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Journal of Modern Power Systems and Clean Energy 2022年第1期10卷 232-240页

作者： mohamed Ghazzali mohamed Haloua Fouad Giri Electrical Engineering Department Mohammadia School of EngineersUniversity Mohammed VRabatMorocco Caen Automation Laboratory(LAC) Caen Normandie University(UNICAEN)CaenFrance

This paper investigates a fixed-time distributed voltage and reactive power compensation of islanded microgrids using sliding-mode and multi-agent consensus design.A distributed sliding-mode control protocol is proposed to ensure voltage regulation and reference tracking before the desired preset fixed-time despite the unknown *** reactive power sharings among distributed generators are *** secondary controller is synthesized without the knowledge of any parameter of the *** is implemented using a sparse one-way communication network modeled as a directed graph.A comparative simulation study is conducted to highlight the performance of the proposed control strategy in comparison with finite-time and asymptotic control systems with load power variations.

关键词： Secondary controller microgrids reactive power control voltage control

Rod and Screw Fixation for Cranio-Cervical Instability

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Open Journal of Modern Neurosurgery 2020年第1期10卷 19-26页

作者： Hedaya Hendam Ahmed Taha.mohamed youssef Department of Neurosurgery Al Azhar Faculty of Medicine Damietta Egypt

Background Data: Atlanto-occipital dislocation is a rare and fatal condition. Pain, limitation of movements, and weakness, were the main complaints of patients with upper cervical lesions. Internal fixation and fusion was indicated in all patients of Atlanto occipital dislocation with deficits. CT scan is the imaging modality of choice for evaluation. Objective: To evaluate the efficacy and safety of rod and screw fixation in cranio-cervical instability. Study Design: Retrospective study reviewed all patient treated by rod and screw fixation, they were 12 patient operated for atlanto-occipital instability from April 2013 to April 2016 in Alazher University Hospital Damietta. Pre and postoperative data collection and analysis of the outcome were completed based on the Frankel classification and grading. Patients and Methods: We operated 12 patients, 10 with traumatic and 2 with pathologically diagnosed Atlanto occipital instability. From April 2013 to April 2016. All patients presented with neck pain, limitation of neck movement, and neurological deficits. The patients were investigated by standard plain X ray to the cervical spine, CT scan and MRI of the cervical spine pre-operatively, and they operated thorough posterior Cranio-cervical fixation. These patients followed post-operatively clinically for improving neural functions and radiologically for alignment, stability, fusion and efficacy of hard ware fixation. Results: The mean age of the studied cases was 42.1 years, trauma was the cause of instability in 10 patients, and 2 patients one with rheumatoid arthritis and one with neoplastic lesion. The mean follows up period is 14.7 months. We used screw rod system in posterior craniocervical fixation with iliac bone graft without operative or post-operative complications. All our patients were improved neurologically post-operatively and no hardware failure during the follow up period. Conclusion: Craniocervical instability was rare condition, with miss diagnosis

关键词： Spine Atlanto-Axial Atlanto-Occipital Cranio-Cervical Internal Fixation

Impact of Mobility on Delay-Throughput Performance in Multi-Service Mobile Ad-Hoc Networks

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International Journal of Communications, Network and System Sciences 2011年第6期4卷 395-402页

作者： mohamed Amnai youssef Fakhri Jaafar Abouchabaka 不详

Mobile Ad-Hoc network is a collection of mobile nodes in communication without using infrastructure. Despite the importance of type of the exchanged data between the knots on the QoS of the MANETs, the mul-tiservice data were not treated by the larger number of previous researches. In this paper we propose an adaptive method which gives the best performances in terms of delay and throughput. We have studied the impact, respectively, of mobility models and the density of nodes on the performances (End-to-End Delay, Throughput and Packet Delivery ratio) of routing protocol (On-Demand Distance Vector) AODV by using in the first a multiservice VBR (MPEG-4) and secondly the Constant Bit Rate (CBR) traffic. Finally we com-pare the performance on both cases. Experimentally, we considered the three mobility models as follows Random Waypoint, Random Direction and Mobgen Steady-State. The experimental results illustrate that the behavior of AODV change according to the model and the used traffics.

关键词： Mobility Models AODV VBR CBR QoS MANET

Real-time stereo matching on CUDA using Fourier descriptors and dynamic programming

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Computational Visual Media 2019年第1期5卷 59-71页

作者： mohamed Hallek Fethi Smach mohamed Atri Faculty of Sciences of Monastir Technologies et services de l'information

Computation of stereoscopic depth and disparity map extraction are dynamic research topics.A large variety of algorithms has been developed,among which we cite feature matching, moment extraction, and image representation using descriptors to determine a disparity map. This paper proposes a new method for stereo matching based on Fourier descriptors. The robustness of these descriptors under photometric and geometric transformations provides a better representation of a template or a local region in the image. In our work, we specifically use generalized Fourier descriptors to compute a robust cost ***, a box filter is applied for cost aggregation to enforce a smoothness constraint between neighboring pixels. Optimization and disparity calculation are done using dynamic programming, with a cost based on similarity between generalized Fourier descriptors using Euclidean distance. This local cost function is used to optimize correspondences. Our stereo matching algorithm is evaluated using the Middlebury stereo benchmark; our approach has been implemented on parallel high-performance graphics hardware using CUDA to accelerate our algorithm, giving a real-time implementation.

