R. Alshenawy^1,2, Mohamed A. H. Sabry³, Ehab M. Almetwally^4,*, Hisham M. Elomngy²

CMC-Computers, Materials & Continua, Vol.66, No.3, pp. 2973-2995, 2021, DOI:10.32604/cmc.2021.014289 - 28 December 2020

Abstract Maximum product spacing for stress–strength model based on progressive Type-II hybrid censored samples with different cases has been obtained. This paper deals with estimation of the stress strength reliability model R = P(Y < X) when the stress and strength are two independent exponentiated Gumbel distribution random variables with different shape parameters but having the same scale parameter. The stress–strength reliability model is estimated under progressive Type-II hybrid censoring samples. Two progressive Type-II hybrid censoring schemes were used, Case I: A sample size of stress is the equal sample size of strength, and same time of… More >

Abdulsattar Abdullah Hamad¹, Ahmed S. Al-Obeidi², Enas H. Al-Taiy², Osamah Ibrahim Khalaf³, Dac-Nhuong Le^4,5,*

CMC-Computers, Materials & Continua, Vol.66, No.3, pp. 3311-3327, 2021, DOI:10.32604/cmc.2021.013395 - 28 December 2020

Abstract Synchronization is one of the most important characteristics of dynamic systems. For this paper, the authors obtained results for the nonlinear systems controller for the custom Synchronization of two 4D systems. The findings have allowed authors to develop two analytical approaches using the second Lyapunov (Lyp) method and the Gardano method. Since the Gardano method does not involve the development of special positive Lyp functions, it is very efficient and convenient to achieve excessive system SYCR phenomena. Error is overcome by using Gardano and overcoming some problems in Lyp. Thus we get a great investigation… More >

Chi Zhang, Yong Shi^*, Xuwei Gui

Energy Engineering, Vol.118, No.2, pp. 341-361, 2021, DOI:10.32604/EE.2021.014229 - 23 December 2020

Abstract To realize effective utilization of renewable energy sources, a novel polymorphic topology with hybrid control strategy based LLC resonant converter was analyzed and designed in this paper. By combining the merits of a full bridge LLC resonant converter, three-level half bridge LLC resonant converter, and variable frequency control mode, the converter realizes an intelligent estimation of input voltage by automatically changing its internal circuit topology. Under this control strategy, different input voltages determine different operation modes. This is achieved in full bridge LLC mode when the input voltage is low. If the input voltage rises More >

Omar Nooh Almotiry¹, Mohemmed Sha^2,*, Mohamudha Parveen Rahamathulla³, Omer Salih Dawood Omer²

Computer Systems Science and Engineering, Vol.36, No.1, pp. 1-12, 2021, DOI:10.32604/csse.2021.014267 - 23 December 2020

Abstract As technology improves, several modernization efforts are taken in the process of teaching and learning. An effective education system should maintain global connectivity, federate security and deliver self-access to its services. The cloud computing services transform the current education system to an advanced one. There exist several tools and services to make teaching and learning more interesting. In the higher education system, the data flow and basic operations are almost the same. These systems need to access cloud-based applications and services for their operational advancement and flexibility. Architecting a suitable cloud-based education system will leverage… More >

Xizheng Zhang^1,2,*, Zhangyu Lu¹, Chongzhuo Tan¹, Zeyu Wang¹

Computer Systems Science and Engineering, Vol.36, No.1, pp. 117-130, 2021, DOI:10.32604/csse.2021.014081 - 23 December 2020

Abstract Regarding the problem of the short driving distance of pure electric vehicles, a battery, super-capacitor, and DC/DC converter are combined to form a hybrid energy storage system (HESS). A fuzzy adaptive filtering-based energy management strategy (FAFBEMS) is proposed to allocate the required power of the vehicle. Firstly, the state of charge (SOC) of the super-capacitor is limited according to the driving/braking mode of the vehicle to ensure that it is in a suitable working state, and fuzzy rules are designed to adaptively adjust the filtering time constant, to realize reasonable power allocation. Then, the positive… More >

Roddy A. Correa¹, Juan Ramón Bermejo Higuera², Javier Bermejo Higuera², Juan Antonio Sicilia Montalvo², Manuel Sánchez Rubio², Á. Alberto Magreñán^3,*

