Call quality has been crucial from the inception of telecommunication networks. Operators need to monitor call quality from the end-user¿s perspective, in order to retain subscribers and reduce subscriber ¿churn¿. Operators worry not only about call quality and interconnect revenue loss, but also about network connectivity issues in areas where mobile network gateways are prevalent. Bandwidth quality as experienced by the end-user is equally important in helping operators to reduce churn. The parameters that network operators use to improve call quality are mainly from the end-user¿s perspective. These parameters are usually ASR (answer seizure ratio), PDD (postdial delay), NER (network efficiency ratio), the number of calls for which these parameters have been analyzed and successful calls. Operators use these parameters to evaluate and optimize the network to meet their quality requirements. Analysis of speech quality is a major arena for research. Traditionally, users¿ perception of speech quality has been measured offline using subjective listening tests. Such tests are, however, slow, tedious and costly. An alternative method is therefore needed; one that can be automatically computed on the subscriber¿s handset, be available to the operator as well as to subscribers and, at the same time, provide results that are comparable with conventional subjective scores. QMeter® ¿ a set of tools for signal and bandwidth measurement that have been developed bearing in mind all the parameters that influence call and bandwidth quality experienced by the end-user ¿ addresses these issues and, additionally, facilitates dynamic tariff propositions which enhance the credibility of the operator. This research focuses on call quality parameters from the end-user¿s perspective. The call parameters used in the research are signal strength, successful call rate, normal drop call rate, and hand-over drop rate. Signal strength is measured for every five milliseconds of an active call and average signal strength is calculated for each successful call. The successful call rate, normal drop rate and hand-over drop rate are used to achieve a measurement of the overall call quality. Call quality with respect to bundles of 10 calls is proposed. An attempt is made to visualize these parameters for better understanding of where the quality is bad, good and excellent. This will help operators, as well as user groups, to measure quality and coverage. Operators boast about their bandwidth but in reality, to know the locations where speed has to be improved, they need a tool that can effectively measure speed from the end-user¿s perspective. BM (bandwidth meter), a tool developed as a part of this research, measures the average speed of data sessions and stores the information for analysis at different locations. To address issues of quality in the subscriber segment, this research proposes the varying of tariffs based on call and bandwidth quality. Call charging based on call quality as perceived by the end-user is proposed, both to satisfy subscribers and help operators to improve customer satisfaction and increase average revenue per user. Tariff redemption procedures are put forward for bundles of 10 calls and 10 data sessions. In addition to the varying of tariffs, quality escalation processes are proposed. Deploying such tools on selected or random samples of users will result in substantial improvement in user loyalty which, in turn, will bring operational and economic advantages.

Majority of the rain producing monsoon systems in India form or intensify over the Bay of Bengal and move onto the land. We expect the air-sea interaction to be a crucial factor in the frequent genesis and intensification of monsoon systems over the Bay. Knowledge of air-sea fluxes is essential in determining the air-sea interactions. However, the Bay remains a poorly monitored ocean basin and the state of the near surface conditions during the monsoon months remains to be studied in detail. For example, we do not know yet which among the various flux formulae used in the General circulation models are appropriate over the Bay since there are no direct measurements of surface fluxes here during the peak monsoon months. The present thesis aims towards filing that gap. In this thesis fluxes were computed using the Bulk method, Inertial dissipation method and direct covariance method. The flux comparisons were reasonable during certain flow conditions which are clearly identified. When these conditions are not met the differences among the fluxes from these methods can be larger than the inherent uncertainties' in the methods. Stratification, flow distortion and averaging time are the key variables that give rise to the differences in the fluxes. It is found that there are significant differences in the surface flux estimates computed from different atmospheric General Circulation Model bulk parameterization schemes. In this thesis, the flow gradients are estimated by taking advantage of the natural pitch and roll motion of the ship. A attempt is made to gain insight into the flow distortion and its influence on the fluxes. In our analysis it is found that the displacement of the streamlines is an important component in quantifying flow distortion.

