2,544 research outputs found

    Implementation of a Computer-Vision System as a Supportive Diagnostic Tool for Parkinson’s Disease

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    Parkinson’s disease is the second most common neurodegenerative disorder, affecting nearly 1 million people in the US and it is predicted that the number will keep increasing. Parkinson’s disease is difficult to diagnose due to its similarity with other diseases that share the parkinsonian symptoms and the subjectivity of its assessment, thus increasing the probabilities of misdiagnosis. Therefore, it is relevant to develop diagnostic tools that are quantitatively based and monitoring tools to improve the patient’s quality of life. Computer-based assessment systems have shown to be successful in this field through diverse approaches that can be classified into two main categories: sensor-based and computer vision-based systems. In this thesis, the implementation of a computer vision system to detect Parkinson’s disease is explored. As Parkinson’s diseases has characteristic motor symptoms, and gait is mainly affected, a computer vision system is proposed to analyze the gait features to classify subjects with Parkinson’s disease. Using Microsoft’s Kinect sensor and Azure Kinect sensor, the position of body joints in a 3D space was obtained and angles between those were calculated. The standard deviation of 7 different angles over time was calculated for each and used as features in a support vector machine with the purpose of classifying Parkinson’s disease patients versus controls. Moreover, challenges and future perspectives for the implementation of computer-vision systems as supportive diagnostic tools for Parkinson’s disease are discussed

    Mechanising an algebraic rely-guarantee refinement calculus

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    PhD ThesisDespite rely-guarantee (RG) being a well-studied program logic established in the 1980s, it was not until recently that researchers realised that rely and guarantee conditions could be treated as independent programming constructs. This recent reformulation of RG paved the way to algebraic characterisations which have helped to better understand the difficulties that arise in the practical application of this development approach. The primary focus of this thesis is to provide automated tool support for a rely-guarantee refinement calculus proposed by Hayes et. al., where rely and guarantee are defined as independent commands. Our motivation is to investigate the application of an algebraic approach to derive concrete examples using this calculus. In the course of this thesis, we locate and fix a few issues involving the refinement language, its operational semantics and preexisting proofs. Moreover, we extend the refinement calculus of Hayes et. al. to cover indexed parallel composition, non-atomic evaluation of expressions within specifications, and assignment to indexed arrays. These extensions are illustrated via concrete examples. Special attention is given to design decisions that simplify the application of the mechanised theory. For example, we leave part of the design of the expression language on the hands of the user, at the cost of the requiring the user to define the notion of undefinedness for unary and binary operators; and we also formalise a notion of indexed parallelism that is parametric on the type of the indexes, this is done deliberately to simplify the formalisation of algorithms. Additionally, we use stratification to reduce the number of cases in in simulation proofs involving the operational semantics. Finally, we also use the algebra to discuss the role of types in program derivation

    Proper Laplacian Representation Learning

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    The ability to learn good representations of states is essential for solving large reinforcement learning problems, where exploration, generalization, and transfer are particularly challenging. The Laplacian representation is a promising approach to address these problems by inducing informative state encoding and intrinsic rewards for temporally-extended action discovery and reward shaping. To obtain the Laplacian representation one needs to compute the eigensystem of the graph Laplacian, which is often approximated through optimization objectives compatible with deep learning approaches. These approximations, however, depend on hyperparameters that are impossible to tune efficiently, converge to arbitrary rotations of the desired eigenvectors, and are unable to accurately recover the corresponding eigenvalues. In this paper we introduce a theoretically sound objective and corresponding optimization algorithm for approximating the Laplacian representation. Our approach naturally recovers both the true eigenvectors and eigenvalues while eliminating the hyperparameter dependence of previous approximations. We provide theoretical guarantees for our method and we show that those results translate empirically into robust learning across multiple environments

    Characteristics and Performance of Knowledge Networks in the Biotechnology Sector

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    This research aimed to analyze the properties and typologies of a biotechnology sector network with regard to their relationships, attributes and performance in research and production of innovations. For this purpose, it had as its empirical field the Northeast Biotechnology Network, using patent reports produced by the network as a data source. In order to track the relationship networks between members, groups, institutions and projects, social networking analysis tools were used, making it possible to construct relationship matrices between thelaboratories and companies and, lastly, researchers. In total, 117 researchers were identified, distributed among 18 research centers and 47 laboratories or companies. Their projects are distributed across three main areas: agriculture, industrial and health, the latter being the strongest of the three with more patents produced and more institutions involved in research. The weak density presented by the network, at all analysis levels, strengthens the necessity for integration strategies. Also, it indicates the possibility for new relationships between agents that are still isolated. However, it does not diminish its importance for economic development in the region in which it operates

    Elastic, dielectric and electromechanical properties of (Bi0.5Na0.5)TiO3-BaTiO3 piezoceramics at the morphotropic phase boundary region

