Search

Troponins are recognized as one of the most specific and sensitive biomarkers for the diagnosis and prognosis of acute coronary syndromes. The use of troponins as acute cardiac isquemic biomarkers impacts positively on the treatment costs and on the mortality rate due to cardiovascular diseases. Nowadays, efforts have been made to develop new methods to detect and quantify troponins in a non-invasive way, reducing the need for blood samples and venipuncture. Saliva started to be increasingly recognized as an attractive diagnostic fluid. However, the challenges in achieving statistically significant correlations between saliva and serum concentrations, the limitations dealing with this high viscosity fluid and the background interferences, have limited the application of biosensors for troponin quantification in saliva. This review briefly approaches the mechanisms of troponin release and reports the methods found in literature for detection of troponin in saliva. Finally, the authors present a discussion of the challenges and perspectives on this topic., This work was supported by Portuguese FCT, under the reference project UIDB/04436/2020, and by Project NORTE-01-0145-FEDER-028178 funded by NORTE 2020 Portugal Regional Operational Program under PORTUGAL 2020 Partnership Agreement through the European Regional Development Fund and the Fundação para a Ciência e Tecnologia

The requirements of Machine Learning applications are changing rapidly. Machine Learning models need to deal with increasing volumes of data, and need to do so quicker as responses are expected more than ever in real-time. Plus, sources of data are becoming more and more dynamic, with patterns that change more frequently. This calls for new approaches and algorithms, that are able to efficiently deal with these challenges. In this paper we propose the use of a Genetic Algorithm to Optimize a Stacking Ensemble specifically developed for streaming scenarios. A pool of solutions is maintained in which each solution represents a distribution of weights in the ensemble. The Genetic Algorithm continuously optimizes these weights to minimize the cost function. Moreover, new models are added at regular intervals, trained on more recent data. These models eventually replace older and less accurate ones, making the ensemble adapt continuously do changes in the distribution of the data., This work was supported by the Northern Regional Operational Program, Portugal 2020 and European Union, trough the European Regional Development Fund (ERDF) and Fundos Europeus Estruturais e de Investimento (FEEI) in the scope of projects 39900 - 31/SI/2017 and NORTE-01-0145-FEDER023577, and by national funds through FCT - Fundacao para a Ciencia e a Tecnologia, through projects UIDB/04728/2020 and UID/CEC/00319/2019.

This paper presents the fabrication of a silicon neural probe using low-cost microfabrication technologies, such as thin-films deposition, blade dicing, and photolithography. The metal stack that forms the 9 microelectrodes of 50 × 50 µm2 area, the tracks and the pads were made of Ti and Pt, while the passivation stack was SiO2 and Si3N4. The fabricated probe was characterized using electrochemical impedance spectroscopy, before and after deposition of poly(3,4-ethylene-dioxythiophene) (PEDOT) on Pt microelectrodes. The electrochemical deposition of PEDOT, a conductive polymer, reduced the impedance of the Pt microelectrodes. The neural probe with PEDOT was used for in vivo electrophysiological acute recordings in an adult rat. The extracellular recordings were filtered to obtain the spike and local field potential (LFP) data, using Butterworth bandpass filters of 400–6000 Hz and 0.1–300 Hz, respectively. The results obtained with the fabricated neural probe validated its functionality, comparing with the signals acquired with a commercial neural probe, and the viability of the fabrication process, which avoids high–cost and complex etching processes., s ANI supports this work through the Brain Lighting project by FEDER funds through Portugal 2020, COMPETE 2020 with the reference POCI-01-0247-FEDER-003416. This work is also supported by FCT with CMEMS-UMinho Strategic Project, reference UIDB/04436/2020, the project Infrastructures Micro&- NanoFabs@PT, reference NORTE-01-0145-FEDER-022090, POR Norte, Portugal 2020 and by the project OpticalBrain, reference PTDC/CTM-REF/28406/2017, by FEDER funds through the COM PETE 2020 - Programa Operacional Competitividade e Interna cionalizac¸a˜o (POCI). The authors acknowledge also FCT CEECIND grants, Bial Foundation Grants 207/14 and 037/18 to JO; Northern Portugal Regional Operational Programme (NORTE 2020), under the Portugal 2020 Partnership Agreement, through the European Regional Development Fund (FEDER) (NORTE-01-0145-FEDER-000013); FEDER Funds, through the Competitiveness Factors Operational Programme (COMPETE), and The National Fund, through the FCT (POCI-01-0145-FEDER-007038). The authors also thank to N. A. P. de Vasconcelos from ICVS-University of Minho for the implemen tation of the setup for the in vivo recordings.

Purpose of Review: With the growing interest for STEM/STEAM, new robotic platforms are being created with different characteristics, extras and options. There are so many diverse solutions, that it is difficult for a teacher/student to choose the ideal one. This paper intends to provide an analysis to the most common robotic platforms existent on the market. The same is happening regarding robotic events all around the world, with objectives so distinctive, and with complexity from easy to very difficult. This paper also describes some of those events which occur in many countries. Recent Findings: As the literature is showing, there has been a visible effort from schools and educators to teach robotics from very young ages, not only because robotics is the future, but also as a tool to teach STEM/STEAM areas. But as time progresses, the options for the right platforms also evolves making difficult to choose among them. Some authors opt to first choose a robotic platform and carry on from there. Others choose first a development environment and then look for which robots can be programmed from it. Summary: An actual review on learning robotics is here presented, firstly showing some literature background on history and trends of robotic platforms used in education in general, the different development environments for robotics and finishing on competitions and events. A comprehensive characterization list of robotic platforms along with robotic competitions and events is also shown.

Conventional sequential processing on software with a general purpose CPU has become significantly insufficient for certain heavy computations due to the high demand of processing power to deliver adequate throughput and performance. Due to many reasons a high degree of interest could be noted for high performance real time video processing on embedded systems. However, embedded processing platforms with limited performance could least cater the processing demand of several such intensive computations in computer vision domain. Therefore, hardware acceleration could be noted as an ideal solution where process intensive computations could be accelerated using application specific hardware integrated with a general purpose CPU. In this research we have focused on building a parallelized high performance application specific architecture for such a hardware accelerator for HOG-SVM computation implemented on Zynq 7000 FPGA. Histogram of Oriented Gradients (HOG) technique combined with a Support Vector Machine (SVM) based classifier is versatile and extremely popular in computer vision domain in contrast to high demand for processing power. Due to the popularity and versatility, various previous research have attempted on obtaining adequate throughput on HOG-SVM. This research with a high throughput of 240 FPS on single scale on VGA frames of size 640x480 out performs the best case performance on a single scale of previous research by approximately a factor of 3-4. Further it's an approximately 15x speed up over the GPU accelerated software version with the same accuracy. This research has explored the possibility of using a novel architecture based on deep pipelining, parallel processing and BRAM structures for achieving high performance on the HOG-SVM computation. Further the above developed (video processing unit) VPU which acts as a hardware accelerator will be integrated as a co-processing peripheral to a host CPU using a novel custom accelerator structure with on chip buses in a System-On-Chip (SoC) fashion. Thi

Programa doutoral em Informática - MAP-i, Internet services play a critical role day-by-day in personal and professional lives. Monitoring these services is of paramount importance for quick detection and solving anomalies in order to reduce downtime and persistence of erroneous behavior, otherwise they end up causing serious negative impact. The availability of detailed data about the behavior of the system as a whole is crucial for analysis and troubleshooting anomalies. Although most software components individually provide outputs that developers foresee useful to diagnose performance and behavioral issues, they are not correlated in a causally-consistent fashion. Collecting cross-component outputs, in turn, requires substantial effort in instrumenting the source code of each software component for enabling the generation of causally-correlated outputs, which is not always viable given the heterogeneity architecture’s components and unaccessible portions of code. This renders a trade-off between black-box outputs and the detail they provide. In this dissertation, we explore this trade-off in order to enable effective analysis and troubleshooting of complex distributed systems without requiring application-specific knowledge. This was achieved by operating at the common layer of all software components, through which all interactions are performed. Specifically, we focused on exploring the operating system’s kernel as the layer of observation to extract information about the behavior of the system. Our approach relies on events triggered by distributed processes within applicational components and their well-known causal relations to aid diagnosing performance and behavior anomalies. Using three case studies, we validated that our approach represents a step forward towards observable complex distributed architectures without application-specific knowledge., Os serviços na Internet desempenham um papel fundamental no dia-a-dia de milhões de pessoas e empresas. A monitorização destes serviços é por isso essencial para a deteção e resolução de anomalias de modo a reduzir indisponibilidade e a persistência de erros. Para resolver anomalias de forma eficaz, é necessário obter dados detalhados sobre o comportamento do sistema como um todo. Embora a maioria das componentes de software forneça isoladamente dados que os programadores consideram úteis para diagnosticar problemas de desempenho e comportamento, estes não incluem informação suficiente para obter uma visão causalmente coerente do comportamento do sistema como um todo. Para que estes dados forneçam uma visão coerente do comportamento do sistema, é exigido um esforço substancial na instrumentação do código-fonte de cada componente. No entanto, isto nem sempre é viável, dada a natureza heterogénea da arquitetura das componentes e até mesmo o facto de terem porções de código-fonte inacessíveis. Assim, existe um compromisso entre os dados gerados isoladamente pelas componentes, cujo comportamento em detalhe é desconhecido, e o detalhe que estes fornecem sobre o comportamento do sistema como um todo. Nesta dissertação, explora-se esse compromisso de modo a permitir a análise e resolução de problemas eficazes de sistemas distribuídos complexos, sem necessitar de conhecimento específico do funcionamento interno das suas componentes de software. Para atingir este objetivo, é apresentada uma abordagem que estebelece o núcleo do sistema operativo como o nível de observação para extrair informação sobre o comportamento do sistema. Esta abordagem assenta sobre eventos despoletados por processos distribuídos pertencentes às componentes de software aplicacionais, bem como nas suas relações causais previamente conhecidas. Utilizando três casos de estudo, conclui-se que a abordagem proposta nesta dissertação representa um passo em frente na observação de sistemas distribuídos complexos sem conhecimento específico das suas componentes aplicacionais., Ao INESC TEC, pelo apoio e financiamento parcial deste doutoramento. À Fundação para a Ciência e a Tecnologia, pelo apoio financeiro durante os últimos três anos através da bolsa de doutoramento SFRH/BD/129771/2017

