Human activity recognition with accelerometry: novel time and frequency features

Human Activity Recognition systems require objective and reliable methods that can be used in the daily routine and must offer consistent results according with the performed activities. These systems are under development and offer objective and personalized support for several applications such as the healthcare area. This thesis aims to create a framework for human activities recognition based on accelerometry signals. Some new features and techniques inspired in the audio recognition methodology are introduced in this work, namely Log Scale Power Bandwidth and the Markov Models application. The Forward Feature Selection was adopted as the feature selection algorithm in order to improve the clustering performances and limit the computational demands. This method selects the most suitable set of features for activities recognition in accelerometry from a 423th dimensional feature vector. Several Machine Learning algorithms were applied to the used accelerometry databases – FCHA and PAMAP databases - and these showed promising results in activities recognition. The developed algorithm set constitutes a mighty contribution for the development of reliable evaluation methods of movement disorders for diagnosis and treatment applications.

Gold nanoparticles for the detection of DNA adducts as biomarkers of exposure to acrylamide

The main objective of this thesis was the development of a gold nanoparticle-based methodology for detection of DNA adducts as biomarkers, to try and overcome existing drawbacks in currently employed techniques. For this objective to be achieved, the experimental work was divided in three components: sample preparation, method of detection and development of a model for exposure to acrylamide. Different techniques were employed and combined for de-complexation and purification of DNA samples (including ultrasonic energy, nuclease digestion and chromatography), resulting in a complete protocol for sample treatment, prior to detection. The detection of alkylated nucleotides using gold nanoparticles was performed by two distinct methodologies: mass spectrometry and colorimetric detection. In mass spectrometry, gold nanoparticles were employed for laser desorption/ionisation instead of the organic matrix. Identification of nucleotides was possible by fingerprint, however no specific mass signals were denoted when using gold nanoparticles to analyse biological samples. An alternate method using the colorimetric properties of gold nanoparticles was employed for detection. This method inspired in the non-cross-linking assay allowed the identification of glycidamide-guanine adducts and DNA adducts generated in vitro. For the development of a model of exposure, two different aquatic organisms were studies: a goldfish and a mussel. Organisms were exposed to waterborne acrylamide, after which mortality was recorded and effect concentrations were estimated. In goldfish, both genotoxicity and metabolic alterations were assessed and revealed dose-effect relationships of acrylamide. Histopathological alterations were verified primarily in pancreatic cells, but also in hepatocytes. Mussels showed higher effect concentrations than goldfish. Biomarkers of oxidative stress, biotransformation and neurotoxicity were analysed after prolonged exposure, showing mild oxidative stress in mussel cells, and induction of enzymes involved in detoxification of oxygen radicals. A qualitative histopathological screening revealed gonadotoxicity in female mussels, which may present some risk to population equilibrium.

Sharp's alliances in China

This report presents a case study to be used in courses of negotiation in masters and executive programs. The case studies the topics of the coalitions´ formation and stability from a negotiation analysis perspective, linking it to value creation. Moreover, it illustrates the problem of western companies investing in the Chinese market. The methodology utilized was the construction of a negotiation case, inspired by a real negotiation in the Consumer Electronics industry. Its purpose is to illustrate the value creation problems in coalitions. It is concluded that by maximizing value creation, negotiating parties are more likely to obtain stable coalitions

