The seismic response of steel monopole wind turbine towers is investigated and their risk is assessed in the Canadian seismic environment. This topic is of concern as wind turbines are increasingly being installed in seismic areas and design codes do not clearly address this aspect of design. An implicit finite element model of a 1.65MW tower was developed and validated. Incremental dynamic analysis was carried out to evaluate its behaviour under seismic excitation, to define several damage states, and to develop a framework for determining its probability of damage. This framework was implemented in two Canadian locations, where the risk was found to be low for the seismic hazard level prescribed for buildings. However, the design of wind turbine towers is subject to change, as is the design spectrum. Thus, a methodology is outlined to thoroughly investigate the probability of reaching predetermined damage states under seismic loading for future considerations.

In the present PhD work, three sophisticated models based on the "Engineering" modeling approach have been utilized to conveniently describe and thoroughly analyze details of Lightning events at the CN Tower. Both the CN Tower and the Lightning Channel are represented by a number of connected in series Transmission Line sections in order to account for the variations in the shape of the tower and for plasma processes that take place within the Lightning Channel. A sum of two Heidler functions is used to describe the "uncontaminated" Return Stroke current, which is injected at the attachment point between the CN Tower and the Lightning Channel. Reflections and refractions at all points of mismatched impedances are considered until their contribution becomes less than 1% of the originally injected current wave. In the proposed models, the problem with the current discontinuity at the Lightning Channel front, commonly taken care of by introducing a "turn-on" term when computing radiation fields, is uniquely treated by introducing reflected and transmitted components. For the first time, variable speed of propagation of the Return Stroke current front has been considered and its influence upon the predicted current distributions along the whole Lightning Channel path and upon the radiated distant fields analyzed. Furthermore, as another novelty, computation of the electromagnetic field is accomplished in Cartesian Coordinates. This fact permits to relax the requirement on the verticality of the Lightning Channel, normally imposed in Cylindrical Coordinates. Therefore, it becomes possible to study without difficulty the influence of a slanted Lightning Channel upon the surrounding electromagnetic field. Since the proposed sophisticated Five-Section Model has the capability to represent very closely the structure of the CN Tower and to emulate faithfully the shape of, as well as physical processes within the Lightning Channel, it is believed to have the potential of truthfully reproducing observed fields. The developed modeling approach can be easily adapted to study the anticipated radiated fields at tall structures even before construction.

The seismic response of steel monopole wind turbine towers is investigated and their risk is assessed in the Canadian seismic environment. This topic is of concern as wind turbines are increasingly being installed in seismic areas and design codes do not clearly address this aspect of design. An implicit finite element model of a 1.65MW tower was developed and validated. Incremental dynamic analysis was carried out to evaluate its behaviour under seismic excitation, to define several damage states, and to develop a framework for determining its probability of damage. This framework was implemented in two Canadian locations, where the risk was found to be low for the seismic hazard level prescribed for buildings. However, the design of wind turbine towers is subject to change, as is the design spectrum. Thus, a methodology is outlined to thoroughly investigate the probability of reaching predetermined damage states under seismic loading for future considerations.

This Thesis researches, explains and provides conclusions for the question of correlation between data and criteria used by Environment Canada (EC) and Lightning Studies Research Group (LSG) of University of Toronto. The necessity of such correlation arises from the question of common criteria between severe weather, as it shown in graphical data from EC, and intense lighting storms, recorded by LSG, despite deep differences in area, time scale and object of observation used by those two organizations. The objective of the Thesis is not only to compare those two, very different sets of data and criteria and find out the common ground between them, but also to provide in-depth explanation of criteria, used by Lighting Studies Research Group, along with revisiting and establishing some of them. Eight storm cases, taken from years 2005-2008 provide cases for practical research, which affects intermediate Greater Toronto Area.

