| 摘要 |
Methods and systems for language translation are disclosed. The translator is based on finite state machines that can convert a pair of input symbol sequences to a pair of output symbol sequences. The translator includes a lexicon associating a finite state machine with a pair of head words with corresponding meanings in the source and target languages. The state machine for a source language head word w and a target language head word &ngr; reads the dependent words of w to its left and right in a source sentence and proposes corresponding dependents to the left and right of &ngr; in a target language sentence being constructed, taking account of the required word order for the target language. The state machines are used by a transduction search engine to generate a plurality of candidate translations via a recursive process wherein, a source language head word is first translated as described above, and then the heads of each of the dependent phrases are similarly translated, and then their dependents and so on. Only the state machines corresponding to the words in the source language string are activated and used by the search engine. The translator also includes a parameter table that provides costs for actions taken by each finite state machine in converting between the source language and the target language. The costs for machine transitions are indicative of the likelihood of co-occurence of pairs of words in the source language, and between corresponding pairs of words in the target language. The transduction search engine provides a total cost, using the parameter table, for each of the candidate translations. The total cost of a translation is the sum of the cost for all actions taken by each machine involved in the translation.
|
