Yuan Liang
2026
Memp: Exploring Agent Procedural Memory
Runnan Fang | Yuan Liang | Xiaobin Wang | Jialong Wu | Shuofei Qiao | Pengjun Xie | Fei Huang | Huajun Chen | Ningyu Zhang
Findings of the Association for Computational Linguistics: ACL 2026
Runnan Fang | Yuan Liang | Xiaobin Wang | Jialong Wu | Shuofei Qiao | Pengjun Xie | Fei Huang | Huajun Chen | Ningyu Zhang
Findings of the Association for Computational Linguistics: ACL 2026
Large Language Models (LLMs) based agents excel at diverse tasks, yet they suffer from brittle procedural memory that is manually engineered or entangled in static parameters. In this work, we investigate strategies to endow agents with a learnable, updatable, and lifelong procedural memory. We propose a procedural-memory repository that distills past agent trajectories into both fine-grained, step-by-step instructions and higher-level, script-like abstractions. Coupled with a dynamic regimen that continuously updates, corrects, and deprecates its contents, this repository evolves in lockstep with new experience. Empirical evaluation on TravelPlanner and Alfworld shows that as the memory repository is refined, agents achieve steadily higher success rates and greater efficiency on analogous tasks. Moreover, procedural memory built from a stronger model retains its value: migrating the procedural memory to a weaker model yields substantial performance gains.
Topology Matters: Measuring Memory Leakage in Multi-Agent LLMs
Jinbo Liu | Defu Cao | Yifei Wei | Tianyao Su | Yuan Liang | Yushun Dong | Yan Liu | Yue Zhao | Xiyang Hu
Findings of the Association for Computational Linguistics: ACL 2026
Jinbo Liu | Defu Cao | Yifei Wei | Tianyao Su | Yuan Liang | Yushun Dong | Yan Liu | Yue Zhao | Xiyang Hu
Findings of the Association for Computational Linguistics: ACL 2026
Graph topology is a fundamental determinant of memory leakage in multi-agent LLM systems, yet its effects remain poorly quantified. We introduce MAMA (Multi-Agent Memory Attack), a controlled evaluation framework for comparing topology-conditioned memory leakage in multi-agent LLM systems. MAMA operates on synthetic documents containing labeled Personally Identifiable Information (PII) entities, from which we generate sanitized task instructions. We execute a two-phase protocol: Engram (seeding private information into a target agent’s memory) and Resonance (multi-round interaction where an attacker attempts extraction). Over 10 rounds, we measure leakage using a two-stage recovery criterion that combines exact-match extraction with LLM-based inference over the attacker’s final output. We evaluate six canonical topologies (complete, circle, chain, tree, star, star-ring) across n∈{4,5,6}, attacker–target placements, and base models. Results are consistent: denser connectivity, shorter attacker–target distance, and higher target centrality increase leakage; most leakage occurs in early rounds and then plateaus; model choice shifts absolute rates but preserves broad structural trends; spatiotemporal/location attributes leak more readily than identity credentials or regulated identifiers. We distill practical guidance for system design: favor sparse or hierarchical connectivity, maximize attacker–target separation, and restrict hub/shortcut pathways via topology-aware access control. Our code is available at https://github.com/llll121/mama-eval.
2025
Low-Hallucination and Efficient Coreference Resolution with LLMs
Yujian Gan | Yuan Liang | Jinxia Xie | Yanni Lin | Juntao Yu | Massimo Poesio
Findings of the Association for Computational Linguistics: EMNLP 2025
Yujian Gan | Yuan Liang | Jinxia Xie | Yanni Lin | Juntao Yu | Massimo Poesio
Findings of the Association for Computational Linguistics: EMNLP 2025
Large Language Models (LLMs) have shown promising results in coreference resolution, especially after fine-tuning. However, recent generative approaches face a critical issue: hallucinations—where the model generates content not present in the original input. These hallucinations make evaluation difficult and decrease overall performance. To address this issue, we analyze the underlying causes of hallucinations and propose a low-hallucination and efficient solution. Specifically, we introduce Efficient Constrained Decoding for Coreference Resolution, which maintains strong robustness while significantly improving computational efficiency. On the English OntoNotes development set, our approach achieved slightly better performance than previous state-of-the-art methods, while requiring substantially fewer parameters.
