Daojian Zeng^1,3, Yuan Dai^1,3, Feng Li^1,3, R. Simon Sherratt², Jin Wang^3,*

CMC-Computers, Materials & Continua, Vol.55, No.1, pp. 121-136, 2018, DOI:10.3970/cmc.2018.055.121

Abstract Recently, many researchers have concentrated on using neural networks to learn features for Distant Supervised Relation Extraction (DSRE). These approaches generally use a softmax classifier with cross-entropy loss, which inevitably brings the noise of artificial class NA into classification process. To address the shortcoming, the classifier with ranking loss is employed to DSRE. Uniformly randomly selecting a relation or heuristically selecting the highest score among all incorrect relations are two common methods for generating a negative class in the ranking loss function. However, the majority of the generated negative class can be easily discriminated from positive class and will contribute… More >

S.D. Akbarov^1,2, M. Negin³

CMC-Computers, Materials & Continua, Vol.53, No.4, pp. 307-341, 2017, DOI:10.3970/cmc.2017.053.307

Abstract Dispersion of the generalized Rayleigh waves propagating in a covered half-space made of viscoelastic materials is investigated by utilizing the exact equations of the theory of linear viscoelasticity. The dispersion equation is obtained for an arbitrary type of hereditary operator of the materials of the constituents and a solution algorithm is developed for obtaining numerical results on the dispersion of the waves under consideration. Dispersion curves are presented for certain attenuation cases and the influence of the viscosity of the materials is studied through three rheological parameters of the viscoelastic materials which characterize the characteristic creep time, long-term values and… More >

A. M. Abd-Alla^{1, 2}, S. M. Abo-Dahab^{1, 3}, Aftab Khan⁴

CMC-Computers, Materials & Continua, Vol.53, No.1, pp. 49-72, 2017, DOI:10.3970/cmc.2017.053.052

Abstract In this paper, we investigated the propagation of the rmo elastic surface waves in fibre-reinforced anisotropic general viscoelastic media of higher order ofnth order, including time rate of strain under the influence of rotation.The general surface wave speed is derived to study the effects of rotation and thermal on surface waves. Particular cases for Stoneley, Love and Rayleigh waves are discussed. The results obtained in this investigation are more general in the sense that some earlier published results are obtained from our result as special cases. Our results for viscoelastic of order zero are well agreed to fibre-reinforced materials. Comparison… More >

Wenxiang Xu^1,2,3,4, Ganquan Yang⁵, Peng Lan², Huaifa Ma¹

CMC-Computers, Materials & Continua, Vol.52, No.1, pp. 25-40, 2016, DOI:10.3970/cmc.2016.052.025

Abstract Understanding the excluded volume of anisotropic particle is of great importance in the evaluation of continuum percolation and random packing behaviors of soft/hard particle systems in heterogeneous disordered media. In this work, we obtain the excluded volumes of several anisotropic convex particles including prolate spheroids, oblate spheroids, spherocylinders, and Platonic particles, using theoretical and numerical approaches. According to the second virial coefficient, we first present a theoretical scheme for determining the excluded volumes of anisotropic particles. Also, the mean tangent diameters of anisotropic convex particles are formulated by the quantitative stereology. Subsequently, Monte Carlo simulations are demonstrated to numerically evaluate… More >

H.-S. Wang^1,2, H. Jiang^3,4, B. Yang²

CMC-Computers, Materials & Continua, Vol.51, No.3, pp. 145-161, 2016, DOI:10.3970/cmc.2016.051.145

Abstract Potential field due to line sources residing on slender heterogeneities is involved in various areas, such as heat conduction, potential flow, and electrostatics. Often dipolar line sources are either prescribed or induced due to close interaction with other objects. Its calculation requires a higher-order scheme to take into account the dipolar effect as well as net source effect. In the present work, we apply such a higher-order line element method to analyze the potential field with cylindrical slender heterogeneities. In a benchmark example of two parallel rods, we compare the line element solution with the boundary element solution to show… More >

