In this dissertation, many novel low-cost planar antenna designs are presented for on-vehicle applications. Promising planar antennas showing the desired broadside and omnidirectional radiation patterns and having low-profile configurations are demonstrated. Also, studies on controlling the radiation patterns are conducted. Details of the measured and simulated results of the studied antennas are presented and discussed.

Στην παρούσα διδακτορική διατριβή παρουσιάζεται µία µελέτη τυπωµένων κεραιών γεωµετρίας φράκταλ για ασύρµατες τερµατικές συσκευές, µε έµφαση στις εφαρµογές των κινητών επικοινωνιών και των ασύρµατων τοπικών δικτύων. Η ραγδαία εξέλιξη των ασύρµατων επικοινωνιών είχε ως αποτέλεσµα την σηµαντική µείωση των διαστάσεων των τερµατικών συσκευών, την ολοκλήρωση διαφορετικών υπηρεσιών διαφορετικών συχνοτήτων λειτουργίας στην ίδια συσκευή και την ανάγκη πολλαπλών κεραιών για την αντιµετώπιση του φαινοµένου της διάλειψης και της διασυµβολικής παρεµβολής του ασύρµατου καναλιού. Αυτές οι εξελίξεις έθεσαν καινούργιες απαιτήσεις στην σχεδίαση της κεραίας οδηγώντας στην ανάγκη κεραιών εξαιρετικά µικρών διαστάσεων, πολυσυχνοτικών, χαµηλού κόστους, υψηλής απόδοσης και επιθυµητών χαρακτηριστικών ακτινοβολίας κατά περίπτωση. Στα πλαίσια της διατριβής διερευνήθηκε η ικανότητα σµίκρυνσης και παραγωγής πολυσυχνοτικής συµπεριφοράς που παρουσιάζουν τα σχήµατα γεωµετρίας φράκταλ αν χρησιµοποιηθούν σαν κεραίες. Αρχικά προτείνεται µία καινούργια κατηγορία κεραιών, οι τυπωµένες µονοπολικές κεραίες γεωµετρίας φράκταλ και συγκρίνονται διάφορες γεωµετρίες φράκταλ τόσο ως προς την ικανότητα σµίκρυνσης όσο και ως προς τα χαρακτηριστικά εµπέδησης και ακτινοβολίας που παρουσιάζουν. Εξετάζεται ο καθοριστικός ρόλος του επιπέδου γείωσης αυτής της κατηγορίας κεραιών και εξάγονται γενικά συµπεράσµατα για την εκµετάλλευσή του µε τον βέλτιστο δυνατό τρόπο. Επιπλέον διερευνήθηκε η χρήση των σχηµάτων φράκταλ για την µείωση των διαστάσεων των µικροταινιακών κεραιών. Η φράκταλ ορθογώνια καµπύλη προτείνεται για εφαρµογές γραµµικής και κυκλικής πόλωσης, η οποία παρουσιάζει σηµαντική ικανότητα σµίκρυνσης και προσφέρει πολλούς σχεδιαστικούς βαθµούς ελευθερίας που µπορούν να χρησιµοποιηθούν είτε για περαιτέρω µείωση του µεγέθους της είτε για την διατήρηση του εύρους ζώνης της σε ικανοποιητικά επίπεδα. Λόγω του συµπαγούς σχήµατος και των επιθυµητών χαρακτηριστικών των τυπωµένων µονοπολικών και µικροταινιακών κεραιών φράκταλ, µελετάται περαιτέρω η χρησιµοποίησή τους για την υλοποίηση συστηµάτων πολλαπλών κεραιών µε σκοπό την βελτίωση της ποιότητας του λαµβανοµένου σήµατος. Ακόµη µελετάται η ικανότητα παραγωγής πολυσυχνοτικής συµπεριφοράς της µονοπολικής κεραίας Sierpinski και προτείνεται µία τροποποίηση η οποία µειώνει σηµαντικά το µέγεθος της κεραίας και καθίσταται δυνατόν να τυπωθεί σε ασύρµατες συσκευές µικρού µεγέθους. Επιπλέον, διερευνώνται διάφορες τεχνικές για να ελεγχθούν οι συχνότητες συντονισµού της κεραίας και να συµπέσουν µε τις εκάστοτε επιθυµητές µπάντες λειτουργίας. Τέλος εξετάζεται η επίδραση των διαστάσεων του επιπέδου γείωσης στα χαρακτηριστικά εµπέδησης του συστήµατος. / This Ph.D. thesis presents a comprehensive study on printed fractal antennas for wireless terminal devices, with emphasis on mobile and wireless local area network applications. The rapid evolution of wireless communications resulted in a decrease of terminal devices’ dimensions, in the integration of different services, operating in different spectra, in the same device and finally in the deployment of multiple antenna systems to mitigate the phenomena of fading and intersymbol interference of wireless channel. These evolutions, in turn, set new demands on antenna’s design leading to the necessity of exceptionally small, multiband and low cost radiators possessing high efficiency and desirable radiation characteristics. In the context of the present work, the miniaturization and multiband ability of fractal shaped antennas is examined. Initially a new antenna type is proposed, that of printed fractal monopole antennas, and several innovative fractal shaped monopoles are compared with respect to their miniaturization ability, input impedance and radiation characteristics. The important role of the ground plane is also investigated and general conclusions are drawn to exploit its effects in the most appropriate way. The application of fractals on microstrip antennas was further studied with the fractal rectangular curve (frc) microstrip antenna being proposed for linear and circular polarization applications. The frc microstrip antenna proved to possess a noticeable miniaturization ability and a geometry with several degrees of freedom that can be used either to reduce further its size, or to keep the bandwidth to a satisfactory level. Due to the compact size and desirable electrical characteristics of printed monopole and microstrip fractal antennas, they were further considered for the implementation of multi element antenna systems in order to improve the SNR of the received signal. Finally, the multiband ability of the Sierpinski monopole antenna is investigated and a modification is proposed to decrease the overall antenna height making it feasible to be printed in small terminal devices. Several techniques to allocate the desirable bands of interest are also discussed along with the effect the ground plane dimension’s on the system’s input impedance.

