Objective and subjective evaluation of speech enhancement methods in the UDASE task of the 7th CHiME challenge

International audienceSupervised models for speech enhancement are trained using artificially generated mixtures of clean speech and noise signals. However, the synthetic training conditions may not accurately reflect real-world conditions encountered during testing. This discrepancy can result in poor performance when the test domain significantly differs from the synthetic training domain. To tackle this issue, the UDASE task of the 7th CHiME challenge aimed to leverage real-world noisy speech recordings from the test domain for unsupervised domain adaptation of speech enhancement models. Specifically, this test domain corresponds to the CHiME-5 dataset, characterized by real multi-speaker and conversational speech recordings made in noisy and reverberant domestic environments, for which ground-truth clean speech signals are not available. In this paper, we present the objective and subjective evaluations of the systems that were submitted to the CHiME-7 UDASE task, and we provide an analysis of the results. This analysis reveals a limited correlation between subjective ratings and several supervised nonintrusive performance metrics recently proposed for speech enhancement. Conversely, the results suggest that more traditional intrusive objective metrics can be used for in-domain performance evaluation using the reverberant LibriCHiME-5 dataset developed for the challenge. The subjective evaluation indicates that all systems successfully reduced the background noise, but always at the expense of increased distortion. Out of the four speech enhancement methods evaluated subjectively, only one demonstrated an improvement in overall quality compared to the unprocessed noisy speech, highlighting the difficulty of the task. The tools and audio material created for the CHiME-7 UDASE task are shared with the community

Efficient single-mode operation in a 10 dB/m absorption very-large-mode-area ytterbium-doped optical fiber via curvature-induced mode filtering

International audienceIn this paper we report our findings on the design, manufacturing and testing of low numerical aperture active step-index optical fibers with very large mode area, operating in a truly single-mode regime. Our approach to efficiently filter higher-order modes in the core relies on applying curvature in a specific direction at a given diameter on a specially designed fiber containing boron-doped silica rods on both sides of the core. The fabricated ytterbium-doped fibers exhibit a mode field diameter of 32 µm , a cladding pump absorption of 10 dB/m and were designed for use in a compact monolithic configuration due to its all-solid nature and its 14 cm targeted bend diameter

Photophysical, cyclic voltammetry, electron paramagnetic resonance, X-ray molecular structure, DFT calculations and molecular docking study of a new Mn(III) metalloporphyrin

International audienceHerein, we have presented a new manganese(III) metalloporphyrin, named, based on the X-ray molecular structure, the bis(4-dimethylaminopyridine)[meso-tetra(para-chlorophenyl)porphyrinato]manganese(III) triflate 1.56 chloroform solvate 0.22 n-hexane solvate 0.22 hydrate with the following formula:[MnIII(TClPP)(DMAP)2] (SO3CF3)and sdot;0.22(C6H14)and sdot;1.56(CHCl3)and sdot;0.22(H2O) (complex I). This coordination compound was characterized by FT-IR and cyclic voltammetry. The dichloromethane solution UV/Vis spectrum of I is typical of a Mn(III) high-spin (S = 2) porphyrin complex with a redshifted Soret band with lambda max value of 487 nm. The single crystal X-diffraction technique was used to determine the molecular structure of our new Mn(III) bis(DMAP) porphyrin complex. Electron paramagnetic resonance (EPR) spectroscopy confirms that this new 3d4 Mn(III) metalloporphyrin (a non-Kramers system) in solid state is high-spin (S = 2). DFT/TD-DFT calculations on complex I were investigated, including (i) the molecular structure optimization using the DFT/B3LYP-D3/LanL2DZ level of theory, (ii) the frontier molecular orbital calculations and the deduction of the global indices of activities, (iii) the molecular electronic potential analysis (MEP), and (iv) the QTAIM and NCI-RDG analyses. Furthermore, complex I was tested against diverse amino acids of the selected Bcl-2 proteins using docking calculations

Mesure de l'efficacité technique et économique des banques commerciales africaines à l'aide de l'analyse de l'enveloppement des données (DEA)

