← Search

Zhaopeng Tu

68 accepted papers

2026

CDE: Curiosity-Driven Exploration for Efficient Reinforcement Learning in Large Language Models

ICLR 2026poster

Reinforcement Learning with Verifiable Rewards (RLVR) is a powerful paradigm for enhancing the reasoning ability of Large Language Models (LLMs). Yet current RLVR methods often explore poorly, leading to premature convergence and entropy collapse. Moreover, they tend to produce poorly calibrated pol…

Cited by 0SourcecodeScholar
2026

DeepMath-103K: A Large-Scale, Challenging, Decontaminated, and Verifiable Mathematical Dataset for Advancing Reasoning

ICLR 2026poster

Reinforcement learning (RL) with large language models shows promise in complex reasoning. However, its progress is hindered by the lack of large-scale training data that is sufficiently challenging, contamination-free and verifiable. To this end, we introduce DeepMath-103K, a large-scale mathematic…

Cited by 0SourcecodeScholar
2026

RLVER: Reinforcement Learning with Verifiable Emotion Rewards for Empathetic Agents

ICLR 2026poster

Large language models (LLMs) excel at logical and algorithmic reasoning, yet their emotional intelligence (EQ) still lags far behind their cognitive prowess. While reinforcement learning from verifiable rewards (RLVR) has advanced in other domains, its application to dialogue—especially for emotion…

Cited by 0SourcecodeScholar
2026

RLVMR: Reinforcement Learning with Verifiable Meta-Reasoning Rewards for Robust Long-Horizon Agents

ICLR 2026poster

The development of autonomous agents for complex, long-horizon tasks is a central goal in AI. However, dominant training paradigms face a critical limitation: reinforcement learning (RL) methods that optimize solely for final task success often reinforce flawed or inefficient reasoning paths, a prob…

Cited by 0SourceScholar
2026

Think Fast and Slow: Step-Level Cognitive Depth Adaptation for LLM Agents

ICML 2026poster

Large language models (LLMs) are increasingly deployed as autonomous agents for multi-turn decision-making tasks. However, current agents typically rely on fixed cognitive patterns: non-thinking models generate immediate responses, while thinking models engage in deep reasoning uniformly. This rigid…

Cited by 0SourceScholar
2025

Beyond Prompt Engineering: Robust Behavior Control in LLMs via Steering Target Atoms

ACL 2025long

Precise control over language model generation is vital for ensuring both safety and reliability. Although prompt engineering and steering are commonly used to intervene in model behaviors, the vast number of parameters in models often results in highly intertwined internal representations. This int…

2025

Can’t See the Forest for the Trees: Benchmarking Multimodal Safety Awareness for Multimodal LLMs

ACL 2025long

Multimodal Large Language Models (MLLMs) have expanded the capabilities of traditional language models by enabling interaction through both text and images. However, ensuring the safety of these models remains a significant challenge, particularly in accurately identifying whether multimodal content…

2025

Chain-of-Jailbreak Attack for Image Generation Models via Step by Step Editing

ACL 2025finding

Text-based image generation models, such as Stable Diffusion and DALL-E 3, hold significant potential in content creation and publishing workflows, making them the focus in recent years. Despite their remarkable capability to generate diverse and vivid images, considerable efforts are being made to…

2025

CogDual: Enhancing Dual Cognition of LLMs via Reinforcement Learning with Implicit Rule-Based Rewards

EMNLP 2025

Role-Playing Language Agents (RPLAs) have emerged as a significant application direction for Large Language Models (LLMs). Existing approaches typically rely on prompt engineering or supervised fine-tuning to enable models to imitate character behaviors in specific scenarios, but often neglect the u

Cited by 0SourcePDFScholar
2025

Competing Large Language Models in Multi-Agent Gaming Environments

ICLR 2025poster

Decision-making is a complex process requiring diverse abilities, making it an excellent framework for evaluating Large Language Models (LLMs). Researchers have examined LLMs' decision-making through the lens of Game Theory. However, existing evaluation mainly focus on two-player scenarios where an…

2025

Critical Tokens Matter: Token-Level Contrastive Estimation Enhances LLM’s Reasoning Capability

