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Exact analytical solutions for the quasistationary electromagnetic fields in the presence of conducting objects require the field solutions both internal and external to the conductors. Such solutions are limited for certain canonically shaped objects but are useful in testing the accuracy of various approximate models and numerical methods developed to solve complex problems related to real world conducting objects and in calibrating instruments designed to measure various field quantities. Theoretical investigations of quasistationary electromagnetic fields also aid in improving the understanding of the physical phenomena of electromagnetic induction. This thesis presents rigorous analytical expressions derived as benchmark solutions for the quasistationary field quantities both inside and outside, Joule losses and the electromagnetic forces acting upon a conducting spheroid placed in the proximity of a non-uniform field produced by current-carrying turns. These expressions are used to generate numerous numerical results of specified accuracy and selected results are presented in a normalized form for extended ranges of the spheroid axial ratio, the ratio of the depth of penetration to the semi-minor axis and the position of the inducing turns relative to the spheroids. They are intended to constitute reference data to be employed for comprehensive comparisons of results from approximate numerical methods or from boundary impedance models used for real world conductors. Approximate boundary conditions such as the simpler perfect electric conductor model or the Leontovich surface impedance boundary condition model can be used to obtain approximate solutions by only analyzing the field external to the conducting object. The range of validity of these impedance boundary condition models for the analysis of axisymmetric eddy-current problems is thoroughly investigated. While the simpler PEC model can be employed only when the electromagnetic depth of penetration is much smaller than the smallest local radius of curvature, the results obtained using the surface impedance boundary condition model for conducting prolate and oblate spheroids of various axial ratios are in good agreement with the exact results for skin depths of about 1/5 of the semi-minor axis when calculating electromagnetic forces and for skin depths less than 1/20 of the semi-minor axis when calculating Joule losses.

Perfect slice sampling is a method to turn Markov Chain Monte Carlo (MCMC) samplers into exact generators for independent random variates. The originally proposed method is rather slow and thus several improvements have been suggested. However, two of them are erroneous. In this article we give a short introduction to perfect slice sampling, point out incorrect methods, and give a new improved version of the original algorithm. (author's abstract) / Series: Preprint Series / Department of Applied Statistics and Data Processing

The primary goal of this study was to determine the impact of price discrimination on tourism demand. Four objectives were defined with reference to the primary research goal. The first objective was to analyse the concept of price discrimination and relevant theories by means of a literature study. In this regard it was found that price discrimination between markets is fairly common and that it occurs if the same goods were sold to different customers at different prices. Price discrimination is also possible as soon as some monopoly power exists and it is feasible when it is impossible or at least impractical for the buyers to trade among themselves. Three different kinds of price discrimination can be applied, namely first-degree, second-degree and third-degree price discrimination. The data also indicated that price discrimination is advantageous (it mainly increases profit) and that it has several other effects too. The second objective was to analyse examples of price discrimination by means of international case studies. In these different case studies it was found that demand and supply, therefore consumer and product, formed the basis of price discrimination. If demand did not exist, it would be impossible to apply price discrimination. The findings also indicated that, for an organisation to be able to practice price discrimination, the markets must be separated effectively and it will only be successful if there is a significant difference in demand elasticity between the different consumers. Furthermore, the ability to charge these different prices will depend on the consumer's ability and willingness to pay. If an organisation should decide to price discriminate, it would lead to a higher profit, a more optimal pricing policy and also to an increase in sales. The third objective was to analyse national case studies. This was done through comparing the data of a tourism organisation price discriminating (Mosetlha Bush Camp, situated in the North West) to two organisations that did not implement price discrimination (Kgalagadi Transfrontier Park in the Northern Cape and Golden Leopard Resort, also situated in the North West). It was found that a customer with low price elasticity is less deterred by a higher price than a customer with a high price elasticity of demand. As long as the customer's price elasticity is less than one, it will be very advantageous to increase the price: the seller will in this case get more money for less goods. With the increase in price the price elasticity tends to rise above one. The fourth objective was to draw conclusions and make recommendations. It was concluded that price discrimination could be applied successfully in virtually any organisation or industry. Furthermore, price discrimination does not always have a negative effect; but can have a positive ass well. It can have a positive effect on tourism demand. The findings emphasised that the main reason for implementing price discrimination is to increase profit at the cost of reducing consumer surplus. From the results it was recommended that more research on this topic should be conducted. / Thesis (M.Com. (Tourism))--North-West University, Potchefstroom Campus, 2006.

