11,512 research outputs found
Theory for spin and orbital orderings in high temperature phase in
Motivated by the recent neutron diffraction experiment on , we
consider a microscopic model where each ion is occupied by two 3d
electrons of parallel spins with two fold degenerate orbital configurations.
The mean field classical solutions of the spin-orbital superexchange model
predicts an antiferro-orbital ordering at a higher temperature followed by a
C-type antiferromagnetic spin ordering at a lower temperature. Our results are
qualitatively consistent with the observed orbital phase transition at and the spin phase transition at in .Comment: 7 pages, 3 figures and 2 tables. Accepted to be published in PR
Towards Semantic Fast-Forward and Stabilized Egocentric Videos
The emergence of low-cost personal mobiles devices and wearable cameras and
the increasing storage capacity of video-sharing websites have pushed forward a
growing interest towards first-person videos. Since most of the recorded videos
compose long-running streams with unedited content, they are tedious and
unpleasant to watch. The fast-forward state-of-the-art methods are facing
challenges of balancing the smoothness of the video and the emphasis in the
relevant frames given a speed-up rate. In this work, we present a methodology
capable of summarizing and stabilizing egocentric videos by extracting the
semantic information from the frames. This paper also describes a dataset
collection with several semantically labeled videos and introduces a new
smoothness evaluation metric for egocentric videos that is used to test our
method.Comment: Accepted for publication and presented in the First International
Workshop on Egocentric Perception, Interaction and Computing at European
Conference on Computer Vision (EPIC@ECCV) 201
PulmoBell: Home-based Pulmonary Rehabilitation Assistive Technology for People with COPD
Chronic Obstructive Pulmonary Disease (COPD) can be fatal and is challenging
to live with due to its severe symptoms. Pulmonary rehabilitation (PR) is one
of the managements means to maintain COPD in a stable status. However,
implementation of PR in the UK has been challenging due to the environmental
and personal barriers faced by patients, which hinder their uptake, adherence,
and completion of the programmes. Moreover, increased exercise capacity
following PR does not always translate into physical activity (PA) and
unfortunately, can lead back to exercise capacity seen prior to PR. Current
alternative solutions using telerehabilitation methods have limitations on
addressing these accessibility problems, and no clear conclusion can be drawn
on the efficacy of telerehabilitation in enhancing the sustainability of PR
outcomes via promoting PA in patients' everyday life. In this work, the authors
propose a novel design of sensor-based assistive product with the aim of
facilitating PR and promoting PA maintenance in a home-based setting.
Prototypes of different levels of fidelity are presented, followed by an
evaluation plan for future research directions.Comment: Short Technical Report: Best student-led project in COMP0145:
Research Methods and Making Skills (2022/23
Quark-Lepton Quartification
We propose that quarks and leptons are interchangeable entities in the
high-energy limit. This naturally results in the extension of [SU(3)]^3
trinification to [SU(3)]^4 quartification. In addition to the unbroken color
SU(3)_q of quarks, there is now also a color SU(3)_l of leptons which reduces
to an unbroken SU(2)_l. We discuss the natural occurrence of SU(2)_l doublets
at the TeV energy scale, which leads remarkably to the unification of all gauge
couplings without supersymmetry. Proton decay occurs through the exchange of
scalar bosons, with a lifetime in the range 10^{34} - 10^{36} years.Comment: 12 pages, 4 figures. Reference adde
Generating Neutrino Mass in the 331 Model
A mechanism for generating small tree-level Majorana mass for neutrinos is
implemented in the 331 Model. No additional fermions or scalars need to be
added, and no mass scale greater than a few TeV is invoked.Comment: LaTex, 7 pages, no figures. Revised version to appear in Phys. Rev.
Theory for Phase Transitions in Insulating Vanadium Oxide
We show that the recently proposed S=2 bond model with orbital degrees of
freedom for insulating VO not only explains the anomalous magnetic
ordering, but also other mysteries of the magnetic phase transition. The model
contains an additional orbital degree of freedom that exhibits a zero
temperature quantum phase transtion in the Ising universality class.Comment: 5 pages, 2 figure
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