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Optimized Two-Level Ensemble Model for Predicting the Parameters of Metamaterial Antenna

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Computers, Materials & Continua 2022年第10期73卷 917-933页

作者： Abdelaziz A.Abdelhamid sultan r.alotaibi Department of Computer Science College of Computing and Information TechnologyShaqra UniversitySaudi Arabia Department of Computer Science College of Science and HumanitiesShaqra UniversitySaudi Arabia Department of Computer Science Faculty of Computer and Information SciencesAin Shams UniversityEgypt

Employing machine learning techniques in predicting the parameters of metamaterial antennas has a significant impact on the reduction of the time needed to design an antenna with optimal parameters using simulation *** this paper,we propose a new approach for predicting the bandwidth of metamaterial antenna using a novel ensemble *** proposed ensemble model is composed of two levels of regression *** first level consists of three strong models namely,random forest,support vector regression,and light gradient boosting *** the second level is based on the ElasticNet regression model,which receives the prediction results from the models in the first level for refinement and producing the final optimal *** achieve the best performance of these regression models,the advanced squirrel search optimization algorithm(ASSOA)is utilized to search for the optimal set of hyper-parameters of each *** results show that the proposed two-level ensemble model could achieve a robust prediction of the bandwidth of metamaterial antenna when compared with the recently published ensemble models based on the same publicly available benchmark *** findings indicate that the proposed approach results in root mean square error(rMSE)of(0.013),mean absolute error(MAE)of(0.004),and mean bias error(MBE)of(0.0017).These results are superior to the other competing ensemble models and can predict the antenna bandwidth more accurately.

关键词： Ensemble model parameter prediction metamaterial antenna machine learning model optimization

Smart Contract:Security and Privacy

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Computer Systems Science & Engineering 2021年第7期38卷 93-101页

作者： Leena S.alotaibi sultan S.Alshamrani Department of Information Technology College of Computer and Information TechnologyTaif UniversityP.O.Box 11099TaifSaudi Arabia

Smart contracts are simply self-activated contracts between two *** idea behind their implementation relies on the concept of blockchain,wherein the details and execution of the contract are turned into code and distributed among users of a *** process controls counterfeiting and money laundering by its ability to trace who owes *** also boosts the general *** research paper shows how smart contracts in modern-day systems have changed the approach to money *** present case studies about the uses of smart contracts with high levels of security and *** a building block of smart contracts,a brief description of blockchain is provided in an *** other cryptography methods and techniques,the usage of hashing and hash functions in blockchain security are also *** also explore the real-time applications of blockchain and smart contract techniques in real *** main advantage of this research paper is that it discusses a state-of-the-art subject,as most of the articles referenced in this paper are from 2018 and onward.

关键词： Blockchain cryptography smart contract security

Tuberculous esophagomediastinal fistula with concomitant mediastinal bronchial artery aneurysm-acute upper gastrointestinal bleeding: A case report

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World Journal of Gastroenterology 2019年第17期25卷 2144-2148页

作者： sultan r Alharbi Interventional radiology Unit King Saud University Medical CityCollage of MedicineKing Saud University

BACKGrOUND Esophagomediastinal fistula is a very rare complication of tuberculosis in otherwise healthy adults, and mediastinal bronchial artery aneurysm is even rarer. In this case report, we describe a rare case of tuberculosis complication that presented with acute upper gastrointestinal(GI) bleeding. It also highlights the benefits of chest computed tomography(CT) as an excellent adjunct diagnostic tool to endoscopy and bronchoscopy and the role of trans-arterial embolization as a minimal invasive therapy alternative to *** SUMMArY A 19-year-old medically free male patient presented with acute multiple episodes of hematemesis for 1 d. Upper GI endoscopy, bronchoscopy, and chest CT with IV contrast confirmed esophagomediastinal fistula with mediastinal bronchial artery aneurysm. After resuscitating patient with IV fluid and blood product transfusion, trans catheter embolization was performed for mediastinal bronchial artery *** We successfully treated a patient with acute upper GI bleeding due to tuberculous esophagomediastinal fistula and mediastinal bronchial artery aneurysm using transcatheter coil embolization.

