Sirui Xia
Author directory2026
From AI Assistant to AI Scientist: Autonomous Discovery of LLM-RL Algorithms with LLM Agents
Sirui Xia | Yikai Zhang | Aili Chen | Siye Wu | Siyu Yuan | Yanghua Xiao
Findings of the Association for Computational Linguistics: EMNLP 2026
Sirui Xia | Yikai Zhang | Aili Chen | Siye Wu | Siyu Yuan | Yanghua Xiao
Findings of the Association for Computational Linguistics: EMNLP 2026
Discovering improved policy optimization algorithms for language models remains a costly manual process requiring repeated mechanism-level modification and validation. Unlike simple combinatorial code search, this problem requires searching over algorithmic mechanisms tightly coupled with training dynamics while reusing empirical evidence across iterations. We propose POISE a closed-loop framework for automated discovery of policy optimization algorithms for language models. POISE maintains an archive that links each candidate design with its implementation, evaluation evidence, and analysis summary, enabling later iterations to build on both successful and failed designs. In mathematical reasoning experiments starting from GRPO, POISE evaluates 64 candidate algorithms and discovers improved mechanisms, including analytic-variance scaling and validity masking. The best variant improves weighted Overall from 47.8 to 52.5 (+4.6) and increases AIME25 pass@32 from 26.7% to 43.3%, demonstrating the feasibility of automated policy optimization discovery while supporting interpretable design principles.
Can LLMs Learn to Map the World from Local Descriptions?
Sirui Xia | Aili Chen | Xintao Wang | Tinghui Zhu | Yikai Zhang | Jiangjie Chen | Yanghua Xiao
Proceedings of the 64th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)
Sirui Xia | Aili Chen | Xintao Wang | Tinghui Zhu | Yikai Zhang | Jiangjie Chen | Yanghua Xiao
Proceedings of the 64th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)
Recent advances in Large Language Models (LLMs) have demonstrated strong capabilities in tasks such as code generation and mathematical reasoning. However, their potential to internalize structured spatial knowledge remains underexplored. This study investigates whether LLMs, grounded in locally relative human observations, can construct coherent global spatial cognition by integrating fragmented relational descriptions. We focus on two core aspects of spatial cognition: spatial perception, where models infer consistent global layouts from local positional relationships, and spatial navigation, where models learn road connectivity from trajectory data and plan optimal paths between unconnected locations. Experiments conducted in a simulated urban environment demonstrate that LLMs not only generalize to unseen spatial relationships between points of interest (POIs) but also exhibit latent representations aligned with real-world spatial distributions. Furthermore, LLMs can learn road connectivity from trajectory descriptions, enabling accurate path planning and dynamic spatial awareness during navigation.
2025
Ground Every Sentence: Improving Retrieval-Augmented LLMs with Interleaved Reference-Claim Generation
Sirui Xia | Xintao Wang | Jiaqing Liang | Yifei Zhang | Weikang Zhou | Jiaji Deng | Fei Yu | Yanghua Xiao
Findings of the Association for Computational Linguistics: NAACL 2025
Sirui Xia | Xintao Wang | Jiaqing Liang | Yifei Zhang | Weikang Zhou | Jiaji Deng | Fei Yu | Yanghua Xiao
Findings of the Association for Computational Linguistics: NAACL 2025
Retrieval-Augmented Generation (RAG) has been widely adopted to enhance Large Language Models (LLMs) in knowledge-intensive tasks. To enhance credibility and verifiability in RAG systems, Attributed Text Generation (ATG) is proposed, which provides citations to retrieval knowledge in LLM-generated responses. Prior methods mainly adopt coarse-grained attributions, with passage-level or paragraph-level references or citations, which fall short in verifiability. This paper proposes ReClaim(Refer & Claim), a fine-grained ATG method that alternates the generation of references and answers step by step. Different from previous coarse-grained attribution, ReClaim provides sentence-level citations in long-form question-answering tasks. With extensive experiments, we verify the effectiveness of ReClaim in extensive settings, achieving a citation accuracy rate of 90%.