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A novel framework for predicting daily reference evapotranspiration using interpretable machine learning techniques

Research Abstract

Abstract Accurate estimation of daily reference evapotranspiration (ETo) is crucial for sustainable water resource management and irrigation scheduling, especially in water-scarce regions like Arizona. The standardized Penman–Monteith (PM) method is costly and requires specialized instruments and expertise, making it generally impractical for commercial growers. This study developed 35 ETo models to predict daily ETo across Coolidge, Maricopa, and Queen Creek in Pinal County, Arizona. Seven input combinations of daily meteorological variables were used for training and testing five machine learning (ML) models: Artificial Neural Network (ANN), Random Forest (RF), Extreme Gradient Boosting (XGBoost), Categorical Boosting (CatBoost), and Support Vector Machine (SVM). Four statistical indicators, coefficient of determination (R2), the normalized root-mean-squared error (RMSEn), mean absolute error (MAE), and simulation error (Se), were used to evaluate the ML models’ performance in comparison with the FAO-56 PM standardized method. The SHapley Additive exPlanations (SHAP) method was used to interpret each meteorological variable’s contribution to the model predictions. Overall, the 35 ETo-developed models showed an excellent to fair performance in predicting daily ETo over the three weather stations. Employing ANN10, RF10, XGBoost10, CatBoost10, and SVM10, incorporating all ten meteorological variables, yielded the highest accuracies during training and testing periods (0.994 ≤ R2 ≤ 1.0, 0.729 ≤ RMSEn ≤ 3.662, 0.030 ≤ MAE ≤ 0.181 mm·day−1, and 0.833 ≤ Se ≤ 2.295). Excluding meteorological variables caused a gradual decline in ET-developed models’ performance across the stations. However, 3-variable models using only maximum, minimum, and average temperatures (Tmax, Tmin, and Tave) predicted ETo well across the three stations during testing (17.655 ≤ RMSEn ≤ 13.469 and Se ≤ 15.45%). Results highlighted that Tmax, solar radiation (Rs), and wind speed at 2 m height (U2) are the most influential factors affecting ETo at the central Arizona sites, followed by extraterrestrial solar radiation (Ra) and Tave. In contrast, humidity-related variables (RHmin, RHmax, and RHave), along with Tmin and precipitation (Pr), had minimal impact on the model’s predictions. The results are informative for assisting growers and policymakers in developing effective water management strategies, especially for arid regions like central Arizona.

Research Authors
Elsayed Ahmed Elsadek, Mosaad Ali Hussein Ali, Clinton Williams, Kelly R Thorp, Diaa Eldin M Elshikha
Research Date
Research Member
Research Year
2025

Respiratory retention of 35 toxicants from e-cigarette gaseous emissions: comprehensive numerical study

Research Abstract
Electronic cigarettes can generate multiple carcinogenic substances and damage respiratory epithelial cells. The absorption mechanisms of e-cigarette toxicants throughout the puffing session remain poorly understood owing to ethical constraints associated with subjective experiments. This study provides an alternative computational method that integrates computational fluid dynamics and physiological pharmacokinetic models to predict respiratory retention rates (Ri). The results show that the arithmetic average retention of 35 substances is 62.2 %, whereas the mass-weighted average retention rate is 86.7 %, which is induced by high-mass-fraction toxicants such as glycerol, nicotine, formaldehyde, and acetaldehyde. This suggests that a considerable proportion of e-cigarette compounds is exhaled, thus reflecting the risk of passive smoking. Diffusivity in air (Da) is not a universal predictor of Ri but is highly relevant for soluble compounds. However, solubility in the watery mucus layer is the primary determinant of Ri for all examined constituents, thus reflecting the logarithmic correlation between Ri and the partition coefficient between mucus and air (Pm:a). We demonstrate the nonlinear relationship between physicochemical properties and respiratory uptake by combining Da and Pm:a, thereby facilitating the prediction of Ri. Simulation of vaping behavioral factors reveals that exhalation through the nostrils can increase Ri by 7 %–12 % compared with oral-only exhalation owing to more significant substance–tissue interactions in the complex passages of the nasal cavity. This model is promising for future health-risk assessments and regulatory decisions aimed at limiting e-cigarette usage.

