Performance of management solutions and cooperation approaches for vehicular delay-tolerant networks

A wide range of daily-life applications supported by vehicular networks attracted the interest, not only from the research community, but also from governments and the automotive industry. For example, they can be used to enable services that assist drivers on the roads (e.g., road safety, traffic monitoring), to spread commercial and entertainment contents (e.g., publicity), or to enable communications on remote or rural regions where it is not possible to have a common network infrastructure. Nonetheless, the unique properties of vehicular networks raise several challenges that greatly impact the deployment of these networks. Most of the challenges faced by vehicular networks arise from the highly dynamic network topology, which leads to short and sporadic contact opportunities, disruption, variable node density, and intermittent connectivity. This situation makes data dissemination an interesting research topic within the vehicular networking area, which is addressed by this study. The work described along this thesis is motivated by the need to propose new solutions to deal with data dissemination problems in vehicular networking focusing on vehicular delay-tolerant networks (VDTNs). To guarantee the success of data dissemination in vehicular networks scenarios it is important to ensure that network nodes cooperate with each other. However, it is not possible to ensure a fully cooperative scenario. This situation makes vehicular networks suitable to the presence of selfish and misbehavior nodes, which may result in a significant decrease of the overall network performance. Thus, cooperative nodes may suffer from the overwhelming load of services from other nodes, which comprises their performance. Trying to solve some of these problems, this thesis presents several proposals and studies on the impact of cooperation, monitoring, and management strategies on the network performance of the VDTN architecture. The main goal of these proposals is to enhance the network performance. In particular, cooperation and management approaches are exploited to improve and optimize the use of network resources. It is demonstrated the performance gains attainable in a VDTN through both types of approaches, not only in terms of bundle delivery probability, but also in terms of wasted resources. The results and achievements observed on this research work are intended to contribute to the advance of the state-of-the-art on methods and strategies for overcome the challenges that arise from the unique characteristics and conceptual design of vehicular networks.O vasto número de aplicações e cenários suportados pelas redes veiculares faz com que estas atraiam o interesse não só da comunidade científica, mas também dos governos e da indústria automóvel. A título de exemplo, estas podem ser usadas para a implementação de serviços e aplicações que podem ajudar os condutores dos veículos a tomar decisões nas estradas, para a disseminação de conteúdos publicitários, ou ainda, para permitir que existam comunicações em zonas rurais ou remotas onde não é possível ter uma infraestrutura de rede convencional. Contudo, as propriedades únicas das redes veiculares fazem com que seja necessário ultrapassar um conjunto de desafios que têm grande impacto na sua aplicabilidade. A maioria dos desafios que as redes veiculares enfrentam advêm da grande mobilidade dos veículos e da topologia de rede que está em constante mutação. Esta situação faz com que este tipo de rede seja suscetível de disrupção, que as oportunidades de contacto sejam escassas e de curta duração, e que a ligação seja intermitente. Fruto destas adversidades, a disseminação dos dados torna-se um tópico de investigação bastante promissor na área das redes veiculares e por esta mesma razão é abordada neste trabalho de investigação. O trabalho descrito nesta tese é motivado pela necessidade de propor novas abordagens para lidar com os problemas inerentes à disseminação dos dados em ambientes veiculares. Para garantir o sucesso da disseminação dos dados em ambientes veiculares é importante que este tipo de redes garanta a cooperação entre os nós da rede. Contudo, neste tipo de ambientes não é possível garantir um cenário totalmente cooperativo. Este cenário faz com que as redes veiculares sejam suscetíveis à presença de nós não cooperativos que comprometem seriamente o desempenho global da rede. Por outro lado, os nós cooperativos podem ver o seu desempenho comprometido por causa da sobrecarga de serviços que poderão suportar. Para tentar resolver alguns destes problemas, esta tese apresenta várias propostas e estudos sobre o impacto de estratégias de cooperação, monitorização e gestão de rede no desempenho das redes veiculares com ligações intermitentes (Vehicular Delay-Tolerant Networks - VDTNs). O objetivo das propostas apresentadas nesta tese é melhorar o desempenho global da rede. Em particular, as estratégias de cooperação e gestão de rede são exploradas para melhorar e optimizar o uso dos recursos da rede. Ficou demonstrado que o uso deste tipo de estratégias e metodologias contribui para um aumento significativo do desempenho da rede, não só em termos de agregados de pacotes (“bundles”) entregues, mas também na diminuição do volume de recursos desperdiçados. Os resultados observados neste trabalho procuram contribuir para o avanço do estado da arte em métodos e estratégias que visam ultrapassar alguns dos desafios que advêm das propriedades e desenho conceptual das redes veiculares