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    A systematic study of the functional properties of the (1-x)(Bi0.5Na0.5)TiO3–xBaTiO3 (BNT-xBT) piezoceramic system for 0.05 = x = 0.07 is performed. The samples are obtained through the conventional solid-state route. The expected microstructure for these compounds, with no significant dependence on the composition, is verified by field-emission scanning electron microscopy. The morphotropic phase boundary (MPB) is detected for x = 0.06–0.07 by means of the Rietveld analysis of X-ray diffraction data. The dielectric spectra show a frequency-independent, completely diffuse phase transition with a composition-dependent diffusivity coefficient. The depolarization temperature is effectively evaluated from pyroelectric measurements, the value being strongly dependent on the composition. A significant contribution of the extrinsic effect to elastic, dielectric and electromechanical properties is revealed for MPB BNT-xBT. The Bi3+ substitution by Ba2+ leads to the formation of A-site vacancies, which give rise to the enhancement of domain wall motion, as occurs in other perovskite-type piezoelectrics. Good functional properties are achieved for x = 0.07 (d33 = 180 pC/N), which are similar or even better than those obtained by complex synthesis routes. This system exhibits a remarkable stability in the permittivity that has hitherto not been reported. This fact may open the way for BNT-BT compositions to be used in specific applications in which lead-free piezoceramics have previously been employed with little success, e.g. in high power devices.Postprint (author's final draft

    Isto não é uma pichação: afrontas (icono)gráficas e ilusões nominalistas em Joinville-SC

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    Com base em narrativas de acontecimentos recentes em Joinville, Santa Catarina, este artigo discute a diferenciação entre as práticas da pichação e do grafite, (icono)grafias que se sobrepõem às paredes e muros da cidade. Argumenta-se que a demarcação da linha que diferencia tais práticas depende de disputas por um poder de nomeação. Em um primeiro momento, são analisados projetos de lei que visaram a criar mecanismos para coibir ações de pichadores e permitir que grafiteiros pudessem expressar sua “arte”, desde que autorizados. Em seguida, a análise se volta a argumentos de estudos que explicaram as diferenças entre pichação e grafite. São perceptíveis esforços para elencar critérios objetivos de diferenciação, apostando em uma neutralidade axiológica. Na parte final do artigo, propõe-se suspender essa pretensa neutralidade para compreender as palavras pichação e grafite como rótulos que atribuem valores a práticas sociais, os quais se adequariam, mais ou menos, aos ideais de “pureza”, “significação” e “beleza”

    Análise das Concepções Prévias de Grupo de Estudantes sobre a Dengue no Município de Foz Do Iguaçu, PR

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    Tendo em vista que a cidade de Foz do Iguaçu é um município com altos índices de notificação de casos de dengue, e esta deve ser encarada como uma questão de saúde pública, este artigo tem como objetivo analisar as concepções prévias de um grupo deestudantes a cerca do tema que frequentam as aulas de Ciências de uma escola pública do município de Foz do Iguaçu. Entendemos que esse reconhecimento prévio se faz importante, uma vez que o professor pode partir dessas concepções sobre o tema para ampliá-los posteriormente com atividades que estimulem a construção e reconstrução do conhecimento. A pesquisa tem caráter qualitativo, com caracterísitcas de estudo de caso, buscando algumas evidências teórico a partir das respostas obtidas.Foi aplicado um questionário padrão para que os estudantes respondessem a quatro questões dissertativas: 1) Você sabe o que é dengue? 2) Como as pessoas contraem dengue?; 3) Você conhece alguém próximo que já foi infectado pelo vírus da dengue?; 4) Qual o procedimento caso um indivíduo tenha suspeita de dengue?. Os resultados obtidos diante de nossa análise sugerem que o grupo de estudantes apresenta um conhecimento fragmentado sobre o tema, e que a maioria dos estudantes não possui a capacidade de estabelecer relação entre o vetor da doença e o vírus da dengue

    Otimização do processo de polimerização em solução de n-vinilpirrolidona utilizando planejamento experimental