ICML 2025poster

Mathematical reasoning tasks pose significant challenges for large language models (LLMs) because they require precise logical deduction and sequence analysis. In this work, we introduce the concept of critical tokens -- elements within reasoning trajectories that significantly influence incorrect o…

2025

DRPruning: Efficient Large Language Model Pruning through Distributionally Robust Optimization

ACL 2025long

Large language models (LLMs) deliver impressive results but face challenges from increasing model sizes and computational costs. Structured pruning reduces model size and speeds up inference but often causes uneven degradation across domains, leading to biased performance. To address this, we propos…

2025

Do NOT Think That Much for 2+3=? On the Overthinking of Long Reasoning Models

ICML 2025poster

The remarkable performance of long reasoning models can be attributed to their ability to emulate human-like long-time thinking during inference. These models employ extended chain-of-thought (CoT) processes, exploring multiple strategies to enhance problem-solving capabilities. However, a critical…

2025

Don’t Get Lost in the Trees: Streamlining LLM Reasoning by Overcoming Tree Search Exploration Pitfalls

ACL 2025long

Recent advancements in tree search algorithms guided by verifiers have significantly enhanced the reasoning capabilities of large language models (LLMs), but at the cost of increased computational resources. In this work, we identify two key challenges contributing to this inefficiency: over-explora…

2025

Draft Model Knows When to Stop: Self-Verification Speculative Decoding for Long-Form Generation

EMNLP 2025

Conventional speculative decoding (SD) methods utilize a predefined length policy for proposing drafts, which implies the premise that the target model smoothly accepts the proposed draft tokens. However, reality deviates from this assumption: the oracle draft length varies significantly, and the fi

Cited by 0SourcePDFScholar
2025

Dynamic Mixture of Experts: An Auto-Tuning Approach for Efficient Transformer Models

ICLR 2025poster

The Sparse Mixture of Experts (SMoE) has been widely employed to enhance the efficiency of training and inference for Transformer-based foundational models, yielding promising results. However, the performance of SMoE heavily depends on the choice of hyper-parameters, such as the number of experts a…

2025

Insight Over Sight: Exploring the Vision-Knowledge Conflicts in Multimodal LLMs

ACL 2025long

This paper explores the problem of commonsense level vision-knowledge conflict in Multimodal Large Language Models (MLLMs), where visual information contradicts model’s internal commonsense knowledge. To study this issue, we introduce an automated framework, augmented with human-in-the-loop quality…

2025

RaSA: Rank-Sharing Low-Rank Adaptation

ICLR 2025poster

Low-rank adaptation (LoRA) has been prominently employed for parameter-efficient fine-tuning of large language models (LLMs). However, the limited expressive capacity of LoRA, stemming from the low-rank constraint, has been recognized as a bottleneck, particularly in rigorous tasks like code generat…

2025

Refuse Whenever You Feel Unsafe: Improving Safety in LLMs via Decoupled Refusal Training

ACL 2025long

This study addresses a critical gap in safety tuning practices for Large Language Models (LLMs) by identifying and tackling a refusal position bias within safety tuning data, which compromises the models’ ability to appropriately refuse generating unsafe content. We introduce a novel approach, Decou…

2025

SCAN: Self-Denoising Monte Carlo Annotation for Robust Process Reward Learning

NeurIPS 2025poster

Process reward models (PRMs) offer fine-grained, step-level evaluations that facilitate deeper reasoning processes in large language models (LLMs), proving effective in complex tasks like mathematical reasoning. However, developing PRMs is challenging due to the high cost and limited scalability of…

Cited by 0SourceScholar
2025

SPC: Evolving Self-Play Critic via Adversarial Games for LLM Reasoning

NeurIPS 2025poster

Evaluating the step-by-step reliability of large language model (LLM) reasoning, such as Chain-of-Thought, remains challenging due to the difficulty and cost of obtaining high-quality step-level supervision. In this paper, we introduce Self-Play Critic (SPC), a novel approach where a critic model ev…

Cited by 0SourceScholar
2025

The First Few Tokens Are All You Need: An Efficient and Effective Unsupervised Prefix Fine-Tuning Method for Reasoning Models

