1,987 research outputs found

    Hyperbolic Interaction Model For Hierarchical Multi-Label Classification

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    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

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    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

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    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

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    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-yl­idene)(phen­yl)meth­yl]amino­meth­yl}benz­yl)amino](phen­yl)methyl­idene}-1-phenyl-1H-pyrazol-5(4H)-one

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    The complete mol­ecule 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 mol­ecule, one amino group is involved in an intra­molecular 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 inter­molecular contacts

    b \to ss\bar{d}$ in a Vector Quark Model

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    The rare decay b→ssdˉb\to ss\bar{d} 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 10−910^{-9} in the branching ratio, while the ZZ-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

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    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 (σrms\sigma_{rms}) 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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