In the "Internet of Things" (IoT) vision the physical world blends with virtual one, while machine-tomachine interaction improve our daily life. Clearly, how these virtual objects are exposed to us is critical, so that their user interface must be designed to support the easiness of usage that is driven by the users' needs, which is different from what machines requires. These two requirements must be solved, and an integrated solution should emerge, if we want to bring the IoT to the 50 billions network that is predicted to became in the next years.We believe that these requirements cannot be met by the same communication protocol, and so we propose a new kind of broker, named QEST that can bridge the two worlds, represented by their state-of-the-art protocols: MQTT and REST. In this paper, we demonstrate that our approach allows rapid development of user-facing IoT systems, while grating machines all the performance they need.

Internet of Things (IoT) application layer protocols are gaining popularity in a wide range of scenarios, where lowcost, low-power or resource constrained devices are present. The most diffused protocols are the Constrained Application Protocol (CoAP) and MQTT. In order to ensure message delivery, CoAP features a retransmission mechanism based on exponential back-off and a finite number of retransmissions, while MQTT relies on TCP. In remote areas lacking fixed terrestrial network infrastructure, the only available Internet access technology is often represented by wireless or satellite links, usually affected by losses and significant delay. At this time, there is no information about MQTT and CoAP performance over high delay links in the literature. The goal of this paper is to provide a quantitative performance analysis of the mentioned IoT protocols over various conditions of offered traffic, packet loss probability and delay. Our findings show that, with default protocol parameters, MQTT offers better performance in terms of throughput in any of the considered scenarios. As far as latency is concerned, CoAP slightly outperforms MQTT in case of low offered traffic, low loss probability and high delay. We suggest to tune CoAP parameters in order to cope with high traffic and high loss probability: the new parameters result in improved latency and throughput in those conditions.

In recent decades, increasing attention is being paid to the multidisciplinary approach that allows the performance of both a preventive conservation and a more invasive restoration action. In this context, the present study aims to acquire information and data from field surveys undertaken in San Domenico Church, Southern Calabria, in order to provide a tool for the recording and the inventory of damage and decay phenomena, and assess their causes and scale. The subsequent calculation of damage indices also provided useful information in order to allow the prioritization of conservation and preservation responses.

The goal of this work was to understand the direction of the emerging web technologies and to\ud evaluate their expected impact on satellite networking.\ud Different aspects have been analysed using both real satellite testbeds and emulation platforms in\ud different test sites in Europe. This analysis included an evaluation of the SPDY protocol performance\ud over satellite and experiments to understand the expected interaction with PEPs (including scenarios\ud with a SPDY proxy at a satellite gateway), the impact of security, and the effect of satellite capacity\ud allocation mechanisms. The analysis also considered the impact of application protocols and the delay\ud induced by end-system networks, such as a satellite-connected WiFi network

<p><strong>Abstract.</strong> The preservation status of an underwater cultural site can be determined as the combination of two primary factors, namely the site physical integrity, which results from the past and present interaction of the site itself with the biological/chemical agents located in the surrounding environment, and the exposure of the site to human-related threats. Methods to survey underwater archaeological sites have evolved considerably in the last years in order to face the challenges and problems in archaeological prospection, documentation, monitoring, and data collection.</p><p>This paper presents a case-study of an archaeological documentation campaign addressed to study and monitor the preservation status of an underwater archaeological site by combining the quantitative measurements coming from optical and acoustic surveys with the study of biological colonization and bioerosion phenomena affecting ancient artefacts. In particular, we present the first results obtained in the survey and documentation campaign carried out during the spring – summer 2018 in the “Nymphaeum of Punta Epitaffio” located in the Marine Protected Area - Underwater Park of Baiae (Naples).</p>