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Energy Efficient Scheduler of Aperiodic Jobs for real-time Embedded Systems

International Journal of Automation and computing 2020年第5期17卷 733-743页

作者： Hussein el Ghor el-Hadi MAggoune University Institute of Technology Lebanese UniversityLebanon Sensor Networks and Cellular Systems(SNCS)Research Center UTSaudi Arabia electrical Engineering Department University of Tabuk Sensor Networks and Cellular Systems(SNCS)Research Center 71491 TabukSaudi Arabia

Energy consumption has become a key metric for evaluating how good an embedded system is,alongside more performance metrics like respecting operation deadlines and speed of *** improvement is no longer the only metric by which optimality is *** fact,energy efficiency is becoming a preferred choice with a fundamental objective to optimize the system's *** this work,we propose an optimal energy efficient scheduling algorithm for aperiodic real-time jobs to reduce CPU energy ***,we apply the concept of real-time process scheduling to a dynamic voltage and frequency scaling(DVFS)*** address a variant of earliest deadline first(EDF)scheduling algorithm called energy saving-dynamic voltage and frequency scaling(ES-DVFS)algorithm that is suited to unpredictable future energy production and irregular job *** prove that ES-DVFS cannot attain a total value greater than C/ˆSα,whereˆS is the minimum speed of any job and C is the available energy *** also investigate the implications of having in advance,information about the largest job size and the minimum speed used for the competitive factor of *** show that such advance knowledge makes possible the design of semi-on-line algorithm,ES-DVFS∗∗,that achieved a constant competitive factor of 0.5 which is proved as an optimal competitive *** experimental study demonstrates that substantial energy savings and highest percentage of feasible job sets can be obtained through our solution that combines EDF and DVFS optimally under the given aperiodic jobs and energy models.

关键词： real-time systems energy efficiency aperiodic jobs scheduling dynamic voltage scaling low-power systems embedded systems

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Congruence Pairs of Decomposable MS-Algebras

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Chinese Annals of Mathematics,Series B 2021年第4期42卷 561-574页

作者： Sanaa el-ASSAr Abd el-Mohsen BADAWY Department of Mathematics Faculty of ScienceTanta UniversityTantaEgypt

In this paper,the authors first introduce the concept of congruence pairs on the class of decomposable MS-algebras generalizing that for principal MS-algebras(see[13]).They show that every congruence relationθon a decomposable MS-algebra L can be uniquely determined by a congruence pair(θ_(1),θ_(2)),whereθ_(1)is a congruence on the de Morgan subalgebra L^(∞)of L andθ_(2)is a lattice congruence on the sublattice D(L)of *** obtain certain congruence pairs of a decomposable MS-algebra L via central elements of ***,they characterize the permutability of congruences and the strong extensions of decomposable MS-algebras in terms of congruence pairs.

关键词： MS-Algebras Decomposable MS-algebras Congruence pairs Strong extension Permutability Congruence lattices

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Physical and Dielectric Properties of Some Nonionic Surfactants

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Journal of Materials Science & Technology 1998年第4期14卷 361-367页

作者： el-Anwar, I.M. el-Henawii, S.A. National research Center Dokki Cairo Egypt Faculty of Science Helwan University Egypt

Fatty acid esters have been prepared by reacting the acid C//1//8 with polyethylene glycols having varying numbers of oxyethylene units (4-88 units) by the direct esterification reaction method. Surface and interfacial tensions were studied at various experimental conditions, including, concentration, temperature and chemical constitution of the surfactant. Critical micelle concentrations (CMC), surface excess and residual area occupied by each surface active agent molecule A have been calculated by using Gibb's equations. CMC values range from 10 to 55 multiplied by 10** minus **5 mole/L for all studied agents, while the residual area occupied by each molecule varies from 0.6 to 1.5 nm**2. Variation of CMC of some of these agents with temperature have been also examined and the obtained data were used to calculate the heat of micellization delta H//m and the entropy change during micellization delta S//m. Values of delta H//m vary from 14.63 kJ/mole to 2.717 kJ/mole depending on the chemical constitution of the agent under consideration. The apparent dipole moments mu of three surfactant were measured following the Headstrand's method. (Edited author abstract) 23 refs.

