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- ItemMobility Impact on Mobile Ad hoc Routing Protocols(IEEE Computer Society, 2003) Djenouri, Djamel; Derhab, Abdelouahid; Badache, NadjibAn ad hoc network is a set of mobile units connected by wireless technologies, making an infrastructureless temporary network. without turning to a central administration. The network topology is unpredictable, dynamic, it may change any time. These topology changes make ad hoc networks challenging to implement routing protocols. In this paper, we study mobility effects on the performance of several mobile ad hoc routing protocols.
- ItemAn Energy Efficient routing protocol for mobile ad hoc networks(IFIP, 2003-06) Djenouri, Djamel; Badache, Nadjibpower consumed for routing data-packets in wireless ad hoc networks can be significantly reduced compared with the current min-hop max-power routing protocols. One of promising mechanisms proposed to reduce energy consumption is power control. Doshi & Timothy  have presented an implementation of this mechanism, and defined a new minimum energy routing scheme. We think that the aim of an efficient routing protocol is not only to minimize energy consumption to route packets, but also to ensure a long life to all nodes. In order to avoid the network partition as long as possible. In this paper, we define new metrics to resolve the tradeoff between: minimising energy consumption to route packets, on the one hand, and ensuring a long life to all nodes’ batteries, on the other hand. We also define a new technique which allows the distribution of the routing task over nodes then we modify DSR protocol, to improve it and to make a new power-aware and power efficient protocol.
- ItemGenetic algorithms and multifractal segmentation of cervical cell images(IEEE, 2003-07) Lassouaoui, Nadia; Hamami, LatifaThis paper deals with the segmentation problem of cervical cell images. Knowing that the malignity criteria appear on the morphology of the core and the cytoplasm of each cell, then, the goal of this segmentation is to separate each cell on its component, that permits to analyze separately their morphology (size and shape) in the recognition step, for deducing decision about the malignity of each cell. For that, we use a multifractal algorithm based on the computation of the singularity exponent on each point of the image. For increasing the quality of the segmentation, we propose to add an optimization step based on genetic algorithms. The proposed processing has been tested on several images. Herein, we present some results obtained by two cervical cell images.
- ItemMorphological geodesic reconstruction in the extraction of the lesions in brain images(Université Aboubekr Belkaïd –Tlemcen, 2003-09) Lassouaoui, Nadia; Hamami, LatifaIn this paper, we present algorithms that permit to extract the lesions in brain images. The goal is to extract the abnormal zones with respect of theirs morphological haracteristics as: size, shape and position. Then, we present to the doctor a simple image of abnormal zone that is easy to analysis and correct to diagnosis. For it, we used an algorithm of edge detection based on morphological gradient for delimit this areas; moreover, we have used algorithm based on complex operator knowing by morphological geodesic reconstruction, it permits to extract the areas where the lesions exist. These algorithms are based on mathematical morphology operators. The results obtained are satisfactory; the edge detection respects the characteristics and the morphology of the sick part of the brain, whereas with the algorithm of segmentation in homogeneous areas, we could make the extraction of the sick part of the brain, with the respect of all characteristics in a reasonable time allowing to think of real-time operation.
- ItemA Study on the Energy Consumption Minimisation in Mobile Ad Hoc Networks(2003-12) Djenouri, Djamel; Badache, NadjibThe emergence of lightweight wireless mobile devices, like laptops, PDAs, and sensors makes mobile ad hoc networks (MANETs) an exciting and important research area in recent years. The MANET community have been concentrating on some problems related to the network layer, especially on the routing protocols. But regarding the MAC level, little has been done. No novel protocol has been proposed but traditional wireless MAC protocols have been largely adopted. Our contribution in this paper is the deep investigation of the mobility impacts on MAC protocols in MANETs, using the GloMoSim simulation tool. We think we are the first who consider nodes’ mobility when analyzing MAC protocols in MANETs.
