Animação [sociocultural] e educação turística e cultural nas fráguas duma pedagogia do encontro e diálogo entre saberes.
Martins, Ernesto Candeias
2014
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A realização deste projecto consiste na implementação de um estudo realizado na área da síntese sonora e de electrónica e telecomunicações.
O objectivo principal é construir um sintetizador analógico, com circuitos desenvolvidos de raiz para este equipamento aplicando o estudo que foi realizado ao longe do terceiro ano lectivo.
Tese de mestrado em Engenharia Eletrónica e Telecomunicações, Universidade de Aveiro, 2004
Tese de Doutoramento em Engenharia Electrotécnica, Universidade de Aveiro, 2014
Dissertação de Mestrado em Engenharia
Electrónica e Telecomunicações
As experiências interactivas são um veículo atractivo de disseminação do conhecimento, em
particular no domínio da óptica e das suas aplicações. Este artigo descreve um módulo expositivo e
interactivo, destinado a explicar os fenómenos físicos relacionados com a luz. O sistema assemelha-se a
uma máquina de jogos, que tem no topo um conjunto de seis experiências e vem equipado com um sistema com informação visual e auditiva. Permite ao utilizador escolher qual a experiência que irá
decorrer, criando um ambiente multimédia motivador para demonstrar efeitos ópticos. Pode ser utilizado
tanto em ambiente de aula, como em eventos científicos ou culturais abertos à comunidade em geral. O resultado final é um módulo didáctico fiável e robusto, que integra diversas experiências e inclui soluçõesde hardware e software numa solução integrada.
Tese de Doutoramento em Engenharia Eletrotécnica apresentada à Universidade de Aveiro.
Social networks are a recent phenomenon of communication, with a high prevalence of young users. This concept
serves as a motto for a multidisciplinary project, which aims to create a simple communication network, using
light as the transmission medium. Mixed team, composed by students from secondary and higher education
schools, are partners on the development of an optical transceiver. A LED lamp array and a small photodiode
are the optical transmitter and receiver, respectively. Using several transceivers aligned with each other, this
con guration creates a ring communication network, enabling the exchange of messages between users. Through
this project, some concepts addressed in physics classes from secondary schools (e.g. photoelectric phenomena
and the properties of light) are experimentally veri ed and used to communicate, in a classroom or a laboratory.
As cidades/regiões inteligentes (Smart
Cities and Communities) são uma
prioridade nas políticas da União
Europeia e de Portugal, nomeadamente
na estratégia de re-industrialização,
na Agenda Digital e nas estratégias
nacionais e regionais de inovação para
uma especialização inteligente.
O conceito de cidade ou território
inteligente parte da implementação de
sensores electrónicos espalhados na
cidade/região e conectados a uma rede
de telecomunicações, que por sua vez
concentra os dados medidos em tempo
real numa base de dados armazenada
na “Cloud”. Sobre esta base de dados
correm aplicações (software) que
processam os dados da cidade/região
através de algoritmos e técnicas de
otimização, potenciando uma gestão eficiente dos recursos disponíveis e em última
análise contribuindo para a sustentabilidade
do território.
Alguns exemplos práticos ensaiados em
cidades da europa são sistemas de mobilidade
inteligente, sistemas inteligentes de gestão
da água e resíduos, controlo da iluminação
pública em função das necessidades,
monitorização de níveis de poluição,
recolha do lixo urbano otimizada através de
contentores com sensores de capacidade,
entre muitos outros.
A Escola Superior de Tecnologia, em
colaboração com a start-up tecnológica
Allbesmart (a primeira empresa Spin-off
do IPCB) instalada no Centro de Empresas
Inovadoras, e o município de Castelo Branco,
têm desenvolvido soluções específicas para
a cidade e territórios adjacentes. De realçar
que o Município de Castelo Branco é membro
fundador da recentemente criada Rede
Nacional de Cidades Inteligentes (RENER).
Throughout the years, the expanded search and flow of information led to an expansion of traffic intensity in today’s optical communication systems. Coherent communications, using the amplitude and phase of the optical wave, resurface as one of the transmission methods to increase the effective bandwidth of optical channels. In this framework, this chapter presents a study on all-optical format conversion of modulated signals, using exclusively interferometric techniques through wavelength conversion, based on Mach-Zehnder interferometers with semiconductor optical amplifiers (MZI-SOA). This technique, when applied in interconnection nodes between optical networks with different bit rates and modulation formats, allows a better efficiency and scalability of the network. The chapter presents an experimental characterization of the static and dynamic properties of the MZI-SOA and explores all-optical techniques for the conversion from amplitude modulation to phase modulation. Finally, it briefly presents the potential of MZI-SOAs for the conversion of amplitude signals to more advanced modulation formats, such as quadrature phase shift keying (QPSK) and quadrature amplitude modulation (QAM) signals.
Este artigo descreve o projecto e a construção de um sistema de controlo para um actuador linear motorizado, utilizado na sintonia mecânica de redes de Bragg. O módulo realizado compõe-se de uma parte electromecânica onde a fibra óptica é colocada para ser comprimida ou esticada, e uma parte electrónica destinada a comandar o motor utilizado. A função de controlo é executada por um programa de computador. São descritos os elementos físicos e lógicos responsáveis pela função de controlo. Finalmente, o sistema é caracterizado em função da repetibilidade e precisão.
São abordados alguns métodos numéricos que conjugados com a teoria dos modos acoplados, servem para modelar e simular o comportamento espectral das redes de Bragg inscritas em fibra óptica. Averigua-se qual o método com o melhor compromisso entre a precisão dos resultados e a complexidade computacional, para redes uniformes e apodizadas.
