A Generalized Approach to Complex Networks

This work describes how the formalization of complex network concepts in terms of discrete mathematics, especially mathematical morphology, allows a series of generalizations and important results ranging from new measurements of the network topology to new network growth models. First, the concepts of node degree and clustering coefficient are extended in order to characterize not only specific nodes, but any generic subnetwork. Second, the consideration of distance transform and rings are used to further extend those concepts in order to obtain a signature, instead of a single scalar measurement, ranging from the single node to whole graph scales. The enhanced discriminative potential of such extended measurements is illustrated with respect to the identification of correspondence between nodes in two complex networks, namely a protein-protein interaction network and a perturbed version of it. The use of other measurements derived from mathematical morphology are also suggested as a means to characterize complex networks connectivity in a more comprehensive fashion.Comment: 10 pages, 2 figur

Adverse Selection and Risk Aversion in Capital Markets

We generalize the Boadway and Keen (2006) model of adverse selection in a capital market to allow for risk aversion on the part of entrepreneurs. We show that the Boadway and Keen conclusion-that adverse selection leads to excessive investment-does not necessarily hold when entrepreneurs are risk averse. We use their framework, with the additional assumption of risk aversion, to analyze the effect of policies that would reduce entrepreneurs' reliance on debt or equity financing by outside investors. We show that such policies, by exposing entrepreneurs to more down-side risk, may reduce the level of investment in risky projects, increase inequality and potentially reduce social welfare.adverse selection; capital markets; inefficiency; risk and entrepreneurship

Polyphase filter with parametric tuning

Tese de mestrado integrado. Engenharia Electrotécnica e de Computadores. Faculdade de Engenharia. Universidade do Porto. 201

Framework para a análise da microestrutura do corpo caloso ao longo de sua extensão

Orientador: Roberto de Alencar LotufoTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de ComputaçãoResumo: O corpo caloso é de grande interesse para a comunidade médica e de pesquisa, e suas características têm sido associadas a muitos distúrbios psicológicos e doenças cerebrais. A análise localizada de suas características é um procedimento usual, particularmente para o diagnóstico de esclerose múltipla e outras doenças inflamatórias. Neste trabalho, propomos um framework para extrair características da microestrutura ao longo da extensão do corpo caloso em uma função de assinatura, permitindo que análises globais e localizadas sejam realizadas no domínio 1--D da assinatura, em vez do domínio 3--D de a imagem original. Nossa solução é uma sucessão de vários métodos especializados, que foram projetados para resolver partes específicas do pipeline de geração de assinatura, incluindo a definição de um plano de simetria local para as fibras internas do corpo caloso, realizar a segmentação do corpo caloso, traçar o eixo médio da estrutura e extrair as características ao longo do eixo médio. Um dataset com imagens de 80 aquisições distintas de indivíduos saudáveis foi usado para avaliar tanto o plano de simetria da fibra quanto as assinaturas geradas. Os resultados mostram que o plano predito pelo nosso método é significativamente distinto dos planos preditos pelos métodos tradicionais de estimativa do plano sagital médio, com uma diferença maior na inclinação em relação ao plano axial, de cerca de 2 graus em média. As assinaturas apresentam um padrão similar na maioria dos casos, mas retêm características individuais. Em uma análise de agrupamento, verificamos que existe um único aglomerado maior que tem seu tamanho reduzido drasticamente apenas quando todas as arestas são removidas, exceto aquelas com pelo menos 90% de similaridade. As assinaturas geradas pelo nosso framework proposto fornecem uma maneira inédita de realizar a análise das características da microestrutura do corpo caloso, que é inerentemente localizada e independente da morfologia da estrutura. Nossa solução abre novas possibilidades no campo para pesquisa e desenvolvimento futuros relacionadosAbstract: The corpus callosum is of great interest for the medical and research community, and its characteristics have been associated with many psychological disorders and brain diseases. Localized analysis of its features is a usual procedure, particularly for the diagnosis of multiple sclerosis and other inflammatory diseases. In this work, we propose a framework for extracting microstructure features along the corpus callosum extent into a signature function, allowing global and localized analyses to be performed in the 1--D domain of the signature, instead of the 3--D domain of the original image. Our solution is a succession of several specialized methods, which were designed to solve specific parts of the signature generation pipeline, including defining a plane of local symmetry for the corpus callosum internal fibers, perform the corpus callosum segmentation, trace the structure median axis, and extract the features along the median axis. A dataset with images from 80 distinct acquisitions from healthy subjects was used to evaluate both, the fiber's symmetry plane, and the generated signatures. Results show that the plane predicted by our method is significantly distinct from the planes predicted by traditional mid--sagittal plane estimation methods, with a larger difference on the inclination relative to the axial plane, of about 2 degrees on average. The signatures present a similar pattern in most cases but retain individual characteristics. In a clustering analysis, we verified that there is one single larger cluster that has its size reduced dramatically only when all edges are removed, except for the ones with at least 90% of similarity. The signatures generated by our proposed framework provide an unprecedented way to perform the analysis of the corpus callosum microstructure features, which is inherently localized, and independent from the structure morphology. Our solution open new possibilities for future related research and development in the fieldDoutoradoEngenharia de ComputaçãoDoutor em Engenharia Elétrica2012/23059-8FAPES

