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Sleep analysis through electroencephalogram cyclic alternating pattern a phase detection
Get PDFSleep deprivation leads to a raise in mortality and other unwanted con sequences, as such, the diagnosis of sleep conditions is crucial for medicine.
Sleep is a complex physiological process which is subdivided into different
stages of deepness. A more detailed analysis of sleep reveals that events may
occur that indicate an abrupt change in the brain electrical activity. Cyclic
alternating pattern is a repetitive pattern associated with sleep instability
that can be detected by analysing bodily signals. This can contribute to the
detection of sleep disorders such as obstructive sleep apnea, using the cyclic
alternating pattern as an indicator of such conditions. These cycles tend to
be hard and slow to manually identify due to the fact that extensive analysis
of long recordings of physiological signals by professionals is required. So,
the automatic detection of such patterns is necessary. This can be achieved
using Machine Learning algorithms such as neural networks that use pa tient data to train a model that can later recognize patterns within the sleep
structure. In this work features extracted from the patient electroencephalo graphic signal are used by the classifier to learn how to identify the cycles.
The classification results were improved by making use of methodologies such
as feature selection and model tuning. The final solution presents very good
results, obtaining an accuracy of 73%, a sensitivity of 77% and a specificity
of 74%.A privação do sono leva a um aumento da mortalidade e as outras situa ções indesejadas, logo, o diagnóstico de condições médicas relacionadas com
o sono é crucial para a medicina. O sono é um processo fisiológico complexo
que é subdividido em diferentes fases de profundidade. Uma análise mais de talhada do sono revela que podem ocorrer eventos que indicam uma mudança
repentina na atividade elétrica cerebral. O padrão alternante cíclico é um
padrão repetitivo associado à instabilidade do sono e que pode ser detetado
através da análise de sinais fisiológicos. Esta análise pode contribuir para
a deteção das doenças do sono como a apneia obstrutiva, usando o padrão
alternante cíclico como um indicador das mesmas. Estes ciclos tendem a ser
difíceis e lentos de identificar manualmente devido ao fato de que é necessária
uma análise de longos registos de sinais fisiológicos por parte de profissionais.
Portanto, a deteção automática destes padrões é necessária. Isto pode ser
feito utilizando algoritmos de aprendizagem automática como as redes neu ronais, que, utilizando dados de pacientes para treinar um modelo, poderão
reconhecer os padrões dentro da estrutura do sono. Neste trabalho, foram
extraídas features do sinal eletroencefalográfico de cada paciente para serem
utilizadas pelo classificador com o objetivo de identificar estes ciclos. Os
resultados da classificação foram melhorados utilizado metodologias como a
seleção de features e a otimização do modelo. A solução final apresentou
muito bons resultados conseguindo obter uma exatidão de 73%, uma sensi bilidade de 77% e uma especificidade de 74%
Modelling and experimental evidence of the cathode erosion in a plasma spray torch
Get PDFThe lifetime of tungsten cathodes used in plasma spray torches is limited by processes leading
to a loss of cathode material. It was reported in the literature that the mechanism of their erosion
is the evaporation. A model of the ionization layer of a cathode is developed to study the
diffusive transport of evaporated tungsten atoms and tungsten ions produced due to ionization
by electron impact in a background argon plasma. It is shown that the Stefan–Maxwell
equations do not reduce to Fick law as one could expect for the transport of diluted species,
which is due to significant diffusion velocities of argon ions. The ionization of tungsten atoms
occurs in a distance of a few micrometers from the cathode surface and leads to a strong sink,
which increases the net flux of tungsten atoms far beyond that obtained in absence of tungsten
ions. This shows that the tungsten ions are driven by the electric field towards the cathode
resulting in no net diffusive flux and no removal of tungsten species from the ionization layer
even if convection is accounted for. A possible mechanism of removal is found by extending the
model to comprise an anode. The extended model resolves the inter-electrode region and
provides the plasma parameters for a current density corresponding to the value at the center of
the cathode under typical arc currents of 600 A and 800 A. The presence of the anode causes a
reversal of the electric field on the anode side, which pulls the ions away from the ionization
layer of the cathode. The net flux of tungsten ions can be further fortified by convection. This
model allows one to evaluate the loss of cathode material under realistic operating conditions in
a quantitative agreement with measured values.info:eu-repo/semantics/publishedVersio
Virtual reality environments as a therapeutic technique in rehabilitation of physical and cognitive training in soccer players
Get PDFUm dos principais problemas dos jogadores de futebol são as lesões que sofrem durante
a carreira. Por isso, os clubes profissionais investem em equipas médicas especializadas
para contornar esse problema. Com a evolução das tecnologias interativas, têm sido muito
os estudos para resolver esse problema e trazer mais opções para o campo científico.
