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  • Open Access

    ARTICLE

    Numerical Study of Natural Convection in an Inclined Porous Cavity

    Saad Adjal1,*, Sabiha Aklouche-Benouaguef1, Belkacem Zeghmati2

    FDMP-Fluid Dynamics & Materials Processing, Vol.18, No.5, pp. 1389-1397, 2022, DOI:10.32604/fdmp.2022.021619

    Abstract Two-dimensional transient laminar natural convection in a square cavity containing a porous medium and inclined at an angle of 30∘ is investigated numerically. The vertical walls are differentially heated, and the horizontal walls are adiabatic. The effect of Rayleigh number on heat transfer and on the road to chaos is analyzed. The natural heat transfer and the Darcy Brinkman equations are solved by using a finite volume method and a Tri Diagonal Matrix Algorithm (TDMA). The results are obtained for a porosity equal to 0.45, a Darcy number and a Prandtl respectively equal to 10−3 and 0.71; they are analyzed… More >

  • Open Access

    ARTICLE

    A Highly Secured Image Encryption Scheme using Quantum Walk and Chaos

    Muhammad Islam Kamran1, Muazzam A. Khan1, Suliman A. Alsuhibany2, Yazeed Yasin Ghadi3, Arshad4, Jameel Arif1, Jawad Ahmad5,*

    CMC-Computers, Materials & Continua, Vol.73, No.1, pp. 657-672, 2022, DOI:10.32604/cmc.2022.028876

    Abstract The use of multimedia data sharing has drastically increased in the past few decades due to the revolutionary improvements in communication technologies such as the 4th generation (4G) and 5th generation (5G) etc. Researchers have proposed many image encryption algorithms based on the classical random walk and chaos theory for sharing an image in a secure way. Instead of the classical random walk, this paper proposes the quantum walk to achieve high image security. Classical random walk exhibits randomness due to the stochastic transitions between states, on the other hand, the quantum walk is more random and achieve randomness due… More >

  • Open Access

    ARTICLE

    A Secure and Lightweight Chaos Based Image Encryption Scheme

    Fadia Ali Khan1, Jameel Ahmed1, Fehaid Alqahtani2, Suliman A. Alsuhibany3, Fawad Ahmed4, Jawad Ahmad5,*

    CMC-Computers, Materials & Continua, Vol.73, No.1, pp. 279-294, 2022, DOI:10.32604/cmc.2022.028789

    Abstract In this paper, we present an image encryption scheme based on the multi-stage chaos-based image encryption algorithm. The method works on the principle of confusion and diffusion. The proposed scheme containing both confusion and diffusion modules are highly secure and effective as compared to the existing schemes. Initially, an image (red, green, and blue components) is partitioned into blocks with an equal number of pixels. Each block is then processed with Tinkerbell Chaotic Map (TBCM) to get shuffled pixels and shuffled blocks. Composite Fractal Function (CFF) change the value of pixels of each color component (layer) to obtain a random… More >

  • Open Access

    ARTICLE

    Resource Load Prediction of Internet of Vehicles Mobile Cloud Computing

    Wenbin Bi1, Fang Yu2, Ning Cao3,*, Russell Higgs4

    CMC-Computers, Materials & Continua, Vol.73, No.1, pp. 165-180, 2022, DOI:10.32604/cmc.2022.027776

    Abstract Load-time series data in mobile cloud computing of Internet of Vehicles (IoV) usually have linear and nonlinear composite characteristics. In order to accurately describe the dynamic change trend of such loads, this study designs a load prediction method by using the resource scheduling model for mobile cloud computing of IoV. Firstly, a chaotic analysis algorithm is implemented to process the load-time series, while some learning samples of load prediction are constructed. Secondly, a support vector machine (SVM) is used to establish a load prediction model, and an improved artificial bee colony (IABC) function is designed to enhance the learning ability… More >

  • Open Access

    ARTICLE

    Image Encryption Using Multi-Scroll Attractor and Chaotic Logistic Map

    R. Anitha*, B. Vijayalakshmi

    CMC-Computers, Materials & Continua, Vol.72, No.2, pp. 3447-3463, 2022, DOI:10.32604/cmc.2022.021519

    Abstract In the current scenario, data transmission over the network is a challenging task as there is a need for protecting sensitive data. Traditional encryption schemes are less sensitive and less complex thus prone to attacks during transmission. It has been observed that an encryption scheme using chaotic theory is more promising due to its non-linear and unpredictable behavior. Hence, proposed a novel hybrid image encryption scheme with multi-scroll attractors and quantum chaos logistic maps (MSA-QCLM). The image data is classified as inter-bits and intra-bits which are permutated separately using multi scroll attractor & quantum logistic maps to generate random keys.… More >

