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Liang Pang

41 accepted papers

2026

DIVA-GRPO: Enhancing Multimodal Reasoning through Difficulty-Adaptive Variant Advantage

ICLR 2026poster

Reinforcement learning (RL) with group relative policy optimization (GRPO) has become a widely adopted approach for enhancing the reasoning capabilities of multimodal large language models (MLLMs). While GRPO enables long-chain reasoning without a traditional critic model, it often suffers from spar…

Cited by 0SourcecodeScholar
2026

RLKD: Distilling LLMs’ Reasoning via Reinforcement Learning

AAAI 2026technical

Distilling reasoning paths from teacher to student models via supervised fine-tuning (SFT) provides a shortcut for improving the reasoning ability of the smaller Large Language Models (LLMs). However, the reasoning paths generated by teacher models often reflect only surface-level traces of their un

Cited by 0SourcePDFScholar
2025

A Theory for Token-Level Harmonization in Retrieval-Augmented Generation

ICLR 2025poster

Retrieval-augmented generation (RAG) utilizes retrieved texts to enhance large language models (LLMs). Studies show that while RAG provides valuable external information (benefit), it may also mislead LLMs (detriment) with noisy or incorrect retrieved texts. Although many existing methods attempt to…

Cited by 1SourcePDFScholar
2025

Bridging Jensen Gap for Max-Min Group Fairness Optimization in Recommendation

ICLR 2025poster

Group max-min fairness (MMF) is commonly used in fairness-aware recommender systems (RS) as an optimization objective, as it aims to protect marginalized item groups and ensures a fair competition platform. However, our theoretical analysis indicates that integrating MMF constraint violates the assu…

2025

Cross-Modal Safety Mechanism Transfer in Large Vision-Language Models

ICLR 2025poster

Vision-language alignment in Large Vision-Language Models (LVLMs) successfully enables LLMs to understand visual input. However, we find that existing vision-language alignment methods fail to transfer the existing safety mechanism for text in LLMs to vision, which leads to vulnerabilities in toxic…

Cited by 3SourcePDFScholar
2025

Do LLMs Play Dice? Exploring Probability Distribution Sampling in Large Language Models for Behavioral Simulation

COLING 2025main

With the rapid advancement of large language models (LLMs) for handling complex language tasks, an increasing number of studies are employing LLMs as agents to emulate the sequential decision-making processes of humans often represented as Markov decision-making processes (MDPs). The actions in MDPs…

Cited by 2SourcePDFScholar
2025

Everything is Editable: Extend Knowledge Editing to Unstructured Data in Large Language Models

ICLR 2025poster

Recent knowledge editing methods have primarily focused on modifying structured knowledge in large language models. However, this task setting overlooks the fact that a significant portion of real-world knowledge is stored in an unstructured format, characterized by long-form content, noise, and a c…

2025

Following the Autoregressive Nature of LLM Embeddings via Compression and Alignment

EMNLP 2025

A new trend uses LLMs as dense text encoders via contrastive learning. However, since LLM embeddings predict the probability distribution of the next token, they are inherently generative and distributive, conflicting with contrastive learning, which requires embeddings to capture full-text semantic

2025

LightPROF: A Lightweight Reasoning Framework for Large Language Model on Knowledge Graph

AAAI 2025technical

Large Language Models (LLMs) have impressive capabilities in text understanding and zero-shot reasoning. However, delays in knowledge updates may cause them to reason incorrectly or produce harmful results. Knowledge Graphs (KGs) provide rich and reliable contextual information for the reasoning pro…

2025

MLaKE: Multilingual Knowledge Editing Benchmark for Large Language Models

COLING 2025main

The extensive utilization of large language models (LLMs) underscores the crucial necessity for precise and contemporary knowledge embedded within their intrinsic parameters. Existing research on knowledge editing primarily concentrates on monolingual scenarios, neglecting the complexities presented…

2025

MaFeRw: Query Rewriting with Multi-Aspect Feedbacks for Retrieval-Augmented Large Language Models

AAAI 2025technical

In a real-world RAG system, the current query often involves spoken ellipses and ambiguous references from dialogue contexts, necessitating query rewriting to better describe user's information needs. However, traditional context-based rewriting has minimal enhancement on downstream generation tasks…

2025

Media Source Matters More Than Content: Unveiling Political Bias in LLM-Generated Citations

EMNLP 2025

Unlike traditional search engines that present ranked lists of webpages, generative search engines rely solely on in-line citations as the key gateway to original real-world webpages, making it crucial to examine whether LLM-generated citations have biases—particularly for politically sensitive quer

