642 research outputs found

    Towards the Internet of Smart Trains: A Review on Industrial IoT-Connected Railways

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    [Abstract] Nowadays, the railway industry is in a position where it is able to exploit the opportunities created by the IIoT (Industrial Internet of Things) and enabling communication technologies under the paradigm of Internet of Trains. This review details the evolution of communication technologies since the deployment of GSM-R, describing the main alternatives and how railway requirements, specifications and recommendations have evolved over time. The advantages of the latest generation of broadband communication systems (e.g., LTE, 5G, IEEE 802.11ad) and the emergence of Wireless Sensor Networks (WSNs) for the railway environment are also explained together with the strategic roadmap to ensure a smooth migration from GSM-R. Furthermore, this survey focuses on providing a holistic approach, identifying scenarios and architectures where railways could leverage better commercial IIoT capabilities. After reviewing the main industrial developments, short and medium-term IIoT-enabled services for smart railways are evaluated. Then, it is analyzed the latest research on predictive maintenance, smart infrastructure, advanced monitoring of assets, video surveillance systems, railway operations, Passenger and Freight Information Systems (PIS/FIS), train control systems, safety assurance, signaling systems, cyber security and energy efficiency. Overall, it can be stated that the aim of this article is to provide a detailed examination of the state-of-the-art of different technologies and services that will revolutionize the railway industry and will allow for confronting today challenges.Galicia. Consellería de Cultura, Educación e Ordenación Universitaria; ED431C 2016-045Galicia. Consellería de Cultura, Educación e Ordenación Universitaria; ED341D R2016/012Galicia. Consellería de Cultura, Educación e Ordenación Universitaria; ED431G/01Agencia Estatal de Investigación (España); TEC2013-47141-C4-1-RAgencia Estatal de Investigación (España); TEC2015-69648-REDCAgencia Estatal de Investigación (España); TEC2016-75067-C4-1-

    Blast Effects on Structural Elements

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    Blast loads can represent a great hazard to existing structures. Their effects on structural elements can be decisive for the integrity of both the structure itself and the people within it. The behaviour of the individual elements of a building is totally different due to the heterogeneity of the materials composing them. This fact makes it necessary to carry out tests on each type of structural element in order to correctly evaluate the response of the structure. In addition, the scale effect can produce inaccurate results, making it necessary for tests to be performed on a full scale to validate the results. In this work, the results of several tests with explosives are presented, in different constructive elements, all of them carried out at full scale. These elements range from the structural elements (beams and concrete slabs) to the weak elements of a building (masonry panels)

    Fire from the Sky in the Anthropocene

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    [EN] Lightning is the prevailing ignition source in many remote or scarcely populated parts of the world, and those fires tend to be larger and more intense than human-caused fires [1]. “Dry” lightning storms can ignite many fires over short periods of time and relatively vast areas and in locations less predictable and accessible than those of human-caused fires. Additionally, and regardless of the ignition cause, thunderstorm wind flows can drastically change the behaviour of on-going fires, amplifying fire–atmosphere interactions and leading to erratic and destructive firestorms. Such was the case of the Pedrogão Grande wildfire in Portugal, where 66 people died on 17 June 2017 [2]. Fires themselves can generate lightning when pyrocumulonimbus form, as in the Black Saturday fires of February 2009 in Australia, where 173 people perished [3]. In 2019–2020, the unprecedented Black Summer mega-fires were mostly lightning-caused fires (LCFs) and burned one-fifth of the Australian temperate broadleaf forest and caused huge social disruption [4]; lightning started most fires in a region where “dry” thunderstorms are now more frequent than in the recent past [5]. Once rare in Tasmania, LCFs are now threatening World Heritage forests non-adapted to fire [6]. In California, the unusual 2020 lightning siege has burned ca. 1 million hectares, destroying at least 4390 structures and killing 22 people after 14,000 lightning strikes [7]. In human-dominated landscapes, such as in southern Europe, LCFs comprise a small fraction of the total number of fires, and so are commonly perceived as irrelevant. Such neglect and focus on human agency can happen even when fire statistics indicate a significant role of LCFs in the fire regime, e.g., in temperate Australia [8]. Consequently, by downplaying or ignoring LCFs, fire management planning will hardly be prepared to handle the particular difficulties posed by an LCF crisis. Here, we characterize the relevance of LCFs in a generically low LCF region, the Iberian Peninsula, and will then address current and future challenges posed by LCFs in relation to climate changeSIThis work is supported by National Funds by FCT—Portuguese Foundation for Science and Technology, under the project UIDB/04033/202

