Use of GPU for time series analysis

The Global Navigation Satellite System (GNSS) provides the position of stations with millimetre accuracy. These positions are not constant over time due to motion of the tectonic plates on which they are installed. The motion of tectonic plates is not the same all over the world, leading stress to build up in some areas, thus increasing the occurrence of earthquakes. The knowledge of such movements is of extreme importance, as is the determination of their uncertainty. The tectonic motion is a very slow process that is constant over thousands of years. As a result, the motion can be represented by a linear trend. Programs such as Hector can estimate linear trends in time series with temporal correlated noise. Correlated noise means that GNSS observations made today are similar to those of the days before, and it implies that one actually has less information than when all observations were independent. This is the reason why the real uncertainty of the estimated tectonic motion is between 5 to 11 times larger than when this temporal correlation was not considered. Unfortunately, taking this temporal correlation into account in the analysis slows down the computations considerably. With the ever growing number of GNSS stations and the increasing length of the existing time series, it is necessary to speed up these computations. This behaviour can also be found in other geodetic time series such as sea level observed at tide gauges, and surface temperature time series. For climate change studies it is important that besides estimating sea level rise or an increase in temperature, also the associated uncertainties are realistic. The Hector software package was developed with also the aim to reduce the computation time as much as possible. In this thesis we will investigate if the use of a powerful Graphics Processing Unit (GPU) can further reduce this computation time. So far, no Hector-like software uses GPUs to perform data processing. This dissertation is therefore the first attempt to go in that direction.Os Sistemas de Navegação por Satélite, (do inglês Global Navigation Satellite System - GNSS) fornecem a posição de estações com uma precisão milimétrica. Estas posições não são constantes ao longo do tempo devido ao movimento das placas tectónicas nas quais as estações se encontram instaladas. O movimento das placas tectónicas não é igual em todas as partes do globo, o que leva à acumulação de stress em algumas áreas, aumentado assim a ocorrência de movimentos sísmicos. O conhecimento de tais movimentos é de extrema importância, bem como a determinação da sua incerteza. O movimento tectónico é um processo muito lento e constante ao longo de milhares de anos. Como resultado, o movimento pode ser representado por uma tendência linear. Programas como o Hector podem estimar tendências lineares em séries temporais com ruído temporal correlacionado. Ruído correlacionado significa que as observações dos Sistemas de Navegação por Satélite feitas hoje são similares às dos dias anteriores, o que implica que haja menos informação do que se as observações fossem independentes. Esta é a razão pela qual a incerteza real do movimento tectónico estimado é entre 5 a 11 vezes maior do que quando esta correlação temporal não é considerada. Infelizmente, ter em consideração essa correlação temporal na análise aumenta consideravelmente o tempo de computação. Com o crescente número de estações GNSS e o aumento da duração das séries temporais existentes, é necessário acelerar essa computação. Este comportamento também pode ser encontrado em outras séries temporais geodésicas, como as do nível do mar observado em medidores de maré ou séries temporais da temperatura da superfície. Para estudos das alterações climáticas, é importante que, para além de estimar a elevação do nível do mar ou um aumento da temperatura, também as incertezas associadas sejam realísticas. O conjunto de software Hector foi desenvolvido com o objetivo de reduzir o tempo de computação tanto quanto possível. Nesta tese, investigaremos se o uso de uma potente Unidade de Processamento Gráfico (do inglês Graphics Processing Unit), vulgarmente conhecida como placa gráfica, pode reduzir ainda mais este tempo de computação. Até ao momento, nenhum software semelhante ao Hector usa placas gráficas para realizar o processamento de dados. Esta dissertação é, portanto, a primeira tentativa a ir nesse sentido

Analytical approach to directed sandpile models on the Apollonian network

We investigate a set of directed sandpile models on the Apollonian network, which are inspired on the work by Dhar and Ramaswamy (PRL \textbf{63}, 1659 (1989)) for Euclidian lattices. They are characterized by a single parameter $q$, that restricts the number of neighbors receiving grains from a toppling node. Due to the geometry of the network, two and three point correlation functions are amenable to exact treatment, leading to analytical results for the avalanche distributions in the limit of an infinite system, for $q=1,2$. The exact recurrence expressions for the correlation functions are numerically iterated to obtain results for finite size systems, when larger values of $q$ are considered. Finally, a detailed description of the local flux properties is provided by a multifractal scaling analysis.Comment: 7 pages in two-column format, 10 illustrations, 5 figure

Initial Stages of Implementation

Multirotors are used in many applications in the present. For some of these applications the capability of the vehicle to perform autonomous missions is a key element. The work for this thesis consists on the initial stages of a multirotor precision landing system implementation. Two commercially available and cheap systems were proposed so that they can be used for commercial purposes. One of the systems (Marvelmind) works by triangulating distances obtained by the relation between the speed of sound and the delay on a transmitted ultrasound (time of flight). The other system (IR-LOCK) works based on a camera (infrared sensible) that detects a target (that emits infrared light) and estimates its relative position. After the initial setup for each system, problems were identified and solutions implemented accordingly. With the Marvelmind system, the autopilot is able to identify its position but is unstable when performing a hover flight and as a result, an autonomous landing is not possible. With the IR-LOCK system, the vehicle is capable of performing autonomous precise landings.Os multirotores são utilizados em imensas aplicações actualmente. Para algumas destas aplicações a capacidade de o veículo efectuar missões de forma autónoma é um ponto-chave. O trabalho para esta disseratção consiste nas etapas iniciais da implementação de um sistema de aterragem de precisão para multirotores. Foram escolhidos dois sistemas cormercialmente disponíveis e baratos para que possam ser utilizados para fins comerciais. Um dos sistemas (Marvelmind) funciona através da triangulação de distâncias obtidas pela relação entre a velocidade do som e o tempo de transmissão de ultrassons (tempo de voo). O outro sistema (IR-LOCK) implementado funciona com base numa câmara (sensível à radiação infravermelha) que deteta um alvo (emissor de radiação infravermelha) e estima a sua posição relativa. Após a configuração inicial de cada sistema, foram identificados problemas e implementadas soluções apropriadas. Com o sistema Marvelmind, o piloto automático é capaz de identificar a sua posição mas é instável ao realizar um voo pairado e por conseguinte, uma aterragem de forma autónoma não é possível. Com o sistema IR-LOCK, o veículo é capaz de executar aterragens autónomas precisas

