Inna Bilous¹, Dmytro Biriukov¹, Dmytro Karpenko², Tatiana Eutukhova², Oleksandr Novoseltsev^2,*, Volodymyr Voloshchuk¹

Energy Engineering, Vol.121, No.12, pp. 3617-3634, 2024, DOI:10.32604/ee.2024.051684 - 22 November 2024

Abstract This article focuses on the challenges of modeling energy supply systems for buildings, encompassing both methods and tools for simulating thermal regimes and engineering systems within buildings. Enhancing the comfort of living or working in buildings often necessitates increased consumption of energy and material, such as for thermal upgrades, which consequently incurs additional economic costs. It is crucial to acknowledge that such improvements do not always lead to a decrease in total pollutant emissions, considering emissions across all stages of production and usage of energy and materials aimed at boosting energy efficiency and comfort in… More > Graphic Abstract

Zainatul Yushaniza Mohamed Yusoff¹, Mohamad Khairi Ishak^2,*, Lukman A. B. Rahim³, Mohd Shahrimie Mohd Asaari¹

Computer Systems Science and Engineering, Vol.48, No.6, pp. 1669-1697, 2024, DOI:10.32604/csse.2024.056741 - 22 November 2024

Abstract The rapid adoption of Internet of Things (IoT) technologies has introduced significant security challenges across the physical, network, and application layers, particularly with the widespread use of the Message Queue Telemetry Transport (MQTT) protocol, which, while efficient in bandwidth consumption, lacks inherent security features, making it vulnerable to various cyber threats. This research addresses these challenges by presenting a secure, lightweight communication proxy that enhances the scalability and security of MQTT-based Internet of Things (IoT) networks. The proposed solution builds upon the Dang-Scheme, a mutual authentication protocol designed explicitly for resource-constrained environments and enhances it… More >

Ziran Li¹, Weihao Zhang², Lei Qi^1,*

The International Conference on Computational & Experimental Engineering and Sciences, Vol.30, No.4, pp. 1-1, 2024, DOI:10.32604/icces.2024.013344

Abstract In the future, the wide speed and altitude range aviation engine will have features such as "wide range of high-bypass-ratio adjustment" and "wide range of high-pressure-ratio adjustment". Therefore, its turbine will work in a very wide range of operating conditions, with a large flow regulation range. Under conditions of high-rate flow regulation, existing flow control technologies can significantly reduce turbine efficiency. To support the performance and technical specifications of future engines, their low-pressure turbines need to maintain high operational efficiency within a flow regulation range and power output range that exceed those of current aircraft engines.
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Mahyar Kargaran^*, Hamid Reza Goshayeshi, Ali Reza Alizadeh Jajarm

Frontiers in Heat and Mass Transfer, Vol.22, No.5, pp. 1461-1476, 2024, DOI:10.32604/fhmt.2024.056284 - 30 October 2024

Abstract Solar energy is a valuable renewable energy source, and photovoltaic (PV) systems are a practical approach to harnessing this energy. Nevertheless, low energy efficiency is considered a major setback of the system. Moreover, high cell temperature and reflection of solar irradiance from the panel are considered chief culprits in this regard. Employing pulsating heat pipes (PHPs) is an innovative and useful approach to improving solar panel performance. This study presents the results of the power performance of a PV panel attached to a newly designed spiral pulsating heat pipe, while graphene oxide nanofluid with three More >

Salma Moushi^1,*, Jaouad Ait lahcen¹, Ahmed El Hana¹, Yassine Ezaier¹, Ahmed Hader^1,2, Imane Bakassi¹, Iliass Tarras¹, Yahia Boughaleb^1,3

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.11, pp. 2509-2521, 2024, DOI:10.32604/fdmp.2024.053501 - 28 October 2024

Abstract Multi-layer membrane filtration is a widely used technology for separating and purifying different components of a liquid mixture. This technique involves passing the liquid mixture through a series of membranes with decreasing pore sizes, which allows for the separation of different components according to their molecular size. This study investigates the filtration process of a fluid through a two-dimensional porous medium designed for seawater desalination. The focus is on understanding the impact of various parameters such as the coefficient of friction, velocity, and the number of layers on filtration efficiency. The results reveal that the More >