    A cost-effective IoT system for monitoring Indoor radon gas concentration

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    [Abstract] Radon is a noble gas originating from the radioactive decay chain of uranium or thorium. Most radon emanates naturally from the soil and from some building materials, so it can be found in many places around the world, in particular in regions with soils containing granite or slate. It is almost impossible for a person to detect radon gas without proper tools, since it is invisible, odorless, tasteless and colorless. The problem is that a correlation has been established between the presence of high radon gas concentrations and the incidence of lung cancer. In fact, the World Health Organization (WHO) has stated that the exposure to radon is the second most common cause of lung cancer after smoking, and it is the primary cause of lung cancer among people who have never smoked. Although there are commercial radon detectors, most of them are either expensive or provide very limited monitoring capabilities. To tackle such an issue, this article presents a cost-effective IoT radon gas remote monitoring system able to obtain accurate concentration measurements. It can also trigger events to prevent dangerous situations and to warn users about them. Moreover, the proposed solution can activate mitigation devices (e.g., forced ventilation) to decrease radon gas concentration. In order to show its performance, the system was evaluated in three different scenarios corresponding to representative buildings in Galicia (Spain), a region where high radon gas concentrations are common due to the composition of the soil. In addition, the influence of using external hardware (i.e., WiFi transceivers and an embedded System-on-Chip (SoC)) next to the radon gas sensor is studied, concluding that, in the tested scenarios, they do not interfere with the measurements.Xunta de Galicia; ED431C 2016-045Xunta de Galicia; ED341D R2016/012Xunta de Galicia; ED431G/01Agencia Estatal de Investigación de España; TEC2015-69648-REDCAgencia Estatal de Investigación de España; TEC2016-75067-C4-1-

    An Electricity Price-Aware Open-Source Smart Socket for the Internet of Energy

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    [Abstracts] The Internet of Energy (IoE) represents a novel paradigm where electrical power systems work cooperatively with smart devices to increase the visibility of energy consumption and create safer, cleaner and sustainable energy systems. The implementation of IoE services involves the use of multiple components, like embedded systems, power electronics or sensors, which are an essential part of the infrastructure dedicated to the generation and distribution energy and the one required by the final consumer. This article focuses on the latter and presents a smart socket system that collects the information about energy price and makes use of sensors and actuators to optimize home energy consumption according to the user preferences. Specifically, this article provides three main novel contributions. First, what to our knowledge is the first hardware prototype that manages in a practical real-world scenario the price values obtained from a public electricity operator is presented. The second contribution is related to the definition of a novel wireless sensor network communications protocol based on Wi-Fi that allows for creating an easy-to-deploy smart plug system that self-organizes and auto-configures to collect the sensed data, minimizing user intervention. Third, it is provided a thorough description of the design of one of the few open-source smart plug systems, including its communications architecture, the protocols implemented, the main sensing and actuation components and the most relevant pieces of the software. Moreover, with the aim of illustrating the capabilities of the smart plug system, the results of different experiments performed are shown. Such experiments evaluate in real-world scenarios the system’s ease of use, its communications range and its performance when using HTTPS. Finally, the economic savings are estimated for different appliances, concluding that, in the practical situation proposed, the smart plug system allows certain energy-demanding appliances to save almost €70 per yearGalicia. Consellería de Cultura, Educación e Ordenación Universitaria; ED431C 2016-045Galicia. Consellería de Cultura, Educación e Ordenación Universitaria; ED341D R2016/012Galicia. Consellería de Cultura, Educación e Ordenación Universitaria; ED431G/01Agencia Estatal de Investigación; TEC2013-47141-C4-1-RAgencia Estatal de Investigación; TEC2015-69648-REDCAgencia Estatal de Investigación; TEC2016-75067-C4-1-

    A Practical Evaluation of a High-Security Energy-Efficient Gateway for IoT Fog Computing Applications

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    [Abstract] Fog computing extends cloud computing to the edge of a network enabling new Internet of Things (IoT) applications and services, which may involve critical data that require privacy and security. In an IoT fog computing system, three elements can be distinguished: IoT nodes that collect data, the cloud, and interconnected IoT gateways that exchange messages with the IoT nodes and with the cloud. This article focuses on securing IoT gateways, which are assumed to be constrained in terms of computational resources, but that are able to offload some processing from the cloud and to reduce the latency in the responses to the IoT nodes. However, it is usually taken for granted that IoT gateways have direct access to the electrical grid, which is not always the case: in mission-critical applications like natural disaster relief or environmental monitoring, it is common to deploy IoT nodes and gateways in large areas where electricity comes from solar or wind energy that charge the batteries that power every device. In this article, how to secure IoT gateway communications while minimizing power consumption is analyzed. The throughput and power consumption of Rivest–Shamir–Adleman (RSA) and Elliptic Curve Cryptography (ECC) are considered, since they are really popular, but have not been thoroughly analyzed when applied to IoT scenarios. Moreover, the most widespread Transport Layer Security (TLS) cipher suites use RSA as the main public key-exchange algorithm, but the key sizes needed are not practical for most IoT devices and cannot be scaled to high security levels. In contrast, ECC represents a much lighter and scalable alternative. Thus, RSA and ECC are compared for equivalent security levels, and power consumption and data throughput are measured using a testbed of IoT gateways. The measurements obtained indicate that, in the specific fog computing scenario proposed, ECC is clearly a much better alternative than RSA, obtaining energy consumption reductions of up to 50% and a data throughput that doubles RSA in most scenarios. These conclusions are then corroborated by a frame temporal analysis of Ethernet packets. In addition, current data compression algorithms are evaluated, concluding that, when dealing with the small payloads related to IoT applications, they do not pay off in terms of real data throughput and power consumption.Galicia. Consellería de Cultura, Educación e Ordenación Universitaria; ED431C 2016-045Agencia Estatal de Investigación (España); TEC2013-47141-C4-1-RAgencia Estatal de Investigación (España); TEC2015-69648-REDCAgencia Estatal de Investigación (España); TEC2016-75067-C4-1-RGalicia. Consellería de Cultura, Educación e Ordenación Universitaria; ED341D2016/012Galicia. Consellería de Cultura, Educación e Ordenación Universitaria; ED431G/0

