Tapering of the interventricular septum can affect ultrasound shear wave elastography: An in vitro and in silico study

Shear wave elastography (SWE) has the potential to determine cardiac tissue stiffness from non-invasive shear wave speed measurements, important, e.g., for predicting heart failure. Previous studies showed that waves traveling in the interventricular septum (IVS) may display Lamb-like dispersive behaviour, introducing a thickness-frequency...

Modelling propagation of sound emitted by mini-airguns

A modelling approach is described in which time-domain underwater-acoustic source functions are generated using a model that predicts the motion of air-bubbles generated by mini-airguns operated at various pressures. These time-series are Fourier-transformed to produce frequency-domain descriptions of the source. These are combined with complex...

Frequency-domain helicopter-borne em survey for delineation of the 3D chloride distribution in Zeeland, the Netherlands

In the project FRESHEM Zeeland the entire Province of Zeeland in the south-western part of the Netherlands was surveyed using frequency-domain helicopter-borne electromagnetics (FDHEM). The airborne survey of more than 9000 line-km was conducted in 2014-15 by the German Federal Institute for Geosciences and Natural Resources (BGR). Together with...

Realization and testing of an active mirror mechanism for in-field pointing in eLISA

An active tilt mirror mechanism, meant for correction of the constellation breathing of the evolved Laser Interferometer Space Antenna, has been designed and realized. Its open-loop performance has been characterized in both time and frequency domain. Based on this, a feedback controller has been designed and the resulting closed-loop...

A control oriented multivariable identification procedure for turbocharged diesel engines

Imaging beyond aliasing

A proper spatial sampling is critical for high quality imaging. If the sampling criterion is not met, artifacts appear in the image, generally referred to as grating lobes. For inspection efficiency the width of the field of view is becoming larger leading to an increase in the number of elements and therefore transducer complexity and cost. The...

Analysis of the lateral dynamic behaviour of articulated commercial vehicles

The challenge of designing stability control functions for trucks is to guarantee robustness for all variations in truck and trailer combinations. The method proposed in this study can be used to quickly narrow down the number of truck and trailer combinations to a critical set to be evaluated with complex nonlinear simulation software or full...

Blind synchronization in asynchronous UWB networks based on the transmit-reference scheme

Ultra-wideband (UWB) wireless communication systems are based on the transmission of extremely narrow pulses, with a duration inferior to a nanosecond. The application of transmit reference(TR) to UWB systems allows to side-step channel estimation at the receiver, with a tradeoff of the effective transmission bandwidth, which is reduced by the...

Application of radon transforms and time-frequency representations to ISAR imagery

The use of ISAR imagery for Automatic Target Recognition is seriously hampered by the difficulty of target motion compensation. Phase perturbations that result from target maneuvers during the processing interval need to be corrected for. In a previous paper, we demonstrated the use of the local Radon transform for estimating the radial velocity...

PHASIM, an advanced phased array antenna software simulator

A sophisticated phased array simulator software package for the design and analysis of planar phased array antennas is presented. This package can accurately simulate the far-field characteristics of a large variety of planar phased array configurations in both the frequency and time domain. The simulator is coded in MATLAB version 5.3. Using...

PHASIM, an advanced phased array antenna software simulator

A sophisticated phased array simulator software package for the design and analysis of planar phased array antennas is presented. This package can accurately simulate the far-field characteristics of a large variety of planar phased array configurations in both the frequency and time domain. The simulator is coded in MATLAB version 5.3. Using...