Dissertations / Theses: 'Analyse de centralité'

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Adam, Sylvie. "La trame urbaine : Hexagone et analyse théorique des semis urbains." Rouen, 1992. http://www.theses.fr/1992ROUEL153.

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L'objet essentiel de cette recherche est d'appréhender la valeur heuristique du modèle hexagonal régulier émanant des théories des lieux centraux. Le lien entre le modèle hexagonal régulier, les principes d'organisation et les concepts des théories des lieux centraux est d'abord examiné. Une attention particulière est donnée à la théorie de la centralité et aux autres travaux de Walter Christaller, ainsi qu'à la théorie des régions économiques d’August Losch. Une vue d'ensemble des théories des lieux centraux plus récentes et des applications du modèle hexagonal sur des trames urbaines régionales est fournie. Le modèle hexagonal sur des trames urbaines régionales est fournie. (seuls les nœuds et les arêtes sont significatifs), soit comme un pavage (la forme et le contenu sont significatifs). La seconde partie traite du maillage hexagonal. Sur l'exemple de la France, il apparait que le modèle géométrique régulier ne s'adapte pas à la structure et à l'organisation de la trame urbaine. La troisième partie, fondée sur les recherches effectuées par Georges Nicolas sur la Suisse occidentale, atteste la même inadéquation pour le pavage hexagonal. Il est donc proposé de substituer une grille polygonale et adaptable à la traditionnelle mosaïque hexagonale régulière
The main aim of this research is to look into the heuristic value of the regular hexagonal patterns as these appear in central place theories. The link between regular hexagonal patterns, principles of organization, and concepts of central place theories is first examined. Particular attention is given to the theory of centrality and other works by Walter Christaller, and to the theory of economic regions proposed by August Losch. An overview of more recent theories of central places and applications of hexagonal patterns on urban webs in regional settings is provided. The regular hexagonal pattern can be conceived either as a mesh (only nodes and edges are significant), or as a grid which actually contains people and functions. The second part deals with the regular hexagonal tesselation. Using the example of France, the regular geometric pattern is shown not to fit the structure and organization of the urban web. The third part, based upon Georges Nicolas research on Western Switzerland, confirms the same lack of fit for the regular hexagonal grid. For this reason, an adaptable polygonal grid is proposed as a substitute for the traditional and regular hexagonal tesselations. (abstract by Peter R. Gould and Sylvie Adam)

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Erraamouche, Amina. "Comprendre la stabilité politique du régime monarchique au Maroc. La centralité de l'expression discursive royale." Doctoral thesis, Universite Libre de Bruxelles, 2018. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/271370.

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C’est pour essayer de répondre, au moins partiellement, à la question qui nous a interpellée pendant les soulèvements arabes de 2011 lorsque le système socio-politique de très nombreux pays arabes a été submergé par la contestation sociale, à l’exception du Maroc où seules desmobilisations timides conduites par le M20F se sont produites, que nous avons élaboré ce travail de recherche doctorale. Les manifestations marocaines qui démarrèrent à partir du mois de février se sont néanmoins taries pour s’arrêter progressivement lors du mois d’octobre 2011. Durant cette période, l’institution royale vécut des moments pénibles, prête à toutes les stratégies aussi bien sur le plan national qu’international, pour faire perdurer son régime.La version officielle prétend que la stabilité du système monarchique marocain revient au fait que le Palais a enclenché des réformes profondes et durables (démocratie/développement), depuis l’accession de Mohammed VI au pouvoir en 1999.Si l’on admet que cette version soit vraie, comment peut-on dès lors expliquer que le Maroc ne cesse de dégringoler dans le classement mondial opéré par l’ONU sur le plan du développement humain, relégué d’après le PNUD (Rapport sur le développement humain de 2016) au 123ème rang, derrière la plupart des pays des soulèvements arabes (Tunisie :97e rang et Égypte :111e rang) ?Cela nous autorise à penser que le tandem démocratie/développement en termes de politiques menées est loin d’avoir été les pierres angulaires de cette stabilité. Notre recherche tentera dès lors d’examiner quelles sont les causes les plus profondes de la stabilité du régime monarchique marocain.
Doctorat en Sciences politiques et sociales
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Chikhi, Nacim Fateh. "Calcul de centralité et identification de structures de communautés dans les graphes de documents." Phd thesis, Université Paul Sabatier - Toulouse III, 2010. http://tel.archives-ouvertes.fr/tel-00619177.

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Dans cette thèse, nous nous intéressons à la caractérisation de grandes collections de documents (en utilisant les liens entre ces derniers) afin de faciliter leur utilisation et leur exploitation par des humains ou par des outils informatiques. Dans un premier temps, nous avons abordé la problématique du calcul de centralité dans les graphes de documents. Nous avons décrit les principaux algorithmes de calcul de centralité existants en mettant l'accent sur le problème TKC (Tightly Knit Community) dont souffre la plupart des mesures de centralité récentes. Ensuite, nous avons proposé trois nouveaux algorithmes de calcul de centralité (MHITS, NHITS et DocRank) permettant d'affronter le phénomène TKC. Les différents algorithmes proposés ont été évalués et comparés aux approches existantes. Des critères d'évaluation ont notamment été proposés pour mesurer l'effet TKC. Dans un deuxième temps, nous nous sommes intéressés au problème de la classification non supervisée de documents. Plus précisément, nous avons envisagé ce regroupement comme une tâche d'identification de structures de communautés (ISC) dans les graphes de documents. Nous avons décrit les principales approches d'ISC existantes en distinguant les approches basées sur un modèle génératif des approches algorithmiques ou classiques. Puis, nous avons proposé un modèle génératif (SPCE) basé sur le lissage et sur une initialisation appropriée pour l'ISC dans des graphes de faible densité. Le modèle SPCE a été évalué et validé en le comparant à d'autres approches d'ISC. Enfin, nous avons montré que le modèle SPCE pouvait être étendu pour prendre en compte simultanément les liens et les contenus des documents.

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Wang, Xi. "Étude du développement structurel de réseau métropolitain de Paris, et les enseignements du cas parisien pour le développement métropolitain de la ville de Wuhan (Chine)." Thesis, Paris 8, 2016. http://www.theses.fr/2016PA080083/document.

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A l’ère de l’urbanisation rapide dans les pays en développement, notre monde est aujourd’hui confronte a de nombreux défis en termes de réchauffement climatique. Pour y remédier, certains pays émergents ont commence ces dernières années a privilégier la mise en place croissante et progressive de transport en commun. C’est ainsi qu’en chine, en 2012, 1755 km de ligne de métro est construit pour seize villes. Or, la construction d’un métro possède d’importants risques financiers selon les expériences internationales. Néanmoins, le développement du métro en chine est en surchauffe. Le but global de la recherche est d’étudier les caractéristiques structurelles du réseau métropolitain a paris et son évolution afin de donner des suggestions au développement du métro de Wuhan. Pour atteindre cet objectif, nous avons adopte l’analyse de centralité structuralité pour étudier le réseau de métro parisien, ainsi que le réseau de métro a Wuhan. L’indicateur centralité structuralité (centralité en résume) consiste ainsi a mettre en évidence la distance « la plus simple » a parcourir pour arriver a sa destination, c’est-a-dire la distance a parcourir avec le moins de tournant a réaliser dans le réseau routier pour y arriver. Pour les réseaux de métro, cela signifie moins de changements de lignes. Des résultats nous monte que l’analyse de centralité pourrait indiquer l’importance relative des stations de métro dans un réseau. Cela pourrait permettre aux urbanistes et designers d’estimer le trafic entrant des stations. Eventuellement, cet indicateur pourrait d’être adopte pour analyser et comparer des projets différents du réseau de métro
In the era of fast urbanisation in the developing countries, our world is now facing many challenges in the context of global warming. In order to solve these difficulties, certain developing countries have started in the last few years to promote increasingly the role of public transportation. It is also the case in china in 2020 that 1755 km of metro line was built in seventeen cities. However, according to the international experiences, there can be great financials risks in construction of metro system. Even though, the metro development in china is overheating. The general research objective is to study the structural characteristic of metro network in Paris and its development in order to give suggestions for the metro development in Wuhan. In order to attain this objective, we have adopted the structural centrality analyse to study the metro network in Paris and Wuhan. The indicator structural centrality (centrality in short) evaluates the simplest distance to reach the destination. It means that with the less turning to do in a road network. For the metro network, it means the less changes of lines. The results showed us that the centrality analyses could indicate the relative importance of the metro stations in a network. It could allow the urban planners and designers to estimate the entering traffic of the stations. Eventually, this indicator could be used to analyse and compare the different plans of metro networks

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Guambe, Egidio. "Réformer l'administration pour renégocier la centralité de l'Etat : une analyse à partir du cas des municipalités de Beira, Mueda et Quissico (Mozambique)." Thesis, Bordeaux, 2016. http://www.theses.fr/2016BORD0347/document.

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Ces dernières années les États du Sud aussi bien que du Nord, se sont engagés dans une succession de réformes des administrations qui semblent suivre les mêmes modèles. La plupart des lectures de ces réformes, dans le contexte des pays du Sud, notamment africains, ne cessent d’invoquer leur caractère imposé, auquel les soumettent les bailleurs de fonds. Sans une vraie analyse au niveau local et sans une étude approfondie, ces réformes sont, grosso modo, présentées comme des échecs successifs. Cette thèse se veut donc une contribution à une lecture critique de ces réformes, de leur mise en oeuvre et des pratiques résultant de leur apprentissage, comme modes d’exercice de pouvoir.À partir d’une restitution empirique de la mise en oeuvre des réformes de décentralisation,notamment à travers le fonctionnement des municipalités, pour la ville de Beira et les bourgs de Mueda et Quissico au Mozambique, la thèse montre que l’apprentissage d’une réforme est influencé par les trajectoires spécifiques des rapports entre État et Sociétés, dans les espaces de mise en oeuvre.En combinant diverses approches de sociologie historique pour l’étude de l’administration à travers ces réformes successives, de sociologie de construction de l’État et de sociologie de l’action publique, ce travail défend la thèse que la réforme de l’administration, notamment décentralisatrice, en permettant une modification des modes d’articulation entre administration et citoyens, participe au redéploiement de l’État. En effet, les observations empiriques du fonctionnement quotidien des municipalités permettent de les voir comme de nouvelles arènes de diffusion et d’apprentissage entre État et administrés. C’est un processus qui doit forcément être resitué à l’intersection des enjeux spécifiques des lieux de mise en oeuvre et des cadres sous-jacents des réformes
Over the last few years, States in the South and in the North have engaged in a series of government reforms that appear to have been created out of the same model. Most studies of these reforms insist on the idea that these reforms were imposed by donors, particularly in the context of developing countries, and especially for Africa. However, these analyses do not take into account local specificities and they therefore tend to present the reforms as successive failures. This thesis contributes to a critical reading of these reforms, their implementation and the practices resulting from their execution, demonstrating that they are means for exercising power. Indeed, starting from an empirical restitution of the implementation of decentralization reforms, notably through the proceedings of the municipalities for the city of Beira and the boroughs of Muedaand Quissico in Mozambique, the thesis shows that the learning curve of integrating reforms is influenced by the specific trajectory of the relationship between the State and society in the areas ofimplementation. By combining various approaches to historical sociology to the study of administration through these successive reforms, coupled with theories of sociology of state building and public action, this thesis argues that allowing changes in the relation between government and citizens through administrative reforms, especially decentralization, contributes to and participates in the redeploymentof the state.In fact, empirically observing the daily functioning of municipalities undergoing reformsenables to look at them as new arenas for propagation and learning in the linkage between States and their citizens. This process must necessarily be resituated into the intersection of the specific issues facing the locations of implementation and the underlying frameworks of reforms

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Morini, Matteo. "Tools for Understanding the Dynamics of Social Networks." Thesis, Lyon, 2017. http://www.theses.fr/2017LYSEN075/document.

