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Smart prediction of liquefaction-induced lateral spreading

Journal of Rock Mechanics and Geotechnical Engineering 2024年第6期16卷 2310-2325页

作者： Muhammad Nouman Amjad Raja Tarek Abdoun waleed el-sekelly New York University(NYU)Abu Dhabi Abu Dhabi129188United Arab Emirates University of Management and Technology Lahore54372Pakistan Department of Civil and Environmental Eng. Rensselaer Polytechnic Institute(RPI)1108th StreetJEC 4049TroyNY12180USA Department of Structural Engineering Mansoura UniversityMansoura35516Egypt

The prediction of liquefaction-induced lateral spreading/displacement(Dh)is a challenging task for civil/geotechnical *** this study,a new approach is proposed to predict Dh using gene expression programming(GEP).Based on statistical reasoning,individual models were developed for two topographies:free-face and gently sloping *** with a comparison with conventional approaches for predicting the Dh,four additional regression-based soft computing models,*** process regression(GPR),relevance vector machine(RVM),sequential minimal optimization regression(SMOR),and M5-tree,were developed and compared with the GEP *** results indicate that the GEP models predict Dh with less bias,as evidenced by the root mean square error(RMSE)and mean absolute error(MAE)for training(i.e.1.092 and 0.815;and 0.643 and 0.526)and for testing(i.e.0.89 and 0.705;and 0.773 and 0.573)in free-face and gently sloping ground topographies,*** overall performance for the free-face topology was ranked as follows:GEP>RVM>M5-tree>GPR>SMOR,with a total score of 40,32,24,15,and 10,*** the gently sloping condition,the performance was ranked as follows:GEP>RVM>GPR>M5-tree>SMOR with a total score of 40,32,21,19,and 8,***,the results of the sensitivity analysis showed that for both free-face and gently sloping ground,the liquefiable layer thickness(T_(15))was the major parameter with percentage deterioration(%D)value of 99.15 and 90.72,respectively.

关键词： Lateral spreading Intelligent modeling Gene expression programming(GEP) Closed-form solution Feature importance

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Development and characterization of a regional lunar soil simulant for emirates lunar missions

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International Journal of Mining Science and Technology 2024年第9期34卷 1305-1315页

作者： Bo Peng Prabu Thannasi waleed el-sekelly Tarek Abdoun Kemal Celik Division of Engineering New York University Abu DhabiAbu Dhabi PO Box 129188United Arab Emirates Structural Engineering Department Faculty of EngineeringMansoura UniversityMansoura 35516Egypt

Lunar soil simulants(LSS)have been pivotal in the success of past and current lunar *** have enhanced the design of lander and rover wheels through interaction studies on the lunar testbed under simulated environmental *** have also been used to evaluate the geotechnical,geomechanical,and dynamic characteristics of the lunar soil(LS),which is vital for future lunar *** most simulants have focused on either the chemical and mineralogical or geotechnical properties,developing a comprehensive LSS that mimics the lunar soil is of paramount importance for lander and rover soft-landing and future lunar *** article presents the significant development and characterization of the new LSS NYUAD-1,the first regional soil simulant tailored for the planned Emirates lunar *** material and geotechnical properties of NYUAD-1,including chemical composition,mineralogy,particle size,morphology,specific gravity,density,shear strength,and compressibility behaviors,were assessed through laboratory tests conducted per ASTM *** analysis with authentic lunar regolith and various regolith simulants confirms the significance and applicability of NYUAD-1 for lunar-based research,offering a promising step toward future lunar habitation.

关键词： LSS Chemical composition Mineralogy Density Shear strength Compressibility

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Preparation and characterization of (CeO2)x-(Fe2O3)1-x nanocomposites:reduction kinetics and hydrogen storage

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Rare Metals 2020年第3期39卷 218-229页

作者： Shimaa G.Sayed waleed M.A.el Rouby Ahmed A.Farghali Materials Science and Nanotechnology Department Faculty of Postgraduate Studies for Advanced Science(PSAS)Beni-Suef UniversityBeni Suef62511Egypt

