Future Transportation

Greenhouse gas (GHG) emissions associated with transportation activities account for approximately 20 percent of all carbon dioxide (co2) emissions globally, making the transportation sector a major contributor to the current global warming. This book focuses on the latest advances in technologies aiming at the sustainable future transportation of people and goods. A reduction in burning fossil fuel and technological transitions are the main approaches toward sustainable future transportation. Particular attention is given to automobile technological transitions, bike sharing systems, supply chain digitalization, and transport performance monitoring and optimization, among others

The Internet is a Series of Tubes

Internet adoption tends to progress in phases: early rapid adoption in urban areas and by relatively well-educated and higher-income households, then transitioning to a slower pace once between 70 and 85% of households subscribe. For example, in a 2013 survey, the Pew Research Internet Project found that approximately 15% of the adult population does not use the Internet; those least likely to use the Internet include “senior citizens, adults with less than a high-school education and those living in households earning less than $30,000 per year.

Software tools for conducting real-time information processing and visualization in industry: an up-to-date review

The processing of information in real-time (through the processing of complex events) has become an essential task for the optimal functioning of manufacturing plants. Only in this way can artificial intelligence, data extraction, and even business intelligence techniques be applied, and the data produced daily be used in a beneficent way, enhancing automation processes and improving service delivery. Therefore, professionals and researchers need a wide range of tools to extract, transform, and load data in real-time efficiently. Additionally, the same tool supports or at least facilitates the visualization of this data intuitively and interactively. The review presented in this document aims to provide an up-to-date review of the various tools available to perform these tasks. Of the selected tools, a brief description of how they work, as well as the advantages and disadvantages of their use, will be presented. Furthermore, a critical analysis of overall operation and performance will be presented. Finally, a hybrid architecture that aims to synergize all tools and technologies is presented and discussed.This work is funded by “FCT—Fundação para a Ciência e Tecnologia” within the R&D Units Project Scope: UIDB/00319/2020. The grants of R.S., R.M., A.M., and N.L. are supported by the European Structural and Investment Funds in the FEDER component, through the Operational Competitiveness and Internalization Programme (COMPETE 2020). [Project n. 039479. Funding Reference: POCI-01-0247-FEDER-039479]

