Qianqian Shao¹, Min Wang^2,*, Nuo Xu¹

CMES-Computer Modeling in Engineering & Sciences, Vol.139, No.2, pp. 1337-1356, 2024, DOI:10.32604/cmes.2023.044313

Abstract To investigate the influences of co-flow and counter-flow modes of reactant flow arrangement on a proton exchange membrane fuel cell (PEMFC) during start-up, unsteady physical and mathematical models fully coupling the flow, heat, and electrochemical reactions in a PEMFC are established. The continuity equation and momentum equation are solved by handling pressure-velocity coupling using the SIMPLE algorithm. The electrochemical reaction rates in the catalyst layers (CLs) of the cathode and anode are calculated using the Butler-Volmer equation. The multiphase mixture model describes the multiphase transport process of gas mixtures and liquid water in the fuel cell. After validation, the influences… More >

Ahmad Almadhor¹, Chitapong Wechtaisong^2,*, Usman Tariq³, Natalia Kryvinska^4,*, Abdullah Al Hejaili⁵, Uzma Ghulam Mohammad⁶, Mohana Alanazi⁷

Computer Systems Science and Engineering, Vol.48, No.1, pp. 199-216, 2024, DOI:10.32604/csse.2023.039546

Abstract Thermal comfort is an essential component of smart cities that helps to upgrade, analyze, and realize intelligent buildings. It strongly affects human psychological and physiological levels. Residents of buildings suffer stress because of poor thermal comfort. Buildings frequently use Heating, Ventilation, and Air Conditioning (HVAC) systems for temperature control. Better thermal states directly impact people’s productivity and health. This study revealed a human thermal comfort model that makes better predictions of thermal sensation by identifying essential features and employing a tuned Extra Tree classifier, MultiLayer Perceptron (MLP) and Naive Bayes (NB) models. The study employs the ASHRAE RP-884 standard dataset… More >

Akmalbek Abdusalomov¹, Alpamis Kutlimuratov², Rashid Nasimov³, Taeg Keun Whangbo^1,*

CMC-Computers, Materials & Continua, Vol.77, No.3, pp. 2915-2933, 2023, DOI:10.32604/cmc.2023.044466

Abstract The performance of a speech emotion recognition (SER) system is heavily influenced by the efficacy of its feature extraction techniques. The study was designed to advance the field of SER by optimizing feature extraction techniques, specifically through the incorporation of high-resolution Mel-spectrograms and the expedited calculation of Mel Frequency Cepstral Coefficients (MFCC). This initiative aimed to refine the system’s accuracy by identifying and mitigating the shortcomings commonly found in current approaches. Ultimately, the primary objective was to elevate both the intricacy and effectiveness of our SER model, with a focus on augmenting its proficiency in the accurate identification of emotions… More >

Ahmed Hassan Abdou^1,*, Omar Abdullah Alkhateeb², Hossam Eldin Hamed Mansour³, Hesham S. Ghazzawy⁴, Muayad Saud Albadrani⁵, Nadi Awad Al-harbi⁶, Wasimah B. Al-Shammari⁷, Khaled Abdelaal^8,*

Phyton-International Journal of Experimental Botany, Vol.92, No.12, pp. 3305-3321, 2023, DOI:10.32604/phyton.2023.044780

Abstract Plant growth-promoting bacteria (PGPB) play an important role in improving agricultural production under several abiotic stress factors. PGPB can be used to increase crop growth and development through hormonal balance and increase nutrient uptake. The positive effect of PGPB may be due to its pivotal role in morphophysiological and biochemical characteristics like leaf number, leaf area, and stem length. Furthermore, relative water content, chlorophyll content, carotenoids, antioxidant enzymes, and plant hormones were improved with PGPB treatment. Crop yield and yield components were also increased with PGPB treatment in numerous crops. The anatomical structure of plant organs was increased such as… More >

Wen Sun¹, Meijing Li², Guoxiang Li¹, Ke Sun^1,*, Shuzhan Bai^1,*

Energy Engineering, Vol.121, No.1, pp. 95-110, 2024, DOI:10.32604/ee.2023.042096

Abstract Proton exchange membrane fuel cells are widely regarded as having the potential to replace internal combustion engines in vehicles. Since fuel cells cannot recover energy and have a slow dynamic response, they need to be used with different power sources. Developing efficient energy management strategies to achieve excellent fuel economy is the goal of research. This paper proposes an adaptive equivalent fuel minimum consumption strategy (AECMS) to solve the problem of the poor economy of the whole vehicle caused by the wrong selection of equivalent factors (EF) in traditional ECMS. In this method, the kinematics interval is used to update… More >

