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Ziel des Beitrags ist, einen Überblick über aktuelle Entwicklungen und Ausprägungen von MOOCs sowie die Erfahrungen und Ergebnisse aus der Untersuchung von zwei MOOCs vorzustellen, die 2011 und 2012 durchgeführt wurden. Besondere Schwerpunkte liegen dabei auf der Bedeutung und Ausprägung der Beteiligungsformen in den verschiedenen MOOC-Formaten, der Beteiligung in den beiden untersuchten MOOCs sowie auf deren Unterschiede auch aufgrund von Veränderungen des Kursdesigns.

In this work, we study the galaxy cluster MS0735.6+7421 that hosts the most energetic observed active galactic nucleus (AGN) outburst so far. Explaining this very energetic AGN outburst is found to be challenging. McNamara et al. 2009 grappled with this problem and proposed two possible solutions: either the black hole (BH) must be an ultra massive one (with mass $> 10^{10} \ \text{M}_\odot$), or the efficiency of the mass to energy conversion ($\epsilon$) should be higher than the generally assumed value of $\epsilon \sim 0.1$. However, the efficiency of the mass to energy conversion depends on the BH's spin {Benson and Babul 2009}; higher $\epsilon$ can be achieved with a higher spinning BH. Here, we explore the second solution in detail, and ask the question: How did the BH spin up to the very high spins in advance of the outburst? We also explore the attendant physical processes, such as star formation, during the spin-up mode and investigate the associated observational implications. Comparing our results with what is generally expected from simulations and observational studies suggests that for all intents and purposes, the existence of an ultra massive BH is the simplest solution. / Graduate

Analyzing massive-data sets and streams is computationally very challenging. Data sets in systems biology, network analysis and security use network abstraction to construct large-scale graphs. Graph algorithms such as traversal and search are memory-intensive and typically require very little computation, with access patterns that are irregular and fine-grained. The increasing streaming data rates in various domains such as security, mining, and finance leaves algorithm designers with only a handful of clock cycles (with current general purpose computing technology) to process every incoming byte of data in-core at real-time. This along with increasing complexity of mining patterns and other analytics puts further pressure on already high computational requirement. Processing streaming data in finance comes with an additional constraint to process at low latency, that restricts the algorithm to use common techniques such as batching to obtain high throughput. The primary contributions of this dissertation are the design of novel parallel data analysis algorithms for graph traversal on large-scale graphs, pattern recognition and keyword scanning on massive streaming data, financial market data feed processing and analytics, and data transformation, that capture the machine-independent aspects, to guarantee portability with performance to future processors, with high performance implementations on multicore processors that embed processorspecific optimizations. Our breadth first search graph traversal algorithm demonstrates a capability to process massive graphs with billions of vertices and edges on commodity multicore processors at rates that are competitive with supercomputing results in the recent literature. We also present high performance scalable keyword scanning on streaming data using novel automata compression algorithm, a model of computation based on small software content addressable memories (CAMs) and a unique data layout that forces data re-use and minimizes memory traffic. Using a high-level algorithmic approach to process financial feeds we present a solution that decodes and normalizes option market data at rates an order of magnitude more than the current needs of the market, yet portable and flexible to other feeds in this domain. In this dissertation we discuss in detail algorithm design challenges to process massive-data and present solutions and techniques that we believe can be used and extended to solve future research problems in this domain.

