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Effect of Multi-Step Tempering on Retained Austenite and Mechanical Properties of Low Alloy Steel

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Journal of Iron and Steel Research International 2011年第12期18卷 49-56页

作者： Hamid Reza Bakhsheshi-Rad ahmad Monshi Hossain Monajatizadeh Mohd Hasbullah idris mohammed Rafiq Abdul Kadir Hassan Jafari Materials Engineering Department Islamic Azad University Materials Engineering Department Faculty of Mechanical EngineeringUniversity Technology Malaysia Materials Engineering Department Faculty of Mechanical EngineeringShahid Rajaee Teacher Training University

The effect of multi-step tempering on retained austenite content and mechanical properties of low alloy steel used in the forged cold back-up roll was *** evolutions were characterized by optical microscope,X-ray diffraction,scanning electron microscope and Feritscope,while the mechanical properties were determined by hardness and tensile *** results revealed that the content of retained austenite decreased by about 2% after multi-step ***,the content of retained austenite increased from 3.6% to 5.1% by increasing multi-step tempering *** hardness and tensile strength increased as the austenitization temperature changed from 800 to 920 ℃,while above 920 ℃,hardness and tensile strength *** addition,the maximum values of hardness,ultimate and yield strength were obtained via triple tempering at 520 ℃,while beyond 520 ℃,the hardness,ultimate and yield strength decreased sharply.

关键词： cold back-up roll retained austenite mechanical property austenite grain size

Mechanical properties of stabilized zirconia nanocrystalline EB-PVD coating evaluated by micro and nano indentation

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Journal of Advanced Ceramics 2013年第4期2卷 333-340页

作者： Meysam KESHAVARZ Mohd Hasbullah idris Norhayati ahmad Department of Materials Science and Engineering Faculty of Mechanical EngineeringUniversiti Teknologi Malaysia81310 UTM Johor BahruJohorMalaysia

Yttria-stabilized zirconia(YSZ)thin nanocrystalline coatings at different substrate preheating temperatures were deposited via electron beam-physical vapour deposition(EB-PVD).Nanocrystalline ZrO_(2)-Y_(2)O_(3) was deposited on the bond coat in order to compensate for the coefficient of thermal expansion(CTE),which can be functionalized as a thermal barrier coating(TBC).The aim of this study was to evaluate mechanical properties with respect to adhesion of zirconia nanocrystalline’s top ceramic layer to the interfacial bond coat by utilizing micro and nano indentation *** the present paper,the structural studies were carried out using X-ray diffraction(XRD)analysis of coating content(8 mol%of Y_(2)O_(3)).The tetragonal phase of stabilized zirconia was *** emission scanning electron microscopy(FESEM)and atomic force microscopy(AFM)were employed to characterize the coatings’morphology and *** mechanical behavior of ZrO_(2)-Y_(2)O_(3) thin films under point loading conditions was studied by nanoindentation using a Berkovich indenter with 130 nm tip ***,adhesion of top coat to the interfacial underlying metallic bond coat known as MCrAlY(M=Ni,Co)was estimated according to the highest peak load tests;for a 120 mN peak load,the film manifested tolerable adhesion ***,nanoindentation of ZrO_(2)-Y_(2)O_(3) nanostructure deposited at 1050℃substrate preheating temperature produced the highest hardness value of about 21.7 *** micro hardness was utilized with the aid of the Tabor equation in order to achieve deeper insight into the correlation between adhesion and deposition process parameters.

