Deep complementary features for speaker identification in TV broadcast data

International audienceThis work tries to investigate the use of a Convolutional Neu-ral Network approach and its fusion with more traditional systems such as Total Variability Space for speaker identification in TV broadcast data. The former uses spectrograms for training, while the latter is based on MFCC features. The dataset poses several challenges such as significant class imbalance or background noise and music. Even though the performance of the Convolutional Neural Network is lower than the state-of-the-art, it is able to complement it and give better results through fusion. Different fusion techniques are evaluated using both early and late fusion

Reduced ceria nanofilms from structure prediction

Experimentally, Ce2O3 films are used to study cerium oxide in its fully or partially reduced state, as present in many applications. We have explored the space of low energy Ce2O3 nanofilms using structure prediction and density functional calculations, yielding more than 30 distinct nanofilm structures. First, our results help to rationalize the roles of thermodynamics and kinetics in the preparation of reduced ceria nanofilms with different bulk crystalline structures (e.g. A-type or bixbyite) depending on the support used. Second, we predict a novel, as yet experimentally unresolved, nanofilm which has a structure that does not correspond to any previously reported bulk A2B3 phase and which has an energetic stability between that of A-type and bixbyite. To assist identification and fabrication of this new Ce2O3 nanofilm we calculate some observable properties and propose supports for its epitaxial growth

Modelling Free and Oxide-supported Nanoalloy Catalysts : Comparison of Bulk-immiscible Pd-Ir and Au-Rh system and influence of a TiO2 support

SSCI-VIDE+ECI2D+LPIInternational audience--

Understanding and controlling the structure and segregation behaviour of AuRh nanocatalysts

Heterogeneous catalysis, which is widely used in the chemical industry, makes a great use of supported late-transition-metal nanoparticles, and bimetallic catalysts often show superior catalytic performances as compared to their single metal counterparts. In order to optimize catalyst efficiency and discover new active combinations, an atomic-level understanding and control of the catalyst structure is desirable. In this work, the structure of catalytically active AuRh bimetallic nanoparticles prepared by colloidal methods and immobilized on rutile titania nanorods was investigated using aberration-corrected scanning transmission electron microscopy. Depending on the applied post-treatment, different types of segregation behaviours were evidenced, ranging from Rh core-Au shell to Janus via Rh ball-Au cup configuration. The stability of these structures was predicted by performing density-functional-theory calculations on unsupported and titania-supported Au-Rh clusters; it can be rationalized from the lower surface and cohesion energies of Au with respect to Rh, and the preferential binding of Rh with the titania support. The bulk-immiscible AuRh/TiO2 system can serve as a model to understand similar supported nanoalloy systems and their synergistic behaviour in catalysis

Offshoring of Service Jobs

Many previously-nontraded services have become tradable, or are expected to become so, as a result of technological advances in information technology. This situation has raised concerns about the future of jobs and workers' incomes in advanced countries, especially in the United States. However, a review of the U.S. evidence shows that the current extent of service offshoring is very modest in the United States, not only as a share of GDP but also in terms of its contribution to worker displacements. Service offshoring is currently a minor part of the overall international economic competition that the United States faces. Service offshoring appears to have been relatively intense for IT occupations, but the employment and wage trends in those occupations still compare favorably to U.S. averages. While offshoring might become much more significant in the future, a closer look at occupation details reveals that most U.S. service jobs are not suitable for performing remotely from abroad, even when some significant cultural and institutional barriers are ignored. In addition, a range of transaction and adjustment costs slow offshoring growth, and it would take a long time, possibly decades, for offshoring to attain its potential limits, although the available estimates of those limits and when they would be reached are very uncertain. This paper's assessment is that the share of existing jobs in the United States that have the possibility of exposure to competition from service offshoring is limited to 10 to 20 percent, and the impact will be sufficiently gradual to blend in with the ongoing ordinary structural changes in the U.S. economy.Offshoring, Outsourcing, Service trade