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Meng Fang

69 accepted papers

2026

Causality-Aware Efficient Exploration for Cooperative Multi-Agent Reinforcement Learning

AAAI 2026technical

Exploration is critical for cooperative multi agent reinforcement learning (MARL) to improve sample efficiency. However, existing intrinsic motivation based exploration strategies in MARL overlook the causal relationships among agents, global states, and rewards, suffering from interference by irrel

Cited by 0SourcePDFScholar
2026

Investigating Social Bias Propagation in Federated Fine-tuning of Large Language Models

AAAI 2026technical

Large language models (LLMs) have achieved remarkable success in many domains, but concerns about data quality and privacy are growing. Federated Learning (FL) offers a privacy-preserving solution by training a model on local clients without sharing data. However, the impact of biased private data o

Cited by 0SourcePDFScholar
2026

MEAL: A Benchmark for Continual Multi-Agent Reinforcement Learning

ICML 2026poster

Benchmarks play a central role in reinforcement learning (RL) research, yet their computational constraints often shape what is studied. Despite the motivation of lifelong learning, most continual RL papers consider only 3–10 sequential tasks, as CPU-bound environments make longer sequences impracti…

Cited by 0SourceScholar
2026

Safe Multi-agent Reinforcement Learning with Natural Language Constraints

AAAI 2026technical

Safe Multi-Agent Reinforcement Learning (MARL) typically relies on manually specified numeric cost functions to ensure that policy behaviours respect safety constraints. As systems scale and human-defined constraints become more diverse, context-dependent, and frequently updated, hand-crafting such

Cited by 0SourcePDFScholar
2026

SafeDialBench: A Fine-Grained Safety Evaluation Benchmark for Large Language Models in Multi-Turn Dialogues with Diverse Jailbreak Attacks

ICLR 2026poster

With the rapid advancement of Large Language Models (LLMs), the safety of LLMs has been a critical concern requiring precise assessment. Current benchmarks primarily concentrate on single-turn dialogues or a single jailbreak attack method to assess the safety. Additionally, these benchmarks have not…

Cited by 0SourcecodeScholar
2026

Vision-Language Reasoning for Geolocalization: A Reinforcement Learning Approach

AAAI 2026technical

Recent advances in vision-language models have opened up new possibilities for reasoning-driven image geolocalization. However, existing approaches often rely on synthetic reasoning annotations or external image retrieval, which can limit interpretability and generalizability. In this paper, we pres

Cited by 0SourcePDFScholar
2025

ATLAS: Agent Tuning via Learning Critical Steps

ACL 2025finding

Large Language Model (LLM) agents have demonstrated remarkable generalization capabilities across multi-domain tasks. Existing agent tuning approaches typically employ supervised finetuning on entire expert trajectories. However, behavior-cloning of full trajectories can introduce expert bias and we…

Cited by 0SourcePDFScholar
2025

Benchmarking Foundation Models with Retrieval-Augmented Generation in Olympic-Level Physics Problem Solving

EMNLP 2025

Retrieval-augmented generation (RAG) with foundation models has achieved strong performance across diverse tasks, but their capacity for expert-level reasoning—such as solving Olympiad-level physics problems—remains largely unexplored. Inspired by the way students prepare for competitions by reviewi

Cited by 0SourcePDFScholar
2025

Enhancing Input-Label Mapping in In-Context Learning with Contrastive Decoding

ACL 2025short

Large language models (LLMs) excel at a range of tasks through in-context learning (ICL), where only a few task examples guide their predictions. However, prior research highlights that LLMs often overlook input-label mapping information in ICL, relying more on their pre-trained knowledge. To addres…

2025

HASARD: A Benchmark for Vision-Based Safe Reinforcement Learning in Embodied Agents

ICLR 2025poster

Advancing safe autonomous systems through reinforcement learning (RL) requires robust benchmarks to evaluate performance, analyze methods, and assess agent competencies. Humans primarily rely on embodied visual perception to safely navigate and interact with their surroundings, making it a valuable…

