Social media is getting more and more important for both customers and companies as the use of social media increases each year. Previous research shows that there is a positive link between the use of social media and online shopping. The purpose of this study is to explore which factors that drives the purchases of clothes online. The factors studied are the traditional factors price, quality and word-of-mouth and the digital factors electronic word-of-mouth, influencers and ads on social media. The study has been limited to the social platforms Instagram, YouTube and Snapchat. In the study a quantitative method has been used and data was collected through a survey. The data material consists of responses from 145 respondents and have been statistically analysed through a bivariate and multivariate analysis in SPSS. The result shows that the factors that have an impact on the customer's online shopping behaviour are price, eWOM, influencers and ads, and that Instagram is the platform where customers are most affected. The study has contributed with an increased understanding of the factors that influence the customer's online clothing purchases, and what social media platform companies should focus their marketing to. The study has also shown that eWOM is becoming more important for customers compared to WOM, which has decreased in relevance for the customers in this context.

Conselho Nacional de Desenvolvimento Científico e Tecnológico / The electromagnetic and gravitational quasinormal mode spectra of plane-symmetric anti-de Sitter black holes are investigated in the present work. According to the AdS/CFT correspondence, the black hole quasinormal frequencies correspond to the poles of R-current and stress-energy tensor correlation functions in the holographically dual field theory: the N = 8 super-Yang-Mills in 2 + 1 dimensions. In the present study, this duality is explored in order to choose the quasinormal mode boundary conditions and the gauge invariant variables governing the black hole perturbations. Among the main results, it is shown that zero wavenumber axial perturbations yield only small rotations on the system, while the polar perturbations lead to a change in the mass of the black hole and may also produce cylindrical gravitational waves. In relation to the quasinormal spectra, the long-distance and low-frequency limit of the dispersion relations present the hydrodynamical behavior that is characteristic of a conformally invariant theory, with diffusion, shear and sound-wave modes. In the electromagnetic perturbation sector, it also appears purely damped modes that tend to the bosonic Matsubara frequencies in the long-wavelength regime. / No presente trabalho, investigou-se o espectro de vibrações eletromagnéticas e gravitacionais de buracos negros anti-de Sitter com horizontes plano-simétricos. Segundo a correspond ência AdS/CFT, os modos quase-normais desses buracos negros estão associados aos pólos de funções de correlação de corrente-R e do tensor energia-momento na teoria de campos holograficamente dual: a super-Yang-Mills N = 8 em 2 + 1 dimensões. Neste estudo, a relação com a teoria de campos foi explorada ao se fixar as condições de contorno que definem os modos quase-normais, bem como na escolha das quantidades invariantes de calibre que governam as perturbações dos buracos negros anti-de Sitter. Para obter as equações de onda gravitacionais, foram utilizados formalismos baseados em variações da métrica e dos escalares de curvatura de Weyl. Entre outros resultados, mostrou-se que as perturbações axiais com número de onda nulo produzem somente pequenas rotações sobre o sistema, enquanto que as perturbações polares conduzem a mudanças na massa e também podem se propagar na forma de ondas gravitacionais cilíndricas. Em relação ao espectro quase-normal, no limite de baixas freqüências e grandes comprimentos de onda, algumas relações de dispersão apresentam o comportamento hidrodinâmico característico de uma teoria conformemente invariante, com o aparecimento de modos de difusão, cisalhamento e de onda sonora. Por fim, no setor eletromagnético das perturbações, surgem também modos puramente amortecidos que tendem às freqüências de Matsubara de um sistema bosônico no regime de grandes comprimentos de onda.

