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Ballistic resistance and energy dissipation of woven-fabric composite targets:Insights on the effects of projectile shape and obliquity angle

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Defence Technology（防务技术） 2023年第3期21卷 14-32页

作者： ibrahim Goda UniversitéBourgogne Franche-Comté FEMTO-ST InstituteDépartement Mécanique Appliquée24 Rue de L’Épitaphe25000BesançonFrance

This study aims at investigating the ballistic resistance and energy absorption in woven E-glass composite panels,considering different projectile nose shapes and oblique incidence *** that scope,three-dimensional finite element(FE)models of both projectiles and the laminated target are developed and numerical investigations are carried out using Abaqus Explicit *** composite damage model’s constitutive law encompasses nonlinear material response,material properties degradation,progressive failure,and an element deletion *** cohesive surface technique is used to represent the interface between two adjacent plies in the laminate,and the traction-separation law is used to characterize the behaviors of interlaminar degradation and *** responses attributable to fiber rupture,matrix cracking,and plasticity caused by micro-matrix cracking due to shear loading are taken into account with suitable damage evolution *** computational framework is first validated against the experimental results reported in the literature by performing ballistic impact tests on the target laminate with conical,hemispherical and blunt-ended projectile,and the numerical results showed a good comparison in terms of residual *** the framework is explored in simulating more complex failure mechanisms,with particular emphasis on the influence of the impact angle of obliquity,a parameter that is not usually analyzed in the *** that regard,the effects of normal and oblique impact on the damage morphologies and ballistic behavior of the fabric composite target in terms of energy absorption,impact contact force,and projectile residual velocity are conducted and analyzed,*** findings showed that the ballistic impact behavior of target composite is substantially influenced by projectile nose shape and incidence angle obliquity.

关键词： resistance cracking composite

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Improving Date Fruit Classification Using Cycle GAN-Generated Dataset

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Computer modeling in Engineering & Sciences 2022年第4期131卷 331-348页

作者： Dina m.ibrahim Nada m.Elshennawy Department of Information Technology College of ComputerQassim UniversityBuraydah51452Saudi Arabia Computers and Control Engineering Department Faculty of EngineeringTanta UniversityTanta37133Egypt

Dates are an important part of human *** are high in essential nutrients and provide a number of health *** fruits are also known to protect against a number of diseases,including cancer and heart *** fruits have several sizes,colors,tastes,and *** are a lot of challenges facing the date *** of the most significant challenges is the classification and sorting of *** there is no public dataset for date fruits,which is a major limitation in order to improve the performance of convolutional neural networks(CNN)models and avoid the overfitting *** this paper,an augmented date fruits dataset was developed using Deep Convolutional Generative Adversarial Networks(DCGAN)and CycleGAN approach to augment our collected date fruit *** augmentation is required to address the issue of a restricted number of images in our datasets,as well as to establish a balanced *** are three types of dates in our proposed dataset:Sukkari,Ajwa,and *** dataset augmentation,we train our created dataset using ResNet152V2 and CNN models to assess the classification process for our three categories in the *** train these two models,we start with the original ***,the models were trained using the DCGAN-generated dataset,followed by the CycleGAN-generated *** resulting results demonstrated that when using the ResNet152V2model,the CycleGAN-generated dataset had the highest classification performance with 96.8%accuracy,followed by the CNN model with 94.3%accuracy.

关键词： Dates fruits data augmentation DCGAN CycleGAN,deep learning convolution neural networks

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Quantile Version of mathai-Haubold Entropy of Order Statistics

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Computer modeling in Engineering & Sciences 2021年第9期128卷 907-925页

作者： ibrahim m.Almanjahie Javid Gani Dar Amer ibrahim Al-Omari Aijaz mir Department of mathematics College of ScienceKing Khalid UniversityAbha62529Saudi Arabia Statistical Research and Studies Support Unit King Khalid UniversityAbha62529Saudi Arabia Department of mathematical Sciences IUSTKashmir192231India Department of mathematics Faculty of ScienceAl al-Bayt UniversityMafraq25113Jordan Department of mathematics Govt.Degree College KilamHigher EducationJ&K192231India

many researchers measure the uncertainty of a random variable using quantile-based entropy *** techniques are useful in engineering applications and have some exceptional characteristics than their distribution function *** order statistics,the key focus of this article is to propose new quantile-based mathai-Haubold entropy and investigate its *** divergence measure of themathai-Haubold is also considered and some of its properties are ***,based on order statistics,we propose the residual entropy of the quantile-based mathai-Haubold and some of its property results are *** performance of the proposed quantile-based mathai-Haubold entropy is investigated by simulation ***,a real data application is used to compare our proposed quantile-based entropy to the existing quantile *** results reveal the outperformance of our proposed entropy to the other entropies.

