Comparing the performance of geostatistical models with additional information from covariates for sewage plume characterization

In this work, kriging with covariates is used to model and map the spatial distribution of salinity measurements gathered by an autonomous underwater vehicle in a sea outfall monitoring campaign aiming to distinguish the effluent plume from the receiving waters and characterize its spatial variability in the vicinity of the discharge. Four different geostatistical linear models for salinity were assumed, where the distance to diffuser, the west-east positioning, and the south-north positioning were used as covariates. Sample variograms were fitted by the Mat`ern models using weighted least squares and maximum likelihood estimation methods as a way to detect eventual discrepancies. Typically, the maximum likelihood method estimated very low ranges which have limited the kriging process. So, at least for these data sets, weighted least squares showed to be the most appropriate estimation method for variogram fitting. The kriged maps show clearly the spatial variation of salinity, and it is possible to identify the effluent plume in the area studied. The results obtained show some guidelines for sewage monitoring if a geostatistical analysis of the data is in mind. It is important to treat properly the existence of anomalous values and to adopt a sampling strategy that includes transects parallel and perpendicular to the effluent dispersion.

Maximum likelihood detection for OFDM signals with strong nonlinear distortion effects

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

Integrating wind generation in the distribution network

Dissertação apresentada na Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa para obtenção do Grau de Mestre em Energias Renováveis – Conversão Eléctrica e Utilização Sustentáveis

Parallelization of web processing services on cloud computing: A case study of Geostatistical Methods

Dissertation submitted in partial fulfillment of the requirements for the Degree of Master of Science in Geospatial Technologies.

Evaluation of Spatial interpolation techniques for mapping climate variables with low sample density: a case study using a new gridded dataset of Bangladesh

Dissertation submitted in partial fulfillment of the requirements for the Degree of Master of Science in Geospatial Technologies.

Análise comparativa das ações do tráfego rodoviário definidas em diversos regulamentos internacionais de pontes

O presente trabalho pretende avaliar as diferenças de efeitos que os modelos de sobrecarga rodoviária de dez regulamentos (RSA, EC1-2, NBR, AASHTO, SATCC, CSA, IRC:6, SNiP, Manual de Hong Kong, NCP) provocam em pontes rodoviárias de pequeno a médio vão. Numa primeira parte são cobertas questões relacionadas com os efeitos dinâmicos em pontes referenciando-se diversos estudos. Em seguida são apresentados os principais fatores que influenciam os efeitos das sobrecargas rodoviárias. Os modelos de sobrecarga rodoviária, definidos nos diversos regulamentos, são descritos pormenorizadamente com o objetivo de clarificar e facilitar a sua aplicação. No que se refere à componente numérica do trabalho, a quantificação dos efeitos que cada modelo origina foi realizada através da modelação em elementos finitos de tabuleiros de comprimento variável entre 10 e 40 metros. Longitudinalmente analisaram-se os valores máximos do momento fletor e do esforço transverso, e numa análise transversal estudaram-se os valores máximos de momentos fletores positivos e negativos originados em cada tabuleiro. No capítulo 7 é realizada uma análise comparativa dos efeitos causados pelos modelos de sobrecarga rodoviária definidos em cada regulamento tomando como referência os valores obtidos pelo RSA.

Utilização de QR Codes em museologia

Trabalho de Projeto apresentado para cumprimento dos requisitos necessários à obtenção do grau de Mestre em Comunicação e Artes

Corporate strategy development: International distance model for the Brazilian market

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

Design, implementation, and performance of a distributed and scalable sensor system for critical distance measurements in the CMS detector at LHC

The “CMS Safety Closing Sensors System” (SCSS, or CSS for brevity) is a remote monitoring system design to control safety clearance and tight mechanical movements of parts of the CMS detector, especially during CMS assembly phases. We present the different systems that makes SCSS: its sensor technologies, the readout system, the data acquisition and control software. We also report on calibration and installation details, which determine the resolution and limits of the system. We present as well our experience from the operation of the system and the analysis of the data collected since 2008. Special emphasis is given to study positioning reproducibility during detector assembly and understanding how the magnetic fields influence the detector structure.

Home Banking

The object of this dissertation is focused on the study of the home banking service and how the allocation of losses due to computer fraud is processed in the scope of this service. When considering the questions raised by the allocation of losses associated with fraudulent operations, it is important to consider, mainly, the behaviour of the user of the home banking service. In our opinion, courts have been too demanding towards the user when judging his action in the use of this service. In this study, we have concluded that, when the user “falls” into a computer fraud scheme, he should not be liable for gross negligent behaviour, even if, due to the fraud, the user revealed all his access codes to a hacker on a page similar to that of his bank. In general, such facts will not be sufficient to qualify the user’s action as grossly negligent. Therefore, the user, under the terms of the Payment Services’ System, must bear the loss up to a maximum of €150, and the bank will face the remainder of the losses. However, if the user, victim of a fraudulent technique, ignored the safety warnings issued by the bank, one must consider, given the specific case, that he contributed to gross negligence in unauthorised payment transactions. Thus, the user must bear all the losses up to the moment when he notifies the bank about the unauthorised transactions. It is the bank’s responsibility to, given the specific case, adduce evidence of the client’s contribution to the identified losses.

