370 research outputs found
Closed-loop control of gamma oscillations in the brain connections through the transcranial stimulations
The reconstruction of brain neural network connections occurs not only during
the infancy and early childhood stages of brain development, but also in
patients with cognitive impairment in middle and old age under the therapy with
stimulated external interference, such as the non-invasive repetitive
transcranial magnetic stimulation (rTMS) and the transcranial direct current
stimulation(tDCS). However, until now, it is not clear how brain stimulation
triggers and controls the reconstruction of neural network connections in the
brain. This paper combines the EEG data analysis and the cortical neuronal
network modeling methods. On one hand, an E-I balanced cortical neural network
model was constructed under a long-lasting external stimulation of
sinusoidal-exponential form TMS or square-wave tDCS was introduced into the
network model for simulate the treatment process for the brain connections. On
the other hand, by combining Butterworth filter and functional connectivity
algorithm, the paper analyzes the relations between the attentional gamma
oscillation responses and the brain connection based on the publicly available
EEGs during the pre-tDCS and post-tDCS treatment phases. Firstly, the
simulation results indicate that, during long-lasting external stimulations of
tDCS/rTMS, The sustained gamma oscillation was found to trigger more release of
BDNF from astrocytes to participate in the positively reshaping the excitatory
neuronal network connection
A Temporal-Pattern Backdoor Attack to Deep Reinforcement Learning
Deep reinforcement learning (DRL) has made significant achievements in many
real-world applications. But these real-world applications typically can only
provide partial observations for making decisions due to occlusions and noisy
sensors. However, partial state observability can be used to hide malicious
behaviors for backdoors. In this paper, we explore the sequential nature of DRL
and propose a novel temporal-pattern backdoor attack to DRL, whose trigger is a
set of temporal constraints on a sequence of observations rather than a single
observation, and effect can be kept in a controllable duration rather than in
the instant. We validate our proposed backdoor attack to a typical job
scheduling task in cloud computing. Numerous experimental results show that our
backdoor can achieve excellent effectiveness, stealthiness, and sustainability.
Our backdoor's average clean data accuracy and attack success rate can reach
97.8% and 97.5%, respectively
Power allocation for D2D communications in heterogeneous networks
In this paper, we study power allocation for D2D communications in heterogeneous networks utilizing game theory approach to improve the performance of the whole system. Given D2D's underlay status in the system, Stackelberg game framework is well suited for the situation. In our scheme, macrocell system and femtocell system are considered as two leaders and D2D pairs are considered as the follower, forming a two-leader-one-follower Stackelberg game. The leaders act first, charging some fees from the follower for using the channel and causing interference to jeopardize their communication equality. The follower observes the leaders' behavior and develops its strategy based on the prices offered by the leaders. We analyse the procedure and obtain the Stackeberg equilibrium, which determines the optimal prices for the leaders and optimal transmit power for the follower. In the end, simulations are executed to validate the proposed allocation method, which significantly improves data rate of user equipments. ? 2014 Global IT Research Institute (GIRI).EICPCI-S(ISTP)
Convolutional neural network- based pelvic floor structure segmentation using magnetic resonance imaging in pelvic organ prolapse
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/162690/2/mp14377.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/162690/1/mp14377_am.pd
Deep Dynamic Epidemiological Modelling for COVID-19 Forecasting in Multi-level Districts
Objective: COVID-19 has spread worldwide and made a huge influence across the
world. Modeling the infectious spread situation of COVID-19 is essential to
understand the current condition and to formulate intervention measurements.
Epidemiological equations based on the SEIR model simulate disease development.
The traditional parameter estimation method to solve SEIR equations could not
precisely fit real-world data due to different situations, such as social
distancing policies and intervention strategies. Additionally, learning-based
models achieve outstanding fitting performance, but cannot visualize
mechanisms. Methods: Thus, we propose a deep dynamic epidemiological (DDE)
method that combines epidemiological equations and deep-learning advantages to
obtain high accuracy and visualization. The DDE contains deep networks to fit
the effect function to simulate the ever-changing situations based on the
neural ODE method in solving variants' equations, ensuring the fitting
performance of multi-level areas. Results: We introduce four SEIR variants to
fit different situations in different countries and regions. We compare our DDE
method with traditional parameter estimation methods (Nelder-Mead, BFGS,
Powell, Truncated Newton Conjugate-Gradient, Neural ODE) in fitting the
real-world data in the cases of countries (the USA, Columbia, South Africa) and
regions (Wuhan in China, Piedmont in Italy). Our DDE method achieves the best
Mean Square Error and Pearson coefficient in all five areas. Further, compared
with the state-of-art learning-based approaches, the DDE outperforms all
techniques, including LSTM, RNN, GRU, Random Forest, Extremely Random Trees,
and Decision Tree. Conclusion: DDE presents outstanding predictive ability and
visualized display of the changes in infection rates in different regions and
countries
Pelvic floor MRI segmentation based on semi-supervised deep learning
The semantic segmentation of pelvic organs via MRI has important clinical
significance. Recently, deep learning-enabled semantic segmentation has
facilitated the three-dimensional geometric reconstruction of pelvic floor
organs, providing clinicians with accurate and intuitive diagnostic results.
However, the task of labeling pelvic floor MRI segmentation, typically
performed by clinicians, is labor-intensive and costly, leading to a scarcity
of labels. Insufficient segmentation labels limit the precise segmentation and
reconstruction of pelvic floor organs. To address these issues, we propose a
semi-supervised framework for pelvic organ segmentation. The implementation of
this framework comprises two stages. In the first stage, it performs
self-supervised pre-training using image restoration tasks. Subsequently,
fine-tuning of the self-supervised model is performed, using labeled data to
train the segmentation model. In the second stage, the self-supervised
segmentation model is used to generate pseudo labels for unlabeled data.
Ultimately, both labeled and unlabeled data are utilized in semi-supervised
training. Upon evaluation, our method significantly enhances the performance in
the semantic segmentation and geometric reconstruction of pelvic organs, Dice
coefficient can increase by 2.65% averagely. Especially for organs that are
difficult to segment, such as the uterus, the accuracy of semantic segmentation
can be improved by up to 3.70%
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