In the last few decades, new centers have emerged at the edges of traditional cities and pre-World War II suburbs. As these evolve, do they converge towards the urban forms of traditional cities? This question is explored based on a study of urban areas in the Atlanta Metropolitan Region. Atlanta Downtown, Decatur and Marietta, are compared to the new centers in Buckhead, Cumberland and Perimeter. The evolution of the street network of Buckhead is examined in detail. The morphological history of a particular urban block in Buckheadâ "the Tower Place blockâ "is documented. Morphological analysis, focusing on street patterns, block shapes and sizes, property boundaries and building footprints, is complemented by Space Syntax, focusing on the structure of street networks and connectivity. It is shown that new urban centers tend to grow on very large blocks accessed through major transportation infrastructure, but situated in otherwise sparse and fragmentary street environments. As these centers grow and as the density of land use increases, a secondary private road system is created, to take advantage of development potential and provide access to major building investments. The effective fragmentation of the large blocks suggests a pattern of metric convergence towards an optimum block size. In traditional cities, however, the street network is stable over time and acts as the framework for changes in architecture and land use. In the new centers, the secondary road system serves to access particular private investments without regard to the creation of a public framework of connections. From a syntactic point of view, the new centers are spatially unintelligible, thus substantially diverging from traditional cities, even as they accommodate dense mixed use developments. The thesis points to the need of developing and using subdivision regulations and zoning classifications in order to better regulate the spatial structure of new urban centers in the future.

Fundação Carlos Chagas Filho de Amparo a Pesquisa do Estado do Rio de Janeiro / Diversas formas de geração de energia vêm sendo desenvolvidas com o objetivo de oferecer alternativas ecologicamente corretas. Neste contexto, a energia eólica vem se destacando na região Nordeste do Brasil, devido ao grande potencial dos ventos da região. As torres, que representam parcela significativa do custo total do sistema, tendem a crescer buscando ventos mais fortes e permitindo assim a utilização de aerogeradores com maior capacidade de geração de energia. Este trabalho tem como objetivo formular um modelo de otimização de torres tubulares de aço, para aerogeradores eólicos. Busca-se minimizar o volume total (custo, indiretamente), tendo como variáveis de projeto as espessuras da parede da torre. São impostas restrições relativas à frequência natural e ao comportamento estrutural (tensão e deslocamento máximo de acordo com recomendações da norma Europeia). A estrutura da torre é modelada com base no Método dos Elementos Finitos e o carregamento atuante na estrutura inclui os pesos da torre, do conjunto de equipamentos instalados no topo (aerogerador), e o efeito estático da ação do vento sobre a torre. Para verificação das tensões, deslocamentos e frequências naturais, foram utilizados elementos finitos de casca disponíveis na biblioteca do programa de análise ANSYS. Os modelos de otimização foram também implementados no modulo de otimização do programa ANSYS (design optimization), que utiliza técnicas matemáticas em um processo iterativo computadorizado até que um projeto considerado ótimo seja alcançado. Nas aplicações foram usados os métodos de aproximação por subproblemas e o método de primeira ordem. Os resultados obtidos revelam que torres para aerogeradores merecem atenção especial, em relação à concepção do projeto estrutural, sendo que seu desempenho deve ser verificado através de metodologias completas que englobem além das análises clássicas (estáticas e dinâmicas), incluam também as análises de otimização. / Different forms energy generation have been developed with the main goal of offering correct ecological alternatives. In this context, wind energy is highly prominent in the northeast Brazil, due to the potential wind in the region. The towers, which represent a significant portion of the total cost of the system tends to find strong winds and permit them to utilize wind turbines as a medium for the generating energy. This work shows an objective way to formulate an model of towers with steel turbines, for wind generation. The work seeks to minimize the total volume (cost, indirectly) with the wall thickness of the tower as design variables. Natural frequencies and structural behavior (allowable stresses and maximum displacement according to the European code) are the design constraints. The tower structure is modeled using the Finite Element Method and the applied loads are the total weight of the structure (including the tower and the wind turbine installed on the top) and the static effect of the wind on the tower. To determine the stresses, displacements and natural frequencies shell elements available in the ANSYS analysis program were used. Optimization models were also implemented using the ANSYS design optimization modulus which uses mathematical programming techniques to find the optimum structure. The first order and sub problem methods were used in the developed applications. The obtained results show that the towers for wind generators deserve special attention related to the conception of the structural project. Its performance has to be verified by a complete methodology that embodies the classical analysis (static and dynamics) and also the optimization analysis.

