Jiayu Ren^1,*, Yoshihisa Fujita², Susumu Nakata²

CMES-Computer Modeling in Engineering & Sciences, Vol.136, No.3, pp. 2111-2125, 2023, DOI:10.32604/cmes.2023.025970

Abstract Implicit surface generation based on the interpolation of surface points is one of the well-known modeling methods in the area of computer graphics. Several methods for the implicit surface reconstruction from surface points have been proposed on the basis of radial basis functions, a weighted sum of local functions, splines, wavelets, and combinations of them. However, if the surface points contain errors or are sparsely distributed, irregular components, such as curvature-shaped redundant bulges and unexpectedly generated high-frequency components, are commonly seen. This paper presents a framework for restoring irregular components generated on and around surfaces. Users are assumed to specify… More >

Salvatore Brischetto^*, Roberto Torre, Domenico Cesare

CMES-Computer Modeling in Engineering & Sciences, Vol.136, No.3, pp. 2551-2594, 2023, DOI:10.32604/cmes.2023.026312

Abstract This new work aims to develop a full coupled thermomechanical method including both the temperature profile and displacements as primary unknowns of the model. This generic full coupled 3D exact shell model permits the thermal stress investigation of laminated isotropic, composite and sandwich structures. Cylindrical and spherical panels, cylinders and plates are analyzed in orthogonal mixed curved reference coordinates. The 3D equilibrium relations and the 3D Fourier heat conduction equation for spherical shells are coupled and they trivially can be simplified in those for plates and cylindrical panels. The exponential matrix methodology is used to find the solutions of a… More >

Daisuke Ishihara^1,*, Prakasha Chigahalli Ramegowda², Shoichi Aikawa¹, Naoki Iwamaru¹

CMES-Computer Modeling in Engineering & Sciences, Vol.136, No.2, pp. 1187-1206, 2023, DOI:10.32604/cmes.2023.024614

Abstract This paper demonstrates the importance of three-dimensional (3-D) piezoelectric coupling in the electromechanical behavior of piezoelectric devices using three-dimensional finite element analyses based on weak and strong coupling models for a thin cantilevered piezoelectric bimorph actuator. It is found that there is a significant difference between the strong and weak coupling solutions given by coupling direct and inverse piezoelectric effects (i.e., piezoelectric coupling effect). In addition, there is significant longitudinal bending caused by the constraint of the inverse piezoelectric effect in the width direction at the fixed end (i.e., 3-D effect). Hence, modeling of these effects or 3-D piezoelectric coupling… More >

Wenhui Li¹, Dazhi Wang^1,*, Shuo Cao², Deshan Kong¹, Sihan Wang¹, Zhong Hua¹

CMC-Computers, Materials & Continua, Vol.75, No.1, pp. 259-276, 2023, DOI:10.32604/cmc.2023.034622

Abstract In this paper, the axial-flux permanent magnet driver is modeled and analyzed in a simple and novel way under three-dimensional cylindrical coordinates. The inherent three-dimensional characteristics of the device are comprehensively considered, and the governing equations are solved by simplifying the boundary conditions. The axial magnetization of the sector-shaped permanent magnets is accurately described in an algebraic form by the parameters, which makes the physical meaning more explicit than the purely mathematical expression in general series forms. The parameters of the Bessel function are determined simply and the magnetic field distribution of permanent magnets and the air-gap is solved. Furthermore,… More >

Muhammad Azhar^1,*, Sehat Ullah¹, Khalil Ullah², Habib Shah³, Abdallah Namoun⁴, Khaliq Ur Rahman⁵

CMC-Computers, Materials & Continua, Vol.75, No.1, pp. 165-182, 2023, DOI:10.32604/cmc.2023.034605

Abstract Human biometric analysis has gotten much attention due to its widespread use in different research areas, such as security, surveillance, health, human identification, and classification. Human gait is one of the key human traits that can identify and classify humans based on their age, gender, and ethnicity. Different approaches have been proposed for the estimation of human age based on gait so far. However, challenges are there, for which an efficient, low-cost technique or algorithm is needed. In this paper, we propose a three-dimensional real-time gait-based age detection system using a machine learning approach. The proposed system consists of training… More >

C. Preethi^*, M. Mohamed Sathik, S. Shajun Nisha

Computer Systems Science and Engineering, Vol.45, No.3, pp. 2971-2988, 2023, DOI:10.32604/csse.2023.033423

