3,190 research outputs found
Learning Adaptive Discriminative Correlation Filters via Temporal Consistency Preserving Spatial Feature Selection for Robust Visual Tracking
With efficient appearance learning models, Discriminative Correlation Filter
(DCF) has been proven to be very successful in recent video object tracking
benchmarks and competitions. However, the existing DCF paradigm suffers from
two major issues, i.e., spatial boundary effect and temporal filter
degradation. To mitigate these challenges, we propose a new DCF-based tracking
method. The key innovations of the proposed method include adaptive spatial
feature selection and temporal consistent constraints, with which the new
tracker enables joint spatial-temporal filter learning in a lower dimensional
discriminative manifold. More specifically, we apply structured spatial
sparsity constraints to multi-channel filers. Consequently, the process of
learning spatial filters can be approximated by the lasso regularisation. To
encourage temporal consistency, the filter model is restricted to lie around
its historical value and updated locally to preserve the global structure in
the manifold. Last, a unified optimisation framework is proposed to jointly
select temporal consistency preserving spatial features and learn
discriminative filters with the augmented Lagrangian method. Qualitative and
quantitative evaluations have been conducted on a number of well-known
benchmarking datasets such as OTB2013, OTB50, OTB100, Temple-Colour, UAV123 and
VOT2018. The experimental results demonstrate the superiority of the proposed
method over the state-of-the-art approaches
Fitting 3D Morphable Models using Local Features
In this paper, we propose a novel fitting method that uses local image
features to fit a 3D Morphable Model to 2D images. To overcome the obstacle of
optimising a cost function that contains a non-differentiable feature
extraction operator, we use a learning-based cascaded regression method that
learns the gradient direction from data. The method allows to simultaneously
solve for shape and pose parameters. Our method is thoroughly evaluated on
Morphable Model generated data and first results on real data are presented.
Compared to traditional fitting methods, which use simple raw features like
pixel colour or edge maps, local features have been shown to be much more
robust against variations in imaging conditions. Our approach is unique in that
we are the first to use local features to fit a Morphable Model.
Because of the speed of our method, it is applicable for realtime
applications. Our cascaded regression framework is available as an open source
library (https://github.com/patrikhuber).Comment: Submitted to ICIP 2015; 4 pages, 4 figure
Quantum information processing architecture with endohedral fullerenes in a carbon nanotube
A potential quantum information processor is proposed using a fullerene
peapod, i.e., an array of the endohedral fullerenes 15N@C60 or 31P@C60
contained in a single walled carbon nanotube (SWCNT). The qubits are encoded in
the nuclear spins of the doped atoms, while the electronic spins are used for
initialization and readout, as well as for two-qubit operations.Comment: 8 pages, 8 figure
Disorder and metal-insulator transitions in Weyl semimetals
The Weyl semimetal (WSM) is a newly proposed quantum state of matter. It has
Weyl nodes in bulk excitations and Fermi arcs surface states. We study the
effects of disorder and localization in WSMs and find three exotic phase
transitions. (I) Two Weyl nodes near the Brillouin zone boundary can be
annihilated pairwise by disorder scattering, resulting in the opening of a
topologically nontrivial gap and a transition from a WSM to a three-dimensional
(3D) quantum anomalous Hall state. (II) When the two Weyl nodes are well
separated in momentum space, the emergent bulk extended states can give rise to
a direct transition from a WSM to a 3D diffusive anomalous Hall metal. (III)
Two Weyl nodes can emerge near the zone center when an insulating gap closes
with increasing disorder, enabling a direct transition from a normal band
insulator to a WSM. We determine the phase diagram by numerically computing the
localization length and the Hall conductivity, and propose that the exotic
phase transitions can be realized on a photonic lattice.Comment: 7 pages with appendix, 6 figure
Stability range of parameters at fixed points for a class of complex dynamics
We study the parameters range for the fixed point of a class of complex
dynamics with the rational fractional function as
, where is specified, and
are two complex parameters. The relationship between two parameters, and
, is obtained at the fixed point. Moreover the explicit expression of the
parameter and in terms of is derived, where is the
derivative function at fixed point. The parameter regimes for the stability of
the fixed point are presented numerically for some typical different cases.Comment: 15 pages, 6 figure
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