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NUMERICAL STUDY OF FLOW AROUND AN OSCILLATING DIAMOND PRISM AND CIRCULAR CYLINDER AT LOW KEULEGAN-CARPenTER NUMBER

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Journal of Hydrodynamics 2012年第5期24卷 767-775页

作者： GHOZLANI Belgacem HAFSIA Zouhaier MAALEL Khlifa ecole nationale d'Ingénieurs de Tunis Laboratoire de Modélisation en'Hydraulique et EnvironnementB.P.37.Le Belvédère1002 TunisTunisia

In order to identify the influence of shape comers on the instantaneous forces in the case of oscillating bodies, the simula- ted flow field is compared for two kinds of cross sections： diamond prism and circular cylinder. For these two flow configurations, the same Reynolds number and a Keulegan-Carpenter are considered. To compute the dynamic flow field surrounding the body, the Navier-Stokes transport equations in a non-inertial reference frame attached to the body are considered. Hence, a source term is added locally to the momentum equation to take into account the body acceleration. The proposed model is solved using the PHOenICS code. For the oscillating circular cylinder, the simulated results are in good agreement with the experimental data availa- ble in the litterature. After validation of this proposed model, flow field for diamond prism is determined. For both bodies, the pro- cess of the vortex formation is similar, with the formation of a recirculation zone in the near-wake containing a symmetric pair of vortices of equal strength and opposite rotation. The length of recirculation zone varies approximately linearly with time. However, the in-line force coefficient of the oscillating diamond prism is found to be greatest, since the recirculation zone is longer compared with that of the oscillating circular cylinder.

关键词： oscillating cylinder diamond prism body shape non-inertial frame numerical simulation in-line and transverse forcecoefficient

Active Queue Management Exploiting the Rate Information in TCP-IP Networks

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IEEE/CAA Journal of Automatica Sinica 2018年第1期5卷 223-231页

作者： Abderrahmane Boudi Malik Loudini Laboratoire de la Communication dans les Systemes Informatiques Ecole nationale Superieure d'Informatique ESI Algiers 16309 Algeria IEEE

In this paper, we propose a new mechanism called explicit rate notification(ERN) to be used in end-to-end communications. The ERN scheme encodes in the header of transmission control protocol(TCP) packets information about the sending rate and the round trip time(RTT) of the flows. This new available information to the intermediate nodes(routers) is used to improve fairness, increase utilization, decrease the number of drops, and minimize queueing delays. Thus, it induces a better management of the queue. A comparison of our scheme with preexistent schemes, like the explicit congestion notification scheme, shows the effectiveness of the proposed mechanism.

关键词： Active queue management congestion control fairness transmission control protocol(TCP)

Kinetic degradation of amoxicillin by using the electro-Fenton process in the presence of a graphite rods from used batteries

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Chinese Journal of Chemical engineering 2021年第4期34卷 183-190页

作者： Hakima Kadji Idris Yahiaoui Zehira Garti Abdeltif Amrane Farida Aissani-Benissad Laboratoire de Genie de l'environnement(LGE) Faculte de TechnologieUniversite de Bejaia06000 BejaiaAlgeria ecole nationale superieure de Chimie de Rennes Universite RenneslCNRSUMR 622611 allee de BeaulieuCS 50837France

This study reports the removal of amoxicillin(AMX)in aqueous media using the electroFenton process in the presence of a graphite cathode recovered from used *** impact of the relevant parameters on the electroFenton process,namely the applied current intensity,the temperature,the initial concentration of AMX and the initial concentration of ferrous ions were *** results showed that the optimal values were:I=600 mA,T=25℃,[AMX]_(0)=0.082 mmol·L^( 1) and[Fe^(2+)]=1 mmol·L^(1),leading to 95%degradation and 74%*** model parameters of AMX mineralization were determined using nonlinear methods,showing that it follows a pseudosecondorder *** energy consumption(EC)calculated under the optimal values was found to be 0.79 kWhg 1,which was of the same order of magnitude of those reported in other findings;while it is noteworthy that the electrodes used in our study are of a lower cost.

关键词： Wastewater Amoxicillin Electro-Fenton Pharmaceuticals Solid waste recovery Kinetic modelling

Adaptive genetic algorithms guided by decomposition for PCSPs： application to frequency assignment problems

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Frontiers of Computer Science 2016年第6期10卷 1012-1025页

作者： Lamia SADEG-BELKACEM Zineb HABBAS Wassila AGGOUNE-MTALAA ecole Militaire Polytechnique Algiers 16111 Algeria ecole nationale superieure d' Informatique Algiers 16309 Algeria Universite de Lorraine Metz 57045 France Luxembourg Institute of Science and Technology Luxembourg L-4362 Luxembourg

This paper proposes Adaptive Genetic Algorithms Guided by structural knowledges coming from decomposition methods, for solving PCSPs. The family of algorithms called AGAGD_x_y is designed to be doubly genetic, meaning that any decomposition method and different heuristics for the genetic operators can be considered. To validate the approach, the decomposition algorithm due to Newman was used and several crossover operators based on structural knowledge such as the cluster, separator and the cut were tested. The experimental results obtained on the most challenging Minimum Interference-FAP problems of CALMA instances are very promising and lead to interesting perspectives to be explored in the future.

关键词： optimization problems partial constraint satisfaction problems frequency assignment problems graph decomposition adaptive genetic algorithm (AGA) AGA guided by decomposition (AGAGD).

