941 resultados para Modelagem estrutural de ambientes informacionais digitais


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Mudas de mamoeiro da cultivar Baixinho de Santa Amália foram transplantadas para covas de 40x60x40 cm, em áreas de três estruturas contíguas: (a) estufa sombreada (cobertura de plástico), (b) estufa sombreada + sombrite (cobertura adicional de sombrite com 30% de sombreamento sobre o plástico) e (c) telado (cobertura exclusiva de sombrite 30%). Ao lado de tais estruturas foi implantada uma área de cultivo de mamoeiro em ambiente natural. Os tratos culturais aplicados foram os condizentes às normas técnicas vigentes na agricultura orgânica. As irrigações foram procedidas com mangueira plástica, evitando-se molhar folhas e frutos. Aos 45 dias pós-transplantio e, subseqüentemente, a intervalos mensais, as plantas foram inspecionadas em relação à incidência de lesões foliares causada pelo fungo Asperisporium caricae. Para efeito de análise estatística, após o teste de homogeneidade das variâncias, foram consideradas quatro repetições por ambiente (tratamento), com seis plantas úteis por parcela. O modelo de quantificação da doença indicou efeito altamente significativo dos ambientes protegidos, estufa e estufa sombreada, quanto à incidência de sintomas, em comparação com ambientes de telado e em área natural de cultivo. Durante os 12 meses de avaliações foi constatada alta correlação entre incidência da doença e pluviosidade e umidade relativa do ar. As estruturas cobertas com plástico demonstraram alto potencial de controle de A. caricae, sendo, portanto, recomendáveis no sistema orgânico de produção do mamoeiro.

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The study object of this thesis intertwines the history of deaf education in the last 30 years in three schools for the deaf in the cities of Campina Grande, Gado Bravo and Aroeiras, Paraiba, the life stories of six deaf teachers of brasilian sign language (Libras) that have formed and works in these educational institutions for the deaf and our own journey, as a teacher and researcher. The study was conducted on the theoretical-methodological principles of (auto)biographical research in education and socio-historical studies on the social formation of the human. The corpus used for analysis was consisted of six narrative interviews conducted in sign language and transcribed into portuguese, documents and personal files and institutional. The analysis allowed us to define three hinge moments of this story: the creation of the first school for the deaf, within the framework of oralism (1980 - 1991), the passage into the Total Communication (1991 - 1995) and, finally, the introduction of Bilingualism (1995 to today). The analyzes show that the trajectories of teacher formation of the research participants reflect the history of the three schools which have costituted bilingual social spaces of paramount importance to the subjects and the deaf community as a group of linguistic and cultural minority. The evolution of this trajectory has allowed to demarcate between the two generations of research participants. The generation of heirs of oralism, which had delayed access to the Libras and lived an education referenced in oralism, whose reminiscences of childhood and adolescence are strongly marked by suffering for the lack of communication, which hinders their social and professional career until today. And the generation of the sons of bilingualism, the youngest in age, who had childhood access to Libras and education within the framework of bilingualism, whose reminiscences are not marked by suffering and have a positive vision of the future. With respect to your teacher formation, three figures stand out as a teacher. The teacher's improvised, closer to the first generation of teachers who were called to teach without proper training. The figure of the teacher craftsman, which corresponds to the image that most of them have of yourself now, understanding that their knowledge are based on the exchange between peers. And finally the figure of the real teacher, which stands on the horizon of expectations as future graduates in Letters |Libras. The narratives allowed to realize that the evolution between these figures is based on the contributions of the other: hearing teachers of EDAC and the Federal University of Campina Grande and deaf teachers of the two generations who learn from each other. The analyzes and reflections allowed to defend the thesis of the centrality of bilingual environments for the establishment of the deaf person as a citizen with full rights, based on the voice of the deaf, muted by the history of education, conducted by listeners

