696 research outputs found
Articulatory features for speech-driven head motion synthesis
This study investigates the use of articulatory features for speech-driven head motion synthesis as opposed to prosody features such as F0 and energy that have been mainly used in the literature. In the proposed approach, multi-stream HMMs are trained jointly on the synchronous streams of speech and head motion data. Articulatory features can be regarded as an intermediate parametrisation of speech that are expected to have a close link with head movement. Measured head and articulatory movements acquired by EMA were synchronously recorded with speech. Measured articulatory data was compared to those predicted from speech using an HMM-based inversion mapping system trained in a semi-supervised fashion. Canonical correlation analysis (CCA) on a data set of free speech of 12 people shows that the articulatory features are more correlated with head rotation than prosodic and/or cepstral speech features. It is also shown that the synthesised head motion using articulatory features gave higher correlations with the original head motion than when only prosodic features are used. Index Terms: head motion synthesis, articulatory features, canonical correlation analysis, acoustic-to-articulatory mappin
The University of Edinburgh Head-Motion and Audio Storytelling (UoE-HAS) Dataset
Abstract. In this paper we announce the release of a large dataset of storytelling monologue with motion capture for the head and body. Initial tests on the dataset indicate that head motion is more dependant on the speaker than the style of speech
Influence of yttrium iron garnet thickness and heater opacity on the nonlocal transport of electrically and thermally excited magnons
We studied the nonlocal transport behavior of both electrically and thermally
excited magnons in yttrium iron garnet (YIG) as a function of its thickness.
For electrically injected magnons, the nonlocal signals decrease monotonically
as the YIG thickness increases. For the nonlocal behavior of the thermally
generated magnons, or the nonlocal spin Seebeck effect (SSE), we observed a
sign reversal which occurs at a certain heater-detector distance, and it is
influenced by both the opacity of the YIG/heater interface and the YIG
thickness. Our nonlocal SSE results can be qualitatively explained by the
bulk-driven SSE mechanism together with the magnon diffusion model. Using a
two-dimensional finite element model (2D-FEM), we estimated the bulk spin
Seebeck coefficient of YIG at room temperature. The quantitative disagreement
between the experimental and modeled results indicates more complex processes
going on in addition to magnon diffusion and relaxation, especially close to
the contacts.Comment: 16 pages, 11 figure
Coherent long-range transfer of angular momentum between magnon Kittel modes by phonons
We report ferromagnetic resonance in the normal configuration of an
electrically insulating magnetic bilayer consisting of two yttrium iron garnet
(YIG) films epitaxially grown on both sides of a 0.5-mm-thick nonmagnetic
gadolinium gallium garnet (GGG) slab. An interference pattern is observed and
it is explained as the strong coupling of the magnetization dynamics of the two
YIG layers either in phase or out of phase by the standing transverse sound
waves, which are excited through a magnetoelastic interaction. This coherent
mediation of angular momentum by circularly polarized phonons through a
nonmagnetic material over macroscopic distances can be useful for future
information technologies
Magnetostrictive hysteresis of TbCo/CoFe multilayers and magnetic domains
Magnetic and magnetostrictive hysteresis loops of TbCo/CoFe multilayers under
field applied along the hard magnetization axis are studied using vectorial
magnetization measurements, optical deflectometry and magneto optical Kerr
microscopy. Even a very small angle misalignment between hard axis and magnetic
field direction is shown to drastically change the shape of magnetization and
magnetostrictive torsion hysteresis loops. Two kinds of magnetic domains are
revealed during the magnetization: big regions with opposite rotation of
spontaneous magnetization vector and spontaneous magnetic domains which appear
in a narrow field interval and provide an inversion of this rotation.
We show that the details of the hysteresis loops of our exchange-coupled
films can be described using the classical model of homogeneous magnetization
rotation of single uniaxial films and the configuration of observed domains.
