Multi-agent systems on wireless sensor networks : a distributed reinforcement learning approach

Master'sMASTER OF ENGINEERIN

Croissance de l'équipe éditoriale, partenariat institutionnel et développement d’un volet grand public = Expanding the Editorial Team, an Institutional Collaboration and a Greater Public Reach

Éditoral / Editoria

Correlation of multi-temporal ground-based optical images for landslide monitoring

The objective of this work is to present a low-cost methodology to monitor the displacement of continuously active landslides from ground-based optical images analyzed with a normalized image correlation technique. The performance of the method is evaluated on a series of images acquired on the Super-Sauze landslide (South French Alps) over the period 2008-2009. The image monitoring system consists of a high resolution optical camera installed on a concrete pillar located on a stable crest in front of the landslide and controlled by a datalogger. The data are processed with a cross-correlation algorithm applied to the full resolution images in the acquisition geometry. Then, the calculated 2D displacement field is orthorectified with a back projection technique using a high resolution DEM interpolated from Airborne Laser Scanning (ALS) data. The heterogeneous displacement field of the landslide is thus characterized in time and space. The performance of the technique is assessed using differential GPS surveys as reference. The sources of error affecting the results are then discussed. The strongest limitations for the application of the technique are related to the meteorological, illumination and ground surface conditions inducing partial or complete loss of coherence among the images. Small movements of the camera and the use of a mono-temporal DEM are the most important factors affecting the accuracy of the ortho-rectification of the displacement field. As the proposed methodology can be routinely and automatically applied, it offers promising perspectives for operational applications like, for instance, in early warning systems. © 2012 International Society for Photogrammetry and Remote Sensing, Inc. (ISPRS)

Acknowledgements 2013 / Remerciements 2013

Éditoral / Editoria

Addenda and errata to “Description of a new species of the genus Adenomera (Amphibia, Anura, Leptodactylidae) from French Guiana"

In the first issue of Acta Herpetologica, Boistel et al. (2006) described a new species of Adenomera (Amphibia, Anura, Leptodactylidae). Because of an unfortunate set of events, there are several aspects of this paper that have to be corrected, or elaborated on. We address these issues herein

In situ HT-XRD study of the UO2_2-PuO2_2-Pu2_2O3_3 sub-system

International audienc

Combination of surfactants and organic compounds for boosting CO2 separation from natural gas by clathrate hydrate formation

This study investigates the effects of several combinations of surfactants and organic compounds on the separation of CO2 from a CO2–CH4 gas mixture by clathrate hydrate formation. Seven additives, three surfactants (SDS, SDBS, DATCl) and four organic compounds (THF, 1,3-dioxolane, 2-methyl-tetrahydrofuran and cyclopentane) were tested for various operating conditions and at different concentrations. The influence of these additives on the quantity of gas removed, the selectivity of the separation toward CO2, and the kinetics of hydrate formation were analyzed through experiments in a batch reactor. It was found that a suitable combination of a surfactant and a organic compound can, in some cases, strongly enhance the hydrate crystallization. The best results were obtained with a combination of the additives SDS and THF