A series of nanosized CeO2-Fe2O3 mixed-oxide nanocomposites with different Ce4+/Fe3+molar ratios were successfully prepared by a co-precipitation *** surface area increased with Fe2O3 content increasing up to 60 wt%in the ***,with further increase in Fe2O3 content,the surface area began to *** reduction processes of the CeO2-Fe2O3 nanocomposites were studied in a hydrogen atmosphere at 300-600℃.The reduction rates increased by increasing both the temperature and Fe2O3 content in the *** microstructure of the reduced composites at 500℃illustrated the presence of a considerable number of macro-and *** activation energy values were calculated which were in the range of 3.56-5.37 kJ mol-1 at the initial stages(up to 35%reduction)and 5.21-10.2 kJ·mol-1 at the final stages(up to 80%reduction)of *** rate-controlling mechanisms in both the initial and final reduction stages were determined,and the initial reaction stage was controlled by combined gaseous diffusion and interfacial chemical reaction mechanisms for all the composites except for pure CeO2,which was controlled by a chemical reaction *** final reaction stage was controlled by a gaseous diffusion mechanism for some composites,while for the others it was controlled by combined gaseous diffusion and interfacial chemical reaction *** hydrogen sorption properties of the nanocomposites were studied by pressure composition isotherms using a volumetric *** storage in the nanocomposites increased by increasing the temperature because of the formation of oxygen vacancies which enhance atomic H adsorption and function as strong adsorption sites forming more metal hydride covalent bonds.

关键词： CeO2-Fe2O3 nanocomposite Reduction kinetics Reduction mechanism Hydrogen storage Oxygen vacancies

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Glycated Hemoglobin HbA1c:Permittivity Experimental Applications with Some Mathematical Concepts,Temperature and Frequency Variations

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Journal of Renewable Materials 2022年第9期10卷 2335-2354页

作者： Soliman Abdalla Sherif Kandil waleed el-Shirbeeny Fatma Bahabri Department of Physics Faculty of ScienceKing Abdulaziz UniversityJeddahSaudi Arabia Department of Materials Science Institute of Graduate Studies and ResearchAlexandria UniversityAlexandriaEgypt Department of Physics Faculty of ScienceJeddah UniversityJeddahSaudi Arabia

Diabetes disorder turns smoothly to be a global epidemic disorder and the glycated hemoglobin(HbA1c)starts to be an efficient marker of *** dielectric spectroscopy on different human normal-and diabetic-blood samples is used to characterize and to estimate the HbA1c concentration.“dc-”and ac-measurement of the complex conductivity in the temperature range from 280 K up to 320 K,and in the frequency range from one Hz up to 32 MHz have been *** thermal activation energy,ΔEσ,of dc-electric conductivity lies in the range 95 meVelaxation time is aboutΔEτ=140 *** experimental data have been modeled by a physical-model and good fittings have been found between calculated and experimental *** effective number of charges,nG,T,is estimated after Cole and Cole *** has found that nG,T increases with both temperature,T,and with the glycation rate *** increase may shed some light on an effective and possible way to treat(and to detect)diabetes disorders via eliminating the excess electric charges produced by glycation *** present work sheds the light on the possible combination of focused ultrasound with magnetic resonance imaging to study the dielectric-thermal variations of glycated-RBCs,which can lead to very precise and non-invasive monitoring of glycation concentration in vivo and in vitro via magnetic resonance-thermometry.

关键词： Glycated-hemoglobin rate thermal characterization red blood cells RBCs relaxation of RBCs dielectric constant mathematical model

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Received Power Based Unmanned Aerial Vehicles (UAVs) Jamming Detection and Nodes Classification Using Machine Learning

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Computers, Materials & Continua 2023年第4期75卷 1253-1269页

作者： waleed Aldosari Department of Computer Engineering College of Computer Engineering and SciencesPrince Sattam bin Abdulaziz UniversityAl-Kharj11942Saudi Arabia

This paper presents a machine-learning method for detecting jamming UAVs and classifying nodes during jamming attacks onWireless Sensor Networks(WSNs).Jamming is a type of Denial of Service(DoS)attack and intentional interference where a malicious node transmits a high-power signal to increase noise on the receiver side to disrupt the communication channel and reduce performance *** defend and prevent such attacks,the first step is to detect *** current detection approaches use centralized techniques to detect jamming,where each node collects information and forwards it to the base *** a result,overhead and communication costs *** this work,we present a jamming attack and classify nodes into different categories based on their location to the jammer by employing a single node *** a result,we introduced a machine learning model that uses distance ratios and power received as features to detect such ***,we considered several types of jammers transmitting at different power levels to evaluate the proposed metrics using *** a detection accuracy of 99.7%for the k-nearest neighbors(KNN)algorithm and average testing accuracy of 99.9%,the presented solution is capable of efficiently and accurately detecting jamming attacks in wireless sensor networks.

