A novel switched excitation method for linear frequency modulated excitation of ultrasonic transducers in pulse compression systems is presented that is simple to realise, yet provides reduced signal sidelobes at the output of the matched filter compared to bipolar pseudo-chirp excitation. Pulse compression signal sidelobes are reduced through the use of simple amplitude tapering at the beginni...

J-Y. Park, M. Garwood Center for Magnetic Resonance Research and Department of Radiology, University of Minnesota, Minneapolis, MN, United States Synopsis: Frequency-swept pulses, like the hyperbolic secant (HS1) pulse, are not typically employed for excitation in MRI. When used for excitation in gradient-echo imaging, the HS1 pulse does not produce a proper echo because the magnetization phase...

Abstract A method for analysing the vehicle–bridge interaction system with enhanced objectivity is proposed in paper, which considers time-variant and random characteristics allows finding power spectral densities (PSDs) of responses directly from PSD track irregularity. The pseudo-excitation adopted framework, where vehicle modelled as a rigid body bridge using finite element method. vertical ...

AIMS In patients without pre-excitation, the differential diagnosis of paroxysmal atrioventricular (AV) reciprocating tachycardias consists mainly of atrioventricular nodal re-entrant tachycardias (AVNRTs) and AV reciprocating tachycardias (AVRTs) through a concealed bypass. Our purpose was to validate the diagnostic accuracy of a predictive logistic model using classical electrocardiographic (...

Random vibration analysis of tall structures faces multiple problems due to the large number of elements and high degrees of freedom; that is why this type of analysis is mostly used in simple structures and low degrees of freedom. In the past two decades, changes have been occurred in this type of analysis to be used in complex structures and the large number of elements. Pseudo-Excitation Met...