856 resultados para Algoritmos experimentais
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In this paper we show how to obtain efficient designs of experiments for fitting Michaelis-Menten and Hill equations useful in chemical studies. The search of exact D-optimal designs by using local and pseudo-Bayesian approaches is considered. Optimal designs were compared to those commonly used in practice using an efficiency measure and theoretical standard errors of the kinetic parameter estimates. In conclusion, the D-optimal designs based on the Hill equation proved efficient for estimating the parameters of both models. Furthermore, these are promising with respect to practical issues, allowing efficient estimation as well as goodness-of-fit tests and comparisons between some kinetic models.
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Pós-graduação em Ciência da Computação - IBILCE
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Pós-graduação em Ciência da Computação - IBILCE
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Pós-graduação em Engenharia Elétrica - FEIS
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Pós-graduação em Engenharia Elétrica - FEIS
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To design connections between timber parts with metal dowels (nails or bolts), two phenomena must be considered: bending of the metal dowel and the embedment strength in the wood. The Brazilian Standard ABNT NBR 7190:1997 proposes the methods used in the laboratory tests to determine the embedment strength with the metal dowell and, in the absence of testing, specifies relations to calculate the embedment strength from the compression strength. The aim of this research was to compare the embedment strength values obtained by experimental tests and calculated by the relationships established by the Brazilian Standard ABNT NBR 7190:1997. By the results of the hypothesis tests, it was possible to conclude that the estimate of the embedment strength parallel to the grain proposed by the Brazilian standard ABNT NBR 7190:1997, establishing equivalence with the strength compression results in the same direction, must be effective to the wood species Pinus taeda L., however, the same was not found in the perpendicular direction with respect to the grain, possibly explained by the alpha(e) values in the equation to calculed fe(90)
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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There are many advantages when using a phantom for the evaluation of the mammographic images, one of them is to test the visibility of the distribution of objects that constitute it, and then, set the best image in order to obtain a diagnostic medical insurance, trying to reach the best risk - benefit ratio for the patient. Typically, the quality of the mammographic image is performed by subjective and quantitative assessments. This study developed algorithms that can quantitatively evaluate digital images (DICOM), obtained from mammographic phantom consisting of test objects. The results were adjusted by the response of the subjective evaluation performed by experts in radiology. This procedure aims to create an independence of the experts in radiology in daily tests of quality control in routine clinical diagnostic radiology
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Techniques of image combination, with extraction of objects to set a final scene, are very used in applications from photos montages to cinematographic productions. These techniques are called digital matting. With them is possible to decrease the cost of productions, because it is not necessary for the actor to be filmed in the location where the final scene occurs. This feature also favors its use in programs made to digital television, which demands a high quality image. Many digital matting algorithms use markings done on the images, to demarcate what is the foreground, the background and the uncertainty areas. This marking is called trimap, which is a triple map containing these three informations. The trimap is done, typically, from manual markings. In this project, methods were created that can be used in digital matting algorithms, with restriction of time and without human interaction, that is, the creation of an algorithm that generates the trimap automatically. This last one can be generated from the difference between a color of an arbitrary background and the foreground, or by using a depth map. It was also created a matting method, based on the Geodesic Matting (BAI; SAPIRO, 2009), which has an inferior processing time then the original one. Aiming to improve the performance of the applications that generates the trimap and of the algorithms that generates the alphamap (map that associates a value to the transparency of each pixel of the image), allowing its use in applications with time restrictions, it was used the CUDA architecture. Taking advantage, this way, of the computational power and the features of the GPGPU, which is massively parallel