Apesar desse esforço, ainda faltam estudos sobre a introdução de tecnologias interativas
nesses contextos. Desenvolvemos um sistema para testar se o uso dessas novas
tecnologias, mais especificamente a realidade virtual, poderia trazer mais motivação e
evitar a monotonia de atletas profissionais na realização de exercícios de reabilitação. Ao
longo desta dissertação, iremos explicar todos os processos que foram realizados até
chegar ao sistema atual. A explicação do processo inclui os exercícios de reabilitação
física escolhidos, bem como o desenvolvimento do software que os envolve. Os estudos
realizados durante esta tese revelaram feedback positivo entre os atletas e há potencial de
trabalho futuro em termos de utilidade do sistema.One of the main problems of football players is the injuries they suffer during their
careers. For that reason, professional clubs invest in specialized medical staff to overpass
this problem. With the evolution of interactive technologies, many studies have been
made to address this problem and bring more options to the scientific field. Despite this
effort, there is still a lack of studies regarding the introduction of interactive technologies
in these contexts. We developed a system to test whether the usage of these new
technologies, more specifically virtual reality, could bring better motivation and avoid
monotony in professional athletes when performing rehabilitation exercises. Throughout
this dissertation, we will explain all the processes that were performed until reaching the
current system. The explanation of the process includes the physical rehabilitation
exercises chosen, as well as the software development entailing those exercises. The
studies performed during this thesis revealed positive feedback among athletes and there
is future work potential in terms of the usefulness of the system
A personalização do processo pedagógico – o diálogo professor-aluno
Get PDFUm processo pedagógico que vise o desenvolvimento das capacidades e poten cialidades do aluno, tem de ser personalizado.
A perceção que o aluno tem da escola, das metodologias, das matérias, de si
próprio e das relações com os outros, não pode ser subestimada no planeamento,
implementação e controlo do processo.
No âmbito do projeto “Educação Física nas Escolas da RAM – Compreender, in tervir, transformar (EFERAM-CIT)”, esta variável tem assumido uma importância
acrescida, permitindo dar resposta às necessidades e motivações do aluno sem se
perder a coerência programática.
Os resultados obtidos evidenciam que, ter em consideração a perceção do aluno
sobre as diferentes vertentes do processo pedagógico, facilita o permanente diálo go professor-aluno, potenciando o desenvolvimento do espírito crítico na linha do
que é defendido por Paulo Freire.A pedagogical process aiming to develop the student’s skills and potential must
be personalized. The student’s perception of school, methodologies, subjects, himself, relation ships with others, cannot be underestimated in the planning cycle, implementa tion and control of the pedagogical process.
In the project “Physical Education in Schools from the Autonomous Region of
Madeira - Understand, intervene, transform (EFERAM-CIT)”, this variable has as sumed extremely importance, allowing to respond to the student’s needs and mo tivations without losing programmatic coherence.
The results obtained show that taking into consideration the student’s percep tion of the different aspects of the pedagogical process, this facilitates the perma nent teacher-student dialogue, enhancing the development of a critical spirit in
line with what is defended by Paulo Freire.info:eu-repo/semantics/publishedVersio
A construção de um parque eólico: potencialidades e desafios na formação de professores
Get PDFEm tempos de mudança é importante introduzir tecnologias no processo de ensino-aprendizagem, uma vez que estas alteram a natureza do trabalho que se realiza na sala de aula. Ao fazê-lo, colocamos em interação e trazemos à discussão três
componentes importantes: o conteúdo curricular, o método pedagógico adotado
e a competência a nível tecnológico e, dessa forma, integramos a tecnologia a três
níveis – o teórico, o pedagógico e o metodológico (Mishra & Koehler, 2006).
