As propriedades da turbulência induzida em um fluido viscoso através da oscilação de uma grade foram investigadas experimentalmente utilizando a técnica DPIV (Digital Particle Image Velocimetry). Perfis verticais da energia cinética turbulenta, taxa de dissipação de energia, viscosidade turbulenta e escala de comprimento foram obtidos e comparados com soluções analíticas existentes. Os dados experimentais mostram uma boa concordância com as predições teóricas. Adicionalmente, foi observado que há uma variação significativa da intensidade turbulenta para distâncias próximas da grade. Com o aumento da distância, a turbulência se torna mais homogênea no plano horizontal, e estas variações tendem a desaparecer. Os resultados mostram também que o escoamento somente pode ser considerado livre de cisalhamento para grandes distâncias da grade, onde as tensões de Reynolds se aproximam de zero. Além disso, descobriu-se que são necessários no mínimo 450 campos de vetores para assegurar a precisão das medidas. Também foram realizadas medidas de turbulência em uma configuração de duas grades. Os resultados mostram que a região central entre as duas grades possui certas propriedades similares à turbulência isotrópica. Adicionalmente, foram realizadas comparações com o modelo k-&#949, mostrando que o mesmo pode ser aplicado a uma configuração de duas grades. / The properties of turbulence induced in a viscous fluid by oscillating a grid were investigated experimentally using the digital particle image velocimetry (DPIV). Vertical profiles of the turbulent energy, the dissipation rate, the eddy viscosity and a lengthscale have been obtained and compared with available analytical solutions. The experimental data agree well with the theoretical predictions. In addition, it could be observed that there are significant variations of the turbulent intensities at a small distance from the grid. With increasing distance from the grid, the turbulence becomes more homogeneous in the horizontal plane, and the variations in the turbulent intensities are reduced. The results also show that the turbulence can be considered to be shear-free only at a distance sufficiently far away from the grid, where the Reynolds shear stress aproaches zero. It became evident, furthermore, that at least 450 vector maps should be taken to ensure the accuracy of the measured velocity fluctuations. Turbulence was also measured for a two-grid configuration. It was found that the central region between the grids has certain properties similar to that of isotropic turbulence. The results show good agreement with the k-&#949 model, validating the application of the k-&#949 model to a pair of oscillating-grids.

