Informal social networks have been established as instruments to combat poverty in slums, supplying the ineffectiveness of the State to provide basic assets necessary for the survival of its population. Under this logic, the Urbe research group developed, in “Conjunto Vitória” - Maceió-AL, a methodology for identifying social-spatial networks in order to legitimize them in the face of public housing policies. Inserted in this context, this dissertation aims to characterize the exchange relations that occur in socio-spatial networks that support the permanency in self-managed slums, it is a qualitative and descriptive research, with an exploratory character, in which was used the Case Study. As a criterion of choice of the empirical object of this study, was sought, among the total households surveyed by Urbe, one who possessed the most nominations and presented greater representation for the “Conjunto Vitória”. The Domicile 52D was presented in a position of centrality in the set and its sociability’s network was used for application of semi-structured interviews in order to get answers on the main questions of the research: the history of that occupation and the different levels of social interaction and exchanges relations that occur there. It is known that trust, equality shortages, lack of resources and residence’s proximity are important requirements for interactions in disadvantaged environments, in this way, the construction of habitus helps to understand the reasons why individuals helps each other in every day’s life. Thus, for the analysis and data’s interpretation, types of values described by Baudrillard were used to categorize, seeking to identify expressions in the interviewed person’s speeches that characterizes them. As a result, it was observed that the sociability’s network, of the Domicile studied, that relations of its participants can be governed by three types of values investigated by this research: Exchange Value, Symbolic Exchange and Sign Value. / Fundação de Amparo a Pesquisa do Estado de Alagoas / As redes de sociabilidade informais têm se constituído como instrumentos de combate à pobreza em assentamentos precários, suprindo a ineficácia do Estado em conceder ativos básicos necessários para a sobrevivência de sua população. Sob esta lógica, o grupo de pesquisa Urbe desenvolveu, no Conjunto Vitória em Maceió-AL, uma metodologia para identificação de redes socieoespaciais a fim de legitimá-las frente às políticas públicas de habitação. Inserida nesse contexto, esta dissertação objetiva caracterizar as relações de troca que ocorrem em redes socioespaciais de apoio à permanência em assentamentos precários autogestionados, trata-se de uma pesquisa qualitativa e descritiva, de caráter exploratório, na qual foi utilizado o procedimento de Estudo de Caso. Como critério de escolha do objeto empírico deste trabalho, buscou-se, dentre a rede total de domicílios estudados pelo Urbe, aquele que possuísse o maior número de indicações e apresentasse maior representatividade para o Conjunto Vitória. O Domicílo 52D foi apresentado em condição de centralidade no conjunto e sua rede de sociabilidade foi utilizada para aplicação de entrevistas semiestruturadas, a fim de obter respostas sobre as principais questões da pesquisa: o histórico daquela ocupação e os diferentes níveis de interação social e relações de trocas que ali ocorrem. Sabe-se que a confiança, a igualdade de carências, a falta de recursos e a proximidade de residência são requisitos importantes para as interações em ambientes precários, neste sentido, a construção de habitus ajuda a entender as razões pelas quais indivíduos se ajudam na vida cotidiana. Desta forma, para a análise e interpretação dos dados, foi utilizado como critérios de categorização das relações de troca os tipos de valores descritos por Baudrillard, buscando identificar expressões nas falas dos entrevistados que os caracterizassem. Como resultado, observou-se que na rede de sociabilidade, do domicílio estudado, as relações de seus participantes podem ser regidas pelos três tipos de valores investigados por esta pesquisa: valor de troca, troca simbólica e valor de signo.

