Formulation of polyurethanes is a complex problem poorly understood as it has developed more as an art rather than a science. Only a few experts have mastered polyurethane (PU) formulation after years of experience and the major raw material manufacturers largely hold such expertise. Understanding of PU formulation is at present insufficient to be developed from first principles. The first principle approach requires time and a detailed understanding of the underlying principles that govern the formulation process (e.g. PU chemistry, kinetics) and a number of measurements of process conditions. Even in the simplest formulations, there are more that 20 variables often interacting with each other in very intricate ways. In this doctoral thesis the use of the Case-Based Reasoning and Artificial Neural Network paradigm is proposed to enable support for PUs formulation tasks by providing a framework for the collection, structure, and representation of real formulating knowledge. The framework is also aimed at facilitating the sharing and deployment of solutions in a consistent and referable way, when appropriate, for future problem solving. Two basic problems in the development of a Case-Based Reasoning tool that uses past flexible PU foam formulation recipes or cases to solve new problems were studied. A PU case was divided into a problem description (i. e. PU measured mechanical properties) and a solution description (i. e. the ingredients and their quantities to produce a PU). The problems investigated are related to the retrieval of former PU cases that are similar to a new problem description, and the adaptation of the retrieved case to meet the problem constraints. For retrieval, an alternative similarity measure based on the moment's description of a case when it is represented as a two dimensional image was studied. The retrieval using geometric, central and Legendre moments was also studied and compared with a standard nearest neighbour algorithm using nine different distance functions (e.g. Euclidean, Canberra, City Block, among others). It was concluded that when cases were represented as 2D images and matching is performed by using moment functions in a similar fashion to the approaches studied in image analysis in pattern recognition, low order geometric and Legendre moments and central moments of any order retrieve the same case as the Euclidean distance does when used in a nearest neighbour algorithm. This means that the Euclidean distance acts a low moment function that represents gross level case features. Higher order (moment's order>3) geometric and Legendre moments while enabling finer details about an image to be represented had no standard distance function counterpart. For the adaptation of retrieved cases, a feed-forward back-propagation artificial neural network was proposed to reduce the adaptation knowledge acquisition effort that has prevented building complete CBR systems and to generate a mapping between change in mechanical properties and formulation ingredients. The proposed network was trained with the differences between problem descriptions (i.e. mechanical properties of a pair of foams) as input patterns and the differences between solution descriptions (i.e. formulation ingredients) as the output patterns. A complete data set was used based on 34 initial formulations and a 16950 epochs trained network with 1102 training exemplars, produced from the case differences, gave only 4% error. However, further work with a data set consisting of a training set and a small validation set failed to generalise returning a high percentage of errors. Further tests on different training/test splits of the data also failed to generalise. The conclusion reached is that the data as such has insufficient common structure to form any general conclusions. Other evidence to suggest that the data does not contain generalisable structure includes the large number of hidden nodes necessary to achieve convergence on the complete data set.

Made available in DSpace on 2016-04-27T14:32:29Z (GMT). No. of bitstreams: 1 Flaminio de Oliveira Rangel.pdf: 1976884 bytes, checksum: b3ae10f963cbea60638c19fdd5219904 (MD5) Previous issue date: 2009-05-15 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Pedagogical mediation in distance education is addressed within the context of increasing use of digital technologies in education, either as a support for onsite education at all levels, or as a support for online learning environments for undergraduate courses, including continuing education for teachers, which is the focus of this research. The research was carried out between 2005 and 2007 as part of a graduate course entitled Contemporary Reading and Writing Practices offered online for technical-pedagogical assistants (ATPs), learning supervisors, coordinators and teacher of Secondary and High schools of the São Paulo, Brazil, state school system. The aim of the study was to show that the arrhythmia among mediation, learning and literacies, perceived as lack of time, had its origin in non-systemic, fragmented conceptual theories that became an important factor of exclusion in relation to social practices for knowledge production, as reflected in the significant dropout rate (61.5%) of in practice mediators. The methodology used was based on action-research. Data was registered in a digital field journal that became a set of digital documents