Conservatoire national des arts et métiers

About: Conservatoire national des arts et métiers is a education organization based out in Paris, France. It is known for research contribution in the topics: Population & Context (language use). The organization has 3573 authors who have published 7127 publications receiving 141430 citations. The organization is also known as: CNAM & Conservatoire des arts et métiers.

MUREL: Multimodal Relational Reasoning for Visual Question Answering

Abstract: Multimodal attentional networks are currently state-of-the-art models for Visual Question Answering (VQA) tasks involving real images. Although attention allows to focus on the visual content relevant to the question, this simple mechanism is arguably insufficient to model complex reasoning features required for VQA or other high-level tasks. In this paper, we propose MuRel, a multimodal relational network which is learned end-to-end to reason over real images. Our first contribution is the introduction of the MuRel cell, an atomic reasoning primitive representing interactions between question and image regions by a rich vectorial representation, and modeling region relations with pairwise combinations. Secondly, we incorporate the cell into a full MuRel network, which progressively refines visual and question interactions, and can be leveraged to define visualization schemes finer than mere attention maps. We validate the relevance of our approach with various ablation studies, and show its superiority to attention-based methods on three datasets: VQA 2.0, VQA-CP v2 and TDIUC. Our final MuRel network is competitive to or outperforms state-of-the-art results in this challenging context. Our code is available: this https URL

Free vibrations of simply-supported piezoelectric adaptive plates: An exact sandwich formulation

Abstract: An exact two-dimensional analytical solution is proposed for the free-vibration analysis of simply-supported piezoelectric adaptive plates. It is based on an original sandwich formulation that considers layerwise first-order shear-deformation theory and quadratic non-uniform electric potential, with no assumptions on electric field and displacement components. Thus, the electric-charge conservation equation is exactly satisfied and the induced potential, hence the electromechanical coupling, is correctly represented. Also, two-dimensional electromechanical equations of motion and generalized piezoelectric constitutive equations, corresponding to introduced stress and electric displacement resultants, are derived and presented for the first time. The proposed approach was numerically validated through modal analysis of several hybrid plates with graphite-epoxy cross-ply substrates and embedded or surface-bonded piezoelectric layers. Compared to available uncoupled and coupled (exact) three-dimensional elasticity (Navier and state space) and finite-element (layerwise and mixed equivalent single-layer/layerwise) solutions, the obtained results were the closest to the exact coupled three-dimensional ones, making the present approach very reliable.

MHC heterozygote advantage in simian immunodeficiency virus-infected Mauritian cynomolgus macaques.

Abstract: The importance of a broad CD8 T lymphocyte (CD8-TL) immune response to HIV is unknown. Ex vivo measurements of immunological activity directed at a limited number of defined epitopes provide an incomplete portrait of the actual immune response. We examined viral loads in simian immunodeficiency virus (SIV)-infected major histocompatibility complex (MHC)-homozygous and MHC-heterozygous Mauritian cynomolgus macaques. Chronic viremia in MHC-homozygous macaques was 80 times that in MHC-heterozygous macaques. Virus from MHC-homozygous macaques accumulated 11 to 14 variants, consistent with escape from CD8-TL responses after 1 year of SIV infection. The pattern of mutations detected in MHC-heterozygous macaques suggests that their epitope-specific CD8-TL responses are a composite of those present in their MHC-homozygous counterparts. These results provide the clearest example of MHC heterozygote advantage among individuals infected with the same immunodeficiency virus strain, suggesting that broad recognition of multiple CD8-TL epitopes should be a key feature of HIV vaccines.

LiGaTe2: A new highly nonlinear chalcopyrite optical crystal for the Mid-IR

Abstract: The chalcopyrite crystal LiGaTe 2 was grown by the Bridgman-Stockbarger technique with sufficient size and optical quality that allowed the characterization of its linear (dispersion and birefringence) and nonlinear optical properties. X-ray structural analysis was performed on single crystals. The transmission was recorded in the 0.5-24 μm range, and Raman and IR-spectra were recorded in the 0-400 cm -1 and 180-400 cm -1 ranges, respectively. The clear transparency range of LiGaTe 2 extends from 2.5 to 12 μm, the band-gap at room temperature is at 2.41 eV (515 nm), residual absorption limits the transmission near the band-edge, and the upper limit for the transmission is determined by the onset two-phonon absorption. LiGaTe 2 is a positive uniaxial crystal that possesses sufficient birefringence for phase-matching. Its nonlinear coefficient d 36 was estimated by phase-matched second harmonic generation to be 43 pm/V ± 10%. It is only the third crystal belonging to the A I B III C VI 2 chalcopyrite family for which phase-matched nonlinear frequency conversion could be demonstrated, and of this group it exhibits the highest nonlinearity and figure of merit for nonlinear optical applications in the mid-infrared.