关键词： Jamming attacks machine learning unmanned aerial vehicle(UAV) WSNs

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Outcomes of pancreaticoduodenectomy in elderly patients

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Hepatobiliary & Pancreatic Diseases International 2016年第4期15卷 419-427页

作者： Ayman el Nakeeb Ehab Atef Ehab el Hanafy Ali Salem waleed Askar Helmy Ezzat Ahmed Shehta Mohamed Abdel Wahab Gastroenterology Surgical Center Mansoura University

BACKGROUND： Although the mortality and morbidity of pancreaticoduodenectomy（PD） have improved significantly over the past years, the concerns for elderly patients undergoing PD are still present. Furthermore, the frequency of PD is increasing because of the increasing proportion of elderly patients and the increasing incidence of periampullary tumors. This study aimed to analyze the outcomes of PD in elderly ***： We studied all patients who had undergone PD in our center between January 1995 and February 2015. The patients were divided into three groups based on age： group I（patients aged 〈60 years）, group II（those aged 60 to 69 years） and group III（those aged ≥70 years）. The primary outcome was the rate of total postoperative complications. Secondary endpoint included total operative time, hospital mortality, length of postoperative hospital stay, delayed gastric emptying, re-exploration, and survival ***： A total of 828 patients who had undergone PD for resection of periampullary tumor were included in this study. There were 579（69.9%） patients in group I, 201（24.3%） in group II, and 48（5.8%） in group III. The overall incidence of complications was higher in elderly patients（25.9% in group I, 36.8% in group II, and 37.5% in group III; P=0.006）. There were more patients complicated with delayed gastric emptying in group II compared with the other two groups. There was no significant difference in the incidence of postoperative pancreatic fistula, biliary leakage, pancreatitis, pulmonary complications and hospital ***： PD can be performed safely in selected elderly patients. Advanced age alone should not be a contraindication for PD. The outcome of elderly patients who have undergone PD is similar to that of younger patients, and the increased rate of complications is due to the presence of associated comorbidities.

关键词： pancreaticoduodenectomy elderly pancreatic fistula delayed gastric emptying

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Biliary leakage following pancreaticoduodenectomy:Prevalence,risk factors and management

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Hepatobiliary & Pancreatic Diseases International 2019年第1期18卷 67-72页

作者： Ayman el Nakeeb Mohamed el Sorogy Hosam Hamed Rami Said Mohamad elrefai Helmy Ezzat waleed Askar Ahmed M elsabbagh Gastroenterology Surgical Center Mansoura University

Background: Few studies investigated biliary leakage after pancreaticoduodenectomy(PD) especially when compared to postoperative pancreatic fistula(POPF). This study was to determine the incidence of biliary leakage after PD, predisposing factors of biliary leakage, and its management. Methods: We retrospectively studied all patients who underwent PD from January 2008 to December 2017 at Gastrointestinal Surgery Center, Mansoura University, Egypt. According to occurrence of postoperative biliary leakage, patients were divided into two groups. Group(1) included patients who developed biliary leakage and group(2) included patients without identified biliary leakage. The preoperative data, operative details, and postoperative morbidity and mortality were analyzed. Results: The study included 555 patients. Forty-four patients(7.9%) developed biliary leakage. Ten patients(1.8%) had concomitant POPF. Multivariate analysis identified obesity and time needed for hepaticojejunostomy reconstruction as independent risk factors of biliary leakage, and no history of preoperative endoscopic retrograde cholangiopancreatiography(ERCP) as protective factor. Biliary leakage from hepaticojejunostomy after PD leads to a significant increase in development of delayed gastric emptying, and wound infection. The median hospital stay and time to resume oral intake were significantly greater in the biliary leakage group. Non-surgical management was needed in 40 patients(90.9%). Only 4 patients(9.1%) required re-exploration due to biliary peritonitis and associated POPF. The mortality rate in the biliary leakage group was significantly higher than that of the non-biliary leakage group(6.8% vs 3.9%, P = 0.05). Conclusions: Obesity and time needed for hepaticojejunostomy reconstruction are independent risk factors of biliary leakage, and no history of preoperative ERCP is protective factor. Biliary leakage increases the risk of morbidity and mortality especially if concomitant with POPF. Howeve

关键词： Pancreatic head carcinoma Pancreaticodudenetomy Postoperative pancreatic fistula Biliary leakage

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Microstructure characteristics and tensile property of ultrasonic treated-thixocast A356 alloy

