Fatemeh Afghah

Dr. Fatemeh Afghah

Northern Arizona University, Flagstaff, USA
orcid

Research Focus & Metrics

Academic Career Length

12Years (2015-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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19 February 2022 in Ad Hoc Networks
Verified
Journal Article
Open access
ARArnau Rovira-Sugranes
Arnau Rovira-Sugranes
ARAbolfazl Razi
Abolfazl Razi
FAFatemeh Afghah
Fatemeh Afghah
JCJacob Chakareski
Jacob Chakareski

1 January 2022 in IEEE Access
Verified
Journal Article
Open access
XCXiwen Chen
Xiwen Chen
BHBryce Hopkins
Bryce Hopkins
HWHao Wang
Hao Wang
LOLeo O’NEill
Leo O’NEill
FAFatemeh Afghah
Fatemeh Afghah
AWAdam Watts
Adam Watts
Current forest monitoring technologies including satellite remote sensing, manned/piloted aircraft, and observation towers leave uncertainties about a wildfire’s extent, behavior, and conditions in the fire’s near environment, particularly during its early growth. Rapid mapping and real-time fire monitoring can inform in-time intervention or management solutions to maximize beneficial fire outcomes. Drone systems’ unique features of 3D mobility, low flight altitude, and fast and easy deployment make them a valuable tool for early detection and assessment of wildland fires, especially in remote forests that are not easily accessible by ground vehicles. In addition, the lack of abundant, well-annotated aerial datasets – in part due to unmanned aerial vehicles’ (UAVs’) flight restrictions during prescribed burns and wildfires – has limited research advances in reliable data-driven fire detection and modeling techniques. While existing wildland fire datasets often include either color or thermal fire images, here we present (1) a multi-modal UAV-collected dataset of dual-feed side-by-side videos including both RGB and thermal images of a prescribed fire in an open canopy pine forest in Northern Arizona and (2) a deep learning-based methodology for detecting fire and smoke pixels at accuracy much higher than the usual single-channel video feeds. The collected images are labeled to "fire" or "no-fire" frames by two human experts using side-by-side RGB and thermal images to determine the label. To provide context to the main dataset’s aerial imagery, the included supplementary dataset provides a georeferenced pre-burn point cloud, an RGB orthomosaic, weather information, a burn plan, and other burn information. By using and expanding on this guide dataset, research can develop new data-driven fire detection, fire segmentation, and fire modeling techniques.

1 December 2020 in Computers in Biology and Medicine
Verified
Journal Article
Closed access
SMSajad Mousavi
Sajad Mousavi
FAFatemeh Afghah
Fatemeh Afghah
U Rajendra AcharyaU Rajendra Acharya
U Rajendra Acharya

3 December 2021 in IEEE Transactions on Green Communications and Networking
Verified
Journal Article
Closed access
SASaeed Alsamhi
Saeed Alsamhi
FAFaris A. Almalki
Faris A. Almalki
FAFatemeh Afghah
Fatemeh Afghah
Ammar HawbaniAmmar Hawbani
Ammar Hawbani
ASAlexey V. Shvetsov
Alexey V. Shvetsov
Houbing Herbert SongHoubing Herbert Song
Houbing Herbert Song
Edge Intelligence is an emerging technology which has attracted significant attention. It applies Artificial Intelligence (AI) closer to the network edge for supporting Beyond fifth Generation (B5G) needs. On the other hand, drones can be used as relay station (mobile drone edge intelligence) to gather data from smart environments. Federated Learning (FL) enables the drones to perform decentralized collaborative learning by developing local models, sharing the model parameters with neighbors and the centralized unit to improve global model accuracy in smart environments. However, drone edge intelligence faces challenges such as security and decentralization management, limiting its functions to support green smart environments. Blockchain is a promising technology that enables privacy-preserving data sharing in a distributed manner. There are several challenges that still need to be addressed in blockchain-based applications, such as scalability, energy efficiency, and transaction capacity. Motivated by the significance of FL and blockchain, this survey focuses on the synergy of FL and blockchain to enable drone edge intelligence for green sustainable environments. Moreover, we discuss the combination of FL and blockchain technological aspects, motivation, and framework for green smart environments. Finally, we discuss the challenges and opportunities, and future trends in this domain.

18 July 2023 in IEEE Access
Verified
Journal Article
Open access
EAEdmonmd Adib
Edmonmd Adib
AFAmanda S. Fernandez
Amanda S. Fernandez
FAFatemeh Afghah
Fatemeh Afghah
JPJeff Prevost
Jeff Prevost
Deep learning image processing models have had remarkable success in recent years in generating high quality images. Particularly, the Improved Denoising Diffusion Probabilistic Models (DDPM) have shown superiority in image quality to the state-of-the-art generative models, which motivated us to investigate their capability in the generation of the synthetic electrocardiogram (ECG) signals. In this work, synthetic ECG signals are generated by the Improved DDPM and by the Wasserstein GAN with Gradient Penalty (WGAN-GP) models and then compared. To this end, we devise a pipeline to utilize DDPM in its original 2D form. First, the 1 D ECG time series data are embedded into the 2 D space, for which we employed the Gramian Angular Summation/Difference Fields (GASF/GADF) as well as Markov Transition Fields (MTF) to generate three 2 D matrices from each ECG time series, which when put together, form a 3-channel 2 D datum. Then 2 D DDPM is used to generate 2 D 3-channel synthetic ECG images. The 1 D ECG signals are created by de-embedding the 2 D generated image files back into the 1 D space. This work focuses on unconditional models and the generation of Normal Sinus Beat ECG signals exclusively, where the Normal Sinus Beat class from the MIT-BIH Arrhythmia dataset is used in the training phase. The quality , distribution , and the authenticity of the generated ECG signals by each model are quantitatively evaluated and compared. Our results show that in the proposed pipeline and in the particular setting of this paper, the WGAN-GP model is consistently superior to DDPM in all the considered metrics.

24 March 2020 in IEEE Access
Verified
Journal Article
Open access
ASAlireza Shamsoshoara
Alireza Shamsoshoara
FAFatemeh Afghah
Fatemeh Afghah
ARAbolfazl Razi
Abolfazl Razi
SMSajad Mousavi
Sajad Mousavi
JAJonathan Ashdown
Jonathan Ashdown
KTKurt Turk
Kurt Turk
This paper studies the problem of spectrum shortage in an unmanned aerial vehicle (UAV) network during critical missions such as wildfire monitoring, search and rescue, and disaster monitoring. Such applications involve a high demand for high-throughput data transmissions such as real-time video-, image-, and voice-streaming where the assigned spectrum to the UAV network may not be adequate to provide the desired Quality of Service (QoS). In these scenarios, the aerial network can borrow an additional spectrum from the available terrestrial networks in trade of a relaying service for them. We propose a spectrum sharing model in which the UAVs are grouped into two classes of relaying UAVs that service the spectrum owner and the sensing UAVs that perform the disaster relief mission using the obtained spectrum. The operation of the UAV network is managed by a hierarchical mechanism in which a central controller assigns the tasks of the UAVs based on their resources and determine their operation region based on the level of priority of impacted areas and then the UAVs autonomously fine-tune their position using a model-free reinforcement learning algorithm to maximize the individual throughput and prolong their lifetime. We analyze the performance and the convergence for the proposed method analytically and with extensive simulations in different scenarios.