关键词： zirconia nanoindentation nanocrystalline electron beam-physical vapour deposition(EB-PVD) thermal barrier coating(TBC)

Jack up reliability analysis:An overview

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Frontiers of Structural and Civil Engineering 2018年第4期12卷 504-514页

作者： ahmad idris Indra Sati Hamonangan HARAHAP Montasir Osman Ahmed ALI Department of Civil and Environmental Engineering Universiti Teknologi PetronasBandar Seri Iskandar32610Malaysia

Jack up is a mobile unit used for oil and gas exploration and production in offshore fields. On demand, the unit is moved and installed in a given location and used for a period up to 12 months before being un-installed and moved to another location. Due to its mobility and re-usability, when the unit is offered for use in a given offshore location, its suitability in terms of safe operation is evaluated in accordance with the guidelines of Site Specific Assessment (SSA) of jack up. When the unit failed safety assessment criteria, the guideline recommended that it is re-assessed by increasing the complexity of the assumptions and methods used. Reliability analysis theories are one of the frameworks recommended for the safety assessment of the units. With recent developments in uncertainty and reliability analysis of structures subject to stochastic excitation, this study aims at providing a review on the past developments in jack up reliability analysis and to identify possible future directions. The results from literature reviewed shows that failure probabilities vary significantly with analysis method used. In addition, from the variants of reliability analysis approach, the method of time dependent reliability for dynamic structures subject to stochastic excitation have not been implemented on jack ups. Consequently, suggestions were made on the areas that need further examination for improvement of the efficiency in safety assessment of the units using reliability theories.

关键词： jack up reliability analysis uncertainty analysis review of jack up

Optimum alternate material selection methodology for an aircraft skin

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Chinese Journal of Aeronautics 2023年第7期36卷 476-488页

作者： Fareed ahmad mohammed Al AWADH Sahar NOOR Industrial Engineering Department University of Engineering and TechnologyPeshawar 25000Pakistan Department of Industrial Engineering College of EngineeringKing Khalid UniversityAbha 62529Saudi Arabia

Weight penalty has been a challenge for design engineers of aerospace ***’s high-efficiency combat aircraft undergoes intense stress and strain during flying missions,which require stronger and stiffer materials to retain structural *** metallic materials have been successfully used for the construction of aircraft structures and components,metals still have a low strength-to-weight *** paper aims to develop an alternate optimised material selection methodology to replace the metallic skin of a medium-sized military *** search for the optimum material will result in reduced aircraft weight which will be benefitted by extra payload on the *** selection methodology is comprised of finding design pressure limits on the aircraft skin,and comparison of properties(strength,elastic modulus,shear modulus,etc.)and performance(safety factor,deflection,and stress)of the existing metallic skin with alternate optimised *** comparison was made under aerodynamic pressure,bending force,and twisting *** Fibre Reinforced Polymer/Epoxy(CFRP)Uni-Directional(UD)prepreg(elastic modolus is 209 GPa)was selected as an alternate optimum material to replace the aluminium alloy skin of the aircraft *** selected alternate optimum material resulted in the reduction of aircraft skin weight by 30%.

关键词： Aircraft skin Carbon Fibre Reinforced Plastic(CFRP) Material index Material selection methodology Optimum material

An Optimized Method for Accounting Information in Logistic Systems

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Computer Systems Science & Engineering 2023年第5期45卷 1595-1609页

作者： ahmad mohammed Alamri ahmad Ali AlZubi Administrative Sciences Department Community CollegeKing Saud UniversityRiyadhSaudi Arabia Computer Science Department Community CollegeKing Saud UniversityP.O.Box 28095Riyadh11437Saudi Arabia

In the era of rapid information development,with the popularity of computers,the advancement of science and technology,and the ongoing expansion of IT technology and business,the enterprise resource planning(ERP)system has evolved into a platform and a guarantee for the fulfilment of company management procedures after long-term *** of developments in information technology,most manual accounting procedures are being replaced by computerized Accounting Information Systems(AIS),which are quicker and more *** primary factors influencing the decisions of logistics firm trading parties are investigated in order to enhance the design of decision-supporting modules and to improve the performance of logistics enterprises through *** paper proposed a novel approach to calculate the weights of each information element in order to establish their important *** main purpose of this research is to present a quantitative analytic approach for determining the important information of logistics business collaboration ***,the idea of total orders and the significant degrees stated above are used to identify the optimal order of all information *** the three ways of marginal revenue,marginal cost,and business matching degree,the information with cumulative weights is which is deployed to form the data from the intersection of the best *** has the ability to drastically reduce the time and effort required to create a logistics business control/decision-making system.