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Transactions of Nonferrous Metals Society of China 2015年第10期25卷 3173-3180页

作者： waleed KHALIFA Shimaa el-HADAD Yoshiki TSUNEKAWA Department of Mining Petroleum and Metallurgical EngineeringFaculty of EngineeringCairo University Central Metallurgical Research & Development Institute Cairo P.O.Box 87Egypt Toyota Technological Institute 2-12-1 HisakataTempakuNagoya 468-8511Japan

Billets of A356 aluminum alloy were treated using ultrasonic vibrations during *** billets were reheated to the semisolid state at different routes to optimize the *** were,then,thixocast using a die casting *** results showed that the ultrasonic-treated billets exhibited finely distributed α（Al） globules after reheating and *** thixocast ultrasonic-treated billets showed higher ultimate tensile strength and elongation compared with the untreated ***,the thixocast parts showed a tendency to ductile fracture under tension when made from ultrasonic-treated billets,while those made of untreated billets showed brittle fracture with obvious straight *** results revealed the feasibility and competence of ultrasonic melt treatment as a potential route for preparing billets for thixocasting.

关键词： A356 alloy semi-solid forming ultrasonic treatment reheating thixocasting tensile property

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Precision time protocol attack strategies and their resistance to existing security extensions

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Cybersecurity 2021年第1期4卷 160-176页

作者： waleed Alghamdi Michael Schukat School of Computer Science National University of Ireland Galway Ireland

The IEEE 1588 precision time protocol(PTP)is very important for many industrial sectors and applications that require time synchronization accuracy between computers down to microsecond and even nanosecond ***,PTP and its underlying network infrastructure are vulnerable to cyber-attacks,which can stealthily reduce the time synchronization accuracy to unacceptable and even damage-causing levels for individual clocks or an entire network,leading to financial loss or even physical *** security protocol extensions only partially address this *** paper provides a comprehensive analysis of strategies for advanced persistent threats to PTP infrastructure,possible attacker locations,and the impact on clock and network synchronization in the presence of security protocol extensions,infrastructure redundancy,and protocol *** distinguishes between attack strategies and attacker types as described in RFC7384,but further distinguishes between the spoofing and time source attack,the simple internal attack,and the advanced internal *** experiments were conducted to demonstrate the impact of PTP *** analysis shows that a sophisticated attacker has a range of methodologies to compromise a PTP ***,all PTP infrastructure components can host an attacker,making the comprehensive protection of a PTP network against a malware infiltration,as for example exercised by Stuxnet,a very tedious task.

关键词： APT Cyber-attacks IEEE 1588 PTP Security Time synchronization protocols

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Efficient Data Compression of ECG Signal Based on Modified Discrete Cosine Transform

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Computers, Materials & Continua 2022年第6期71卷 4391-4408页

作者： Ashraf Mohamed Ali Hassan Mohammed S.Alzaidi Sherif S.M.Ghoneim waleed el Nahal electronics and Communications Engineering Department Faculty of EngineeringSinai UniversityArishCO 45511Egypt Department of electrical Engineering College of EngineeringTaif UniversityTaif21944Saudi Arabia Faculty of Technology and Education Suez UniversitySuez43527Egypt electronics and Communications Engineering Department Faculty of EngineeringMSA UniversityCO 12585Egypt

This paper introduced an efficient compression technique that uses the compressive sensing(CS)method to obtain and recover sparse electrocardiography(ECG)*** recovery of the signal can be achieved by using sampling rates lower than the Nyquist frequency.A novel analysis was proposed in this *** apply CS on ECG signal,the first step is to generate a sparse signal,which can be obtained using Modified Discrete Cosine Transform(MDCT)on the given *** transformation is a promising key for other transformations used in this search domain and can be considered as the main contribution of this paper.A small number of wavelet components can describe the ECG signal as related work to obtain a sparse *** technique for ECGsignal compression,which is a novel area of research,is *** signals are introduced randomly between any successive beats of the ***-BIH database can be represented as the experimental database in this domain of ***-BIH database consists of various ECG signals involving a patient and standard ECG *** can be considered as the simulation tool used in this *** proposed method’s uniqueness was inspired by the compression ratio(CR)and achieved by *** performance measurement of the recovered signal was done by calculating the percentage root mean difference(PRD),mean square error(MSE),and peak signal to noise ratio(PSNR)besides the calculation of ***,the simulation results indicated that this work is one of the most important works in ECG signal compression.

关键词： Compressive sensing sparse beats of hearts compression ratio percentage root mean difference

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