关键词： Surface active agents

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Improved Supervised and Unsupervised Metaheuristic-Based Approaches to Detect Intrusion in Various Datasets

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Computer Modeling in Engineering & Sciences 2023年第10期137卷 265-298页

作者： Ouail Mjahed Salah el Hadaj el Mahdi el Guarmah Soukaina Mjahed Faculty of Sciences and Technology Department of Computer SciencesCadi Ayyad UniversityMarrakech40000Morocco Mathematics and Informatics Department Royal Air SchoolMarrakech40000Morocco

Due to the increasing number of cyber-attacks,the necessity to develop efficient intrusion detection systems(IDS)is more imperative than *** IDS research,the most effectively used methodology is based on supervised Neural Networks(NN)and unsupervised clustering,but there are few works dedicated to their hybridization with metaheuristic *** intrusion detection data usually contains several features,it is essential to select the best ones *** Discriminant Analysis(LDA)and t-statistic are considered as efficient conventional techniques to select the best features,but they have been little exploited in IDS ***,the research proposed in this paper can be summarized as follows.a)The proposed approach aims to use hybridized unsupervised and hybridized supervised detection processes of all the attack categories in the CICIDS2017 ***,owing to the large size of the CICIDS2017 Dataset,only 25%of the data was used.b)As a feature selection method,the LDAperformancemeasure is chosen and combinedwith the t-statistic.c)For intrusion detection,unsupervised Fuzzy C-means(FCM)clustering and supervised Back-propagation NN are adopted.d)In addition and in order to enhance the suggested classifiers,FCM and NN are hybridized with the seven most known metaheuristic algorithms,including Genetic Algorithm(GA),Particle Swarm Optimization(PSO),Differential Evolution(DE),Cultural Algorithm(CA),Harmony Search(HS),Ant-Lion Optimizer(ALO)and Black Hole(BH)*** metrics extracted from confusion matrices,such as accuracy,precision,sensitivity and F1-score are *** experimental result for the proposed intrusion detection,based on training and test CICIDS2017 datasets,indicated that PSO,GA and ALO-based NNs can achieve promising ***-NN produces a tested accuracy,global sensitivity and F1-score of 99.97%,99.95%and 99.96%,respectively,outperforming performance concluded in several related ***,the best-p

关键词： Classification neural networks Fuzzy C-means metaheuristic algorithm CICIDS2017 intrusion detection system

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Experimental and numerical investigation of the abrasive waterjet machining of aluminum-7075-T6 for aerospace applications

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Advances in Manufacturing 2021年第2期9卷 286-303页

作者： Joseck Nyaboro Mahmoud Ahmed Hassan el-Hofy Mohamed el-Hofy Department of Industrial and Manufacturing Engineering Egypt-Japan University of Science and Technology(E-JUST)Alexandria 21934Egypt Department of Energy resources Engineering Egypt-Japan University of Science and Technology(E-JUST)Alexandria 21934Egypt Advanced Manufacturing research Centre(AMrC)with Boeing The University of SheffieldRotherham S605TZUK

The machining of hard-to-cut materials with a high degree of precision and high surface quality is one of the most critical considerations when fabricating various state-of-the-art engineered *** this investigation,a comprehensive three-dimensional model was developed and numerically simulated to predict kerf profiles and material removal rates while drilling the aluminum-7075-T6 aerospace *** profile and material removal prediction involved three stages:jet dynamic flow modeling,abrasive particle tracking,and erosion rate *** investigations were conducted to validate the developed *** results indicate that the jet dynamic characteristics and flow of abrasive particles alter the kerf profiles,where the top kerf diameter increases with increasing jet pressure and standoff *** kerf depth and hole aspect ratio increase with jet pressure,but decrease with standoff distance and machining *** profiles were characterized by progressive edge rounding and parabolic *** can be minimized by utilizing high jet pressure and small standoff *** material removal rate increases with increasing jet pressure,abrasive particle size,and exposure time,but decreases with increasing standoff distance.