Cited by 0SourcePDFScholar
2025

Hazards in Daily Life? Enabling Robots to Proactively Detect and Resolve Anomalies

NAACL 2025long

Existing household robots have made significant progress in performing routine tasks, such as cleaning floors or delivering objects. However, a key limitation of these robots is their inability to recognize potential problems or dangers in home environments. For example, a child may pick up and inge…

Cited by 1SourcePDFScholar
2025

MTPChat: A Multimodal Time-Aware Persona Dataset for Conversational Agents

NAACL 2025findings

Understanding temporal dynamics is critical for conversational agents, enabling effective content analysis and informed decision-making. However, time-aware datasets, particularly for persona-grounded conversations, are still limited, which narrows their scope and diminishes their complexity. To add…

Cited by 1SourcePDFScholar
2025

MuRating: A High Quality Data Selecting Approach to Multilingual Large Language Model Pretraining

NeurIPS 2025poster

Data quality is a critical driver of large language model performance, yet existing model-based selection methods focus almost exclusively on English, neglecting other languages that are essential in the training mix for multilingual LLMs. We introduce MuRating, a scalable framework that transfers h…

Cited by 0SourceScholar
2025

Preference Controllable Reinforcement Learning with Advanced Multi-Objective Optimization

ICML 2025poster

Practical reinforcement learning (RL) usually requires agents to be optimized for multiple potentially conflicting criteria, e.g. speed vs. safety. Although Multi-Objective RL (MORL) algorithms have been studied in previous works, their trained agents often cover limited Pareto optimal solutions an…

Cited by 0SourcePDFScholar
2025

RuAG: Learned-rule-augmented Generation for Large Language Models

ICLR 2025poster

In-context learning (ICL) and Retrieval-Augmented Generation (RAG) have gained attention for their ability to enhance LLMs' reasoning by incorporating external knowledge but suffer from limited contextual window size, leading to insufficient information injection. To this end, we propose a novel fra…

Cited by 2SourcePDFScholar
2025

Spiral of Silence in Large Language Model Agents

EMNLP 2025

The Spiral of Silence (SoS) theory holds that individuals with minority views often refrain from speaking out for fear of social isolation, enabling majority positions to dominate public discourse. When the “agents” are large language models (LLMs), however, the classical psychological explanation i

Cited by 0SourcePDFScholar
2025

Tackling Data Corruption in Offline Reinforcement Learning via Sequence Modeling

ICLR 2025poster

Learning policy from offline datasets through offline reinforcement learning (RL) holds promise for scaling data-driven decision-making while avoiding unsafe and costly online interactions. However, real-world data collected from sensors or humans often contains noise and errors, posing a significan…

2025

Towards Empowerment Gain through Causal Structure Learning in Model-Based Reinforcement Learning

ICLR 2025poster

In Model-Based Reinforcement Learning (MBRL), incorporating causal structures into dynamics models provides agents with a structured understanding of the environments, enabling efficient decision. Empowerment as an intrinsic motivation enhances the ability of agents to actively control their enviro…

Cited by 0SourcePDFScholar
2025

Understanding Large Language Model Vulnerabilities to Social Bias Attacks

ACL 2025long

Large Language Models (LLMs) have become foundational in human-computer interaction, demonstrating remarkable linguistic capabilities across various tasks. However, there is a growing concern about their potential to perpetuate social biases present in their training data. In this paper, we comprehe…

Cited by 0SourcePDFScholar
2025

Unmasking Style Sensitivity: A Causal Analysis of Bias Evaluation Instability in Large Language Models

ACL 2025long

Natural language processing applications are increasingly prevalent, but social biases in their outputs remain a critical challenge. While various bias evaluation methods have been proposed, these assessments show unexpected instability when input texts undergo minor stylistic changes. This paper co…

Cited by 0SourcePDFScholar
2025

Who Can Withstand Chat-Audio Attacks? An Evaluation Benchmark for Large Audio-Language Models