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Cette thèse fournit au lecteur un recueil d'applications de la théorie des graphes ; à ce but, des outils sur mesure, adaptés aux applications considérées, ont été conçus et mis en œuvre de manière inspirée par les données.Dans la première partie, une nouvelle métrique de centralité, nommée “bridgeness”, est présentée, basée sur une décomposition de la centralité intermédiaire (“betweenness centrality”) standard. Une composante, la “connectivité locale”, correspondante approximativement au degré d'un noeud, est différenciée de l'autre, qui, en revanche, évalue les propriétés structurelles à longue distance. En effet, cette dernière fournit une mesure de l'efficacité de chaque noeud à “relayer” parties faiblement connectées d'un réseau ; une caractéristique importante de cette métrique est son agnosticisme en ce qui concerne la structure de la communauté sous jacente éventuelle.Une deuxième application vise à décrire les caractéristiques dynamiques des graphes temporels qui apparaissent au niveau mésoscopique. L'ensemble de données de choix comprend 40 ans de publications scientifiques sélectionnées. L'apparition et l'évolution dans le temps d'un domaine d'étude spécifique (les ondelettes) sont capturées, en discriminant les caractéristiques persistantes des artefacts transitoires résultants du processus de détection des communautés, intrinsèquement bruité, effectué indépendamment sur des instantanées statiques successives. La notion de “flux laminaire”, sur laquelle repose le “score de complexité” que nous cherchons à optimiser, est présentée.Dans le même ordre d'idées, un réseau d'investisseurs japonais a été construit, sur la base d'un ensemble de données qui comprend des informations (indirectes) sur les filiales étrangères en copropriété. Une question très débattue dans le domaine de l'économie industrielle, l'hypothèse de Miwa-Ramseyer, a été démontrée de manière concluante comme fausse, du moins sous sa forme forte
This thesis provides the reader with a compendium of applications of network theory; tailor-madetools suited for the purpose have been devised and implemented in a data-driven fashion. In the first part, a novel centrality metric, aptly named “bridgeness”, is presented, based on adecomposition of the standard betweenness centrality. One component, local connectivity, roughlycorresponding to the degree of a node, is set apart from the other, which evaluates longer-rangestructural properties. Indeed, the latter provides a measure of the relevance of each node in“bridging” weakly connected parts of a network; a prominent feature of the metric is its agnosticism with regard to the eventual ground truth community structure.A second application is aimed at describing dynamic features of temporal graphs which are apparent at the mesoscopic level. The dataset of choice includes 40 years of selected scientific publications.The appearance and evolution in time of a specific field of study (“wavelets”) is captured,discriminating persistent features from transient artifacts, which result from the intrinsically noisy community detection process, independently performed on successive static snapshots. The concept of “laminar stream”, on which the “complexity score” we seek to optimize is based, is introduced.In a similar vein, a network of Japanese investors has been constructed, based on a dataset which includes (indirect) information on co-owned overseas subsidiaries. A hotly debated issue in the field of industrial economics, the Miwa-Ramseyer hypothesis, has been conclusively shown to be false, at least in its strong form

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Cassé, Clement. "Prévision des performances des services Web en environnement Cloud." Electronic Thesis or Diss., Toulouse 3, 2023. http://www.theses.fr/2023TOU30268.

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Le Cloud Computing a bouleversé la façon dont sont développés et déployées les logiciels. De nos jours, les applications Cloud sont conçues comme des systèmes distribués, en constante évolution, hébergés dans des data~center gérés par des tiers, et potentiellement même dispersés dans le monde entier. Ce changement de paradigme a également eu un impact considérable sur la façon dont les logiciels sont monitorés : les applications cloud se sont développées pour atteindre l'ordre de centaines de services, et les outils de monitoring ont rapidement rencontré des problèmes de mise à l'échelle. De plus, ces outils de monitoring doivent désormais également traiter les défaillances et les pannes inhérentes aux systèmes distribués, comme par exemple, les pannes partielles, les configurations incohérentes, les goulots d'étranglement ou même la vampirisation de ressources. Dans cette thèse, nous présentons une approche basée sur une nouvelle source de télémétrie qui s'est développée dans le domaine du monitoring des applications Cloud. En effet, en nous appuyant sur le récent standard OpenTelemetry, nous présentons un système qui convertit les données de "traces distribuées" en un graphe de propriétés hiérarchique. Grâce un tel modèle, il devient possible de mettre en évidence la topologie des applications, y compris la répartition sur les différentes machines des programmes, y compris sur plusieurs data-centers. L'objectif de ce modèle est donc d'exposer le comportement des fournisseurs de service Cloud aux développeurs qui maintiennent et optimisent leur application. Ensuite, nous présentons l'utilisation de ce modèle pour résoudre certains des défis majeurs des systèmes distribués~: la détection des communications inefficaces entre les services et l'anticipation des goulots d'étranglement. Nous abordons ces deux problèmes avec une approche basée sur la théorie des graphes. La composition inefficace des services est détectée avec le calcul de l'indice de hiérarchie de flux. Une plateforme Proof-of-Concept représentant un cluster Kubernetes zonal pourvu d'une instrumentation OpenTelemetry est utilisée pour créer et détecter les compositions de services inefficaces. Dans une dernière partie, nous abordons la problématique de la détection des goulots d'étranglement dans un réseau de services au travers de l'analyse de centralité du graphe hiérarchique précédent. Ce travail s'appuie sur un programme de simulation qui a aussi été instrumenté avec OpenTelemetry afin d'émettre des données de traçage. Ces traces ont été converties en un graphe de propriétés hiérarchique et une étude sur les algorithmes de centralité a permis d'identifier les points d'étranglement. Les deux approches présentées dans cette thèse utilisent et exploitent l'état de l'art en matière de monitoring des applications Cloud. Elles proposent une nouvelle utilisation des données de "distributed tracing" pas uniquement pour l'investigation et le débogage, mais pour la détection et la réaction automatiques sur un système réel
Cloud Computing has changed how software is now developed and deployed. Nowadays, Cloud applications are designed as rapidly evolving distributed systems that are hosted in third-party data centre and potentially scattered around the globe. This shift of paradigms also had a considerable impact on how software is monitored: Cloud application have been growing to reach the scale of hundreds of services, and state-of-the-art monitoring quickly faced scaling issues. In addition, monitoring tools also now have to address distributed systems failures, like partial failures, configuration inconsistencies, networking bottlenecks or even noisy neighbours. In this thesis we present an approach based on a new source of telemetry that has been growing in the realm of Cloud application monitoring. Indeed, by leveraging the recent OpenTelemetry standard, we present a system that converts "distributed tracing" data in a hierarchical property graph. With such a model, it becomes possible to highlight the actual topology of Cloud applications like the physical distribution of its workloads in multiple data centres. The goal of this model is to exhibit the behaviour of Cloud Providers to the developers maintaining and optimizing their application. Then, we present how this model can be used to solve some prominent distributed systems challenges: the detection of inefficient communications and the anticipation of hot points in a network of services. We tackle both of these problems with a graph-theory approach. Inefficient composition of services is detected with the computation of the Flow Hierarchy index. A Proof of Concept is presented based on a real OpenTelemetry instrumentation of a Zonal Kubernetes Cluster. In, a last part we address the concern of hot point detection in a network of services through the perspective of graph centrality analysis. This work is supported by a simulation program that has been instrumented with OpenTelemetry in order to emit tracing data. These traces have been converted in a hierarchical property graph and a study on the centrality algorithms allowed to identify choke points. Both of the approaches presented in this thesis comply with state-of-the-art Cloud application monitoring. They propose a new usage of Distributed Tracing not only for investigation and debugging but for automatic detection and reaction on a full system

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Delage, Matthieu. "Mobilités pour achats et centralités métropolitaine : le cas de la métropole parisienne." Paris 1, 2012. https://tel.archives-ouvertes.fr/tel-00824626v2.

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Cette thèse envisage les mobilités pour achats comme des vecteurs et des révélateurs des logiques de structuration polycentrique de la métropole parisienne. La démarche prend appui sur une étude à plusieurs échelles spatiales et temporelles - des dynamiques métropolitaines en général aux trajectoires individuelles quotidiennes dans la métropole -, et combine les méthodes de l'analyse spatiale, avec l'exploration de deux bases de données, portant sur les commerces et sur les mobilités quotidiennes, avec un travail d'entretiens qualitatifs et de cartes mentales. Ces analyses mettent en évidence un polycentrisme morphologique et relationnel, donnant à voir une métropole-réseau, articulant une pluralité de centralités. Par ailleurs, cette double focale sur les mobilités pour achats et les logiques de structuration commerciale, enrichit les connaissances sur la métropole parisienne, qui se fondent généralement sur des approches essentiellement en termes d'emploi et de mobilités domicile-travail. Dans un second temps, les dynamiques métropolitaines sont interrogées par les pratiques des groupes et des individus mobiles. Ce changement de perspective met en évidence des trajectoires différenciées, renvoyant à plusieurs échelles de proximités. Ainsi qu'à des budgets-temps particulièrement contrastés, inscrits dans une logique d'inégalités, comme le révèle une analyse plus approfondie centrée sur le cas de la population étudiante. Entre ancrage et mise en réseau, les mobilités pour achats constituent ainsi un prisme particulièrement opératoire pour appréhender, analyser et différencier les dynamiques de la métropole parisienne, de l'échelle métropolitaine à l'échelle individuelle.

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Sanchez, Trenado Corentin. "« Faire ressource » en quartier populaire: Analyse des logiques d’interaction entre activités économiques et habitants des classes populaires." Doctoral thesis, Universite Libre de Bruxelles, 2021. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/326534.

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L’objet de cette thèse était de comprendre les multiples relations qui unissaient activités économiques (industrielles et commerciales) et habitants des quartiers populaires, envisagés l’un et l’autre au prisme de la notion de « ressource ». Fortement centrée autour du cas d’étude du site des Abattoirs et Marchés de Cureghem et de son quartier d’implantation, Cureghem, cette thèse avait en effet pour objectif principal d’identifier les éléments qui permettaient de « faire ressource » du point de vue des classes populaires bruxelloises ainsi que de celui des acteurs économiques du site des Abattoirs. Ce travail de thèse a ainsi permis de mettre en évidence différents types de ressources, à la fois matérielles et symboliques, bénéficiant, d’une part, aux habitants des classes populaires et, de l’autre, aux acteurs économiques du secteur de la viande. Parmi les premières, on peut notamment mentionner le rôle particulièrement important du marché des Abattoirs en tant que lieu pourvoyeur de produits abordables et adaptés culturellement, mais également d’opportunités d’emplois, en particulier pour des personnes primo-arrivantes. Ce marché constitue en outre un lieu de ressourcement et de sociabilité favorisant les rencontres et la circulation de l’information au sein des classes populaires. Concernant les secondes, outre les avantages résultant des logiques d’économie d’agglomération et de centralité, les activités du secteur de la viande bénéficient en particulier de la vitalité du secteur de la boucherie halal ainsi que des possibilités de vente au détail sur le marché des Abattoirs, qui constituent des alternatives au secteur de la boucherie non-halal, sur le déclin. Cette entrée par les ressources permet donc de changer de perspective sur les membres des classes populaires et ces acteurs économiques qui, s’ils se situent dans une position dominée économiquement et socialement, disposent malgré tout d’une certaine marge de manœuvre dans la production de leurs propres moyens de subsistance, de leurs propres facteurs de maintien et, par extension, de leurs propres espaces de centralité. Cependant, en l’absence d’une reconnaissance par les acteurs institutionnels des moyens de subsistance dont disposent les classes populaires, les politiques de rénovation urbaine et les dynamiques de gentrification qui touchent actuellement les quartiers populaires centraux, menacent de détruire les ressources constitutives de ces espaces populaires. Ceci pourrait donc remettre en question l’occupation populaire du quartier et déstabiliser l’équilibre fragile sur lequel repose la subsistance des classes populaires.
Option Géographie du Doctorat en Sciences
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Alatriste, Contreras Martha Gabriela. "Essais sur les propriétés structurelles et la dynamique du système économique." Paris, EHESS, 2014. http://www.theses.fr/2014EHES0132.

