1,082 research outputs found

    Human-in-the-Loop Cyber-Physical-Systems based on Smartphones

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    Tese de doutoramento em Ciências e Tecnologias da Informação, apresentada ao Departamento de Engenharia Informática da Faculdade de Ciências e Tecnologia da Universidade de CoimbraTechnological devices increasingly become smaller, more mobile, powerful and efficient. However, each time we have to hurdle through unintuitive menus, errors and incompatibilities we become stressed by our technology. As first put forward by the renowned computer scientist Mark Weiser, the ultimate form of computers may be an extension of our subconscious. The ideal computer would be capable of truly understanding people's unconscious actions and desires. Instead of humans adapting to technology and learning how to use it, it would be technology that would adapt to the disposition and uniqueness of each human being. This thesis focuses on the realm of Human-in-the-loop Cyber-Physical Systems (HiTLCPSs). HiTLCPSs infer the users’ intents, psychological states, emotions and actions, using this information to determine the system's behavior. This involves using a large variety of sensors and mobile devices to monitor and evaluate human nature. Therefore, this technology has strong ties with wireless sensor networks, robotics, machine-learning and the Internet of Things. In particular, our work focuses on the usage of smartphones within these systems. It begins by describing a framework to understand the principles and theory of HiTLCPSs. It provides some insights into current research being done on this topic, its challenges, and requirements. Another of the thesis' objectives is to present our innovative taxonomy of human roles, where we attempt to understand how a human may interact with HiTLCPSs and how to best explore this resource. This thesis also describes concrete examples of the practical usage of HiTL paradigms. As such, we included a comprehensive description of our research work and associated prototypes, where the major theoretical concepts behind HiTLCPS were applied and evaluated to specific scenarios. Finally, we discuss our personal view on the future and evolution of these systems.A tecnologia tem vindo a tornar-se cada vez mais pequena, móvel, poderosa e eficiente. No entanto, lidar com menus pouco intuitivos, erros, e incompatibilidades, causa frustração aos seus utilizadores. Segundo o reconhecido cientista Mark Weiser, os computadores do futuro poderão vir a existir como se fossem uma extensão do nosso subconsciente. O computador ideal seria capaz de entender, em toda a sua plenitude, as ações e os desejos inconscientes dos seres humanos. Em vez de serem os humanos a adaptarem-se à tecnologia e a aprender a usá-la, seria a tecnologia a aprender a adaptar-se à disposição e individualidade de cada ser humano. Esta tese foca-se na área dos Human-in-the-loop Cyber-Physical Systems (HiTLCPSs). Os HiTLCPSs inferem as intenções, estados psicológicos, emoções e ações dos seus utilizadores, usando esta informação para determinar o comportamento do sistema ciber-físico. Isto envolve a utilização de uma grande variedade de sensores e dispositivos móveis que monitorizam e avaliam a natureza humana. Assim sendo, esta tecnologia tem fortes ligações com redes de sensores sem fios, robótica, algoritmos de aprendizagem de máquina e a Internet das Coisas. Em particular, o nosso trabalho focou-se na utilização de smartphones dentro destes sistemas. Começamos por descrever uma estrutura para compreender os princípios e teoria associados aos HiTLCPSs. Esta análise permitiu-nos adquirir alguma clareza sobre a investigação a ser feita sobre este tópico, e sobre os seus desafios e requisitos. Outro dos objetivos desta tese é o de apresentar a nossa inovadora taxonomia sobre os papeis do ser humano nos HiTLCPSs, onde tentamos perceber as possíveis interações do ser humano com estes sistemas e as melhores formas de explorar este recurso. Esta tese também descreve exemplos concretos da utilização prática dos paradigmas HiTL. Desta forma, incluímos uma descrição do nosso trabalho experimental e dos protótipos que lhe estão associados, onde os conceitos teóricos dos HiTLCPSs foram aplicados e avaliados em diversos casos de estudo. Por fim, apresentamos a nossa perspetiva pessoal sobre o futuro e evolução destes sistemas.Fundação Luso-Americana para o DesenvolvimentoFP7-ICT-2007-2 GINSENG projectiCIS project (CENTRO-07-ST24-FEDER-002003)SOCIALITE project (PTDC/EEI-SCR/2072/2014