As redes de Bragg (FBG) tornaram-se componentes importantes nos sistemas de comunicação suportados por fibras ópticas, pois permitem a realização de várias operações sem a necessidade de conversão opto-electrónica. Neste âmbito, é desenvolvida uma ferramenta de software para simulação e caracterização de redes de Bragg. A interface gráfica é programada utilizando o ambiente GUIDE do Matlab. É assim possível analisar um leque variado de FBGs, tendo em consideração os efeitos secundários provocados pela variação do índice de refracção médio, durante o processo de fabrico.
O sistema descrito utiliza um feixe de luz laser e um conjunto de espelhos rotativos para criar padrões geométricos ópticos. A utilização de outro espelho, acoplado a uma coluna de som, faz vibrar o padrão óptico.
Fiber bragg grating is widely used in optical fiber applications as a filter or a sensor due to its compact size and high sensitivity to physical conditions, such as temperature and strain. The purpose of this chapter is to describe the implementation and characterization of two tuning methods for optical fiber Bragg gratings, varying the temperature or the length of the fiber. Among the methods using mechanical deformation, compression of the fiber by bending a flexible sheet aggregated with the Bragg grating has shown very interesting tuning results, reaching 19.0 nm with minimum reflection bandwidth variation over the entire tuning range. Stretching the fiber has presented several drawbacks, including breaking of the fiber and a lower tuning range of 4.9 nm. Temperature tuning technique presents good linearity between tuning range and temperature variation but at the cost of a low tuning range (0.4 nm) and a permanent high current electrical source.
With the current use of mobile devices across the world, with increasing demands on bandwidth resources, solving the congestion in the radio spectrum is becoming a challenging task to spectrum regulators. Radiocommunication systems must share the resources efficiently using different
multiplexing techniques using space, frequency or time dimension. Sharing and compatibility studies are required to assess the possibilities for radio systems to coexist in the same or in adjacent frequency bands. SEAMCAT (www.seamcat.org) is a software tool based on the Monte-Carlo simulation method, which is developed within the frame of European Conference of Postal and Telecommunication administrations (CEPT). This tool permits statistical modelling of different radio interference scenarios for performing sharing and compatibility studies between radio-communications systems in the same or adjacent frequency. SEAMCAT is used by many regulatory agencies across the world for various spectrum sharing and compatibility studies such as between mobile systems and terrestrial broadcasting networks.
O surgimento de várias inovações tecnológicas permitiu a digitalização e a
transformação da indústria, acompanhando o paradigma da Indústria 4.0.
Tecnologias ligadas à robótica, aos sensores inteligentes, ao fabrico assistido por
computador, à Internet das Coisas ou à Inteligência Artificial permitem a interligação
entre os mundos físicos e virtuais. A interoperação entre todos estes domínios do
saber é o princípio para transformar o processo de produção e criar uma fábrica
inteligente.
O foco deste artigo centra-se no desenvolvimento e teste de uma smartBox, capaz
de comunicar eficientemente com os equipamentos no chão de fábrica e integrá-los
em plataformas de IIOT (Industrial Internet of Things). À smartBox estão acopladas
cartas e módulos de sensores e atuadores adequados às especificidades de cada
máquina. esta tem de ser capaz de operar em tempo-real, ter uma boa performance
e escalabilidade e bons canais de comunicação. O hardware da smartBox tem, por
isso, de ser robusto, flexível, escalável, funcional, suportar diferentes tecnologias e
permitir atualizações futuras, características essenciais a uma disseminação do
conceito de Indústria 4.0 no chão de fábrica.
Atualmente, existe no mercado uma diversidade de plataformas de hardware capazes
de suportar o desenvolvimento da smartBox e servir de Gateway com qualquer
equipamento no chão de fábrica. Por sua vez, os controladores lógicos programáveis
e as suas plataformas de programação atuais são cada vez mais versáteis e intuitivos
de programar, facilitando o processo de desenvolvimento, no sentido em que cada
equipamento do chão de fábrica tem a sua especificidade, processo e tecnologia.
Dado que muitas instalações industriais têm alguns anos de existência, por vezes as
linhas de comunicação andam a par com as linhas de potência e é necessário prestar
atenção às questões das interferências e formas de as minimizar. Nesse caso, os
protocolos de comunicação a utilizar devem corresponder aos requisitos necessários
em comunicações industriais, tal como a redundância, tolerância a interferências,
reduzida latência, e minimizar as retransmissões e a perda de pacotes de dados.
Nesse âmbito, apresentamos um caso de estudo em que é analisada a vibração de
um motor elétrico; testamos duas soluções distintas para a smartBox: uma é baseada
num sistema de aquisição de dados da National Instruments, onde o software
LabVIEW é usado para adquirir, processar e armazenar os dados num servidor OPC
(Object Linking and Embedding for Process Control). A outra solução incorpora as
plataformas Arduino e EtherCAT. As características de ambas as propostas são
analisadas e comparadas.
Nos tempos actuais o recurso a sistemas cimputorizados é cada vez mais frequente e procurado em todos os ramos de actividade. A crescente utilização de sistemas de reconhecimento de fala, de detecção de sinais e até mesmo de afinação de instrumentos musicais tem levado ao desenvolvimento de novas técnicas nestes variados campos, o que tem originado o interesse cada vez maior por estas tecnologias. Verificando-se uma necessidade de recuros no apoio à instrumentação no laboratório, desenvolveu-se um espectrograma para PC na banda áudio, capaz de adquirir um sinal e fazer a sua análise no tempo e na frequência, com recurso à Transformada Rápida de Fourier (FFT). Para tal desenvolveu-se um programa de computador capaz de aplicar a FFT para posterior visualização dos resultados.
This paper presents two methodologies for the design and development of new products called Design-with-
IoT (DwIoT) that aims to integrate IoT technology into products, focusing on a set of guidelines for its
implementation, and the concept of Design-for-Automation (DFA), important in the development of new automation oriented products in an industry 4.0 context.
