Weifang Yang¹, Yaping Liu^1,*, Chao Gui¹, Yangyu Shi², Mengyi Ge¹

Frontiers in Heat and Mass Transfer, Vol.23, No.6, pp. 2051-2072, 2025, DOI:10.32604/fhmt.2025.070138 - 31 December 2025

Abstract This study experimentally investigates the operational performance of a scroll compressor using R513A to expand its application range as a substitute for R134a. A vapor compression heat pump test platform was established to analyze the variation trends of heating capacity, refrigerant mass flow rate, compressor power consumption, and current by controlling the compressor inlet and outlet pressures (i.e., evaporating and condensing temperatures). The results indicate that both heating capacity and refrigerant mass flow rate decrease with increasing pressure ratio. Compressor power consumption and current initially increase and then decrease with rising evaporating temperature, whereas they… More > Graphic Abstract

David S. Bhatti^1,*, Annas W. Malik², Haeung Choi¹, Ki-Il Kim^3,*

CMC-Computers, Materials & Continua, Vol.85, No.1, pp. 2157-2177, 2025, DOI:10.32604/cmc.2025.068360 - 29 August 2025

Abstract Traditional chaotic maps struggle with narrow chaotic ranges and inefficiencies, limiting their use for lightweight, secure image encryption in resource-constrained Wireless Sensor Networks (WSNs). We propose the SPCM, a novel one-dimensional discontinuous chaotic system integrating polynomial and sine functions, leveraging a piecewise function to achieve a broad chaotic range () and a high Lyapunov exponent (5.04). Validated through nine benchmarks, including standard randomness tests, Diehard tests, and Shannon entropy (3.883), SPCM demonstrates superior randomness and high sensitivity to initial conditions. Applied to image encryption, SPCM achieves 0.152582 s (39% faster than some techniques) and 433.42 More >

Kunbolat T. Algazy¹, Kairat S. Sakan^1,2,*, Saule E. Nyssanbayeva^1,2, Ardabek Khompysh^1,3

CMC-Computers, Materials & Continua, Vol.84, No.1, pp. 1581-1595, 2025, DOI:10.32604/cmc.2025.065085 - 09 June 2025

Abstract This paper examines the application of the Verkle tree—an efficient data structure that leverages commitments and a novel proof technique in cryptographic solutions. Unlike traditional Merkle trees, the Verkle tree significantly reduces signature size by utilizing polynomial and vector commitments. Compact proofs also accelerate the verification process, reducing computational overhead, which makes Verkle trees particularly useful. The study proposes a new approach based on a non-positional polynomial notation (NPN) employing the Chinese Remainder Theorem (CRT). CRT enables efficient data representation and verification by decomposing data into smaller, independent components, simplifying computations, reducing overhead, and enhancing… More >

Buwei Dang, Huanming Chen^*, Heng Zhang, Jixian Wang, Jian Zhou

CMC-Computers, Materials & Continua, Vol.83, No.2, pp. 2003-2023, 2025, DOI:10.32604/cmc.2025.062653 - 16 April 2025

Abstract This paper introduces a lane-changing strategy aimed at trajectory planning and tracking control for intelligent vehicles navigating complex driving environments. A fifth-degree polynomial is employed to generate a set of potential lane-changing trajectories in the Frenet coordinate system. These trajectories are evaluated using non-cooperative game theory, considering the interaction between the target vehicle and its surroundings. Models considering safety payoffs, speed payoffs, comfort payoffs, and aggressiveness are formulated to obtain a Nash equilibrium solution. This way, collision avoidance is ensured, and an optimal lane change trajectory is planned. Three game scenarios are discussed, and the More >

Wenpeng Li¹, Zhenghe Liu¹, Yujing Ma¹, Zhuxuan Meng^2,*, Ji Ma³, Weisong Liu², Vinh Phu Nguyen⁴

CMES-Computer Modeling in Engineering & Sciences, Vol.142, No.2, pp. 1515-1543, 2025, DOI:10.32604/cmes.2025.059235 - 27 January 2025

Abstract This paper presents a framework for constructing surrogate models for sensitivity analysis of structural dynamics behavior. Physical models involving deformation, such as collisions, vibrations, and penetration, are developed using the material point method. To reduce the computational cost of Monte Carlo simulations, response surface models are created as surrogate models for the material point system to approximate its dynamic behavior. An adaptive randomized greedy algorithm is employed to construct a sparse polynomial chaos expansion model with a fixed order, effectively balancing the accuracy and computational efficiency of the surrogate model. Based on the sparse polynomial More >