 
Research Authors
Islam Mohamed Sayed Abouelhamd, K Kuga, T Mansuy, Kazuhide Ito
Research Date
Research Journal
Building and Environment
Research Pages
113663
Research Publisher
Elsevier
Research Rank
Q1
Research Vol
285
Research Website
https://www.sciencedirect.com/science/article/abs/pii/S0360132325011345
Research Year
2025

Experimental and computational predictions of odorant transport dynamics from indoor environment to olfactory tissue

Research Abstract

The intricate dynamics of odorants in the indoor environment and human respiratory system remain poorly understood. In the present study, we integrate odor sensory tests (OSTs) and computational fluid dynamics coupled with a physiologically based pharmacokinetic (CFD-PBPK) model to elucidate various aspects of odorant transport and olfaction dynamics. Safe yogurt-derived substances were incorporated into OSTs to prevent harmful exposure. Acetaldehyde was identified as a key active component in determining odor intensity, prompting further analysis of acetone and other four constituents. Logarithmic correlations were established between the perceived odor intensity from the OSTs and both time-averaged absorption flux and equilibrium concentration within the olfactory mucus layer. These parameters were numerically captured, enabling the logarithmic approximation of odor intensity for different breathing profiles and developing reliable prediction models for odor sensation in the indoor environment based on quantifiable physiological parameters. Location-specific analysis revealed the nostrils and olfactory regions as the most accurate indicators of perceived odor intensity, proving the limitations of rough sensory assessments in the indoor/breathing zone scales. This study offers insights for potential safe and sustainable applications, such as smart odor displays, e-noses, and sensors/control systems in the indoor environment, particularly for long-term exposure in industries that emit harmful compounds.

Research Authors
Islam Mohamed Sayed Abouelhamd, K Kuga, K Saito, M Takai, T Kikuchi, Kazuhide Ito
Research Date
Research Journal
Sustainable Cities and Society
Research Pages
106397
Research Publisher
Elsevier
Research Rank
Q1
Research Vol
126
Research Website
https://www.sciencedirect.com/science/article/abs/pii/S2210670725002732
Research Year
2025

Ellipsoidal K-Means: An Automatic Clustering Approach for Non-Uniform Data Distributions

Research Abstract

Traditional K-means clustering assumes, to some extent, a uniform distribution of data around predefined centroids, which limits its effectiveness for many realistic datasets. In this paper, a new clustering technique, simulated-annealing-based ellipsoidal clustering (SAELLC), is proposed to automatically partition data into an optimal number of ellipsoidal clusters, a capability absent in traditional methods. SAELLC transforms each identified cluster into a hyperspherical cluster, where the diameter of the hypersphere equals the minor axis of the original ellipsoid, and the center is encoded to represent the entire cluster. During the assignment of points to clusters, local ellipsoidal properties are independently considered. For objective function evaluation, the method adaptively transforms these ellipsoidal clusters into a variable number of global clusters. Two objective functions are simultaneously optimized: one reflecting partition compactness using the silhouette function (SF) and Euclidean distance, and another addressing cluster connectedness through a nearest-neighbor algorithm. This optimization is achieved using a newly-developed multiobjective simulated annealing approach. SAELLC is designed to automatically determine the optimal number of clusters, achieve precise partitioning, and accommodate a wide range of cluster shapes, including spherical, ellipsoidal, and non-symmetric forms. Extensive experiments conducted on UCI datasets demonstrated SAELLC’s superior performance compared to six well-known clustering algorithms. The results highlight its remarkable ability to handle diverse data distributions and automatically …

Research Authors
Alaa E Abdel-Hakim, Abdel-Monem M Ibrahim, Kheir Eddine Bouazza, Wael Deabes, Abdel-Rahman Hedar
Research Date
Research Department
Research Journal
Algorithms
Research Member
Research Pages
551
Research Publisher
MDPI
Research Vol
Volume 17, Issue 12
Research Website
https://scholar.google.com/scholar?oi=bibs&cluster=1136932969198565742&btnI=1&hl=en
Research Year
2024

