Chang-Chun Lee^1,*, Pei-Chen Huang¹

CMES-Computer Modeling in Engineering & Sciences, Vol.120, No.2, pp. 239-260, 2019, DOI:10.32604/cmes.2019.06859

Abstract This research reviews the application of computational mechanics on the properties of nano/micro scaled thin films, in which the application of different computational methods is included. The concept and fundamental theories of concerned applications, material behavior estimations, interfacial delamination behavior, strain engineering, and multilevel modeling are thoroughly discussed. Moreover, an example of an interfacial adhesion estimation is presented to systematically estimate the related mechanical reliability issue in the microelectronic industry. The presented results show that the peeled mode fracture is the dominant delamination behavior of layered material system, with high stiffness along the bonding interface. However, the shear mode fracture… More >

Sahib Khan^1,*, M A Irfan¹, Arslan Arif¹, Syed Tahir Hussain Rizvi², Asma Gul³, Muhammad Naeem⁴, Nasir Ahmad⁵

CMES-Computer Modeling in Engineering & Sciences, Vol.118, No.3, pp. 529-546, 2019, DOI:10.31614/cmes.2019.06179

Abstract This work presents a new method of data hiding in digital images, in discrete cosine transform domain. The proposed method uses the least significant bits of the medium frequency components of the cover image for hiding the secret information, while the low and high frequency coefficients are kept unaltered. The unaltered low frequency DCT coefficients preserves the quality of the smooth region of the cover image, while no changes in the high DCT coefficient preserve the quality of the edges. As the medium frequency components have less contribution towards energy and image details, so the modification of these coefficients for… More >

Shurong Li^1,*, Yulei Ge², Renlin Zang²

CMES-Computer Modeling in Engineering & Sciences, Vol.114, No.1, pp. 95-116, 2018, DOI:10.3970/cmes.2018.114.095

Abstract In this paper, an interacting multiple-model (IMM) method based on data-driven identification model is proposed for the prediction of nonlinear dynamic systems. Firstly, two basic models are selected as combination components due to their proved effectiveness. One is Gaussian process (GP) model, which can provide the predictive variance of the predicted output and only has several optimizing parameters. The other is regularized extreme learning machine (RELM) model, which can improve the over-fitting problem resulted by empirical risk minimization principle and enhances the overall generalization performance. Then both of the models are updated continually using meaningful new data selected by data… More >

Ali Bekir YILDIZ¹

CMES-Computer Modeling in Engineering & Sciences, Vol.113, No.3, pp. 261-274, 2017, DOI:10.3970/cmes.2017.113.273

Abstract In this paper, a computer-based systematic and efficient formulation method is presented for obtaining the network functions of linear or linearized time-invariant dynamic circuits. The method employs the modified nodal approach to obtain the system equations. The technique is based on developing a matrix formulation for modelling network functions. By using both symbolic manipulation of algebraic expressions and numeric processes, the network functions are expressed with a matrix-based method. Application examples are given to illustrate the features of the method. More >

Meng Li^1,2, Jixiong Zhang^1,3, Nan Zhou¹, Qiang Zhang¹

CMES-Computer Modeling in Engineering & Sciences, Vol.113, No.2, pp. 183-194, 2017, DOI:10.3970/cmes.2017.113.189

Abstract To study the influence of coal mining on the stability of river levees, a mechanical model of mining-induced river levee deformation was established. This was based on the mining-induced deformation characteristics of river levees and the application of a typical surface subsidence function. Meanwhile, a failure criterion was proposed for river levees. Using some examples, the deformation of, and stress distribution through, river levees under the influence of mining were obtained: the maximum tensile stress on the bottom of the river levee was less than the tensile strength, under which circumstance the river levee remained undamaged. Meanwhile, this research analyzed… More >

T. V. Viknesh¹, V. Manik,an

CMES-Computer Modeling in Engineering & Sciences, Vol.113, No.1, pp. 109-116, 2017, DOI:10.3970/cmes.2017.113.107

Abstract The working of Canonical switching cell (CSC) converter was studied and its equivalent circuit during ON and OFF states were obtained. State space model of CSC converter in ON and OFF states were developed using the Kirchhoff laws. The state space matrices were used to construct the transfer functions of ON & OFF states. The step response of the converter was simulated using MATLAB. The step response curve was obtained using different values of circuit components (L, C1, C2 and RL)and optimized. The characteristic parameters such as rise time, overshoot, settling time, steady state error and stability were determined using… More >

M. Ohsaki¹, T. Miyamura², J. Y. Zhang³

CMES-Computer Modeling in Engineering & Sciences, Vol.111, No.4, pp. 303-333, 2016, DOI:10.3970/cmes.2016.111.303

Abstract A simple constitutive model, called semi-implicit model, for cyclic loading is proposed for steel materials used for structures such as building frames in civil engineering. The constitutive model is implemented in the E-Simulator, which is a software package for large-scale seismic response analysis. The constitutive relation is defined in an algorithmic manner based on the piecewise linear combined isotropic-kinematic hardening. Different rules are used for the first and subsequent loading states to incorporate characteristics such as yield plateau and Bauschinger effect of rolled mild steel materials. An optimization method is also presented for parameter identification from the results of cyclic… More >

Hui Yin¹, Dejie Yu^1,2, Shengwen Yin¹, Baizhan Xia¹

CMES-Computer Modeling in Engineering & Sciences, Vol.109-110, No.3, pp. 221-246, 2015, DOI:10.3970/cmes.2015.109.221

Abstract This paper presents a new hybrid Chebyshev-perturbation method (HCPM) for the prediction of acoustic field with random and interval parameters. In HCPM, the perturbation method based on the first-order Taylor series that accounts for the random uncertainty is organically integrated with the first-order Chebyshev polynomials that deal with the interval uncertainty; specifically, a random interval function is firstly expanded with the first-order Taylor series by treating the interval variables as constants, and the expressions of the expectation and variance can be obtained by using the random moment method; then the expectation and variance of the function are approximated by using… More >

Liming Yang¹, Yongping Gao², Qun Sun³

CMES-Computer Modeling in Engineering & Sciences, Vol.104, No.6, pp. 493-506, 2015, DOI:10.3970/cmes.2015.104.493

Abstract Minimax probability machine (MPM) has been recently proposed and shown its advantage in pattern recognition. In this paper, we present a new minimax probabilistic approach (MPA),which can provide an explicit lower bound on prediction accuracy. Applying the Chebyshev-Cantelli inequality, the MPA is posed as a second order cone program formulation and solved effectively. Following that, this method is exploited directly to recognize the purity of hybrid seeds using near-infrared spectroscopic data. Experimental results in different spectral regions show that the proposed MPA is competitive with the existing minimax probability machine and support vector machine in generalization, while requires less computational… More >

X. X. Cui¹, X. Zhang^1,2, X. Zhou³, Y. Liu¹, F. Zhang¹

CMES-Computer Modeling in Engineering & Sciences, Vol.98, No.6, pp. 565-599, 2014, DOI:10.3970/cmes.2014.098.565

Abstract The material point method (MPM) discretizes the material domain by a set of particles, and has showed advantages over the mesh-based methods for many challenging problems associated with large deformation. However, at the same time, it requires more computational resource and has difficulties to construct high order scheme when simulating the fluid in high explosive (HE) explosion problems. A coupled finite difference material point (CFDMP) method is proposed through a bridge region to combine the advantages of the finite difference method (FDM) and MPM. It solves a 3D HE explosion and its interaction with the surrounding structures by dividing the… More >