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Cette thèse analyse empiriquement les propriétés structurelles de l'économie et évalue l'impact des changements de sa structure sur les résultats agrèges. L’analyse se base sur une approche multidisciplinaire ou l'analyse des entrées-sorties est combinée avec l'analyse de systèmes complexes. Le premier chapitre étudie la structure des liaisons entre secteurs en identifian les secteurs les plus importantes. Nous comparons ces secteurs aux secteurs qui, simultanément génèrent les effets sur la production agrégée les plus élevés et qui ont la diffusion la plus grande sur l'économie. Nous avons trouvée des structures asymétriques ou il y a seulement quelques secteurs qui sont très importants. Le deuxième chapitre de la thèse évalue l'impact de deux types de chocs sectoriels : sur la demande finale et un choc technologique. L’objective est d'étudier l'émergence des avalanches. Nous appliquons trois modèles. Un premier modèle est base sur le modèle d'entrées-sorties, et les deux autres modèles sont basés sur un type de modèle de diffusion des réseaux. Les résultats montrent que la diffusion des chocs les avalanches sont grands grâce à la structure asymmetric du system. Le troisième chapitre propose un modèle dynamique de la structure de l'économie et de son évolution qui capture les différentes étapes du développement. Le modèle est inspire par les propriétés structurelles de l'économie française et les changements technologiques observées de 1959 à 2008. Les résultats les plus importants montrent que un mécanisme de type `preferential attachment' génère une structure qui est très proche de la structure réelle de l'économie français
This thesis analyses empirically the structural properties of the economy and evaluates the impact of changes in its structure on aggregate outcomes such as production and the spreading of shocks. The analysis in this thesis is part of a multidisciplinary approach where input-output is combined with complex network analysis to study the productive structure of an economy. We analyze the european union's input-output network as a whole, the input-output network of 22 member countries, and the french input-output network using a more disaggregated classification of sectors. The first chapter studies the structural properties of the economy identifying the most important sectors. In this first chapter, we investigate if global centrality measures in network analysis provide additional information of the productive structure and the role and importance of sectors in it. We found that the economy has an asymmetric structure with only a few very important sectors that have good diffusion properties. The second chapter evaluates the impact of these properties as the capability of sectors to spread shocks and form avalanches in the economy. We use three models to measure the impact of two types of sectoral shocks : a shock on final demand and a shock on technology. Results show that the asymmetrical structure of european economies makes them vulnerable to large avalanchess. Finally, third explores the mechanism generating the structure of the economy and its evolution through time driven by technological progress. In the model proposed in the third chapter sectors create new connections and change the intensity of old ones according to their centrality

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11

Lillieberg, Linnéa, and Tommy Rosén. "Inställning till arbete hos generation Y : En kvalitativ studie om arbetsvärderingar hos tio svenska individer födda mellan 1984 - 1994." Thesis, Högskolan i Jönköping, Högskolan för lärande och kommunikation, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:hj:diva-35479.

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Syftet med denna studie var att undersöka framträdande arbetsrelaterade värderingar hos generation Y. Urvalet bestod av tio yrkesverksamma respondenter födda mellan 1984 – 1994 utvalda via bekvämlighetsurval. En kvalitativ design tillämpades med semistrukturerade intervjuer. Insamlade data analyserades genom tematisk analys och författarna fann tre huvudteman som kan förklara värderingar hos generation Y: arbetets centralitet, sociala värderingar och kommunikation samt motivation. Framträdande arbetsvärderingar för respondenterna var balans i livet, utvecklingsmöjligheter och möjligheten att skräddarsy sitt arbete.
The purpose of this study was to investigate prominent work values of generation Y. Ten working respondents born between 1984 – 1994 participated by convenience sampling. A qualitative research design was used together with semi structured interviews. Collected data were analysed with thematic analysis and the authors found three main themes that could explain values within generation Y: work centrality, social values and communication and motivation. Prominent work values for respondents consisted of: work life balance, development opportunities, and the ability to customize their work.

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12

Bohn, Angela, Stefan Theußl, Ingo Feinerer, Kurt Hornik, Patrick Mair, and Norbert Walchhofer. "Combining Weighted Centrality and Network Clustering." Department of Statistics and Mathematics, WU Vienna University of Economics and Business, 2009. http://epub.wu.ac.at/1466/1/document.pdf.

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In Social Network Analysis (SNA) centrality measures focus on activity (degree), information access (betweenness), distance to all the nodes (closeness), or popularity (pagerank). We introduce a new measure quantifying the distance of nodes to the network center. It is called weighted distance to nearest center (WDNC) and it is based on edge-weighted closeness (EWC), a weighted version of closeness. It combines elements of weighted centrality as well as clustering. The WDNC will be tested on two e-mail networks of the R community, one of the most important open source programs for statistical computing and graphics. We will find that there is a relationship between the WDNC and the formal organization of the R community.
Series: Research Report Series / Department of Statistics and Mathematics

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13

García-García, Isabel, María Ángeles Jurado, Maite Garolera, Idoia Marqués-Iturria, Annette Horstmann, Bàrbara Segura, Roser Pueyo, et al. "Functional network centrality in obesity." Universitätsbibliothek Leipzig, 2016. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-205556.

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Obesity is associated with structural and functional alterations in brain areas that are often functionally distinct and anatomically distant. This suggests that obesity is associated with differences in functional connectivity of regions distributed across the brain. However, studies addressing whole brain functional connectivity in obesity remain scarce. Here, we compared voxel-wise degree centrality and eigenvector centrality between participants with obesity (n=20) and normal-weight controls (n=21). We analyzed resting state and task-related fMRI data acquired from the same individuals. Relative to normal-weight controls, participants with obesity exhibited reduced degree centrality in the right middle frontal gyrus in the resting-state condition. During the task fMRI condition, obese participants exhibited less degree centrality in the left middle frontal gyrus and the lateral occipital cortex along with reduced eigenvector centrality in the lateral occipital cortex and occipital pole. Our results highlight the central role of the middle frontal gyrus in the pathophysiology of obesity, a structure involved in several brain circuits signaling attention, executive functions and motor functions. Additionally, our analysis suggests the existence of task-dependent reduced centrality in occipital areas; regions with a role in perceptual processes and that are profoundly modulated by attention.

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Appelgren, Jörgen, and Fredrik Kjellström. "LCC-analys av FTX-system : En jämförelse av centralt- och lägenhetsplacerat." Thesis, Uppsala universitet, Institutionen för geovetenskaper, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-172562.

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This report is the result of a thesis conducted at the consulting firm Bjerking AB andis the final part of the Bachelor Programme in Construction Engineering at Universityof Uppsala. The work aims to investigate the costs and how the choice of ventilationsystem affects building projects during a long-term period. This report covers costssuch as investment, maintenance and energy but also how they affect residents andbuilders. Building regulations for energy consumption are expected to be tougher;therefore a comparison of two different heat recovery ventilation systems(HRV-system) was made. One system is based on a centrally placed unit that coversthe whole buildings ventilation through vertical shafts. The second system is based onapartment placed unit that only covers the individual apartment’s ventilation. The unitmakes it possible for the individual user to control the ventilation flow.The method used for comparison of the costs was Life Cycle Cost (LCC). It results inthe total cost during a selected calculation period of 20 years, where yearly basedcosts as energy and maintenance is included. Two housing projects in central Uppsalawere chosen as a reference. They were similar in design but with the two differentsystems of ventilation. A questionnaire was handed out to provide experience fromresidents with apartment units. The results were used in the analysis of the systemsand to determine its pros and cons.Information of costs was collected from different companies and resulted intocustomized spreadsheets to determine the cost per apartment. The result shows thatthe difference in investment is not significant between the systems but is big inmaintenance and energy. The biggest difference is maintenance where the apartmentsystems many service points is increasing the cost. Energy consumption for theapartment system leads to higher energy costs than with a central system, even if thecontrol function is used. The explanation is that a central systems fans have lowerpower usage and the heat recovery is more efficient then an apartment system.The conclusion is that a central system has a lower total cost compared to anapartment system during the calculation period. A reason for choosing the apartmentsystem would be if a need to maximize living space is a priority, and the developingphase of the project is well thought thru.Keywords: LCC-analysis, HRV-systems, Central unit, Apartment unit.

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Sinha, Ravi Som Mihalcea Rada F. "Graph-based centrality algorithms for unsupervised word sense disambiguation." [Denton, Tex.] : University of North Texas, 2008. http://digital.library.unt.edu/permalink/meta-dc-9736.

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16

Rifi, Mouna. "Modélisation et Analyse des Réseaux Complexes : application à la sûreté nucléaire." Thesis, Sorbonne Paris Cité, 2019. http://www.theses.fr/2019USPCD049.

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Ce travail propose une modélisation adéquate en graphes pour les systèmes et séquences accidentelles de sûreté nucléaire. Ces systèmes et séquences proviennent des "Etudes Probabilistes de Sûreté" (EPS) qui consistent à analyser de façon exhaustive tous les scénarios accidentels envisageables, d’estimer leurs probabilités d’occurrence (en les regroupant par famille) et les conséquences associées.Ensuite une analyse des réseaux complexes résultants est effectuée par des mesures de centralités.Une première application consiste à la prédiction du Facteur d’Accroissement du Risque nucléaire en utilisant les algorithmes d’apprentissages supervisé : méthodes à base d’arbre de classification, régression logistique et méthodes ensemblistes, sur des données déséquilibrées.Par ailleurs, un nouveau coefficient synthétique de centralité et une mesure de similarité sont conçus pour comparer les structures de réseaux, indépendamment de leurs caractéristiques topologiques, en se basant sur les interdépendances entre leurs vecteurs de centralités.Cette nouvelle approche utilise des techniques statistiques (échantillonnage, corrélation ethomogénéité).La pertinence et l’efficacité de cette nouvelle mesure de similarité sont validées sur le clustering de graphes théoriques classiques et la prédiction du type de graphes. Enfin, une application de cette approche est réalisée pour le clustering des réseaux complexes des systèmes de sûreté nucléaire
This work aims to propose an adequate graph modeling approach for nuclear safety accident systems and sequences.These systems and sequences come from "Probabilistic Safety Analysis" (PSA) which is an exhaustive analysis of all possible accident scenarios, to estimate their probabilities of occurrence (by grouping them by families) and the associated consequences.Then, an analysis of the resulting networks is performed by network centrality measures. A first application consists on predicting the nuclear Risk Increase Factor, which is a PSA importance factor, using supervised learning algorithms : classification tree methods, logistic regression and ensemble learning methods, on un balanced data. Furthermore, a new synthetic centrality coefficient and a similarity measure are developed to compare the networks structures and their topological characteristics, based on their centrality vectors interdependencies. This new approach uses statistical techniques (sampling,correlation and homogeneity).The relevance and appreciation of this new measure of similarity are validated on the clustering of most popular theoretical graphs and on the prediction of the type of these graphs. Finally, an application of this approach has been conducted for the clustering of nuclear safety systems networks

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Moretti, Nicolas. "Collaudo e analisi termografica di centraline elettroniche per sistemi automotive." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2012. http://amslaurea.unibo.it/4347/.

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Questa tesi affronta lo sviluppo di sistemi elettronici per il collaudo automatizzato di centraline elettroniche per sistemi automotive. Viene illustrato lo sviluppo di un simulatore per il collaudo basato su ambiente Labview. Inoltre, viene presentata un'analisi di fattibiltà del rilevamento di malfunzionamenti basata sull'elaborazione di immagini termografiche.

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Afrasiabi, Rad Amir. "Social Network Analysis and Time Varying Graphs." Thesis, Université d'Ottawa / University of Ottawa, 2016. http://hdl.handle.net/10393/34441.

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The thesis focuses on the social web and on the analysis of social networks with particular emphasis on their temporal aspects. Social networks are represented here by Time Varying Graphs (TVG), a general model for dynamic graphs borrowed from distributed computing. In the first part of the thesis we focus on the temporal aspects of social networks. We develop various temporal centrality measures for TVGs including betweenness, closeness, and eigenvector centralities, which are well known in the context of static graphs. Unfortunately the computational complexities of these temporal centrality metrics are not comparable with their static counterparts. For example, the computation of betweenness becomes intractable in the dynamic setting. For this reason, approximation techniques will also be considered. We apply these temporal measures to two very different datasets, one in the context of knowledge mobilization in a small community of university researchers, the other in the context of Facebook commenting activities among a large number of web users. In both settings, we perform a temporal analysis so to understand the importance of the temporal factors in the dynamics of those networks and to detect nodes that act as “accelerators”. In the second part of the thesis, we focus on a more standard static graph representation. We conduct a propagation study on YouTube datasets to understand and compare the propagation dynamics of two different types of users: subscribers and friends. Finally, we conclude the thesis with the proposal of a general framework to present, in a comprehensive model, the influence of the social web on e-commerce decision making.