Kollektive biologische Systeme sammeln Informationen und leiten diese intern weiter, um Umweltveränderungen zu detektieren und auf sie zu reagieren. In Tiergruppen können die probabilistischen Entscheidungen von Individuen durch diese kollektive Informationsverarbeitung verbessert werden. Die dem sozialen Austausch zu Grunde liegenden Sinneswahrnehmungen finden jedoch in gängigen Modellen kollektiven Verhaltens kaum Beachtung. Hier untersuche ich, wie der individuelle Zugang zu sozialen Informationen durch visuelle Wahrnehmung und räumliche Gruppenstruktur geformt wird. Zuerst untersuche ich Fluchtwellen in Fischschwärmen in zwei als unterschiedlich riskant wahrgenommenen Kontexten mithilfe empirisch ermittelter visueller Interaktionsnetzwerke. Die beobachtete strukturelle Änderung der Gruppen zwischen den Kontexten erweist sich als essenziell, um die Änderung der Fluchtwellengröße zu erklären und optimiert potenziell die kollektive Informationsverarbeitung im jeweiligen Kontext. Von optimaler Informationsverarbeitung wird in biologischen Systemen oft angenommen, dass sie an Phasenübergängen in deren kollektiver Dynamik stattfindet, sogenannten kritischen Punkten. Die beobachtete strukturelle Änderung ändert den Abstand des Schwarmverhaltens zu einem solchen kritischen Punkt. Jedoch bleiben die Gruppen subkritisch in beiden Kontexten, vermutlich aus Notwendigkeit, tatsächliche Warnungen zu verstärken und falsche zu unterdrücken. Im zweiten Teil vergleiche ich visuelle Netzwerke mit anderen räumlichen Netzwerken bezüglich ihrer Struktur und dem Verhalten von Ausbreitungsprozessen auf ihnen. Einzig visuelle Netzwerke zeigen bei mittleren Gruppendichten Optima in zentralen Netzwerkeigenschaften und behalten realistische Eigenschaften bei hohen und niedrigen Dichten. Abschließend entwickle ich eine analytische Näherung zentraler Netzwerkeigenschaften solcher visuellen Netzwerke. / Collective biological systems gather information and propagate it internally to detect and react to environmental changes. In animal groups the probabilistic decisions of individuals can be improved by this collective information processing. Animals rely on sensory cues for social communication, yet common models of collective behavior neglect this sensory basis of interactions. Here, I investigate how an individual’s access to social information is shaped by visual sensory limitations and spatial group structure. First, escape waves in fish schools are studied under two levels of perceived environmental risk using empirically inferred visual interaction networks. Group-structural change is found to be crucial to explain the observed differences in size of escape waves and potentially optimize collective information processing according to the state of the environment. Optimal information processing in biological systems is often hypothesized to occur at phase transitions in their collective dynamics, so-called critical points. Here, the observed change in group structure modifies the schools’ distance to a critical point. Yet groups stay subcritical in both experimental setups, which may manage a trade-off between sensitivity to true alarms and robustness to false ones. In a second part, visual networks are compared to other spatial networks in structure and behavior of spreading processes on them. Visual networks show a unique dependence on group density with optima in network structural measures at intermediate densities, making them more realistic than other networks at high and low densities. Finally, an analytical approximation of central properties of visual networks is developed. Overall, this thesis identifies group structure as a potential control mechanism of collective information processing, highlights the trade-off associated with criticality in noisy systems and provides a systematic study and analytic approximation of visual sensory networks.

La problématique de ce doctorat est : comment la structure des réseaux constitue une nouvelle matrice pour la production d’oeuvres artistiques. Pour répondre à cette question, nous commencerons en étudiant l’évolution de la notion de « réseau » de l’antiquité jusqu’à aujourd’hui ; les théories des réseaux concernant leur structure et/ou leur dynamique. Ensuite nous présenterons les applications –de la notion ou des théories de réseaux– tant dans les sciences que dans l’art. Nous listerons et nous analyserons huit types de réseaux et puis nous mentionnerons des oeuvres artistiques qui ont été inspirées par ces types de réseaux et/ou qui utilisent certains (types de) réseaux comme matrice pour leur création. Nous proposerons le projet Lignes Imaginaires, un modèle 3D qui se fonde sur la conception d’un métro de lignes imaginaires, voire de lignes dynamiques et/ou paradoxales qui sont en mouvement, apparaissent/disparaissent, créent de l’infrastructure supplémentaire. L’analyse du métro Lignes Imaginaires dévoile l'importance de la géographie et de la spatialité des réseaux, tandis que leur représentation graphique topologique reste insuffisante pour la représentation précise et pour la compréhension de leur structure (paradoxale). En outre, l’innovation du métro Lignes Imaginaires est que son infrastructure est dynamique et auto-organisée, contrairement aux métros traditionnels où les lignes et leurs itinéraires sont fixes. L’objectif du projet artistique Lignes Imaginaires est de visualiser un concept en créant un métro hors du commun qui pourrait aussi proposer des formes alternatives des réseaux de transports dans le contexte urbain. / This thesis examines and shows ways in which the structure of networks can provide a new matrix for the production of artworks. In order to answer this question we start by studying: the evolution of the term ‘network’ from the ancient times up to nowadays; the theories that refer to network structure or network dynamics. Then we present the applications of these theories into both art and science. We list and analyze eight different types of networks and then we feature artworks which have been inspired by these network types or have used the network structure of a certain type as a matrix for art making. We propose the Imaginary Lines project, a three-dimensional network model which is based on the concept of a metro composed of imaginary lines. More precisely Imaginary Lines metro network encompasses seven paradoxical lines which move, (dis)appear and produce supplementary infrastructure. The Imaginary Lines metro unveils the importance of geography and spatiality, in contrast with topological network graphic representations, which remain insufficient, in terms of utmost accuracy in representation and comprehension of network structure. Additionally, the Imaginary Lines network innovation lays in its infrastructure dynamics as well as in its self-organisation. The objective of the Imaginary Lines artistic project is to visualise a concept by creating an unusual metro, which goes beyond traditional fixed-route transport networks and can support alternative forms of urban transport development.