    Health monitoring sensor suppliers integration

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    Alguma da população idosa é incapaz de viver de uma maneira independente e requer algum tipo de apoio e supervisão. Instituições que fornecem assistência ou cuidados a longo prazo a idosos servem o propósito de garantir o bem-estar e a saúde de pessoas da terceira idade, tendo em atenção os seus sinais vitais, garantindo a medicação apropriada e ajudando nas suas necessidades diárias. A plataforma Wisedome permite que os idosos nestas instituições tenham os seus sinais vitais monitorizados de forma contínua recorrendo ao uso de sensores, alertando os profissionais prestadores de cuidados de situações potencialmente perigosas como quedas de um idoso ou alterações do seu ritmo cardíaco. De maneira a garantir que os seus clientes tenham sempre os melhores e mais actuais sensores, a plataforma de monitorização de saúde Wisedome deverá ser independente do tipo de sensores utilizado e permitir integrar vários sensores de diferentes fornecedores, que se adaptem a diferentes tipos de idosos com diferentes necessidades. O objectivo deste projecto foi o de contribuir para o desenvolvimento e evolução da aplicação de monitorização Wisedome. Este objectivo pode ser dividido em três grandes tarefas: pesquisar as principais alianças que procuram atingir a interoperabilidade entre sensores de saúde; melhorar as funcionalidades da plataforma Wisedome para que esta possa vir a suportar não só o uso de diferentes tipos de sensores, mas que os suporte simultaneamente e de uma forma dinâmica; contribuir para o controlo de qualidade do software, nomeadamente em termos análise de requisitos e testes de sistema. Este documento serve de relatório das tarefas desempenhadas e das contribuições feitas para o desenvolvimento do Wisedome durante a execução deste project

    Small-scale photovoltaic systems: investigation of energy harvesting applications and development of a phone charging system

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    Dissertação de mestrado em Engenharia Física, apresentada à Faculdade de Ciências e Tecnologia da Universidade de Coimbra.Esta tese aborda o desenvolvimento de um sistema de medida de características de módulos fotovoltaicos orgânicos, bem como uma aplicação de baixo custo destes módulos, para o carregamento de telemóveis. Todo o trabalho foi realizado em estágio, numa empresa que produz e comercializa módulos fotovoltaicos orgânicos, sediada em Cambridge, no Reino Unido – Eight19. O sistema de medida tem o intuito de permitir uma avaliação do desempenho dos módulos fotovoltaicos em situações de fraca iluminação, com a possibilidade de serem utilizados para energy harvesting. Este sistema baseia-se num microcontrolador que, através de um circuito electrónico de interface com o módulo fotovoltaico, mede a corrente de curto-circuito e a tensão em circuito aberto do mesmo, permitindo um cálculo posterior da sua potência máxima. São apresentados alguns resultados deste sistema em diferentes condições de iluminação. Quanto à aplicação de carregamento de telemóveis, é primeiro efectuado um estudo acerca da energia solar disponível em África, que corresponde ao mercadoalvo da empresa onde este trabalho foi realizado. De seguida são planeados e desenvolvidos protótipos para esta aplicação, baseados em diferentes hipóteses de aproveitamento de energia, permitindo a sua comparação. Palavras-chave: módulos fotovoltaicos; aplicação de baixo custo; carregamento de dispositivos móveis; energy harvestin

    An Oxalate-Bridged Copper(II) Complex Combining Monodentate Benzoate, 2,2'-bipyridine and Aqua Ligands:Synthesis, Crystal Structure and Investigation of Magnetic Properties

