Among the figures of the Scientific Revolution, Galileo was the most influential in moving science away from Aristotle’s concept of scientific explanation to what became Modern science. My primary goal in this thesis is to explicate Galileo’s concept of scientific explanation, as well as the metaphysical and methodological underpinnings relied upon by Galileo, and to investigate where these depart from Aristotle as well as the Aristotelians of Galileo’s time. Galileo’s most revolutionary scientific achievement was to advance a new, more practical aim for scientific inquiry: he changed the focus of scientific investigations to the measuring, modeling, and predicting of phenomena. In order to increase the reliability of his hypotheses Galileo rejected those aspects of Aristotle’s account of scientific explanation that could not be rigorously empirically justified. The result was that empirical science no longer searched for the essential attributes of bodies or for Aristotle’s causes such as the “final” cause. The identified contributions and innovations promulgated by Galileo are significant because they dictated changes that became formative to contemporary models of scientific explanation. I argue that analyses such as the one given in this dissertation can provide a framework for better understanding twentieth-century criticisms that argue that Aristotle’s concept of scientific explanation contained elements that are indispensable to genuine scientific explanations but that are missing from standard contemporary accounts such as Hempel’s covering law models. Finally, I conclude that my analysis of Galileo’s contributions to scientific explanation suggests that contemporary claims that covering law models should be more receptive to Aristotle’s ideas of causation and essence are misguided. / text

Made available in DSpace on 2015-04-22T22:18:27Z (GMT). No. of bitstreams: 1 Jerry Luiz Soares.pdf: 672406 bytes, checksum: e88bbef6ba318d131d840409b6860292 (MD5) Previous issue date: 2013-07-18 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Galileo Galilei supported Nicolaus Copernicus astronomic theory, from which the former has attracted philosophical as well theological consequences. The celestial discoveries made possible with the usage of spyglasses allowed Galileo to challenge some of the aristotelic principles of cosmology and to break up the limits imposed to astronomy as hypothetical discipline which would aim just to "save the phenomena". / Galileu Galilei defendeu a teoria astronômica de Nicolau Copérnico, e dela extraiu consequências filosóficas e teológicas. As descobertas celestes com a utilização da luneta permitiram a Galileu questionar alguns princípios da cosmologia aristotélica, e romper os limites impostos à Astronomia, enquanto disciplina hipotética que teria como objetivo tão somente "salvar os fenômenos".

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Les systèmes de navigation par satellite sont connus pour être sensibles aux interférences. Cette thèse étudie les techniques d'antennes adaptatives comme une solution au problème du brouillage des signaux militaires (GPS et Galileo) par des interférences de forte puissance et à grande occupation spectrale. L'objectif est de réaliser, à terme, une antenne réseau indépendante du récepteur de radionavigation, ce qui nous a rapidement conduit à privilégier les systèmes MISO.<br />Divers algorithmes de traitement ont été évalués sur plusieurs géométries de réseau. Nous avons mis en évidence que le SINR moyen de sortie du réseau n'est pas représentatif des performances d'un récepteur de radionavigation. Un critère de sélection des méthodes, basé sur la précision finale de localisation, a donc été défini. Nous avons montré que, selon ce critère, la connaissance a priori des DOA ne permet pas forcément de gain de traitement avec un système MISO. La stabilité de la réponse des réseaux a également été étudiée, nous conduisant finalement à restreindre notre étude aux méthodes aveugles de minimisation de puissance sous contrainte linéaire. <br />Nous avons ensuite caractérisé les principaux défauts de la chaîne RF (dus aux dispersions de fabrication des capteurs et des filtres analogiques, et au couplage inter-capteurs) et en avons évalué l'impact sur les performances des filtres spatiaux. Physiquement, comme l'effet large bande, les défauts du réseau se traduisent par une augmentation du nombre de degrés de liberté consommés par un signal de forte puissance. Le traitement Spatio-Temporel (STAP) constitue une solution possible à cette augmentation du rang du sous-espace interférent car il permet d'accroitre le nombre de degrés de liberté disponibles, sans augmenter la taille du réseau. Cependant, la composante fréquentielle du filtrage STAP peut dégrader les performances du corrélateur d'un récepteur GNSS générique. Aussi, avons-nous défini un nouveau critère de performance, adapté au traitement des signaux GNSS. Nous avons ainsi pu écrire le filtre STAP optimal et nous en avons déduit une version simplifiée qui constitue un bon compromis performances - complexité.<br /> Globalement, le réseau STAP ne permet pas de gain de traitement sur la puissance utile transmise au récepteur mais il permet de mieux rejeter les signaux interférents de forte puissance en présence de défauts linéaires de chaîne.