No âmbito da "campanha Cerâmica", promovida pelo Instituto de Desenvolvimento e Inspeçcão das Condições de Trabalho (IDICT), foi desenvolvido o sistema SEMIC. O SEMIC é uma ferramenta eletrónica para monitorização remota de parâmetros ambientassem postos de trabalho. Depois de instalado numa unidade fabril, o SEMIC permite realizar medidas de uma forma contínua e sem intervenção humana. O SEMIC integra numa única solução a monitorização do empoeiramento, temperatura, humidade relativa e nível de ruído acústico (intensidade e frequência), de forma a facilitar o trabalho dos técnicos de higiene e segurança.
The digitization of various agricultural processes is a growing reality in Portugal and in the world.
Some of the application areas use sensor networks to monitor several parameters, including monitoring plant
growth, atmospheric conditions or optimizing the irrigation process. However, in the agricultural environment
where energy sources may be scarce, the implementation of an autonomous sensor network must consider the
limitations imposed by the energy consumption of sensor nodes, powered by batteries. Moreover, spatial
distribution models must be tested to optimize the number of sensors and their placement in the field.
This paper presents an ongoing work, being developed in partnership with a company, owner of an extensive
almond grove in the region of Idanha-a-Nova and Fundão, Portugal. The objective is to implement a sensor
network, making use of a LoRa technology and battery-powered nodes, and collect information on various
parameters associated with intensive almond trees groves.
The proposed sensor network is part of an IoT middleware framework that captures multiple data from
different sources. Through smart farming, precision agriculture, real time monitoring and business intelligence
solutions, the expected results are productivity increase and optimization of the use of resources in the almond
cultivation process and a significative reduction of the environmental impact.
Dissertação apresentada à Escola Superior de Tecnologia do Instituto Politécnico de Castelo Branco para cumprimento dos requisitos necessários à obtenção do grau de Mestre em Desenvolvimento de Software e Sistemas Interactivos, realizada sob a orientação científica do Professor Doutor Filipe Miguel Bispo Fidalgo, do Instituto Politécnico de Castelo Branco e da coorientação científica do Professor Doutor Rogério Pais Dionísio, Instituto Politécnico de Castelo Branco.
This paper describes outdoor field measurements in television white spaces (TVWS) carried out in Munich, Germany. Fixed and mobile measurements in rural, sub-urban and urban scenarios showed that the modified
Hata model is appropriate to describe the path loss over distances up to few kilometers, and may be used in the process to populate a geo-location database.
Over the years, the increased search and exchange of information lead to an increase of traffic intensity in
todays optical communication networks. Coherent communications, using the amplitude and phase of the signal,
reappears as one of the transmission techniques to increase the spectral efficiency and throughput of optical
channels. In this context, this paper present a survey on format conversion of modulated signals using MZI-
SOAs, based exclusively on all-optical techniques through wavelength conversion. We also present two proposal using all-optical techniques: One for the conversion of amplitude modulation signals to a continuous phase modulation format, and another technique for the conversion of OOK signals to QPSK and QAM signals. Both approaches are experimentally validated.
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The rapidly increasing popularity of WiFi has created
unprecedent levels of congestion in the unlicensed frequency
bands, especially in densely populated urban areas. This results
mainly because of the uncoordinated operation and the unmanaged
interference between WiFi access points. Recently, Radio
Environment Maps (REM) have been suggested as a support for
coordination strategies that optimize the overall WiFi network
performance. Despite some theoretical work done in this area,
there are no clear experimental evidences of the benefit brought
by WiFi coordination. In this context, the main objective of this
experiment is to assess the benefit of a coordinated management
of radio resources in dense WiFi networks using REMs for
indoor scenarios. This experiment has used the w-iLab.t test
environment provided by iMINDS, a cognitive-radio testbed for
remote experimentation. It was shown that REMs are capable
of detecting the presence of interfering links on the network
(co-channel or adjacent channel interference), and a suitable
coordination strategy can use this information to reconfigure
Access Points (AP) channel assignment and reestablish the client
connection. The coordination strategy almost double the capacity
of a WiFi link under strong co–channel interference, from
6.8 Mbps to 11.8 Mbps, increasing the aggregate throughput
of the network from 58.7 Mbps to 71.5 Mbps. However, this
gain comes with the cost of a relatively high density network
of spectrum sensors (12 sensors for an area of 60 × 20 m),
increasing the cost of deployment.
Este artigo apresenta duas aplicações
desenvolvidas em Software Labview com rádios definidos por
Software USRP2, destinadas às aulas laboratoriais no ensino das
Telecomunicações. Uma das aplicações é um analisador de
espectro, com uma gama espectral entre 50 MHz e 2.2 GHz, na
qual podem ser visualizados e analisados sinais no domínio do
tempo e da frequência. Este módulo possui uma interface
intuitiva e vários parâmetros fundamentais para análise
espectral, o que permite o seu uso em aulas práticas laboratoriais.
A outra aplicação implementada foi um rádio analógico FM;
para além de permitir desmodular os sinais FM e ouvir as
emissões rádio na gama de frequências entre 87,5MHz a
108MHz, é também possível transmitir ou receber sinais FM em
qualquer uma das frequências disponíveis no dispositivo. No
entanto, devido a restrições regulamentares, não deve ser
utilizado como emissor rádio no espectro licenciado em Portugal.
This paper approaches the permanent struggle that less favoured regions
must deal with regarding economic opportunities, job creation, income and
regional production increase. Since an increased demand for nature and protected
areas is taking place in a more and more urban society, some innovation potential
is emerging. The study we have developed is focused on sustainable tourism
practices in a specific natural area (Malcata Mountain Reserve), using electric
mobility, which is known for its zero emission, no polluting and noise-free travelling.