O presente trabalho visa propor metodologia inovadora e abrangente que permita a avaliação sistêmica das diversas funcionalidades envolvidas no conceito de Redes Elétricas Inteligentes Smart Grids - (REI). Tal metodologia possibilita a avaliação de políticas de implementação destas funcionalidades de acordo com as características atuais das empresas, tendo como balizador central o benefício social fundamentado na visão dicotômica entre Concessionária e Consumidor. A metodologia proposta parte de modelagem inovadora de representação da rede e das funcionalidades emergentes de REIs, culminando em modelo de otimização que visa propor roadmaps tecnológicos fundamentados em avaliações de custos e benefícios de implantação. A importância das contribuições contidas na presente tese reside no fato de que o conceito de REI vem ganhando destaque nos cenários nacional e internacional, sendo apontado por especialistas do mundo todo como uma possível quebra de paradigma no setor elétrico. O referido conceito traz consigo uma série de funcionalidades e novas formas de integração e relacionamento entre os diversos agentes do setor. Tais funcionalidades necessitam de conceituação clara e objetiva, assim como metodologias de análise dos benefícios e dos custos decorrentes de sua aplicação nos respectivos segmentos do sistema de distribuição. Funcionalidades de REIs impactam tanto os processos de gestão do sistema de distribuição como os procedimentos de planejamento, operação e engenharia, além de permitirem ao consumidor, com possível papel adicional de produtor, maior gerência sobre seu consumo de energia. Diante de um cenário com diversos agentes, com alternância de papéis e com intensa interação entre si, somado às funcionalidades sistêmicas e de rede propiciadas pelos avanços tecnológicos crescentes, é fundamental uma análise global que estabeleça políticas ótimas de implantação das funcionalidades de REI, buscando a maximização do benefício social associado. Destarte, o produto principal desta tese, qual seja o modelo de proposição de plano ótimo de implantação de funcionalidades de REI, considerando os custos de implantação e os benefícios associados, não só ao setor elétrico, mas à sociedade como um todo, consiste em ferramenta valiosa para o planejamento de empresas concessionárias de distribuição na definição de roadmaps tecnológicos. Além disso, tal ferramenta permitirá a realização de estudos nacionais que fundamentem o balizamento de políticas públicas para o tema. / This thesis proposes an innovative and comprehensive methodology that allows the systematic evaluation of various functionalities involved in the concept of Smart Grids. Such methodology enables the proposition and evaluation of different policies for the implementation of smart grid functionalities according to the current characteristics of the utilities. Furthermore, the methodology is basically centered on the social benefits that consider a dichotomy view regarding Utility and Customer. This methodology considers an innovative model for network representation and Smart Grid emerging functionalities. Based on that, it leads to an optimization model that produces technologic roadmaps that take into account the evaluation of costs and benefits for the policies implementation. The importance of the contributions in this thesis lay in the fact that the concept of smart grids has been gaining attention in the national and international scenes, being pointed out by experts around the world as a possible paradigm break for the electricity sector. This concept brings a number of functionalities and new forms of integration and relationships amongst the various agents. These functionalities require clear and objective concepts, as well as methods for cost-benefit analysis regarding their implementation on the various segments of the distribution system. Smart grid functionalities impact most of the management processes in a distribution company as well as planning, operation and engineering procedures. Besides that customers are enabled to better manage their energy consumption, especially when playing the role of producers as well. Facing a scenario with several agents playing different roles with intense interaction, as well as systemic functionalities propitiated by advances in technology, one should devise a global analysis in order to establish optimal policies to implement Smart Grid functionalities, pursuing maximization of associated social benefits. In such a context, the main product of this thesis is an innovative model that produces optimal cost effective plans regarding the deployment of Smart Grid functionalities. Such a product is to be applied not only in the electricity sector but in society as a whole, consisting in a valuable planning tool for distribution utilities to define technological roadmaps as well as countrywide studies for the proposition of new public policies for smart grid implementation.