This thesis consists in a self-contained study of gauge/gravity dualities in the line of the Klebanov-Witten model. Here we explore first the known Maldacena duality that relates N=4 SYM theory in four dimensions to type IIB supergravity on AdS_5×S^5 in reasonable detail, after some necessary preliminaries on supersymmetric gauge theories, where we display in detail the supersymmetry algebra and representations for N 1 supersymmetry. There we also construct the so-called superfields that will be helpful to write invariant lagrangians for gauge theoriesmreadily, and then useful to construct the gauge theory side of the Klebanov-Witten model. In the original AdS/CFT correspondence and its phenomenologically interesting extensions, Dp-branes as solutions of supergravity and nonperturbative objects in string theory where gauge theory lives are crucial. So, to preserve the self-contained nature of this work, we include a brief review of superstring theory addressed to understand the need to include this higher-dimensional objects by T-duality and, at low-energy limit of the string theory, as solutions of the Einstein equations. The first climax of this work occurs when we use all we learned to establish the Maldacena conjecture, N=4 SU(Nc) SYM theory we study in the supersymmetry chapter, living on the four-dimensional worldvolume of a stack of Nc D3-branes in a flat-space, corresponds exactly to type IIB supergravity on AdS_5×S^5 .In order to prove it, we match symmetries and operators with states in both sides. But actually this corresponds to the weak form of the correspondence, because it is not possible to handle neither string theory or gauge theory at strong coupling. The focus and main motive to have to learn the first hundred of pages here will be to extend the dual gauge theory we studied in AdS/CFT towards more realistic gauge theories as duals of some supergravity theory. The Klebanov-Witten model, consists in replacing the five-sphere in the gravity background of type IIB for a more interesting Einstein manifold X5 , a coset space called T^1,1 .The resulting dual gauge theory is expected to be less supersymmetric, and it is indeed N = 1 superconformal field theory with matter content in the bifundamental representation of the gauge group SU(N)×SU(N), and a quartic superpotential that exhibits SU(2)×SU(2)×U(1) global symmetry, which is precisely the symmetry of the coset space in the gravity side. This is not the end of the story, the Klebanov-Witten model extended the Maldacena correspondence and found as a dual gauge theory a less supersymmetric but still conformal theory. Breaking of the conformal theory, proposed by Klebanov, Nekrasov and Tseytlin, is achieved by introducing fractional M D3-branes in addition to the N regular D3-branes. The resulting theory is an SU(N+M)×SU(N) gauge theory with N = 1 supersymmetry, no longer conformal and then a little more interesting as a part of the crusade to find a QCD-like theory. This is still not the end, the last model suffers from a singularity in the deep IR, rendering the gravitational description invalid in that regime. It was conjectured that the strong dynamics of the gauge theory should somehow resolve this problem. Klebanov, again, and Strassler showed that this conjecture was correct, and argue that the RG flow is in fact an infinite series of Seiberg duality transformations- a cascade - in which the number of colors repeatedly drops from N NM , so the gaugegroup changes from SU(N+M)×SU(N) to SU(NM) ×SU(N). This process can be repeated until the IR limit where the gauge group simply becomes SU(M). So, at the end we get a N=1 SU(M) gauge theory, a QCD-like theory. We say that the standard model itself may lie at the base of a duality cascade. / Essa tese consiste num estudo autocontido das dualidades calibre/gravidade na linha do modelo do Klebanov-Witten. Aqui nos exploramos primeiro de um jeito razoavelmente