TAILIEUCHUNG - Báo cáo khoa học: "How to train your multi bottom-up tree transducer"

The local multi bottom-up tree transducer is introduced and related to the (non-contiguous) synchronous tree sequence substitution grammar. It is then shown how to obtain a weighted local multi bottom-up tree transducer from a bilingual and biparsed corpus. Finally, the problem of non-preservation of regularity is addressed. Three properties that ensure preservation are introduced, and it is discussed how to adjust the rule extraction process such that they are automatically fulfilled. | How to train your multi bottom-up tree transducer Andreas Maletti Universitat Stuttgart Institute for Natural Language Processing AzenbergstraBe 12 70174 Stuttgart Germany Abstract The local multi bottom-up tree transducer is introduced and related to the non-contiguous synchronous tree sequence substitution grammar. It is then shown how to obtain a weighted local multi bottom-up tree transducer from a bilingual and biparsed corpus. Finally the problem of non-preservation of regularity is addressed. Three properties that ensure preservation are introduced and it is discussed how to adjust the rule extraction process such that they are automatically fulfilled. 1 Introduction A formal translation model is at the core of every machine translation system. Predominantly statistical processes are used to instantiate the formal model and derive a specific translation device. Brown et al. 1990 discuss automatically trainable translation models in their seminal paper. However the IBM models of Brown et al. 1993 are stringbased in the sense that they base the translation decision on the words and their surrounding context. Contrary in the field of syntax-based machine translation the translation models have full access to the syntax of the sentences and can base their decision on it. A good exposition to both fields is presented in Knight 2007 . In this paper we deal exclusively with syntaxbased translation models such as synchronous tree substitution grammars STSG multi bottom-up tree transducers MBOT and synchronous tree-sequence substitution grammars STSSG . Chiang 2006 gives a good introduction to STSG which originate from the syntax-directed translation schemes of Aho 825 and Ullman 1972 . Roughly speaking an STSG has rules in which two linked nonterminals are replaced at the same time by two corresponding trees containing terminal and nonterminal symbols. In addition the nonterminals in the two replacement trees are linked which .

TỪ KHÓA LIÊN QUAN
TAILIEUCHUNG - Chia sẻ tài liệu không giới hạn
Địa chỉ : 444 Hoang Hoa Tham, Hanoi, Viet Nam
Website : tailieuchung.com
Email : tailieuchung20@gmail.com
Tailieuchung.com là thư viện tài liệu trực tuyến, nơi chia sẽ trao đổi hàng triệu tài liệu như luận văn đồ án, sách, giáo trình, đề thi.
Chúng tôi không chịu trách nhiệm liên quan đến các vấn đề bản quyền nội dung tài liệu được thành viên tự nguyện đăng tải lên, nếu phát hiện thấy tài liệu xấu hoặc tài liệu có bản quyền xin hãy email cho chúng tôi.
Đã phát hiện trình chặn quảng cáo AdBlock
Trang web này phụ thuộc vào doanh thu từ số lần hiển thị quảng cáo để tồn tại. Vui lòng tắt trình chặn quảng cáo của bạn hoặc tạm dừng tính năng chặn quảng cáo cho trang web này.