Fei Song^1,2, Puyou Jia^1,*, Caiying Bo¹, Xiaoli Ren¹, Lihong Hu¹, Yonghong Zhou^1,*

Journal of Renewable Materials, Vol.8, No.5, pp. 535-547, 2020, DOI:10.32604/jrm.2020.09304 - 29 April 2020

Abstract In this study, we prepared a series of tung oil phenolic foams (TPF) by a one-pot method. The FT-IR and 1 H NMR spectra confirm the successful FriedelCrafts grafting of phenol to the long-chain alkyl group in tung oil. Modified TPFs exhibit enhanced mechanical properties, including compressive and flexural strengths of up to 0.278 ± 0.036 MPa and 0.450 ± 0.017 MPa, respectively, which represent increases of 68.75% and 86.72% over those of pure phenolic foam (PF). SEM spectra reveal the TPF microstructure to have uniform hexagonal cell morphology, narrower cell size distribution, and smaller 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 >

Qixi Fu¹, Xiaolong Liang^{1, 2}, Jiaqiang Zhang^{1, *}, Xiangyu Fan^{1, 2}

CMC-Computers, Materials & Continua, Vol.63, No.1, pp. 417-444, 2020, DOI:10.32604/cmc.2020.07044 - 30 March 2020

Abstract In order to meet the higher accuracy requirement of trajectory prediction for Unmanned Aircraft System (UAS) in Unmanned Aircraft System Traffic Management (UTM), an Intent Based Trajectory Prediction and Smooth Based on Constrained State-dependent-transition Hybrid Estimation (CSDTHE-IBTPS) algorithm is proposed. Firstly, an intent inference method of UAS is constructed based on the information of ADS-B and geofence system. Moreover, a geofence layering algorithm is proposed. Secondly, the Flight Mode Change Points (FMCP) are used to define the relevant mode transition parameters and design the guard conditions, so as to generate the mode transition probability matrix… More >

Xiaofeng Yang^{1, *}, Yanhong Li¹, Aiguo Nie¹, Sheng Zhi², Liyuan Liu³

CMES-Computer Modeling in Engineering & Sciences, Vol.122, No.3, pp. 1141-1157, 2020, DOI:10.32604/cmes.2020.08538 - 01 March 2020

Abstract Supercritical carbon dioxide (Sc-CO₂) jet rock breaking is a nonlinear impact dynamics problem involving many factors. Considering the complexity of the physical properties of the Sc-CO₂ jet and the mesh distortion problem in dealing with large deformation problems using the finite element method, the smoothed particle hydrodynamics (SPH) method is used to simulate and analyze the rock breaking process by Sc-CO₂ jet based on the derivation of the jet velocity-density evolution mathematical model. The results indicate that there exisits an optimal rock breaking temperature by Sc-CO₂. The volume and length of the rock fracture increase with the… More >

M. Al-Saad¹, C. A. Suarez^{2, 4}, A. Obeidat², S. P. A. Bordas^{1, 2, 3, *}, S. Kulasegaram¹

CMES-Computer Modeling in Engineering & Sciences, Vol.122, No.3, pp. 831-862, 2020, DOI:10.32604/cmes.2020.08527 - 01 March 2020

Abstract Thrombosis plays a crucial role in atherosclerosis or in haemostasis when a blood vessel is injured. This article focuses on using a meshless particle-based Lagrangian numerical technique, the smoothed particles hydrodynamic (SPH) method, to study the flow behaviour of blood and to explore the flow parameters that induce formation of a thrombus in a blood vessel. Due to its simplicity and effectiveness, the SPH method is employed here to simulate the process of thrombogenesis and to study the effect of various blood flow parameters. In the present SPH simulation, blood is modelled by two sets More >

Wujie Hu¹, Gonglin Yuan^{1, *}, Hongtruong Pham²

CMC-Computers, Materials & Continua, Vol.62, No.2, pp. 787-800, 2020, DOI:10.32604/cmc.2020.02993

Abstract It is well known that Newton and quasi-Newton algorithms are effective to small and medium scale smooth problems because they take full use of corresponding gradient function’s information but fail to solve nonsmooth problems. The perfect algorithm stems from concept of ‘bundle’ successfully addresses both smooth and nonsmooth complex problems, but it is regrettable that it is merely effective to small and medium optimization models since it needs to store and update relevant information of parameter’s bundle. The conjugate gradient algorithm is effective both large-scale smooth and nonsmooth optimization model since its simplicity that utilizes More >

Shichao Ma^{1, 2, *}, Xin Ning^{1, 2, *}, Liang Wang³

CMES-Computer Modeling in Engineering & Sciences, Vol.122, No.1, pp. 49-59, 2020, DOI:10.32604/cmes.2020.06911 - 01 January 2020

Abstract Friction systems are a kind of typical non-linear dynamical systems in the actual engineering and often generate abundant dynamics phenomena. Because of non-smooth characteristics, it is difficult to handle these systems by conventional analysis methods directly. At the same time, random perturbation often affects friction systems and makes these systems more complicated. In this context, we investigate the steady-state stochastic responses and stochastic P-bifurcation of friction systems under random excitations in this paper. And in order to retain the non-smooth of friction system, the generalized cell mapping (GCM) method is first used to the original… More >

Haresh Kumar Sharma, Kriti Kumari, Samarjit Kar

Intelligent Automation & Soft Computing, Vol.25, No.1, pp. 1-14, 2019, DOI:10.31209/2018.100000036

Abstract This article focuses on the use of the rough set theory in modeling of time series forecasting. In this paper, we have used the double exponential smoothing (DES) model for forecasting. The classical DES model has been improved by using the rough set technique. The improved double exponential smoothing (IDES) method can be used for the time series data without any statistical assumptions. The proposed method is applied on tourism demand of the air transportation passenger data set in Australia and the results are compared with the classical DES model. It has been observed that More >

Huilong Ren¹, Xiaoying Zhuang^2,3,*, Timon Rabczuk¹

CMES-Computer Modeling in Engineering & Sciences, Vol.121, No.2, pp. 353-383, 2019, DOI:10.32604/cmes.2019.05146

Abstract A dual-support smoothed particle hydrodynamics (DS-SPH) that allows variable smoothing lengths while satisfying the conservations of linear momentum, angular momentum and energy is developed. The present DS-SPH is inspired by the dual-support, a concept introduced from dual-horizon peridynamics from the authors and applied here to SPH so that the unbalanced interactions between the particles with different smoothing lengths can be correctly considered and computed. Conventionally, the SPH formulation employs either the influence domain or the support domain. The concept of dual-support identifies that the influence domain and the support domain involves the duality and should More >

Takeo Matsumoto^1,*, Chizuru Hirooka¹, Yong Fan¹, Junfeng Wang¹, Naoki Mori¹, Eijiro Maeda¹

Molecular & Cellular Biomechanics, Vol.16, Suppl.2, pp. 81-81, 2019, DOI:10.32604/mcb.2019.07102

Abstract Aortic wall thickens in response to hypertension. Many studies reported that the wall thickening occurs to maintain the wall stress in the circumferential direction at a constant level. In case of the longitudinal direction, however, there are few studies suggesting the constancy of the stress. Such anisotropic response may be attributable to the circumferential alignment of the smooth muscle cells (SMCs) in the wall [1]. However, to the authors’ knowledge, there are no study discussing the underlying mechanism of the anisotropic response. It has been reported that mechanical deformation of the nuclei causes transcription upregulation… More >