关键词： generalized Fourier descriptors stereo matching dynamic programming CUDA

A robust multi-objective and multi-physics optimization of multi-physics behavior of microstructure

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Journal of Central South University 2016年第12期23卷 3225-3238页

作者： Hamda Chagraoui mohamed Soula.mohamed Guedri Research Unit in Structural Dynamics Modeling and Engineering of Multi-Physics SystemsSDMESMNabeul Preparatory Engineering Institute-IPEINUniversity of Carthage Laboratory of Applied Mechanics and Engineering ENITDepartment of Mechanical engineering ENSITTunis University of Tunisia

A new strategy is presented to solve robust multi-physics multi-objective optimization problem known as improved multi-objective collaborative optimization （IMOCO） and its extension improved multi-objective robust collaborative （IMORCO）. In this work, the proposed IMORCO approach combined the IMOCO method, the worst possible point （WPP） constraint cuts and the Genetic algorithm NSGA-II type as an optimizer in order to solve the robust optimization problem of multi-physics of microstructures with uncertainties. The optimization problem is hierarchically decomposed into two levels： a microstructure level, and a disciplines levels, For validation purposes, two examples were selected： a numerical example, and an engineering example of capacitive micro machined ultrasonic transducers （CMUT） type. The obtained results are compared with those obtained from robust non-distributed and distributed optimization approach, non-distributed multi-objective robust optimization （NDMORO） and multi-objective collaborative robust optimization （McRO）, respectively. Results obtained from the application of the IMOCO approach to an optimization problem of a CMUT cell have reduced the CPU time by 44% ensuring a Pareto front close to the reference non-distributed multi-objective optimization （NDMO） approach （mahalanobis distance, D2M =0.9503 and overall spread, So=0.2309）. In addition, the consideration of robustness in IMORCO approach applied to a CMUT cell of optimization problem under interval uncertainty has reduced the CPU time by 23% keeping a robust Pareto front overlaps with that obtained by the robust NDMORO approach （D2M =10.3869 and So=0.0537）.

关键词： multi-physics multi-objective optimization robust optimization collaborative optimization non-distributed anddistributed optimization uncertainty interval

Phytochemical and biological studies of Butia capitata *** cultivated in Egypt

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Asian Pacific Journal of Tropical Biomedicine 2014年第6期4卷 456-462页

作者： Nagwa.mohamed Ammar Mohammed Said Hefnawy Sahar youssef Al-Okbi Doha Abdou mohamed Nabil Khamis El-Sayed Amira Ahmed El-Anssary Tom Mabry Pharmacognosy Department National Research Centre Pharmacognosy Department Faculty of PharmacyCairo University Food Sciences and Nutrition Department National Research Centre Tanning Materials and Protein Chemistry National Research Centre Molecular Cell and Developmental Biology The School of Biological ScienceBotany DepartmentTaxas State University

Objective:To study the antioxidant and anti-inflammatory activity of Butia capitata(***)leaf extracts along with phytochemical analysis of the proposed bioactive ***:Different successive extracts of *** *** were prepared with selective organic solvents and screened for their anti-inflammatory activities in tested animals and invitro antioxidant *** extensive phytochemical investigation of the bioactive extracts through paper chromatography,thin layer chromatography,column chromatography,gasliquid chromatography(GLC),high pressure liquid chromatography and spectral ***,ultraviolet,hydrogen and carbon nuclear magnetic resonance,electron ionization-mass spectrometry,heteronuclear multiple bond correlation and heteronuclear multiple quantum correlation were carried out Results:Results showed that different extracts possess promising antioxidant effect and significant anti-inflammatory activity with variable *** results of the phytochemical investigation of the bioactive extracts revealed the presence of volatile substances,lipoidal matter,α-tocopherol,free sugars,polysaccharides and flavonoidal ***:*** leaf extracts were shown to possess variable antioxidant effect,the most promising was methanol extract Both polar and non polar extracts were proved to have anti-inflammatory activity,the non polar extract was superior in this respect The bioactivity of the extracts was ascribed to the presence of flavonoids,sterols andα-tocopherol.

关键词： Butia capitata leaves antioxidant effect anti-inflammatory activity bioactive constituents rats.

