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In this article we analyze the M=G=1 retrial queue with two-way communication and n types of outgoing calls from a stochastic comparison viewpoint. The main idea is that given a complex Markov chain that cannot be analyzed numerically, we... more
In this article we analyze the M=G=1 retrial queue with two-way communication and n types of outgoing calls from a stochastic comparison viewpoint. The main idea is that given a complex Markov chain that cannot be analyzed numerically, we propose to bound it by a new Markov chain, which is easier to solve by using a stochastic comparison approach. Particularly, we study the monotonicity of the transition operator of the embedded Markov chain relative to the stochastic and convex orderings. Bounds are also obtained for the stationary distribution of the embedded Markov chain at departure epochs. Additionally, the performance measures of the considered system can be estimated by those of an M=M=1 retrial queue with two-way communication and n types of outgoing calls when the service time distribution is NBUE (respectively, NWUE). Finally, we test numerically the accuracy of the proposed bounds.
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Research Interests: Philosophy and Humanities
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Vehicular Ad Hoc Network (VANET) is an emerging new technology and a promising approach for Intelligent Transportation Systems (ITS) domain. Many researchers focused on the creation of reliable, scalable and efficient routing protocols... more
Vehicular Ad Hoc Network (VANET) is an emerging new technology and a promising approach for Intelligent Transportation Systems (ITS) domain. Many researchers focused on the creation of reliable, scalable and efficient routing protocols for VANET and improve their Quality of Service (QoS). Communication among vehicular nodes which enable drivers to take appropriate decision needs a high reliability, therefore the design of a routing protocol that ensures a certain level of QoS, represents one of the most important challenges of the vehicular networks, because VANET are characterized by specific features, such as restricted mobility, high node speed and a very dynamic topology. keeping in view of the above, this paper provides a detailed description of various existing QoS routing protocols in literature with an aim to classify them. Based on the optimization methods used to improve routing protocols in VANET, we have surveyed and classified the routing protocols into two classes, QoS routing protocols not based on meta-heuristics and QoS routing protocols based on meta-heuristics.
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Strong stability in an <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si17.gif" overflow="scroll"><mml:mo stretchy="false">(</mml:mo><mml:mi>R</mml:mi><mml:mo>,</mml:mo><mml:mi
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International audienc
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In this article, a queueing inventory system with finite sources of demands, retrial demands, service time, lead time, ( s , S ) \left(s,S) replenishment policy, and demands search from the orbit was studied. When the lead time is... more
In this article, a queueing inventory system with finite sources of demands, retrial demands, service time, lead time, ( s , S ) \left(s,S) replenishment policy, and demands search from the orbit was studied. When the lead time is exponentially distributed (resp. lead time is generally distributed), generalized stochastic Petri net (GSPN) (resp. Markov regenerative stochastic Petri net [MRSPN]) is proposed for this inventory system. The quantitative analysis of this stochastic Petri net model was obtained by continuous time Markov chain for the GSPN model (resp. the supplementary variable method for the MRSPN model). The probability distributions are obtained, witch allowed us to compute performance measures and the expected cost rate of the studied system.
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In this work, we considered the parametric estimation of the characteristics of the M / M / 1 / N {M/M/1/N} waiting model with Bernoulli feedback. Through a Monte-Carlo simulation study, we have illustrated the effect of the estimation of... more
In this work, we considered the parametric estimation of the characteristics of the M / M / 1 / N {M/M/1/N} waiting model with Bernoulli feedback. Through a Monte-Carlo simulation study, we have illustrated the effect of the estimation of the starting parameters of the considered waiting system on the statistical properties of its performance measures estimates, when these latter are obtained using the plug-in method. In addition, several types of convergence (bias, variance, MSE, in law) of these performance measure estimators have also been showed by simulation.
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The aim of this work is the study of the impact of interferences on the link disconnection probability in Ad hoc networks. We first calculated the critical distance for successful transmission. Then we modeled the motion of an ad hoc... more
The aim of this work is the study of the impact of interferences on the link disconnection probability in Ad hoc networks. We first calculated the critical distance for successful transmission. Then we modeled the motion of an ad hoc nodes using a Markov process of {Xn} ({Yn}), and under the assumption that the Hello messages arrive according to a Poisson process with rate λ, we calculated the probability that a link becomes unavailable by exploiting data Hello messages like node position and node speed.