Apoiadas no modelo Technological Pedagogical Content Knowledge (TPCK)
- Conhecimento Tecnológico Pedagógico do Conteúdo (TPACK) bem como nos
princípios da Educação Crítica de Paulo Freire, trazemos à discussão uma prática
de formação de professores que tem como foco a transformação de práticas dos
professores em formação, através da inclusão de tecnologias digitais e de metodologias de trabalho nas quais o diálogo é fundamental para que o aluno/formando
tenha um papel ativo e crítico na sua aprendizagem. Analisaremos a implementação de um cenário de aprendizagem que tem como foco a construção de um parque eólico, com utilização da modelação 3D, no sentido de analisar as potencialidades e desafios deste tipo de trabalho no processo de ensino-aprendizagem.In times of change, it is important to introduce technologies in the teaching-learning process, as these alter the nature of the work that is carried out in the classroom. In doing so, we put into interaction and bring to the discussion three
important components: the curricular content, the pedagogical method adopted
and the competence at the technological level and, thus, we integrate technology
at three levels - the theoretical, the pedagogical and the methodological (Mishra &
Koehler, 2006).
Supported by the Technological Pedagogical Content Knowledge (TPCK) model as well as the principles of Critical Education by Paulo Freire, in this commu nication, we will analyze a teacher training practice that focuses on transforming
teacher practices in training, through the inclusion of digital technologies and
work methodologies in which dialogue is essential for the teacher that learns to
have an active and critical role in their learning. We will analyze the implementation of a learning scenario that focuses on the construction of a wind farm, using
3D modeling, to analyze the potential and challenges of this type of work in the
teaching-learning process.info:eu-repo/semantics/publishedVersio
Aumentando a usabilidade dos sistemas gestores de exposições interativas para curadores de museus
Get PDFA investigação sobre os museus e património cultural tem-se centrado no envolvimento da experi ência do visitante em exposições interativas e na forma como esta experiência pode ser apoiada e
melhorada, em vez de se centrar no processo e práticas de conceção dos curadores dos museus que
criam as exposições interativas.
Os curadores dos museus são responsáveis por moldar experiências nos espaços museológicos e
devem estar envolvidos na idealização de ferramentas interativas como atores ativos no desenvolvi mento do processo de conceção tecnológica. Pelo facto destes profissionais terem a responsabilidade
de cuidar, manter e divulgar o património cultural existente, estes são frequentemente denominados
Profissionais do Património Cultural (PPC).
A inclusão da tecnologia digital pode ser vista como o desejo de comunicar material invisível
presente nos museus, tornando os visitantes mais conscientes do seu ambiente. Contudo, se as
ferramentas de criação de experiências interativas forem difíceis de utilizar, estas podem dificultar
e prejudicar o entendimento dos curadores. Da mesma forma se as experiências interativas criadas
pelos curadores forem difíceis de consumir e manipular, estas podem distrair os visitantes de se
envolverem nas exposições.
Esta tese apresenta um sistema que procura auxiliar os curadores de museus na conceção de
ferramentas interativas, de forma fácil e intuitiva. Além disso, é também apresentado um protótipo
de aplicação móvel, de fácil utilização, que permite que os visitantes dos museus, consigam usufruir
das experiências interativas criadas pelos curadores do próprio museu. Como forma de validar o
sistema procedeu-se à realização de 4 casos de estudo distintos. Todos os casos de estudo tiveram
lugar na Ilha da Madeira, mais precisamente na cidade do Funchal e envolveram 3 diferentes
museus. Contabilizando todos os casos de estudo efetuados, foram possíveis obter dados referentes
a um total de 9 curadores e 59 visitantes.Research on museums and cultural heritage has focused on engaging the visitor experience in
interactive exhibitions and on how this experience can be supported and enhanced, rather than on
the design process and practices of museum curators who create the interactive exhibits.
