Yingyu Shan
Author directory2026
Learning from Own Solutions: Self-Conditioned Credit Assignment for Reinforcement Learning with Verifiable Rewards
Yingyu Shan | Yuhang Guo | Zihao Cheng | Zeming Liu | Xiangrong Zhu | Xinyi Wang | Jiashu Yao | Wei Lin | Hongru Wang | Heyan Huang
Findings of the Association for Computational Linguistics: EMNLP 2026
Yingyu Shan | Yuhang Guo | Zihao Cheng | Zeming Liu | Xiangrong Zhu | Xinyi Wang | Jiashu Yao | Wei Lin | Hongru Wang | Heyan Huang
Findings of the Association for Computational Linguistics: EMNLP 2026
Reinforcement learning with verifiable rewards (RLVR) has driven substantial progress in training LLMs for reasoning tasks, but representative methods such as GRPO assign uniform credit across all tokens, wasting gradient on routine tokens while under-crediting pivotal reasoning steps. Existing token-level credit assignment methods require resources beyond the model’s own rollouts. GRPO variants rely on process reward models or ground-truth answers. Knowledge distillation assigns credit through per-token divergence but requires external teachers (On-Policy Distillation) or privileged information (On-Policy Self Distillation). However, these dependencies limit applicability in the pure RLVR setting. We observe that conditioning the model on its own verified trajectories induces a measurable per-token KL divergence between the original and conditioned distributions, and prove that distilling from a self-teacher constructed by verified trajectories leads to infeasible weighted-average solutions when multiple verified trajectories exist. We propose SC-GRPO (Self-Conditioned GRPO), which uses KL divergence mentioned before as a multiplicative weight on GRPO gradients. Across five benchmarks spanning math, code, and agentic tasks, SC-GRPO consistently outperforms 8.1% over GRPO and 5.9% over DAPO with stronger OOD performance. Moreover, SC-GRPO achieves higher performance than OPD.
Behavior2Trip: Towards Personalized Travel Planning via User Behavior Trajectory
Zihao Cheng | Yingyu Shan | Hongru Wang | Zeming Liu | Xinyi Wang | Xiangrong Zhu | Yuhang Guo | Wei Lin | Yunhong Wang
Findings of the Association for Computational Linguistics: EMNLP 2026
Zihao Cheng | Yingyu Shan | Hongru Wang | Zeming Liu | Xinyi Wang | Xiangrong Zhu | Yuhang Guo | Wei Lin | Yunhong Wang
Findings of the Association for Computational Linguistics: EMNLP 2026
Travel planning agents assist users in generating personalized travel plans by modeling their individual preferences. Existing agents either rely on explicit user instructions or engage in multi-turn clarification to elicit user preferences. However, both approaches overlook the rich behavioral signals latent in users’ past behaviors, which implicitly encode their preferences. This over-reliance on active user input increases interaction burden and limits plan personalization. To bridge this gap, we introduce a new task, **Behavior-Aware Travel Planning**, which infers user preferences directly from past behaviors and generates personalized travel plans. To facilitate research on this task, we introduce **Behavior2Trip**, a benchmark constructed from one of the largest Chinese online travel platforms, comprising 11,400 instances. Each instance represents an average of 39.8 past user behaviors spanning 14 attributes across 5 preference dimensions. We further propose **B2T-Agent**, a reinforcement learning-based agent that leverages user behavior trajectories, interacts with external tools for preference-aligned retrieval, and maintains an internal memory module. Experiments on Behavior2Trip show that GPT-4.1 achieves a full-constraint pass rate of only 0.5% on the hardest tasks, while B2T-Agent built upon Qwen3-8B outperforms all baselines, highlighting the substantial challenge of this task. Moreover, Qwen3-8B trained with B2T-Agent also outperforms GPT-4.1 on the TravelPlanner benchmark, demonstrating strong generalization.
PEC-Home: Interpretation of Progressively Elliptical Commands in Smart Homes
Yingyu Shan | Zeming Liu | Silin Li | Boao Qian | Jiashu Yao | Yuhang Guo | Haifeng Wang
Findings of the Association for Computational Linguistics: ACL 2026
Yingyu Shan | Zeming Liu | Silin Li | Boao Qian | Jiashu Yao | Yuhang Guo | Haifeng Wang
Findings of the Association for Computational Linguistics: ACL 2026
Recent advancements in Large Language Models (LLMs) have empowered home assistants with natural language interaction capabilities. However, current assistants overlook the progressive omission that occurs in human dialogue as shared context accumulates, leading to more elliptical expressions for efficient communication. Thus, current assistants still struggle to interpret such elliptical expressions accurately, which limits their effectiveness in real-world applications. In practical smart home scenarios, assistants face two major challenges caused by elliptical commands: (1) referential ambiguity caused by different environmental expectations among multiple users; and (2) intention ambiguity resulting from user preferences that evolve over time or change with the environment. To address these challenges, we introduce PEC-Home, the first simulated home dataset specifically designed for interpreting progressively elliptical commands in smart homes. Extensive experiments on various LLMs, including GPT-4o, show that existing home assistants struggle to execute user-intended operations based solely on elliptical commands. Even when equipped with tools for storing and retrieving user dialogue history, execution accuracy remains below that achieved with complete commands. Our code and dataset will be publicly available.