Les provinces canadiennes sont présentement aux prises avec des dépenses élevées en matière de médicaments. Afin de contrôler ces dépenses, plusieurs d'entre elles ont adopté différentes politiques visant à promouvoir et à accélérer la vente de médicaments génériques, lesquels sont équivalents aux médicaments novateurs mais de trente à quarante pourcents moins chers. Le gouvernement canadien, en vertu de son pouvoir de réglementation en matière de brevets, pourrait contribuer aux efforts des gouvernements provinciaux en assouplissant les règles relatives aux brevets pharmaceutiques pour ainsi promouvoir l'accélération de la mise en marché de médicaments génériques. Le gouvernement hésite toutefois à le faire en raison de sa politique en matière de brevets pharmaceutiques dont les effets se veulent équilibrés tant pour l'industrie pharmaceutique novatrice que pour l'industrie du médicament generique. Précisément, cette politique vise, d'une part, à encourager les investissements en recherche et développement par l'industrie novatrice et, d'autre part, à garantir la vente rapide de médicaments génériques au Canada pour que soient contrôlées les dépenses en matière de médicaments. Ce mémoire consiste en un examen du cadre juridique de la politique canadienne en matière de brevets pharmaceutiques. Nous y soulevons et analysons particulièrement ses glissements, quant à l'objectif d'équilibre recherché de la politique canadienne, qui résultent de son application dans le contexte juridique, politique, scientifique et économique actuel. Notre intention est de démontrer que, dans l'intérêt des Canadiens à court et à long terme, la politique canadienne en matière de brevets pharmaceutiques ne doit pas être assouplie en faveur de l'industrie du médicament générique seulement, ceci malgré la croissance des dépenses en matière de médicaments. En effet, l'intérêt des Canadiens ne peut être maximisé que si cette politique est rééquilibrée en tenant compte de l'ensemble de ses glissements juridiques observés. / All Canadian provinces are presently facing increasingly growing drug expenditures. In order to control these expenditures the provinces have adopted different policies to promote and accelerate the sale of generic drugs, these drugs being equivalent to brand-name drugs but thirty to fourthly percent less expensive. Considering its jurisdiction in the field of patents, the Canadian government could contribute to the efforts of the provincial governments in making more flexible the Canadian patent rules, thus promoting the marketing ofgeneric drugs in Canada. The government is however hesitating to do so because of its policy on pharmaceutical patents, which policy aims at balancing the interests of both the brand-name and generic drug industries. Effectively, the purpose ofthe poltey is to promote, on the one hand, the investments in research and development of new drugs in Canada and, on the other hand, to guarantee the rapid marketing of generic drugs, thus controlling drug expenditures. The purpose of this thesis is to examine the judicial framework of the Canadian policy on pharmaceutical patents. Its weaknesses, with regard to the balanced objective of the policy, resulting from its application in the present judicial, political, and economical and scientific context are the focus of this analysis. Our goal is to demonstrate that, to reach the Canadian social benefit, both in the short and long run, the Canadian policy on pharmaceutical patents should not be relaxed for the sole benefit of the generic drug industry, although the drug expenditures are growing. Rather, the social Canadian benefit would only be maximised by re-balancing the Canadian policy in the light of all its demonstrated weaknesses. / "Mémoire présenté à la Faculté des études supérieures en vue de l'obtention du grade de maîtrise en droit". Ce mémoire a été accepté à l'unanimité et classé parmi les 10% des mémoires de la discipline.

