An optimal opportunistic maintenance policy for a two-unit series system with general repair using proportional hazards models. - Seyedvahid Najafi; Rui Zheng; Chi-Guhn Lee (Reliab. Eng. Syst. Saf., 2021)

A recursive method for the health assessment of systems using the proportional hazards model. - Rui Zheng; Seyedvahid Najafi; Yingzhi Zhang (Reliab. Eng. Syst. Saf., 2022)

A deep reinforcement learning approach for repair-based maintenance of multi-unit systems using proportional hazards model. - Seyedvahid Najafi; Chi-Guhn Lee (Reliab. Eng. Syst. Saf., 2023)