Made available in DSpace on 2014-12-17T15:01:32Z (GMT). No. of bitstreams: 1 ThayseNPD_DISSERT.pdf: 3011136 bytes, checksum: 3c14c7c4fc8b4067013feadbd30be411 (MD5) Previous issue date: 2013-08-08 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / The objective of this work was the development and improvement of the mathematical models based on mass and heat balances, representing the drying transient process fruit pulp in spouted bed dryer with intermittent feeding. Mass and energy balance for drying, represented by a system of differential equations, were developed in Fortran language and adapted to the condition of intermittent feeding and mass accumulation. Were used the DASSL routine (Differential Algebraic System Solver) for solving the differential equation system and used a heuristic optimization algorithm in parameter estimation, the Particle Swarm algorithm. From the experimental data food drying, the differential models were used to determine the quantity of water and the drying air temperature at the exit of a spouted bed and accumulated mass of powder in the dryer. The models were validated using the experimental data of drying whose operating conditions, air temperature, flow rate and time intermittency, varied within the limits studied. In reviewing the results predicted, it was found that these models represent the experimental data of the kinetics of production and accumulation of powder and humidity and air temperature at the outlet of the dryer / O objetivo principal deste trabalho foi o estudo e aperfei?oamento de modelos matem?ticos, baseados em balan?os de massa e de energia, que representem o processo de secagem transiente de polpas de frutas em secador de leito de jorro com alimenta??o intermitente. Os balan?os de massa e de energia para a secagem, representados por um sistema de equa??es diferenciais, foram desenvolvidos em linguagem Fortran e adaptados para a condi??o de alimenta??o intermitente e de ac?mulo de massa no interior do equipamento. Este programa realiza a integra??o deste sistema de equa??es diferenciais utilizando a rotina DASSL (Differential Algebraic System Solver) e o procedimento de estima??o do par?metro do modelo foi fundamentado na minimiza??o da fun??o objetivo da t?cnica de m?nimos quadrados utilizando um m?todo heur?stico de otimiza??o PSO (Particle Swarm Optimization). Utilizando dados experimentais gerados nas pesquisas de secagem de alimentos realizadas nos laborat?rio de Tecnologia de Alimentos e de Sistemas Particulados da UFRN, determinaram-se equa??es emp?ricas estat?sticas e aplicaram-se os modelos referentes aos balan?os para verifica??o da quantidade de ?gua e da temperatura do ar de secagem na sa?da do leito de jorro e da massa de material acumulada no secador. Os modelos foram validados a partir dos dados experimentais de secagens cujas condi??es operacionais, de temperatura do ar, vaz?o da pasta e tempo de intermit?ncia, variavam dentro dos limites estudados. Na an?lise dos resultados preditos, foi constatado que estes modelos representam bem os dados experimentais da cin?tica de produ??o e de ac?mulo de p? e da umidade e da temperatura do ar na sa?da do secado

Made available in DSpace on 2014-12-17T15:01:32Z (GMT). No. of bitstreams: 1 HannielFSF_DISSERT.pdf: 2655706 bytes, checksum: fff21ca883e2c0c137ef98496660b572 (MD5) Previous issue date: 2013-07-05 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The present work has the main goal to study the modeling and simulation of a biphasic separator with induced phase inversion, the MDIF, with the utilization of the finite differences method for the resolution of the partial differencial equations which describe the transport of contaminant s mass fraction inside the equipment s settling chamber. With this aim, was developed the deterministic differential model AMADDA, wich was admensionalizated and then semidiscretizated with the method of lines. The integration of the resultant system of ordinary differential equations was realized by means of a modified algorithm of the Adam-Bashfort- Moulton method, and the sthocastic optimization routine of Basin-Hopping was used in the model s parameter estimation procedure . With the aim to establish a comparative referential for the results obtained with the model AMADDA, were used experimental data presented in previous works of the MDIF s research group. The experimental data and those obtained with the model was assessed regarding its normality by means of the Shapiro-Wilk s test, and validated against the experimental results with the Student s t test and the Kruskal-Wallis s test, depending on the result. The results showed satisfactory performance of the model AMADDA in the evaluation of the MDIF s separation efficiency, being possible to determinate that at 1% significance level the calculated results are equivalent to those determinated experimentally in the reference works / O presente trabalho tem como objetivo estudar a modelagem e simula??o de um separador bif?sico com invers?o de fases induzida, o MDIF (Misturador Decantador ? Invers?o de Fases), por meio da utiliza??o do m?todo das diferen?as finitas para a resolu??o das equa??es diferenciais parciais que descrevem o transporte da fra??o m?ssica do contaminante no interior da c?mara de decanta??o do equipamento. Com esse intuito, foi desenvolvido o modelo determin?stico diferencial AMADDA, o qual foi admensionalizado e ent?o semidiscretizado atrav?s do m?todo