关键词： Mediastinal bronchial artery aneurysm Esophagomediastinal fistula Upper gastrointestinal bleeding Mediastinal tuberculosis Case report

Dissolution mechanism and kinetics ofβ(Mg_(17)Al_(12))phases in AZ91 magnesium alloy

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Journal of Magnesium and Alloys 2024年第4期12卷 1581-1592页

作者： sultan Alomairy Department of Physics College of ScienceTaif UniversityTaif 21944Saudi Arabia

In this study,the phase transformations,crystallization kinetics and dissolution mechanism ofβphase(Mg_(17)Al_(12))in magnesium alloy AZ91 were investigated by optical microscopy,X-ray diffraction,differential scanning calorimetry and differential *** results indicate that this AZ91 alloy undergoes a phase transformation during aging,a discontinuous precipitation of theβphase(Mg_(17)Al_(12))at 150℃at the grain boundaries and another continuous at 350℃within the *** activation energy of the dissolution reaction of theβphase(Mg_(17)Al_(12))under non-isothermal conditions is 116.781 kJ/mol,while it is 129.7383 kJ/mol under isothermal *** Avrami coefficient,n,relevant for the dissolution kinetics of theβphase(Mg_(17)Al_(12))is 1.152 and 1.211 in the non-isothermal and isothermal conditions *** numerical coefficients m and Avrami n are 0.993 and 1.152.

关键词： AZ91 kinetics β(Mg_(17)Al_(12)) Activation energy Discontinuous precipitation Continuous precipitation DSC

LEGA:A Lightweight and Efficient Group Authentication Protocol for Massive Machine Type Communication in 5G Networks

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Journal of Communications and Information Networks 2020年第4期5卷 457-466页

作者： sultan Basudan Department of Information Technology and Security Jazan UniversitySaudi Arabia

Massive machine type communication(mMTC)is anticipated to be an essential part of fifth generation(5G)*** main challenge for mMTC devices(mMTCDs)is the design of an access authentication scheme that can fulfill the security and privacy requirements of 5G applications,which have specific conditions,including rigorous latency and si-multaneous ***,a novel 5G authentication and key agreement(5G-AKA)protocol was introduced by the 3rd generation partnership project(3GPP)to achieve mMTCD access ***,5G-AKA protocol comes with some security vulnerabilities and significant delay for real-time mMTC applications,particularly when mMTCDs concurrently roam into new *** order to address the real-time secure and efficient access issues of multiple mMTCDs,this paper proposes a lightweight and efficient group authen-tication protocol for mMTC in 5G wireless *** proposed protocol,which integrates bilinear maps and an aggregate certificateless signature mechanism,can achieve several security goals,including avoidance of signaling congestion in the authentication process,mutual authentication,session key agreement,perfect forward/backward secrecy,and masked attack and key escrow *** to existing conventional protocols,the proposed protocol demonstrates robust security and improved performance in terms of signaling cost authentication,bandwidth consumption and compu-tational cost.

关键词： 5G group authentication mMTC roaming privacy security

Sea Turtle Foraging Optimization-Based Controller Placement with Blockchain-Assisted Intrusion Detection in Software-Defined Networks

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Computers, Materials & Continua 2023年第6期75卷 4735-4752页

作者： sultan Alkhliwi Department of Computer Science Faculty of ScienceNorthern Border UniversityArarSaudi Arabia

Software-defined networking(SDN)algorithms are gaining increas-ing interest and are making networks flexible and *** basic idea of SDN is to move the control planes to more than one server’s named controllers and limit the data planes to numerous sending network components,enabling flexible and dynamic network management.A distinctive characteristic of SDN is that it can logically centralize the control plane by utilizing many physical *** deployment of the controller—that is,the controller placement problem(CPP)—becomes a vital model *** the advancements of blockchain technology,data integrity between nodes can be enhanced with no requirement for a trusted third *** the lat-est developments in blockchain technology,this article designs a novel sea turtle foraging optimization algorithm for the controller placement problem(STFOA-CPP)with blockchain-based intrusion detection in an SDN *** major intention of the STFOA-CPP technique is the maximization of lifetime,network connectivity,and load balancing with the minimization of *** addition,the STFOA-CPP technique is based on the sea turtles’food-searching characteristics of tracking the odour path of dimethyl sulphide(DMS)released from food ***,the presented STFOA-CPP technique can adapt with the controller’s count mandated and the shift to controller mapping to variable network ***,the blockchain can inspect the data integrity,determine significantly malicious input,and improve the robust nature of developing a trust relationship between sev-eral nodes in the *** demonstrate the improved performance of the STFOA-CPP algorithm,a wide-ranging experimental analysis was carried *** extensive comparison study highlighted the improved outcomes of the STFOA-CPP technique over other recent approaches.