A doença pulmonar obstrutiva crónica e o exercício: impacto da doença no declínio funcional e importância do treino de exercício nos benefícios para a saúde

RESUMO: A reabilitação respiratória (RR) é uma intervenção abrangente e interdisciplinar dirigida aos doentes respiratórios crónicos e inclui o treino de exercício, programas de educação e de modificação comportamental, entre outros, desenhados individualmente para melhorar o desempenho físico e psicossocial e promover a adesão a longo prazo a comportamentos promotores de saúde. A doença pulmonar obstrutiva crónica (DPOC) é uma doença comum, afetando cerca de 210 milhões de pessoas em todo o mundo, com elevada mortalidade e com custos económicos significativos decorrentes do agravamento progressivo da doença, das hospitalizações e de reinternamentos frequentes. Apesar do crescente conhecimento da DPOC e do papel da RR nos benefícios para a saúde, existem aspetos ainda não esclarecidos que têm impacto na prática clínica e de investigação e nas decisões das autoridades de saúde. A primeira parte desta tese focou a DPOC e o seu impacto negativo e incluiu: o estudo da prevalência da DPOC em Portugal; os fatores clínicos e funcionais que se associam à mortalidade em doentes com DPOC avançada; a morbilidade, impacto funcional e risco dos doentes se tornarem dependentes para as atividades diárias e a influência da inflamação sistémica. A prevalência estimada da DPOC de 14,2% indica que esta é uma doença comum em Portugal e alerta para a necessidade de uma maior sensibilização da população, dos profissionais de saúde e autoridades de saúde com vista a um diagnóstico precoce e à alocação dos recursos terapêuticos adequados. A elevada taxa de mortalidade em doentes com DPOC avançada - 36,6% em 3 anos - associou-se a insuficiência respiratória, a elevado número de exacerbações, ao cancro do pulmão e a reduzida capacidade funcional para a marcha, salientando a importância da referenciação precoce para RR, a identificação e o tratamento das comorbilidades e a prevenção das exacerbações. A aplicação de um questionário que avaliou as atividades da vida diária básicas e instrumentais, permitiu identificar um marcador clínico do risco de dependência, complementando as avaliações funcionais e associando-se a outros marcadores de mau prognóstico, como as exacerbações. Em doentes com DPOC, com FEV1 médio de 46,76% (desvio padrão: 20,90%), 67% da categoria D do GOLD, verificou-se uma associação positiva entre a expressão de genes inflamatórios avaliada pela reação em cadeia da polimerase (ARN mensageiro de IFNg, IL1b, IL6, IL8, TNFa, TGFb1, iNOS) e o índice de massa corporal em repouso, acentuando-se após o exercício. Este estudo aponta a inflamação como o potencial elo de ligação entre a obesidade e a inflamação sistémica em doentes com DPOC. A segunda parte da tese focou a RR, nomeadamente os seus efeitos em doentes das categorias GOLD A, B, C e D; o impacto das comorbilidades nos resultados da RR e os resultados de diferentes intensidades de treino aeróbio. Após o programa de RR, verificaram-se melhorias significativas na capacidade de exercício funcional e de endurance e no estado geral de saúde dos doentes de todas as categorias GOLD. Esta classificação não distingue os doentes que melhor poderão beneficiar desta intervenção, indicando que devem ser referenciados para RR, os doentes sintomáticos ou com repercussão na qualidade de vida, independentemente da categoria da DPOC a que pertençam. A prevalência das comorbilidades no grupo de doentes com DPOC que é referenciado para RR, é elevada, sendo as mais frequentes, as cardiovasculares, as respiratórias e as psicológicas. Apesar de poderem diminuir o impacto da RR, os resultados desta foram semelhantes independentemente do número de comorbilidades. A identificação e o tratamento sistemáticos das comorbilidades conferem maior segurança clínica a esta intervenção terapêutica a qual, por apresentar bons resultados, não deve limitar a referenciação dos doentes. Com o programa de RR, verificou-se melhoria significativa em todos os resultados centrados no doente para ambas as intensidades de treino aeróbio, a 60% e a 80% da potência aeróbica máxima (Wmax), com melhoria do estado geral de saúde, nos sintomas e na capacidade para o exercício, o que questiona a indicação sistemática de elevadas intensidades de treino em doentes com DPOC para a obtenção de benefícios a curto prazo. Na terceira e última parte da tese foi estudado o papel da atividade física na DPOC, focando os fatores que influenciam a atividade física diária; a evolução da capacidade funcional e o estado de saúde 2 anos após um programa de RR e o papel da telemonitorização na quantificação e monitorização da atividade física. Confirmámos que os doentes com DPOC são marcadamente sedentários e os fatores que se associaram ao sedentarismo nestes doentes foram a dispneia e a distância percorrida na prova de marcha de seis minutos. Este estudo sublinha a importância do controlo sintomático, nomeadamente da dispneia, bem como, mais uma vez, o potencial papel da reabilitação respiratória no aumento da capacidade funcional para o exercício e na aquisição de hábitos de vida fisicamente ativa. Verificámos que, apesar de os doentes com DPOC apresentarem benefícios clinicamente significativos na capacidade funcional para o exercício e no estado geral de saúde com o programa de RR, apenas os que se mantêm ativos, podem, no final dos dois anos de seguimento, manter os efeitos benéficos desse programa. O sistema de telemonitorização que combina a oximetria e a quantificação da atividade física provou ser clinicamente útil na avaliação da necessidade de oxigenoterapia de longa duração (OLD) e na aferição do débito de oxigénio em repouso, no esforço e no sono, podendo contribuir para uma melhor adequação da prescrição da OLD. A monitorização dos níveis de atividade física regular é um importante instrumento de avaliação dos programas de RR e o seu uso potencial na telereabilitação permitirá prolongar a eficácia dos programas e reduzir os custos associados aos cuidados de saúde.