The broader study is carried out under the Interreg Funding Program in
the Moveletur Project. Our aims are to promote a model of sustainable and clean
tourism for visitors of natural areas, to create a network of green tourism itineraries
connecting sites of natural and/or cultural value using electric vehicles and
to empower tourism sector entrepreneurs with a new added-value service for their
activity. Joint work with other natural areas is required to increase results. After
the project is finished (by the end of 2018) there will be an improved knowledge
about natural and cultural values that natural areas hold and that can be used for
visitors’ enjoyment. There will be a more respectful way of ‘doing tourism’ in
natural areas and hopefully it will address employment creation and improved
territorial competitiveness. Finally, tourism experiences will have more quality
and the project will promote smart villages’ further development by using technological
components.
The authors would like to acknowledge EP INTERREG V A España-Portugal Program (POCTEP) for financing MOVELETUR project.
O projeto Chronos consiste num sistema onde se integra um microprocessador assíncrono implementado em FPGA. O microprocessador é capaz de executar as funções dos microprocessadores RISC tipo PIC da Microchip®, possuindo unidades de entrada/saída (I/O) para ligação a sensores e capacidade de comunicação com um computador pessoal (PC).
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Television White Spaces (TVWS) are a spectral opportunity, for secondary users of the spectrum to deliver broadband access to rural areas. Most of the approaches now under test worldwide use a geo-location database to inform secondary users of the available channels, and avoid interference with primary users of the spectrum. The secondary network should follow a approach capable to communicate with a geo-location spectrum database, to store and retrieve information on spectrum occupancy, location of DVB-T broadcast towers and wireless microphones, maximum EIRP of secondary White Space devices (WSDs), sensing activity and other technical parameters. One group from the Internet Engineering Task Force (IETF) is presently working on the definition of a protocol to access white spaces databases – PAWS. The IETF draft protocol was chosen and considered flexible enough to be adapted for the CREW-TV project model and requirements, since it is more comprehensive and less specific on details than other proposals.
Constant search for efficiency and productivity has led to innovation on the factory shop floor,
representing an evolution of the current production systems combined with new technologies of industrial
automation and information technology. This work presents a versatile gateway for experimental
demonstration of Industrial IoT technologies in a loom machine, allowing sensing, monitoring and data
acquisition that was not originally available. We have implemented an approach, based on the OPC UA
communication protocol for real time applications, and OPC UA to MQTT conversion mechanism. Raspberry
Pi’s platform act as an OPC UA server. From the measurements, data stored in a cloud server can be accessed
remotely with improved security and visualized from a computer dashboard. One of the conclusions that can
be drawn is that the proposed gateway allows data to be stored and monitored from a smartphone application
or a computer web interface.
This paper proposes a new methodology for the generation of quadrature amplitude modulation signals, based on all-optical processing from nonlinear interferometric devices. The degradation of the systems performance is numerically analyzed, as a function of operational parameter’s unbalance and physical impairments of the system. The results shows that the probe laser power and the coupling factor of optical couplers are the most sensitive parameters of the proposed format conversion system.
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from IEEE must be obtained for all other uses, in any current or future
media, including reprinting/republishing this material for advertising or
promotional purposes, creating new collective works, for resale or
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component of this work in other works.”
The rapidly increasing popularity of WiFi has
created unprecedented levels of congestion in the unlicensed
frequency bands, especially in densely populated urban areas.
This results mainly because of the uncoordinated operation and
the unmanaged interference between WiFi access points. In this
context, the main objective of this experiment is to assess the
benefit of a coordinated management of radio resources in dense
WiFi networks for both 2.4 GHz and 5 GHz bands, using
Radio Environment Maps (REM). This experiment has used the
w-iLab.t test environment and the portable test-bed provided by
iMINDS for indoor scenarios. It was shown that REMs can detect
the presence of interfering links on the network (co-channel
or adjacent channel interference), and a suitable coordination
strategy can use this information to reconfigure Access Points
(AP) channel assignment and re-establish the client connection.
The coordination strategy almost double the capacity of a WiFi
link under strong co–channel interference, from 6.8 Mbps to
11.8 Mbps, increasing the aggregate throughput of the network
from 58.7 Mbps to 71.5 Mbps. However, this gain comes with
the cost of a relatively high-density network of spectrum sensors,
increasing the cost of deployment. The technique of AP handoff
was tested to balance the load form one AP to another,
although the aggregate throughput is lower after load balancing.
REMs are also capable of detecting coverage holes on the
network, and a suitable Radio Resource Management strategy
use this information to reconfigure the APs transmit power to reestablish
the client connection and increase the throughput of the
overloaded AP, at a cost of diminishing the aggregate throughput
of the network. The insights coming out from this experiment
helped to understand the opportunities and limitations of WiFi
coordination strategies in realistic scenarios.
“This is a post-peer-review, pre-copyedit version of an article published in Lecture Notes in Electrical Engineering. The final authenticated version is available online at: https://doi.org/10.1007/978-3-319-91334-6_40"
This book chapter proposes a description of smart gateways and cyber-physical systems (CPS) for the
industrial internet of things (I-IOT). It also presents a case study where a smart gateway is developed to
be used in different types of industrial equipment for the shop floor. The case study is developed under
the specifications of different industries in the region of Castelo Branco. It is a proof that the 4th industrial
revolution will be the engine for SME innovation, independence of the regions and their financial
strength. It is also proof that the cooperation between universities, industries and startups can evolve to
break barriers and add value in the improvement of regional industries competitiveness. Topics that will
be addressed on the chapter can be used for developers, students, researchers and enthusiasts to learn
topics related to I-IOT, such as data acquisitions systems, wired and wireless communication devices
and protocols, OPC servers and LabVIEW programming.