Programa doutoral em Engenharia Eletrónica e de Computadores – Instrumentação e Microssistemas Eletrónicos, A investigação sobre acelerómetros MEMS está constantemente à procura de melhor desempenho para atender aos requisitos exigentes das aplicações de grau de nevegação. Os acelerómetros MEMS modulados em frequência são uma abordagem adequada para atender a este objetivo, baseando-se num ressoador cuja frequência de ressonância varia com a aceleração externa. Fatores de qualidade elevados são fundamentais no desempenho destes ressoadores, melhorando a imunidado ao ruído, a estabilidade a longo termo, a resolução e a gama dinâmica. Na literatura recente, ressoadores baseados numa viga piezoresistiva que apresentam um mecanismo inovador – a amplificação termo piezoresistiva interna (TPA) – demonstraram fatores de qualidade acima de um milhão. Assim, nesta tese, é proposto o desenvolvimento de um acelerómetro MEMS FM baseado neste mecanismo, pretendendo-se alcançar um elevado desempenho utilizando os benefícios de um fator de qualidade elevado. O mecanismo interno de TPA foi caracterizado usando ressoadores atuados electrostaticamente com massa única (SMR) ou dupla (DMR). Modelos analíticos e discretos foram desenvolvidos e os dois tipos de ressoadores foram fabricados e caracterizados para validação experimental dos modelos. O ressoador com melhor desempenho em termos de frequência de ressonância, fator de qualidade e mecanismo interno de TPA foi usado para projetar duas versões de um acelerómetro FM diferencial, que incluem um sistema de alavancas. Estes acelerómetros diferem na forma como a força amplificada é transmitida aos ressoadores e o seu desempenho foi simulado usando a análise de elementos finitos. Foram fabricados e caracterizados em termos de sensibilidade e linearidade, na faixa de aceleração compreendida entre -1 g a 1 g, usando um teste estático de inclinação controlado por circuito fechado. Apesar das várias fontes de erro identificadas, os modelos para o SMR ajustam-se bem aos resultados experimentais. Contudo, estes erros não permitiram confirmar se o DMR se comporta de acordo com o modelo desenvolvido. O mecanismo de TPA foi somente verificado em ressoadores com uma viga piezoresistiva de dimensões específicas, indicando que este mecanismo é bastante sensível a variações da estrutura e das suas condições ambientais. O DMR apresentou melhor desempenho em vácuo do que o SMR, alcançando frequências de ressonância, fatores de qualidade e amplificações superiores. Assim, o projeto das duas versões do acelerómetro basearam-se no DMR. Na primeira versão, cada DMR demonstrou uma sensibilidade inferior a 1 Hz/g, enquanto que os DMRs da segunda versão são mais sensíveis (~30 Hz/g) e têm melhor linearidade. No entanto, nenhum destes DMRs apresentou mecanismo de TPA, quando colocados em conjunto com os restantes elementos do acelerómetro, mostrando a sensibilidade do mecanismo a variações estruturais e ambientais. A presença do mecanismo aumentaria o fator de qualidade dos DMRs, melhorando o desempenho global do acelerómetro. Portanto, esta é uma tecnologia promissora, que deve continuar a ser estudada para alcançar acelerómetros com desempenho elevado, atendendo aos requisitos de grau de navegação., Research on MEMS accelerometers is constantly seeking for better performance to fit the demanding requirements of navigation grade applications. Frequency-modulated MEMS accelerometers are a suitable approach to meet this objective. They are based on a resonator that changes the resonance frequency with external acceleration. High quality-factors are key to the performance of these resonant sensors improving the immunity to noise, long-term stability, resolution and dynamic range. Recently, in the literature, resonators based on a piezoresistive beam that present a novel mechanism – the internal thermal-piezoresistive amplification (TPA) – demonstrated Q-factors above one million. Therefore, in this thesis, the development of a FM MEMS accelerometer based on this novel mechanism is proposed, aiming to achieve enhanced performance using the benefits of a high Q-factor. The internal TPA mechanism was characterised using electrostatic actuated resonators with single (SMR) or double-mass (DMR). Analytical and lumped-models were developed and the two type of resonators were fabricated and characterised for experimental validation of the models. The resonator with the best performance, in terms of resonance frequency, Q-factor and internal TPA mechanism, was used to design two versions of a differential FM accelerometer, which includes a leverage system. They differ in the way the amplified force is transmitted to the resonator and their performance was simulated using finite element analysis. These accelerometers were fabricated and characterised in terms of sensitivity and linearity in a -1 g to 1 g acceleration range using a closed-loop controlled-tilt static test. Despite the several sources of errors identified, the models for the SMR fit quite well the experimental results. However, these errors did not allow to confirm whether the DMR behaves according to the model developed. The TPA mechanism was only present in resonators with a specific piezoresistive beam, indicating that this mechanism is very sensitive to variations of the structure or its environmental conditions. The DMR performed better than the SMR, achieving higher resonance frequency, higher Q-factor, and higher amplification in vacuum. Thus, the accelerometer designs were based on the DMR. Each DMR in the first accelerometer design had an experimental sensitivity inferior to 1 Hz/g, while the DMRs in the second design are more sensitive (~30 Hz/g) and have a better linearity. However, none of these DMRs presented the internal TPA mechanism, when placed together with the other elements of the accelerometer, confirming the mechanism sensitivity to structural and environmental variations. The presence of the TPA mechanism would enhance the Q-factor of the DMRs, improving the accelerometer’s overall performance. Therefore, this is a promising technology, and it is important to continue to study it to achieve even higher performance accelerometers to fulfil the requirements of navigation grade., Fundação para a Ciência e a Tecnologia (FCT)

Tese de doutoramento em Tecnologias e Sistemas de Informação, Os seres Humanos confiam em padrões de linguagem não verbal, como posturas, gestos ou movimentos, para aferir a qualidade da interação em contexto de interação social. Essa capacidade de interpretar e de responder a esses sinais sociais é inata. Esses sinais sociais também estão presentes em outros contextos, como contextos de interação Homem-Máquina ou Homem-Computador. Porém, nesses contextos, essa modalidade de comunicação é ignorada pelos dispositivos durante a interação. A nossa dependência diária de computadores, máquinas e outros dispositivos enfatiza a necessidade de interações de qualidade. A tecnologia mais recente disponibilizou no mercado uma nova geração de sensores não invasivos e acessíveis, como câmaras 3D ou sensores de movimento, possibilitando que os dispositivos possam detectar sinais subtis do comportamento humano, durante interação com o computador. Neste trabalho de doutoramento propomos um Support Vector Machine capaz de classificar a dificuldade da tarefa sentida por um utilizador, durante uma interação com um tablet, usando métricas extraídas do movimento do corpo, mãos e do dispositivo. Este trabalho é uma contribuição para o domínio de Interação Homem-Computador, explorando sinais sociais gravados por sensores não invasivos, para entender o contexto e propor um modelo que, combinando movimento do corpo, gestos e informação do dispositivo, classifica a dificuldade da tarefa sentida pelos utilizadores., Humans unconsciously rely on patterns of non-verbal language, such as posture, gestures and body motion, to infer the effectiveness of the communication in their social interactions. As humans we have an innate ability to recognize and respond to that social signaling. Social signaling is also present in other contexts, such as Human Machine Interaction lih II and Human Computer Interaction (Ha though for the most part it is a communication modality ignored during the interaction. Our daily dependence on computerized systems emphasizes the need and importance of good inter-action quality. Recent technological developments brought to the market a new generation of non-evasive low-cost sensors, such as 3D cameras and motion sensors, enabling computers to read subtle aspects and cues of the human behavior, in a IHCI interaction. In this thesis we propose a Support Vector Machine model that infers the level of task difficulty of a user while interacting with a tablet using features extracted from body motion, hands' motion and other interaction metrics. This is a contribution to Human-Computer Interaction field by exploring social signals, extracted using commercial sensors, to describe and understand the context and proposing a model that's combines motion's, gestures' features and device's log-file information to infer users task difficulty.

Tese de Doutoramento em Tecnologias e Sistemas de Informação

Facial expressions are of utmost importance in social interactions, allowing communicative prompts for a speaking turn and feedback. Nevertheless, not all have the ability to express themselves socially and emotionally in verbal and non-verbal communication. In particular, individuals with Autism Spectrum Disorder (ASD) are characterized by impairments in social communication, repetitive patterns of behaviour, and restricted activities or interests. In the literature, the use of robotic tools is reported to promote social interaction with children with ASD. The main goal of this work is to develop a system capable of automatic detecting emotions through facial expressions and interfacing them with a robotic platform (Zeno R50 Robokind® robotic platform, named ZECA) in order to allow social interaction with children with ASD. ZECA was used as a mediator in social communication activities. The experimental setup and methodology for a real-time facial expression (happiness, sadness, anger, surprise, fear, and neutral) recognition system was based on the Intel® RealSense™ 3D sensor and on facial features extraction and multiclass Support Vector Machine classifier. The results obtained allowed to infer that the proposed system is adequate in support sessions with children with ASD, giving a strong indication that it may be used in fostering emotion recognition and imitation skills., Centro Algoritmi & CIEd. CT—Fundação para a Ciência e Tecnologia within the R&D Units Project Scope: UIDB/00319/2020. Vinicius Silva thanks FCT for the PhD scholarship SFRH/BD/SFRH/BD/133314/2017.

The static stability of hexapods motivates their design for tasks in which stable locomotion is required, such as navigation across complex environments. This task is of high interest due to the possibility of replacing human beings in exploration, surveillance and rescue missions. For this application, the control system must adapt the actuation of the limbs according to their surroundings to ensure that the hexapod does not tumble during locomotion. The most traditional approach considers their limbs as robotic manipulators and relies on mechanical models to actuate them. However, the increasing interest in model-free models for the control of these systems has led to the design of novel solutions. Through a systematic literature review, this paper intends to overview the trends in this field of research and determine in which stage the design of autonomous and adaptable controllers for hexapods is., The first author received funding through a doctoral scholarship from the Portuguese Foundation for Science and Technology (FCT) (Grant No. SFRH/BD/145818/2019), with funds from the Portuguese Ministry of Science, Technology and Higher Education and the European Social Fund through the Programa Operacional Regional Norte. This work has been supported by the FCT national funds, under the national support to R&D units grant, through the reference project UIDB/04436/2020 and UIDP/04436/2020.

Malaria diagnosis relies on optical microscopy and/or rapid diagnostic tests based on detecting specific malaria antigens. The clinical sensitivity of these methods is highly dependent on parasite density, with low levels of detection at low parasite density, challenging the worldwide malaria elimination efforts. Therefore, there is a need for diagnostic methods with higher sensitivity, demanding innovative diagnostics devices able to detect malaria at low parasite density and at early stages of the disease. We propose an innovative optical device for malaria diagnosis, based on optical reflectance spectrophotometry, for the detection of parasites through the quantification of haemozoin. For this purpose, a set of eight thin-film optical filters, based on multilayer stacks of MgO/TiO2 and SiO2/TiO2 thin-films, with high transmittance and low full width at half maximum (FWHM) at specific wavelengths, was designed and fully characterized (both numerically and experimentally). A preliminary assessment of its potential to reconstruct the original spectra of red blood cells was performed, both in uninfected and Plasmodium falciparum-infected samples. The obtained results show that, although the experimental filters have a non-ideal performance characteristic, they allow us to distinguish, based on only 8 discrete points in the optical spectrum, between healthy and malaria infected samples, up to a detection limit of 12 parasites/μL of red blood cells. Those results enhance the potential of using such a device for malaria diagnostics, aiming for non-invasiveness., Project NORTE-01-0145-FEDER-028178 funded by NORTE 2020 Portugal Regional Operational Program under PORTUGAL 2020 Partnership Agreement through the European Regional Development Fund and the Fundação para a Ciência e Tecnologia (FCT), IP. This work was also supported by national funds, through the Portuguese FCT, under the reference projects UIDB/04436/2020, UIDP/04436/2020, UIDB/50026/2020 and UIDP/50026/2020, and by the ICVS Scientific Microscopy Platform, member of the national infrastructure PPBIPortuguese Platform of Bioimaging (PPBI-POCI-01-0145-FEDER-022122). V. Baptista thanks FCT for the SFRH/BD/145427/2019 grant. Maria Isabel Veiga thanks FCT for her contract funding provided through 2020.03113.CEECIND. Susana Catarino thanks FCT for her contract funding provided through 2020.00215.CEECIND