We introduce the historical context and motivation for the search for magnetic monopoles or monopole-like objects. Beginning the theoretical part we investigate the properties of groups as they relate to symmetries in physical theories. Using this as a basis we investigate the requirements for global and local gauge invariance for a scalar field, the latter giving the non-trivial connection to a gauge field. From this we present the Georgi-Glashow model and develop its particle spectrum using the connected Higgs field and its associated Higgs mechanism. We then present the electromagnetic duality by extending the Maxwell's equations toinclude magnetic sources. Using the assumption of magnetic sources we present the Dirac quantization condition, motivating the quantization of electric charge. Returning to our model we present the 't Hooft-Polyakov ansatz and investigate its defining properties as a finite energy soliton in our Higgs field. We show the magnetic properties and motivate its validity as a monopole like object. Continuing we define BPS-states on the lower bound for the mass of a monopole like object with magnetic and electric charge. Giving a BPS monopole as a solution in the vein of 't Hooft and Polyakov. Returning to the electromagnetic duality we propose the Montonen-Olive conjecture by exchanging massive vector bosons in our model with the BPS monopoles we developed. We shortly comment on evident problems and present supersymmetry as a possible solution. Finally we present the Witten Effect by allowing a CP violating term in our Lagrangian. From this we extend the Montonen-Olive conjecture to include invariance under the SL(2,Z) group.

