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Conditional Probability Approach for Fault Detection in Photovoltaic Energy Farms

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Computer Systems Science & Engineering 2022年第9期42卷 1109-1120页

作者： Nagy I.Elkalashy ibrahim B.m.Taha Electrical Engineering Department Faculty of EngineeringMenoufia University32511Egypt Electrical Engineering Department College of EngineeringTaif University21944Saudi Arabia

Detection of electric faults in photovoltaic (PV) farms enhances a sustainable service continuity of farm energy generation. In this paper, a probabilisticfunction is introduced to detect the faults in the PV farms. The conditional probability functions are adopted to detect different fault conditions such as internalstring faults, string-to-string faults, and string-to-negative terminal faults. As thediodes are important to make the PV farms in-service safely during the faults,the distribution currents of these faults are evaluated with different concepts ofdiode consideration as well as without considering any diode installation. Thispart of the study enhances the diode utilization in the PV farms concerning theprotection point of view. The PV string currents are used as inputs to the conditional probability detection algorithms. However, the setting of the fault detectiontechnique is not portable for the other PV systems due to broad ranges of PV system ratings. To accordingly generalize the proposed fault detection algorithm, thePV string currents are first normalized to the total array current for universallyapplying the detection function at different PV string ratings. The limiting faultresistances are evaluated to show the sensitivity of the proposed fault *** results ensure the application of the proposed probabilistic detection functionfor PV farms.

关键词： Photovoltaic farm fault detection conditional probability diodes

Replication Strategy with Comprehensive Data Center Selection method in Cloud Environments

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Computers, materials & Continua 2023年第1期74卷 415-433页

作者： m.A.Fazlina Rohaya Latip Hamidah ibrahim Azizol Abdullah Faculty of Computer Science and Information Technology Universiti Putra MalaysiaSerdang43400SelangorMalaysia

As the amount of data continues to grow rapidly,the variety of data produced by applications is becoming more affluent than *** computing is the best technology evolving today to provide multi-services for the mass and variety of *** cloud computing features are capable of processing,managing,and storing all sorts of *** data is stored in many high-end nodes,either in the same data centers or across many data centers in cloud,performance issues are still *** cloud replication strategy is one of best solutions to address risk of performance degradation in the cloud *** real challenge here is developing the right data replication strategy with minimal data movement that guarantees efficient network usage,low fault tolerance,and minimal replication *** key problem discussed in this research is inefficient network usage discovered during selecting a suitable data center to store replica copies induced by inadequate data center selection ***,to mitigate the issue,we proposed Replication Strategy with a comprehensive Data Center Selection method(RS-DCSm),which can determine the appropriate data center to place replicas by considering three key factors:Popularity,space availability,and *** proposed RS-DCSm was simulated using CloudSim and the results proved that data movement between data centers is significantly reduced by 14%reduction in overall replication frequency and 20%decrement in network usage,which outperformed the current replication strategy,known as Dynamic Popularity aware Replication Strategy(DPRS)algorithm.

关键词： Cloud computing data replication replica placement data center merits replication algorithm

Frequency and voltage-dependent electrical and dielectric properties of Al/Co-doped PVA/p-Si structures at room temperature

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Chinese Physics B 2014年第4期23卷 545-550页

作者： ibrahim Ycedag Ahmet Kaya Semsettin Altindal ibrahim Uslu Department of Computer Engineering Technology Faculty Duzce University Department of Opticianry Vocationel School of Medical Sciences Turgut Ozal University Department of Physics Faculty of Science and Arts Gazi University Department of Chemistry Faculty of Science and Arts Gazi University

In order to investigate of cobalt-doped interracial polyvinyl alcohol （PVA） layer and interface trap （Dit） effects, A1/p- Si Schottky barrier diodes （SBDs） are fabricated, and their electrical and dielectric properties are investigated at room temperature. The forward and reverse admittance measurements are carded out in the frequency and voltage ranges of 30 kHz-300 kHz and -5 V-6 V, respectively. C-V or er-V plots exhibit two distinct peaks corresponding to inversion and accumulation regions. The first peak is attributed to the existence of Dit, the other to the series resistance （Rs）, and interfacial layer. Both the real and imaginary parts of dielectric constant （er and err） and electric modulus （mr and mrr）, loss tangent （tan~）, and AC electrical conductivity （aac） are investigated, each as a function of frequency and applied bias voltage. Each of the m~ versus V and mrr versus V plots shows a peak and the magnitude of peak increases with the increasing of frequency. Especially due to the Dit and interfacial PVA layer, both capacitance （C） and conductance （G/w） values are strongly affected, which consequently contributes to deviation from both the electrical and dielectric properties of A1/Co-doped PVA/p-Si （mPS） type SBD. In addition, the voltage-dependent profile of Dit is obtained from the low-high frequency capacitance （CLF-CHF） method.

