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Xiaojun Quan

53 accepted papers

2026

ProFuser: Progressive Fusion of Large Language Models

AAAI 2026technical

While fusing the capacities and advantages of various large language models offers a pathway to construct more powerful and versatile models, a fundamental challenge is to properly select advantageous model during training. Existing fusion methods primarily focus on the training mode that uses cros

Cited by 0SourcePDFScholar
2026

SPELL: Self-Play Reinforcement Learning for Evolving Long-Context Language Models

ICLR 2026poster

Progress in long-context reasoning for large language models (LLMs) has lagged behind other recent advances. This gap arises not only from the intrinsic difficulty of processing long texts, but also from the scarcity of reliable human annotations and programmatically verifiable reward signals. In th…

Cited by 0SourcecodeScholar
2026

Unleashing Implicit Rewards: Prefix-Value Learning for Distribution-Level Optimization

ICML 2026poster

Process reward models (PRMs) provide fine-grained reward signals along the reasoning process, improving credit assignment beyond outcome-only rewards. Training reliable PRMs often relies on step annotations or heavy verification pipelines, making them expensive to scale and refresh during online RL.…

Cited by 0SourceScholar
2026

When Model Merging Breaks Routing: Training-Free Calibration for MoE

ICML 2026poster

Model merging has emerged as a cost-effective approach for consolidating the capabilities of multiple LLMs without retraining. However, existing merging techniques, largely based on linear parameter arithmetic or optimization, struggle when applied to Mixture-of-Experts (MoE) architectures. We ident…

Cited by 0SourceScholar
2025

Advantage-Guided Distillation for Preference Alignment in Small Language Models

ICLR 2025spotlight

Alignment techniques enable Large Language Models (LLMs) to generate outputs that align with human preferences and play a crucial role in their effectiveness. However, their impact often diminishes when applied to Small Language Models (SLMs), likely due to the limited capacity of these models. Inst…

2025

BlockPruner: Fine-grained Pruning for Large Language Models

ACL 2025finding

With the rapid growth in the size and complexity of large language models (LLMs), the costs associated with their training and inference have escalated significantly. Research indicates that certain layers in LLMs harbor substantial redundancy, and pruning these layers has minimal impact on the over…

2025

Cool-Fusion: Fuse Large Language Models without Training

ACL 2025long

We focus on the problem of fusing two or more heterogeneous large language models (LLMs) to leverage their complementary strengths. One of the challenges of model fusion is high computational load, specifically in fine-tuning or aligning vocabularies. To address this, we propose Cool-Fusion, a simpl…

2025

Discriminative Policy Optimization for Token-Level Reward Models

ICML 2025poster

Process reward models (PRMs) provide more nuanced supervision compared to outcome reward models (ORMs) for optimizing policy models, positioning them as a promising approach to enhancing the capabilities of LLMs in complex reasoning tasks. Recent efforts have advanced PRMs from step-level to token-l…

2025

Edit-Wise Preference Optimization for Grammatical Error Correction

COLING 2025main

While large language models (LLMs) have achieved remarkable success in various natural language processing tasks, their strengths have yet to be fully demonstrated in grammatical error correction (GEC). This is partly due to the misalignment between their pre-training objectives and the GEC principl…

2025

Mutual-Taught for Co-adapting Policy and Reward Models

ACL 2025long

During the preference optimization of large language models (LLMs), distribution shifts may arise between newly generated model samples and the data used to train the reward model (RM). This shift reduces the efficacy of the RM, which in turn negatively impacts the performance of the policy model (P…

2025

Probabilistic Token Alignment for Large Language Model Fusion

NeurIPS 2025poster

Training large language models (LLMs) from scratch can yield models with unique functionalities and strengths, but it is costly and often leads to redundant capabilities. A more cost-effective alternative is to fuse existing pre-trained LLMs with different architectures into a more powerful model. H…

Cited by 0SourceScholar
2025

ReAlign: Structured Revision for Small Language Model Alignment

EMNLP 2025

Aligning small language models with human preferences is challenging, as weak policies struggle to generate informative on-policy samples and suffer from unstable gradients when trained on off-policy signals from stronger models. In this work, we propose ReAlign, a training framework that combines t

2025

Weighted-Reward Preference Optimization for Implicit Model Fusion

ICLR 2025poster

While fusing heterogeneous open-source LLMs with varying architectures and sizes can potentially integrate the strengths of different models, existing fusion methods face significant challenges, such as vocabulary alignment and merging distribution matrices. These procedures are not only complex but…

2024

Knowledge Fusion of Large Language Models

ICLR 2024poster

While training large language models (LLMs) from scratch can generate models with distinct functionalities and strengths, it comes at significant costs and may result in redundant capabilities. Alternatively, a cost-effective and compelling approach is to merge existing pre-trained LLMs into a more…

2024

Knowledge Verification to Nip Hallucination in the Bud

EMNLP 2024main

While large language models (LLMs) have demonstrated exceptional performance across various tasks following human alignment, they may still generate responses that sound plausible but contradict factual knowledge, a phenomenon known as hallucination. In this paper, we demonstrate the feasibility of…

