CERIST

Algiers, Algeria
Algiers, Algeria
SEARCH FILTERS
Time filter
Source Type

Lebib F.Z.,CERIST | Lebib F.Z.,University of Science and Technology Houari Boumediene | Mellah H.,CERIST | Drias H.,University of Science and Technology Houari Boumediene
International Journal of Information Management | Year: 2017

The selection of information sources in a distributed information retrieval environment remains a critical issue. In this context, it is known that a distributed information retrieval system consists of a huge number of sources. Ensuring retrieval effectiveness is to search only sources which are likely to contain relevant information for a query. An important number of heuristics exist among which we quote genetic algorithm that is used to solve the above problem. The proposed genetic algorithm consists in finding the best selection in large space of potential solutions; where a solution is represented as a combination of a set of sources. The improvement of selection accuracy is assured based on the user's track through the use of sources, to say that source description is enriched with tags from the tagging history. © 2017 Elsevier Ltd.


Younis M.,University of Maryland Baltimore County | Badache N.,CERIST
Computer Networks | Year: 2017

We consider the problem of deploying the least count of relay nodes to restore connectivity in a network that got partitioned into multiple disjoint segments. Such a problem has been generally formalized as a Steiner Minimum Tree (SMT) by assuming that each segment is a terminal, e.g., by picking a single node in a segment to serve as an interface point. We argue that such formulation is ineffective since the size and the shape of the segment are not factored in. To overcome this drawback, we propose a novel approach for Boundary-aware optimized Interconnection of Disjoint segments (BIND). BIND opts to restore network connectivity by forming the shortest length topology in the Euclidean plane that interconnects a subset of nodes on the segment boundaries through extra Steiner points so that there is a path between every pair of segments. Since constructing the SMT connecting boundary nodes (terminals) subject to obstacle avoidance is NP-hard, BIND pursues a heuristic based on the generation and concatenation of full Steiner trees (FSTs). As the number of distinct FSTs grows exponentially with the number of terminals, BIND further promotes a new geosteiner technique based on the straight skeleton of the segment boundaries within the deployment area in order to reduce the complexity. The simulation results confirm the effectiveness of BIND and its advantage compared to competing schemes. © 2017.


Lebib F.Z.,University of Science and Technology Houari Boumediene | Drias H.,University of Science and Technology Houari Boumediene | Mellah H.,CERIST
Advances in Intelligent Systems and Computing | Year: 2017

We address the problem of information sources selection in a context of a large number of distributed sources. We formulate the sources selection problem as a combinatorial optimization problem in order to yield the best set of relevant information sources for a given query.We define a solution as a combination of sources among a huge predefined set of sources. We propose a genetic algorithm to tackle the issue by maximizing the similarity between a selection and the query. Extensive experiments were performed on databases of scientific research documents covering different domains such as computer science and medicine. The results based on the precision measure are very encouraging. © Springer International Publishing AG 2017.


Yu Y.,University of Kentucky | Belazzougui D.,CERIST | Qian C.,University of California at Santa Cruz | Zhang Q.,Indiana University
SIGMETRICS 2017 Abstracts - Proceedings of the 2017 ACM SIGMETRICS / International Conference on Measurement and Modeling of Computer Systems | Year: 2017

Concise is a Forwarding information base (FIB) design that uses very little memory to support fast query of a large number of dynamic network names or flow IDs. Concise makes use of minimal perfect hashing and the SDN framework to de- sign and implement the data structure, protocols, and system. Experimental results show that Concise uses significantly smaller memory to achieve faster query speed compared to existing FIB solutions and it can be updated very efficiently. © 2017 ACM.


Bagaa M.,CERIST | Taleb T.,Aalto University | Ksentini A.,University of Rennes 1
2015 IEEE Global Communications Conference, GLOBECOM 2015 | Year: 2015

One important objective of 5G mobile networks is to accommodate a diverse and ever-creasing number of user equipment (UEs). Coping with the massive signaling overhead expected from UEs is an important hurdle to tackle to achieve this objective. In this paper, we propose three solutions that aim for finding optimal distributions of tracking areas (TAs) in the form of TA lists (TALs) and assigning them to UEs, with the objectives of minimizing two conflicting metrics, namely paging overhead and tracking area update (TAU) overhead. Two solutions favors one objective than the other. The third one incorporates a novel scheme, dubbed Fair and Optimal TAL Assignment (FOTA), based on Nash bargaining game theory. FOTA improves overall network performance minimizing overhead due to both paging and TAU messages, taking into account the behavior and mobility features of UEs. The performance of proposed schemes are evaluated via simulations and the obtained results demonstrate their feasibility and ability in achieving their design goals, improving network performance by minimizing cost associated with paging and TAU. © 2015 IEEE.