Pugazhenthi Sivasankar^1,*, Austin B. Probe², Tarek A. Elgohary¹

Digital Engineering and Digital Twin, Vol.2, pp. 169-205, 2024, DOI:10.32604/dedt.2024.052805 - 31 December 2024

Abstract In Space Situational Awareness (SSA), accurate and efficient uncertainty quantification and propagation are essential for various applications, such as conjunction analysis, track correlation, and orbit prediction. The propagation of the probability density function (PDF) in nonlinear systems results in non-Gaussian distributions, which are difficult to approximate. Furthermore, the computational cost of approximating the PDF increases exponentially with the number of random variables, a phenomenon known as the curse of dimensionality. To address these challenges, the Orthogonal Probability Approximation (OPA) method is presented for high-fidelity uncertainty propagation and PDF approximation in nonlinear dynamical systems. The method… More >

Jiayu Ren^1,*, Susumu Nakata²

CMES-Computer Modeling in Engineering & Sciences, Vol.141, No.2, pp. 1033-1046, 2024, DOI:10.32604/cmes.2024.054238 - 27 September 2024

Abstract Three-dimensional surfaces are typically modeled as implicit surfaces. However, direct rendering of implicit surfaces is not simple, especially when such surfaces contain finely detailed shapes. One approach is ray-casting, where the field of the implicit surface is assumed to be piecewise polynomials defined on the grid of a rectangular domain. A critical issue for direct rendering based on ray-casting is the computational cost of finding intersections between surfaces and rays. In particular, ray-casting requires many function evaluations along each ray, severely slowing the rendering speed. In this paper, a method is proposed to achieve direct More >

Rajan Aravind^1,2, Sundararajan Natarajan¹, Krishnankutty Jayakumar², Ratna Kumar Annabattula^1,*

CMES-Computer Modeling in Engineering & Sciences, Vol.141, No.2, pp. 997-1032, 2024, DOI:10.32604/cmes.2024.053047 - 27 September 2024

Abstract Understanding the probabilistic nature of brittle materials due to inherent dispersions in their mechanical properties is important to assess their reliability and safety for sensitive engineering applications. This is all the more important when elements composed of brittle materials are exposed to dynamic environments, resulting in catastrophic fatigue failures. The authors propose the application of a non-intrusive polynomial chaos expansion method for probabilistic studies on brittle materials undergoing fatigue fracture when geometrical parameters and material properties are random independent variables. Understanding the probabilistic nature of fatigue fracture in brittle materials is crucial for ensuring the… More >

Gamze Yıldırım^1,2, Şuayip Yüzbaşı^3,*

CMES-Computer Modeling in Engineering & Sciences, Vol.141, No.1, pp. 281-310, 2024, DOI:10.32604/cmes.2024.052181 - 20 August 2024

Abstract In this study, a numerical method based on the Pell-Lucas polynomials (PLPs) is developed to solve the fractional order HIV/AIDS epidemic model with a treatment compartment. The HIV/AIDS mathematical model with a treatment compartment is divided into five classes, namely, susceptible patients (S), HIV-positive individuals (I), individuals with full-blown AIDS but not receiving ARV treatment (A), individuals being treated (T), and individuals who have changed their sexual habits sufficiently (R). According to the method, by utilizing the PLPs and the collocation points, we convert the fractional order HIV/AIDS epidemic model with a treatment compartment into… More >

Ibrahim Alameri^1,*, Jitka Komarkova², Tawfik Al-Hadhrami³, Abdulsamad Ebrahim Yahya⁴, Atef Gharbi⁵

CMES-Computer Modeling in Engineering & Sciences, Vol.141, No.1, pp. 787-807, 2024, DOI:10.32604/cmes.2024.052107 - 20 August 2024

Abstract This study is trying to address the critical need for efficient routing in Mobile Ad Hoc Networks (MANETs) from dynamic topologies that pose great challenges because of the mobility of nodes. The main objective was to delve into and refine the application of the Dijkstra's algorithm in this context, a method conventionally esteemed for its efficiency in static networks. Thus, this paper has carried out a comparative theoretical analysis with the Bellman-Ford algorithm, considering adaptation to the dynamic network conditions that are typical for MANETs. This paper has shown through detailed algorithmic analysis that Dijkstra’s… More >