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HOMOGENIZATION OF SEMILINEAR PARABOLIC EQUATIONS IN PERFORATED DOMAINS

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Chinese Annals of Mathematics,Series B 2004年第2期25卷 143-156页

作者： P.DONATO A.nabil Universite de Rouen UFR des SciencesLaboratoire de Mathematiques Raphael Salemsite Colbert76821 Mont Saint AignanFrance.Universite Ibn ZohrENSABP 33/SAgadirMaroc.

This paper is devoted to the homogenization of a semilinear parabolic equation with rapidly oscillating coefficients in a domain periodically perforated byε-periodic holes of size ε. A Neumann condition is prescribed on the boundary of the *** presence of the holes does not allow to prove a compactness of the solutions in L2. To overcome this difficulty, the authors introduce a suitable auxiliary linear problem to which a corrector result is applied. Then, the asymptotic behaviour of the semilinear problem as ε→ 0 is described, and the limit equation is given.

关键词： Periodic homogenization Perforated domains Semilinear parabolic equations

Contact Stress Distribution of a Pear Cam Profile with Roller Follower Mechanism

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Chinese Journal of Mechanical Engineering 2021年第1期34卷 266-279页

作者： Louay S.Yousuf nabil Hassan Hadi Department of Mechanical Engineering San Diego State University5500 Campanile DriveSan DiegoCA 92182-1323USA Aeron autical Fngineering Department College of FngineeringUniversity of BaghdadBaghdadIraq

The problem of this paper is the high contact stress at the point of contact between the cam and the follower.A pear cam and roller follower mechanism were studied and analyzed for different position of the follower and different contact compression *** objective of this paper is to study the effect of contact compression load on the contact stress distribution of the cam profile at the point of *** different positions of the follower with the cam was considered(0°,90°,180°,and 270°).The theory of circular plate was applied to derive the analytic solution of the contact *** numerical simulation had been done using ANSYS Ver.19.2 package to determine the contact stress,while SolidWorks software was used to investigate follower displacement,velocity,and *** distinct values of the compression contact load,such as 3.121 N,6.242 N,9.364 N,and 12.485 N,were used in the numerical *** the experiment setup,a photo-elastic technique was carried out in the field of polarized light to exhibit the stress distribution on the cam *** annealed PSM-4 backalate material was used in the experiment *** experimental value of contact stress was checked and verified analytically and numerically at the point of *** innovation in this paper the use of spring-damper system which reduce the value of contact stress at the point of *** contact stress was maximum 2.136 MPa when the follower located at 270°with the cam,while the contact stress was minimum 1.802 MPa when the follower located at 180°at compression load 12.485 N.

关键词： Contact stress Compression load Bending deflection Photo-elastic technique Finite element analysis

Wind-diesel hybrid power system integration in the south Algeria

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Frontiers in Energy 2015年第3期9卷 259-271页

作者： Khaireddine ALLALI El Bahi AZZAG nabil KAHOUL Department of Electrical Engineering Badji Mokhtar University- Annaba Annaba 23000 Algeria Laboratoire d'Electrotechnique d'Annaba Badji Mokhtar University-Annaba Annaba 23000 Algeria

In most isolated sites situated in south Algeria, the diesel generators are the major source of electrical energy. Indeed, the power supply of these remote regions still poses order problems （technical, economical and ecological）. The electricity produced with the help of diesel generators is very expensive and responsible for CO2 emission. These isolated sites have significant wind energy potential. Hence, the use of twinning wind-diesel is widely recommended, especially to reduce operating deficits. The objective of this paper is to study the global modeling of a hybrid system which compounds wind turbine generator, diesel generator and storage system. This model is based on the control strategy to optimize the functioning of the hybrid system and to consolidate the gains to provide proper management of energy sources （wind, diesel, battery） depending on the load curve of the proposed site. The management is controlled by a controller which ensures the opening/closing of different power switches according to meteorological conditions （wind speed, air mass, temperature, etc）.

