Leveraging video annotations in video-based e-learning

The e-learning community has been producing and using video content for a long time, and in the last years, the advent of MOOCs greatly relied on video recordings of teacher courses. Video annotations are information pieces that can be anchored in the temporality of the video so as to sustain various processes ranging from active reading to rich media editing. In this position paper we study how video annotations can be used in an e-learning context - especially MOOCs - from the triple point of view of pedagogical processes, current technical platforms functionalities, and current challenges. Our analysis is that there is still plenty of room for leveraging video annotations in MOOCs beyond simple active reading, namely live annotation, performance annotation and annotation for assignment; and that new developments are needed to accompany this evolution.Comment: 7th International Conference on Computer Supported Education (CSEDU), Barcelone : Spain (2014

The Impact of Interface Quality on Trust in Web Retailers

Web retailing is expected to grow at aggressive rates in future years. One of the most important factors that is slowing down this growth is the lack of trust of potential customers. So, as transactions through the internet develop and mature, success will largely be dependent on gaining and0501ntaining this trust. It has been suggested that the quality of the user interface of the Web site is a determinant of the initial establishment of trust. In this article, we describe a study where 66 subjects were asked to perform some predefined book purchasing task in a series of sites with varying interface quality. We found a strong relationship between interface quality and trust. We also found some components of user interface quality to be more important than others and discuss the implications for Web site design. Le manque de confiance constitue une des barrières les plus importantes à l'adoption et au développement du commerce électronique. Centré sur le commerce électronique de détail, ce travail présente un modèle permettant d'analyser le développement de la confiance du consommateur en fonction des caractéristiques de ce dernier - sa propension - et de la perception qu'il a de certaines caractéristiques du commerçant, soit l'intégrité, l'habilité et la bienveillance de ce dernier. L'utilisabilité de l'interface graphique a été retenue comme étant le facteur-clé en ce qui concerne la perception de ces caractéristiques. Le rôle de chacune des dimensions composant l'utilisabilité a donc été étudié et mis en évidence relativement à la confiance développée par le consommateur.User interface, laboratory experiment, trust, usability, electronic retailing, web design, Interface utilisateur, expérimentation en laboratoire, confiance, b2c, commerce électronique (détail), design de site web

Instrumental genesis through interdisciplinary collaboration -- reflections on the emergence of a visualisation framework for video annotation data

Instrumental genesis through interdisciplinary collaboration-reflections on the emergence of a visualisation framework for video annotation data XML This paper presents, discusses and reflects on the development of a visualization framework for the analysis of the temporal dynamics of audiovisual expressivity. The main focus lies on the instrumental genesis process (Rabardel 1995; Longchamp 2012)-a concept trying to express and analyze the co-evolution of instruments and the practices they make possible-underlying this development. It is described through the collaboration and communication processes between computer science scholars and humanities scholars in finding new ways of visualizing complex datasets for exploration and presentation in the realm of film-studies research. It draws on the outcome and concrete usage of the visualizations in publications and presentations of a research group, the AdAproject, that investigates the audiovisual rhetorics of affect in audiovisual media on the financial crisis (2007-). These film analyses are based on theoretical assumptions on the process of film-viewing, the relation of the viewer's perception and the temporally unfolding audiovisual images, and a methodical approach that draws on 'steps' in the research process such as segmentation, description and qualification, called eMAEX (Kappelhoff et al. 2011-2016) to reconstruct these experiential figurations (Bakels et al. 2020a, 2020b). The main focus of this paper is the process of iterative development of visualizations as interactive interfaces generated with the open-source software Advene, that were an integral part of the research process. In this regard, the timeline visualization is not only of interest for visual argumentation in (digital) humanities publications, but also for the creation of annotations as well as the exploration of this data. In the first part of the paper we describe this interdisciplinary collaboration as instrumental genesis on a general level-as an evolving and iterative process. In the second part we focus on the specific challenge of designing a visualization framework for the temporal dynamics of audiovisual aesthetics. Lastly we zoom out by reflecting on experiences and insights that might be of interest for the wider digital humanities community

