The visual system integrates information over space to see surfaces, contours and edges. This integration can be described by a divisive normalization framework in which surrounding contextual information normalizes response to a central target. We ran a set of studies examining perceptual illusions with the intention of better understanding the neural mechanisms responsible for how the visual system integrates information over space. We measured surround integration using the Simultaneous Tilt Illusion. In the first study, we determined the extent to which the probability that different surround regions were co-assigned to the same object as the center impacts how much they are integrated. We found that the magnitude of the illusion was a sum of regional surround effects weighted by their dependency to the center. These results are consistent with a system that uses prior experience with natural scene statistics to integrate regions of space. In the second study, we measured the relationship between individual differences in spatial integration and autistic traits. We found no evidence for reduced normalization in people who score high on autistic traits. In the third study, we determined the extent to which arousal modulates spatial integration. Although we did not observe an effect of natural fluctuations in arousal, as indexed by pupil diameter, we observed a reduction in the magnitude of the illusion following an alerting tone. While more work is still needed to verify this effect, it suggests that we context information less under moderately alert states. We interpret these results in the context of the neural and perceptual mechanisms underlying spatial integration. Specifically, these results seem to indicate that the normalization process is gated by our expectancies about the structure of a scene and by our internal brain state. These results are consistent with a system that uses prior experience with scene statistics to represent patterns more efficiently.

Este trabalho tem por objetivo analisar o potencial de desenvolvimento do contrato futuro de soja no Brasil, por meio da atração de hedgers brasileiros e argentinos. Para tanto, faz-se necessário conhecer os padrões das conexões dos preços entre as regiões analisadas. Nesse sentido, o Capítulo 2 investigou a integração espacial do mercado físico de soja no Brasil (região de Sorriso, no Mato Grosso) e na Argentina (região de Rosário, na província de Santa Fé) e comparou ao grau de integração com os Estados Unidos. Foram empregados modelos autorregressivos com threshold (TAR e M-TAR) e modelos vetoriais de correção de erros, lineares e com threshold (VECM e TVECM), visando captar os efeitos dos custos de transação sobre a integração espacial entre essas regiões. Os resultados apontaram que o mercado de soja brasileiro, argentino e norte-americano são integrados, mesmo considerando-se os efeitos dos custos de transação sobre as decisões de arbitragem espacial. Consequentemente, os preços da soja no mercado internacional tendem a refletir o comportamento dos principais países produtores. Apesar disso, o tempo de transmissão de choques de preços mostrou-se, em geral, menor entre Brasil e Argentina, refletindo a proximidade geográfica. Apontou-se também o comportamento assimétrico da transmissão desses choques, uma vez que choques positivos sobre a relação de longo prazo tendem a ser mais persistentes que os negativos. Se o contrato futuro reflete o comportamento de preços de um único mercado físico integrado, deve-se então esperar que o risco de base seja menor para este mercado e, portanto, que a eficiência do hedge seja maior. No Capítulo 3, o objetivo se constituiu em verificar se há maior eficiência no hedge realizado com os contratos com vencimento em março na CME em relação à BM&FBOVESPA, considerando-se as relações de longo prazo entre os preços à vista e futuros, bem como a dinâmica na estrutura de covariâncias condicionais, por meio de modelos de correção de erros (VECM) e modelos de heterocedasticidade condicional generalizados com correlação condicional dinâmica (DCC-GARCH). Os resultados mostraram que, em geral, a introdução da dinâmica nos segundos momentos das distribuições dos erros tende a aumentar a eficiência da estratégia de hedge. Além disso, foi observado que os produtores de Sorriso tendem a obter melhores condições de hedge na CME, embora haja redução da variância ao se operar na BM&FBOVESPA. Por outro lado, a eficiência do hedge para os produtores de Rosário foi significativamente maior na BM&FBOVESPA do que na CME, o que indica o mercado potencial de hedgers argentinos para negociar o contrato futuro de soja local no Brasil. / This work aims to analyze the potential for development of soybean futures contract in Brazil, through the attraction of Brazil and Argentina hedgers. Therefore, it is necessary to know the patterns of price connections between these regions. Chapter 2 investigated the spatial integration of the spot market for soybeans in Brazil (Sorriso in Mato Grosso State) and Argentina (Rosario in Santa Fe Province) and compared the degree of integration with the United States. They were employed autoregressive models with threshold (TAR and M-TAR) and vector error correction models, linear and threshold (VECM and TVECM), to capture the effects of transaction costs on the spatial integration of these regions. The results indicate that the soybeans market in Brazil, Argentina and United States are integrated, even considering the effects of transaction costs on the spatial arbitration decisions. Consequently, soybean prices in the international market tend to reflect the behavior of the main producing countries. Nevertheless, the timing of the price shocks transmission proved to be generally lower between Argentina and Brazil, reflecting the geographical proximity. It was pointed out also the asymmetric behavior of the shocks transmissions, since positive shocks on the long-term relationships tend to be more persistent than the negatives. If the futures contract reflects the behavior of prices from a single integrated physical market, one should then expect lower basis risk and therefore greater hedge efficiency. In Chapter 3, the goal was check for greater hedging efficiency using March contracts in CME compared to BM&FBOVESPA, considering the long-term relationships between spot prices and futures, as well as the dynamics in the structure of conditional covariance, using error correction model (ECM) and models of conditional heteroscedasticity widespread with dynamic conditional correlation (DCC-GARCH). The results showed that, in general, the introduction of the dynamic second moments of distributions of errors tends to increase the hedging efficiency. Moreover, Sorriso producers tend to get better hedge conditions in CME, although there is variance reduction when operating at BM&FBOVESPA. On the other hand, the hedge efficiency for Rosario producers was significantly higher on the BM&FBOVESPA than in CME, which indicates the potential market of Argentine hedgers to trade the futures contract local soybeans in Brazil.