Abstract Three dimensional (3D) echocardiogram enables cardiologists to visualize suspicious cardiac structures in detail. In recent years, this three-dimensional echocardiogram carries important clinical value in virtual surgical simulation. However, this 3D echocardiogram involves a trade-off difficulty between accuracy and efficient computation in clinical diagnosis. This paper presents a novel Flip Directional 3D Volume Reconstruction (FD-3DVR) method for the reconstruction of echocardiogram images. The proposed method consists of two main steps: multiplanar volumetric imaging and 3D volume reconstruction. In the creation of multiplanar volumetric imaging, two-dimensional (2D) image pixels are mapped into voxels of the volumetric grid. As the obtained slices are… More >

Qizhi Chen¹, Chuli Xu¹, Baoping Zou^1,*, Zhanyou Luo², Changjie Xu³, Xu Long^4,*

CMES-Computer Modeling in Engineering & Sciences, Vol.135, No.2, pp. 1503-1520, 2023, DOI:10.32604/cmes.2022.022823

Abstract Load transformation from the yielding part of the soil to the adjacent part is known as the soil arching effect, which plays an important role in the design of various geotechnical infrastructures. Terzaghi’s trapdoor test was an important milestone in the development of theories on soil arching. The research on earth pressure of the trapdoor problem is presented in this paper using the three-dimensional (3D) discrete element method (DEM). Five 3D trapdoor models with different heights are established by 3D DEM software PFC 3D. The variation of earth pressure on the trapdoor with the downward movement of the trapdoor, the… More >

Huan Zhou^1,#, Jin Kang^2,#, Jun Gao^2,*, Xiaoyuan Feng¹, Li Zhou², Xia Xiao², Zhengliang Meng², Chengwen Guo²

Congenital Heart Disease, Vol.17, No.6, pp. 697-707, 2022, DOI:10.32604/chd.2022.022648

Abstract Background: Real-time three-dimensional echocardiography (RT-3DE) could obtain ventricular volume and ejection fraction rapidly and non-invasively without relying on ventricular morphology. This study aims to use RT-3DE to evaluate the changes in biventricular volume and systolic function in children with ventricular septal defect (VSD) and moderate to severe pulmonary hypertension (PH) before surgery. Methods: In this study 18 children with VSD and moderate to severe PH (VSD + PH Group) and 18 healthy children of the same age (Control Group) were recruited. Biventricular volume and systolic function were evaluated by RT-3DE. The measurements included: left and right ventricular volume indexed to… More > Graphic Abstract

Jufeng Wang¹, Yong Wu¹, Ying Xu¹, Fengxin Sun^2,*

CMES-Computer Modeling in Engineering & Sciences, Vol.135, No.1, pp. 341-356, 2023, DOI:10.32604/cmes.2022.023140

Abstract By introducing the dimensional splitting (DS) method into the multiscale interpolating element-free Galerkin (VMIEFG) method, a dimension-splitting multiscale interpolating element-free Galerkin (DS-VMIEFG) method is proposed for three-dimensional (3D) singular perturbed convection-diffusion (SPCD) problems. In the DS-VMIEFG method, the 3D problem is decomposed into a series of 2D problems by the DS method, and the discrete equations on the 2D splitting surface are obtained by the VMIEFG method. The improved interpolation-type moving least squares (IIMLS) method is used to construct shape functions in the weak form and to combine 2D discrete equations into a global system of discrete equations for the… More >

Yuhang He¹, Rongzhuo Zhang¹, Sarah Mohrmann², Zheng Wang^1,*, Jiujin Fang³

Journal of Renewable Materials, Vol.10, No.12, pp. 3303-3311, 2022, DOI:10.32604/jrm.2022.020681

Abstract In order to explore the characteristics of the three-dimensional surface morphology of sawn timber, a threedimensional wood surface morphology tester based on the scanning probe method and the principle of atomic force microscope was used to test the three-dimensional surface morphology of three kinds of sawn timber and calculate its surface roughness. This study also analyzed the reasonable plan for the value of wood surface roughness and the advantages of the three-dimensional shape tester, as well as the influence of tree species, three sections, air-dry density and other factors on the surface roughness of the specimen after mechanical processing. The… More >