Exact analytical solutions for the quasistationary electromagnetic fields in the presence of conducting objects require the field solutions both internal and external to the conductors. Such solutions are limited for certain canonically shaped objects but are useful in testing the accuracy of various approximate models and numerical methods developed to solve complex problems related to real world conducting objects and in calibrating instruments designed to measure various field quantities. Theoretical investigations of quasistationary electromagnetic fields also aid in improving the understanding of the physical phenomena of electromagnetic induction. This thesis presents rigorous analytical expressions derived as benchmark solutions for the quasistationary field quantities both inside and outside, Joule losses and the electromagnetic forces acting upon a conducting spheroid placed in the proximity of a non-uniform field produced by current-carrying turns. These expressions are used to generate numerous numerical results of specified accuracy and selected results are presented in a normalized form for extended ranges of the spheroid axial ratio, the ratio of the depth of penetration to the semi-minor axis and the position of the inducing turns relative to the spheroids. They are intended to constitute reference data to be employed for comprehensive comparisons of results from approximate numerical methods or from boundary impedance models used for real world conductors. Approximate boundary conditions such as the simpler perfect electric conductor model or the Leontovich surface impedance boundary condition model can be used to obtain approximate solutions by only analyzing the field external to the conducting object. The range of validity of these impedance boundary condition models for the analysis of axisymmetric eddy-current problems is thoroughly investigated. While the simpler PEC model can be employed only when the electromagnetic depth of penetration is much smaller than the smallest local radius of curvature, the results obtained using the surface impedance boundary condition model for conducting prolate and oblate spheroids of various axial ratios are in good agreement with the exact results for skin depths of about 1/5 of the semi-minor axis when calculating electromagnetic forces and for skin depths less than 1/20 of the semi-minor axis when calculating Joule losses.

A major Norwegian defence procurement project takes decades from project initiation to the desired military capability is delivered and has reached full operational capability. The Norwegian Armed Forces’ primary mission is to maintain a credible deterrence and prevent armed conflicts arising, meaning that the capability acquired through military procurement projects must play into future general deterrence. Do Norway’s strategic military capability procurement projects contribute to a credible and capable deterrence? The purpose of this study is to gain a deeper understanding of the deterrence potential of two chosen Norwegian military procurement projects of strategic importance. The capabilities studied are the acquisition of the US fifth generation fighter, F-35 Lightning II and the 212CD submarine to be designed and built by Germany. The two projects have a combined estimated investment cost of 113 billion NOK. Deterrence is a large area in social science and the discipline of War Studies. This study applies a deterrence theory lens, primarily based on the conclusion in Zagare’s and Kilgour’s perfect deterrence theory regarding the importance of capable and credible threats, operationalised through Dalsjö’s five dimensions of threshold defence. The analysis identifies a clear credibility issue with one of the projects and the paradox that cost saving decisions intended to ensure operational availability and increase credibility also make the capability more vulnerable and less credible due to lack of redundancy.

