Ricerc@Sapienza

In this contribution, we analyze the forward-scatter cross-section (FS-CS) of three-dimensional (3-D) metallic targets in a forward scatter radar (FSR) system, moving along arbitrary trajectories, in the transition between far- and near-field regions with respect to the receiving antenna. A vector formulation is introduced, together with a simplified approach based on a physical-optics solution of the scattering integral, and validated by means of full-wave numerical evaluations.

Herein we present a super resolution and electromagnetic interference suppression technique based on Maximum Entropy Method and applied to data acquired by the SHAllow RADar (SHARAD) on board the NASA's 2005 Mars Reconnaissance Orbiter (MRO) mission, currently operating on Mars. We show that the proposed algorithm allows to enhance signal-to-noise ratio by several decibels and the range resolution over a factor of three. Subsurface imaging is improved remarkably, allowing additional insights for the scientific community in the interpretation of the SHARAD radar data.

In this work we define a framework for the assessment of the Traffic Matrix (TM) of an Internet Service Provider (ISP) network. The solution, referred to as mrT, i) is completely distributed among network nodes, ii) is based on different Map-Reduce building blocks, iii) and is able to extract the Ingress-Egress nodes traffic relationships starting from raw traces captured on node interfaces. Each network node is able to compute a row of the TM having as input the local trace and low size files sent by other network nodes.

The mono-static Radar Cross Section (RCS) of a commercial Drone (IRIS) has been simulated and measured. For simulations, the electromagnetic CAD Microwave Studio by CST has been used. This software allows to accurately model the drone geometry and material complex permittivity. Measurements have been performed in an anechoic chamber equipped with a network analyzer and a horn antenna. The foreseen applications are the localization of drones in critical scenarios by using both passive and conventional radars.

In this paper, a reconfigurable novel S-band patch antenna system for cubesat satellites is presented. It is shown that, with the same antenna, it is possible to achieve different radiation patterns and polarization, using power divider and digital control phase shifter, thus allowing the use of the designed S-Band patch antenna system for a large number of space mission.

Upper and lower bounds on capacity of low-dense code-domain NOMA were investigated in the context of 5G New Radio (5G-NR), under the worst hypothesis of no channel knowledge at the receiver, i.e. operation without channel state information (CSI). The impact of peculiar features of 5G-NR on capacity bounds of optimum receivers was investigated. The upper bound, defined as the system capacity with perfect CSI, and the lower bound corresponding to a pilot-based communication model, were found.

Asbestos recognition, inside different matrices (i.e. Asbestos Containing Materials: ACMs), is of great importance both "in situ" and in the further analysis at lab scale. Among the industrial sectors utilizing asbestos, the building and construction sector is the most important, especially with reference to all the constructions built before the '90s. The large utilization of asbestos is mainly linked to its technical properties (i.e. resistance to abrasion, heat and chemicals).

Lithium-ion batteries are a popular choice of power source for a variety of energy and power demanding applications for both stationary applications and electromobility. Among electrochemical storage systems, Lithium-ion batteries were found to be promising candidate, due to their high power and high energy density. In order to assemble high power batteries for plug-in hybrid electric vehicles and pure electric vehicles, several hundreds of large-format Lithium-ion cells will be required, and even more cells for power/energy demanding stationary applications.

The performance and stability of secondary batteries depend on the working temperature of the cells. This paper describes a set of experimental tests carried out to better understand the thermal behavior of Lithium-ion batteries under load. Different types of batteries have been analyzed to check the influence of a number of parameters that characterize the cells.

Lithium ion batteries represent a well established technology in a range of applications (laptops, mobile phones, etc.) but they are becoming key factors in many other areas were reliability and safety are of paramount importance (e.g. the space and automobile industries). However, a number of drawbacks still raise concerns about their wider use and hamper a more structured introduction in these additional applications.