Submitted by Cristiane Oliveira (cristiane.oliveira@fgv.br) on 2011-06-13T16:04:48Z No. of bitstreams: 1 61080200037.pdf: 2311848 bytes, checksum: fbf28a6d46c2c0ab74e653cc55b05635 (MD5) / Approved for entry into archive by Vera Lúcia Mourão(vera.mourao@fgv.br) on 2011-06-13T16:08:55Z (GMT) No. of bitstreams: 1 61080200037.pdf: 2311848 bytes, checksum: fbf28a6d46c2c0ab74e653cc55b05635 (MD5) / Approved for entry into archive by Vera Lúcia Mourão(vera.mourao@fgv.br) on 2011-06-13T16:10:14Z (GMT) No. of bitstreams: 1 61080200037.pdf: 2311848 bytes, checksum: fbf28a6d46c2c0ab74e653cc55b05635 (MD5) / Made available in DSpace on 2011-06-13T17:51:50Z (GMT). No. of bitstreams: 1 61080200037.pdf: 2311848 bytes, checksum: fbf28a6d46c2c0ab74e653cc55b05635 (MD5) Previous issue date: 2010-08-30 / Esta dissertação analisa o controle societário nas companhias com investimentos de fundos de private equity e venture capital (PE/VC). Lerner e Schoar argumentam que os fundos de PE/VC assumem o controle através da participação acionária majoritária em países do civil law, como o Brasil, em virtude dos baixos índices de proteção aos investidores. Este trabalho investiga a aplicabilidade dessa hipótese nas companhias com investimento de fundos de PE/VC que realizaram a abertura de capital entre os anos de 2004 a 2008. Neste período, 38 companhias com investimento de fundos de PE/VC ingressaram no Novo Mercado da BM&FBovespa. Algumas companhias do Novo Mercado possuem uma estrutura de propriedade mais dispersa e a ausência de um controlador definido. Nessas companhias, acionistas vinculam os seus direitos de voto em um acordo de acionistas para obtenção de mais de 50% do capital votante e para o exercício do controle da sociedade. O acordo de acionistas, portanto, serve como um substituto à participação majoritária em algumas companhias do Novo Mercado. Desta forma, este trabalho analisa a hipótese de que o acordo de acionistas serve como substituto à participação acionária nas companhias com investimentos de fundos de PE/VC, regulando um controle compartilhado. / This research analyzes the corporate control in private equity and venture capital fund (PE/VC) backed companies. Lerner and Schoar argue that PE/VC funds take control over the majority stake in civil law countries, such as Brazil, because of low rates protection for investors. This work investigates the applicability of this assumption in companies with PE/VC investment funds that made an IPO in BM&FBovespa between the years 2004 to 2008. During this period, 38 PE/VC backed companies in the Novo Mercado have a more dispersed ownership structure and the absence of a controlling shareholder. In these companies, investors bind their voting rights in shareholders agreements works as a substitute for a majority stake in some companies in Novo Mercado. This study analyses the assumption that shareholders’ agreement works as a substitute for majority ownership in PE/VC backed companies regulating a joint control.

Made available in DSpace on 2016-06-02T19:50:09Z (GMT). No. of bitstreams: 1 3161.pdf: 4637531 bytes, checksum: 4c53d765063e54a9fc0993350014649e (MD5) Previous issue date: 2010-06-18 / Financiadora de Estudos e Projetos / The complexity assigned to the strategy term has been largely discussed in the literature. The large amount of theoretical contributions to this issue, brought by several knowledge areas; the different tools proposed by academicians and consultants to operationalize its concepts, the plurality of actors that play their roles inside the organizational field are just some examples of the building blocks of such complexity. Also relevant to this discussion is the movement named Strategy as Practice , initiated by European researchers in order to bring a sociological focus to organizational strategies, considering them as something a company does instead of something a company has. Thus, the main goal of this thesis is to identify and compare how Brazilian companies actually practice their competitive strategy, and to what extent/in which way such practice is aligned with the main firm s idiosyncratic variables and with their competitive environments. In order to achieve such goal, this work took advantage of a mixed research method, with a survey with companies listed on Brazilian Stock Exchange and six case studies. Concerning industry perception and company praxis, the main findings indicate that: (1) the internal and external views of competitive advantage are, indeed, perceived as complementary regarding firm strategies; (2) even in more traditional industries, companies perceive their environment as dynamic, due to companies´ mobility, group consolidations or internal rivalry; (3) even in industry with high barriers to entry, firms regularly adopt a surveillance approach to monitor newcomers; (4) innovation tends to be more focused on process than on products, and there is a gap between intended and implemented innovation; (5) the perception of resources and competences spread throughout