Submitted by Sandro Camargo (sandro.camargo@unipampa.edu.br) on 2015-05-09T18:28:47Z No. of bitstreams: 1 107110006.pdf: 2090462 bytes, checksum: 5fecbc3cc993bd7ac1637e41b7b2be41 (MD5) / Made available in DSpace on 2015-05-09T18:28:47Z (GMT). No. of bitstreams: 1 107110006.pdf: 2090462 bytes, checksum: 5fecbc3cc993bd7ac1637e41b7b2be41 (MD5) Previous issue date: 2012-10-19 / Com a total dependência pela energia elétrica em todos os setores da sociedade e a consequente regulamentação, é necessário que as concessionárias se preocupem em manter a continuidade do seu fornecimento, além de atender aos padrões que remetem à qualidade. A continuidade do fornecimento de energia elétrica é algo fundamental tanto para os consumidores quanto para a concessionária, a qual deixa de vender energia elétrica e ainda pode ser penalizada por interrupções muito longas ou em áreas críticas (hospitais ou indústrias, por exemplo). Como nem sempre é possível manter a continuidade do fornecimento devido a diversos fatores, sendo os defeitos permanentes os mais críticos, as empresas concessionárias são levadas a procurar novas metodologias e tecnologias para diminuir o tempo que o fornecimento de energia elétrica é interrompido. Nesse trabalho é descrita uma metodologia para o restabelecimento da energia em redes de distribuição de maneira automática. Essa metodologia se baseia no uso de tecnologias de comunicação e na automação dos equipamentos de manobras das redes. Com isso é possível obter os dados do estado da rede em tempo real, e é possível enviar os comandos para tais equipamentos de forma direta, sem a necessidade de intervenção humana. A metodologia aqui apresentada tem como objetivo detectar a localização de um defeito na rede através de leituras dos estados dos equipamentos, e então procurar as melhores manobras que restabeleçam o fornecimento ao máximo de consumidores sem que isso coloque todo sistema de distribuição, ou mesmo parte dele, em sobrecarga. Também é considerado que a rede pode ter sofrido alterações em equipamentos não automatizados (chaves manuais), e que as características de carga mudam no decorrer do tempo. Assim, a topologia deve ser atualizada antes de executar simulações e que os dados para tais simulações devem prever o comportamento da carga para o tempo que a contingência possa durar. Como teste da metodologia, foram executadas simulações em dados de redes reais de distribuição com diferentes topologias e diferentes cenários de defeitos. Os resultados obtidos foram satisfatórios na medida que tais soluções de restabelecimento eram viáveis em termos de carregamento da rede e foram calculadas em um curto espaço de tempo (poucos segundos). Essa agilidade traz vantagens tanto para os clientes quanto para a própria concessionária. / With the total dependency for electric power in all society sectors and the following regumen-tation, is necessary that the utilities worry in maintaining the continuity of power supply, in addition to meeting the standards that refer to quality. The continuity of power supply is fun- damental both for consumers and for the utility, which stops selling electricity and can still be penalized for too long interruptions or in critical areas (hospitals or industries, for example). As it is not allways possible to maintain the continuity of power supply due several factors, being the most critical the permanets defects, the utilities are driven to seek new methods and tecnologies to reduce the time that power supply is interrupted. In this work we describe a methodology for automatic restoration in power grids. This methodology is based on the use of communication technologies and automation equipment maneuvers networks. With this is possible to get the data status from the grid in real time, and also can send commands to these devices directly, without the need for human intervention. The methodology presented here tries to detect the location of a fault on the grid, through readings of the equipments status, and then search for the best maneuvers to restores supply to maximum consumers without putting the entire distribution system, or portion thereof, in overload . It is also considered that the grid may have changed in non-automated equipment (manual keys), and that the load characteristics change over time. Thus, the topology must be updated before running simulations and data for such simulations should predict the behavior of the load for time that can last contingency. As a test of the methodology, simulations were performed on real power grids data with different topologies and different scenarios defects. The results were satisfactory as such restoration solutions were viable in terms of network loading and were calculated in a short time (few seconds). This agility has benefits both for customers and for the own utility.

'Feminine Rhyme' is a sequence of objects and paintings that resonate with women's experience in contemporary culture. The components I have used are: the structure of the grid, aggressive surface handling, and language derived from text. I have reconfigured these elements to direct the viewer in exploring layers of information that can be viewed in fragments as well as understood within the containment of a sound whole. I have explored the relationship of gender identity in our culture, and the role women play in association to masculine power. Through repetitive use of the grid, combined with isolated words and images, I have created paintings that can be read either in a formal manner through the use of structure and materials that are visually pleasing, or in context to a visual dialogue of contemporary gender myths. By fragmenting text in the form of torn book pages, I have altered and personalized the order, lending weight to chaos. Words become a form of mark making, a lyrical device to be read at random. I have obscured the imagery by hiding the text, leaving only scattered bits of information. These bits are derived from a 'therapeutic model' found in self help books, diet books and romance novels which exploit "feminism" as a commodity, serve as cultural documents, and influence women as to how they should perceive their bodies, their minds, their freedom. The end result is a visual interplay of form and color within the context of personal testimony and societal conditioning of the female experience in contemporary culture.