Made available in DSpace on 2014-12-17T14:55:37Z (GMT). No. of bitstreams: 1 AntonioSA.pdf: 2010232 bytes, checksum: 027e876fa92242a6ba0e73009f5debd5 (MD5) Previous issue date: 2009-08-11 / This work is the analysis of a structure of the microstrip antenna designed for application in ultra wide band systems (Ultra Wideband - UWB). This is a prospective analytical study where they tested the changes in the geometry of the antenna, observing their suitability to the proposed objectives. It is known that the UWB antenna must operate in a range of at least 500 MHz, and answer a fractional bandwidth greater than or equal to 25%. It is also desirable that the antenna meets the specifications of track determined by FCC - Federal Communication Commission, which regulates the system in 2002 designating the UWB bandwidth of 7.5 GHz, a range that varies from 3.1 GHz to 10, 6 GHz. by setting the maximum power spectral density of operation in -41.3 dB / MHz, and defining the fractional bandwidth by 20%. The study starts of a structure of geometry in the form of stylized @, which evolves through changes in its form, in simulated commercial software CST MICROWAVE STUDIO, version 5.3.1, and then tested using the ANSOFT HFSS, version 9. These variations, based on observations of publications available from literature referring to the microstrip monopole planar antennas. As a result it is proposed an antenna, called Monopole Antenna Planar Spiral Almost Rectangular for applications in UWB systems - AMQEUWB, which presents simulated and measured results satisfactory, consistent with the objectives of the study. Some proposals for future work are mentioned / Este trabalho consiste na an?lise de uma estrutura de antena de microfita projetada para aplica??o em sistemas de banda ultra larga (ultra wideband UWB). Trata-se de um estudo prospectivo e anal?tico onde s?o experimentadas as modifica??es na geometria da antena, observando-se sua adequa??o aos objetivos propostos. Sabe-se que a antena UWB deve operar numa faixa de no m?nimo 500 MHz, e atender uma banda fracion?ria maior ou igual a 25%. ? desej?vel ainda, que a antena atenda ?s especifica??es de faixa determinadas pela FCC Federal Communication Commission, que em 2002 regulamentou o sistema UWB designando a largura de banda de 7,5 GHz, numa faixa que varia de 3,1 GHz a 10,6 GHz. fixando a densidade espectral de pot?ncia m?xima de opera??o em -41,3 dBm/MHz, e definindo a banda fracion?ria em 20%. O estudo parte de uma estrutura de geometria em forma de @ estilizada, que evolui atrav?s de modifica??es na sua forma, simuladas nos softwares comerciais CST MICROWAVE STUDIO, vers?o 5.3.1, e, em seguida, testado com o uso do ANSOFT HFSS, vers?o 9. Varia??es estas, com base em observa??es de publica??es dispon?veis na literatura, referentes a antenas de microfita monopolo planar. Como resultado ? proposta uma antena, denominada Antena Monopolo Quase-Espiral Planar Retangular para aplica??es em sistemas UWB AMQEUWB, que apresenta resultados simulados e medidos satisfat?rios, coerente com os objetivos do estudo. Algumas propostas para trabalhos futuros est?o citadas

The thesis deals with numerical modeling of planar Sierpinski monopole and modified Sierpinski monopole, outgoing from Sierpinski structure. Next, it focuses on modeling of the conical modified monopole and conical Sierpinski monopole created by transferring of modified structure to conical surface. The properties of these multi-band antennas are verified by simulations in CST Microwave Studio 2009 and compared with the results published in available literature. The conical Sierpinski monopole is then optimized according to specified criteria. The optimized antenna is designed and its properties are experimentally verified.

This master’s thesis describes the theoretical analysis of the Sierpinski triangle structure. On the basis of this structure, a planar version of the Sierpinski monopole is firstly designed. Then, by using a transfer of the planar motive to the conical surface, conical and cascade Sierpinski monopoles are designed. All simulations are calculated by CST Microwave Studio 2011. In the thesis, four types of cascade Sierpinski monopole are proposed. The investigated parameters are reflection coefficient, input impedance, radiation properties, polarization and bandwidth. The attention is primarily focused on the design and experimental verification of the selected conical shape cascade Sierpinski monopole set on the bands GSM 900, GSM 1800 and Wi-fi 2,4 GHz.

This thesis deals with the design of omnidirectional monopole antennas. Using the parabolic reflector and the directors, the directional characteristics of monopole antennas are modified. This directional antenna, together with the omnidirectional antenna, examines the effect of various materials, the emission characteristics and the input reflection factor, near the antennas. These antennas are made of 3D textile, measured in anechoic chamber and compared to the designed antennas. At the end of the thesis is the summary and evaluation of the result.