Programa doutoral em Engenharia Biomédica, A cápsula endoscópica é um dispositivo médico que tem como como principal vantagem a possibilidade de visualizar todo o trato gastrointestinal. Este exame não invasivo é especialmente usado e vantajoso para o diagnóstico de patologias do intestino delgado, já que a endoscopia convencional é um exame invasivo que não possibilita a visualização deste órgão. Para analisar os exames de cápsula endoscópica o pessoal médico necessita de treino especializado, tendo sido provado que a quantidade massiva de imagens de cada exame pode levar à existência de erros médicos e uma propensão a que exista um subdiagnóstico de algumas patologias. Esta tese teve como objetivo o desenvolvimento de sistemas de deteção automática de diferentes tipos de lesões presentes no intestino delgado. Estes métodos envolveram o uso de algoritmos de segmentação baseados em métodos probabilísticos (nomeadamente o Expectation- Maximization), com a apresentação de um método de aceleração da convergência do algoritmo e do desenvolvimento de um novo método para melhorar as fronteiras de segmentação, baseado em Campos Aleatórios de Markov. Além disso, foram estudadas diferentes metodologias de classificação supervisionada, desde classificadores mais simples e classificadores ensemble para deteção de lesões individuais, e redes neuronais convolucionais e segmentação de instâncias para deteção e segmentação de multi-patologias. Com o apoio do Hospital de Braga, foi efetuado um estudo clínico com o método desenvolvido para deteção automática de angioectasias. Este trabalho teve como principal objetivo comparar a eficiência e performance deste método com a performance de diferentes médicos a analisar exames de cápsula endoscópica. Os diferentes métodos desenvolvidos demonstraram resultados superiores aos encontrados na bibliografia mais recente. É importante referir que o trabalho desenvolvido nesta tese permitiu uma melhor análise à necessidade de uma maior implantação de métodos de deteção de lesões em sistemas de cápsula endoscópica, tal como a necessidade de maiores e melhores estudos clínicos, tal como a disponibilização de melhores bases de dados públicas., The wireless capsule endoscopy is a medical device with the main advantage of being able to visualize the whole gastrointestinal tract. This non-invasive exam is specially used for the diagnosis of small bowel pathologies, since the conventional endoscopy is not able to visualize this organ. To analyze these exams the medical staff need specialized training and it was recently proven that the massive quantity of images that are generated lead to medical errors and consequently the sub diagnosis of certain pathologies. In this thesis the main objective was to develop systems for automatic detection of different lesions present in the small bowel. These developments included the use of segmentation algorithms based on probabilistic methods (namely the Expectation-Maximization), with the presentation of an acceleration method and a new approach for improving the borders of the segmentation based on Markov Random Fields. Beyond that, several supervised classification strategies were studied, with the use of single-based classifiers and ensemble-based classifiers for detection of single lesions and convolutional neural networks, and instance segmentation for multipathology detection and segmentation. With the support of Hospital of Braga, a clinical studied was performed with the developed method for angioectasia detection. This work had the main purpose of comparing the efficiency and performance of the method with the performance of different physicians when analyzing wireless capsule endoscopy exams. The developed methods were tested in different applications and it was found that the performance was improved when compared to the most recent bibliography. It is important to state that all this work allowed to conclude that these systems need to have a greater implantation in the clinical practice. While there is a lot of advances in computer vision methods for lesion detection, there are still lacking better clinical studies and better and bigger public databases to improve the testing of the methodologies., The author was funded by the grant SFRH/BD/92143/2013 from the Portuguese Foundation for Science and Technology (FCT), with funds from the European Social Fund (FSE), under the Human Capital Operational Programme (POCH) from Portugal 2020 Programme.

Doctoral Program in Informatics, Desde o início dos tempos, tudo temos feito para melhorar a nossa qualidade de vida. A nossa caminhada tem sido incrível, mas está longe de ter terminado. Infelizmente, um problema em destaque na nossa sociedade prende-se com os acidentes rodoviários, a principal causa de morte de crianças e jovens adultos. Na estrada existem grupos de pessoas mais vulneráveis que outros, sendo estes descritos como Utilizadores Vulneráveis da Estrada (UVE). Na sua essência, este grupo caracteriza-se por pedestres, ciclistas e motociclistas. Estima-se que, actualmente, mais de metade dos mortos na estrada sejam UVE. Estes números são consequência de políticas que prioritizam veículos em vez de pessoas. Reduzir acidentes entre UVE permanece um desafio. Nenhuma solução monolítica conseguirá resolver todos os problemas. Pelo contrário, a expectativa é que serão várias pequenas contribuições a fazer a diferença. Desta forma, a nossa contribuição é baseada na percepção de pessoas como actores activos e proactivos de uma cidade inteligente. Desta premissa surge o 3-C, o qual se foca em sensorizar a Cidade, a Comunidade e o Cidadão. O 3-C, que define as directrizes e objectivos deste trabalho, quando complementado com a metodologia de investigação adoptada, permitiu a organização de uma sequência lógica de procedimentos replicáveis, precisos e parcimoniosos para a concepção de conhecimento científico. Esta tese de doutoramento apresenta, entre outros, um arquétipo, SafeCity, que agrega várias soluções que tiveram origem no processo de investigação realizado. Este arquétipo apresenta métodos e modelos disruptivos para inferência de aborrecimento e personalidade, para concepção de mapas de sentimentos e para previsão do fluxo de tráfego rodoviário, entre outros. O objectivo é o de permitir que as pessoas sejam actores participativos e que, assim, tenham acesso a um conjunto de informação sobre o estado actual e futuro do ambiente onde estão inseridas, permitindo que os UVE adaptem o seu comportamento perante cada situação, hora e local de uma cidade. Arquétipos adicionais incluem uma blockchain sobre um sistema multi-agente para gestão de grandes quantidades de dados estruturados., Since the dawn of times, the human being has always endeavored to improve his quality of life. Our journey has been amazing but it has not yet finished. Unfortunately, an issue that has been rising to prominence is related to road traffic accidents, the leading cause of death for children and young adults. On the road, there are groups of people more vulnerable than others to injuries and accidents. Those are known as Vulnerable Road Users (VRUs), being defined as pedestrians, cyclists, and motorcyclists. It is estimated that, currently, more than half of all road traffic deaths are amongst VRUs. These numbers are a consequence of policies that prioritize vehicles instead of people. Reduce injuries among VRUs remains a big challenge. No monolithic solution will, singularly, settle out all problems. Instead, the expectation is that multiple small contributions may help answering important challenges raised by this group of road users. Hence, our contribution is grounded on the perception of people as active, reactive, and proactive actors of a Smart City’s ecosystem. From this premise emerges the 3-C, i.e., City, Crowd, and Citizen sensing. The 3-C, which defines the guidelines and goals of this work, when complemented with the adopted research methodology, allowed the organization of a logical sequence of replicable, precise, and parsimonious procedures to build scientific knowledge. This thesis presents, among others, an archetype platform, SafeCity, which aggregates multiple solution specimens produced as a result of the conducted research. SafeCity makes use of multiple disruptive methods and models for on-device boredom inference, to assess one’s personality, to conceive emotional maps, and to provide accurate multi-step traffic flow forecasts, among many others. The goal is to allow people to be participative actors, thus having access to a set of information about the current and future status of the environment where they stand, allowing VRUs to adapt their behavior upon each situation, hour, and place of a city. Additional archetypes include a multi-agent system blockchain for the management of large amounts of data of different types and sources., Fundação para a Ciência e a Tecnologia (FCT)

Tese de doutoramento em Informática, Os robôs são agora parte do nosso quotidiano e a sua utilidade parece não ter limites. Fabricam os nossos bens, colhem alimentos de plantações e conduzem-nos de um lugar para o outro. A inovação na área da robótica é uma constante, as expectativas são altas, e as responsabilidades que depositamos nos robôs são cada vez maiores; os robôs são a nova definição de sistema crítico. Em parte, este sucesso deve-se à abundância de frameworks livres para o desenvolvimento de sistemas robóticos, como é o caso do Robot Operating System (ROS). A comunidade ROS é numerosa e bastante ativa. O ROS tem sido usado principalmente ao nível da investigação, mas, ultimamente, tem sido a base para vários projetos comerciais ou governamentais. Sendo um ecossistema de componentes de software reutilizáveis, suportado por uma comunidade muito diversa, garantir que sistemas baseados em ROS são confiáveis é da maior importância. No entanto, mostrar que um software robótico é confiável não é, de todo, uma tarefa fácil. Várias técnicas, como a Verificação Formal, Model Checking, Verificação Runtime, entre outras, têm dado inúmeras provas da sua aptidão e eficácia para verificar uma variedade de propriedades críticas, noutros domínios de software. Contudo, se há algo que todos estes métodos têm em comum, é a sua complexidade. É necessária uma formação especializada para uma aplicação eficaz, e a maioria da comunidade ROS não tem tais conhecimentos. Nesta tese, respondemos à questão de como adaptar o estado da arte em técnicas de garantia de qualidade para aplicações ROS, e como torná-las acessíveis a não especialistas. Temos em conta o facto de que a maioria dos sistemas são desenvolvidos em torno do código-fonte, em vez de seguirem práticas de Engenharia à base de modelos. Propomos um fluxo de trabalho unificado que, dado o código-fonte de uma aplicação ROS, extrai modelos automaticamente e, de seguida, aplica uma série de técnicas de verificação, estáticas e dinâmicas, relativamente a propriedades do sistema especificadas pelo utilizador. No caso de as análises detetarem uma violação de propriedades, os resultados podem ser utilizados como guias para a resolução de problemas. Caso contrário, os resultados constituem evidência da confiabilidade do sistema, respetivamente às propriedades, que pode ser usada para construção de um argumento de confiabilidade. Este fluxo de trabalho é implementado na plataforma HAROS, e avaliado com dois estudos de caso em robôs reais. O resultado revelou-se eficaz, quer na construção automática de modelos, quer na deteção de falhas, relativamente a propriedades especificadas pelo utilizador. De um modo geral, esta abordagem foi bem recebida pela comunidade ROS. Vários membros já a usam de forma independente, e estão até a propôr as suas próprias extensões., Robots are now part of our daily lives and their usefulness is, seemingly, never-ending. They manufacture our goods, harvest our crops and drive us from place to place. Innovation in the field of robotics is constant, expectations are high, and the responsibilities we place on robots are ever increasing; robots are the new definition of safety-critical devices. In part, this success is due to the abundance of open source frameworks to help develop robotic systems, such as the Robot Operating System (ROS). ROS has a large and active community. It was mostly used in research, but is recently finding its way into commercial and government projects as well. With such a diverse community, and being based on an ecosystem of reusable software components, ensuring that ROS-based systems are dependable is paramount. However, showing that robotic software is dependable is not an easy task. Many techniques, such as Formal Verification, Model Checking, Runtime Verification, and more, have proved, over and over, to be capable of verifying a diverse range of properties in other software domains. However, if there is one characteristic that often defines these techniques, it is their steep learning curve. They have a hard requirement on expert knowledge, and the vast majority of the ROS community is composed of non-experts. In this thesis, we answer the research question of how to adapt state-of-the-art quality assurance techniques to ROS applications, and how to make them usable by non-experts. We take into consideration the fact that most systems are developed with a code-first approach, rather than following Model-driven Engineering practices. We propose a unified workflow that takes in ROS application code, automatically extracts system models from it, and then applies a variety of static and dynamic analysis techniques with respect to user-specified properties. If a property violation is detected, the results of the analyses can be used as a debugging aid. Otherwise, they provide compelling evidence to structure a dependability case for the given properties. This workflow is implemented in the HAROS framework, and later evaluated with two robot case studies. We have found this approach to be effective, both at building models and at finding faults for user-specified properties. Overall, it has been well-received in the ROS community. Several members are now independently using it, as well as proposing their own extensions., This work is financed by the ERDF – European Regional Development Fund through the Operational Programme for Competitiveness and Internationalisation - COMPETE 2020 Programme and by National Funds through the Portuguese funding agency, FCT - Fundação para a Ciência e a Tecnologia within project PTDC/CCI-INF/29583/2017(POCI-01-0145-FEDER-029583) and the PhD grant SFRH/BD/124836/2016.