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Sinha, Ravi Som. "Graph-based Centrality Algorithms for Unsupervised Word Sense Disambiguation." Thesis, University of North Texas, 2008. https://digital.library.unt.edu/ark:/67531/metadc9736/.

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This thesis introduces an innovative methodology of combining some traditional dictionary based approaches to word sense disambiguation (semantic similarity measures and overlap of word glosses, both based on WordNet) with some graph-based centrality methods, namely the degree of the vertices, Pagerank, closeness, and betweenness. The approach is completely unsupervised, and is based on creating graphs for the words to be disambiguated. We experiment with several possible combinations of the semantic similarity measures as the first stage in our experiments. The next stage attempts to score individual vertices in the graphs previously created based on several graph connectivity measures. During the final stage, several voting schemes are applied on the results obtained from the different centrality algorithms. The most important contributions of this work are not only that it is a novel approach and it works well, but also that it has great potential in overcoming the new-knowledge-acquisition bottleneck which has apparently brought research in supervised WSD as an explicit application to a plateau. The type of research reported in this thesis, which does not require manually annotated data, holds promise of a lot of new and interesting things, and our work is one of the first steps, despite being a small one, in this direction. The complete system is built and tested on standard benchmarks, and is comparable with work done on graph-based word sense disambiguation as well as lexical chains. The evaluation indicates that the right combination of the above mentioned metrics can be used to develop an unsupervised disambiguation engine as powerful as the state-of-the-art in WSD.

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Saad, Kristen M. "Bulk Synchronous Parallel Implementation of Percolation Centrality for Large Scale Graphs." Case Western Reserve University School of Graduate Studies / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=case149619082195966.

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21

Brewer, Meredith Jane. "FUEL OR FIZZLE: THE ROLE OF COLLABORATION NETWORK CENTRALITY ON TEACHER BURNOUT." UKnowledge, 2018. https://uknowledge.uky.edu/edsc_etds/43.

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Professional burnout refers to the development of negative emotions, cynical thoughts, and physical and mental exhaustion as a response to stressors associated with one’s career. Within the teaching profession, professional burnout has been associated with an increase in teacher attrition. In an effort to promote a positive school environment where teachers feel supported and committed to the profession, many administrators have implemented structured collaborative opportunities within their buildings. While personal relationships within the school network can provide a mitigating effect against professional burnout, the possibility exists that teacher leaders can be overcentralized and negatively impacted by the maintained relationships. By potentially forcing centralization on critical team members and emphasizing them as the “go-to” person for collaboration, schools may be inadvertently putting their best at risk for burnout. Using a mixed-methods design, the following study investigates the perceived benefits and constraints of centrality within the school network on reported burnout. The social networks at four elementary schools were analyzed to determine the level of connectivity for each certified staff member. Participants were asked to identify the colleagues with whom they collaborate. Using Social Network Analysis, the level of centrality (as measured by number of network connections both received and directed) was calculated for each participant based on number of network ties both received and directed. Centrality scores were included with previously identified variables associated with teacher burnout including level of perceived stress, perception of school environment, principal support, and other demographic data in a series of hypothesis tests to assess the relationship between network connectivity and reported burnout. A series of semi-structured interviews were conducted with a selection of participants to further explore the impact of network connections on participant burnout. The results of this exploratory study found that not all collegial relationships are beneficial. A significant positive relationship between number of collaborative ties directed toward a teacher and their depersonalization score on the Maslach Burnout Inventory was identified, indicating that individuals who are frequently identified as a collaborator report higher burnout. The findings from this study produce a unique perspective on collaboration within the school network. As has been reported previously, level of connectivity within the school network as measured by the number of teachers one can identify as collaborators appears to mitigate (or not significantly increase) a teacher’s risk of professional burnout. However, being identified as a collaborator by a large number of teachers (in-degree) significantly increases one’s risk for depersonalization behaviors.

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Felts, Christopher P. "Social Centrality, Deviance, and Well-Being: Understanding the Immediate and Long-Term Relationships." University of Cincinnati / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1573570021775454.

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23

GERBER, Philippe. "Gentrification et confort postmoderne. Eléments émergents de nouvelles centralités. L'exemple de Strasbourg." Phd thesis, Université Louis Pasteur - Strasbourg I, 2000. http://tel.archives-ouvertes.fr/tel-00007500.

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Véritables lieux d'enjeux économiques, culturels et résidentiels, la plupart des centres-villes occidentaux ont connu de nombreuses rénovations qui ont renforcé leurs centralités de commerces et de services. En outre, les réhabilitations ont indéniablement amélioré le confort des résidences. Ces diverses politiques urbaines, associées à l'accroissement des ménages solvables au cours des Trente Glorieuses, entraînent un changement de population des centres, phénomène appelé gentrification. Caracérisée par une infiltration de classes moyennes et aisées aux dépens des couches populaires, la gentrification correspond aux mobilités résidentielles de ces ménages solvables, attirés par les logements de confort et les équipements commerciaux centraux. Car aujourd'hui le confort dépasse le cadre technique de la résidence. Il concerne également la demande de plus en plus exigeante des citadins solvables quant à l'usage des centralités : le confort d'appareillage, lié à la proximité, à la diversité et à la qualité de ces équipements, devient dans le choix du logement tout aussi prépondérant que le confort résidentiel. La notion de confort moderne, alliant appareillage et résidence, se présente alors comme un facteur essentiel de la compréhension du processus de gentrification. L'évolution de la demande citadine solvable se traduit encore par l'émergence d'un autre type de confort, nommé discret, nouvelle expression sociale et qualitative de l'individu. Confort moderne et confort discret forment ainsi le confort postmoderne, grille de lecture novatrice, évolutive et nécessaire à l'explication de la gentrification. En appliquant cette grille à l'analyse de Strasbourg et de sa Communauté, le confort postmoderne permet, grâce à son emploi systématique, d'appréhender différemment les articulations entre le ménage solvable, sa résidence, son environnement et les centralités, le tout dans un souci de saisir les aspirations du citadin, sans pour autant se limiter à l'étude du centre d'une ville.

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24

Edstrand, Gustav, and Jacob Engberg. "Analys av centralt beslutad extern tredjepartslogistik i Vallastaden : En fallstudie gällande värdeskapande för byggentreprenörens logistikverksamhet." Thesis, Tekniska Högskolan, Högskolan i Jönköping, JTH, Byggnadsteknik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:hj:diva-35225.

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Purpose: External logistics coordination was decided after a long procurement process while parts of the project Vallastaden already started construction. The external logistics company creates and implements a logistics solution in a short time. The municipality has no formal connection requirements on developers, but has transferred to the third-party logistics to contract with the developers. The goal is to examine how the implementation of the external solution contract affects residential building and how an external third-party logistics solution works value creation for the building contractor. Method: For data collection observation and interviews have been used as methods of work. Findings: In order to create favourable condition for a builder and/or contractor in the implementation of a centrally decided external third party logistics solution requires: Early involvement of third-party logistics contractor in the planning stage with the motto "first and last on site" Clear and well-developed conditions for procurement of connectivity requirements, and the possibility of adaptation of the technical solution according to the customer identified needs. Open and continuous dialogue at all levels within the organizational structure. Implications: The complexity of how building projects should plan their logistics allows a handling of the issue at an early stage in the project is crucial. If the potential of the third party logistics for construction projects should be used needs to be early dialogue between the parties involved which the project's conditions have to control how the service should be designed. Limitations: The problem area and the number of actors involved in the external third-partylogistics make it difficult to pinpoint exact events that contributed to the situation has become in Vallastaden. The authors have not found the source of why it has been difficult to implement third-party logistics solution at an early stage in Vallastaden. What emerged during the process is that it needs to be sought answers higher up in the organizational structure of Vallastaden, but there is work boundaries made this a priority away and therefore not addressed in this report. Selected methods aimed solely at Skanska role in Vallastaden. Alternative viewpoints from different developers and construction contractors in Vallastaden has partly been highlighted in logistics meetings. It is important to point out that the work contains only a limited number of viewpoints on centrally approved third party logistics based on the many actors who are part of the project Vallastaden.
Syfte: Extern logistiksamordning beslutades efter en utdragen upphandlingsprocess samtidigt som delar av projektet Vallastaden redan påbörjat byggnation. Det externa logistikföretaget dimensionerar och implementerar en helt fungerande lösning på kort tid. Kommunen har inte formellt anslutningskrav på byggherrarna utan har överlåtit till tredjepartslogistikern att ingå avtal med byggherrarna. Målet är att undersöka hur implementeringen av den externa tredjeparts-logistiklösningenpåverkar entreprenaden Bostadshuset samt hur en extern tredjeparts-logistiklösningarbetar värdeskapande för byggentreprenören. Metod: För datainsamling har observation samt intervju använts som metoder i arbetet. Resultat: För att skapa goda förutsättning för en byggherre och/eller byggentreprenör vid implementering av en centralt beslutat externt tredjepartslogistiklösning så krävs: Tidig involvering av tredjepartslogistikentreprenören i projekteringsskedet med mottot ”först och sist på plats vid produktion” Tydliga och väl utarbetade förutsättningar vid upphandling med anslutningskrav samt möjligheten till anpassning av den tekniska lösningen utefter kundens identifierade behov. Öppen och kontinuerlig dialog i alla led inom organisationsstrukturen. Konsekvenser: Komplexiteten kring hur byggprojekt ska planera sin logistik gör att en hantering av frågan i tidigt skede i projekten är avgörande. Om potentialen i tredjepartslogistik för byggprojekt ska nyttjas behöver dialog föras tidigt mellan de inblandade parterna där projektets förutsättningar måste styra hur tjänsten ska utformas. Begränsningar: Författarna har inte hittat källan till varför det har varit svårt att implementera tredjepartslogistiklösningen i ett tidigt skede i Vallastaden. Det som framkommit under arbetets gång är att det behöver sökas svar högre upp i organisationsstrukturen för Vallastaden, men där har arbetets avgränsningar gjort att detta prioriterats bort och behandlas därför inte i denna rapport. Valda metoder riktar sig enbart på Skanskas verksamhet inom Vallastaden. Alternativa synpunkter från olika byggherrar och byggentreprenörer inom Vallastaden har delvis uppmärksammats vid logistikmöten. Det är viktigt att poängtera att arbetet enbart innehåller ett begränsat antal synvinklar på centralt beslutad tredjepartslogistik utifrån de många aktörer som är en del av projektet Vallastaden.

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Pages, Jean-Christophe. "Modélisation, analyse et régulation des aménagements du Rhône par commande prédictive : gestion locale et centralisée du passage des crues." Lyon 1, 2000. http://www.theses.fr/2000LYO10057.

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Cette these est consacree a la mise en uvre d'une regulation par commande predictive d'amenagements fluviaux en periode de crue integrant un grand nombre de contraintes liees a l'exploitation des ouvrages. L'aboutissement de cette etude est une serie de logiciels industriels en cours de developpement et qui seront deployes sur le rhone en aval de lyon. Le premier objectif que nous nous sommes fixe est la capitalisation du savoir de la compagnie nationale du rhone, concessionnaire du fleuve, en integrant les modeles mathematiques de ses amenagements en tant que modeles embarques. Pour cela, deux voies ont ete explorees, la commande predictive par scenarios de commande et l'identification en ligne de modeles lineaires adaptatifs a partir des modeles mathematiques. Cette derniere solution a ete retenue car elle nous a permis d'implementer une commande predictive lineaire de type pfc (predictive functionnal control), d'en analyser la robustesse et d'en optimiser les reglages grace aux outils de l'automatique. Apres le developpement d'un premier logiciel de regulation locale, une conduite coordonnee de l'ensemble des amenagements du rhone en periode de crue, basee sur une pfc multivariables, a ete etudiee. Le but recherche (et atteint) etait la reduction des effets des crues en optimisant la gestion des volumes dans les retenues.

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García-García, Isabel, María Ángeles Jurado, Maite Garolera, Idoia Marqués-Iturria, Annette Horstmann, Bàrbara Segura, Roser Pueyo, et al. "Functional network centrality in obesity: a resting-state and task fMRI study." Psychiatry research (2015) 233, 3, S. 331-338, 2015. https://ul.qucosa.de/id/qucosa%3A14785.

