174 research outputs found
Asymptotic Stability, Orbital Stability of Hopf-Bifurcating Periodic Solution of a Simple Three-Neuron Artificial Neural Network with Distributed Delay
A distributed delay model of a class of three-neuron network has been investigated. Sufficient conditions for existence of unique equilibrium, multiple equilibria and their local stability are derived. A closed interval for a parameter of the system is identified in which Hopf-bifurcating periodic solution occurs for each point of such interval. The orbital stability of such bifurcating periodic solution at the extreme points of the interval is ascertained. Lastly global bifurcation aspect of such periodic solutions is studied. The results are illustrated by numerical simulations
Stability and Hopf-Bifurcation Analysis of Delayed BAM Neural Network under Dynamic Thresholds
In this paper the dynamics of a three neuron model with self-connection and distributed delay under dynamical threshold is investigated. With the help of topological degree theory and Homotopy invariance principle existence and uniqueness of equilibrium point are established. The conditions for which the Hopf-bifurcation occurs at the equilibrium are obtained for the weak kernel of the distributed delay. The direction and stability of the bifurcating periodic solutions are determined by the normal form theory and central manifold theorem. Lastly global bifurcation aspect of such periodic solutions is studied. Some numerical simulations for justifying the theoretical analysis are also presented
4D X-Ray CT Reconstruction using Multi-Slice Fusion
There is an increasing need to reconstruct objects in four or more dimensions
corresponding to space, time and other independent parameters. The best 4D
reconstruction algorithms use regularized iterative reconstruction approaches
such as model based iterative reconstruction (MBIR), which depends critically
on the quality of the prior modeling. Recently, Plug-and-Play methods have been
shown to be an effective way to incorporate advanced prior models using
state-of-the-art denoising algorithms designed to remove additive white
Gaussian noise (AWGN). However, state-of-the-art denoising algorithms such as
BM4D and deep convolutional neural networks (CNNs) are primarily available for
2D and sometimes 3D images. In particular, CNNs are difficult and
computationally expensive to implement in four or more dimensions, and training
may be impossible if there is no associated high-dimensional training data.
In this paper, we present Multi-Slice Fusion, a novel algorithm for 4D and
higher-dimensional reconstruction, based on the fusion of multiple
low-dimensional denoisers. Our approach uses multi-agent consensus equilibrium
(MACE), an extension of Plug-and-Play, as a framework for integrating the
multiple lower-dimensional prior models. We apply our method to the problem of
4D cone-beam X-ray CT reconstruction for Non Destructive Evaluation (NDE) of
moving parts. This is done by solving the MACE equations using
lower-dimensional CNN denoisers implemented in parallel on a heterogeneous
cluster. Results on experimental CT data demonstrate that Multi-Slice Fusion
can substantially improve the quality of reconstructions relative to
traditional 4D priors, while also being practical to implement and train.Comment: 8 pages, 8 figures, IEEE International Conference on Computational
Photography 2019, Toky
A Self-Management Training Intervention: Perceptions and Practices of Community Health Workers in South Africa
Background. While community health workers
(CHWs) are increasingly being used as a strategy for
increasing health care access, particularly in rural
communities, interventions are needed to improve
their skill sets in inspiring health behavior change,
both for themselves and among their community clients. Self-management (SM) education interventions have shown to improve health behaviors and wellbeing. Purpose
A Mild and Efficient Method for the Syntheses and Regioselective Ring-Opening of Aziridines
We have developed a new synthetic method for the synthesis of aziridines using Chloramine-T as an effective reagent in the presence of NH2OH center dot HCl and NaIO4. We found that the same combination of NH2OH center dot HCl and NaIO4 is also very effective for nucleophilic ring opening of aziridines.This research was funded by the Russian Science Foundation, grant number 18-19-00090
A PASE-Based Approach Towards Synthesis of Epoxy Ketones
This work was supported by the Russian Science Foundation (Ref. № 18-73-00301). A. Majee acknowledges financial support from the DST-RSF Major Research Project (Ref. № INT/RUS/RSF/P-08)
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