Diptiranjan Behera^1,2, Hong-Zhong Huang¹, S. Chakraverty³

CMES-Computer Modeling in Engineering & Sciences, Vol.108, No.2, pp. 67-87, 2015, DOI:10.3970/cmes.2015.108.067

Abstract Fuzzy systems of linear equations play a vital role in various applications of engineering, science and finance problems. This paper proposes a new method for solving Fully Fuzzy System of Linear Equations (FFSLE) using the linear programming problem approach. There is no restriction on the elements of coefficient matrix. The proposed method is able to solve the system, when the elements of the fuzzy unknown vector are both non-negative and non-positive. Triangular convex normalized fuzzy sets are considered for the present analysis. Known example problems are solved and compared with the results of existing methods More >

Liming Yang^1,2, Junjian Bai¹, Qun Sun³

CMES-Computer Modeling in Engineering & Sciences, Vol.108, No.1, pp. 49-65, 2015, DOI:10.3970/cmes.2015.108.049

Abstract Extreme learning machine (ELM) has demonstrated great potential in machine learning and data mining fields owing to its simplicity, rapidity and good generalization performance. In this work, a general framework for ELM regression is first investigated based on least absolute deviation (LAD) estimation (called LADELM), and then we develop two regularized LADELM formulations with the l₂-norm and l₁-norm regularization, respectively. Moreover, the proposed models are posed as simple linear programming or quadratic programming problems. Furthermore, the proposed models are used directly to analyze the hard rate of licorice seeds using near-infrared spectroscopy data. Experimental results on More >

Isa Ahmadi¹, M.M. Aghdam²

CMES-Computer Modeling in Engineering & Sciences, Vol.108, No.1, pp. 21-48, 2015, DOI:10.3970/cmes.2015.108.021

Abstract In this study, a truly meshless method based on the meshless local Petrov-Galerkin method is formulated for analysis of the elastic-plastic behavior of heterogeneous solid materials. The incremental theory of plasticity is employed for modeling the nonlinearity of the material behavior due to plastic strains. The well-known Prandtl-Reuss flow rule of plasticity is used as the constitutive equation of the material. In the presented method, the computational cost is reduced due to elimination of the domain integration from the formulation. As a practical example, the presented elastic-plastic meshless formulation is employed for micromechanical analysis of More >

Chen Chang¹, Su Shaohui¹, Chen Guojin¹

CMES-Computer Modeling in Engineering & Sciences, Vol.108, No.1, pp. 1-20, 2015, DOI:10.3970/cmes.2015.108.001

Abstract For modeling and simulation of energy system in lunar vehicle, there are many special purpose tools along with their models, such as PSIM, EMTP/ATP, could be used. But the models in these tools lack of flexibility and are not open to the end-user. Models developed in one tool can’t be conveniently used in others because of the barriers among these simulators. Usually these models are expressed in an explicit state-space form and their topology gets lost and future extension and reuse of the model is almost impossible. In order to solve those problems, a flexible… More >

Marjan Uddin^1,2, Hazrat Ali¹, Amjad Ali¹

CMES-Computer Modeling in Engineering & Sciences, Vol.107, No.6, pp. 463-479, 2015, DOI:10.3970/cmes.2015.107.463

Abstract This work explores the application of kernel based local meshless method for solving multi-dimensional wave equations in irregular domain. The method is tested for various types of boundary conditions in irregular shaped domain. The method is capable of solving multi-dimension large scaled problems in complex shaped domain. More >

I. Kvasnica¹, P. Kvasnica²

CMES-Computer Modeling in Engineering & Sciences, Vol.107, No.6, pp. 447-462, 2015, DOI:10.3970/cmes.2015.107.447

Abstract The issue of simulation of decentralized mathematical models is discussed in the paper. The authors’ knowledge is based on a theory of design of decentralized computer control systems. Their knowledge is gained in the process of designing mathematical models that are simulated. A decomposed control system is required to meet the conditions of observation and control. The methodology of a multi-model design is based on main principles of object orientation such as abstraction, hierarchy, and modularity. Modelling on a parallel architecture has an impact on a simulator system. The system is defined by the equations More >

Xiaojing Liu^1,2, Jizeng Wang¹, Youhe Zhou¹

CMES-Computer Modeling in Engineering & Sciences, Vol.107, No.6, pp. 433-446, 2015, DOI:10.3970/cmes.2015.107.433

Abstract Based on the approximation scheme for a L²-function defined on a three-dimensional bounded space by combining techniques of boundary extension and Coiflet-type wavelet expansion, a modified wavelet Galerkin method is proposed for solving three-dimensional Poisson problems with various boundary conditions. Such a wavelet-based solution procedure has been justified by solving five test examples. Numerical results demonstrate that the present wavelet method has an excellent numerical accuracy, a fast convergence rate, and a very good capability in handling complex boundary conditions. More >

W.C. Wang¹, F.L. Chang², Y.L. Liu¹, X. J. Wu¹

CMES-Computer Modeling in Engineering & Sciences, Vol.107, No.5, pp. 411-431, 2015, DOI:10.3970/cmes.2015.107.411

Abstract The detection of macroscopic irregularities is an essential procedure during the production of gears, and it helps to guarantee the quality of electromechanical transmission equipment. The working principles of template matching and the image nonequivalence operation are described in detail in this paper. Gray-level transformation, edge-preserving filtering, image segmentation, feature extraction, and pattern recognition were analyzed, leading to the design of a defect detection system based on template matching and the nonequivalence operation, followed by the development of a hardware platform and application software for the system. The experimental results indicate that the proposed detection More >

C.V. Nastos, T.C. Theodosiou, C.S. Rekatsinas, D.A. Saravanos¹

CMES-Computer Modeling in Engineering & Sciences, Vol.107, No.5, pp. 379-409, 2015, DOI:10.3970/cmes.2015.107.379

Abstract A computationally efficient numerical method is developed for the prediction of transient response in orthotropic rod and beam structures. The method takes advantage of the outstanding properties of compactly supported Daubechies wavelet scaling functions for the spatial approximation of displacements in a finite domain of the structure, hence is termed Finite Wavelet Domain (FWD) method. The basic principles and advantages of the method are presented and the discretization of the equations of motion is formulated for one-dimensional structures. Numerical results for the simulation of propagating guided waves in rods and strips are presented and compared More >

A. Tadeu¹, P. Stanak², J. Antonio¹, J. Sladek², V. Sladek²

CMES-Computer Modeling in Engineering & Sciences, Vol.107, No.5, pp. 345-378, 2015, DOI:10.3970/cmes.2015.107.345

Abstract This paper implements a numerical method based on the mutual coupling of the boundary element method (BEM) and the meshless local Petrov-Galerkin (MLPG) method to simulate elastic wave propagation in fluid-filled boreholes. The fluid-solid interaction is solved in the frequency domain assuming longitudinally invariant geometry in the axial direction (2.5D formulation).
This model is used to assess the influence of the non-homogeneous material properties of a borehole wall that can be caused by a damaged zone, construction process or the ageing of material. The BEM is used to model propagation within the unbounded homogeneous domain… More >