Muhammad Nadeem¹, Ali Arshad², Saman Riaz², Syeda Wajiha Zahra¹, Shahab S. Band³, Amir Mosavi^4,5,6,*

CMC-Computers, Materials & Continua, Vol.74, No.2, pp. 2625-2640, 2023, DOI:10.32604/cmc.2023.030899 - 31 October 2022

Abstract Many organizations have insisted on protecting the cloud server from the outside, although the risks of attacking the cloud server are mostly from the inside. There are many algorithms designed to protect the cloud server from attacks that have been able to protect the cloud server attacks. Still, the attackers have designed even better mechanisms to break these security algorithms. Cloud cryptography is the best data protection algorithm that exchanges data between authentic users. In this article, one symmetric cryptography algorithm will be designed to secure cloud server data, used to send and receive cloud… More >

Quanchun Yan^1,2,*, Chao Yuan¹, Wen Gu¹, Yanan Liu¹, Yiming Tang¹

Energy Engineering, Vol.120, No.1, pp. 49-68, 2023, DOI:10.32604/ee.2022.018555 - 27 October 2022

Abstract In order to solve the problems of rotor overvoltage, overcurrent and DC side voltage rise caused by grid voltage drops, a coordinated control strategy based on symmetrical and asymmetrical low voltage ride through of rotor side converter of the doubly-fed generator is proposed. When the power grid voltage drops symmetrically, the generator approximate equation under steady-state conditions is no longer applicable. Considering the dynamic process of stator current excitation, according to the change of stator flux and the depth of voltage drop, the system can dynamically provide reactive power support for parallel nodes and suppress… More >

Peng Wang¹, Yulu Tian², Bolong Men^1,*, Hailong Song¹

Intelligent Automation & Soft Computing, Vol.36, No.1, pp. 83-95, 2023, DOI:10.32604/iasc.2023.027602 - 29 September 2022

Abstract Here the estimating problem of a single sinusoidal signal in the additive symmetric α-stable Gaussian (ASαSG) noise is investigated. The ASαSG noise here is expressed as the additive of a Gaussian noise and a symmetric α-stable distributed variable. As the probability density function (PDF) of the ASαSG is complicated, traditional estimators cannot provide optimum estimates. Based on the Metropolis-Hastings (M-H) sampling scheme, a robust frequency estimator is proposed for ASαSG noise. Moreover, to accelerate the convergence rate of the developed algorithm, a new criterion of reconstructing the proposal covariance is derived, whose main idea is More >

Awny Sayed^1,2, Maha Mahrous³, Enas Elgeldawi^1,*

CMC-Computers, Materials & Continua, Vol.74, No.1, pp. 1723-1734, 2023, DOI:10.32604/cmc.2023.032838 - 22 September 2022

Abstract Securing digital data from unauthorized access throughout its entire lifecycle has been always a critical concern. A robust data security system should protect the information assets of any organization against cybercriminal activities. The Twofish algorithm is one of the well-known symmetric key block cipher cryptographic algorithms and has been known for its rapid convergence. But when it comes to security, it is not the preferred cryptographic algorithm to use compared to other algorithms that have shown better security. Many applications and social platforms have adopted other symmetric key block cipher cryptographic algorithms such as the… More >

Umair Khan^1,2, Aurang Zaib³, Anuar Ishak¹, Iskandar Waini⁴, El-Sayed M. Sherif⁵, Dumitru Baleanu^6,7,8,*

CMES-Computer Modeling in Engineering & Sciences, Vol.134, No.2, pp. 1371-1392, 2023, DOI:10.32604/cmes.2022.020911 - 31 August 2022

Abstract The utilization of solar energy is essential to all living things since the beginning of time. In addition to being a constant source of energy, solar energy (SE) can also be used to generate heat and electricity. Recent technology enables to convert the solar energy into electricity by using thermal solar heat. Solar energy is perhaps the most easily accessible and plentiful source of sustainable energy. Copper-based nanofluid has been considered as a method to improve solar collector performance by absorbing incoming solar energy directly. The goal of this research is to explore theoretically the… More >

