Gang Zhao^1,2, Jiaming Yang¹, Wei Wang^1,*, Yang Zhang¹, Xiaoxiao Du¹, Mayi Guo¹

CMES-Computer Modeling in Engineering & Sciences, Vol.123, No.3, pp. 1033-1059, 2020, DOI:10.32604/cmes.2020.09920 - 28 May 2020

Abstract In this paper, a new isogeometric topology optimization (ITO) method is proposed by using T-splines based isogeometric analysis (IGA). The arbitrarily shaped design domains, directly obtained from CAD, are represented by a single T-spline surface which overcomes the topological limitations of Non-Uniform Rational B-Spline (NURBS). The coefficients correlated with control points are directly used as design variables. Therefore, the T-spline basis functions applied for geometry description and calculation of structural response are simultaneously introduced to represent the density distribution. Several numerical examples show that the proposed approach leads to a coherent workflow to handle design More >

Yang Yang^1,*, Jing Dong¹, Chao Fang², Ping Xie³, Na An³

CMES-Computer Modeling in Engineering & Sciences, Vol.123, No.3, pp. 1015-1031, 2020, DOI:10.32604/cmes.2020.09404 - 28 May 2020

Abstract The development of cloud computing and virtualization technology has brought great challenges to the reliability of data center services. Data centers typically contain a large number of compute and storage nodes which may fail and affect the quality of service. Failure prediction is an important means of ensuring service availability. Predicting node failure in cloud-based data centers is challenging because the failure symptoms reflected have complex characteristics, and the distribution imbalance between the failure sample and the normal sample is widespread, resulting in inaccurate failure prediction. Targeting these challenges, this paper proposes a novel failure… More >

Tao Li¹, Qingsheng Yang^{1, *}, Lianhua Ma², Xiaojun Zhang^{2, *}

CMES-Computer Modeling in Engineering & Sciences, Vol.123, No.3, pp. 995-1014, 2020, DOI:10.32604/cmes.2020.09152 - 28 May 2020

Abstract Phase transition of hydrogel, which is polymerized by polymer network, can be regarded as the transition of polymer network stability. The stability of the polymer network might be changed when the external environment changed. This change will lead to the transformation of sensitive hydrogels stability, thus phase transition of hydrogel take place. Here, we present a new free density energy function, which considers the non-gaussianity of the polymer network, chains entanglement and functionality of junctions through adding Gent hyplastic model and Edwards-Vilgis slip-link model to Flory-Huggins theory. A program to calculate the phase transition temperature More >

Gökçe Yıldız¹, Gültekin Tınaztepe^{2, *}, Mehmet Sezer¹

CMES-Computer Modeling in Engineering & Sciences, Vol.123, No.3, pp. 973-993, 2020, DOI:10.32604/cmes.2020.09329 - 28 May 2020

Abstract In this article, we approximate the solution of high order linear Fredholm integro-differential equations with a variable coefficient under the initial-boundary conditions by Bell polynomials. Using collocation points and treating the solution as a linear combination of Bell polynomials, the problem is reduced to linear system of equations whose unknown variables are Bell coefficients. The solution to this algebraic system determines the approximate solution. Error estimation of approximate solution is done. Some examples are provided to illustrate the performance of the method. The numerical results are compared with the collocation method based on Legendre polynomials More >

Marjan Uddin^{1, *}, Najeeb Ullah², Syed Inayat Ali Shah²

CMES-Computer Modeling in Engineering & Sciences, Vol.123, No.3, pp. 957-972, 2020, DOI:10.32604/cmes.2020.08911 - 28 May 2020

Abstract In this work, a numerical scheme is constructed for solving nonlinear parabolictype partial-integro differential equations. The proposed numerical scheme is based on radial basis functions which are local in nature like finite difference numerical schemes. The radial basis functions are used to approximate the derivatives involved and the integral is approximated by equal width integration rule. The resultant differentiation matrices are sparse in nature. After spatial approximation using RBF the partial integro-differential equations reduce to the system of ODEs. Then ODEs system can be solved by various types of ODE solvers. The proposed numerical scheme More >

Şuayip Yüzbaşı^{1, *}, Murat Karaçayır¹

CMES-Computer Modeling in Engineering & Sciences, Vol.123, No.3, pp. 941-956, 2020, DOI:10.32604/cmes.2020.08938 - 28 May 2020

Abstract In this study, we present a numerical scheme similar to the Galerkin method in order to obtain numerical solutions of the Bagley Torvik equation of fractional order 3/2. In this approach, the approximate solution is assumed to have the form of a polynomial in the variable t = x^α , where α is a positive real parameter of our choice. The problem is firstly expressed in vectoral form via substituting the matrix counterparts of the terms present in the equation. After taking inner product of this vector with nonnegative integer powers of t up to a More >

An Chen^{1, *}

CMES-Computer Modeling in Engineering & Sciences, Vol.123, No.3, pp. 917-939, 2020, DOI:10.32604/cmes.2020.09224 - 28 May 2020

Abstract In this paper, two classes of Riesz space fractional partial differential equations including space-fractional and space-time-fractional ones are considered. These two models can be regarded as the generalization of the classical wave equation in two space dimensions. Combining with the Crank-Nicolson method in temporal direction, efficient alternating direction implicit Galerkin finite element methods for solving these two fractional models are developed, respectively. The corresponding stability and convergence analysis of the numerical methods are discussed. Numerical results are provided to verify the theoretical analysis. More >

Şuayip Yüzbaşı^1,*, Kamel Al-Khaled², Nurcan Baykuş Savaşaneril³, Devendra Kumar⁴

CMES-Computer Modeling in Engineering & Sciences, Vol.123, No.3, pp. 913-915, 2020, DOI:10.32604/cmes.2020.011225 - 28 May 2020

Abstract This article has no abstract. More >

Yongtong Li¹, Liang Gong^{1, *}, Hui Lu¹, Dexin Zhang¹, Bin Ding¹

CMES-Computer Modeling in Engineering & Sciences, Vol.123, No.2, pp. 895-912, 2020, DOI:10.32604/cmes.2020.09009 - 01 May 2020

Abstract In the present study, the thermal performance of metal foam heat sink was numerically investigated by adopting the local thermal non-equilibrium (LTNE) model and local thermal equilibrium (LTE) model. Temperature field distributions and temperature difference field distributions of solid and fluid phases were presented. Detailed thermal performance comparisons based on the LTE and LTNE models were evaluated by considering the effects of the relevant metal foam morphological and channel geometrical parameters. Results indicate that a distinct temperature difference exists between the solid and fluid phases when the LTNE effect is pronounced. The average Nusselt numbers… More >

Zelong Wang^{1, 2, 3, *}, Xiangui Liu^{1, 2, 3}, Haifa Tang³, Zhikai Lv³, Qunming Liu³

CMES-Computer Modeling in Engineering & Sciences, Vol.123, No.2, pp. 873-893, 2020, DOI:10.32604/cmes.2020.08993 - 01 May 2020

Abstract The Ensemble Kalman Filter (EnKF), as the most popular sequential data assimilation algorithm for history matching, has the intrinsic problem of high computational cost and the potential inconsistency of state variables updated at each loop of data assimilation and its corresponding reservoir simulated result. This problem forbids the reservoir engineers to make the best use of the 4D seismic data, which provides valuable information about the fluid change inside the reservoir. Moreover, only matching the production data in the past is not enough to accurately forecast the future, and the development plan based on the… More >