Intersecting Hierarchical and Phrase-Based Models of Translation. Formal Aspects and Algorithms
We address the problem of construct- ing hybrid translation systems by inter- secting a Hiero-style hierarchical sys- tem with a phrase-based system and present formal techniques for doing so. We model the phrase-based component by introducing a variant of weighted ﬁnite-state automata, called σ-automata, provide a self-contained description of a general algorithm for intersect- ing weighted synchronous context-free grammars with ﬁnite-state automata, and extend these constructs to σ-automata. We end by brieﬂy discussing complexity properties of the presented algorithms.