Tuning the Dynamics of Bistable Mechanisms by Introducing Travel Limits

Vibrations are a promising source for powering wireless sensors, for example in low-frequency environments like human motion. These environments suffer from unpredictable vibration spectra and their low-frequency and large amplitude characteristics offer great possibilities for mechanisms with double well potential energy characteristics. The...

An Auto-Zero Stabilized Voltage Buffer with a Quiet Chopping Scheme and Constant Input Current

The readout of high-impedance sensors and sampled voltage references [1] requires amplifiers that can achieve both low offset and low input current. Recently, it has been shown that this unique combination can be achieved by an auto-zero (AZ) stabilized buffer [2]. However, its low-frequency noise density is surd 5 times higher than the...

Radar micro-Doppler of Wind Turbines: Low-Frequency Polarimetric Extension of Simplified Analytical Model

A simplified polarimetric model for radar signal scattering on wind turbines (WT) is proposed, which can be used for interpretation of observation in time and Doppler domains. This model uses representation of real WT as slowly rotating linear wire structures. The earlier proposed model has been extended to more general cases of WT with...

Low frequency wave resonance in fringing reef environments

Low frequency wave resonance has been postulated to enhance damage to coral reef protected coastlines during storm events. This paper uses the numerical model XBeach to examine the dynamics that contribute to resonance that have been previously observed on a fringing reef on Guam during tropical storm Man-Yi (Péquignet et al., 2009). The methods...

Vortical VLF motions under shore-normal incident waves

Field observations and numerical model simulations are examined to investigate the magnitude of vortical very low frequency (VLF) velocity fluctuations (i.e. large scale surfzone eddies) under different offshore wave forcing. Observations of vortical VLF motions under shore -normal wave incidence at Duck, NC, USA are re-analyzed and compared...

Short wave breaking effects on low frequency waves

The effect of short wave breaking on low frequency waves is investigated using two breaker formulations implemented in a time-dependent numerical model (XBeach): (1) an advective-deterministic approach (ADA) and (2) the probabilistic breaker formulation of Roelvink (1993). Previous research has shown that the ADA breaker model gives different...

Low-frequency noise in quantum point contacts