34 resultados para Funções quase-periodicas

em Universidade Federal do Rio Grande do Norte(UFRN)


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This study was presented to the Post-Graduation Program in Social Sciences at UFRN as part of the requisites for obtaining the title of Master in Social Sciences. It describes the results of the research From social movements to the institutional functions: the consolidation of a generation . Its main objective is to describe the history of a political generation that emerged from the social movements, in the 80 s, in Sergipe, and that nowadays occupies the main governmental positions in the State s political scenario. As its specific objectives, the research described the emerging of social movements in the 80s in Sergipe; it found in the social movements in Sergipe, in the 80s, the beginning of the history of a new political generation, and described the consolidation of this new political generation in institutional positions as the expression of a new group of power in Sergipe s politics. Among the social movements that gained visibility in that period and that projected their leadership into the political scenario of Sergipe, this study highlights: the students movement, teacher s movement, bank clercks movement, miners movement, and rural workers movement. It utilized as methodology the research in sites, magazines, and the use of testimonies from semi-structured interviews. The main leadership of the five movements that were analyzed is, nowadays, governing the state, administering the capital s city hall, and performing legislative work at the Legislative Assembly of Sergipe, and at the Chamber of City Councilmen of Aracaju. This study described the political history of the main leadership of that generation of militants and organizers of social movements, and of left party groups in Sergipe, highlighting that their consolidation in the political scenario of the State meant the consolidation of a new group of power in Sergipe s politics.

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A assistência psiquiátrica e as políticas de atenção à saúde mental passaram por diversas transformações, marcadas ora por avanços, ora por retrocessos centrados no estigma, desinteresse e preconceito que ainda permeiam a sociedade e o senso comum. Este estudo objetivou analisar o processo de reforma psiquiátrica e a política de saúde mental do Município de Natal/RN a partir dos papéis e funções dos profissionais de nível superior dos serviços substitutivos em saúde mental. Trata-se de uma pesquisa analítica, transversal, com dados quantitativos e qualitativos, realizada nos sete serviços substitutivos de saúde mental de Natal, entre os meses de março a agosto de 2013, após aprovação do estudo pelo Comitê de Ética em Pesquisa da Universidade Federal do Rio Grande do Norte, Parecer nº 217.808, CAAE: 10650612.8.1001.5537, em 01 de março de 2013. A amostra por conveniência compôs-se por 65 profissionais de nível superior das equipes de saúde mental. Utilizou-se um questionário com questões fechadas e semiabertas sobre o perfil socioeconômico, as políticas, as práticas e a formação em saúde mental. Tabularam-se e submeteram-se as respostas das questões fechadas do questionário no programa estatístico SPSS versão 20.0, analisando-os por meio de estatística descritiva, com a formulação de gráficos e tabelas. Para verificar o nível de significância, adotando-se p-valor<0,05, optou-se pela aplicação dos testes qui-quadrado e exato de Fisher. Submeteram-se os dados das questões semiabertas ao software ALCESTE e à luz da análise de conteúdo de Bardin. O perfil dos participantes caracterizou-se por maioria do sexo feminino (79%), faixa etária de 36 a 55 anos (52%), média de 42 anos, carga horária de 40 horas semanais (62%), tempo de conclusão da graduação de 6 a 15 anos (57%), trabalhavam na área de saúde mental há menos de 10 anos (72%) e na instituição pesquisada há 5 anos ou menos (52%). Da amostra estudada, 86% atendiam grupos de usuários, 97% realizavam atendimento individual, 94% observavam o comportamento do paciente, 92% realizavam atendimento familiar, utilizando, principalmente, a abordagem cognitiva (28%). Os dados qualitativos originaram cinco categorias: Formação acadêmica e atuação em saúde mental; Ausência de capacitação e supervisão em saúde mental; Dificuldades da prática profissional nos serviços substitutivos de saúde mental; Trabalho em equipe: entre acertos e conflitos; Política Nacional de Saúde Mental: uma realidade ainda distante. Detectou-se adequabilidade dos papéis e funções dos profissionais quanto ao tempo de trabalho na saúde mental e na instituição pesquisada; no atendimento e atividades individuais; na promoção de ações visando à autonomia do paciente; no atendimento em grupo de pacientes; e, em parte, à família/familiar dos portadores de transtorno mental, havendo inadequação quanto ao atendimento aos grupos de familiares (52.3%), à formação especializada em saúde mental (69.2%; p=0,02) e às dificuldades de trabalho nos serviços (87.7%). Evidenciou-se adequação nos papéis e nas funções d esenvolvidas pelos profissionais nos serviços substitutivos em saúde mental de Natal, embora convivendo em seu cotidiano com inúmeras dificuldades encontradas no desenvolvimento de suas práticas profissiona is frente às condições de trabalho