Essays on bounded rationality: Individual decision and strategic interaction

Economics is a social science which, therefore, focuses on people and on the decisions they make, be it in an individual context, or in group situations. It studies human choices, in face of needs to be fulfilled, and a limited amount of resources to fulfill them. For a long time, there was a convergence between the normative and positive views of human behavior, in that the ideal and predicted decisions of agents in economic models were entangled in one single concept. That is, it was assumed that the best that could be done in each situation was exactly the choice that would prevail. Or, at least, that the facts that economics needed to explain could be understood in the light of models in which individual agents act as if they are able to make ideal decisions. However, in the last decades, the complexity of the environment in which economic decisions are made and the limits on the ability of agents to deal with it have been recognized, and incorporated into models of decision making in what came to be known as the bounded rationality paradigm. This was triggered by the incapacity of the unboundedly rationality paradigm to explain observed phenomena and behavior. This thesis contributes to the literature in three different ways. Chapter 1 is a survey on bounded rationality, which gathers and organizes the contributions to the field since Simon (1955) first recognized the necessity to account for the limits on human rationality. The focus of the survey is on theoretical work rather than the experimental literature which presents evidence of actual behavior that differs from what classic rationality predicts. The general framework is as follows. Given a set of exogenous variables, the economic agent needs to choose an element from the choice set that is avail- able to him, in order to optimize the expected value of an objective function (assuming his preferences are representable by such a function). If this problem is too complex for the agent to deal with, one or more of its elements is simplified. Each bounded rationality theory is categorized according to the most relevant element it simplifes. Chapter 2 proposes a novel theory of bounded rationality. Much in the same fashion as Conlisk (1980) and Gabaix (2014), we assume that thinking is costly in the sense that agents have to pay a cost for performing mental operations. In our model, if they choose not to think, such cost is avoided, but they are left with a single alternative, labeled the default choice. We exemplify the idea with a very simple model of consumer choice and identify the concept of isofin curves, i.e., sets of default choices which generate the same utility net of thinking cost. Then, we apply the idea to a linear symmetric Cournot duopoly, in which the default choice can be interpreted as the most natural quantity to be produced in the market. We find that, as the thinking cost increases, the number of firms thinking in equilibrium decreases. More interestingly, for intermediate levels of thinking cost, an equilibrium in which one of the firms chooses the default quantity and the other best responds to it exists, generating asymmetric choices in a symmetric model. Our model is able to explain well-known regularities identified in the Cournot experimental literature, such as the adoption of different strategies by players (Huck et al. , 1999), the inter temporal rigidity of choices (Bosch-Dom enech & Vriend, 2003) and the dispersion of quantities in the context of di cult decision making (Bosch-Dom enech & Vriend, 2003). Chapter 3 applies a model of bounded rationality in a game-theoretic set- ting to the well-known turnout paradox in large elections, pivotal probabilities vanish very quickly and no one should vote, in sharp contrast with the ob- served high levels of turnout. Inspired by the concept of rhizomatic thinking, introduced by Bravo-Furtado & Côrte-Real (2009a), we assume that each per- son is self-delusional in the sense that, when making a decision, she believes that a fraction of the people who support the same party decides alike, even if no communication is established between them. This kind of belief simplifies the decision of the agent, as it reduces the number of players he believes to be playing against { it is thus a bounded rationality approach. Studying a two-party first-past-the-post election with a continuum of self-delusional agents, we show that the turnout rate is positive in all the possible equilibria, and that it can be as high as 100%. The game displays multiple equilibria, at least one of which entails a victory of the bigger party. The smaller one may also win, provided its relative size is not too small; more self-delusional voters in the minority party decreases this threshold size. Our model is able to explain some empirical facts, such as the possibility that a close election leads to low turnout (Geys, 2006), a lower margin of victory when turnout is higher (Geys, 2006) and high turnout rates favoring the minority (Bernhagen & Marsh, 1997).

Light harvesting in solar cells using natural pigments from red fruits adsorbed to mesoporous TiO2

Nature has developed strategies to present us with a wide variety of colours, from the green of leaves to the bright colours seen in flowers. Anthocyanins are between these natural pigments that are responsible for the great diversity of colours seen in flowers and fruits. Anthocyanins have been used to sensitize titanium dioxide (TiO2) in Dye-Sensitized Solar Cells (DSSCs). DSSCs have become one of the most popular research topic in photovoltaic cells due to their low production costs when compared to other alternatives. DSSCs are inspired in what happens in nature during photosynthesis. A primary charge separation is achieved by means of a photoexcited dye capable of performing the electron injection into the conduction band of a wide band-gap semiconductor, usually TiO2. With this work we aimed to synthesize a novel mesoporous TiO2 structure as the semiconductor in order to increase the dye loading. We used natural occurring dyes such as anthocyanins and their synthetic flavylium relatives, as an alternative to the widely used metal complexes of Ru(II) which are expensive and are environmentally unsafe. This offers not only the chance to use safer dyes for DSSCs, but also to take profit of waste biological products, such as wine and olive oil production residues that are heavily loaded with anthocyanin dyes. We also performed a photodegradation study using TiO2 as the catalyst to degrade dye contaminants, such as those from the wine production waste, by photo-irradiation of the system in the visible region of the light spectrum. We were able to succeed in the synthesis of mesoporous TiO2 both powder and thin film, with a high capacity to load a large amount of dye. We proved the concept of photodegradation using TiO2 as catalyst. And finally, we show that wine production waste is a possible dye source to DSSCs application.

