198 resultados para Patrocinio


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In this dissertation, are presented two microstrip antennas and two arrays for applications in wireless communication systems multiband. Initially, we studied an antenna and a linear array consisting of two elements identical to the patch antenna isolated. The shape of the patch used in both structures is based on fractal geometry and has multiband behavior. Next a new antenna is analyzed and a new array such as initial structure, but with the truncated ground plane, in order to obtain better bandwidths and return loss. For feeding the structures, we used microstrip transmission line. In the design of planar structures, was used HFSS software for the simulation. Next were built and measures electromagnetic parameters such as input impedance and return loss, using vector network analyzer in the telecommunications laboratory of Federal University of Rio Grande do Norte. The experimental results were compared with the simulated and showed improved return loss for the first array and also appeared a fourth band and increased directivity compared with the isolated antenna. The first two benefits are not commonly found in the literature. For structures with a truncated ground planes, the technique improved impedance matching, bandwidth and return loss when compared to the initial structure with filled ground planes. Moreover, these structures exhibited a better distribution of frequency, facilitating the adjustment of frequencies. Thus, it is expected that the planar structures presented in this study, particularly arrays may be suitable for specific applications in wireless communication systems when frequency multiband and wideband transmission signals are required.

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Considering the fact that, the use of wireless communication systems has grown too fast, investigations concerning absorbers of electromagnetic waves has called closer attention of researchers. It is applicable from indoor systems to military applications. Paralleling with this growth, some extremely relevant investigations through Frequency Selective Surfaces (FSS) allows its filter property to be applicable in several systems, for example: reflector antennas, band-pass radomes, and absorbers, which are the main objective of this work. Therefore, the main goal of this work concerns to design micro-waves absorbers through FSS. Thus, the methodology consists basically in two steps: the first step concerns a theoretical and numerical analysis of the structures involved in the process of absorption, the second step, the analysis of the cascaded structures. In order to carry out the analysis, the Equivalent Circuit Method will be used. This method provides characteristics of transmission from the structure, for a plane wave incidence and it requires an extremely limited computing resource in relation if compared to full wave analyses method. Hence, it is useful to allow fast predictions of the development of the structures. Furthermore, a spreading matrix will be used in order to cascade the conductive FSS and the resistive FSS achieving absorption characteristics in the designed band. The experimental results used for the analysis are found in the literature due to the difficulty of building soon, given that it is not a simple construction technique. To conclude, a mathematical development through the Equivalent Circuit Method of a FSS modeling with cross-dipole geometry and a resistive FSS will be presented, as well as the cascading involving the two structures. The same setting is used with a square loop geometry. Besides it, the next steps will be discussed in the conclusion.

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The microstrip antennas in your simplest form consist of a ground plane and a dielectric substrate which supports a conductive tape. As these antennas have some limitations, this work presents a study of anisotropic substrates, as well as some results in microstrip antennas with circular patch, aiming to overcome these limitations, especially in applications at 4G technology. These anisotropic substrates are those in which electrical permittivity and magnetic permeability are represented by tensors of second order. The study consists of a theoretical analysis of substrates and development of a mathematical formalism, the Transverse Transmission Line Method, aimed the application of these substrates in microstrip antennas. Among the substrates used in this study, there are the ferrimagnetic and metamaterials, in which some miniaturizations of the antennas are achieved. For antennas with circular patch, are considered arrays and modified ground planes in order to achieve improvement in parameters, in particular, gain and bandwidth. Several simulations have been made and antennas were constructed so that the measured values could be compared with the simulated values.

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This work aims to propose a new model of metasurface with simplified basic cell, able to convert linearly polarized signals generated by planar antenna array in circularly polarized signals, for the ISM frequency band (2.45 GHz), with good bandwidth of return loss and axial ratio. To study the behavior of the proposed structure, the metasurface is coupled to three different structures. First, initial tests are made with the metasurface coupled to a microstrip antenna in its simple configuration. Then the metasurface is coupled to an array with two elements of patch type. And later it is coupled to an optimized array, that uses a stub in its main feed, to get a better impedance matching. The structures are analyzed numerically through Ansoft HFSS™, and to validate these results, the structures are characterized experimentally. The characteristics of transmissions simulated and measures are presented. A good agreement between simulated and measured results was obtained. The structure proposed here has the advantage of meeting the desired characteristics, with a simple geometry to be built using a low-cost substrate (FR-4).