ACL 2025finding

Adversarial audio attacks pose a significant threat to the growing use of large audio-language models (LALMs) in voice-based human-machine interactions. While existing research focused on model-specific adversarial methods, real-world applications demand a more generalizable and universal approach t…

2024

Adaptive Regularization of Representation Rank as an Implicit Constraint of Bellman Equation

ICLR 2024poster

Representation rank is an important concept for understanding the role of Neural Networks (NNs) in Deep Reinforcement learning (DRL), which measures the expressive capacity of value networks. Existing studies focus on unboundedly maximizing this rank; nevertheless, that approach would introduce over…

2024

CHAmbi: A New Benchmark on Chinese Ambiguity Challenges for Large Language Models

EMNLP 2024finding

Ambiguity is an inherent feature of language, whose management is crucial for effective communication and collaboration. This is particularly true for Chinese, a language with extensive lexical-morphemic ambiguity. Despite the wide use of large language models (LLMs) in numerous domains and their gr…

2024

Enhancing Temporal Sensitivity and Reasoning for Time-Sensitive Question Answering

EMNLP 2024finding

Time-Sensitive Question Answering (TSQA) demands the effective utilization of specific temporal contexts, encompassing multiple time-evolving facts, to address time-sensitive questions. This necessitates not only the parsing of temporal information within questions but also the identification and un…

Cited by 3SourcePDFScholar
2024

LLMs Assist NLP Researchers: Critique Paper (Meta-)Reviewing

EMNLP 2024main

Claim: This work is not advocating the use of LLMs for paper (meta-)reviewing. Instead, wepresent a comparative analysis to identify and distinguish LLM activities from human activities. Two research goals: i) Enable better recognition of instances when someone implicitly uses LLMs for reviewing act…

2024

Large Language Models Are Neurosymbolic Reasoners

AAAI 2024technical

A wide range of real-world applications is characterized by their symbolic nature, necessitating a strong capability for symbolic reasoning. This paper investigates the potential application of Large Language Models (LLMs) as symbolic reasoners. We focus on text-based games, significant benchmarks f…

2024

Learning to Discuss Strategically: A Case Study on One Night Ultimate Werewolf

NeurIPS 2024poster

Communication is a fundamental aspect of human society, facilitating the exchange of information and beliefs among people. Despite the advancements in large language models (LLMs), recent agents built with these often neglect the control over discussion tactics, which are essential in communication…

Cited by 8SourcePDFScholar
2024

MedINST: Meta Dataset of Biomedical Instructions

EMNLP 2024finding

The integration of large language model (LLM) techniques in the field of medical analysis has brought about significant advancements, yet the scarcity of large, diverse, and well-annotated datasets remains a major challenge. Medical data and tasks, which vary in format, size, and other parameters, r…

2024

More than Minorities and Majorities: Understanding Multilateral Bias in Language Generation

ACL 2024findings

Pretrained models learned from real corpora can often capture undesirable features, leading to bias issues against different demographic groups. Most existing studies on bias dataset construction or bias mitigation methods only focus on one demographic group pair to study a certain bias, e.g. black…

Cited by 0SourcePDFScholar
2024

Policy Learning from Tutorial Books via Understanding, Rehearsing and Introspecting

NeurIPS 2024oral

When humans need to learn a new skill, we can acquire knowledge through written books, including textbooks, tutorials, etc. However, current research for decision-making, like reinforcement learning (RL), has primarily required numerous real interactions with the target environment to learn a skill,…

2024

Representation-Based Robustness in Goal-Conditioned Reinforcement Learning

AAAI 2024technical

While Goal-Conditioned Reinforcement Learning (GCRL) has gained attention, its algorithmic robustness against adversarial perturbations remains unexplored. The attacks and robust representation training methods that are designed for traditional RL become less effective when applied to GCRL. To addre…

2024

RetrievalQA: Assessing Adaptive Retrieval-Augmented Generation for Short-form Open-Domain Question Answering