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Dissatisfaction with certain aspects of the educational processes of the traditional teaching has always existed, and new teaching methods have been routinely studied. The experimental investigative activity is one of those alternative practices. In this type of activity the experimentation is inserted with an investigative approach, in which the student must build the concept, with proposals that represent solutions to the excited problems. In the teaching of chemistry, specifically, the need and importance of experimentation is evident, beyond motivate students, aid in the understanding of chemical concepts relating them to reality. Realizing the contributions of this methodology for teaching and learning, through this research was conducted to understand the difficulties encountered by teachers for planning and implementation of these activities in the teaching of chemistry and therefore the reasons for the dominance of traditional teaching method. The subjects were undergraduate students of chemistry course that developed and implemented differentiated learning activities for teaching and teachers who accompanied the high school students who participated in the university extension project Inclusion Science and University students and teachers from public: Teaching and Learning Chemistry focuses on research and practice”. Through the data it was possible to identify some factors that affect and hinder the implementation of experimental activities in general, not only the investigative. However, despite the difficulties experienced by undergraduates, the majority considered the activity as an alternative teaching method interesting and innovative, able to produce interest, motivation and participation of students with subsequent learning. As well as the teachers, what with all the difficulties that they had declared facing when applying experimental activities, they admitted the pedagogical... (Complete abstract click electronic access belo)
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We discuss in the work the importance of experiential activities for Physics Teaching in the first years at Elementary Education. For this we start from the experience provided by the Teaching Project Initiation under Pibid CAPES, linked to the Department of Education from the Institute of Biosciences and activities of the Graduate Diploma in Physics Supervised, at Rio Claro Campus, São Paulo State, in partnership with Basic Education schools of the city. Based on some patterns and studies on the Teaching of Science in Elementary Education and particularly in the Ferreira’s work with Instrumentation for Physics Teaching, Electrostatic was chosen as base theme. We opted for the use of didactic experiments that provided in its construction the utilization of low cost materials, easy access and portability. Teaching strategies were aimed at inserting experiential activities during Elementary School I (first and third years of elementary school), intending to rescue the trial of Physics Education and Science for Basic Education. These experimental teaching activities were analyzed in this paper from the perspective of playfulness. We argue that experimentation with recreational attributes when properly used provides the interaction of individuals with the knowledge of Physical Sciences
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Combining the characteristics of good adhesion and sealing of the AH Plus sealer the biological properties of the MTA, zinc oxide and calcium hydroxide, the purpose of this study was to evaluate the cytotoxicity of these associations. The specimens of the sealers and their associations were mixed and exposure to culture medium (82.4 mm2surface/mL) after the manipulation and incubated in a humidified incubator (37°C and 100% humidity) for 24 h. Chinese hamster lung fibroblasts (V79) were exposed to different dilutions of this extracts for 24 h and cell viability was measured by MTT test. The differences between the cell survival rates were statistically analyzed for Kruskal-Wallis and Dunn (p≤0.05). All sealers showed a significant difference with the group control, except the MTA. Cytotoxicity with the control group increased in the following order: AH Plus < AH Plus + Ca(OH) 2 < AH Plus + OxZn< AH Plus + MTA < MTA (p≤ 0,05). It was concluded that the addition of biological materials in order to improve the consistency of AH Plus for use in retro cavities its toxicity has not decreased significantly
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As úlceras gástricas, além de representarem eventos patológicos comuns na clínica médica, são atualmente consideradas importantes desafios para a terapêutica, à medida que o tratamento e/ou prevenção dessa doença ainda apresentam limitações, como os efeitos adversos e a baixa qualidade de cicatrização. Outro grande problema é a difícil acessibilidade às terapias disponíveis pela população de baixa renda, devido ao seu alto custo. Considerando a problemática abordada, e levando em consideração que estudos têm mostrado que terpenóides têm apresentado atividade antiúlcera bastante significativa, propusemos investigar o efeito gastroprotetor do monoterpeno Citral em úlceras gástricas experimentais induzidas tanto por etanol quanto por antiinflamatórios não esteroidais (utilizando a Indometacina como agente indutor das ulcerações), bem como avaliar seu efeito cicatrizante. O Citral mostrou ser gastroprotetor frente ao agente lesivo etanol, a partir da dose de 25 mg/kg, em uma relação dose-dependente quando administrado oralmente, sendo mais potente do que a Carbenoxolona, utilizada como controle positivo, a partir de uma dose duas vezes menor [dose de 50 mg/kg, na qual o Citral apresentou 98 % de proteção em relação ao controle negativo (Tween 80 a 8%), contra 85 % de proteção proporcionada pela Carbenoxolona na dose de 100 mg/kg]. No entanto, no modelo de indução de úlceras gástricas por Indometacina o Citral mostrou um efeito dual, ao passo que em doses intermediárias (25 e 50 mg/kg) apresentou efeito gastroprotetor, e em doses extremas (100 e 200 mg/kg) apresentou uma significativa potencialização das lesões, permitindo assim a hipótese de um possível efeito antiinflamatório e/ou antinociceptivo nessas doses. Também foi verificado seu efeito cicatrizante na dose de 25 mg/kg, sendo tão eficaz quanto o Lansoprazol (controle positivo)... (Resumo completo, clicar acesso eletrônico abaixo)