  • Open Access

    ARTICLE

    Hyperchaos and MD5 Based Efficient Color Image Cipher

    Muhammad Samiullah1, Waqar Aslam1, Saima Sadiq2, Arif Mehmood1, Gyu Sang Choi3,*

    CMC-Computers, Materials & Continua, Vol.72, No.1, pp. 1645-1670, 2022, DOI:10.32604/cmc.2022.021019

    Abstract While designing and developing encryption algorithms for text and images, the main focus has remained on security. This has led to insufficient attention on the improvement of encryption efficiency, enhancement of hyperchaotic sequence randomness, and dynamic DNA-based S-box. In this regard, a new symmetric block cipher scheme has been proposed. It uses dynamic DNA-based S-box connected with MD5 and a hyperchaotic system to produce confusion and diffusion for encrypting color images. Our proposed scheme supports various size color images. It generates three DNA based S-boxes for substitution namely DNA_1_s-box, DNA_2_s-box and DNA_3_s-box, each of size . Next, the 4D hyperchaotic… More >

  • Open Access

    ARTICLE

    A Novel Medical Image Encryption Using Rössler System

    K. Sundara Krishnan1,*, Syed Suhaila1, S. P. Raja2

    Intelligent Automation & Soft Computing, Vol.33, No.2, pp. 1081-1101, 2022, DOI:10.32604/iasc.2022.024023

    Abstract The technological advances made possible by the Internet, coupled with the unforeseen critical circumstances set in motion by the Covid-19 pandemic, have greatly increased the generation and transmission of medical images every day. Medical image transmission over an unsecured public network threatens the privacy of sensitive patient information. We have, in this paper, designed a new secure color medical image encryption algorithm based on binary plane decomposition, DNA (deoxyribonucleic acid) computing, and the chaotic Rössler dynamical system. At first, a bit-by-bit swap is performed on twenty four binary planes of the input image and encoded using DNA encoding rules. Thereafter,… More >

  • Open Access

    ARTICLE

    A Chaos Sparrow Search Algorithm with Logarithmic Spiral and Adaptive Step for Engineering Problems

    Andi Tang, Huan Zhou*, Tong Han, Lei Xie

    CMES-Computer Modeling in Engineering & Sciences, Vol.130, No.1, pp. 331-364, 2022, DOI:10.32604/cmes.2021.017310

    Abstract The sparrow search algorithm (SSA) is a newly proposed meta-heuristic optimization algorithm based on the sparrow foraging principle. Similar to other meta-heuristic algorithms, SSA has problems such as slow convergence speed and difficulty in jumping out of the local optimum. In order to overcome these shortcomings, a chaotic sparrow search algorithm based on logarithmic spiral strategy and adaptive step strategy (CLSSA) is proposed in this paper. Firstly, in order to balance the exploration and exploitation ability of the algorithm, chaotic mapping is introduced to adjust the main parameters of SSA. Secondly, in order to improve the diversity of the population… More >

  • Open Access

    ARTICLE

    Pressure-Induced Instability Characteristics of a Transient Flow and Energy Distribution through a Loosely Bent Square Duct

    Sreedham Chandra Adhikari1, Ratan Kumar Chanda1, Sidhartha Bhowmick1, Rabindra Nath Mondal1, Suvash Chandra Saha2,*

    Energy Engineering, Vol.119, No.1, pp. 429-451, 2022, DOI:10.32604/EE.2022.018145

    Abstract Due to widespread applications of the bent ducts in engineering fields such as in chemical, mechanical, bio-mechanical and bio-medical engineering, scientists have paid considerable attention to invent new characteristics of fluid flow in a bent duct (BD). In the ongoing study, a spectral-based numerical technique is applied to explore flow characteristics and energy distribution through a loosely bent square duct (BSD) of small curvature. Flow is accelerated due to combined action of the non-dimensional parameters; the Grashof number Gr (=1000), the curvature (=0.001), and the Prandtl number Pr (=7.0) over a wide domain of the Dean number . Fortran code… More >

  • Open Access

    ARTICLE

    Optimal Parameter Estimation of Transmission Line Using Chaotic Initialized Time-Varying PSO Algorithm

    Abdullah Shoukat1, Muhammad Ali Mughal1,*, Saifullah Younus Gondal1, Farhana Umer2, Tahir Ejaz3, Ashiq Hussain1

    CMC-Computers, Materials & Continua, Vol.71, No.1, pp. 269-285, 2022, DOI:10.32604/cmc.2022.021575

    Abstract Transmission line is a vital part of the power system that connects two major points, the generation, and the distribution. For an efficient design, stable control, and steady operation of the power system, adequate knowledge of the transmission line parameters resistance, inductance, capacitance, and conductance is of great importance. These parameters are essential for transmission network expansion planning in which a new parallel line is needed to be installed due to increased load demand or the overhead line is replaced with an underground cable. This paper presents a method to optimally estimate the parameters using the input-output quantities i.e., voltages,… More >

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