Fengyu Xu^1,2, Masoud Kalantari³, Bangjian Li², Xingsong Wang^2,*

CMC-Computers, Materials & Continua, Vol.75, No.1, pp. 2209-2226, 2023, DOI:10.32604/cmc.2023.027102

Abstract The automatically defect detection method using vision inspection is a promising direction. In this paper, an efficient defect detection method for detecting surface damage to cables on a cable-stayed bridge automatically is developed. A mechanism design method for the protective layer of cables of a bridge based on vision inspection and diameter measurement is proposed by combining computer vision and diameter measurement techniques. A detection system for the surface damages of cables is de-signed. Images of cable surfaces are then enhanced and subjected to threshold segmentation by utilizing the improved local grey contrast enhancement method and the improved maximum correlation… More >

Li Ding, Yong Yao^*, Rui Ma

CMES-Computer Modeling in Engineering & Sciences, Vol.135, No.2, pp. 1539-1558, 2023, DOI:10.32604/cmes.2022.023003

Abstract With the increasing demand for interactive aerial operations, the application of aerial manipulators is becoming more promising. However, there are a few critical problems on how to improve the energetic efficiency and pose control of the aerial manipulator for practical application. In this paper, a novel cable-driven aerial manipulator used for remote water sampling is proposed and then its rigid-flexible coupling dynamics model is constructed which takes joint flexibility into account. To achieve high precision joint position tracking under lumped disturbances, a newly controller, which consists of three parts: linear extended state observer, adaptive super-twisting strategy, and fractional-order nonsingular terminal… More >

Li Ding^1,*, Rui Ma¹, Zhengtian Wu², Rongzhi Qi¹, Wenrui Ruan¹

CMES-Computer Modeling in Engineering & Sciences, Vol.135, No.1, pp. 441-464, 2023, DOI:10.32604/cmes.2022.022642

Abstract This article proposes a novel method for maintaining the trajectory of an aerial manipulator by utilizing a fast nonsingular terminal sliding mode (FNTSM) manifold and a linear extended state observer (LESO). The developed control method applies an FNTSM to ensure the tracking performance’s control accuracy, and an LESO to estimate the system’s unmodeled dynamics and external disturbances. Additionally, an improved salp swarm algorithm (ISSA) is employed to parameter tune the suggested controller by integrating the salp swarm technique with a cloud model. This approach also uses a model-free scheme to reduce the complexity of controller design without relying on complex… More >

Huisong Wu, Kaichun Zeng, Li Yu, Yan Li, Xiping Kou^*

CMES-Computer Modeling in Engineering & Sciences, Vol.135, No.1, pp. 395-416, 2023, DOI:10.32604/cmes.2022.021650

Abstract An underconstrained cable-driven parallel robot (CDPR) suspension system was designed for a virtual flight testing (VFT) model. This mechanism includes two identical upper and lower kinematic chains, each of which comprises a cylindrical pair, rotating pair, and cable parallelogram. The model is pulled via two cables at the top and bottom and fixed by a yaw turntable, which can realize free coupling and decoupling with three rotational degrees of freedom of the model. First, the underconstrained CDPR suspension system of the VFT model was designed according to the mechanics theory, the degrees of freedom were verified, and the support platform… More >

S. Saravanakumar^1,*, S. Chitra²

Computer Systems Science and Engineering, Vol.43, No.3, pp. 985-996, 2022, DOI:10.32604/csse.2022.019508

Abstract Cloud storage is a service involving cloud service providers providing storage space to customers. Cloud storage services have numerous advantages, including convenience, high computation, and capacity, thereby attracting users to outsource data in the cloud. However, users outsource data directly via cloud stage services that are unsafe when outsourcing data is sensitive for users. Therefore, cipher text-policy attribute-based encryption is a promising cryptographic solution in a cloud environment, and can be drawn up for access control by data owners (DO) to define access policy. Unfortunately, an outsourced architecture applied with attribute-based encryption introduces numerous challenges, including revocation. This issue is… More >