Farah Zemani-Kaci^*, Amina Sabeur-Bendhina

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.2, pp. 513-539, 2023, DOI:10.32604/fdmp.2022.021974 - 29 August 2022

Abstract A two-dimensional numerical study of laminar natural convection in a square enclosure filled with air with a wall partially heated on the bottom is presented. The heat source is located on the lower wall with different heated widths varied from 20 to 80%(ε = 0.2–0.8) of the total width of the lower wall and different heights h = H/4 and H/2 of the partition. The effect of the partition height on the main system dynamics is investigated through solution of the two-dimensional Navier–Stokes equations and the energy equation by means of a finite volume method More > Graphic Abstract

Xiaowei Nie¹, Lihui Ma^2,*, Yiqiu Xu³, Dong Sun², Weibo Zheng², Liang Zhou², Xiaodong Wang², Xiaohan Zhang², Weijia Dong², Yunfei Li²

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.1, pp. 37-50, 2023, DOI:10.32604/fdmp.2023.021118 - 02 August 2022

Abstract An experimental study was conducted to investigate the properties of stratified regular or wavy two-phase flow in two parallel separators located after a manifold. A total of 103 experiments with various gas and liquid velocity combinations in three inlet pipes were conducted, including 77 groups of outlet pipe resistance symmetry and 26 groups of outlet pipe resistance asymmetry trials. The experimental results have revealed that when the gas-liquid flow rate is low, the degree of uneven splitting is high, and “extreme” conditions are attained. When the superficial gas velocity is greater than that established in More >

N. Krishnammal^1,*, C. Kalaiarasan², A. Bharathi³

Computer Systems Science and Engineering, Vol.44, No.2, pp. 1531-1549, 2023, DOI:10.32604/csse.2023.024251 - 15 June 2022

Abstract Link asymmetry in wireless mesh access networks (WMAN) of Mobile ad-hoc Networks (MANETs) is due mesh routers’ transmission range. It is depicted as significant research challenges that pose during the design of network protocol in wireless networks. Based on the extensive review, it is noted that the substantial link percentage is symmetric, i.e., many links are unidirectional. It is identified that the synchronous acknowledgement reliability is higher than the asynchronous message. Therefore, the process of establishing bidirectional link quality through asynchronous beacons underrates the link reliability of asymmetric links. It paves the way to exploit… More >

Chih-Fang Huang^1,*, Ai-Hsien Fan², Jin-Huang Huang³, Hsing-Cheng Huang³

Intelligent Automation & Soft Computing, Vol.35, No.1, pp. 661-673, 2023, DOI:10.32604/iasc.2023.027165 - 06 June 2022

Abstract This study applies the diatonic chord in music theory, utilization rate, and the close relationship between the main chord system, the dominant chord system, and the subordinate chord system. From the perspective of music theory, the computer can automatically and quickly analyze the music, and establish a set of algorithms for configuring the chord accompaniment for the main melody, called the symmetrical circle of fifths algorithm, SCFA (Symmetrical Circle of Fifths Algorithm). SCFA can immediately confirm the key, perform harmony analysis, configure chord accompaniment for the main melody, and effectively and correctly complete any given More >

Samuel Bimenyimana¹, Chen Wang^1,*, Godwin Norense Osarumwense Asemota², Aphrodis Nduwamungu², Francis Mulolani⁶, Jean De Dieu Niyonteze⁸, Shilpi Bora^1,7, Chun-Ling Ho¹, Noel Hagumimana³, Theobald Habineza⁴, Waqar Bashir⁵, Yiyi Mo¹

Energy Engineering, Vol.119, No.6, pp. 2369-2406, 2022, DOI:10.32604/ee.2022.019257 - 14 September 2022

Abstract The world’s energy consumption and power generation demand will continue to rise. Furthermore, the bulk of the energy resources needed to satisfy the rising demand is far from the load centers. The aforementioned requires long-distance transmission systems and one way to accomplish this is to use high voltage direct current (HVDC) transmission systems. The main technical issues for HVDC transmission systems are loss of synchronism, variation of quadrature currents, amplitude, the inability of station 1 (rectifier), and station 2 (inverter) to either inject, or absorb active, or reactive power in the network in any circumstances… More >