7,209 research outputs found
Semi-supervised Domain Adaptation in Graph Transfer Learning
As a specific case of graph transfer learning, unsupervised domain adaptation
on graphs aims for knowledge transfer from label-rich source graphs to
unlabeled target graphs. However, graphs with topology and attributes usually
have considerable cross-domain disparity and there are numerous real-world
scenarios where merely a subset of nodes are labeled in the source graph. This
imposes critical challenges on graph transfer learning due to serious domain
shifts and label scarcity. To address these challenges, we propose a method
named Semi-supervised Graph Domain Adaptation (SGDA). To deal with the domain
shift, we add adaptive shift parameters to each of the source nodes, which are
trained in an adversarial manner to align the cross-domain distributions of
node embedding, thus the node classifier trained on labeled source nodes can be
transferred to the target nodes. Moreover, to address the label scarcity, we
propose pseudo-labeling on unlabeled nodes, which improves classification on
the target graph via measuring the posterior influence of nodes based on their
relative position to the class centroids. Finally, extensive experiments on a
range of publicly accessible datasets validate the effectiveness of our
proposed SGDA in different experimental settings
Magnetic Borophenes from an Evolutionary Search
A computational methodology based on ab initio evolutionary algorithms and spin-polarized density functional theory was developed to predict two-dimensional magnetic materials. Its application to a model system borophene reveals an unexpected rich magnetism and polymorphism. A metastable borophene with nonzero thickness is an antiferromagnetic semiconductor from first-principles calculations, and can be further tuned into a half-metal by finite electron doping. In this borophene, the buckling and coupling among three atomic layers are not only responsible for magnetism, but also result in an out-of-plane negative Poisson\u27s ratio under uniaxial tension, making it the first elemental material possessing auxetic and magnetic properties simultaneously
Multi-point geostatistics for ore grade estimation
A multi-point geostatistical method for ore grade estimation is introduced in order to fully utilize existing sampling information. A block model is used to construct a new three-dimensional training image instead of a variogram. Data events and pattern matching is improved, and the directionality of the data template is considered in the matching. The inverse distance weighted method is used to make up for the lack of multi-point geostatistics. The research improves the reliability of multi-point geostatistical estimation. Optimal estimation results for Li2O and Ta2O5 come from the inverse distance weighted, ordinary Kriging, and multi-point geostatistical methods. Multi-point geostatistical estimation results are compared with those of the inverse distance weighted and ordinary Kriging methods. Deviation, trend, and variogram analyses are used to assess the effect of multipoint geostatistical estimation. This study shows that reducing the samples participating in the estimation can reduce the maximum and minimum deviation of the estimated grade to a certain extent. The grade distribution pattern is the primary factor affecting minimum and maximum deviation. This study proves the reliability and accuracy of the multi-point geostatistical method for ore grade estimation.</p
Theoretical calculations of proton emission half-lives based on a deformed Gamow-like model
In the present study, proton emission half-lives have been investigated for
the deformed proton emitters with in the deformed Gamow-like
model, where the deformation effect has been included in the Coulomb potential.
The experimental half-lives of proton emitters can be reproduced within a
factor of 3.45. For comparison, other results from the universal decay law and
the new Geiger-Nuttall law are presented as well. Furthermore, the relevance of
the half-lives to the angular momentum for La, Pr,
Tb and Ho has been analyzed, and corresponding possible values
of has been put forward: 3, 3, 4, 4
Disturbance Rejection Control for Autonomous Trolley Collection Robots with Prescribed Performance
Trajectory tracking control of autonomous trolley collection robots (ATCR) is
an ambitious work due to the complex environment, serious noise and external
disturbances. This work investigates a control scheme for ATCR subjecting to
severe environmental interference. A kinematics model based adaptive sliding
mode disturbance observer with fast convergence is first proposed to estimate
the lumped disturbances. On this basis, a robust controller with prescribed
performance is proposed using a backstepping technique, which improves the
transient performance and guarantees fast convergence. Simulation outcomes have
been provided to illustrate the effectiveness of the proposed control scheme
- …