2024

Self-Evolution Fine-Tuning for Policy Optimization

EMNLP 2024finding

The alignment of large language models (LLMs) is crucial not only for unlocking their potential in specific tasks but also for ensuring that responses meet human expectations and adhere to safety and ethical principles. To address the challenges of current alignment methodologies, we introduce self-…

2024

Small LLMs Are Weak Tool Learners: A Multi-LLM Agent

EMNLP 2024main

Large Language Model (LLM) agents significantly extend the capabilities of standalone LLMs, empowering them to interact with external tools (e.g., APIs, functions) and complete various tasks in a self-directed fashion. The challenge of tool use demands that LLMs not only understand user queries and…

2024

SocialBench: Sociality Evaluation of Role-Playing Conversational Agents

ACL 2024findings

Large language models (LLMs) have advanced the development of various AI conversational agents, including role-playing agents that mimic diverse characters and human behaviors. While prior research has predominantly focused on enhancing the conversational capability, role-specific knowledge and styl…

2023

A Graph Fusion Approach for Cross-Lingual Machine Reading Comprehension

AAAI 2023technical

Although great progress has been made for Machine Reading Comprehension (MRC) in English, scaling out to a large number of languages remains a huge challenge due to the lack of large amounts of annotated training data in non-English languages. To address this challenge, some recent efforts of cross-…

2023

AD-KD: Attribution-Driven Knowledge Distillation for Language Model Compression

ACL 2023long

Knowledge distillation has attracted a great deal of interest recently to compress large language models. However, existing knowledge distillation methods suffer from two limitations. First, the student model simply imitates the teacher’s behavior while ignoring the reasoning behind it. Second, thes…

2023

APrompt: Attention Prompt Tuning for Efficient Adaptation of Pre-trained Language Models

EMNLP 2023long main

With the continuous growth of large language models, the process of fine-tuning these models for new tasks has become increasingly parameter-intensive. Prompt tuning, a method that involves tuning a small set of soft prompts, has emerged as an effective and efficient approach for adapting large pre-…

Cited by 0SourceScholar
2023

Clustering-Aware Negative Sampling for Unsupervised Sentence Representation

ACL 2023findings

Contrastive learning has been widely studied in sentence representation learning. However, earlier works mainly focus on the construction of positive examples, while in-batch samples are often simply treated as negative examples. This approach overlooks the importance of selecting appropriate negati…

2023

Disentangled Phonetic Representation for Chinese Spelling Correction

ACL 2023long

Chinese Spelling Correction (CSC) aims to detect and correct erroneous characters in Chinese texts. Although efforts have been made to introduce phonetic information (Hanyu Pinyin) in this task, they typically merge phonetic representations with character representations, which tends to weaken the r…

2023

Dual-Feedback Knowledge Retrieval for Task-Oriented Dialogue Systems

EMNLP 2023long main

Efficient knowledge retrieval plays a pivotal role in ensuring the success of end-to-end task-oriented dialogue systems by facilitating the selection of relevant information necessary to fulfill user requests. However, current approaches generally integrate knowledge retrieval and response generatio…

Cited by 0SourceScholar
2023

Explore-Instruct: Enhancing Domain-Specific Instruction Coverage through Active Exploration

EMNLP 2023long main

Instruction-tuning can be substantially optimized through enhanced diversity, resulting in models capable of handling a broader spectrum of tasks. However, existing data employed for such tuning often exhibit an inadequate coverage of individual domains, limiting the scope for nuanced comprehension…

Cited by 0SourcecodeScholar
2023

Joint Generator-Ranker Learning for Natural Language Generation

ACL 2023findings

Generate-then-rank is a widely used mechanism for text generation, where a generator produces multiple text candidates and a ranker chooses the best one among the text candidates. However, existing methods usually train the generator and the ranker individually, neglecting the mutual feedback that c…

2023

MCC-KD: Multi-CoT Consistent Knowledge Distillation

EMNLP 2023long findings

Large language models (LLMs) have showcased remarkable capabilities in complex reasoning through chain of thought (CoT) prompting. Recently, there has been a growing interest in transferring these reasoning abilities from LLMs to smaller models. However, achieving both the diversity and consistency…

Cited by 0SourcecodeScholar
2023

MUSTIE: Multimodal Structural Transformer for Web Information Extraction

ACL 2023long

The task of web information extraction is to extract target fields of an object from web pages, such as extracting the name, genre and actor from a movie page. Recent sequential modeling approaches have achieved state-of-the-art results on web information extraction. However, most of these methods o…

Cited by 18SourcePDFScholar
2023

MixPAVE: Mix-Prompt Tuning for Few-shot Product Attribute Value Extraction

ACL 2023findings

The task of product attribute value extraction is to identify values of an attribute from product information. Product attributes are important features, which help improve online shopping experience of customers, such as product search, recommendation and comparison. Most existing works only focus…

Cited by 31SourcePDFScholar
2023

Multi-Grained Knowledge Retrieval for End-to-End Task-Oriented Dialog

ACL 2023long

Retrieving proper domain knowledge from an external database lies at the heart of end-to-end task-oriented dialog systems to generate informative responses. Most existing systems blend knowledge retrieval with response generation and optimize them with direct supervision from reference responses, le…