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    A dinuclear copper(II) complex of formula [{Cu(bipy)(bzt)(OH2)}2(μ-ox)] (1) (where bipy = 2,2'-bipyridine, bzt = benzoate and ox = oxalate) was synthesised and characterised by diffractometric (powder and single-crystal XRD) and thermogravimetric (TG/DTG) analyses, spectroscopic techniques (IR, Raman, electron paramagnetic resonance spectroscopy (EPR) and electronic spectroscopy), magnetic measurements and density functional theory (DFT) calculations. The analysis of the crystal structure revealed that the oxalate ligand is in bis(bidentate) coordination mode between two copper(II) centres. The other four positions of the coordination environment of the copper(II) ion are occupied by one water molecule, a bidentate bipy and a monodentate bzt ligand. An inversion centre located on the ox ligand generates the other half of the dinuclear complex. Intermolecular hydrogen bonds and π-π interactions are responsible for the organisation of the molecules in the solid state. Molar magnetic susceptibility and field dependence magnetisation studies evidenced a weak intramolecular-ferromagnetic interaction (J = +2.9 cm-1) between the metal ions. The sign and magnitude of the calculated J value by density functional theory (DFT) are in agreement with the experimental data

    WikiChanges : exposing Wikipedia revision activity

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    Wikis are popular tools commonly used to support distributedcollaborative work. Wikis can be seen as virtual scrapbooksthat anyone can edit without having any specific technicalknow-how. The Wikipedia is a flagship example of areal-word application of wikis. Due to the large scale ofWikipedia its difficult to easily grasp much of the informationthat is stored in this wiki. We address one particularaspect of this issue by looking at the revision history of eacharticle. Plotting the revision activity in a timeline we exposethe complete articles history in a easily understandableformat. We present WikiChanges, a web-based applicationdesigned to plot an articles revision timeline in realtime. WikiChanges also includes a web browser extensionthat incorporates activity sparklines in the real Wikipedia.Finally, we introduce a revisions summarization task thataddresses the need to understand what occurred during agiven set of revisions. We present a first approach to thistask using tag clouds to present the revisions made

    Structure and magnetic properties of two new lanthanide complexes with the 1-((E)-2-pyridinylmethylidene)semicarbazone ligand

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    Two novel semicarbazone-lanthanide(III) complexes were prepared and structurally characterized as [Ln (Hscpy)2 (NO3)2]NO3·MeOH (Ln = Gd and Tb; Hscpy = 1-((E)-2-pyridinylmethylidene)semicarbazone). The 4f metal ions experience deca-coordination geometry. Each molecular formula contains two neutral Hscpy molecules in the keto form coordinated through two nitrogen atoms and one oxygen atom, while two nitrate ligands are both coordinated in a chelate mode. The 1 + charge of the cation-complex is balanced by a nitrate anion. Extensive intermolecular hydrogen bonds are formed through the methanol solvate molecule, which acts both as a donor and an acceptor molecule. The chemical composition of the compounds was confirmed by high resolution mass spectra (ESI-MS); peaks at m/z = 122.07 and 148.05, assigned to the fragments C6H8N3+ and C7H6N3O+, respectively, are in agreement with the coordination of Hscpy. Alternating current magnetic susceptibility analysis was performed in the 10–10000 Hz range, and the terbium-complex showed slow relaxation of the magnetization when immersed in a static magnetic field of 1 kOe and 1.5 kOe, with an activation barrier to the relaxation (21.9(4) cm−1) among the highest found for ten-coordinated Tb(III) complexes. This behavior of slow relaxation of the magnetization is relevant as a memory effect regarding the development of Single Molecule Magnets (SMM)

    The intricate determination of magnetic anisotropy in quasi-octahedral vanadium(III): An HF-EPR and magnetic study

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    We report here the synthesis and a preliminary characterization of the tetranuclear complex of formula [Ga3V(LEt)2(dpm)6], Ga3VEt, in which H3LEt = 2-Ethyl-2-(hydroxymethyl)-propane-1,3-diol and Hdpm = dipivaloylmethane, containing a single paramagnetic vanadium(III) center, from a structural, magnetic, and spectroscopic point of view. Structural characterization by X-ray diffraction evidenced that this derivative is isostructural with the star-shaped Single-Molecule Magnet [Fe3V(LEt)2(dpm)6], Fe3VEt, and can, thus, be considered a model to analyze the magnetic anisotropy of the vanadium(III) ion in that system. The observed results confirm the complexity in obtaining a rationalization of the magnetic behavior of this metal ion, with magnetization data and High Field Electron Paramagnetic Resonance (HF-EPR) spectroscopy providing apparently conflicting results. Indeed, the former were rationalized assuming a rhombic distortion of the ligand field and a dominant easy-axis type anisotropy (equivalent to D ≈ −14.1 cm−1, E ≈ 1.2 cm−1), while a simple axial Spin Hamiltonian approach could explain HF-EPR data (|D| ≈ 6.98 cm−1)