company networks suggests that controlling these resources may be more important than owning them; (6) at least in the studied companies, low relevance has been assigned to knowledge as a strategic advantage. Regarding strategy practices: (7) an annual strategy planning cycle takes place, focused on formulation activities and perceived as static in nature; (8) workshops and performance meetings were the most often identified strategic events; (9) strategy tools were perceived as highly effective and mainly targeted at structuring analysis and ensuring strategy implementation, with special emphasis to the abundance of financial tools and lack of creativity ones. Concluding, concerning practitioners: (10) it could by empirically identified the existence of an organizational structure responsible for companies strategic planning, generally close to financial areas; (11) those generally involved in strategic activities show a primarily analytical profile, with low presence of women; (12) senior executives have developed their careers mainly inside the company or inside the industry, with relevant business knowledge, while middle management plays its role by implementing decisions made by high executives; (13) consultancies tend to be highly used, and their recontracting is contingent upon the patterns of their involvement in the strategy process; (14) business press has been assigned low relevance, being substituted in some cases by financial releases or by information from industry entities. / A complexidade do tema estratégia tem sido amplamente discutida por diversos autores na literatura. O grande conjunto de contribuições teóricas ao tema, prestadas pelas mais diversas áreas do conhecimento; as diversas ferramentas propostas por acadêmicos e consultores para a operacionalização de seus conceitos; e a pluralidade dos vários atores deste espaço organizacional são apenas alguns exemplos dos fatores constituintes desta complexidade. Relevante também ao tema é o movimento Estratégia como Prática , iniciado por pesquisadores europeus no sentido de trazer um enfoque sociológico às estratégias, considerando-as como algo que as empresas fazem e não algo que as mesmas puramente possuem. Desta forma, o principal objetivo desta tese foi identificar e comparar como as empresas brasileiras efetivamente praticam sua estratégia competitiva e como esta prática está alinhada com as diversas variáveis intrínsecas às firmas e aos seus ambientes competitivos. Para tanto, foi empregado um método de pesquisa combinado, com a realização de survey junto às empresas da BM&F Bovespa e seis estudos de caso. No que se refere à compreensão setorial e à práxis das empresas, as principais conclusões do trabalham apontam que: (1) as visões internas e externas da origem de vantagem competitiva são, de fato, percebidas como complementares no que tange às estratégias da firma; (2) mesmo em setores mais tradicionais, as empresas os percebem como dinâmicos, seja por mobilidade de empresas, por consolidação de grupos ou por rivalidades internas; (3) mesmo em setores com elevadas barreiras à entrada, as firmas adotam postura de vigilância permanente sobre novos competidores; (4) a inovação tende a ser mais focada em processos que produtos, e existe uma lacuna entre inovação pretendida e aquela efetivamente implementada; (5) a percepção de recursos e competências espalhados na rede indica que talvez seja mais relevante controlar do que efetivamente possuir tais recursos; (6) ao menos nas empresas estudadas, baixa relevância pode ser atribuída à questão do conhecimento como diferencial estratégico. No que se refere às práticas, tem-se que: (7) na maioria das empresas existe um ciclo anual de planejamento estratégico, com foco em atividades de formulação e que são percebidos como estáticos; (8) workshops e reuniões de resultado foram os eventos estratégicos mais frequentemente identificados; (9) as ferramentas de estratégia foram percebidas como de alta eficácia e principalmente voltadas para estruturação de análise e garantia de implementação, com destaque para abundância de ferramentas financeiras e escassez de ferramentas de criatividade. Por fim, acerca dos praticantes tem-se que: (10) ficou evidenciada a existência de uma estrutura organizacional com responsabilidade sobre planejamento estratégico da empresa, geralmente próxima a áreas de finanças; (11) os profissionais envolvidos possuem perfil eminentemente analítico e com baixa presença de mulheres; (12) o executivo sênior desenvolveu sua carreira eminentemente na empresa ou no setor, com relevante conhecimento do negócio, enquanto a média gerência assume papel de implementadora de decisões da alta direção; (13) as consultorias tendem a ser bastante utilizadas e a recontratação das mesmas é contingente à forma do envolvimento no processo estratégico da companhia; (14) a imprensa de negócios assume pouca relevância, sendo substituída, em alguma medida, por releases financeiros das empresas ou informações de entidades setoriais.