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Eventually, violations of voltage limits at buses or admissible loadings of transmission lines and/or power transformers may occur by the power system operation. If violations are detected in the supervision process, corrective measures may be carried out in order to eliminate them or to reduce their intensity. Loading restriction is an extreme solution and should only be adopted as the last control action. Previous researches have shown that it is possible to control constraints in electrical systems by changing the network topology, using the technique named Corrective Switching, which requires no additional costs. In previous works, the proposed calculations for verifying the ability of a switching variant in eliminating an overload in a specific branch were based on network reduction or heuristic analysis. The purpose of this work is to develop analytical derivation of linear equations to estimate current changes in a specific branch (due to switching measures) by means of few calculations. For bus-bar coupling, derivations will be based on short-circuit theory and Relief Function methodology. For bus-bar splitting, a Relief Function will be derived based on a technique of equivalent circuit. Although systems of linear equations are used to substantiate deductions, its formal solution for each variant, in real time does not become necessary. A priority list of promising variants is then assigned for final check by an exact load flow calculation and a transient analysis using ATP Alternative Transient Program. At last, results obtained by simulation in networks with different features will be presented

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The characteristic properties of the fractal geometry have shown to be very useful for the construction of filters, frequency selective surfaces, synchronized circuits and antennas, enabling optimized solutions in many different commercial uses at microwaves frequency band. The fractal geometry is included in the technology of the microwave communication systems due to some interesting properties to the fabrication of compact devices, with higher performance in terms of bandwidth, as well as multiband behavior. This work describes the design, fabrication and measurement procedures for the Koch quasi-fractal monopoles, with 1 and 2 iteration levels, in order to investigate the bandwidth behavior of planar antennas, from the use of quasi-fractal elements printed on their rectangular patches. The electromagnetic effect produced by the variation of the fractal iterations and the miniaturization of the structures is analyzed. Moreover, a parametric study is performed to verify the bandwidth behavior, not only at the return loss but also in terms of SWR. Experimental results were obtained through the accomplishment of measurements with the aid of a vetorial network analyzer and compared to simulations performed using the Ansoft HFSS software. Finally, some proposals for future works are presented

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The microstrip antennas are in constant evidence in current researches due to several advantages that it presents. Fractal geometry coupled with good performance and convenience of the planar structures are an excellent combination for design and analysis of structures with ever smaller features and multi-resonant and broadband. This geometry has been applied in such patch microstrip antennas to reduce its size and highlight its multi-band behavior. Compared with the conventional microstrip antennas, the quasifractal patch antennas have lower frequencies of resonance, enabling the manufacture of more compact antennas. The aim of this work is the design of quasi-fractal patch antennas through the use of Koch and Minkowski fractal curves applied to radiating and nonradiating antenna s edges of conventional rectangular patch fed by microstrip inset-fed line, initially designed for the frequency of 2.45 GHz. The inset-fed technique is investigated for the impedance matching of fractal antennas, which are fed through lines of microstrip. The efficiency of this technique is investigated experimentally and compared with simulations carried out by commercial software Ansoft Designer used for precise analysis of the electromagnetic behavior of antennas by the method of moments and the neural model proposed. In this dissertation a study of literature on theory of microstrip antennas is done, the same study is performed on the fractal geometry, giving more emphasis to its various forms, techniques for generation of fractals and its applicability. This work also presents a study on artificial neural networks, showing the types/architecture of networks used and their characteristics as well as the training algorithms that were used for their implementation. The equations of settings of the parameters for networks used in this study were derived from the gradient method. It will also be carried out research with emphasis on miniaturization of the proposed new structures, showing how an antenna designed with contours fractals is capable of a miniaturized antenna conventional rectangular patch. The study also consists of a modeling through artificial neural networks of the various parameters of the electromagnetic near-fractal antennas. The presented results demonstrate the excellent capacity of modeling techniques for neural microstrip antennas and all algorithms used in this work in achieving the proposed models were implemented in commercial software simulation of Matlab 7. In order to validate the results, several prototypes of antennas were built, measured on a vector network analyzer and simulated in software for comparison