das linhas. A integra??o do sistema de equa??es diferenciais ordin?rias resultante foi realizada atrav?s de um algoritmo modificado do m?todo de Adam-Bashfort-Moulton, e a rotina de otimiza??o estoc?stica de Basin-Hopping foi utilizada no procedimento de estima??o de par?metros do modelo. Com o intuito de estabelecer um referencial comparativo para a valida??o dos resultados obtidos com o modelo AMADDA, foram utilizados dados experimentais apresentados na literatura (FERNANDES JR, 2002; FERNANDES JR, 2006; MEDEIROS, 2008). Os resultados experimentais e aqueles obtidos com o modelo foram avaliados quanto ? sua normalidade por meio do teste de Shapiro-Wilk, e validados frente aos resultados experimentais atrav?s do teste t de Student e o o teste de Kruskal-Wallis, ? depender do resultado. Os resultados obtidos atrav?s do modelo AMADDA mostraram um desempenho satisfat?rio na determina??o da efici?ncia de separa??o do MDIF, sendo poss?vel determinar que, a um n?vel de signific?ncia de 1%, os resultados calculados s?o equivalentes ?queles determinados experimentalmente nos trabalhos de refer?ncia

Orientador: João Maurício Rosário / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica / Made available in DSpace on 2018-08-24T03:06:34Z (GMT). No. of bitstreams: 1 Floriano-Batista_Rayanne_M.pdf: 3969597 bytes, checksum: fb7104633c8e24f84be507eaef10073d (MD5) Previous issue date: 2013 / Resumo: Nesta dissertação realiza-se um estudo cinemático e dinâmico da marcha humana tendo como base a biomecânica e a antropomorfia dos membros inferiores, assim como nos paradigmas que regem a reabilitação assistida por meio da robótica. Propõe-se uma estratégia de controle de um exoesqueleto robótico para membros inferiores através do cálculo do torque computado, com a finalidade terapêutica de reabilitação da marcha. Adota-se a marcha dinâmica como inspiração para o modelo do sistema, usando uma estrutura simplificada que atuará em dois modos de funcionamento, onde a transição entre um módulo e outro será controlada por meio do formalismo de sistema de eventos. O sistema foi modelado a partir do desenvolvimento de suas equações dinâmicas e implementação em Matlab®, como também através do uso da plataforma SimMechanics® que permitiu a modelagem de componentes externas com maior grau de complexidade. Através de simulação computacional verificou-se que sistema em estudo apresentou um desempenho preciso no desenvolvimento da marcha, onde se considerou, inclusive, os efeitos do impacto que ocorrem a partir da interação do pé com solo / Abstract: In this dissertation is executed a cinematic and dynamic study of human's gait based on the field of knowledge of biomechanics and the anthropomorphic characteristics of human's leg, based as well on paradigms the rules the assisted rehabilitation with the use of robots. Here it's proposed and strategy of control of robotic exoskeletons for lower limbs through the computed torque with therapeutic goal to improve the human gait. The dynamic gait inspire the system's model, it's used a simplified structure which will function in two distinctive modes of operation, the transition between the modes is control by a system of discrete events. The modeled system is developed from its dynamic equations in Matlab® and also with the use of SimMechanics® simulation platform the allowed the inclusion of external components with greater complexity in the model. Through the computational simulation is concluded that the studied system had a precise performance in development of the gait, the control simulation included the effects of the impact that occurs when the foot interact with the solo / Mestrado / Mecanica dos Sólidos e Projeto Mecanico / Mestra em Engenharia Mecânica

The thesis focuses on the use of multiagent systems to model the rental housing market. At first the aim was to create the simulation, which would bring a new perspective on the development of the entire market. For this purpose I selected a relatively young methodology titled Agentology, which was subjected to the criticism of a model after finishing the model. That was a secondary principal objective of this thesis. The work is divided into two parts. In the first theoretical part the rental housing market is described and there are discussed the most important factors affecting its state. Simultaneously the chapter describes the most significant State interventions into the market, as we know them from the official housing policies. In the next stage the reader is made familiar with the basic principles of multi-agent modeling. In this chapter there is also an overview of selected methodologies of multiagent systems and one of them is selected and applied in further phases of this work. The second part refers to the multi-agent model. Using the Agentology methodology market model is assembled. The methodology accompanies all stages of model development from the task formulation, through conceptual and technological level to the final evaluation. This work strictly adheres to the methodology and all its recommendations. In the end, the result represents a model whose functionality has been verified by analyzing the output data. Finally the thesis deals with criticism of the Agentology methodology. This criticism is a result of experience gained from previous development. It concerns evaluation of concrete steps and also of methodology as a whole in terms of admittance, integrity and practicality.

