Azam Zaka¹, Ahmad Saeed Akhter¹, Riffat Jabeen^2,*, Aamir Sanaullah²

CMES-Computer Modeling in Engineering & Sciences, Vol.127, No.3, pp. 1201-1223, 2021, DOI:10.32604/cmes.2021.014477

Abstract In practice, the control charts for monitoring of process mean are based on the normality assumption. But the performance of the control charts is seriously affected if the process of quality characteristics departs from normality. For such situations, we have modified the already existing control charts such as Shewhart control chart, exponentially weighted moving average (EWMA) control chart and hybrid exponentially weighted moving average (HEWMA) control chart by assuming that the distribution of underlying process follows Power function distribution (PFD). By considering the situation that the parameters of PFD are unknown, we estimate them by using three classical estimation methods,… More >

Tao Zhang^1,*, Ke Xu^1,2, Wenxiong Huang¹

CMES-Computer Modeling in Engineering & Sciences, Vol.127, No.3, pp. 1101-1117, 2021, DOI:10.32604/cmes.2021.015406

Abstract In this paper, the densely arrayed bonded particle model is proposed for simulation of granular materials with discrete element method (DEM) considering particle crushing. This model can solve the problem of pore calculation after the grains are crushed, and reduce the producing time of specimen. In this work, several one-dimensional compressing simulations are carried out to investigate the effect of particle crushing on mechanical properties of granular materials under a wide range of stress. The results show that the crushing process of granular materials can be divided into four different stages according to e_r-logσ_y curves. At the end of the… More >

Yudong Zhang^1,3,*, Xin Zhang^2,*, Weiguo Zhu¹

CMES-Computer Modeling in Engineering & Sciences, Vol.127, No.3, pp. 1037-1058, 2021, DOI:10.32604/cmes.2021.015807

Abstract Aim: To diagnose COVID-19 more efficiently and more correctly, this study proposed a novel attention network for COVID-19 (ANC). Methods: Two datasets were used in this study. An 18-way data augmentation was proposed to avoid overfitting. Then, convolutional block attention module (CBAM) was integrated to our model, the structure of which is fine-tuned. Finally, Grad-CAM was used to provide an explainable diagnosis. Results: The accuracy of our ANC methods on two datasets are 96.32% ± 1.06%, and 96.00% ± 1.03%, respectively. Conclusions: This proposed ANC method is superior to 9 state-of-the-art approaches. More >

P. Veeresha¹, Esin Ilhan², D. G. Prakasha³, Haci Mehmet Baskonus⁴, Wei Gao^5,*

CMES-Computer Modeling in Engineering & Sciences, Vol.127, No.3, pp. 1013-1036, 2021, DOI:10.32604/cmes.2021.014988

Abstract In this paper, we analyze the behaviour of solution for the system exemplifying model of tumour invasion and metastasis by the help of q-homotopy analysis transform method (q-HATM) with the fractional operator. The analyzed model consists of a system of three nonlinear differential equations elucidating the activation and the migratory response of the degradation of the matrix, tumour cells and production of degradative enzymes by the tumour cells. The considered method is graceful amalgamations of q-homotopy analysis technique with Laplace transform (LT), and Caputo–Fabrizio (CF) fractional operator is hired in the present study. By using the fixed point theory, existence… More >

Heonmoo Kim, Yosoon Choi^*

CMES-Computer Modeling in Engineering & Sciences, Vol.127, No.3, pp. 943-964, 2021, DOI:10.32604/cmes.2021.015300

Abstract In underground mine environments where various hazards exist, such as tunnel collapse, toxic gases, the application of autonomous robots can improve the stability of exploration and efficiently perform repetitive exploratory operations. In this study, we developed a small autonomous driving robot for unmanned environmental monitoring in underground mines. The developed autonomous driving robot controls the steering according to the distance to the tunnel wall measured using the light detection and ranging sensor mounted on the robot to estimate its location by simultaneously considering the measured values of the inertial measurement unit and encoder sensors. In addition, the robot autonomously drives… More >

