activity
20212026
most citedLevel Generation for Angry Birds with Sequential VAE and Latent Variable Evolution

9 citations · 11 across the 7 of their papers we have counts for

collaborators
Showing cs.LGShow all

6 papers · 1 filter

cs.LG2026

Safety Hacking in Constrained Best-of- Inference-time Scaling

Akifumi Wachi, Takumi Tanabe, Youhei Akimoto

Inference-time pipelines often sample multiple outputs, filter them with a learned safety model, and return the proxy-feasible output with the highest learned reward. We show that…

cs.LG2026

Sample-Efficient Hypergradient Estimation for Decentralized Bi-Level Reinforcement Learning

Mikoto Kudo, Takumi Tanabe, Akifumi Wachi +1

Many strategic decision-making problems, such as environment design for warehouse robots, can be naturally formulated as bi-level reinforcement learning (RL), where a leader agent…

cs.LG2025

Cost-Minimized Label-Flipping Poisoning Attack to LLM Alignment

Shigeki Kusaka, Keita Saito, Mikoto Kudo +3

Large language models (LLMs) are increasingly deployed in real-world systems, making it critical to understand their vulnerabilities. While data poisoning attacks during RLHF/DPO a…

cs.LG2025

A Provable Approach for End-to-End Safe Reinforcement Learning

Akifumi Wachi, Kohei Miyaguchi, Takumi Tanabe +2

A longstanding goal in safe reinforcement learning (RL) is a method to ensure the safety of a policy throughout the entire process, from learning to operation. However, existing sa…

cs.LG2024

Stepwise Alignment for Constrained Language Model Policy Optimization

Akifumi Wachi, Thien Q. Tran, Rei Sato +2

Safety and trustworthiness are indispensable requirements for real-world applications of AI systems using large language models (LLMs). This paper formulates human value alignment…

cs.LG2022★ 2 cited

Max-Min Off-Policy Actor-Critic Method Focusing on Worst-Case Robustness to Model Misspecification

Takumi Tanabe, Rei Sato, Kazuto Fukuchi +2

In the field of reinforcement learning, because of the high cost and risk of policy training in the real world, policies are trained in a simulation environment and transferred to…