In this paper we present an approach to the analysis of the contribution of a small subregion in a dataset to the global flow. To this purpose, we subtract the potential flow that is induced by the boundary of the sub-domain from the original flow. Since the potential flow is free of both divergence and rotation, the localized flow field retains the original features. In contrast to similar approaches, by making explicit use of the boundary flow of the subregion, we manage to isolate the region-specific flow that contains exactly the local contribution of the considered subdomain to the global flow. In the remainder of the paper, we describe an implementation on unstructured grids in both two and three dimensions. We discuss the application of several widely used feature extraction methods on the localized flow, with an emphasis on topological schemes.

L’un des objectifs de la microélectronique est de concevoir et fabriquer des SoCs de petites tailles, à moindre coût et visant des marchés tel que l’internet des objets. À matériel fixe sur lequel l’on ne dispose d’aucune marge de manœuvre, l’un des challenges pour un développeur de logiciels embarqués est d’écrire son programme de manière à ce qu’à l’exécution, le logiciel développé puisse utiliser au mieux les capacités de ces SoCs. Cependant, ces programmes n’utilisent pas toujours correctement les capacités de traitement disponibles sur le SoC. L’estimation et l’optimisation de la performance du logiciel devient donc une activité cruciale. A l’exécution, ces programmes sont très souvent victimes de l’apparition de cycles de gel de processeur dus à l’absence de données en mémoire cache. Il existe plusieurs approches permettant d’éviter ces cycles de gel de processeur. Par l’exemple l’utilisation des options de compilation adéquates pour la génération du meilleur code exécutable possible. Cependant les compilateurs n’ont qu’une idée abstraite (sous forme de formules analytiques) de l’architecture du matériel sur lequel le logiciel s’exécutera. Une alternative est l’utilisation des processeurs « Out–Of–Order ». Mais ces processeurs sont très couteux en terme de coût de fabrication car nécessites une surface de silicium importante pour l’implantation de ces mécanismes. Dans cette thèse, nous proposons une méthode itérative basée sur les plateformes virtuelles précises au niveau du cycle qui permet d’identifier les instructions du programme à optimiser responsables à l’exécution, de l’apparition des cycles de gel de processeur dus à l’absence de données dans le cache L1. L’objectif est de fournir au développeur des indices sur les emplacements du code source de son programme en langage de haut niveau (C/C++ typiquement) qui sont responsables de ces gels. Pour chacune de ces instructions, nous fournissons leur contribution au rallongement du temps d’exécution totale du programme. Finalement nous estimons le gain potentiel maximal qu’il est possible d’obtenir si tous les cycles de gel identifiés sont évités en insérant manuellement dans le code source du programme à optimiser, des instructions de pré–chargement de données dirigé par le logiciel. / One of microelectronics purposes is to design and manufacture small-sized, low-cost SoCs targeting markets such as the Internet of Things. With fixed hardware on which there is no possible flexibility, one of the challenges for an embedded software developer is to write his program so that, at runtime, the software developed can make the best use of these SoC capabilities. However, these programs do not always properly use the available SoC processing capabilities. Software performance estimation and optimization is then a crucial activity. At runtime, these programs are very often victims of processor data stall cycles. There are several approaches to avoiding these processor data stall cycles. For example, using the appropriate compilation options to generate the best executable code. However, the compilers have only an abstract knowledge (as analytical formulas) of the hardware architecture on which the software will be executed. Another way of solving this issue is to use Out-Of- Order processors. But these processors are very expensive in terms of manufacturing cost because they require a large silicon surface for the implementation of the Out-Of-Order mechanism. In this thesis, we propose an iterative methodology based on cycle accurate virtual platforms, which helps identifying precisely instructions of the program which are responsible of the generation of processor data stall cycles. The goal is to provide the developer with clues on the source code lignes of his program’s in high level language (C/C++ typically) which are responsible of these stalls. For each instructions, we provide their contribution to lengthening of the total program execution time. Finally, we estimate the maximum potential gain that can be achieved if all identified stall cycles are avoided by manually inserting software preloading instructions into the source code of the program to optimize.