关键词： Accounting information systems decisions systems corporate accounting logistic system

Robust Adaptive Multi-Switching Synchronization of Multiple Different Orders Unknown Chaotic Systems

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Journal of Systems Science & Complexity 2020年第5期33卷 1330-1359页

作者： MUHAMMAD Shafiq ISRAR ahmad AMBUSAIDI mohammed BASHIR Naderi Department of Electrical Engineering Sultan Qaboos UniversityOman Department of General Requirements College of Appled Sciences NizwaOman Department of Mathematics Payame Noor University

Multi-switching synchronizatio of multiple different orders unknown chaotisystems confines hacking in the digital transmission ***,the suppression of undesirable chattering increases synchronization *** paper proposes a new robust synchronization contro technique and discusses the MSS of multiple different orders UC *** controller accomplishe quick convergence reduces the transient oscillations,an the rate of convergence decreases in the vicinity of the origin that causes the suppression of *** based on the Lyapunov direct method assures this convergence behavior with any positive values of the feedback *** work also provides parameters updated law that estimates the true values of unknown *** examples of five UC systems different orders are *** computer based graphical results validate the efficiency and performance of the proposed RASC technique and the synchronization strategy when compare to peer *** the simulation,the proposed synchronization strategy successfully recovers an encrypted received image on a communication *** article suggests some future research problems to extend the use of the proposed work.

关键词： Chaos synchronization Lyapunov stability theory robust adaptive controller unknown chaotic systems

Novel Framework for an Intrusion Detection System Using Multiple Feature Selection Methods Based on Deep Learning

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Tsinghua Science and Technology 2024年第4期29卷 948-958页

作者： A.E.M.Eljialy mohammed Yousuf Uddin Sultan ahmad Department of Information Systems College of Computer Engineering and SciencesPrince Sattam Bin Abdulaziz UniversityAlkharjSaudi Arabia Department of Computer Science College of Computer Engineering and SciencesPrince Sattam Bin Abdulaziz UniversityAlkharjSaudi Arabiaand also with University Center for Research and Development(UCRD)Department of Computer Science and EngineeringChandigarh UniversityPunjabIndia

Intrusion detection systems (IDSs) are deployed to detect anomalies in real time. They classify a network’s incoming traffic as benign or anomalous (attack). An efficient and robust IDS in software-defined networks is an inevitable component of network security. The main challenges of such an IDS are achieving zero or extremely low false positive rates and high detection rates. Internet of Things (IoT) networks run by using devices with minimal resources. This situation makes deploying traditional IDSs in IoT networks unfeasible. Machine learning (ML) techniques are extensively applied to build robust IDSs. Many researchers have utilized different ML methods and techniques to address the above challenges. The development of an efficient IDS starts with a good feature selection process to avoid overfitting the ML model. This work proposes a multiple feature selection process followed by classification. In this study, the Software-defined networking (SDN) dataset is used to train and test the proposed model. This model applies multiple feature selection techniques to select high-scoring features from a set of features. Highly relevant features for anomaly detection are selected on the basis of their scores to generate the candidate dataset. Multiple classification algorithms are applied to the candidate dataset to build models. The proposed model exhibits considerable improvement in the detection of attacks with high accuracy and low false positive rates, even with a few features selected.