Machine diagnosis based on artificial immune systems

Nowadays, many of the manufactory and industrial system has a diagnosis system on top of it, responsible for ensuring the lifetime of the system itself. It achieves this by performing both diagnosis and error recovery procedures in real production time, on each of the individual parts of the system. There are many paradigms currently being used for diagnosis. However, they still fail to answer all the requirements imposed by the enterprises making it necessary for a different approach to take place. This happens mostly on the error recovery paradigms since the great diversity that is nowadays present in the industrial environment makes it highly unlikely for every single error to be fixed under a real time, no production stop, perspective. This work proposes a still relatively unknown paradigm to manufactory. The Artificial Immune Systems (AIS), which relies on bio-inspired algorithms, comes as a valid alternative to the ones currently being used. The proposed work is a multi-agent architecture that establishes the Artificial Immune Systems, based on bio-inspired algorithms. The main goal of this architecture is to solve for a resolution to the error currently detected by the system. The proposed architecture was tested using two different simulation environment, each meant to prove different points of views, using different tests. These tests will determine if, as the research suggests, this paradigm is a promising alternative for the industrial environment. It will also define what should be done to improve the current architecture and if it should be applied in a decentralised system.

Les Très Riches Heures et les Heures Bedford

The article presents new stylistic material in support of the discovery (in 2005) that the Bedford Hours were designed in the years 1414-1415, at the same time as the Très Riches Heures du duc de Berry. The Bedford Hours would appear to have been made for the dauphin, Louis de Guyenne, in light of the occurrence of several of his emblems under the principle miniatures, as well as the calendar programme, which is inspired by Ovid’s Fasti. The identification of the heraldry in the miniature of the history of the fl eur de lis (f. 288v) by Michel Pastoureau demonstrates that the miniature also represents the coronation of Henry V in 1429 in the presence of Philippe le Bon, Anne de Bourgogne and John de Mowbray, duke of Norfolk and earl marshall.

Criminosos popularizados na narrativa de divulgação (De 1838 aos Alvores da República)

O presente estudo incide sobre obras impressas que tomaram como motivo central as «façanhas» de criminosos com referência histórica celebrizados em Portugal na segunda metade do século XIX e inícios de XX e mostra que, enquanto narrativas elaboradas para o grande público, os textos foram não só um reflexo da popularidade prévia dos famigerados transgressores, como também um fator incontornável da sua «lendarização» ao longo de décadas. São as seguintes as figuras dos infratores que protagonizaram as ficções em apreço: José Joaquim de Sousa Reis, ou «o Remexido» (1797-1838), Diogo Alves, ou «o Pancada» (1810-1841), Francisco de Matos Lobo (1814-1842), José Teixeira da Silva, ou «o José do Telhado» (1816-1875), João Victor da Silva Brandão, ou «o João Brandão de Midões» (1825-1880), e Vicente Urbino de Freitas (1859-1913). A tese agora apresentada aborda um corpus textual de características singulares, nunca antes coligido nem estudado. Comprova que os textos sobre as figuras criminosas tiveram uma função iminentemente noticiosa, pedagógico-edificante e política, apropriando-se de relatos orais, adotando procedimentos de atestação da veracidade (transcrição de documentos na primeira pessoa, referenciação cronológica, espacial, geográfica dos eventos, alusão às fontes) e incorporando diversas fontes do conhecimento dos crimes, quer de origem popular (geralmente designadas de «musa popular», «tradição»), quer de caráter erudito e teórico-científico («estudo», «estudo social»). Assim, foram analisadas as condições históricas excecionais nas quais as ficções emergiram: as características específicas do seu universo editorial, a apropriação a um público amplo (o formato de coleção, uso de sinopses e de outros elementos gráficos), as regularidades discursivas das obras (ocorrência de determinados dispositivos de organização textual), os procedimentos narrativos (recurso abundante a paratextos com intuito explicativo e aproximação a modalidades ficcionais conhecidas do público da época) e, ainda, as configurações imagéticas inspiradas nos discursos oficiais (influência de ciências e doutrinas epocais emergentes, como a criminologia, a antropologia criminal, a frenologia, a psiquiatria, a sociologia). Em suma, estas edições produzidas em diversos contextos e por um elenco autoral heterogéneo não só viveram da relação com as edições predecessoras, ao longo de gerações, como recriaram e ampliaram as «façanhas» dos transgressores em função de diversos propósitos e fontes: ampla divulgação dos casos criminais, condenação pública dos infratores, análise médico-científica dos sujeitos culpados, especulação política, pressão sobre o foro judiciário, edificação moral do público leitor. Trata-se, sem dúvida, de produções únicas, que erigiram a comemoração dos facínoras e sucessivamente reinscreveram as suas histórias reais na problemática do homem criminal e na consciência ética do seu tempo.

Why an entrepreneur should be a marketeer

Inspired by the booming startup culture that’s transforming Lisbon’s business setting, the present case study tests the hypothesis that great marketing is the main key to any new business’ success, by analyzing the history and environment of a premature Portuguese tech startup company exploring the market of destination weddings, Wedmint, and its inbound marketing strategy.