    Staff SARS-CoV-2 Seroprevalence and Mental Health as Key Factors in University Response to COVID-19 Pandemic

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    Copyright © 2021 Lopes, Henriques, Santos-Dias, Nunes-da-Silva, Gonçalves, de Sousa, Abdulghani, Eletério, Braga, Soares, Branco, Canhão and Rodrigues.Background: In response to rapid global spread of the newly emerged coronavirus disease 2019 (COVID-19), universities transitioned to online learning and telework to decrease risks of inter-person contact. To help administrators respond to the COVID-19 pandemic and better understand its impacts, we surveyed SARS-CoV-2 seroprevalence among NOVA University employees and assessed community mental health. Methods: Data were collected from voluntary participants at six NOVA University locations, in the Lisbon metropolitan area, from June 15-30, 2020. All subjects provided written informed consent. Of 1,627 recruited participants (mean age 42.0 ± 12.3 years), 1,624 were tested. Prior to blood collection, participants completed a questionnaire that assessed: COVID-19 symptoms during the previous 14 days, chronic non-communicable diseases, chronic medication, anxiety, and depression symptoms. SARS-CoV-2 serology tests were then performed, and results communicated approximately 4 days after blood draw. Participants with positive serology tests were contacted to assess COVID-19 symptoms since February. Results: Estimated prevalence of SARS-CoV-2 IgG antibodies was 3.1% (n = 50), of which 43.5% reported symptoms in the previous 4 months. The Medical School had the highest seroprevalence (6.2%). Participants reported having at least one chronic disease (63.7%), depression-like symptoms (2.1%), and anxiety symptoms (8.1%). Rates of depression and anxiety symptoms were significantly higher in women, with sleep hours and occasional alcohol consumption negatively associated with depression. Male gender, older age, and sleep hours negatively associated with anxiety symptoms. School of employment and presence of comorbidities positively associated with anxiety. Conclusion: By measuring seroprevalence of SARS-CoV-2 antibodies among NOVA employees and assessing subjects' mental health, we aim to help administrators at European public universities in urban areas, such as Lisbon, Portugal, better understand the needs of their communities. This study resulted in implementation of a stricter contingency plan in the Medical School, while other schools continued to follow Government mitigation guidelines. These findings may also guide the development of tailored strategies to ensure physical and mental health of the academic community during this pandemic crisis. We conclude that, together with COVID-19 contingency plans, psychological support services and facilities to help people effectively face pandemic-associated challenges and minimise anxiety and depression should be implemented.publishersversionpublishe

    possible impact of COVID-19 lockdown?

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    59301]. Publisher Copyright: © 2021, The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.Cytomegalovirus (CMV) is the most frequent cause of congenital infection all over the world. Its prevalence ranges from 0.2 to 2.2%. Transmission from children to their pregnant mothers is a well-known risk factor, particularly if they attend a childcare centre. This study aims to compare the prevalence of CMV congenital infection (CMV_CI) in Portugal (Lisbon) between two studies, performed respectively in 2019 and 2020. In the 2019 study, performed in two hospitals, we found a 0.67% CMV_CI prevalence, using a pool strategy previously tested with saliva samples. In the 2020 study, using the same pool approach in four hospitals (the previous and two additional), and based on 1277 samples, the prevalence was 0.078%. Conclusion: The close temporal coincidence with COVID-19 lockdown suggests that these measures may have had a significant impact on this reduction, although other explanations cannot be ruled-out.What is Known:• Cytomegalovirus is the leading cause of congenital infection.• Behavioural measures decrease cytomegalovirus seroconversion in pregnant women.What is New:• From 2019 to 2020 there was a significant reduction in the prevalence of congenital CMV infection.publishersversionpublishe
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