detalhado,a conhecida dualidade do Maldacena que relaciona a teoria N=4 SYM em quatro dimensões com as supercordas tipo IIB no espaço AdS_5×S^5, depois de alguns preliminares necessários sobre teorias supersimétricas de calibre, onde nós mostramos em detalhe à algebra supersimétrica e as representações para N 1 supersimetria. Nós também construímos os conhecidos supercampos que são úteis para escrever lagrangianas invariantes para teorias de calibre facilmente, e então serão úteis para construir a teoría de calibre do modelo de Klebanov-Witten. Na correspondência AdS/CFT original e as suas extensões fenomenologicamente interessantes, as Dp-branas, como soluções de supergravidade e objetos não perturbativos na teoria de cordas onde as teorias de calibre moram, são essenciais. Assim ,a fim de preservar a natureza autocontida desse trabalho, nós incluímos uma breve revisão sobre teoria de supercordas dirigida a entender a necessidade de incluir esses objetos extra-dimensionais usando dualidade-T e, no limite de baixa-energia da teoria de cordas, como soluções das equações de Einstein. O primeiro clímax desse trabalho ocorre quando nós usamos tudo o que aprendemos para estabelecer a conjectura do Maldacena, a teoria de calibre N=4 SYM que nós estudamos no capítulo de supersimetria, morando no volume de mundo quadridimensional de uma pilha de Nc D3-branas (sim, o subscrito c significa cor!) em espaço plano, corresponde exatamente à teoria de supergravidade tipo IIB no espaço AdS_5×S^5 . A fim de testar ela, nós identificamos simetrias e operadores com estados em ambos lados da dualidade. Mas na verdade isto corresponde à forma fraca da correspondência, porque não é possível lidar nem com a teoria de cordas nem com a teoria de calibre no limite de acoplamento forte. O foco e motivo principal de porque nós temos que aprender as primeiras cem páginas aqui, será estender a teoria de calibre dual que estudamos em AdS/CFT, para teorias de calibre mais realisticas como duais de alguma teoria de supergravidade. O modelo do Klebanov-Witten, consiste em substituir a esfera de cinco dimensões no fundo de supergravidade da teoria de supercordas tipo IIB por um espaço que é mais interessante X5, um espaço coset chamado T^1,1. Nós esperamos que a teoria de calibre dual que resulta é menos supersimetrica, e na verdade é N =1 superconforme com um conteúdo de matéria na representação bifundamental do grupo de calibre SU(N)×SU(N), e um superpotencial quártico que tem simetria global SU(2)×SU(2)×U(1), que é precisamente a simetria do espaço coset no lado da gravidade. Mas isso não é tudo, o modelo do Klebanov-Witten estendeu a correspondência do Maldacena e encontrou como teoria dual uma teoria menos supersimetrica mas ainda conforme. A quebra da simetria conforme, proposta pelo Klebanov, Nekrasov e Tseytlin, é obtida introduzindo M D3-branas fracionais além das N D3-branas regulares. A teoria resultante é uma teoria de calibre SU(N+M)×SU(N) com N = 1 supersimetria, não mais conforme e então um pouco mais interessante como parte da nossa cruzada para encontrar uma teoria tipo-QCD. Isso ainda não é o final, o modelo anterior sofre de uma singularidade no IR profundo, tornando inválido a descrição gravitacional. Foi conjeturado então que a dinâmica do acoplamento forte na teoria de gauge deveria de algum jeito resolver esse problema. Klebanov, de novo, e Strassler mostraram que essa conjetura foi correta, e argumentaram que o fluxo do GR é de fato uma serie infinita de transformações de dualidade de Seiberg - uma cascata - onde o numero de cores cai repetidamente de NNM, e o grupo de calibre muda de SU(N+M)×SU(N) a SU(NM)×SU(N). O processo pode ser repetido até o limite IV onde o grupo de calibre simplesmente torna-se SU(M). Então, no final nós obtemos uma N = 1 teoria de calibre SU (M ), ou seja uma teoria tipo-QCD. Então, nós dissemos que o modelo padrão mesmo pode se situar na base da cascata de dualidade.

Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / Estudaremos uma tÃcnica de suavizaÃÃo de uma singularidade nua em um conifold chamada Brane Resolution Por um lado a singularidade aparece como uma soluÃÃo de brana de supergravidade contendo apenas termos do setor de Neveu-Schwarz Por outro lado podemos ver a singularidade do conifold como oriunda de um ponto fixo do grupo de simetria discreto responsÃvel pela geraÃÃo do conifold O conifold tem bastante importÃncia no processo de compactificaÃÃo em teorias de cordas em particular nas chamadas transiÃÃes cÃnicas De fato existem diferentes tipos de espaÃos deCalabi-Yau que podem ser variedades internas Apesar de tais espaÃos terem caracterÃsticas to- polÃgicas distintas pode-se transformar um espaÃo no outro atravÃs das transiÃÃes cÃnicas Isso se faz atravÃs da geraÃÃo de singularidades no espaÃo de Calabi-Yau que surpreendentemente nÃo gera problemas quÃnticos. A tÃcnica consiste em acrescentar um termo topolÃgico do setor de Ramond-Ramond à aÃÃo A inclusÃo de um termo de Chern-Simons responsÃvel pela interaÃÃo entre os campos do setor de Ramond-Ramond (Cn ), gera um fluxo dos campos H3 = dB2 e F3 = dC2 sobre a singularidade do conifold. A partir da equaÃÃo de movimento do campo pode-se, dado uma escolha adequada para a configuraÃÃo da mÃtrica e dos campos, encontrar os fatores de warp que sÃo responsÃveis pela retirada da singularidade O mÃtodo tambÃm pode ser entendido topologicamente como a incisÃo de uma esfera no lugar da vizinhanÃa do nodo do cone O estudo do comportamento de campos sobre o conifold à feito no intuito de extender a correspondÃncia AdS-CFT originalmente a correspondÃncia foi proposta para o espaÃo AdS5 ÃS 5 mas logo surgiram extensÃes utilizando outras variedades como M4 à C6 PrÃximo a singula- ridade o espaÃo pode ser escrito como AdS5 à X 5 onde X 5 à o espaÃo base do conifold Geralmente toma-se o espaÃo base como um espaÃo homogÃneo de Einstein Ricci-plana onde X 5 = SU (3)/SU (2) à SU (2). Contudo, para manter a invariÃncia conforme da teoria de campos dual à necessÃrio suavizar o conifold atravÃs de incisÃes do tipo Eguchi-Hanson que podem ser de dois tipos: por uma 3-esfera S 3 à chamada deformation ou por uma 2-esfera S 2 à chamada resolution Recentemente foram propostas resoluÃÃes do conifold em um cenÃrio de teoria heterÃtica dotada de torÃÃo Tal efeito à relevante em teorias onde soluÃÃes do tipo buraco negro existem na variedade interna como as black branes e spinning branes esta Ãltima leva em conta o momento angular do buraco negro - spin - e à uma soluÃÃo do tipo Kerr A partir da transgressÃo da identidade de Bianchi para a 3-forma intensidade de campo de Kalb-Ramond oriundo de um termo de Gauss-Bonnet e de instanton podemos introduzir uma torÃÃo e com isso um novo termo na conexÃo nÃo dependente da mÃtrica. Estudaremos os efeitos de tais termos sobre a suavizaÃÃo de um conifold comparando com o caso sem torÃÃo AlÃm disso buscamos estudar o efeito que um outro termo topolÃgico tem sobre a resoluÃÃo de branas o termo BF Tal termo surgiu como uma extensÃo do termo de Chern-Simons para quatro dimensÃes tendo como funÃÃo gerar massa topologicamente para campos de calibre Nesse trabalho iremos modificar a aÃÃo da teoria heterÃtica de modo a obtermos o termo BF como um dos termos de anomalia e logo responsÃvel pelo fluxo que retira a singularidade Encontramos para um ansatz bastante conhecido uma configuraÃÃo onde o fluxo gerado pelo termo BF à o responsÃvel pela desingularizaÃÃo do espaÃo / We will study a technique for smoothing a naked singularity in a conifold called Brane Resolution On the one hand the singularity appears as a brane solution of supergravity containing only terms of sector Neveu-Schwarz On the other hand we can see the singularity of the conifold as coming from a fixed point of the discrete symmetry group responsible for generating the conifold The conifold is of most importance in the process of compactification in string theories in particular in so-called conical transitions In fact there are different kinds Calabi-Yau varieties that can be built Despite such spaces have distint topological characteristics it can become a space on the other transitions through conical transitions This is done through the generation of singularities in Calabi-Yau that surprisingly does not generate quantum problems. The technique consists of adding a topological term sector Ramond-Ramond action to the inclusion of a Chern-Simons term responsible for interaction between the fields of the Ramond-Ramond sector (Cn), generates a flow field and H3 = DB2 F3 = DC2 on the singularity of the conifold. From