that stored the emerging observations as the course unfolded. Results showed that online mediation, learning and different types of literacies actually constitute a single, complex process, which, if not considered as a systemic relation among its components, can produce an arrhythmia among its elements, leading to drop-outs/exclusion. Hence the arrhythmia among mediation, learning and literacies appears as an important analytical category to measure the quality of social practices in distance education / Este trabalho tem como tema a mediação pedagógica em educação a distância e insere-se no contexto de uso crescente das tecnologias digitais na educação, seja como suporte ao ensino presencial, em qualquer nível, seja passando pela graduação a distância e se estendendo à formação continuada dos educadores, foco desta investigação. A pesquisa foi desenvolvida entre os anos de 2005 e 2007 como parte do curso de aperfeiçoamento Práticas de Leitura e Escrita na Contemporaneidade, oferecido a distância para assistentes técnico-pedagógicos (ATPs), supervisores de ensino, professores coordenadores e professores de Ensino Fundamental II e do Ensino Médio da rede pública estadual de São Paulo. Ela teve como objetivo mostrar que o processo de arritmia entre a mediação, a aprendizagem e os letramentos, apontado pelo sintoma da falta de tempo, foi originado por concepções teóricas fragmentadas e não sistêmicas, e constituiu em um importante fator de exclusão em relação às práticas sociais de produção do conhecimento, fato ocorrido no curso quando uma parcela significativa dos mediadores em formação (61,5%) abandou suas turmas. O referencial metodológico baseou-se na pesquisa-ação, e os dados foram registrados no diário digital de campo que se constituiu em um conjunto de documentos digitais que armazenavam as observações emergentes no desenvolvimento do curso. Com os resultados obtidos foi possível verificar que a mediação on-line, aprendizagem e letramentos se constituem, de fato, como um único e complexo processo e que, por não ser considerado globalmente enquanto relações sistêmicas entre seus componentes, pode introduzir elementos de arritmia e levar à desistência/exclusão. Assim, a arritmia entre mediação, aprendizagem e letramentos surge como uma categoria de análise importante para se aferir a qualidade das práticas sociais de educação a distância

La presente tesis pretende analizar si la orientación empresarial estimula los diferentes tipos de conocimiento en el proceso de internacionalización, para desarrollar la investigación nos centraremos en las Pyme textiles ubicadas en Lima Metropolitana que se encuentren exportando de manera activa a mercados internacionales. El desarrollo del análisis se divide en un total de cinco capítulos, siendo de esta manera el primer capítulo centrado en el marco teórico el cual contextualiza y define los términos y teorías a emplear en la investigación. Luego, en el segundo capítulo se plantea el plan de investigación donde se detalla la problemática y el planteamiento de las hipótesis, así como también los objetivos específicos como el general. Seguidamente en el tercer capítulo, donde se desarrolla la metodología de la investigación en el cual se establecerá el tipo de investigación a seguir, siendo así de tipo mixta para la tesis presentada. Así también, se detalla el alcance, diseño de la investigación, el planteamiento de las variables a trabajar definiendo la población, el tamaño de la muestra y las herramientas metodológicas para la recolección de data. En el cuarto capítulo se enfoca en el desarrollo y análisis de los resultados de la herramienta cualitativa, la cual es la entrevista a profundidad a expertos y de la cuantitativa a través de entrevistas. Los cuales se interpretarán mediante el uso de la regresión lineal, prueba de normalidad y chi cuadrado utilizando el programa SPSS. Por último, las conclusiones y recomendaciones finales respecto a las hipótesis planteadas inicialmente. / This thesis aims to analyze whether business orientation stimulates the different types of knowledge in the internationalization process. In order to develop the research, we will focus on textile SMEs located in Metropolitan Lima that are actively exporting to international markets. The development of the analysis is divided into a total of five chapters, thus being the first chapter focused on the theoretical framework which contextualizes and defines the terms to be used in the research. Then, in the second chapter, the research plan is presented where the problems and the hypotheses are detailed, as well as the specific and general objectives. Then in the third chapter, where the research methodology is developed in which the type of research to be followed will be established, thus being a mixed type for the thesis presented. Likewise, the scope, design of the research, the approach of the variables to work defining the population, the sample size and the methodological tools for data collection are detailed. The fourth chapter focuses on the development and analysis of the results of the qualitative tool, which is the in-depth interview with experts and the quantitative one through interviews. Which will be interpreted through the use of linear regression, normality test and chi square using the SPSS program. Finally, the final conclusions and recommendations regarding the hypotheses initially raised. / Tesis