108 research outputs found

    High-Fidelity Eye Animatable Neural Radiance Fields for Human Face

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    Face rendering using neural radiance fields (NeRF) is a rapidly developing research area in computer vision. While recent methods primarily focus on controlling facial attributes such as identity and expression, they often overlook the crucial aspect of modeling eyeball rotation, which holds importance for various downstream tasks. In this paper, we aim to learn a face NeRF model that is sensitive to eye movements from multi-view images. We address two key challenges in eye-aware face NeRF learning: how to effectively capture eyeball rotation for training and how to construct a manifold for representing eyeball rotation. To accomplish this, we first fit FLAME, a well-established parametric face model, to the multi-view images considering multi-view consistency. Subsequently, we introduce a new Dynamic Eye-aware NeRF (DeNeRF). DeNeRF transforms 3D points from different views into a canonical space to learn a unified face NeRF model. We design an eye deformation field for the transformation, including rigid transformation, e.g., eyeball rotation, and non-rigid transformation. Through experiments conducted on the ETH-XGaze dataset, we demonstrate that our model is capable of generating high-fidelity images with accurate eyeball rotation and non-rigid periocular deformation, even under novel viewing angles. Furthermore, we show that utilizing the rendered images can effectively enhance gaze estimation performance.Comment: Under revie

    A Fermi-LAT Study of Globular Cluster Dynamical Evolution in Milky Way Galaxy: Millisecond Pulsars as the Probe

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    Using archival {\it Fermi}-LAT data with a time span of 12\sim12 years, we study the population of Millisecond Pulsars (MSPs) in Globular Clusters (GlCs) and investigate their dependence on cluster dynamical evolution in the Milky Way Galaxy. We show that the γ\gamma-ray luminosity (LγL_{\gamma}) and emissivity (ϵγ=Lγ/M\epsilon_{\gamma}=L_{\gamma}/M) are good indicators of the population and abundance of MSPs in GlCs, and they are highly dependent on the dynamical evolution history of the host clusters. Specifically speaking, the dynamically older GlCs with more compact structures are more likely to have larger LγL_{\gamma} and ϵγ\epsilon_{\gamma}, and these trends can be summarized as strong correlations with cluster stellar encounter rate Γ\Gamma and the specific encounter rate (Λ=Γ/M\Lambda=\Gamma/M), with LγΓ0.70±0.11L_{\gamma}\propto \Gamma^{0.70\pm0.11} and ϵγΛ0.73±0.13\epsilon_{\gamma}\propto \Lambda^{0.73\pm0.13} for dynamically normal GlCs. However, as GlCs evolve into deep core collapse, these trends are found to be reversed, implying that strong encounters may have lead to the ejection of MSPs from core-collapsed Systems. Besides, the GlCs are found to exhibit larger ϵγ\epsilon_{\gamma} with increasing stellar mass function slope, decreasing tidal radius and distances from the Galactic Center (GC). These correlations indicate that, as GlCs losing kinetic energy and spiral in towards GC, tidal stripping and mass segregation have a preference in leading to the loss of normal stars from GlCs, while MSPs are more likely to concentrate to cluster center and be deposited into the GC. Moreover, we gauge ϵγ\epsilon_{\gamma} of GlCs is 101000\sim10-1000 times larger than the Galactic bulge, the latter is thought to reside thousands of unresolved MSPs and may responsible for the GC γ\gamma-ray excess, which support that GlCs are generous contributors to the population of MSPs in the GC.Comment: 23 pages, 9 figures, 3 tables, accepted for publication in RA

    CNx-modified Fe3O4 as Pt nanoparticle support for the oxygen reduction reaction

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    A novel electrocatalyst support material, nitrogendoped carbon (CNx)-modified Fe3O4 (Fe3O4-CNx), was synthesized through carbonizing a polypyrrole-Fe3O4 hybridized precursor. Subsequently, Fe3O4-CNx-supported Pt (Pt/Fe3O4-CNx) nanocomposites were prepared by reducing Pt precursor in ethylene glycol solution and evaluated for the oxygen reduction reaction (ORR). The Pt/Fe3O4-CNx catalysts were characterized by X-ray diffraction, Raman spectra, X-ray photoelectron spectroscopy, scanning electron microscopy, and transmission electron microscopy. The electrocatalytic activity and stability of the as-prepared electrocatalysts toward ORR were studied by cyclic voltammetry and steady-state polarization measurements. The results showed that Pt/ Fe3O4-CNx catalysts exhibited superior catalytic performance for ORR to the conventional Pt/C and Pt/C-CNx catalysts.Web of Scienc

    Metastable state nanoparticle-enhanced Raman spectroscopy for highly sensitive detection

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    Metastable state silver nanoparticle surface-enhanced Raman scattering has been experimentally and theoretically demonstrated; the signal is two to three orders of magnitude higher than that for the traditional method. Ultrasensitive surface-enhanced Raman scattering signals of illicit drug cocaine and organophosphate pesticide methyl-parathion were observed.National Basic Research Program of China[2007CB936603, 2011CB933700]; Hi-tech Research and Development Program of China[2009AA03Z330]; Anhui Provincial Education Department[KJ2010ZD09

    The Ninth Visual Object Tracking VOT2021 Challenge Results

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