Limits of performance of chirped- pulse phase-sensitive OTDR

Distributed acoustic sensing is an emerging field of research which aims to develop methods capable of using a single optical fiber as a long, dense, and high-sensitivity sensor array. Currently, the most promising implementations measure the interference of Rayleigh backscattered light, obtained by probing the fiber with light from a source of high coherence. These methods are known as Phase-sensitive Optical Time-Domain Reflectometers (φOTDR), and are currently undergoing a period of active research and development, both academically and industrially. One of its variants, known as the Chirped-Pulse φOTDR (CP-φOTDR), was developed in 2016. This technique has proven to be remarkably sensitive to strain and temperature, with an attractively simple implementation. In this thesis, we delve into the intricacies of this technique, probing its fundamental limits and addressing current limitations. We discuss the implications of estimation on the performance statistics, the impact of different noise sources and the origin of cross-talk between independent measured positions. In doing so, we also propose methods to reach the current fundamental limitations, and overcome the upper bound of measurable perturbations. We then demonstrate new potential applications of the technique: in seismology, by exploiting the high spatial density of measurements for array signal processing; in the fast characterization of linear birefringence in standard single-mode fibers; and on the measurement of sound pressure waves, by using a special flat cable structure to embed the fiber under test. Finally, we summarize and comment on the aforementioned achievements, proposing some open lines of research that may originate from these results.Distributed acoustic sensing is an emerging field of research which aims to develop methods capable of using a single optical fiber as a long, dense, and highsensitivity sensor array. Currently, the most promising implementations measure the interference of Rayleigh backscattered light, obtained by probing the fiber with light from a source of high coherence. These methods are known as Phase-sensitive Optical Time-Domain Reflectometers (φOTDR), and are currently undergoing a period of active research and development, both academically and industrially. One of its variants, known as the Chirped- Pulse φOTDR (CP-φOTDR), was developed in 2016. This technique has proven to be remarkably sensitive to strain and temperature, with an attractively simple implementation. In this thesis, we delve into the intricacies of this technique, probing its fundamental limits and addressing current limitations. We discuss the implications of estimation on the performance statistics, the impact of different noise sources and the origin of cross-talk between independent measured positions. In doing so, we also propose methods to reach the current fundamental limitations, and overcome the upper bound of measurable perturbations. We then demonstrate new potential applications of the technique: in seismology, by exploiting the high spatial density of measurements for array signal processing; in the fast characterization of linear birefringence in standard single-mode fibers; and on the measurement of sound pressure waves, by using a special flat cable structure to embed the fiber under test. Finally, we summarize and comment on the aforementioned achievements, proposing some open lines of research that may originate from these results

SOS Ambiente

Relatório de Estágio apresentado à Escola Superior de Educação do Instituto Politécnico de Santarém para obtenção de grau de Mestre em Educação e Comunicação MultimédiaO presente Relatório de Estágio refere-se às actividades programadas e realizadas durante o ano lectivo de 2009 – 2010 no âmbito Mestrado de Educação e Comunicação Multimédia da Escola Superior de Educação de Santarém. O Relatório de Estágio reporta-se a um Projecto de Intervenção, que apelidámos de SOS Ambiente, na Escola Secundária da Marquesa, através do qual procurámos aprofundar e aplicar os conhecimentos adquiridos no MECM. Para o desenvolvimento deste Projecto de intervenção contámos com o apoio dos alunos, que se envolveram nas várias actividades propostas, com o apoio de muitos colegas da mesma Escola, que articularam o desenvolvimento das suas actividades curriculares com a importância de actividades e comunicações multimodais de articulação a nível de Escola, com o apoio da Direcção da Escola, que nos deu as devidas autorizações e, finalmente, com o apoio da Câmara Municipal de Almeirim, que, mais uma vez, foi inexcedível.N/