Este trabalho tem por objetivo analisar o potencial de desenvolvimento do contrato futuro de soja no Brasil, por meio da atração de hedgers brasileiros e argentinos. Para tanto, faz-se necessário conhecer os padrões das conexões dos preços entre as regiões analisadas. Nesse sentido, o Capítulo 2 investigou a integração espacial do mercado físico de soja no Brasil (região de Sorriso, no Mato Grosso) e na Argentina (região de Rosário, na província de Santa Fé) e comparou ao grau de integração com os Estados Unidos. Foram empregados modelos autorregressivos com threshold (TAR e M-TAR) e modelos vetoriais de correção de erros, lineares e com threshold (VECM e TVECM), visando captar os efeitos dos custos de transação sobre a integração espacial entre essas regiões. Os resultados apontaram que o mercado de soja brasileiro, argentino e norte-americano são integrados, mesmo considerando-se os efeitos dos custos de transação sobre as decisões de arbitragem espacial. Consequentemente, os preços da soja no mercado internacional tendem a refletir o comportamento dos principais países produtores. Apesar disso, o tempo de transmissão de choques de preços mostrou-se, em geral, menor entre Brasil e Argentina, refletindo a proximidade geográfica. Apontou-se também o comportamento assimétrico da transmissão desses choques, uma vez que choques positivos sobre a relação de longo prazo tendem a ser mais persistentes que os negativos. Se o contrato futuro reflete o comportamento de preços de um único mercado físico integrado, deve-se então esperar que o risco de base seja menor para este mercado e, portanto, que a eficiência do hedge seja maior. No Capítulo 3, o objetivo se constituiu em verificar se há maior eficiência no hedge realizado com os contratos com vencimento em março na CME em relação à BM&FBOVESPA, considerando-se as relações de longo prazo entre os preços à vista e futuros, bem como a dinâmica na estrutura de covariâncias condicionais, por meio de modelos de correção de erros (VECM) e modelos de heterocedasticidade condicional generalizados com correlação condicional dinâmica (DCC-GARCH). Os resultados mostraram que, em geral, a introdução da dinâmica nos segundos momentos das distribuições dos erros tende a aumentar a eficiência da estratégia de hedge. Além disso, foi observado que os produtores de Sorriso tendem a obter melhores condições de hedge na CME, embora haja redução da variância ao se operar na BM&FBOVESPA. Por outro lado, a eficiência do hedge para os produtores de Rosário foi significativamente maior na BM&FBOVESPA do que na CME, o que indica o mercado potencial de hedgers argentinos para negociar o contrato futuro de soja local no Brasil. / This work aims to analyze the potential for development of soybean futures contract in Brazil, through the attraction of Brazil and Argentina hedgers. Therefore, it is necessary to know the patterns of price connections between these regions. Chapter 2 investigated the spatial integration of the spot market for soybeans in Brazil (Sorriso in Mato Grosso State) and Argentina (Rosario in Santa Fe Province) and compared the degree of integration with the United States. They were employed autoregressive models with threshold (TAR and M-TAR) and vector error correction models, linear and threshold (VECM and TVECM), to capture the effects of transaction costs on the spatial integration of these regions. The results indicate that the soybeans market in Brazil, Argentina and United States are integrated, even considering the effects of transaction costs on the spatial arbitration decisions. Consequently, soybean prices in the international market tend to reflect the behavior of the main producing countries. Nevertheless, the timing of the price shocks transmission proved to be generally lower between Argentina and Brazil, reflecting the geographical proximity. It was pointed out also the asymmetric behavior of the shocks transmissions, since positive shocks on the long-term relationships tend to be more persistent than the negatives. If the futures contract reflects the behavior of prices from a single integrated physical market, one should then expect lower basis risk and therefore greater hedge efficiency. In Chapter 3, the goal was check for greater hedging efficiency using March contracts in CME compared to BM&FBOVESPA, considering the long-term relationships between spot prices and futures, as well as the dynamics in the structure of conditional covariance, using error correction model (ECM) and models of conditional heteroscedasticity widespread with dynamic conditional correlation (DCC-GARCH). The results showed that, in general, the introduction of the dynamic second moments of distributions of errors tends to increase the hedging efficiency. Moreover, Sorriso producers tend to get better hedge conditions in CME, although there is variance reduction when operating at BM&FBOVESPA. On the other hand, the hedge efficiency for Rosario producers was significantly higher on the BM&FBOVESPA than in CME, which indicates the potential market of Argentine hedgers to trade the futures contract local soybeans in Brazil.

