Sizhe Liu

Also published as: 斯哲


2024

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kNN-BOX: A Unified Framework for Nearest Neighbor Generation
Wenhao Zhu | Qianfeng Zhao | Yunzhe Lv | Shujian Huang | Siheng Zhao | Sizhe Liu | Jiajun Chen
Proceedings of the 18th Conference of the European Chapter of the Association for Computational Linguistics: System Demonstrations

Augmenting the base neural model with a token-level symbolic datastore is a novel generation paradigm and has achieved promising results in machine translation (MT). In this paper, we introduce a unified framework kNN-BOX, which enables quick development and visualization for this novel paradigm. kNN-BOX decomposes the datastore-augmentation approach into three modules: datastore, retriever and combiner, thus putting diverse kNN generation methods into a unified way. Currently, kNN-BOX has provided implementation of seven popular kNN-MT variants, covering research from performance enhancement to efficiency optimization. It is easy for users to reproduce these existing work or customize their own models. Besides, users can interact with their kNN generation systems with kNN-BOX to better understand the underlying inference process in a visualized way. In experiment section, we apply kNN-BOX for machine translation and three other seq2seq generation tasks (text simplification, paraphrase generation and question generation). Experiment results show that augmenting the base neural model with kNN-BOX can bring large performance improvement in all these tasks. The code and document of kNN-BOX is available at https://github.com/NJUNLP/knn-box. The demo can be accessed at http://nlp.nju.edu.cn/demo/knn-box/. The introduction video is available at https://www.youtube.com/watch?v=m0eJldHVR3w.

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Multilingual Contrastive Decoding via Language-Agnostic Layers Skipping
Wenhao Zhu | Sizhe Liu | Shujian Huang | Shuaijie She | Chris Wendler | Jiajun Chen
Findings of the Association for Computational Linguistics: EMNLP 2024

Decoding by contrasting layers (DoLa), is designed to improve the generation quality of large language models (LLMs) by contrasting the prediction probabilities between an early exit output (amateur logits) and the final output (expert logits).However, we find that this approach does not work well on non-English tasks.Inspired by previous interpretability work on language transition during the model’s forward pass, we discover that this issue arises from a language mismatch between early exit output and final output.In this work, we propose an improved contrastive decoding algorithm that is effective for diverse languages beyond English.To obtain more helpful amateur logits, we devise two strategies to skip a set of bottom, language-agnostic layers based on our preliminary analysis.Experimental results on multilingual reasoning benchmarks demonstrate that our proposed method outperforms previous contrastive decoding baselines and substantially improves LLM’s chain-of-thought reasoning accuracy across 11 languages.

2023

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机器翻译和大语言模型研究进展(Research Development of Machine translation and Large Language Model)
Wenhao Zhu (文昊 朱) | Hao Zhou (昊 周) | Changjiang Gao (长江 高) | Sizhe Liu (斯哲 刘) | Shujian Huang (书剑 黄)
Proceedings of the 22nd Chinese National Conference on Computational Linguistics (Volume 2: Frontier Forum)

“机器翻译旨在通过计算机自动将一种自然语言翻译成另一种自然语言,这个过程对于机器翻译模型的语言理解、语言生成能力有着极高的要求。因此机器翻译一直以来都是一项极具研究价值和研究难度的自然语言处理任务。近期研究表明,大语言模型能够根据人类指令完成包括翻译在内的许多任务,在这一过程中展现出强大的语言理解和生成能力,为自然语言处理范式革新提供了新的可能。为了在大语言模型支持下更好地完成机器翻译任务,研究人员对大语言模型的机器翻译和多语言能力进行了大量的研究和分析。本文从以下三方面介绍相关研究热点和最新进展,包括:大语言模型翻译能力评估、大语言模型翻译能力激发、大语言模型在不同语言上的能力展现。”