Mem2Evolve: Towards Self-Evolving Agents via Co-Evolutionary Capability Expansion and Experience Distillation
Zihao Cheng | Zeming Liu | Yingyu Shan | Xinyi Wang | Xiangrong Zhu | Yunpu Ma | Hongru Wang | Yuhang Guo | Wei Lin | Yunhong Wang
Proceedings of the 64th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)
Zihao Cheng | Zeming Liu | Yingyu Shan | Xinyi Wang | Xiangrong Zhu | Yunpu Ma | Hongru Wang | Yuhang Guo | Wei Lin | Yunhong Wang
Proceedings of the 64th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)
While large language model–powered agents can self-evolve by accumulating experience or by dynamically creating new assets (i.e., tools or expert agents), existing frameworks typically treat these two evolutionary processes in isolation. This separation overlooks their intrinsic interdependence: the former is inherently bounded by a manually predefined static toolset, while the latter generates new assets from scratch without experiential guidance, leading to limited capability growth and unstable evolution. To address this limitation, we introduce a novel paradigm of co-evolutionary Capability Expansion and Experience Distillation. Guided by this paradigm, we propose the Mem2Evolve, which integrates two core components: Experience Memory and Asset Memory. Specifically, Mem2Evolve leverages accumulated experience to guide the dynamic creation of assets, thereby expanding the agent’s capability space while simultaneously acquiring new experience to achieve co-evolution. Extensive experiments across 6 task categories and 8 benchmarks demonstrate that Mem2Evolve achieves improvement of 18.53% over standard LLMs, 11.80% over agents evolving solely through experience, and 6.46% over those evolving solely through asset creation, establishing it as a substantially more effective and stable self-evolving agent framework.
2024
FAME: Towards Factual Multi-Task Model Editing
Li Zeng | Yingyu Shan | Zeming Liu | Jiashu Yao | Yuhang Guo
Proceedings of the 2024 Conference on Empirical Methods in Natural Language Processing
Li Zeng | Yingyu Shan | Zeming Liu | Jiashu Yao | Yuhang Guo
Proceedings of the 2024 Conference on Empirical Methods in Natural Language Processing
Large language models (LLMs) embed extensive knowledge and utilize it to perform exceptionally well across various tasks. Nevertheless, outdated knowledge or factual errors within LLMs can lead to misleading or incorrect responses, causing significant issues in practical applications. To rectify the fatal flaw without the necessity for costly model retraining, various model editing approaches have been proposed to correct inaccurate information within LLMs in a cost-efficient way. To evaluate these model editing methods, previous work introduced a series of datasets. However, most of the previous datasets only contain fabricated data in a single format, which diverges from real-world model editing scenarios, raising doubts about their usability in practice. To facilitate the application of model editing in real-world scenarios, we propose the challenge of practicality. To resolve such challenges and effectively enhance the capabilities of LLMs, we present FAME, an authentic, comprehensive, and multi-task dataset, which is designed to enhance the practicality of model editing. We then propose SKEME, a model editing method that uses a novel caching mechanism to ensure synchronization with the real world. The experiments demonstrate that our method performs excellently across various tasks and scenarios, confirming its practicality.
2023
BIT-ACT: An Ancient Chinese Translation System Using Data Augmentation
Li Zeng | Yanzhi Tian | Yingyu Shan | Yuhang Guo
Proceedings of ALT2023: Ancient Language Translation Workshop
Li Zeng | Yanzhi Tian | Yingyu Shan | Yuhang Guo
Proceedings of ALT2023: Ancient Language Translation Workshop
This paper describes a translation model for ancient Chinese to modern Chinese and English for the Evahan 2023 competition, a subtask of the Ancient Language Translation 2023 challenge. During the training of our model, we applied various data augmentation techniques and used SiKu-RoBERTa as part of our model architecture. The results indicate that back translation improves the model’s performance, but double back translation introduces noise and harms the model’s performance. Fine-tuning on the original dataset can be helpful in solving the issue.