Informal social networks have been established as instruments to combat poverty in slums, supplying the ineffectiveness of the State to provide basic assets necessary for the survival of its population. Under this logic, the Urbe research group developed, in “Conjunto Vitória” - Maceió-AL, a methodology for identifying social-spatial networks in order to legitimize them in the face of public housing policies. Inserted in this context, this dissertation aims to characterize the exchange relations that occur in socio-spatial networks that support the permanency in self-managed slums, it is a qualitative and descriptive research, with an exploratory character, in which was used the Case Study. As a criterion of choice of the empirical object of this study, was sought, among the total households surveyed by Urbe, one who possessed the most nominations and presented greater representation for the “Conjunto Vitória”. The Domicile 52D was presented in a position of centrality in the set and its sociability’s network was used for application of semi-structured interviews in order to get answers on the main questions of the research: the history of that occupation and the different levels of social interaction and exchanges relations that occur there. It is known that trust, equality shortages, lack of resources and residence’s proximity are important requirements for interactions in disadvantaged environments, in this way, the construction of habitus helps to understand the reasons why individuals helps each other in every day’s life. Thus, for the analysis and data’s interpretation, types of values described by Baudrillard were used to categorize, seeking to identify expressions in the interviewed person’s speeches that characterizes them. As a result, it was observed that the sociability’s network, of the Domicile studied, that relations of its participants can be governed by three types of values investigated by this research: Exchange Value, Symbolic Exchange and Sign Value. / Fundação de Amparo a Pesquisa do Estado de Alagoas / As redes de sociabilidade informais têm se constituído como instrumentos de combate à pobreza em assentamentos precários, suprindo a ineficácia do Estado em conceder ativos básicos necessários para a sobrevivência de sua população. Sob esta lógica, o grupo de pesquisa Urbe desenvolveu, no Conjunto Vitória em Maceió-AL, uma metodologia para identificação de redes socieoespaciais a fim de legitimá-las frente às políticas públicas de habitação. Inserida nesse contexto, esta dissertação objetiva caracterizar as relações de troca que ocorrem em redes socioespaciais de apoio à permanência em assentamentos precários autogestionados, trata-se de uma pesquisa qualitativa e descritiva, de caráter exploratório, na qual foi utilizado o procedimento de Estudo de Caso. Como critério de escolha do objeto empírico deste trabalho, buscou-se, dentre a rede total de domicílios estudados pelo Urbe, aquele que possuísse o maior número de indicações e apresentasse maior representatividade para o Conjunto Vitória. O Domicílo 52D foi apresentado em condição de centralidade no conjunto e sua rede de sociabilidade foi utilizada para aplicação de entrevistas semiestruturadas, a fim de obter respostas sobre as principais questões da pesquisa: o histórico daquela ocupação e os diferentes níveis de interação social e relações de trocas que ali ocorrem. Sabe-se que a confiança, a igualdade de carências, a falta de recursos e a proximidade de residência são requisitos importantes para as interações em ambientes precários, neste sentido, a construção de habitus ajuda a entender as razões pelas quais indivíduos se ajudam na vida cotidiana. Desta forma, para a análise e interpretação dos dados, foi utilizado como critérios de categorização das relações de troca os tipos de valores descritos por Baudrillard, buscando identificar expressões nas falas dos entrevistados que os caracterizassem. Como resultado, observou-se que na rede de sociabilidade, do domicílio estudado, as relações de seus participantes podem ser regidas pelos três tipos de valores investigados por esta pesquisa: valor de troca, troca simbólica e valor de signo.