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Genetic parameters for weights (17, 942 records), obtained in intervals of 60 days, from the birth to selection (378 days of age), of 2,582 males of the Nellore breed was estimated in univariate analyses by the Maximum Restricted Likelihood method. The models of analysis models included the fixed effects of contemporary groups, month of birth, mother age and age when the weights were collected as covariate. Three models differing in random effects were tested: the model 1 (M1) was adjusted for the direct and maternal addictive genetic effects and maternal permanent environment; in model 2 (M2) the maternal genetic effect was excluded; and the model 3 (M3) was only adjusted for the direct addictive genetic effect. The test of likelihood (LRT) detected significant differences, for all the ages, of M2 and M1 in relation to the simple model (M3), evidencing the importance of the maternal effects. Except for the birth weight (0.40), low values (0.05 to 0.12) of h(2) were found for M1 and M2 until 8 months of age and, after this period, reasonable increase could be observed, reaching 0.28 until 13 months of age. The estimates of the total variance fraction, due to the effect of maternal permanent environment, were high and practically became unaffected between the models 1 and 2. Maternal effects, not necessarily decomposed (in genetic addictive and permanent environment), affected the Nellore males growth. Models that contemplate maternal effects, besides the genetic addictive direct effects, are more realistic to describe the trajectory of the variances in the initial phases of growth of Nelore male calves.

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A cobertura vegetal do solo é decisiva para redução dos efeitos erosivos do impacto direto das gotas de chuva na superfície do solo. Desta forma, objetivou-se com este estudo determinar o índice de cobertura vegetal (CV) e desenvolver modelos para sua estimativa para a cultura da soja, usando os atributos climáticos no período de chuvas intensas no Sul de Minas Gerais. As determinações da CV foram feitas semanalmente, na área experimental do Departamento de Ciência do Solo, Universidade Federal de Lavras (UFLA), no período de novembro de 1999 a maio de 2000, em 28 cultivares de soja com potencial para cultivo nesta região. Para avaliação da cobertura vegetal foi utilizada a metodologia descrita por Stocking (1988). Na modelagem procurou-se relacionar a CV com os valores acumulados dos seguintes atributos climáticos: temperatura média (Tmed), precipitação (PREC) e umidade relativa do ar (UR). Os valores de cobertura vegetal apresentaram uma amplitude de variação de 56 a 83%, sendo BR 162, LO 12 L e M. Soy 108 as cultivares mais eficientes e FT Abyara e Tucano as menos eficientes. O hábito diferencial de crescimento das cultivares ajuda a explicar esse comportamento. O modelo ajustado adequado para estimativa da CV foi: CV = 116589,976 + 0,422 . Tmed + 0,132 . PREC - 0,095 . UR + 0,000024 . Tmed², R² = 0,99 (P < 0,01). A determinação da CV nas diferentes fases de desenvolvimento da cultura é de grande importância, uma vez que seu estabelecimento coincide com o período de maior potencial erosivo das chuvas na região estudada.

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A numerical study on the behavior of tied-back retaining walls in sand, using the finite element method (FEM) is presented. The analyses were performed using the software Plaxis 2D, and were focused on the development of horizontal displacements, horizontal stresses, shear forces and bending moments in the structure during the construction process. Emphasis was placed on the evaluation of wall embedment, tie-back horizontal spacing, wall thickness, and free anchor length on wall behavior. A representative soil profile of a specific region at the City of Natal, Brazil, was used in the numerical analyses. New facilities built on this region often include retaining structures of the same type studied herein. Soil behavior was modeled using the Mohr-Coulomb constitutive model, whereas the structural elements were modeled using the linear elastic model. Shear strength parameters of the soil layers were obtained from direct shear test results conducted with samples collected at the studied site. Deformation parameters were obtained from empirical correlations from SPT test results carried out on the studied site. The results of the numerical analyses revealed that the effect of wall embedment on the investigated parameters is virtually negligible. Conversely, the tie-back horizontal spacing plays an important role on the investigated parameters. The results also demonstrated that the wall thickness significantly affects the wall horizontal displacements, and the shear forces and bending moments within the retaining structure. However, wall thickness was not found to influence horizontal stresses in the structure

