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Spectral hole burning effects initiated by uniform signal intensities in a gain-flattened EDFA

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Chinese Optics Letters 2011年第2期9卷 11-14页

作者： A.R.Sarmani S-J Sheih F.R.mahamd Adikan m.a.mahdi Wireless and Photonics Networks Research Center Faculty of Engineering Universiti Putra Malaysia Taiwan International Securities Group Department of Electrical Engineering Faculty of Engineering Universitiy of Malaya

Spectral hole burning （SHB） effects in a gain-flattened erbium-doped fiber amplifier （EDFA） are demonstrated to be significant in the presence of large signal power around the 1530-1532-nm wavelength range. These are the first effects reported in a setup employing equivalent power level distribution of 40 channels ranging from 1530 to 1561 nm. To explain this, the introduction of a new local population variable into the laser equation is required to support the original inversion ratio that is determined by the pump lasers. In the analysis section, spectroscopic parameters and high signal powers are considered to be other contributing parameters to the change in the gain characteristics. An improvement to this theoretical basis is suggested by implementing mathematical modeling to validate similarities between the gain shape of simulation to that obtained in the experiment.

关键词： Erbium Fiber amplifiers Pumping (laser) Spectroscopic analysis

In situ aberration measurement technique based on multi-illumination settings and principal component analysis of aerial images

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Chinese Optics Letters 2012年第12期10卷 35-38页

作者： A.W.Al-Alimi A.F.Abas m.a.mahdi m.H.Al-mansoori m.mokhtar Wireless and Photonic Networks Research Centre Englneering and Technology ComplexUniversiti Putra Malaysia43400 SerdangSelangorMalaysia Photonics and Fiber Optic Systems Laboratory Department of Computer and Communication Systems Engineering Universiti Putra Malaysia43400 SerdangSelangorMalaysia Faculty of Engineering Sohar UniversityP.O Box 44 Sohar P.C.311Oman

A multiwavelength Brillouin/erbium fiber laser （BEFL） with low threshold power is realized. A low threshold power of 3 mW and a wide tuning range of 18 nm can be achieved by controlling the reflected power in the nonlinear optical loop mirror （NOLm）. Up to 24 lines with a wavelength spacing of 0,086 nm are generated at the Brillouin pump and at the 1 480-nm pump with -0.5 dBm （0.9 roW） and 25 mW of power, respectively.

关键词： 140.3510 Lasers, fiber 290.5900 Scattering, stimulated Brillouin 060.2410 Fibers, erbium

Using neural network modeling to improve the detection accuracy of land subsidence due to groundwater withdrawal

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Journal of mountain Science 2024年第7期21卷 2320-2333页

作者： Ali m.RAJABI Ali EDALAT Yasaman ABOLGHASEmI mahdi KHODAPARAST Department of Engineering Geology University of TehranTehran ***Iran Department of Civil Engineering University of QomQom ***Iran

Despite the high efficiency of remote sensing methods for rapid and large-scale detection of subsidence phenomena,this technique has limitations such as atmospheric impact and temporal and spatial decorrelation that affect the accuracy of the *** paper proposes a method based on an artificial neural network to improve the results of monitoring land subsidence due to groundwater overexploitation by radar interferometry in the Aliabad plain(Central Iran).In this regard,vertical ground deformations were monitored over 18 months using the Sentinel-1A SAR *** model the land subsidence by a multilayer perceptron(mLP)artificial neural network,four parameters,including groundwater level,alluvial thickness,elastic modulus,and transmissivity have been *** model's generalizability was assessed using data derived for 144 *** to the results,the neural network estimates the land subsidence at each ground point with an accuracy of 6.8 mm.A comparison between the predicted and actual values indicated a significant *** mLP model can be used to improve the results of subsidence detection in the study area or other areas with similar characteristics.

关键词： DInSAR Land subsidence Groundwater withdrawal Aliabad plain Artificial neural network

Investigation on the pre-compensation and post-compensation cascaded multi-channel-chirped fiber Bragg gratings for a repeaterless transmission system

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Chinese Optics Letters 2018年第4期16卷 45-50页

作者： K.Khairi H.Fong Kok Z.Lambak m.I.Abdan m.A.Farhan m.H.Othman m.L.H.Jamaluddin S.A.mohamad Rofie Tee Din Chai K.Chia Ching A.mohd.Ramli m.A.mokhtar S.A.Syed Ahmad m.mokhtar S.B.Ahmad Anas m.a.mahdi Tm Research & Development Sdn.Bhd. Lingkaran Teknokrat Timur Wireless and Photonics Network Research Center Department of Computer & Communication Systems EngineeringFaculty of Engineering Universiti Putra Malaysia

We experimentally designed dispersion-managed repeaterless transmission systems with a pre-compensation and post-compensation technique using multi-channel-chirped fiber Bragg gratings. The repeaterless transmission link supports a single channel（1548.51 nm） with a 10 Gbps repeaterless transmission system over 300 km standard single-mode fiber（SSmF）. In the system design, two distributed Raman amplifiers（DRAs） were used to improve the signal level propagated along the 300 km SSmF. The co-propagating DRA provided 15 dB on–off gain and the counter-propagating produced 32 dB on–off gain at the signal wavelength. The experiment results show that the post-compensation configuration achieves an optimal performance with a bit error rate at 1 × 10-9.

