Vol.129, No.2, 2021-Table of Contents
  • A Simplified Approach of Open Boundary Conditions for the Smoothed Particle Hydrodynamics Method
  • Abstract In this paper, we propose a simplified approach of open boundary conditions for particle-based fluid simulations using the weakly compressible smoothed-particle hydrodynamics (SPH) method. In this scheme, the values of the inflow/outflow particles are calculated as fluid particles or imposed desired values to ensure the appropriate evolution of the flow field instead of using a renormalization process involving the fluid particles. We concentrate on handling the generation of new inflow particles using several simple approaches that contribute to the flow field stability. The advantages of the . -SPH scheme, specifically the particle shifting technique, were successfully applied to correct the… More
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  • Multi-Objective High-Fidelity Optimization Using NSGA-III and MO-RPSOLC
  • Abstract Optimizing the performance of composite structures is a real-world application with significant benefits. In this paper, a high-fidelity finite element method (FEM) is combined with the iterative improvement capability of metaheuristic optimization algorithms to obtain optimized composite plates. The FEM module comprises of ninenode isoparametric plate bending element in conjunction with the first-order shear deformation theory (FSDT). A recently proposed memetic version of particle swarm optimization called RPSOLC is modified in the current research to carry out multi-objective Pareto optimization. The performance of the MO-RPSOLC is found to be comparable with the NSGA-III. This work successfully highlights the use of… More
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  • Traffic Flow Statistics Method Based on Deep Learning and Multi-Feature Fusion
  • Abstract Traffic flow statistics have become a particularly important part of intelligent transportation. To solve the problems of low real-time robustness and accuracy in traffic flow statistics. In the DeepSort tracking algorithm, the Kalman filter (KF), which is only suitable for linear problems, is replaced by the extended Kalman filter (EKF), which can effectively solve nonlinear problems and integrate the Histogram of Oriented Gradient (HOG) of the target. The multi-target tracking framework was constructed with YOLO V5 target detection algorithm. An efficient and long-running Traffic Flow Statistical framework (TFSF) is established based on the tracking framework. Virtual lines are set up… More
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  • Modelling of Contact Damage in Brittle Materials Based on Peridynamics
  • Abstract As a typical brittle material, glass is widely used in construction, transportation, shipbuilding, aviation, aerospace and other industries. The unsafe factors of glass mainly come from its rupture. Thus, establishing a set of prediction models for the cracks growth of glass under dynamic load is necessary. This paper presents a contact damage model for glass based on the ordinary state-based peridynamic theory by introducing a contact force function. The Hertz contact (nonembedded contact) problem is simulated, and the elastic contact force is determined by adjusting the penalty factor. The proposed model verifies the feasibility of penalty-based method to simulate the… More
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  • Combinatorial Method with Static Analysis for Source Code Security in Web Applications
  • Abstract Security weaknesses in web applications deployed in cloud architectures can seriously affect its data confidentiality and integrity. The construction of the procedure utilized in the static analysis tools of source code security differs and therefore each tool finds a different number of each weakness type for which it is designed. To utilize the possible synergies different static analysis tools may process, this work uses a new method to combine several source codes aiming to investigate how to increase the performance of security weakness detection while reducing the number of false positives. Specifically, five static analysis tools will be combined with… More
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  • An Effective Feature Generation and Selection Approach for Lymph Disease Recognition
  • Abstract Health care data mining is noteworthy in disease diagnosis and recognition procedures. There exist several potentials to further improve the performance of machine learning based-classification methods in healthcare data analysis. The selection of a substantial subset of features is one of the feasible approaches to achieve improved recognition results of classification methods in disease diagnosis prediction. In the present study, a novel combined approach of feature generation using latent semantic analysis (LSA) and selection using ranker search (RAS) has been proposed to improve the performance of classification methods in lymph disease diagnosis prediction. The performance of the proposed combined approach… More
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  • A GPU-Based Parallel Algorithm for 2D Large Deformation Contact Problems Using the Finite Particle Method
  • Abstract Large deformation contact problems generally involve highly nonlinear behaviors, which are very time-consuming and may lead to convergence issues. The finite particle method (FPM) effectively separates pure deformation from total motion in large deformation problems. In addition, the decoupled procedures of the FPM make it suitable for parallel computing, which may provide an approach to solve time-consuming issues. In this study, a graphics processing unit (GPU)-based parallel algorithm is proposed for two-dimensional large deformation contact problems. The fundamentals of the FPM for planar solids are first briefly introduced, including the equations of motion of particles and the internal forces of… More
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  • An XBi-CFAO Method for the Optimization of Multi-Layered Variable Stiffness Composites Using Isogeometric Analysis
  • Abstract This paper presents an effective fiber angle optimization method for two and multi-layered variable stiffness composites. A gradient-based fiber angle optimization method is developed based on isogeometric analysis (IGA). Firstly, the element densities and fiber angles for two and multi-layered composites are synchronously optimized using an extended Bi-layered continuous fiber angle optimization method (XBi-CFAO). The densities and fiber angles in the base layer are attached to the control points. The structure response and sensitivity analysis are accomplished using the non-uniform rational B-spline (NURBS) based IGA. By the benefit of the B-spline space, this method is free from checkerboards, and no… More
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  • Fail-Safe Topology Optimization of Continuum Structures with Multiple Constraints Based on ICM Method