the equation of motion of the field and an appropriate choice for the configuration of the metric and fields find the warp factors that are responsible for the removal of the singularity method can also be understood topologically as the incision of a sphere in the vicinity of the place node of the cone The behavior of fields on the conifold is done in order to extend the correspondence AdS-CFT correspondence was originally proposed for the space AdS5 à S 5 but soon emerged as extensions using other varieties M4 à C6 Near the natural perity space can be written as AdS5 5 à X 5 where X is the base of the conifold space usually takes up the space base as a homogeneous space of Ricci-flat Einstein where X = 5 SU (3) / SU (2) à SU (2). However, to maintain conformal invariance of the theory of dual fields is necessary to soften the conifold through incisions of the Eguchi-Hanson type that can be of two types: a 3-sphere S 3 is called deformation or by a 2-sphere S 2 is called resolution Recently it has been proposed resolutions conifold in a scenario of heterotic theory endowed with torsion Such an effect is relevant in theories where the black hole type solutions exist in the internal variety as the branes and spinning black branes latter takes into account the black hole's angular momentum - spin - and it is a solution of Kerr From the transgression of the Bianchi identity for the 3-form field strength of the Kalb-Ramond term derived from a Gauss-Bonnet and instanton can introduce a twist and hence a new term not dependent on the connection meter. We will study the effects of such terms on conifold a smoothing compared with the case without torsion Furthermore we study the effect that another term has topological branes on the resolution of the term BF This term originated as an extension of the Chern-Simons term to four dimensions with topologically generate mass function as gauge fields for this work, we modify the action of the heterotic theory in order to obtain the term BF as one of the terms fault and then responsible for the flow that removes the singularity found for an ansatz well known a configuration where the flow generated by the BF term is responsible for resolution

Devido ao alto número de propagandas que um consumidor é exposto em um único dia, torna-se fundamental que as empresas produzam anúncios que atinjam de forma efetiva seu público-alvo. Um anúncio precisa chamar a atenção de uma pessoa e, ainda, impactar em suas atitudes. Ressalta-se que fatores como gênero e nível de envolvimento do consumidor são variáveis que impactam na atenção dedicada a um anúncio e nas ações posteriores a este. Ainda, a forma como o anúncio é elaborado, ou seja, o tipo de anúncio, pode interferir nas reações dos consumidores. Este estudo teve por objetivo identificar como diferentes tipos de anúncio, sejam estes direcionados ao público masculino, feminino ou neutros impactam na atenção visual e nas atitudes em relação a estes anúncios e, também, como o gênero e o nível de envolvimento influenciam nessa relação. Através de um pré-teste, foram selecionadas seis imagens para compor o estudo. Através de um experimento, os participantes foram divididos em três grupos e submetidos a visualização de um dos tipos de anúncio escolhido. A coleta de dados foi dada por meio do eye-tracking e de questionários e os dados foram analisados por meio da análise fatorial, testes de hipótese e complementados com estatística descritiva. Foi identificado que o tipo de anúncio impacta na atenção visual e nas atitudes em relação ao anúncio. Em relação às variáveis moderadoras do estudo, foi visto que o gênero impacta apenas nas respostas dos anúncios considerados masculinos e que, de forma mais evidente, o nível de envolvimento impacta nas respostas dos anúncios, principalmente nas atitudes em relação ao anúncio / Due to the high number of advertisements that a consumer is exposed in a single day, it is critical that companies produce ads that effectively reach their target audience. An ad needs to catch a person\'s attention and still impact their attitudes. It should be noted that factors such as gender and level of consumer involvement are variables that impact on the attention devoted to an ad and on the actions subsequent to it. Yet, the way the ad is designed, that is, the type of ad, can interfere with consumer reactions. The purpose of this study was to identify how different types of advertisements, whether directed at the male, female or neutral public, impact on visual attention and attitudes towards these ads, and how gender and level of involvement influence this relationship. Through a pre-test, six