Cette thèse étudie les techniques de gestion intelligente du spectre et de topologie des réseaux via une approche radio intelligente dans le but d’améliorer leur capacité, leur qualité de service (QoS – Quality of Service) et leur consommation énergétique. Les techniques d’apprentissage par renforcement y sont utilisées dans le but d’améliorer les performances d’un système radio intelligent. Dans ce manuscrit, nous traitons du problème d’accès opportuniste au spectre dans le cas de réseaux intelligents sans infrastructure. Nous nous plaçons dans le cas où aucune information n’est échangée entre les utilisateurs secondaires (pour éviter les surcoûts en transmissions). Ce problème particulier est modélisé par une approche dite de bandits manchots « restless » markoviens multi-utilisateurs (multi-user restless Markov MAB -multi¬armed bandit). La contribution principale de cette thèse propose une stratégie d’apprentissage multi-joueurs qui prend en compte non seulement le critère de disponibilité des canaux (comme déjà étudié dans la littérature et une thèse précédente au laboratoire), mais aussi une métrique de qualité, comme par exemple le niveau d’interférence mesuré (sensing) dans un canal (perturbations issues des canaux adjacents ou de signaux distants). Nous prouvons que notre stratégie, RQoS-UCB distribuée (distributed restless QoS-UCB – Upper Confidence Bound), est quasi optimale car on obtient des performances au moins d’ordre logarithmique sur son regret. En outre, nous montrons par des simulations que les performances du système intelligent proposé sont améliorées significativement par l’utilisation de la solution d’apprentissage proposée permettant à l’utilisateur secondaire d’identifier plus efficacement les ressources fréquentielles les plus disponibles et de meilleure qualité. Cette thèse propose également un nouveau modèle d’apprentissage par renforcement combiné à un transfert de connaissance afin d’améliorer l’efficacité énergétique (EE) des réseaux cellulaires hétérogènes. Nous formulons et résolvons un problème de maximisation de l’EE pour le cas de stations de base (BS – Base Stations) dynamiquement éteintes et allumées (ON-OFF). Ce problème d’optimisation combinatoire peut aussi être modélisé par des bandits manchots « restless » markoviens. Par ailleurs, une gestion dynamique de la topologie des réseaux hétérogènes, utilisant l’algorithme RQoS-UCB, est proposée pour contrôler intelligemment le mode de fonctionnement ON-OFF des BS, dans un contexte de trafic et d’étude de capacité multi-cellulaires. Enfin une méthode incluant le transfert de connaissance « transfer RQoS-UCB » est proposée et validée par des simulations, pour pallier les pertes de récompense initiales et accélérer le processus d’apprentissage, grâce à la connaissance acquise à d’autres périodes temporelles correspondantes à la période courante (même heure de la journée la veille, ou même jour de la semaine par exemple). La solution proposée de gestion dynamique du mode ON-OFF des BS permet de diminuer le nombre de BS actives tout en garantissant une QoS adéquate en atténuant les fluctuations de la QoS lors des variations du trafic et en améliorant les conditions au démarrage de l’apprentissage. Ainsi, l’efficacité énergétique est grandement améliorée. Enfin des démonstrateurs en conditions radio réelles ont été développés pour valider les solutions d’apprentissage étudiées. Les algorithmes ont également été confrontés à des bases de données de mesures effectuées par un partenaire dans la gamme de fréquence HF, pour des liaisons transhorizon. Les résultats confirment la pertinence des solutions d’apprentissage proposées, aussi bien en termes d’optimisation de l’utilisation du spectre fréquentiel, qu’en termes d’efficacité énergétique. / Future cellular network technologies are targeted at delivering self-organizable and ultra-high capacity networks, while reducing their energy consumption. This thesis studies intelligent spectrum and topology management through cognitive radio techniques to improve the capacity density and Quality of Service (QoS) as well as to reduce the cooperation overhead and energy consumption. This thesis investigates how reinforcement learning can be used to improve the performance of a cognitive radio system. In this dissertation, we deal with the problem of opportunistic spectrum access in infrastructureless cognitive networks. We assume that there is no information exchange between users, and they have no knowledge of channel statistics and other user's actions. This particular problem is designed as multi-user restless Markov multi-armed bandit framework, in which multiple users collect a priori unknown reward