  • Abstract Traditional topology optimization methods may lead to a great reduction in the redundancy of the optimized structure due to unexpected material removal at the critical components. The local failure in critical components can instantly cause the overall failure in the structure. More and more scholars have taken the fail-safe design into consideration when conducting topology optimization. A lot of good designs have been obtained in their research, though limited regarding minimizing structural compliance (maximizing stiffness) with given amount of material. In terms of practical engineering applications considering fail-safe design, it is more meaningful to seek for the lightweight structure with… More
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  • Dynamical Analysis of Radiation and Heat Transfer on MHD Second Grade Fluid
  • Abstract Convective flow is a self-sustained flow with the effect of the temperature gradient. The density is non-uniform due to the variation of temperature. The effect of the magnetic flux plays a major role in convective flow. The process of heat transfer is accompanied by a mass transfer process; for instance, condensation, evaporation, and chemical process. Due to the applications of the heat and mass transfer combined effects in a different field, the main aim of this paper is to do a comprehensive analysis of heat and mass transfer of MHD unsteady second-grade fluid in the presence of ramped boundary conditions… More
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  • Fractional Analysis of Dynamical Novel COVID-19 by Semi-Analytical Technique
  • Abstract This study employs a semi-analytical approach, called Optimal Homotopy Asymptotic Method (OHAM), to analyze a coronavirus (COVID-19) transmission model of fractional order. The proposed method employs Caputo's fractional derivatives and Reimann-Liouville fractional integral sense to solve the underlying model. To the best of our knowledge, this work presents the first application of an optimal homotopy asymptotic scheme for better estimation of the future dynamics of the COVID-19 pandemic. Our proposed fractional-order scheme for the parameterized model is based on the available number of infected cases from January 21 to January 28, 2020, in Wuhan City of China. For the considered… More
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  • Quantification of Urban Sprawl for Past-To-Future in Abha City, Saudi Arabia
  • Abstract Given that many cities in Saudi Arabia have been observing rapid urbanization since the 1990s, scarce studies on the spatial pattern of urban expansion in Saudi Arabia have been conducted. Therefore, the present study investigates the evidence of land use and land cover (LULC) dynamics and urban sprawl in Abha City of Saudi Arabia, which has been experiencing rapid urbanization, from the past to the future using novel and sophisticated methods. The SVM classifier was used in this study to classify the LULC maps for 1990, 2000, and 2018. The LULC dynamics between 1990–2000, 2000–2018, and 1990–2018 have been analyzed… More
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  • Study on the Whole Process Simulation and Regulation Mechanism of Urban Green Ecological Rainwater Drainage System
  • Abstract In view of the frequent waterlogging caused by rapid urbanization and the public’s dissatisfaction with the drainage system, the article based on the concept of the green ecological drainage system, constructed the urban green ecological drainage comprehensive simulation research system, and quickly evaluated pipe network operation and surface water of an industrial park under typical rainfall conditions. The results showed that the drainage capacity of the designed green ecological rainwater drainage system reached 100%, and there was no ponding phenomenon, which indicated that the green ecological rainwater drainage system could effectively solve the practical problems of urban drainage. The green… More
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  • MIA-UNet: Multi-Scale Iterative Aggregation U-Network for Retinal Vessel Segmentation
  • Abstract As an important part of the new generation of information technology, the Internet of Things (IoT) has been widely concerned and regarded as an enabling technology of the next generation of health care system. The fundus photography equipment is connected to the cloud platform through the IoT, so as to realize the real-time uploading of fundus images and the rapid issuance of diagnostic suggestions by artificial intelligence. At the same time, important security and privacy issues have emerged. The data uploaded to the cloud platform involves more personal attributes, health status and medical application data of patients. Once leaked, abused… More
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  • Empirical Thermal Investigation of Oil–Immersed Distribution Transformer under Various Loading Conditions
  • Abstract The distribution transformer is the mainstay of the power system. Its internal temperature study is desirable for its safe operation in the power system. The purpose of the present study is to determine direct comprehensive thermal distribution in the distribution transformers for different loading conditions. To achieve this goal, the temperature distribution in the oil, core, and windings are studied at each loading. An experimental study is performed with a 10/0.38 kV, 10 kVA oil–immersed transformer equipped with forty–two PT100 sensors (PTs) for temperature measurement installed inside during its manufacturing process. All possible locations for the hottest spot temperature (HST)… More
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  • Fusion Fault Diagnosis Approach to Rolling Bearing with Vibrational and Acoustic Emission Signals
  • Abstract As the key component in aeroengine rotor systems, the health status of rolling bearings directly influences the reliability and safety of aeroengine rotor systems. In order to monitor rolling bearing conditions, a fusion fault diagnosis method, namely empirical mode decomposition (EMD)-Mahalanobis distance (E2MD) and improved wavelet threshold (IWT) (E2MD-IWT) for vibrational signals and acoustic emission (AE) signals is developed to improve the diagnostic accuracy of rolling bearings. The IWT method is proposed with a hard wavelet threshold and a soft wavelet threshold. Moreover, it is shown to be effective through numerical simulation. EMD is utilized to process the original AE… More
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  • Novel Kriging-Based Decomposed-Coordinated Approach for Estimating the Clearance Reliability of Assembled Structures
  • Abstract Turbine blisks are assembled using blades, disks and casings. They can endure complex loads at a high temperature, high pressure and high speed. The safe operation of assembled structures depends on the reliability of each component. Monte Carlo (MC) simulation is commonly used to analyze structural reliability, but this method needs to run thousands of computations. In order to assess the clearance reliability of assembled structures in an efficient and precise manner, the novel Kriging-based decomposed-coordinated (DC) (DCNK) approach is proposed by integrating the DC strategy, the Kriging model and the importance sampling-based Markov chain (MCIS) technique. In this method,… More
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