NeurIPS 2025poster

Improving the reasoning capabilities of large language models (LLMs) typically requires supervised fine-tuning with labeled data or computationally expensive sampling. We introduce Unsupervised Prefix Fine-Tuning (UPFT), which leverages the observation of Prefix Self-Consistency -- the shared initia…

Cited by 0SourceScholar
2025

The Lighthouse of Language: Enhancing LLM Agents via Critique-Guided Improvement

NeurIPS 2025poster

Large language models (LLMs) have recently transformed from text-based assistants to autonomous agents capable of planning, reasoning, and iteratively improving their actions. While numerical reward signals and verifiers can effectively rank candidate actions, they often provide limited contextual g…

Cited by 0SourceScholar
2025

Thoughts Are All Over the Place: On the Underthinking of Long Reasoning Models

NeurIPS 2025spotlight

Long reasoning models (LRMs) such as OpenAI's o1 and DeepSeek's R1 have demonstrated remarkable abilities in complex reasoning tasks by scaling test-time compute and exhibiting human-like deep thinking. However, we identify a phenomenon we term underthinking, where LRMs frequently switch between dif…

Cited by 0SourcecodeScholar
2025

Trust, But Verify: A Self-Verification Approach to Reinforcement Learning with Verifiable Rewards

NeurIPS 2025poster

Large Language Models (LLMs) show great promise in complex reasoning, with Reinforcement Learning with Verifiable Rewards (RLVR) being a key enhancement strategy. However, a prevalent issue is ``superficial self-reflection'', where models fail to robustly verify their own outputs. We introduce RISE…

Cited by 0SourcecodeScholar
2025

Two Experts Are All You Need for Steering Thinking: Reinforcing Cognitive Effort in MoE Reasoning Models Without Additional Training

NeurIPS 2025poster

Mixture-of-Experts (MoE) architectures within Large Reasoning Models (LRMs) have achieved impressive reasoning capabilities by selectively activating experts to facilitate structured cognitive processes. Despite notable advances, existing reasoning models often suffer from cognitive inefficiencies l…

Cited by 0SourceScholar
2025

Unleashing LLM Reasoning Capability via Scalable Question Synthesis from Scratch

ACL 2025long

Improving the mathematical reasoning capabilities of Large Language Models (LLMs) is critical for advancing artificial intelligence. However, access to extensive, diverse, and high-quality reasoning datasets remains a significant challenge, particularly for the open-source community. In this paper,…

Cited by 0SourcePDFScholar
2024

Addressing Entity Translation Problem via Translation Difficulty and Context Diversity

ACL 2024findings

Neural machine translation (NMT) systems often produce inadequate translations for named entities. In this study, we conducted preliminary experiments to examine the factors affecting the translation accuracy of named entities, specifically focusing on their translation difficulty and context divers…

2024

All Languages Matter: On the Multilingual Safety of LLMs

ACL 2024findings

Safety lies at the core of developing and deploying large language models (LLMs). However, previous safety benchmarks only concern the safety in one language, e.g. the majority language in the pretraining data such as English. In this work, we build the first multilingual safety benchmark for LLMs,…

2024

Apathetic or Empathetic? Evaluating LLMs' Emotional Alignments with Humans

NeurIPS 2024poster

Evaluating Large Language Models’ (LLMs) anthropomorphic capabilities has become increasingly important in contemporary discourse. Utilizing the emotion appraisal theory from psychology, we propose to evaluate the empathy ability of LLMs, i.e., how their feelings change when presented with specific…

2024

Benchmarking LLMs via Uncertainty Quantification

NeurIPS 2024poster

The proliferation of open-source Large Language Models (LLMs) from various institutions has highlighted the urgent need for comprehensive evaluation methods. However, current evaluation platforms, such as the widely recognized HuggingFace open LLM leaderboard, neglect a crucial aspect -- uncertainty…

2024

Benchmarking and Improving Long-Text Translation with Large Language Models

ACL 2024findings

Recent studies have illuminated the promising capabilities of large language models (LLMs) in handling long texts. However, their performance in machine translation (MT) of long documents remains underexplored. This paper aims to shed light on how LLMs navigate this complex task, offering a comprehe…

2024

Can Watermarks Survive Translation? On the Cross-lingual Consistency of Text Watermark for Large Language Models