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This work is the analysis of a structure of the microstrip antenna designed for application in ultra wide band systems (Ultra Wideband - UWB). This is a prospective analytical study where they tested the changes in the geometry of the antenna, observing their suitability to the proposed objectives. It is known that the UWB antenna must operate in a range of at least 500 MHz, and answer a fractional bandwidth greater than or equal to 25%. It is also desirable that the antenna meets the specifications of track determined by FCC - Federal Communication Commission, which regulates the system in 2002 designating the UWB bandwidth of 7.5 GHz, a range that varies from 3.1 GHz to 10, 6 GHz. by setting the maximum power spectral density of operation in -41.3 dB / MHz, and defining the fractional bandwidth by 20%. The study starts of a structure of geometry in the form of stylized @, which evolves through changes in its form, in simulated commercial software CST MICROWAVE STUDIO, version 5.3.1, and then tested using the ANSOFT HFSS, version 9. These variations, based on observations of publications available from literature referring to the microstrip monopole planar antennas. As a result it is proposed an antenna, called Monopole Antenna Planar Spiral Almost Rectangular for applications in UWB systems - AMQEUWB, which presents simulated and measured results satisfactory, consistent with the objectives of the study. Some proposals for future work are mentioned

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This study aims to seek a more viable alternative for the calculation of differences in images of stereo vision, using a factor that reduces heel the amount of points that are considered on the captured image, and a network neural-based radial basis functions to interpolate the results. The objective to be achieved is to produce an approximate picture of disparities using algorithms with low computational cost, unlike the classical algorithms

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An alternative nonlinear technique for decoupling and control is presented. This technique is based on a RBF (Radial Basis Functions) neural network and it is applied to the synchronous generator model. The synchronous generator is a coupled system, in other words, a change at one input variable of the system, changes more than one output. The RBF network will perform the decoupling, separating the control of the following outputs variables: the load angle and flux linkage in the field winding. This technique does not require knowledge of the system parameters and, due the nature of radial basis functions, it shows itself stable to parametric uncertainties, disturbances and simpler when it is applied in control. The RBF decoupler is designed in this work for decouple a nonlinear MIMO system with two inputs and two outputs. The weights between hidden and output layer are modified online, using an adaptive law in real time. The adaptive law is developed by Lyapunov s Method. A decoupling adaptive controller uses the errors between system outputs and model outputs, and filtered outputs of the system to produce control signals. The RBF network forces each outputs of generator to behave like reference model. When the RBF approaches adequately control signals, the system decoupling is achieved. A mathematical proof and analysis are showed. Simulations are presented to show the performance and robustness of the RBF network