The use of wireless communications systems on the factory shop floor is becoming an appealing solution with many advantages compared to cable-based solutions, including low cost, easy deployment, and flexibility. This, combined with the continuous growth of low-cost mobile devices, creates opportunities to develop innovative and powerful applications that, in many cases, rely on computing and memory-intensive algorithms and low-latency requirements. However, as the density of connected wireless devices increases, the spectral noise density rises, and, consequently, the radio interference between radio devices increase. In this paper, we discuss how the density of AR/VR mobile applications with high throughput and low latency affect industrial environments where other wireless devices use the same frequency channel. We also discuss how the growing number of these applications may have an impact on the radio interference of wireless networks. We present an agnostic methodology to assess the radio interferences between wireless communication systems on the factory floor by using appropriate radio and system models. Several interference scenarios are simulated between commonly used radio systems: Bluetooth, Wi-Fi, and WirelessHART, using SEAMCAT. For a 1% probability of interference and considering a criterion of C/I = 14 dB, the simulations on an 80 m × 80 m factory shop floor show that low-bandwidth systems, such as Bluetooth and WirelessHART, can coexist with high-bandwidth and low-latency AR/VR applications running on Wi-Fi mobile terminals if the number of 11 Wi-Fi access points and 80 mobile AR/VR devices transmitting simultaneously is not exceeded.
Turismo e mobilidade suave : conflitos e virtudes a partir de um projeto Interreg.
This work focuses on the evaluation of blind sensing techniques for the detection of multiple wireless microphones in the UHF band, by means of simulation. The metrics used for the comparisons include probability of detection, probability of false alarm and minimum SNR detected for a given observation time. As an example, simulation results showed that blind detection algorithms can sense multiple wireless microphone signals with SNR = -19 dB, in a Rayleigh channel environment, considering 100 ms sensing time, 90 % probability of detection and 10 % probability of false alarm. In these conditions, blind detection techniques suffer maximum SNR degradation of 3.5 dB, as compared with single wireless microphone scenarios.
This paper describes a fully automated system for remote infrared and visible light detection and surveillance of forest fires. The project includes a set-up of a laboratory demonstrator. Topics such as image acquisition, automatic control and radiation levels detection are discussed.
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his experimental study focuses on the comparison between two different sensors for vibration signals: a magnetoresistive sensor and an accelerometer as a calibrated reference. The vibrations are collected from a variable speed inductor motor setup, coupled to a ball bearing load with adjustable misalignments. To evaluate the performance of the magnetoresistive sensor against the accelerometer, several vibration measurements are performed in three different axes: axial, horizontal and vertical. Vibration velocity measurements from both sensors were collected and analyzed based on spectral decomposition of the signals. The high cross-correlation coefficient between spectrum vibration signatures in all experimental measurements shows good agreement between the proposed magnetoresistive sensor and the reference accelerometer performances. The results demonstrate the potential of this type of innovative and non-contact approach to vibration data collection and a prospective use of magnetoresistive sensors for predictive maintenance models for inductive motors in Industry 4.0 applications.
Com o switch off da televisão analógica libertou-se uma importante e útil parte do espectro que possui
características que o tornam bastante importante e útil para utilização por outros sistemas radiofrequência. Mas é também nesta banda de espectro que funcionam inúmeros dispositivos sem fios, de forma anárquica, e sem qualquer tipo de regulamentação. Desta forma tornou-se necessário regular estes aparelhos. Neste artigo propõe-se uma plataforma que possibilita a regulamentação e correcta utilização destes dispositivos que operam anarquicamente nestas frequências.
Dissertação apresentada à Escola Superior de Tecnologia do Instituto Politécnico de Castelo Branco para obtenção do grau de Mestre em Desenvolvimento de Software e Sistemas Interativos.
As redes de Bragg (FBG) tornaram-se componentes importantes na redes de comunicações ópticas, pois permitem a realização de várias operações sem a necessidade de conversão opto-electrónica. Este artigo descreve uma ferramenta de software para simulação e caracterização de redes de Bragg por nós inteiramente concebida. A interface gráfica foi programada utilizando o ambiente GUIDE do Matlab. É assim possível analisar um leque variado de FBGs, tendo em consideração os efeitos secundários provocados pela variação do índice de refracção médio, durante o processo de fabrico.
“Copyright © [2010] IEEE. Reprinted from 15th IEEE Mediterranean Electrotechnical Conference. ISBN: 978-1-4244-5793-9.
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“Copyright © [2009] IEEE. Reprinted from ICTON-MW 3rd. ISBN:978-1-4244-5745-8. This material is posted here with permission of the IEEE. Internal or personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution must be obtained from the IEEE by writing to pubs-permissions@ieee.org.
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In this paper, we propose a method to mitigate the temporal power transients arising from Erbium doped fiber amplifiers (EDFAs) on packeted/bursty scenario. The technique, applicable on hybrid WDM/TDM-PON for extended reach, is based on a low power clamping provided by a distributed feedback (DFB) laser and a fiber Bragg grating (FBG). An mprovement in the data signal Q factor was achieved keeping the clamping control signal with a low power, accompanied by a maximum reduction in the gain excursion of 1.12 dB
“Copyright © [2012] IEEE. Reprinted from ICT Future Network & Mobile Summit 2012. ISBN: 978-1-4673-0320-0.
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This paper presents a counting system project for the Naturtejo Global Geopark, which is structured in two phases. The objective of the first phase was to develop, install and test an electronic system able to remotely count the number of visitors on the Naturtejo Geopark walking routes and touristic sites. The data is reported through a web interface. A Pilot test is currently installed on Trail PR3 – “Fossil’s Route”, near the village of Penha Garcia. Since May 2015, more than 6000 tourists where monitored. The second phase of the project aims to track tourists based on the detection of Wi-Fi signals generated by their smartphones. Thanks to data mining algorithms, useful insights can be extracted that helps to understand the behaviour of tourists when they travel around the large territory of the Geopark.
