Yang Yang^{1, *}

CMES-Computer Modeling in Engineering & Sciences, Vol.116, No.3, pp. 365-389, 2018, DOI:10.31614/cmes.2018.03847

Abstract The selection of machining parameters directly affects the production time, quality, cost, and other process performance measures for multi-pass milling. Optimization of machining parameters is of great significance. However, it is a nonlinear constrained optimization problem, which is very difficult to obtain satisfactory solutions by traditional optimization methods. A new optimization technique combined chaotic operator and imperialist competitive algorithm (ICA) is proposed to solve this problem. The ICA simulates the competition between the empires. It is a population-based meta-heuristic algorithm for unconstrained optimization problems. Imperialist development operator based on chaotic sequence is introduced to improve… More >

Shengbiao Wu^1,2,3, Weihua Cao^1,3,*, Can Liu^1,3, Min Wu^1,3

CMES-Computer Modeling in Engineering & Sciences, Vol.116, No.3, pp. 433-453, 2018, DOI:10.31614/cmes.2018.03309

Abstract A computer-aided tuning method that combines T-S fuzzy neural network (T-S FNN) and offers improved space mapping (SM) is presented in this study. This method consists of three main aspects. First, the coupling matrix is effectively extracted under the influence of phase shift and cavity loss after the initial tuning. Second, the surrogate model is realized by using a T-S FNN based on subspace clustering. Third, the mapping relationship between the actual and the surrogate models is established by the improved space mapping algorithm, and the optimal position of the tuning screws are found by More >

Z. Xu¹, M. Chen¹, X. M. Fan^1,2,*

CMES-Computer Modeling in Engineering & Sciences, Vol.116, No.3, pp. 407-431, 2018, DOI:10.31614/cmes.2018.01816

Abstract The alternating method based on the fundamental solutions of the infinite domain containing a crack, namely Muskhelishvili’s solutions, divides the complex structure with a crack into a simple model without crack which can be solved by traditional numerical methods and an infinite domain with a crack which can be solved by Muskhelishvili’s solutions. However, this alternating method cannot be directly applied to the edge crack problems since partial crack surface of Muskhelishvili’s solutions is located outside the computational domain. In this paper, an improved alternating method, the spline fictitious boundary element alternating method (SFBEAM), based More >

Mizuma Takehito^1,*, Takei Amane¹

CMES-Computer Modeling in Engineering & Sciences, Vol.116, No.3, pp. 349-363, 2018, DOI:10.31614/cmes.2018.01714

Abstract A matrix equation solved in an eddy current analysis, A-ϕ method based on a domain decomposition method becomes a complex symmetric system. In general, iterative method is used as the solver. Convergence of iterative method in an interface problem is improved by increasing an accuracy of a solution of an iterative method of a subdomain problem. However, it is difficult to improve the convergence by using a small convergence criterion in the subdomain problem. Therefore, authors propose a method to introduce double-double precision into the interface problem and the subdomain problem. This proposed method improves More >

Xinyue Liu¹, Yunqiao Liu¹, Xiaobo Gong^1,*, Huaxiong Huang²

CMES-Computer Modeling in Engineering & Sciences, Vol.116, No.2, pp. 281-300, 2018, DOI:10.31614/cmes.2018.04989

Abstract In this work, a three-dimensional axisymmetric model with nanoparticle, receptor-ligand bonds and cell membrane as a system was used to study the quasi-static receptor-mediated endocytosis process of spherical nanoparticles in drug delivery. The minimization of the system energy function was carried out numerically, and the deformations of nanoparticle, receptor-ligand bonds and cell membrane were predicted. Results show that passive endocytosis may fail due to the rupture of receptor-ligand bonds during the wrapping process, and the size and rigidity of nanoparticles affect the total deformation energy and the terminal wrapping stage. Our results suggest that, in More >

Jing Zhang^1,2,3, Xiuqing Qian^1,2, Haixia Zhang^1,2, Zhicheng Liu^1,2,*

CMES-Computer Modeling in Engineering & Sciences, Vol.116, No.2, pp. 301-314, 2018, DOI:10.31614/cmes.2018.04239

