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Algiers, Algeria

Belazzougui D.,CERIST | Karkkainen J.,Aalto University | Kempa D.,Aalto University | Puglisi S.J.,Aalto University
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2016

Simple and fast decoding is one of the main advantages of LZ77-type text encoding used in many popular file compressors such as gzip and 7zip. With the recent introduction of external memory algorithms for Lempel-Ziv factorization there is a need for external memory LZ77 decoding but the standard algorithm makes random accesses to the text and cannot be trivially modified for external memory computation. We describe the first external memory algorithms for LZ77 decoding, prove that their I/O complexity is optimal, and demonstrate that they are very fast in practice, only about three times slower than in-memory decoding (when reading input and writing output is included in the time). © Springer International Publishing Switzerland 2016. Source

Aliradi R.,University of Science and Technology Houari Boumediene | Bouzera N.,University of Abderrahmane Mira de Bejaia | Meziane A.,CERIST | Belkhir A.,University of Science and Technology Houari Boumediene
Proceedings - 2013 IEEE/WIC/ACM International Joint Conference on Web Intelligence and Intelligent Agent Technology - Workshops, WI-IATW 2013 | Year: 2013

Facial features determination is essential in many applications such as personal identification several approaches have been proposed, but an effective method for face detection is still a research problem. In this paper we focus on a recent method called the support vector machines (SVM) has been adapted and applied to the problem of pattern recognition such as face detection. The idea information of the skin color is used to reduce the search region and the main idea based on SVM is to project the data input space (belonging to two different classes) non-linearly separable in a larger space called feature space so that data are linearly separable. About fusion a non-parametric model is applied for the segmentation of the pixels of skin color. This last is used to reduce area of research within the image. However the SVMs help us to find exactly the faces in the segmented area. We implemented the SVM using a RBF kernel as a classification technique for face detection by block" approach of considering the face as a set of components (eyes, nose and mouth). The method succeeds in locating facial features in the facial region exactly and is insensitive to face deformation. The method is executable in a reasonably short time. © 2013 IEEE. Source

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

Cloud offerings represent a promising solution for mobile network operators to cope with the surging mobile traffic. The concept of carrier cloud has therefore emerged as an important topic of inquiry. For a successful carrier cloud, algorithms for optimal placement of Virtual Network Functions (VNFs) on federated cloud are of crucial importance. In this paper, we introduce different VNF placement algorithms for carrier cloud with two main design goals: i) minimizing path between users and their respective data anchor gateways and ii) optimizing their sessions' mobility. The two design goals effectively represent two conflicting objectives, that we deal with considering the mobility features and service usage behavioral patterns of mobile users, in addition to the mobile operators' cost in terms of the total number of instantiated VNFs to build a Virtual Network Infrastructure (VNI). Different solutions are evaluated based on different metrics and encouraging results are obtained. © 2015 IEEE. Source

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. Source

Mohand-Oussaid L.,CERIST | Ait-Sadoune I.,Supelec | Ait-Ameur Y.,IRIT | Ahmed-Nacer M.,University of Science and Technology Houari Boumediene
Computing | Year: 2015

Multimodal human–computer interaction (HCI) combine modalities at an abstract specification level in order to get information from the user (input multimodality) and to return information to the user (output multimodality). These multimodal interfaces use two mechanisms: first, the fusion of information transmitted by the user on different modalities during input interaction and second, the fission or decomposition of information produced by the functional core in order to distribute the composite information on the different modalities during output interaction. In this paper, we present a generic approach to design output multimodal interfaces. This approach is based on a formal model, composed of two models: semantic fission model for information decomposition process and allocation model for modalities and media allocation to composite information. An Event-B formalization has been proposed for the fission model and for allocation model. This Event-B formalization extends the generic model and support the verification of some relevant properties such as safety or liveness. An example of collision freeness property verification is presented in this paper. © 2015, Springer-Verlag Wien. Source

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