关键词： mC DRA Investigation on the pre-compensation and post-compensation cascaded multi-channel-chirped fiber Bragg gratings for a repeaterle WDm NRZ

High resolution sequence stratigraphy of the mishrif Formation(Cenomanian-Early Turonian)at zubair oilfield(al-rafdhiah dome),southern Iraq

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Petroleum Research 2024年第1期9卷 61-71页

作者： Aymen A.Lazim maher J.Ismail maher m.mahdi Geoscience Department Zubair Field Operation DivisionBasra Oil CompanyIraq Basrah Oil Company WQ1 FODBasrahIraq University of Basrah College of ScienceGeology Dept.BasrahIraq

The mishrif Formation(Cenomanian-E Turonian)is one of the most important geological formations in the middle East and Iraq because it contains enormous petroleum *** is considered to be the first reservoir in the region,and is still being studied because of its economic *** carbonate of the mishrif Formation derives from a variety of depositional settings,including mid-ramp,shoal,lagoon,and *** five main microfacies discussed in this paper are wackestone,packstone,grainstone,floatstone,and *** most frequent fossilised components found in the mishrif Formation are rudists,benthic foraminifera,echinoderms,burrows molluscs,and *** to the microfacies and analysed wireline log data,the sequence stratigraphy of the studied formation is composed of two regression *** parasequences of transgressive-regressive cycles make up the depositional sequence of the mishrif *** standard depositional environments seem to demonstrate a gradual regression,beginning with a short period of the outer ramp,then a steady period of the mid-ramp,and ending in the intertidal ***,the study recorded two regional maximum flooding surfaces:K-135 and *** former is present in the lowermost part of the formation,while the other lies in the *** study shows a close relationship between facies(environments)and hydrocarbon *** increased accumulation focuses on the lower part of the studied formation,and seems to be lower in the upper part of the formation as a result of changes in the environment of deposition.

关键词： mishrif formation Cenomanian Sequence stratigraphy Zubair oilfield Iraq

Efficient ECG classification based on Chi-square distance for arrhythmia detection

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Journal of Electronic Science and Technology 2024年第2期22卷 1-15页

作者： Dhiah Al-Shammary mustafa Noaman Kadhim Ahmed m.mahdi Ayman Ibaida Khandakar Ahmedb College of Computer Science and Information Technology University of Al-QadisiyahAl Diwaniyah58001Iraq Intelligent Technology Innovation Lab Victoria UniversityMelbourne3011Australia

This study introduces a new classifier tailored to address the limitations inherent in conventional classifiers such as K-nearest neighbor(KNN),random forest(RF),decision tree(DT),and support vector machine(SVm)for arrhythmia *** proposed classifier leverages the Chi-square distance as a primary metric,providing a specialized and original approach for precise arrhythmia *** optimize feature selection and refine the classifier’s performance,particle swarm optimization(PSO)is integrated with the Chi-square distance as a fitness *** synergistic integration enhances the classifier’s capabilities,resulting in a substantial improvement in accuracy for arrhythmia *** results demonstrate the efficacy of the proposed method,achieving a noteworthy accuracy rate of 98% with PSO,higher than 89% achieved without any previous *** classifier outperforms machine learning(mL)and deep learning(DL)techniques,underscoring its reliability and superiority in the realm of arrhythmia *** promising results render it an effective method to support both academic and medical communities,offering an advanced and precise solution for arrhythmia detection in electrocardiogram(ECG)data.

关键词： Arrhythmia classification Chi-square distance Electrocardiogram(ECG)signal Particle swarm optimization(PSO)

Intelligent Solution System for Cloud Security Based on Equity Distribution:model and Algorithms

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Computers, materials & Continua 2024年第1期78卷 1461-1479页

作者： Sarah mustafa Eljack mahdi Jemmali mohsen Denden mutasim Al Sadig Abdullah m.Algashami Sadok Turki Department of Computer Science and Information College of Science at ZulfiMajmaah UniversityAl-Majmaah11952Saudi Arabia Department of Computer Science College of Computing and InformaticsUniversity of SharjahSharjahUnited Arab Emirates Higher Institute of Computer Science and mathematics University of MonastirMonastir5000Tunisia mars Laboratory University of SousseSousseTunisia Department of Logistic and maintenance UFR MIM at MetzUniversity of LorraineMetzFrance Department of Computer and Information Technologies College of Telecommunicationand Information Riyadh CTITechnical and Vocational Training Corporation TVTCRiyadh12464Saudi Arabia Department of Computer Science Higher Institute of Applied Sciences of SousseSousse UniversitySousse4000Tunisia

