6,252 research outputs found
Kondo Metal and Ferrimagnetic Insulator on the Triangular Kagom\'e Lattice
We obtain the rich phase diagrams in the Hubbard model on the triangular
Kagom\'e lattice as a function of interaction, temperature and asymmetry, by
combining the cellular dynamical mean-field theory with the continuous time
quantum Monte Carlo method. The phase diagrams show the asymmetry separates the
critical points in Mott transition of two sublattices on the triangular
Kagom\'e lattice and produces two novel phases called plaquette insulator with
an obvious gap and a gapless Kondo metal. When the Coulomb interaction is
stronger than the critical value Uc, a short range paramagnetic insulating
phase, which is a candidate for the short rang resonating valence-bond spin
liquid, emerges before the ferrimagnetic order is formed independent of
asymmetry. Furthermore, we discuss how to measure these phases in future
experiments
Stability and bifurcation of a delayed diffusive predator-prey model affected by toxins
In this work, a diffusive predator-prey model with the effects of toxins and delay is considered. Initially, we investigated the presence of solutions and the stability of the system. Then, we examined the local stability of the equilibria and Hopf bifurcation generated by delay, as well as the global stability of the equilibria using a Lyapunov function. In addition, we extract additional results regarding the presence and nonexistence of non-constant steady states in this model by taking into account the influence of diffusion. We show several numerical simulations to validate our theoretical findings
Continual Graph Convolutional Network for Text Classification
Graph convolutional network (GCN) has been successfully applied to capture
global non-consecutive and long-distance semantic information for text
classification. However, while GCN-based methods have shown promising results
in offline evaluations, they commonly follow a seen-token-seen-document
paradigm by constructing a fixed document-token graph and cannot make
inferences on new documents. It is a challenge to deploy them in online systems
to infer steaming text data. In this work, we present a continual GCN model
(ContGCN) to generalize inferences from observed documents to unobserved
documents. Concretely, we propose a new all-token-any-document paradigm to
dynamically update the document-token graph in every batch during both the
training and testing phases of an online system. Moreover, we design an
occurrence memory module and a self-supervised contrastive learning objective
to update ContGCN in a label-free manner. A 3-month A/B test on Huawei public
opinion analysis system shows ContGCN achieves 8.86% performance gain compared
with state-of-the-art methods. Offline experiments on five public datasets also
show ContGCN can improve inference quality. The source code will be released at
https://github.com/Jyonn/ContGCN.Comment: 9 pages, 4 figures, AAAI 2023 accepted pape
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