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The main objective of this thesis was the study of bracing panels of structural masonry, by applying the Finite Element Method and Strut and Tie Method. It was analyzed the following aspects: the effect of orthotropy on the behavior of the panels; distribution of horizontal forces between panels for buildings; comparison between Equivalent Frame and Finite Elements models; panels design with the Strut and Tie Method. The results showed that one should not disregard the orthotropy, otherwise this can lead to models stiffer than the real. Regarding the distribution of horizontal forces, showed that the disregard of lintels and shear deformation leads to significant differences in the simplified model. The results showed also that the models in Finite Element and Equivalent Frame exhibit similar behavior in respect to stiffness of panels and stress distribution over the sessions requested. It was discussing criteria for designing Strut and Tie Method models in one floor panels. Then, the theoretical strength these panels was compared with the rupture strength of panels tested in the literature. The theoretical maximum strength were always less than the rupture strength of the panels obtained in tests, due to the fact that the proposed model cannot represent the behavior of the masonry after the start of the panel cracking due to plasticization of the reinforcement

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Este trabalho tem dois objetivos: avaliar a usabilidade de três interfaces de ambientes virtuais de educação à distância através de duas técnicas avaliativas e identificar os fatores influenciadores da percepção de usabilidade dos ambientes avaliados. Os sistemas de educação à distância escolhidos foram o AulaNet, o E-Proinfo e o Teleduc, por serem desenvolvidos no Brasil e terem distribuição gratuita. A avaliação da usabilidade foi realizada através de duas técnicas documentadas na literatura. A primeira técnica de avaliação, do tipo preditiva ou diagnóstica, foi realizada pelo autor e um concluinte do curso de Sistemas de Informação do Centro Federal de Educação Tecnológica do estado do Piauí (CEFET-PI), mediante a observação de um checklist denominado Ergolist. A segunda avaliação, do tipo prospectivo, foi efetivada com o usuário sendo o próprio avaliador das interfaces, através de um questionário. A amostra foi composta de 15 professores e 15 alunos do CEFET-PI. Os resultados colhidos foram analisados a partir da estatística descritiva e testes de chi-quadrado. Os resultados mostraram que os ambientes apresentarem problemas de adaptabilidade, pois não possuem flexibilidade e nem levam em consideração a experiência do usuário. Na análise inferencial, foi constatado que o tempo de uso da Internet não afetou significativamente sua avaliação da usabilidade dos três ambientes, assim como na maior parte das variáveis de usabilidade não foram influenciadas pelo tipo de usuário , sexo e escolaridade . Por outro lado, em vários dos critérios ergonômicos avaliados, as variáveis de sistema tipo de ambiente e experiência com computador e a variável demográfica faixa etária afetaram a percepção de usabilidade dos ambientes virtuais de educação à distância

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The objective of this dissertation is to propose a Multi Criteria Decision Aid Model to be used by the costumers of the travel agencies and help them to choose the best package travel. The main objective is to contribute for the simplification of the travel package decision choice from the identification of the models of values and preference of the customers and applying them to the existing package. It is used the Analytic Hierarchy Process (AHP) method to structuralize a decision hierarchic model composed by six criteria (package cost, hotel category, security of the city, travel time, direct flight and position in ranking of the 10 most visited destination) and five real alternatives of packages for a holiday of three days created from travel agency data. The decision analysis was realized for the choice of a travel package by a group composed by two couples that regularly travels together, to which was asked to do a pairwise judgment of the criteria and the alternatives. The mains results show that, although been a group that travels together, there are different models of values in the weights of the criteria and a certain convergence in the scales of preferences of the alternatives in the criteria. It was not pointed a dominant alternative for all the members of the group separately, but an analysis of a total utility of the group shows a classification and an order of the travel packages and an alternative clearly in front of the others. The sensitivity analysis revels that there are changes in the ranking, but the two alternatives best classified in the normal analysis are the same ones in the sensitivity analysis, although with the positions changed. The analysis also led to a simplification of the process with the exclusion of alternatives dominated for the others ones. As main conclusion, it is evaluated that the model and method suggested allow a simplification of the decision process in the choice of travel packages

