Yacine Belhoul

String Comparators Based Algorithms for Process Model Matchmaking

Retrieving matchings between process models becomes a significant challenge in many applications. 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 must be proposed to obtain approximations. In this paper, we propose an approach to find relevant process models based on their decomposition into paths of possible execution sequences. Then, we propose a schema to compute the similarity between two process models using the proposed decomposition. Moreover, we give particular attention to the problem of ranking a collection of process models according to a particular query.

Efficient self-stabilizing algorithms for minimal total k-dominating sets in graphs

We propose the first polynomial self-stabilizing distributed algorithm for the minimal total dominating set problem in an arbitrary graph. Then, we generalize the proposed algorithm for the minimal total k-dominating set problem. Under an unfair distributed scheduler, the proposed algorithms converge in O(mn) moves starting from any arbitrary state, and require O(logn) storage per node.

Spectral Graph Approach for Process Model Matchmaking

In this paper, we propose a novel approach for graph based web service matching. Our approach is inspired by spectral graph matching methods, in particular, by eigen-based projections. We introduce new mechanisms to perform the matchmaking at both structural and semantic levels. These mechanisms are based on algebraic graph techniques that make them run fast and thus suitable for large scale web service matching problems. Experimentation is provided to show the performance of the proposed approach.

Self-stabilizing algorithms for minimal global powerful alliance sets in graphs

We propose a self-stabilizing distributed algorithm for the minimal global powerful alliance set problem in an arbitrary graph. Then, we give self-stabilizing algorithms for some generalizations of the problem. Using an unfair distributed scheduler, the proposed algorithms converge in O(mn) moves starting from an arbitrary state.

AdSIP: Decentralized SIP for Mobile Ad Hoc Networks

SIP signaling protocol relies on centralized SIP servers deployed on the infrastructure of the network to route SIP messages in order to enable user endpoints to discover each other. However, the lack of the infrastructure in ad hoc networks requires that the network nodes support the tasks of participants discovery and SIP messages routing. In this paper, we propose AdSIP protocol which is a completely distributed architecture for SIP that implements SIP servers in selected nodes. The SIP servers are selected using a distributed algorithm constructing a connected minimal global offensive alliance. AdSIP is implemented and compared under NS-2 with TCA protocol which uses a cluster based approach. The simulation results show the advantages of AdSIP and confirm that it is adapted to mobile ad hoc networks by giving low session establishment time, low control overhead and high service availability.

TopCoF: A Topology Control Framework for Wireless Ad Hoc Networks

Topology Control (TC) is a well known technique used in wireless ad hoc and sensor networks to reduce energy consumption. 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, 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.