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In the next coming years global satellite navigation systems (GNSS) will make part of our daily life, as the world is becoming "GNSS-dependant in the same way that it has become Internet-dependant". Indeed, more than ten years folowing the opening up to civilians of satellite-based navigation systems initially designed for military purposes, civil satellite navigation applications are becoming more and more numerous. The potential benefits have proven enormous in terms of transport safety and efficiency as well as for non-transport-related industries. / Dans les toutes prochaines années, les systèmes globaux de navigation par satellite (GNSS) feront partie intégrante de notre vie quotidienne. En effet, un peu plus de dix ans après la libéralisation de l'accès des civils aux systèmes de navigation par satellite initialement conçus à des fins militaires, les applications civiles permises par la navigation par satellite sont de plus en plus nombreuses et les bénéfices potentiels sont énormes en matière de sécurité et d'efficacité des transports comme pour d'autres secteurs et industries. fr

"Author biographies are available in the expanded on-line version of this article [http://www.insidegnss.com/auto/julyaug09-tetewsky-final.pdf]" / "July/August 2009." Web site title: Making Sense of GPS Inter-Signal Corrections : Satellite Calibration Parameters in Legacy and Modernized Ionosphere Correction Algorithms.

Thesis (Ph. D.)--University of Oregon, 2002. / Typescript. Includes vita and abstract. Includes bibliographical references (leaves 273-292). Also available for download via the World Wide Web; free to University of Oregon users.

Made available in DSpace on 2014-06-11T19:22:26Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-02-25Bitstream added on 2014-06-13T20:09:31Z : No. of bitstreams: 1 polezel_wgc_me_prud.pdf: 1240950 bytes, checksum: 142fe3cb11a3c5af3d674c07f9b8cc46 (MD5) / Com a inclusão de novos sinais nos satélites GPS e o advento do sistema Galileo, o posicionamento por satélite entrará em uma nova era, trazendo inovações tecnológicas e científicas, principalmente nas combinações entre diferentes sistemas. Logo, verifica-se a importância de analisar a qualidade dos novos sinais, quantificando suas contribuições na acurácia do posicionamento. Visando contribuir com essa demanda, este trabalho tem o intuito de dar continuidade às pesquisas no Brasil sobre a qualidade advinda da modernização do GNSS utilizando os novos sinais transmitidos pelos satélites. O GNSS engloba o GPS, o GLONASS, o Galileo, o SBAS, o Beidou e o LAAS. Entretanto, neste trabalho apenas os sistemas GPS, GLONASS e Galileo serão abordados. Com esses três sistemas é possível realizar combinações lineares para integrá-los no posicionamento por ponto e relativo. Alguns problemas nessa combinação foram detectados com indicações de soluções para os efeitos não modelados. No que concerne aos efeitos da ionosfera, uma combinação ion-free utilizando três freqüências foi apresentada, permitindo eliminar os efeitos de primeira e segunda ordem da ionosfera. Apresenta-se também uma revisão bibliográfica do estado da arte da solução da ambigüidade utilizando esses três sistemas. Além disso, foi realizado um experimento a fim de analisar a qualidade do novo sinal L2C. Nas análises, tal como esperado, os satélites modernizados apresentaram melhores resultados do que os satélites não modernizados. Como o sistema Galileo ainda não está operacional, foi implementado no software GPSeq a interoperabilidade dos sinais GPS e GLONASS e realizadas análises comparando tais sistemas no posicionamento relativo. Além disso, comparou-se os resultados do software GPSeq com softwares comerciais. Os resultados, em alguns momento... / With the addition of new signals in GPS satellites and the advent of Galileo system, the satellite positioning will start a new era, which will require technologic and scientific innovations mainly in combinations of these systems. Therefore, analyzing the new signal quality and quantifying their contribution in the positioning accuracy are very important. Thus, this research points out the importance of continuing investigations in Brazil about GNSS modernization using the new signals transmitted by the satellites. The GNSS include GPS, GLONASS, Galileo, SBAS, Beidou and LAAS. However, in this work only GPS, GLONASS and Galileo system are taken into account. In order to integrate these three systems it is possible to accomplish linear combinations in absolute and relative positioning. Some problems in these combinations were detected and solutions for the unmodeled effects were recommended. For the ionospheric effect, an ion-free combination using three frequencies was performed. This combination can eliminate the ionosphere effects of first and second order. In this paper a bibliographical revision of the ambiguity solution using three systems is accomplished. Furthermore, an experiment was carried out to analyze... (Complete abstract click electronic access below)