Mild Solutions of a Class of Conformable Fractional Differential Equations with Nonlocal Conditions

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Acta Mathematicae Applicatae Sinica 2023年第2期39卷 249-261页

作者： mohamed BOUAOUID Sultan Moulay Slimane University Faculty of Sciences and TechnicsDepartment of MathematicsBP 52323000Beni MellalMorocco

This paper deals with the existence,uniqueness and continuous dependence of mild solutions for a class of conformable fractional differential equations with nonlocal initial *** results are obtained by means of the cl... 详细信息

关键词： fractional partial differential equations fractional derivatives and integrals cosine family of linear operators nonlocal conditions

Heat transfer of copper/water nanofluid flow through converging-diverging channel

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Journal of Central South University 2016年第2期23卷 484-496页

作者： mohamed Rafik SARI mohamed KEZZAR Rachid ADJABI Mechanical Engineering Department University of Skikda Industrial Mechanics Laboratory Badji-Mokhtar University of Annaba

The main objective of this work is to investigate analytically the steady nanofluid flow and heat transfer characteristics between nonparallel plane walls. Using appropriate transformations for the velocity and temperature, the basic nonlinear partial differential equations are reduced to the ordinary differential equations. Then, these equations have been solved analytically and numerically for some values of the governing parameters, Reynolds number, Re, channel half angle, α, Prandtl number, Pr, and Eckert number, Ec, using Adomian decomposition method and the Runge-Kutta method with mathematic package. Analytical and numerical results are searched for the skin friction coefficient, Nusselt number and the velocity and temperature profiles. It is found on one hand that the Nusselt number increases as Eckert number or channel half-angle increases, but it decreases as Reynolds number increases. On the other hand, it is also found that the presence of Cu nanoparticles in a water base fluid enhances heat transfer between nonparallel plane walls and in consequence the Nusselt number increases with the increase of nanoparticles volume fraction. Finally, an excellent agreement between analytical results and those obtained by numerical Runge-Kutta method is highly noticed.

关键词： nanofluid flow heat transfer copper nanoparticles inclined walls analytical solution

Urinary Kidney Injury Molocule-1 Level in Preterm Neonates with Respiratory Distress Syndrome

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Open Journal of Pediatrics 2016年第1期6卷 1-9页

作者： Maha youssef Manal Abdelsalam Radwa Saeed Alshimaa.mohamed Department of Pediatrics Faculty of Medicine (Girls) Al-Azhar University Cairo Egypt Department of Clinical Pathology Faculty of Medicine (Girls) Al-Azhar University Cairo Egypt

Background: Despite recent advances in perinatal and neonatal care in respiratory distress syndrome (RDS) prevention and treatment, a considerable number of these neonates suffer from acute kidney injury (AKI), and it is associated with poor outcome as an independent risk factor. KIM-1 mRNA and protein are expressed at a low level in normal kidney but are increased in post ischemic kidney. Aim: The aim is to detect the value of urinary KIM-1 measurement as an early predictor marker of acute kidney injury in preterm neonates with respiratory distress syndrome. Patients and methods: The study included 30 preterm newborn with (RDS) ≤36 weeks during the period from October 2014 to March 2015. Also the study included 30 apparently healthy newborn ≤36 weeks as controls. They were selected from NICU of Manshiate Elbakry hospital Cairo, Egypt. uKIM-1 along with serum creatinine levels and eGFR were assessed in days 1 of life for both groups and in day 3 for cases. Results: In day one of life, we found a significant increase in uKIM-1 levels in preterm newborn with RDS compared to their controls (2.88 ± 1.01 ng/ml and 0.95 ± 0.52 ng/ml respectively (p = 0.001)). There is no significant difference between both groups regarding serum creatinine and eGFR. In day 3 of life, preterm with RDS had significant decrease in uKIM-1 levels compared to day 1 of life with significant increase in non-survivor compared to survivor group ( 2.30 ± 1.56 ng/ml and 1.30 ± 0.90 ng/ml respectively (p = 0.03)). The sensitivity and specificity of uKIM-1 and serum creatinine was calculated (100.00%, 86.67% and 33.33%;95.00%) respectively. Conclusion: Preterm neonate with RDS is at high risk of developing AKI. Early and serial uKIM-1 measurements can be used as a non-invasive indicator of kidney injury in premature newborn with RDS.

关键词： Premature Respiratory Distress Syndrome Urinary Kidney Injury Molocule-1 Acute Kidney Injury

Completed Tensor Product and Flatness

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Algebra Colloquium 2020年第3期27卷 599-606页

作者： mohamed Tabaa Department of Mathematics Faculty of Sciences Mohammed v University in RabatMorocco

We give,in a more general case than the Noetherian case,an answer to the question posed by Shaul on the flatness of the completed tensor product.

关键词： preadic topology completed tensor product coherent ring flat module