关键词： Non-traditional machining Abrasive waterjet machining Computational fluid dynamics(CFD) Erosion modeling Kerf characteristics

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Extension of i-Modularity

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Algebra Colloquium 2020年第3期27卷 483-494页

作者： el Hassane Fliouet regional Center for the Professions of Education and Training AgadirMorocco

Let k be a field of characteristic p≠*** main purpose of this paper is to extend the results and definitions of i-modularity that have already been estalished by Chellali and the present author when[k:k^(P)]is finite to the case of finite irrationality degree extensions.A number of properties of i-modular extensions are determined and examples are presented illustrating the *** particular,we characterize some special cases.

关键词： purely inseparable q-finite extension lq-modular extension i-modular extension e-closed extension

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Photovoltaic-based DC microgrid with partial shading and fault tolerance

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Journal of Modern Power Systems and Clean Energy 2019年第2期7卷 340-349页

作者： Carlos COrrEA-BETANZO Hugo CALLEJA Carlos AGUILAr Adolfo r.LOPEZ-NUNEZ elías rODrIGUEZ electronics Department National Center for Research and Development of Technology62490 CuernavacaMorelosMexico electronics Department Technological Institute of Celaya38010 CelayaGuanajuatoMexico

Partial shading is a common problem that affects bus regulation in DC microgrids with several photovoltaic(PV) modules as energy sources, as a result of reduced solar irradiance reaching the *** problem can be mitigated by incorporating batteries, but if they are not included, appropriate control strategies must be used. This paper presents a new approach in a PV-based DC microgrid, which provides a high-quality bus voltage regulation in islanding mode, without being affected by partial shading or problems associated with PV module connection and disconnection. The solution proposed herein ensures a proper voltage regulation without being affected by problems such as failures in PV modules or mismatch between them. Besides, it can help to prevent PV partial shade stress by disconnecting the affected modules. A further advantage of the approach is the flexibility to connect more PV modules. The advantages of this approach were verified in a 200 W prototype.

关键词： Photovoltaic Microgrid Partial shading Fault Control strategy

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New carbazole based dyes as effective co-sensitizers for DSSCs sensitized with ruthenium(Ⅱ) complex(NCSU-10)

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Journal of Energy Chemistry 2018年第2期27卷 351-360页

作者： Praveen Naik rui Su Mohamed r.elmorsy Ahmed el-Shafei Airody Vasudeva Adhikari Organic Materials Laboratory Department of ChemistryNational Institute of Technology Karnataka Polymer and Color Chemistry Program North Carolina State University

Herein, we report the design and synthesis of three new D-A type metal-free carbazole based dyes（S1-3）as effective co-sensitizers for dye-sensitized solar cell（DSSC） sensitized with ru（Ⅱ） complex（NCSU-10）.In this new design, the electron rich carbazole unit was attached to three different electron withdrawing/anchoring species, viz. 4-amino benzoic acid, sulfanilic acid and barbituric acid. The dyes were characterized by spectral, photophysical and electrochemical analysis. Their optical and electrochemical parameters along with molecular geometries, optimized from DFT have been employed to apprehend the effect of the structures of these co-sensitizers on the photovoltaic performances. Further, S1-3 dyes were co-sensitized along with a well-known NCSU-10 dye in order to broaden the spectral response of the co-sensitized devices and hence improve the efficiency. The photovoltaic performance studies indicated that, the device fabricated using S1 dye as co-sensitizer with 0.2 mM of NCSU-10 exhibited improved PCE of 9.55% with JSC of 22.85 mA cm-2, VOC of 0.672 V and FF of 62.2%, whereas the DSSC fabricated with dye NCSU-10（0.2 mM） alone displayed PCE of 8.25% with JSC of 20.41 mA cm-2, VOC of 0.667 V and FF of 60.6%. Furthermore, electronic excitations simulated using time-dependent DFT, were in good agreement with the experimentally obtained results of the co-sensitizers, indicating that the exchange-correlation function and basis set utilized for predicting the spectra of the co-sensitizers are quite appropriate for the calculations. In conclusion, the results showed the potential of simple organic co-sensitizers in the development of efficient DSSCs.

