Abstract
The miniaturization of GPS buoys is important for reducing tsunami hazard because a lot of them enable to observe marine phenomenon swiftly. A smart structure is effective for making vibration powered generator small without performance degradation. However the resonance type cannot generate enough electricity when input frequency is different form resonant one. The downsizing of them requires to reduce buoy weight and increase buoyancy. The increase in decay constant of the generator is also effective realistically. This policy to improve the generator is serviceable for the device with piezoelectric element. To increase rigidity of the beam and decay constant of piezoelectric element contributes to improve the generator.
