1 Subjects: “...physical layer...”

2 Subjects: “...physicians...”

3 Subjects: “...physical environment...”

4 Subjects: “...physical therapy...”

5 Subjects: “...physical education...”

6 Subjects: “...physical activity...”

7 Subjects: “...physical health...”

8 Subjects: “...physical exercise...”

9 Subjects: “...industrial cyber-physical system (ICPS)...”

10 “... and be managed from anywhere via the Internet, allowing tight integration between the physical and cyber worlds...”

11 “... the multiple time scales in physical systems were proposed in the early 2000s. Since then, these approaches...”