SynWorld: Virtual Scenario Synthesis for Agentic Action Knowledge Refinement
Runnan Fang | Xiaobin Wang | Yuan Liang | Shuofei Qiao | Jialong Wu | Zekun Xi | Ningyu Zhang | Yong Jiang | Pengjun Xie | Fei Huang | Huajun Chen
Proceedings of the 63rd Annual Meeting of the Association for Computational Linguistics (Volume 2: Short Papers)
Runnan Fang | Xiaobin Wang | Yuan Liang | Shuofei Qiao | Jialong Wu | Zekun Xi | Ningyu Zhang | Yong Jiang | Pengjun Xie | Fei Huang | Huajun Chen
Proceedings of the 63rd Annual Meeting of the Association for Computational Linguistics (Volume 2: Short Papers)
In the interaction between agents and their environments, agents expand their capabilities by planning and executing actions. However, LLM-based agents face substantial challenges when deployed in novel environments or required to navigate unconventional action spaces. To empower agents to autonomously explore environments, optimize workflows, and enhance their understanding of actions, we propose SynWorld, a framework that allows agents to synthesize possible scenarios with multi-step action invocation within the action space and perform Monte Carlo Tree Search (MCTS) exploration to effectively refine their action knowledge in the current environment. Our experiments demonstrate that SynWorld is an effective and general approach to learning action knowledge in new environments.
Improving LLMs’ Learning of Coreference Resolution
Yujian Gan | Yuan Liang | Yanni Lin | Juntao Yu | Massimo Poesio
Proceedings of the 26th Annual Meeting of the Special Interest Group on Discourse and Dialogue
Yujian Gan | Yuan Liang | Yanni Lin | Juntao Yu | Massimo Poesio
Proceedings of the 26th Annual Meeting of the Special Interest Group on Discourse and Dialogue
Coreference Resolution (CR) is crucial for many NLP tasks, but existing LLMs struggle with hallucination and under-performance. In this paper, we investigate the limitations of existing LLM-based approaches to CR—specifically the Question-Answering (QA) Template and Document Template methods—and propose two novel techniques: Reversed Training with Joint Inference and Iterative Document Generation. Our experiments show that Reversed Training improves the QA Template method, while Iterative Document Generation eliminates hallucinations in the generated source text and boosts coreference resolution. Integrating these methods and techniques offers an effective and robust solution to LLM-based coreference resolution
Beyond Citations: Integrating Finding-Based Relations for Improved Biomedical Article Representations
Yuan Liang | Massimo Poesio | Roonak Rezvani
Proceedings of the 24th Workshop on Biomedical Language Processing
Yuan Liang | Massimo Poesio | Roonak Rezvani
Proceedings of the 24th Workshop on Biomedical Language Processing
High-quality scientific article embeddings are essential for tasks like document retrieval, citation recommendation, and classification. Traditional citation-based approaches assume citations reflect semantic similarity—an assumption that introduces bias and noise. Recent models like SciNCL and SPECTER2 have attempted to refine citation-based representations but still struggle with noisy citation edges and fail to fully leverage textual information. To address these limitations, we propose a hybrid approach that combines Finding-Citation Graphs (FCG) with contrastive learning. Our method improves triplet selection by filtering out less important citations and incorporating finding similarity relations, leading to better semantic relationship capture. Evaluated on the SciRepEval benchmark, our approach consistently outperforms citation-only baselines, showing the value of text-based semantic structures. While we do not surpass state-of-the-art models in most tasks, our results reveal the limitations of purely citation-based embeddings and suggest paths for improvement through enhanced semantic integration and domain-specific adaptations.
