635 research outputs found
Intrinsic localized modes in a two-dimensional checkerboard ferromagnetic lattice
An analytical work on intrinsic localized modes in a two-dimensional
Heisenberg ferromagnet on the checkerboard lattice is presented. Taking
advantage of an asymptotic method, the governing lattice dynamical equations
are reduced to one (2+1) -dimensional nonlinear Schr\"odinger. In our work, we
obtain two types of nonlinear localized mode solutions, namely, Brillouin zone
center modes and Brillouin zone corner modes. The occurrence conditions for
these intrinsic localized modes are given in detail. Especially, we find that
the competition between the Dzialozinskii-Moriy interaction and the
next-nearest neighbor interaction of the checkerboard ferromagnet has an effect
on the local structure of the Brillouin zone corner acoustic mode
The Cognitive Processes of Image Schema in Sino-American Economic News on The Belt and Road
This contrastive study decodes the language applications employed in news reports through image schematization to reproduce the ‘cognitive map’ of news writers in their ways of perceiving the world and exerting influence on news readers’ ways of perception. By analysing American economic news (AEN) and Chinese economic news (CEN) on the issue of ‘The Belt and Road’ (B&R) from the perspective of cognitive linguistics, the authors uncover and sketch out the hidden epistemic cognitive patterns and processes of both the Chinese and American writers. The study demonstrates that the schematic images and their constructions are organized in the mind of an individual as a network, with both metaphorical and formulaic schemas at different schematic levels, presenting a different process of cognitive entrenchment through which, in news discourses, image schema is utilized as a projection lens, projecting the covert cognitive processes onto overt language use and function
Influences of Several Insecticides on the Survival of Lysiphlebus japonicus
When pesticides are used to control soybean aphids, a fraction of larvae, pupae (mummies) and adults of Lysiphlebus japonicus survive. To understand the influence of pesticides on the development of those surviving parasitoids, we carried out toxicity experiments of pesticides commonly used in the field and surveyed the survival of parasitoids.Originating text in Chinese.Citation: Gao, Junffeng, Zhu, Junyi, Yu, Kai, Ren, Wenhui. (1993). Influences of Several Insecticides on the Survival of Lysiphlebus japonicus. Natural Enemies of Insects, 15(4), 160-161
Adaptive Control for Robotic Manipulators base on RBF Neural Network
An adaptive neural network controller is brought forward by the paper to solve trajectory tracking problems of robotic manipulators with uncertainties. The first scheme consists of a PD feedback and a dynamic compensator which is composed by neural network controller and variable structure controller. Neutral network controller is designed to adaptive learn and compensate the unknown uncertainties, variable structure controller is designed to eliminate approach errors of neutral network. The adaptive weight learning algorithm of neural network is designed to ensure online real-time adjustment, offline learning phase is not need; Global asymptotic stability (GAS) of system base on Lyapunov theory is analysised to ensure the convergence of the algorithm. The simulation results show that the kind of the control scheme is effective and has good robustness
PDL: Regularizing Multiple Instance Learning with Progressive Dropout Layers
Multiple instance learning (MIL) was a weakly supervised learning approach
that sought to assign binary class labels to collections of instances known as
bags. However, due to their weak supervision nature, the MIL methods were
susceptible to overfitting and required assistance in developing comprehensive
representations of target instances. While regularization typically effectively
combated overfitting, its integration with the MIL model has been frequently
overlooked in prior studies. Meanwhile, current regularization methods for MIL
have shown limitations in their capacity to uncover a diverse array of
representations. In this study, we delve into the realm of regularization
within the MIL model, presenting a novel approach in the form of a Progressive
Dropout Layer (PDL). We aim to not only address overfitting but also empower
the MIL model in uncovering intricate and impactful feature representations.
The proposed method was orthogonal to existing MIL methods and could be easily
integrated into them to boost performance. Our extensive evaluation across a
range of MIL benchmark datasets demonstrated that the incorporation of the PDL
into multiple MIL methods not only elevated their classification performance
but also augmented their potential for weakly-supervised feature localizations.Comment: The code is available in https://github.com/ChongQingNoSubway/PD
TetCNN: Convolutional Neural Networks on Tetrahedral Meshes
Convolutional neural networks (CNN) have been broadly studied on images,
videos, graphs, and triangular meshes. However, it has seldom been studied on
tetrahedral meshes. Given the merits of using volumetric meshes in applications
like brain image analysis, we introduce a novel interpretable graph CNN
framework for the tetrahedral mesh structure. Inspired by ChebyNet, our model
exploits the volumetric Laplace-Beltrami Operator (LBO) to define filters over
commonly used graph Laplacian which lacks the Riemannian metric information of
3D manifolds. For pooling adaptation, we introduce new objective functions for
localized minimum cuts in the Graclus algorithm based on the LBO. We employ a
piece-wise constant approximation scheme that uses the clustering assignment
matrix to estimate the LBO on sampled meshes after each pooling. Finally,
adapting the Gradient-weighted Class Activation Mapping algorithm for
tetrahedral meshes, we use the obtained heatmaps to visualize discovered
regions-of-interest as biomarkers. We demonstrate the effectiveness of our
model on cortical tetrahedral meshes from patients with Alzheimer's disease, as
there is scientific evidence showing the correlation of cortical thickness to
neurodegenerative disease progression. Our results show the superiority of our
LBO-based convolution layer and adapted pooling over the conventionally used
unitary cortical thickness, graph Laplacian, and point cloud representation.Comment: Accepted as a conference paper to Information Processing in Medical
Imaging (IPMI 2023) conferenc
Metal-to-semiconductor transition in squashed armchair carbon nanotubes
We investigate electronic transport properties of the squashed armchair
carbon nanotubes, using tight-binding molecular dynamics and Green's function
method. We demonstrate a metal-to-semiconductor transistion while squashing the
nanotubes and a general mechanism for such transistion. It is the distinction
of the two sublattices in the nanotube that opens an energy gap near the Fermi
energy. We show that the transition has to be achieved by a combined effect of
breaking of mirror symmetry and bond formation between the flattened faces in
the squashed nanotubes.Comment: 4 papges, 4 figures, to appear in Phys. Rev. Let
NNMobile-Net: Rethinking CNN Design for Deep Learning-Based Retinopathy Research
Retinal diseases (RD) are the leading cause of severe vision loss or
blindness. Deep learning-based automated tools play an indispensable role in
assisting clinicians in diagnosing and monitoring RD in modern medicine.
Recently, an increasing number of works in this field have taken advantage of
Vision Transformer to achieve state-of-the-art performance with more parameters
and higher model complexity compared to Convolutional Neural Networks (CNNs).
Such sophisticated and task-specific model designs, however, are prone to be
overfitting and hinder their generalizability. In this work, we argue that a
channel-aware and well-calibrated CNN model may overcome these problems. To
this end, we empirically studied CNN's macro and micro designs and its training
strategies. Based on the investigation, we proposed a no-new-MobleNet
(nn-MobileNet) developed for retinal diseases. In our experiments, our generic,
simple and efficient model superseded most current state-of-the-art methods on
four public datasets for multiple tasks, including diabetic retinopathy
grading, fundus multi-disease detection, and diabetic macular edema
classification. Our work may provide novel insights into deep learning
architecture design and advance retinopathy research.Comment: Code will publish soon:
https://github.com/Retinal-Research/NNMOBILE-NE
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