- ItemUne approche basée sur le simplexe pour le formatage spatial de documents multimédia interactifs(IEEE, 2004-03) Maredj, Azze-Eddine; Ider, A.; Hammour, AchourL'objectif de ce papier est de montrer comment utiliser les techniques de programmation par contraintes, particulièrement la technique basée sur le simplexe, pour le formatage spatial des documents multimédia interactifs. Nous présentons dans la suite de ce papier le formalisme de la programmation par contrainte basée sur le simplexe, puis nous décrivons la nature des relations spatiales définies dans notre formateur ainsi que son implémentation avec le résolveur Cassowary. Nous nous intéressons principalement au problème de la spécification incrémentale du placement spatial relatif.
- ItemSimulation evaluation of an energy efficient routing protocol for mobile ad hoc networks(IEEE Computer Society, 2004-07) Djenouri, Djamel; Badache, NadjibEnergy conservation is one of the most important issues in ad hoc networks, where computers used are usually supplied with limited autonomous resources. Recent studies show that the energy consumed for routing data-packets in wireless ad hoc networks can be significantly reduced compared with the current min-hop max-power routing protocols. But designing a power efficient routing protocol is one of the most challenging issues. In this work, we have conducted a detailed simulation to evaluate the performance of our energy efficient routing protocol [An energy efficient routing protocol for mobile ad hoc network] derived from DSR, in this simulation we have compared our protocol with the standard DSR considered as benchmark.
- ItemA two-phase commit protocol for mobile wireless environment(ACM, 2005) Nouali-Taboudjemat, Nadia; Doucet, Anne; Drias, HabibaThe challenges of wireless and mobile computing environments have attracted the attention of researchers to revisit the conventional implementation of distributed computing paradigms. In this paper we propose to revisit the conventional implementation of the Two Phase Commit (2PC) protocol which is a fundamental asset of transactional technology for ensuring the consistent commitment of distributed transactions. We propose a new execution framework providing an efficient extension that is aware of the mobility. The proposed M2PC (Mobile 2PC) protocol preserves the 2PC principle and the freedom of the mobile clients and servers while it minimizes the impact of unreliable wireless communications.
- ItemLa Gestion du Recouvrement Spatial dans les Documents Multimédia(2005-03-27) Maredj, Azze-Eddine; Hammour, AchourDans le domaine de l’édition et de la présentation des documents multimédia interactifs, le problème du recouvrement spatial constitue un élément déterminant pour une bonne qualité de service des applications qui ont découlent. En effet, de part le fait qu’un même espace de présentation peut être occupé, en même temps, par plusieurs éléments d’un document et que le principe de WYSIWYG est inapplicable du fait de la séparation de la phase d’édition de la phase de présentation, ce problème reste très fréquent. Actuellement, sa gestion est laissée entièrement à la charge de l’auteur. Il est alors contraint d’effectuer des vérifications répétitives entre la phase d’édition et la phase de présentation. Dans ce papier, nous proposons une approche, basée sur les contraintes disjonctives, pour une gestion automatique de se problème pour le domaine de l’édition et de la présentation des documents multimédia interactifs.
- ItemA Novel Approach for Selfish Nodes Detection in MANETs: Proposal and Petri Nets Based Modeling(IEEE, 2005-06) Djenouri, Djamel; Badache, NadjibThe resource limitation of nodes used in selforganized ad hoc networks, along with the multi-hop nature of these networks, may cause a new behavioral phenomena which does not exist in traditional infrastructured environments. To save its energy, a node may behave sel shly, then it would not forward packets for other nodes while using their resources to forward its own packets. This deviation from the normal behavior is a potential threat against the service availability, one of the most important security requirements. Resolving this problem is challenging, due to the self-organization and the infrastructureless features of these networks. Recently, some solutions have been proposed, but almost all these solutions rely on the watchdog technique , which suffers from many problems. Especially when using the power control technique, employed by some new poweraware routing protocols following the watchdog's proposal. To overcome this problem, we propose in this paper a new approach we call two hops ACK (acknowledgment). Using petri nets we model and analyze our solution based on this novel approach.
