Comparing different ultrasound imaging methods for breast cancer detection

Ultrasound is frequently used to evaluate suspicious masses in breasts. These evaluations could be improved by taking advantage of advanced imaging algorithms, which become feasible for low frequencies if accurate knowledge about the phase and amplitude of the wave field illuminating the volume of interest is available. In this study, we compare...

Probing the solution space of an EM inversion problem with a genetic algorithm

In an inversion for the subsurface conductivity distribution using frequency-domain Controlled-Source Electromagnetic data, various amounts of horizontal components may be included. We investigate which combination of components are best suited to invert for a vertical transverse isotropic (VTI) subsurface. We do this by probing the...

Solid-State Camera System for Fluorescence Lifetime Microscopy

Fluorescence microscopy is a well-established platform for biology and biomedical research (Chapter 2). Based on this platform, fluorescence lifetime imaging microscopy (FLIM) has been developed to measure fluorescence lifetimes, which are independent of fluorophore concentration and excitation intensity and offer more information about the...

Structural similarity regularization scheme for multiparameter seismic full waveform inversion

We introduce a new regularization scheme for multiparameter seismic full-waveform inversion (FWI). Using this scheme, we can constrain spatial variations of parameters which are having a weak sensitivity with the one that having a good sensitivity to the measurement, assuming that these parameters have similarities in their structures. In...

Decoupling of elastic parameters with iterative linearized inversion

Three model parameters as a function of position describe wave propagation in an isotropic elastic medium. Ideally, imaging of data for a point scatterer that consists of a perturbation in one of the elastic parameters should only provide a reconstruction of that perturbation, without cross-talk into the other parameters. This is not the case...

Numerical modeling of dam-reservoir interaction seismic response using the Hybrid Frequency–Time Domain (HFTD) method

The research work studies the fundamentals of the Hybrid Frequency-Time Domain (HFTD) method for dynamic analysis of structures, applied to the seismic analysis of dam-reservoir interaction systems. The theoretical consistency and accuracy of the HFTD method, based on the frequency domain Fourier analysis, is demonstrated through all the parts...

Preliminary design of offshore wind turbine support structures: The importance of proper mode shape estimation

Offshore wind turbines are highly exposed to timevarying loads. For support structures, estimation of the fatigue damage during the lifetime of the structure is an essential design aspect. This already applies for the preliminary design stage. In determining the dynamic amplification in the frequency domain, modal analysis is a common tool. This...

Aircushion Supported Mega-Floaters

The increase of the global population and expanding coastal mega-cities will necessitate an innovative pursuit of the utilization of the ocean space in which mega-floaters will play an important role in the future. These types of structures are very large floating artificial islands that can be used for various facilities and purposes similar to...

Effect of wave direction relative to wind on the motions of offshore floating wind turbine systems

Time-domain modeling of electromagnetic diffusion with a frequency-domain code

We modeled time-domain EM measurements of induction currents for marine and land applications with a frequency-domain code. An analysis of the computational complexity of a number of numerical methods shows that frequency-domain modeling followed by a Fourier transform is an attractive choice if a sufficiently powerful solver is available. A...

Design of support structures for offshore wind turbines

To meet growing energy demands, the Kyoto protocol and the much desired diversification of supply, wind energy has become a mainstream source of energy in the EU. Cost wise it is already competing with gas fired electricity. In the last decade wind moved offshore to accommodate even more wind power. The offshore wind resource is more abundant...

Frequency Domain Analysis for Nonlinear Electronic Circuits

Aircraft responses to atmospheric turbulence. A comparative study

Classification of events in the tau -p domains

Prestack shotpoint and common midpoint migration using the split-step Fourier algorithm

The radiation of a piezo-electric cylindrical bender-type transducer located in an infinite fluid

A new method for matching stacked seismic data with well log information