Applying machine learning techniques for real-time detection and tracking of objects in very high-resolution video is a problem that has not been extensively studied. In this thesis, the practical uses of object detection for airport remote towers are explored. We present a Kalman filter-based tracking framework for low-latency aircraft tracking in very high-resolution video streams. The object detector was trained and tested on a dataset containing 3000 labelled images of aircrafts taken at Swedish airports, reaching an mAP of 90.91% with an average IoU of 89.05% on the test set. The tracker was benchmarked on remote tower video footage from Örnsköldsvik and Sundsvall using slightly modified variants of the MOT-CLEAR and ID metrics for multiple object trackers, obtaining an IDF1 score of 91.9%, and a MOTA score of 83.3%. The prototype runs the tracking pipeline on seven high resolution cameras simultaneously at 10 Hz on a single thread, suggesting large potential speed gains being attainable through parallelization.

Fundação Carlos Chagas Filho de Amparo a Pesquisa do Estado do Rio de Janeiro / Diversas formas de geração de energia vêm sendo desenvolvidas com o objetivo de oferecer alternativas ecologicamente corretas. Neste contexto, a energia eólica vem se destacando na região Nordeste do Brasil, devido ao grande potencial dos ventos da região. As torres, que representam parcela significativa do custo total do sistema, tendem a crescer buscando ventos mais fortes e permitindo assim a utilização de aerogeradores com maior capacidade de geração de energia. Este trabalho tem como objetivo formular um modelo de otimização de torres tubulares de aço, para aerogeradores eólicos. Busca-se minimizar o volume total (custo, indiretamente), tendo como variáveis de projeto as espessuras da parede da torre. São impostas restrições relativas à frequência natural e ao comportamento estrutural (tensão e deslocamento máximo de acordo com recomendações da norma Europeia). A estrutura da torre é modelada com base no Método dos Elementos Finitos e o carregamento atuante na estrutura inclui os pesos da torre, do conjunto de equipamentos instalados no topo (aerogerador), e o efeito estático da ação do vento sobre a torre. Para verificação das tensões, deslocamentos e frequências naturais, foram utilizados elementos finitos de casca disponíveis na biblioteca do programa de análise ANSYS. Os modelos de otimização foram também implementados no modulo de otimização do programa ANSYS (design optimization), que utiliza técnicas matemáticas em um processo iterativo computadorizado até que um projeto considerado ótimo seja alcançado. Nas aplicações foram usados os métodos de aproximação por subproblemas e o método de primeira ordem. Os resultados obtidos revelam que torres para aerogeradores merecem atenção especial, em relação à concepção do projeto estrutural, sendo que seu desempenho deve ser verificado através de metodologias completas que englobem além das análises clássicas (estáticas e dinâmicas), incluam também as análises de otimização. / Different forms energy generation have been developed with the main goal of offering correct ecological alternatives. In this context, wind energy is highly prominent in the northeast Brazil, due to the potential wind in the region. The towers, which represent a significant portion of the total cost of the system tends to find strong winds and permit them to utilize wind turbines as a medium for the generating energy. This work shows an objective way to formulate an model of towers with steel turbines, for wind generation. The work seeks to minimize the total volume (cost, indirectly) with the wall thickness of the tower as design variables. Natural frequencies and structural behavior (allowable stresses and maximum displacement according to the European code) are the design constraints. The tower structure is modeled using the Finite Element Method and the applied loads are the total weight of the structure (including the tower and the wind turbine installed on the top) and the static effect of the wind on the tower. To determine the stresses, displacements and natural frequencies shell elements available in the ANSYS analysis program were used. Optimization models were also implemented using the ANSYS design optimization modulus which uses mathematical programming techniques to find the optimum structure. The first order and sub problem methods were used in the developed applications. The obtained results show that the towers for wind generators deserve special attention related to the conception of the structural project. Its performance has to be verified by a complete methodology that embodies the classical analysis (static and dynamics) and also the optimization analysis.

