Compte rendu Kopylov

Ici j'écris des trucs en texte clair. que ce passe-t-il avec les 'a  apostrophes ?

One of the initial promises of MOOCs was to enable learners from around the world to learn and build knowledge together. There is significant research showing that student collaboration can improve learning outcomes. Students are forced to externalize their ideas, working with multiple shared representations of knowledge structures, and collaborating to converge on a shared understanding of meaning. (Fischer & Mandl, 2005; Stahl, Koschmann, & Suthers, 2006). Globally distributed MOOCs bring in the added potential advantage of incredible student diversity, in terms of geographical location, life experience, culture and language. Ideally, we would treat the number of learners, and their diversity, as an incredible opportunity for rich learning and communal knowledge building, rather than as an obstacle to be overcome. Early work on MOOCs from Kotturi, Bernstein and Klemmer (2015) have shown that students learn more from geographically diverse discussion groups. However, several studies show that simply asking students to solve a task or discuss a problem is unlikely to engage them in a productive process of collaborative knowledge construction (Cohen, 1994; Mandl, Gruber, & Renkl, 1996). A key question, which has guided much of the research in the field of Learning Sciences, is how this process can best be supported and guided by an instructor or learning designer, as well as by the careful design of the physical and digital learning context and its affordances. Fischer and his colleagues (Kollar, Fischer, & Hesse, 2006; Fischer, Kollar, Stegmann, & Wecker, 2012) proposed a form of scaffold, which they call an “external collaboration script”, that specifies the roles and goals of the participants, allocates material and tasks, and coordinates student grouping and learning activities. This new way of conceptualizing a “script” became a more general means of referring to any designs that helped to guide students and teachers through prescribed forms of learning interaction (Dillenbourg & Jermann, 2007). Once scripts have been designed (Tchounikine (2008) presents a proposed design approach), they need to be implemented or enacted. Dillenbourg, Nussbaum, Dimitriadis, and Roschelle (2012) call this process “orchestration”, defined as “how a teacher manages, in real time, multi- layered activities in a multi-constraints context” (p. 1). CHALLENGE Despite a long history of research on pedagogical scripts for small groups and school classes, there have been very little research on appropriate pedagogical scripts that take advantage of very large numbers of heterogeneous learners. Håklev (2016) suggested some design principles for pedagogical scripts for MOOCs, with a matrix of weekly thematic scripts which feed into a set of interdependent longer running scripts. We need more creativity and sharing in this area, and to enable this, a common notation, or educational modeling language, as well as tools for editing and sharing educational scenarios, could help. However, our largest challenge is how to implement these scripts in very large settings. A school teacher can fall back to using sticky notes and “talk to your neighbour” strategies, but currently implementing even a trivially simple script in a MOOC which is not supported by the platform (even wanting to do peer-review, but in a different way than the built-in approach) requires significant software development resources not available to most groups. This paper will present a suggested common educational modeling language called Orchestration Graphs, our prototype framework for authoring and collaborating on Orchestration Graphs, as well as the design of an ecosystem of activities and operators which can be “run” by an Orchestration Engine. We posit that this is an innovation which has the potential to promote the development of richer collaborative activities at scale. ORCHESTRATION GRAPHS An Orchestration Graph is a structured view of a learning scenario, consisting of learning activities (nodes). These nodes have a start and an end-time. The X-axis of the graph denotes time, and the placement and width of activities denote start and duration. In short synchronous scripts, these time cut-offs might be absolute, to enable students to “sync up” (e.g., after five minutes, everyone has to switch groups), whereas in long-running asynchronous activities, activities might be open for several days, and students can choose when to visit them. Activities take place at different social planes (Y axis), the three key ones being individual activities, team-activities, and whole class activities. One can also add additional planes to include the community and the entire world outside of the specific course. Activities (nodes) are connected through edges. These can contain pedagogical justifications (e.g., activity 1 is an advanced organiser for activity 2), learning analytics information (e.g., student success is activity 1 is 34% correlated with/predictive of success in activity 2), and operators which transform student output, and generate social structures. Prior art The idea of a modelling language that visually expresses pedagogical design also has a long history with ‘Educational Modelling Languages’(EML). The best known EML is LEARNING DESIGN (IMS-LD3) a standardized specification of learning activities. However, it does not support rich collaborative scenarios, for instance with automatic group formation (Van Es & Koper, 2006). LAMS (McAndrew, et al, 2006) offers a graphical editor of templates based on IMS-LD and executes them. COLLAGE (Hernandez-Leo et al, 2006) proposes richer design patterns, which can be executed within GLU!-PS (Prieto et al, 2011). Two recent platforms, ILDE (Hernandez-Leo et al, 2014.) and LEARNING DESIGNER, inspired by Laurillard’s popular book (2013), builds upon a community of designers. The latter provides feedback to designers, for instance the proportion of various learning activity types (investigation, practice, etc.). However, the designed scenarios are not runnable on the platform. EXAMPLE Collaboration scripts (graphs) can describe tightly orchestrated live interactions, such as a “jigsaw script” centred around earthquake mitigation in San Francisco, where each team comprises 4 roles: the mayor of San Francisco (a2a), a seismology expert (a2b), a security o cer (a2c), and an insurance agent (a2d). Students begin by discussing the task in groups composed of all four roles, but are then interrupted by “expert group meetings”, where all mayors meet with each other separately. This cycle can be repeated several times, before the teams (a4), which are then aggregated by the teacher (a5).