images were selected to compose the study. Then, through an experiment, the participants were divided into three groups and submitted to the visualization of one of the chosen ad types. Data were collected through eye-tracking and questionnaires and the data were analyzed through factorial analysis, hypothesis tests and complemented with descriptive statistics. It has been identified that the type of ad impacts on visual attention and attitudes toward the ad. Regarding the moderating variables of the study, it was seen that the gender impacts only on the responses of the ads considered masculine and that, more clearly, the level of involvement impacts on the responses of the ads, mainly in the attitudes towards the advertisement

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Quasinormal modes of plane-symmetric anti-de Sitter (AdS) black holes in d spacetime dimensions are investigated. Following the gauge invariant prescription developed by Kodama, Ishibashi and Seto (2000), fundamental equations for gravitational perturbation in such a background are constructed. Within such a prescription, metric perturbations naturally split into three disjoint classes. Namely, tensor, vector and scalar perturbations. However, different gauge invariant quantities are chosen in the present work, because they are more suited to the particular boundary conditions usually imposed to find quasinormal modes in AdS spacetimes than those used by Kodama, Ishibashi and Seto. In particular, the quantities used here present also the so called hydrodynamic modes, i. e., shear modes for vector perturbations and sound wave modes for the scalar ones, what is not found using the former quantities. It is also shown that there is just one shear mode, which does not depend upon the number of spacetime dimensions (d). Moreover, it is also found a general expression for the sound wave modes in terms of the number of the parameter d for scalar perturbations, and that there is no such a hydrodynamic mode for the tensor sector. Horowitz-Hubeny power series method is used in numerical analysis to find the dispersion relations for the first few quasinormal modes, and also for the hydrodynamic modes. This analysis is performed for five and six spacetime dimensions in the case of tensor perturbations, and for four, five and six dimensions in the cases of vector and scalar perturbations. The dispersion relations of regular modes present the same general behavior for all kinds of perturbations, Re(w) → q and Im(w) → 0 in the limit q → ∞, where w and q are the normalized frequency and the normalized wave number, respectively. / Investiga-se os modos quase-normais gravitacionais de buracos negros plano-simétricos anti-de Sitter em d dimensões, cuja geometria das seções espaciais é plana e cuja topologia pode ser plana, cilíndrica ou toroidal. Deduz-se equações fundamentais de perturbação gravitacional para este background, seguindo o formalismo invariante de gauge desenvolvido por Kodama, Ishibashi e Seto (2000), segundo o qual as perturbações métricas são naturalmente separadas em três setores ortogonais: tensorial, vetorial e escalar. Entretanto, são escolhidas diferentes quantidades invariantes de gauge tais que sob condições de contorno apropriadas fornecem os modos quase-normais hidrodinâmicos do buraco negro em questão. Particularmente, no limite hidrodinâmico, os modos de cisalhamento nas perturbações gravitacionais vetoriais e modos de onda sonora nas perturbações escalares são encontrados explicitamente. Mostra-se que o modo de cisalhamento é único e independe do número de dimensões, apresenta-se uma expressão para o modo de onda sonora válida para qualquer dimensão e verifica-se que as perturbações gravitacionais tensoriais não apresentam modos hidrodinâmicos. Utiliza-se o método de Horowitz-Hubeny para calcular numericamente os primeiros modos quase-normais comuns para cada setor de perturbação e apresentam-se as respectivas relações de dispersão Re(w) × q e Im(w)×q, onde w são as freqüências quase-normais e q é o número de onda normalizados. Também obtêm-se numericamente os modos hidrodinâmicos e suas relações de dispersão. Os modos quase-normais das perturbações tensoriais são calculados para buracos negros plano-simétricos anti-de Sitter em cinco e seis dimensões, e os modos quase-normais das perturbações vetoriais e escalares são calculados para buracos negros em quatro, cinco e seis dimensões. Observa-se que as relações de dispersão apresentam um comportamento geral onde Re(w) → q e Im(w) → 0 conforme q → ∞ independentemente do tipo de perturbação, número de dimensões e do modo quase-normal analisado.