Abstract Elevated intraocular pressure appears to have a broader impact on increased resistance to aqueous humor outflow through the conventional aqueous outflow system (AOS). However, there is still no consensus about exact location of the increased outflow resistance of aqueous humor, and the mechanism is not perfect. In addition, it is difficult to accurately obtain hydrodynamic parameters of aqueous humor within the trabecular meshwork outflow pathways based on the current technology. In this paper, a two-way fluid-structure interaction simulation was performed to study the pressure difference and velocity in the superficial trabecular meshwork, juxtacanalicular meshwork (JCM) More >

Wenxin Wang^1,2, Dalin Tang², Boyan Mao¹, Bao Li¹, Xi Zhao³, Jian Liu⁴, Youjun Liu^1,*

CMES-Computer Modeling in Engineering & Sciences, Vol.116, No.2, pp. 163-173, 2018, DOI:10.31614/cmes.2018.04219

Abstract Fractional flow reserve (FFR) is the gold standard to identify individual stenosis causing myocardial ischemia in catheter laboratory. The purpose of this study is to present a fast simulation method to estimate FFR value of a coronary artery, which can evaluate the performance of vascular stenosis, based on resistance boundary conditions. A patient-specific 3-dimensional (3D) model of the left coronary system with intermediate diameter stenosis was reconstructed based on the CTA images. The resistance boundary conditions used to simulate the coronary microcirculation were computed based on anatomical reconstruction of coronary 3D model. This study was More >

Zhou Zhao¹, Boyan Mao², Youjun Liu², Haisheng Yang², Yu Chen^1,*

CMES-Computer Modeling in Engineering & Sciences, Vol.116, No.2, pp. 229-245, 2018, DOI:10.31614/cmes.2018.04192

Abstract In coronary artery bypass grafting (CABG), graft’s poor instant patency may lead to an abnormal hemodynamic environment in anastomosis, which could further cause graft failure after the surgery. This paper investigates the graft hemodynamics with different instant patency, and explores its effect on graft postoperative efficiency. Six CABG 0D/3D coupling multi-scale models which used left internal mammary artery (LIMA) and saphenous vein (SVG) as grafts were constructed. Different types of grafts were examined in the models, including normal grafts, grafts with competitive flow and grafts with anastomotic stenosis. Simulation results indicated that comparing with SVG… More >

Xudong Liu¹, Yunhan Cai¹, Bing Jia², Shengzhang Wang^1,*, Guanghong Ding¹

CMES-Computer Modeling in Engineering & Sciences, Vol.116, No.2, pp. 215-228, 2018, DOI:10.31614/cmes.2018.04158

Abstract Our study evaluated the hemodynamic performance of an axial flow blood pump surgically implanted in idealized total cavopulmonary connection (TCPC) models. This blood pump was designed to augment pressure from the inferior vena cava (IVC) to the pulmonary circulation. Two Fontan procedures with single and bilateral superior vena cava (SVC) were compared to fit the mechanical supported TCPC physiologies. Computational fluid dynamics (CFD) analyses of two Pump-TCPC models were performed in the analyses. Pressure-flow characteristics, energy efficiency, fluid streamlines, hemolysis and thrombosis analyses were implemented. Numerical simulations indicate that the pump produces pressure generations of… More >

Sihan Chen¹, Bao Li¹, Haisheng Yang¹, Jianhang Du², Xiaoling Li², Youjun Liu^1,*

CMES-Computer Modeling in Engineering & Sciences, Vol.116, No.2, pp. 149-162, 2018, DOI:10.31614/cmes.2018.04133

Abstract Enhanced external counterpulsation (EECP) is able to treat myocardial ischemia, which is usually caused by coronary artery stenosis. However, the underlying mechanisms regarding why this technique is effective in treating myocardial ischemia remains unclear and there is no patient-specific counterpulsation mode for different rates of coronary artery stenosis in clinic. This study sought to investigate the hemodynamic effect of varied coronary artery stenosis rates when using EECP and the necessity of adopting targeted counterpulsation mode to consider different rates of coronary artery stenosis. Three 3-dimensional (3D) coronary models with different stenosis rates, including 55% (Model… More >