关键词： Carbazole dyes DSSC DFF NCSU-10 Co-sensitization and photovoltaic performance

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Effect of substitution group on dielectric properties of 4H-pyrano [3,2-c] quinoline derivatives thin films

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Chinese Physics B 2016年第7期25卷 440-449页

作者： H M Zeyada F M el-Taweel M M el-Nahass M M el-Shabaan Department of Physics Faculty of Science Damietta University Department of Chemistry Faculty of Science Damietta University Department of Physics Faculty of Education Ain Shams University

The AC electrical conductivity and dielectrical properties of 2-amino-6-ethyl-5-oxo-4-（3-phenoxyphenyl）-5,6-dihydro-4H-pyrano[3, 2-c]quinoline-3-carbonitrile（Ph-HPQ） and 2-amino-4-（2-chlorophenyl）-6-ethyl-5-oxo-5,6-dihydro-4H-pyrano [3, 2-c] quinoline-3-carbonitrile（Ch-HPQ） thin films were determined in the frequency range of 0.5 k Hz–5 MHz and the temperature range of 290–443 K. The AC electrical conduction of both compounds in thin film form is governed by the correlated barrier hopping（CBH） mechanism. Some parameters such as the barrier height, the maximum barrier height, the density of charges, and the hopping distance were determined as functions of temperature and frequency. The phenoxyphenyl group has a greater influence on those parameters than the chlorophenyl group. The AC activation energies were determined at different frequencies and temperatures. The dielectric behaviors of Ph-HPQ and Ch-HPQ were investigated using the impedance spectroscopy technique. The impedance data are presented in Nyquist diagrams for different temperatures. The Ch-HPQ films have higher impedance than the Ph-HPQ films. The real dielectric constant and dielectric loss show a remarkable dependence on the frequency and temperature. The Ph-HPQ has higher dielectric constants than the Ch-HPQ.

关键词： thin films quinoline derivatives dielectrical properties correlated barrier hopping

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Effect of Heat Input on the Microstructure and Properties of Dissimilar Weld Joint Between Incoloy 28 and Superaustenitic Stainless Steel

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Acta Metallurgica Sinica(English Letters) 2014年第2期27卷 259-266页

作者： M.S.Abdel rahman N.A.Abdel raheem M.r.el Koussy Department of Metallurgy Faculty of EngineeringCairo University

Abstract This work focuses on studying the effect of welding heat input within the range from 1 to 5 kJ/mm on the microstructure and the corresponding mechanical and corrosion properties of dissimilar joint between superaustenitic stainless steel （UNS S31254） and Incoloy 28 （UNS N08028）. The two materials were butt-welded with Er NiCrMo3. The metallurgical changes associated with welding of SASS and Incoloy 28 were studied using optical microscope, SEM, and EDX. The mechanical and corrosion properties were investigated using tensile test, Vickers hardness test, and pitting and crevice corrosion tests. The weld metal microstructure showed precipitates with needle-like shape at 3 and 5 kJ/mm. Also, the microstructure showed unmixed zone （UMZ） at the fusion line of both SASS and Incoloy 28 sides at all the investigated heat inputs. The Mo microsegregation within UMZ at Incoloy 28 side increased as the heat input increased from 1 to 5 k J/ram but that in SASS increased with increasing heat input from 1 to 3 kJ/mm and then decreased with increasing from 3 to 5 kJ/mm. The ultimate tensile strengths for all specimens at all the investigated heat inputs are acceptable. The average hardness noticeably changed in weld metal as the heat input increased from 1 to 5 kJ/mm. Other zones such as HAZ or UMZ did not demonstrate marked changes in the average hardness. The pitting and crevice corrosion rates of the weld joint were found significant at l and 3 kJ/mm but insignificant at 5 kJ/mm according to ASTM G48.

关键词： Superaustenitic Incoloy 28 Welding Heat input Unmixed zone Microsegregation Corrosion

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