Carlos Pereira

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In this work, we evaluate the performance of 802.11p-based vehicular communications in the presence of RF jamming attacks. Specifically, we characterize the transmission success rate of a car-to-car link subject to constant, periodic, and reactive RF jamming. First, we conduct extensive measurements in an anechoic chamber, where we study the benefits of(More)
Machine-to-Machine (M2M) communications enable networked devices and services to exchange information and perform actions seamlessly without the need for human intervention. They are viewed as a key enabler of the Internet of Things (IoT) and ubiquitous applications, like mobile healthcare, telemetry, or intelligent transport systems. We survey existing(More)
Epidemiologic studies have shown that insomnia is the most prevalent sleep disorder at all ages, associated with sociodemographic and environmental factors and lifestyle. The aim of this study was to quantify the prevalence of insomnia and analyze its determinants among Portuguese adolescents. In a cross-sectional study, we evaluated 6,919 students from the(More)
Smartphones, with vast connectivity and sensing capabilities, are the natural choice to serve as gateways for physiologic sensors and body area networks. Machine-to-Machine (M2M) middleware standards are driving the emergence of Internet of Things (IoT) applications by providing autonomic interoperability. However, standards remain opaque and difficult to(More)
Online Failure Prediction is a cutting-edge technique for improving the dependability of software systems. It makes extensive use of machine learning techniques applied to variables monitored from the system at regular intervals of time (e.g. mutexes/s, paged bytes/s, etc.). The goal of this work is to assess the impact of considering the time dimension in(More)
Technologies capable of being used by the older adults, with their specificities, to provide new services in the areas of telehealth and Ambient Assisted Living are needed. In this paper, we describe a new service, and its first prototype implementation, in the area of elderly health support at home. Special care was taken to improve the usability,(More)
The oral cavity is a complex ecosystem where human chemical compounds coexist with a particular microbiota. However, shifts in the normal composition of this microbiota may result in the onset of oral ailments, such as periodontitis and dental caries. In addition, it is known that the microbial colonization of the oral cavity is mediated by protein-protein(More)