Dynamic Deployment of Mobile Roadside Units in Internet of Vehicles

Research Abstract

Mobile roadside units have crucial role in ensuring efficient communication, computing, and caching services in internet of vehicles (IoVs) for vehicles traversing urban landscapes. The dynamic nature of urban environments faces challenges in optimizing the deployment of mRSUs to adapt to varying vehicular densities and traffic patterns in real-time. In this article, we propose a novel real-time optimization approach for the dynamic deployment of mobile Roadside Units (mRSUs) in urban environments to support the rapid growth of the IoV. The proposed method is a novel allocation strategy based on Minimum Dominating Set (MDS) theory, which is demonstrated to significantly reduce the number of mRSUs required. This reduction is achieved without compromising the efficiency and effectiveness of the network, thereby ensuring rapid and reliable communication within the IoV. This approach addresses critical …

Research Authors
Alaa E Abdel-Hakim, Wael Deabes, Kheir Eddine Bouazza, Abdel-Rahman Hedar
Research Date
Research Department
Research Journal
IEEE Access
Research Member
Research Pages
155548-155534
Research Publisher
IEEE
Research Vol
12
Research Website
https://scholar.google.com/scholar?oi=bibs&cluster=9429625967726641888&btnI=1&hl=en
Research Year
2024

Economic Viability of Irrigation Canal Lining in Upper Egypt: A Benefit-Cost Analysis for Sustainable Water Management

Research Abstract

This study evaluates the economic viability of lining irrigation canals in Upper Egypt, focusing on the El-Sont Canal network as a case study. Using a benefit-cost analysis (BCA), the research assesses the financial feasibility of canal lining by comparing the costs of implementation with the anticipated benefits, including water savings, reduced maintenance, and increased agricultural productivity. The estimated cost of lining the El-Sont Canal network is approximately $34.193 million, with annual benefits ranging from $5.451 million to $7.515 million. The benefit-cost ratio (BCR) exceeds 1.0, ranging from 1.99 to 4.02, indicating strong economic viability. Additionally, the cost recovery period is estimated at 4.5–6.3 years, making the project a sustainable investment. Compared to alternative water resource solutions such as desalination and wastewater reuse, canal lining proves to be the most cost-effective and permanent solution for water conservation in the region. While canal lining is cost-effective, potential trade-offs include impacts on groundwater recharge and the equitable distribution of water savings among different farming communities. The findings underscore the importance of canal lining as a strategic intervention for sustainable water management in Upper Egypt, aligning with national agricultural development goals and addressing water scarcity challenges under changing climatic conditions

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Research Authors
Mohamed A. Ashour, Hassan I. Mohamed, Abdallah A. Abdou , Tarek S. Abu-Zaid
Research Date
Research Department
Research Journal
AQUA - Water Infrastructure, Ecosystems and Society
Research Pages
DOI: 10.2166/aqua.2025.014
Research Publisher
IWA Publishing
Research Rank
international journal
Research Vol
DOI: 10.2166/aqua.2025.014
Research Website
DOI: 10.2166/aqua.2025.014
Research Year
2025

Engineering Mechanics

Description

The Engineering Mechanics course introduces the fundamental principles governing the behavior of bodies under the action of forces. It provides students with the analytical tools necessary to model, analyze, and solve real-world engineering problems involving static and dynamic systems.

The course begins with an introduction to vector mechanics, covering force systems, equilibrium of particles and rigid bodies, and free-body diagrams. Students then explore concepts of centroids, moments of inertia, and structural analysis of trusses, frames, and beams. Emphasis is placed on understanding how equilibrium conditions ensure structural stability and how loads are transmitted through components.

In the second part of the course, kinematics and kinetics of particles and rigid bodies are studied to describe motion and determine the effects of forces on moving systems. Topics include rectilinear and curvilinear motion, Newton’s laws, work and energy principles, impulse and momentum, and planar motion of rigid bodies.

By the end of the course, students will be able to:

  • Apply Newtonian mechanics to analyze static and dynamic systems.

  • Draw and interpret free-body diagrams for a variety of mechanical problems.

  • Calculate internal and external forces in mechanical structures.

  • Use energy and momentum methods to evaluate motion and equilibrium conditions.

This foundational course builds the essential problem-solving and reasoning skills needed for advanced subjects such as strength of materials, machine design, and fluid mechanics, and others.

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