ACL 2024long

Text watermarking technology aims to tag and identify content produced by large language models (LLMs) to prevent misuse. In this study, we introduce the concept of cross-lingual consistency in text watermarking, which assesses the ability of text watermarks to maintain their effectiveness after bei…

2024

Encouraging Divergent Thinking in Large Language Models through Multi-Agent Debate

EMNLP 2024main

Modern large language models (LLMs) like ChatGPT have shown remarkable performance on general language tasks but still struggle on complex reasoning tasks, which drives the research on cognitive behaviors of LLMs to explore human-like problem-solving strategies. Along this direction, one representat…

2024

GPT-4 Is Too Smart To Be Safe: Stealthy Chat with LLMs via Cipher

ICLR 2024poster

Safety lies at the core of the development of Large Language Models (LLMs). There is ample work on aligning LLMs with human ethics and preferences, including data filtering in pretraining, supervised fine-tuning, reinforcement learning from human feedback, red teaming, etc. In this study, we discove…

2024

GliDe with a CaPE: A Low-Hassle Method to Accelerate Speculative Decoding

ICML 2024poster

Speculative decoding is a relatively new decoding framework that leverages small and efficient draft models to reduce the latency of LLMs. In this study, we introduce GliDe and CaPE, two low-hassle modifications to vanilla speculative decoding to further improve the decoding speed of a frozen LLM. S…

Cited by 19SourcePDFScholar
2024

Improving Machine Translation with Human Feedback: An Exploration of Quality Estimation as a Reward Model

NAACL 2024long

Insufficient modeling of human preferences within the reward model is a major obstacle for leveraging human feedback to improve translation quality. Fortunately, quality estimation (QE), which predicts the quality of a given translation without reference, has achieved impressive alignment with human…

2024

NewTerm: Benchmarking Real-Time New Terms for Large Language Models with Annual Updates

NeurIPS 2024poster

Despite their remarkable abilities in various tasks, large language models (LLMs) still struggle with real-time information (e.g., new facts and terms) due to the knowledge cutoff in their development process. However, existing benchmarks focus on outdated content and limited fields, facing difficul…

2024

Not All Countries Celebrate Thanksgiving: On the Cultural Dominance in Large Language Models

ACL 2024long

This paper identifies a cultural dominance issue within large language models (LLMs) due to the predominant use of English data in model training (e.g., ChatGPT). LLMs often provide inappropriate English-culture-related answers that are not relevant to the expected culture when users ask in non-Engl…

Cited by 62SourcePDFScholar
2024

On the Humanity of Conversational AI: Evaluating the Psychological Portrayal of LLMs

ICLR 2024oral

Large Language Models (LLMs) have recently showcased their remarkable capacities, not only in natural language processing tasks but also across diverse domains such as clinical medicine, legal consultation, and education. LLMs become more than mere applications, evolving into assistants capable of a…

2024

Unsupervised Sign Language Translation and Generation

ACL 2024findings

Motivated by the success of unsupervised neural machine translation (UNMT), we introduce an unsupervised sign language translation and generation network (USLNet), which learns from abundant single-modality (text and video) data without parallel sign language data. USLNet comprises two main componen…

2023

A Survey on Zero Pronoun Translation

ACL 2023long

Zero pronouns (ZPs) are frequently omitted in pro-drop languages (e.g. Chinese, Hungarian, and Hindi), but should be recalled in non-pro-drop languages (e.g. English). This phenomenon has been studied extensively in machine translation (MT), as it poses a significant challenge for MT systems due to…

2023

Cross-modality Data Augmentation for End-to-End Sign Language Translation

EMNLP 2023long findings

End-to-end sign language translation (SLT) aims to directly convert sign language videos into spoken language texts without intermediate representations. It has been challenging due to the data scarcity of labeled data and the modality gap between sign videos and texts. To tackle these challenges, w…

Cited by 0SourcecodeScholar
2023

Document-Level Machine Translation with Large Language Models

EMNLP 2023long main

Large language models (LLMs) such as ChatGPT can produce coherent, cohesive, relevant, and fluent answers for various natural language processing (NLP) tasks. Taking document-level machine translation (MT) as a testbed, this paper provides an in-depth evaluation of LLMs' ability on discourse modelin…

