4,187 research outputs found
Multi-Label Learning with Label Enhancement
The task of multi-label learning is to predict a set of relevant labels for
the unseen instance. Traditional multi-label learning algorithms treat each
class label as a logical indicator of whether the corresponding label is
relevant or irrelevant to the instance, i.e., +1 represents relevant to the
instance and -1 represents irrelevant to the instance. Such label represented
by -1 or +1 is called logical label. Logical label cannot reflect different
label importance. However, for real-world multi-label learning problems, the
importance of each possible label is generally different. For the real
applications, it is difficult to obtain the label importance information
directly. Thus we need a method to reconstruct the essential label importance
from the logical multilabel data. To solve this problem, we assume that each
multi-label instance is described by a vector of latent real-valued labels,
which can reflect the importance of the corresponding labels. Such label is
called numerical label. The process of reconstructing the numerical labels from
the logical multi-label data via utilizing the logical label information and
the topological structure in the feature space is called Label Enhancement. In
this paper, we propose a novel multi-label learning framework called LEMLL,
i.e., Label Enhanced Multi-Label Learning, which incorporates regression of the
numerical labels and label enhancement into a unified framework. Extensive
comparative studies validate that the performance of multi-label learning can
be improved significantly with label enhancement and LEMLL can effectively
reconstruct latent label importance information from logical multi-label data.Comment: ICDM 201
Dynamics of the sub-Ohmic spin-boson model: a time-dependent variational study
The Dirac-Frenkel time-dependent variation is employed to probe the dynamics
of the zero temperature sub-Ohmic spin-boson model with strong friction
utilizing the Davydov D1 ansatz. It is shown that initial conditions of the
phonon bath have considerable influence on the dynamics. Counterintuitively,
even in the very strong coupling regime, quantum coherence features still
manage to survive under the polarized bath initial condition, while such
features are absent under the factorized bath initial condition. In addition, a
coherent-incoherent transition is found at a critical coupling strength alpha ~
0.1 for s=0.25 under the factorized bath initial condition. We quantify how
faithfully our ansatz follows the Schr\"{o}dinger equation, finding that the
time-dependent variational approach is robust for strong dissipation and deep
sub-Ohmic baths (s<<1).Comment: 8 pages, 6 figure
Topological gauge theory, symmetry fractionalization, and classification of symmetry-enriched topological phases in three dimensions
Symmetry plays a crucial role in enriching topological phases of matter.
Phases with intrinsic topological order that are symmetric are called
symmetry-enriched topological phases (SET). In this paper, we focus on SETs in
three spatial dimensions, where the intrinsic topological orders are described
by Abelian gauge theory and the symmetry groups are also Abelian. As a series
work of our previous research [Phys. Rev. B 94, 245120 (2016);
(arXiv:1609.00985)], we study these topological phases described by twisted
gauge theories with global symmetry and consider all possible topologically
inequivalent "charge matrices". Within each equivalence class, there is a
unique pattern of symmetry fractionalization on both point-like and string-like
topological excitations. In this way, we classify Abelian topological order
enriched by Abelian symmetry within our field-theoretic approach. To
illustrate, we concretely calculate many representative examples of SETs and
discuss future directions
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