by selecting a channel. The main contribution of the dissertation is to propose a learning policy for distributed users, that takes into account not only the availability criterion of a band but also a quality metric linked to the interference power from the neighboring cells experienced on the sensed band. We also prove that the policy, named distributed restless QoS-UCB (RQoS-UCB), achieves at most logarithmic order regret. Moreover, numerical studies show that the performance of the cognitive radio system can be significantly enhanced by utilizing proposed learning policies since the cognitive devices are able to identify the appropriate resources more efficiently. This dissertation also introduces a reinforcement learning and transfer learning frameworks to improve the energy efficiency (EE) of the heterogeneous cellular network. Specifically, we formulate and solve an energy efficiency maximization problem pertaining to dynamic base stations (BS) switching operation, which is identified as a combinatorial learning problem, with restless Markov multi-armed bandit framework. Furthermore, a dynamic topology management using the previously defined algorithm, RQoS-UCB, is introduced to intelligently control the working modes of BSs, based on traffic load and capacity in multiple cells. Moreover, to cope with initial reward loss and to speed up the learning process, a transfer RQoS-UCB policy, which benefits from the transferred knowledge observed in historical periods, is proposed and provably converges. Then, proposed dynamic BS switching operation is demonstrated to reduce the number of activated BSs while maintaining an adequate QoS. Extensive numerical simulations demonstrate that the transfer learning significantly reduces the QoS fluctuation during traffic variation, and it also contributes to a performance jump-start and presents significant EE improvement under various practical traffic load profiles. Finally, a proof-of-concept is developed to verify the performance of proposed learning policies on a real radio environment and real measurement database of HF band. Results show that proposed multi-armed bandit learning policies using dual criterion (e.g. availability and quality) optimization for opportunistic spectrum access is not only superior in terms of spectrum utilization but also energy efficient.

Cette thèse étudie les techniques de gestion intelligente du spectre et de topologie des réseaux via une approche radio intelligente dans le but d’améliorer leur capacité, leur qualité de service (QoS – Quality of Service) et leur consommation énergétique. Les techniques d’apprentissage par renforcement y sont utilisées dans le but d’améliorer les performances d’un système radio intelligent. Dans ce manuscrit, nous traitons du problème d’accès opportuniste au spectre dans le cas de réseaux intelligents sans infrastructure. Nous nous plaçons dans le cas où aucune information n’est échangée entre les utilisateurs secondaires (pour éviter les surcoûts en transmissions). Ce problème particulier est modélisé par une approche dite de bandits manchots « restless » markoviens multi-utilisateurs (multi-user restless Markov MAB -multi¬armed bandit). La contribution principale de cette thèse propose une stratégie d’apprentissage multi-joueurs qui prend en compte non seulement le critère de disponibilité des canaux (comme déjà étudié dans la littérature et une thèse précédente au laboratoire), mais aussi une métrique de qualité, comme par exemple le niveau d’interférence mesuré (sensing) dans un canal (perturbations issues des canaux adjacents ou de signaux distants). Nous prouvons que notre stratégie, RQoS-UCB distribuée (distributed restless QoS-UCB – Upper Confidence Bound), est quasi optimale car on obtient des performances au moins d’ordre logarithmique sur son regret. En outre, nous montrons par des simulations que les performances du système intelligent proposé sont améliorées significativement par l’utilisation de la solution d’apprentissage proposée permettant à l’utilisateur secondaire d’identifier plus efficacement les ressources fréquentielles les plus disponibles et de meilleure qualité. Cette thèse propose également un nouveau modèle d’apprentissage par renforcement combiné à un transfert de connaissance afin d’améliorer l’efficacité énergétique (EE) des réseaux cellulaires hétérogènes. Nous formulons et résolvons un problème de maximisation de l’EE pour le cas de stations de base (BS – Base Stations) dynamiquement éteintes et allumées (ON-OFF). Ce problème d’optimisation combinatoire peut aussi être modélisé par des bandits manchots « restless » markoviens. Par ailleurs, une gestion dynamique de la topologie