Chao Ma, Yunkai Gao^*, Yuexing Duan, Zhe Liu

CMES-Computer Modeling in Engineering & Sciences, Vol.126, No.2, pp. 715-738, 2021, DOI:10.32604/cmes.2021.011187

Abstract Stress-based topology optimization is one of the most concerns of structural optimization and receives much attention in a wide range of engineering designs. To solve the inherent issues of stress-based topology optimization, many schemes are added to the conventional bi-directional evolutionary structural optimization (BESO) method in the previous studies. However, these schemes degrade the generality of BESO and increase the computational cost. This study proposes an improved topology optimization method for the continuum structures considering stress minimization in the framework of the conventional BESO method. A global stress measure constructed by p-norm function is treated as the objective function. To… More >

Jian Li¹, Yang Lv¹, Bin Ma^1,*, Meihong Yang², Chunpeng Wang¹, Yang Zheng³

Computer Systems Science and Engineering, Vol.35, No.6, pp. 513-521, 2020, DOI:10.32604/csse.2020.35.513

Abstract Digital video has become one of the most preferred ways for people to share information. Considering people tend to release illegal information in anonymous way, the problem of video source identification attracts more and more attention as an important part of multimedia forensics. The Photo-Response Non-Uniformity (PRNU) based algorithm shows to be a promising solution for the problem of video source identification. However, it is necessary to make a geometric transformation for testing PRNU noise to align it with the reference noise, due to the effect of video stabilization. This paper analyzes the three-dimensional (3D) characteristics of camera jitters and… More >

T. Vu-Huu^{1, 2}, C. Le-Thanh³, H. Nguyen-Xuan⁴, M. Abdel-Wahab^{5, 6, *}

CMC-Computers, Materials & Continua, Vol.62, No.3, pp. 1109-1123, 2020, DOI:10.32604/cmc.2020.07989

Abstract This paper presents an adapted stabilisation method for the equal-order mixed scheme of finite elements on convex polygonal meshes to analyse the high velocity and pressure gradient of incompressible fluid flows that are governed by Stokes equations system. This technique is constructed by a local pressure projection which is extremely simple, yet effective, to eliminate the poor or even non-convergence as well as the instability of equal-order mixed polygonal technique. In this research, some numerical examples of incompressible Stokes fluid flow that is coded and programmed by MATLAB will be presented to examine the effectiveness of the proposed stabilised method. More >

Qiancai Ma¹, Fengjie Gao², Yang Wang³, Qiuxiong Gou³, Liangyu Zhao^{1, *}

CMES-Computer Modeling in Engineering & Sciences, Vol.122, No.1, pp. 109-130, 2020, DOI:10.32604/cmes.2020.08109

Abstract Combining adaptive theory with an advanced second-order sliding mode control algorithm, a roll stabilization controller with aerodynamic disturbance and actuator failure consideration for spinning flight vehicles is proposed in this paper. The presented controller is summarized as an “observer-controller” system. More specifically, an adaptive second-order sliding mode observer is presented to select the proper design parameters and estimate the knowledge of aerodynamic disturbance and actuator failure, while the proposed roll stabilization control scheme can drive both roll angle and rotation rate smoothly converge to the desired value. Theoretical analysis and numerical simulation results demonstrate the effectiveness of the proposed controller. More >

Muyi Guo¹, Yan Cai¹, Zhiyong Li^1,2,*

Molecular & Cellular Biomechanics, Vol.16, Suppl.1, pp. 49-49, 2019, DOI:10.32604/mcb.2019.05727

Abstract Observational studies have identified angiogenesis from the adventitial vasa vasorum and intraplaque hemorrhage (IPH) as critical factors in atherosclerotic plaque progression and destabilization. Here we propose a mathematical model incorporating intraplaque neovascularization and hemodynamic calculation for the quantitative evaluation of atherosclerotic plaque hemorrhage. An angiogenic microvasculature based on histology of a patient’s carotid plaque is generated by two-dimensional nine-point model of endothelial cell migration. Three key cells (endothelial cells, smooth muscle cells and macrophages) and three key chemicals (vascular endothelial growth factors, extracellular matrix and matrix metalloproteinase) are involved in the intraplaque angiogenesis model, and described by the reaction-diffusion partial… More >

J. J. Wentzel^1,*

Molecular & Cellular Biomechanics, Vol.16, Suppl.1, pp. 7-8, 2019, DOI:10.32604/mcb.2019.05696

Abstract The pathophysiology of atherosclerosis is complex and multifactorial, involving systemic risk factors and biomechanical stimuli. Atherosclerotic plaques predominantly form in regions that are exposed to low shear stress of the blood at the vessel wall, whereas regions of moderate and high shear stress are generally protected. For more than 20 years, my research group performs studies to investigate the role of shear stress in atherosclerotic plaque formation and rupture in coronary and carotid arteries of patients and laboratory animals. For that reason, new technology was developed to 3D reconstruct arteries based on fusion of multiple invasive and non-invasive imaging modalities.… More >

Fadhel Aloulou^1,*, Sabrine Alila², Habib Sammouda¹

Journal of Renewable Materials, Vol.7, No.8, pp. 763-774, 2019, DOI:10.32604/jrm.2019.04071

Abstract The influence of nanofiberwood on the properties of the fresh condition of cement based mortars is not known in detail, despite recent advances in nanocellulose technology and it is related composite materials. Nanofiber wood from industrial waste, produced by high-pressure homogenization, was used as cement partial replacement for cement paste at a content ranging from 0% to 2% by weight of cement. The effect of the nanofiber wood content on the porosity, the compressive strength and the degree of hydration of the cement was investigated. Results have shown an improvement in the compressive strength by more than 50% with 1%… More >

Durgesh Vikram¹, Sanjay Mittal², Partha Chakroborty¹

CMES-Computer Modeling in Engineering & Sciences, Vol.79, No.3&4, pp. 237-260, 2011, DOI:10.3970/cmes.2011.079.237

Abstract A stabilized finite element formulation is presented to solve the governing equations for traffic flow. The flow is assumed to be one-dimensional. Both, PW-type (Payne-Whitham) 2-equation models and the LWR-type (Lighthill-Whitham-Richards) 1-equation models are considered. The SUPG (Streamline-Upwind/Petrov-Galerkin) and shock capturing stabilizations are utilized. These stabilizations are sufficient for the 1-equation models. However, an additional stabilization is necessary for the 2-equation models. For the first time, such a stabilization is proposed. It arises from the coupling between the two equations and is termed as IEPG (Inter-Equation/Petrov-Galerkin) stabilization. Two behavioral models are studied: Greenshields' (GS) and Greenberg's (GB) models. Numerical tests… More >

Marcello Lappa¹

FDMP-Fluid Dynamics & Materials Processing, Vol.1, No.2, pp. 171-188, 2005, DOI:10.3970/fdmp.2005.001.171

Abstract The paper presents a comparative and critical analysis of some theoretical/experimental/numerical arguments concerning the possible stabilization of the surface-tension-driven (Marangoni) flow in the Floating Zone technique and in various related fluid-dynamic models. It is conceived as a natural extension of the focused overview published in Cryst. Res. Tech. 40(6), 531, (2005) where much room was devoted to discuss the intrinsic physical mechanisms responsible for three-dimensional and oscillatory flows in a variety of technological processes. Here, a significant effort is provided to illustrate the genesis of possible control strategies (many of which are still in a very embryonic condition), the underlying… More >