1,797 research outputs found
Scars in Dirac fermion systems: the influence of an Aharonov--Bohm flux
Time-reversal (-) symmetry is fundamental to many physical
processes. Typically, -breaking for microscopic processes requires
the presence of magnetic field. However, for 2D massless Dirac billiards,
-symmetry is broken automatically by the mass confinement, leading
to chiral quantum scars. In this paper, we investigate the mechanism of
-breaking by analyzing the local current of the scarring
eigenstates and their magnetic response to an Aharonov--Bohm flux. Our results
unveil the complete understanding of the subtle -breaking
phenomena from both the semiclassical formula of chiral scars and the
microscopic current and spin reflection at the boundaries, leading to a
controlling scheme to change the chirality of the relativistic quantum scars.
Our findings not only have significant implications on the transport behavior
and spin textures of the relativistic pseudoparticles, but also add basic
knowledge to relativistic quantum chaos.Comment: 37 pages, 11 figure
THE STUDY OF ENERGY LOSS FROM IMPACT ON A CURVED BALL OF GOLF SWINGS
Practicing and correcting positions and movements without understanding the principles were involved with the ball impact and subsequent flight path. This research was focused on the relationships between energy creation and loss when open and closed clubfaces were used to create a curved flight path of the ball. Based on the results of the experiments, the energy loss from different clubface angles was varied and caused different flight trajectories of the ball
Techniques for Deblurring Faces in Images by Utilizing Multi-Camera Fusion
This publication describes techniques for deblurring faces in images by utilizing multi-camera (e.g., dual-camera) fusion processes. In the techniques, multiple cameras of a computing device (e.g., wide-angle camera, an ultrawide-angle camera) concurrently capture a scene. A multi-camera fusion technique is utilized to fuse the captured images together to generate an image with increased sharpness while preserving the brightness of the scene and other details under a motion scene. The images are processed by a Deblur Module, which includes an optical flow machine-learned model for generating a warped ultrawide-angle image, a subject mask trained to identify and mask faces detected in the wide-angle image, and an occlusion mask for handling occlusion artifacts. The warped ultrawide-angle image, the raw wide-angle image (with blurred faces), the sharp ultrawide-angle image, the subject mask, and the occlusion map are then stacked and merged (fused) using a machine-learning model to output a sharp image without the presence of motion blur. This publication further describes techniques utilizing adaptive multi-streaming to optimize power consumption and dual camera usage on computing devices
Dynamic generation or removal of a scalar hair
We study dynamic processes through which the scalar hair of black holes is
generated or detached in a theory with a scalar field non-minimally coupled to
Gauss-Bonnet and Ricci scalar invariants. We concentrate on the nonlinear
temporal evolution of a far-from-equilibrium gravitational system. In our
simulations, we choose the initial spacetime to be either a bald Schwarzschild
or a scalarized spherically symmetric black hole. Succeeding continuous
accretion of the scalar field onto the original black hole, the final fate of
the system displays intriguing features, which depend on the initial
configurations, strengths of the perturbation, and specific metric parameters.
In addition to the scalarization process through which the bald black hole
addresses scalar hair, we observe the dynamical descalarization, which removes
scalar hair from an original hairy hole after continuous scalar field
accretion. We examine the temporal evolution of the scalar field, the metrics,
and the Misner-Sharp mass of the spacetime and exhibit rich phase structures
through nonlinear dynamical processes.Comment: 22 pages, 11 figure
THE EFFECT OF FOOT POSITION ON KINETICS OF LOWER LIMBS DURING SQUAT
The purposes of this study were to evaluate the effects of the foot position on the joint forces and moments of lower limbs during squat. Eleven male weightlifters were recruited in this study to perform squat with different foot position (forward position and toe-out 20 degrees). The VICON motion analysis system and two KISTLER force platforms were used to record the kinematical and kinetic data during squat. The results showed that the ankle joint maximal shear force, maximal adduction moment, external rotation moment and knee external rotation moment during squat with foot forward position were significantly greater than the results in toe-out position. Squat with foot forward position could be suggested to improve the ankle stability in rehabilitative training
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