This chapter describes outdoor transmission tests and field measurements in TV white spaces (TVWS) carried out in Europe. TVWS Measurements in Germany showed that the extended Hata model is appropriate to describe the path loss over distances up to a few kilometers. During the TVWS trial in Slovenia, we combine infrastructure sensing with geo-location database access to protect not only DVB-T, but also wireless microphone (WM) signals from TVWS devices interference.
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The concept of smart cities grew with the need to rethink the use of urban spaces based
on the constant technological advances and respecting sustainability. Today the urbanism and the
methodologies to think about the city are changing, as citizens want more access to digital
information on almost everything. Therefore, cities need to be planned and equipped with
infrastructures that enable connectivity between the citizens’ devices and the digital information.
This challenge raises technological problems, such as traffic management, in an attempt to
guarantee fair network access to all users. Solutions based on wireless resource management and
self-organizing networks are key when design the connectivity for these smart cities. This paper
presents a study on forecasting the daily load of Wi-Fi city hotspots, taking also in consideration the
weather conditions. This is particularly interesting to predict the network load and resource
requirements needed to ensure proper quality of service is provided to the hotspot users. The study
was performed in a Wi-Fi hotspot located in the city of Castelo Branco, Portugal. The results show
the ARIMA model is capable of identifying and forecasting seasonality events for one week in
advance including its capability to correlate the number of hotspot users with weather conditions.
Although previous research on the e-learning system acceptance has been conducted using UTAUT, no
study followed the longitudinal approach. Accordingly, this research examines the engineering students' (N = 291) elearning system acceptance by three years of study. The structural equation modelling analysis confirmed UTAUTrelationships in each year. Effort expectancy and social influence resulted as significant predictors of behavioural intention in all three years. In contrast, performance expectancy influence got lower in later usage. Altogether, our longitudinal study presented that the UTAUT model has weakened over time. Therefore, we propose extending the UTAUT model in future research to better understand user satisfaction and positively contribute to system acceptance.
Our research findings can be used for university leaders to investigate and evaluate any implemented information system acceptance through the years.
“This is a post-peer-review, pre-copyedit version of an article published in Lecture Notes in Mechanical Engineering. The final authenticated version is available online at: https://doi.org/10.1007/978-3-030-79168-1_20".
We are witnessing how digital technologies can be used to transform everyday life – launch new or grow incumbent companies, change teaching and learning environment, and research. The latest literature research has overwhelmingly positively assessed the use of digital technologies in higher education, indicating certain challenges in this regard. In the modern era, higher education institutions need to evolve steadily, following the digital transformation. Overall, the emphasis is on the encouragement and promotion of digital technology in the learning process. However, a small number of research papers addressed the learning environment’s digital transformation in the past decade. With the aim of contributing to a relevant topic, this paper presents a systematic literature review of related articles published on learning environment digital transformation in ten years. Accordingly, significant and eminent results are discussed, together with guidelines for future research.
The COVID-19 pandemic and the need for selfisolation
has decreased the frequency of visits to senior citizens
by family members or caregivers. Because of this, many health
concerns of the elderly remained unresolved. We created a IoT
system, called Zelar@CB, that monitors the daily activities of
isolated elderly people who do not have access to at-home care.
The proposed project detects unusual activity by monitoring the
person’s usage of electrical appliances to track if the user left the
stove on or if there is a change in usage. It can also detect when
the user falls, and sends an alert to family members or
caregivers.
Because senior citizens are at a higher risk of suffering serious complications from COVID-19, medical officials have cautioned them to stay at home. Their family and caregivers have also cut back on visits due to fear of spreading the virus to them. This situation has left many of the elderly increasingly isolated and without anyone to keep a watchful eye on their health. Zelar@CB is a wearable monitoring system that keeps track of a person’s daily routine and alerts caregivers if it suspects something is amiss. The system detects unusual activity by monitoring the person’s usage of electrical appliances to track if the user left the stove on or if there is a change in usage. The system sends an alert to family members or caregivers if it detects that. It can also detect when the user falls.
The system uses a LoRa Network, combined with a low-power wearable device that can be worn as a bracelet or embedded in clothing, and an energy monitor that connects to the user’s electrical appliances. The wearable device is equipped with an accelerometer and a gyroscope. The gyroscope can detect if the user has fallen. The energy monitor is connected to the main electrical line of the home. The system monitors the power consumption of each electrical appliance and timestamps related to the users’ daily activities. Zelar@CB also uses an artificial intelligence algorithm previously trained with data on the user’s regular consumption of power.
The energy monitor uses Wi-Fi to send either an SMS or email alert, or a message through the mobile application we developed. Because the amount of data produced by the energy monitor is substantial, the monitor cannot use LoRa alone. The LoRa system implements a Fair Access Policy: 10 downlink messages and 30 seconds uplink time on air per 24 hours, perdevice. Although this is adequate for the rare fall detection events, it is not enough for regular energy consumption measurements.
