Feature Extraction in Densely Sensed Environments: Extensions to Multiple Broadcast Domains

The vision of the Internet of Things (IoT) includes large and dense deployment of interconnected smart sensing and monitoring devices. This vast deployment necessitates collection and processing of large volume of measurement data. However, collecting all the measured data from individual devices on such a scale may be impractical and time consuming. Moreover, processing these measurements requires complex algorithms to extract useful information. Thus, it becomes imperative to devise distributed information processing mechanisms that identify application-specific features in a timely manner and with a low overhead. In this article, we present a feature extraction mechanism for dense networks that takes advantage of dominance-based medium access control (MAC) protocols to (i) efficiently obtain global extrema of the sensed quantities, (ii) extract local extrema, and (iii) detect the boundaries of events, by using simple transforms that nodes employ on their local data. We extend our results for a large dense network with multiple broadcast domains (MBD). We discuss and compare two approaches for addressing the challenges with MBD and we show through extensive evaluations that our proposed distributed MBD approach is fast and efficient at retrieving the most valuable measurements, independent of the number sensor nodes in the network.

Measuring data transfer in heterogeneous IoT environments

Dissertação para obtenção do Grau de Mestre em Engenharia Electrotécnica e de Computadores

Organising interoperability information on highly dynamic and heterogeneous environments

Dissertação para obtenção do Grau de Mestre em Engenharia Electrotécnica e de Computadores

ezGo: A voice operated wheelchair with biosignal monitoring for home environments

In this paper we present ezGo, an electric powered wheelchair with a speech based interface and biosignal monitoring instrumentation. The user can use the voice, a natural communication method, for controlling the chair movement and obtain information about his health. Additionally a set of semi-autonomous modes with macro recording enable the execution of navigation tasks with little effort and improved precision. The main purpose of the system is to provide severely disabled persons with an assistive device that can improve their confidence and daily independence. The obtained results on usability tests showed that users consider ezGo a valuable help on their daily tasks and a very desirable addition to standard wheelchairs.

Sustainability of systems interoperability in dynamic business networks

Dissertação para obtenção do Grau de Doutor em Engenharia Electrotécnica e de Computadores

A flexible navigation system for autonomous robots operating in heterogeneous environments

Dissertação para obtenção do Grau de Mestre em Engenharia Electrotécnica e de Computadores

Improvements in the geocoding process in organizational environments

Dissertação para obtenção do Grau de Mestre em Engenharia Informática

Improvisation in tightly controlled work environments: The case of medical practice

We present a qualitative analysis of organizational improvisation and provide a preliminary insight into the following question: how is improvisation present in tightly controlled work environments? We conducted in situ observations of, and interviews with, several emergency medical teams and complemented this information with statistical and media data. Using grounded theory, we developed four propositions that were arranged into a model that allowed the identification of two use levels of established routines: (1) the visible side that accommodates contextual requirements, and (2) the improvisational side that provides a response to activity characteristics. This dual process is related to the existence of pressures that operate at the institutional level with practical needs emerging from the operational domain. In contrast with most of the literature, this study reveals that the presence of a broad procedural organizational memory does not restrict improvisation but enables a bureaucratic system to produce flexible improvised performance.

Drivers of participation in collaborative consumption ventures

A Work Project, presented as part of the requirements for the Award of a Masters Degree in Management from the NOVA – School of Business and Economics

Personal Learning Environments – Um Ecossistema de Aprendizagem em e-Learning

Esta investigação tem como tema de estudo os ambientes pessoais de aprendizagem que se podem desenvolver em e-learning. Estes ambientes com características singulares, face ao atual estado de desenvolvimento tecnológico e social, têm sido designados na doutrina científica pela expressão anglo-saxónica Personal Learning Environments, da qual derivam os acrónimos PLE ou PLEs. Este estudo tem, como objetivo, compreender o papel dos PLEs na aprendizagem dos alunos da parte letiva do Mestrado em Gestão de Sistemas de e-Learning, da Faculdade de Ciências Sociais e Humanas da Universidade Nova de Lisboa, nos biénios que decorreram de 2010-2011 a 2012-2013. Estes alunos, ao longo da sua aprendizagem, utilizaram várias ferramentas e/ou serviços associados com as TIC e Web 2.0. Esta utilização permitiu aos alunos criarem um ecossistema de aprendizagem próprio. A metodologia de investigação utilizada teve em consideração sobretudo aspetos qualitativos. A estratégia utilizada para a recolha de informações foi o inquérito por questionário. As informações recolhidas foram sujeitas a tratamento estatístico descritivo, e posterior triangulação dos resultados de algumas das variáveis.Dos resultados obtidos, é possível concluir que os alunos do Mestrado criaram os seus próprios PLEs e que estes facilitaram as suas aprendizagens. Que a sua utilização conferiu vantagens aos alunos. Que os PLEs foram fundamentais para poderem desenvolver atividades colaborativas, e que criaram um ecossistema próprio, uma rede de troca de conhecimentos.