2025

Perplexity Trap: PLM-Based Retrievers Overrate Low Perplexity Documents

ICLR 2025poster

Previous studies have found that PLM-based retrieval models exhibit a preference for LLM-generated content, assigning higher relevance scores to these documents even when their semantic quality is comparable to human-written ones. This phenomenon, known as source bias, threatens the sustainable deve…

2025

ToolCoder: A Systematic Code-Empowered Tool Learning Framework for Large Language Models

ACL 2025long

Tool learning has emerged as a crucial capability for large language models (LLMs) to solve complex real-world tasks through interaction with external tools. Existing approaches face significant challenges, including reliance on hand-crafted prompts, difficulty in multi-step planning, and lack of pr…

2024

A Study of Implicit Ranking Unfairness in Large Language Models

EMNLP 2024finding

Recently, Large Language Models (LLMs) have demonstrated a superior ability to serve as ranking models. However, concerns have arisen as LLMs will exhibit discriminatory ranking behaviors based on users’ sensitive attributes (gender). Worse still, in this paper, we identify a subtler form of discrim…

2024

Beyond Memorization: The Challenge of Random Memory Access in Language Models

ACL 2024long

Recent developments in Language Models (LMs) have shown their effectiveness in NLP tasks, particularly in knowledge-intensive tasks.However, the mechanisms underlying knowledge storage and memory access within their parameters remain elusive. In this paper, we investigate whether a generative LM (e.…

2024

Cocktail: A Comprehensive Information Retrieval Benchmark with LLM-Generated Documents Integration

ACL 2024findings

The proliferation of Large Language Models (LLMs) has led to an influx of AI-generated content (AIGC) on the internet, transforming the corpus of Information Retrieval (IR) systems from solely human-written to a coexistence with LLM-generated content. The impact of this surge in AIGC on IR systems r…

2024

Enhancing Training Data Attribution for Large Language Models with Fitting Error Consideration

EMNLP 2024main

The black-box nature of large language models (LLMs) poses challenges in interpreting results, impacting issues such as data intellectual property protection and hallucination tracing. Training data attribution (TDA) methods are considered effective solutions to address these challenges.Most recent…

2024

HalluciDoctor: Mitigating Hallucinatory Toxicity in Visual Instruction Data

CVPR 2024poster

Multi-modal Large Language Models (MLLMs) tuned on machine-generated instruction-following data have demonstrated remarkable performance in various multimodal understanding and generation tasks. However the hallucinations inherent in machine-generated data which could lead to hallucinatory outputs i…

2024

Qsnail: A Questionnaire Dataset for Sequential Question Generation

COLING 2024main

The questionnaire is a professional research methodology used for both qualitative and quantitative analysis of human opinions, preferences, attitudes, and behaviors. However, designing and evaluating questionnaires demands significant effort due to their intricate and complex structure. Questionnai…

2024

Thermal-NeRF: Neural Radiance Fields from an Infrared Camera

IROS 2024poster

In recent years, Neural Radiance Fields (NeRFs) have demonstrated significant potential in encoding highly-detailed 3D geometry and environmental appearance, positioning themselves as a promising alternative to traditional explicit representation for 3D scene reconstruction. However, the predominant…

Cited by 13SourcecodeScholar
2024

Think Before You Speak: Cultivating Communication Skills of Large Language Models via Inner Monologue

NAACL 2024findings

The emergence of large language models (LLMs) further improves the capabilities of open-domain dialogue systems and can generate fluent, coherent, and diverse responses. However, LLMs still lack a crucial ability: communication skills. This limitation renders them more like information seeking tools…

2024

Unsupervised Information Refinement Training of Large Language Models for Retrieval-Augmented Generation

ACL 2024long

Retrieval-augmented generation (RAG) enhances large language models (LLMs) by incorporating additional information from retrieval. However, studies have shown that LLMs still face challenges in effectively using the retrieved information, even ignore it or be misled by it. The key reason is that the…

2023

A Disentangled-Attention Based Framework with Persona-Aware Prompt Learning for Dialogue Generation

AAAI 2023technical

Endowing dialogue agents with personas is the key to delivering more human-like conversations. However, existing persona-grounded dialogue systems still lack informative details of human conversations and tend to reply with inconsistent and generic responses. One of the main underlying causes is tha…

Cited by 5SourcePDFScholar
2023

BERM: Training the Balanced and Extractable Representation for Matching to Improve Generalization Ability of Dense Retrieval

ACL 2023long

Dense retrieval has shown promise in the first-stage retrieval process when trained on in-domain labeled datasets. However, previous studies have found that dense retrieval is hard to generalize to unseen domains due to its weak modeling of domain-invariant and interpretable feature (i.e., matching…

2023

LLMDet: A Third Party Large Language Models Generated Text Detection Tool

EMNLP 2023long findings

Generated texts from large language models (LLMs) are remarkably close to high-quality human-authored text, raising concerns about their potential misuse in spreading false information and academic misconduct. Consequently, there is an urgent need for a highly practical detection tool capable of acc…