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Obesity is associated with structural and functional alterations in brain areas that are often functionally distinct and anatomically distant. This suggests that obesity is associated with differences in functional connectivity of regions distributed across the brain. However, studies addressing whole brain functional connectivity in obesity remain scarce. Here, we compared voxel-wise degree centrality and eigenvector centrality between participants with obesity (n=20) and normal-weight controls (n=21). We analyzed resting state and task-related fMRI data acquired from the same individuals. Relative to normal-weight controls, participants with obesity exhibited reduced degree centrality in the right middle frontal gyrus in the resting-state condition. During the task fMRI condition, obese participants exhibited less degree centrality in the left middle frontal gyrus and the lateral occipital cortex along with reduced eigenvector centrality in the lateral occipital cortex and occipital pole. Our results highlight the central role of the middle frontal gyrus in the pathophysiology of obesity, a structure involved in several brain circuits signaling attention, executive functions and motor functions. Additionally, our analysis suggests the existence of task-dependent reduced centrality in occipital areas; regions with a role in perceptual processes and that are profoundly modulated by attention.

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Ibrahim, Hassan. "Analyse à base de SAT de la diagnosticabilité et de la prédictabilité des systèmes à événements discrets centralisés et distribués." Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLS539.

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Les systèmes complexes sont omniprésents dans nos vies, mais sujet à des pannes qu’il est important de détecter ou de prédire. Leur modélisation comme des systèmes à événements discrets (SED) est un moyen naturel de les représenter pour les étudier. Ainsi, un système peut être décrit par un ensemble d'états tels que son état actuel est obtenu après avoir déclenché une séquence d'événements. Ces événements sont prédéfinis dans un ensemble fini et peuvent être déclenchés spontanément dans le système. Tous ces événements ne sont pas observables / mesurables et certains d'entre eux sont considérés comme fautifs, donc ils modélisent un changement anormal entre deux états du système. Le processus de diagnostic de SED a pour but de déterminer avec certitude si le système est actuellement dans un état défectueux ou dans un état normal, c'est-à-dire si un changement anormal d'un état du système s'est produit ou non. À cette fin, un observateur de système ne dispose que de la séquence d'événements observables pour décider le diagnostic de l'état actuel du système. Cependant, cet état peut être ambigu (normal ou défectueux) en fonction des observations disponibles. En outre, il peut être définitivement ambigu ! La possibilité de le désambiguïser en utilisant un nombre fini d'observations est appelée la diagnosticabilité d'une occurrence d'événement fautif. La faute est diagnosticable si toutes ses occurrences le sont et le système est diagnosticable si toutes ses fautes le sont. De même, la possibilité de prédire une occurrence future d'une faute en utilisant les événements observables la précédant est appelée la prédictabilité d'un événement fautif. Les deux problèmes de la diagnosticabilité et de la prédictabilité d'un événement peuvent être généralisés pour étudier celles d'un motif d’événements, soit un langage clos par extension représenté par une machine à états finis. Cette thèse considère dans sa première partie les problèmes de vérification de la diagnosticabilité et de la prédictabilité d'un événement fautif et de la diagnosticabilité d'un motif d'événements dans les systèmes à événements discrets centralisés et distribués (avec des événements de communication synchrone observables ou non), à l'aide de solveurs SAT. Ainsi, nous les avons encodés comme des problèmes SAT, avons étudié des variantes incrémentales et fourni des résultats expérimentaux qui prouvent le passage à l’échelle et la flexibilité de cette approche. Dans la deuxième partie, nous avons introduit le problème de la planification de la diagnosticabilité. Ce problème consiste à trouver un plan d'actions (une séquence d'événements intentionnels prédéfinis à la conception) qui garantit, lorsqu'il est appliqué à un ensemble donné d'états potentiels du système actuel appelé état courant de croyances, de conduire le système dans un état de croyances diagnosticable d’où on peut le laisser s'exécuter librement (sans les actions de contrôle). Ce problème peut survenir après une intervention externe sur le système, comme par exemple l'application d'un plan de réparation après la détection d'une faute. Ainsi, cette approche peut garantir la possibilité de détecter d'autres futures fautes du système. Nous avons analysé ce problème et prouvé qu’il est PSpace-complet puis nous avons proposé trois méthodes pour engendrer un plan diagnosticable, que nous avons comparées sur un banc d’essais créé à cette fin
Complex systems are omnipresent in our lives, but subject to failures that it is important to detect or predict. Discrete event system (DES) modeling is a natural way to represent and study such systems. Thus a system can be described by a set of states such that its current state is obtained after firing a sequence of events. These events are predefined in a finite set and can be fired spontaneously in the system. Not all these events are observable (measurable) and some of them are considered faulty, thus they model an abnormal change between two system states. The diagnosis process in DES aims at determining with certainty if the system is currently in a faulty state or in a normal one, i.e., if an abnormal change of a system state has occurred or not. To this end, a system observer has only the sequence of observable events to decide the current status of the system state. However this state might be currently ambiguous (normal or faulty) according to the available observations. Moreover it can be permanently ambiguous! The possibility to disambiguate it using a finite number of observations is called the diagnosability of a faulty event occurrence. The fault is diagnosable if all its occurrences are diagnosable and the system is diagnosable if all its faults are diagnosable. Similarly, the possibility to predict a future occurrence of a fault using its preceding observable events is called the predictability of a faulty event occurrence. Both problems of diagnosability and predictability can be generalized to study the diagnosability or the predictability of a pattern of events, i.e., an extension-closed language represented by a finite state machine.This thesis considers in its first part the problems of checking event diagnosability, event predictability and pattern diagnosability in centralized and distributed (with observable or unobservable synchronous communication events) discrete event systems, using SAT solvers. Thus we have encoded them as SAT problems, studied incremental SAT variants and provided experimental results that prove the scalability and flexibility of this approach. In the second part, we have introduced the diagnosability planning problem. This problem consists in finding a plan of actions (intentional/designful predefined events) that ensures, when applied on a set of potential current system states (called a current belief state), to drive the system in a diagnosable belief state from which it can be left to run freely (without control actions). This problem can arise after an external intervention on the system, like the application of a repair plan after a fault detection.Thus this approach can ensure the possibility to detect the system further faults. We analyzed this problem, proved its PSpace-completeness and proposed three methods to find the intended plan that we compared on a benchmark created for this purpose

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Azhakathu, Anisha Tresa. "Elaborazione di segnali EEG e analisi di connettività cerebrale durante crisi epilettiche." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2022. http://amslaurea.unibo.it/25090/.

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L’epilessia è una patologia neurologica cronica in cui l’attività anomala dei neuroni causa crisi ricorrenti. Il trattamento di prima scelta nella cura dell’epilessia sono i farmaci antiepilettici. Tuttavia, circa il 30% dei pazienti epilettici è resistente ai farmaci: una possibile soluzione consiste nella rimozione chirurgica della zona responsabile dell’insorgenza delle crisi, definita zona epilettogena (ZE). La precisa localizzazione della ZE è fondamentale per il successo della chirurgia dell’epilessia. In questo lavoro di tesi, sono stati analizzati i tracciati EEG di tre pazienti epilettici, ricoverati presso l’ospedale Bellaria di Bologna, con l’obiettivo di identificare grandezze in grado di localizzare e lateralizzare l’origine delle crisi epilettiche. In particolare, i segnali sono stati analizzati in termini di potenza e connettività. La connettività cerebrale è stata studiata attraverso la causalità di Granger. Il network cerebrale è stato analizzato utilizzando la teoria dei grafi, con particolare interesse agli indici di degree centrality. I risultati ottenuti dall’analisi di outdegree centrality hanno permesso di confermare le valutazioni cliniche. Due dei tre pazienti analizzati erano affetti da crisi temporali destre; la valutazione dell’outdegree centrality, durante le crisi epilettiche, ha mostrato lateralizzazione destra, con coinvolgimento delle regioni temporali in particolare. Nel caso del paziente affetto da crisi bitemporali, l’indice di outdegree centrality ha confermato il coinvolgimento di entrambi gli emisferi durante le crisi. I risultati ottenuti hanno evidenziato la capacità dello studio di connettività, insieme all’applicazione della teoria dei grafi, di permettere una maggiore comprensione del funzionamento del network cerebrale. Ulteriori studi possono permettere di definire un metodo di localizzazione precisa della ZE, a partire dai tracciati EEG ottenuti in maniera non invasiva.

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Pietrangeli, Marco. "Analisi e caratterizzazione di isolanti polimerici per cavi di bassa tensione utilizzati nelle centrali nucleari." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2020.

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Questo elaborato di tesi ha l'obbiettivo di studiare gli effetti dell’invecchiamento termico e radiativo sui parametri elettrici dell’isolante polimerico, utilizzato nei cavi di bassa tensione nelle centrali nucleari. Il materiale studiato è il polietilene crosslinkato (XLPE), additivato in diverse concentrazioni tra antiossidanti a base fenolica, antiossidanti a base tioeterica e ritardanti di fiamma (ATH). Le tecniche di misura impiegate sono state la spettroscopia dielettrica, la conducibilità e il voltage breakdown in AC.

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Engström, Sara, and Paulina Passos. "Det centrala innehållet i svenska : En jämförande analys av läromedel för årskurs 2." Thesis, Uppsala universitet, Institutionen för pedagogik, didaktik och utbildningsstudier, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-413345.

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Syftet med detta självständiga arbete är att undersöka hur det centrala innehållet i svenska för årskurs 1-3 representeras i fem olika läromedelsserier anpassade för årskurs 2. De granskade läromedlen var Vips!, Robin, Prima svenska, Glad svenska och Språkskrinet. Den använda metoden var en kvalitativ innehållsanalys med ett eget utformat analysverktyg där de granskade uppgifternas karaktär togs i beaktande för att kunna delas upp efter punkterna i det centrala innehållet i Lgr11. Samma punkter i Lgr11 delades också in i Pedagogiska gruppens tre olika svenskämneskonceptioner. Resultatet visade att läromedelsförlagen hade en övergripande gemensam syn på vilket innehåll läroböckerna ska behandla i årskurs 2. Det var en avvikande serie, Glad svenska, som hade ett större fokus gentemot punkterna “Alfabetet och alfabetisk ordning” samt “Sambandet mellan ljud och bokstav” i det centrala innehållet, vilket skilde sig från de andra serierna som inte lade lika stor vikt på nämnda punkter. De andra serierna hade istället ett större fokus gentemot punkterna “Lässtrategier för att förstå och tolka texter samt för att anpassa läsningen efter textens form och innehåll” samt “Strategier för att skriva olika typer av texter med anpassning till deras typiska uppbyggnad och språkliga drag. Skapande av texter där ord och bild samspelar, såväl med som utan digitala verktyg”. I de senast nämnda punkterna representerades majoriteten av uppgifterna i serierna, Vips!, Robin, Språkskrinet samt Prima svenska. Ett annat resultat som redovisas i studien är att alla granskade läromedelsserier förutom en (Robin) hade flest uppgifter tillhörande svenskämneskonceptionen Färdighetsämnet (Bergöö, 2005) som utmärks av uppgifter som kan beskrivas som färdighetsträning. En slutsats som kunde dras av studien var att alla granskade läromedel innehöll uppgifter kopplade till de tre konceptionerna Färdighetsämnet, det Litteraturhistoriska bildningsämnet och det Erfarenhetspedagogiska svenskämnet.

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Bohn, Angela, Norbert Walchhofer, Patrick Mair, and Kurt Hornik. "Social Network Analysis of Weighted Telecommunications Graphs." Department of Statistics and Mathematics, WU Vienna University of Economics and Business, 2009. http://epub.wu.ac.at/708/1/document.pdf.

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SNA provides a wide range of tools that allow examination of telecommunications graphs. Those graphs contain vertices representing cell phone users and lines standing for established connections. Many sna tools do not incorporate the intensity of interaction. This may lead to wrong conclusions because the difference between best friends and random contacts can be defined by the accumulated duration of talks. To solve this problem, we propose a closeness centrality measure (ewc) that incorporates line values and compare it to Freeman's closeness. Small exemplary networks will demonstrate the characteristics of the weighted closeness compared to other centrality measures. Finally, the ewc will be tested on a real-world telecommunications graph provided by a large Austrian mobile service provider and the advantages of the ewc will be discussed.
Series: Research Report Series / Department of Statistics and Mathematics

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Panzetta, Cosimo <1991&gt. "Analisi di impatto sui bilanci delle banche italiane a seguito di una ipotesi di modifica del trattamento prudenziale riservato alle esposizioni verso le amministrazioni centrali e banche centrali con ponderazione nulla." Master's Degree Thesis, Università Ca' Foscari Venezia, 2018. http://hdl.handle.net/10579/12138.