The understanding of these features is crucial for applications (for MEMS or
microactuators) which benefit from the greatly enhanced sensitivity near the
point of magnetic saturation at the transverse applied field.Comment: 10 pages, 11 figure
Thermal simulation of magnetization reversals for size-distributed assemblies of core-shell exchange biased nanoparticles
A temperature dependent coherent magnetization reversal model is proposed for
size-distributed assemblies of ferromagnetic nanoparticles and
ferromagnetic-antiferromagnetic core-shell nanoparticles. The nanoparticles are
assumed to be of uniaxial anisotropy and all aligned along their easy axis. The
thermal dependence is included by considering thermal fluctuations, implemented
via the N\'eel-Arrhenius theory. Thermal and angular dependence of
magnetization reversal loops, coercive field and exchange-bias field are
obtained, showing that F-AF size-distributed exchange-coupled nanoparticles
exhibit temperature-dependent asymmetric magnetization reversal. Also,
non-monotonic evolutions of He and Hc with T are demonstrated. The angular
dependence of Hc with T exhibits a complex behavior, with the presence of an
apex, whose position and amplitude are strongly T dependent. The angular
dependence of He with T exhibits complex behaviors, which depends on the AF
anisotropy and exchange coupling. The resulting angular behavior demonstrates
the key role of the size distribution and temperature in the magnetic response
of nanoparticles.Comment: Revised arguments in Introduction and last sectio
Annuaire hydrologique des lacs collinaires 1998-1999 : réseau pilote de surveillance hydrologique
Annuaire hydrologique des lacs collinaires 1999-2000 : réseau pilote de surveillance hydrologique
Speech driven talking head from estimated articulatory features
In this paper, we present a talking head in which the lips and head motion are controlled using articulatory movements estimated from speech. A phone-size HMM-based inversion mapping is employed and trained in a semi-supervised fashion. The advantage of the use of articulatory features is that they can drive the lips motions and they have a close link with head movements. Speech inversion normally requires the training data recorded with electromagnetic articulograph (EMA), which restricts the naturalness of head movements. The present study considers a more realistic recording condition where the training data for the target speaker are recorded with a usual motion capture system rather than EMA. Different temporal clustering techniques are investigated for HMMbased mapping as well as a GMM-based frame-wise mapping as a baseline system. Objective and subjective experiments show that the synthesised motions are more natural using an HMM system than a GMM one, and estimated EMA features outperform prosodic features. Index Terms — inversion mapping, clustering, head motion synthesis 1
Développement d’une formulation pour l’étude du comportement dynamique non linéaire des coques cylindriques isotropes
Les structures minces auxquelles l’industrie fait de nos jours appel, sont sujettes à des sollicitations conduisant aux grands déplacements. Ces grandes amplitudes se manifestent par des non linéarités de type géométriques. Le développement des méthodes analytiques et numériques optant pour le contrôle et l’atténuation des vibrations de telles structures a fait l’objet de plusieurs travaux de recherche et a suscité l’intérêt de la communauté scientifique dans la dernière décennie au niveau international.
S’inscrivant dans le même contexte, le présent travail exhibite une nouvelle formulation combinant la théorie non linéaire de Novozhilov avec la méthode des éléments finis classique et visant l’évaluation des caractéristiques vibratoires des structures cylindriques minces, fermées et isotropes. La théorie, développée dans ce manuscrit, tient en compte de l’effet de courbure au niveau du champ de déplacement circonférentiel et considère l’impact des imperfections géométriques initiales sur la réponse dynamique du système. La formulation prend d’abord une forme générale en considérant le champ de déplacement comme une alliance entre une fonction temporelle et une autre spatiale. Les relations cinématiques non linéaires sont induites de la théorie de Novozhilov. L’équation de mouvement ainsi que les matrices de masse et de rigidité linéaire et non linéaire qui en découlent, sont déterminées en employant les équations de Lagrange et en tenant compte de la phénomologie de couplage entre les différents modes. Une application de ce modèle a été illustrée dans un second temps en adoptant le champ de déplacement représentant la solution exacte des équations d’équilibres de Sanders issues de l’analyse linéaire. La résolution de l’équation de mouvement se base principalement sur le principe de linéarisation en procédant d’abord à une transformation du système dans sa base modale. Les résultats ressortis de cette théorie montrent une excellente concordance avec ceux trouvés dans la littérature. L’effet des ratios (longueur/rayon) et (épaisseur/rayon) ainsi que la fluctuation des conditions aux limites sont explorés dans cette analyse
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