Bibliographic Control in the Digital Ecosystem

With the contributions of international experts, the book aims to explore the new boundaries of universal bibliographic control. Bibliographic control is radically changing because the bibliographic universe is radically changing: resources, agents, technologies, standards and practices. Among the main topics addressed: library cooperation networks; legal deposit; national bibliographies; new tools and standards (IFLA LRM, RDA, BIBFRAME); authority control and new alliances (Wikidata, Wikibase, Identifiers); new ways of indexing resources (artificial intelligence); institutional repositories; new book supply chain; “discoverability” in the IIIF digital ecosystem; role of thesauri and ontologies in the digital ecosystem; bibliographic control and search engines

Care Robotics in Aging Japan: Creating Technical Solutions for the World’s Demographic Problem?

Japan is an ideal country for studying the effects of population aging that cause a wide range of societal issues, ranging from labor shortages and increasing pressure on the welfare state, to growing old age-related poverty and the need for improving productivity to sustain economic prosperity. The research question, which the scientific exploration at hand addresses, is what kind of technologies, generically referred to as robots, may be able to mitigate care problems and generate new solutions, and even further, improve the general health of the Japanese population or serve as a blueprint for other aging societies. Therefore, the case of Japan can be utilized to describe which strategies decision-makers face, as well as the challenges and opportunities caused by such a demographic transition to cope with the effects. The Japanese government prioritizes the large-scale introduction of robotics in areas of worsening labor shortages and daily life. The New Robot Strategy (NRS), a five-year policy-action plan compiled in 2015, is the new tool to coordinate the support for actors in the robotics industry, to finally leverage the predicted large market potential. Whereas policy-makers are concerned with creating a better infrastructure for the creation of versatile robots (e.g. regulative considerations, channeling of subsidies), the bureaucracy (e.g. METI, MHLW) is supposed to supervise the policy implementation and to link important public and private actors of robotics development (e.g. universities, robot-makers, research institutes). The coordination of this triangle of three stakeholder groups will be vital for the success of large-scale implementation of robotics to lessen the burden on caregivers, improve average health and wellbeing and exploit the economic potential of the silver market. Rapidly aging societies are a worldwide demographic phenomenon. Whatever feasible technical solution for care Japan invents for its own society is likely to have an impact elsewhere in the world. If the development of care robots works in Japan, it will likely be of fundamental relevance to other aging societies and may incidentally come to be one of the next export successes for Japan. It might be a chance for the government to kill two birds with one stone: taking care of Japan’s elderly and the Japanese economy at the same time. Whether there is a realistic chance this unique technical-driven approach to solving social problems to work out will be at the heart of this academic inquiry

Regime elites and transitions from authoritarian rule: a comparative analysis of the Tunisian and Egyptian uprisings

This thesis proposes an explanation for why elites in authoritarian regimes withdraw their support for incumbents when faced with mass popular uprisings. Building upon the substantial scholarship on MENA (Middle East and North Africa) elites, I argue that the elite cadres supporting the region’s incumbents are drawn from three distinct elite constituencies: the military, the ruling party, and, the incumbent’s extended personal network and the security services, each of which possess their own distinct interests and preferences regarding regime change. The argument is tested against two endogenous and exogenous variables, synthesised from the authoritarian resilience literature. Through the use of an analytic narrative this thesis finds that the withdrawal of elite support during the mass uprisings was the result of long-term processes in both regimes. First, the increasing personalisation of both regimes contributed to withdrawal of elite support from both countries’ ruling parties and militaries. And second, the implementation of structural adjustment programmes accelerated this personalisation and inhibited the abilities of both countries’ ruling parties to mobilise support for the regime during the uprisings. The thesis further finds that the degree of military involvement in the formal political sphere contributed to shaping the divergent outcomes experienced by both Tunisia and Egypt in the immediate aftermath of the ouster of Ben Ali and Mubarak