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Il rischio di credito ha da sempre costituito la principale causa delle perdite registrate dalle istituzioni finanziare durante l’esercizio della loro attività. La necessità di gestire tale situazione, se da un lato ha portato alla nascita e al conseguente sviluppo di modelli analitici funzionali alla quantificazione del rischio di credito, dall’altro è stata supportata dalla normativa di vigilanza, mediante la definizione di criteri di adeguatezza patrimoniale, al fine di promuovere una maggiore solidità ed efficienza del sistema bancario internazionale. Con riferimento a quest’ultimo aspetto rileva l’accordo sul capitale, che ha avuto la sua prima formulazione nel 1988 e che è stato successivamente oggetto di continui aggiornamenti e modifiche, fino ad arrivare alla definizione del nuovo impianto regolamentare, conosciuto con il nome di Basilea 3. Il principio di adeguatezza patrimoniale, in un’ottica di gestione del rischio di credito, trova applicazione con riferimento a tutte le posizioni bancarie per le quali è previsto il pagamento, da parte del debitore, di somme di denaro prestabilite. Tuttavia ai nostri fini si cercherà, dapprima, di rappresentare ed analizzare l’andamento negli ultimi dieci anni dei titoli governativi emessi dallo stato italiano, per poi individuare, con riferimento ad un campione casuale di banche italiane, il possibile impatto patrimoniale derivante da un’ipotetica modifica normativa che attribuisce un diverso trattamento prudenziale a quelle esposizioni verso o garantite da amministrazioni centrali e banche centrali per le quali, in un contesto di applicazione del metodo standardizzato ai fini della determinazione del requisito minimo patrimoniale, è previsto attualmente un fattore di ponderazione nullo.

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Qu, Xiaoyan Angela. "Discovery and Prioritization of Drug Candidates for Repositioning Using Semantic Web-based Representation of Integrated Diseasome-Pharmacome Knowledge." University of Cincinnati / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1254403900.

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Soltis, Scott Matthew. "WHO YOU ARE AND WHO YOU KNOW: THE INFLUENCE OF PERSONENVIRONMENT FIT AND SOCIAL NETWORK CENTRALITY ON INDIVIDUAL PERFORMANCE." UKnowledge, 2012. http://uknowledge.uky.edu/management_etds/1.

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Job seekers and employers frequently make application and selection decisions based on how well they believe there is a ‘fit’ with the organization and job. The personenvironment fit literature has strongly supported this practice demonstrating that fit is an antecedent to attraction, selection, and attrition. What has been lacking, however, is evidence that once individuals enter the organization their fit relates to performance. Using a social network analytical lens, I develop a framework that integrates PE fit and social networks to explore antecedents to employee performance. Using this framework, I explore how informal workplace relationships may act as catalysts through which fit either enhances or detracts from individual performance, how fit might directly influence performance once the social context is taken into account, and how fit might make an individual an attractive exchange partner benefiting performance. Results suggest that PE fit is related to individual performance (both in- and extra-role) but that this relationship differs depending on how well embedded the employee is in the informal social networks of the organization. It is only when accounting for the ‘who you know’ element of organizational life that we can see how ‘who you are’ relates to performance.

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Santolin, Alberto. "Procedure per la progettazione standardizzata delle turbine delle piccole centrali idroelettriche." Doctoral thesis, Università degli studi di Padova, 2009. http://hdl.handle.net/11577/3426010.

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The thesis presents the definition and development of standardized design procedures of three type of hydraulic turbines for small hydraulic power plants: Pelton, Francis and Kaplan. In order to properly define the design parameter of each type of turbine, a technical-economical criterion was first applied to the flow duration curves of the turbine installation sites. Then, the critical aspects of the design procedure of each type of turbine were analyzed. As regards the Pelton turbines, a numerical investigation of the interaction between the jet and the bucket is presented. Unsteady numerical analyses were carried out on a single jet Pelton Turbine installed in the north of Italy. A two-phase inhomogeneous model was used. Two different jet configurations were analyzed and compared. In the first configuration the interaction between the runner and an axial-symmetric jet characterized by a given velocity jet profile was investigated, whereas in the second configuration the runner was coupled with the needle nozzle and the final part of the penstock and the interaction between the jet and the bucket was analyzed. A detailed analysis of the torque highlighted the influence of the shape of the water jet on the turbine losses and the influence of the stator on the efficiency of this type of hydraulic machines was shown. The numerical results was compared with the experimental data derived from the installation test of the turbine in order to validate the numerical analysis. As regards the Francis turbines, the analysis was focused on the design procedure of the statorical part. Numerical analyses, carried out on an installed and working machine, highlighted problems on the prediction of the operating conditions due to the distributor design procedure. To overcome these problems, an alternative distributor design procedure was presented and validated by numerical analysis. Finally, for the Kaplan turbines a new design methodology of the blade profiles is presented. Moreover, in order to overcome the prediction problems highlighted for the Francis turbines, a prediction criterion of the flow deflection obtainable from the distributor is also proposed.
La tesi presenta procedure di progettazione standardizzata sviluppate per tre tipologie di turbine idrauliche impiegate in centrali idroelettriche di piccola potenza: turbine Pelton, Francis e Kaplan. In primo luogo, per definire in modo appropriato e razionale i parametri progettuali delle turbine, le curve di durata delle portate dei siti di installazione sono state analizzate mediante un criterio sviluppato sulla base di parametri sia tecnici che economici. Si sono poi analizzati in dettaglio gli aspetti critici della procedura di progettazione delle varie tipologie di turbine. Per quanto riguarda le turbine Pelton, oggetto dell'indagine è stata l'interazione tra il getto e la pala a doppio cucchiaio. Analisi numeriche non-stazionarie multifase sono state condotte su di una turbina Pelton a singolo getto installata nel Nord Italia della quale si sono prese in considerazione due diverse configurazioni. Nella prima si è analizzata l'interazione tra la girante e un getto ideale assial-simmetrico a cui è stato assegnato un definito profilo di velocità, mentre nella seconda configurazione la girante è stata accoppiata con l'ugello e la parte finale della condotta forzata per analizzare l'interazione tra la girante e un getto dalle caratteristiche più vicine alla realtà. Un'analisi dettagliata della coppia all'albero ha consentito di valutare l'influenza della forma del getto e dell'elemento statorico sulle perdite e l'efficienza di questa tipologia di macchine idrauliche. I risultati numerici sono stati quindi confrontati con i dati sperimentali dei test di installazione della turbina allo scopo di valutare l'accuratezza dell'analisi numerica. Per quanto riguarda invece la turbine Francis, analisi numeriche condotte su di una macchina installata e funzionante, hanno evidenziato problemi di predizione della condizione di funzionamento dovuti alle procedure di progettazione dell'organo statorico. Per ovviare a questi problemi, si è sviluppata una procedura alternativa per il dimensionamento del distributore che consentisse di prevedere la condizione di funzionamento della macchina in modo più accurato. Tale procedura è stata convalidata tramite analisi numerica. Per quanto attiene le turbi ne Kaplan, è stata sviluppata una metodologia standardizzata di calcolo dei profili palari. Inoltre per ovviare ai problemi di predizione riscontrati anche per questa tipologia di turbine si è sviluppato un criterio di predizione della deviazione all'uscita dell'organo statorico, verificato per via numerica.

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Laurent, Faustine. "Évaluation des performances environnementales de l'insertion d'une filière de méthanisation centralisée au sein d'un territoire." Thesis, Rennes 1, 2015. http://www.theses.fr/2015REN1S022/document.

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En France, le développement rapide de la méthanisation, procédé de production d'énergie renouvelable par dégradation de résidus organiques, soulève la question de la pertinence environnementale de la filière. Cette dernière mérite d'autant plus d'être évaluée que le développement de la filière est inscrit dans les plans climatiques et énergétiques nationaux. La méthanisation centralisée s'insère d'ailleurs de manière profitable dans diverses démarches d'écologie industrielle et territoriale (EIT), au sein desquelles la multifonctionnalité du procédé constitue un atout substantiel en faveur du bouclage des flux de matière et d'énergie. Cette multifonctionnalité représente néanmoins la principale source de difficultés méthodologiques rencontrées lors de l'évaluation des performances environnementales de systèmes de méthanisation. Sa résolution, à savoir la définition de la fonction principale d'un système, passe par la contextualisation de la méthode. Pour l'analyse du cycle de vie (ACV), cette contextualisation se révèle pertinente dès la première étape de la méthodologie. Ce travail de thèse propose un cadre conceptuel visant à définir des scénarios de méthanisation contraints par leur territoire d'implantation. Pour cela, une approche systémique territoriale, impliquant les systèmes d'information géographique (SIG) et la modélisation orientée objet, a été développée. Elle résulte en un modèle spatial de l'insertion territoriale d'une filière de méthanisation centralisée, qui intègre l'ensemble de ses éléments constitutifs, réseaux ou variables. A l'issue de l'approche systémique a lieu une phase d'optimisation fonctionnelle et spatiale qui met en jeu trois séries successives d'indicateurs, permettant de définir : (i) la fonction principale que remplirait un système de méthanisation au sein du territoire étudié, (ii) les configurations possibles d'un système de méthanisation qui puissent satisfaire à cette fonction principale et (iii) les zones préférentielles d'implantation des scénarios élaborés. Cette méthodologie, conçue de manière à être transposable à tout territoire français, s'intègre aux étapes de l'ACV de définition des objectifs et d'inventaire du cycle de vie. Afin de valider l'applicabilité de la méthode développée, deux territoires contrastés ont été soumis à l'approche systémique territoriale. Ces cas d'étude ont mis en évidence les liens entre spécificités territoriales et conception de la filière. L'influence de la fonction principale retenue pour un système de méthanisation sur la réalisation et les résultats de l'ACV a par ailleurs été étudiée pour l'un de ces territoires. Les différences les plus notoires tiennent aux substitutions et montrent l'importance de développer la méthanisation en priorité lorsque le contexte local permet aux fonctions multiples de la filière de remplacer des filières existantes dont les impacts sur l'environnement sont particulièrement préjudiciables
In France, the rapid development of anaerobic digestion (a process used to generate renewable energy by breaking down organic residues) has led to the environmental relevance of this solution being questioned. It is particularly worthwhile evaluating inasmuch as development of the sector forms part of national climate and energy plans. Centralised anaerobic digestion also fits in profitably with various industrial ecology approaches, with the multifunctionality of the process constituting a substantial asset in that it favours circular flows of materials and energy. However, this multifunctionality also represents the main source of the methodological difficulties encountered in the evaluation of the environmental performance of anaerobic digestion systems. Resolving this, i.e. defining the main function of a system, requires the environmental evaluation method to be contextualised. For life cycle assessment (LCA), this contextualisation emerges as being appropriate to the first stage of the methodology. This thesis puts forward a conceptual framework, aimed at defining anaerobic digestion scenarios that are consistent with the particularities of the territory in which they are located. To do this, a territorial systemic approach, involving geographic information systems (GIS) and object-oriented modelling, was developed. The approach has resulted in a spatial model for territorial location of a centralised anaerobic digestion solution, incorporating all its component parts, networks and variables. The systemic approach was followed by a phase of functional and spatial optimisation involving three successive sets of indicators, enabling the following to be defined: (i) the main function to be played by an anaerobic digestion system within the territory studied, (ii) the possible configurations of an anaerobic digestion system capable of fulfilling this main function and (iii) the preferential zones for locating the scenarios envisaged. This methodology, designed to be transposable to any territory within France, forms part of the first two LCA stages, i.e. definition of objectives and life cycle inventory. In order to validate the applicability of the method developed, the territorial systemic approach was applied to two different territories. These case studies highlight the links between specific territorial characteristics and the design of the local solution. The influence of the main function selected for an anaerobic digestion system on the performance and results of the LCA was also studied for one of these territories. The most noteworthy differences relate to substitution, highlighting the importance of developing anaerobic digestion as a priority when the local context makes it possible for the multiple functions of the solution to replace existing sectors with particularly harmful effects on the environment

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Hamre, Lynne Janine. "Exploring the use of social capital to support technology adoption and implementation." Thesis, University of Bath, 2008. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.492258.