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... Ath U Ameur de Tamazirt et le patron de la Zawiya de Chellata, Ben Ali Chérif, l ... partie de ces derniers, recueillis dans [6], a été transmise par dada Ait Hammouda (femme de ... la suite obtenu une idjaza de la principale... more
... Ath U Ameur de Tamazirt et le patron de la Zawiya de Chellata, Ben Ali Chérif, l ... partie de ces derniers, recueillis dans [6], a été transmise par dada Ait Hammouda (femme de ... la suite obtenu une idjaza de la principale personnalité religieuse d&amp;amp;#x27;Alger, Abd ar-Rahman ath Thaaliby ...
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The electrical substation components are often subject to degradation due to over-voltage or over-current, caused by a short circuit or a lightning. A particular interest is given to the circuit breaker, regarding the importance of its... more
The electrical substation components are often subject to degradation due to over-voltage or over-current, caused by a short circuit or a lightning. A particular interest is given to the circuit breaker, regarding the importance of its function and its dangerous failure. This component degrades gradually due to the use, and it is also subject to the shock process resulted from the stress of isolating the fault when a short circuit occurs in the system. In this paper, based on failure mechanisms developments, the wear out of the circuit breaker contacts is modeled. The aim of this work is to evaluate its reliability and consequently its residual lifetime. The shock process is based on two random variables such as: the arrival of shocks and their magnitudes. The arrival of shocks was modeled using homogeneous Poisson process (HPP). By simulation, the dates of short-circuit arrivals were generated accompanied with their magnitudes. The same principle of simulation is applied to the amo...
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The Web service technology provides an environment in which heterogeneous components can collaborate together to achieve a common goal. However, the opening of Web services on the Internet is still subject to security vulnerability. The... more
The Web service technology provides an environment in which heterogeneous components can collaborate together to achieve a common goal. However, the opening of Web services on the Internet is still subject to security vulnerability. The increased awareness of the importance of security in composite Web services has made access control a relevant component. In recent years, Attribute Based Access Control (ABAC) is an emerging paradigm that has been studied, the latter allows the creation of access policies based on the attributes of the users, the objects and the environment. In this paper, an intuitive graphical access control model for composite web services based on conceptual graph is proposed. The proposed model allows the formalization of all ABAC attributes on conceptual graph, and the security process is also performed by the conceptual graph operations. On the one hand, the proposed model provides an intuitive tool to help the providers of Web service to manage their access control policies. On the other hand, the model makes a step towards in the development of access control models based on formal model.
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In this work, we introduce the qualitative and<br> quantitative concept of the strong stability method in the risk process<br> modeling two lines of business of the same insurance company or<br> an insurance and... more
In this work, we introduce the qualitative and<br> quantitative concept of the strong stability method in the risk process<br> modeling two lines of business of the same insurance company or<br> an insurance and re-insurance companies that divide between them<br> both claims and premiums with a certain proportion. The approach<br> proposed is based on the identification of the ruin probability<br> associate to the model considered, with a stationary distribution of a<br> Markov random process called a reversed process. Our objective, after clarifying the condition and the perturbation<br> domain of parameters, is to obtain the stability inequality of the ruin<br> probability which is applied to estimate the approximation error of a<br> model with disturbance parameters by the considered model. In the<br> stability bound obtained, all constants are explicitly written.
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Research Interests: Philosophy and Humanities
Dans ce chapitre, nous présentons une synthèse des résultats sur l’application de la méthode de stabilité forte à l’étude de la robustesse des systèmes et des réseaux de files d’attente. En plus de l’affirmation qualitative de la... more
Dans ce chapitre, nous présentons une synthèse des résultats sur l’application de la méthode de stabilité forte à l’étude de la robustesse des systèmes et des réseaux de files d’attente. En plus de l’affirmation qualitative de la stabilité forte, nous obtenons souvent des bornes de perturbation. Enfin, l’utilisation des méthodes d’estimation non paramétrique de densité dans ce contexte est discutée.