O aumento exponencial do número de idosos das últimas décadas impõe novos desafios. O
envelhecimento é um processo natural que ocorre ao longo de toda a vida e, apesar de
bastante heterogéneo, acarreta uma panóplia de alterações biopsicossociais que potenciam
situações de maior fragilidade e vulnerabilidade, entre elas as quedas. Mundialmente, as
quedas são uma das principais causas de mortalidade e morbilidade nos idosos,
decorrentes de diversas causas: biológicas, comportamentais, ambientais e
socioeconómicas. A solidão e o isolamento são fatores que contribuem também para a sua
ocorrência, diminuindo a qualidade de vida dos idosos. Este trabalho pretende dar a
conhecer o protótipo de um dispositivo de detecção de quedas em pessoas idosas e os
seus benefícios. Materiais e métodos: O protótipo foi desenvolvido em contexto académico
no âmbito do projeto ZELAR@CB. Trata-se de um dispositivo de deteção de quedas de
dimensões e consumo reduzidos, alimentado por uma bateria, passível de ser utilizado
numa peça de vestuário ou acessório de acordo com a preferência do idoso. Usa um
acelerómetro que em caso de queda, detecta o evento e classifica-o como queda através de
algoritmos de inteligência artificial incorporados. Este dispositivo vem equipado com
tecnologia LoRa rede comparável à rede WIFI, contudo com maior alcance, até cerca de
10 km. Aliado à Internet das Coisas IOT tem a capacidade de reunir e transmitir um
conjunto de informações para um servidor na cloud. Esta arquitetura permite armazenar
dados, e em simultâneo, emitir um alerta ao cuidador (in)formal, sob a forma de mensagem
SMS ou de e-mail. O presente dispositivo permitirá reduzir o tempo decorrido entre a queda
e a chegada de auxílio, seja auxílio da pessoa mais próxima do idoso ou às pessoas que
mais rapidamente o podem ajudar, e consequentemente reduzir as consequências
decorridas da queda. A utilização de uma rede LoRa permite um maior alcance
comparativamente à rede Wi-Fi e restantes redes, pelo que o dispositivo poderá ser usado
no exterior da habitação, possibilitando aos idosos manter as suas atividades diárias.
Conclusão: A tecnologia atual pode ser usada na manutenção do bem-estar e qualidade de
vida dos idosos, contribuindo para a sua autonomia e independência, mesmo quando estes
vivem isolados. Este protótipo, ainda em fase experimental, beneficiará os idosos na medida
em que diminuirá o tempo entre a ocorrência da queda e a chegada de auxílio, reduzindo as
consequências e os recursos necessários ao tratamento e recuperação das quedas nesta
população. Este dispositivo, permitirá a perceção de maior segurança melhorando a
mobilidade e incentivando o Ageing in place.
Pressure ulcers are a critical issue not only for patients, decreasing their quality of life, but also for healthcare professionals, contributing to burnout from continuous monitoring, with a consequent increase in healthcare costs. Due to the relevance of this problem, many hardware and software approaches have been proposed to ameliorate some aspects of pressure ulcer prevention and monitoring. In this article, we focus on reviewing solutions that use sensor-based data, possibly in combination with other intrinsic or extrinsic information, processed by some form of intelligent algorithm, to provide healthcare professionals with knowledge that improves the decision-making process when dealing with a patient at risk of developing pressure ulcers. We used a systematic approach to select 21 studies that were thoroughly reviewed and summarized, considering which sensors and algorithms were used, the most relevant data features, the recommendations provided, and the results obtained after deployment. This review allowed us not only to describe the state of the art regarding the previous items, but also to identify the three main stages where intelligent algorithms can bring meaningful improvement to pressure ulcer prevention and mitigation. Finally, as a result of this review and following discussion, we drew guidelines for a general architecture of an intelligent pressure ulcer prevention system.
Falls are one of the main causes of mortality and morbidity in the elderly worldwide. This had let to the research and development of electronic fall-detection systems. We propose a complete fall-detection system, that combines a wearable device (called Nyon) and a message microservice (for email and SMS) to alert caregiver every time a fall occurs. The wearable uses a simple threshold method and has the capability of search and switch between Wi-Fi and Bluetooth, using the available communication technology when a fall occurs. The results have shown that the wearable autonomy is adequate for a daily use and the server microservices are reliable and deliver a message to the caregiver every time a fall alert occurs. Several improvements are planned to increase the autonomy and range of the wearable device.
This paper experimentally demonstrate an all-optical phase modulation technique using both arms of a Mach-Zehnder interferometer structure with Semiconductor Optical Amplifiers (MZI-SOA), with NRZ modulated signals driven at 10 Gbit/s. The proposed optical phase modulator can be used in multi-level modulation signals generation, as an optical routing element, as well in optical code division multiple access transmission systems.
A novel generation scheme of QPSK format using dual MZI-SOA in serial configuration
is presented. The feasibility of 20 Gb/s QPSK signal with coherent detection is
experimentally shown.
This study investigated the crucial factors for measuring the success of the information system used in the e-learning process, considering the transformations in the work environment. This study was motivated by the changes caused by COVID-19 witnessed after the shift to fully online learning environments supported by e-learning systems, i.e., learning emphasized with information systems. Empirical research was conducted on a sample comprising teaching staff from two European universities: the University of Novi Sad, Faculty of Technical Sciences in Serbia and the Polytechnic Institute of Castelo Branco in Portugal. By synthesizing knowledge from review of the prior literature, supported by the findings of this study, the authors propose an Extended Information System Success Measurement Model—EISSMM. EISSMM underlines the importance of workforce agility, which includes the factors of proactivity, adaptability, and resistance to change, in the information system performance measurement model. The results of our research provide more extensive evidence and findings for scholars and practitioners that could support measuring information system success primarily in e-learning and other various contextual settings, highlighting the importance of people’s responses to work environment changes.
This chapter provides an overview on European Telecommunications Standards Institute (ETSI) activities related to opportunistic spectrum sharing technology with a specific focus on (TV) white spaces. Key use cases are outlined and a novel approach for a coordinated and an uncoordinated approach for accessing the spectrum resource is given. A spectrum coordinator is indeed introduced in order to handle resource management. Furthermore, database system design and inter-database communication solutions are discussed as they are introduced by ETSI. Finally, various sensing mechanisms are detailed, which allow to monitor the radio environment and to feed decision-making components correspondingly.
