1,987 research outputs found
Hyperbolic Interaction Model For Hierarchical Multi-Label Classification
Different from the traditional classification tasks which assume mutual
exclusion of labels, hierarchical multi-label classification (HMLC) aims to
assign multiple labels to every instance with the labels organized under
hierarchical relations. Besides the labels, since linguistic ontologies are
intrinsic hierarchies, the conceptual relations between words can also form
hierarchical structures. Thus it can be a challenge to learn mappings from word
hierarchies to label hierarchies. We propose to model the word and label
hierarchies by embedding them jointly in the hyperbolic space. The main reason
is that the tree-likeness of the hyperbolic space matches the complexity of
symbolic data with hierarchical structures. A new Hyperbolic Interaction Model
(HyperIM) is designed to learn the label-aware document representations and
make predictions for HMLC. Extensive experiments are conducted on three
benchmark datasets. The results have demonstrated that the new model can
realistically capture the complex data structures and further improve the
performance for HMLC comparing with the state-of-the-art methods. To facilitate
future research, our code is publicly available
Distributed strategy-updating rules for aggregative games of multi-integrator systems with coupled constraints
In this paper, we explore aggregative games over networks of multi-integrator
agents with coupled constraints. To reach the general Nash equilibrium of an
aggregative game, a distributed strategy-updating rule is proposed by a
combination of the coordination of Lagrange multipliers and the estimation of
the aggregator. Each player has only access to partial-decision information and
communicates with his neighbors in a weight-balanced digraph which
characterizes players' preferences as to the values of information received
from neighbors. We first consider networks of double-integrator agents and then
focus on multi-integrator agents. The effectiveness of the proposed
strategy-updating rules is demonstrated by analyzing the convergence of
corresponding dynamical systems via the Lyapunov stability theory, singular
perturbation theory and passive theory. Numerical examples are given to
illustrate our results.Comment: 9 pages, 4 figure
Firstborn microcrystallization method to prepare nanocapsules containing artesunate
We developed a novel method to prepare nanocapsules. A solute often crystallizes when its solubility alters from one solvent to another, and its firstborn crystals are used as templates to prepare nanocapsules for the first time, which is called firstborn microcrystallization method. By using this method, the maximum diameter of the nanocapsules including artesunate is about 76 nm, and wrapping state is well. One important advantage of our method is that the preparation of the nanocapsules operates easily and is a one-time process with no other cumbersome processes necessary, therefore avoiding secondary pollution. The proposed method provides a new route to prepare monodisperse nanocapsules to increase bioavailability of hydrophobic solutes
Distributed event-triggered aggregative optimization with applications to price-based energy management
This paper studies a distributed continuous-time aggregative optimization
problem, which is a fundamental problem in the price-based energy management.
The objective of the distributed aggregative optimization is to minimize the
sum of local objective functions, which have a specific expression that relies
on agents' own decisions and the aggregation of all agents' decisions. To solve
the problem, a novel distributed continuous-time algorithm is proposed by
combining gradient dynamics with a dynamic average consensus estimator in a
two-time scale. The exponential convergence of the proposed algorithm is
established under the assumption of a convex global cost function by virtue of
the stability theory of singular perturbation systems. Motivated by practical
applications, the implementation of the continuous-time algorithm with
event-triggered communication is investigated. Simulations on the price-based
energy management of distributed energy resources are given to illustrate the
proposed method.Comment: 7 pages,7 figure
3-Methyl-4-{[(3-{[(3-methyl-5-oxo-1-phenyl-4,5-dihydro-1H-pyrazol-4-ylÂidene)(phenÂyl)methÂyl]aminoÂmethÂyl}benzÂyl)amino](phenÂyl)methylÂidene}-1-phenyl-1H-pyrazol-5(4H)-one
The complete molÂecule of the title compound, C42H36N6O2, is generated by a crystallographic twofold axis with two C atoms of the central phenyl group lying on the axis. In the independent part of the molÂecule, one amino group is involved in an intraÂmolecular N—H⋯O hydrogen bond, and the two adjacent phenyl rings are twisted from the plane of the pyrazolone ring with dihedral angles of 6.82 (3) and 88.32 (6)°. The crystal packing exhibits no classical interÂmolecular contacts
b \to ss\bar{d}$ in a Vector Quark Model
The rare decay is studied in a vector quark model by adding
the contributions from exotic vector-like quarks. We find that the contribution
from box diagrams amounts to in the branching ratio, while the
-mediated tree level contribution is negligible.Comment: LaTeX, 9 pages with 1 figur
An intrinsic link between long-term UV/optical variations and X-ray loudness in quasars
Observations have shown that UV/optical variation amplitude of quasars depend
on several physi- cal parameters including luminosity, Eddington ratio, and
likely also black hole mass. Identifying new factors which correlate with the
variation is essential to probe the underlying physical processes. Combining
~ten years long quasar light curves from SDSS stripe 82 and X-ray data from
Stripe 82X, we build a sample of X-ray detected quasars to investigate the
relation between UV/optical variation amplitude () and X-ray
loudness. We find that quasars with more intense X-ray radiation (com- pared to
bolometric luminosity) are more variable in UV/optical. Such correlation
remains highly significant after excluding the effect of other parameters
including luminosity, black hole mass, Ed- dington ratio, redshift, rest-frame
wavelength (i.e., through partial correlation analyses). We further find the
intrinsic link between X-ray loudness and UV/optical variation is gradually
more prominent on longer timescales (up to 10 years in the observed frame), but
tends to disappear at timescales < 100 days. This suggests a slow and long-term
underlying physical process. The X-ray reprocessing paradigm, in which
UV/optical variation is produced by a variable central X-ray emission
illuminating the accretion disk, is thus disfavored. The discovery points to an
interesting scheme that both the X-ray corona heating and UV/optical variation
is quasars are closely associated with magnetic disc turbulence, and the
innermost disc turbulence (where corona heating occurs) correlates with the
slow turbulence at larger radii (where UV/optical emission is produced).Comment: 9 pages, 4 figures, 1 table, accepted by Ap
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