The strand-Cartesian grid approach is a unique method of generating and computing fluid dynamic simulations. The strand-Cartesian approach provides highly desirable qual- ities of fully-automatic grid generation and high-order accuracy. This thesis focuses on the implementation of the Spalart-Allmaras turbulence model to the strand-Cartesian grid framework. Verification and validation is required to ensure correct implementation of the turbulence model.Mathematical code verification is used to ensure correct implementation of new algo- rithms within the code framework. The Spalart-Allmaras model is verified with the Method of Manufactured Solutions (MMS). MMS shows second-order convergence, which implies that the new algorithms are correctly implemented.Validation of the strand-Cartesian solver is completed by simulating certain cases for comparison against the results of two independent compressible codes; CFL3D and FUN3D. The NASA-Langley turbulence resource provided the inputs and conditions required to run the cases, as well as the case results for these two codes. The strand solver showed excellent agreement with both NASA resource codes for a zero-pressure gradient flat plate and bump- in-channel. The treatment of the sharp corner on a NACA 0012 airfoil is investigated, resulting in an optimal external sharp corner configuration of strand vector smoothing with a base Cartesian grid and telescoping Cartesian refinement around the trailing edge. Results from the case agree well with those from CFL3D and FUN3D. Additionally, a NACA 4412 airfoil case is examined, and shows good agreement with CFL3D and FUN3D, resulting in validation for this case.

This study focused on the extent to which professional development can bring about changes in ministerial leaders' thinking and practice, and was based on a constructivist approach to learning. The study adopted a qualitative methodology to answer the three research questions: 1. To what extent can professional development assist ministerial leaders to change their thinking about themselves as leaders and their actual leadership practices? 2.What changes (if any) occurred in each of the participants' conceptions of ministerial leadership during a Ministerial Leadership Development Program (MLDP)? 3. To what extent did changes in participants' thinking about ministerial leadership affect their actual practice? There were nineteen participants in a Ministerial Leadership Development Program which was conducted between March and October 2000 by the Uniting Church in Australia (Queensland Synod). Data were gathered at the beginning and end of the MLDP and one year after its completion. The methods used to collect data were concept maps of 'effective leaders', repertory grids based on participants' views of 'effective' and 'ineffective' leaders, interviews and a survey. The concept maps and repertory grids were completed at the beginning and end of the MLDP. The interviews and survey were conducted one year after the program was completed. The interviews were conducted with a small group of the participants (five) and the survey was completed by lay leaders from the congregations where the nineteen participants were ministering. For each of the five interviewees a case was constructed using methodological triangulation and an interpretive approach. Triangulation of the three types of data (concept maps, repertory grids and interviews) enabled identification of important components of individuals' thinking and practice. The survey produced data on the perspectives of lay leaders, thus enabling comparison between the perspectives of the ministerial leaders and their lay leaders. The study found a variety of initial conceptions of effective ministerial leadership amongst the participants. Most of these conceptions were related to leadership skills and qualities. Very few participants demonstrated an understanding of the nature of effective ministerial leadership at the beginning of the program. However, during the MLDP, the conceptions of participants developed and by the end of the program most of them demonstrated a more holistic understanding of the nature of leadership, and particularly, the nature of Christian leadership. In relation to changes in leaders' practice, the study found that significant changes were reported as taking place in leaders' practice and most of this was linked to their thinking changing first. Many of these changes in practice were attributed to the encouragement leaders received in mentor groups. These reported changes in practice were also supported by data from the lay leaders' survey. Thus there was consistency in data from ministerial leaders' perspectives and from lay leaders' perspectives. Apparent trends across the cases included links between the leaders' feelings of self confidence and their capacity to lead effectively; the difficulties associated with following a minister who had a very different conception of effective leadership from his/her own; the unrealistic expectations some congregational members have of their ministers; and the difficulty of moving a congregation from one understanding of ministry to another. The results of this study have implications for pre-service education, continuing education, and the policy-making committees of the Synod, and suggest fruitful areas for further research. The results of the research are discussed in relation to relevant literature. Implications of the findings for the appropriate stakeholders are highlighted, and some ongoing issues for ministerial leadership are raised.

Thesis (Ph. D.)--University of Hong Kong, 2007. / Title proper from title frame. Also available in printed format.