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Information System (IS) implementations are a risky business with studies showing only a 16%-29% success rate. This research explores the use of social capital to support technology implementations. This research brings together two distinct bodies of knowledge: social network analysis (SNA) and technology acceptance models, in order to better understand the relationship between social capital and technology acceptance. The first aspect of the research looks at social network centrality and influence measures as an alternative means to measure social influence in the Unified Theory of Acceptance and Use of Technology (UTAUT) model. The social influence construct has proven to be inconsistent in past research. An individual‟s decision to adopt a new technology is influenced by their social context or the informal social network within which they work. The social capital of others influences their attitudes and decision to adopt a new technology. Social Capital, as measured through social network analysis, could be substituted for the social influence construct of the UTAUT model. Two revised UTAUT models are developed and tested. The second aspect of this research uses social capital to inform membership of a Community of Practice (CoP) to support a Finance Management System implementation in a higher education organization. SNA can be used to gain an understanding of the social network and identify individuals with high social capital. There is growing evidence that CoP support successful organizational change initiatives but it is less clear how CoP membership might be determined. SNA provides an evidence-based approach to CoP formation. The IS implementation cases described in the paper demonstrate an innovative approach to IS implementation grounded in social capital and technology acceptance research that add to the body of knowledge in both theory and practice.

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Payen, Aurore. "Importance de la temporalité dans les phénomènes de propagation. Une illustration sur des échanges d'animaux d'élevage." Electronic Thesis or Diss., Sorbonne université, 2018. http://www.theses.fr/2018SORUS247.

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Les échanges d'animaux d'élevages entre exploitations agricoles favorisent la diffusion à grande échelle des maladies. L’enjeu est non seulement économique, de par les répercussions fortes sur les marchés de produits d’origine animale en cas de crise, mais également de santé publique, de nombreuses maladies animales étant transmissibles à l’homme (comme la tuberculose bovine). La traçabilité des animaux devient alors une question de plus en plus importante pour retrouver les foyers infectieux, et lutter contre la propagation des maladies. Le développement de ce type de données et leur accessibilité grandissante a permis l’émergence d’études sur leur organisation et leur dynamique. Les outils et modèles développés pour l’étude des réseaux sociaux ont été adaptés à l’étude de ces données. L'apport de cette thèse réside dans l’utilisation de mesures et de modèles intégrant l’information temporelle sur les échanges d’animaux. En effet, le développement des réseaux temporels est relativement récent, et peu d’études les ont à ce jour appliqué échanges d’animaux. L’objectif est donc double, participer au développement des outils d’analyse des réseaux temporels, et en déduire des pistes de développement de mesures de surveillance et de lutte contre la propagation des maladies entre exploitations
Disease spread among agricultural premises is greatly enhanced by cattle trade movements. Preventing spreading is a key issue for economical issues, for instance to prevent trade restrictions, but also for public health. Indeed, many animal diseases affect human beings, such as bovine tuberculosis. Tracing cattle trade movements is aiming at detecting the sources of infection, and thus, helps fighting against disease spread. Accessing databases recording cattle trade movements allows to study the structure and dynamic of the exchanges. To do so, methods developed for Social Network Analysis are more and more adapted and use for these purposes. The aim of this work is to use temporal models and methods to study cattle trade movements. As the development of temporal networks is relatively recent, few analyzes using these methods have been conduct on cattle trade data. Thus, contributions are twofold in this work: taking part to the development of analysis tools of temporal networks, and then, deducting potential ways of enhancement to control and fight against disease spread among holdings

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Sirotti, Bianca. "Analisi e ottimizzazione della gestione dei trasporti secondari di pazienti: il caso AUSL della Romagna." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2021.

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In un momento storico in cui le aziende sanitarie hanno sperimentato strumenti e approcci diversi per la riduzione dei costi e il miglioramento della qualità, la funzione logistica è destinata a crescere e offrire un nuovo approccio per il funzionamento di questa macchina. Questo elaborato nasce con lo scopo di studiare il processo di gestione dei trasporti secondari all'interno dell'AUSL della Romagna. Il trasporto secondario è un evento frequente che coinvolge un elevato numero di attori; per questo motivo il compito di ogni struttura è dunque programmare e pianificare il trasporto, in base alle risorse disponibili e alle problematiche specifiche. L'analisi ha evidenziato i punti di forza, di debolezza, le minacce e le opportunità dell'organizzazione attuale delle Centrali Operative di Ravenna, Rimini e Forlì-Cesena. Il progetto di ottimizzazione dei viaggi delle ambulanze ha condotto a considerazioni utili sul raggiungimento di un utilizzo più efficiente dei mezzi a disposizione. Tutto ciò a dimostrazione dell'importanza, per il futuro, dell'implementazione di una Centrale Unica nella quale il cittadino troverebbe la risposta ai propri problemi. In conclusione, sono stati studiati alcuni indicatori per valutare l'impatto della progettazione futura della centrale.

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Sandt, Emily. "A Social Network Analysis of an Introductory Calculus-Based Physics Class with Comparisons of Traditional and Non-Traditional Students, FCI Scores, and Network Centralities." Wright State University / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=wright1469627559.

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Tsipenyuk, Gregory. "Evaluation of decentralized email architecture and social network analysis based on email attachment sharing." Thesis, University of Cambridge, 2018. https://www.repository.cam.ac.uk/handle/1810/273963.

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Present day email is provided by centralized services running in the cloud. The services transparently connect users behind middleboxes and provide backup, redundancy, and high availability at the expense of user privacy. In present day mobile environments, users can access and modify email from multiple devices with updates reconciled on the central server. Prioritizing updates is difficult and may be undesirable. Moreover, legacy email protocols do not provide optimal email synchronization and access. Recent phenomena of the Internet of Things (IoT) will see the number of interconnected devices grow to 27 billion by 2021. In the first part of my dissertation I am proposing a decentralized email architecture which takes advantage of user's a IoT devices to maintain a complete email history. This addresses the email reconciliation issue and places data under user control. I replace legacy email protocols with a synchronization protocol to achieve eventual consistency of email and optimize bandwidth and energy usage. The architecture is evaluated on a Raspberry Pi computer. There is an extensive body of research on Social Network Analysis (SNA) based on email archives. Typically, the analyzed network reflects either communication between users or a relationship between the email and the information found in the email's header and the body. This approach discards either all or some email attachments that cannot be converted to text; for instance, images. Yet attachments may use up to 90% of an email archive size. In the second part of my dissertation I suggest extracting the network from email attachments shared between users. I hypothesize that the network extracted from shared email attachments might provide more insight into the social structure of the email archive. I evaluate communication and shared email attachments networks by analyzing common centrality measures and classication and clustering algorithms. I further demonstrate how the analysis of the shared attachments network can be used to optimize the proposed decentralized email architecture.

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Di, Pumpo Antonio. "Energie rinnovabili e rete elettrica: modelli stocastici per la scelta della configurazione ottima delle centrali di produzione dell'energia elettrica." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2018.

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Il dispacciamento è l'attività diretta ad impartire disposizioni per l'esercizio coordinato degli impianti di produzione dell'energia elettrica. Questa tesi è focalizzata sull'utilizzo della programmazione stocastica per il dispacciamento in presenza di incertezza sul carico non alimentato dagli impianti eolici. Sono stati definiti tre tipi di modelli stocastici a due stadi: il modello Risk-Neutral e due diversi modelli con considerazione dei rischi tramite Conditional Value at Risk, indicati in questa tesi come Rockafellar e Conejo, dai nomi degli autori delle pubblicazioni che li hanno presentati. E' stato inoltre definito il modello deterministico corrispondente. Ogni modello è stato implementato, tramite il software AIMMS, in modo completo e sono state sviluppate specifiche procedure di controllo post-esecuzione che, in caso di difficoltà di soluzione a causa della mancata possibilità di bilanciamento fra produzione e carico, aggiungono le opportune variabili di slack al modello. E' presente anche una procedura dedicata all'after uncertainty: viene risolto il modello deterministico per ogni scenario con la configurazione acceso/spento ottenuta dalla risoluzione del modello stocastico. Il programma è stato utilizzato per l'analisi della rete di trasmissione est degli Stati Uniti. I risultati indicano che il programma stocastico con CVaR valutato per basse tail probability e per basso peso del rischio garantisce un migliore andamento costi-rischi. I risultati mostrano inoltre l'inefficienza del modello deterministico Expected Value e i significativi vantaggi di tutti i modelli stocastici implementati. Il confronto dei Value of Stochastic Solution, Expected Value of Perfect Information e dei valori delle funzioni obiettivo dell'after uncertainty mostra che, per il caso in studio, il modello Risk-Neutral è la migliore strategia.

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Liljeqvist, Anna. "En jämförande analys av styrdokument för Svenska 3 och Svenska som andraspråk 3 : Centralt innehåll, kunskapskrav och bedömningsmatrisen för det nationella provet i kurserna Sve03 och Sva03." Thesis, Mälardalens högskola, Akademin för utbildning, kultur och kommunikation, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-27821.

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Uppsatsen handlar om hur styrdokumenten i form av centralt innehåll, kunskapskrav och bedömningsmatrisen för det nationella provet ser ut i kurserna Svenska 3 (Sve03) respektive Svenska som andraspråk 3 (Sva03). Syftet är att se eventuella likheter och skillnader samt hur väl respektive kurs styrdokument överensstämmer med bedömningsmatrisen för det nationella provet. Fokus ligger på att jämföra kursernas styrdokument utifrån begreppet likvärdighet i bedömning som är ett tungt vägande argument för de nationella proven enligt Skolverket. Kursernas centrala innehåll och kunskapskrav har analyserats kvantitativt och kvalitativt. De kvantitativa aspekter som analyserats är: antal ord i texten, texternas nominalkvot eller informationstäthet samt texternas LIX-värde. De kvalitativa aspekter som studerats är polerna abstrakt- konkret samt textens samband i form av tema-rema. Resultatet visar att det fanns både kvantitativa och kvalitativa skillnader mellan kursernas styrdokument. Sva03 har ett centralt innehåll som är längre i antal ord och med en betydligt mycket högre nominalkvot än den för kursen Sve03. Kursen Sva03 skilde ut sig även när det gällde kunskapskraven (för betyget E) där kursen har ett betydligt högre LIX-värde än Sve03. Kvalitativa skillnader hittades likaså. Styrdokumenten för Sva03 är exempelvis mer abstrakt formulerade än de för Sve03. De texter som visade störst likheter var bedömningsmatriserna för det nationella provet och respektive kurs. I jämförelse med styrdokumenten för kurserna stämde matrisen bättre för Sve03 än för Sva03. Detta kan vara ett tecken på att det nationella provet inte ger en möjlighet att bedöma eleverna som läser Sva03 på ett likvärdigt sätt.

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Cheng, Biao. "Using Social Network Analysis to Investigate Potential Bias in Editorial Peer Review in Core Journals of Comparative/International Education." Diss., CLICK HERE for online access, 2006. http://contentdm.lib.byu.edu/ETD/image/etd1633.pdf.

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FICARA, Annamaria. "Social network analysis approaches to study crime." Doctoral thesis, Università degli Studi di Palermo, 2022. http://hdl.handle.net/10447/537005.

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Social Network Analysis (SNA) studies groups of individuals and can be applied in a lot of areas such us organizational studies, psychology, economics, information science and criminology. One of the most important results of SNA has been the definition of a set of centrality measures (e.g., degree, closeness, betweenness, or clustering coefficient) which can be used to identify the most influential people with respect to their network of relationships. The main problem with computing centrality metrics on social networks is the typical big size of the data. From the computational point of view, SNA represents social networks as graphs composed of a set of nodes connected by another set of edges on which the metrics of interest are computed. To overcome the problem of big data, some computationally-light alternatives to the standard measures, such as Game of Thieves or WERW-Kpath, can be studied. In this regard, one of my main research activities was to analyze the correlation among standard and nonstandard centrality measures on network models and real-world networks. The centrality metrics can greatly contribute to intelligence and criminal investigations allowing to identify, within a covert network, the most central members in terms of connections or information flow. Covert networks are terrorist or criminal networks which are built from the criminal relationships among members of criminal organizations. One of the most renowned criminal organizations is the Sicilian Mafia. The focal point of my research work was the creation of two real-world criminal networks from the judicial documents of an anti-mafia operation called Montagna conducted by a specialized anti-mafia police unit of the Italian Carabinieri in Messina (i.e., the third largest city on the island of Sicily). One network includes meetings and the other one records telephone calls among suspected criminals of two Sicilian Mafia families. This dataset is unique and it might represent a valuable resource for better understanding complex criminal phenomena from a quantitative standpoint. Different SNA approaches have been used on these Montagna networks to describe their structure and functioning, to predict missing links, to identify leaders or to evaluate police interventions aimed at dismantling and disrupting the networks. Graph distances have been used to find a network model able to properly mime the structure of a Mafia network and to quantify the impact of incomplete data not only on Mafia networks such as the Montagna ones but also on terrorist and street gangs networks. The two simple Montagna networks have been finally used to build a multilayer network trying to obtain a more nuanced understanding of the network structure and of the strategic position of nodes in the network.

