Phaseless Microwave Tomography Assessment for Breast Imaging: Preliminary Results

In the present work, a phaseless approach for microwave imaging applications is presented. The proposed solution strategy is based on the formulation of the scattering phenomena in terms of contrast source, while no phase-recovery stage is involved into the numerical procedure, thus providing a phaseless single-step resolution method. The image recovering potentialities of the discussed method are numerically validated by successfully distinguishing different tissues of a slice breast model, with a tumor located wherein. The above preliminary assessment encourages the adoption of the proposed solution in the framework of biomedical imaging

Non-linear coupled approach for the evaluation of seismic slope displacements

The design procedures to evaluate earthquake-induced sliding displacements typically refer to three different approaches: simplified methods; displacements methods and advanced dynamic methods. In the first class of methods, empirical relationships are used to predict the permanent slope displacement. The second class includes simplified dynamic analysis, by means of the conventional Newmark rigid block model, as well as through its improvements to account for soil deformability. The dynamic site response and the sliding block displacements are computed separately in the “decoupled” approach or simultaneously in the “coupled” analysis (stick-slip model). The advanced dynamic methods are based on finite element (FEM) or finite difference (FDM) formulations, which permit to account for topography and heterogeneity by two or three dimensional analysis. The paper describes the developments of a 1D lumped-mass stick-slip model for a layered subsoil including more generalized assumptions than a previous version (Ausilio et al., 2008). The depth of the sliding surface is considered not necessarily coincident with that of the bedrock, and located in a generic layer. This latter can be identified during the analysis. In the non-linear site response analysis, a recent soil damping formulation was used (Phillips & Hashash, 2009). In this formulation, a reduction factor modifying the extended Masing loading/unloading strain-stress relationship was introduced. The predictions of the coupled stick-slip model with non-linear soil behaviour were compared with the results of the equivalent linear approach for ideal slopes to show the effects of non linearity on seismic performance. Besides, the results show that the sliding surface depth, automatically researched, is function of main ground motion parameters

Grey-box Modelling of a Household Refrigeration Unit Using Time Series Data in Application to Demand Side Management

This paper describes the application of stochastic grey-box modeling to identify electrical power consumption-to-temperature models of a domestic freezer using experimental measurements. The models are formulated using stochastic differential equations (SDEs), estimated by maximum likelihood estimation (MLE), validated through the model residuals analysis and cross-validated to detect model over-fitting. A nonlinear model based on the reversed Carnot cycle is also presented and included in the modeling performance analysis. As an application of the models, we apply model predictive control (MPC) to shift the electricity consumption of a freezer in demand response experiments, thereby addressing the model selection problem also from the application point of view and showing in an experimental context the ability of MPC to exploit the freezer as a demand side resource (DSR).Comment: Submitted to Sustainable Energy Grids and Networks (SEGAN). Accepted for publicatio