Kunpeng Zhou¹, Tao Wu^1,*, Jia Zhang²

CMC-Computers, Materials & Continua, Vol.86, No.1, pp. 1-27, 2026, DOI:10.32604/cmc.2025.068160 - 10 November 2025

Abstract Over the past few years, video live streaming has gained immense popularity as a leading internet application. In current solutions offered by cloud service providers, the Group of Pictures (GOP) length of the video source often significantly impacts end-to-end (E2E) latency. However, designing an optimized GOP structure to reduce this effect remains a significant challenge. This paper presents two key contributions. First, it explores how the GOP length at the video source influences E2E latency in mainstream cloud streaming services. Experimental results reveal that the mean E2E latency increases linearly with longer GOP lengths. Second, More >

Sahbi Boubaker^1,2,*, Salim Hadj Said³, Souad Kamel¹, Habib Dimassi³

CMC-Computers, Materials & Continua, Vol.85, No.3, pp. 5703-5721, 2025, DOI:10.32604/cmc.2025.069047 - 23 October 2025

Abstract Accurate trajectory tracking in lower-limb exoskeletons is challenged by the nonlinear, time-varying dynamics of human-robot interaction, limited sensor availability, and unknown external disturbances. This study proposes a novel control strategy that combines flatness-based control with two cascaded observers: a high-gain observer to estimate unmeasured joint velocities, and a nonlinear disturbance observer to reconstruct external torque disturbances in real time. These estimates are integrated into the control law to enable robust, state-feedback-based trajectory tracking. The approach is validated through simulation scenarios involving partial state measurements and abrupt external torque perturbations, reflecting realistic rehabilitation conditions. Results confirm More >

Mohammad Soleimani Amiri¹, Sahbi Boubaker^2,3,*, Rizauddin Ramli^4,*, Souad Kamel²

CMES-Computer Modeling in Engineering & Sciences, Vol.144, No.3, pp. 3113-3133, 2025, DOI:10.32604/cmes.2025.069167 - 30 September 2025

Abstract Disability is defined as a condition that makes it difficult for a person to perform certain vital activities. In recent years, the integration of the concepts of intelligence in solving various problems for disabled persons has become more frequent. However, controlling an exoskeleton for rehabilitation presents challenges due to their non-linear characteristics and external disturbances caused by the structure itself or the patient wearing the exoskeleton. To remedy these problems, this paper presents a novel adaptive control strategy for upper-limb rehabilitation exoskeletons, addressing the challenges of nonlinear dynamics and external disturbances. The proposed controller integrated… More >

Huy Q. Tran¹, Tan Nguyen Van^2,*, Cheolkeun Ha³

CMC-Computers, Materials & Continua, Vol.85, No.1, pp. 1053-1072, 2025, DOI:10.32604/cmc.2025.064386 - 29 August 2025

Abstract Hydraulic-electric systems are widely utilized in various applications. However, over time, these systems may encounter random faults such as loose cables, ambient environmental noise, or sensor aging, leading to inaccurate sensor readings. These faults may result in system instability or compromise safety. In this paper, we propose a fault compensation control system to mitigate the effects of sensor faults and ensure system safety. Specifically, we utilize the pressure sensor within the system to implement the control process and evaluate performance based on the piston position. First, we develop a mathematical model to identify optimal parameters… More >

Peizheng Lai¹, Minqing Zhang^1,2,*, Yixin Tang¹, Ya Yue¹, Fuqiang Di^1,2

CMC-Computers, Materials & Continua, Vol.84, No.2, pp. 2935-2957, 2025, DOI:10.32604/cmc.2025.065887 - 03 July 2025

Abstract Federated Learning (FL) has emerged as a promising distributed machine learning paradigm that enables multi-party collaborative training while eliminating the need for raw data sharing. However, its reliance on a server introduces critical security vulnerabilities: malicious servers can infer private information from received local model updates or deliberately manipulate aggregation results. Consequently, achieving verifiable aggregation without compromising client privacy remains a critical challenge. To address these problem, we propose a reversible data hiding in encrypted domains (RDHED) scheme, which designs joint secret message embedding and extraction mechanism. This approach enables clients to embed secret messages… More >

Zerui Chen^*, Xin Wu, Houpeng Hu, Yang Zhou, Shang Yang

Frontiers in Heat and Mass Transfer, Vol.23, No.3, pp. 991-1011, 2025, DOI:10.32604/fhmt.2025.065936 - 30 June 2025