Ying Zhang¹, Wei Li^1,*, Guidong Yang¹, Snezana Kirin²

CMES-Computer Modeling in Engineering & Sciences, Vol.138, No.3, pp. 2177-2199, 2024, DOI:10.32604/cmes.2023.030728

Abstract The Mean First-Passage Time (MFPT) and Stochastic Resonance (SR) of a stochastic tumor-immune model with noise perturbation are discussed in this paper. Firstly, considering environmental perturbation, Gaussian white noise and Gaussian colored noise are introduced into a tumor growth model under immune surveillance. As follows, the long-time evolution of the tumor characterized by the Stationary Probability Density (SPD) and MFPT is obtained in theory on the basis of the Approximated Fokker-Planck Equation (AFPE). Herein the recurrence of the tumor from the extinction state to the tumor-present state is more concerned in this paper. A more efficient algorithm of Back-Propagation Neural… More >

Shimaa M. Amer¹, Ashraf A. M. Khalaf², Amr H. Hussein^3,4, Salman A. Alqahtani⁵, Mostafa H. Dahshan⁶, Hossam M. Kassem^3,4,*

CMES-Computer Modeling in Engineering & Sciences, Vol.138, No.3, pp. 2749-2767, 2024, DOI:10.32604/cmes.2023.029138

Abstract Side lobe level reduction (SLL) of antenna arrays significantly enhances the signal-to-interference ratio and improves the quality of service (QOS) in recent and future wireless communication systems starting from 5G up to 7G. Furthermore, it improves the array gain and directivity, increasing the detection range and angular resolution of radar systems. This study proposes two highly efficient SLL reduction techniques. These techniques are based on the hybridization between either the single convolution or the double convolution algorithms and the genetic algorithm (GA) to develop the Conv/GA and DConv/GA, respectively. The convolution process determines the element’s excitations while the GA optimizes… More >

Sang Seo¹, Jaeyeon Lee², Byeongjin Kim², Woojin Lee², Dohoon Kim^3,*

CMC-Computers, Materials & Continua, Vol.77, No.2, pp. 2595-2628, 2023, DOI:10.32604/cmc.2023.042668

Abstract Moving-target-defense (MTD) fundamentally avoids an illegal initial compromise by asymmetrically increasing the uncertainty as the attack surface of the observable defender changes depending on spatial-temporal mutations. However, the existing naive MTD studies were conducted focusing only on wired network mutations. And these cases have also been no formal research on wireless aircraft domains with attributes that are extremely unfavorable to embedded system operations, such as hostility, mobility, and dependency. Therefore, to solve these conceptual limitations, this study proposes normalized drone-type MTD that maximizes defender superiority by mutating the unique fingerprints of wireless drones and that optimizes the period-based mutation principle… More >

Huda Adel Hassan Ali, Ameer Abed Jaddoa^*, Jafaar Mohamme Daif

Frontiers in Heat and Mass Transfer, Vol.21, pp. 443-465, 2023, DOI:10.32604/fhmt.2023.042288

Abstract This paper is twofold. First, the effect of non-linear thermophysical property variation was presented using supercritical carbon dioxide (SCO₂) around the thermodynamic pivotal point. The second part exhibits an experimental examination of the heat transfer (HT) behaviour of SCO₂ in a helical tube with a hydraulic diameter of 2 mm at different mass fluxes (MF), heat fluxes (HF), and pressures (P). The experiments were carried out based on various pressures, mass fluxes, and heat fluxes for both scenarios. CO₂ was cooled in a 2 mm diameter serpentine tube made of copper material. The experimental results showed that HT degradation could… More > Graphic Abstract

Yangyang Bao, Mingliang Yang, Haibo Huang, Liyuan Liu, Honglin Zhu, Weiping Ding^*

Sound & Vibration, Vol.57, pp. 45-68, 2023, DOI:10.32604/sv.2023.043279

Abstract The hub-driven virtual rail train is a novel urban transportation system that amalgamates the benefits of modern trams and buses. However, this system is plagued by issues such as decreased ride comfort and severe deformation of urban roads due to the increase in sprung mass and long-term rolling at the same position. To address these concerns and improve the human-vehicle-road friendliness of the virtual rail train, we propose an Improved Sky-Ground Hook and Acceleration-Driven Damper control (Improved SH-GH-ADD control) strategy for the semi-active suspension system. This control monitors the vibration acceleration signal of the unsprung mass in real-time and selects… More >