International audienceThe paper aims to analyze the Technical Efficiency of 70 Commercial banks from 19 African countries from 2009-2020. Using the Data Envelopment Analysis (DEA) method of the two main approaches, Variable Return to Scale (VRS) and Constant Return to Scale (CRS) technique on a Panel Data. We find that African banks have a higher efficacy assessment with the VRS than the CRS technique, thus, with a Pure Technical Efficiency (PTE) score than Technical Efficiency (TE) . Our findings show that the majority of the banks are operating at very low levels of efficiency (not technically efficient), and inability to optimize the conversion of bank assets and liabilities into loan production for customers. Furthermore, the banks are operating inefficiently in scale, economic, and allocative manner due to mismatches in scale of production. Considering these findings, the implications of these inefficiencies extend to the overall economic development and financial stability of the region.Le présent article vise à analyser l'efficacité technique de 70 banques commerciales de 19 pays africains sur la période 2009-2020. En utilisant la méthode d'analyse de l'enveloppement des données (DEA) des deux approches principales, le rendement variable de l'échelle (VRS) et la technique du rendement constant de l'échelle (CRS) sur des données de panel. Nous constatons que les banques africaines ont une évaluation de l'efficacité plus élevée avec la technique VRS qu'avec la technique CRS, donc avec un score d'efficacité technique pure (PTE) plutôt que d'efficacité technique (TE). Nos résultats montrent que la majorité des banques opèrent à des niveaux d'efficacité très bas (pas techniquement efficaces), et sont incapables d'optimiser la conversion des actifs et des passifs bancaires en production de prêts pour les clients. En outre, les banques opèrent de manière inefficace en termes d'échelle, d'économie et d'allocation en raison d'une inadéquation de l'échelle de production. Compte tenu de ces résultats, les implications de ces inefficacités s'étendent au développement économique global et à la stabilité financière de la région

Innovative gate driver structure achieving low jitter across isolation barrier for parallel connected SiC modules

International audienceThe parallel connection of power transistors is a common approach to enhance the current capability ofconverter systems. However, the development of wide bandgap semiconductors introduces significantchallenges in parallel operation, primarily due to the need to synchronize sharp current edges duringswitching. One cause of current imbalance is the delay between gate signals resulting from mismatches ingate drivers. This article presents a novel structure designed to ensure synchronization of eight gate driversfor SiC modules in parallel while addressing the issue of gate loop oscillation. Rigorous measurements areconducted to investigate the performances of a low-jitter isolation barrier and the gate driver's behaviourunder different temperatures. Additionally, part-to-part variations among four gate drivers were examined.The results demonstrate a jitter below 2 ns on the parallel gate voltage, highlighting the effectiveness of theproposed solution

Flower strips in winter reduce barley yellow dwarf virus incidence in cereal crops

International audienceMost studies that have explored the effect of biological control in maintaining pest populations at acceptable levels have focused on the ability of natural enemies to reduce pest abundances. The reduction in pest populations induced by natural enemies, however, is rarely studied in association with the incidence of viruses transmitted by pests, as well as its impact on crop damage and yield. Here, we performed large-scale winter field monitoring to assess the direct and indirect effects (via arthropod natural enemies) of flower strips along cereal crop margins, on (i) cereal aphid abundance, (ii) the incidence of barley yellow dwarf viruses (BYDVs) transmitted by aphids in autumn and winter, (iii) crop damage, and (iv) crop yield. In 28 cereal fields (over 2 years), we used a paired experimental design to compare a cereal field edge directly adjacent to a flower strip with an opposite (at least 50 m apart) cereal field edge adjacent to a grassy margin. Our results highlight that winter flower strips favoured the activity of ground arthropod predators in the adjacent cereal field but not aphid parasitism rate in winter. Parasitism rate only increased with the complexity of the surrounding landscape. Our results also showed that flower strips reduced both vector abundance and virus incidence in the adjacent cereal field in winter but did not affect virus symptom levels or yields. Damages were low and yield remained high in our study, which may encourage farmers to stop insecticides during the autumn-winter. This study provides a first example of how flower strips along field edges can decrease the incidence of a vector-borne virus in winter and could be used as a strategy to promote more sustainable agriculture

Platinum nanoparticles decorated TiO2 nanotubes for VOCs and bacteria removal in simulated real condition: Effect of the deposition method on the photocatalytic degradation process efficiency