Este trabalho tem como propósito examinar o efeito da representação gráfica do tempo como meio para facilitar a construção de um esquema mental capaz de acomodar os usos do Present Perfect e de seu contraste com o Simple Past em um módulo de língua inglesa mediado por computador. O Present Perfect constitui-se, reconhecidamente, em um problema para professores e alunos de língua inglesa. Dowty (1979) observa que, “com exceção do progressivo, nenhum outro tempo da língua inglesa recebeu mais atenção dos lingüistas do que o Present Perfect e mesmo assim não há um consenso geral no que se refere à sua estrutura semântica.” Dois estudos foram realizados (2003 e 2005) nos quais os participantes foram distribuídos aleatoriamente em uma de duas condições experimentais: (1) Somente texto e (2) Texto+Gráficos. No segundo estudo foram incorporados gráficos interativos, seguindo a recomendação de Peeck (1993) e o princípio de interatividade de Mayer (2002). Os dados coletados através de um pré-teste, pósteste imediato e pós-teste deslocado, foram analisados através de análises de variância (ANOVAs) de um fator e análises de variância para medidas repetidas. Os resultados das ANOVAs, aliados às respostas de um questionário aplicado logo após o pós-teste imediato sugerem que os tratamentos tiveram pouca influência na compreensão e retenção de informações a curto prazo; o princípio de fatiamento de Sweller (1988), utilizando o modelo temporal de Declerck (1986) e o modelo aspectual de Godoi (1992), aliado com o princípio de multimídia da teoria de aprendizado por multimídia de Mayer (2002), mostraram-se eficazes na compreensão e retenção a longo prazo dos usos e contrastes entre o Present Perfect e o Simple Past; e a inclusão de gráficos interativos no estudo de 2005, serviu para diminuir a confusão causada pelos gráficos estáticos, ocorrida no estudo de 2003. / The present study examined the effect of graphical representation of time in facilitating both interpretation and construction of schemata capable of accounting for the uses of the Present Perfect and its contrast with the Simple Past in an English intermediate course mediated by computer. The English Present Perfect is a wellknown troublemaker for EFL/ESL teachers and learners. Dowty (1979) observes that, “aside from the progressive, no English tense has received more attention from linguists and yet eluded a convincing analysis so completely as the Present Perfect.” Two studies were carried out (2003 and 2005) in which the students were randomly distributed between two treatments: (1) Text only and (2) Text+Graphics. In the second study, interactive graphics were added, following Peeck’s (1993) advice to improve active learning and Mayer’s (2002) interactivity principle to give students more control over the material. The data collected in the pre-test, immediate post-test and delayed post-test were analyzed through analyses of variance (ANOVAs) of one factor and repeated measures ANOVAs. The results of the ANOVAs, together with the answers of the questionnaire applied right after the immediate post-test, suggest that the treatments had low influence over the comprehension and retention of information for the immediate post-test; Sweller’s (1988) chunking principle, utilizing Declerck’s (1986) temporal model and Godoi’s (1992) aspectual model, allied with Mayer’s (2002) principle of multimedia, were effective to promote long lasting comprehension and retention of the uses of the Present Perfect and its contrast with the Simple Past; the inclusion of interactive graphics in the second study (2005), was effective to diminish the confusion caused by the static graphics utilized in the first study (2003).

