مقـــــــــالات 2010-2015

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A cellular automaton based approach for real time
(Springer, 2015) Boutekkouk, Fateh
Real Time Embedded Systems are becoming ubiquitous. Since these systems have autonomous batteries, their design must minimize power consumption in order to extend batteries life time. On the other hand, Cellular Automaton (CA) appears a good choice to simulate the future behavior of complex dynamic and parallel systems. Due to some intrinsic characteristics such as neighborhood and local transitions, CA can exhibit some complex behaviors. In this work, we apply CA to model the well known problem of Real time scheduling and eventually to optimize the power consumption of a Real time multicores embedded system with periodic tasks. CA algorithm is focused on the so-called technique: Dynamic Voltage Scaling (DVS). The proposed CA is a 2D grid.
A Detailed Chemical Kinetic Mechanism for Methanol Combustion in Laminar Flames1
(Pleiades Publishing, 2011) Hamdane, S; Rezgui, Y; Guemini, M
On the basis of existing detailed kinetic schemes a general and consistent mechanism of the oxi dation of methanol was compiled for computational studies covering a wide range of lean to rich flames. The proposed model, featuring 21 species and 115 reactions, has been validated using three data sets and the com puted reactants, products and intermediates mole fractions. This scheme was compared to those by Held⎯Dryer, Egolfopolous and Pauwels under the same conditions. The developed mechanism predicts well the concentrations of the major reactants, intermediates, and products at all the studied equivalence ratios and it gives the best calculated values, as compared to the other used models, as well. The production rates analysis of selected species allowed the identification of the major formation and depletion pathways. A reac tion path analysis snowed that the main channels in methanol consumption involved H, OH and O attack and the resulting radicals CH2OH and CH3O produced formaldehyde.
A hybrid approach to extend the life time of heterogeneous wireless sensor networks
(Elsevier, 2015) boutekkouk, Fateh; Taibi, Fatima; Meziani, Khawla
In this work, we propose to use two optimization meta-heuristics that are: firefly and simulated annealing to extend the life time of a heterogeneous wireless sensors network (WSN) with a fixed base station by reducing the communication energy consumption. The proposed approach combines between the clustering and the chain approaches. Our optimization algorithm tries at first time to find the optimal clustering over the network nodes using the firefly algorithm then inside each cluster it attempts to find the best chain using simulated annealing. A particularity in our algorithm is the dynamic adjustment of clusters number over rounds.
A Method of solution for integro-differential parabolic equation with purely integral conditions
(2015) Merad, Ahcene; Bouziani, Abdelfatah
The objective of this paper is to prove existence, uniqueness, and continuous dependence upon the data of solution to integro-differential parabolic equation with purely integral conditions. The proofs are based on a priory estimates and Laplace transform method. Finally, we obtain the solution by using a numerical technique for inverting the Laplace transforms. 20.1 Introduction
A Novel conformance testing technique for agent interaction protocols
(London, UK, 2013) Mokhati, Farid; Badri, Mourad; Zerrougui, Salim
Agent Interaction Protocols (AIP) play a crucial role in multi-agent systems development. AIP allow specifying interactions (sequences of messages) between agents. As agent-oriented development emerges, testing agent-based software is receiving increased research attention. We present, in this paper, a novel conformance testing technique for agent interaction protocols. The approach supports an incremental testing strategy that considers both agent and society testing of Multi-Agent Systems. It uses aspect-oriented technology to support and monitor the testing process. The proposed technique consists in two main phases: (1) Generating adequate test cases from a formal description of Multi-Agent Systems’ behavior, and (2) Verifying the execution of test cases. The technique is supported by a visual tool (AIPTE: Agent Interaction Protocols Testing Environment). A case study is presented to illustrate the approach.
A novel fuzzy approach for handwritten arabic character recognition
(Springer, 2015) Kef, Maamar; Chergui, Leila; Chikhi, Salim
The aim of our work is to present a new method based on structural characteristics and a fuzzy classifier for off-line recognition of handwritten Arabic characters in all their forms (beginning, end, middle and isolated). The proposed method can be integrated in any handwritten Arabic words recognition system based on an explicit segmentation process. First, three preprocessing operations are applied on character images: thinning, contour tracing and connected components detection. These operations extract structural characteristics used to divide the set of characters into five subsets. Next, features are extracted using invariant pseudo-Zernike moments. Classification was done using the Fuzzy ARTMAP neural network, which is very fast in training and supports incremental learning. Five Fuzzy ARTMAP neural networks were employed; each one is designed to recognize one subset of characters. The recognition process is achieved in two steps: in the first one, a clustering method affects characters to one of the five character subsets. In the second one, the pseudo-Zernike features are used by the appropriate Fuzzy ARTMAP classifier to identify the character. Training process and tests were performed on a set of character images manually extracted from the IFN/ENIT database. A height recognition rate was reported.