Cited by 0SourcecodeScholar
2023

ParroT: Translating during Chat using Large Language Models tuned with Human Translation and Feedback

EMNLP 2023long findings

Large language models (LLMs) like ChatGPT have exhibited remarkable abilities on a wide range of natural language processing (NLP) tasks, including various machine translation abilities accomplished during chat. However, these models are only accessible through restricted APIs, which creates barrier…

Cited by 0SourcecodeScholar
2023

Revisiting Non-Autoregressive Translation at Scale

ACL 2023findings

In real-world systems, scaling has been critical for improving the translation quality in autoregressive translation (AT), which however has not been well studied for non-autoregressive translation (NAT). In this work, we bridge the gap by systematically studying the impact of scaling on NAT behavio…

2023

Towards a Unified Training for Levenshtein Transformer

ICASSP 2023accepted

Levenshtein Transformer (LevT) is a widely-used text-editing model, which generates a sequence based on editing operations (deletion and insertion) in a non-autoregressive manner. However, it is challenging to train the key refinement components of LevT due to training-inference discrepancy. By care…

Cited by 0SourceScholar
2022

A Template-based Method for Constrained Neural Machine Translation

EMNLP 2022main

Machine translation systems are expected to cope with various types of constraints in many practical scenarios. While neural machine translation (NMT) has achieved strong performance in unconstrained cases, it is non-trivial to impose pre-specified constraints into the translation process of NMT mod…

2022

Adapters for Enhanced Modeling of Multilingual Knowledge and Text

EMNLP 2022finding

Large language models appear to learn facts from the large text corpora they are trained on. Such facts are encoded implicitly within their many parameters, making it difficult to verify or manipulate what knowledge has been learned. Language models have recently been extended to multilingual langua…

2022

Bridging the Data Gap between Training and Inference for Unsupervised Neural Machine Translation

ACL 2022long

Back-translation is a critical component of Unsupervised Neural Machine Translation (UNMT), which generates pseudo parallel data from target monolingual data. A UNMT model is trained on the pseudo parallel data with translated source, and translates natural source sentences in inference. The source…

2022

GuoFeng: A Benchmark for Zero Pronoun Recovery and Translation

EMNLP 2022main

The phenomenon of zero pronoun (ZP) has attracted increasing interest in the machine translation (MT) community due to its importance and difficulty. However, previous studies generally evaluate the quality of translating ZPs with BLEU scores on MT testsets, which is not expressive or sensitive enou…

2022

Redistributing Low-Frequency Words: Making the Most of Monolingual Data in Non-Autoregressive Translation

ACL 2022long

Knowledge distillation (KD) is the preliminary step for training non-autoregressive translation (NAT) models, which eases the training of NAT models at the cost of losing important information for translating low-frequency words. In this work, we provide an appealing alternative for NAT – monolingua…

2022

Understanding and Improving Sequence-to-Sequence Pretraining for Neural Machine Translation

ACL 2022long

In this paper, we present a substantial step in better understanding the SOTA sequence-to-sequence (Seq2Seq) pretraining for neural machine translation (NMT). We focus on studying the impact of the jointly pretrained decoder, which is the main difference between Seq2Seq pretraining and previous enco…

2022

ngram-OAXE: Phrase-Based Order-Agnostic Cross Entropy for Non-Autoregressive Machine Translation

COLING 2022main

Recently, a new training oaxe loss has proven effective to ameliorate the effect of multimodality for non-autoregressive translation (NAT), which removes the penalty of word order errors in the standard cross-entropy loss. Starting from the intuition that reordering generally occurs between phrases,…

2021

Multi-Task Learning with Shared Encoder for Non-Autoregressive Machine Translation

NAACL 2021long

Non-Autoregressive machine Translation (NAT) models have demonstrated significant inference speedup but suffer from inferior translation accuracy. The common practice to tackle the problem is transferring the Autoregressive machine Translation (AT) knowledge to NAT models, e.g., with knowledge disti…

2021

On the Complementarity between Pre-Training and Back-Translation for Neural Machine Translation