Submitted by Edileide Reis (leyde-landy@hotmail.com) on 2013-05-24T13:40:57Z No. of bitstreams: 3 Annamaria da Rocha Jatobá Palacios Parte 3.pdf: 3132345 bytes, checksum: 582aa71fa423f58936af9a4c6749fcc8 (MD5) Annamaria da Rocha Jatobá Palacios Parte 2.pdf: 2426722 bytes, checksum: 992dc6f146472e7203f9a513e0fbec18 (MD5) Annamaria da Rocha Jatobá Palacios Parte 1.pdf: 1998486 bytes, checksum: 46b1af9894dd42deaa795bba2db7ed3c (MD5) / Made available in DSpace on 2013-05-24T13:40:57Z (GMT). No. of bitstreams: 3 Annamaria da Rocha Jatobá Palacios Parte 3.pdf: 3132345 bytes, checksum: 582aa71fa423f58936af9a4c6749fcc8 (MD5) Annamaria da Rocha Jatobá Palacios Parte 2.pdf: 2426722 bytes, checksum: 992dc6f146472e7203f9a513e0fbec18 (MD5) Annamaria da Rocha Jatobá Palacios Parte 1.pdf: 1998486 bytes, checksum: 46b1af9894dd42deaa795bba2db7ed3c (MD5) Previous issue date: 2004 / O trabalho investigativo identifica como as marcas discursivas de tempo, juventude e saúde participam da construção do universo enunciativo da publicidade impressa de cosméticos, produzida na década de 90 e veiculada nas revistas femininas brasileiras Elle, Marie Claire e Claudia. Em perspectiva analítica, aborda, inicialmente, os três principais marcos teóricos da pesquisa: a) insere o tempo como categoria social e foco central de análise para o entendimento das transformações sociais nas últimas décadas do século XX; b) discute o conceito de saúde perfeita e modelos que sugerem novas maneiras de se tratar o corpo, a saúde e a beleza, na cultura contemporânea; c) situa criticamente o papel da publicidade como uma prática que reforça e instaura matrizes de sentidos e percepções sociais na atualidade. Em um segundo momento, explicita e justifica o compromisso teórico-metodológico, preferencial mas não esxclusivo, com a prática instrumental e analítica da análise de discurso. Em um terceiro momento, aborda aspectos do amplo universo discursivo da publicidade contemporânea. Ao final, realiza a análise dos anúncios publicitários de cosméticos que compõem o corpus da pesquisa, à luz do referencial teórico-metodológico apresentado ao longo do trabalho. A análise traz à mostra alguns mecanismos específicos de funcionamento da publicidade de cosméticos, ao mesmo tempo em que confirma e elucida princípios norteadores da prática discursiva e social da publicidade contemporânea. / Salvador

Este trabalho trata da aplicação do método Design Construtal para investigar a transferência de calor através de caminhos de alta condutividade térmica com geometrias definidas. O objetivo é obter a configuração que reduz a temperatura máxima em excesso do sistema considerando que as áreas ocupadas pelos materiais de alta e baixa condutividade são tratadas como constantes. Assim, o objeto de estudo é um volume de área finita onde ocorre a geração de calor. O escoamento da energia térmica para fora do volume é feito através de um caminho condutor de alta condutividade térmica. O trabalho considerou a resistência térmica de contato entre o elemento condutivo e o corpo gerador de calor, onde um terceiro material com resistência térmica equivalente à resistência de contato é interposto entre os dois primeiros. Na solução da equação da difusão do calor, foi realizado um tratamento numérico através de um código baseado em elementos finitos e utilizando o toolbox PDETool, Partial Differential Equations Tool, que pertence ao aplicativo comercial MatLab®. O tratamento numérico foi realizado considerando-se caminhos condutivos com geometrias em forma de "I" e em forma de "T", mantendo-se as frações de área constantes e variando-se os comprimentos dos materiais de alta condutividade e os da resistência térmica de contato. A otimização geométrica foi feita considerando-se os graus de liberdade existentes para cada geometria, onde os valores otimizados para a situação ideal, ou de acoplamento térmico perfeito, foram comparados para os resultados envolvendo a resistência térmica de contato (RTC). Os resultados indicam que a RTC pode aumentar a temperatura máxima em excesso, assim como tem efeito significativo sobre as ótimas configurações calculadas quando a resistência de contato é levada em consideração para ambas as configurações "I" e "T" estudadas. / This work applies Constructal Design to investigate the heat transfer through high conductive pathways with defined geometries. The objective is to find the configuration which reduces the maximal excess of temperature considering the areas with high and low thermal conductivity are constants. Thus, the object studied here is a volume with a finite area and heat generation. The outside heat flux is conducted through a high thermal conductive pathway. Here, special attention is given to the thermal contact resistance between the high conductive pathway and the solid body, where a third material with a thermal resistance equivalent to the thermal contact resistance is inserted between them. A numerical treatment was given in order to solve the heat diffusive equation. It was used a numerical code based on finite elements and the toolbox – PDETool, Partial Differential Equations Tool, which is part of the MatLab® applicative. The numerical treatment was achieved considering "I" and "T" geometries for the high conductive pathways keeping the areas fraction constants and varying the lengths of both high conductive and the equivalent thermal contact layer materials. The optimization was performed considering the degrees of freedom of each geometry, where the optimized values for the ideal situation, i.e., perfect thermal contact were compared with the results considering the thermal contact resistance. The results indicate that the thermal contact resistance can increase the excess of temperature, as well as it has a significant effect on the optimal configurations when using perfect thermal contact or taking into account the thermal contact resistance for "I" and "T" shaped geometries.

