Ricerc@Sapienza

We develop and study adaptive rate scheduling mechanisms over cellular wireless networks, as used for the unicast provision of video streams to client mobiles at variable quality of experience (QoE) levels. Under service type I, mobile users receive video streams at a QoE level that is not lower than a specified value. In addition, mobile users that experience sufficiently high communications channel quality levels, may be provided video streams at higher video quality levels.

In the present paper, a preliminary study for the development of a portable setup suitable for in vivo measurements of tissue dielectric properties is presented. The setup consists of a hand-held spectrum analyzer, equipped with a tracking generator to operate as a vector network analyzer, and an in-house software for the post-processing of measured parameters. The proposed setup was optimized to operate in a broad frequency band (from 500 MHz to 3 GHz), minimizing the measurement uncertainty.

The AlphaSat TDP5 experiment, also now as Aldo Paraboni, is a scientific experiment held by the European Space Agency (ESA) to investigate radio propagation channel in the Ka and Q bands. The AlphaSat satellite was launched in orbit in 2013 and since then several European research group have been monitoring the received beacon signals to model physical effects of the atmosphere on the transmitted electromagnetic field. This article is aimed to describe the AlphaSat receiving station in Rome, focusing on the latest upgrade of the Ka-band receiver.

The knowledge of dielectric properties of biological tissue is of fundamental importance for the development of diagnostic or therapeutic applications of electromagnetic fields, as microwave imaging or microwave thermal ablation. In this paper, a quality factor is introduced to identify the soundness of measurements of dielectric properties performed with different set-ups and procedures.

In-service wheel-rail contact force measurements are increasingly being performed with both on-board and wayside systems for various purposes, such as identifying problems on single vehicles (overloading and unbalance, wheel flats etc.) and enabling predictive maintenance of components. Such a wealth of measurements can be expected not only to fulfil their original purposes, but also to steadily fill in vehicle-track interaction knowledge gaps if properly exploited - e.g. with a big-data approach.

In the maintenance of large infrastructures such as dams, bridges, railways, underground structures (tunnels, mines) and others, monitoring of deformations plays a key role in maintaining the safety serviceability conditions and for mitigating any consequences due to ageing factors and possible structural failures. [...].