- ItemScalability of Wireless MAC Protocols in Mobile Ad hoc Networks(IEEE, 2005-07) Djenouri, Djamel; Bouznada, Mohamed; Khiyat, Faten; Khelladi, LyesThe rapid proliferation of lightweight wireless mobile devices, such as laptops, PDAs, and sensors makes mobile ad hoc networks (MANETs) an exciting and important research area nowadays. The MANET community have been concentrating on some problems related to the network layer, especially on the routing protocols. But regarding the MAC layer, little has been done. Our contri- bution in this paper is the deep investigation of the MAC protocols scalability in MANETs, using the GloMoSim simulation tool. We think we are the first who consider the scalability factor when analyzing MAC protocols in MANETs.
- ItemNew Approach for Selfish Nodes Detection in Mobile Ad hoc Networks(IEEE, 2005-09) Djenouri, Djamel; Badache, NadjibA mobile ad hoc network (MANET) is a temporary infrastructureless network, formed by a set of mobile hosts that dynamically establish their own network on the fly without relying on any central administration. Mobile hosts used in MANET have to ensure the services that were ensured by the powerful fixed infrastructure in traditional networks, the packet forwarding is one of these services. The resource limitation of nodes used in MANET, particularly in energy supply, along with the multi-hop nature of this network may cause new phenomena which do not exist in traditional networks. To save its energy a node may behave selfishly and uses the forwarding service of other nodes without correctly forwarding packets for them. This deviation from the correct behavior represents a potential threat against the quality of service (QoS), as well as the service availability, one of the most important security requirements. Some solutions have been recently proposed, but almost all these solutions rely on the watchdog technique as stated in S. Marti et al. (2000) in their monitoring components, which suffers from many problems. In this paper we propose an approach to mitigate some of these problems, and we assess its performance by simulation.
- ItemRandom Feedbacks for Selfish Nodes Detection in Mobile Ad Hoc Networks(Springer, 2005-10) Djenouri, Djamel; Ouali, Nabil; Mahmoudi, Ahmed; Badache, NadjibA mobile ad hoc network (MANET) is a temporary infrastructureless network, formed by a set of mobile hosts that dynamically establish their own network on the fly without relying on any central administration. Mobile hosts used in MANET have to ensure the services ensured by the powerful fixed infrastructure in traditional networks, the packet forwarding is one of these services. Resource limitation of MANET’s nodes, particulary in energy supply, along with the multi-hop nature of these networks may cause a new problem that does not exist in traditional networks. To save its energy a node may behave selfishly(no-cooperatively), thus it misbehaves by not forwarding packets originated from other nodes, while using their resources to forward its own packets to remote recipients. Such a behavior hugely threatens the QoS (Quality of Service), and particulary the packet forwarding service availability. Some solutions for selfish nodes detection have been recently proposed, but almost all these solutions rely on the monitoring in the promiscuous mode technique of the watchdog , which suffers from many problems especially when using the power control technique. In this paper we propose a new approach to detect selfish nodes unwilling to participate in packet forwarding, that mitigates some watchdog’s problems. We also assess the performance of our solution by simulation.
- ItemDetection and Description the Lesions in Brain Images(University Cadi Ayyad (Marroc), 2005-11) Lassouaoui, Nadia; Hamami, Latifa; Nouali-Taboudjemat, Nadia; Hadjar, Samir; Saadi, HocineIn this paper, we present the various stages for lesion recognition in brain images. We firstly apply a filtering based on geodesic reconstruction operator for increasing the quality of image. After, we use an unsupervised segmentation genetic algorithm for detecting the abnormal zones with respect of theirs morphological characteristics because they define the nature of illness (cyst, tumour, malignant, benign, …). The obtained segmented images are analyzed for computing the characteristics of illness which are necessary for the recognition stage for deducing a decision about the type of illness. So, we give also the various algorithms used for computing the morphological characteristics of lesions (size, shape, position, texture, …). Since we obtain a decision about the malignity or benignity of the lesion and a quantitative information for helping the doctors to locate the sick part.
