Wind power predictions from nowcasts to 4-hour forecasts: a learning approach with variable selection

We study the prediction of short term wind speed and wind power (every 10 minutes up to 4 hours ahead). Accurate forecasts for those quantities are crucial to mitigate the negative effects of wind farms' intermittent production on energy systems and markets. For those time scales, outputs of numerical weather prediction models are usually overlooked even though they should provide valuable information on higher scales dynamics. In this work, we combine those outputs with local observations using machine learning. So as to make the results usable for practitioners, we focus on simple and well known methods which can handle a high volume of data. We study first variable selection through two simple techniques, a linear one and a nonlinear one. Then we exploit those results to forecast wind speed and wind power still with an emphasis on linear models versus nonlinear ones. For the wind power prediction, we also compare the indirect approach (wind speed predictions passed through a power curve) and the indirect one (directly predict wind power)

Analysis of Gallica and Data BnF logs and Modelling of Behaviour Patterns: Presentation of the Main Results

Gallica (http://gallica.bnf.fr) is one of the major digital libraries available for free via the Internet. It provides access to million of documents of any type and receive around 1.5 million visits per month. In the context of a research partnership between the BnF and Télécom ParisTech, an analysis of Gallica servers’ connection logs was carried out, applying machine-learning methods to them. The aim was not to collect information on users or their profiles but rather to use logs, which act as records of usage, as a basis for identifying typical clickstreams. For 15 months, a data clusterisation algorithm was developed, enabling grouping of Gallica sessions with similarities in sequencing and duration of actions . Logs analysed covered a range of durations, from a week to a month, with systematic checking of the stability of models obtained. Such learning methods take advantage of the very factor that undermines traditional methods for gathering information on usage: the extremely high numbers of connections. Despite the power of the algorithms involved, machine learning also requires numerous decisions to be taken, necessitating availability of other sources of knowledge on usages and users. For this reason, the preferred methodological choice was to have statistical models dialogue with results obtained from other approaches (ethnographic observations, interviews, etc.). The interest of the work carried out on the Gallica logs persuaded the BnF and Télécom ParisTech to add a further stage to the research devoted to Data BnF logs as well as clickstreams between Gallica, Data BnF and BnF General Catalogue

PRIMA subretinal wireless photovoltaic microchip implantation in non-human primate and feline models

Purpose To evaluate the surgical technique for subretinal implantation of two sizes of PRIMA photovoltaic wireless microchip in two animal models, and refine these surgical procedures for human trials. Methods Cats and Macaca fascicularis primates with healthy retina underwent vitrectomy surgery and were implanted with subretinal wireless photovoltaic microchip at the macula/central retina. The 1.5mm PRIMA chip was initially studied in feline eyes. PRIMA implant (2mm,1.5mm sizes) arrays were studied in primates. Feasibility of subretinal chip implantation was evaluated with a newly-developed surgical technique, with surgical complications and adverse events recorded. Results The 1.5mm implant was placed in the central retina of 11 feline eyes, with implantation duration 43-106 days. The 1.5mm implant was correctly positioned into central macula of 11 primate eyes, with follow-up periods of minimum 6 weeks (n = 11), 2 years (n = 2), and one eye for 3 years. One primate eye underwent multi-chip 1.5mm implantation using two 1.5mm chips. The 2mm implant was delivered to 4 primate eyes. Optical coherence tomography confirmed correct surgical placement of photovoltaic arrays in the subretinal space in all 26 eyes. Intraoperative complications in primate eyes included retinal tear, macular hole, retinal detachment, and vitreous hemorrhage that resolved spontaneously. Postoperatively, there was no case of significant ocular inflammation in the 1.5mm implant group. Conclusions We report subretinal implantation of 1.5mm and 2mm photovoltaic arrays in the central retina of feline and central macula of primate eyes with a low rate of device-related complications. The in vivo PRIMA implantation technique has been developed and refined for use for a 2mm PRIMA implant in ongoing human trials

Les fonctions des saints dans le monde occidental (IIIe-XIIIe siècle)

Buc Philippe. Les fonctions des saints dans le monde occidental (IIIe-XIIIe siècle). In: Annales. Histoire, Sciences Sociales. 50ᵉ année, N. 4, 1995. pp. 887-889

Odette Pontal, Les conciles de la France capétienne jusqu'en 1215

Buc Philippe. Odette Pontal, Les conciles de la France capétienne jusqu'en 1215. In: Annales. Histoire, Sciences Sociales. 53ᵉ année, N. 6, 1998. pp. 1292-1293

Alain Boureau, L'événement sans fin. Récit et christianisme au Moyen Âge

Buc Philippe. Alain Boureau, L'événement sans fin. Récit et christianisme au Moyen Âge. In: Annales. Histoire, Sciences Sociales. 50ᵉ année, N. 1, 1995. pp. 200-201

L’empreinte du Moyen Âge : la guerre sainte

« On peut bien se moquer du dieu de Marcion, lequel ne sait ni se mettre en colère, ni se venger »(Tertullien, Contre Marcion, 5.4.14) Les événements des vingt dernières années, sous l’égide d’Oussama Ben Laden, ont reposé la question du rapport entre religion et violence. Les religions sont-elles par essence porteuses de violence ? Ou sont-elles tout du moins prédisposées, du fait de leur accès privilégié au sacré sublime, à être captées par cet autre sublime qu’est la violence ? C’est ce qu..

Corinne Leveleux, Des prêtresses déchues : l'image des Vestales chez les Pères de l'Église latine (fin IIe-début Ve siècle)

Buc Philippe. Corinne Leveleux, Des prêtresses déchues : l'image des Vestales chez les Pères de l'Église latine (fin IIe-début Ve siècle). In: Annales. Histoire, Sciences Sociales. 53ᵉ année, N. 6, 1998. pp. 1285-1286

À propos de Communities of Violence de David Nirenberg (note critique)

Buc Philippe. À propos de Communities of Violence de David Nirenberg (note critique). In: Annales. Histoire, Sciences Sociales. 53ᵉ année, N. 6, 1998. pp. 1243-1249