Abstract. Recent studies have shown that the Internet-related energy consumption represents a significant, and increasing, part of the overall energy consumption of our society. Therefore, it is extremely important to look for energy-efficient Internet applications and protocols. The largest contribution to this energy consumption is due to Internet edge devices (PCs and data centers). As a particularly significant example, in this paper we address the fact that users leave their PCs continuously powered on for satisfying connectivity requirements of Peer-toPeer (P2P) file sharing applications, like BitTorrent (currently the most popular P2P Internet platform). To reduce these energy consumptions, without penalizing the Quality of Service of BitTorrent users, in this paper we propose a novel architecture based on the introduction of a BitTorrent proxy. BitTorrent users delegate the download operations to the proxy and, then, power off their PC, while the proxy downloads the requested files. We implemented our solution and validated it in a realistic testbed. Experimental results show that, with respect to the legacy BitTorrent approach, our solution is very effective in reducing the energy consumption without introducing any QoS degradation. Specifically, our results show that the proxy-based solution can provide up to 95% reduction in the energy consumption and, at the same time, a significant reduction in the average file download time.

The management and the safeguard of existing buildings and infrastructures are actual tasks for structural engineering. Non-invasive structural monitoring techniques can provide useful information for supporting the management process and the safety evaluation, reducing at once the impact of disturbances on the structure’s functionality. This paper focuses on the exploitation of advanced multi-temporal differential synthetic aperture radar interferometry (DInSAR) products for the structural monitoring of buildings and infrastructures, subjected to different external actions. In this framework, a methodological approach is proposed, based on the integration of DInSAR measurements with historical sources, accurate 3D modelling and consistent positioning of the reflecting targets in the GIS environment. Documentary sources can prove particularly helpful in collecting technical information, to reconstruct an accurate 3D geometry of the building under monitoring, limiting in-situ surveys. The analysis of DInSAR-based displacements time series and mean deformation velocity values allows the identification of possible critical situations for buildings to be monitored. The paper presents different approaches, with increasing accuracy levels, to study the active deformative processes of the examined buildings and the related damage assessment. An insight into these interpretative approaches is given through the application of the proposed procedure to two case studies in the city of Rome (Italy), the residential building named Torri Stellari in Valco San Paolo (1951–1953) and the housing complex referred to as Corviale (1967–1983), by exploiting the whole COSMO-SkyMed data archive (both ascending and descending acquisitions), collected during the 2011–2019 time interval. Pros and cons of the various approaches are deeply discussed, together with an estimation of the required computational effort.

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Recent studies indicate that the Internet-related energy consumption represents a significant, and increasing, part of the overall energy consumption of our society. The largest contribution to this consumption is due to Internet edge devices. Typically, users leave their pes continuously on for satisfying the connectivity requirements of file sharing p2p applications, like BitTorrent. In this paper we propose a novel proxy-based BitTorrent architecture. Bit'I'orrent users can delegate the download operations to the proxy and then power off, while the proxy downloads the requested jiles. We implemented our solution and validated it in a realistic testbed. Experimental results show that, with respect to a legacy approach, our solution is very effective in reducing the energy consumption (up to 95%) without introducing any QoS degradation.