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Author: search.filters.author.Belhoul, Yacine

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    A Graph Approach for Enhancing Process Models Matchmaking
    (CERIST, 2015-04) Belhoul, Yacine; Yahiaoui, Saïd
    Recent attempts have been done to measure similarity of process models based on graph-edit distance. This problem is known to be difficult and computational complexity of exact algorithms for graph matching is exponential. Thus, heuristics should be proposed to obtain approximations. Spectral graph matching methods, in particular eigenvalue-based projections, are know to be fast but they lost some quality in the obtained matchmaking. In this paper, we propose a graph approach for the problem of inexact matching of process models. Our approach combines a spectral graph matching method and a string comparator based algorithm in order to improve the quality of process model matchmaking. The proposed method performs the matchmaking at both structural and semantic levels. Experimentation is provided to show the performance of our method, compared to previous work, to rank a collection of process model according to a particular query.
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    AdSIP: Decentralized SIP for Mobile Ad hoc Networks
    (CERIST, 2011-12) Nouali-Taboudjemat, Nadia; Belhoul, Yacine; Yahiaoui, Saïd
    SIP (Session Initiation Protocol) is an IETF signaling protocol designed to create, modify and terminate sessions between two or many users in multimedia applications. The implementation of SIP needs the use of proxy servers which are centralized entities to route SIP requests and responses to enable user endpoints to discover each other. However, the infrastructureless of ad hoc networks requires that the network nodes support the tasks of participants’ discovery and SIP routing messages. In this paper, we propose the AdSIP protocol which is a completely distributed architecture for SIP that implements the proxy servers in selected nodes. The proxy servers are selected using a distributed algorithm constructing a connected minimal global offensive alliance. AdSIP is implemented and compared under NS-2 with another protocol which uses a cluster based approach. The simulation results show the advantages of AdSIP and demonstrate that it is adapted to mobile ad hoc networks by giving low session establishment time, low control overhead and high service availability.
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    TopCoF: NS2-based Topology Control Framework for Wireless Ad hoc Networks
    (CERIST, 2010-02) Yahiaoui, Saïd; Belhoul, Yacine; Faoudi, Farid; Kheddouci, Hamamache
    Topology Control (TC) is the most well known technique used in wireless ad hoc and sensor networks to reduce energy consumption and radio interferences. This technique coordinates the decisions of network nodes about their transmission power to save energy, prolong network lifetime, and mitigate MAC-level medium contention, while maintaining network connectivity. In order to ease the implementation and the study in systematic way of proposed TC protocols and algorithms, in terms of energy usage and network graph properties, we propose a new framework based on NS-2 simulator. The framework is named TopCoF and composed of two main parts. The first one consists of a set of NS-2 extensions to support TC, while the second is a graphical user interface for statistical analysis and visualization of simulation results traced by the first part. TopCoF is modular and generic since it implements a set of basic components used by TC protocols. We illustrate, by an example, how TopCoF facilitates the implementation and performance evaluation of TC
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    Mobility and Performance of Routing Protocols in Wireless Mobile Ad hoc Networks
    (CERIST, 2010-02) Belhoul, Yacine; Yahiaoui, Saïd; Kheddouci, Hamamache
    Among routing protocols designed for wireless mobile ad hoc networks, DSDV from the proactive class and AODV from the reactive one, are well known. In this paper, we evaluate the performance of these protocols using NS-2 simulator. We use three mobility models, namely: the RWP entity model, as well as the RPGM and Column group models. Scenarios considered in simulations take into account several factors that affect the performance of routing protocols. We compare them in term of average end-to-end delay, normalized routing load, and packet delivery fraction. The results we obtain show that the performance of routing protocols in mobile ad hoc networks strongly depends on the used mobility models and the considered scenarios.
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    Information technology for Enhancing Disaster Management
    (CERIST, 2009-04) Nouali-Taboudjemat, Nadia; Bouchama, Nadir; Bendjoudi, Ahcène; Babakhouya, Abdelaziz; Yahiaoui, Saïd; Belhoul, Yacine; Saadi, Hocine
    Responding to natural or man-made disasters, in a timely and effective manner, can reduce deaths and injuries as well as economic losses. Predicated on the assumption that better information leads to efficient decision-making and more effective performance of crisis response, research projects applying advanced information technology solutions to the crisis management field have emerged. This paper provides an overview of most recent projects, in this area, all over the world. Furthermore, the study highlights that using scalable and robust IT solutions can drastically facilitate access to the right information, by the right individuals and organizations, at the right time.