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Yuxian Meng

17 accepted papers

2023

Defending against Backdoor Attacks in Natural Language Generation

AAAI 2023technical

The frustratingly fragile nature of neural network models make current natural language generation (NLG) systems prone to backdoor attacks and generate malicious sequences that could be sexist or offensive. Unfortunately, little effort has been invested to how backdoor attacks can affect current NL…

2023

GNN-SL: Sequence Labeling Based on Nearest Examples via GNN

ACL 2023findings

To better handle long-tail cases in the sequence labeling (SL) task, in this work, we introduce graph neural networks sequence labeling (GNN-SL), which augments the vanilla SL model output with similar tagging examples retrieved from the whole training set. Since not all the retrieved tagging exampl…

2022

An MRC Framework for Semantic Role Labeling

COLING 2022main

Semantic Role Labeling (SRL) aims at recognizing the predicate-argument structure of a sentence and can be decomposed into two subtasks: predicate disambiguation and argument labeling. Prior work deals with these two tasks independently, which ignores the semantic connection between the two tasks. I…

2022

BadPre: Task-agnostic Backdoor Attacks to Pre-trained NLP Foundation Models

ICLR 2022poster

Pre-trained Natural Language Processing (NLP) models, which can be adapted to a variety of downstream language tasks via fine-tuning, highly accelerate the learning progress of NLP models. However, NLP models have been shown to be vulnerable to backdoor attacks. Previous NLP backdoor attacks mainly…

Cited by 125SourcePDFScholar
2022

Dependency Parsing as MRC-based Span-Span Prediction

ACL 2022long

Higher-order methods for dependency parsing can partially but not fully address the issue that edges in dependency trees should be constructed at the text span/subtree level rather than word level. In this paper, we propose a new method for dependency parsing to address this issue. The proposed meth…

2022

Fast Nearest Neighbor Machine Translation

ACL 2022findings

Though nearest neighbor Machine Translation (kNN-MT) (CITATION) has proved to introduce significant performance boosts over standard neural MT systems, it is prohibitively slow since it uses the entire reference corpus as the datastore for the nearest neighbor search. This means each step for each b…

2022

GNN-LM: Language Modeling based on Global Contexts via GNN

ICLR 2022spotlight

Inspired by the notion that "it to copy is easier than to memorize", in this work, we introduce GNN-LM, which extends vanilla neural language model (LM) by allowing to reference similar contexts in the entire training corpus. We build a directed heterogeneous graph between an input context and its s…

2022

Paraphrase Generation as Unsupervised Machine Translation

COLING 2022main

In this paper, we propose a new paradigm for paraphrase generation by treating the task as unsupervised machine translation (UMT) based on the assumption that there must be pairs of sentences expressing the same meaning in a large-scale unlabeled monolingual corpus. The proposed paradigm first split…

Cited by 5SourcePDFScholar
2022

Summarize, Outline, and Elaborate: Long-Text Generation via Hierarchical Supervision from Extractive Summaries

COLING 2022main

The difficulty of generating coherent long texts lies in the fact that existing models overwhelmingly focus on the tasks of local word prediction, and cannot make high level plans on what to generate or capture the high-level discourse dependencies between chunks of texts. Inspired by how humans wri…

Cited by 23SourcePDFScholar
2022

Triggerless Backdoor Attack for NLP Tasks with Clean Labels

NAACL 2022long

Backdoor attacks pose a new threat to NLP models. A standard strategy to construct poisoned data in backdoor attacks is to insert triggers (e.g., rare words) into selected sentences and alter the original label to a target label. This strategy comes with a severe flaw of being easily detected from b…

2021

ChineseBERT: Chinese Pretraining Enhanced by Glyph and Pinyin Information

ACL 2021long

Recent pretraining models in Chinese neglect two important aspects specific to the Chinese language: glyph and pinyin, which carry significant syntax and semantic information for language understanding. In this work, we propose ChineseBERT, which incorporates both the glyph and pinyin information of…

2021

ConRPG: Paraphrase Generation using Contexts as Regularizer

EMNLP 2021main

A long-standing issue with paraphrase generation is the lack of reliable supervision signals. In this paper, we propose a new unsupervised paradigm for paraphrase generation based on the assumption that the probabilities of generating two sentences with the same meaning given the same context should…

Cited by 26SourcePDFScholar
2021

Layer-wise Model Pruning based on Mutual Information

EMNLP 2021main

Inspired by mutual information (MI) based feature selection in SVMs and logistic regression, in this paper, we propose MI-based layer-wise pruning: for each layer of a multi-layer neural network, neurons with higher values of MI with respect to preserved neurons in the upper layer are preserved. Sta…

Cited by 23SourcePDFScholar
2021

Self Question-answering: Aspect-based Sentiment Analysis by Role Flipped Machine Reading Comprehension

EMNLP 2021finding

The pivot for the unified Aspect-based Sentiment Analysis (ABSA) is to couple aspect terms with their corresponding opinion terms, which might further derive easier sentiment predictions. In this paper, we investigate the unified ABSA task from the perspective of Machine Reading Comprehension (MRC)…

Cited by 20SourcePDFScholar
2021

kFolden: k-Fold Ensemble for Out-Of-Distribution Detection

EMNLP 2021main

Out-of-Distribution (OOD) detection is an important problem in natural language processing (NLP). In this work, we propose a simple yet effective framework kFolden, which mimics the behaviors of OOD detection during training without the use of any external data. For a task with k training labels, kF…

2020

SAC: Accelerating and Structuring Self-Attention via Sparse Adaptive Connection

NeurIPS 2020poster

While the self-attention mechanism has been widely used in a wide variety of tasks, it has the unfortunate property of a quadratic cost with respect to the input length, which makes it difficult to deal with long inputs. In this paper, we present a method for accelerating and structuring self-atte…

Cited by 28SourcePDFScholar
2019

Glyce: Glyph-vectors for Chinese Character Representations

NeurIPS 2019poster

It is intuitive that NLP tasks for logographic languages like Chinese should benefit from the use of the glyph information in those languages. However, due to the lack of rich pictographic evidence in glyphs and the weak generalization ability of standard computer vision models on character data, a…