Yiru Sun^1,2, Yuling Chen^1,*, Haseeb Ahmad³, Zhanhong Wei⁴

CMC-Computers, Materials & Continua, Vol.59, No.1, pp. 215-227, 2019, DOI:10.32604/cmc.2019.05253

Abstract In this paper, we propose an asymmetric controlled bidirectional transmission protocol. In the protocol, by using the thirteen-qubit entangled state as the quantum channel, Alice can realize the transmission of a two-qubit equatorial state for Bob and Bob can transmit a four-qubit equatorial state for Alice under the control of Charlie. Firstly, we give the construction of the quantum channel, which can be done by performing several H and CNOT operations. Secondly, through implementing the appropriate measurements and the corresponding recovery operations, the desired states can be transmitted simultaneously, securely and deterministically. Finally, we analyze the performance of the protocol,… More >

Zhiguo Qu^1,*, Tiancheng Zhu², Jinwei Wang¹, Xiaojun Wang³

CMC-Computers, Materials & Continua, Vol.56, No.1, pp. 47-59, 2018, DOI: 10.3970/cmc.2018.02215

Abstract In this paper, a novel quantum steganography protocol based on Brown entangled states is proposed. The new protocol adopts the CNOT operation to achieve the transmission of secret information by the best use of the characteristics of entangled states. Comparing with the previous quantum steganography algorithms, the new protocol focuses on its anti-noise capability for the phase-flip noise, which proved its good security resisting on quantum noise. Furthermore, the covert communication of secret information in the quantum secure direct communication channel would not affect the normal information transmission process due to the new protocol’s good imperceptibility. If the number of… More >

Zihao Yang¹, Junzhi Cui², Yufeng Nie¹, Yatao Wu¹, Bin Yang³, Bo Wu⁴

CMC-Computers, Materials & Continua, Vol.38, No.3, pp. 175-194, 2013, DOI:10.3970/cmc.2013.038.175

Abstract This study is concerned with the microstructural modeling and mechanical properties computation of three-dimensional (3D) 4-directional braided composites. Microstructure of the braided composite determines its mechanical properties and a precise geometry modeling of the composite is essential to predict the material properties. On the basis of microscopic observation, a new parameterized microstructural unit cell model is established in this paper. And this model truly simulates the microstructure of the braided composites. Furthermore, the mathematical relationships among the structural parameters, including the braiding angle, fiber volume fraction and braiding bitch, are derived. By using the unit cell model, the second-order two-scale… More >

Chenpeng Song^1,2, Yulong Chen^3,*, Jiehao Wang^2,*

CMES-Computer Modeling in Engineering & Sciences, Vol.120, No.3, pp. 779-797, 2019, DOI:10.32604/cmes.2019.07000

Abstract Hydraulic fracturing has been applied to enhance CBM production and prevent gas dynamical hazard in underground coal mines in China. However, affected by in situ stress orientation, hydrofracture can hardly continuously propagate within coal seam but may easily extend to the adjacent roof-floor strata, causing ineffective permeability enhancement in coal seam and increasing the risk of gas transfinite during mining coal. Thus, it is very necessary to artificially control the propagation direction of hydrofracture and make it well-aligned in large scale in coal seam. In this study, a method for controlling propagation direction of hydrofracture by multi-boreholes is investigated by… More >

Tianliang Qin¹, Libin Zhao^2,3,*, Jifeng Xu¹, Fengrui Liu^2,3,4, Jianyu Zhang⁵

CMES-Computer Modeling in Engineering & Sciences, Vol.118, No.1, pp. 157-176, 2019, DOI:10.31614/cmes.2019.04379

Abstract Progressive damage models (PDMs) have been increasingly used to simulate the failure process of composite material structures. To accurately simulate the damage in each ply, 3D PDMs of composite materials have received more attention recently. A characteristic element length (CEL), which is an important dimensional parameter of PDMs for composite materials, is quite difficult to obtain for 3D elements, especially considering the crack directions during damage propagation. In this paper, CEL models for 3D elements in PDMs of unidirectional composite structures are presented, and their approximate formulae are deduced. The damage in unidirectional composite materials can be divided into fiber… More >