A. M. Abd-Alla^1,2,3, Mohamed I. A. Othman^1,4, S. M. Abo-Dahab^1,5

CMC-Computers, Materials & Continua, Vol.51, No.2, pp. 63-79, 2016, DOI:10.3970/cmc.2016.051.063

Abstract The aim of this paper is to study the reflection of plane harmonic waves from a semi-infinite elastic solid under the effect of magnetic field in a vacuum. The expressions for the reflection coefficients, which are the relations of the amplitudes of the reflected waves to the amplitude of the incident waves, are obtained. Similarly, the reflection coefficient ratio variations with the angle of incident under different conditions are shown graphically. Comparisons are made with the results predicted by the dual-phase-lag model and Lord-Shulman theory in the presence and absence of magnetic field. More >

Xing Wei^1,2, Wen Chen^1,3, Bin Chen¹

CMC-Computers, Materials & Continua, Vol.48, No.1, pp. 1-23, 2015, DOI:10.3970/cmc.2015.048.001

Abstract The thermal residual stress in the fabrication of functionally graded material (FGM) systems can give rise to various mechanical failures. For a FGM system under a given fabrication environment, the thermal residual stresses are determined by the spatial distribution of its constituent components. In this study, we optimize a Ni/Al₂O₃ FGM plate aiming at minimizing the thermal residual stresses through controlling its compositional distribution. Material properties are graded in the thickness direction following a power law distribution in terms of the volume fractions of constituents (P-FGM). An analytical model and a hybrid genetic algorithm with the pattern search are employed… More >

Tianhu He^1,2,3, Yongbin Ma^2,3, Shuanhu Shi³

CMC-Computers, Materials & Continua, Vol.47, No.1, pp. 15-29, 2015, DOI:10.3970/cmc.2015.047.015

Abstract The dynamic response of a two-dimensional generalized thermoelastic problem with temperature-dependent properties is investigated in the context of generalized thermoelasticity proposed by Lord and Shulman. The governing equations are formulated, and due to the nonlinearity and complexity of the governing equations resulted from the temperature-dependent properties, a numerical method, i.e., finite element method is adopted to solve such problem. By means of virtual displacement principle, the nonlinear finite element equations are derived. To demonstrate the solution process, a thermoelastic half-space subjected to a thermal shock on its bounding surface is considered in detail. The nonlinear finite element equations for this… More >

Mohamed I. A. Othman^1,2,3, W. M. Hasona^2,4, Nehal T. Mansour^2,5

CMC-Computers, Materials & Continua, Vol.45, No.3, pp. 203-220, 2015, DOI:10.3970/cmc.2015.045.203

Abstract The problem of the generalized thermoelastic medium for three different theories under the effect of a gravitational field is investigated. The Lord- Shulman, Green-Naghdi III, three-phase-lag theories are discussed with twotemperature. The normal mode analysis is used to obtain the analytical expressions of the displacement components, force stress, thermodynamic temperature and conductive temperature. The numerical results are given and presented graphically, when the thermal force is applied. Comparisons are made with the results predicted by three-phase-lag model, Green-Naghdi III and Lord-Shulman theories in the presence and absence of gravity as well as two temperature. More >

Ang Li¹, Guo-jian Shao^1,2, Pei-rong Du³, Sheng-yong Ding¹, Jing-bo Su⁴

CMC-Computers, Materials & Continua, Vol.45, No.1, pp. 17-38, 2015, DOI:10.3970/cmc.2015.045.017

Abstract This paper investigates the failure behaviors of stratified rocks under uniaxial compression using a digital image processing (DIP) based finite difference method (FDM). The two-dimensional (2D) mesostructure of stratified rocks, represented as the internal spatial distribution of two main rock materials (marble and greenschist), is first identified with the DIP technique. And then the binaryzation image information is used to generate the finite difference grid. Finally, the failure behaviors of stratified rock samples are simulated by FDM considering the inhomogeneity of rock materials. In the DIP, an image segmentation algorithm based on seeded region growing (SRG) is proposed, instead of… More >