91 resultados para Point process

em Repositório Científico do Instituto Politécnico de Lisboa - Portugal


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Nowadays, the Portuguese insurance industry operates in a market with a much more aggressive structure than a few decades ago. Markets and the economy have become globalised since the last decade of the 20th century. Market forces have gradually shifted – power is now mainly on the demand side. In order to meet the new requirements, the insurance industry must develop a strong strategic ability to respond to constant changes of the new international economic order.One of the basic aspects of this strategic development will focus on the ability to predict the future. We introduce the subject by briefly describing the sector, its organisational structure in the Portuguese market, and challenges arising from the development of the European Union. We then analyse the economic and financial structure of the sector. From this point of view, we aim at the possibility of designing models that could explain the demand for insurance, claims and technical reserves evolution. Such models, (even if based on the past), would resolve, at least partly, one of the greatest difficulties experienced by insurance companies when estimating the budget. Thus, we examine the existence of variables that explain the previous points, which are capable of forming a basis for designing models that are simple but efficient, and can be used for strategic planning.

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The deposition of highly oriented a-axis CrO(2) films onto Al(2)O(3)(0001) by atmospheric pressure (AP)CVD at temperatures as low as 330 C is reported. Deposition rates strongly depend on the substrate temperature, whereas for film surface microstructures the dependence is mainly on film thickness. For the experimental conditions used in this work, CrO(2) growth kinetics are dominated by a surface reaction mechanism with an apparent activation energy of (121.0 +/- 4.3) kJ mol(-1). The magnitude and temperature dependence of the saturation magnetization, up to room temperature, is consistent with bulk measurements.

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In the Sparse Point Representation (SPR) method the principle is to retain the function data indicated by significant interpolatory wavelet coefficients, which are defined as interpolation errors by means of an interpolating subdivision scheme. Typically, a SPR grid is coarse in smooth regions, and refined close to irregularities. Furthermore, the computation of partial derivatives of a function from the information of its SPR content is performed in two steps. The first one is a refinement procedure to extend the SPR by the inclusion of new interpolated point values in a security zone. Then, for points in the refined grid, such derivatives are approximated by uniform finite differences, using a step size proportional to each point local scale. If required neighboring stencils are not present in the grid, the corresponding missing point values are approximated from coarser scales using the interpolating subdivision scheme. Using the cubic interpolation subdivision scheme, we demonstrate that such adaptive finite differences can be formulated in terms of a collocation scheme based on the wavelet expansion associated to the SPR. For this purpose, we prove some results concerning the local behavior of such wavelet reconstruction operators, which stand for SPR grids having appropriate structures. This statement implies that the adaptive finite difference scheme and the one using the step size of the finest level produce the same result at SPR grid points. Consequently, in addition to the refinement strategy, our analysis indicates that some care must be taken concerning the grid structure, in order to keep the truncation error under a certain accuracy limit. Illustrating results are presented for 2D Maxwell's equation numerical solutions.

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This article presents the design and test of a receiver front end aimed at LMDS applications at 28.5 GHz. It presents a system-level design after which the receiver was designed. The receiver comprises an LNA, quadrature mixer and quadrature local oscillator. Experimental results at 24 GHz center frequency show a conversion voltage gain of 15 dB and conversion noise figure of 14 5 dB. The receiver operates from a 2 5 V power supply with a total current consumption of 31 mA.

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We report in this paper the recent advances we obtained in optimizing a color image sensor based on the laser-scanned-photodiode (LSP) technique. A novel device structure based on a a-SiC:H/a-Si:H pin/pin tandem structure has been tested for a proper color separation process that takes advantage on the different filtering properties due to the different light penetration depth at different wavelengths a-SM and a-SiC:H. While the green and the red images give, in comparison with previous tested structures, a weak response, this structure shows a very good recognition of blue color under reverse bias, leaving a good margin for future device optimization in order to achieve a complete and satisfactory RGB image mapping. Experimental results about the spectral collection efficiency are presented and discussed from the point of view of the color sensor applications. The physics behind the device functioning is explained by recurring to a numerical simulation of the internal electrical configuration of the device.

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In this work we report on the structure and magnetic and electrical transport properties of CrO2 films deposited onto (0001) sapphire by atmospheric pressure (AP)CVD from a CrO3 precursor. Films are grown within a broad range of deposition temperatures, from 320 to 410 degrees C, and oxygen carrier gas flow rates of 50-500 seem, showing that it is viable to grow highly oriented a-axis CrO2 films at temperatures as low as 330 degrees C i.e., 60-70 degrees C lower than is reported in published data for the same chemical system. Depending on the experimental conditions, growth kinetic regimes dominated either by surface reaction or by mass-transport mechanisms are identified. The growth of a Cr2O3 interfacial layer as an intrinsic feature of the deposition process is studied and discussed. Films synthesized at 330 degrees C keep the same high quality magnetic and transport properties as those deposited at higher temperatures.

