Approximate oracle sentence selection device, method, and program

摘要

PROBLEM TO BE SOLVED: To make it possible to accurately obtain an approximate oracle sentence by restricting an increase in an amount of calculation.SOLUTION: Of nodes A and B that are specified nodes located on the furthest inside, one with fewer next candidates is determined as a specified target end node by a specified target end determination part 21. A portion lattice connecting the nodes A and B is extracted from a word lattice by a next node determination part 22. For each of the next node candidates, a portion path that passes through the next node candidates is generated a predetermined number of times. A translation evaluation scale for a translation candidate sentence corresponding to each of the portion paths is calculated, an improved rate for the next candidate is calculated, and the node candidate with the highest improved rate is used as a specified node. A termination determining part 24 repeats processes by the specified target end determination part 21 and next node determination part 22 until the specified node connects a sentence beginning node to a sentence end node. A translated candidate sentence expressed by each of the specified nodes is output as an approximate oracle sentence.