关键词： Shannon entropy mathai-Haubold entropy quantile function residual entropy order statistics failure time reliability measures

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Simplified mathematical model of proton exchange membrane fuel cell based on horizon fuel cell stack

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Journal of modern Power Systems and Clean Energy 2016年第4期4卷 668-679页

作者： ibrahim m.m.SALEH Rashid ALI Hongwei ZHANG materials and Engineering Research Institute Sheffield Hallam UniversitySheffieldUK

This paper presents a simplified zero-dimensional mathematical model for a self-humidifying proton exchange membrane(PEm)fuel cell stack of 1 k *** model incorporates major electric and thermodynamic variables and parameters involved in the operation of the PEm fuel cell under different operational *** of each of these parameters and variables upon the operation and the performance of the PEm fuel cell are *** mathematical equations are modeled by using matlab-Simulink tools in order to simulate the operation of the developed model with a commercial available 1kW horizon PEm fuel cell stack(H-1000),which is used for the purposes of model validation and tuning of the developed *** model can be extrapolated to higher wattage fuel cells of similar *** equation is presented to determine the impact of using air to supply the PEm fuel cell instead of pure oxygen upon the concentration losses and the output voltage when useful current is drawn from it.

关键词： Proton exchange membrane(PEm)fuel cell Activation losses Ohmic losses Concentration losses Cathode-anode model membrane hydration model

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Numerical investigations of asymmetric flow of a micropolar fluid between two porous disks

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Acta mechanica Sinica 2009年第6期25卷 787-794页

作者： muhammad Ashraf m.Anwar Kamal K.S.syed Centre for Advanced Studies in Pure and Applied mathematics Bahauddin Zakariya University Multan Pakistan Department of mathematics King Saud University RiyadhSaudi Arabia

Numerical solution is presented for the two- dimensional flow of a micropolar fluid between two porous coaxial disks of different permeability for a range of Reynolds number Re （-300≤ Re 〈 0） and permeability parameter A （1.0≤A ≤2.0）. The main flow is superimposed by the injection at the surfaces of the two disks. Von Karman＇s similarity transformations are used to reduce the governing equations of motion to a set of non-linear coupled ordinary differential equations （ODEs） in dimensionless form. An algorithm based on the finite difference method is employed to solve these ODEs and Richardson＇s extrapolation is used to obtain higher order accuracy. The results indicate that the parameters Re and A have a strong influence on the velocity and microrotation profiles, shear stresses at the disks and the position of the viscous/shear layer. The micropolar material constants cl, c2, c3 have profound effect on microrotation as compared to their effect on streamwise and axial velocity profiles. The results of micropolar fluids are compared with the results for Newtonian fluids.

关键词： Porous disks . Asymmetric flow .micropolar fluid . Finite differences.Viscous layer

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Bianchi type I in f(T) gravitational theories

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Chinese Physics B 2016年第5期25卷 58-64页

作者： m I Wanas G G L Nashed O A ibrahim Astronomy Department Faculty of Science Cairo University Cairo Egypt Centre for Theoretical Physics The British University in Egypt El-Sherouk City Egypt mathematics Department Faculty of Science Ain Shams University Cairo Egypt Egyptian Relativity Group (ERG) Giza Egypt

A tetrad field that is homogeneous and anisotropic which contains two unknown functions A（t） and B（t） of cosmic time is applied to the field equations of f（T）, where T is the torsion scalar, T = T~μ_（νρ）S_μ^（νρ）. We calculate the equation of continuity and rewrite it as a product of two brackets, the first is a function of f（T） and the second is a function of the two unknowns A（t） and B（t）. We use two different relations between the two unknown functions A（t） and B（t） in the second bracket to solve it. Both of these relations give constant scalar torsion and solutions coincide with the de Sitter one. So,another assumption related to the contents of the matter fields is postulated. This assumption enables us to drive a solution with a non-constant value of the scalar torsion and a form of f（T） which represents ΛCDm.

关键词： f(T) gravitational theory Bianchi type I special solutions

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Implementation Study of Dynamic Load Balancing Algorithm of Parallel Tree Computation on Clusters of Heterogeneous Workstation

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Journal of Donghua University(English Edition) 2005年第2期22卷 81-86页

作者： mohammed A.m. ibrahim m.Saifmokbel Faculty of Engineering Department of Software Engineering Taiz University Republic of Yemen Taiz city P. O.Box:6038

The rapid growth of interconnected high performance workstations has produced a new computing paradigm called clustered of workstations computing. In these systems load balance problem is a serious impediment to achieve good performance. The main concern of this paper is the implementation of dynamic load balancing algorithm, asynchronous Round Robin (ARR), for balancing workload of parallel tree computation depth-first-search algorithm on Cluster of Heterogeneous Workstations (COW) many algorithms in artificial intelligence and other areas of computer science are based on depth first search in implicitty defined trees. For these algorithms a load-balancing scheme is required, which is able to evenly distribute parts of an irregularly shaped tree over the workstations with minimal interprocessor communication and without prior knowledge of the tree’s shape. For the (ARR) algorithm only minimal interprocessor communication is needed when necessary and it runs under the mPI (message passing interface) that allows parallel execution on heterogeneous SUN cluster of workstation platform. The program code is written in C language and executed under UNIX operating system (Solaris version).