关键词： Software-defined networking NP hard problem metaheuristics controller placement problem objective function

Arsenic and major cation hydrogeochemistry of the Central Victorian （Australia） surface waters

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Journal of Environmental Sciences 2006年第1期18卷 184-192页

作者： Khawar sultan Kim DOWLING School of Science and Engineering University of Ballarat Mount Helen University Drive Ballarat Victoria 3353 Australia

This paper reports on the major cations（Ca, Mg, Na and K） and arsenic（As） compositions of surface waters collected from major creeks, rivers and lakes in Central Victoria （Australia）. The surface waters were found to be neutral to alkaline （pH 6.7-9.4）, oxidised （average redox potential （Eh） about 130 mV） and showed variable concentrations of dissolved ions （EC, about 51-4386 /μS/cm）. The concen- trations of dissolved major cations in surface waters were found to be in the order of Na〉〉Mg〉Ca〉K and in soils the contents of metals followed an order of abundance as： Ca〉Mg〉〉K〉Na. While Na was the least abundant in soils, it registered the highest dissolved cation in surface waters. Of the four major cations, the average concentration ofNa（98.7 mg/L） was attributed to the weathering of feldspars and atmospheric input. relatively highly dissolved concentrations of Na and Mg compared with the world average values of rivers reflected the weathering of rock and soil minerals within the catchments. The As soil level is naturally high（linked to lithology） as reflected by high background soil values and mining operations are also considered to be a contributory factor. Under relatively alkaline-oxidative conditions low mobility of dissolved As （average about 7.9 μg/L） was observed in most of the surface waters with a few higher values（〉15 μg/L） around a sewage disposal site and mine railings. Arsenic in soils is slowly released into water under alkaline and/or lower Eh conditions. The efficient sink of Fe, AI and Mn oxides acts as a barrier against the As release under near neutral-oxidising conditions. High As content （average about 28.3 mg/kg） in soils was found to be associated with Fe-hydroxides as revealed by XrD and SEM analysis. The dissolved As concentration was found to be below the recommended maximum levels for recreational water in all surface waters（lakes and rivers） in the study area. Catchment lithology exerted the fundamental control on surface water chemistr

关键词： surface water major cations arsenic soil Australia

In situ infiltration-precipitation processes in some rock systems

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Acta Geochimica 2023年第5期42卷 870-878页

作者： Zahraa Ibrahim rabih sultan Department of Chemistry American University of BeirutBeirutLebanon

We carry out a chemical treatment(acidization or basification)of typical rock specimens in-situ,and characterize the emerging pattern resulting from the infil-tration-precipitation *** and limestone sam-ples were treated with sulfuric acid,while pyrite was reacted with sodium *** infiltration tech-niques were employed,after selection of the most feasible method for each rock *** patterns of anglesite(PbSO_(4)),anhydrite(CaSO_(4))and goethite(FeOOH)depo-sition presented different alteration modes of the bare rock *** the three deposited minerals,only the anhydrite(CaSO_(4))displayed a band *** formation of a Liesegang pattern in the rock of highest porosity indicates a plausible correlation between the band formation and a minimum porosity requirement.A banded rock of compact texture could then be formed by a cementation mechanism,governing the long time evolution of the rock.

关键词： Liesegang Limestone Galena Pyrite Anglesite Goethite reaction–diffusion Percolation Porosity Pattern formation

rare earth elements in tropical surface water,soil and sediments of the Terengganu river Basin,Malaysia

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Journal of rare Earths 2009年第6期27卷 1072-1078页

作者： Khawar sultan Noor Azhar Shazili Institute of Oceanography University Malaysia TerengganuMengabang Telipot21030 Kuala TerengganuTerengganuMalaysia

The 14 stable rare earth element(rEE) concentrations and distribution patterns were investigated for surface waters(n=51),soils(n=52) and sediments(n=42) from the tropical Terengganu river basin,*** chondrite normalized rEE patterns of soils developed on four geological units showed enrichment of LrEE,a pronounced negative Eu,and depletion of HrEE with an enrichment order granite>>metasedimentary>alluvium>*** rEE patterns in sediments reflected the soil rEE patterns with an ove...

关键词： rare earth elements river/lake water soil sediment Malaysia