_Abstract_ This initial report serves as a background structure for the later final report. It does not claim to be complete, as it only demonstrate that the chosen mesh and physical models are verified, and just need to be refined before the post-processing.

AbstractHuman movements are associated with the feeling that sensory consequences are self-generated (sense of agency). Though it has shown that the sense of agency for our movements is sensitive to the temporal coherence between our actions and their outcomes, previous research has focused on a particular temporal ordering, namely that movements (action) precede sensory consequences (outcome). Here, we wondered whether SOA could be felt for movements in the artificial case where this ordering is inversed; when sensory effects precede their corresponding movement. To test this, we predict voluntary motor movements (finger deflections) and provide visual sensory consequences that precede them (negative delay). Furthermore, in the same participants, we test the standard temporal ordering, investigating trials where motor movements precede their visual consequences (positive delay). By performing hundreds of trials per participant and utilizing methods from psychophysics, we fully characterize SOA as a function of the temporal offset between visuo-motor actions and effects, offering a comprehensive view of the dependence of SOA on the temporal coherence of action and effect.IntroductionMaterials and MethodsThe principle of the experiment is to let the participants perform a self-paced simple hand movement (index finger deflection) within a XX seconds trial and to show them, in place of their real hand, a virtual hand performing the same movement (3D animation) but at a random time within the same interval. Two cases can therefore occur: either the participant is first (movement onset precedes animation onset), either the animation is first (animation onset precedes movement onset). For each trial the participants answered a forced choice question about whether the movement they saw corresponded to the movement they made. The system was precisely tuned to guarantee an optimal visual correspondence between real and virtual hands, a precise recording of the timings, and to minimize the time interval between the two events by influencing the randomization of the animation onset time.ParticipantsFor the main experiment 10 healthy, right-handed participants were recruited (ages XX.X ± X.XXX mean±SD; XXX females). For the pilot behavioral study, we recruited an additional 14 healthy participants (XX handed; ages XX.X ± X.XXX mean±SD; XXX females). Both studies were undertaken in accordance with the ethical standards as defined in the Declaration of Helsinki and were approved by the local ethics research committee at the University of Lausanne. Material and procedure Participants sat at a table and placed their right hand underneath a computer monitor, holding a block containing a touch sensor. The monitor occluded vision of their forearm and, in correspondence with their real hand, displayed in stereoscopic 3D a virtual hand holding a virtual block (Fig. 2A). Head movements were restrained with a chin rest and the experiment took place in a darkened room.The touch sensor, an Arduino™ microcontroller with a 16MHz sampling rate, allowed for the detection at millisecond precision of the precise moment the index finger broke contact with a conductive surface when lifting (movement onset time). The 3D graphics were rendered using OpenGL on an nVidia Quadro 2000 graphics card using Quad-Buffer extension and nVidia 3DVision glasses for stereoscopic display on a XXX monitor at 120Hz. The constant latency of the graphics hardware was measured to be 30ms and accounted for in all estimations of the visual onset times (interval from the trigger time by the CPU to the actual visual onset of the event on the LCD monitor).In a short training block, participants learned to make index finger deflections that mirrored the velocity and amplitude of an animated finger in the virtual scene. During these 20 trials, no delay was introduced between movement and visual onset.The following question was then presented and participants were asked to remember it: “Did the movement that you did correspond to the movement that you saw?” No specific explanation was given about what could correspond or not. Answers to the question were given with the left hand by pressing buttons of a gamepad (index for yes, middle finger for no, reaction times ignored).For each trial of the actual experiment, the participants saw the virtual scene appear (T0) and were instructed to lift their finger at the time of their choosing (TM, movement onset time). The animation of the virtual finger occurred at a random time (TV, visual onset time).  