Cette thèse s'inscrit dans le domaine de l’étude des lois de commandes de vol pour hélicoptères. Les automaticiens doivent régler les gains de ces lois de manière à respecter au mieux les exigences de Qualités de Pilotage extraites de la norme ADS-33. La norme traduit ces exigences en termes de critères de Qualités de Vol. Ils évaluent la qualité de la stabilité, de l'agilité, et du suivi des consignes du pilote par la machine. Ils traduisent la pilotabilité de l'hélicoptère pour un pilote « moyen » de référence. A part une technique d’optimisation interactive développée à la NASA et l'US Army depuis 40 ans, il n’existe pas de méthode appropriée à ce problème. Les réglages sont effectués de manière empirique et itérative. L’ONERA propose une approche méthodologique structurée. L’objectif de la thèse consiste à développer cette méthodologie de manière à gérer deux contraintes supplémentaires par rapport aux capacités des méthodes de synthèse classiques en automatique : la capacité à prendre en compte la structure contrainte des lois de commande et les exigences spécifiques en terme de Qualités de Vol selon la norme ADS-33.Une technique d'amélioration des Qualités de Vol par analyse de sensibilités entre les gains et les critères est développée. Puis une méthodologie d’initialisation des gains est proposée, via la création et l’utilisation efficace de nouveaux abaques de Qualités de Vol pour modèles équivalents simplifiés. Afin d'améliorer l'efficacité de ce réglage initial, deux contraintes supplémentaires sont prises en compte (énergie et découplage). Enfin, un processus complet de réglage est proposé : initialisation, ajustement linéaire et ajustement non linéaire. / This study is in the field of designing helicopter control laws. Designers must tune the gains of these laws in order to meet as much as possible Handling Qualities requirements from ADS-33. This standard translates these requirements in terms of Flying Qualities requirements. Then, we can evaluate the quality of the stability, of the quickness, and of the ability of the machine to follow the inputs from the pilot. Apart from an interactive optimization technique developed at NASA and US Army over the last 40 years, no appropriate method exists to solve this problem. Then, empirical iterative tunings are led. ONERA addresses this issue through a structured methodological approach. The aim of the thesis is to develop this methodology, taking into account two additional constraints compared with the capabilities of usual synthesis methods used in automatics: the capability to deal with the constraints from the control law structures and with the Handling Qualities requirements from the ADS-33 standards. A technique is developed to improve the Flying Qualities using sensitivity studies between gains and criteria. Then, a methodology to initialize the gains is developed, through the creation and the efficient usage of new Flying Qualities-based charts for equivalent simplified models. In order to improve the efficiency of the initial tuning, two additional constraints are taken into account (uncoupling and energy). Thus, a complete full procedure of tuning is proposed: initialization, linear adjustment and non linear adjustment.

