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Topological modes in phononic waveguide interfaces
No full textInternational audienceWe report phononic waveguide interfaces capable of supporting topological edge modes. Weinvestigate the topological properties of the edge modes in different waveguide interfaces, revealing robustpropagation with negligible backscattering. Our results provide valuable insights for the design of low-lossphononic components for device applications
Experimental Demonstration of 73 Gb/s QPSK and 150 Gb/s QAM-32 Wireless Data Links in the Sub-THz Band Through Frequency Selective Surface Filters
No full textInternational audienceInvestigations on the beneficial effects of microfabricated frequency selective surfaces (FSS) filters in terahertz (THz) wireless links have been recently proposed for amplitude-only on-off keying modulation schemes. Preliminary results on the error performance of amplitude-phase modulations were obtained and compared with a simple model to serve as a testbed for future, more accurate analyses. Here, we further increase the data rate of wireless data links based on FSS filters while maintaining an error below the forward error correction limit. This improvement is achieved by resorting to modulation schemes with higher spectral efficiency such as 4-level phase shift keying, and 32-level quadrature amplitude modulation, measuring 73 Gb/s and 150 Gb/s, with error vector magnitudes (EVM) lower than 16% and 10% respectively. Measurement results for the EVM are predicted through an innovative use of the k-means algorithm which is here suitably modified to deal with FSS-based communications. A remarkable agreement is observed, which makes the proposed tool a promising candidate for the calibration of future wireless links based on FSS filters for next-generation high data rate THz communications
Advanced Resource Management in Cell-Free Massive MIMO Systems with WINNER II Channels
No full textInternational audienceThe evolution toward Beyond 5G (B5G) and Sixth-Generation (6G) networks demands innovative solutions to enhance connectivity and network efficiency. Cell-free massive multiple-input multiple-output (CF-mMIMO) systems address these challenges by deploying distributed access points (APs) to provide consistent coverage and mitigate interference, making them particularly valuable in high-mobility scenarios like vehicular communications. This paper presents novel algorithms for efficient frequency resource allocation in CF-mMIMO systems, focusing on user pairing and subband sharing. By enabling multiple users to share a single subband while minimizing condition number (CN) and channel correlation (CC), these strategies significantly improve resource utilization. Simulation results using the WINNER II channel model demonstrate notable gains in efficiency and sustained user spectral efficiency (SE). Comparisons with a Best-Fit Subband (BFS) allocation strategy further highlight the importance of effective resource allocation in advancing the performance and scalability of CF-mMIMO for future networks
Locally sealed microfabricated vapor cells filled from an ex situ Cs source
No full textInternational audienceMicrofabricated alkali vapor cells are key to enable miniature devices such as atomic clocks and optically pumped magnetometers with reduced size, weight and power. Yet, more versatile fabrication methods are still needed to further expand their use cases. Here, we demonstrate a novel approach to collectively fill and seal microfabricated cesium cells using locally-sealed microchannels patterned within one of the glass substrates comprising the cells. Unlike current methods that rely on wafer-level anodic bonding as the last sealing step, an approach based on local sealing opens the path to features so far limited to traditional glass-blown cells, including the ability to deposit temperature-sensitive antirelaxation coatings, reaching lower background gas pressure without an additional gettering material or filling with diverse atomic or molecular species
A Sub-400-nW Real-Time Event-Driven Spectrogram Extraction Unit in 28-nm FD-SOI CMOS for Keyword Spotting Application
No full textInternational audienceConsidering the power-hungry nature of speech processing, a keyword spotting (KWS) unit, used to detect multiple spoken words, is often integrated as a front-end layer. KWS systems are always active, and thus, it is extremely important to optimize the devoted power budget. In this context, this article presents a programmable low-power event-driven real-time spectrogram extraction unit tested for the KWS application. This chip, fabricated in 28-nm FD-SOI CMOS technology, has been combined with a software-defined convolutional neural network to demonstrate the recognition of 11 audio classes (ten keywords + background + unknown) with an accuracy equal to 87.9% and an activity-dependent power consumption measured at 391.6 nW, for a 12-keyword/min average speech rate
DyCE: Dynamically Configurable Exiting for deep learning compression and real-time scaling
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El mundo pop. Paisajes icónicos y temáticas recurrentes en la obra de Antonio de Felipe
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Corneal endothelial dysfunction treatments: Recent advances in non-invasive treatment strategies
No full textInternational audienceThe corneal endothelium plays an essential role in the maintenance of a healthy vision. However, in contrast to epithelial cells with high proliferation rates and a turnover lifespan of six to seven days that allows maintenance of constant cell density and high control of cell adhesion, human corneal endothelial cells (HCECs) do not normally proliferate. Therefore, loss of HCECs density over time leads to corneal transparency loss, and the development of corneal edema, bullous keratopathy and other eye diseases. Developments for repairing HCECs are continuously searched for and are evolving around possible topical drug applications as well as emerging strategies such as CRISPR-Cas9 gene editing, antisense oligonucleotides (ASOs) and nanotechnological concepts. Here, the state-of-the-art treatment strategies for corneal endothelial diseases (e.g. Fuch's endothelial corneal dystrophy (FECD), corneal edema, bullous keratopathy) will be outlined with a special focus on where topical applications have shown positive therapeutic outcomes
Aimer son travail malgré un déclassement : entre contraintes et ressources
No full textInternational audienceDonnant souvent lieu à une fragilisation à la fois matérielle et symbolique, les trajectoires descendantes de personnes issues de milieux favorisés invitent à réinterroger la problématique du bonheur au travail. L’analyse de quatre récits de déclassement dans des secteurs contrastés (restauration, coiffure, transport routier), parfois entremêlés à des expériences de stigmatisation, permet de donner une réponse nuancée à cette question