关键词： Al/Co-PVA/p-Si (mPS) electrical and dielectric properties AC electrical conductivity frequencyand voltage dependence

On the nonclassical dynamics of cavity-assisted four-channel nonlinear coupler

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Chinese Physics B 2018年第11期27卷 498-505页

作者： Rafael Julius Abdel-Baset m A ibrahim Pankaj Kumar Choudhury Hichem Eleuch Faculty of Applied Sciences Universiti Teknologi MARA (UiTM) Faculty of Applied Sciences Universiti Teknologi Mara (UiTM) Perak Tapah Campus Institute of microengineering and Nanoelectronics Universiti Kebangsaan Malaysia Department of Applied Sciences and mathematics College of Arts and Sciences Abu Dhabi University Institute for Quantum Science and Engineering Texas A&M University College Station

The non-classical properties of light propagating in four-channel Kerr waveguides, confined in an optical cavity, are studied. The solution to the Hamiltonian of field operators is obtained semi-analytically by using symmetrically ordered phase-space representation. Full quantum analysis of the input coherent fields displays a strong transition of photon property between the super-Poissonian and sub-Poissonian statistics. It is found that the cavity-assisted multichannel system exhibits enhanced squeezing both in single-and compound-mode. This multichannel system may be utilized as an efficient quantumlight generator.

关键词： squeezed states Kerr effects Langevin equation

A ROUGH SET APPROACH TO FEATURE SELECTION BASED ON SCATTER SEARCH mETAHEURISTIC

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Journal of Systems Science & Complexity 2014年第1期27卷 157-168页

作者： WANG Jue ZHANG Qi ABDEL-RAHmAN Hedar ABDEL-mONEm m ibrahim Center for Forecasting Science Academy of Mathematics and System Science Chinese Academy of ScienceBeijing 100190 China. Department of Computer Science Faculty of Computers and Information Assiut University Assiut 71516Egypt.

Rough set theory is an effective method to feature selection, which has recently fascinated many researchers. The essence of rough set approach to feature selection is to find a subset of the original features. It is, however, an NP-hard problem finding a minimal subset of the features, and it is necessary to investigate effective and efficient heuristic algorithms. This paper presents a novel rough set approach to feature selection based on scatter search metaheuristic. The proposed method, called scatter search rough set attribute reduction （SSAR）, is illustrated by 13 well known datasets from UCI machine learning repository. The proposed heuristic strategy is compared with typical attribute reduction methods including genetic algorithm, ant colony, simulated annealing, and Tabu search. Computational results demonstrate that our algorithm can provide efficient solution to find a minimal subset of the features and show promising and competitive performance on the considered datasets.

关键词： Attribute reduction computational intelligence metaheuristics rough set scatter search.

mHD stagnation point flow of nanofluid with SWCNT and mWCNT over a stretching surface driven by Arrhenius kinetics

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Applied mathematics(A Journal of Chinese Universities) 2022年第3期37卷 366-382页

作者： Sohail Nadeem Shafiq Ahmad Alibek Issakhov ibrahim m.Alarifi Department of mathematics Quaid-I-Azam UniversityIslamabad 44000Pakistan Al-Farabi Kazakh National University av.al-Farabi 71050040AlmatyKazakhstan Department of mechanical and Industrial Engineering College of engineering Majmaah UniversityAl-Majmaah 11952RiyadhSaudi Arabia

The intention of the current research is to address the conclusion of non-isothermal heterogeneous reaction on the stagnation-point flow of SWCNT-engine oil and mWCNT-engine oil nanofluid over a shrinking/stretching ***,exemplify the aspect of heat and mass transfer the upshot of magnetohydrodynamics(mHD),thermal radiation,and heat generation/absorption coefficient are *** bvp4 c from matlab is pledged to acquire the numerical explanation of the problem that contains nonlinear system of ordinary differential equations(ODE).The impacts of miscellaneous important parameters on axial velocity,temperature field,concentration profile,skin friction coefficient,and local Nusselt number,are deliberated through graphical and numerically erected tabulated *** solid volume fraction diminishes the velocity distribution while enhancing the temperature ***,the rate of shear stress declines with increasing the magnetic and stretching parameter for both SWCNT and mWCNT.