关键词： random forest feature selection decision tree software-defined network logistic regression intrusion detection system XGB classifier AdaBoost

Hyper-Tuned Convolutional Neural Networks for Authorship Verification in Digital Forensic Investigations

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Computers, Materials & Continua 2023年第8期76卷 1947-1976页

作者： Asif Rahim Yanru Zhong Tariq ahmad Sadique ahmad mohammed A.ElAffendi School of Computer and Information Security Guilin University of Electronic TechnologyGuilin541004China Guangxi Key Laboratory of Intelligent Processing of Computer Images and Graphics Guilin University of Electronic TechnologyGuilin541004China School of Information and Communication Guilin University of Electronic TechnologyGuilin541004China EIAS:Data Science and Blockchain Laboratory College of Computer and Information SciencesPrince Sultan UniversityRiyadh11586Saudi Arabia

Authorship verification is a crucial task in digital forensic investigations,where it is often necessary to determine whether a specific individual wrote a particular piece of *** Neural Networks(CNNs)have shown promise in solving this problem,but their performance highly depends on the choice of *** this paper,we explore the effectiveness of hyperparameter tuning in improving the performance of CNNs for authorship *** conduct experiments using a Hyper Tuned CNN model with three popular optimization algorithms:Adaptive Moment Estimation(ADAM),StochasticGradientDescent(SGD),andRoot Mean Squared Propagation(RMSPROP).The model is trained and tested on a dataset of text samples collected from various authors,and the performance is evaluated using accuracy,precision,recall,and F1 *** compare the performance of the three optimization algorithms and demonstrate the effectiveness of hyperparameter tuning in improving the accuracy of the CNN *** results show that the Hyper Tuned CNN model with ADAM Optimizer achieves the highest accuracy of up to 90%.Furthermore,we demonstrate that hyperparameter tuning can help achieve significant performance improvements,even using a relatively simple model architecture like *** findings suggest that the choice of the optimization algorithm is a crucial factor in the performance of CNNs for authorship verification and that hyperparameter tuning can be an effective way to optimize this ***,this paper demonstrates the effectiveness of hyperparameter tuning in improving the performance of CNNs for authorship verification in digital forensic *** findings have important implications for developing accurate and reliable authorship verification systems,which are crucial for various applications in digital forensics,such as identifying the author of anonymous threatening messages or detecting cases of plagiarism.

关键词： Convolutional Neural Network(CNN) hyper-tuning authorship verification digital forensics

Characterization of lauryl betaine foam in the Hele-Shaw cell at high foam qualities(80%-98%)

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Petroleum Science 2020年第6期17卷 1634-1654页

作者： Asad Hassan Syed Nurudeen Yekeen Eswaran Padmanabhan ahmad Kamal idris Dzeti Farhah Mohshim Department of Petroleum Engineering Faculty of Geoscience and Petroleum Engineering32610 Seri IskandarPerakMalaysia Institute of Hydrocarbon Recovery Universiti Teknologi PETRONAS32610 Bandar Seri IskandarPerakMalaysia

Lauryl betaine(LB)as an amphoteric surfactant carries both positive and negative charges and should be able to generate stable foam through electrostatic interaction with nanoparticles and ***,no previous attempts have been made to investigate the influence of nanoparticles and other co-surfactants on the stability and apparent viscosity of LBstabilized *** this study,a thorough investigation on the influence of silicon dioxide(SiO2)nanoparticles,alpha olefin sulfonate(AOS)and sodium dodecyl sulfate(SDS),on foam stability and apparent viscosity was carried *** experiments were conducted with the 2D Hele-Shaw cell at high foam qualities(80%-98%).Influence of AOS on the interaction between the LB foam and oil was also *** showed that the SiO2-LB foam apparent viscosity decreased with increasing surfactant concentration from 0.1 wt%to 0.3 wt%.0.1 wt%SiO2 was the optimum concentration and increased the 0.1 wt%LB foam stability by 108.65%at 96%foam *** the presence of co-surfactants,the most stable foam,with the highest apparent viscosity,was generated by AOS/LB solution at a ratio of 9:*** emulsified crude oil did not imbibe into AOS-LB foam ***,oil was redirected into the plateau borders where the accumulated oil drops delayed the rate of film thinning,bubble coalescence and coarsening.

关键词： Foam stability Surfactant Nanoparticles Lauryl betaine Foam quality Foam apparent viscosity