Kenji Matsuda, Tenta Suzuki, Tomohiro Harada, Johei Matsuoka, Mao Tobisawa, Jyunya Hoshino, Yuuki Itoh, Kaito Kumagae, Toshinori Kagawa, and Kiyohiko Hattori. ” Hierarchical Reward Model of Deep Reinforcement Learning for Enhancing Cooperative Behavior in Automated Driving.” Journal of Advanced Computational Intelligence and Intelligent Informatics (JACIII), 2023. (accepted)