Data fluidity in DARIAH -- pushing the agenda forward

This paper provides both an update concerning the setting up of the European DARIAH infrastructure and a series of strong action lines related to the development of a data centred strategy for the humanities in the coming years. In particular we tackle various aspect of data management: data hosting, the setting up of a DARIAH seal of approval, the establishment of a charter between cultural heritage institutions and scholars and finally a specific view on certification mechanisms for data

The Bosonic Ancestor of Closed and Open Fermionic Strings

We review the emergence of the ten-dimensional fermionic closed string theories from subspaces of the Hilbert space of the 26-dimensional bosonic closed string theory compactified on an $E_8\times SO(16)$ lattice. They arise from a consistent truncation procedure which generates space-time fermions out of bosons. This procedure is extended to open string sectors. We prove, from bosonic considerations alone, that truncation of the unique tadpole-free $SO(2^{13})$ bosonic string theory compactified on the above lattice determines the anomaly free Chan-Paton group of the Type I theory. It also yields the Chan-Paton groups making Type O theories tadpole-free. These results establish a link between all M-theory strings and the bosonic string within the framework of conformal field theory. Its significance is discussed.Comment: LaTeX files, 16 pages. Contribution to the Francqui meeting, Brussels 2001 and Corfu Summer Institute 2001. Based on hep-th/010623

Silicon recovery from silicon-iron alloys by electrorefining in molten fluorides

Electrorefining of a silicon-iron material (Si-4.7at%Fe) in molten NaF-KF at 850°C has been investigated in view of recovering pure Si, using electrochemical techniques, SEM-EDS and ICP-AES analyses. The selective electrochemical dissolution of Si was evidenced. Electrorefining runs led to a maximum Si recovery of 80% of the initial Si contained in the material, in the form of a dense deposit at the cathode, with very high current efficiencies. The Si purity has been examined and no Fe was detected by ICP-AES analysis: the recovered Si purity is thus assumed to be higher than 99.99%

Silicon electrodeposition in molten fluorides

Silicon nucleation process was investigated in molten NaF-KF (40-60 mol%) on silver electrodes in the 820-950°C temperature range in order to optimize silicon coating operating conditions. Chronoamperometric measurements evidenced that silicon electrodeposition process involved an instantaneous nucleation with diffusion-controlled nuclei growth whatever temperature and Si(IV) ions concentration in the mixture. The overpotential and temperature influence on nucleation sites number was also studied. Silicon deposits were obtained using the same temperature range as nucleation study, for different current densities on substrates: Ni, Ag, Cgraphite and Cvitreous. A sensitive influence of the cathodic substrate on the deposit adherence and roughness was observed and discussed

Fluoroacidity evaluation in molten salts

The fluoroacidity of several alkaline fluoride media was studied by monitoring the concentration of electroactive species which is decreasing versus time due to a gas species release, such as silicon fluorides, as indicated by the reaction: SiF(4+x)x- = SiF4(g) + x F- This article relates the Si(IV) reaction study to define a relative fluoroacidity scale by studying the silicon ions stability in different melts. Electrochemical techniques allow the measurement of SiF4+xx- concentration evolution and thus the reaction rate constant to be calculated at different temperatures and for several fluoride media. The article shows that the free F- content depends on the fluoride mixture and that the rate values are correlated with the fluoroacidity allowing a qualitative estimation. Then a fluoride solvents fluoroacidity scale was proposed, scaling the different eutectic melts from basic melt to acidic one: NaF-KF < LiF-KF < NaF-MgF2 < NaF-CaF2 < LiF-NaF < LiF < LiF-CaF2

Allocating and Funding Universal Service Obligations in a Competitive Network Market

We examine, in a network market open to competition, various mechanisms of allocating and funding ''universal service obligations'' among agents (rival operators and consumers). The obligations we consider are geographic ubiquity and non discrimination. We analyze, from both the efficiency and equity point of views, the respective advantages of a ''restricted-entry'' system (where the entrant is not allowed to serve high cost consumers) and the ''pay or play'' system at work for instance in Australia. We show that the pay or play regulation always dominates the restricted-entry regulation under ubiquity constraint alone. This result no longer holds when the regulator imposes also the non discrimination constraint.

Increasing stability and interpretability of gene expression signatures

Motivation : Molecular signatures for diagnosis or prognosis estimated from large-scale gene expression data often lack robustness and stability, rendering their biological interpretation challenging. Increasing the signature's interpretability and stability across perturbations of a given dataset and, if possible, across datasets, is urgently needed to ease the discovery of important biological processes and, eventually, new drug targets. Results : We propose a new method to construct signatures with increased stability and easier interpretability. The method uses a gene network as side interpretation and enforces a large connectivity among the genes in the signature, leading to signatures typically made of genes clustered in a few subnetworks. It combines the recently proposed graph Lasso procedure with a stability selection procedure. We evaluate its relevance for the estimation of a prognostic signature in breast cancer, and highlight in particular the increase in interpretability and stability of the signature

Laser Doppler Velocimetry for Joint Measurements of Acoustic and Mean Flow Velocities : LMS-based Algorithm and CRB Calculation

This paper presents a least mean square (LMS) algorithm for the joint estimation of acoustic and mean flow velocities from laser doppler velocimetry (LDV) measurements. The usual algorithms used for measuring with LDV purely acoustic velocity or mean flow velocity may not be used when the acoustic field is disturbed by a mean flow component. The LMS-based algorithm allows accurate estimations of both acoustic and mean flow velocities. The Cram\'er-Rao bound (CRB) of the associated problem is determined. The variance of the estimators of both acoustic and mean flow velocities is also given. Simulation results of this algorithm are compared with the CRB and the comparison leads to validate this estimator