Alduraibi F.,University of Maryland, Baltimore | Lasla N.,CERIST | Younis M.,University of Maryland, Baltimore
2016 IEEE International Conference on Communications, ICC 2016 | Year: 2016

Wireless sensor networks have become an attractive choice for many monitoring applications in an unattended setups; some of these applications such as pipeline, railroad and highways monitoring require the sensors to be placed in a linear topology. These sensors need to be placed as far apart while still maintaining a minimum required coverage in order to minimize the required node count and reduce cost. In this paper, we present three optimization models for determining the node density that varies in the objective. The first opts to achieve a desired level of detection fidelity while minimizing the number of deployed sensors. The second model considers the scenario with a constrained node count and determines the position of the available nodes such that the coverage is maximized. In the third model, we strive to minimize the number of deployed nodes when the desired fidelity is not uniform and some locations require higher coverage than others. The proposed optimization formulations are generic in nature and can be applied to any sensor coverage model. The three optimization models are validated through implementation using an attenuated disc coverage model where the detectability of a sensor is inversely proportional to the distance. © 2016 IEEE.


Bagaa M.,CERIST | Younis M.,University of Maryland Baltimore County | Ouadjaout A.,CERIST | Badache N.,CERIST
IEEE International Conference on Communications | Year: 2013

In wireless sensor networks, in-network data aggregation filters out redundant sensor readings in order to reduce the energy and bandwidth consumed in disseminating the data to the base-station. In this paper, we investigate the problem of reliable collection of aggregated data with minimal latency. The aim is to form an aggregation tree such that there are k disjoint paths from each node to the base-station and find a collision-free schedule for node transmissions so that the aggregated data reaches the base-station in minimal time. We propose a novel algorithm for Reliable and Timely dissemination of Aggregated Data (RTAD). RTAD intertwines the formation of the aggregation tree and the allocation of time slots to nodes, and assigns parents to the individual nodes in order to maximize time slot reuse. The simulation results show that RTAD outperforms competing algorithms in the literature. © 2013 IEEE.


Lasla N.,CERIST | Derhab A.,King Saud University | Ouadjaout A.,CERIST | Bagaa M.,CERIST | Challal Y.,Laboratoire Of Methodes Of Conception Des Systemes Lmcs
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2014

In this paper, we propose a novel secure routing protocol named Secure Multi-pAths Routing for wireless sensor neTworks (SMART) as well as its underlying key management scheme named Extended Two-hop Keys Establishment (ETKE). The proposed framework keeps consistent routing topology by protecting the hop count information from being forged. It also ensures a fast detection of inconsistent routing information without referring to the sink node. We analyze the security of the proposed scheme as well as its resilience probability against the forged hop count attack. We have demonstrated through simulations that SMART outperforms a comparative solution in literature, i.e., SeRINS, in terms of energy consumption. © 2014 Springer International Publishing Switzerland.


Bagaa M.,CERIST | Derhab A.,CERIST | Lasla N.,CERIST | Ouadjaout A.,CERIST | Badache N.,CERIST
Proceedings - IEEE INFOCOM | Year: 2012

This paper focuses on data aggregation scheduling problem in wireless sensor networks (WSNs), to minimize time latency. Prior works on this problem have adopted a structured approach, in which a tree-based structure is used as an input for the scheduling algorithm. As the scheduling performance mainly depends on the supplied aggregation tree, such an approach cannot guarantee optimal performance. To address this problem, we propose approaches based on Semi-structured Topology (DAS-ST) and Unstructured Topology (DAS-UT). The approaches are based on two key design features, which are: (1) simultaneous execution of aggregation tree construction and scheduling, and (2) parent selection criteria that maximize the choices of parents for each node and maximize time slot reuse. We prove that the latency of DAS-ST is upper-bounded by (⌊ 2π/arcos(1/1+ε)⌋ + 4) R + Δ - 4, where R is the network radius, Δ is the maximum node degree, and 0.05 < ε ≤ 1. Simulations results show that DAS-UT outperforms DAS-ST and four competitive state-of-the-art aggregation scheduling algorithms in terms of latency and network lifetime. © 2012 IEEE.


Al-Nemrat A.,ACE Inc | Benzaid C.,CERIST
Proceedings - 14th IEEE International Conference on Trust, Security and Privacy in Computing and Communications, TrustCom 2015 | Year: 2015

The Internet can be a double-edged sword. While offering a range of benefits, it also provides an opportunity for criminals to extend their work to areas previously unimagined. Every country faces the same challenges regarding the fight against cybercrime and how to effectively promote security for its citizens and organisations. The main aim of this study is to introduce and apply a data-mining technique (decision-tree) to cybercrime profiling. This paper also aims to draw attention to the growing number of cybercrime victims, and the relationship between online behaviour and computer victimisation. This study used secondhand data collected for a study was carried out using Jordan a s a case study to investigate whether or not individuals effectively protect themselves against cybercrime, and to examine how perception of law influences actions towards incidents of cybercrime. In Jordan, cybercafe's have become culturally acceptable alternatives for individuals wishing to access the Internet in private, away from the prying eyes of society. © 2015 IEEE.

Loading CERIST collaborators
Loading CERIST collaborators