Museum curators are responsible for shaping experiences in museum spaces and must be invol ved in the idealization of interactive tools as active actors in the development of the technological
design process. Because these professionals are responsible for caring, maintaining and dissemina ting the existing cultural heritage, they are often called Cultural Heritage Professionals.
The inclusion of digital technology can be seen as the desire to communicate invisible material
present in museums, making visitors more aware of their environment. However, if tools for creating
interactive experiences are difficult to use, they can be hard for curators to understand. Likewise,
if the interactive experiences created by curators are difficult to consume and manipulate, they can
distract visitors from engaging with the exhibits.
This thesis presents a system that seeks to help museum curators in the design of interactive
tools, in an easy and intuitive way. In addition, an easy-to-use mobile application prototype is
also presented, which allows museum visitors to enjoy the interactive experiences created by the
museum’s curators. As a way of validating the system, 4 different case studies were carried out.
All case studies took place on Madeira Island, more precisely in the city of Funchal and involved 3
different museums. Counting all the case studies carried out, it was possible to obtain data referring
to a total of 9 curators and 59 visitors
TerraSenseTK: a toolkit for remote soil nutrient estimation
Get PDFIntensive farming endangers soil quality in various ways. Researchers show that if these practices
continue, humanity will be faced with food production issues. For this matter, Earth Observation, more
concretely Soil Sensing, along with Machine Learning, can be employed to monitor several indicators of
soil degradation, such as soil salinity, soil heavy metal contamination and soil nutrients estimation. More
concretely, Soil Nutrients are of great importance. For instance, to understand which crop better suits
the land, the soil nutrients must be identified. However, sampling soil is a laborous and expensive task,
which can be leveraged by Remote Sensing and Machine Learning.
Several studies have already been developed in this matter, although many gaps still exist. Among
them, the lack of cross-dataset evaluations of existing algorithms, and also the steep learning curve to
the Earth Observation domain that prevents many researchers from embracing this field. In this sense,
we propose TerraSense ToolKit (TSTK), a python toolkit that addresses these challenges.
In this work, the possibility to use Remote sensing along with Machine Learning algorithms to per form Soil Nutrient Estimation is explored, additionally, a nutrient estimation toolkit is proposed, and the
effectivity of it is tested in a soil nutrient estimation case study.
This toolkit is capable of simplifying Remote Sensing experiments and aims at reducing the barrier
to entry to the field of Earth Observation. It comes with a preconfigured case study which implements a
soil sensing pipeline. To evaluate the usability of the toolkit, experiments with five different crops were
executed, namely with Wheat, Barley, Maize, Sunflower and Vineyards. This case study gave visibility
to an underlying unbalanced data problem, which is not well addressed in the current State of the Art.A agricultura intensiva poe em perigo a qualidade do solo de v ˜ arias formas. Os investigadores ´
mostram que, se continuarmos com estas praticas, a humanidade ser ´ a confrontada com quest ´ oes de ˜
produc¸ao alimentar. Para este efeito, a Observac¸ ˜ ao da Terra, mais concretamente o Sensoriamento ˜
do Solo, juntamente com a aprendizagem automatica, podem ser utilizadas para monitorizar v ´ arios ´
indicadores da degradac¸ao do solo, tais como a salinidade do solo, a contaminac¸ ˜ ao do solo por metais ˜
pesados e a quantificac¸ao dos nutrientes do solo. Mais concretamente, os Nutrientes do Solo s ˜ ao de ˜
grande importancia. Por exemplo para compreender qual a cultura que melhor se adapta ao solo, os ˆ
nutrientes do solo devem ser identificados. No entanto, a amostragem do solo e uma tarefa trabalhosa ´
e dispendiosa, que pode ser impulsionada pela percepc¸ao remota e pela aprendizagem autom ˜ atica. ´
Ja foram desenvolvidos v ´ arios estudos sobre este assunto, embora ainda existam muitas lacunas. ´
Entre eles, a falta de avaliac¸oes cruzadas dos algoritmos existentes, e tamb ˜ em a curva de aprendiza- ´
gem acentuada para o campo de Observac¸ao da Terra que impede muitos investigadores de enveredar ˜
por este campo. Neste sentido, propomos TSTK, um toolkit em python que aborda estes desafios.