The use of robots had already been proven to encourage the promotion of social interaction and skills lacking in children with Autism Spectrum Disorders (ASD), who typically have difficulties in recognizing facial expressions and emotions. The main goal of this research is to study the influence of a humanoid robot to develop socio-emotional skills in children with ASD. The children’s performance in game scenarios aiming to develop facial expressions recognition skills is presented. Along the sessions, children who performed the game scenarios with the robot and the experimenter had a significantly better performance than the children who performed the game scenarios without the robot. The main conclusions of this research support that a humanoid robot is a useful tool to develop socio-emotional skills in the intervention of children with ASD, due to the engagement and positive learning outcome observed., CIEd & Algoritmi

The experimental validation of a novel operation mode for electric vehicles (EVs) to support the grid power quality is presented. The proposed operation mode, denominated improved vehicle-for-grid (iV4G), is directly associated with the EVs operation aiming the compensation of power quality problems associated with current harmonic distortion and reactive power, improving the total power factor of the electrical installation. Simultaneously with the proposed iV4G, where the EV injects current harmonics and provides reactive power, the EV can exchange active power with the grid (grid-to-vehicle, G2V, to charge the batteries or vehicle-to-grid, V2G, to deliver energy back to the power grid). In this paper, the proposed iV4G operation mode is experimentally validated with a developed EV battery charger prototype connected to an electrical installation of 230 V, 16 A, 50 Hz. The control strategies of the iV4G operation mode and the used prototype are described in detail along the paper. The achieved results confirm the feasibility and good performance of the proposed iV4G operation mode, working alone, and also when associated with the G2V and V2G operating modes., This work has been supported by FCT project 0302836 NORTE-01-0145-FEDER-030283. This work is also part of the COMPETE: POCI-01-0145-FEDER-007043 and FCT within the Project Scope: UID/CEC/00319/2013. This work isfinanced by the ERDF–European RegionalDevelopment Fund through the Operational Programme forCompetitiveness and Internationalisation–COMPETE 2020Programme, and by National Funds through the Portuguese fundingagency, FCT, within project SAICTPAC/0004/2015–POCI–01–0145–FEDER–016434.

Use error is one of the leading causes of medical device incidents. It is crucial for all stakeholders to have a unified means to better understand, classify, communicate, and prevent/avoid medical device use errors. In this paper, we present our ongoing work on developing a new use error taxonomy for medical devices that has the potential to enable fine-grained analysis of use errors and their root causes in system design. Our ultimate goal is to create a generic framework that can be used by medical device designers to better identify effective design solutions to mitigating use errors., Paolo Masci is funded by the ERDF (European Regional De-velopment Fund) through the Operational Programme for Compet-itiveness and Internationalisation – COMPETE 2020 Programmewithin the project POCI-01-0145-FEDER-006961, and by NationalFunds through the Portuguese funding agency FCT (Fundação paraa Ciência e a Tecnologia) as part of project UID/EEA/50014/2013. José C. Campos is funded by project NanoSTIMA: Macro-to-NanoHuman Sensing: Towards Integrated Multimodal Health Monitor-ing and Analytics/NORTE-01-0145-FEDER-000016, financed bythe North Portugal Regional Operational Programme NORTE 2020,under the PORTUGAL 2020 Partnership Agreement, and through the European Regional Development Fund (ERDF).

The paper describes templates for model-based analysis of usability and safety aspects of user interface software design. The templates crystallize general usability principles commonly addressed in user-centred safety requirements, such as the ability to undo user actions, the visibility of operational modes, and the predictability of user interface behavior. These requirements have standard forms across different application domains, and can be instantiated as properties of specific devices. The modeling and analysis process is carried out using the Prototype Verification System (PVS), and is further facilitated by structuring the specification of the device using a format that is designed to be generic across interactive systems. A concrete case study based on a commercial infusion pump is used to illustrate the approach. A detailed presentation of the automated verification process using PVS shows how failed proof attempts provide precise information about problematic user interface software features., This work has been funded by the EPSRC research grant EP/G059063/1: CHI+ MED (Computer-Human Interaction for Medical Devices). We are grateful to Harold Thimbleby's team at Swansea University, part of the CHI+ MED project, and especially Patrick Oladimeji who developed the infusion pump simulation that helped us develop the models. We also thank the anonymous reviewers for valuable feedback. Jose C. Campos and Paolo Masci were funded by project NORTE-01-0145-FEDER-000016, financed by the North Portugal Regional Operational Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, and through the European Regional Development Fund (ERDF).

Context-free languages are highly important in computer language processing technology as well as in formal language theory. The Pumping Lemma for Context-Free Languages states a property that is valid for all context-free languages, which makes it a tool for showing the existence of non-context-free languages. This paper presents a formalization, extending the previously formalized Lemma, of the fact that several well-known languages are not context-free. Moreover, we build on those results to construct a formal proof of the well-known property that context-free languages are not closed under intersection. All the formalization has been mechanized in the Coq proof assistant., (undefined)

Nowadays, society is in constant evolution, which allows constant production of new knowledge. In this way, citizens are constantly pressured to obtain new qualifications through training/requalification. The need for qualified people has been growing exponentially, which means that resources for education/training are limited to being used more efficiently. In this paper we will focus in the design the user model, so, we propose an innovative approach to design a user model that monitors the user's biometric behaviour by measuring their level of attention during e-learning activities. In addition, a machine learning catego-rization model is presented that oversees user activity during the session. We intend to use non-invasive methods of intelligent tutoring systems, observing the interaction of users during the session. Furthermore, this article highlights the main biometric behavioural variations for each activity and bases the set of attributes relevant to the development of machine learning classifiers to predict users' learning preference. The results show that there are still mechanisms that can be explored and improved to better understand the complex relationship between human behaviour, attention and evaluation that could be used to implement better learning strategies. These results can be decisive in improving ITS in e-learning environments and to predict user behaviour based on their interaction with technology devices., This work has been supported by FCT - Fundacao para a Ciencia e Tecnologia within the Project Scope: UID/CEC/00319/2019.

In this work, we propose an argumentation-based dialogue model designed for Web-based Group Decision Support Systems, that considers the decision-makers' intentions. The intentions are modeled as behavior styles which allow agents to interact with each other as humans would in face-to-face meetings. In addition, we propose a set of arguments that can be used by the agents to perform and evaluate requests, while considering the agents' behavior style. The inclusion of decision-makers' intentions intends to create a more reliable and realistic process. Our model proved, in different contexts, that higher levels of consensus and satisfaction are achieved when using agents modeled with behavior styles compared to agents without any features to represent the decision-makers' intentions., (undefined)

Research collaboration between industry and academia supports improvement and innovation in industry and helps ensure the industrial relevance of academic research. However, many researchers and practitioners in the community believe that the level of joint industry-academia collaboration (IAC) projects in Software Engineering (SE) research is relatively low, creating a barrier between research and practice. The goal of the empirical study reported in this paper is to explore and characterize the state of IAC with respect to industrial needs, developed solutions, impacts of the projects and also a set of challenges, patterns and anti-patterns identified by a recent Systematic Literature Review (SLR) study. To address the above goal, we conducted an opinion survey among researchers and practitioners with respect to their experience in IAC. Our dataset includes 101 data points from IAC projects conducted in 21 different countries. Our findings include: (1) the most popular topics of the IAC projects, in the dataset, are: software testing, quality, process, and project managements; (2) over 90% of IAC projects result in at least one publication; (3) almost 50% of IACs are initiated by industry, busting the myth that industry tends to avoid IACs; and (4) 61% of the IAC projects report having a positive impact on their industrial context, while 31% report no noticeable impacts or were “not sure”. To improve this situation, we present evidence-based recommendations to increase the success of IAC projects, such as the importance of testing pilot solutions before using them in industry. This study aims to contribute to the body of evidence in the area of IAC, and benefit researchers and practitioners. Using the data and evidence presented in this paper, they can conduct more successful IAC projects in SE by being aware of the challenges and how to overcome them, by applying best practices (patterns), and by preventing anti-patterns., The authors would like to thank the researchers and practitioners who participated in this survey. João M. Fernandes was supported by FCT (Fundação para a Ciência e Tecnologia) within the Project Scope UID/CEC/00319/2013. Dietmar Pfahl was supported by the institutional research grant IUT20-55 of the Estonian Research Council. Andrea Arcuri was supported by the Research Council of Norway (grant agreement No 274385). Mika Mäntylä was partially supported by Academy of Finland grant and ITEA3 / TEKES grant.

FastGraph is a novel positioning approach recently proposed to address the challenges of positioning in large spaces. Wi-Fi-based indoor positioning solutions often require complex and time-consuming deployments. Fingerprinting, as one of most used approaches, relies on a radio map, usually created by manual site survey, a process unpractical even for small spaces. Moreover, the site survey has to be repeated frequently due to the changes in the radio environment. Wi-Fi-based solutions are also frequently discarded for applications such as indoor vehicle navigation due to limited accuracy. This article introduces FastGraph Enhanced, a new version of FastGraph, able to provide high accuracy positioning, opening new fields of application, such as navigation for autonomous vehicles. In FastGraph Enhanced, the 3D Force-Directed Graph-Based method, used to model the radio environment, is extended with new algorithms, allowing to improve, among other aspects, the positioning performance. The core advantages of FastGraph are maintained, not requiring previous calibration or knowledge about the space. The proposed solution was evaluated in real world, with very significative improvements in positioning accuracy when compared with the basic version of FastGraph (from around 5m to 0.5m), and with state-of-the-art solutions., This work has been supported by FCT – Fundação para a Ciência e Tecnologia within the R&D Units Project Scope: UIDB/00319/2020 and the PhD fellowship PD/BD/105865/ 2014.

