Chang Liu


2020

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基于跨语言双语预训练及Bi-LSTM的汉-越平行句对抽取方法(Chinese-Vietnamese Parallel Sentence Pair Extraction Method Based on Cross-lingual Bilingual Pre-training and Bi-LSTM)
Chang Liu (刘畅) | Shengxiang Gao (高盛祥) | Zhengtao Yu (余正涛) | Yuxin Huang (黄于欣) | Congcong You (尤丛丛)
Proceedings of the 19th Chinese National Conference on Computational Linguistics

汉越平行句对抽取是缓解汉越平行语料库数据稀缺的重要方法。平行句对抽取可转换为同一语义空间下的句子相似性分类任务,其核心在于双语语义空间对齐。传统语义空间对齐方法依赖于大规模的双语平行语料,越南语作为低资源语言获取大规模平行语料相对困难。针对这个问题本文提出一种利用种子词典进行跨语言双语预训练及Bi-LSTM(Bi-directional Long Short-Term Memory)的汉-越平行句对抽取方法。预训练中仅需要大量的汉越单语和一个汉越种子词典,通过利用汉越种子词典将汉越双语映射到公共语义空间进行词对齐。再利用Bi-LSTM和CNN(Convolutional Neural Networks)分别提取句子的全局特征和局部特征从而最大化表示汉-越句对之间的语义相关性。实验结果表明,本文模型在F1得分上提升7.1%,优于基线模型。

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面向人工智能伦理计算的中文道德词典构建方法研究(Construction of a Chinese Moral Dictionary for Artificial Intelligence Ethical Computing)
Hongrui Wang (王弘睿) | Chang Liu (刘畅) | Dong Yu (于东)
Proceedings of the 19th Chinese National Conference on Computational Linguistics

道德词典资源的建设是人工智能伦理计算的一个研究重点。由于道德行为复杂多样,现有的英文道德词典分类体系并不完善,而中文方面目前尚未有相关的词典资源,理论体系和构建方法仍待探究。针对以上问题,该文提出了面向人工智能伦理计算的中文道德词典构建任务,设计了四类标签和四种类型,得到包含25,012个词的中文道德词典资源。实验结果表明,该词典资源不仅能够使机器学会道德知识,判断词的道德标签和类型,而且能够为句子级别的道德文本分析提供数据支持。

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BLCU-NLP at SemEval-2020 Task 5: Data Augmentation for Efficient Counterfactual Detecting
Chang Liu | Dong Yu
Proceedings of the Fourteenth Workshop on Semantic Evaluation

Counterfactuals describe events counter to facts and hence naturally involve common sense, knowledge, and reasoning. SemEval 2020 task 5 is focusing on this field. We participate in the subtask 1 and we use BERT as our system. Our Innovations are feature extraction and data augmentation. We extract and summarize features of counterfactual statements, augment counterfactual examples in training set with the help of these features, and two general methods of data augmentation is experimented in our work. We demonstrate the effectiveness of our approaches, which achieves 0.95 of subtask 1 in F1 while using only a subset of giving training set to fine-tune the BERT model, and our official submission achieves F1 0.802, which ranks us 16th in the competition.

2019

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Kingsoft’s Neural Machine Translation System for WMT19
Xinze Guo | Chang Liu | Xiaolong Li | Yiran Wang | Guoliang Li | Feng Wang | Zhitao Xu | Liuyi Yang | Li Ma | Changliang Li
Proceedings of the Fourth Conference on Machine Translation (Volume 2: Shared Task Papers, Day 1)

This paper describes the Kingsoft AI Lab’s submission to the WMT2019 news translation shared task. We participated in two language directions: English-Chinese and Chinese-English. For both language directions, we trained several variants of Transformer models using the provided parallel data enlarged with a large quantity of back-translated monolingual data. The best translation result was obtained with ensemble and reranking techniques. According to automatic metrics (BLEU) our Chinese-English system reached the second highest score, and our English-Chinese system reached the second highest score for this subtask.

2012

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Character-Level Machine Translation Evaluation for Languages with Ambiguous Word Boundaries
Chang Liu | Hwee Tou Ng
Proceedings of the 50th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)

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Combining Coherence Models and Machine Translation Evaluation Metrics for Summarization Evaluation
Ziheng Lin | Chang Liu | Hwee Tou Ng | Min-Yen Kan
Proceedings of the 50th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)

2011

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Better Evaluation Metrics Lead to Better Machine Translation
Chang Liu | Daniel Dahlmeier | Hwee Tou Ng
Proceedings of the 2011 Conference on Empirical Methods in Natural Language Processing

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TESLA at WMT 2011: Translation Evaluation and Tunable Metric
Daniel Dahlmeier | Chang Liu | Hwee Tou Ng
Proceedings of the Sixth Workshop on Statistical Machine Translation

2010

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TESLA: Translation Evaluation of Sentences with Linear-Programming-Based Analysis
Chang Liu | Daniel Dahlmeier | Hwee Tou Ng
Proceedings of the Joint Fifth Workshop on Statistical Machine Translation and MetricsMATR

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PEM: A Paraphrase Evaluation Metric Exploiting Parallel Texts
Chang Liu | Daniel Dahlmeier | Hwee Tou Ng
Proceedings of the 2010 Conference on Empirical Methods in Natural Language Processing

2007

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Learning Predictive Structures for Semantic Role Labeling of NomBank
Chang Liu | Hwee Tou Ng
Proceedings of the 45th Annual Meeting of the Association of Computational Linguistics