Yang Xiang


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Controllable Contrastive Generation for Multilingual Biomedical Entity Linking
Tiantian Zhu | Yang Qin | Qingcai Chen | Xin Mu | Changlong Yu | Yang Xiang
Proceedings of the 2023 Conference on Empirical Methods in Natural Language Processing

Multilingual biomedical entity linking (MBEL) aims to map language-specific mentions in the biomedical text to standardized concepts in a multilingual knowledge base (KB) such as Unified Medical Language System (UMLS). In this paper, we propose Con2GEN, a prompt-based controllable contrastive generation framework for MBEL, which summarizes multidimensional information of the UMLS concept mentioned in biomedical text into a natural sentence following a predefined template. Instead of tackling the MBEL problem with a discriminative classifier, we formulate it as a sequence-to-sequence generation task, which better exploits the shared dependencies between source mentions and target entities. Moreover, Con2GEN matches against UMLS concepts in as many languages and types as possible, hence facilitating cross-information disambiguation. Extensive experiments show that our model achieves promising performance improvements compared with several state-of-the-art techniques on the XL-BEL and the Mantra GSC datasets spanning 12 typologically diverse languages.

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EARA: Improving Biomedical Semantic Textual Similarity with Entity-Aligned Attention and Retrieval Augmentation
Ying Xiong | Xin Yang | Linjing Liu | Ka-Chun Wong | Qingcai Chen | Yang Xiang | Buzhou Tang
Findings of the Association for Computational Linguistics: EMNLP 2023

Measuring Semantic Textual Similarity (STS) is a fundamental task in biomedical text processing, which aims at quantifying the similarity between two input biomedical sentences. Unfortunately, the STS datasets in the biomedical domain are relatively smaller but more complex in semantics than common domain, often leading to overfitting issues and insufficient text representation even based on Pre-trained Language Models (PLMs) due to too many biomedical entities. In this paper, we propose EARA, an entity-aligned, attention-based and retrieval-augmented PLMs. Our proposed EARA first aligns the same type of fine-grained entity information in each sentence pair with an entity alignment matrix. Then, EARA regularizes the attention mechanism with an entity alignment matrix with an auxiliary loss. Finally, we add a retrieval module that retrieves similar instances to expand the scope of entity pairs and improve the model’s generalization. The comprehensive experiments reflect that EARA can achieve state-of-the-art performance on both in-domain and out-of-domain datasets. Source code is available.

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CCEval: A Representative Evaluation Benchmark for the Chinese-centric Multilingual Machine Translation
Lianzhang Lou | Xi Yin | Yutao Xie | Yang Xiang
Findings of the Association for Computational Linguistics: EMNLP 2023

The Chinese-centric Multilingual Machine Translation (MMT) has gained more importance recently due to increasing demands from international business development and cross-cultural exchanges. However, an important factor that limits the progress of this area is the lack of highly representative and high-quality evaluation benchmarks. To fill this gap, we propose CCEval, an impartial and representative Chinese-centric MMT evaluation dataset. This benchmark dataset consists of 2500 Chinese sentences we meticulously selected and processed, and covers more diverse linguistic features as compared to other MMT evaluation benchmarks. These sentences have been translated into 11 languages of various resource levels by professional translators via a rigorously controlled process pipeline to ensure their high quality. We conduct experiments to demonstrate our sampling methodology’s effectiveness in constructing evaluation datasets strongly correlated with human evaluations. The resulting dataset enables better assessments of the Chinese-centric MMT quality. Our CCEval benchmark dataset is available at https://bright.pcl.ac.cn/en/offlineTasks.

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Improving Low-resource Question Answering by Augmenting Question Information
Andong Chen | Yuan Sun | Xiaobing Zhao | Rosella Galindo Esparza | Kehai Chen | Yang Xiang | Tiejun Zhao | Min Zhang
Findings of the Association for Computational Linguistics: EMNLP 2023

In the era of large models, low-resource question-answering tasks lag, emphasizing the importance of data augmentation - a key research avenue in natural language processing. The main challenges include leveraging the large model’s internal knowledge for data augmentation, determining which QA data component - the question, passage, or answer - benefits most from augmentation, and retaining consistency in the augmented content without inducing excessive noise. To tackle these, we introduce PQQ, an innovative approach for question data augmentation consisting of Prompt Answer, Question Generation, and Question Filter. Our experiments reveal that ChatGPT underperforms on the experimental data, yet our PQQ method excels beyond existing augmentation strategies. Further, its universal applicability is validated through successful tests on high-resource QA tasks like SQUAD1.1 and TriviaQA.


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CLLE: A Benchmark for Continual Language Learning Evaluation in Multilingual Machine Translation
Han Zhang | Sheng Zhang | Yang Xiang | Bin Liang | Jinsong Su | Zhongjian Miao | Hui Wang | Ruifeng Xu
Findings of the Association for Computational Linguistics: EMNLP 2022

Continual Language Learning (CLL) in multilingual translation is inevitable when new languages are required to be translated. Due to the lack of unified and generalized benchmarks, the evaluation of existing methods is greatly influenced by experimental design which usually has a big gap from the industrial demands. In this work, we propose the first Continual Language Learning Evaluation benchmark CLLE in multilingual translation. CLLE consists of a Chinese-centric corpus — CN-25 and two CLL tasks — the close-distance language continual learning task and the language family continual learning task designed for real and disparate demands. Different from existing translation benchmarks, CLLE considers several restrictions for CLL, including domain distribution alignment, content overlap, language diversity, and the balance of corpus. Furthermore, we propose a novel framework COMETA based on Constrained Optimization and META-learning to alleviate catastrophic forgetting and dependency on history training data by using a meta-model to retain the important parameters for old languages. Our experiments prove that CLLE is a challenging CLL benchmark and that our proposed method is effective when compared with other strong baselines. Due to the construction of the corpus, the task designing and the evaluation method are independent of the centric language, we also construct and release the English-centric corpus EN-25 to facilitate academic research.