Thin-films based photodiodes are an advantageous alternative to the photodetectors based on semiconductor doping processes, especially in optical sensors implemented on non-semiconductor substrates. This is the first report of a p-i-n junction photodiode, based on n-SnOx/p-SnOx and amorphous silicon (a-Si) thin-films, fabricated in a polymeric, flexible and photosensitive substrate, only considering different annealing conditions and thicknesses of evaporated metallic Sn and sputtered a-Si. Seebeck coefficient measurements were performed, using a custom-built setup, to assess the implementation of n- and p-type thin-films. The obtained Seebeck coefficients were −167 µV/K and +266 µV/K for the n-SnOx and p-SnOx, respectively. X–ray diffraction (XRD) analysis also confirmed the deposition of an a-Si thin-film as the intrinsic layer of the p-i-n junction. The photodiode responsivity and response times were measured, using a custom-built optical setup for the visible spectral region. The measured responsivity (at 0 V reverse bias) was 2.8 µA/W at 572 nm and the rise and fall times were 0.203 s and 0.312 s, respectively. The developed photodiode provides a promising solution for high level light detection applications in flexible optical sensors., This work is supported by FCT: OpticalBrain PTDC/CTMREF/28406/2017 operation code NORTE-01-0145-FEDER- 028406; OCT-RAMAN, PTDC/FIS- OTI/28296/2017 operation code NORTE01-0145-FEDER-028296; CMEMS-UMinho strategic project UIDB/04436/2020; project of Infrastructures Micro&NanoFabs@PT NORTE- 01-0145-FEDER-022090, PORNorte, Portugal 2020 by FEDER funds through the COMPETE 2020 Programa Operacional Competitividade e Internacionalização (POCI).

The concept of high electrocatalytic activity for chlorine generation has been pioneered through the develop-ment of a new system to prevent biofouling onto marine optical sensors surfaces. A combination of impregnatedplatinum (Pt) nanoparticles into the surface offluorine tin oxide (FTO) was developed to create high opticaltransparent electrodes in glass substrates, with high catalytic properties, high durability, high stability and costeffectiveness, capable of generating sufficient biocide concentration (chlorine) with low electrical current. Whilechlorine generation, based on conventional electrodes with noble metal oxides, have been widely used forbiofouling prevention, their difficulty of integration and their opacity makes them inappropriate for opticalsensors protection. In the other hand, state-of-the-art FTO and ITO transparentfilms suffer from poor stabilityand durability in chlorine generation. This study highlights the effectiveness of creating simultaneous highoptical transparent and high electrical conductivity electrodes, suitable for long-term electrochlorination andthus long-term monitoring in marine optoelectronic devices. Furthermore, their fabrication relies in an easy andlow-cost process. The combination of specific Pt concentrations with FTO has been successfully proven forantifouling effect under seawater, exhibiting low consumption (100–350 μW/cm2), high catalytic activity withhigh binding stability of Pt nanoparticles against seawater properties. This new approach accelerates the searchfor high-performance antibiofouling strategies for marine optical sensors, This work was co-financed by Programa Operacional Regional do Norte (NORTE2020), through Fundo Europeu de Desenvolvimento Regional (FEDER), Project NORTE-01-0145-FEDER-000032 – NextSea, and by the European Regional Development Fund (ERDF) through the Interreg V-A Spain-Portugal Programme (POCTEP) 2014-2020, Project N. 0591_FOODSENS_1_E, and by Portuguese FCT, under the reference project UIDB/04436/2020 and UIDP/04436/2020.

This work describes the development and evaluation of two smart home-based Internet of Things (IoT) systems applied to HVAC (Heating, Ventilation and Air Conditioning) monitoring and control, including parameters such as temperature, humidity, air quality, smoke detection, and human presence. These systems are based on a flexible hybrid wireless network architecture combining Bluetooth Low Energy (BLE) and IEEE 802.11/Wi-Fi, in order to adapt to the requirements of different types of sensor and actuator devices. The original implemented network is based on Cypress PSoC 4 BLE boards and HyperText Transfer Protocol (HTTP), whereas the new network uses ESP32 boards and includes Message Queue Telemetry Transport (MQTT), a lightweight messaging protocol suitable for IoT devices which provides additional quality of service (QoS) mechanisms to guarantee the delivery of messages. A smart temperature control system was implemented in the BLE/Wi-Fi gateway (Raspberry Pi) to keep the room temperature inside a user-defined range. An online database was also developed using the Amazon Web Services (AWS) cloud platform, allowing the users to access the HVAC data and control the system parameters, through the Internet, using a mobile app developed for Android devices. Experimental tests were performed to validate the functionalities and performance of the developed systems. The obtained results demonstrate that the new network provides lower delay values compared with the original implementation., This work was supported by FCT national funds, under the national support to R&D units grant, through the reference project UIDB/04436/2020 and UIDP/04436/2020.

The worldwide adoption of mobile devices is raising the value of Mobile Performance Marketing, which is supported by Demand-Side Platforms (DSP) that match mobile users to advertisements. In these markets, monetary compensation only occurs when there is a user conversion. Thus, a key DSP issue is the design of a data-driven model to predict user conversion. To handle this nontrivial task, we propose a novel Multi-objective Optimization (MO) approach to evolve Decision Trees (DT) using a Grammatical Evolution (GE), under two main variants: a pure GE method (MGEDT) and a GE with Lamarckian Evolution (MGEDTL). Both variants evolve variable-length DTs and perform a simultaneous optimization of the predictive performance and model complexity. To handle big data, the GE methods include a training sampling and parallelism evaluation mechanism. The algorithms were applied to a recent database with around 6 million records from a real-world DSP. Using a realistic Rolling Window (RW) validation, the two GE variants were compared with a standard DT algorithm (CART), a Random Forest and a state-of-the-art Deep Learning (DL) model. Competitive results were obtained by the GE methods, which present affordable training times and very fast predictive response times., This article is a result of the project NORTE-01-0247-FEDER-017497, supported by Norte Portugal Regional Operational Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF). This work was also supported by FCT – Fundação para a Ciência e Tecnologia, Portugal within the Project Scope: UID/CEC/00319/2019. We wish to thank the OLAmobile company for providing the data and domain feedback. We would also like to thank the anonymous reviewers for their helpful suggestions.

We are living a change of paradigm regarding decision-making. On the one hand, there is a growing need to make decisions in group at both professional and personal levels, on the other hand, it is increasingly difficult for decision-makers to meet at the same place and at the same time. The Web-based Group Decision Support Systems intend to overcome this limitation, allowing decision-makers to contribute to the decision process anytime and anywhere. However, they have been defined inadequately which has been compromising its success. This work discusses the current Group Decision Support Systems limitations in terms of challenges and possible impediments for their acceptance by the organizations and propose a conceptual definition of a Web-based Group Decision Support System that intends to overcome the existing limitations and help them to affirm as a reliable and useful tool. In addition, some crucial topics are addressed, such as communication and perception, that are essential and sometimes forgotten in the support of dispersed decision-makers. We concluded that there are still some limitations, mostly in terms of models and applications, that prevent the design of higher quality systems., This work was supported by the GrouPlanner Project (POCI-01-0145-FEDER-29178) and by National Funds through the FCT – Fundação para a Ciência e a Tecnologia (Portuguese Foundation for Science and Technology) within the Projects UIDB/00319/2020 and UIDB/00760/2020.

Dissertação de mestrado integrado em Engenharia e Gestão de Sistemas de Informação, Este trabalho de dissertação ocorreu num momento em que havia sido concluído um estágio profissional de 9 meses de duração. Este estágio foi possivel através do Instituto do Emprego e Formação Profissional (IEFP), tendo contrato com a Aubay mas trabalhando como outsourcing para um cliente XPTO da Oracle. O trabalho correu no Innovation and Technology Center (ITC), em Leça do Balio, Porto. O ITC é considerado uma fábrica de software, isto é, é um conjunto estruturado de ativos relacionados com software que ajuda na produção de aplicações, ou componentes de software, de acordo com requisitos específicos dos clientes. Como abordagem de gestão de projeto, para o cliente XPTO foi usada a abordagem Scrum utilizando metologias do AGILE. O projeto foi estruturado em Program Increments (PIs) divididos em sprints – PIs de 3 meses de duração cada, sendo que cada sprint tinha uma duração de 2 semanas – sendo que em todos os sprints havia sempre uma sessão de esclarecimento daquilo que seria para fazer e depois havia o tempo de desenvolvimento até ao momento da entrega no final do sprint. No final de cada PI, o cliente XPTO fazia, juntamente com a equipa de desenvolvimento, um balanço de todo o PI, identificando quantos bugs foram abertos, o que é que a equipa de desenvolvimento achava que poder-se-ia melhorar na abordagem de desenvolvimento do projeto, quais as dificuldades que estariam a enfrentar, etc. A nível de tecnologia Enterprise Resource Planning (ERP), durante o estágio para o cliente XPTO da Oracle foi usado o Oracle Retail Merchandising System (RMS). Neste produto foram desenvolvidas, ao longo dos sprints, não só algumas costumizações de partes que já existiam, de forma a servir as necessidades do cliente, como também foram criadas um conjunto de APIs de forma a servir novas funcionalidades pretendidas pelo cliente. Este trabalho decorreu especificamente em módulos diferentes, tal como se poderá verificar nas tarefas que são demonstradas ao longo do trabalho de dissertação, tarefas essas que estão descritas e que apresentam nos anexos conteúdo, como por exemplo, algum código desenvolvido e ainda alguns testes efetuados que comprovam o bom funcionamento da funcionalidade imprementada., This dissertation work took place at a time when a 9-month professional internship was concluded. This internship was made possible by the Institute of Employment and Professional Training (IEFP), having a contract with Aubay but working as outsourcing to an XPTO client from Oracle. The work took place at the Innovation and Technology Center (ITC), in Leça do Balio, Porto. ITC is considered to be a software factory wich is a structured set of software-related assets that helps in the production of applications, or software components, according to specific customer requirements. As a project management approach, for the XPTO client, the Scrum approach was used using AGILE methodologies. The project was structured into Program Increments (PIs) divided by sprints - 3 months in duration, each sprint lasting 2 weeks - and in all sprints there was always a session to clarify what it would be done and then there was development time until delivery at the end of the sprint. At the end of each PI, the XPTO client was made a balance of the entire PI, with the development team, identifying how many bugs were opened, what the development team thought could be improved in the development approach of the project, what difficulties they would be facing, etc. In terms of Enterprise Resource Planning (ERP) technology, during the internship for Oracle's XPTO client, the Oracle Retail Merchandising System (RMS) was used. In this product, not only some customizations of parts that already exist to serve the customer's needs were developed, over the sprints, but also a set of new APIs were also created to serve the new features that the customer wanted. This work took place in different modules, as can be seen in the tasks that are demonstrated throughout the dissertation work, tasks that are described and, in the annexes, contain content, such as some developed code and some tests performed that prove the good functioning of the implemented functionality.

Traditional explicit authentication mechanisms, in which the device remains unlocked after the introduction of some kind of password, are slowly being complemented with the so-called implicit or continuous authentication mechanisms. In the latter, the user is constantly monitored in one or more ways, in search for signs of unauthorized access, which may happen if a third party has access to the phone after it has been unlocked. There are some different forms of continuous authentication, some of which based on Machine Learning. These are generally black box models, that provide a decision but not an explanation. In this paper we propose an approach for continuous authentication based on behavioral biometrics, machine learning, and that includes domain-dependent aspects for the user to interpret the actions and decisions of the system. It is non-intrusive, does not require any additional hardware, and can be used continuously to monitor user identity., This work has been supported by national funds through FCT – Fundação para a Ciência e Tecnologia through project UIDB/04728/2020.

