57 research outputs found
CLVOS23: A Long Video Object Segmentation Dataset for Continual Learning
Continual learning in real-world scenarios is a major challenge. A general
continual learning model should have a constant memory size and no predefined
task boundaries, as is the case in semi-supervised Video Object Segmentation
(VOS), where continual learning challenges particularly present themselves in
working on long video sequences. In this article, we first formulate the
problem of semi-supervised VOS, specifically online VOS, as a continual
learning problem, and then secondly provide a public VOS dataset, CLVOS23,
focusing on continual learning. Finally, we propose and implement a
regularization-based continual learning approach on LWL, an existing online VOS
baseline, to demonstrate the efficacy of continual learning when applied to
online VOS and to establish a CLVOS23 baseline. We apply the proposed baseline
to the Long Videos dataset as well as to two short video VOS datasets, DAVIS16
and DAVIS17. To the best of our knowledge, this is the first time that VOS has
been defined and addressed as a continual learning problem
Dental Management of Ectodermal Dysplasia Syndrome at an Early Age: A Case Report
Objectives: Ectodermal dysplasia (ED) is a relatively common sex-linked dermatitis characterized by congenital dysplasia of one or more ectodermal structures and their accessory appendages. Common manifestations include fragile skin and nails, defective teeth and salivary glands, frontal bossing with prominent supra orbital ridges, nasal bridge depression and protuberant lips. Teeth are often few in number (hypodontia or oligodontia) and have a conical form that results in generalized spacing. In extreme cases, both deciduous and the permanent dentition may fail to form (anodontia) and consequently, hypoplasia of the jaws may happen. This article reports a case of ED with its management protocol.Case report: A 4 year-old boy with hypohydrotic ED was referred to Dental School of shahid Beheshti University of Medical Sciences. Clinical examination revealed classical features of ED, with only a few teeth. He had fine scanty hair, dry skin and depressed nasal bridge. Removable denture was made with particular limitations for his lower jaw to restore esthetics and masticatory function. The existing upper teeth were initially reshaped using composite resin restoration material.Conclusion: Preventive treatments in ED patients are very important to save the existing teeth. In patients with oligodontia, removable dentures can be used as a cost-benefit and pleasant intermediate treatment to restore function and esthetics and improve patientās psychological status
A Hardware-Friendly Algorithm for Scalable Training and Deployment of Dimensionality Reduction Models on FPGA
With ever-increasing application of machine learning models in various
domains such as image classification, speech recognition and synthesis, and
health care, designing efficient hardware for these models has gained a lot of
popularity. While the majority of researches in this area focus on efficient
deployment of machine learning models (a.k.a inference), this work concentrates
on challenges of training these models in hardware. In particular, this paper
presents a high-performance, scalable, reconfigurable solution for both
training and deployment of different dimensionality reduction models in
hardware by introducing a hardware-friendly algorithm. Compared to
state-of-the-art implementations, our proposed algorithm and its hardware
realization decrease resource consumption by 50\% without any degradation in
accuracy
Application of feature extraction and artificial intelligence techniques for increasing the accuracy of x-ray radiation based two phase flow meter
The increasing consumption of fossil fuel resources in the world has placed emphasis on flow measurements in the oil industry. This has generated a growing niche in the flowmeter industry. In this regard, in this study, an artificial neural network (ANN) and various feature extractions have been utilized to enhance the precision of X-ray radiation-based two-phase flowmeters. The detection system proposed in this article comprises an X-ray tube, a NaI detector to record the photons, and a Pyrex-glass pipe, which is placed between detector and source. To model the mentioned geometry, the Monte Carlo MCNP-X code was utilized. Five features in the time domain were derived from the collected data to be used as the neural network input. Multi-Layer Perceptron (MLP) was applied to approximate the function related to the input-output relationship. Finally, the introduced approach was able to correctly recognize the flow pattern and predict the volume fraction of two-phase flowās components with root mean square error (RMSE), mean absolute error (MAE), and mean absolute percentage error (MAPE) of less than 0.51, 0.4 and 1.16%, respectively. The obtained precision of the proposed system in this study is better than those reported in previous works
Estimation of void fraction for homogenous regime of two-phase flows in unstable operational conditions using gamma-ray and neural networks
Almost all the multi-phase flow meters (MPFMs) using gamma-ray attenuation, are calibrated for liquid and gas phases with constant density and pressure. When operational conditions such as temperature and pressure change in pipelines, the radiation-based multi-phase flowmeters would measure the flow rate with error. Therefore, performance of MPFMs would be improved by eliminating any dependency on the fluid properties such as density. In this work, a method based on dual modality densitometry combined with Artificial Neural Network (ANN) is proposed in order to estimate the void fraction in homogenous regime of gas-liquid two-phase flows in unstable operational conditions (changeable temperature and pressure) in oil industry. An experimental setup was implemented to generate the optimum required input data for training the network. ANNs were trained on the registered counts of the transmission and scattering detectors in various liquid phase densities and void fractions. Void fractions were predicted by ANNs with mean relative error of less than 0.78% in density variations range of 0.735 up to 0.98 g/cm
Applications of discrete wavelet transform for feature extraction to increase the accuracy of monitoring systems of liquid petroleum products
This paper presents a methodology to monitor the liquid petroleum products which pass through transmission pipes. A simulation setup consisting of an X-ray tube, a detector, and a pipe was established using a Monte Carlo n-particle X-version transport code to investigate a two-by-two mixture of four different petroleum products, namely, ethylene glycol, crude oil, gasoline, and gasoil, in deferent volumetric ratios. After collecting the signals of each simulation, discrete wavelet transform (DWT) was applied as the feature extraction system. Then, the statistical feature, named the standard deviation, was calculated from the approximation of the fifth level, and the details of the second to fifth level provide appropriate inputs for neural network training. Three multilayer perceptron neural networks were utilized to predict the volume ratio of three types of petroleum products, and the volume ratio of the fourth product could easily be obtained from the results of the three presented networks. Finally, a root mean square error of less than 1.77 was obtained in predicting the volume ratio, which was much more accurate than in previous research. This high accuracy was due to the use of DWT for feature extraction
Evaluation of RANKL/OPG Serum Concentration Ratio as a New Biomarker for Coronary Artery Calcification: A Pilot Study
Objective. There is a strong need for biomarkers to identify patients at risk for future cardiovascular events related with progressive atherosclerotic disease. Osteoprotegerin (OPG) protects the skeleton from excessive bone resorption by binding to receptor activator of nuclear factor-ĪŗB ligand (RANKL) and preventing it from binding to its receptor, receptor activator of nuclear factor-ĪŗB. However, conflicting results have been obtained about association of serum level of OPG or RANKL with coronary artery disease (CAD). Based on their role in inflammation and matrix degradation and the fact that atherosclerotic plaque formation is an inflammatory process, we hypothesized that RANKLā:āOPG ratio could be a better biomarker for CAD. Methods. In this cross-sectional study, the correlation between RANKLā:āOPG ratio serum concentration and coronary artery calcification (CAC) in 50 patients with ischemic coronary disease has been investigated. We used ELISA method for measuring RANKL and OPG serum concentrations. Results. There was a significant correlation between RANKLā:āOPG serum concentration ratio and CAC in our study population (P = 0.01). Conclusion. Our results suggested that RANKLā:āOPG ratio concentration has a potential of being used as a marker for coronary artery disease
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