A question screen was displayed after both events have occurred and the trial ended after participants’ pressed a button to respond. If participants did not lift their finger before Tmax (XXs), the protocol moved forward and the trial was rejected. Timings (movement and visual onsets) and participants’ answers were logged for all valid trials.Finally, because using a purely uniform distribution for the randomization of the visual onset times (between T0 and Tmax) would require an extremely high number of trials for statistical analysis of data points with very close timings (TM and TV at less than 100ms apart), our system had a double strategy. First it tried to anticipate the movement onset time with the aim of providing visual consequences just prior to that moment by using a dynamic predictive algorithm based on per-subject movement history profiles. Second, if participants moved prior to the visual onset of the predictive algorithm, the visual consequence were presented with a delay shuffled within a uniform distribution in a small window of interest (0 to 750 ms).Experimental design and statistical analyses The first experiment consisted in 600 trials executed in 4 blocs, preceded by XX training trials. Here we manipulated the coherence (ΔT) between visual and motor events using a continuous design. To analyze these continuous data, we binned SOA responses for 20ms ΔT intervals. As our predictive algorithm used to anticipate movement onset, the number of trials for each bin was not balanced (Fig. ; Fig. SXX). To assess the electrical brain activity associated with the individual visual and motor events, two additional baseline condition blocks were recorded while participants saw the same virtual scene. In a first baseline condition, participants were instructed to relax while watching the fixation cross as the virtual finger moved (random time onset; vision only). In the second condition, participants were instructed to perform a voluntary finger deflection as in the main experiment, but no virtual visual counterpart accompanied the movement (motor only). Each experimental block consisted of XXX trials and was repeated XXX times, resulting in XXX trials. Pilot Study: Agency for virtual hands versus virtual objects· Refer to supplemental materials for our confirmation / “negative” finding that object vs body doesn’t matter? · It’s smartest if we save these extra findings for the last section in the results, briefly mention that we did it in the introduction, and describe here that it’s the same procedure as above, just with 300 trials with hand; 300 with object. 

Here we study the XXZ spin chain under the boundary strong-coupling to non-markovian baths which we model as additional spin chains . The bath spin chains essentially work as a magnetization battery that drive the spin transport through the system. More specifically we prepare one terminal of the battery in the fully up-magnetized state |11...111⟩ while the other in the down-magnetized state |00...000⟩. The global initial state is of the from |ΨS⟩=|11...111⟩|S⟩|00...000⟩, with |S⟩ being an arbitrary system state. The system itself is prepared in a demagnetized state taken and we focus most of the manuscript on the case |S⟩=|G⟩, with G labelling the ground state of the Hamiltonian. This initial configuration |ΨG⟩ induces a strongly nonlinear transport response resembling the maximal bias regime in . Lower magnetization differences between the terminals of the battery eventually lead to the linear response regime at low bias . As opposed to the Markovian open system setting , we remark that the system-battery coupling we have suggested, in general, does not map to a simple phenomenological master equation. Deriving a closed form master equation for strongly interacting systems requires, in principle, the knowledge of the full eigen-decomposition of the system Hamiltonian , thus a hopeless task for a many-body problem. Therefore, addressing the full system plus bath Hamiltonian dynamics seems most appropriate in order to capture the strong coupling regime. Furthermore, the battery bears memory on the system initial state . As an alternative we prepare the system in the GHZ state $|GHZ\rangle=(|11...111\rangle+|00...000\rangle)/$ which has macroscopic similarities to the ground state preparation such as magnetization zero, however it is orthogonal to the ground state preparation. Interestingly, this initial state |ΨGHZ⟩ leads to different dynamical signatures providing an example of how microscopic details and non-Markovianity may affect the emergent phenomena.