Nowadays, the majority of electronic equipment behaves as nonlinear loads, introducing power quality problems into the power grid, namely, current harmonics and low power factor. These problems contribute to reduce the efficiency of the power grid and can cause malfunctioning of sensitive loads connected to the power grid. Therefore, it is important to develop power electronics solutions capable to mitigate these power quality problems. In this context, this paper presents a novel single-phase shunt active power filter (SAPF) based on a current-source converter, where the key differencing factor, when compared with the conventional approach, is the reduced dc-link. As the proposed topology requires a reduced dc-link, it represents a relevant advantage, requiring a less bulky inductance in the dc-link, reducing the losses, cost, and volume. The proposed SAPF with reduced dc-link is introduced in detail along the paper, and a comprehensive comparison with the conventional SAPF is established based on computer simulations. Besides, an experimental validation is carried out with a developed laboratory prototype, validating the main advantages of the proposed SAPF with reduced dc-link., This work has been supported by FCT – Fundação para a Ciência e Tecnologia with-in the Project Scope: UIDB/00319/2020. This work has been supported by the FCT Project newERA4GRIDs PTDC/EEI-EEE/30283/2017 and the FCT Project QUALITY4POWER PTDC/EEI-EEE/28813/2017, and by. Mr. Luis A. M. Barros is supported by the doctoral scholarship PD/BD/143006/2018 granted by the Portuguese FCT foundation.

Indoor positioning systems (IPSs) suffer from a lack of standard evaluation procedures enabling credible com- parisons: this is one of the main challenges hindering their widespread market adoption. Traditionally, accuracy evaluation is based on positioning errors defined as the Euclidean distance between the true positions and the estimated positions. While Euclidean is simple, it ignores obstacles and floor transitions. In this article, we describe procedures that measure a posi- tioning error defined as the length of the pedestrian path that connects the estimated position to the true position. The procedures apply pathfinding on floor maps using visibility graphs (VGs) or navigational meshes (NMs) for vector maps and fast marching (FM) for raster maps. Multifloor and multibuilding paths use the information on vertical in-building communication ways and outdoor paths. The proposed measurement procedures are applied to position estimates provided by the IPSs that participated in the EvAAL-ETRI 2015 competition. Procedures are compared in terms of pedestrian path realism, indoor model complexity, path computation time, and error magnitudes. The VGs algorithm computes shortest distance paths; NMs produce very similar paths with significantly shorter computation time; and FM computes longer, more natural-looking paths at the expense of longer computation time and memory size. The 75th percentile of the measured error differs among the methods from 2.2 to 3.7 m across the evaluation sets., The work of Germán Martín Mendoza-Silva was supported by Universitat Jaume I under Grant PREDOC/2016/55. The work of Joaquín Torres-Sospedra was supported by the Ministerio de Ciencia, Innovación y Universidades (INSIGNIA) under Grant PTQ2018-009981.

Writing style is considered the manner in which an author expresses his thoughts, influenced by language characteristics, period, school, or nation. Often, this writing style can identify the author. One of the most famous examples comes from 1914 in Portuguese literature. With Fernando Pessoa and his heteronyms Alberto Caeiro, alvaro de Campos, and Ricardo Reis, who had completely different writing styles, led people to believe that they were different individuals. Currently, the discussion of authorship identification is more relevant because of the considerable amount of widespread fake news in social media, in which it is hard to identify who authored a text and even a simple quote can impact the public image of an author, especially if these texts or quotes are from politicians. This paper presents a process to analyse the emotion contained in social media messages such as Facebook to identify the author's emotional profile and use it to improve the ability to predict the author of the message. Using preprocessing techniques, lexicon-based approaches, and machine learning, we achieved an authorship identification improvement of approximately 5% in the whole dataset and more than 50% in specific authors when considering the emotional profile on the writing style, thus increasing the ability to identify the author of a text by considering only the author's emotional profile, previously detected from prior texts., FCT has supported this work – Fundação para a Ciência e Tecnologia within the Project Scope: UID/CEC/00319/2019.

Dissertação de mestrado integrado em Engenharia e Gestão de Sistemas de Informação, A evolução tecnológica das últimas décadas possibilitou o acesso à informação de forma instantânea através de dispositivos que fazem parte do nosso quotidiano, tal como o smartphone e o computador. O grande volume de dados gerado diariamente através destes dispositivos constitui uma oportunidade de negócio para as organizações, uma vez que, através da sua exploração, é possível monitorizar o desempenho de uma organização, perspetivar cenários futuros e suportar o processo de tomada de decisão estratégica. Contudo, as soluções de software empresarial, responsáveis pelo armazenamento centralizado dos dados transacionais das organizações, têm vindo a revelar-se insuficiente para o alcance de vantagem competitiva no mercado devido às suas capacidades analíticas limitadas. Neste sentido, as organizações têm vindo a investir em soluções de software analíticas que lhes permitam acrescentar valor às suas atuais soluções de software empresarial e inovar no âmbito da transformação digital. Esta dissertação está enquadrada no âmbito de um estágio realizado na empresa PRIMAVERA - Business Software Solutions que pretende a evolução com funcionalidades analíticas do EyePeak, uma solução de software que permite suportar os principais processos logísticos de uma organização. Desta forma, esta dissertação visa a identificação de objetivos, métricas e indicadores de desempenho de suporte à tomada de decisão em processos de negócio associados a warehouse management (WM). Enquanto caso de demonstração, estes conceitos são prototipados através da conceção de artefactos de natureza analítica (dashboards e reports) com base em dados reais disponíveis no EyePeak, recorrendo a uma tecnologia que enquadra a estratégia tecnológica da PRIMAVERA. A seleção desta tecnologia resulta da experimentação e avaliação das tecnologias Elastic Stack e Power BI. No final, o protótipo desenvolvido é avaliado com base nos requisitos funcionais, nas métricas e nos indicadores de desempenho previamente estabelecidos e através da demonstração dos artefactos aos stakeholders da PRIMAVERA. Os resultados obtidos confirmam que os artefactos produzidos permitem suportar o processo de tomada de decisão em processos de WM associados aos dois perfis de decisão retratados., The technological evolution of the last decades allows instant access to information through devices that are part of our daily lives, such as the smartphone and the computer. The large volume of data generated daily through these devices constitutes a business opportunity for associations, since, through its exploration, it is possible to monitor the performance of an organization, to envision future scenarios and strategic decision-making processes. However, as business software solutions, responsible for the centralized storage of the transactional data of the associations, they have proved to be insufficient to achieve competitive advantage in the market due to their limited analytical characteristics. In this sense, associations have been investing in analytical software solutions that add value to their current business software solutions and innovate in the context of digital transformation. This dissertation is part of an internship carried out at the company PRIMAVERA - Business software solutions that intends to evolve with the analytical functionalities of EyePeak, a software solution that supports the organization's main logistical processes. In this way, this dissertation aims to identify objectives, metrics and performance indicators to support decision making in business processes associated with warehouse management (WM). As a demonstration case, these concepts are prototyped through the design of analytical artifacts (dashboards and reports) based on real data available at EyePeak, using a technology that fits PRIMAVERA's technological strategy. The selection of this technology results from the experimentation and evaluation of the Elastic Stack and Power BI technologies. In the end, the developed prototype is evaluated based on the functional requirements, metrics and performance indicators implemented and through the demonstration of the artifacts to PRIMAVERA's stakeholders. The results obtained were confirmed that these artifacts support the decision-making process in WM processes associated with the two decision profiles portrayed.

Dissertação de mestrado integrado em Engenharia e Gestão de Sistemas de Informação, O crescente aumento do número de pessoas que vivem em ambiente urbano tem acarretado alguns problemas na mobilidade urbana, isto porque o investimento em infraestruturas não tem acompanhado o aumento. A lotação das cidades é uma realidade à qual não se pode ficar indiferente, e diariamente os habitantes e pessoas que frequentam os ambientes urbanos deparam-se com situações que causam incómodo. Na atualidade, um dos principais problemas da mobilidade urbana é o congestionamento do trânsito. Isto deve-se muito ao facto dos cidadãos preferirem o uso de transportes motorizados próprios face aos coletivos, o que acaba por levantar algumas questões ambientais em grande parte das cidades europeias. Um dos principais fatores que contribui para o congestionamento do trânsito é o tempo despendido na procura de um lugar de estacionamento resultante da dificuldade em encontrar lugares disponíveis. Muitos destes problemas podem ser atenuados otimizando o dia-a-dia das cidades. É precisamente este o objetivo das Smart Cities, garantir mais eficiência e eficácia nas atividades citadinas. A otimização dos processos da cidade está, atualmente, dependente da evolução das tecnologias de informação e mais precisamente de áreas como a inteligência artificial, que possam dotar a cidade de ferramentas e mecanismos que lhes confira a versatilidade e inteligência necessária. A principal finalidade desta dissertação de mestrado inside na otimização do processo de busca de um lugar de estacionamento. Através da Inteligência Artificial e exploração de algoritmos de Machine Learning pretende-se fornecer ao cidadão informações que possibilitem a redução do tempo de procura de um lugar para estacionar. Para atingir a finalidade, foram recolhidos dados de diversas plataformas, tratando-os por forma a darem suporte aos modelos de Machine Learning desenvolvidos na fase de modelação. Depois de concluída esta fase, construiu-se uma API Rest que possibilita a utilização dos modelos inteligentes como um serviço. Por fim, foi desenvolvida uma aplicação móvel que representa o protótipo funcional do projeto., The increase in the number of people living in an urban environment has caused some problems in urban mobility, because the investment in infrastructure has not kept pace with the increase. The crowding of cities is a reality to which no one can remain indifferent, and daily the inhabitants and people who frequent urban environments face situations that cause discomfort. Currently, one of the main problems of urban mobility is traffic congestion. This is largely due to the fact that citizens prefer the use of their own vehicles instead of using public services, which ends up raising some environmental issues in most European cities. One of the main factors that contributes to traffic congestion is the time spent looking for a parking lot resulting from the difficulty in finding available parking lot. Many of these problems can be mitigated by optimizing the daily lives in cities. This is precisely the objective of Smart Cities, to ensure more efficiency and effectiveness in city activities. The optimization of city processes is currently dependent on the evolution of information technologies and more precisely on areas such as artificial intelligence, which can provide cities tools and mechanisms that gives them the necessary versatility and intelligence. The main purpose of this master’s dissertation is the optimization of the parking lot searching process. Through Artificial Intelligence and exploration of Machine Learning algorithms, it is intended to provide citizens with information that will enable them to reduce the time spent finding a free parking lot. To achieve the purpose, data were collected from many platforms, treating them in order to support the Machine Learning models developed in the modeling phase. After this phase was completed, an API Rest was built, which allows the use of intelligent models as a service. Finally, a mobile application was developed that represents the project’s functional prototype.