2024
A Fine-grained citation graph for biomedical academic papers: the finding-citation graph
Yuan Liang | Massimo Poesio | Roonak Rezvani
Proceedings of the 23rd Workshop on Biomedical Natural Language Processing
Yuan Liang | Massimo Poesio | Roonak Rezvani
Proceedings of the 23rd Workshop on Biomedical Natural Language Processing
Citations typically mention findings as well as papers. To model this richer notion of citation, we introduce a richer form of citation graph with nodes for both academic papers and their findings: the finding-citation graph (FCG). We also present a new pipeline to construct such a graph, which includes a finding identification module and a citation sentence extraction module. From each paper, it extracts rich basic information, abstract, and structured full text first. The abstract and vital sections, such as the results and discussion, are input into the finding identification module. This module identifies multiple findings from a paper, achieving an 80% accuracy in multiple findings evaluation. The full text is input into the citation sentence extraction module to identify inline citation sentences and citation markers, achieving 97.7% accuracy. Then, the graph is constructed using the outputs from the two modules mentioned above. We used the Europe PMC to build such a graph using the pipeline, resulting in a graph with 14.25 million nodes and 76 million edges.
2022
RAAT: Relation-Augmented Attention Transformer for Relation Modeling in Document-Level Event Extraction
Yuan Liang | Zhuoxuan Jiang | Di Yin | Bo Ren
Proceedings of the 2022 Conference of the North American Chapter of the Association for Computational Linguistics: Human Language Technologies
Yuan Liang | Zhuoxuan Jiang | Di Yin | Bo Ren
Proceedings of the 2022 Conference of the North American Chapter of the Association for Computational Linguistics: Human Language Technologies
In document-level event extraction (DEE) task, event arguments always scatter across sentences (across-sentence issue) and multipleevents may lie in one document (multi-event issue). In this paper, we argue that the relation information of event arguments is of greatsignificance for addressing the above two issues, and propose a new DEE framework which can model the relation dependencies, calledRelation-augmented Document-level Event Extraction (ReDEE). More specifically, this framework features a novel and tailored transformer,named as Relation-augmented Attention Transformer (RAAT). RAAT is scalable to capture multi-scale and multi-amount argument relations. To further leverage relation information, we introduce a separate event relation prediction task and adopt multi-task learning method to explicitly enhance event extraction performance. Extensive experiments demonstrate the effectiveness of the proposed method, which can achieve state-of-the-art performance on two public datasets. Our code is available at https://github.com/TencentYoutuResearch/RAAT.
Towards Socially Intelligent Agents with Mental State Transition and Human Value
Liang Qiu | Yizhou Zhao | Yuan Liang | Pan Lu | Weiyan Shi | Zhou Yu | Song-Chun Zhu
Proceedings of the 23rd Annual Meeting of the Special Interest Group on Discourse and Dialogue
Liang Qiu | Yizhou Zhao | Yuan Liang | Pan Lu | Weiyan Shi | Zhou Yu | Song-Chun Zhu
Proceedings of the 23rd Annual Meeting of the Special Interest Group on Discourse and Dialogue
Building a socially intelligent agent involves many challenges. One of which is to track the agent’s mental state transition and teach the agent to make decisions guided by its value like a human. Towards this end, we propose to incorporate mental state simulation and value modeling into dialogue agents. First, we build a hybrid mental state parser that extracts information from both the dialogue and event observations and maintains a graphical representation of the agent’s mind; Meanwhile, the transformer-based value model learns human preferences from the human value dataset, ValueNet. Empirical results show that the proposed model attains state-of-the-art performance on the dialogue/action/emotion prediction task in the fantasy text-adventure game dataset, LIGHT. We also show example cases to demonstrate: (i) how the proposed mental state parser can assist the agent’s decision by grounding on the context like locations and objects, and (ii) how the value model can help the agent make decisions based on its personal priorities.