The world energy consumption has dramatically increased since the end of the World War II. The main share of this energy comes from fossil fuel combustion. The worldwide domestic sector consumes about 30% of the global energy supply and the biggest share of that is dedicated to space and water heating. In this context where sustainable energy consumption is required to limit our impact on the environment and the climate, energy efficiency is a key factor to successfully transition to energy sobriety. Electrically-driven heat pumps are known to be a key technology to increase our energy efficiency. More efficient, more compact, more silent heat pumps, built with less raw material, and using lower refrigerant charges are needed. In electrically-driven heat pumps, the compression process is responsible for most of the energy losses. However, for decades now, the heat pump performance has been stagnating, mainly because of the compression process efficiency which has not been increasing significantly. Consequently, the improvement of the compression process is indeed needed. A new single-stage compression unit design has been developed, built, and tested in a previous thesis work. This current thesis work uses a twin-stage successor of the initial single-stage compression unit and tests it into two oil-free domestic heat pump prototypes. This work aims at studying the integration of the radial compression units in domestic heat pumps and at demonstrating their feasibility and potential. The tested prototypes are a twin-stage Air/Water domestic heat pump and a twin-stage Brine/Water domestic heat pump. Both of them are equipped with a twin-stage oil-free radial compression unit rotating on gas bearings. By which, the maximum rotor speed of the compression units is 180 krpm. Six stable operating points have been documented with the Air/Water heat pump prototype. More notably so, the operating point A-7/W35 has been reached and demonstrates a coefficient of performance of 2.36 for a heating power of 10.7 kW. The Brine/Water heat pump prototype has been used to perform partial tests of circuit improvements, in order to solve some of the issues observed on the Air/Water prototype. The analysis of the experimental results uses a mass and energy balance modeling approach to improve the level of understanding of the internal and non measurable flows in the heat pump circuits. This model also propagates the uncertainties of the measurements through the equations. New improvements and innovative circuit layouts, notably at the level of the economizer, a key-component of the two-stage heat pump circuit, are offered to integrate further the compression unit in the heat pump circuits, and to make the whole system more efficient, more compact, more silent, less demanding in raw materials and reducing the refrigerant charge needed for the heat pump cycle. La consommation mondiale d’énergie a augmenté dramatiquement depuis la fin de la seconde guerre mondiale. La part principale de cette énergie provient de la combustion d’énergie fossile. Le secteur résidentiel consomme environ 30% de la production totale d’énergie et la plus grande part de cette dernière est dédiée au chauffage des espaces de vie et à la production d’eau chaude sanitaire. Dans ce contexte une consommation d’énergie soutenable est requise afin de limiter notre impact sur l’environnement et le climat, l’efficacité énergétique est un facteur clé pour amorcer la transition vers la sobriété énergétique. Les pompes à chaleur alimentées par électricité sont identifiées comme une technologie clé pour augmenter notre efficacité énergétique. Nous avons besoin de pompes à chaleur plus efficaces, plus compactes, plus silencieuses, construites avec moins de matières premières, et utilisant des charges en réfrigérant plus faibles. La phase de compression est responsable de la plupart des pertes d’énergie. Depuis des décennies maintenant, les performances des pompes à chaleur stagnent, principalement parce que l’efficacité de la phase de compression stagne. Par conséquent, il est nécessaire d’améliorer l’efficacité de la phase de compression. Une nouvelle conception d’unité compresseur mono-étagé a été développée, construite, et testée lors d’une thèse de doctorat précédente. La thèse présentée ici utilise une unité compresseurs bi-étagés ayant succédé à l’unité compresseur mono-étagée initiale, et a testé l’unité en question dans deux prototypes de pompe à chaleur domestique sans huile. Ce travail vise à étudier l’intégration d’unités compresseurs radiaux dans des pompes à chaleur domestiques et à démontrer la faisabilité et le potentiel de ces dernières. Les prototypes testés sont une pompe à chaleur domestique Air/Eau sans huile et une pompe à chaleur domestique Saumure/Eau sans huile. Les deux prototypes sont équipés