Image smoothing and segmentation algorithms are frequently formulatedsas optimization problems. Linear and nonlinear (reciprocal) resistivesnetworks have solutions characterized by an extremum principle. Thus,sappropriately designed networks can automatically solve certainssmoothing and segmentation problems in robot vision. This papersconsiders switched linear resistive networks and nonlinear resistivesnetworks for such tasks. The latter network type is derived from thesformer via an intermediate stochastic formulation, and a new resultsrelating the solution sets of the two is given for the "zerostermperature'' limit. We then present simulation studies of severalscontinuation methods that can be gracefully implemented in analog VLSIsand that seem to give "good'' results for these non-convexsoptimization problems.

La tolérance et la gestion des fautes dans les grilles de données/calcul est d’une importance capitale. En effet, comme dans tout autre système distribué, les composants d’une grille sont susceptibles de tomber en panne à tout moment. Mais le risque de panne croît avec la taille du système, et est donc plus exacerbé dans un système de grille. En plus, tout en essayant de mettre à profit les ressources offertes par la grille, les applications tournant sur celle-ci sont de plus en plus complexes (ex. impliquent des interactions complexes, prennent des jours d’exécution), ce qui les rend plus vulnérables aux fautes. Le plus difficile dans la gestion des fautes dans une grille, c’est qu’il est difficile de savoir si une faute qui survient sur une entité de la grille est induite malicieusement ou accidentellement. Dans notre travail de thèse, nous utilisons le terme faute, au sens large, pour faire référence à tout étant inattendu qui survient sur tout composant de la grille. Certains de ces états provoquent des comportements aussi inattendus et perceptibles au niveau de la grille tandis que d’autres passent inaperçues. De plus, certaines de ces fautes sont le résultat d’une action malveillante alors que d’autres surviennent accidentellement ou instantanément. Dans ce travail de thèse, nous avons traité le cas de ces fautes induites malicieusement, et qui généralement passent inaperçues. Nous avons considéré en particulier le problème de la confidentialité et de l’intégrité des données stockées à long-terme sur la grille. L’étude de la confidentialité des données a été faite en deux temps dont la première partie concerne la confidentialité des données actives. Dans cette partie, nous avons considéré une application liée à la recherche des similitudes d’une séquence d’ADN dans une base de données contenant des séquences d’ADN et stockée sur la grille. Pour cela, nous avons proposé une méthode qui permet d’effectuer la comparaison sur un composant distant, mais tout en gardant confidentielle la séquence qui fait l’objet de la comparaison. Concernant les données passives, nous avons proposé une méthode de partage des données confidentielles et chiffrés sur la grille. En rapport avec l’intégrité des données, nous avons considéré le cas des données anonymes dans le cadre de l’intégrité des données passives. Pour les données actives, nous avons considéré le problème de la corruption des jobs exécutés sur la grille. Pour chacune des cas, nous avons proposé des mécanismes permettant de vérifier l’authenticité des données utilisées ou produites par ces applications.

Power grids in today's developed societies are designed to meet consumer demands in a highly reliable manner. In order to guarantee reliability to consumers, the grid is required to be sized for infrequently occurring demand peaks. The cost of maintaining generation sources that make up the relatively unused capacity of the grid can be extremely high. In addition to high costs, environmental impacts of these sources are also of great concern. In order to serve highly fluctuating peak demands, energy sources such as coal, gas and bio-gas are commissioned by utilities. These sources have a high carbon footprint. In order to prevent wasting extensive amounts of money in maintaining infrequently used grid capacity and causing an adverse environmental impact, a comprehensive study on how elasticity of domestic appliances can be used to reduce the impact of these issues is made. A thorough analysis of appliances in four distinct regions is presented. Significant reduction of peak demands is shown quantitatively for all of the four regions. Based on these positive results, an elasticity based scheme that takes into account user discomfort is proposed for reducing monetary and environmental issues faced by today's utilities.