[pt] O crescente uso de antenas para a transmissão de dados tem demandado a instalação de um número crescente de torres, com destaque para as torres estaiadas. Essas estruturas são compostas por um mastro central e diversos níveis de estais. As torres são estruturas esbeltas e apresentam um comportamento altamente não linear sob cargas estáticas e dinâmicas, devido à interação mastro-cabos e altura elevada da torre. O objetivo deste trabalho é estudar a influência da não linearidade no comportamento estático e dinâmico de uma torre estaiada. Para isto, desenvolvem-se modelos de torre estaiada em elementos finitos, com dois níveis de cabos pré-tensionados. Consideram-se dois tipos de geometria para a disposição dos cabos: em leque e em paralelo. Em particular, investiga-se o efeito da ruptura de um ou mais cabos e do comportamento elastoplástico dos materiais que compõem a torre estaiada na estabilidade e vibrações não lineares da estrutura. Inicialmente, avalia-se o comportamento linear da estrutura, obtendo-se as frequências naturais e cargas críticas. A seguir, obtêm-se os caminhos não lineares de equilíbrio de cada modelo, aplicando o conceito de imperfeição modal. Finalmente, realiza-se a análise da vibração livres e forçada amortecida. Para isto utilizam-se as respostas no tempo e plano de fase, transformadas de Fourier e espectrográficos. Em todos os casos analisa-se em detalhe o efeito da perda de cabos e da plastificação dos elementos na capacidade de carga, estabilidade e deslocamentos da estrutura. Os resultados demonstram que a perda de cabos e plastificação dos elementos têm grande influência nas frequências naturais e cargas críticas. Finalmente, nessas condições observa-se um comportamento não linear com perda de capacidade de carga e aumento significativo de deslocamentos, velocidades e acelerações, evidenciando a necessidade de investigação do comportamento não linear desse tipo de estrutura. / [en] The growing use of antennas for data transmission calls for the installation of growing number of high towers, with the cable-stayed towers standing out. These structures are composed of a central mast and several levels of stays. These towers are slender structures and exhibit a highly non-linear behavior under static and dynamic loads, due to the mast-cable interaction and the tower height. The objective of this work is to study the influence of the nonlinearity on the static and dynamic behavior of a cable-stayed tower. For this, finite element models of cable-stayed towers with two levels of pre-tensioned cables are developed. Two cable disposition geometries are considered: fan and parallel. In particular, the effect of the rupture of one or more cables and the elastoplastic behavior of the cable-stayed tower materials on the stability and non-linear vibrations of the structure is investigated. Initially, the linear behavior of the structure is evaluated through the natural frequencies and critical loads. Next, the non-linear equilibrium paths of each model are obtained, applying the concept of modal imperfection. Finally, free and forced damped vibration analysis is performed. For this purpose, responses in time and phase plane, Fourier transforms and spectrographs are used. In all cases, the effect of the loss of cables and the plastification of the elements on the load capacity, stability and displacements of the structure is analyzed in detail. The results demonstrate that the loss of cables and plastification of elements have a great influence on natural frequencies and critical loads. Under such conditions, non-linear behavior with loss of load capacity and significant increase in displacements, velocities and accelerations stand out, and highlight the need for investigation of the nonlinear behavior of this type of structure.

L'étude du nombre de points rationnels d'une courbe définie sur un corps fini se divise naturellement en deux cas : lorsque le genre est petit (typiquement g<=50), et lorsqu'il tend vers l'infini. Nous consacrons une partie de cette thèse à chacun de ces cas. Dans la première partie de notre étude nous expliquons comment calculer l'équation de n'importe quel revêtement abélien d'une courbe définie sur un corps fini. Nous utilisons pour cela la théorie explicite du corps de classe fournie par les extensions de Kummer et d'Artin-Schreier-Witt. Nous détaillons également un algorithme pour la recherche de bonnes courbes, dont l'implémentation fournit de nouveaux records de nombre de points sur les corps finis d'ordres 2 et 3. Nous étudions dans la seconde partie une formule de trace d'opérateurs de Hecke sur des formes modulaires quaternioniques, et montrons que les courbes de Shimura associées forment naturellement des suites récursives de courbes asymptotiquement optimales sur une extension quadratique du corps de base. Nous prouvons également qu'alors la contribution essentielle en points rationnels est fournie par les points supersinguliers. / The study of the number of rational points of a curve defined over a finite field naturally falls into two cases: when the genus is small (typically g<=50), and when it tends to infinity. We devote one part of this thesis to each of these cases. In the first part of our study, we explain how to compute the equation of any abelian covering of a curve defined over a finite field. For this we use explicit class field theory provided by Kummer and Artin-Schreier-Witt extensions. We also detail an algorithm for the search of good curves, whose implementation provides new records of number of points over the finite fields of order 2 and 3. In the second part, we study a trace formula of Hecke operators on quaternionic modular forms, and we show that the associated Shimura curves of the form naturally form recursive sequences of asymptotically optimal curves over a quadratic extension of the base field. Moreover, we then prove that the essential contribution to the rational points is provided by supersingular points.