Orientador: Prof. Dr. João Batista de Aguiar / Dissertação (mestrado) - Universidade Federal do ABC, Programa de Pós-Graduação em Engenharia Mecânica, 2014. / Neste trabalho é desenvolvida a estrutura de uma torre eólica destinada ao território brasileiro em uma montagem com dimensões compatíveis com as realidades técnicas, físico ambientais e sócios econômicas brasileiras. Inicialmente a escolha da potencia eólica é considerada, estudando a mecânica do vento, a influência da topologia, a escolha de materiais disponíveis no Brasil, os processos de fabricação possíveis dentro do território nacional, a escolha de um fabricante de gerador, a escolha de pás ou aerofólios de acordo com a necessidade de projeto. O sistema modular da torre fornece algumas vantagens e benefícios no processo de fabricação, transporte, montagem, manutenção e projeto. No projeto a torre eólica é projetada para dar o máximo de estabilidade em condições extremas. Diferentes critérios de estabilidade são abordados e analisados tanto analiticamente quanto numericamente com a ajuda de diferentes normas (EN, AISC). Para a análise numérica todas as tarefas foram executadas com o pacote de elementos finitos do programa Abaqus¿. O modelo de torre tubular foi primeiramente analisado e verificou-se satisfazer os critérios de estabilidade (flambagem global e a flambagem local). Verificou-se que a torre é segura contra flambagens local e global e permanece estável sob a carga de vento extremo. As metodologias adotadas na concepção da torre eólica buscaram um resultado otimizado com minimização da massa, maximização da rigidez e maximização da frequência natural. Durante a otimização observou-se que o modelo de torre dá um resultado mais econômico se o seu projeto for com espessura variável, módulo a módulo, ou seja, menos material é necessário para a fabricação o qual reduz o custo, porém, o projeto requer a aplicação de amortecedores. Um segundo modelo de torre com espessura constante apesar de usar mais material traz o benefício de não usar amortecedores. / This work addresses the design and analysis of a wind tower destined to the Brazilian territory in an "onshore" assembly, compatible with the physical reality and environmental conditions of Brazilian territory and based in a modular concept. Wind power unit is discussed in the design process from studies of mechanics of wind, influence of topology, choice of materials available in Brazil and manufacturing processes possible within the national territory, leading to the choice of a generator manufacturer, of blades and airfoils according to need for the project. Other issues, such as design of bolt connections plus flanges to assemble the modules are also discussed. The modular system of the tower leads to some advantages and benefits in the manufacturing, transportation, installation, maintenance and design process. In this project the wind tower is first designed to give maximum stability in extreme conditions. Different stability criteria are addressed, both analytically and numerically, with the help of different standards (EN, AISC). Numerical analyses for all tasks were performed with Abaqus¿ finite element package. The tower model satisfied the stability criteria (bending, global buckling and local buckling). The methodologies adopted in the design of the wind tower sought as outcome an optimized, minimum weight, maximum stiffness and higher first natural frequency tower. During the optimization it is observed that the tower model gives a better economical result if variable thicknesses among moduli are allowed, with less need for manufacturing, which reduces material cost. However in this case the project requires the application of dampers. A second tower model with constant thickness even though using more material, has the benefit of dispensing the use of dampers.

From the first generation, 1G, to the fourth generation, 4G, the development and technological advancements in telecommunications network systems have been remarkable. Faster and better connections have opened up for new markets, ideas and possibilities, to that extent that there now is a demand that surpasses the supply. Despite all these advancements made in the mobile communications field most of the concept of how the technology works and its infrastructure has remained the same. This however, is about to change with the introduction of the fifth generation (5G) mobile communication. With the introduction of 5G much of the technology introduced will be different from that of previous generations. This change extends to include the entire infrastructure of the mobile communications system. With these major changes, many of the tools available today for telecommunications network evaluation do not really suffice to include the 5G network standard. For this reason, there is a need to develop a new kind of tool that will be able to include the changes brought by this new network standard. In this thesis a simulation framework adapted for the next generation telecommunication standard 5G is set to be developed. This framework should include many of the characteristics that set 5G aside from previous generations.