Content Caching and Delivery in Heterogeneous Vehicular Networks

Connected and automated vehicles (CAVs), which enable information exchange and content delivery in real time, are expected to revolutionize current transportation systems for better driving safety, traffic efficiency, and environmental sustainability. However, the emerging CAV applications such as content delivery pose stringent requirements on latency, throughput, reliability, and global connectivity. The current wireless networks face significant challenges to satisfy the requirements due to scarce radio spectrum resources, inflexibility to dynamic traffic demands, and geographic-constrained fixed infrastructure deployment. To empower multifarious CAV content delivery, heterogeneous vehicular networks (HetVNets), which integrate the terrestrial networks with aerial networks formed by unmanned aerial vehicles (UAVs) and space networks constituting of low Earth orbit (LEO) satellites, can guarantee reliable, flexible, cost-effective, and globally seamless service provisioning. In addition, edge caching is a promising solution to facilitate content delivery by caching popular files in the HetVNet access points (APs) to relieve the backhaul traffic with a lower delivery delay. The main technical issues are: 1) to fully reveal the potential of HetVNets for content delivery performance enhancement, content caching scheme design in HetVNets should jointly consider network characteristics, vehicle mobility patterns, content popularity, and APs’ caching capacities; 2) to fully exploit the controllable mobility and agility of UAVs to support dynamic vehicular content demands, the caching scheme and trajectory design for UAVs should be jointly optimized, which has not been well addressed due to their intricate inter-coupling relationships; and 3) for caching-based content delivery in HetVNets, a cooperative content delivery scheme should be designed to enable the cooperation among different network segments with ingenious utilization of heterogeneous network resources. In this thesis, we design the content caching and delivery schemes in the caching-enabled HetVNet to address the three technical issues. First, we study the content caching in HetVNets with fixed terrestrial APs including cellular base stations (CBSs), Wi-Fi roadside units (RSUs), and TV white space (TVWS) stations. To characterize the intermittent network connection caused by limited network coverage and high vehicle mobility, we establish an on-off model with service interruptions to describe the vehicular content delivery process. Content coding then is leveraged to resist the impact of unstable network connections and enhance caching efficiency. By jointly considering file characteristics and network conditions, the content placement is formulated as an integer linear programming (ILP) problem. Adopting the idea of the student admission model, the ILP problem is then transformed into a many-to-one matching problem between content files and HetVNet APs and solved by our proposed stable-matching-based caching scheme. Simulation results demonstrate that the proposed scheme can achieve near-optimal performances in terms of delivery delay and offloading ratio with a low complexity. Second, UAV-aided caching is considered to assist vehicular content delivery in aerial-ground vehicular networks (AGVN) and a joint caching and trajectory optimization (JCTO) problem is investigated to jointly optimize content caching, content delivery, and UAV trajectory. To enable real-time decision-making in highly dynamic vehicular networks, we propose a deep supervised learning scheme to solve the JCTO problem. Specifically, we first devise a clustering-based two-layered (CBTL) algorithm to solve the JCTO problem offline. With a given content caching policy, we design a time-based graph decomposition method to jointly optimize content delivery and UAV trajectory, with which we then leverage the particle swarm optimization algorithm to optimize the content caching. We then design a deep supervised learning architecture of the convolutional neural network (CNN) to make online decisions. With the CNN-based model, a function mapping the input network information to output decisions can be intelligently learnt to make timely inferences. Extensive trace-driven experiments are conducted to demonstrate the efficiency of CBTL in solving the JCTO problem and the superior learning performance with the CNN-based model. Third, we investigate caching-assisted cooperative content delivery in space-air-ground integrated vehicular networks (SAGVNs), where vehicular content requests can be cooperatively served by multiple APs in space, aerial, and terrestrial networks. In specific, a joint optimization problem of vehicle-to-AP association, bandwidth allocation, and content delivery ratio, referred to as the ABC problem, is formulated to minimize the overall content delivery delay while satisfying vehicular quality-of-service (QoS) requirements. To address the tightly-coupled optimization variables, we propose a load- and mobility-aware ABC (LMA-ABC) scheme to solve the joint optimization problem as follows. We first decompose the ABC problem to optimize the content delivery ratio. Then the impact of bandwidth allocation on the achievable delay performance is analyzed, and an effect of diminishing delay performance gain is revealed. Based on the analysis results, the LMA-ABC scheme is designed with the consideration of user fairness, load balancing, and vehicle mobility. Simulation results demonstrate that the proposed LMA-ABC scheme can significantly reduce the cooperative content delivery delay compared to the benchmark schemes. In summary, we have investigated the content caching in terrestrial networks with fixed APs, joint caching and trajectory optimization in the AGVN, and caching-assisted cooperative content delivery in the SAGVN. The proposed schemes and theoretical results should provide useful guidelines for future research in the caching scheme design and efficient utilization of network resources in caching-enabled heterogeneous wireless networks

Semantic-based framework for the generation of travel demand

Traffic and transportation have a wide-ranging impact on the daily lives of the human population and society. Activity-based travel demand generation models and traffic simulators are tools that have been developed to investigate traffic and transport problems and assist in developing solutions. The closer modelling of human behaviour, the emergence of new technologies and the availability of more detailed datasets is leading to greater modelling complexity. The robustness of conclusions in investigations is supported by comparison of multiple techniques and models yet variations in the platform, data requirements and dataset availability present barriers to their breadth. This thesis investigates the development of a Semantic Web framework for activity-based travel demand generation. It is proposed that the application of a knowledge-based approach and development of an orchestrating framework will enable a loosely coupled modular architecture. This approach will reduce the burden in preparing and accessing datasets through the construction of a platform-independent knowledge-base and facilitate switching between modules and datasets. The principal contributions of this work are the application of a knowledge-based approach to travel demand generation; the development of a Semantic-based framework to control the configuration of the process and the design; and demonstration of the Semantic based framework through the implementation and evaluation of the modular travel demand generation process, including integration with two third-party traffic simulators. The investigation found that the proposed approach can be successfully applied to model and control the travel demand generation process. Multiple configurations were explored, including utilising network communications, and found that this had a noticeable impact on execution duration but also the potential for mitigation through distributed computing. This presents the opportunity for an online infrastructure of datasets and module implementations for travel demand generation that users can select and access through the framework. This infrastructure would remove the need for ad hoc interfaces; data format conversion or platform dependence to facilitate the process of traffic modelling becoming quicker and more robust

New Secure IoT Architectures, Communication Protocols and User Interaction Technologies for Home Automation, Industrial and Smart Environments