This thesis contributes to knowledge about how Massive Open Online Courses (MOOCs) as educational online platforms can be utilized in achieving the purposes of Education for Sustainable Development (ESD). Starting out from a view that, in the face of global challenges every individual is an important actor with agency to drive for necessary social changes, the overall ambition of this thesis is to investigate the role of MOOCs, as a specific form of online learning, in empowering and enabling learners to acquire the competences needed to take responsible actions and informed decisions in a rapidly changing, interdependent and unequal world. More specifically, this thesis aims at providing a deeper insight into the question of whether the pedagogic approaches used in ESD (learner-centered, action-oriented and transformative learning) and the learning processes that they promote, can be incorporated in the MOOC environment. This issue holds importance due to the global and intergenerational character of ESD where providing access to training and learning for sustainable development for all is vital. In this respect, MOOCs have been envisioned as revolutionary in the provision of access to education to a wider audience. Nevertheless, the “massive” part of MOOCs could pose a challenge in connection to ESD, due to the fact that ESD is not easily generalized and aims at upholding local relevance. Therefore, this thesis also looks into the question of the implications posed by scale and the issue of scalability when investigating how MOOCs can enable the application of ESD pedagogic approaches, thus also contributing to the achievement of the purposes and learning objectives of ESD and Climate Change Education as its constituent part. Utilizing a case study methodology, the MOOC in Climate Change Leadership at Uppsala University is chosen as a case example of the MOOC learning environment and learning circumstances. By conducting a content analysis of the MOOC materials as presented on the online platform, and developing an analytical framework based on the ESD pedagogic approaches, this thesis reaches the conclusion that some aspects of the ESD approaches benefit from the networked environment and large-scale participation in the MOOC environment, while the incorporation of others is more challenging and asks for further research and improvement of the MOOC learning environment in order for them to provide for the optimal learning circumstances and outcomes in connection to ESD.

La recherche des exoplanètes traverse aujourd'hui une période décisive. D'un côté, notre connaissance des planètes géantes gazeuses s'est considérablement développée, et l'objectif de la recherche est maintenant de caractériser leurs propriétés physiques et de mieux comprendre leurs mécanismes de formation et d'évolution. D'un autre côté, la précision et la stabilité des instruments ont atteint un niveau qui rend techniquement possible la détection de planètes telluriques situées dans la zone habitable de leur étoile. Cependant, les perturbations du signal dues à l'étoile elle-même constituent un obstacle important à cette avancée. Mon travail de thèse se situe à la rencontre de ces problématiques. Il a consisté d'une part en l'analyse de deux relevés de vitesses radiales visant des étoiles relativement exotiques pour la recherche d'exoplanètes: les étoiles naines de type AF massives. Ce travail a donné lieu à la première caractérisation de la population de planètes géantes autour de ces étoiles et a montré que les mécanismes de migration planétaire étaient au moins partiellement inhibés autour de ces étoiles par rapport aux étoiles de type FGKM. Dans un second temps, j'ai conduit les observations et l'analyse des premiers résultats de deux grands relevés de vitesses radiales débutés pendant ma thèse et visant à détecter des planètes géantes en orbite autour d'étoiles jeunes et proches. Ces étoiles jeunes sont les seules sources pour lesquelles une exploration complète des planètes géantes à toutes les séparations devient possible, par combinaison des techniques de vitesses radiales et de l'imagerie. Cette combinaison permettra de tester de manière unique les modèles de formation et d'évolution planétaire. Les résultats provisoires de ces relevés indiquent une absence de planètes géantes à très courte séparation (Jupiters chauds) autour de nos cibles. Un autre résultat intéressant est la découverte d'une binaire spectroscopique eccentrique au centre d'un système planétaire imagé à grande séparation. Pour compléter cette approche observationnelle et mieux évaluer la détectabilité des exoplanètes semblables à la Terre, j'ai étalonné et caractérisé un modèle entièrement paramétré de l'activité d'une étoile semblable au Soleil et de son impact sur les vitesses radiales. Je l'ai dans un premier temps étalonné en comparant ses résultats à ceux obtenus à partir d'observations des zones actives du Soleil, puis je l'ai utilisé pour caractériser l'impact de l'inclinaison de l'étoile sur le signal induit par l'activité. Ce modèle paramétré ouvre de très nombreuses possibilités, étant en effet potentiellement adaptable à des types d'étoiles et d'activité différents. Il permettrait ainsi de caractériser les perturbations en vitesses radiales attendues pour chaque cas testé, et donc à la fois de déterminer quelles étoiles et quels types d'activité sont les plus favorables pour la détection de planètes de masse terrestre dans la zone habitable. En explorant ces trois problématiques en apparence très diverses mais complémentaires, j'y ai retrouvé un motif commun, celui de l'importance des étoiles elles-mêmes et de la physique stellaire pour la recherche d'exoplanètes. / The search for exoplanets has reached a decisive moment. On the one hand, our knowledge of giant gaseous planets has significantly developed, and the aim of the research is now to characterize their physical properties and to better understand the formation and evolution processes. On the other hand, the instrumental precision and stability have reached a level that makes it technically possible to detect telluric planets in the habitable zone of their host star. However, the signal alterations induced by the star itself definitely challenge this breakthrough. My PhD stands at the crossroads of these problems. It consisted first in the analysis of two radial velocity surveys dedicated to stars somewhat exotic to exoplanet searches: the massive AF dwarf stars. This work has led to the first characterization of the giant planet population found around these stars and has showed that the planetary migration mechanisms were at least partially inhibited around these stars compared to FGKM stars. I then made the observations and the first analysis of two radial velocity surveys dedicated to the search for giant planets around young, nearby stars. Young stars are the only sources for which a full exploration of the giant planets at all separations can be reached, through the combination of radial velocities techniques and direct imaging. Such a combination will allow to test uniquely the planetary formation and evolution processes. The first results of these surveys show an absence of giant planets at very short separations (Hot Jupiters) around our targets. Another interesting result is the detection of an eccentric spectroscopic binary at the center of a planetary system imaged at a wide separation. To complete this observational approach and better estimate the detectability of Earth-like planets, I calibrated and characterized a fully parameterized model of the activity pattern of a Sun-like star and its impact on the radial velocities. I first calibrated it by comparing it to the results obtained with observations of the solar active structures, and then characterized the impact of stellar inclination on the activity-induced signal. Such a fully parameterized model is potentially adaptable to different types of stars and of activity and would thus allow to characterize the expected radial velocity jitter for each tested case, and then allow both to determine which types of stars and of activity patterns are the most favorable for detecting Earth-like planets in the habitable zone. While investigating these three seemingly different but complementary topics, I found that they shared a basic feature, namely the importance of the stars themselves and of stellar physics in exoplanet searches.

