628 research outputs found

    UIT-Saviors at MEDVQA-GI 2023: Improving Multimodal Learning with Image Enhancement for Gastrointestinal Visual Question Answering

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    In recent years, artificial intelligence has played an important role in medicine and disease diagnosis, with many applications to be mentioned, one of which is Medical Visual Question Answering (MedVQA). By combining computer vision and natural language processing, MedVQA systems can assist experts in extracting relevant information from medical image based on a given question and providing precise diagnostic answers. The ImageCLEFmed-MEDVQA-GI-2023 challenge carried out visual question answering task in the gastrointestinal domain, which includes gastroscopy and colonoscopy images. Our team approached Task 1 of the challenge by proposing a multimodal learning method with image enhancement to improve the VQA performance on gastrointestinal images. The multimodal architecture is set up with BERT encoder and different pre-trained vision models based on convolutional neural network (CNN) and Transformer architecture for features extraction from question and endoscopy image. The result of this study highlights the dominance of Transformer-based vision models over the CNNs and demonstrates the effectiveness of the image enhancement process, with six out of the eight vision models achieving better F1-Score. Our best method, which takes advantages of BERT+BEiT fusion and image enhancement, achieves up to 87.25% accuracy and 91.85% F1-Score on the development test set, while also producing good result on the private test set with accuracy of 82.01%.Comment: ImageCLEF2023 published version: https://ceur-ws.org/Vol-3497/paper-129.pd

    Inverse lift: a signature of the elasticity of complex fluids?

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    To understand the mechanics of a complex fluid such as a foam we propose a model experiment (a bidimensional flow around an obstacle) for which an external sollicitation is applied, and a local response is measured, simultaneously. We observe that an asymmetric obstacle (cambered airfoil profile) experiences a downards lift, opposite to the lift usually known (in a different context) in aerodynamics. Correlations of velocity, deformations and pressure fields yield a clear explanation of this inverse lift, involving the elasticity of the foam. We argue that such an inverse lift is likely common to complex fluids with elasticity.Comment: 4 pages, 4 figures, revised version, submitted to PR

    Design of directional couplers for marine applications with artificial transmission lines

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    The article describes the design of the coupler for marine applications, on which the miniaturization of its dimensions was carried out. The description of the compact device is given. It consists of artificial transmission lines of the original form. The use of such lines for the coupler allowed to achieve good results in reducing the size. So the area of the resulting device is 72.25% less than that of a conventional device, while it has comparable characteristics. The described approach can be used for other devices requiring miniaturization and implemented on a printed circuit board. © Published under licence by IOP Publishing Ltd

    Using discrete choice experiments to investigate subject preferences for preventive asthma medication

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    Background and objective: Long-term adherence to inhaled corticosteroids is poor despite the crucial role of preventer medications in achieving good asthma outcomes. This study was undertaken to explore patient preferences in relation to their current inhaled corticosteroid medication, a hypothetical preventer or no medication. Methods: A discrete choice experiment was conducted in 57 adults with mild-moderate asthma and airway hyper-responsiveness, who were using inhaled corticosteroid ≤500 μg/day (beclomethasone equivalent). In the discrete choice experiment, subjects evaluated 16 hypothetical scenarios made up of 10 attributes that described the process and outcomes of taking asthma medication, with two to four levels for each attribute. For each scenario, subjects chose between the hypothetical medication, the medication they were currently taking and no asthma medication. A random parameter multinomial logit model was estimated to quantify subject preferences for the aspects of taking asthma medication and the influence of attributes on medication decisions. Results: Subjects consistently made choices in favour of being able to do strenuous and sporting activities with or without reliever, experiencing no side-effects and never having to monitor their peak flow. Frequency of collecting prescriptions, frequency of taking the medication, its route of administration and the strength of the doctor recommendation about the medication were not significant determinants of choice. Conclusions: The results of this study suggest that patients prefer a preventer that confers capacity to maximize physical activity, has no side-effects and does not require daily peak flow monitoring. © 2007 The Authors

    Role of dynamic Jahn-Teller distortions in Na2C60 and Na2CsC60 studied by NMR

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    Through 13C NMR spin lattice relaxation (T1) measurements in cubic Na2C60, we detect a gap in its electronic excitations, similar to that observed in tetragonal A4C60. This establishes that Jahn-Teller distortions (JTD) and strong electronic correlations must be considered to understand the behaviour of even electron systems, regardless of the structure. Furthermore, in metallic Na2CsC60, a similar contribution to T1 is also detected for 13C and 133Cs NMR, implying the occurence of excitations typical of JT distorted C60^{2-} (or equivalently C60^{4-}). This supports the idea that dynamic JTD can induce attractive electronic interactions in odd electron systems.Comment: 3 figure

    Elastic interactions of active cells with soft materials

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    Anchorage-dependent cells collect information on the mechanical properties of the environment through their contractile machineries and use this information to position and orient themselves. Since the probing process is anisotropic, cellular force patterns during active mechanosensing can be modelled as anisotropic force contraction dipoles. Their build-up depends on the mechanical properties of the environment, including elastic rigidity and prestrain. In a finite sized sample, it also depends on sample geometry and boundary conditions through image strain fields. We discuss the interactions of active cells with an elastic environment and compare it to the case of physical force dipoles. Despite marked differences, both cases can be described in the same theoretical framework. We exactly solve the elastic equations for anisotropic force contraction dipoles in different geometries (full space, halfspace and sphere) and with different boundary conditions. These results are then used to predict optimal position and orientation of mechanosensing cells in soft material.Comment: Revtex, 38 pages, 8 Postscript files included; revised version, accepted for publication in Phys. Rev.
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