This paper presents a compact low-cost weather station specially dedicated to renewable energy applications based on solar photovoltaic (PV) technologies. The main objective of the weather station is to verify which technology of solar PV modules would be more suitable for the specific location where the weather station is installed. Therefore, the developed weather station includes three technologies of PV modules (polycrystalline, monocrystalline, and amorphous silicon), each one connected to a dedicated DC-DC power converter with a maximum power point control (MPPC) functionality, as well as a set of sensors (solar irradiance, temperature, humidity, wind speed, and wind direction) used to measure the local weather. The acquired data is processed and stored locally in the weather station and, when necessary, the user can download the data to an Android mobile device through a Bluetooth Low Energy (BLE) wireless network connection using the developed mobile app, where the transferred data is stored in a SQLite database and can be visualized in graphs. Throughout the paper, the design of the developed weather station and the associated technologies are described, as well as the details of the mobile app. The developed system comprising the weather station and the mobile app was validated through a set of experimental tests ranging from the data acquisition to its visualization, as well as the achieved wireless data transfer performance., This work was supported by FCT national funds, under the national support to R&D units grant, through the reference project UIDB/04436/2020 and UIDP/04436/2020.

The three-phase induction motor is the main electric motor used in industrial applications, contributing significantly to the industrial electricity consumption. Additionally, the traditional variable speed drivers, due to the internal constitution based on a passive rectifier, contribute to accentuate power quality problems on the grid side. In this context, this paper presents thesimulation, implementation and subsequent experimental verification of an electronic variable speed drive for three-phase induction motors, which is composed by a three-phase ac-dc converter on the grid side and by a three-phase dc-ac converter on the motor side. With the proposed solution, besides driving the motor, it is possible to mitigate power quality problems on the grid side (e.g., current harmonics and reactive power) associated with the use of diode-bridge ac-dc converters in the conventional variable speed drives. Besides, with the proposed solution, a bidirectional operation is possible, allowing to deliver to the power grid the energy generated in motor braking processes. As demonstrated along the paper, with the proposed variable speed drive it is possible to control the motor speed (including the rotation direction), and to achieve operation with sinusoidal currents and unitary power factor on the grid side. A laboratory prototype was developed, allowing to perform experimental validation and to verify the main functionalities of the variable speed drive, UIDB/00319/2020, PTDC/EEI-EEE/30382/2017, PTDC/EEI-EEE/28813/2017. FCT– Fundação para a Ciência e Tecnologia within the Project Scope: UIDB/00319/2020. This work has been supported by the FCT Project DAIPESEV PTDC/EEI-EEE/30382/2017, and by the FCT Project QUALITY4POWER PTDC/EEI-EEE/28813/2017

One of the most important factors to determine the success of an organization is the quality of decisions made. Supporting a decision-making process is a complex task, mainly when decision-makers are dispersed. Group decision support systems (GDSSs) have been studied over the last decades with the goal of providing support to decision-makers; however, their acceptance by organizations has been difficult. This happens mostly due to usability problems, loss of interaction between decision-makers, and consequently, loss of information. In this work, we present a web-based GDSS developed to support groups of decision-makers, regardless of their geographic location. The system allows the creation of multicriteria problems and the configuration of the preferences, intentions, and interests of each decision-maker. The presented system uses a multiagent system to combine and process this information, using virtual agents that represent each decision-maker. We believe that, with this approach, we will proceed in the refinements of a successful GDSS to correctly support decision-makers while preserving the valuable intelligence and knowledge that can be generated in face-to-face meetings. Furthermore, the high level of usability that the system provides will contribute to an easier acceptance and adoption of this kind of systems., This work was supported by by National Funds through the FCT – Fundação para a Ciência e a Tecnologia (Portuguese Foundation for Science and Technology) with GrouPlanner Project (POCI-01-0145-FEDER29178) and within the Projects UID/CEC/00319/2019 and UID/EEA/00760/2019, and the Luís Conceição Ph.D. Grant with the reference SFRH/BD/137150/2018.

The Supplementary Material for this article canbe found online at: https://www.frontiersin.org/articles/10.3389/fcimb.2020.550505/ full#supplementary-material, Modern medicine is currently facing huge setbacks concerning infection therapeutics as microorganisms are consistently knocking down every antimicrobial wall set before them. The situation becomes more worrying when taking into account that, in both environmental and disease scenarios, microorganisms present themselves as biofilm communities that are often polymicrobial. This comprises a competitive advantage, with interactions between different species altering host responses, antimicrobial effectiveness, microbial pathogenesis and virulence, usually augmenting the severity of the infection and contributing for the recalcitrance towards conventional therapy. Pseudomonas aeruginosa and Candida albicans are two opportunistic pathogens often co-isolated from infections, mainly from mucosal tissues like the lung. Despite the billions of years of co-existence, this pair of microorganisms is a great example on how little is known about cross-kingdom interactions, particularly within the context of coinfections. Given the described scenario, this study aimed to collect, curate, and analyze all published experimental information on the molecular basis of P. aeruginosa and C. albicans interactions in biofilms, in order to shed light into key mechanisms that may affect infection prognosis, increasing this area of knowledge. Publications were optimally retrieved from PubMed and Web of Science and classified as to their relevance. Data was then systematically and manually curated, analyzed, and further reconstructed as networks. A total of 641 interactions between the two pathogens were annotated, outputting knowledge on important molecular players affecting key virulence mechanisms, such as hyphal growth, and related genes and proteins, constituting potential therapeutic targets for infections related to these bacterial-fungal consortia. Contrasting interactions were also analyzed, and quorum-sensing inhibition approaches were highlighted. All annotated data was made publicly available at www.ceb.uminho.pt/ISCTD, a database already containing similar data for P. aeruginosa and Staphylococcus aureus communication. This will allow researchers to cut on time and effort when studying this particular subject, facilitating the understanding of the basis of the inter-species and inter-kingdom interactions and how it can be modulated to help design alternative and more effective tailored therapies. Finally, data deposition will serve as base for future dataset integration, whose analysis will hopefully give insights into communications in more complex and varied biofilm communities., This work was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2020 unit and BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020–Programa Operacional Regional do Norte. The authors also acknowledge COMPETE2020 and FCT for the project POCI-01-0145-FEDER-029841 and FCT for the PhD Grant of TG [grant number SFRH/BD/136544/2018]., info:eu-repo/semantics/publishedVersion

In the last decade, the objectives outlined by the needs of personal robotics have led to the rise of new biologically-inspired techniques for arm motion planning. This paper presents a literature review of the most recent research on the generation of human-like arm movements in humanoid and manipulation robotic systems. Search methods and inclusion criteria are described. The studies are analyzed taking into consideration the sources of publication, the experimental settings, the type of movements, the technical approach, and the human motor principles that have been used to inspire and assess human-likeness. Results show that there is a strong focus on the generation of single-arm reaching movements and biomimetic-based methods. However, there has been poor attention to manipulation, obstacle-avoidance mechanisms, and dual-arm motion generation. For these reasons, human-like arm motion generation may not fully respect human behavioral and neurological key features and may result restricted to specific tasks of human-robot interaction. Limitations and challenges are discussed to provide meaningful directions for future investigations., FCT Project UID/MAT/00013/2013FCT–Fundação para a Ciência e Tecnologia within the R&D Units Project Scope: UIDB/00319/2020.

Dissertação Mestrado Integrado em Engenharia Electrónica Industrial e Computadores, O controlo e a análise do comportamento de robôs em tempo real pode ser uma tarefa difícil, sobretudo quando se trata de robôs cooperantes. Neste contexto a utilização de um software de monitorização e controlo torna-se uma ferramenta essencial no desenvolvimento de uma equipa de robôs cooperativos. MINHO TEAM é a equipa de futebol robótico da Universidade do Minho que participa na liga de futebol robótico médio no RoboCup. A equipa foi criada pelo Laboratório de Automação e Robótica (LAR) que está inserido no Departamento de Electrónica Industrial (DEI). O objectivo desta dissertação é criar um software de monitorização e controlo para uma equipa de futebol robótico. O software deve funcionar autonomamente e exibir num ecrã informações sobre o estado dos robôs (como localização em campo, capacidade das baterias, detecção da bola e obstáculos), assim como gerir as posições e papéis atribuídos aos robôs fazendo com que joguem em equipa. O software deve conter outras funcionalidades relacionadas com as necessidades da equipa MINHO TEAM, como criar e editar tácticas para as situações de bola parada, reproduzir os jogos com base em registos ou processar os comandos recebidos da Referee Box. O software criado foi usado no desenvolvimento da nova geração de robôs futebolistas - no auxílio da produção e teste dos algoritmos de localização e de controlo, e permitiu a participação da equipa MINHO TEAM na prova do futebol robótico médio do RoboCup 2011 realizada em Istambul., The robot behavior control and analysis in real time can be a hard task, particularly what concerns cooperative robots. In this context, the use of control and monitoring software becomes an essential tool for the development of cooperative robots team. MINHO TEAM is a robotics soccer team from University of Minho that participates in RoboCup Middle Size League. The team was developed on the Laboratory of Automation and Robotics which belongs to the Department of Industrial Electronics. The purpose of this work consists of developing a monitoring and control software for a robotic soccer team. The software should run autonomously and show information regarding the state of the robots (such as localization on the field, batteries capacity, detection of ball and obstacles), as well as manage positions and roles assigned to robots, making them to play as a team. The software should also include other features required by MINHO TEAM, such as creating and editing tactics for set pieces, replay games based on previous logs or process commands received by the Referee Box. The engineered software was written for the next generation of soccer robots, to help the development and testing of localization and control algorithms, and allowed the participation of MINHO TEAM on RoboCup 2011 Middle Size League held in Istanbul.