La conception de machines électriques tend à intégrer l’impact des procédés de fabrication dans le but d’optimiser la conversion d’énergie mécanique en énergie électrique, en lien avec la maîtrise des propriétés électromagnétiques des composants des machines. Les interactions entre procédés, propriétés électromagnétiques et autres propriétés du matériau ont beaucoup été étudiées dans le cas des tôles compte tenu de leur large utilisation dans le domaine de l’électrotechnique et des moyens de caractérisation magnétique normalisés actuels. Cependant, un alternateur à griffes, utilisé dans l’industrie automobile, comporte des composants massifs au rotor pour la conversion mécanique/électrique. Ces composants, appelés roues polaires, sont obtenus par un processus de fabrication comprenant des opérations de forgeage et dont l’impact sur les performances de la machine est encore mal déterminé. Les nouvelles problématiques que pose ce genre de pièces ont mené, dans le cadre des présents travaux, au développement d’une méthodologie spécifique comprenant : l’identification du lien procédés – produit, le développement d’un banc de caractérisation magnétique d’échantillons représentatifs ainsi que la construction de lois de comportement sur des paramètres matériau pertinents à partir de ces échantillons. Les résultats, en accord avec la littérature, ont montré un impact fort de la déformation plastique et de la taille de grain sur les propriétés magnétiques. Cela se traduit, une fois les propriétés modifiées intégrées dans la simulation des performances d’un alternateur, par une baisse significative du courant débité. / The design of electrical machines aims to integrate the impact of the manufacturing process in order to optimize the conversion from mechanical to electrical energy, with the consideration of the electromagnetic properties of the machine components. The interactions between processes, electromagnetic properties and other material properties have been well studied in the case of the steel laminations, regarding their wide use in electrical engineering and the current standards of magnetic characterization devices. However, the claw pole alternator used in automotive industry has a rotor with massive components for the mechanical-to-electrical energy conversion. These components, called claw poles, are manufactured with forging operations whose impact on the machine performance is yet not well determined. The new challenges brought by this kind of work pieces led, in the frame of the current study, to the development of a specific methodology involving: identification of the link process – product, designing of a magnetic characterization device specific for representative samples as well as the establishment of behavior laws regarding relevant material parameters. The results, in accordance with the literature, have shown a strong influence of plastic strain and grain size on magnetic properties. Once these modified properties integrated in the electromagnetic model of the claw pole alternator, a significant decreased of the output current is eventually observed.