Cited by 0SourcecodeScholar
2023

MacLaSa: Multi-Aspect Controllable Text Generation via Efficient Sampling from Compact Latent Space

EMNLP 2023long findings

Multi-aspect controllable text generation aims to generate fluent sentences that possess multiple desired attributes simultaneously. Traditional methods either require expensive iteration / searching within the discrete text space during the decoding stage, or train separate controllers for each asp…

Cited by 0SourcecodeScholar
2023

Multi-level Adaptive Contrastive Learning for Knowledge Internalization in Dialogue Generation

EMNLP 2023long main

Knowledge-grounded dialogue generation aims to mitigate the issue of text degeneration by incorporating external knowledge to supplement the context. However, the model often fails to internalize this information into responses in a human-like manner. Instead, it simply inserts segments of the provi…

Cited by 0SourceScholar
2023

RegaVAE: A Retrieval-Augmented Gaussian Mixture Variational Auto-Encoder for Language Modeling

EMNLP 2023long findings

Retrieval-augmented language models show promise in addressing issues like outdated information and hallucinations in language models (LMs). However, current research faces two main problems: 1) determining what information to retrieve, and 2) effectively combining retrieved information during gener…

Cited by 0SourcecodeScholar
2023

SimOAP: Improve Coherence and Consistency in Persona-based Dialogue Generation via Over-sampling and Post-evaluation

ACL 2023long

Language models trained on large-scale corpora can generate remarkably fluent results in open-domain dialogue. However, for the persona-based dialogue generation task, consistency and coherence are also key factors, which are great challenges for language models. Existing works mainly focus on valua…

2022

Optimal Partial Transport Based Sentence Selection for Long-form Document Matching

COLING 2022main

One typical approach to long-form document matching is first conducting alignment between cross-document sentence pairs, and then aggregating all of the sentence-level matching signals. However, this approach could be problematic because the alignment between documents is partial — despite two docum…

2021

Adaptive Information Seeking for Open-Domain Question Answering

EMNLP 2021main

Information seeking is an essential step for open-domain question answering to efficiently gather evidence from a large corpus. Recently, iterative approaches have been proven to be effective for complex questions, by recursively retrieving new evidence at each step. However, almost all existing ite…

2021

Sketch and Customize: A Counterfactual Story Generator

AAAI 2021technical

Recent text generation models are easy to generate relevant and fluent text for the given text, while lack of causal reasoning ability when we change some parts of the given text. Counterfactual story rewriting is a recently proposed task to test the causal reasoning ability for text generation mode…

2021

Transductive Learning for Unsupervised Text Style Transfer

EMNLP 2021main

Unsupervised style transfer models are mainly based on an inductive learning approach, which represents the style as embeddings, decoder parameters, or discriminator parameters and directly applies these general rules to the test cases. However, the lacking of parallel corpus hinders the ability of…

2021

Uncertainty Calibration for Ensemble-Based Debiasing Methods

NeurIPS 2021poster

Ensemble-based debiasing methods have been shown effective in mitigating the reliance of classifiers on specific dataset bias, by exploiting the output of a bias-only model to adjust the learning target. In this paper, we focus on the bias-only model in these ensemble-based methods, which plays an i…

Cited by 22SourcePDFScholar
2020

Evaluating Natural Language Generation via Unbalanced Optimal Transport

IJCAI 2020poster

Embedding-based evaluation measures have shown promising improvements on the correlation with human judgments in natural language generation. In these measures, various intrinsic metrics are used in the computation, including generalized precision, recall, F-score and the earth mover's distance. How…

2020

METNet: A Mutual Enhanced Transformation Network for Aspect-based Sentiment Analysis

COLING 2020main

Aspect-based sentiment analysis (ABSA) aims to determine the sentiment polarity of each specific aspect in a given sentence. Existing researches have realized the importance of the aspect for the ABSA task and have derived many interactive learning methods that model context based on specific aspect…

Cited by 18SourcePDFScholar
2020

Modeling Topical Relevance for Multi-Turn Dialogue Generation

IJCAI 2020poster

Topic drift is a common phenomenon in multi-turn dialogue. Therefore, an ideal dialogue generation models should be able to capture the topic information of each context, detect the relevant context, and produce appropriate responses accordingly. However, existing models usually use word or sentence…

2020

PEDNet: A Persona Enhanced Dual Alternating Learning Network for Conversational Response Generation

COLING 2020main

Endowing a chatbot with a personality is essential to deliver more realistic conversations. Various persona-based dialogue models have been proposed to generate personalized and diverse responses by utilizing predefined persona information. However, generating personalized responses is still a chall…