关键词： cluster of workstations parallel tree computation dynamic load balancing performance metrics

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Wear Behaviour of Plasma Paste Boronized of AISI 8620 Steel with Borax and B_2O_3 Paste mixtures

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Journal of materials Science & Technology 2013年第7期29卷 662-668页

作者： ibrahim Gunes Department of metallurgical and materials Engineering Faculty of TechnologyAfyon Kocatepe UniversityAfyonkarahisar 03200Turkey

In the present study, AlSl 8620 steel was plasma paste boronized （PPB） by using paste mixtures with different borax and B2O3 percentages. The PPB process was carried out in a DC plasma system at 973, 1023 and 1073 K for 5 h in a gas mixture with 70% H2-30% Ar under a constant pressure of 103 Pa （10 mbar）. The thickness of boride layers ranged from 15.9 to 53.6 tim depending on the temperature and process time. The hardness of the borides formed on the surface of the steel substrate and unborided steel substrate were 1648-1924 HV0.05 and 226 HV0.05, respectively. X-ray diffraction analysis of the boride layers on the surface of the samples were obtained for FeB and Fe2B phases. The wear tests on the steel were performed by using a ball-on-disc test device at room temperature with applied load of 10 N and with a shear velocity of 0.2 m/s. Wear test results showed that the highest value of wear rate was observed in the unborided sample while the lowest wear rate was observed in the PPB samples with 30% borax ＋ 70% B4C paste at 1073 K for 5 h.

关键词： Coating Borax B2O3 Wear Coefficient of friction

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Deep Imitation Learning for Autonomous Vehicles Based on Convolutional Neural Networks

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IEEE/CAA Journal of Automatica Sinica 2020年第1期7卷 82-95页

作者： Parham m.Kebria Abbas Khosravi syed moshfeq Salaken Saeid Nahavandi Intelligent Systems Research and Innovation(IISRI) Deakin UniversityWaurn PondsVIC 3216Australia

Providing autonomous systems with an effective quantity and quality of information from a desired task is challenging. In particular, autonomous vehicles, must have a reliable vision of their workspace to robustly accomplish driving functions. Speaking of machine vision, deep learning techniques, and specifically convolutional neural networks, have been proven to be the state of the art technology in the field. As these networks typically involve millions of parameters and elements, designing an optimal architecture for deep learning structures is a difficult task which is globally under investigation by researchers. This study experimentally evaluates the impact of three major architectural properties of convolutional networks, including the number of layers, filters, and filter size on their performance. In this study, several models with different properties are developed,equally trained, and then applied to an autonomous car in a realistic simulation environment. A new ensemble approach is also proposed to calculate and update weights for the models regarding their mean squared error values. Based on design properties,performance results are reported and compared for further investigations. Surprisingly, the number of filters itself does not largely affect the performance efficiency. As a result, proper allocation of filters with different kernel sizes through the layers introduces a considerable improvement in the *** of this study will provide the researchers with a clear clue and direction in designing optimal network architectures for deep learning purposes.

关键词： Autonomous vehicles convolutional neural networks deep learning imitation learning

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multi-Physics Numerical Simulation of Thermoelectric Devices

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Journal of Electronics Cooling and Thermal Control 2017年第4期7卷 123-135页

作者： ibrahim m. Abdel-motaleb syed m. Qadri Department of Electrical Engineering Northern Illinois University DeKalb IL USA

To optimize the performance of a thermoelectric device for a specific application, the device should be uniquely designed for the application. Achieving an optimum design requires accurate measurements and credible analysis to evaluate the performance of the device and its relationship with the device parameters. To do that, we designed, fabricated, and tested four devices based on Bi2Te3 and Sb2Te3. To evaluate the accuracy of our analysis, experimental measurements were compared with the numerical simulation performed using COmSOLTm. The two sets of results were found to be in full agreement. This is a proof of the accuracy of our experimental measurements and the credibility of our simulation. The study shows that testing or simulating the devices without heat sink will lead to skewed results. This is because the junction will not hold its temperatures value, but will, instead, automatically change its value to the direction of thermal equilibrium. The study shows also that there is no reciprocity between the input and the output characteristics of the devices. Therefore, a device optimized for cooling and heating may not be automatically optimized for energy harvesting. For heating and cooling, temperature sensitivity should be optimized;while for energy harvesting, voltage sensitivity should be optimized. Using heat sink, our devices achieved a voltage sensitivity of 187.77 μV/K and a temperature sensitivity of 6.12 K/mV.

关键词： Thermoelectric Devices multi-Leg Devices Bi2Te3 Sb2Te3 COmSOL Fi-nite Element Simulation Voltage Sensitivity Temperature Sensitivity

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