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Laser-assisted chemical vapour deposition (LCVD) has been extensively studied in the last two decades. A vast range of applications encompass various areas such as microelectronics, micromechanics, microelectromechanics and integrated optics, and a variety of metals, semiconductors and insulators have been grown by LCVD. In this article, we review briefly the LCVD process and present two case studies of thin film deposition related to laser thermal excitation (e.g., boron carbide) and non-thermal excitation (e.g., CrO(2)) of the gas phase.

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The subject matter of this book is about piano methodology, including technical, musical, artistic, ethical and philosophical issues and reflections. The purpose of this work is to share a personal professional experience insight in the field of piano performance. This text assumes a certain continuity to the major contributions of artists like Ludwig Deppe, Tobias Matthay, Grigory Kogan, Heinrich Neuhaus and George Kochevitsky. At the same time, it tries to integrate and complement this selected literature, bringing new ideas and hints to specific professional issues.

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This paper presents a step-up micro-power converter for solar energy harvesting applications. The circuit uses a SC voltage tripler architecture, controlled by an MPPT circuit based on the Hill Climbing algorithm. This circuit was designed in a 0.13 mu m CMOS technology in order to work with an a-Si PV cell. The circuit has a local power supply voltage, created using a scaled down SC voltage tripler, controlled by the same MPPT circuit, to make the circuit robust to load and illumination variations. The SC circuits use a combination of PMOS and NMOS transistors to reduce the occupied area. A charge re-use scheme is used to compensate the large parasitic capacitors associated to the MOS transistors. The simulation results show that the circuit can deliver a power of 1266 mu W to the load using 1712 mu W of power from the PV cell, corresponding to an efficiency as high as 73.91%. The simulations also show that the circuit is capable of starting up with only 19% of the maximum illumination level.

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A dissertação de mestrado subordinada ao tema das Relações Intergeracionais e as Sociedades Envelhecidas surgiu, no âmbito do Mestrado em Educação Social e Intervenção Comunitária, da Escola Superior de Educação de Lisboa e teve como ponto de partida saber se a participação em actividades intergeracionais promove o envelhecimento ativo de 8 mulheres com 65 e mais anos, residentes num território multigeracional de Lisboa Oriental. A abordagem concetual do envelhecimento social, do envelhecimento ativo, das relações intergeracionais e da participação conduziu o estudo, através da triangulação dos instrumentos de análise qualitativa de entrevistas de histórias de vida e de focus group. As mulheres entrevistadas têm entre 65 e 85 anos de idade cronológica, mas em média dizem sentir que têm menos 34 anos. Afirmam, ser jovens de espirito e por isso preferem ser chamadas de seniores. Manifestam que sempre foram e são, mulheres autónomas, livres, independentes, com poder de decisão, com auto-estima elevada e com qualidade de vida. Mulheres que ocupam o tempo em actividades da vida diária, em actividades de tempos livres, e voluntariado. Mulheres reivindicativas, proativas, frontais e determinadas que assumem um papel social ativo envolvendo-se socialmente em todas as actividades produtivas ou orientadas para a performance e em actividades colectivas e ou orientadas para a união, com vista alcançar objetivos comuns. Mulheres, que ganham prestígio e estatuto na comunidade por se envolverem socialmente no processo de tomadas de decisão, organização, execução e avaliação, com as gerações mais novas. São visionárias ancestrais de espirito jovem que abrem novas portas para a construção social da velhice nas sociedades neoliberais e desafiam os humanistas quando afirmam que as atividades produtivas na velhice dão sentido à própria existência. São histórias de mulheres que nos fazem acreditar que a participação social contribui espontaneamente para o diálogo entre as gerações, em todas as fases da vida. - Abstract A dissertation on the subject of Intergenerational Relationships and Societies Aged emerged within the Master of Education Social and Community Intervention, School of Education and Lisbon had as starting point whether participation promotes intergenerational activities on aging 8 active women aged 65 years and older, residing in the territory of Eastern Lisbon multigenerational. The conceptual approach of social aging, active aging, intergenerational relations and participation conducted the study through triangulation of instruments qualitative analysis of interviews and life stories focus group. The women interviewed are between 65 and 85 years of chronological age, but on average say they feel they are under 34 years old. They claim to be young in spirit and so they prefer to be called seniors. Demonstrate that have always been and are women autonomous, free, independent, decision-making, self-esteem and quality of life. Women who occupy the time in activities of daily life, in leisure activities, and volunteering. Women reivindicativas, proactive, front and determined to play an active social role by engaging in socially productive activities or any performance-oriented and collective activities and or targeted at the union in order to achieve common objectives. Women who gain prestige and status in the community by becoming involved socially in the process of decision making, organization, implementation and evaluation with the younger generations. They are young visionary spirit of ancestors that open new doors to the social construction of old age in neoliberal societies and challenge humanists say when productive activities in old age give meaning to their own existence. These are stories of women who have us believe that social participation contributes to spontaneous dialogue between generations, in all stages of life.