Kexin Zhang^*, Tianyu Qi, Dachao Li, Xingwei Xue, Yanfeng Li

Structural Durability & Health Monitoring, Vol.16, No.1, pp. 53-80, 2022, DOI:10.32604/sdhm.2021.016130

Abstract This paper presents the method of reinforcing main girder of reinforced concrete cable-stayed bridge with prestressed steel strands. To verify the effectiveness of external prestressed strand reinforcement method. Static load tests and health monitoring-based assessment were carried out before and after reinforcement. Field load test shows that the deflection and stress values of the main girder are reduced by 10%~20% after reinforcement, and the flexural strength and stiffness of the strengthened beam are improved. The deflection and strain data of health monitoring of the specified section are collected. The deflection of the second span is 4 mm~10 mm, the strain… More >

N. B. Ghazali¹, F. C. Seman^1,*, K. Isa¹, K. N. Ramli¹, Z. Z. Abidin¹, S. M. Mustam¹, M. A. Haek², A. N. Z. Abidin², A. Asrokin²

CMC-Computers, Materials & Continua, Vol.71, No.3, pp. 5427-5440, 2022, DOI:10.32604/cmc.2022.023211

Abstract Applying the fault diagnosis techniques to twisted pair copper cable is beneficial to improve the stability and reliability of internet access in Digital Subscriber Line (DSL) Access Network System. The network performance depends on the occurrence of cable fault along the copper cable. Currently, most of the telecommunication providers monitor the network performance degradation hence troubleshoot the present of the fault by using commercial test gear on-site, which may be resolved using data analytics and machine learning algorithm. This paper presents a fault diagnosis method for twisted pair cable fault detection based on knowledge-based and data-driven machine learning methods. The… More >

Zhiyuan Tu¹, Fusheng Peng^1,*, Zijie Wei¹, Guo Qian², Jie Wang¹, Chunjie Huang¹

FDMP-Fluid Dynamics & Materials Processing, Vol.17, No.6, pp. 1195-1211, 2021, DOI:10.32604/fdmp.2021.011753

Abstract To calculate the flow resistance of a main cable dehumidification system, this study considers the air flow in the main cable as the flow in a porous medium, and adopts the Hagen–Poiseuille equation by using average hydraulic radius and capillary bundle models. A mathematical derivation is combined with an experimental study to obtain a semi-empirical flow resistance formula. Additionally, Fluent software is used to simulate the flow resistance across the main cable relative to the experimental values. Based on the actual measured results for a Yangtze River bridge, this study verifies the semi-empirical formula, and indicates that it can be… More >

Jie Chen¹, Wei Zhang¹, Man Ding^2,*, Libin Hu¹, Jinpeng Wang², Chenying Li¹, Jingying Cao¹

Energy Engineering, Vol.118, No.5, pp. 1537-1548, 2021, DOI:10.32604/EE.2021.015439

Abstract The aging characteristics of the XLPE insulation of 110 kV power cables in the initial stage of operation are studied in this paper. The XLPE insulation from cables with different running time was tested by using electrical and physicochemical methods, from which the degradation state of XLPE under multiple stresses during operation was derived. The broadband dielectric spectrum test taken from 10^–1 to 10⁶ Hz showed that the dielectric constant and dielectric loss of the XLPE insulation first decrease and then increase with the increase of cable running time, which show obvious variation until 10 years of operation. The AC… More >

Nehmdoh A. Sabiha^*, Hend I. Alkhammash

Intelligent Automation & Soft Computing, Vol.28, No.3, pp. 769-784, 2021, DOI:10.32604/iasc.2021.016752

Abstract The maximum temperature that cable insulation can withstand determines the maximum load that the cable conductor can carry, which is called cable ampacity. However, a temperature far from this value under normal load conditions affects the transients due to earth faults in the distribution network. Accordingly, error estimation in the fault location occurs, and the smart grids do not accept such errors. Considering heterogenous unearthed and compensated distribution networks, the temperature rise in different underground cables is estimated under different load conditions. These loads are full load, three quarters (3/4) load, one half (1/2) load, and one quarter (1/4) load.… More >