Made available in DSpace on 2014-12-17T14:08:56Z (GMT). No. of bitstreams: 1 JofranyaWAP_DISSERT.pdf: 2973696 bytes, checksum: 2de846649570e278d51d0d67ec195c5e (MD5) Previous issue date: 2014-03-06 / After the decline of production from natural energy of the reservoir, the methods of enhanced oil recovery, which methods result from the application of special processes such as chemical injection, miscible gases, thermal and others can be applied. The advanced recovery method with alternating - CO2 injection WAG uses the injection of water and gas, normally miscible that will come in contact with the stock oil. In Brazil with the discovery of pre-salt layer that gas gained prominence. The amount of CO2 present in the oil produced in the pre-salt layer, as well as some reservoirs is one of the challenges to be overcome in relation to sustainable production once this gas needs to be processed in some way. Many targets for CO2 are proposed by researchers to describe some alternatives to the use of CO2 gas produced such as enhanced recovery, storage depleted fields, salt caverns storage and marketing of CO2 even in plants. The largest oil discoveries in Brazil have recently been made by Petrobras in the pre -salt layer located between the states of Santa Catarina and Esp?rito Santo, where he met large volumes of light oil with a density of approximately 28 ? API, low acidity and low sulfur content. This oil that has a large amount of dissolved CO2 and thus a pioneering solution for the fate of this gas comes with an advanced recovery. The objective of this research is to analyze which parameters had the greatest influence on the enhanced recovery process. The simulations were performed using the "GEM" module of the Computer Modelling Group, with the aim of studying the advanced recovery method in question. For this work, semi - synthetic models were used with reservoir and fluid data that can be extrapolated to practical situations in the Brazilian Northeast. The results showed the influence of the alternating injection of water and gas on the recovery factor and flow rate of oil production process, when compared to primary recovery and continuous water injection or continuous gas injection / O m?todo de recupera??o avan?ada com inje??o alternada WAG-CO2 utiliza da inje??o de ?gua e g?s, g?s esse normalmente misc?vel que vai entrar em contato com o banco de ?leo. No Brasil com a descoberta da camada pr?-sal esse g?s ganhou destaque. A quantidade de CO2 presente no ?leo produzido na camada pr?-sal, assim como acontece em alguns reservat?rios ? um dos desafios a serem vencidos com rela??o ? produ??o sustent?vel uma vez que esse g?s precisa ser processado de alguma maneira. Muitos os destinos para o CO2 s?o propostos por estudiosos, que descrevem algumas alternativas para uso do g?s CO2 produzido, tais como, recupera??o avan?ada, armazenamento em campos depletados, armazenamento em cavernas de sal e ainda comercializa??o do CO2 em plantas. As maiores descobertas de petr?leo, no Brasil, foram feitas recentemente pela Petrobras na camada pr?-sal localizada entre os estados de Santa Catarina e Esp?rito Santo, onde se encontrou grandes volumes de ?leo leve com uma densidade em torno de 28? API, baixa acidez e baixo teor de enxofre. ?leo esse que possui uma grande quantidade de CO2 dissolvido e assim uma solu??o pioneira para o destino desse g?s vem sendo a recupera??o avan?ada. O objetivo dessa pesquisa ? analisar quais os par?metros que tiveram maior influ?ncia no processo de recupera??o avan?ada. As simula??es foram realizadas utilizando o m?dulo GEM da Computer Modelling Group, com o objetivo de realizar estudos do m?todo de recupera??o avan?ada em quest?o. Para a realiza??o deste trabalho, modelos semi-sint?ticos foram utilizados com dados de reservat?rio e fluidos que podem ser extrapolados para situa??es pr?ticas do Nordeste brasileiro. Os resultados mostraram a influ?ncia do processo de inje??o alternada de ?gua e g?s sobre o fator de recupera??o e vaz?o de produ??o de ?leo, quando comparados ? recupera??o prim?ria e inje??o cont?nua de ?gua ou inje??o cont?nua de g?s