The ability to recall a spatial layout from multiple orientations – spatial flexibility – is a challenging cognitive process, especially when the global configuration cannot be viewed from a single vantage point, as spatial information must first be integrated before it can be flexibly recalled. The current study examined if experiencing the transition between multiple viewpoints enhances spatial flexibility for both non-integrated (Exp. 1) and integrated environments (Exp. 2), if the type of transition matters, and if action provides an additional advantage over passive visual flow. In Experiment 1, participants viewed an array of dollhouse furniture from four viewpoints that presented the global configuration from multiple orientations. In Experiment 2, the array was viewed piecemeal, from four viewpoints that presented the global configuration in partial chunks. The control condition presented the dollhouse as a series of static views, whereas in the remaining conditions, visual flow was continuous. Participants viewed the natural transition between viewpoints, and either passively experienced the transitions (i.e., by watching the dollhouse rotate or being rolled around it), or actively generated them (i.e., by rotating the dollhouse or walking around it). Across both experiments, continuous visual flow significantly enhanced spatial flexibility when paired with observer movement around the dollhouse, either active or passive. Furthermore, when participants had to integrate spatial information across discrete learning experiences (Exp. 2), active movement provided a significant advantage above passive experience. These findings suggest that array stability is key to flexible spatial memory, with action providing an additional boost to spatial integration. / Psychology

L’étude des Tamouls à Colombo, Kuala Lumpur et Singapour montre l’intérêt d’adopter une perspective comparative et multiscalaire pour saisir dans toute leur complexité les différents facteurs agissant sur l’identification et l’intégration socio-spatiale d’un groupe minoritaire transnational. Ces Tamouls évoluent dans des contextes politiques nationaux très différents. À Sri Lanka, ils se retrouvent au cœur d’un conflit intercommunautaire. À Singapour, ils sont reconnus officiellement comme l’une des composantes de la société multiculturelle alors qu’en Malaise, l’État privilégie les Malais. L’analyse des politiques menées par la puissance coloniale, puis par les trois États indépendants à l’égard des minorités, permet de mieux comprendre leurs impacts sur le sentiment d’identification et d’intégration des Tamouls à la Nation, ainsi que sur leur répartition dans ces villes. À l’échelle locale, l’inscription spatiale de leur identité et les pratiques citadines des Tamouls favorisent une appropriation de leur environnement urbain. Toutefois, cette dernière n’est pas immuable. Les politiques urbaines développées par les États, qui selon les cas préservent ou détruisent les ethnoterritoires, ont des conséquences sur l’empreinte urbaine tamoule et leur pratique de la ville. Cette réalité n’est pas sans conséquences sur la façon dont les Tamouls perçoivent leur appartenance à la Nation. Enfin, les liens transnationaux (culturels, politiques, économiques) entre Tamouls et les dynamiques migratoires internationales contemporaines des Tamouls dans ces trois pays ont également des conséquences sur l’identification et l’intégration de ceux de Colombo, Kuala Lumpur et Singapour. / The study of Tamils in Colombo, Kuala Lumpur and Singapore shows the importance of adopting a multi-scale and comparative perspective in order to fully grasp an understanding of the complexity of the various factors affecting the identification and socio-spatial integration of a transnational minority group. These Tamils evolve in very different national political contexts. In Sri Lanka, they are at the heart of inter-communal conflicts. In Singapore, they are officially recognized as a component of a multicultural society, whilst in Malaysia the government officially favors Malays. The analysis of the policies enforced by the colonial power, followed by the three independent states toward minorities provides a better understanding of their impacts on the sense of identity and integration of Tamils in the Nation, as well as their geographical distribution in these cities. At the local level, the spatial inscription of tamil identity and their urban practices favor an appropriation of their urban environment. However, it is not immutable. Urban policies developed by states, which according to the cases preserve or destroy ethnoterritories, have an impact on the Tamil urban footprint and their practical of the city. This reality is not without consequence on how Tamils perceive their attachement to the nation. Finally, transnational ties (cultural, political, economical) between Tamils and contemporary dynamics of international migration of Tamils in these three countries also have consequences on the identification and integration of those from Colombo, Kuala Lumpur and Singapore.

