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  • Open Access


    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


    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


    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


    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


    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 >

  • Open Access


    Chaos-Based Cryptographic Mechanism for Smart Healthcare IoT Systems

    Muhammad Samiullah1, Waqar Aslam1, Arif Mehmood1, Muhammad Saeed Ahmad2, Shafiq Ahmad3, Adel M. Al-Shayea3, Muhammad Shafiq4,*

    CMC-Computers, Materials & Continua, Vol.71, No.1, pp. 753-769, 2022, DOI:10.32604/cmc.2022.020432

    Abstract Smart and interconnected devices can generate meaningful patient data and exchange it automatically without any human intervention in order to realize the Internet of Things (IoT) in healthcare (HIoT). Due to more and more online security and data hijacking attacks, the confidentiality, integrity and availability of data are considered serious issues in HIoT applications. In this regard, lightweight block ciphers (LBCs) are promising in resource-constrained environment where security is the primary consideration. The prevalent challenge while designing an LBC for the HIoT environment is how to ascertain platform performance, cost, and security. Most of the existing LBCs primarily focus on… More >

  • Open Access


    Uncertainty Analysis of Seepage-Induced Consolidation in a Fractured Porous Medium

    Lingai Guo1, Marwan Fahs2, Hussein Hoteit3, Rui Gao1,*, Qian Shao1,*

    CMES-Computer Modeling in Engineering & Sciences, Vol.129, No.1, pp. 279-297, 2021, DOI:10.32604/cmes.2021.016619

    Abstract Numerical modeling of seepage-induced consolidation process usually encounters significant uncertainty in the properties of geotechnical materials. Assessing the effect of uncertain parameters on the performance variability of the seepage consolidation model is of critical importance to the simulation and tests of this process. To this end, the uncertainty and sensitivity analyses are performed on a seepage consolidation model in a fractured porous medium using the Bayesian sparse polynomial chaos expansion (SPCE) method. Five uncertain parameters including Young’s modulus, Poisson’s ratio, and the permeability of the porous matrix, the permeability within the fracture, and Biot’s constant are studied. Bayesian SPCE models… More >

  • Open Access


    Using Big Data to Discover Chaos in China’s Futures Market During COVID-19

    Lin Tie1, Bin Huang1, Bin Pan1, Guang Sun1,2,*

    CMC-Computers, Materials & Continua, Vol.69, No.3, pp. 3095-3107, 2021, DOI:10.32604/cmc.2021.019363

    Abstract COVID-19 was first reported in China and quickly spread throughout the world. Weak investor confidence in government efforts to control the pandemic seriously affected global financial markets. This study investigated chaos in China’s futures market during COVID-19, focusing on the degree of chaos at different periods during the pandemic. We constructed a phase diagram to observe the attractor trajectory of index futures (IFs). During the COVID-19 outbreak, overall chaos in China’s futures market was increasing, and there was a clear correlation between market volatility and the macroenvironment (mainly government regulation). The Hurst index, calculated by rescaled range (R/S) analysis, was… More >

  • Open Access


    An Uncertainty Analysis Method for Artillery Dynamics with Hybrid Stochastic and Interval Parameters

    Liqun Wang1, Zengtao Chen2, Guolai Yang1,*

    CMES-Computer Modeling in Engineering & Sciences, Vol.126, No.2, pp. 479-503, 2021, DOI:10.32604/cmes.2021.011954

    Abstract This paper proposes a non-intrusive uncertainty analysis method for artillery dynamics involving hybrid uncertainty using polynomial chaos expansion (PCE). The uncertainty parameters with sufficient information are regarded as stochastic variables, whereas the interval variables are used to treat the uncertainty parameters with limited stochastic knowledge. In this method, the PCE model is constructed through the Galerkin projection method, in which the sparse grid strategy is used to generate the integral points and the corresponding integral weights. Through the sampling in PCE, the original dynamic systems with hybrid stochastic and interval parameters can be transformed into deterministic dynamic systems, without changing… More >

  • Open Access


    SDN Controller Allocation and Assignment Based on Multicriterion Chaotic Salp Swarm Algorithm

    Suresh Krishnamoorthy1,*, Kumaratharan Narayanaswamy2

    Intelligent Automation & Soft Computing, Vol.27, No.1, pp. 89-102, 2021, DOI:10.32604/iasc.2021.013643

    Abstract Increase in demand for multimedia and quality services requires 5G networks to resolve issues such as slicing, allocation, forwarding, and control using techniques such as software-defined networking (SDN) and network function virtualization. In this study, the optimum number of SDN multi-controllers are implemented based on a multi-criterion advanced genetic algorithm that takes into consideration three key parameters: Switch controller latency, hopcount, and link utilization. Preprocessing is the first step, in which delay, delay paths, hopcount, and hoppaths are computed as an information matrix (Infomat). Randomization is the second step, and consists of initially placing controllers randomly, followed by an analytical… More >

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