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This master´s thesis presents a reliability study conducted among onshore oil fields in the Potiguar Basin (RN/CE) of Petrobras company, Brazil. The main study objective was to build a regression model to predict the risk of failures that impede production wells to function properly using the information of explanatory variables related to wells such as the elevation method, the amount of water produced in the well (BSW), the ratio gas-oil (RGO), the depth of the production bomb, the operational unit of the oil field, among others. The study was based on a retrospective sample of 603 oil columns from all that were functioning between 2000 and 2006. Statistical hypothesis tests under a Weibull regression model fitted to the failure data allowed the selection of some significant predictors in the set considered to explain the first failure time in the wells

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The main goal of this dissertation is to develop a Multi Criteria Decision Aid Model to be used in Oils and Gas perforation rigs contracts choices. The developed model should permit the utilization of multiples criterions, covering problems that exist with models that mainly use the price of the contracts as its decision criterion. The AHP has been chosen because its large utilization, not only academic, but in many other areas, its simplicity of use and flexibility, and also fill all the requirements necessary to complete the task. The development of the model was conducted by interviews and surveys with one specialist in this specific area, who also acts as the main actor on the decision process. The final model consists in six criterions: Costs, mobility, automation, technical support, how fast the service could be concluded and availability to start the operations. Three rigs were chosen as possible solutions for the problem. The results reached by the utilizations of the model suggests that the utilization of AHP as a decision support system in this kind of situation is possible, allowing a simplifications of the problem, and also it s a useful tool to improve every one involved on the process s knowledge about the problem subject, and its possible solutions

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Dados de 32.779 controles mensais, de 3.605 lactações em 305 dias (PL305), de 2.082 vacas Gir, filhas de 281 touros, com partos ocorridos de 1987 a 1999, em 11 rebanhos, foram usados com o objetivo de verificar a viabilidade de utilização da produção de leite no dia do controle (PLDC1 a PLDC10) em avaliações genéticas da raça Gir. Foram realizadas análises bivariadas entre as PLDC1 a PLDC10 e PL305, usando para estimar os componentes de (co)variâncias o método de máxima verossimilhança restrita, sob modelo animal, incluindo as três primeiras lactações como medidas repetidas de uma mesma vaca, diferenciadas conforme o grupo contemporâneo de rebanho-ano-estação, de acordo com a idade da vaca ao parto e o intervalo parto-primeiro controle na PLDC1. As médias observadas e os respectivos desvios-padrão (kg) para PLDC1 a PLDC10 e PL305 foram: 11,97±4,64; 11,93±4,68; 10,98±4,40; 10,18±4,12; 9,66±3,88; 9,20±3,69; 8,63±3,51; 8,08±3,33; 7,59±3,27; 7,22±3,15 e 2.746,17±1.299,90. A duração de lactação foi de 273,72±48,95 dias. As estimativas de herdabilidade variaram nas PLDC de 0,24 a 0,14, sendo maior no primeiro controle e decrescendo até o décimo. A herdabilidade da PL305 foi de 0,19. As estimativas de correlações genéticas entre as PLDC e PL305 variaram de 0,85 a 1,00. As correlações genéticas entre PLDC1 a PLDC9 com PLDC6 a PLDC10 foram acima de 0,80, à exceção entre PLDC9 com PLDC1 e PLDC10 com PLDC1, PLDC2, PLDC3 e PLDC6, que foram inferiores. As correlações fenotípicas tiveram valores intermediários entre as correlações genéticas e as residuais (menores). Considerando a eficiência relativa de seleção, esta mostrou que se baseada nas PLDC2 a PLDC4 ocorrerá a mesma ou melhor resposta que se praticada na PL305.