ACL 2024findings

Adaptive retrieval-augmented generation (ARAG) aims to dynamically determine the necessity of retrieval for queries instead of retrieving indiscriminately to enhance the efficiency and relevance of the sourced information. However, previous works largely overlook the evaluation of ARAG approaches, l…

2024

Revisiting Catastrophic Forgetting in Large Language Model Tuning

EMNLP 2024finding

Catastrophic Forgetting (CF) means models forgetting previously acquired knowledge when learning new data. It compromises the effectiveness of large language models (LLMs) during fine-tuning, yet the underlying causes have not been thoroughly investigated. This paper takes the first step to reveal t…

2024

Task Adaptation from Skills: Information Geometry, Disentanglement, and New Objectives for Unsupervised Reinforcement Learning

ICLR 2024spotlight

Unsupervised reinforcement learning (URL) aims to learn general skills for unseen downstream tasks. Mutual Information Skill Learning (MISL) addresses URL by maximizing the mutual information between states and skills but lacks sufficient theoretical analysis, e.g., how well its learned skills can i…

Cited by 7SourcePDFScholar
2023

A Survey for Efficient Open Domain Question Answering

ACL 2023long

Open domain question answering (ODQA) is a longstanding task aimed at answering factual questions from a large knowledge corpus without any explicit evidence in natural language processing (NLP). Recent works have predominantly focused on improving the answering accuracy and have achieved promising…

2023

Are Large Kernels Better Teachers than Transformers for ConvNets?

ICML 2023poster

This paper reveals a new appeal of the recently emerged large-kernel Convolutional Neural Networks (ConvNets): as the teacher in Knowledge Distillation (KD) for small-kernel ConvNets. While Transformers have led state-of-the-art (SOTA) performance in various fields with ever-larger models and labele…

2023

CHBias: Bias Evaluation and Mitigation of Chinese Conversational Language Models

ACL 2023long

redWarning: This paper contains content that may be offensive or upsetting.Pretrained conversational agents have been exposed to safety issues, exhibiting a range of stereotypical human biases such as gender bias. However, there are still limited bias categories in current research, and most of them…

2023

CITB: A Benchmark for Continual Instruction Tuning

EMNLP 2023long findings

Continual learning (CL) is a paradigm that aims to replicate the human ability to learn and accumulate knowledge continually without forgetting previous knowledge and transferring it to new tasks. Recent instruction tuning (IT) involves fine-tuning models to make them more adaptable to solving NLP t…

Cited by 0SourcecodeScholar
2023

COOM: A Game Benchmark for Continual Reinforcement Learning

NeurIPS 2023poster

The advancement of continual reinforcement learning (RL) has been facing various obstacles, including standardized metrics and evaluation protocols, demanding computational requirements, and a lack of widely accepted standard benchmarks. In response to these challenges, we present COOM ($\textbf{C}$…

2023

Dynamic Sparsity Is Channel-Level Sparsity Learner

NeurIPS 2023poster

Sparse training has received an upsurging interest in machine learning due to its tantalizing saving potential for both the entire training process as well as the inference. Dynamic sparse training (DST) as a leading approach can train deep neural networks at high sparsity from scratch to match the…

2023

Enhancing Conversational Search: Large Language Model-Aided Informative Query Rewriting

EMNLP 2023long findings

Query rewriting plays a vital role in enhancing conversational search by transforming context-dependent user queries into standalone forms. Existing approaches primarily leverage human-rewritten queries as labels to train query rewriting models. However, human rewrites may lack sufficient informatio…

Cited by 0SourcecodeScholar
2023

How Do Large Language Models Capture the Ever-changing World Knowledge? A Review of Recent Advances

EMNLP 2023long main

Although large language models (LLMs) are impressive in solving various tasks, they can quickly be outdated after deployment. Maintaining their up-to-date status is a pressing concern in the current era. This paper provides a comprehensive review of recent advances in aligning deployed LLMs with the…