In the cloud environment,ensuring a high level of data security is in high *** planning storage optimization is part of the whole security process in the cloud *** enables data security by avoiding the risk of data loss and data *** development of data flow scheduling approaches in the cloud environment taking security parameters into account is *** our work,we propose a data scheduling model for the cloud *** is made up of three parts that together help dispatch user data flow to the appropriate *** first component is the Collector Agent whichmust periodically collect information on the state of the network *** second one is the monitoring agent which must then analyze,classify,and make a decision on the state of the link and finally transmit this information to the *** third one is the scheduler who must consider previous information to transfer user data,including fair distribution and reliable *** should be noted that each part of the proposedmodel requires the development of its *** this article,we are interested in the development of data transfer algorithms,including fairness distribution with the consideration of a stable link *** algorithms are based on the grouping of transmitted files and the iterative *** proposed algorithms showthe performances to obtain an approximate solution to the studied problem which is an NP-hard(Non-Polynomial solution)*** experimental results show that the best algorithm is the half-grouped minimum excluding(HmE),with a percentage of 91.3%,an average deviation of 0.042,and an execution time of 0.001 s.

关键词： Cyber-security cloud computing cloud security algorithms heuristics

A machine Learning Classification model for Detecting Prediabetes

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Journal of Data Analysis and Information Processing 2024年第3期12卷 462-478页

作者： A. K. m. Raquibul Bashar mahdi Goudarzi Chris P. Tsokos Department of mathematics & Computer Science Augustana College Rock Island Illinois USA Independent Researcher San Francisco California USA Department of mathematics & Statistics University of South Florida Tampa Florida USA

The incidence of prediabetes is in a dangerous condition in the USA. The likelihood of increasing chronic and complex health issues is very high if this stage of prediabetes is ignored. So, early detection of prediabetes conditions is critical to decrease or avoid type 2 diabetes and other health issues that come as a result of untreated and undiagnosed prediabetes condition. This study is done in order to detect the prediabetes condition with an artificial intelligence method. Data used for this study is collected from the Centers for Disease Control and Prevention’s (CDC) survey conducted by the Division of Health and Nutrition Examination Surveys (DHANES). In this study, several machine learning algorithms are exploited and compared to determine the best algorithm based on Average Squared Error (ASE), Kolmogorov-Smirnov (Youden) scores, areas under the ROC and some other measures of the machine learning algorithm. Based on these scores, the champion model is selected, and Random Forest is the champion model with approximately 89% accuracy.

关键词： Prediabetes machine Learning SVm Forest Cumulative Lift

Toward a comprehensive hypothesis of oxygen-evolution reaction in the presence of iron and gold

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Journal of Energy Chemistry 2024年第2期89卷 172-183,I0005页

作者： Negah Hashemi Jafar Hussain Shah Cejun Hu Subhajit Nandy Pavlo Aleshkevych Sumbal Farid Keun Hwa Chae Wei Xie Taifeng Liu Junhu Wang mohammad mahdi Najafpour Department of Chemistry Institute for Advanced Studies in Basic Sciences(IASBS)Zanjan 45137-66731Iran Center for Advanced mössbauer Spectroscopy Mössbauer Effect Data CenterDalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023LiaoningChina Key Lab of Advanced Energy materials Chemistry(ministry of Education) Renewable Energy Conversion and Storage CenterCollege of ChemistryNankai UniversityTianjin 300071China Advanced Analysis Center Korea Institute of Science and TechnologySeoul 02792Republic of Korea Institute of Physics Polish Academy of SciencesWarsaw 02-668Poland National and Local Joint Engineering Research Center for Applied Technology of Hybrid Nanomaterials Henan UniversityKaifeng 475004HenanChina Center of Climate Change and Global Warming Institute for Advanced Studies in Basic Sciences(IASBS)Zanjan 45137-66731Iran Research Center for Basic Sciences&modern Technologies(RBST) Institute for Advanced Studies in Basic Sciences(IASBS)Zanjan 45137-66731Iran

This study investigates the effects of Fe on the oxygen-evolution reaction(OER)in the presence of *** distinct areas of OER were identified:the first associated with Fe sites at low overpotential(~330 mV),and the second with Au sites at high overpotential(~870 mV).Various factors such as surface Fe concentration,electrochemical method,scan rate,potential range,concentration,method of adding K_(2)Fe O_(4),nature of Fe,and temperature were varied to observe diverse behaviors during OER for Fe O_(x)H_(y)/*** amounts of Fe ions had a significant impact on OER,reaching a saturation point where the activity did not increase *** electronic interaction between Fe and Au ions was indicated by X-ray photoelectron spectroscopy(XPS)and electron paramagnetic resonance(EPR)*** situ visible spectroscopy confirmed the formation of Fe O_(4)^(2-)during *** situ mossbauer and surfaceenhanced Raman spectroscopy(SERS)analyses suggest the involvement of Fe-based species as intermediates during the rate-determining step of OER.A lattice OER mechanism based on Fe O_(x)H_(y)was proposed for operation at low *** functional theory(DFT)calculations revealed that Fe oxide,Fe-oxide clusters,and Fe doping on the Au foil exhibited different activities and stabilities during *** study provides insights into the interplay between Fe and Au in OER,advancing the understanding of OER mechanisms and offering implications for the design of efficient electrocatalytic systems.

关键词： DFT calculation Fe/Au electrocatalysis mechanism Oxygen evolution Water oxidation