Sökning: "small amplitude excitation"
Visar resultat 1 - 5 av 10 avhandlingar innehållade orden small amplitude excitation.
1. Vibrational energy harvesting for sensors in vehicles
Sammanfattning : The miniaturization of semiconductor technology and reduction in power requirements have begun to enable wireless self-sufficient devices, powered by ambient energy. To date the primary application lies in generating and transmitting sensory data. LÄS MER
2. Rail Corrugation Growth on Curves
Sammanfattning : The development of periodic irregularities with distinct wavelengths (corrugation) on the low rail of small radius curves is studied through mathematical modelling, numerical simulations, field measurements and laboratory investigations. One year of monitoring of roughness on the low rail of a 120 m radius curve on the metro of Stockholm Public Transport (SL) showed severe growth of rail corrugation with wavelengths of about 5 cm and 8 cm. LÄS MER
3. Modeling of losses in power transformers from dc to the low kilohertz range
Sammanfattning : The development of HVDC converters, local generation and tractions systems increases the demand for power converters. While a lot of studies have been conducted on the power electronics, there are still open questions concerning the contained power transformer that operates at a few kilohertz. LÄS MER
4. Low-cost control of discontinuous systems including impacts and friction
Sammanfattning : For a successful design of an engineering system it is essential to pay careful attention to its dynamic response. This is particularly true, in the case of nonlinear systems, since they can exhibit very complex dynamic behaviour, including multiple co-existing stable solutions and chaotic motions, characterized by large sensitivity to initial conditions. LÄS MER
5. On Nonlinear Acoustics in Contrast Echocardiography
Sammanfattning : Ultrasound is one of the most commonly used noninvasive medical imaging techniques. Ultrasound contrast agents (UCA), consisting of encapsulated gas-filled microbubbles, have shown to increase the diagnostic precision in selected low echogenic patients. LÄS MER