Tese de Doutoramento em Engenharia Electrónica e de Computadores, A diversity of current applications, such as Netflix, YouTube, and social media, have used the Internet mainly as a content distribution network. Named Data Networking (NDN) is a network paradigm that attempts to answer today’s applications need by naming the content. NDN promises an optimized content distribution through a named content-centric design. One of the NDN key features is the use of in-network caching to improve network efficiency in terms of content distribution. However, the cached contents may put the consumer privacy at risk. Since the time response of cached contents is different from un-cached contents, the adversary may distinguish the cached contents (targets) from un-cached ones, through the side-channel timing responses. The scope of attack can be towards the content, the name, or the signature. For instance, the adversary may obtain the call history, the callee or caller location on a trusted Voice over NDN (VoNDN) and the popularity of contents in streaming applications (e.g. NDNtube, NDNlive) through side-channel timing responses of the cache. The side-channel timing attack can be mitigated by manipulating the time of the router responses. The countermeasures proposed by other researches, such as additional delay, random/probabilistic caching, group signatures, and no-caching can effectively be used to mitigate the attack. However, the content distribution may be affected by pre-configured countermeasures which may go against the goal of the original NDN paradigm. In this work, the detection and defense (DaD) approach is proposed to mitigate the attack efficiently and effectively. With the DaD usage, an attack can be detected by a multi-level detection mechanism, in order to apply the countermeasures against the adversarial faces. Also, the detections can be used to determine the severity of the attack. In order to detect the behavior of an adversary, a brute-force timing attack was implemented and simulated with the following applications and testbeds: i. a trusted application that mimics the VoNDN and identifies the cached certificate on a worldwide NDN testbed, and ii. a streaming-like NDNtube application to identify the popularity of videos on the NDN testbed and AT&T company. In simulation primary results showed that the multi-level detection based on DaD mitigated the attack about 39.1% in best-route, and 36.6% in multicast communications. Additionally, the results showed that DaD preserves privacy without compromising the efficiency benefits of in-network caching in NDNtube and VoNDN applications., Várias aplicações atuais, como o Netflix e o YouTube, têm vindo a usar a Internet como uma rede de distribuição de conteúdos. O Named Data Networking (NDN) é um paradigma recente nas redes de comunicações que tenta responder às necessidades das aplicações modernas, através da nomeação dos conteúdos. O NDN promete uma otimização da distribuição dos conteúdos usando uma rede centrada nos conteúdos. Uma das características principais do NDN é o uso da cache disponivel nos nós da rede para melhorar a eficiência desta em termos de distribuição de conteúdos. No entanto, a colocação dos conteúdos em cache pode colocar em risco a privacidade dos consumidores. Uma vez que a resposta temporal de um conteúdo em cache é diferente do de um conteúdo que não está em cache, o adversário pode distinguir os conteúdos que estão em cache dos que não estão em cache, através das respostas de side-channel. O objectivo do ataque pode ser direcionado para o conteúdo, o nome ou a assinatura da mensagem. Por exemplo, o adversário pode obter o histórico de chamadas, a localização do callee ou do caller num serviço seguro de voz sobre NDN (VoNDN) e a popularidade do conteúdos em aplicações de streaming (e.g. NDNtube, NDNlive) através das respostas temporais de side-channel. O side-channel timing attack pode ser mitigado manipulando o tempo das respostas dos routers. As contramedidas propostas por outros pesquisadores, tais como o atraso adicional, o cache aleatório /probabilístico, as assinaturas de grupo e não fazer cache, podem ser efetivamente usadas para mitigar um ataque. No entanto, a distribuição de conteúdos pode ser afetada por contramedidas pré-configuradas que podem ir contra o propósito original do paradigma NDN. Neste trabalho, a abordagem de detecção e defesa (DaD) é proposta para mitigar o ataque de forma eficiente e eficaz. Com o uso do DaD, um ataque pode ser detectado por um mecanismo de detecção multi-nível, a fim de aplicar as contramedidas contra as interfaces dos adversários. Além disso, as detecções podem ser usadas para determinar a gravidade do ataque. A fim de detectar o comportamento de um adversário, um timing attack de força-bruta foi implementado e simulado com as seguintes aplicações e plataformas (testbeds): i. uma aplicação segura que implementa o VoNDN e identifica o certificado em cache numa plataforma NDN mundial; e ii. uma aplicação de streaming do tipo NDNtube para identificar a popularidade de vídeos na plataforma NDN da empresa AT&T. Os resultados da simulação mostraram que a detecção multi-nível oferecida pelo DaD atenuou o ataque cerca de 39,1% em best-route e 36,5% em comunicações multicast. Para avaliar o efeito nos pedidos legítimos, comparou-se o DaD com uma contramedida estática, tendo-se verificado que o DaD foi capaz de preservar todos os pedidos legítimos.

In a context of increased environmental awareness, the Internet of Things has allowed individuals or entities to build their own connected devices to share data about the environment. These data are often obtained from widely available low-cost sensors. Some companies are also selling low-cost sensing kits for in-house or outdoor use. The work described in this paper evaluated, in the short term, the performance of a set of low-cost sensors for temperature, relative humidity, atmospheric pressure and carbon dioxide, commonly used in these platforms. The research challenge addressed with this work was assessing how trustable the raw data obtained from these sensors are. The experiments made use of 18 climatic sensors from six different models, and they were evaluated in a controlled climatic chamber that reproduced controlled situations for temperature and humidity. Four CO2 sensors from two different models were analysed through exposure to different gas concentrations in an indoor environment. Our results revealed temperature sensors with a very high positive coefficient of determination (r2 &ge, 0.99), as well as the presence of bias and almost zero random error, the humidity sensors demonstrated a very high positive correlation (r2 &ge, 0.98), significant bias and small-yet-relevant random error, the atmospheric pressure sensors presented good reproducibility, but further studies are required to evaluate their accuracy and precision. For carbon dioxide, the non-dispersive infra-red sensors demonstrated very satisfactory results (r2 &ge, 0.97, with a minimum root mean squared error (RMSE) value of 26 ppm), the metal oxide sensors, despite their moderate results (minimum RMSE equal to 40 ppm and r2 of 0.8&ndash, 0.96), presented hysteresis, environmental dependence and even positioning interference. The results suggest that most of the evaluated low-cost sensors can provide a good sense of reality at a very good cost&ndash, benefit ratio in certain situations.

Wi-Fi fingerprinting is a well-known technique used for indoor positioning. It relies on a pattern recognition method that compares the captured operational fingerprint with a set of previously collected reference samples (radio map) using a similarity function. The matching algorithms suffer from a scalability problem in large deployments with a huge density of fingerprints, where the number of reference samples in the radio map is prohibitively large. This paper presents a comprehensive comparative study of existing methods to reduce the complexity and size of the radio map used at the operational stage. Our empirical results show that most of the methods reduce the computational burden at the expense of a degraded accuracy. Among the studied methods, only k-means, affinity propagation, and the rules based on the strongest access point properly balance the positioning accuracy and computational time. In addition to the comparative results, this paper also introduces a new evaluation framework with multiple datasets, aiming at getting more general results and contributing to a better reproducibility of new proposed solutions in the future., This project have been funded by: Ministerio de Ciencia, Innovacion y Universidades – INSIGNIA project (Programa Torres-Quevedo, PTQ2018-009981), Academy of Finland – PRISMA project (#313039); FCT – Fundação para a Ciencia e a Tecnologia within the R&D Units Project Scope: UIDB/00319/2020; UJI’s research programme (PREDOC/2016/55 and POSDOC-B/2018/12).

This paper proposes a novel multifunctional isolated microinverter which is able to extract the maximum available power from a solar photovoltaic module and inject it into the power grid, while simultaneously charging a battery energy storage system (BESS). The proposed microinverter integrates a novel DC–DC power converter and a conventional DC–AC power converter. The DC–DC power converter is able to send electrical energy to the secondary side of a high-frequency transformer and to the BESS, using only two power switches. Throughout this paper, the converter topology, the operation modes, the control algorithms, and the development of a laboratory prototype of the proposed microinverter are described in detail. Moreover, simulation and experimental results are presented to demonstrate the feasibility of the proposed solution., This work has been supported by FCT—Fundação para a Ciência e Tecnologia within the R&DUnits Project Scope: UIDB/00319/2020. This work has been supported by the FCT Project QUALITY4POWERPTDC/EEI-EEE/28813/2017. Luis A. M. Barros is supported by the doctoral scholarship PD/BD/143006/2018 granted by the Portuguese FCT foundation. Mohamed Tanta was supported by FCT PhD grant with a reference PD/BD/127815/2016 granted by the Portuguese FCT agency. Tiago J. C. Sousa is supported by the doctoralscholarship SFRH/BD/134353/2017 granted by the Portuguese FCT agency.

In AC railway electrification systems, the impact of reactive power flow in the feeding voltage magnitude is one aspect contributing to the quality of supply degradation. Specifically, this issue results in limitations in the infrastructure capacity, either in the maximum number of trains and in maximum train power. In this paper, two reactive power compensation strategies are presented and compared, in terms of the theoretical railway infrastructure capacity. The first strategy considers a static VAR compensator, located in the neutral zone and compensating the substation reactive power, achieving a maximum capacity increase up to 50% without depending on each train active power. The second strategy adapts each train reactive power, achieving also a capacity increase around 50%, only with an increase of the train apparent power below 10%. With a smart metering infrastructure, the implementation of such compensation strategy is viable, satisfying the requirements of real-time knowledge of the railway electrification system state. Specifically, the usage of droop curves to adapt in real time the compensation scheme can bring the operation closer to optimality. Thus, the quality of supply and the infrastructure capacity can be increased with a mobile reactive power compensation scheme, based on a smart metering framework., This research was funded by FCT (Fundação Ciência e Tecnologia) under grant PD/BD/128051/2016.This research is also associated with the Shift2Rail In2Stempo project (grant 777515).

Nowadays, the success or failure of software-based startups is highly dependent on a good alignment of technology, market needs and business model. In this context, an appropriate business design is extremely important for such (new) companies. Commonly, software-based startups are technology-centred and tend to neglect the importance of the business model. Nevertheless, they need to go beyond the development of innovative and effective products or services and take into account the profitability of the company through a proper business model. Based on an exploratory case study of a Portuguese startup, this paper suggests three different levels of maturity for software startups named here as first phase: (i) first product and rookie mistakes, (ii) second phase: the market-driven approach and (iii) third phase: mass market orientation., This work has been supported by COMPETE: POCI-01-0145-FEDER-007043 and FCT – Fundação para a Ciência e Tecnologia within the Project Scope: UID/CEC/00319/2013.

Electric locomotives in AC traction power systems represent a huge single-phase non-linear load and, detrimentally, affect the power quality and the efficiency of the three-phase power grid. Nevertheless, along the last decades, power electronics are being used to mitigate power quality problems in the three-phase power grid. In particular, Rail Power Conditioner (RPC) helps to increase the loading capacity of traction substations and improve the power quality of three-phase power grids. As the main characteristics, an RPC can supply reactive power, suppress current harmonics and overcome currents imbalance of the three-phase power grid. On the other hand, the traction substations may be constituted by different types of power transformers. For instance, single-phase power transformers and open-delta (V/V) power transformers are widely used, while Scott power transformers are less frequently used, since they are more complex and expensive. In this framework, this work presents a review study of RPC topologies, including their operation modes, and a comprehensive comparison between the characteristics of the RPC topologies when using different types of AC traction substations and power transformers. This helps to ensure the correct selection of the RPC topology for a specific application, according to the main structure of the traction substation. Consequently, and based on the established review, it is possible to sort and allocate each RPC topology for limited or wider applications., This work was supported by the Portuguese Foundation of Science and Technology (FCT) (in Portuguese, Fundação para a Ciência e Tecnologia, within the R&D Units Project Scope: UIDB/00319/2020). The first author Mohamed Tanta is supported by FCT Ph.D. grant with a reference PD/BD/127815/2016.

This paper presents a cost- and time-effective wearable inertial sensor system, the InertialLAB. It includes gyroscopes and accelerometers for the real-time monitoring of 3D-angular velocity and 3D-acceleration of up to six lower limbs and trunk segment and sagittal joint angle up to six joints. InertialLAB followed an open architecture with a low computational load to be executed by wearable processing units up to 200 Hz for fostering kinematic gait data to third-party systems, advancing similar commercial systems. For joint angle estimation, we developed a trigonometric method based on the segments&rsquo, orientation previously computed by fusion-based methods. The validation covered healthy gait patterns in varying speed and terrain (flat, ramp, and stairs) and including turns, extending the experiments approached in the literature. The benchmarking analysis to MVN BIOMECH reported that InertialLAB provides more reliable measures in stairs than in flat terrain and ramp. The joint angle time-series of InertialLAB showed good waveform similarity (&gt, 0.898) with MVN BIOMECH, resulting in high reliability and excellent validity. User-independent neural network regression models successfully minimized the drift errors observed in InertialLAB&rsquo, s joint angles (NRMSE &lt, 0.092). Further, users ranked InertialLAB as good in terms of usability. InertialLAB shows promise for daily kinematic gait analysis and real-time kinematic feedback for wearable third-party systems.