Made available in DSpace on 2014-12-17T15:01:32Z (GMT). No. of bitstreams: 1 FranciscoCMF_DISSERT.pdf: 2311444 bytes, checksum: 85931d2109432c72956fc554bf2cff9d (MD5) Previous issue date: 2013-09-06 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / This work studies the development, implementation and improvement of a macroscopic model to describe the behavior of the spouted bed dryer with continuous feeding for pastes and suspensions drying. This model is based on the CST model (Freire et al., 2009) and the model of Fernandes (2005), whose theoretical foundation is based on macroscopic mass and heat balances for the three phases involved in the process: gas, liquid and solid. Because this technique is quite relevant, the studies of modeling and simulation of spouted bed drying are essential in the analysis of the process as a whole, because through them it is possible to predict and understand the behavior of the process, which contributes significantly to more efficient project and operation. The development and understanding of the phenomena involved in the drying process can be obtained by comparing the experimental data with those from computer simulations. Such knowledge is critical for choosing properly the process conditions in order to obtain a good drying efficiency. Over the past few years, researches and development of works in the field of pastes and suspensions drying in spouted bed has been gaining ground in Brazil. The Particulate Systems Laboratory at Universidade Federal do Rio Grande do Norte, has been developing several researches and generating a huge collection of experimental data concerning the drying of fruit pulps, vegetables pastes, goat milk and suspensions of agro-industrial residues. From this collection, some data of goat milk and residue from acerola (Malpighia glabra L.) drying were collected. For the first time, these data were used for the development and validation of a model that can describe the behavior of spouted bed dryer. Thus, it was possible to model the dryer and to evaluate the influence of process variables (paste feeding, temperature and flow rate of the drying air) in the drying dynamics. We also performed water evaporation experiments in order to understand and to study the behavior of the dryer wall temperature and the evaporation rate. All these analysis will contribute to future works involving the implementation of control strategies in the pastes and suspensions drying. The results obtained in transient analysis were compared with experimental data indicating that this model well represents the process / No presente trabalho estuda-se o desenvolvimento, a aplica??o e o aprimoramento de um modelo macrosc?pico para descrever o comportamento do secador leito de jorro com alimenta??o cont?nua para a secagem de pastas e suspens?es. Tal modelo est? baseado nos modelos CST (Freire et al., 2009) e de Fernandes (2005), cuja base te?rica ? fundamentada em balan?os macrosc?picos de calor e massa para as tr?s fases envolvidas no processo: gasosa, l?quida e s?lida. Pelo fato dessa t?cnica ser bastante relevante, os estudos da modelagem e simula??o da secagem em leito de jorro s?o fundamentais na an?lise do processo como um todo, pois atrav?s deles ? poss?vel prever e compreender o comportamento do processo, o que contribui significativamente para um projeto e opera??o mais eficazes. O desenvolvimento e entendimento dos fen?menos envolvidos no processo de secagem podem ser adquiridos atrav?s da compara??o dos dados obtidos experimentalmente com os provenientes de simula??es computacionais. Tal conhecimento ? de suma import?ncia para que haja a escolha adequada das condi??es de processo, a fim de se obter uma boa efici?ncia da secagem. Ao longo dos ?ltimos anos, a pesquisa e o desenvolvimento de trabalhos voltados ? secagem de pastas e suspens?es em leito de jorro vem ganhando espa?o no Brasil. O Laborat?rio de Sistemas Particulados, localizado na Universidade Federal do Rio Grande do Norte, vem desenvolvendo diversas pesquisas e gerando um enorme acervo de dados experimentais relativos ? secagem de polpas de frutas, pastas de legumes, leite de cabra e de suspens?es de res?duos da agroind?stria. Desse acervo foram coletados dados para secagem de leite de cabra e res?duo da acerola (Malpighia glabra L.). Pela primeira vez esses dados foram utilizados para o desenvolvimento e valida??o de um modelo que consiga descrever o comportamento do secador leito de jorro. Com isso, foi poss?vel modelar o secador e avaliar a influ?ncia das vari?veis de processo (vaz?o da pasta, temperatura e vaz?o do ar de secagem) na din?mica da secagem. Foram realizados ainda, experimentos de evapora??o de ?gua a fim de entender e equacionar o comportamento da temperatura na parede do secador e da taxa de evapora??o. Todas essas an?lises contribuir?o para trabalhos futuros que envolvam a implementa??o de estrat?gias de controle na secagem de pastas e suspens?es. Os resultados obtidos nas an?lises em regime transiente foram comparados com dados experimentais indicando que o modelo representa bem o processo