关键词： wind-diesel storage system isolated site,management simulation

Forward–Backward SDEs Driven by Levy Process in Stopping Time Duration

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Communications in Mathematics and Statistics 2017年第2期5卷 141-157页

作者： Dalila Guerdouh nabil Khelfallah Laboratoire de Mathematiques Appliquees Universite de BiskraB.P14507000 BiskraAlgeria

As the first part in the present paper,we study a class of backward stochastic differential equation(BSDE,for short)driven by Teugels martingales associated with some Levy processes having moment of all orders and an independent Brownian *** obtain an existence and uniqueness result for this type of BSDEs when the final time is allowed to be *** the second part,we prove,under a monotonicity condition,an existence and uniqueness result for fully coupled forward-backward stochastic differential equation(FBSDE,for short)driven by Teugels martingales in stopping time *** an illustration of our theoretical results,we deal with a portfolio selection in Levy-type market.

关键词： backward stochastic differential equations Teugels martingale Levyprocess Stopping time

Geochemical assessment, mixing behavior and environmental impact of thermal waters in the Guelma geothermal system,Algeria

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Acta Geochimica 2019年第5期38卷 683-702页

作者： Foued Bouaicha Henia Dib Oualid Bouteraa nabil Manchar Kamel Boufaa nabil Chabour Abdeslam Demdoum Department of Applied Biology Universite des Freres Mentouri Constantine 1025000 ConstantineAlgeria Department of Geology Universite des Freres Mentouri Constantine 1025000 ConstantineAlgeria Laboratory of Geology and Environment (LGE) Uni versite des Freres Mentouri Constantine 1ConstantineAlgeria Department of Geology Sciences University of Larbi Ben M'hidi04000 Oum El BouaghiAlgeria Department of Earth Sciences University of Setif 119000 SetifAlgeria

A study of thirteen geothermal springs located in the geothermal field of Guelma,northeastern Algeria,was *** were collected during the period between January 2014 and February *** processes responsible for the chemical composition of thermal and mineralized water were *** hydrochemical analysis shows that the thermal waters are characterized by the presence of two different chemical facies,the first type SO4-Ca in the east,west and south of Guelma,the second type HCO3-Ca in the *** analysis also attributed to sodium,chlorides,and sulfates to an evaporitic terrigenous origin by the molar ratio Sr2+/Ca2+.The thermal spring waters from Guelma geothermal system have a meteoric origin,and all samples are immature with strong mixing between hot and shallow waters with 19-38.5%rate of *** silica geothermometer shows that these thermal waters have a temperature varying from 84 to 122℃and that the water came from a depth of 2100-3000 m through a fault system that limits the pullapart basin of *** environmental effluent from thermal spas could pollute in both the irrigation and drinking waters,and which imposes danger on the health of the inhabitants of the region.

关键词： Geochemistry Geothermometry Mixing Thermal effluents Guelma Algeria

Quantifying non-classical correlations under thermal effects in a double cavity optomechanical system

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Chinese Physics B 2020年第2期29卷 121-128页

作者： Mohamed Amazioug Larbi Jebli Mostafa Nassik nabil Habiballah Department of Physics Ecole Normale Supérieure(ENS)Mohammed V University in RabatMorocco LPHE-MS Department of PhysicsFaculty of SciencesMohammed V UniversityRabatMorocco EPTHE Department of PhysicsFaculty of SciencesIbn Zohr UniversityAgadirMorocco Faculty of Applied Sciences Ibn Zohr UniversityAit-MelloulMorocco Abdus Salam International Center for Theoretical Physics Strada Costiera1134151TriesteItaly

We investigate the generation of quantum correlations between mechanical modes and optical modes in an optomechanical system,using the rotating wave *** system is composed of two Fabry-Pérot cavities separated in space;each of the two cavities has a movable *** aim is the evaluation of entanglement between mechanical modes and optical modes,generated by correlations transfer from the squeezed light to the system,using Gaussian intrinsic entanglement as a witness of entanglement in continuous variables Gaussian states,and the quantification of the degree of mixedness of the Gaussian states using the ***,we quantify nonclassical correlations between mechanical modes and optical modes even beyond entanglement by considering Gaussian geometric discord via the Hellinger ***,entanglement,mixdness,and quantum discord are analyzed as a function of the parameters characterizing the system(thermal bath temperature,squeezing parameter,and optomechanical cooperativity).We find that,under thermal effect,when entanglement vanishes,purity and quantum discord remain ***,the Gaussian Hellinger discord is more robust than *** effects of the other parameters are discussed in detail.