Made available in DSpace on 2016-06-02T20:25:00Z (GMT). No. of bitstreams: 1 DissSPE.pdf: 993314 bytes, checksum: 979ffb4878aaf229085ece40596fbffd (MD5) Previous issue date: 2007-09-27 / This study approaches the present perfect simple (PP) in English, a verb structure that does not have a semantic equivalent in Brazilian Portuguese language. This fact brings out teaching and learning issues that one occasionally tries to answer. Frequently taught through out of context sentences and treated in grammar and language teaching books in a fragmented way, through confusing and haphazard explanations, this structure is difficult for Brazilian English learners to grasp. Although morphologically similar to the compound past tense in Portuguese, once both are formed by have and the past participle of a given verb, it is acknowledged that these structures do not always operate in the same way. Besides the concept of Tense, the PP also bears strong aspectual information which is rarely taken into consideration in its teaching, but essential for its understanding. With this in mind, this investigation goal was to analyze if a contextual approach facilitates the comprehension of the notion of Aspect underlying the PP. The experiment consisted of two distinct tasks, one structural and another contextual, and also a questionnaire with questions concerning some verb structures. Based on verbal protocols technique, the participants, 20 English language students attending the last year of Language College in two public universities in the state of São Paulo, were instructed to verbalize their thoughts while performing the tasks. The results are favorable to the use of contextual activities in the understanding of the aspectual feature that underlies the meaning of the PP, since this type of approach seems to attenuate the difficulties found by learners when carrying out tasks involving several verb structures, therefore providing greater possibility of focusing in aspectual features and less in temporality. / Este estudo visa a problematizar a questão do ensino-aprendizagem e aquisição do present perfect simples (PP) em inglês, estrutura verbal que não possui equivalente semântico na língua portuguesa. Freqüentemente ensinada de forma fragmentada e abordada em gramáticas e livros didáticos de maneira descontextualizada e por meio de explicações confusas e incompatíveis, tal estrutura é de difícil compreensão para aprendizes brasileiros. Mesmo sendo morfologicamente análoga ao pretérito perfeito composto do português, já que ambas são formadas pelo verbo ter + particípio passado de algum verbo qualquer, sabe-se que elas nem sempre operam da mesma forma. Além da noção de Tempo, o PP carrega também forte informação aspectual, que é raramente abordada em seu ensino, porém essencial para seu entendimento. Com isso em mente, o intuito deste estudo foi analisar em que medida uma abordagem contextual facilita a compreensão da questão de Aspecto subjacente ao PP e a partir disso apontar alguns caminhos para seu ensino. O experimento, realizado com 20 alunos do último ano do curso de Letras com habilitação na língua inglesa de duas universidades públicas do interior de São Paulo, constou de duas tarefas distintas, uma de base estrutural e outra contextual, além de um questionário com perguntas acerca de algumas estruturas verbais. Tendo como base a técnica de protocolos verbais, os participantes foram instruídos a verbalizar seus pensamentos quando realizavam as tarefas. Os resultados obtidos se mostram favoráveis ao uso de atividades contextualizadas no entendimento da noção de Aspecto que abarca o PP, uma vez que esse tipo de tratamento parece amenizar as dificuldades encontradas pelos aprendizes ao realizarem uma tarefa que envolve diversas estruturas verbais, pois proporciona uma maior possibilidade de focar na questão aspectual e menos na temporal.