CO2 and economic growth: An analysis for emissions from burning fossil fuels in liquid form in Brazil.

The relationship between economic growth and environmental degradation has been widely studied in recent years. Defenders of the Environmental Kuznets Curve (EKC) hypothesis argue that the environmental pressure coming from economic growth is growing at first and as the economy moves on its development stages, the relationship becomes decreasing. In this discussion, this paper aims to analyze the relationship between CO2 emissions, resulting from burning fossil fuels in liquid form, and the Brazilian economic growth, by means of per capita GDP, with a time series beginning at 1903. Additionally, it is discussed the avoided CO2 emissions arising from the Brazilian energy policy adopted from the 1970s to the transport sector. The evidence found indicates that the relationship between the two variables is linearly increasing, not allowing to conclude that there is an EKC for the case in study.Emissões de CO2, PIB per capita, Transportes, Curva de Kuznets Ambiental.

An analysis of the relationship between economy, energy and environment

This article aims to identify the debate on the triad economy, energy and environment, providing a greater focus to the issue of climate change. After historically contextualize the economic use of energy and expose the current global energy picture, describes the environmental issue in the light of economic science, stating the two main theoretical approaches of environmental economics. Finally, the article devoted to the important and urgent but controversial debate about the impact of energy model on climate change. Pointed out that, despite a current minority dissenting, the world has significant and reliable evidence that the economic system through several segments, especially the intensive use of energy, may be contributing to the changes in climatic conditions of planet. Energy use and the need to readjust it, both in terms of greater efficiency on the issue of replacing the current fossil energy sources to less carbon-intensive, was one of the main conclusions of the discussion about how to direct the economic system to a path of greater sustainability.energía; medio ambiente; economía; cambio climático.

E-participation with social media in Science, Technology and Innovation: Brazilian States Research Support Foundations case

The use of social media has advanced in all social strata with effect on citizen participation in political discussions. In the context of Science, Technology and Innovation (ST&I) policies, bringing citizens closer together is a challenge for scientific and governmental institutions. The Brazilian States Research Support Foundations (RSF) show interest in promoting this approach to legitimize investments in science. Studies on the effects of social media on the relations between science, society and government are scarce. This research analyzed how e-participation, through social media, promotes citizen participation in the ST&I policies and actions of the RSFs. Nine organizations, including at least one Foundation from each Brazilian region, participated in this study. The main contribution of social media was the ability to intensify the interactions between government, researchers and citizens, using an informal and accessible language

Plataforma para rastreio neonatal com suporte a múltiplos formatos de dados e patologias

It is currently difficult to find a society that is not surrounded by new technologies, which are constantly emerging and evolving. With this technological evolution, many areas also began to enter a new era, as is the case of medicine, more specifically the screening of metabolic diseases in newborns. For a long time, it has been a great concern to discover the reasons why newborn babies, apparently healthy, die. With the emergence of new analysis techniques, it was possible to begin to unravel and find solutions to avoid these fatalities. Nowadays, there are already programs for diagnosing metabolic diseases in newborns and equipment capable of analyzing samples that allow diagnosing these diseases. In order to support technicians who examine the data coming from these equipment, and to prevent errors, there was a need to create systems capable of providing this support.Atualmente é dificil encontrar uma sociedade que não se rodeie com as novas tecnologias, que não param de surgir e evolir. Com esta evolução tecnológica, muitas àreas começaram também a entrar numa nova era, como é o caso da medicina, mais especifiacamente o rastreio de doenças metabólicas em recém nascidos. À muito tempo, que é uma grande preocupação descobrir os motivos aos quais levavam bebés recém nascidos, aparentemente saudáveis, a vir a falecer. Com o aparecimento de novas técnicas de análise, foi possível começar a desvendar e encontrar soluções para evitar essas fatalidades. Nos dias de hoje, já existem programas para diagnóstico de doenças metabólicas em recém nascidos e equipamentos capazes de analisar amostras que permitem diagnosticar essas doenças. Tendo em vista dar suporte a técnicos que examinam os dados vindos desses equipamentos, e prevenir erros, houve a necessidade de criar sistemas capazes de dar esse apoio.Mestrado em Engenharia Informátic

Academic analytics: mapping the genome of the University

Higher education institutions have multiple technologic subsystems for administrative, pedagogical management, and quality purposes, which gather an immense volume of data from various sources and which do not communicate with each other. The domain of the analytic performances in education emerges from the need to aggregate multiple sources of data, which the complexity of treatment associated with the ease of mobilizing selected information will make it possible to understand reality and optimize management actions. In this paper, we present the architecture and results achieved in the development of an academic analytics aggregator of multiple sources of data on the educational activity.info:eu-repo/semantics/publishedVersio