| 摘要 |
<p>PROBLEM TO BE SOLVED: To reduce a processing load while searching for a digraph.SOLUTION: A decoder according to an embodiment of the present invention searches for a digraph and generates a lattice, in part or whole, corresponding to an inputted signal string or a feature quantity string of the signal. The decoder includes a token manipulation unit, a node addition unit, and a connection detection unit. The token manipulation unit moves, each time a signal or feature quantity is inputted, each of a plurality of tokens which are the objects having had the beginning state of a path under search assigned thereto, in accordance with the digraph, until a state or transition is reached in which an input signal that is not empty is assigned. The node addition unit adds, each time the tokens are moved, a lattice to a node that corresponds to the state assigned to each of the plurality of tokens. The connection detection unit detects, by referring to the digraph, a node which is connected to the node that was added to the lattice at the i'th time (i is an integer greater than or equal to 1) and which was added to the lattice at the i+1'th time.</p> |
