70 research outputs found
Thermal analysis of dual-phase-lag model in a two-dimensional plate subjected to a heat source moving along elliptical trajectories
In this paper, we focus on the study of heat transfer behavior for the
dual-phase-lag heat conduction model, which describes the evolution of
temperature in a two-dimensional rectangular plate caused by the activity of a
point heat source moving along elliptical trajectories. At first, Green's
function approach is applied to derive the analytical solution of temperature
for the given model. Based on the series representation of this analytical
solution, the thermal responses for the underlying heat transfer problem,
including the relations between the moving heat source and the concomitant
temperature peak, the influences of the pair of phase lags and the angular
velocity of heat source on temperature, are then investigated, analyzed and
discussed in detail for three different movement trajectories. Compared with
the results revealed for the common situation that the heat source moves in a
straight line with a constant speed, the present results show quite distinctive
thermal behaviors for all cases, which subsequently can help us to better
understand the internal mechanism of the dual-phase-lag heat transfer subjected
to a moving heat source with curved trajectory.Comment: 15 pages, 41 figure
Dynamical relaxation behavior of extended XY chain with gapless phase following a quantum quench
We investigate the dynamical relaxation behavior of the two-point correlation
in extended XY models with a gapless phase after quenches from various initial
states. Specifically, we study the XY chain with gapless phase induced by the
additional interactions: Dzyaloshinskii-Moriya interaction and XZY-YZX type of
three-site interaction. When quenching from the gapped phase, we observe that
the additional interactions have no effect on the relaxation behavior. The
relaxation behavior is and for
the quench to the commensurate phase and the incommensurate phase,
respectively. However, when quenching from the gapless phase, we demonstrate
that the scaling behavior of is changed to for
the quench to the commensurate phase, and the decay of
follows or for the quench to the incommensurate
phase depending on the parameters of pre-quench Hamiltonian. We also establish
the dynamical phase diagrams based on the dynamical relaxation behavior of
in the extended XY models.Comment: 12 pages, 10 figure
Dynamics of the Geometric Phase in Inhomogeneous Quantum Spin Chains
The dynamics of the geometric phase are studied in inhomogeneous quantum spin
chains after a quench. Analytic expressions of the Pancharatnam geometric phase
(PGP) are derived, for both the period-two quantum Ising chain
(QIC) and the disordered QIC. In the period-two QIC, due to the periodic
modulation, the PGP changes with time at the boundary of the Brillouin zone,
and consequently, the winding number
based on
the PGP is not quantized and thus not topological anymore. Nevertheless, the
PGP and its winding number show non-analytic singularities at the critical
times of the dynamical quantum phase transitions (DQPTs). This relation between
the PGP and the DQPT is further confirmed in the disordered QIC, where the
winding number is not defined. It is found that the critical time of DQPT
inherited from the homogeneous system and the additional one induced by the
weak disorder are also accompanied by the non-analytic singularity of the PGP,
by decomposing the PGP into each quasiparticle mode. The connection between the
non-analytic behavior of the PGP at the critical time and the DQPT, regardless
of whether the winding number is topological, can be explained by the fact that
they both arise when the Loschmidt amplitude vanishes.Comment: 14 pages, 8 figure
From Capture to Display: A Survey on Volumetric Video
Volumetric video, which offers immersive viewing experiences, is gaining
increasing prominence. With its six degrees of freedom, it provides viewers
with greater immersion and interactivity compared to traditional videos.
Despite their potential, volumetric video services poses significant
challenges. This survey conducts a comprehensive review of the existing
literature on volumetric video. We firstly provide a general framework of
volumetric video services, followed by a discussion on prerequisites for
volumetric video, encompassing representations, open datasets, and quality
assessment metrics. Then we delve into the current methodologies for each stage
of the volumetric video service pipeline, detailing capturing, compression,
transmission, rendering, and display techniques. Lastly, we explore various
applications enabled by this pioneering technology and we present an array of
research challenges and opportunities in the domain of volumetric video
services. This survey aspires to provide a holistic understanding of this
burgeoning field and shed light on potential future research trajectories,
aiming to bring the vision of volumetric video to fruition.Comment: Submitte
Understanding User Behavior in Volumetric Video Watching: Dataset, Analysis and Prediction
Volumetric video emerges as a new attractive video paradigm in recent years
since it provides an immersive and interactive 3D viewing experience with six
degree-of-freedom (DoF). Unlike traditional 2D or panoramic videos, volumetric
videos require dense point clouds, voxels, meshes, or huge neural models to
depict volumetric scenes, which results in a prohibitively high bandwidth
burden for video delivery. Users' behavior analysis, especially the viewport
and gaze analysis, then plays a significant role in prioritizing the content
streaming within users' viewport and degrading the remaining content to
maximize user QoE with limited bandwidth. Although understanding user behavior
is crucial, to the best of our best knowledge, there are no available 3D
volumetric video viewing datasets containing fine-grained user interactivity
features, not to mention further analysis and behavior prediction. In this
paper, we for the first time release a volumetric video viewing behavior
dataset, with a large scale, multiple dimensions, and diverse conditions. We
conduct an in-depth analysis to understand user behaviors when viewing
volumetric videos. Interesting findings on user viewport, gaze, and motion
preference related to different videos and users are revealed. We finally
design a transformer-based viewport prediction model that fuses the features of
both gaze and motion, which is able to achieve high accuracy at various
conditions. Our prediction model is expected to further benefit volumetric
video streaming optimization. Our dataset, along with the corresponding
visualization tools is accessible at
https://cuhksz-inml.github.io/user-behavior-in-vv-watching/Comment: Accepted by ACM MM'2
The Influence of Social Comparison and Peer Group Size on Risky Decision-Making
This study explores the influence of different social reference points and different comparison group sizes on risky decision-making. Participants were presented with a scenario describing an exam, and presented with the opportunity of making a risky decision in the context of different information provided about the performance of their peers. We found that behavior was influenced, not only by comparison with peers, but also by the size of the comparison group. Specifically, the larger the reference group, the more polarized the behavior it prompted. In situations describing social loss, participants were led to make riskier decisions after comparing themselves against larger groups, while in situations describing social gain, they become more risk averse. These results indicate that decision making is influenced both by social comparison and the number of people making up the social reference group
- …