2D position system for a mobile robot in unstructured environments

Nowadays, several sensors and mechanisms are available to estimate a mobile robot trajectory and location with respect to its surroundings. Usually absolute positioning mechanisms are the most accurate, but they also are the most expensive ones, and require pre installed equipment in the environment. Therefore, a system capable of measuring its motion and location within the environment (relative positioning) has been a research goal since the beginning of autonomous vehicles. With the increasing of the computational performance, computer vision has become faster and, therefore, became possible to incorporate it in a mobile robot. In visual odometry feature based approaches, the model estimation requires absence of feature association outliers for an accurate motion. Outliers rejection is a delicate process considering there is always a trade-off between speed and reliability of the system. This dissertation proposes an indoor 2D position system using Visual Odometry. The mobile robot has a camera pointed to the ceiling, for image analysis. As requirements, the ceiling and the oor (where the robot moves) must be planes. In the literature, RANSAC is a widely used method for outlier rejection. However, it might be slow in critical circumstances. Therefore, it is proposed a new algorithm that accelerates RANSAC, maintaining its reliability. The algorithm, called FMBF, consists on comparing image texture patterns between pictures, preserving the most similar ones. There are several types of comparisons, with different computational cost and reliability. FMBF manages those comparisons in order to optimize the trade-off between speed and reliability.

Real-time collaborative editing of OutSystems DSL models

Real-time collaborative editing systems are common nowadays, and their advantages are widely recognized. Examples of such systems include Google Docs, ShareLaTeX, among others. This thesis aims to adopt this paradigm in a software development environment. The OutSystems visual language lends itself very appropriate to this kind of collaboration, since the visual code enables a natural flow of knowledge between developers regarding the developed code. Furthermore, communication and coordination are simplified. This proposal explores the field of collaboration on a very structured and rigid model, where collaboration is made through the copy-modify-merge paradigm, in which a developer gets its own private copy from the shared repository, modifies it in isolation and later uploads his changes to be merged with modifications concurrently produced by other developers. To this end, we designed and implemented an extension to the OutSystems Platform, in order to enable real-time collaborative editing. The solution guarantees consistency among the artefacts distributed across several developers working on the same project. We believe that it is possible to achieve a much more intense collaboration over the same models with a low negative impact on the individual productivity of each developer.

Transactions in dynamic reactive environments

Most of today’s systems, especially when related to the Web or to multi-agent systems, are not standalone or independent, but are part of a greater ecosystem, where they need to interact with other entities, react to complex changes in the environment, and act both over its own knowledge base and on the external environment itself. Moreover, these systems are clearly not static, but are constantly evolving due to the execution of self updates or external actions. Whenever actions and updates are possible, the need to ensure properties regarding the outcome of performing such actions emerges. Originally purposed in the context of databases, transactions solve this problem by guaranteeing atomicity, consistency, isolation and durability of a special set of actions. However, current transaction solutions fail to guarantee such properties in dynamic environments, since they cannot combine transaction execution with reactive features, or with the execution of actions over domains that the system does not completely control (thus making rolling back a non-viable proposition). In this thesis, we investigate what and how transaction properties can be ensured over these dynamic environments. To achieve this goal, we provide logic-based solutions, based on Transaction Logic, to precisely model and execute transactions in such environments, and where knowledge bases can be defined by arbitrary logic theories.

Natural infection of triatomines (Hemiptera: Reduviidae) by trypanosomatids in two different environments in the municipality of Ouro Preto do Oeste, State of Rondônia, Brazil

INTRODUCTION: This study analyzed the occurrence and the contamination of triatomines by trypanosomatids in Orbignya speciosa (babassu) specimens in the State of Rondônia, Brazil, in two different environments (pasture and woods). METHODS: Capture of triatomines on babassus and microscopic search for trypanosomatids in their digestive tube were carried out. RESULTS: Four hundred ninety-four (494) specimens were captured (Rhodnius prolixus and R.robustus), of which 35.6% of the triatomines were positive for trypanosomatids. CONCLUSIONS: The high index of natural infection along with the abundance of triatomines points out to the necessity to create an epidemiological surveillance system to monitor vector-borne transmission and deepen the studies on the ecology of such vectors in the Amazon.

Uncertain Spaces: Virtual Configurations in Contemporary Art and Museums

Contém artigos apresentados na International Conference “Uncertain Spaces: Virtual Configurations in Contemporary Art and Museums”, na Fundação Calouste Gulbenkian (Lisboa), 31 Outubro - 1 de Novembro de 2014) de: Helena Barranha e Susana S. Martins - Introduction: Art, Museums and Uncertainty (pp.1-12); Alexandra Bounia e Eleni Myrivili - Beyond the ‘Virtual’: Intangible Museographies and Collaborative Museum Experiences (pp.15-32); Annet Dekker - Curating in Progress. Moving Between Objects and Processes (pp.33-54); Giselle Beiguelman - Corrupted Memories. The aesthetics of Digital Ruins and the Museum of the Unfinished (pp.55-82); Andrew Vaas Brooks - The Planetary Datalinks (pp.85-110); Sören Meschede - Curators’ Network: Creating a Promotional Database for Contemporary Visual Arts (pp.11-130); Stefanie Kogler - Divergent Histories and Digital Archives of Latin American and Latino Art in the United States – Old Problems in New Digital Formats (pp.131-156); Luise Reitstätter e Florian Bettel - Right to the City! Right to the Museum!(pp.159-182); Roberto Terracciano - On Geo-poetic systems: virtual interventions inside and outside the museum space (pp.183-210); e, Catarina Carneiro de Sousa e Luís Eustáquio - Art Practice in Collaborative Virtual Environments (pp.211-240).