collaborators

5 papers

cs.AI2026

Beyond Trajectory Rewards: Step-level Credit Assignment for Agentic Search via Graph Modeling

Yuchen Liu, Yingjie Feng, Lixiong Qin +5

In Agentic Search, trajectory-level outcome rewards fail to quantify the behavioral contributions of individual steps, while existing step-level reward methods typically rely on co…

cs.LG2026

VSPO: Vector-Steered Policy Optimization for Behavioral Control

Xuechen Zhang, Zijian Huang, Kai Yang +3

Modern language models often need to optimize a primary accuracy objective while also accommodating secondary behavioral preferences, such as verbosity, agreeableness, or the level…

cs.IR2025

SmartChunk Retrieval: Query-Aware Chunk Compression with Planning for Efficient Document RAG

Xuechen Zhang, Koustava Goswami, Samet Oymak +2

Retrieval-augmented generation (RAG) has strong potential for producing accurate and factual outputs by combining language models (LMs) with evidence retrieved from large text corp…

cs.LG2025

BREAD: Branched Rollouts from Expert Anchors Bridge SFT & RL for Reasoning

Xuechen Zhang, Zijian Huang, Yingcong Li +3

Small language models (SLMs) struggle to learn complex reasoning behaviors, especially when high-quality traces are scarce or difficult to learn from. The standard training approac…

cs.LG2025

Making Small Language Models Efficient Reasoners: Intervention, Supervision, Reinforcement

Xuechen Zhang, Zijian Huang, Chenshun Ni +3

Recent research enhances language model reasoning by scaling test-time compute via longer chain-of-thought traces. This often improves accuracy but also introduces redundancy and h…