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Wadsworth, Cassidy Jo. "Reject or Redemptive Fathers? A Content Analysis of Father Portrayals in Top Box Office Family Films." BYU ScholarsArchive, 2015. https://scholarsarchive.byu.edu/etd/5818.

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More research is needed to fully understand the way in which parents, particularly fathers, are portrayed in family films and the effects those portrayals might have. Viewers, particularly parents, need to understand how the material their children view presents reality and how it may shape their children's perspectives of the real world, particularly where the family unit and parenting role are concerned. By exploring these portrayals through the lens of Cultivation Theory, this study sought to answer this overarching question: How are fathers portrayed in family films as opposed to television? This quantitative study explores the top twenty films from the 1980s, the 1990s and the decade spanning 2004-2014 in order to ascertain this. Families within those films, particularly parents and most specifically fathers, are the primary subjects of study. Observations were made through content analysis. The findings show that fathers are portrayed more positively in family films than they are on television. The data suggest that the differences between fathers and mothers in film are not so marked and sexist as they are in television shows, and that fathers may exert a stronger and more positive role in film families than they do in television families. This study begins to establish film as a genre to further be explored as a medium for family relations studies as television has been. Film is a powerful media tool in its own right and should further be studied with regard to portrayal of families in its material.

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Cazan, Ioana. "Analyse de l'évolution de la relation banque-entreprise, dans la perspective de la théorie des stakeholders, dans les conditions du passage d'une économie centralisée vers une économie en transition. Le cas de la Roumanie." Nice, 2002. http://www.theses.fr/2002NICE0022.

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Les changements de l'Europe Centrale et de l'Est ont bouleversé le paysage économique dans cette partie du monde. Les agents de la vie économique ont du s'adapter, pour faire face aux nouvelles conditions. Dans ce contexte, la relation banque - entreprise a du évoluer. L'objet de notre recherche est justement l'évolution de cette relation. A partir de l'ancienne relation banque - entreprise, telle qu'elle était dans une économie centralisée, nous présentons et analysons les changements qui ont été faits. Les résultats obtenus mettent en évidence l'obtention de l'attribut de légitimité informelle et de l'attribut de légitimité pragmatique. Ces attributs étaient absents de la relation banque - entreprise dans une économie centralisée. Leur obtention signifie la liberté de faire ses propres choix (la liberté informelle), et la liberté de suivre son propre intérêt (la légitimité pragmatique). La nouvelle relation banque - entreprise ainsi apparue est une relation entre deux stakeholders, entre deux vrais partenaires. Les évolutions sont étudiées et mises en évidence par l'analyse du dossier de crédit, et par les changements faits à ce niveau-là.

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Nedkovski, V. "Enhancing the employee's innovative behaviour: A social network perspective." Doctoral thesis, Università degli Studi di Milano, 2017. http://hdl.handle.net/2434/505721.

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The thesis is composed of three, highly interrelated studies. In the first paper, we explore the motivational antecedents of advantageous network positions. Specifically, we propose a counterpoised relationship between intrinsic and extrinsic motivation from one, and in-degree centrality in advice networks on the other hand. We show that intrinsic motivation is positively related to in-degree centrality, whereas the impact of extrinsic motivation on in-degree centrality is negative. Furthermore, we suggest that such an outcome can be expected also when we consider the motivational orientation of the ego’s advice providers. With this, we provide new knowledge about the motivational micro-foundations of social networks (Tasselli et al., 2015). In the second study, we go a step further to show that in-degree centrality mediates the relationship between intrinsic motivation and innovative behaviour. These findings contribute to the literatures on motivation and creativity, which have for long focused solely on psychological mechanisms to explain the well-established relationship between intrinsic motivation and innovative behaviour (e.g. Grant and Berry, 2011). Finally, in the third paper, we focus on the conditions under which brokerage is related to innovative behaviour. By showing that network diversity moderates this relationship, we contribute to the ongoing debate about the contextual conditions that enable or impede brokers to enhance their innovative behaviour (e.g. Tortoriello and Krackhardt, 2010). The three papers rely on the same dataset, which was collected in a multinational company, located in the Northern Italian region of Lombardy. All the employees (N = 134) were invited to participate in our online survey, which was distributed to them via e-mail. The company’s core business is providing consulting services and solutions regarding efficient consumption and use of energy. The clients’ portfolio is composed of large energy consumers such as manufacturing companies, large corporations as well as public institutions. To satisfy the differing needs of its customers, and at the same time to gain competitive advantage, the company is devoted to nurturing a highly innovative corporate climate. During our preliminary interviews with the director of Human Resources Department, we were informed that the company is highly committed in fostering an environment, where employees are encouraged and rewarded for their innovative beahviour. The individual innovative behaviour is indeed, a substantial part of the overall employees’ performance appraisal system. Moreover, the organizational chart of the company shows that the formal structure is set horizontally, which is expected to foster an increased collaboration and interaction among organizational members (Tichy et al., 1979). The preliminary interviews with the HRM further suggested that the company cultivates an informal corporate culture and collaborative leaderships style, where employees are free to choose their collaborators. Taking into consideration the factual conditions, I believe that the company represents an appropriate empirical setting for addressing the research questions that I would try to address in this thesis.

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Arnesén, Lisa. "Vems landskap ska förändras för att öka den biologiska mångfalden? : En studie av skillnaderna i odlingslandskapets konnektivitet med avseende på två skyddsvärda arter med olika preferenser." Thesis, Högskolan i Skövde, Institutionen för biovetenskap, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:his:diva-9641.

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Organisms relevant for nature conservation dont follow administrative borders. Because of this there is a need for a landscape perspective within conservation and planning, and a need for the species of interest to have legal protection. Network analysis adapted for ecological purposes has grown to become a powerful tool for studying and communicating the relationships between species dispersion and access to habitat. In this study the following question is posed: How is the Osmoderma eremita and the Pernis apivorus dispersal possibilities in the small scale cultivated landscape of Borås affected by exploitation in respect to a) dispersal ability, b) habitat quality, c) position of habitat patches in a network? The analysis were based on municipal and regional nature conservation data, which in due to confidentiality is not accounted for in the report by maps, coordinates, etc. Several networks were established for both species to indicate how habitat patches are distributed today and how the species dispersal changes depending on which patches are excluded – this was done to imitate how exploitation can affect the species future survival and dispersion. The results showed that the O.e. is mainly inhibited by its poor dispersal abilities, followed by patch position, while the P.a. is the most affected by degrading habitat quality. The most important conclusions of the study were that the O.e. natural dispersal may be restricted but can be improved by linking small network components together and by maintaining the largest components. As for the P.a. it was concluded that a different type of analysis, focusing on its behaviour and need for different patches for different purposes, would generate more interesting results.
Eftersom skyddsvärda organismer inte följer administrativa gränser behövs ett landskapsperspektiv i naturvårds- och planarbete, och de arter som studeras behöver ha juridiska belägg för att skyddas. Nätverksanalyser anpassade för ekologi har vuxit fram som ett kraftfullt verktyg för att studera och kommunicera sambanden mellan arters spridning över större områden. I denna rapport ställs därför frågan: hur läderbaggens (Osmoderma eremita) respektive bivråkens (Pernis apivorus) spridningsmöjligheter i odlingslandskapet i Borås kommun påverkas vid exploatering, med avseende på a)spridningsförmåga, b) habitatkvalitet c) habitatpatchers position i ett nätverk? Analyserna baserades på kommunal och regional naturvårdsdata, som p.g.a. sekretess inte redovisas med kartmaterial, koordinater eller liknande. Flera nätverk etablerades för varje art för att indikera hur nätverken av patcher ser ut idag och hur arternas spridning förändras beroende på vilka patcher som utesluts – detta för att imitera hur exploatering kan påverka arternas fortsatta överlevnad och spridning. Resultaten visade att läderbaggens största begränsning är dess dåliga spridningsförmåga, tätt följd av patchernas position, medan bivråken påverkas mer av habitatkvalitet. De viktigaste slutsatserna som kunde dras var att läderbaggens naturliga spridning må vara begränsad men kan förbättras genom att länka samman små nätverkskomponenter och fortsätta sköta de som är störst idag. För bivråkens del skulle en annan typ av analys med mer fokus på artens beteende och behov av olika patcher för olika aktiviteter ge ett bättre underlag.

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Hernandez, Perez Sara. "Que faut-il choisir entre une gestion centralisée et un système d’autogestion base sur des mécanismes de marché pour réduire le trafic illégal des espèces faunistiques sauvages : analyse comparative économique et institutionnelle appliquée aux tortues marines en Colombie." Thesis, Paris 10, 2012. http://www.theses.fr/2012PA100206/document.

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Depuis plus de 30 ans, la Colombie construit sa politique de préservation des espèces faunistiques et de lutte contre le trafic illégal de ces espèces. Ce cadre institutionnel national s’est vu renforcé par la ratification de la convention CITES (Convention sur le commerce international des espèces de la flore et de la faune sauvages menacées d’extinction) en 1981. Pourtant, ce cadre institutionnel ne suffit pas à infléchir sur le trafic illégal des tortues marines en Colombie. L’analyse des failles du mode de régulation de type « commande et contrôle » montre les limites de l’intervention de l’Etat comme seul modèle possible à gérer le trafic illicite de tortues marines. D’où ma proposition de concevoir et mettre en place un mécanisme de quotas négociables de tortues marines décroissants dans le temps, renforcé par arrangements contractuels. Cette thèse a pour objectif de comparer l’efficacité de ces deux modes de gouvernance à réduire le trafic illégal de tortues marines, du point de vue la performance environnementale, de l’efficacité économique et de l’équité sociale. J’ai évalué les coûts de transactions pour démontrer que la variation dans la structure des coûts de transactions et la distribution de ces coûts auprès des acteurs concernés influent sur la performance finale du cadre institutionnel. Une analyse coûts-avantage a été réalisée pour justifier d’un changement institutionnel, en complément de l’analyse des coûts de transactions. Cette étude s’est situe au nord de la Colombie, sur un territoire de 30 km, territoire des indigènes Wayùu, étant le plus concerné par le trafic illégal de tortues vertes (Chelonia mydas) et tortues à écailles (Eretmochelys imbricata)
For over 30 years, Colombia built its national policy to protect wildlife species against the illegal traffic. The national institutional framework was strengthened by the ratification of the CITES (Convention on International Trade in Endangered Species of flora and fauna threatened with extinction) in 1981. However, this institutional framework is not sufficient to curb the illegal trade of marine turtles species. Despite some success to protect and recover some species, what really matters is the effectiveness of the national policy to conserve wildlife species. Hence my proposal to design and implement a cap and trade system based on transferable quotas decreasing in time, reinforced by contractual arrangements. This self-organized system aims at having zero catches level and enhance conformity and cooperation within the environmental regulation. This thesis aims to compare the efficacy of these two modes of governance to reduce the illegal trade of sea turtles based on the following criteria: the environmental performance, economic efficiency and social equity. I pursuit by estimating the corresponding transaction costs to show that the variation in the structure of transaction costs and the distribution of these costs among stakeholders affect the final performance of the institutional framework. Cost-benefit analysis was performed to justify institutional change, in addition to the analysis of transaction costs. This study is located in the north of Colombia, an area of 30 km, indigenous Wayuu territory, being more concerned with the illegal green turtles (Chelonia mydas) and hawksbill (Eretmochelys imbricata)

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Dissertations / Theses on the topic 'Analyse de centralité'

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