collaborators

6 papers

cs.LG2025

Asymmetric Proximal Policy Optimization: mini-critics boost LLM reasoning

Jiashun Liu, Johan Obando-Ceron, Han Lu +7

Most recent RL for LLMs (RL4LLM) methods avoid explicit critics, replacing them with average advantage baselines. This shift is largely pragmatic: conventional value functions are…

cs.LG2025

The Courage to Stop: Overcoming Sunk Cost Fallacy in Deep Reinforcement Learning

Jiashun Liu, Johan Obando-Ceron, Pablo Samuel Castro +2

Off-policy deep reinforcement learning (RL) typically leverages replay buffers for reusing past experiences during learning. This can help improve sample efficiency when the collec…

cs.LG2025

The Impact of On-Policy Parallelized Data Collection on Deep Reinforcement Learning Networks

Walter Mayor, Johan Obando-Ceron, Aaron Courville +1

The use of parallel actors for data collection has been an effective technique used in reinforcement learning (RL) algorithms. The manner in which data is collected in these algori…

cs.LG2025

Stable Gradients for Stable Learning at Scale in Deep Reinforcement Learning

Roger Creus Castanyer, Johan Obando-Ceron, Lu Li +4

Scaling deep reinforcement learning networks is challenging and often results in degraded performance, yet the root causes of this failure mode remain poorly understood. Several re…

cs.LG2025

Mitigating Plasticity Loss in Continual Reinforcement Learning by Reducing Churn

Hongyao Tang, Johan Obando-Ceron, Pablo Samuel Castro +2

Plasticity, or the ability of an agent to adapt to new tasks, environments, or distributions, is crucial for continual learning. In this paper, we study the loss of plasticity in d…

cs.LG2025

Measure gradients, not activations! Enhancing neuronal activity in deep reinforcement learning

Jiashun Liu, Zihao Wu, Johan Obando-Ceron +3

Deep reinforcement learning (RL) agents frequently suffer from neuronal activity loss, which impairs their ability to adapt to new data and learn continually. A common method to qu…