Cited by 0SourcecodeScholar
2023

Interpretable Reward Redistribution in Reinforcement Learning: A Causal Approach

NeurIPS 2023poster

A major challenge in reinforcement learning is to determine which state-action pairs are responsible for future rewards that are delayed. Reward redistribution serves as a solution to re-assign credits for each time step from observed sequences. While the majority of current approaches construct th…

2023

Lottery Pools: Winning More by Interpolating Tickets without Increasing Training or Inference Cost

AAAI 2023technical

Lottery tickets (LTs) is able to discover accurate and sparse subnetworks that could be trained in isolation to match the performance of dense networks. Ensemble, in parallel, is one of the oldest time-proven tricks in machine learning to improve performance by combining the output of multiple indep…

2023

NLG Evaluation Metrics Beyond Correlation Analysis: An Empirical Metric Preference Checklist

ACL 2023long

In this study, we analyze automatic evaluation metrics for Natural Language Generation (NLG), specifically task-agnostic metrics and human-aligned metrics. Task-agnostic metrics, such as Perplexity, BLEU, BERTScore, are cost-effective and highly adaptable to diverse NLG tasks, yet they have a weak c…

2023

Stay Moral and Explore: Learn to Behave Morally in Text-based Games

ICLR 2023poster

Reinforcement learning (RL) in text-based games has developed rapidly and achieved promising results. However, little effort has been expended to design agents that pursue objectives while behaving morally, which is a critical issue in the field of autonomous agents. In this paper, we propose a gene…

Cited by 13SourcePDFScholar
2023

Turn-Level Active Learning for Dialogue State Tracking

EMNLP 2023long main

Dialogue state tracking (DST) plays an important role in task-oriented dialogue systems. However, collecting a large amount of turn-by-turn annotated dialogue data is costly and inefficient. In this paper, we propose a novel turn-level active learning framework for DST to actively select turns in di…

Cited by 0SourcecodeScholar
2022

A Model-agnostic Data Manipulation Method for Persona-based Dialogue Generation

ACL 2022long

Towards building intelligent dialogue agents, there has been a growing interest in introducing explicit personas in generation models. However, with limited persona-based dialogue data at hand, it may be difficult to train a dialogue generation model well. We point out that the data challenges of th…

2022

Fire Burns, Sword Cuts: Commonsense Inductive Bias for Exploration in Text-based Games

ACL 2022short

Text-based games (TGs) are exciting testbeds for developing deep reinforcement learning techniques due to their partially observed environments and large action spaces. In these games, the agent learns to explore the environment via natural language interactions with the game simulator. A fundamenta…

2022

Is Neural Topic Modelling Better than Clustering? An Empirical Study on Clustering with Contextual Embeddings for Topics

NAACL 2022long

Recent work incorporates pre-trained word embeddings such as BERT embeddings into Neural Topic Models (NTMs), generating highly coherent topics. However, with high-quality contextualized document representations, do we really need sophisticated neural models to obtain coherent and interpretable topi…

2022

Perceiving the World: Question-guided Reinforcement Learning for Text-based Games

ACL 2022long

Text-based games provide an interactive way to study natural language processing. While deep reinforcement learning has shown effectiveness in developing the game playing agent, the low sample efficiency and the large action space remain to be the two major challenges that hinder the DRL from being…

2022

Phrase-level Textual Adversarial Attack with Label Preservation

NAACL 2022findings

Generating high-quality textual adversarial examples is critical for investigating the pitfalls of natural language processing (NLP) models and further promoting their robustness. Existing attacks are usually realized through word-level or sentence-level perturbations, which either limit the perturb…

2022

Rethinking Goal-Conditioned Supervised Learning and Its Connection to Offline RL

ICLR 2022poster

Solving goal-conditioned tasks with sparse rewards using self-supervised learning is promising because of its simplicity and stability over current reinforcement learning (RL) algorithms. A recent work, called Goal-Conditioned Supervised Learning (GCSL), provides a new learning framework by iterativ…

2022

Superposing many tickets into one: A performance booster for sparse neural network training