The relationships between maladaptive personality traits and experiences in closerelationships

The proposed classification for Personality Disorders in section III of the DSM5conceptually differentiates impaired personality functioning (criterion A) from theoccurrence of maladaptive personality traits (criterion B). Criterion B offers analternative trait approach with five higher order domains (Negative Affectivity,Detachment, Antagonism, Disinhibition, and Psychoticism), and criterion A specifies anumber of problems common to all Personality Disorders, specifically impairments inself- and interpersonal functioning. This Thesis aimed to establish significantrelationships between personality pathology and experiences in close relationships. Toachieve this goal, the following aims were proposed: the examination of relationshipsbetween maladaptive personality and personality functioning; the exploration of thelinks between maladaptive personality and attachment; the investigation of the linksbetween maladaptive traits and relationship intimacy and satisfaction; and theexamination of the maladaptive personality traits among different samples. The firststudy showed that Personality Functioning and maladaptive personality are negativelyassociated, with the latter being a negative predictor of Personality Functioning,replicating and extending the findings of previous research. Two studies alsoestablished associations between maladaptive personality and attachment styles(anxious and avoidant), finding that personality pathology is positively associated withanxious and avoidant attachment, but can also predict these domains. Another studyaddressed the associations of satisfaction and intimacy in relationships, with resultsshowing how maladaptive personality can impact these. The last study inspected howthe severity of maladaptive personality differed across samples and examined howcombinations of traits and their severity are a helpful way to categorize distinct andmeaningful groups. These findings help to further understand the role of personalitypathology in the way it impacts experiences of close relationships, and to contribute tothe conceptualization and operationalization of personality pathology as proposed bythe DSM-5

História familiar de Diabetes Tipo 2 está associada com Síndrome Metabólica em indivíduos obesos do sexo feminino

The aim of this study was to evaluate the association between the family history (FH) of type 2 diabetes and metabolic syndrome (MetS) in a group of non-diabetic obese female subjects. A cross-sectional study was conducted in 239 female patients with obesity, regularly attending the Internal Medicine Division’s outpatient clinic (Hospital de Clínicas de Porto Alegre, Brazil). The inclusion criteria were patients with body mass index /30 kg/m2 and absence of type 2 diabetes. The FH was considered positive if a first degree relative had a diagnosis of diabetes. Seventy-four of 239 patients evaluated (30%) had a positive FH for type 2 diabetes. Patients with positive FH had higher waist/hip ratio and MetS more often than patients with negative FH. FH of type 2 diabetes was associated with MetS in this sample of nondiabetic obese female patients. Waist/hip ratio and fasting plasma glucose, markers of insulin resistance, were also associated with FH of type 2 diabetes. The simple question: “Do you have a FH of type 2 diabetes?” may help to identify the obese patients that should be better evaluated and intensively treated with the objective of preventing type 2 diabetes.O objetivo deste estudo foi avaliar a associação entre história familiar (HF) de diabetes melito tipo 2 (DM2) e síndrome metabólica (SM) em um grupo de mulheres obesas não-diabéticas. Conduzimos um estudo transversal com 239 mulheres com obesidade, regularmente atendidas no ambulatório de medicina interrna do Hospital de Clínicas de Porto Alegre, Brasil. Os critérios de inclusão foram pacientes com índice de massa corporal /30 kg/m2 e ausência de DM2. A HF de DM2 foi considerada positiva se um familiar de primeiro grau tivesse o diagnóstico de diabetes. Setenta e quatro das 239 pacientes avaliadas (30%) tiveram uma HF positiva de DM2. Pacientes com HF positiva tiveram maior razão cintura/quadril e mais frequentemente a presença de SM que as pacientes com HF negativa. A HF de DM2 foi associada com SM nesta amostra de pacientes femininas obesas não-diabéticas. A razão cintura/quadril e a glicemia de jejum, ambos marcadores de resistência à ação da insulina, foram também associadas com HF de DM2. A simples pergunta: “Você tem uma HF de DM2”? pode ajudar a identificar pacientes obesos que devem ser mais bem avaliados e intensamente tratados com o objetivo de prevenção do DM2