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

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La dificultad que los alumnos encuentran en el aprendizaje de matemática viene siendo objeto de investigación por estudiosos en educación matemática, tanto en Brasil como en el exterior. El objetivo de este estudio consiste em investigar las dificuldades en el aprendizado sobre funciones matemáticas y la influencia de las concepciones alternativas a partir de los errores que los candidatos acerca de las cuestiones sobre funciones en la prueba objetiva de matemática del acceso a la universidad de los años de 2001 a 2008. Teniendo como cuestiones de estudio para alcanzar el objetivo propuesto: identificar la relevancia del tema funciones que son contemplados en las pruebas de acceso a la Universidad; asi como cuáles han sido los tipos de funciones más privilegiados y menos privilegiados; analizar si la contextualización de la pregunta y la presencia de elementos no textuales han influenciado en el aumento de tal dificultad; analizar si la representación semiótica agrega mayor exigencia a la pregunta; analizar respecto a la exigencia matemática de la pregunta; analizar lo que se refiere al desempeño de los candidatos para verificar cuál pregunta tuvo mejor desempeño y cuál el peor e identificar los errores más frecuentemente cometidos por los candidatos en esas pruebas. Las reflexiones de los estudiosos como: Radatz (1980), Cury (1994), Socas (1997), Borasi (1997), Franchi e Rincón (2004), Pochulu (2004) presentan las dificultades en el aprendizaje matemático, que aparecen a partir de los errores cometidos por los alumnos, quando estos errores reciben la influencia de las concepciones alternativas. El estudio que se presenta en esta disertación configura un análisis de los errores que los candidatos han cometido en las preguntas objetivas sobre el tema funciones de las pruebas de acceso a la Universidad de los años de 2001 a 2008, a partir de los relatorios de la Comissão Permanente do Vestibular COMPERVE/UFRN. Con la intención de alcanzar los objetivos propuestos para este estudio, fueran sido construidas categorías de análisis. Los resultados encontrados han sido: El tema funciones es el más frecuente entre los demás con (28,1%); el tipo de función priorizada durante esos años ha sido la función logarítmica con (24%); la contextualización de las preguntas exige una mayor comprensión por parte del candidato de lo que las situaciones directas; la caracterización semiótica posee elementos que estructuran esas preguntas que el educando debe saber asociar al texto; la exigencia matemática posibilitó analizar que el procedimiento medio ha sido el más requisitado; el desempeño de los candidatos ha sido en la mayoría bajo (50%); y los principales errores que ellos han cometido han sido de realizar traducciones incorrectas de las expresiones que aparecen en las situaciones-problema; utilizar todos los datos que aparezcan en el problema sin tomar en cuenta si el cálculo realizado responde a la pregunta solicitada; no interpretar coherentemente las informaciones del gráfico; decodificar incorrectamente los valores representados por literales en una recta numérica. Los resultados señalizan la necesidad de una revisión didáctico-metodológicas de la enseñanza de funciones a raíz de las cuales las dificultades en el aprendizaje se han presentado

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This study describes about graduation s students difficulties of to draw functions graph. Specifically, we intend to observe their abilities evolution, as well as their difficulties during Calculus I subject in engineering course. For that, we show them publications about the elaboration of graphs and its difficulties in obstacle terms and some researches witch contain this subject and that it was done during postgraduate studies in mathematical education. It shows by research methodology aspects related to French didatic s mathematic and some theories of cognitive psychology considering the high value between theoretical-methodological relation that was evidenced in both theoretical conceptions about ways to understand and teach mathematic. This methodology is based on didactic engineering purpose, that consist in preliminaries analysis, conception and didactic sequence analysis prior, trials by application followed analysis up and conclusion. We had also used pedagogicals actions and analysis of results achieved, to classify types of errors made by the 2005 s students during second semester, from conceptions related to the episthemologic and didactics obstacles

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Conselho Nacional de Desenvolvimento Científico e Tecnológico

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Today, one of the topics that attracts interest of the scientific community is the understanding of magnetic properties of magnetic systems with reduced dimensions, in particular, ferromagnetic thin films. In this case, the comprehension and control of these properties, as well as the development of routes to obtain them, are crucial issues in many aspects of current and future technologies for storage and transmission of information in the electro-electronic industry. There are several materials that exhibit soft magnetic properties, and we highlight the amorphous alloys and that ones obtained by partial crystallization, so-called nanocrystalline materials. The production of these alloys as magnetic ribbons is very common in scientific and technological area, but there are just a few works related to the production of these alloys as thin films. In this work, we studied the quasi-static magnetic properties of ferromagnetic thin films based on FeCuNbSiB in a wide range of thicknesses, from 20 to 500 nm, produced by sputtering. In particular, after the structural characterization performed via X-ray diffraction, the magnetic properties of the sets of samples were investigated using experimental magnetization curve, obtained using a vibrating sample magnetometer, as well as through theoretical curves obtained by theoretical modeling and numerical computation. The modeling process is based on the Stoner Wohlfarth model applied to three dimensions, and adds some energy terms, using as reference experimental results of magnetization. In this case, from the comparison between theoretical and experimental results and the analysis of the constant anisotropy behavior as a function of film thickness, we aim to obtain further information on the magnetization process of the samples, to identify routes for the production of thin films and develop a theoretical to films to use it, in the future, in the obtainment of the theoretical curves of some magnetic measurements, such as magnetoimpedance and magnetoresistance

