Fatigue among Employees Who Work Over the Karoshi Line (More Than 80 Hours Overtime per Month): Hybrid Approach Based on Experimental and Field Studies - Kubo, Tomohide; Shun, Matsumoto; Ikeda, Hiroki; Nishimura, Yuki; Liu, Xinxin; Izawa, Shuhei; Yoshikawa, Toru; Sayaka, Aritake-Okada; Tamaki, Masako (Sleep Science, 2025)