Ali. F. Jameel^1,*, N. R. Anakira², A. K. Alomari³, Noraziah H. Man¹

CMES-Computer Modeling in Engineering & Sciences, Vol.127, No.3, pp. 875-899, 2021, DOI:10.32604/cmes.2021.014460

Abstract Homotopy Analysis Method (HAM) is semi-analytic method to solve the linear and nonlinear mathematical models which can be used to obtain the approximate solution. The HAM includes an auxiliary parameter, which is an efficient way to examine and analyze the accuracy of linear and nonlinear problems. The main aim of this work is to explore the approximate solutions of fuzzy Volterra integral equations (both linear and nonlinear) with a separable kernel via HAM. This method provides a reliable way to ensure the convergence of the approximation series. A new general form of HAM is presented and analyzed in the fuzzy… More >

Huinan Sun^1,*, Siqiang Wang², Zhuoqing Zhang¹, Chaoyong Xia¹, Xu Chen¹

CMES-Computer Modeling in Engineering & Sciences, Vol.127, No.3, pp. 855-873, 2021, DOI:10.32604/cmes.2021.015791

Abstract Grains are widely present in industrial productions and processing, and are stored in silos. In the silo, auxiliary structures are added to achieve efficient production. However, little effort has been devoted to the influence of the internal structure of the silo on the granular flow. In this work, a silo with a central decompression tube is studied through experimental measurements and discrete element methods. Then, the influences of the central decompression tube on the flow behavior of grains and wall pressure are analyzed. Results show that the grains are in mass flow in the silo without a central decompression tube,… More >

Zhengquan Li^1,*, Pei Zhang¹, Yongchang Sun¹, Chenglin Zheng¹, Liang Xu², Dianyu E¹

CMES-Computer Modeling in Engineering & Sciences, Vol.127, No.3, pp. 1119-1132, 2021, DOI:10.32604/cmes.2021.016019

Abstract In this paper, the gas and seed flow characters in the air-blowing seed metering device are investigated by using the coupled computational fluid dynamics and discrete element method (CFD-DEM) in three dimensions (3D). The method of establishing boundary model based on the computer-aided design (CAD) drawing, has been used to build the boundary model of seed metering device. The 3D laser scanning technique and multi-element method are adopted to establish the particle model. Through a combined numerical and experimental effort, using 3D CFD-DEM software, which is based on the in-house codes, the mechanisms governing the gas and solid dynamic behaviors… More >

Bin Zhang^1,2, Yiming Huang^3,4, Tingting Zhao^5,*

CMES-Computer Modeling in Engineering & Sciences, Vol.127, No.3, pp. 1133-1150, 2021, DOI:10.32604/cmes.2021.016018

Abstract The simulation of a large number of particles requires unacceptable computational time that is the most critical problem existing in the industrial application of the DEM. Coarse graining is a promising approach to facilitate the application of DEM to industrial problems. While the current coarse graining framework is often developed in an ad-hoc manner, leading to different formulations and different solution accuracy and efficiency. Therefore, in this paper, existing coarse graining techniques have been carefully analysed by the exact scaling law which can provide the theory basis for the upscaling method. A proper scaling rule for the size of particles… More >

Baoyu Ma^1,*, Guansuo Dui², Zhenglin Jia¹, Bo Yang¹, Chunyan Yang¹, Quangui Gao¹, Longhua Qin¹, Ju Ma¹

CMES-Computer Modeling in Engineering & Sciences, Vol.127, No.3, pp. 1059-1067, 2021, DOI:10.32604/cmes.2021.015776

Abstract A simple hydration model is used here by taking the composition of the cement and the initial water: cement ratio (w/c) into account explicitly. Its conceptual basis is a combination of the Avrami equation and Bentz’s model based on simple spatial considerations. In this model, the Avrami equation determines the initial reaction, and Bentz’s model describes the following hydration stage. The model favors engineers for it relies on one experimental parameter and has a reliable approximation in the practice. More >