Sun-Beom Kwon¹, Jae-Myung Lee^1,*

CMES-Computer Modeling in Engineering & Sciences, Vol.118, No.1, pp. 41-89, 2019, DOI:10.31614/cmes.2019.03879

Abstract A direct time integration scheme based on Gauss-Legendre quadrature is proposed to solve problems in linear structural dynamics. The proposed method is a one-parameter non-dissipative scheme. Improved stability, accuracy, and dispersion characteristics are achieved using appropriate values of the parameter. The proposed scheme has second-order accuracy with and without physical damping. Moreover, its stability, accuracy, and dispersion are analyzed. In addition, its performance is demonstrated by the two-dimensional scalar wave problem, the single-degree-of-freedom problem, two degrees-of-freedom spring system, and beam with boundary constraints. The wave propagation problem is solved in the high frequency wave regime to demonstrate the advantage of… More >

C. F. Loeffle¹, L. Zamprogno², W. J. Mansur³, A. Bulcão⁴

CMES-Computer Modeling in Engineering & Sciences, Vol.113, No.3, pp. 367-387, 2017, DOI:10.3970/cmes.2017.113.387

Abstract This study evaluates the effectiveness of a new technique that transforms domain integrals into boundary integrals that is applicable to the boundary element method. Simulations were conducted in which two-dimensional surfaces were approximated by interpolation using radial basis functions with full and compact supports. Examples involving Poisson’s equation are presented using the boundary element method and the proposed technique with compact radial basis functions. The advantages and the disadvantages are examined through simulations. The effects of internal poles, the boundary mesh refinement and the value for the support of the radial basis functions on performance are assessed. More >

Dengfeng Su¹, Yong Kang^1,2,*, Xiaochuan Wang², andan Zheng¹, DongyangLi¹, Binyuan Yan¹, Fuwen Yan¹

CMES-Computer Modeling in Engineering & Sciences, Vol.111, No.5, pp. 375-393, 2016, DOI:10.3970/cmes.2016.111.375

Abstract Tunnel though coal seam is one of the most difficult tunnels since its risk of coal and gas outburst and the complex geological conditions. According to the directional cutting of water jet and the characteristic of the coal seam and rock mass, this paper presents a new method of tunnelling though coal seam assisted by water jet slotting, which can be divided into improving permeability of coal seam and directional cracking in the rock mass. The mechanism of improving permeability of coal seam was stated, and the crack criterion of rock during blasting was established based on fracture theory. Then,… More >

Maruthi R. Akella¹, Sofokli Cakalli²

CMES-Computer Modeling in Engineering & Sciences, Vol.111, No.2, pp. 119-127, 2016, DOI:10.3970/cmes.2016.111.119

Abstract The planar motion of a particle within an arbitrary potential field is considered. The particle is additionally subject to an external force wherein the applied thrust-acceleration is constrained to remain normal to the velocity vector. The system is thus non-conservative but since the thrust force is non-working, the total energy is a conserved quantity. Under this setting, a major result of fundamental importance is established in this paper: that the flight direction angle (more precisely, the sine of the angle between the position and velocity vectors) is shown to always satisfy a linear first-order differential equation with variable coefficients that… More >

V. Vittaldev¹, R. P. Russell²

CMES-Computer Modeling in Engineering & Sciences, Vol.111, No.1, pp. 83-117, 2016, DOI:10.3970/cmes.2016.111.083

Abstract Monte Carlo simulations are an accurate but computationally expensive procedure for approximating the resultant non-Gaussian probability density function (PDF) after propagation of an initial Gaussian PDF through a nonlinear function. Univariate splitting libraries for Gaussian Mixture Models (GMMs) exist with up to five elements in the literature. The number of splits are extended in the present work by generating three homoscedastic univariate splitting libraries with up to 39 elements. Mulitvariate GMMs are typically handled with splits along a single direction. Instead, we generate a regular multidirectional grid over the initial multivariate Gaussian distribution by recursively applying the splitting library along… More >