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This work aims to propose a new model of metasurface with simplified basic cell, able to convert linearly polarized signals generated by planar antenna array in circularly polarized signals, for the ISM frequency band (2.45 GHz), with good bandwidth of return loss and axial ratio. To study the behavior of the proposed structure, the metasurface is coupled to three different structures. First, initial tests are made with the metasurface coupled to a microstrip antenna in its simple configuration. Then the metasurface is coupled to an array with two elements of patch type. And later it is coupled to an optimized array, that uses a stub in its main feed, to get a better impedance matching. The structures are analyzed numerically through Ansoft HFSS™, and to validate these results, the structures are characterized experimentally. The characteristics of transmissions simulated and measures are presented. A good agreement between simulated and measured results was obtained. The structure proposed here has the advantage of meeting the desired characteristics, with a simple geometry to be built using a low-cost substrate (FR-4).

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This thesis presents a hybrid technique of frequency selective surfaces project (FSS) on a isotropic dielectric layer, considering various geometries for the elements of the unit cell. Specifically, the hybrid technique uses the equivalent circuit method in conjunction with genetic algorithm, aiming at the synthesis of structures with response single-band and dual-band. The equivalent circuit method allows you to model the structure by using an equivalent circuit and also obtaining circuits for different geometries. From the obtaining of the parameters of these circuits, you can get the transmission and reflection characteristics of patterned structures. For the optimization of patterned structures, according to the desired frequency response, Matlab™ optimization tool named optimtool proved to be easy to use, allowing you to explore important results on the optimization analysis. In this thesis, numeric and experimental results are presented for the different characteristics of the analyzed geometries. For this, it was determined a technique to obtain the parameter N, which is based on genetic algorithms and differential geometry, to obtain the algebraic rational models that determine values of N more accurate, facilitating new projects of FSS with these geometries. The optimal results of N are grouped according to the occupancy factor of the cell and the thickness of the dielectric, for modeling of the structures by means of rational algebraic equations. Furthermore, for the proposed hybrid model was developed a fitness function for the purpose of calculating the error occurred in the definitions of FSS bandwidths with transmission features single band and dual band. This thesis deals with the construction of prototypes of FSS with frequency settings and band widths obtained with the use of this function. The FSS were initially reviewed through simulations performed with the commercial software Ansoft Designer ™, followed by simulation with the equivalent circuit method for obtaining a value of N in order to converge the resonance frequency and the bandwidth of the FSS analyzed, then the results obtained were compared. The methodology applied is validated with the construction and measurement of prototypes with different geometries of the cells of the arrays of FSS.

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This thesis presents a hybrid technique of frequency selective surfaces project (FSS) on a isotropic dielectric layer, considering various geometries for the elements of the unit cell. Specifically, the hybrid technique uses the equivalent circuit method in conjunction with genetic algorithm, aiming at the synthesis of structures with response single-band and dual-band. The equivalent circuit method allows you to model the structure by using an equivalent circuit and also obtaining circuits for different geometries. From the obtaining of the parameters of these circuits, you can get the transmission and reflection characteristics of patterned structures. For the optimization of patterned structures, according to the desired frequency response, Matlab™ optimization tool named optimtool proved to be easy to use, allowing you to explore important results on the optimization analysis. In this thesis, numeric and experimental results are presented for the different characteristics of the analyzed geometries. For this, it was determined a technique to obtain the parameter N, which is based on genetic algorithms and differential geometry, to obtain the algebraic rational models that determine values of N more accurate, facilitating new projects of FSS with these geometries. The optimal results of N are grouped according to the occupancy factor of the cell and the thickness of the dielectric, for modeling of the structures by means of rational algebraic equations. Furthermore, for the proposed hybrid model was developed a fitness function for the purpose of calculating the error occurred in the definitions of FSS bandwidths with transmission features single band and dual band. This thesis deals with the construction of prototypes of FSS with frequency settings and band widths obtained with the use of this function. The FSS were initially reviewed through simulations performed with the commercial software Ansoft Designer ™, followed by simulation with the equivalent circuit method for obtaining a value of N in order to converge the resonance frequency and the bandwidth of the FSS analyzed, then the results obtained were compared. The methodology applied is validated with the construction and measurement of prototypes with different geometries of the cells of the arrays of FSS.

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The aim of this research is to reveal how caregivers have lived the experiences from adult patients admitted in a Rio Grande do Norte’s state hospital. This is a study where the use of the participant observation, associated with the use of interviews and informal conversations handled categories such as the mismatch between the prerogatives of Brazilian Health Care Policies (HumanizaSUS) and practices performed in hospitals, the relationships established between the caregivers and the other subjects of the research field, family relationships, permanence of women as caregivers, therapeutic itineraries, dramas, religiosity and secrets. To sew up it appears the role of a caregiver is more than emotional support or help, it is a complex act in several directions.