Abstract As the integration of electronic components in high-performance servers increases, heat generation significantly impacts performance and raises failure rates. Therefore, heat dissipation has become a critical concern in electronic circuit design. This study uses numerical simulations to investigate the heat dissipation characteristics of electronic components in air-cooled servers. By adjusting airflow speed, heat sink configurations, and the arrangement of straight-fin heat sinks, we optimize heat dissipation performance and analyze the mechanisms at different airflow speeds. The results show that, at the same airflow speed, the temperature of the heat sink is lower than that of… More >

Lang Qin¹, Zhengrui Jiang¹, Xueshu Xing², Xiao Wang¹, Yaohua Yin², Yuhui Zhou², Zhiqin He^1,*

CMC-Computers, Materials & Continua, Vol.83, No.3, pp. 5279-5298, 2025, DOI:10.32604/cmc.2025.063358 - 19 May 2025

Abstract In permanent magnet synchronous motor (PMSM) control, the jitter problem affects the system performance, so a novel reaching law is proposed to construct a non-singular fast terminal sliding mode controller (NFTSMC) to reduce the jitter. To enhance the immunity of the system, a disturbance observer is designed to observe and compensate for the disturbance to the sliding mode controller. In addition, considering that the controller parameters are difficult to adjust, and the traditional zebra optimization algorithm (ZOA) is prone to converge prematurely and fall into local optimum when solving the optimal solution, the improved zebra… More >

Yiming Rongyang¹, Zhenyue Yu¹, Ruisheng Liang^2,*, Wei Su¹, Jianjian Wei^2,3

Frontiers in Heat and Mass Transfer, Vol.23, No.1, pp. 279-298, 2025, DOI:10.32604/fhmt.2025.059637 - 26 February 2025

Abstract Data center cooling systems are substantial energy consumers, and managing the heat generated by electronic devices is becoming more complex as chip power levels continue to rise. The single-phase immersion cooling (SPIC) server with oil coolant is numerically investigated using the validated Re-Normalization Group (RNG) k-ε model. For the investigated scenarios where coolant velocity at the tank inlet is 0.004 m/s and the total power is 740 W, the heat transfer between the heat sinks and the coolant is dominated by natural convection, although forced convection mediates the overall heat transfer inside the tank. The maximum… More >

Khawaja Tahir Mehmood^1,2,*, Shahid Atiq¹, Intisar Ali Sajjad³, Muhammad Majid Hussain⁴, Malik M. Abdul Basit²

CMES-Computer Modeling in Engineering & Sciences, Vol.141, No.2, pp. 1673-1708, 2024, DOI:10.32604/cmes.2024.053903 - 27 September 2024

Abstract Software-Defined Networking (SDN), with segregated data and control planes, provides faster data routing, stability, and enhanced quality metrics, such as throughput (T_h), maximum available bandwidth (B_d(max)), data transfer (D_Transfer), and reduction in end-to-end delay (D_(E-E)). This paper explores the critical work of deploying SDN in large­scale Data Center Networks (DCNs) to enhance its Quality of Service (QoS) parameters, using logically distributed control configurations. There is a noticeable increase in Delay_(E-E) when adopting SDN with a unified (single) control structure in big DCNs to handle Hypertext Transfer Protocol (HTTP) requests causing a reduction in network quality parameters (B_d(max), T_h, D_Transfer, D_(E-E),… More > Graphic Abstract

Muhammad Dawood¹, Shanshan Tu¹, Chuangbai Xiao¹, Muhammad Haris², Hisham Alasmary³, Muhammad Waqas^4,5,*, Sadaqat Ur Rehman⁶

CMC-Computers, Materials & Continua, Vol.80, No.3, pp. 4513-4542, 2024, DOI:10.32604/cmc.2024.050049 - 12 September 2024

Abstract The DNS over HTTPS (Hypertext Transfer Protocol Secure) (DoH) is a new technology that encrypts DNS traffic, enhancing the privacy and security of end-users. However, the adoption of DoH is still facing several research challenges, such as ensuring security, compatibility, standardization, performance, privacy, and increasing user awareness. DoH significantly impacts network security, including better end-user privacy and security, challenges for network security professionals, increasing usage of encrypted malware communication, and difficulty adapting DNS-based security measures. Therefore, it is important to understand the impact of DoH on network security and develop new privacy-preserving techniques to allow More >