In recent years the Internet of Things, in addition to use cases in 'smart cities', has also increasingly been used in precision agriculture. As in the rest of the world, it has been a growing reality in Portugal. In an agricultural environment, where energy resources can be scarce and dispersed, the implementation of a LoRa network with autonomous sensor nodes must consider the limitations imposed by the energy consumed by the sensor node, when powered by a battery and a solar panel. For this, experimental tests must be carried out so that there is enough data for the implementation and optimization of the devices. This article presents a work focused on the study of the autonomy and energy efficiency of the sensor device, using algorithms capable of managing energy consumption as a function of the luminosity of the place. Preliminary results attest to the relevance of this approach, keeping the sensor node in operation without interruptions.
Pressure ulcers are a critical issue for patients and healthcare professionals, requiring their frequent monitoring, with a consequent impact on healthcare costs. This problem has been gaining attention and approaches have been proposed, using sensor-based systems, to facilitate this monitoring and help health caregivers to achieve greater effectiveness in the treatment of this type of ulcer. In this paper, the architecture, and the prototype of a new system for pressure ulcer monitoring and prevention are presented. It considers information related to both intrinsic and extrinsic predisposing factors and it addresses the components of data acquisition, data analysis, and production of complementary support to well-informed clinical decision-making. The system includes a pressure ulcer management portal and a mobile application, that allows caregivers to manage clinical information about pressure ulcers of the patients and uses data acquired from a pressure sensor sheet under the mattress to provide useful information for monitoring the patients. Considering the situation of each patient, the system will produce indicators/alerts to healthcare professionals, simultaneously improving pressure-ulcer patient care quality and safety and minimizing the burnout in healthcare professionals.
Pressure ulcers are skin injuries that develop mainly over bony areas as the result of prolonged pressure caused by the immo- bility of bedridden patients. They constitute not only a source of additional suffering for these patients but also contribute to the burnout of healthcare professionals who must maintain continuous monitoring of these patients. Data from countries such as the UK or the USA allows the cost of this problem to be estimated to be, respectively, near £2 billion and $80 billion. In this article, we describe the SensoMatt approach to pressure ulcer prevention and management, which is being developed as a research project that includes partners from industry, healthcare, and academia. The SensoMatt solution is centered on a pressure sheet that is placed under the patient’s mattress, complemented by an online management portal and a mobile app. These provide patients and healthcare providers with an unparalleled set of services that include personalized analysis, prevention warnings and recommendations.
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Copyright © [2009] IEEE. Reprinted from ICTON 2009. ISBN 978-1-4244-4826-5.
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“Copyright © [2010] IEEE. Reprinted from International Computer Engineering Conference ICENCO’2010. ISBN: 978-1-61284-184-7 This material is posted here with permission of the IEEE. Internal or personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution must be obtained from the IEEE by writing to pubs-permissions@ieee.org. By choosing to view this document, you agree to all provisions of the copyright laws protecting it.”
International Conference on Production Economics and Project Evaluation.
Efficient use of resources is a critical factor in almond crops. Technological solutions can significantly contribute to this purpose. The VeraTech project aims to explore the integration of sensors and cloud-based technologies in almond crops for efficient use of resources and reduction of environmental impact. It also makes available a set of relevant and impactful performance indicators in agricultural activity, which promote productivity gains supported by efficient use of resources. The proposed solution includes a sensor network in the almond crops, the transmission of data and its integration in the cloud, making this data available to be consumed, processed, and presented in the monitoring and alerts dashboard. In the current state of the development, several data are collected by sensors, transmitted over LoRaWAN, integrated using AWS IoT Core, and monitored and analysed through a cloud business analytics service.
In this paper, we investigate through simulation the feasibility of amplification solutions
for WDM ring PON encompassing C+L transmission bands. The system under analysis
is composed by a bidirectional pump at 1480 nm with 1 W of power in each direction
and 16 channels (8 C band + 8 L band). The simulation describes an 80 km WDM ring
with 8 nodes in which 2 channels are added/dropped. Two scenarios were
implemented, one with simple Raman amplification that considers that all the pump
power travels along the ring being selected the optimal order to drop channels and
another with C- band in line EDFA in the link mid length that performs and additional
amplification on C band signals. The results of both approaches are compared and their
suitability for practical PON is analyzed.
Efficient use of resources is a critical factor in almond crops. Technological solutions can significantly contribute to this purpose. The VeraTech project aims to explore the integration of sensors and cloud-based technologies in almond crops for efficient use of resources and reduction of environmental impact. It also makes available a set of relevant and impactful performance indicators in agricultural activity, which promote productivity gains supported by efficient use of resources. The proposed solution includes a sensor network in the almond crops, the transmission of data and its integration in the cloud, making this data available to be consumed, processed, and presented in the monitoring and alerts dashboard. In the current state of the development, several data are collected by sensors, transmitted over LoRaWAN, integrated using AWS IoT Core, and monitored and analysed through a cloud business analytics service. This project is implemented on a farm located in the Beira-Baixa region of Portugal and involves a partnership between Vera Cruz (owner of the farm), Veratech, and the Polytechnic Institute of Castelo Branco.
“Copyright © [2014] IEEE. Reprinted from 1st International Workshop on Cognitive Cellular Systems 2014 . ISBN: 978-1-4799-4139-1 .This material is posted here with permission of the IEEE. Internal or personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution must be obtained from the IEEE by writing to pubs-permissions@ieee.org. By choosing to view this document, you agree to all provisions of the copyright laws protecting it.”
“Copyright © [2015] IEEE. Reprinted from Vehicular Technology Conference (VTC Spring), 2015 IEEE 81st. ISBN: 978-1-4799-8088-8.
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