power spectral density: 27 phrases in 13 subjects |
Astronautics | 3 |
Electrical engineering | 1 |
Electronics | 3 |
Gyroscopes | 1 |
Household appliances | 1 |
Mass media | 2 |
Medical appliances | 1 |
Metrology | 3 |
Nautical | 1 |
Radio | 1 |
Seismology | 3 |
Technology | 4 |
Telecommunications | 3 |