Neste trabalho, e explorada a possibilidade de usar a Percepc¸ ´ ao Remota juntamente com os algo- ˜
ritmos de Aprendizagem Automatica para realizar a Estimativa de Nutrientes do Solo. Al ´ em disso, ´ e´
proposto um toolkit de estimativa de nutrientes e tambem um pipeline para o devido efeito, a efetividade ´
do toolkit e testada num caso de estudo de Estimac¸ ´ ao de Nutrientes no Solo. ˜
Este toolkit e capaz de simplificar as experi ´ encias de Percepc¸ ˆ ao Remota e visa reduzir a barreira ˜
de entrada no campo da Observac¸ao da Terra. Para avaliar a usabilidade do toolkit, foram executadas ˜
experiencias com cinco culturas diferentes, nomeadamente Trigo, Cevada, Milho, Girassol e Vinha. Este ˆ
caso de estudo deu visibilidade a um problema subjacente de dados desiquilibrados, o qual nao˜ e bem ´
identificado no Estado da Arte atual
Current challenges in the sustainable valorisation of agri-food wastes: a review
Get PDFIn the upcoming years, the world will face societal challenges arising, in particular, from the impact of climate change and the inefficient use of natural resources, in addition to an exponential growth of the world population, which according to the United Nations (UN) estimations will be 9.8 billion in 2050. This increasing trend requires optimized management of natural resources with the use of value-added waste and a significant reduction in food loss and food waste. Moreover, the recent pandemic situation, COVID-19, has contributed indisputably. Along with the agri-food supply chain, several amounts of waste or by-products are generated. In most cases, these biomass wastes cause serious environmental concerns and high costs to enterprises. The valorisation of the agri-food loss and food industry wastes emerged as a useful strategy to produce certain value-added compounds with several potential applications, namely in the food, health, pharmaceutical, cosmetic, and environmental fields. Therefore, in this review, some of the crucial sustainable challenges with impacts on the valorisation of agri-food loss/wastes and by-products are discussed and identified, in addition to several opportunities, trends and innovations. Potential applications and usages of the most important compounds found in food loss/waste will be highlighted, with a focus on the food industry, pharmaceutical industry, and the environment.</jats:p
Spices volatilomic fingerprinting: a comprehensive approach to explore its authentication and bioactive properties
Get PDFVolatile organic metabolites (VOMs) present in different spices can provide distinct analytical biosignatures related to organoleptic properties and health benefits. This study aimed to establish the volatilomic fingerprint of six of the most consumed spices all over the world (saffron (Crocus sativus L.), cinnamon (Cinnamomum verum), cumin (Cuminum cyminum L.), black pepper, (Piper nigrum L.), sweet paprika (Capsicum annuum L.), and curry (a mix of different herbs and spices)). Based on headspace solid phase microextraction (HS-SPME) followed by gas chromatography-mass spectrometry (GC-MS) analysis, this is a powerful strategy to explore and establish the spice’s volatile pattern and unravel the potential health benefits related to the most important VOMs identified in each spice. This comprehensive knowledge will help in the definition of their authenticity, while simultaneously protecting against potential frauds and adulterations. A total of 162 VOMs were identified. Semi-quantitative assessments revealed that terpenoids and sesquiterpenoids amounted to the major volatile class in the investigated spices, except for cinnamon, where carbonyl compounds are the major group. Most of the studied spices comprised key characteristics of aroma and health bioactive compounds, e.g., dihydrojuneol in saffron, cinnamaldehyde in cinnamon, cuminaldehyde in cumin and curry, and caryophyllene in black pepper. The principal component analysis (PCA) and partial least-squares discriminant analysis (PLS-DA) successfully discriminated the investigated spices, being α-cubebene, 3-methyl butanal, β-patchoulene and β-selinene, the most important VOMs (highest VIP’s) that contributed to its discrimination. Moreover, some VOMs have a high influence on the spice’s bioactive potential, helping to prevent certain diseases including cancer, inflammatory-related diseases, diabetes, and cardiovascular diseases.</jats:p