144 research outputs found

    The Stength of Weak cooperation: A Case Study on Flickr

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    Web 2.0 works with the principle of weak cooperation, where a huge amount of individual contributions build solid and structured sources of data. In this paper, we detail the main properties of this weak cooperation by illustrating them on the photo publication website Flickr, showing the variety of uses producing a rich content and the various procedures devised by Flickr users themselves to select quality. We underlined the interaction between small and heavy users as a specific form of collective production in large social networks communities. We also give the main statistics on the (5M-users, 150M-photos) data basis we worked on for this study, collected from Flickr website using the public API

    From Historical Documents To Social Network Visualization: Potential Pitfalls and Network Modeling

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    International audienceWe describe the workflow followed by historians when conducting a Historical Social Network Analysis (HSNA) with five steps: textual sources acquisition, digitization, annotation, network creation, and analysis/visualization. While most analysis and visualization tools only support the last step, we argue that addressing the 2-3 last steps would boost the humanists' analytical capabilities. We explain why the network modeling process is particularly challenging and can lead to distortions of the sources, biases, and traceability problems. We list three main properties that we believe the constructed network should satisfy: alignment with reality/documents (not only with concepts), traceability (from documents to analysis/visualization and back), and simplicity (understandable by most and not more complex than needed). We claim that the model of bipartite dynamic multivariate network with roles allows an effective annotation/encoding of historical sources while satisfying these properties. We provide real-world examples of how this model has been used to answer socio-historical questions using visual analytics tools

    CRH-LaDĂ©HiS – Laboratoire de dĂ©mographie et d’histoire sociale

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    Pascal Cristofoli, ingĂ©nieur d’étudesArnaud BringĂ©, ingĂ©nieur de recherche Ă  l’INEDBĂ©nĂ©dicte Garnier, ingĂ©nieure d’études Ă  l’INED Atelier « Analyse des donnĂ©es relationnelles » Lieu d’enseignement, de discussion et de collaboration entre Ă©tudiants, ingĂ©nieurs et chercheurs associĂ©s, l’atelier vise Ă  interroger les diffĂ©rentes opĂ©rations pratiques et thĂ©oriques impliquĂ©es par la mise en Ɠuvre d’analyses relationnelles. Depuis plusieurs annĂ©es maintenant, le sĂ©minaire est organisĂ© en trois jou..

    CRH-LaDĂ©HiS – Laboratoire de dĂ©mographie et d’histoire sociale

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    Pascal Cristofoli, ingĂ©nieur d’étudesArnaud BringĂ©, ingĂ©nieur de recherche Ă  l’INEDBĂ©nĂ©dicte Garnier, ingĂ©nieure d’études Ă  l’INED Atelier « Analyse des donnĂ©es relationnelles » Lieu d’enseignement, de discussion et de collaboration entre Ă©tudiants, ingĂ©nieurs et chercheurs associĂ©s, l’atelier vise Ă  interroger les diffĂ©rentes opĂ©rations pratiques et thĂ©oriques impliquĂ©es par la mise en Ɠuvre d’analyses relationnelles. Depuis plusieurs annĂ©es maintenant, le sĂ©minaire est organisĂ© en trois jou..

    CRH – Laboratoire de dĂ©mographie et d’histoire sociale (LaDĂ©HiS)

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    Pascal Cristofoli, ingĂ©nieur d’étudesFlorence Maillochon, chargĂ©e de recherche au CNRSZacarias Moutoukias, professeur Ă  l’UniversitĂ© Paris-VII/DiderotChristophe Prieur, maĂźtre de confĂ©rences Ă  l’UniversitĂ© Paris-VII/DiderotMarie-Carmen Smyrnelis, ingĂ©nieur de recherche Approches des rĂ©seaux sociaux Depuis plusieurs annĂ©es, le sĂ©minaire se propose d’aborder, de façon interdisciplinaire, les diffĂ©rentes approches pratiques et thĂ©oriques impliquĂ©es lors de la mise en Ɠuvre d’analyses relationnel..

    CRH – Laboratoire de dĂ©mographie et d’histoire sociale (LaDĂ©HiS)

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    Pascal Cristofoli, ingĂ©nieur d’étudesFlorence Maillochon, chargĂ©e de recherche au CNRSZacarias Moutoukias, professeur Ă  l’UniversitĂ© Paris-VII/DiderotChristophe Prieur, maĂźtre de confĂ©rences Ă  l’UniversitĂ© Paris-VII/DiderotMarie-Carmen Smyrnelis, ingĂ©nieur de recherche Approches des rĂ©seaux sociaux Depuis plusieurs annĂ©es, le sĂ©minaire se propose d’aborder, de façon interdisciplinaire, les diffĂ©rentes approches pratiques et thĂ©oriques impliquĂ©es lors de la mise en Ɠuvre d’analyses relationnel..

    CRH – Laboratoire de dĂ©mographie historique (LDH)

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    StĂ©phane Baciocchi, Pascal Cristofoli, ingĂ©nieurs d’étudesFlorence Maillochon, chargĂ©e de recherche au CNRSZacarias Moutoukias, professeur Ă  l’UniversitĂ© Paris-VII/DiderotChristophe Prieur, maĂźtre de confĂ©rences Ă  l’UniversitĂ© Paris-VII/DiderotMarie-Carmen Smyrnelis Approches des rĂ©seaux sociaux Ce sĂ©minaire se propose d’aborder, avec une posture interdisciplinaire, les diffĂ©rentes approches pratiques et thĂ©oriques impliquĂ©es lors de la mise en oeuvre d’analyses relationnelles. Il s’est organ..

    MICROSCOPE mission analysis, requirements and expected performance

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    The MICROSCOPE mission aimed to test the Weak Equivalence Principle (WEP) to a precision of 10−1510^{-15}. The WEP states that two bodies fall at the same rate on a gravitational field independently of their mass or composition. In MICROSCOPE, two masses of different compositions (titanium and platinum alloys) are placed on a quasi-circular trajectory around the Earth. They are the test-masses of a double accelerometer. The measurement of their accelerations is used to extract a potential WEP violation that would occur at a frequency defined by the motion and attitude of the satellite around the Earth. This paper details the major drivers of the mission leading to the specification of the major subsystems (satellite, ground segment, instrument, orbit...). Building upon the measurement equation, we derive the objective of the test in statistical and systematic error allocation and provide the mission's expected error budget.Comment: References update
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