UAI 2022poster

Recent works on sparse neural network training have shown that a compelling trade-off between performance and efficiency can be achieved. Existing sparse training methods usually strive to find the best sparse subnetwork possible in one single run, without involving any expensive dense or pre-traini…

Cited by 9SourcePDFScholar
2022

TASA: Deceiving Question Answering Models by Twin Answer Sentences Attack

EMNLP 2022main

We present Twin Answer Sentences Attack (TASA), an adversarial attack method for question answering (QA) models that produces fluent and grammatical adversarial contexts while maintaining gold answers. Despite phenomenal progress on general adversarial attacks, few works have investigated the vulner…

2021

DAGN: Discourse-Aware Graph Network for Logical Reasoning

NAACL 2021long

Recent QA with logical reasoning questions requires passage-level relations among the sentences. However, current approaches still focus on sentence-level relations interacting among tokens. In this work, we explore aggregating passage-level clues for solving logical reasoning QA by using discourse-…

2021

Generalization in Text-based Games via Hierarchical Reinforcement Learning

EMNLP 2021finding

Deep reinforcement learning provides a promising approach for text-based games in studying natural language communication between humans and artificial agents. However, the generalization still remains a big challenge as the agents depend critically on the complexity and variety of training tasks. I…

2021

ProtoInfoMax: Prototypical Networks with Mutual Information Maximization for Out-of-Domain Detection

EMNLP 2021finding

The ability to detect Out-of-Domain (OOD) inputs has been a critical requirement in many real-world NLP applications. For example, intent classification in dialogue systems. The reason is that the inclusion of unsupported OOD inputs may lead to catastrophic failure of systems. However, it remains an…

2021

REM-Net: Recursive Erasure Memory Network for Commonsense Evidence Refinement

AAAI 2021technical

When answering a question, people often draw upon their rich world knowledge in addition to the particular context. While recent works retrieve supporting facts/evidence from commonsense knowledge bases to supply additional information to each question, there is still ample opportunity to advance it…

Cited by 10SourcePDFScholar
2021

Towards Efficiently Diversifying Dialogue Generation Via Embedding Augmentation

ICASSP 2021accepted

Dialogue generation models face the challenge of producing generic and repetitive responses. Unlike previous augmentation methods that mostly focus on token manipulation and ignore the essential variety within a single sample using hard labels, we propose to promote the generation diversity of the n…

Cited by 0SourceScholar
2020

Deep Reinforcement Learning with Stacked Hierarchical Attention for Text-based Games

NeurIPS 2020poster

We study reinforcement learning (RL) for text-based games, which are interactive simulations in the context of natural language. While different methods have been developed to represent the environment information and language actions, existing RL agents are not empowered with any reasoning capabili…

2019

Curriculum-guided Hindsight Experience Replay

NeurIPS 2019poster

In off-policy deep reinforcement learning, it is usually hard to collect sufficient successful experiences with sparse rewards to learn from. Hindsight experience replay (HER) enables an agent to learn from failures by treating the achieved state of a failed experience as a pseudo goal. However, not…

2019

DHER: Hindsight Experience Replay for Dynamic Goals

ICLR 2019poster

Dealing with sparse rewards is one of the most important challenges in reinforcement learning (RL), especially when a goal is dynamic (e.g., to grasp a moving object). Hindsight experience replay (HER) has been shown an effective solution to handling sparse rewards with fixed goals. However, it doe…

2019

LIIR: Learning Individual Intrinsic Reward in Multi-Agent Reinforcement Learning

NeurIPS 2019poster

A great challenge in cooperative decentralized multi-agent reinforcement learning (MARL) is generating diversified behaviors for each individual agent when receiving only a team reward. Prior studies have paid much effort on reward shaping or designing a centralized critic that can discriminatively…

2015

Saliency Propagation From Simple to Difficult

CVPR 2015poster

Saliency propagation has been widely adopted for identifying the most attractive object in an image. The propagation sequence generated by existing saliency detection methods is governed by the spatial relationships of image regions, i.e., the saliency value is transmitted between two adjacent regio…

Cited by 179SourcePDFScholar