Abdulaziz Almehmadi

Dr. Abdulaziz Almehmadi

orcid

Research Focus & Metrics

Academic Career Length

14Years (2013-Present)

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

Representative Publications

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15 February 2022 in Computers and Electrical Engineering
Verified
Journal Article
Closed access
JWJason Whelan
Jason Whelan
AAAbdulaziz Almehmadi
Abdulaziz Almehmadi
Khalil El-KhatibKhalil El-Khatib
Khalil El-Khatib

1 April 2019 in Pervasive and Mobile Computing
Verified
Journal Article
Closed access
JCJames Curzon
James Curzon
AAAbdulaziz Almehmadi
Abdulaziz Almehmadi
KEKhalil El-Khatib
Khalil El-Khatib

18 July 2018 in IEEE Access
Verified
Journal Article
Open access
AAAbdulaziz Almehmadi
Abdulaziz Almehmadi
Behavioral measurements have provided insightful information in many research areas, including insider threats; however, none of the previous research investigated the use of head micromovement patterns while presenting visual stimuli that represent possible malicious intentions to detect insiders’ intentions; hence, to detect insider threats. In this paper, we hypothesize that involuntary head micromovement patterns toward visual stimuli allow for detecting intentions of access. Because detecting intentions does not state the probability of an intention to be executed, we hypothesize that the motivation toward an intention is inversely correlated with the number of micromovements. This paper also investigates the potential of substituting the physiological measurements of the intent-based access control (IBAC) model, which is a risk-based access control model that assesses risk based on involuntary physiological signals, electroencephalogram data, with the proposed behavioral measurements and compares the results. We assessed the IBAC model with the proposed behavioral measurement using experiments on 30 participants and it suggests the potential of the proposed behavioral measurement with 100% intention detection accuracy, similar to the physiological measurement results; however, the behavioral measurement showed 100% correctly accepted, but 70% correctly rejected users when compared with the physiological measurement, which showed 100% correctly accepted and rejected users. Further, the behavioral measurement showed 80% user acceptance when compared with the physiological measurement, which showed only 10% user acceptance.

28 November 2019 in Sensors
Verified
Journal Article
Open access
PDF file
FLFelipe Lobo
Felipe Lobo
DGDanilo Grael
Danilo Grael
Horacio OliveiraHoracio Oliveira
Horacio Oliveira
LVLeandro Villas
Leandro Villas
AAAbdulaziz Almehmadi
Abdulaziz Almehmadi
Khalil El-KhatibKhalil El-Khatib
Khalil El-Khatib
In vehicular ad hoc networks (VANets), a precise localization system is a crucial factor for several critical safety applications. The global positioning system (GPS) is commonly used to determine the vehicles’ position estimation. However, it has unwanted errors yet that can be worse in some areas, such as urban street canyons and indoor parking lots, making it inaccurate for most critical safety applications. In this work, we present a new position estimation method called cooperative vehicle localization improvement using distance information (CoVaLID), which improves GPS positions of nearby vehicles and minimize their errors through an extended Kalman filter to execute Data Fusion using GPS and distance information. Our solution also uses distance information to assess the position accuracy related to three different aspects: the number of vehicles, vehicle trajectory, and distance information error. For that purpose, we use a weighted average method to put more confidence in distance information given by neighbors closer to the target. We implement and evaluate the performance of CoVaLID using real-world data, as well as discuss the impact of different distance sensors in our proposed solution. Our results clearly show that CoVaLID is capable of reducing the GPS error by 63%, and 53% when compared to the state-of-the-art VANet location improve (VLOCI) algorithm.

4 October 2023 in Applied Sciences
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Journal Article
Open access
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AKAlexander Keith
Alexander Keith
TSThanigajan Sangarapillai
Thanigajan Sangarapillai
AAAbdulaziz Almehmadi
Abdulaziz Almehmadi
Khalil El-KhatibKhalil El-Khatib
Khalil El-Khatib
The increasing popularity and usage of unmanned aerial vehicles (UAVs) has brought about new challenges in airspace management. With the number of drones expected to grow even further in the coming years, there is an urgent need for an autonomous traffic management system (TMS) that can safely and effectively manage drone traffic in the airspace. It is critical that this TMS be built with principles of the Confidentiality, Integrity, and Availability (CIA) triad. In this paper, a traffic management system for UAVs is presented that takes advantage of a Hyperledger Fabric blockchain network. The TMS provides a decentralized and secure method to manage and deconflict drone flight paths, allowing for safe navigation in crowded airspaces. Through a series of simulated experiments, we demonstrated the system’s capabilities in handling path creation, multiple conflict resolutions, and large numbers of drones. Simulated tests showed that the proposed system was able to handle deconfliction of 1000 drones inside of a one square kilometer, and returned calculated paths for drones in 60 to 2000 ms with up to 100 deconflictions. The Hyperledger Fabric powered traffic management system showcased the potential to leverage permissioned blockchain technology in improving drone traffic management.

1 January 2021 in Computer Systems Science and Engineering
Verified
Journal Article
Open access
AAAbdulaziz Almehmadi
Abdulaziz Almehmadi
Unlike the 2007–2008 market crash, which was caused by a banking failure and led to an economic recession, the 1918 influenza pandemic triggered a worldwide financial depression. Pandemics usually affect the global economy, and the COVID-19 pandemic is no exception. Many stock markets have fallen over 40%, and companies are shutting down, ending contracts, and issuing voluntary and involuntary leaves for thousands of employees. These economic effects have led to an increase in unemployment rates, crime, and instability. Studying pandemics’ economic effects, especially on the stock market, has not been urgent or feasible until recently. However, with advances in artificial intelligence (AI) and the inter-connectivity that social media provides, such research has become possible. In this paper, we propose a COVID-19-based stock market prediction system (C19-SM2) that utilizes social media. Our AI system enables economists to study how COVID-19 pandemic data influence social media and, hence, the stock market. C19-SM2 gathers COVID-19 infection and death cases reported by the authorities and social media data from a geographic area and extracts the sentiments and events that occur in that area. The information is then fed to the support vector machine (SVM) and random forest and random tree classifiers along with current stock market values. Then, the system produces a projection of the stock market’s movement during the next day. We tested the system with the Dow Jones Industrial Average (DJI) and the Tadawul All Share Index (TASI). Our system achieved a stock market prediction accuracy of 99.71%, substantially higher than the 89.93% accuracy reported in the related literature; the inclusion of COVID-19 data improved accuracy by 9.78%.