Baijun Ji


Increasing Visual Awareness in Multimodal Neural Machine Translation from an Information Theoretic Perspective
Baijun Ji | Tong Zhang | Yicheng Zou | Bojie Hu | Si Shen
Proceedings of the 2022 Conference on Empirical Methods in Natural Language Processing

Multimodal machine translation (MMT) aims to improve translation quality by equipping the source sentence with its corresponding image. Despite the promising performance, MMT models still suffer the problem of input degradation: models focus more on textual information while visual information is generally overlooked. In this paper, we endeavor to improve MMT performance by increasing visual awareness from an information theoretic perspective. In detail, we decompose the informative visual signals into two parts: source-specific information and target-specific information. We use mutual information to quantify them and propose two methods for objective optimization to better leverage visual signals. Experiments on two datasets demonstrate that our approach can effectively enhance the visual awareness of MMT model and achieve superior results against strong baselines.


Combining Static Word Embeddings and Contextual Representations for Bilingual Lexicon Induction
Jinpeng Zhang | Baijun Ji | Nini Xiao | Xiangyu Duan | Min Zhang | Yangbin Shi | Weihua Luo
Findings of the Association for Computational Linguistics: ACL-IJCNLP 2021


Bilingual Dictionary Based Neural Machine Translation without Using Parallel Sentences
Xiangyu Duan | Baijun Ji | Hao Jia | Min Tan | Min Zhang | Boxing Chen | Weihua Luo | Yue Zhang
Proceedings of the 58th Annual Meeting of the Association for Computational Linguistics

In this paper, we propose a new task of machine translation (MT), which is based on no parallel sentences but can refer to a ground-truth bilingual dictionary. Motivated by the ability of a monolingual speaker learning to translate via looking up the bilingual dictionary, we propose the task to see how much potential an MT system can attain using the bilingual dictionary and large scale monolingual corpora, while is independent on parallel sentences. We propose anchored training (AT) to tackle the task. AT uses the bilingual dictionary to establish anchoring points for closing the gap between source language and target language. Experiments on various language pairs show that our approaches are significantly better than various baselines, including dictionary-based word-by-word translation, dictionary-supervised cross-lingual word embedding transformation, and unsupervised MT. On distant language pairs that are hard for unsupervised MT to perform well, AT performs remarkably better, achieving performances comparable to supervised SMT trained on more than 4M parallel sentences.