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Incorporating Uncertain Segmentation Information into Chinese NER for Social Media Text
Shengbin Jia | Ling Ding | Xiaojun Chen | Shijia E | Yang Xiang
Proceedings of the Eighth International Workshop on Natural Language Processing for Social Media

Chinese word segmentation is necessary to provide word-level information for Chinese named entity recognition (NER) systems. However, segmentation error propagation is a challenge for Chinese NER while processing colloquial data like social media text. In this paper, we propose a model (UIcwsNN) that specializes in identifying entities from Chinese social media text, especially by leveraging uncertain information of word segmentation. Such ambiguous information contains all the potential segmentation states of a sentence that provides a channel for the model to infer deep word-level characteristics. We propose a trilogy (i.e., Candidate Position Embedding => Position Selective Attention => Adaptive Word Convolution) to encode uncertain word segmentation information and acquire appropriate word-level representation. Experimental results on the social media corpus show that our model alleviates the segmentation error cascading trouble effectively, and achieves a significant performance improvement of 2% over previous state-of-the-art methods.


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Naive Bayes and BiLSTM Ensemble for Discriminating between Mainland and Taiwan Variation of Mandarin Chinese
Li Yang | Yang Xiang
Proceedings of the Sixth Workshop on NLP for Similar Languages, Varieties and Dialects

Automatic dialect identification is a more challengingctask than language identification, as it requires the ability to discriminate between varieties of one language. In this paper, we propose an ensemble based system, which combines traditional machine learning models trained on bag of n-gram fetures, with deep learning models trained on word embeddings, to solve the Discriminating between Mainland and Taiwan Variation of Mandarin Chinese (DMT) shared task at VarDial 2019. Our experiments show that a character bigram-trigram combination based Naive Bayes is a very strong model for identifying varieties of Mandarin Chinense. Through further ensemble of Navie Bayes and BiLSTM, our system (team: itsalexyang) achived an macro-averaged F1 score of 0.8530 and 0.8687 in two tracks.


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Incorporating Label Dependency for Answer Quality Tagging in Community Question Answering via CNN-LSTM-CRF
Yang Xiang | Xiaoqiang Zhou | Qingcai Chen | Zhihui Zheng | Buzhou Tang | Xiaolong Wang | Yang Qin
Proceedings of COLING 2016, the 26th International Conference on Computational Linguistics: Technical Papers

In community question answering (cQA), the quality of answers are determined by the matching degree between question-answer pairs and the correlation among the answers. In this paper, we show that the dependency between the answer quality labels also plays a pivotal role. To validate the effectiveness of label dependency, we propose two neural network-based models, with different combination modes of Convolutional Neural Net-works, Long Short Term Memory and Conditional Random Fields. Extensive experi-ments are taken on the dataset released by the SemEval-2015 cQA shared task. The first model is a stacked ensemble of the networks. It achieves 58.96% on macro averaged F1, which improves the state-of-the-art neural network-based method by 2.82% and outper-forms the Top-1 system in the shared task by 1.77%. The second is a simple attention-based model whose input is the connection of the question and its corresponding answers. It produces promising results with 58.29% on overall F1 and gains the best performance on the Good and Bad categories.


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ICRC-HIT: A Deep Learning based Comment Sequence Labeling System for Answer Selection Challenge
Xiaoqiang Zhou | Baotian Hu | Jiaxin Lin | Yang Xiang | Xiaolong Wang
Proceedings of the 9th International Workshop on Semantic Evaluation (SemEval 2015)

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Chinese Grammatical Error Diagnosis Using Ensemble Learning
Yang Xiang | Xiaolong Wang | Wenying Han | Qinghua Hong
Proceedings of the 2nd Workshop on Natural Language Processing Techniques for Educational Applications


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Problematic Situation Analysis and Automatic Recognition for Chinese Online Conversational System
Yang Xiang | Yaoyun Zhang | Xiaoqiang Zhou | Xiaolong Wang | Yang Qin
Proceedings of the Third CIPS-SIGHAN Joint Conference on Chinese Language Processing


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Grammatical Error Correction Using Feature Selection and Confidence Tuning
Yang Xiang | Yaoyun Zhang | Xiaolong Wang | Chongqiang Wei | Wen Zheng | Xiaoqiang Zhou | Yuxiu Hu | Yang Qin
Proceedings of the Sixth International Joint Conference on Natural Language Processing

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A Hybrid Model For Grammatical Error Correction
Yang Xiang | Bo Yuan | Yaoyun Zhang | Xiaolong Wang | Wen Zheng | Chongqiang Wei
Proceedings of the Seventeenth Conference on Computational Natural Language Learning: Shared Task


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A Mixed Deterministic Model for Coreference Resolution
Bo Yuan | Qingcai Chen | Yang Xiang | Xiaolong Wang | Liping Ge | Zengjian Liu | Meng Liao | Xianbo Si
Joint Conference on EMNLP and CoNLL - Shared Task