CMES-Computer Modeling in Engineering & Sciences, Vol.126, No.1, pp. 89-124, 2021, DOI:10.32604/cmes.2021.010700 - 22 December 2020

Abstract This study presents a methodology to evaluate and prevent security vulnerabilities issues for web applications. The analysis process is based on the use of techniques and tools that allow to perform security assessments of white box and black box, to carry out the security validation of a web application in an agile and precise way. The objective of the methodology is to take advantage of the synergies of semi-automatic static and dynamic security analysis tools and manual checks. Each one of the phases contemplated in the methodology is supported by security analysis tools of different… More >

Tabrej Khan¹, Mohamed Thariq Hameed Sultan^1,2,3,*, Mohammad Jawaid², Syafiqah Nur Azrie Safri², Ain Umaira Md Shah², Mohd Shukry Abdul Majid^4,5,*, Nik Noriman Zulkepli⁶, Haliza Jaya⁶

Journal of Renewable Materials, Vol.9, No.1, pp. 73-84, 2021, DOI:10.32604/jrm.2021.011385 - 30 November 2020

Abstract This research focused on the dynamic mechanical and thermal properties of woven mat jute/kenaf/jute (J/K/J) and kenaf/jute/kenaf (K/J/K) hybrid composites. Dynamic mechanical analysis (DMA) and Thermo-gravimetric Analysis (TGA) were used to study the effect of layering sequence on the thermal properties of kenaf/jute hybrid composites. The DMA results; it was found that the differences in the stacking sequence between the kenaf/jute composites do not affect their storage modulus, loss modulus and damping factor. From the TGA and DMA results, it has been shown that stacking sequence has given positive effect to the kenaf/jute hybrid composite… More >

Kamlendra Vikram¹, Uvaraja Ragavendran², Kanak Kalita^1,*, Ranjan Kumar Ghadai³, Xiao-Zhi Gao⁴

CMC-Computers, Materials & Continua, Vol.66, No.2, pp. 1771-1784, 2021, DOI:10.32604/cmc.2020.013946 - 26 November 2020

Abstract In this work, diamond-like carbon (DLC) thin film coatings are deposited on silicon substrates by using plasma-enhanced chemical vapour deposition (PECVD) technique. By varying the hydrogen (H₂) flow rate, CH₄−Argon (Ar) flow rate and deposition temperature (T_d) as per a Box-Behnken experimental design (BBD), 15 DLC deposition experiments are carried out. The Young’s modulus (E) and the coefficient of friction (COF) for the DLCs are measured. By using a second-order polynomial regression approach, two metamodels are built for E and COF, that establish them as functions of H₂ flow rate, CH₄-Ar flow rate and T_d. A non-dominated sorting More >

Youseef Alotaibi^*

CMC-Computers, Materials & Continua, Vol.66, No.2, pp. 1879-1895, 2021, DOI:10.32604/cmc.2020.013739 - 26 November 2020

Abstract A new secured database management system architecture using intrusion detection systems (IDS) is proposed in this paper for organizations with no previous role mapping for users. A simple representation of Structured Query Language queries is proposed to easily permit the use of the worked clustering algorithm. A new clustering algorithm that uses a tube search with adaptive memory is applied to database log files to create users’ profiles. Then, queries issued for each user are checked against the related user profile using a classifier to determine whether or not each query is malicious. The IDS… More >

Gopi Krishna Durbhaka¹, Barani Selvaraj¹, Mamta Mittal², Tanzila Saba^3,*, Amjad Rehman³, Lalit Mohan Goyal⁴

CMC-Computers, Materials & Continua, Vol.66, No.2, pp. 2041-2059, 2021, DOI:10.32604/cmc.2020.013131 - 26 November 2020

Abstract Nowadays, renewable energy has been emerging as the major source of energy and is driven by its aggressive expansion and falling costs. Most of the renewable energy sources involve turbines and their operation and maintenance are vital and a difficult task. Condition monitoring and fault diagnosis have seen remarkable and revolutionary up-gradation in approaches, practices and technology during the last decade. Turbines mostly do use a rotating type of machinery and analysis of those signals has been challenging to localize the defect. This paper proposes a new hybrid model wherein multiple swarm intelligence models have More >