102,065 research outputs found
Transfer Learning for Domain Adaptation in MRI: Application in Brain Lesion Segmentation
Magnetic Resonance Imaging (MRI) is widely used in routine clinical diagnosis
and treatment. However, variations in MRI acquisition protocols result in
different appearances of normal and diseased tissue in the images.
Convolutional neural networks (CNNs), which have shown to be successful in many
medical image analysis tasks, are typically sensitive to the variations in
imaging protocols. Therefore, in many cases, networks trained on data acquired
with one MRI protocol, do not perform satisfactorily on data acquired with
different protocols. This limits the use of models trained with large annotated
legacy datasets on a new dataset with a different domain which is often a
recurring situation in clinical settings. In this study, we aim to answer the
following central questions regarding domain adaptation in medical image
analysis: Given a fitted legacy model, 1) How much data from the new domain is
required for a decent adaptation of the original network?; and, 2) What portion
of the pre-trained model parameters should be retrained given a certain number
of the new domain training samples? To address these questions, we conducted
extensive experiments in white matter hyperintensity segmentation task. We
trained a CNN on legacy MR images of brain and evaluated the performance of the
domain-adapted network on the same task with images from a different domain. We
then compared the performance of the model to the surrogate scenarios where
either the same trained network is used or a new network is trained from
scratch on the new dataset.The domain-adapted network tuned only by two
training examples achieved a Dice score of 0.63 substantially outperforming a
similar network trained on the same set of examples from scratch.Comment: 8 pages, 3 figure
New Method of Measuring TCP Performance of IP Network using Bio-computing
The measurement of performance of Internet Protocol IP network can be done by
Transmission Control Protocol TCP because it guarantees send data from one end
of the connection actually gets to the other end and in the same order it was
send, otherwise an error is reported. There are several methods to measure the
performance of TCP among these methods genetic algorithms, neural network, data
mining etc, all these methods have weakness and can't reach to correct measure
of TCP performance. This paper proposed a new method of measuring TCP
performance for real time IP network using Biocomputing, especially molecular
calculation because it provides wisdom results and it can exploit all
facilities of phylogentic analysis. Applying the new method at real time on
Biological Kurdish Messenger BIOKM model designed to measure the TCP
performance in two types of protocols File Transfer Protocol FTP and Internet
Relay Chat Daemon IRCD. This application gives very close result of TCP
performance comparing with TCP performance which obtains from Little's law
using same model (BIOKM), i.e. the different percentage of utilization (Busy or
traffic industry) and the idle time which are obtained from a new method base
on Bio-computing comparing with Little's law was (nearly) 0.13%.
KEYWORDS Bio-computing, TCP performance, Phylogenetic tree, Hybridized Model
(Normalized), FTP, IRCDComment: 17 Pages,10 Figures,5 Table
Deep-Reinforcement Learning Multiple Access for Heterogeneous Wireless Networks
This paper investigates the use of deep reinforcement learning (DRL) in a MAC
protocol for heterogeneous wireless networking referred to as
Deep-reinforcement Learning Multiple Access (DLMA). The thrust of this work is
partially inspired by the vision of DARPA SC2, a 3-year competition whereby
competitors are to come up with a clean-slate design that "best share spectrum
with any network(s), in any environment, without prior knowledge, leveraging on
machine-learning technique". Specifically, this paper considers the problem of
sharing time slots among a multiple of time-slotted networks that adopt
different MAC protocols. One of the MAC protocols is DLMA. The other two are
TDMA and ALOHA. The nodes operating DLMA do not know that the other two MAC
protocols are TDMA and ALOHA. Yet, by a series of observations of the
environment, its own actions, and the resulting rewards, a DLMA node can learn
an optimal MAC strategy to coexist harmoniously with the TDMA and ALOHA nodes
according to a specified objective (e.g., the objective could be the sum
throughput of all networks, or a general alpha-fairness objective)
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