2023

Orders Are Unwanted: Dynamic Deep Graph Convolutional Network for Personality Detection

AAAI 2023technical

Predicting personality traits based on online posts has emerged as an important task in many fields such as social network analysis. One of the challenges of this task is assembling information from various posts into an overall profile for each user. While many previous solutions simply concatenate…

2023

PsyCoT: Psychological Questionnaire as Powerful Chain-of-Thought for Personality Detection

EMNLP 2023long findings

Recent advances in large language models (LLMs), such as ChatGPT, have showcased remarkable zero-shot performance across various NLP tasks. However, the potential of LLMs in personality detection, which involves identifying an individual's personality from their written texts, remains largely unexpl…

Cited by 0SourcecodeScholar
2023

Retrieval-Generation Alignment for End-to-End Task-Oriented Dialogue System

EMNLP 2023long main

Developing an efficient retriever to retrieve knowledge from a large-scale knowledge base (KB) is critical for task-oriented dialogue systems to effectively handle localized and specialized tasks. However, widely used generative models such as T5 and ChatGPT often struggle to differentiate subtle di…

Cited by 0SourcecodeScholar
2022

AD-DROP: Attribution-Driven Dropout for Robust Language Model Fine-Tuning

NeurIPS 2022accept

Fine-tuning large pre-trained language models on downstream tasks is apt to suffer from overfitting when limited training data is available. While dropout proves to be an effective antidote by randomly dropping a proportion of units, existing research has not examined its effect on the self-attentio…

2022

GL-RG: Global-Local Representation Granularity for Video Captioning

IJCAI 2022poster

Video captioning is a challenging task as it needs to accurately transform visual understanding into natural language description. To date, state-of-the-art methods inadequately model global-local representation across video frames for caption generation, leaving plenty of room for improve…

2022

Learning to Generate Question by Asking Question: A Primal-Dual Approach with Uncommon Word Generation

EMNLP 2022main

Automatic question generation (AQG) is the task of generating a question from a given passage and an answer. Most existing AQG methods aim at encoding the passage and the answer to generate the question. However, limited work has focused on modeling the correlation between the target answer and the…

Cited by 9SourcePDFScholar
2022

XPrompt: Exploring the Extreme of Prompt Tuning

EMNLP 2022main

Prompt tuning learns soft prompts to condition the frozen Pre-trained Language Models (PLMs) for performing downstream tasks in a parameter-efficient manner. While prompt tuning has gradually reached the performance level of fine-tuning as the model scale increases, there is still a large performanc…

Cited by 39SourcePDFScholar
2021

DialogXL: All-in-One XLNet for Multi-Party Conversation Emotion Recognition

AAAI 2021technical

This paper presents our pioneering effort for emotion recognition in conversation (ERC) with pre-trained language models. Unlike regular documents, conversational utterances appear alternately from different parties and are usually organized as hierarchical structures in previous work. Such structur…

2021

Directed Acyclic Graph Network for Conversational Emotion Recognition

ACL 2021long

The modeling of conversational context plays a vital role in emotion recognition from conversation (ERC). In this paper, we put forward a novel idea of encoding the utterances with a directed acyclic graph (DAG) to better model the intrinsic structure within a conversation, and design a directed acy…

2021

Learning to Answer Psychological Questionnaire for Personality Detection

EMNLP 2021finding

Existing text-based personality detection research mostly relies on data-driven approaches to implicitly capture personality cues in online posts, lacking the guidance of psychological knowledge. Psychological questionnaire, which contains a series of dedicated questions highly related to personalit…

Cited by 22SourcePDFScholar
2021

Psycholinguistic Tripartite Graph Network for Personality Detection

ACL 2021long

Most of the recent work on personality detection from online posts adopts multifarious deep neural networks to represent the posts and builds predictive models in a data-driven manner, without the exploitation of psycholinguistic knowledge that may unveil the connections between one’s language use a…

Cited by 42SourcePDFScholar
2020

Constituency Lattice Encoding for Aspect Term Extraction

COLING 2020main

One of the remaining challenges for aspect term extraction in sentiment analysis resides in the extraction of phrase-level aspect terms, which is non-trivial to determine the boundaries of such terms. In this paper, we aim to address this issue by incorporating the span annotations of constituents o…

2020

Embedding Dynamic Attributed Networks by Modeling the Evolution Processes

COLING 2020main

Network embedding has recently emerged as a promising technique to embed nodes of a network into low-dimensional vectors. While fairly successful, most existing works focus on the embedding techniques for static networks. But in practice, there are many networks that are evolving over time and hence…

Cited by 15SourcePDFScholar
2020

Multi-choice Relational Reasoning for Machine Reading Comprehension

COLING 2020main

This paper presents our study of cloze-style reading comprehension by imitating human reading comprehension, which normally involves tactical comparing and reasoning over candidates while choosing the best answer. We propose a multi-choice relational reasoning (McR2) model with an aim to enable rela…

Cited by 6SourcePDFScholar