Decision Support to Crowdsourcing for Annotation and Transcription of Ancient Documents: The RECITAL Workshop

In the 18th century in Paris, only two public theatres could officially perform comedies: the Com{\'e}die-Fran{\c c}aise, and the Com{\'e}die-Italienne. The latter was much less well known. By studying a century of accounting registers, we aim to learn more about its successful plays, its actors, musicians, set designers, and all the small trades necessary for its operation, its administration, logistics and finances. To this end, we employ a mass of untapped and unpublished resources, the 27,544 pages of 63 daily registers available at the Biblioth{\`e}que Nationale de France (BnF). And we take a decidedly fresh look at emerging forms of creation and changes in the entertainmenteconomy. We developed the crowdsourcing platform RECITAL to collect and index the data from theregisters, following an emerging trend in Digital Humanities. RECITAL is built upon the ScribeAPI framework and it offers a fully-fledged web application to classify the pages, annotate with marks and tags, transcribe the indexed marks and even to verify the previous transcripts. We also describe a multi-level data model and to develop a series of monitoring anddecision tools to support crowdsourced data management up to their definitive form

Miniaturisation d'antennes en bande VHF pour applications spatiales

Le développement de l électronique embarquée et miniaturisée est pleinement d actualité de nos jours, dans les domaines tels que l armement, la médecine, et les télécommunications. La miniaturisation des antennes large-bande, opérationnelles sur plus d une décade, présentent un défi particulier. Ces travaux de thèse proposent de travailler sur la miniaturisation d une antenne spirale, afin d en réduire l encombrement, à savoir son diamètre, tout en conservant au mieux ses caractéristiques de rayonnement et polarisation intrinsèques. Cette recherche sera appliquée à la bande des Très hautes Fréquence (Very High Frequencies VHF), allant de 30MHz à 300MHz La géométrie inédite proposée consiste à associer à une antenne spirale un ensemble d anneaux résonnants, dont le diamètre n excède pas celui de la spirale, et permettant de diminuer la fréquence basse de fonctionnement. Pour un ensemble de cinq anneaux associé à la spirale, la réduction de la fréquence basse de fonctionnement est de plus de 30%. Pour deux antennes spirales de même fréquence basse de fonctionnement, l antenne miniaturisée a donc un diamètre réduit de 30%, soit une surface réduite de 50%. Les performances de l état de l art d après lesquelles les réductions sur le diamètre des antennes spirales n excèdent pas 15% sont donc dépassées. De plus, d après cet état de l art, les méthodes de réduction appliquées aux antennes large bande dégradent en général le gain et l axial ratio dans les bandes basses de fréquences de fonctionnement. La méthode proposée permet de conserver l efficacité de l antenne, voire de l augmenter, dans les fréquences proches de la fréquence basse de fonctionnement. Le rayonnement de l antenne spirale miniaturisée dans la bande passante de l antenne sans anneaux n est pour autant pas modifiée. Ces résultats très encourageant ont été confirmés par la mesure d antennes spirales miniaturisées, réalisées pour un diamètre de 8cm et de 1m : une réduction de 30% du diamètre sans dégradation du rayonnement a été observée. Les mesures ont par ailleurs donné lieu à l étude de la réalisation d une antenne en bande VHF, avec pour implication les problématiques de réalisation (masse, encombrement, résistance mécanique) et de mesure (isolation, effets parasites en VHF avec une longueur d onde de 4m).Miniaturizing electronic devices is a great challenge in crucial research domain such as defense, medicine, and telecommunications. Wideband antenna miniaturization operating on more than a decade is a particular issue. This thesis presents an original method for miniaturizing a spiral antenna, reducing its diameter while keeping its bandwidth, its radiating performances and its axial ratio characteristics. This method is applied to UHF spiral antenna (from 750MHz) and VHF antenna (from 75MHz). The new geometry adds stacked resonant rings to an Archimedean spiral antenna. Their diameter are the same, hence no rise of the antenna diameter. For a 5-ring spiral antenna, the lowest operating frequency reduction is higher than 30%. That is equivalent to a 30% reduction of the diameter for two antennas sharing the same lowest operating frequency, hence a 50% reduction of the area of the antenna. These reduction factors surpass the reduction factors of the state of art of 15%. Besides, according to the state of art, the miniaturizing techniques imply some degradation of the gain and axial ratio performances at the lowest operating frequencies. The new method improves on the other hand these characteristics at these frequencies. At higher frequencies, the rings do not interfere with the matching of neither the spiral antenna nor its radiation characteristics. These results were validated by fabricated antenna measurements. A 30% reduction of the diameter was obtained on a 5-ring-8cm-large antenna as well as on a 5-ring-1m-large antenna. No impairment was noticed on the radiation of the antennas, even at the lowest operating frequencies. The thesis also discusses the difficulties which came in addition for the fabrication (mass, size and mechanical resistance) and measurement (radiation interferences and measurement isolation the wavelength being 4m) of the VHF antenna.TOULOUSE-INP (315552154) / SudocSudocFranceF