des réseaux hétérogènes, utilisant l’algorithme RQoS-UCB, est proposée pour contrôler intelligemment le mode de fonctionnement ON-OFF des BS, dans un contexte de trafic et d’étude de capacité multi-cellulaires. Enfin une méthode incluant le transfert de connaissance « transfer RQoS-UCB » est proposée et validée par des simulations, pour pallier les pertes de récompense initiales et accélérer le processus d’apprentissage, grâce à la connaissance acquise à d’autres périodes temporelles correspondantes à la période courante (même heure de la journée la veille, ou même jour de la semaine par exemple). La solution proposée de gestion dynamique du mode ON-OFF des BS permet de diminuer le nombre de BS actives tout en garantissant une QoS adéquate en atténuant les fluctuations de la QoS lors des variations du trafic et en améliorant les conditions au démarrage de l’apprentissage. Ainsi, l’efficacité énergétique est grandement améliorée. Enfin des démonstrateurs en conditions radio réelles ont été développés pour valider les solutions d’apprentissage étudiées. Les algorithmes ont également été confrontés à des bases de données de mesures effectuées par un partenaire dans la gamme de fréquence HF, pour des liaisons transhorizon. Les résultats confirment la pertinence des solutions d’apprentissage proposées, aussi bien en termes d’optimisation de l’utilisation du spectre fréquentiel, qu’en termes d’efficacité énergétique. / Future cellular network technologies are targeted at delivering self-organizable and ultra-high capacity networks, while reducing their energy consumption. This thesis studies intelligent spectrum and topology management through cognitive radio techniques to improve the capacity density and Quality of Service (QoS) as well as to reduce the cooperation overhead and energy consumption. This thesis investigates how reinforcement learning can be used to improve the performance of a cognitive radio system. In this dissertation, we deal with the problem of opportunistic spectrum access in infrastructureless cognitive networks. We assume that there is no information exchange between users, and they have no knowledge of channel statistics and other user's actions. This particular problem is designed as multi-user restless Markov multi-armed bandit framework, in which multiple users collect a priori unknown reward by selecting a channel. The main contribution of the dissertation is to propose a learning policy for distributed users, that takes into account not only the availability criterion of a band but also a quality metric linked to the interference power from the neighboring cells experienced on the sensed band. We also prove that the policy, named distributed restless QoS-UCB (RQoS-UCB), achieves at most logarithmic order regret. Moreover, numerical studies show that the performance of the cognitive radio system can be significantly enhanced by utilizing proposed learning policies since the cognitive devices are able to identify the appropriate resources more efficiently. This dissertation also introduces a reinforcement learning and transfer learning frameworks to improve the energy efficiency (EE) of the heterogeneous cellular network. Specifically, we formulate and solve an energy efficiency maximization problem pertaining to dynamic base stations (BS) switching operation, which is identified as a combinatorial learning problem, with restless Markov multi-armed bandit framework. Furthermore, a dynamic topology management using the previously defined algorithm, RQoS-UCB, is introduced to intelligently control the working modes of BSs, based on traffic load and capacity in multiple cells. Moreover, to cope with initial reward loss and to speed up the learning process, a transfer RQoS-UCB policy, which benefits from the transferred knowledge observed in historical periods, is proposed and provably converges. Then, proposed dynamic BS switching operation is demonstrated to reduce the number of activated BSs while maintaining an adequate QoS. Extensive numerical simulations demonstrate that the transfer learning significantly reduces the QoS fluctuation during traffic variation, and it also contributes to a performance jump-start and presents significant EE improvement under various practical traffic load profiles. Finally, a proof-of-concept is developed to verify the performance of proposed learning policies on a real radio environment and real measurement database of HF band. Results show that proposed multi-armed bandit learning policies using dual criterion (e.g. availability and quality) optimization for opportunistic spectrum access is not only superior in terms of spectrum utilization but also energy efficient.