---------------------------------------------------------------------------------------------------ABSTRACT: Pulmonary rehabilitation (PR) is a comprehensive interdisciplinary intervention that includes, but is not limited to, exercise training, education, and behavior change, individually designed to improve physical and psychological conditions of people with chronic respiratory disease and to promote long-term adherence to health-enhancing behaviors. Chronic obstructive pulmonary disease (COPD) is a common disease, affecting about 210 million people worldwide, with high mortality and significant health-related costs due to disease progression, hospitalizations and frequent hospital readmissions. Although the increasing knowledge about COPD and benefitial outcomes of PR, some aspects with impact in clinical practice, research and health authorities’ decisions, remain to be clarified. The first part of this thesis focused on COPD and its negative impact, including the study of COPD prevalence in Portugal; clinical and functional factors associated with mortality in advanced COPD patients; morbidity, functional impact and risk of others’ dependance to perform activities of daily living; and the role of systemic inflammation. The evidence of 14.2% estimated COPD prevalence as a common disease in Portugal raises the need of an increasing awareness of population, health care professionals and health authorities towards an earlier diagnosis and apropriate treatment resources allocation. High mortality in patients with advanced COPD – 36.6% in 3 years - was associated with respiratory failure, high frequency of exacerbations, lung cancer and a low functional capacity in walking. This highlightens the importance of an earlier referral to PR, comorbidity identification and treatment, and prevention of exacerbations. A questionnaire evaluated basic and instrumental activities of daily living, and identified a clinical marker of the risk of becoming dependent. This clinical marker complemented other functional evaluations and was associated with prognosis markers such as the number of exacerbations. In COPD patients with a mean FEV1 46.76% (SD 20.90%), 67% belonging to GOLD grade D, we found a positive association between inflammatory gene expression evaluated by polymerase chain reaction (IFNg, IL1b, IL6, IL8, TNFa, TGFb1, iNOS RNA messenger) and body mass index at rest, and a further increase with exercise. This study evidenced obesity as one potential link between COPD and systemic inflammation. The second part of this thesis focused PR, namely its outcomes in patients of GOLD categories A, B, C and D; comorbidities impact in PR outcomes, and the impact of different exercise training intensities in patient related outcomes. xviii With PR intervention, we found significant improvement in functional exercise capacity, endurance exercise capacity and health status in patients of all GOLD categories. This classification did not differentiate which patients would benefit more from PR, hence all symptomatic patients with a negative impact in health status should be referred to PR, regardless of the GOLD category they belong to. There is a high prevalence of comorbidities in COPD patients referred to PR, being cardiovascular, respiratory and psychological, the most prevalent. Although some comorbidities might reduce PR impact, the results were similar regardless of the number of comorbidities. Systematic comorbidities identification and treatment provides safety to PR intervention, and its good results should not preclude patients referral. With PR intervention we found a significant improvement in all patient reported outcomes for exercise training intensities at 60% and 80% maximum work rate (Wmax), namely in health status, symptoms and exercise capacity. These findings challenge the current systematic indication of high exercise training intensities to achieve PR short-term benefits. In the third and last part of the thesis, the role of physical activity in COPD was studied, focusing factors that may influence daily physical activity; the evolution of functional capacity and health status two years after a PR program, and the role of a telemonitoring system in physical activity quantification and monitoring. We confirmed that COPD patients are markedly inactive and factors associated with a sedentary lifestyle are dyspnea and 6 minute walking distance. This study emphasized the importance of symptom control, namely of dyspnea, as well as, once again, the potential role of PR in functional exercise improvement and in integrating physically active habits in daily life. We verified that, although COPD patients improve functional exercise capacity and health status after a PR program, only those who kept physical activity habits were able to maintain those effects after 2 years of follow-up. A telemonitoring system that combines oximetry and physical activity quantification proved to be clinically useful in the evaluation of long-term oxygen therapy (LTOT) indication, as well as in the titration of oxygen levels at rest, exertion, and sleeping, which might contribute to a more adequate LTOT prescription. Monitoring of daily physical activity levels is an important PR evaluation instrument and its potential use in telerehabilitation might allow lengthening programs efficacy, while reducing health-care costs.