La correspondance AdS/CFT est la première réalisation précise de la dualité jauge/gravité. Jusqu’à maintenant la correspondance AdS/CFT reste une conjecture. La dualité de N = 4 SYM et la théorie des cordes est un exemple le plus notable de correspondance AdS/CFT. Un des obstacles principaux à l’explorer est le fait que le régime de couplage faible pour la théorie de jauge est le régime de couplage fort pour la théorie des cordes et vice versa. Par conséquent, aussi longtemps que les méthodes perturbatives sont appliquées, on ne peut pas comparer les observables de deux cotés de la correspondance directement en dehors de quelques cas particuliers. A ce stade, l’énorme symétrie de N = 4 SYM joue un rôle important en permettant le calcul exact des observables de la théorie au moins dans la limite planaire. Cette thèse est consacrée au calcul des fonctions à trois, l’un des principaux observables de N = 4 SYM, et est composée de deux parties. Dans la première partie nous considérons l’approche générale pour le calcul des fonctions à trois points sur la base de soi-disant vertex de spin, qui est inspiré de la théorie de champs des cordes. Dans la deuxième partie, nous considérons un type spécifique de fonctions à trois points appelés lourd-lourd-léger, qui sont caractérisés par la propriété que la longueur de l’un des opérateurs est beaucoup plus petite des longueurs de deux autres. Il s’avère que ces fonctions de corrélations peuvent être identifiées à des facteurs de forme diagonaux et ainsi on peut appliquer les résultats concernant les facteurs de forme. / N=4 SYM theory has been drawing the attention of a lot of physicists during two last decades mainly due to the two aspects: AdS/CFT correspondence and integrability. AdS/CFT correspondence is the first precise realization of the gauge/string duality whose history starts in the 60's, when a string theory was considered as a candidate for describing the strong interactions. In 1997 Maldacena made a proposal about the duality between certain conformal field theories (CFT) and string theories defined on the product of AdS space and some compact manifold, which implies a one to one map between the observables of the gauge and string counterparts. Up to now AdS/CFT correspondence still remains a conjecture. The duality of N=4 SYM and the appropriate string counterpart is the most notable example of the AdS/CFT correspondence. One of the main obstructions to exploring it is the fact that weak coupling regime for the gauge theory is the strong coupling regime for the string theory and vice versa. Therefore as long as perturbative methods are applied, one can not compare the observables of dual counterparts directly apart from some specific cases. At this point the huge symmetry of N=4 SYM plays an important role allowing exact computation of the theory observables at least in the planar limit. This property of the theory is called integrability. The observables of the N=4 SYM are Wilson loops and correlation functions built out of gauge invariant operators. The space-time dependence of the two- and three-point correlators is fixed by the conformal symmetry up to some parameters: dimensions of the operators in the case of two-point functions and dimensions of the operators and structure constants in the case of three-point functions. It's commonly accepted to refer to the problem of finding the dimensions of the operators as the spectral problem. On the classical level the operator dimension is equal to the sum of the dimensions of the fundamental fields out of which the operator is composed. When the interaction is turned on, the conformal dimension gets quantum correction. In order to compute three-point functions, apart from the conformal dimensions of corresponding operators one needs to compute the structure constants. In CFT computation of the higher-point correlators eventually can be reduced to computation of two- and three-point functions by means of the operator product expansion. Therefore two- and three-point functions appear to be building blocks of any correlator of the theory. This thesis is devoted to computation of three-point functions and consists of two parts. In the first part we consider the general approach for computing three-point functions based on the so-called spin vertex, which is inspired from the string field theory. In the second part we consider a specific kind of three-point functions called heavy-heavy-light, which are characterized by the property that the length of one of the operators is much smaller the lengthes of other two. It happens that this kind of correlators can be considered as diagonal form factors which supposes that in this case one can apply the results obtained in the form factor theory.

Diploma thesis deals with the ADS-B system and its possible use at the Airport Václav Havel in Prague. In the beginning of this thesis there is described the history leading to the introduction of this system and then the ADS-B is explained. In this thesis is also included a schedule for the introduction of the system. Them the application is presented to the airport with integrity verification, functionality, reliability and safety.

This article investigates the effectiveness of bathroom print ads. Using liquor as the product domain, field study data (n = 146) indicate a high level of ad (60%) and product category (80%) recall. Contrary to the literature and the researchers' hypothesis, respondents had a significantly higher level of recall for copy dominant than for visual dominant ads. Hypotheses suggesting that color advertisements would outperform non-color advertisements and interactions between ages and visual-based versus copy-based stimuli and gender and visual-based versus copy-based stimuliwere not supported by the data. The implications for practitioners of the effectiveness of copy rich ads and suggested directions for future research are discussed.