Facile synthesis of high-surface area platinum-doped ceria for low temperature CO oxidation

International audienceUsing a simple slow decomposition method of nitrate precursors, high-surface area platinum-doped ceria with a crystallite size of 9 nm can be prepared. The catalytic performance of the compound can be tuned by changing the reduction temperature under hydrogen (300°C, 500°C and 700°C). The catalyst treated at 300°C shows the best catalytic performance, being active at room temperature. The materials were analysed using a combination of structural characterization methods (X-ray diffraction (XRD), nitrogen physisorption, high angle annular dark field scanning transmission electron microscopy (HAADF-STEM)), surface sensitive methods (X-ray photoelectron spectroscopy (XPS), H 2-chemisorption and H 2-temperature-programmed reduction (TPR)) and X-ray absorption fluorescence spectroscopy (XAFS). HAADF-STEM and XAFS analysis suggests successful doping of platinum in the ceria lattice. After pretreatment at 300°C, the situation is slightly different. While no defined platinum nanoparticles can be identified on the surface, some platinum is in a reduced state (XPS, H 2-chemisorption)

Inter-layer charge disproportionation in the dual-layer organic metal (tTTF-I)2ClO4 with unsymmetrical I***O halogen bond interactions.

Accepted 19 Nov 2013International audienceA mixed-valence salt of tTTF-I with ClO4(-), formulated as (tTTF-I)2ClO4, is characterized by the presence of two crystallographically independent donor molecules, segregated in different layers and linked together through I***O interactions with the ClO4(-) anion disordered at room temperature. The tTTF-I donor molecule was prepared by metallation of tTTF (trimethylene tetrathiafulvalene) followed by reaction with iodine to afford the mono and diiodo derivatives tTTF-I and tTTFI2, respectively. The crystal structure of the latter neutral tTTFI2 shows the occurrence of strong type II, II halogen bond interactions. Band structure calculations of the dual-layer structure of the 2 : 1 salt (tTTF-I)2ClO4 show co-existence of both 1D open and 2D closed Fermi surfaces. The salt undergoes a metal-insulator phase transition at T(MI) = 90 K, associated with an electronic dimensionality decrease, since already at 100 K, the 2D part of the Fermi surface transforms into 1D corrugated planes. High resolution X-ray investigations performed at 100 K, combined with multipolar refinements, indicate an approximately equivalent +0.5e charge in both donor molecules, as also deduced from the intramolecular bond distances. On the other hand, Raman spectroscopic investigations show that at ambient temperature the charge is actually distributed non-uniformly in conducting layers of tTTF-I molecules, with the identification of molecules with charges +1, +0.5, 0e, while at low temperature the charge distribution becomes essentially uniform (+0.5e), as confirmed from the X-ray high resolution data. These apparently contradictory behaviors are actually a consequence of a partial electron transfer between the two independent slabs to reach a common Fermi level in the metallic phase