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O conceito de poesia é uma forma de arte e traduz-se como um espelho do pensamento do homem realizado na palavra oral e escrita. A poesia poderá ensinar o homem no estudo da palavra, através do seu significado nos valores denotativo e/ou conotativo. A aplicação destes conceitos faz sentido, a partir da ideia de que a palavra no contexto da poesia pode produzir emoções e sensações nas pessoas a quem ela é transmitida. A poesia tem funções multissensoriais que podem definir o input linguístico como forma de desenvolver a linguagem. Vários são os estudos que apontam para as principais competências deficitárias nos indivíduos com Trissomia 21, mas poucas são as investigações que se debruçam sobre a influência da poesia nas várias competências linguísticas. Uma perceção mais ampla e visionária da Arte na voz da poesia pela parte da escola, professores e, em particular, professores de Educação Especial permitirá adotar estratégias de intervenção inovadoras. Pretende este estudo investigar e analisar a forma como a poesia pode influenciar o desenvolvimento da linguagem oral numa aluna com Trissomia 21. Neste projeto, a partir da identificação do caso-problema e da constatação da ausência da poesia no currículo da aluna, procurou-se intervir, no sentido de melhorar as suas competências linguísticas, utilizando para tanto a poesia. A implementação do projeto aconteceu ao longo de seis meses durante quinze sessões de intervenção individuais. Os resultados do projeto mostram que, em todas as competências linguísticas, houve um processo evolutivo, sendo particularmente significativo o desenvolvimento da competência fonológica, aumento de vocabulário e uma maior noção da palavra em contexto. Estes dados levam-nos a crer que a utilização da poesia poderá, também, constituir uma forma de promover a socialização e a autonomia, revelando os efeitos colaterais que poderão decorrer deste tipo de intervenção. - Abstract The concept of poetry is a form of art, showing the man's thought held in the spoken and written word. Poetry can teach man in the study of the word, its meaning through denotative and/or connotative values. The application of these concepts makes sense, from the idea that the word in the context of poetry can stir emotions and feelings in the people to whom it is transmitted. Poetry has multisensory functions that can set the linguistic input as a way to develop language at phonological, lexical, semantics, pragmatic and morfosyntactic skills. There are several studies that point out to the key skills deficit in individuals with Trisomy 21, but there are few investigations that focus on the influence of poetry in various language skills. A broader perception and vision of poetry as art given by school, and teachers, and, particularly teachers of Special Education will allow a more effective intervention strategies. This study aims to investigate and analyze how poetry can influence the development of oral language in a student with Trisomy 21. In this project, we tried to intervene, improving the language skills of the student, using poetry from the identification case-problem and confirmation of the absence of poetry in her curriculum. The implementation of the project took place throughout six months for fifteen individual intervention sessions. The project results show that, in all language skills, there was a progressive process, being particularly significant the development of the phonological skills, increased vocabulary and a greater sense of the word into context. These data lead us to believe that the use of poetry can also be a way to promote socialization and autonomy, revealing the side effects that may result from this type of intervention.

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Dissertação apresentada à Escola Superior de Comunicação Social como parte dos requisitos para obtenção de grau de mestre em Audiovisual e Multimédia.

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Neste trabalho aborda-se o desenvolvimento da carroçaria do Veículo Eléctrico Ecológico – VEECO recorrendo a tecnologias assistidas por computador. Devido à impossibilidade de abranger toda a temática das tecnologias assistidas por computador, associadas ao desenvolvimento de uma carroçaria automóvel, o foco deste trabalho assenta no processo de obtenção de um modelo digital válido e no estudo do desempenho aerodinâmico da carroçaria. A existência de um modelo digital válido é a base de qualquer processo de desenvolvimento associado a tecnologias assistidas por computador. Neste sentido, numa primeira etapa, foram aplicadas e desenvolvidas técnicas e metodologias que permitem o desenvolvimento de uma carroçaria desde a sua fase de “design” até à obtenção de um modelo digital CAD. Estas abrangem a conversão e importação de dados, a realização de engenharia inversa, a construção/reconstrução CAD em CATIA V5 e a preparação/correcção de modelos CAD para a análise numérica. Numa segunda etapa realizou-se o estudo da aerodinâmica exterior da carroçaria, recorrendo à ferramenta de análise computacional de fluidos (CFD) Flow Simulation da CosmosFloworks integrado no programa SolidWorks 2010. Associado à temática do estudo aerodinâmico e devido à elevada importância da validação dos resultados numéricos por meio de dados experimentais, foi realizado o estudo de análise dimensional que permite a realização de ensaios experimentais à escala, bem como a análise dos resultados experimentais obtidos.

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Neste artigo, são discutidos os conceitos de demonstração e de esquema demonstrativo, bem como a relevância curricular da demonstração e os contextos favoráveis à sua aprendizagem. Alguns dos resultados do estudo, relativamente ao papel da demonstração no currículo, bem como ao modo como se desenvolveu o processo demonstrativo, são apresentados e discutidos. A metodologia adotada no estudo teve uma natureza interpretativa e os participantes no estudo foram uma turma de 9.º ano e a respetiva professora de Matemática. As conclusões do estudo apontam para o facto de os alunos tenderem a usar exemplos particulares para validar as suas afirmações matemáticas. Apontam ainda para as múltiplas funções da demonstração nas tarefas em que esta surgiu como um meio de descoberta da solução do problema. Sugerem também que a introdução e a negociação da importância da demonstração implicam uma intervenção curricular, na qual a professora detém um papel fundamental.