Regional gradient observability for semilinear hyperbolic systems： HUM approach

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Control Theory and Technology 2018年第1期16卷 72-80页

作者： Adil KHAZARI Ali BOUTOULOUT Imad EL HARRAKI Sidi Mohamed Ben Abdellah University Ecole Nationale de Commerce et de gestion Fez Morocco TSI Team MACS Laboratory Faculty of Sciences Moulay Ismail University Meknes Morocco ecole nationale superieure des mines de Rabat Rabat Morocco

The paper aims to extend the notion of regional observability of the gradient to the semilinear hyperbolic case, in order to reconstruct the gradient of the initial conditions in a subregion w of the domain evolution Ω. We start with an asymptotically linear system, the approach is based on an extension of the Hilbert uniqueness method （HUM） and Schauder＇s fixed point theorem. The analysis leads to an algorithm which is successfully numerically implemented and illustrated with examples and simulations.

关键词： Distributed systems fixed point regional gradient observability regional reconstruction semilinear hyperbolic systems

Machine Learning Techniques for Software Maintainability Prediction:Accuracy Analysis

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Journal of Computer Science & Technology 2020年第5期35卷 1147-1174页

作者： Sara Elmidaoui Laila Cheikhi Ali Idri Alain Abran Softtrare Project Management TeamEcole Nationale Superieure d'Informattique et d'Analyse des SystemesMadinate Al IrfaneMohammed V University in Rabat.Agdal RabatBP 713Morocco Department of Software engineering&Infonnation Technology Ecole de Technologie Superieure(ETS)Montreal HSC IKSCanada

Maintaining software once implemented on the end-user side is laborious and,over its lifetime,is most often considerably more expensive than the initial software *** prediction of software maintainability lias emerged as an important research topic to address industry expectations for reducing costs,in particular,maintenance *** and practitioners have been working on proposing and identifying a variety of techniques ranging from statistical to machine learning(ML)for better prediction of software *** review has been carried out to analyze the empirical evidence on the accuracy of software product maintainability prediction(SPMP)using ML *** paper analyzes and discusses the findings of 77 selected studies published from 2000 to 2018 according to the following criteria:maintainability prediction techniques,validation methods,accuracy criteria,overall accuracy of ML techniques,and the techniques offering the best *** review process followed the well-known syslematic review *** results show that ML techniques are frequently used in predicting *** particular,artificial neural network(ANN),support vector machine/regression(SVM/R).regression&decision trees(DT),and fuzzy neuro fuzzy(FNF)techniques are more accurate in terms of PRED and *** N-fold and leave-one-out cross-validation methods,and the MMRE and PRED accuracy criteria are frequently used in empirical *** general,ML techniques outperformed non-machine learning techniques,e.g.,regression analysis(RA)techniques,while FNF outperformed SVM/*** ANN in most ***,while many techniques were reported superior,no specific one can be identified as the best.

关键词： accuracy criterion accuracy value machine learning technique maintainability prediction

Quasi-Local energy Distribution and Thermodynamics of Reissner-Nordstrom Black Hole Surrounded by Quintessence

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Communications in Theoretical Physics 2011年第2期55卷 291-295页

作者： Mahamat Saleh Bouetou Bouetou Thomas Timoleon Crepin Kofane Department of Physics Faculty of Science University of Yaounde Dpartment of Physics Higher Teacher's Training College University of Maroua ecole nationale superieure Polytechnique University of Yaounde

We investigate quasi-local energy distribution and thermodynamics of the Reissner-Nordstr6m black hole space-time surrounded by quintessence. We use the quasi-local energy distribution from Einstein energy-momentum complex. We plot the variation of the energies, temperature and heat capacity with the state parameter related to the quintessence ωq. We show that due to the presence of quintessence, the total energy of the outer region as well as the temperature and heat capacity decreases with the increase of the density of quintessence, while the total energy of the black hole region increases.

关键词： quasi-local energy distribution thermodynamics Reissner-NordstrSm black hole quintessence

Travelling Wave Solutions to Stretched Beam's Equation: Phase Portraits Survey

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Communications in Theoretical Physics 2011年第4期55卷 605-608页

作者： Gambo Betchewe Kuetche Kamgang Victor Bouetou Bouetou Thomas Timoleon Crepin Kofane Higher Teacher's Training College of Maroua University of Maroua ecole nationale superieure Polytechnique University of Yaounde I Department of Physics Faculty of ScienceUniversity of Yaounde I

In this paper, following the phase portraits analysis, we investigate the integrability of a system which physically describes the transverse oscillation of an elastic beam under end-thrust. As a result, we find that this system actually comprises two families of travelling waves： the sub- and super-sonic periodic waves of positive- and negative- definite velocities, respectively, and the localized sub-sonic loop-shaped waves of positive-definite velocity. Expressing the energy-like of this system while depicting its phase portrait dynamics, we show that these multivaiued localized travelling waves appear as the boundary solutions to which the periodic travelling waves tend asymptotically

关键词： phase portraits elastic beam travelling waves

Exergo-environmental Study of a Recent Organic Solar Hybrid Heat Pump

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Fluid Dynamics & Materials Processing 2023年第4期19卷 991-1001页

作者： Rabeb Toujani Nahla Bouaziz Universitéde Tunis El Manar Ecole Nationale D’Ingénieurs de TunisUnitéde Recherche Energ tique et EnvironnementTunis1002Tunisie

A hybrid heat pump(compression/absorption)with an integrated thermal photovoltaic unit is *** considered working fluids are organic mixtures:R245fa/DMAC and R236fa/DMAC,chosen for their low Global Warming *** main objective is the optimization of energy efficiency in order to minimize the environmental impact through the implementation of a sustainable *** is shown that Exergy Analysis itself is a valuable tool in energy *** the imposed framework of minimizing total annual costs,entropy analysis can be instrumental in determining the optimal plant concept,optimizing energy conversion and use,and improving *** present results are discussed under the optimistic hope that they may help to define new energy and environmental policies.

关键词： Impact environmental exergy analysis CO_(2)emissions solar hybrid heat pump