关键词： cavity optomechanics quantum correlations Gaussian intrinsic entanglement purity Gaussian Hellinger discord Gaussian geometric discord

Global Stability Analysis of Switched Nonlinear Observers

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International Journal of Automation and computing 2015年第4期12卷 432-439页

作者： Imen Manaa nabil Barhoumi Faouzi Msahli The National Engineering School of Monastir Department of Electrical EngineeringStudy of Industrial Systems and Renewable Energy

This paper considers the problem of simultaneous estimation of the system states and the strategy of commutation for a larger class of nonlinear switched ***,a hybrid high gain observer is considered to get the exact estimation of the continuous states where the strategy of switching is previously ***,an extension to a larger class of nonlinear hybrid systems with arbitrary switching is *** analysis is widely discussed for the two cases to provide a finite-time convergence of the estimation *** effectiveness of the proposed hybrid high gain observer has been proved by applying it to a quadruple tank process.

关键词： Nonlinear hybrid system switching strategies Lyapunov function stability analysis

An Efficient Method to Estimate Admittance of Black-boxed Inverter-based Resources for Varying Operating Points

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CSEE Journal of Power and Energy Systems 2024年第1期10卷 421-426页

作者： Weihua Zhou Bin Liu nabil Mohammed Behrooz Bahrani Department of Electrical and Computer Systems Engineering Monash UniversityMelbourne 3800Australia Energy Centre Commonwealth Scientific and Industrial Research Organisation(CSIRO)Newcastle 2300Australia.He is now with the Network Planning DivisionTransgridSydney 2000Australia

Traditional analytical approaches for stability assessment of inverter-based resources(IBRs),often requiring detailed knowledge of IBR internals,become impractical due to IBRs’proprietary *** measurements,relying on electromagnetic transient simulation or laboratory settings,are not only time-intensive but also operationally inflexible,since various non-linear control loops make IBRs’admittance models operating-point ***,such admittance measurements must be performed repeatedly when operating point *** avoid time-consuming and cumbersome measurements,admittance estimation for arbitrary operating points is highly ***,existing admittance estimation algorithms usually face challenges in versatility,data demands,and *** this challenge,this letter presents a simple and efficient admittance estimation method for blackboxed IBRs,by utilizing a minimal set of seven operating points to solve a homogeneous linear equation *** studies demonstrate this proposed method ensures high accuracy across various types of *** accuracy is satisfying even when non-negligible measurement errors exist.

关键词： Admittance estimation black box inverterbased resource measurement error operating point

Second-order Sliding Mode Approaches for the Control of a Class of Underactuated Systems

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International Journal of Automation and computing 2015年第2期12卷 134-141页

作者： Sonia Mahjoub Faical Mnif nabil Derbel Advanced Control and Energy Management Laboratory University of SfaxSfax Engineering School Department of Electrical and Computer Engineering Sultan Qaboos University

In this paper, first-order and second-order sliding mode controllers for underactuated manipulators are proposed. Sliding mode control(SMC) is considered as an effective tool in different studies for control systems. However, the associated chattering phenomenon degrades the system performance. To overcome this phenomenon and track a desired trajectory, a twisting, a supertwisting and a modified super-twisting algorithms are presented respectively. The stability analysis is performed using a Lyapunov function for the proposed controllers. Further, the four different controllers are compared with each other. As an illustration, an example of an inverted pendulum is considered. Simulation results are given to demonstrate the effectiveness of the proposed approaches.

关键词： Underactuated manipulator sliding mode control twisting algorithm super-twisting algorithm inverted pendulum.