Submitted by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2018-03-08T15:34:35Z No. of bitstreams: 2 Dissertação_Joao Marcos Oliveira.pdf: 90263888 bytes, checksum: 401126ad345a27c9fd7da27e1a6232d9 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2018-03-08T15:43:41Z (GMT) No. of bitstreams: 2 Dissertação_Joao Marcos Oliveira.pdf: 90263888 bytes, checksum: 401126ad345a27c9fd7da27e1a6232d9 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2018-03-08T15:43:41Z (GMT). No. of bitstreams: 2 Dissertação_Joao Marcos Oliveira.pdf: 90263888 bytes, checksum: 401126ad345a27c9fd7da27e1a6232d9 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2016-07-27 / FAPEAM - Fundação de Amparo à Pesquisa do Estado do Amazonas / Data modeling and simulation may contribute to process improvement avoiding unnecessary expenses. Once they allow us to evaluate hypothesis without modify the local structure and relocate human resources. Usually, researches who uses these tool direct their efforts on experimentations and on the results obtained, giving much less attention on the planning phase of the event on research. The planning phase of the event is crucial and once it is skipped the consequences may result on time consuming and lose effectiveness. This work address this gap on data modeling and simulation looking for learning resources focus on minimize this problem with the following questions? How could the professors provide help to students of engineering to build conceptual models using IDEF-SIM (Integration Definition for Function Modeling-Simulation)? We used as methodology the Didactic Engineering. We planned and performed a training course with a group of students of Production and Software Engineering. During the course, we developed six activities. These activities were differentiated according to how the problem was exposed and data disposition as well. Both based on theoretical model of Statistics Investigation called PPDAC (Problem, Plan, Data, Analysis, Conclusions) and the modeling software ProModel®. The information obtained at the analysis phase performed a posteriori and internal validation suggested that the learning structural developed apparently propitiate to the group of the students which attended to the training course a deep understanding regarding to how a system work and how it bring benefits to the development of the conceptual model. / A técnica de modelagem e simulação pode contribuir para melhoria de processos, evitando desperdícios e gastos desnecessários, pois permite avaliar hipóteses sem modificar estruturas físicas nem realocar recursos humanos. Contudo, o investigador que a utiliza, normalmente foca seu trabalho na realização de experiências e nos resultados obtidos, dando pouca atenção à fase de planejamento, que ocasiona perda de tempo e efetividade. Buscando recursos didáticos para minimizar esse problema, o trabalho aqui apresentado focou na seguinte questão: Como auxiliar estudantes de cursos de engenharias a construir modelos conceituais com a técnica IDEF-SIM (Integration Definition for Function Modeling-Simulation)? Utilizando como metodologia a Engenharia Didática, planejou-se e executou-se, com um grupo de estudantes de engenharia de produção e engenharia de software, um curso de formação, composto por seis atividades fundamentadas no modelo teórico de investigação estatística PPDAC (Problema, Planejamento, Dados, Ação e Conclusão) e no software de modelagem ProModel® que se diferenciaram pelo modo de exposição dos problemas e pela disposição dos dados. As informações obtidas na fase de análise a posteriori e validação interna sugeriram que a estrutura formativa desenvolvida, aparentemente, propiciou aos futuros engenheiros uma compreensão mais profunda sobre a forma como um sistema funciona, beneficiando o desenvolvimento do modelo conceitual.

This paper shows that the two most common impedance transformation networks for power amplifiers (PAs) can be designed to achieve optimum transformation at two frequencies. Hence, a larger bandwidth for the required impedance transformation ratio is achieved. A design procedure is proposed, which takes imperfections like losses into account. Furthermore, an analysis method is presented to estimate the maximum uncompressed output power of a PA with respect to frequency. Based on these results, a fully integrated PA with a dual-band impedance transformation network is designed and its functionality is proven by large signal measurement results. The amplifier covers the frequency band from 450 MHz to 1.2 GHz (3 dB bandwidth of the output power and efficiency), corresponding to a relative bandwidth of more than 100%. It delivers 23.7 dBm output power in the 1 dB compression point, having a power-added efficiency of 33%.