See Japanese page) |
| Keyword(in English) | Parameter Estimation / Smoothing / PCFG / Dependency Constraints |
| Paper # | NLC98-12 |
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| Conference Information | |
| Committee | NLC |
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| Conference Date | 1998/7/23(1days) |
| Place (in Japanese) | (See Japanese page) |
| Place (in English) | |
| Topics (in Japanese) | (See Japanese page) |
| Topics (in English) | |
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| Vice Chair | |
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| Paper Information | |
| Registration To | Natural Language Understanding and Models of Communication (NLC) |
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| Language | JPN |
| Title (in Japanese) | (See Japanese page) |
| Sub Title (in Japanese) | (See Japanese page) |
| Title (in English) | A Parameter Estimation of a Probabilistic Context Free Grammar on a Sparse Sample |
| Sub Title (in English) | |
| Keyword(1) | Parameter Estimation |
| Keyword(2) | Smoothing |
| Keyword(3) | PCFG |
| Keyword(4) | Dependency Constraints |
| 1st Author's Name | Yoichi TOMIURA |
| 1st Author's Affiliation | Graduate School of Information Science and Electrical Engineering, Kyushu University() |
| 2nd Author's Name | Takeshi NISHIDA |
| 2nd Author's Affiliation | Graduate School of Information Science and Electrical Engineering, Kyushu University |
| 3rd Author's Name | Toru HITAKA |
| 3rd Author's Affiliation | Graduate School of Information Science and Electrical Engineering, Kyushu University |
| Date | 1998/7/23 |
| Paper # | NLC98-12 |
| Volume (vol) | vol.98 |
| Number (no) | 209 |
| Page | pp.pp.- |
| #Pages | 8 |
| Date of Issue | |