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The increasing demand for Internet data traffic in wireless broadband access networks requires both the development of efficient, novel wireless broadband access technologies and the allocation of new spectrum bands for that purpose. The introduction of a great number of small cells in cellular networks allied to the complimentary adoption of Wireless Local Area Network (WLAN) technologies in unlicensed spectrum is one of the most promising concepts to attend this demand. One alternative is the aggregation of Industrial, Science and Medical (ISM) unlicensed spectrum to licensed bands, using wireless networks defined by Institute of Electrical and Electronics Engineers (IEEE) and Third Generation Partnership Project (3GPP). While IEEE 802.11 (Wi-Fi) networks are aggregated to Long Term Evolution (LTE) small cells via LTE / WLAN Aggregation (LWA), in proposals like Unlicensed LTE (LTE-U) and LWA the LTE air interface itself is used for transmission on the unlicensed band. Wi-Fi technology is widespread and operates in the same 5 GHz ISM spectrum bands as the LTE proposals, which may bring performance decrease due to the coexistence of both technologies in the same spectrum bands. Besides, there is the need to improve Wi-Fi operation to support scenarios with a large number of neighbor Overlapping Basic Subscriber Set (OBSS) networks, with a large number of Wi-Fi nodes (i.e. dense deployments). It is long known that the overall Wi-Fi performance falls sharply with the increase of Wi-Fi nodes sharing the channel, therefore there is the need for introducing mechanisms to increase its spectral efficiency. This work is dedicated to the study of coexistence between different wireless broadband access systems operating in the same unlicensed spectrum bands, and how to solve the coexistence problems via distributed coordination mechanisms. The problem of coexistence between different networks (i.e. LTE and Wi-Fi) and the problem of coexistence between different networks of the same technology (i.e. multiple Wi-Fi OBSSs) is analyzed both qualitatively and quantitatively via system-level simulations, and the main issues to be faced are identified from these results. From that, distributed coordination mechanisms are proposed and evaluated via system-level simulations, both for the inter-technology coexistence problem and intra-technology coexistence problem. Results indicate that the proposed solutions provide significant gains when compare to the situation without distributed coordination.

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Lung cancer is the most common of malignant tumors, with 1.59 million new cases worldwide in 2012. Early detection is the main factor to determine the survival of patients affected by this disease. Furthermore, the correct classification is important to define the most appropriate therapeutic approach as well as suggest the prognosis and the clinical disease evolution. Among the exams used to detect lung cancer, computed tomography have been the most indicated. However, CT images are naturally complex and even experts medical are subject to fault detection or classification. In order to assist the detection of malignant tumors, computer-aided diagnosis systems have been developed to aid reduce the amount of false positives biopsies. In this work it was developed an automatic classification system of pulmonary nodules on CT images by using Artificial Neural Networks. Morphological, texture and intensity attributes were extracted from lung nodules cut tomographic images using elliptical regions of interest that they were subsequently segmented by Otsu method. These features were selected through statistical tests that compare populations (T test of Student and U test of Mann-Whitney); from which it originated a ranking. The features after selected, were inserted in Artificial Neural Networks (backpropagation) to compose two types of classification; one to classify nodules in malignant and benign (network 1); and another to classify two types of malignancies (network 2); featuring a cascade classifier. The best networks were associated and its performance was measured by the area under the ROC curve, where the network 1 and network 2 achieved performance equal to 0.901 and 0.892 respectively.

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Advertising investment and audience figures indicate that television continues to lead as a mass advertising medium. However, its effectiveness is questioned due to problems such as zapping, saturation and audience fragmentation. This has favoured the development of non-conventional advertising formats. This study provides empirical evidence for the theoretical development. This investigation analyzes the recall generated by four non-conventional advertising formats in a real environment: short programme (branded content), television sponsorship, internal and external telepromotion versus the more conventional spot. The methodology employed has integrated secondary data with primary data from computer assisted telephone interviewing (CATI) were performed ad-hoc on a sample of 2000 individuals, aged 16 to 65, representative of the total television audience. Our findings show that non-conventional advertising formats are more effective at a cognitive level, as they generate higher levels of both unaided and aided recall, in all analyzed formats when compared to the spot.

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Online gambling is a popular activity among adolescents. However, there has been a notable increase in the number of young people who suffer or are on the verge of pathological gambling. We review the impact of online gambling on young people and discuss the desiderability of the concept of “gambling responsibly” in order to alert of their risks and effectively prevent access to minors. The main factors associated with pathological gambling are the age of start, the family environment, the infl uence of advertising, the consumption of stimulants, and the attitudes of the peer group. Both the government and the gaming industry itself should consider these factors and develop comprehensive plans that ensure a safe and controlled model game. In this context, advertising must take into account criteria of consumer protection knowing that even if they are not allowed, children can easily have access to online gambling. All agents involved, including public and social agents, must provide mechanisms for prevention and awareness of a problem that arouses little social consciousness and excessive carelessness.