A reduced maximality labeled transition system generation for recursive Petri nets
(Elsevier, 2015) Bouneb, Messaouda; Saidouni, Djamel Eddine; Ilie, Jean Michel
In Saidouni et al. (Maximality semantic for recursive Petri net. Europeen conference on modelling and simulation (ECMS’13) pp 544–550, 2013) a maximality operational semantics has been defined for the recursive Petri net model. This operational semantics generates a true concurrency structure named maximality-based labeled transition systems (MLTS). This paper proposes an approach that generates an on-the-fly reducedMLTS modulo a maximality bisimulation relation. The interest of the approach is shown using an example concerning the woodshop cutting system
A Serial combination of neural network for arabic OCR
(Springer, 2014) Chergui, Leila; Kef, Maamar
Today, handwriting recognition is one of the most challenging tasks and exciting areas of search in computer science. Indeed, despite the growing interest in this field, no satisfactory solution is available. For this reason Multiple Classifier Systems (MCS) based on the combination of outputs of a set of different classifiers have been proposed as a method for the developing of high performance classifier system. In this paper we describe a serial combination scheme of an Arabic Optical Character Recognition System. The classification engine is based on Adaptive Resonance Theory and Radial Basic Function, where an RBF network acting as the first classifier is properly combined with a set of ART1 network (one for each group) trained to classify the word image. The experiments applied on the IFN/ENIT database show that the proposed architecture exhibits best performance
An experimental approach to improve the basin type solar still using an integrated natural circulation loop
(Elsevier, 2015) Rahmani, Ahmed; Boutriaa, Abdelouahab; Hadef, Amar
In this paper, a new experimental approach is proposed to enhance the performances of the conventional solar still using the natural circulation effect inside the still. The idea consists in generating air flow by a rectangular natural circulation loop appended to the rear side of the still. The proposed still was tested during summer period and the experimental data presented in this paper concerns four typical days. The convective heat transfer coefficient is evaluated and compared with Dunkle’s model. The comparison shows that convective heat transfer is considerably improved by the air convection created inside the still. The natural circulation phenomenon in the still is studied and a good agreement between the experimental data and Vijajan’s laminar correlation is found. Therefore, natural circulation phenomenon is found to have a good effect on the still performances where the still daily productivity is of 3.72 kg/m2 and the maximum efficiency is of 45.15%.
An observer based backstepping control for a greenhouse
(2011) Belhani, Ahmed; M’sirdi, Nacer Kouider
In this paper we use the backstepping approach to control climate parameters of greenhouse. To get realistic simulation, we use real weather data collected in the south region of Algeria (Biskra). We control temperature, relative humidity and CO2 concentration by acting on four variables such as heating, ventilation, CO2 injection and water injection. However as the CO2 sensors is not available, we use an nonlinear observer based on temperature and steam density measurements, To get an optimal controller, the multi- objective genetic algorithms based on Non dominated Sorting Genetic Algorithms (NSGA) techniques and Multi-Criteria Decision Analysis (MCDA) approach are introduced.
Benzene Combustion: A Detailed Chemical Kinetic Modeling in Laminar Flames Conditions1
(Pleiades Publishing, 2014) Rezgui, Y; Guemini, M
Models resulting from the merging of validated kinetic schemes were used to compile a new detailed mechanism for benzene combustion in laminar flames. The proposed model, featuring 215 species and 1313 reactions, has been validated using fuelrich, lowpressure, premixed benzene–oxygen–argon flames available in the literature. Good agreement between simulated and experimental data is achieved for the major reactants, intermediates, and products. However, computed maxima for some polyaromatic hydro carbons were lower than experimental ones.
Box and jenkins nonlinear system modelling using RBF neural networks designed by NSGAII
(Springer, 2015) Lamamra, Kheireddine; Belarbi, Khaled; Boukhtini, Souaad
In this work, we use radial basis function neural network for modeling nonlinear systems. Generally, the main problem in artificial neural network is often to find a better structure. The choice of the architecture of artificial neural network for a given problem has long been a problem. Developments show that it is often possible to find architecture of artificial neural network that greatly improves the results obtained with conventional methods. We propose in this work a method based on No Sorting Genetic Algorithm II (NSGA II) to determine the best parameters of a radial basis function neural network. The NSGAII should provide the best connection weights between the hidden layer and output layer, find the parameters of the radial function of neurons in the hidden layer and the optimal number of neurons in the hidden layers and thus ensure learning necessary. Two functions are optimized by NSGAII: the number of neurons in the hidden layer of the radial basis function neural network, and the error which is the difference between desired input and the output of the radial basis function neural network. This method is applied to modeling Box and Jenkins system. The obtained results are very satisfactory.