Cette thèse déchiffre les défis rencontrés par les petits producteurs dans l'approvisionnement alimentaire urbain dans les Andes du Nord en Équateur, avec une étude de la structure et du fonctionnement du système d'approvisionnement urbain en produits laitiers à l'échelle nationale. Les stratégies de production et de commercialisation des petits producteurs sont observées au niveau local à travers deux exemples: Machachi et Nono. Le système d'approvisionnement est analysé comme un réseau spatial où les zones de production, les points de vente et de consommation sont interconnectés, ceci générant des dynamiques dialectiques de transformation mutuelle il travers les interactions des différents acteurs. Historiquement, le système s'est structuré en fonction des besoins et des caractéristiques des producteurs de moyenne et grande taille. Cependant, au cours des dernières décennies, les petits producteurs sont devenus des acteurs essentiels grâce à des stratégies entre les villes et la campagne. L'incorporation des petits producteurs dans cette dynamique montre leur grande capacité d'adaptation face aux opportunités générées par un marché en pleine croissance. Malgré tout, leur interaction avec les autres acteurs dénote une inégalité dans les relations de pouvoir qui reste encore peu modifiée. D'autres modalités d'intégration des petits producteurs restent à construire. / This thesis focuses on the small producers challenges in the food supply to cities in the Northern Andes in Ecuador. It analyses the structure and functioning of the complex of dairy product supply to cities at national level. Production and commercialisation strategies adopted by small producers' are studied at local level with two examples: Machachi and Nono. The supply complex is analysed as a spatial network where the areas of production and points of sale and consumption arc interconnected generating dialectical dynamics of mutual transformation through the interaction of all the different stakeholders. Historically the complex has been structured according to the needs and characteristics of the medium and large-sized producers. In the last decades though, small producers have been using different strategies between the countryside and cities und have become key stakeholders. The incorporation of small producers in this dynamic shows their great ability to adapt to opportunities created by a growing market. However, their interactions with the other stakeholders show inequality in the power relations, which has only marginally been addressed. Different modes of integration for small producers are yet to be created. / Esta tesis se interesa por los desafíos de los pequeños productores en el abastecimiento alimentario urbano a través del caso de los Andes norte en Ecuador. Se estudia la estructura y el funcionamiento del complejo de aprovisionamiento urbano de productos lácteos en una escala nacional. Las estrategias productivas y de comercialización de los pequeños productores son observados en una escala local a través de dos ejemplos: Machachi y Nono. El complejo de abastecimiento es analizado como una red espacial, donde las áreas de producción, los puntos de comercialización y de consumo están interelacionados generando dinámicas dialécticas de transformación mutua a través de las interacciones de los diversos actores.Históricamente el complejo ha sido estructurado acorde a las necesidades y características de los productores medianos y grandes. En las últimas décadas, los pequeños productores empleando diversas estrategias productivas y comerciales entre campos y ciudades se han convertido en actores fundamentales.La inclusión de los pequeños productores en esta dinámica muestra su gran capacidad de adaptación frente a las oportunidades generadas por un mercado en crecimiento. A pesar de esto, sus interacciones con a otros actores muestran las inequidades en las relaciones de poder que no han podido ser sino débilmente modificadas. Diferentes modalidades de integración de los pequeños productores lácteos quedan por construirse.

Le but de cette thèse est de développer des outils statistiques permettant d'initialiser et de calibrer les modèles de microsimulation dynamique stochastique, en partant de l’exemple du modèle SimVillages (développé dans le cadre du projet Européen PRIMA). Ce modèle couple des dynamiques démographiques et économiques appliquées à une population de municipalités rurales. Chaque individu de la population, représenté explicitement dans un ménage au sein d’une commune, travaille éventuellement dans une autre, et possède sa propre trajectoire de vie. Ainsi, le modèle inclut-il des dynamiques de choix de vie, d’étude, de carrière, d’union, de naissance, de divorce, de migration et de décès. Nous avons développé, implémenté et testé les modèles et méthodes suivants : 1 / un modèle permettant de générer une population synthétique à partir de données agrégées, où chaque individu est membre d’un ménage, vit dans une commune et possède un statut au regard de l’emploi. Cette population synthétique est l’état initial du modèle. 2 / un modèle permettant de simuler une table d’origine-destination des déplacements domicile-travail à partir de données agrégées. 3 / un modèle permettant d’estimer le nombre d’emplois dans les services de proximité dans une commune donnée en fonction de son nombre d’habitants et de son voisinage en termes de service. 4 / une méthode de calibration des paramètres inconnus du modèle SimVillages de manière à satisfaire un ensemble de critères d'erreurs définis sur des sources de données hétérogènes. Cette méthode est fondée sur un nouvel algorithme d’échantillonnage séquentiel de type Approximate Bayesian Computation. / The purpose of this thesis is to develop statistical tools to initialize and to calibrate dynamic stochastic microsimulation models, starting from their application to the SimVillages model (developed within the European PRIMA project). This model includes demographic and economic dynamics applied to the population of a set of rural municipalities. Each individual, represented explicitly in a household living in a municipality, possibly working in another, has its own life trajectory. Thus, model includes rules for the choice of study, career, marriage, birth children, divorce, migration, and death. We developed, implemented and tested the following models : • a model to generate a synthetic population from aggregate data, where each individual lives in a household in a municipality and has a status with regard to employment. The synthetic population is the initial state of the model. • a model to simulate a table of origin-destination commuting from aggregate data in order to assign a place of work for each individual working outside his municipality of residence. • a sub-model to estimate the number of jobs in local services in a given municipality in terms of its number of inhabitants and its neighbors in terms of service. • a method to calibrate the unknown SimVillages model parameters in order to satisfy a set of criteria. This method is based on a new Approximate Bayesian Computation algorithm using importance sampling. When applied to a toy example and to the SimVillages model, our algorithm is 2 to 8 times faster than the three main sequential ABC algorithms currently available.