6,135 research outputs found
Holistic gaze strategy to categorize facial expression of varying intensities
Using faces representing exaggerated emotional expressions, recent behaviour and eye-tracking studies have suggested a
dominant role of individual facial features in transmitting diagnostic cues for decoding facial expressions. Considering that in everyday life we frequently view low-intensity expressive faces in which local facial cues are more ambiguous, we probably need to combine expressive cues from more than one facial feature to reliably decode naturalistic facial affects. In this study we applied a morphing technique to systematically vary intensities of six basic facial expressions of emotion, and employed a self-paced expression categorization task to measure participantsâ categorization performance and associated
gaze patterns. The analysis of pooled data from all expressions showed that increasing expression intensity would improve categorization accuracy, shorten reaction time and reduce number of fixations directed at faces. The proportion of fixations and viewing time directed at internal facial features (eyes, nose and mouth region), however, was not affected by varying levels of intensity. Further comparison between individual facial expressions revealed that although proportional gaze allocation at individual facial features was quantitatively modulated by the viewed expressions, the overall gaze distribution
in face viewing was qualitatively similar across different facial expressions and different intensities. It seems that we adopt a holistic viewing strategy to extract expressive cues from all internal facial features in processing of naturalistic facial expressions
Robust Non-Rigid Registration with Reweighted Position and Transformation Sparsity
Non-rigid registration is challenging because it is ill-posed with high
degrees of freedom and is thus sensitive to noise and outliers. We propose a
robust non-rigid registration method using reweighted sparsities on position
and transformation to estimate the deformations between 3-D shapes. We
formulate the energy function with position and transformation sparsity on both
the data term and the smoothness term, and define the smoothness constraint
using local rigidity. The double sparsity based non-rigid registration model is
enhanced with a reweighting scheme, and solved by transferring the model into
four alternately-optimized subproblems which have exact solutions and
guaranteed convergence. Experimental results on both public datasets and real
scanned datasets show that our method outperforms the state-of-the-art methods
and is more robust to noise and outliers than conventional non-rigid
registration methods.Comment: IEEE Transactions on Visualization and Computer Graphic
Novel insights into the transition form factor
BaBar's observation of significant deviations of the pion transition form
factor (TFF) from the asymptotic expectation with GeV has brought a
serious crisis to a fundamental picture established for such a simplest
system by perturbative QCD, i.e. the dominance of collinear
factorization at high momentum transfers for the pion TFF. We show that
non-factorizable contributions due to open flavors in
could be an important source that contaminates the pQCD asymptotic limit and
causes such deviations with GeV. Within an effective Lagrangian
approach, the non-factorizable amplitudes can be related to intermediate hadron
loops, i.e. and etc, and their corrections to the
and TFFs can be estimated.Comment: Revtex, 6 pages and 4 eps figures; Extended version accepted by Eur.
Phys. J.
Automatic landmark annotation and dense correspondence registration for 3D human facial images
Dense surface registration of three-dimensional (3D) human facial images
holds great potential for studies of human trait diversity, disease genetics,
and forensics. Non-rigid registration is particularly useful for establishing
dense anatomical correspondences between faces. Here we describe a novel
non-rigid registration method for fully automatic 3D facial image mapping. This
method comprises two steps: first, seventeen facial landmarks are automatically
annotated, mainly via PCA-based feature recognition following 3D-to-2D data
transformation. Second, an efficient thin-plate spline (TPS) protocol is used
to establish the dense anatomical correspondence between facial images, under
the guidance of the predefined landmarks. We demonstrate that this method is
robust and highly accurate, even for different ethnicities. The average face is
calculated for individuals of Han Chinese and Uyghur origins. While fully
automatic and computationally efficient, this method enables high-throughput
analysis of human facial feature variation.Comment: 33 pages, 6 figures, 1 tabl
Baryon electric dipole moments from strong CP violation
The electric dipole form factors and moments of the ground state baryons are
calculated in chiral perturbation theory at next-to-leading order. We show that
the baryon electric dipole form factors at this order depend only on two
combinations of low-energy constants. We also derive various relations that are
free of unknown low-energy constants. We use recent lattice QCD data to
calculate all baryon EDMs. In particular, we find d_n = -2.9\pm 0.9 and d_p =
1.1\pm 1.1 in units of 10^{-16} e \theta_0 cm. Finite volume corrections to the
moments are also worked out. We show that for a precision extraction from
lattice QCD data, the next-to-leading order terms have to be accounted for.Comment: 30 pages, 8 figures, to appear in JHE
Triangular singularity and a possible resonance in the decay
We study the decay by considering a triangle
singularity mechanism. In this mechanism, the decays into the
, the decays into the (or
), and then the (or ) interact to produce the
in the final state. This mechanism produces a peak structure around
MeV. In addition, the possibility that there is a hidden-strange
pentaquark-like state is also considered by taking into account the final state
interactions of , , and . We conclude that it
is difficult to search for the hidden-strange analogue of the states in
this decay. However, we do expect nontrivial behavior in the invariant
mass distribution. The predictions can be tested by experiments such as BESIII,
LHCb and Belle-II.Comment: 7 pages, 3 figure
Human spontaneous gaze patterns in viewing of faces of different species
Human studies have reported clear differences in perceptual and neural processing of faces of different species, implying the contribution of visual experience to face perception. Can these differences be manifested in our eye scanning patterns while extracting salient facial information? Here we systematically compared non-pet ownersâ gaze patterns while exploring human, monkey, dog and cat faces in a passive viewing task. Our analysis revealed that the faces of different species induced similar patterns of fixation distribution between left and right hemi-face, and among key local facial features with the eyes attracting the highest proportion of fixations and viewing times, followed by the nose and then the mouth. Only the proportion of fixation directed at the mouth region was species-dependent and could be differentiated at the earliest stage of face viewing. It seems that our spontaneous eye scanning patterns associated with face exploration were mainly constrained by general facial configurations; the species affiliation of the inspected faces had limited impact on gaze allocation, at least under free viewing conditions
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