2021
SocAoG: Incremental Graph Parsing for Social Relation Inference in Dialogues
Liang Qiu | Yuan Liang | Yizhou Zhao | Pan Lu | Baolin Peng | Zhou Yu | Ying Nian Wu | Song-Chun Zhu
Proceedings of the 59th Annual Meeting of the Association for Computational Linguistics and the 11th International Joint Conference on Natural Language Processing (Volume 1: Long Papers)
Liang Qiu | Yuan Liang | Yizhou Zhao | Pan Lu | Baolin Peng | Zhou Yu | Ying Nian Wu | Song-Chun Zhu
Proceedings of the 59th Annual Meeting of the Association for Computational Linguistics and the 11th International Joint Conference on Natural Language Processing (Volume 1: Long Papers)
Inferring social relations from dialogues is vital for building emotionally intelligent robots to interpret human language better and act accordingly. We model the social network as an And-or Graph, named SocAoG, for the consistency of relations among a group and leveraging attributes as inference cues. Moreover, we formulate a sequential structure prediction task, and propose an 𝛼-𝛽-𝛾 strategy to incrementally parse SocAoG for the dynamic inference upon any incoming utterance: (i) an 𝛼 process predicting attributes and relations conditioned on the semantics of dialogues, (ii) a 𝛽 process updating the social relations based on related attributes, and (iii) a 𝛾 process updating individual’s attributes based on interpersonal social relations. Empirical results on DialogRE and MovieGraph show that our model infers social relations more accurately than the state-of-the-art methods. Moreover, the ablation study shows the three processes complement each other, and the case study demonstrates the dynamic relational inference.
2020
Structured Attention for Unsupervised Dialogue Structure Induction
Liang Qiu | Yizhou Zhao | Weiyan Shi | Yuan Liang | Feng Shi | Tao Yuan | Zhou Yu | Song-Chun Zhu
Proceedings of the 2020 Conference on Empirical Methods in Natural Language Processing (EMNLP)
Liang Qiu | Yizhou Zhao | Weiyan Shi | Yuan Liang | Feng Shi | Tao Yuan | Zhou Yu | Song-Chun Zhu
Proceedings of the 2020 Conference on Empirical Methods in Natural Language Processing (EMNLP)
Inducing a meaningful structural representation from one or a set of dialogues is a crucial but challenging task in computational linguistics. Advancement made in this area is critical for dialogue system design and discourse analysis. It can also be extended to solve grammatical inference. In this work, we propose to incorporate structured attention layers into a Variational Recurrent Neural Network (VRNN) model with discrete latent states to learn dialogue structure in an unsupervised fashion. Compared to a vanilla VRNN, structured attention enables a model to focus on different parts of the source sentence embeddings while enforcing a structural inductive bias. Experiments show that on two-party dialogue datasets, VRNN with structured attention learns semantic structures that are similar to templates used to generate this dialogue corpus. While on multi-party dialogue datasets, our model learns an interactive structure demonstrating its capability of distinguishing speakers or addresses, automatically disentangling dialogues without explicit human annotation.
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- Massimo Poesio 4
- Liang Qiu 3
- Zhou Yu 3
- Yizhou Zhao 3
- Song-chun Zhu 3
- Huajun Chen 2
- Runnan Fang 2
- Yujian Gan 2
- Yanni Lin 2
- Pan Lu 2
- Shuofei Qiao 2
- Roonak Rezvani 2
- Weiyan Shi 2
- Xiaobin Wang 2
- Jialong Wu 2
- Pengjun Xie 2
- Juntao Yu 2
- Ningyu Zhang 2
- Defu Cao 1
- Yushun Dong 1
- Xiyang Hu 1
- Fei Huang 1
- Fei Huang 1
- Zhuoxuan Jiang 1
- Yong Jiang 1
- Jinbo Liu 1
- Yan Liu 1
- Baolin Peng 1
- Bo Ren 1
- Feng Shi 1
- Tianyao Su 1
- Yifei Wei 1
- Ying Nian Wu 1
- Zekun Xi 1
- Jinxia Xie 1
- di Yin 1
- Tao Yuan 1
- Yue Zhao 1