Oxidische Materialien bieten ein weites Spektrum an möglichen Anwendungen. Vor allem Isolatoren mit Perowskitstruktur eignen sich hervorragend für die optische Datenverarbeitung und -speicherung. Andere, leitende, Oxide können für die magnetische Datenspeicherung eingesetzt werden. Vorraussetzung für den praktischen Einsatz der Werkstoffe sind jedoch grundlegende Kenntnisse über deren mikroskopischen Eigenschaften und ablaufende Prozesse. Mittels Photoelektronen- und Röntgenspektroskopie können Aussagen über die elektronische Struktur getroffen werden. Die noch junge Methode der Fluoreszenz weicher Röntgenstrahlung (SXF) wurde zur Charakterisierung der elektronischen Struktur hinzugezogen. SXF-Messungen wurden an der Beamline 8.0.1 am ALS in Berkeley, Kalifornien, durchgeführt. An der Modellsubstanz MgO wurden Röntgenabsorptions- und Röntgenemissionsspektren an der Sauerstoffkante erstellt. Es zeigt sich eine hervorragende Übereinstimmung mit Modellrechnungen. Ein Bandmapping unter Ausnutzung von Resonanzphänomenen, ähnlich wie in Graphit, scheint jedoch nicht möglich zu sein. In TiO2 wurde das Ti 3d Niveau untersucht. Die Emissionsspetkren zeigen Verluststrukturen, deren Feinstruktur mit der berechneten rJDOS nachvollzogen werden konnte. In KNbO3 wurde der Beitrag der Nb 5p und O 2p-Zustandsdichte zum Valenzband untersucht. Es wurde versucht, die Anregungsenergieabhängigkeit der O 2p-Emissionsspektren mit der Bandstruktur in Verbindung zu bringen. In KTaO3 wurde erstmals der Ta 5d-pDOS-Anteil am Valenzband direkt nachgewiesen. Zudem weisen die anregungsenergieabhängigen Emissionsspektren Verluststrukturen auf, die auf eine O 2p-Ta 5d Interbandanregung schließen lassen. An Sr2FeMoO6 wurden erstmals XES-Messungen zur Bestimmung der elektronischen Struktur durchgeführt. Es zeigen sich hybridisierte O 2p-Mo 4d Zustände, die Leitungselektronen haben einen leichten Fe-Charakter. Eine gute Übereinstimmung mit Bandstrukturrechnungen wird beobachtet. Für photorefraktive Material Sn2P2S6 wurde die elektronische Struktur mittels XPS, XES und FP-LAW-Rechnungen detailliert bestimmt. An Fe-dotiertem Ba0.77Ca0.23TiO3 wurde mittels XPD unter erstmaliger Erstellung von Azimuthalspektren der Einbauplatz von Ca verifiziert und der Einbauplatz von Eisen bestimmt. Für beide Elemente ergibt sich ein vollständiger bzw. überwiegender Einbau auf dem Ba-Platz.

L'objectif de cette thèse est d'analyser le système juridique français et brésilien concernant les stratégies de défense contre les offres publiques d'acquisition visant à prendre le contrôle des sociétés cotées en bourse. Les offres publiques d'acquisition font l'objet d'un vif débat, plus particulièrement lorsqu'elles présentent un caractère hostile pour la société cible. En France, de nombreux efforts législatifs ont été mis en œuvre en vue d'encadrer les OPA et de lutter contre les prises de contrôle rampantes. L'analyse du droit positif permet de mettre en lumière ces différents efforts ainsi que leur mise en œuvre à travers diverses techniques par les sociétés visées. Grâce à l'analyse juridique des stratégies anti-OPA en France, le système brésilien peut prendre connaissance de cette expérience et trouver la meilleure approche juridique pour les sociétés cotées ayant un capital flottant important. Au Brésil, la récente vague d'IPO a été possible grâce à la réforme dans la bourse BM&FBOVESPA. Dorénavant, la BM&FBOVESPA présente le scénario idéal pour prendre le contrôle des sociétés cotées. Ainsi, l'importance de ce thème est le résultat de la dispersion de l'actionnariat après la première vague d'introduction en bourse dans le marché de capitaux brésilien, et en France, elle se traduit par l'évolution dans environnement légal des défenses anti-OPA face à des pratiques qui ne cessent d'évoluer. / The objective of this thesis is to analyse the French experience and the Brazilian legal environment concerning the defense strategies against hostile corporate takeovers aimed at taking control over public companies. Through the analysis of the French legal system of the anti-takeover strategies, the Brazilian system will be able to acquire this experience and find the best legal approach for Brazilian public companies with dispersed ownership. The importance of this theme is the result of the ownership dispersion following the first IPOs in the current Brazilian securities exchange market, which provides the ideal scenario for taking control of these publicly-traded companies, as well as the changes and the evolution in the French legal environment.