Este proyecto consiste en el diseño de un Mercado Gastronómico en el distrito del Rímac, enfocado a una población que busca difundir, promover y aprender acerca de la gastronomía peruana. El proyecto tiene como objetivo principal, proponer nuevos espacios donde se pueda satisfacer la demanda actual que está generando la gastronomía y así en este proyecto se puedan desarrollar las distintas actividades que actualmente no tienen un espacio permanente donde se puedan realizar. Además, este será un espacio articulador entre el espacio interior y el espacio exterior, y así lograr una integración con su entorno urbano. Por otro lado, es importante también el entorno urbano en donde se ubica el proyecto, ya que este tiene como concepto principal que todas sus funciones se organicen mediante un espacio central de encuentro y circulación de donde se distribuyan a las demás zonas del proyecto. / This Project consist in the design of a Gastronomic Market in the district of Rímac, focused on a population that seeks to spread, promote and learn about peruvian gastronomy. The main objetive of the Project is to propose new spaces where the current demand generated by gastronomy can be satisfy, and so in this project the different activities that currently do not have a permanent space where they can be carried out can be developed. In addition, this will be an articulating space between the interior space and the exterior space, and thus achieve an integration with its urban enviroment. On the other hand, it is also important the urban enviroment where the project is located, since it has as main concept that all its functions are organized through a central metting and circulation space from where they are distributed to the other areas of the proyect. / Tesis

L'objectif principal de la thèse est d'établir un modèle sous forme hamiltonienne à ports pour la dynamique du plasma dans les réacteurs de fusion de type tokamak, puis de démontrer le potentiel de cette approche pour aborder les problèmes d'intégration numérique et de commande non linéaire. Les bilans thermo-magnéto-hydrodynamiques, écrits sous forme hamiltonienne à ports à l'aide de structures Stokes-Dirac, conduisent à un modèle 3D “ multi-physique ” du plasma. Ensuite, un modèle 1D équivalent au modèle de diffusion résistive est obtenu en supposant les mêmes hypothèses d'équilibre quasi-statique et de symétries. Un schéma symplectique de réduction spatiale de ce modèle 1D qui préserve la structure du modèle et ses invariants est établi. Il ouvre la voie à des travaux ultérieurs de commande non linéaire fondés sur la structure géométrique d'interconnexion et les bilans du modèle. La commande IDA-PBC (Interconnection and Damping Assignment - Passivity Based Control) basée sur la passivité du modèle est d'abord synthétisée pour ce système en dimension finie. Finalement, une commande IDA-PBC associée avec la commande à la frontière est proposée pour le système en dimension infinie. Les controlleurs sont testés et validés avec les simulateurs des tokamak (METIS pour le Tore Supra de CEA/ Cadarache, et RAPTOR pour le TCV de l'EPFL Lausanne, Suisse). / The modelling and analysis of the plasma dynamics in tokamaks using the port-Hamiltonian approach is the main project purpose. Thermo-mMagnetohydrodynamics balances have been written in port-Hamiltonian form using Stokes-Dirac interconnection structures and 3D differential forms. A simplified 1D model for control has been derived using quasi-static and symmetry assumptions. It has been proved to be equivalent to a classical 1D control model: the resistive diffusion model for the poloidal magnetic flux. Then a geometric spatial integration scheme has been developped. It preserves both the symplecticity of the Dirac interconnection structure and physically conserved extensive quantities. This will allow coming works on energy-based approaches for the non linear control of the plasma dynamics.An Interconnection and Damping Assignment - Passivity Based Control (IDA-PBC) , the most general Port-Hamiltonian control, is chosen first to deal with the studied Tokamak system. It is based on a model made of the two coupled PDEs of resistive diffusion for the magnetic poloidal flux and of radial thermal diffusion. The used TMHD couplings are the Lorentz forces (with non-uniform resistivity) and the bootstrap current. The loop voltage at the plasma boundary, the total external current and the plasma heating power are considered as controller outputs. Due to the actuator constraints which imply to have a physically feasible current profile deposits, a feedforward control is used to ensure the compatibility with the actuator physical capability. Then, the IDA-PBC controllers, both finite-dimensional and infinite-dimensional, are designed to improve the system stabilization and convergence speed. The proposed works are validated against the simulation data obtained from the Tore-Supra WEST (CEA/Cadarache, France) test case and from RAPTOR code for the TCV real-time control system (CRPP/ EPFL, Lausanne, Switzerland).

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