Chemical composition and antibacterial activity of the essential oils from Launaea resedifolia L
(Springer, 2012) Zellagui, Amar; Gherraf, Noureddine; Ladjel, Segni; Hameurlaine, Samir
Background: Several species of the genus Launaea are used in folk medicine such as in bitter stomachic, skin diseases, and reported to have antitumor, insecticide, and cytotoxic activities. The antimicrobial activities of coumarin constituents and the neuropharmacological properties have been investigated as well. In this study, the chemical composition of essential oils from Launaea resedifolia L. has been identified using the ordinary GC-MS technique to reveal the presence of 19 compounds dominated by dioctyl phthalate. Moreover, the antibacterial activity of the crude oil has been carried out using disk diffusion method against seven bacteria strains. Results: Nineteen compounds of essential oil of L. resedifolia L. were identified, representing 86.68% of the total oil. The compounds were identified by spectral comparison to be mainly esters, alcohols, ketones, and terpenes. The principal constituents are dioctyl phthalate (39.84%), Decanoic acid, decyl ester (12.09%), 11-Octadecenal (11.24%), and Eucalyptol (07.31%), while others were present in relatively small amounts. As far as antibacterial essays are concerned, it was found that the oils are active against most of the tested bacterial strains. Conclusion: A major constituent in visible parts was Dioctyl phthalate (39.84%) and the yield of essential oils was 0.9%. These extracts reveal in vitro antibacterial activity on the studied bacterial, confirmed by the inhibition zone diameter ranging from 11 to 37 mm and a MIC value between 0.09 and 0.69 depending on the microorganism being tested.
Chemical constituents and antimicrobial activity of essential oils of Ammodaucus leucotricus
(Elsevier, 2013) Gherraf, Noureddine; Zellagui, Amar; Kabouche, Azeddine; Lahouel, Mesbah; Salhi, Ramdane; Rhouati, Salah
Ammodaucus belongs to the family Apiaceae (Umbelliferae), subfamily Apioideae, trib Caucalideae, and comprises one species in Algeria (Quezel and Santa, 1962). The biological importance of members of this genus promoted us to reinvestigate the volatile constituents of the fruits of Ammodaucus leucotricus Coss. et Dur., and to carry out a biological study as far as the antibacterial activity is concerned. The present work deals with the chemical composition and antibacterial activities of the hydrodistilled oils. After extraction, the oil was analyzed by gas chromatography–mass spectrometry to afford 14 components. The major components were found to be, 1-cyclohexene-1-carboxaldehyde (56.40%), D-limonene (28.82%), and 2-pentanone- 4-hydroxy-4-methyl (5.73%). Moreover, the antimicrobial activities of the volatile oils were evaluated by disk diffusion method against Gram-positive and Gram-negative bacteria. The results showed a strong antibacterial activity against Staphylococcus aureus, Escherichia coli and Klebsiella pneumonia.
Chemical constituents of the roots of Algerian Bunium incrassatum and evaluation of its antimicrobial activity
(Elsevier, 2011) Bousetla, Ahlem; Zellagui, Amar; Derouiche, Kamel; Rhouati, Salah
In this study we investigated the chemical composition of the roots of Bunium incrassatum growing in Algeria, two coumarins, b-sitosterol, sucrose and oleic acid were isolated from methylene chloride:methanol (1/1) extract of the roots of this species. Furthermore, antimicrobial activity of the crude extract was evaluated using agar diffusion method. The antimicrobial results showed that the crude extract had a great potential antimicrobial activity against all the test microorganisms especially fungal strains.
Combining neural networks for arabic handwriting recognition
(IEEE, 2011) Chergui, Leila; Kef, Maâmar; Chikhi, Salim
Combining classifiers is an approach that has been shown to be useful on numerous occasions when striving for further improvement over the performance of individual classifiers. In this paper we present an off-line Multiple Classifier System (MCS) for Arabic handwriting recognition. The MCS combine two individual recognition systems based on Fuzzy ART network used for the first time in Arabic OCR, and Radial Basis Functions. We use various feature sets based on Hu and Zernike Invariant moments. For deriving the final decision, different combining schemes are applied. The best combination ensemble has a recognition rate of 90,1 %, which is significantly higher than the 84,31% achieved by the best individual classifier. To demonstrate the high performance of the classification system, the results are compared with three research using IFN/ENIT database.