    Rapid Prototyping for Evaluating Vehicular Communications

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    [Abstract] This Thesis details the different elements of a rapid prototyping system able to implement and evaluate vehicular communications fast, according to the continuously evolving requirements of the industry. The system is basically composed of a testbed and a channel emulator, which allow evaluating communication transceivers in realistic vehicular scenarios. Two different testbeds are introduced: a generic 2x2 system and a vehicular platform. The former is used to compare and study space-time block coding (STBC) transmissions at 2.4 GHz over different indoor channels. The latter makes use of software transceivers whose performance is evaluated when they work under artificial high-speed Rayleigh-fading scenarios. To show the capabilities of both platforms, three software transceivers have been developed following the specifications for the physical layers of the standards IEEE 802.11p, IEEE 802.11a and IEEE 802.16e (Mobile WiMAX). The present work details the different elements that make up each transceiver and indicates how to connect them to the rest of the system to perform evaluation measurements. Finally, single-antenna and multi-antenna performances are measured thanks to the design and implementation of three FPGA-based channel emulators that are able to recreate up to seven different vehicular scenarios that include urban canyons, suburban areas and highways[Resumo] A presente Tese detalla os elementos necesarios para constituir un sistema basado en prototipado rápido capaz de levar a cabo e avaliar comunicacións vehiculares. O hardware do sistema está composto básicamente por unha plataforma de probas (testbed) e un emulador de canal, os cales permiten avaliar o rendemento de transceptores inartiamicos recreando diferentes escenarios vehiculares. Inicialmente, este traballo céntrase na descripción do hardware do sistema, detallando a construcción e proba dunha plataforma multi-antena e un testebed vehicular. Estos sistemas permitiron, respectivamente, estudar o comportamento de códigos STBC (space-time block codes) en interiores e medir o rendemento de tranceptores software ao traballar a distintas velocidades vehiculares en canais con desvaecemento Rayleigh. Tres transceptores software foron creados seguindo as especificacións das capas físicas dos estándares IEEE 802.11p, IEEE 802.11a e IEEE 802.16e (Mobile WiMAX). Este traballo detalla os diferentes componentes de cada transceptor, indicando cómo conectalos ao resto do sistema para realizar a avaliacition do seu rendemento. Dita avaliación realizouse coa axuda de tres emuladores de canal basados en tecnoloxía FPGA (Field Programmable Gate Array), os cales son capaces de recrear ata sete escenarios vehiculares distintos, incluindo cañóns urbanos, zonas suburbanas e autopistas.[Resumen] La presente Tesis detalla los elementos necesarios para constituir un sistema basado en prototipado rtiapido capaz de llevar a cabo y evaluar comunicaciones vehiculares. El hardware del sistema está compuesto por una plataforma de pruebas (testbed) y un emulador de canal, los cuales permiten evaluar el rendimiento de transceptores inaltiambricos recreando diferentes escenarios vehiculares. Inicialmente, este trabajo se centra en la descripcition del hardware del sistema, detallando la construccition y prueba de una plataforma multi-antena y un testebed vehicular. Estos sistemas han permitido, respectivamente, estudiar el comportamiento de ctiodigos STBC (space-time block codes) en interiores y medir el rendimiento en canal con desvanecimiento Rayleigh de tranceptores software a distintas velocidades vehiculares. Tres transceptores software han sido creados siguiendo las especificaciones de las capas físicas de los estandares IEEE 802.11p, IEEE 802.11a e IEEE 802.16e (Mobile WiMAX). Este trabajo detalla los diferentes componentes de cada transceptor, indicando ctiomo conectarlos al resto del sistema para realizar la evaluacition de su rendimiento. Dicha evaluacition se realiztio con la ayuda de tres emuladores de canal basados en FPGAs (Field Programmable Gate Array), los cuales son capaces de recrear comunicaciones multi-antena en hasta siete escenarios vehiculares distintos, incluyendo cañones urbanos, zonas suburbanas y autopistas
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