Underwater acoustic modem with streaming video capabilities

Oceans have shown tremendous importance and impact on our lives. Thus the need for monitoring and protecting the oceans has grown exponentially in recent years. On the other hand, oceans have economical and industrial potential in areas such as pharmaceutical, oil, minerals and biodiversity. This demand is increasing and the need for high data rate and near real-time communications between submerged agents became of paramount importance. Among the needs for underwater communications, streaming video (e.g. for inspecting risers or hydrothermal vents) can be seen as the top challenge, which when solved will make all the other applications possible. Presently, the only reliable approach for underwater video streaming relies on wired connections or tethers (e.g. from ROVs to the surface) which presents severe operational constraints that makes acoustic links together with AUVs and sensor networks strongly appealing. Using new polymer-based acoustic transducers, which in very recent works have shown to have bandwidth and power efficiency much higher than the usual ceramics, this article proposes the development of a reprogrammable acoustic modem for operating in underwater communications with video streaming capabilities. The results have shown a maximum data-rate of 1Mbps with a simple modulation scheme such as OOK, at a distance of 20 m.

Dispersal of seeds of Hymenaea courbaril (Fabaceae) in a logged rain forest in the Peruvian Amazonian

Seed dispersal of Hymenaea courbaril was studied by following the fate of 585 seeds embedded with small magnets and set in displays in and near a logged strip in rain forest in the Peruvian Amazonian. Mammals took fruits from all displays, which were located in the forest, edge, and cleared strip. Overall removal rates were low - a median of 8.1 fruits / month from displays maintained with 8-10 fruits - but were higher in August than in earlier months. Most fruits were dropped near the display or had their seeds eaten, but > 13% were successfully dispersed. Most of the dispersed seeds were buried, which increases probability of germination. Maximum dispersal distance of live seeds was 12.1 m (median 3.1 m), but other magnets were transported up to 34 m, indicating seeds were dispersed further, but then eaten. Acouchies (most likely Myoprocta pratti) and agoutis (Dasyprocta fuliginosa) were apparently the main dispersal agents. Dispersal of seeds from the forest into the logged strip was rare, suggesting that although rodents disperse H. courbaril, they cannot be relied on for the reseeding this and similar species in recent clearings.

Distance perception in immersive environments: the role of photorealism

Immersive environments (IE) are being increasingly used in order to perform psychophysical experiments. The versatility in terms of stimuli presentation and control and the less time-consuming procedures are their greatest strengths. However, to ensure that IE results can be generalized to real world scenarios we must first provide evidence that performance in IE is quantitatively indistinguishable from performance in real-world. Our goal was to perceptually validate distance perception for CAVE-like IEs. Participants performed a Frontal Matching Distance Task (Durgin & Li, 2011) in three different conditions: real-world scenario (RWS); photorealistic IE (IEPH) and non-photorealistic IE (IENPH). Underestimation of distance was found across all the conditions, with a significant difference between the three conditions (Wilks’ Lambda = .38, F(2,134)= 110.8, p<.01, significant pairwise differences with p<.01). We found a mean error of 2.3 meters for the RWS, 5 meters for the IEPH, and of 6 meters for the IENPH in a pooled data set of 5 participants. Results indicate that while having a photorealistic IE with perspective and stereoscopic depth cues might not be enough to elicit a real-world performance in distance judgment tasks, nevertheless this type of environment minimizes the discrepancy between simulation and real-world when compared with non-photorealistic IEs.

O efeito da deposição salina nas características das escorrências rodoviárias em zonas costeiras

Tese de Doutoramento em Engenharia Civil.