EMNLP 2021finding

Pre-training (PT) and back-translation (BT) are two simple and powerful methods to utilize monolingual data for improving the model performance of neural machine translation (NMT). This paper takes the first step to investigate the complementarity between PT and BT. We introduce two probing tasks fo…

2021

Order-Agnostic Cross Entropy for Non-Autoregressive Machine Translation

ICML 2021oral

We propose a new training objective named order-agnostic cross entropy (OaXE) for fully non-autoregressive translation (NAT) models. OaXE improves the standard cross-entropy loss to ameliorate the effect of word reordering, which is a common source of the critical multimodality problem in NAT. Concr…

2021

RAST: Domain-Robust Dialogue Rewriting as Sequence Tagging

EMNLP 2021main

The task of dialogue rewriting aims to reconstruct the latest dialogue utterance by copying the missing content from the dialogue context. Until now, the existing models for this task suffer from the robustness issue, i.e., performances drop dramatically when testing on a different dataset. We addre…

2021

Rejuvenating Low-Frequency Words: Making the Most of Parallel Data in Non-Autoregressive Translation

ACL 2021long

Knowledge distillation (KD) is commonly used to construct synthetic data for training non-autoregressive translation (NAT) models. However, there exists a discrepancy on low-frequency words between the distilled and the original data, leading to more errors on predicting low-frequency words. To alle…

2021

Self-Training Sampling with Monolingual Data Uncertainty for Neural Machine Translation

ACL 2021long

Self-training has proven effective for improving NMT performance by augmenting model training with synthetic parallel data. The common practice is to construct synthetic data based on a randomly sampled subset of large-scale monolingual data, which we empirically show is sub-optimal. In this work, w…

2021

Understanding and Improving Encoder Layer Fusion in Sequence-to-Sequence Learning

ICLR 2021poster

Encoder layer fusion (EncoderFusion) is a technique to fuse all the encoder layers (instead of the uppermost layer) for sequence-to-sequence (Seq2Seq) models, which has proven effective on various NLP tasks. However, it is still not entirely clear why and when EncoderFusion should work. In this pape…

2021

Understanding and Improving Lexical Choice in Non-Autoregressive Translation

ICLR 2021poster

Knowledge distillation (KD) is essential for training non-autoregressive translation (NAT) models by reducing the complexity of the raw data with an autoregressive teacher model. In this study, we empirically show that as a side effect of this training, the lexical choice errors on low-frequency wor…

Cited by 100SourcePDFScholar
2020

Auxiliary Template-Enhanced Generative Compatibility Modeling

IJCAI 2020poster

In recent years, there has been a growing interest in the fashion analysis (e.g., clothing matching) due to the huge economic value of the fashion industry. The essential problem is to model the compatibility between the complementary fashion items, such as the top and bottom in clothing matching. T…

Cited by 0SourcePDFScholar
2020

Context-Aware Cross-Attention for Non-Autoregressive Translation

COLING 2020main

Non-autoregressive translation (NAT) significantly accelerates the inference process by predicting the entire target sequence. However, due to the lack of target dependency modelling in the decoder, the conditional generation process heavily depends on the cross-attention. In this paper, we reveal a…

Cited by 48SourcePDFScholar
2020

Emotion Classification by Jointly Learning to Lexiconize and Classify

COLING 2020main

Emotion lexicons have been shown effective for emotion classification (Baziotis et al., 2018). Previous studies handle emotion lexicon construction and emotion classification separately. In this paper, we propose an emotional network (EmNet) to jointly learn sentence emotions and construct emotion l…

2020

EmpDG: Multi-resolution Interactive Empathetic Dialogue Generation

COLING 2020main

A humanized dialogue system is expected to generate empathetic replies, which should be sensitive to the users’ expressed emotion. The task of empathetic dialogue generation is proposed to address this problem. The essential challenges lie in accurately capturing the nuances of human emotion and con…

2016

Dropped pronoun generation for dialogue machine translation

ICASSP 2016accepted

Dropped pronoun (DP) is a common problem in dialogue machine translation, in which pronouns are frequently dropped in the source sentence and thus are missing in its translation. In response to this problem, we propose a novel approach to improve the translation of DPs for dialogue machine translati…

Cited by 0SourceScholar