Complexity measurement of multi-agent systems
(Springer, 2014) Marir, Toufik; Mokhati, Farid; Bouchelaghem-Seridi, Hassina; Tamrabet, Zouheyr
Multi-Agent Systems (MAS) is a promising software paradigm. Considered as a natural metaphor to modeling complex systems, MAS are applied to develop a wide range of applications. However, the developed system’s complexity is a hard obstacle to understand and maintain them. In this paper, some metrics are presented to measure the complexity of MAS. The proposition of these metrics is passed through the proposition of a complexity model for MAS. To validate our proposal, a tool has been developed to measure the JADE-based applications complexity. Furthermore, the collected metrics can also be used as a base to estimate the required effort to maintain JADE-based applications.
Comprehensive experimental and numerical investigations of the effect of frequency and acoustic intensity on the sonolytic degradation of naphthol blue black in water
(Elsevier, 2015) Ferkous, Hamza; Merouani, Slimane; Hamdaoui, Oualid; Rezgui, Yacine; Guemini, Miloud
In the present work, comprehensive experimental and numerical investigations of the effects of frequency and acoustic intensity on the sonochemical degradation of naphthol blue black (NBB) in water have been carried out. The experiments have been examined at three frequencies (585, 860 and 1140 kHz) and over a wide range of acoustic intensities. The observed experimental results have been discussed using a more realistic approach that combines the single bubble sonochemistry and the number of active bubbles. The single bubble yield has been predicted using a model that combines the bubble dynamics with chemical kinetics consisting of series of chemical reactions (73 reversible reactions) occurring inside an air bubble during the strong collapse. The experimental results showed that the sonochemical degradation rate of NBB increased substantially with increasing acoustic intensity and decreased with increasing ultrasound frequency. The numerical simulations revealed that NBB degraded mainly through the reaction with hydroxyl radical ( OH), which is the dominant oxidant detected in the bubble during collapse. The production rate of OH radical inside a single bubble followed the same trend as that of NBB degradation rate. It increased with increasing acoustic intensity and decreased with increasing frequency. The enhancing effect of acoustic intensity toward the degradation of NBB was attributed to the rise of both the individual chemical bubble yield and the number of active bubbles with increasing acoustic intensity. The reducing effect of frequency was attributed to the sharp decrease in the chemical bubble yield with increasing frequency, which would not compensated by the rise of the number of active bubbles with the increase in ultrasound frequency.
Computer simulation of chemical reactions occurring in collapsing acoustical bubble
(Springer, 2013) Merouani, Slimane; Hamdaoui, Oualid; Rezgui, Yacine; Guemini, Miloud
Acoustic cavitation is responsible for both sonochemistry and sonoluminescence. In this theoretical investigation, computer simulation of chemical reactions occurring in an isolated cavitation bubble oscillating in water irradiated by an ultrasonic wave has been performed for various acoustic amplitudes, different static pressures and diverse liquid temperatures to study the relationship between these three key parameters in sonochemistry and the oxidants created in the bubble. The results of the numerical simulations indicated that the main oxidants created in an O2 bubble are •OH radical and O atom. The amount of the oxidants formed in the bubble at the end of the bubble collapse increases as the acoustic amplitude increases from 1.5 to 3 atm. For each acoustic amplitude, there exists an optimal static pressure for the production of the oxidants, which shifts toward a higher value as the acoustic amplitude increases. Correspondingly, for each acoustic amplitude, an optimum of liquid temperature was observed at 20 C for •OH, HO2 • and H2O2. The simple model adopted in this work, after comparisons with the trends obtained with the literature experimental observations, seems to satisfactorily explain the experimental observations and should practically aid in optimization of operating conditions for sonochemical reactions. Results from this study were discussed and some recommendations were given
Design of a multifunction low power converter with reduced freedom degrees for photovoltaic and mobile applications
(IEEE, 2012) Belkacem, F.; Saidi, A.; Diallo, D.
This paper is an approach to design a new full bridge single-phase multifunction converter. Reduction of freedom degrees is the principal mean to build the converter dedicated mainly to mobile applications fed by photovoltaic cells. The rules of reducing controllable semiconductors are analyzed and simulation and experimental results prove the feasibility of the approach.

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