d’une unité compresseurs bi-étagés radiaux sans huile dont l’arbre est en rotation sur des paliers à gaz. La vitesse maximum du rotor de ces unités est de 180000 tours/min. Six points de fonctionnement stables ont été documentés avec le prototype Air/Eau. Notamment, le point de fonctionnement A-7/W35 a été atteint et démontre un coefficient de performance de 2.36 pour une puissance chaleur de 10.7 kW. Le prototype Saumure/Eau a été utilisé pour procéder à des tests partiels d’amélioration apportées aux circuits de pompe à chaleur, afin d’apporter des solutions aux problèmes rencontrés avec le prototype Air/Eau. L’analyse des données expérimentales utilise une modélisation dont l’approche est basée sur les équations de conservation de masse et d’énergie. Cette approche permet d’améliorer le niveau de compréhension des débits internes ou non-mesurables du système. Le modèle propage aussi, à travers les équations, les incertitudes de mesure des données expérimentales. De nouvelles améliorations et circuits de pompes à chaleur innovants, notamment, au niveau de l’économiseur, composant-clé du circuit, sont proposés et intègrent plus intimement l’unité compresseur dans les circuits de la pompe à chaleur bi-étagée, et cela afin de parvenir à des systèmes globalement plus efficaces, plus compacts, plus silencieux, moins gourmand en terme de matières premières, et nécessitant moins de charge de réfrigérant.

In the context of the energy transition, efficiency and renewable energy integration are identified as having the highest potential for mitigating the CO₂ emissions . From the energy system engineering point of view, this means that not only one has to convert renewable energy resources into distributed energy but also to make it available to supply the energy services when they are needed. In this paper, we demonstrate the role of process system engineering for designing the future energy systems and we explore the possible role that CO₂ could play as a material to help the energy transition. Considering CO₂ as a carbon support, we show on the one hand the possible role of CO₂ in the energy system : as an energy carrier in district energy systems or as a possible carbon source for long term renewable energy storage when considering power to gas concept. We also highlight the importance of understanding the carbon cycle, considering the CO₂ in the atmosphere and the possible ways to replace fossil fuel produced CO₂ by the one harvested in the atmosphere.

IntroductionChild mortality is considered as an indicator of child health and well being UNICEF 2015. Cambodia, a low income country located in South-eastern Asia has recently achieved the Millennium Development Goal for 2015 (MDG 2015), which was to achieve an under 5 years-old-mortality (U5MR) of 39 deaths per 1000 live births UNICEF 2015. Cambodia accomplished an enormous progress during the past decades, going from 117 deaths per 1000 live births in 1990 to 29 in 2015. Rates of Neonatal mortality (number of neonates dying before reaching 28 days of age per 1000 live births) went from 41 in 1990 to 15 in 2015 the_world_bank_mortality_2015. However, even if at a country level Cambodia attained the MDG 2015, a recent study showed significant inequalities within the country Jimenez-Soto 2014. The authors showed that high-income household have a lower rate of under-5 and neonatal mortality. They also pointed out the disparities in terms of U5MR and neonatal mortality between rural and urban areas (especially in Phnom Penh). Studies linking neonatal mortality to other variables have already been done in the past. In 2009, Matsuoka and al, listed perceived barriers to utilization of maternal health service in Cambodia Matsuoka 2010. By interviewing a sample of reproductive-age women aged 15-49 years in six different communities, they conclude that 5 main barriers were present: “Financial barriers”, “Physical barriers” which includes poor geographic access to clinics, “Cognitive barriers”, “Organisational barriers” and “Psychological and socio-economical barriers”. In 1998, Shireen J. Jejeebhoy revealed a link between wife-beating and fetal and infant death based on a survey in rural India Jejeebhoy 1998. More recently, Seetha Menon, in her article: “ Unfinished Lives:  The effect of domestic violence on  neonatal and infant  mortality” Menon 2014, showed a causal relationship between domestic violence and neonatal and infant mortality.Based on this, this study aim to analyse, by using an exploratory spatial data analysis, the probable linear behaviour between the dependent variable: “Neonatal mortality rate” and other independent variables: “ Household sizes”, “Percentages of households with electricity”, “travel time to the closest health facility” and “total domestic violence” at a district level in Cambodia.