1 Subjects: “...active power control...”

2 Subjects: “...hydraulic power systems...”

3 Subjects: “...power distribution...”

4 Subjects: “...Fukushima Daiichi Nuclear Power Station accident...”

5 Subjects: “...electric power industry...”

6 Subjects: “...nuclear power plant...”

7 Subjects: “...class-C power amplifier...”

8 Subjects: “...photovoltaic power...”

9 Subjects: “...purchasing power...”

10 Subjects: “...power grid...”

11 Subjects: “...power grid...”

12 Subjects: “...power system failure...”