This paper presents an impact-induced frequency up-conversion piezoelectric energy harvester (FUC-PEH) to improve low-frequency output performance. The FUC-PEH includes a high-frequency piezoelectric ...

In this paper, an improved sensorless control method based on high-frequency square-wave signal injection of PMSM is proposed. The frequency spectrum of high-frequency current is expanded by injecting ...

We investigate the impact of high frequency monetary policy shocks in Brazil using daily data and Rigobon’ s identification via heteroskedasticity. We show that positive changes in interest rates ...