Submitted by Hector Rodrigo Ribeiro Paes Ferraz (hferraz@gmail.com) on 2017-05-28T21:08:53Z No. of bitstreams: 2 transparencia_em_websites_-_v._final_Hector _Ferraz_2.docx: 264144 bytes, checksum: 767061ac59ca18d36384fcc1cd43abd8 (MD5) quadro informações resolução anticorrupcao e estatais 13.xlsx: 134947 bytes, checksum: f4f67c1c1ade0e15dcc3d7c457be8edd (MD5) / Rejected by ÁUREA CORRÊA DA FONSECA CORRÊA DA FONSECA (aurea.fonseca@fgv.br), reason: Prezado aluno, Sua submissão está sendo novamente rejeitada, porque o Título tem que ser igual a Ata e a Folha de Assinatura "TRANSPARÊNCIA DAS SOCIEDADES DE ECONOMIA MISTA LISTADAS EM BOLSA: UMA PERSPECTIVA A PARTIR DOS WEBSITES" . Favor refazer os acertos do título e submeter novamente em um único PDF. Favor fazer as substituições da capa e contracapa do impresso entregue na SRA. Att., ÁUREA SRA on 2017-06-21T16:50:55Z (GMT) / Submitted by Hector Rodrigo Ribeiro Paes Ferraz (hferraz@gmail.com) on 2017-06-25T15:57:49Z No. of bitstreams: 2 transparencia_em_websites_-_v._final_Hector _Ferraz_2.docx: 264144 bytes, checksum: 767061ac59ca18d36384fcc1cd43abd8 (MD5) quadro informações resolução anticorrupcao e estatais 13.xlsx: 134947 bytes, checksum: f4f67c1c1ade0e15dcc3d7c457be8edd (MD5) / Approved for entry into archive by ÁUREA CORRÊA DA FONSECA CORRÊA DA FONSECA (aurea.fonseca@fgv.br) on 2017-07-06T14:30:10Z (GMT) No. of bitstreams: 2 transparencia_em_websites_-_v._final_Hector _Ferraz_2.docx: 264144 bytes, checksum: 767061ac59ca18d36384fcc1cd43abd8 (MD5) quadro informações resolução anticorrupcao e estatais 13.xlsx: 134947 bytes, checksum: f4f67c1c1ade0e15dcc3d7c457be8edd (MD5) / Made available in DSpace on 2017-07-20T19:13:22Z (GMT). No. of bitstreams: 2 transparencia_em_websites_-_v._final_Hector _Ferraz_2.docx: 264144 bytes, checksum: 767061ac59ca18d36384fcc1cd43abd8 (MD5) quadro informações resolução anticorrupcao e estatais 13.xlsx: 134947 bytes, checksum: f4f67c1c1ade0e15dcc3d7c457be8edd (MD5) Previous issue date: 2016-12-21 / The present study examines and evaluates public policies that promote transparency and the disclosure of data on web portals. The focus of the analysis is on state-owned enterprises listed on the Brazilian Stock Exchange (BM&FBOVESPA).These enterprises are evaluated in conformity with obligations imposed upon them by the aforementioned policies, as well as the Court of Auditors, the Ministry of Transparency, the Ministry of Planning, State Legislative Assemblies, and the national Congress. Propositions are then made for improvements in structure and organization of transparency policies, for the benefit of investors and society. / O presente trabalho se propõe a discutir as políticas públicas promovidas pelos órgãos governamentais no tocante à transparência da divulgação de dados em portais de internet. O foco de análise são as sociedades de economia mista federais listadas em bolsa, que serão observadas na perspectiva das diversas normas produzidas em relação ao tema, expedidas pelo Tribunal de Contas da União, Ministério da Transparência (Controladoria-Geral da União), Ministério do Planejamento, Assembleias Legislativas Estaduais e Congresso Nacional. Ainda são feitas avaliações de alguns websites em cotejo com as normas vigentes, bem como proposições de melhorias na concepção de uma política de transparência mais estruturada, em benefício dos investidores e da sociedade.