[pt] Nesta tese é apresentada uma arquitetura altamente escalável para storytelling interativo em massa baseado em streams de vídeo. A arquitetura proposta pode suportar diferentes demandas para interatividade, geração e visualização de histórias em ambientes de televisão digital, que inclui set-top boxes de TV, tablets, smartphones e computadores. Nesta arquitetura, a mesma história se adapta ao aparelho do espectador em termos de renderização e processo de interface automaticamente. Também é apresentado um modelo para compartilhar histórias interativas em massa. Além disso, o sistema proposto preserva a coerência lógica da história que se desenrola enquanto a mantém interativa. / [en] In this thesis we present a highly scalable architecture for massive multi-user interactive storytelling systems based on video streams. The proposed architecture can support different demands for interactivity, generation, and visualization of stories in digital television environments, which include TV set-top boxes, tablets, smartphones, and computers. In this architecture, the same story adapts itself to the spectator s device in terms of rendering and interface processes automatically. Also a model for sharing massive interactive stories is presented. Moreover, the proposed system preserves the logical coherence of the story that unfolds while keeping it interactive.

La Conférence du Désarmement en tant que « forum unique de négociation multilatéral sur le désarmement » subit une impasse de plus de 15 ans. Elle demeure sans aucun résultat après la dernière négociation du TICE qui s’est terminé en 1996. C’est la raison pour laquelle, tout d’abord nous essayons d’analyser les cadres de négociation et les contenus des traités dans le domaine du désarmement et de la non-prolifération en présentant en deux titres, pour analyser la formation de la normativité et des accords dans ce domaine. En effet, cette thèse couvre tous les types d’armes et ses traités pour la limitation ou l’interdiction de l’arme de destruction massive, y compris les armes nucléaires, biologiques et chimiques, et conventionnelles. La portée de ces instruments varie aussi à partir de traités comme le TNP jusqu’au soft law comme le programme d’action pour les armes légères et de petit calibre. En ce qui concerne la formation de la normativité, le dernier titre essaye d’analyser aussi l’aspect juridique de la négociation et le mécanisme pour renforcer le respect du traité. Ce sont les éléments essentiels pour la naissance de la normativité primordiale des accords en tant que documents juridiquement contraignants, et leur validité. Nous essayons aussi l’analyse du soft law et de la jurisprudence de la Cour internationale de Justice comme source de normativité dans l’ensemble de normes autour du désarmement et de la non-prolifération. C’est ainsi que cette thèse va essayer l’étude minutieuse des problèmes autour de la formation et de la normativité des accords multilatéraux dans le domaine du désarmement et de la non-prolifération. / The Conference on Disarmament as “the single multilateral forum of negotiation on disarmament” suffers from more than 15 years’ stalemate. Its annual session ends without any result every year after the last negotiation of the CTBT until 1996. That is the reason why this doctoral dissertation tries to analyze the framework of negotiation first of all and then the content of the treaties in the field of disarmament and non-proliferation. It also tries to analyze for the normativity of the various instruments in this field. In fact, this dissertation covers every type of weapons and the treaties for their limitation and prohibition starting for weapons of mass destruction to conventional weapons. The coverage of the instruments also varies from the treaties such as NPT to the soft law like the program of action for small arms and light weapons. As for the formation of the normativity, the last part tries to analyze the legal aspect of the negotiation and the mechanism to strengthen the compliance of the treaty. They are the essential elements for the primordial normativity of the treaties as legally binding documents and their validity. The analysis also covers the soft law and legal cases sentenced by the International Court of Justice as a source of normativity in the holistic approach so as to clarify the norms related to disarmament and non-proliferation. In this way this doctoral dissertation tries the in depth study of the process for the formation and the normativity of the multilateral treaties in the field of disarmament and the non-proliferation.

Big Data on cities and regions bring new opportunities and challenges to data analysts and city planners. On the one side, they hold great promise to combine increasingly detailed data for each citizen with critical infrastructures to plan, govern and manage cities and regions, improve their sustainability, optimize processes and maximize the provision of public and private services. On the other side, the massive sample size and high-dimensionality of Big Data and their geo-temporal character introduce unique computational and statistical challenges. This chapter provides overviews on the salient characteristics of Big Data and how these features impact on paradigm change of data management and analysis, and also on the computing environment. / Series: Working Papers in Regional Science