10 research outputs found

    Hybrid ultrasonic elastic force motors micromachined in silicon

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    A micromotor for low power applications is being developed using silicon micromachining technologies and organometallic PZT films sol-gel deposition. The construction of a hybrid ultrasonic motor suitable for batch fabrication is proposed. A fabrication process for the stator resonator compatible with both bulk micromachining and 0.3 mu m PZT films deposition on a SiNx/Ta/Pt substrate has been tested. Comparison of PZT actuated and previously fabricated ZnO actuated diaphragms are performed using laser interferometry, PZT samples show promising results for applications where a low voltage operation is a key benefit. Poled PZT films are obtained after process completion and influence of DC biases on the resonance frequencies are observed

    The IICT-Yverdon system for the WMT 2021 unsupervised MT and very low resource supervised MT task

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    In this paper, we present the systems submitted by our team from the Institute of ICT (HEIG-VD / HES-SO) to the Unsupervised MT and Very Low Resource Supervised MT task. We first study the improvements brought to a baseline system by techniques such as back-translation and initialization from a parent model. We find that both techniques are beneficial and suffice to reach performance that compares with more sophisticated systems from the 2020 task. We then present the application of this system to the 2021 task for low-resource supervised Upper Sorbian (HSB) to German translation, in both directions. Finally, we present a contrastive system for HSBDE in both directions, and for unsupervised German to Lower Sorbian (DSB) translation, which uses multi-task training with various training schedules to improve over the baseline

    Constrained language models for interactive poem generation

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    This paper describes a system for interactive poem generation, which combines neural language models (LMs) for poem generation with explicit constraints that can be set by users on form, topic, emotion, and rhyming scheme. LMs cannot learn such constraints from the data, which is scarce with respect to their needs even for a well-resourced language such as French. We propose a method to generate verses and stanzas by combining LMs with rule-based algorithms, and compare several approaches for adjusting the words of a poem to a desired combination of topics or emotions. An approach to automatic rhyme setting using a phonetic dictionary is proposed as well. Our system has been demonstrated at public events, and log analysis shows that users found it engaging

    Design of high-temperature solar-selective coatings based on aluminium titanium oxynitrides AlyTi1−y(OxN1−x). Part 1: Advanced microstructural characterization and optical simulation

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    Aluminium titanium oxynitrides were studied as candidate materials for high temperature absorbers in solar selective coatings due to their excellent stability and their tuneable optical behaviour. A set of individual AlyTi1−y(OxN1−x) layers with different oxygen content was prepared by cathodic vacuum arc (CVA) deposition. The composition, morphology, phase structure and microstructure of the films were characterized by elastic recoil detection (ERD), scanning and transmission electron microscopy and X-ray diffraction. An fcc phase structure is found in a broad compositional range of AlyTi1−y(OxN1−x). Simultaneously, sample microstructure and morphology undergo systematic changes from a columnar growth to the development of a heterogeneous structure with spherical nanoparticle inclusions when the oxygen concentration is increased. The optical properties were determined by spectroscopic ellipsometry and UV–Vis–NIR and FTIR spectrophotometry. A comprehensive analysis of the film properties allowed an accurate modelling of the optical constants of the AlyTi1−y(OxN1−x) in the whole wavelength range of solar interest (from 190 nm to 25 ”m). It points to a transition from metallic to dielectric behaviour with increasing oxygen content. Consequently, it is demonstrated that the optical properties of these AlyTi1−y(OxN1−x) deposited films can be controlled in a wide range from metallic to dielectric character by adjusting the oxygen concentration, opening a huge range of possibilities for the design of solar selective coatings (SSC) based on this material. Complete SSC, including a TiN layer as IR reflector, were designed by applying optical simulations, obtaining excellent optical selective properties of α = 94.0% and ΔRT = 4.8%

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