Changtao Wang¹, Honghua Dai^1,*

The International Conference on Computational & Experimental Engineering and Sciences, Vol.29, No.3, pp. 1-2, 2024, DOI:10.32604/icces.2024.010943

Abstract Orbital uncertainty propagation is fundamental in space situational awareness-related missions such as orbit prediction and tracking. Linear models and full nonlinear Monte Carlo simulations were primarily used to propagate uncertainties [1]. However, these methods hampered the application due to low precision and intensive computation. Over the past two decades, numerous nonlinear uncertainty propagators have been proposed. Among these methods, the state transition tensor (STT) method has been widely used due to its controllable accuracy and high efficiency [2]. However, this method has two drawbacks. First, its semi-analytical formulation is too intricate to implement, which hinders… More >

Mahdi Goucem^*

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.10, pp. 2265-2279, 2024, DOI:10.32604/fdmp.2024.052365 - 23 September 2024

Abstract In hot and arid regions like the Saharan area, effective methods for cooling and humidifying intake air are essential. This study explores the utilization of a water trickle cooler as a promising solution to meet this objective. In particular, the HASSI MESSAOUD area is considered as a testbed. The water trickle cooler is chosen for its adaptability to arid conditions. Modeling results demonstrate its effectiveness in conditioning air before it enters the compressor. The cooling system achieves a significant temperature reduction of 6 to 8 degrees Celsius, enhancing mass flow rate dynamics by 3 percent More >

Tajim Md. Niamat Ullah Akhund^1,2,*, Waleed M. Al-Nuwaiser³

CMC-Computers, Materials & Continua, Vol.80, No.3, pp. 3485-3506, 2024, DOI:10.32604/cmc.2024.054222 - 12 September 2024

Abstract This study explores the impact of hyperparameter optimization on machine learning models for predicting cardiovascular disease using data from an IoST (Internet of Sensing Things) device. Ten distinct machine learning approaches were implemented and systematically evaluated before and after hyperparameter tuning. Significant improvements were observed across various models, with SVM and Neural Networks consistently showing enhanced performance metrics such as F1-Score, recall, and precision. The study underscores the critical role of tailored hyperparameter tuning in optimizing these models, revealing diverse outcomes among algorithms. Decision Trees and Random Forests exhibited stable performance throughout the evaluation. While More >

Syed Kamran Haider^1,2, Abbas Ahmed², Noman Mujeeb Khan², Ali Nauman^3,*, Sung Won Kim^3,*

CMC-Computers, Materials & Continua, Vol.80, No.3, pp. 4085-4110, 2024, DOI:10.32604/cmc.2024.052997 - 12 September 2024

Abstract In recent advancements within wireless sensor networks (WSN), the deployment of unmanned aerial vehicles (UAVs) has emerged as a groundbreaking strategy for enhancing routing efficiency and overall network functionality. This research introduces a sophisticated framework, driven by computational intelligence, that merges clustering techniques with UAV mobility to refine routing strategies in WSNs. The proposed approach divides the sensor field into distinct sectors and implements a novel weighting system for the selection of cluster heads (CHs). This system is primarily aimed at reducing energy consumption through meticulously planned routing and path determination. Employing a greedy algorithm More >

Mingxuan Chen¹, Jun Jia², Baoping Zhang¹, Leiyan Han³, Mengbo Ji^3,4, Zhangtao Yu¹, Dongfang Li¹, Wenyong Wang¹, Hongjing Jia¹, Huachi Xu^2,*

Energy Engineering, Vol.121, No.10, pp. 3055-3074, 2024, DOI:10.32604/ee.2024.051524 - 11 September 2024

Abstract The rise in hydrogen production powered by renewable energy is driving the field toward the adoption of systems comprising multiple alkaline water electrolyzers. These setups present various operational modes: independent operation and multi-electrolyzer parallelization, each with distinct advantages and challenges. This study introduces an innovative configuration that incorporates a mutual lye mixer among electrolyzers, establishing a weakly coupled system that combines the advantages of two modes. This approach enables efficient heat utilization for faster hot-startup and maintains heat conservation post-lye interconnection, while preserving the option for independent operation after decoupling. A specialized thermal exchange model… More >