- ItemMobility and MAC protocols in MANETs(2005-12) Djenouri, Djamel; Bouznada, Mohamed; Khiyat, FatenThe emergence of lightweight wireless mobile de-vices, like laptops, PDAs, and sensors makes mo-bile ad hoc networks (MANETs) an exciting and important research area in recent years. The MANET community have been concentrating on some problems related to the network layer, es-pecially on the routing protocols. But regarding the MAC level, little has been done. No novel protocol has been proposed but traditional wire¬less MAC protocols have been largely adopted. Our contribution in this paper is the deep inves¬tigation of the mobility impacts on MAC proto¬cols in MANETs, using the GloMoSim simula¬tion tool. We think we are the first who consider nodes' mobility when analyzing MAC protocols in MANETs.
- ItemA Communication model of distributed information sources bacteria colonies inspired(IEEE, 2006) Mellah, Hakima; Hassas, Salima; Drias, HabibaThe implementation of communication organizational strategies constitutes an essential performance factor. Nowadays, the organization becomes companies competitiveness element (organizational structures), networks, knowledge and competences management, and cooperation. This, to be better reactive to ensure the competing character, to support better new information technologies, concerning the data exchange inside as outside an organization. The information systems specification gives a partial description of the organization, which integrated with other descriptions is regarded as being the organization model. Using the abstraction level of an information system (information source) was proven to be not sufficient to face the conflicts confronted by the organizations. These conflicts are the improvement and the change with an aim of adapting constantly to the environment new requirements. These latter are essential to support the dynamic character which tends to characterize the current organizations and which is often nature taken. In order to implement this dynamism, we took as a starting point the biological sciences and more particularly the bacteria colonies. This paper presents a correspondence model between a communication system of distributed information sources and a bacteria colony
- ItemXML-DFG : A Dynamic Forms Generator for XML Valid DTD Document(2006-04) Maredj, Azze-Eddine; Khouatmi-Boukhatem, Samia; Adjerad, Halima DouniazedToday, new needs place internet at the center of very huge technological challenges. Structure standardization of the data diffused and exchanged on the web is one of conditions to meet these challenges. New technologies are thus necessary and a great hope is built on XML technology. However, and in spite of the profusion of XML editors, most of them are complex and intended for experimented users. Consequently, this can represent a financial constraint for the companies wishing to use this technology. In this paper, we present a dynamic forms generator system for the edition of valid DTD XML documents, aiming to reduce production cost.
- ItemImprovement of a retrieval and f iltering systems by an automatic multi words extraction tool(Ghassan Issa, General Chair, 2006-04) Nouali, Omar; Krinah, AbdelghaniThe role of all retrieval systems consists in finding documents (or document excerpts) that best answer an information need. This need, whether precise and instant (a request) or general and long term (a profile), is most often expre ssed by a list of entities called terms. The goal of this article is to present an automatic mu lti words recognition and extraction tool, compiled from text extracts, in order to build a thesaurus, or terminological basis, useful by search engines and filtering systems in order to boost their performances.
- ItemAnonymous Mobile Agents(IEEE, 2006-04-24) Benmeziane, Souad; Larab, BaghdadOne of the most important issues of the agent security is to keep the agent anonymity, not only in regard of the outsider (eavesdropper) but from the visited hosts too. Indeed, the observer may access agent's data, like the agent's route information data, and thus collecting sensitive information about the agent's owner. In this paper, we present a solution based on mixes to hide the itinerary of the agent. We extend the existing agent based Ajanta platform by adding this functionality. It is then possible to create protected agents capable of roaming in the Internet without revealing their whereabouts information
- ItemTestimony-Based Isolation: New Approach to Overcome packet Dropping Attacks in MANET(John Moors University, 2006-06) Djenouri, Djamel; Badache, NadjibAttackers could take advantage of the cooperative nature of MANET’s routing protocols, by participating in the route discovery procedure to include themselves in routes, then simply drop data packets during the forwarding phase, aiming at a DoS (Denial of Service) attack. In this paper we deal with the detection and isolation of such malicious nodes. We ﬁrst propose a monitoring technique different from the promiscuous overhearing (watchdog) used by almost all the current solutions, that overcomes many watchdog’s shortcomes. After that we propose a testimony-based isolation protocols basing on our monitoring technique.