Programa Oficial de Doutoramento en Tecnoloxías da Información e das Comunicacións en Redes Móbiles. 5029V01Tese por compendio de publicacións[Abstract] The Internet of Things (IoT) presents a communication network where heterogeneous physical devices such as vehicles, homes, urban infrastructures or industrial machinery are interconnected and share data. For these communications to be successful, it is necessary to integrate and embed electronic devices that allow for obtaining environmental information (sensors), for performing physical actuations (actuators) as well as for sending and receiving data (network interfaces). This integration of embedded systems poses several challenges. It is needed for these devices to present very low power consumption. In many cases IoT nodes are powered by batteries or constrained power supplies. Moreover, the great amount of devices needed in an IoT network makes power e ciency one of the major concerns of these deployments, due to the cost and environmental impact of the energy consumption. This need for low energy consumption is demanded by resource constrained devices, con icting with the second major concern of IoT: security and data privacy. There are critical urban and industrial systems, such as tra c management, water supply, maritime control, railway control or high risk industrial manufacturing systems such as oil re neries that will obtain great bene ts from IoT deployments, for which non-authorized access can posse severe risks for public safety. On the other hand, both these public systems and the ones deployed on private environments (homes, working places, malls) present a risk for the privacy and security of their users. These IoT deployments need advanced security mechanisms, both to prevent access to the devices and to protect the data exchanged by them. As a consequence, it is needed to improve two main aspects: energy e ciency of IoT devices and the use of lightweight security mechanisms that can be implemented by these resource constrained devices but at the same time guarantee a fair degree of security. The huge amount of data transmitted by this type of networks also presents another challenge. There are big data systems capable of processing large amounts of data, but with IoT the granularity and dispersion of the generated information presents a new scenario very di erent from the one existing nowadays. Forecasts anticipate that there will be a growth from the 15 billion installed devices in 2015 to more than 75 billion devices in 2025. Moreover, there will be much more services exploiting the data produced by these networks, meaning the resulting tra c will be even higher. The information must not only be processed in real time, but data mining processes will have to be performed to historical data. The main goal of this Ph.D. thesis is to analyze each one of the previously described challenges and to provide solutions that allow for an adequate adoption of IoT in Industrial, domestic and, in general, any scenario that can obtain any bene t from the interconnection and exibility that IoT brings.[Resumen] La internet de las cosas (IoT o Internet of Things) representa una red de intercomunicaciones en la que participan dispositivos físicos de toda índole, como vehículos, viviendas, electrodomésticos, infraestructuras urbanas o maquinaria y dispositivos industriales. Para que esta comunicación se pueda llevar a cabo es necesario integrar elementos electr onicos que permitan obtener informaci on del entorno (sensores), realizar acciones f sicas (actuadores) y enviar y recibir la informaci on necesaria (interfaces de comunicaciones de red). La integración y uso de estos sistemas electrónicos embebidos supone varios retos. Es necesario que dichos dispositivos presenten un consumo reducido. En muchos casos deberían ser alimentados por baterías o fuentes de alimentación limitadas. Además, la gran cantidad de dispositivos que involucra la IoT hace necesario que la e ciencia energética de los mismos sea una de las principales preocupaciones, por el coste e implicaciones medioambientales que supone el consumo de electricidad de los mismos. Esta necesidad de limitar el consumo provoca que dichos dispositivos tengan unas prestaciones muy limitadas, lo que entra en conflicto con la segunda mayor preocupación de la IoT: la seguridad y privacidad de los datos. Por un lado existen sistemas críticos urbanos e industriales, como puede ser la regulación del tráfi co, el control del suministro de agua, el control marítimo, el control ferroviario o los sistemas de producción industrial de alto riesgo, como refi nerías, que son claros candidatos a benefi ciarse de la IoT, pero cuyo acceso no autorizado supone graves problemas de seguridad ciudadana. Por otro lado, tanto estos sistemas de naturaleza publica, como los que se desplieguen en entornos privados (viviendas, entornos de trabajo o centros comerciales, entre otros) suponen un riesgo para la privacidad y también para la seguridad de los usuarios. Todo esto hace que sean necesarios mecanismos de seguridad avanzados, tanto de acceso a los dispositivos como de protección de los datos que estos intercambian. En