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    Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico, Programa de Pós-Graduação em Engenharia Química, Florianópolis, 2014Dependo das especificações do produto, a poli (pirrolidona vinílica), possui diversas aplicações. Porém, a qualidade dela é facilmente comprometida se ocorrer pequenas variações durante a reação, em especial, na quantidade de monômero residual, devida sua alta toxicidade. Visto que as principais aplicações são na formulação de fármacos, cosméticos e na produção de polímeros, realizou-se uma otimização na reação de polimerização da n-vinilpirrolidona, adotando um planejamento fatorial 32, que tem como variáveis a interação entre dois iniciadores e a temperatura de reação. Os iniciadores utilizados foram perpivolato de terc-butilae 2-etil-hexanoato de terc-butila. A resposta do planejamento é verificada por meio dos valores de massa molar e conversão. A partir do perfil de valores preditos, utilizando software de estatística, foram obtidos valores otimizados para reação. Como verificação, realizou-se a reação com os referidos valores, obtendo assim a confirmação de massa molar e conversão. Ainda, verificou-se a viabilidade de modelagem matemática do processo de polimerização em solução via radical livre para n-vinilpirrolidona, no qual é possível constar a validação da simulação. Por fim, fez-se a aplicação da poli (pirrolidona vinílica) a partir do planejamento na reação de poliestireno expansível, na qual não foram encontradas diferenças substanciais nos produtos da polimerização.Abstract: Depending on the product specifications, polyvinylpyrrolidone (PVP) has several applications. However, the polymer quality is easily compromised if slight variations occur during the reaction, particularly on the amount of residual monomer, which is a highly toxic material. Since its main applications are in the formulation of pharmaceuticals, cosmetics and in the polymers production, it was made a optimization in the polymerization reaction of n-vinylpyrrolidone, by adopting a factorial design 32, using the interaction between two initiators and reaction temperature as variables.The iniciators adopted in process were tert-butyl peroxypivalate and tertbutyl peroxy-2-ethylhexanoate. The design response is verified by molecularweight and conversion. By the analysis of the predicted values using statistical software, optimized values for the reaction process was founded. To confirm the software response, the reaction was performed with those values, obtaining confirmation of molecular weight and conversion. In addition to it, was realized the study to verify the viability of mathematical modeling of free-radical solution polymerization for n-vinylpyrrolidone, in which, it was confirmed the validation of simulation. Finally, the PVP obtained from the planning was applied in the polystyrene expansion process, which no significant differences were found in the products obtained on comparsion with a commercial sample

    A FRAGILIDADE AMBIENTAL E SUAS RELAÇÕES COM A VULNERABILIDADE SOCIAL EM SÃO SEBASTIÃO (LITORAL NORTE DE SÃO PAULO): UM ENFOQUE NA BACIA DO CÓRREGO MÃE IZABEL.

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    Resumo A atuação do homem sobre o meio deve ser testada de modo a proporcionar o entendimento sobre as possibilidades de desequilíbrio que possam ocorrer. Neste texto nos propomos a um estudo sobre o Município de São Sebastião no Litoral Norte do estado de São Paulo, apresentando um maior enfoque a Bacia do Córrego Mãe Izabel, objetivando a identificação dos possíveis desequilíbrios que possam ocorrer na relação sociedade-natureza através do mapeamento destas informações em escala de 1:10.000. A análise sobreposta entre os dados de fragilidade ambiental e vulnerabilidade social indicam que há uma relação espacial entre a fragilidade do relevo e as populações socialmente vulneráveis nesta bacia hidrográfica. Concluímos que as fragilidades naturais do espaço de estudo são potencializadas pela presença de uma ocupação urbana associada à precarização das condições de vida das populações em suas estruturas sócio familiares e pela falta de uma intervenção gestora eficiente. Palavras-chave: Fragilidade Ambiental. Bacia Hidrográfica. Geografia. Planejamento. Vulnerabilidade. Social. Natureza. Abstract The action of man on the environment should be tested in order to provide an understanding of the imbalance of possibilities that may occur. In this paper we propose a study on the city of São Sebastião on the north coast of São Paulo, with a greater focus Basin Stream Mãe Izabel, aiming at the identification of possible imbalances that may occur in the relationship between society and nature by mapping this information on a scale of 1: 10.000. The analysis overlap between data environmental fragility and social vulnerability indicate that there is a spatial relationship between the fragility of relief and socially vulnerable populations in this watershed. We conclude that the natural weaknesses of the study space are enhanced by the presence of an urban occupation associated with precarious conditions of populations stocks in their family social structures and the lack of an efficient management intervention. Key words: Environmental Fragility. Watershed. Geography. Planning. Social Vulnerability. Nature. Resumen La acción del hombre sobre el medio ambiente debe ser probado con el fin de proporcionar una comprensión del desequilibrio de las posibilidades que se pueden presentar. En esta investigacione se propone un estudio sobre la ciudad de São Sebastião, en la costa norte de São Paulo, con un mayor enfoque por la Cuenca Mãe Izabel, con miras a la identificación de los posibles desequilibrios que puedan producirse en la relación entre la sociedad y la naturaleza de la cartografía esta información en una escala de 1: 10.000. La superposición de análisis entre la fragilidad ambiental de los datos y la vulnerabilidad social indican que existe una relación espacial entre la fragilidad de alivio y poblaciones socialmente vulnerables en esta cuenca. Llegamos a la conclusión de que las debilidades naturales del espacio de estudio se ven reforzadas por la presencia de una ocupación urbana asociada a las condiciones precarias de las poblaciones de las poblaciones en sus estructuras sociales de la familia y la falta de una intervención de gestión eficiente. Palabras claves: Fragilidad Ambiental. Cuenca. Geografía. Planificación. La Vulnerabilidad Social. Naturaleza
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