2,540 research outputs found
Analyses of celestial pole offsets with VLBI, LLR, and optical observations
This work aims to explore the possibilities of determining the long-period
part of the precession-nutation of the Earth with techniques other than very
long baseline interferometry (VLBI). Lunar laser ranging (LLR) is chosen for
its relatively high accuracy and long period. Results of previous studies could
be updated using the latest data with generally higher quality, which would
also add ten years to the total time span. Historical optical data are also
analyzed for their rather long time-coverage to determine whether it is
possible to improve the current Earth precession-nutation model
Quantum Spin Liquid with Even Ising Gauge Field Structure on Kagome Lattice
Employing large-scale quantum Monte Carlo simulations, we study the extended
model on the kagome lattice. A quantum spin liquid phase
with effective even Ising gauge field structure emerges from the delicate
balance among three symmetry-breaking phases including stripe solid, staggered
solid and ferromagnet. This spin liquid is stabilized by an
extended interaction related to the Rokhsar-Kivelson potential in the quantum
dimer model limit. The phase transitions from the staggered solid to a spin
liquid or ferromagnet are found to be first order and so is the transition
between the stripe solid and ferromagnet. However, the transition between a
spin liquid and ferromagnet is found to be continuous and belongs to the 3D
universality class associated with the condensation of spinons. The
transition between a spin liquid and stripe solid appears to be continuous and
associated with the condensation of visons.Comment: 7 pages, 8 figure
Mesoscopic Interactions and Species Coexistence in Evolutionary Game Dynamics of Cyclic Competitions
Date of Acceptance: 27/11/2014Peer reviewedPublisher PD
Solving the Cold-Start Problem in Recommender Systems with Social Tags
In this paper, based on the user-tag-object tripartite graphs, we propose a
recommendation algorithm, which considers social tags as an important role for
information retrieval. Besides its low cost of computational time, the
experiment results of two real-world data sets, \emph{Del.icio.us} and
\emph{MovieLens}, show it can enhance the algorithmic accuracy and diversity.
Especially, it can obtain more personalized recommendation results when users
have diverse topics of tags. In addition, the numerical results on the
dependence of algorithmic accuracy indicates that the proposed algorithm is
particularly effective for small degree objects, which reminds us of the
well-known \emph{cold-start} problem in recommender systems. Further empirical
study shows that the proposed algorithm can significantly solve this problem in
social tagging systems with heterogeneous object degree distributions
Emergence of multicluster chimera states
We thank Prof. L. Huang for helpful discussions. This work was partially supported by ARO under Grant No. W911NF-14-1-0504 and by NSF of China under Grant No. 11275003. The visit of NY to Arizona State University was partially sponsored by Prof. Z. Zheng and the State Scholarship Fund of China.Peer reviewedPublisher PD
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