International audienceThe incorporation of noble metals onto TiO2 nanostructure is considered as a promoting method to enhance the photocatalytic degradation of pollutant in air treatment process. In this study, highly organized TiO2 nanotubes (NTs) were grown by the anodization method of Titanium substrates. The TiO2-NTs were successfully decorated by platinum (Pt) nanoparticles (NPs) using two different deposition methods: (1) electrodeposition and (2) photodeposition. We explore the impact of different deposition methods on the morphology of Pt nanoparticles (NPs) dispersed onto TiO2 nanotubes and the optical characteristics of Pt-TiO2 nanocomposites, investigating their efficacy in photocatalytic degradation We investigate the effect of varying the deposition method on the morphology of PtNPs dispersed onto TiO2 nanotubes and the optical properties of the Pt-TiO2 nanocomposites and their efficient photocatalytic activity degradation against Volatile Organic Compounds (VOCs) and bacteria. Scanning and Transmission Electron Microscopy (SEM and TEM) reveal a nanotubular TiO2 anatase structure adorned with Pt NPs, with the quantity and size of NPs contingent upon the deposition technique employed. The photoluminescence (PL) spectra demonstrate that the Pt/TiO2 heterojunction facilitates the separation of photogenerated charges, thereby diminishing carrier recombination rates. To point out the effect of Pt NPS, both pure TiO2 and Pt/TiO2 heterojunction were tested in the photodegradation of Ethyl Acetate (EA). The Pt/TiO2 heterojunction exhibits superior photocatalytic performance compared to TiO2 in EA degradation, regardless of the Pt deposition method employed. Optimal results are achieved with 120 s of Pt electrodeposition and 3 h of Pt photodeposition under visible irradiation, yielding kinetic constants of approximately 0.245 and 0.195 mg.m(-3).s(-1), respectively, underscoring the pivotal role of the platinum deposition method in pollutant photodegradation. Respectively simultaneous removal of EA and bacteria (Escherichia coli) was tested using Pt and non-Pt decorated TiO2 NTs. We attributed a total degradation of the bacteria after 180 min using the two efficient photocatalysts Electro 120 s and Photo 3 h compared to 60 % of degradation using pure TiO2 nanotubes

Kinetic analysis of TCPP emission from fireproofed upholstered furniture under realistic indoor conditions

Pre-print : https://papers.ssrn.com/sol3/papers.cfm?abstract_id=4925260.International audienceBetter understanding the characteristics and mechanisms governing the indoor emissions of organophosphorus flame-retardants is important to more accurately estimate the human exposure to these compounds and develop risk management strategies that protect human health. This study provides an analysis of short- and long-term trends in Tris(chloropropyl)phosphate (TCPP) emissions from furniture. It is based on the monitoring over a period of almost one year of TCPP concentrations in indoor air and at the surface of a source material (upholstered furniture made of polyurethane (PU) foam containing TCPP) in two rooms for office use. The emission rate was estimated at 8 µg.m-2.h-1 in average with no decline trend observed after about one year's emission. The released mass of TCPP over one year represented about 0.2 % of the initial content of TCPP in the material (2 % w/w). The source material/air partition coefficient (Kma) and its dependence on temperature appear to be the key parameters which control the emission rate. Kma was estimated at 8 × 107 for a temperature of 23 °C. The temperature dependence of Kma was addressed using the Clausius–Clapeyron relationship and the enthalpy of partitioning between the source material and air, ΔHma (previously estimated at 91 kJ mol−1). This study led to the development of a model providing predictions on the long-term trend in TCPP emission from the source material. The simulations showed that the emission should persist over extended periods (several years) with the same intensity level. This characteristic increases the risks associated with inhalation exposure to TCPP

Federated Representation Learning for Encrypted Application Type Classification in beyond 5G RAN

International audienceMobile application classification is essential for advanced network management and application-based QoS policy enforcement in future, AI-enhanced, beyond 5G and 6G mobile networks. This article proposes to use AI methods to categorize applications as functional types (e.g., Video, Audio, Browsing) despite encryption and limited labeled data. We tackle these challenges through unsupervised representation learning, which maximizes the use of abundant unlabeled data in mobile networks. Due to the distributed nature of beyond 5G and 6G networks, we use this method in federated learning scenarios and compare it to the centralized ones. Our findings highlight that unsupervised learning improves model performance, especially with scarce labeled data. Additionally, federated learning provides effective results as compared to centralized methods.</div

Waveguide fabrication with integrated coupling optic

International audienceWe present the fabrication of a waveguide with integrated injection optics using a laser photoinscription technique in the bulk of a chalcogenide glass. The injection optic is a gradient index lens with a parabolic refractive index profile. Its focusing characteristics depend on the amplitude of the index gradient and the thickness of the lens. These two parameters can be used to optimize light injection when the lens is written in front of a waveguide. We show experimentally that the coupling efficiency can be superior to that obtained by conventional injection with an external lens. Numerical simulations show that this coupling efficiency can be as high as 85%. The simultaneous inscription of a waveguide and its injection lens result in a monolithic component that is compact, lightweight and insensitive to mechanical or thermal perturbations. Performance has been evaluated in the mid-infrared range, but these results can be extended to the visible