L’histoire de Gazprom est une série de constantes adaptations – avec divers degrés de succès – aux conditions du marché européen et au format de dialogue avec toutes les parties impliquées dans le commerce du gaz à travers le continent. La compagnie a prospéré durant les années 1990 et 2000 dans un environnement où les principales caractéristiques de l’ancien modèle perduraient. Au même moment, Gazprom saisit constamment les nouvelles opportunités qui étaient offertes par la libéralisation et l’ouverture des marchés nationaux du gaz. Cela n’a pas empêché la compagnie de rencontrer des difficultés qui illustrent bien à quel point l’adaptation peut être difficile de temps à autres. Gazprom fait face actuellement à des défis qui sont devenus à travers le temps une cause particulière d’inquiétude. La principale difficulté est que cela arrive à une époque où le dialogue énergétique UE-Russie est mis à mal par des tensions plus générales qui affectent le dialogue entre l’Union européenne et la Fédération de Russie. / The history of Gazprom is a series of constant adaptations – with varying degrees of success – to both European market conditions and the format of dialogue with all parties involved in the gas business across the continent. The company thrived during the 1990s and the 2000s in an environment where the main characteristics of the former model were retained. At the same time, Gazprom constantly seized any new opportunity which was offered by the liberalization and opening up of national gas markets. This has not prevented the company from encountering a few difficulties, illustrating that adaptation can be difficult from time to time. Gazprom is facing structural challenges that have been of particular concern over the last few years. The major difficulty is that this occurs at a time when the wider EU-Russia energy dialogue is highly fraught due to severe tensions which are more broadly affecting the dialogue between the European Union and the Russian Federation.

Cette thèse de doctorat se fixe tout particulièrement pour objectif d’apporter un éclairage sur la problématique de la production des éléments de terres rares aux États-Unis. Ces minéraux, aux qualités nucléaire très particulières, constituent des intrants cruciaux dans certaines technologies et industries stratégiques : technologies « vertes », technologies d’information et de communication, ainsi que dans les technologies militaires. Ces minéraux stratégiques constituent aujourd’hui un enjeu géoéconomique mais aussi géopolitique et environnemental majeur. En 2011, 97 % des éléments de terres rares dans le monde proviennent de la Chine (qui dispose donc d’un monopole), selon l’United States Geological Survey. Cette position de la Chine a soulevé des inquiétudes chez les responsables américains concernant l’accès à ces ressources minérales, de manière évidente depuis 2010. Cette recherche questionne le rôle crucial joué par les acteurs au sein des agences étatsuniennes dans l’objectif d’élaborer une politique solide pour faire face au risque géopolitique lié à la vulnérabilité des États-Unis face au risque de ruptures d’approvisionnement de ces minéraux stratégiques. Ces minéraux sont donc une source de conflit international, surtout en raison de la montée de la Chine comme un nouveau joueur sur la scène internationale, dotée d’un quasi monopole sur les terres rares. Situé à la croisée des préoccupations géoéconomiques et géopolitiques et environnementales, il a semblé nécessaire de comprendre quels enjeux essentiels soulèvent ces minéraux stratégiques : enjeux géoéconomiques, défis géopolitique ou danger écologique ? C’est donc en ces termes que nous examinerons la question des minéraux de terres rares par les États-Unis. / This doctoral dissertation particularly aims at shedding light on the issue of U.S. rare earth production, a group of minerals with very special qualities nuclear, which are vital inputs in certain strategic industries and technologies: green technologies, information and communication technologies, as well as in military technologies. These strategic minerals constitute nowadays one of the major challenges associated with geo-economic, geopolitical and environmental issues. In 2011, China has provided approximately 97 percent of the world’s rare earth minerals (near-monopoly) according to U.S. Geological Survey data. This position of China has raised concerns about access to these mineral resources among American officials, obviously since 2010. This research discuss the crucial role played by actors within the U.S. Agencies to develop a robust policy to deal with the geopolitical risks about U.S. vulnerability to a supply disruption of these critical strategic minerals, as part of a source of international conflict, especially with the rise of China as a new player on the international stage. Located at the crossroads of geo-economic, geopolitical, and environmental concerns, it seems necessary to understand what key impasses constitute rare earths strategic minerals, economic power or geopolitical challenges or ecological danger? It is in these terms that we will deal with the issue of rare earths as considered by the United States.