consecuencia, es necesario avanzar en dos aspectos principales: la e ciencia energética de los dispositivos y el uso de mecanismos de seguridad e ficientes, tanto computacional como energéticamente, que permitan la implantación de la IoT sin comprometer la seguridad y la privacidad de los usuarios. Por otro lado, la ingente cantidad de información que estos sistemas puede llegar a producir presenta otros dos retos que deben ser afrontados. En primer lugar, el tratamiento y análisis de datos toma una nueva dimensión. Existen sistemas de big data capaces de procesar cantidades enormes de información, pero con la internet de las cosas la granularidad y dispersión de los datos plantean un escenario muy distinto al actual. La previsión es pasar de 15.000.000.000 de dispositivos instalados en 2015 a más de 75.000.000.000 en 2025. Además existirán multitud de servicios que harán un uso intensivo de estos dispositivos y de los datos que estos intercambian, por lo que el volumen de tráfico será todavía mayor. Asimismo, la información debe ser procesada tanto en tiempo real como a posteriori sobre históricos, lo que permite obtener información estadística muy relevante en diferentes entornos. El principal objetivo de la presente tesis doctoral es analizar cada uno de estos retos (e ciencia energética, seguridad, procesamiento de datos e interacción con el usuario) y plantear soluciones que permitan una correcta adopción de la internet de las cosas en ámbitos industriales, domésticos y en general en cualquier escenario que se pueda bene ciar de la interconexión y flexibilidad de acceso que proporciona el IoT.[Resumo] O internet das cousas (IoT ou Internet of Things) representa unha rede de intercomunicaci óns na que participan dispositivos físicos moi diversos, coma vehículos, vivendas, electrodomésticos, infraestruturas urbanas ou maquinaria e dispositivos industriais. Para que estas comunicacións se poidan levar a cabo é necesario integrar elementos electrónicos que permitan obter información da contorna (sensores), realizar accións físicas (actuadores) e enviar e recibir a información necesaria (interfaces de comunicacións de rede). A integración e uso destes sistemas electrónicos integrados supón varios retos. En primeiro lugar, é necesario que estes dispositivos teñan un consumo reducido. En moitos casos deberían ser alimentados por baterías ou fontes de alimentación limitadas. Ademais, a gran cantidade de dispositivos que se empregan na IoT fai necesario que a e ciencia enerxética dos mesmos sexa unha das principais preocupacións, polo custo e implicacións medioambientais que supón o consumo de electricidade dos mesmos. Esta necesidade de limitar o consumo provoca que estes dispositivos teñan unhas prestacións moi limitadas, o que entra en con ito coa segunda maior preocupación da IoT: a seguridade e privacidade dos datos. Por un lado existen sistemas críticos urbanos e industriais, como pode ser a regulación do tráfi co, o control de augas, o control marítimo, o control ferroviario ou os sistemas de produción industrial de alto risco, como refinerías, que son claros candidatos a obter benefi cios da IoT, pero cuxo acceso non autorizado supón graves problemas de seguridade cidadá. Por outra parte tanto estes sistemas de natureza pública como os que se despreguen en contornas privadas (vivendas, contornas de traballo ou centros comerciais entre outros) supoñen un risco para a privacidade e tamén para a seguridade dos usuarios. Todo isto fai que sexan necesarios mecanismos de seguridade avanzados, tanto de acceso aos dispositivos como de protección dos datos que estes intercambian. En consecuencia, é necesario avanzar en dous aspectos principais: a e ciencia enerxética dos dispositivos e o uso de mecanismos de seguridade re cientes, tanto computacional como enerxéticamente, que permitan o despregue da IoT sen comprometer a seguridade e a privacidade dos usuarios. Por outro lado, a inxente cantidade de información que estes sistemas poden chegar a xerar presenta outros retos que deben ser tratados. O tratamento e a análise de datos toma unha nova dimensión. Existen sistemas de big data capaces de procesar cantidades enormes de información, pero coa internet das cousas a granularidade e dispersión dos datos supón un escenario moi distinto ao actual. A previsión e pasar de 15.000.000.000 de dispositivos instalados no ano 2015 a m ais de 75.000.000.000 de dispositivos no ano 2025. Ademais existirían multitude de servizos que farían un uso intensivo destes dispositivos e dos datos que intercambian, polo que o volume de tráfico sería aínda maior. Do mesmo xeito a información debe ser procesada tanto en tempo real como posteriormente sobre históricos, o que permite obter información estatística moi relevante en diferentes contornas. O principal obxectivo da presente tese doutoral é analizar cada un destes retos (e ciencia enerxética, seguridade, procesamento de datos e interacción co usuario) e propor solucións que permitan unha correcta adopción da internet das cousas en ámbitos industriais, domésticos e en xeral en todo aquel escenario que se poda bene ciar da interconexión e flexibilidade de acceso que proporciona a IoT