关键词： heat generation surface reaction CNTs based nanofluid stretching/shrinking sheet thermal radiation

Prediction of pressure gradient and hold-up in horizontal liquid-liquid pipe flow

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Petroleum Science 2023年第6期20卷 3766-3782页

作者： syed Amjad Ahmed Bibin John School of mechanical Engineering Vellore Institute of TechnologyIndia Department of mechanical Engineering C Abdul Hakeem College of Engineering&TechnologyIndia

This paper aims to propose correlations to predict pressure gradient,friction factor and fluid phase hold-up in liquid-liquid horizontal pipe *** develop the correlations,experiments are conducted using high viscous oils(202 and 630 mPa⋅s)in a steel pipe of length 11.25 m and length-to-diameter ratio of *** addition,the experimental data from the literature comprising wide range of flow and fluid properties is *** the analysis,the liquid-liquid pipe flow data is categorized into two as:stratified and *** existing friction factor correlations are modified to incorporate the effects of viscosity of the oil phase,interfacial curvature(contact/wetting angle-in lieu of material of the pipe)and fluid phase *** the two-fluid model of stratified flow,the wall stress and interfacial stress correlations are substituted with superficial velocities of fluids and superficial Reynolds numbers of fluid phases replacing fluid phase velocities and fluid Reynolds ***,for dispersed flow,an effective Reynolds number is described as the sum of superficial Reynolds number of oil and water *** the generally employed mean or mixture Reynolds number with the effective Reynolds number into the existing single-phase turbulent flow friction factor correlation,an effective friction factor for oil-water flow is *** the proposed correlations,the pressure gradient across the oil-water flow and hold-up volume fraction are predicted with significant reduction in error compared with that of conventionally employed *** average error and standard deviation values of−7.06%,20.72%and 0.31%,18.79%are found for stratified flow and dispersed flow respectively.

关键词： oil-water flow two-fluid model pressure gradient stratified flow dispersed flow

Numerical damage evaluation of perforated steel columns subjected to blast loading

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Defence Technology（防务技术） 2022年第5期18卷 735-746页

作者： mahmoud T.Nawar ibrahim T.Arafa Osama m.Elhosseiny Structural Engineering Department Zagazig UniversityZagazig44519Egypt

The structural performance of perforated steel columns(PSCs)is significantly more complex than the one of solid web I-shaped elements under the diversity of blast loading *** damage criterion of PSCs is not only related to initial deformation response during the blast but also the residual axial load capacity and it can be considered as a reliable index after the blast ***,the PSCs damages will be studied in two stages;direct and post blast *** the present study,the dynamic response of PSCs was numerically evaluated under different levels of blast threats using LS-DYNA *** explicit finite element(FE)analyses are carried out to investigate the effect of various parameters,such as web opening shapes,boundary conditions and strengthening details on the damage index and toughness of the PSCs compared to the parent steel *** results of the comparative study show that the damage and toughness decrease when the support condition changes from pinned to fixed ends through the two stages of *** give high toughness compared to its parent sections during blast shock stage while,a remarkable decrease in toughness is observed during the application of axial gravity after blast ***,the web opening shapes have slight effects on the global dynamic behavior of PSCs,particularly in terms of residual *** the contrary,the retrofitting strategy using both closed holes at end and vertical stiffeners have an effective enhancement to get higher toughness in case of the extreme blasts.

关键词： Perforated steel columns Blast load Damage criterion Numerical modeling Explicit finite element analysis Web-opening shapes

Kumaraswamy Inverted Topp–Leone Distribution with Applications to COVID-19 Data

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Computers, materials & Continua 2021年第7期68卷 337-358页

作者： Amal S.Hassan Ehab m.Almetwally Gamal m.ibrahim Faculty of Graduate Studies for Statistical Research Cairo UniversityGiza12613Egypt Faculty of Business Administration Delta University of Science and TechnologyMansoura35511Egypt High Institute for management Sciences Belqas35511Egypt

In this paper, an attempt is made to discover the distributionof COVID-19 spread in different countries such as;Saudi Arabia, Italy,Argentina and Angola by specifying an optimal statistical distribution for analyzing the mortality rate of COVID-19. A new generalization of the recentlyinverted Topp Leone distribution, called Kumaraswamy inverted Topp–Leonedistribution, is proposed by combining the Kumaraswamy-G family and theinverted Topp–Leone distribution. We initially provide a linear representationof its density function. We give some of its structure properties, such as quantile function, median, moments, incomplete moments, Lorenz and Bonferronicurves, entropies measures and stress-strength reliability. Then, Bayesian andmaximum likelihood estimators for parameters of the Kumaraswamy invertedTopp–Leone distribution under Type-II censored sample are *** estimator is regarded using symmetric and asymmetric loss functions. As analytical solution is too hard, behaviours of estimates have beendone viz monte Carlo simulation study and some reasonable comparisonshave been presented. The outcomes of the simulation study confirmed theefficiencies of obtained estimates as well as yielded the superiority of Bayesianestimate under adequate priors compared to the maximum likelihood *** to COVID-19 in some countries showed that the new distributionis more appropriate than some other competitive models.

关键词： Kumaraswamy-G family maximum likelihood Bayesian method COVID-19 moments quantile function stress-strength reliability