collaborators
Showing cs.LGShow all

9 papers · 1 filter

cs.LG2026

Smaller Models, Better Rejects: Preference Distillation Scaling

Rui Cai, Wenhui Zhu, Xiwen Chen +15

Preference distillation typically treats a teacher response as preferred and the student's own response as rejected. This assumes that self-generated failures are the most informat…

cs.LG2026

TRIAGE: Role-Typed Credit Assignment for Agentic Reinforcement Learning

Yuanda Xu, Zhengze Zhou, Hejian Sang +6

Agentic reinforcement learning requires assigning credit to environment-facing actions such as searches, clicks, edits, navigation commands, and object interactions. Standard GRPO…

cs.LG2026

TREK: Distill to Explore, Reinforce to Refine

Yuanda Xu, Zhengze Zhou, Kayhan Behdin +10

Group Relative Policy Optimization (GRPO) is effective when the current policy already samples useful reasoning trajectories, but it stalls on hard prompts whose correct solution m…

cs.LG2026

TIP: Token Importance in On-Policy Distillation

Yuanda Xu, Hejian Sang, Zhengze Zhou +3

On-policy knowledge distillation (OPD) trains a student on its own rollouts under token-level supervision from a teacher. Not all token positions matter equally, but existing views…

cs.LG2026

Beyond GRPO and On-Policy Distillation: An Empirical Sparse-to-Dense Reward Principle for Language-Model Post-Training

Yuanda Xu, Hejian Sang, Zhengze Zhou +3

In settings where labeled verifiable training data is the binding constraint, each checked example should be allocated to the model and reward density where it is most informative.…

cs.LG2026

Robust Batch-Level Query Routing for Large Language Models under Cost and Capacity Constraints

Jelena Markovic-Voronov, Kayhan Behdin, Yuanda Xu +3

We study the problem of routing queries to large language models (LLMs) under cost, GPU resources, and concurrency constraints. Prior per-query routing methods often fail to contro…

cs.LG2026

CRISP: Compressed Reasoning via Iterative Self-Policy Distillation

Hejian Sang, Yuanda Xu, Zhengze Zhou +3

Reasoning models often generate far more tokens than a task requires, which raises inference cost and can compound errors. We introduce CRISP (Compressed Reasoning via Iterative Se…

cs.LG2026

Overconfident Errors Need Stronger Correction: Asymmetric Confidence Penalties for Reinforcement Learning

Yuanda Xu, Hejian Sang, Zhengze Zhou +2

Reinforcement Learning with Verifiable Rewards (RLVR) has become the leading paradigm for enhancing reasoning in Large Language Models (LLMs). However, standard RLVR algorithms suf…

cs.LG2026

Not all tokens are needed(NAT): token efficient reinforcement learning

Hejian Sang, Yuanda Xu, Zhengze Zhou +2

Reinforcement learning (RL) has become a key driver of progress in large language models, but scaling RL to long chain-of-thought (CoT) trajectories is increasingly constrained by…