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Family Health Strategy (FHS), founded in 1994 has appeared to play a strategic role in the SUS construction and consolidation. It has reaffirmed its Principles and Guidelines and has elected family as core of attention. The principle that has guided the work concerns the quality of the relationship between professional and family. Thus, the FHS has the family as a subject of health-disease process, and relations with its own characteristics and can be partners in building their health and improvement of quality of life of its members and the entire community. This study aims to characterize the surgeon-dentist (SD) working process in the family health strategy, from the knowledge of the SD integration with other team members; organization of services; development of shares, changes perceived by SDs, as well as knowing the surgeon-dentist profile who is part of this strategy. The collecting tool used was a semi-structured questionnaire, in which participated 30 professionals. As for profile, most professionals were women, completed the graduation in public university and did not have any training to work by joining the FHS. Almost all have other public or private working ties. They often carry out activities with students, and occasionally do home visits. In relation to team work, in activities such as home visits, school health, community activities, among others, they sometimes seek the cooperation of other members. The way of accessing for users in the most part has occurred through the schedule. The most frequently activities made to the Centro Especialidades Odontológicas (CEO), are in Endodontics and Prosthesis. The majority of them participate in team meetings, but they do not have frequency set to happen. As for the planning and programming of activities to be conducted, most said that individually develops them. Concerning the performance of their duties, most reported being satisfied, but that improvements could happen. Besides, they reported improvements in dental care following the inclusion of SD in the FHS in various aspects, such as access, organization, humanization, care and oral disease prevention. The professionals had poor integration with other team members, in addition to have a profile to more individualistic work, a fact seized by way of development and planning of actions. They work the actions in individual and curative way, in detriment promotion and collective ones. They work humanization, definition of territory and adscript population. Thus, it is concluded that the working process developed by SDs, includes the part which is advocated by FHS. This points out to a greater undertaking of this process aiming to detect the weakness met in order to reach the potential that the FHS represents in organization of basic attention

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The use and the demand for substances that enhance masculinity, strength and sexual power are not novel. Over the years, this search has assisted the research directions in this area, leading to the discovery of the primary male sex hormone testosterone in 1935. Since then, numerous testosterone analogue compounds were synthesized, which are generically called Anabolic Androgenic Steroids (AAS). The AAS were produced for therapeutic purposes, but an increase in the use of these compounds for other purposes occurred over time. Initially they were used mainly to improve performance in athletes. However, recent studies have shown that the use of AAS by non-athletes with aesthetical purposes have been increasing as well. The abuse of AAS with non-clinical purposes can promote a number of physiological alterations, such as heart, liver, respiratory and psychological problems such as changes in mood, levels of anxiety and aggression. Exposure to supraphysiological doses of AAS is associated with behavioral changes, however, little is known about the effects of AAS on cognitive functions. In this work, we aimed to mimic the AAS abuse in humans with intramuscular administration of a supraphysiological dose of testosterone propionate (TP) in rats. We investigated the effects of this treatment on different aspects of cognitive function, specifically learning, memory and anxiety. Adult male Wistar rats were tested in the spontaneous alternation, novel object recognition and plus-maze discriminative avoidance tasks. The control group received intramuscular injections of vegetable oil (vehicle), and the TP group received injections of TP (10 mg/kg, i.m.). The injections were administered for 40 days, with intervals of 48 hours (chronic treatment) or in a single injection (acute treatment). In addition to the behavioral assessments, we performed biochemical analyzes as indicators of the endocrine effects of the treatment. Our results show that chronic treatment with a supraphysiological dose of TP caused memory impairments in the novel object recognition and the discriminative avoidance tasks. The spatial working memory (evaluated by spontaneous alternation task) was not affected. Also, we did not observe changes in anxiety levels. Regarding the biochemical parameters, chronic treatment increased serum levels of glutamicpyruvic transaminase, an indicator of hepatic and pancreatic lesions (as those observed after chronic use of these substances in humans). On the other hand, acute treatment with PT did not promote significant changes in any of these parameters when compared to the control group. In summary, we conclude that chronic treatment with a supraphysiological dose of testosterone propionate produces memory deficits in novel object recognition and retrieval of the discriminative avoidance task in adult male rats