Home / Journals / CMES / Vol.117, No.1, 2018
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  • Open AccessOpen Access

    ARTICLE

    Increasing Distance Increasing Bits Substitution (IDIBS) Algorithm for Implementation of VTVB Steganography

    Sahib Khan1, *, Arslan Arif1, Syed Tahir Hussain Rizvi2, Nasir Ahmad3
    CMES-Computer Modeling in Engineering & Sciences, Vol.117, No.1, pp. 1-16, 2018, DOI:10.31614/cmes.2018.04141
    Abstract Cryptography and steganography are two important and related fields of infor- mation security. But, steganography is slightly different in the sense that it hides the ex- istence of secret information from unauthorized users. It is one of the most appealing research domains, have applications like copyright protection, data integrity protection and manipulation detection. Several steganography techniques have been proposed in literature. But, in this work a new information hiding algorithm is presented. The proposed technique de-correlates frequency components of cover image using discrete cosine transform and uses the least significant bits of frequency components for hiding secret information. The tech-nique… More >

  • Open AccessOpen Access

    ARTICLE

    Structural Design and Numerical Analysis of a Novel Biodegradable Zinc Alloy Stent

    Kun Peng1, Aike Qiao1,*, Makoto Ohta2, Narendra Kurnia Putra2, Xinyang Cui1, Yongliang Mu3, Hitomi Anzai2
    CMES-Computer Modeling in Engineering & Sciences, Vol.117, No.1, pp. 17-28, 2018, DOI:10.31614/cmes.2018.04113
    Abstract Biodegradable zinc alloy stents are a prospective solution for complications caused by the incompatibility between artery and permanent stents. However, insufficient scaffolding has limited the clinical application of biodegradable zinc alloy stents. Therefore, in this study, a new stent concept was designed to improve the scaffolding. The mechanical performances of the new and a traditional design stent were investigated and compared using finite element analysis (FEA). The new and traditional design stent were expanded to the intended radial displacement of 0.24 mm under the expansion pressure of 0.58 MPa and 0.45 MPa, respectively. Then, a pressure load of 0.35 MPa… More >

  • Open AccessOpen Access

    ARTICLE

    Improved Teaching-Learning-Based Optimization Algorithm for Modeling NOX Emissions of a Boiler

    Xia Li1,2, Peifeng Niu1,*, Jianping Liu2, Qing Liu2
    CMES-Computer Modeling in Engineering & Sciences, Vol.117, No.1, pp. 29-57, 2018, DOI:10.31614/cmes.2018.04020
    Abstract An improved teaching-learning-based optimization (I-TLBO) algorithm is proposed to adjust the parameters of extreme learning machine with parallel layer perception (PELM), and a well-generalized I-TLBO-PELM model is obtained to build the model of NOX emissions of a boiler. In the I-TLBO algorithm, there are four major highlights. Firstly, a quantum initialized population by using the qubits on Bloch sphere replaces a randomly initialized population. Secondly, two kinds of angles in Bloch sphere are generated by using cube chaos mapping. Thirdly, an adaptive control parameter is added into the teacher phase to speed up the convergent speed. And then, according to… More >

  • Open AccessOpen Access

    ARTICLE

    A Finite Element Study of the Influence of Graphite Nodule Characteristics on a Subsurface Crack in a Ductile Cast Iron Matrix under a Contact Load

    G. Suguinoshita1, C. H. Silva1, M. A. Luersen1, *
    CMES-Computer Modeling in Engineering & Sciences, Vol.117, No.1, pp. 59-71, 2018, DOI:10.31614/cmes.2018.01777
    Abstract This paper describes a study of the effects of graphite nodule characteristics on a subsurface crack in austempered ductile iron (ADI). A representative specimen of ADI, subjected to sliding contact load, is modeled using finite elements aiming to obtain the shear stress intensity factor (KII). The parameters varied were (i) the nodule diameter (two different values were considered), (ii) the distance between the nodule and the tip of the crack and (iii) the position of the load relative to the tip of the crack. The results of the numerical simulations show that the smaller diameter nodule has a larger influence… More >

  • Open AccessOpen Access

    ARTICLE

    Form Finding and Collapse Analysis of Cable Nets Under Dynamic Loads Based on Finite Particle Method

    Ying Yu1,*, Ping Xia1, Chunwei Yang1
    CMES-Computer Modeling in Engineering & Sciences, Vol.117, No.1, pp. 73-89, 2018, DOI:10.31614/cmes.2018.04063
    Abstract This paper presents form finding and collapse analysis of cable net structure under strong wind using the finite particle method (FPM). As a kind of particle method, the theoretical fundamentals of the FPM are given. Methods to handle geometric and material nonlinearities of cable element are proposed. The fracture criterion and model for cable element are built to simulate the failure of cable nets. The form-finding and load analysis of two cable nets are then performed in order to initialize the successive of nonlinear analysis. The failure progress of cable nets under dynamic loads is simulated, and the dynamic responses… More >

  • Open AccessOpen Access

    ARTICLE

    Numerical Shock Viscosity for Impact Analysis Using ALE Formulation

    Souli Mhamed1, Paul Du Bois2, Essam Al-Bahkali3,*
    CMES-Computer Modeling in Engineering & Sciences, Vol.117, No.1, pp. 91-107, 2018, DOI:10.31614/cmes.2018.03888
    Abstract When the simulation takes account of dissipative mechanisms, e.g. heat conduction and viscosity, the shocks become smeared out to produce thin layers of rapidly and continuously varying energy, density, pressure and velocity rather than discrete surfaces of mathematical discontinuity. In the mid twentieth century, Von Neumann and Richtmyer suggested the use of a viscous pressure term (bulk viscosity) in the equilibrium equations for ideal gases in order to examine the shock while avoiding numerical oscillations at the shock front. When the bulk viscosity is included in the conservation equations, the comprehensive physics present a continuous solution satisfying the Rankine-Hugoniot conditions.… More >

  • Open AccessOpen Access

    ARTICLE

    Analysis of High-Cr Cast Iron/Low Carbon Steel Wear-resistant Laminated Composite Plate Prepared by Hot-rolled Symmetrical Billet

    Yanwei Li1, Yugui Li1, Peisheng Han1, Shun Wang1, Zhengyi Jiang1,2, Xiaogang Wang1, *
    CMES-Computer Modeling in Engineering & Sciences, Vol.117, No.1, pp. 109-123, 2018, DOI:10.31614/cmes.2018.04077
    Abstract This study developed a new technology for preparing high-chromium cast iron (HCCI)/low-carbon steel (LCS) wear-resistant composite plates by hot rolling at a 1050 °C and a rolling speed of 0.2 m/s. The effects of different rolling reductions (30%, 45%, and 60%) on the microstructure (interface and HCCI layer) and mechanical properties (bonding strength, hardness, and wear resistance) of the composite plate were studied. SEM images showed that when the reduction was increased, no impurities and interlayers were found between the microscopic interfaces after hot rolling, and the bonding interface exhibited a wave-like shape. EDS analysis showed that the Cr element… More >

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