The tragic and devastating September 11 attacks resulted in a variety of original musical responses. Exemplary works expressed their reactions through overt 9/11-concentric dialogues to express themes of mourning, military retribution, dissent and commemoration. An examination of such works concludes that effective musical responses express a direct message clarified by supporting musical and/or textual materials. Musical materials can accentuate the specific thematic message of the responsive work as they often evoke images and emotions reminiscent of the attacks and their aftermath. Compositional techniques used in these works are often reminiscent of historical works written in similar circumstances. The recurrence of these historical approaches illuminates the timeless compositional design of historical examples and exemplifies modern advancements in music composition and production. A comparison between classical and popular post-9/11 musical compositions concludes that certain classical and popular genres deal with responsive themes more effectively than others. A recommendation for further study is enclosed.

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Les espaces fortifiés médiévaux du Velay (diocèse médiéval du Puy-en-Velay), sont analysés dans leur constitution et leur utilisation. L’enquête concerne un corpus de sites castraux, bourgs fortifiés, maisons fortes, prieurés et églises fortifiées de 145 communes situées en majorité dans le département de la Haute-Loire (France- Auvergne). Les changements que ces espaces fortifiés opèrent sur la période XIIIe-XVe s. sont mis en avant : morphologie spatiale et choix d’occupation des espaces, évolution de l’habitat individuel seigneurial et des enceintes en contexte rural et urbain. L’ensemble est documenté par des textes qui indique la nature des relations entre les différents groupes sociaux, acteurs de la construction du territoire fortifié : relations entre les seigneurs et l’évêque du Puy ou le roi, relations entre les seigneurs et les communautés urbaines ou rurales, émergence de nouveaux groupes sociaux (la petite noblesse). L’accent est mis sur l’articulation de ces espaces et le rapport social et symbolique que chacun des groupes sociaux entretient avec la fortification. Les intentions de dominations et les résistances de chacun des groupes sociaux sont ainsi mis en évidence par l’analyse du parcellaire, des édifices et de la forme de la fortification. / The fortified medieval areas of the Velay (medieval diocese of Puy-en-Velay) are analysed in their constitution and their use. The survey concerns a corpus of castle sites, fortified towns, fortified houses, priories and fortified churches in 145 communes, mostly in the department of Haute-Loire (France-Auvergne). The changes that these fortified spaces operate during the 13th-15th centuries are highlighted: spatial morphology and choices of occupancy of these areas, evolution of individual seigneurial habitats and enclosures in rural and urban context. The nature of the relations between the different social groups building this fortified territory is mainly documented by texts : relationships between the lords and the bishop of Le Puy or the king, relationships between the lords and the urban or rural communities, emergence of new social groups (the small gentry). The purpose focuses on the articulation of these areas and the social and symbolic relationships that each of the social groups has with fortifications. Thus, the intentions of domination and the resistance of each of the medieval social groups are revealed by analysing the plots, the buildings and the form of the fortification

Thesis (Ph.D.) - James Cook University, 2004. / Thesis submitted by Sally Marie Babidge, BA (Hons) UWA June 2004, for the Degree of Doctor of Philosophy in the School of Anthropology, Archaeology and Sociology, James Cook University. Bibliography: leaves 283-303.

Until a few decades ago few people could imagine that the photovoltaic, solar thermal and other power based on renewable resources, will become a reality. Today people from all over the world on the contrary try at full blast derive benefit from of all possible available source. Using sunlight as a source of energy is first enforced only for small devices such as calculators for charging the battery, but now we are able to produced energy from the sun to supply people around the world. Of course it is not possible supply consumer sector plus firm only from performances renewable power supply. Therefore endeavour is derive benefit from classical energy production at the same time with others power supply. The basic components of photovoltaic and solar thermal power are panels. The panels are made of different materials in different shapes and sizes. During production, the resulting effect looks in addition to costs associated with production. For photovoltaic and solar thermal power plant requires sufficient sunlight. The sunshine has biggest intensity on south of ours planets. Therefore endeavour is build lump these power station just in stand with bigger intensity sunshine. One of them is just Cyprus, too.