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Desde la fecunda obra de Caro Baroja, la renovación de las élites de gobierno localizada a comienzos del setecientos ha llamado la atención de una parte de la historiografía preocupada en proponer diversos enfoques con los que interpretar este proceso de enormes consecuencias sociales y políticas. El caso de los Macanaz presenta una serie de peculiaridades que lo hacen propicio para un análisis detallado de su proceso de promoción familiar en el que sobresale la trascendencia de ciertos factores escasamente subrayados hasta el momento. El importante papel desempeñado por la casa aristocrática de Villena y el escaso peso de lo local o regnícola en su proyección posterior, nos servirá para cuestionar la dimensión de los Macanaz como iniciadores de una hipotética “hora murciana”, destacando en su caso la importancia de otros elementos complementarios como el patrocinio nobiliario, el mérito, la formación y la capacidad e iniciativa individual, vías también de acceso al servicio del rey.

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En el análisis de la situación se identifican y analizan tendencias, fuerzas y fenómenos claves que tienen un impacto potencial en la formulación e implementación de estrategias. Es sustancial tener en cuenta tanto los factores internos como los externos. La evaluación actual del negocio es importante ya que tiene como propósito utilizar la información para el plan de la empresa, para un crecimiento, éxito y liderazgo en el mercado; sin embargo es igualmente importante saber como el entorno externo afecta las actividades del día a día, tomando en consideración el ambiente inmediato a la empresa, el ambiente global y macro ambiental. Antes de tomar cualquier decisión estratégica es imprescindible realizar un diagnostico de la organización para decidir sobre el futuro, puesto que nos ayuda a plantear las acciones que se deben poner en marchar para aprovechar las oportunidades detectadas y preparar a la empresa contra las amenazas teniendo conciencia de las debilidades y fortalezas. Ante la irregular situación en la que se encuentra la empresa al no hacer uso de las diferentes herramientas de mercadotecnia para darse a conocer y lograr tener una mayor afluencia de visitantes que conlleve al incremento de las ventas, se plantea el diseño de un plan de mercadotecnia dado que es de vital importancia porque permitirá darse a conocer, persuadir, informar y estimular el consumo, obteniendo de esta manera un desarrollo sostenible y un posicionamiento en la mente de los visitantes teniendo una mayor participación en el mercado turístico. Tomando en cuenta que cada plan exitoso en los negocios requiere una estrategia se han establecido entre ellas: Mejoramiento en el servicio al cliente, oferta especial de precios a clientes frecuentes, distribución (lugar destino), promociones de venta, artículos promocionales, campaña publicitaria, patrocinio de eventos, comercio electrónico y relaciones públicas internas. De igual manera se han determinado las tácticas para el cumplimiento de las diferentes estrategias, es decir, la definición de las mismas en puntos específicos de acciones determinadas.

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La División Manufacturera cada día demanda mayor calidad en el servicio y beneficio, aunando a esto que existe un número determinado de organizaciones que ofrecen servicios de apoyo a dicho sector. Razón por la cual la Asociación Salvadoreña de Industriales se ha visto en la necesidad de contar con un plan táctico que no solo le permita mantenerse en el mercado, sino también de proyectarse a una economía globalizada. En este sentido, para contar con una mayor aceptación de los servicios la presente investigación tiene como propósito primordial el diseñar un plan táctico de mercadotecnia que le permita la retención y captación de socios, con el objeto de posicionarse en la mediana empresa de la división industrial manufacturera en la ciudad de San Salvador, mediante la proposición de estrategias competitiva de mercado y un plan de acción sistemático para ponerlos en práctica. De acuerdo a la investigación se detectó que la asociación no cuenta con un plan que le permita impulsar los servicios que ofrece, ya que carece de patrocinio por parte de instituciones públicas y privadas, deficiente promoción de membresía, poca comunicación con los socios, falta de un sistema de información para el manejo estadístico industrial manufacturero y carencia de una estrategia de venta definida para el mercado nacional. El método que se utilizó para la realización del estudio es el científico. Se utilizó además técnicas estadísticas a fin de que ésta sea representativa del universo de estudio. Se ha desarrollado una investigación de tipo correlacional teniendo un universo conformado por socios y no socios de la división manufacturera, en el caso de los socios, el universo está compuesto por 23 medianas empresas dedicada a manufacturar diversos productos, así mismo, un universo comprendido por empresas de la división manufacturera que no están afiliados a la asociación que según información proporcionada por la Dirección General de Estadísticas y Censo son 75 medianas empresas. Para facilitar la compresión del estudio se conceptualizan aspectos teóricos relacionados con la división manufacturera, mercadotecnia, planeación táctica y el proceso de elaboración de un plan de mercadotecnia, presentando un diagnóstico, realizado a través de distintas técnicas. Se determinó que la estrategia genérica que más se adapta a la situación competitiva actual es la de diferenciación, sustentada en la alta calidad de los servicios, diseños novedosos y variados y una excelente atención al cliente que le permita dar a conocer los servicios ofrecidos y así lograr aceptación por parte de los consumidores del mercado meta.