Eikonal Equation Adaptation on Weighted Graphs: Fast Geometric Diffusion Process for Local and Non-local Image and Data Processing

In this paper we propose an adaptation of the Eikonal equation on weighted graphs, using the framework of Partial difference Equations, and with the motivation of extending this equation’s applications to any discrete data that can be represented by graphs. This adaptation leads to a finite difference equation defined on weighted graphs and a new efficient algorithm for multiple labels simultaneous propagation on graphs, based on such equation. We will show that such approach enables the resolution of many applications in image and high dimensional data processing using a unique framework.     

WEBEXPIR: Windowless target electron beam experimental irradiation

The windowless target electron beam experimental irradiation (WEBEXPIR) program was set-up as part of the MYRRHA/XT-ADS R&D effort on the spallation target design to investigate the interaction of a proton beam with a liquid lead-bismuth eutectic (LBE) free surface. In particular, possible free surface distortion or shockwave effects in nominal conditions and during sudden beam on/off transient situations, as well as possible enhanced evaporation were assessed. An experiment was conceived at the IBA TT-1000 Rhodotron, where a 7 MeV electron beam was used to simulate the high power deposition at the MYRRHA/XT-ADS LBE free surface. The geometry and the LBE flow characteristics in the WEBEXPIR set-up were made as representative as possible of the actual situation in the MYRRHA/XT-ADS spallation target. Irradiation experiments were carried out at beam currents of up to 10 mA, corresponding to 40 times the nominal beam current necessary to reproduce the MYRRHA/XT-ADS conditions. Preliminary analyses show that the WEBEXPIR free surface flow was not disturbed by the interaction with the electron beam and that vacuum conditions stayed well within the design specifications.     

Multiple glass transition temperatures of polymer thin films as probed by multi-wavelength ellipsometry

Ellipsometry was used as a technique to determine glass temperature transitions of homopolymer thin films of polystyrene and poly(methyl methacrylate) ranging from 5 to 200 nm. The technique operated systematically at various energies reveals the presence of multiple transitions in these films under certain conditions of preparation. It was observed that in the case of strong polymer-substrate interactions, several Tg were measured and ascribed to a layered structure in the film. In the absence of strong interactions, a more uniform film presenting a single Tg was observed no matter the thickness. The results confirm the recent assumption of thin films organised in multilayers and emphasize the importance of using a highly sensitive multi-wavelength technique in probing such properties.     

Novel dynamic color image watermarking based on DWT-SVD and the human visual system

Multimedia Tools and Applications - In this paper, a novel dynamic color image watermarking based on discrete wavelet transform (DWT) and singular value decomposition (SVD) is proposed. The...