Research Reports
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Item New Technique to Deal With Verbose Queries in Social Book Search(CERIST, 2017) Chaa, Messaoud; Nouali, Omar; Bellot, PatriceVerbose query reduction and query term weighting are automatic techniques to deal with verbose queries. The objective is either to assign an appropriate weight to query terms according to their importance in the topic, or outright remove unsuitable terms from the query and keep only the suitable terms to the topic and user’s need. These techniques improve performance and provide good results for ad hoc information retrieval. In this paper we propose a new approach to deal with long verbose queries in Social Information Re-trieval (SIR) by taking Social Book Search as an example. In this approach, a new statistical measure was introduced to reduce and weight terms of verbose queries. Next, we expand he query by exploiting the similar books mentioned by users in their queries. We find that the proposed approach improves significantly the results.Item Infrastructure de communication sans fil avec qualité de service pour la gestion de crises et catastrophes(CERIST, 2016-11) Kabou, Abdelbasset; Nouali-Taboudjemat, Nadia; Nouali, OmarLa Qualité de service (Quality of Service ou QoS) est un terme largement utilisé dans le domaine des technologies de communication. Dans les recommandations E.800, le CCITT (United Nations Consultative Committee for International Telephony and Telegraphy) défini la qualité de service comme : “Ensemble des effets portant sur les performances d’un service de communication et qui détermine le degré de satisfaction d’un utilisateur de ce même service”. Un intérêt particulier est porté dans ce rapport à la problématique du maintien de la QoS pour les applications multimédia. Ce type d'applications est très sensible aux variations des conditions régissant le réseau. Des métriques comme la bande passante, le taux de perte des paquets, la latence, la gigue ou des mécanismes tels le contrôle d’admission, les protocoles de signalisation, etc., sont de très grande importance pour ces applications et plus particulièrement durant une situation d'urgence. Ce rapport donne un aperçu de nos travaux sur la QoS des réseaux déployés en situation d'urgence.Item Verbose Query Reduction by Learning to Rank for Social Book Search Track(CERIST, 2016-07) Chaa, Messaoud; Nouali, Omar; Bellot, PatriceIn this paper, we describe our participation in the INEX 2016 Social Book Search Suggestion Track (SBS). We have exploited machine learning techniques to rank query terms and assign an appropriate weight to each one before applying a probabilistic information retrieval model (BM15). Thereafter, only the top-k terms are used in the matching model. Several features are used to describe each term, such as statistical features, syntactic features and others features like whether the term is present in similar books and in the profile of the topic starter. The model was learned using the 2014 and 2015 topics and tested with the 2016 topics. Our experiments show that our approach improves the search results.Item CERIST at INEX 2015: Social Book Search Track(CERIST, 2015) Chaa, Messaoud; Nouali, OmarIn this paper, we describe our participation in the INEX 2015 Social Book Search Suggestion Track (SBS). We have exploited in our experiments only the tags assigned by users to books provided from LibraryThing (LT). We have investigated the impact of the weight of each term of the topic in the retrieval model using two methods. In the first method, we have used the TF-IQF formula to assign a weight to each term of the topic. In the second method, we have used Rocchio algorithm to expand the query and calculate the weight of the tags assigned to the example books mentioned in the book search request. Parameters of our models have been tuned using the topics of INEX 2014 and tested on INEX 2015 Social Book Search track.Item Réponse automatique au courriel : Architecture basé sur les SQR et classification des questions(CERIST, 2014-11-02) Said, Ahmed; Nouali, Omar; Guemraoui, LilaCet article relate une approche pour la mise en œuvre d’un système de réponse automatique au courrier électronique, qui s’appuie essentiellement sur l’utilisation de l’approche par question-réponse. Toutefois, notre étude a montré que l'analyse et la classification des questions est un élément essentiel pour chercher efficacement une réponse à la question, Ainsi, nous nous somme focalisé sur ce point, où nous avons proposé une approche de classification qui se base sur différents critères de classification. Dans cette approche nous avons introduit le sujet du courriel comme un nouveau critère pour la classification des questions. Nous avons aussi expérimenté notre approche avec le classifieur SVM et les résultats de tests obtenus ont été satisfaisants.Item Metadata’s Protection in CKMS-As-A-Security Services(CERIST, 2014-02-20) Fehis, Saad; Nouali, Omar; Bentayeb, SarahTo ensure the confidentiality and integrity of data, it is necessary to use encryption techniques; the safety of these techniques is based on the pro- tection of keys and algorithms used by those techniques. Indeed, the estab- lishment of an encryption key management system (creation, storage, distribu- tion, etc...) is paramount. However, the safety of this type of system in the context of Cloud Computing is based on the protection of the data dictionary (metadata). The protection of this dictionary is a real challenge in a no-trust context. This paper describes the implementation of a protection technique for the Cryptographic Key Management System’s metadata, which provides handling (Consulting / Editing) data without offending the confidentiality and integrity of the dictionary.Item Designing Energy Efficient Virtualized Web Servers(CERIST, 2013-06) Chait, Khaled; Nouali, OmarThere’s actually a kind of Moore’s Law for the Internet, which states that the Internet doubles in size every 5 years. About 2.4 billion of Internet users were registered worldwide in 2012. Having more users increases the need for more and larger data processing centers with thousands of servers. One consequence is the excessive energy consumption caused by web servers, which run web applications and web- based services. We propose a short study of energy consumption in relation to web server performance. We also propose a methodology to design energy efficient web systems using virtualization technologies.Item Queries reformulation for the discovery of semantic web services(CERIST, 2011-06) Makhzoumi, Dalila; Aliane, Hassina; Nouali, OmarThe semantic web services have been introduced to better describe web services and improve their functioning. Several approaches have been proposed in this field. The most used is OWL-S, where the discovery is to match the user query and the service profile of OWL-S service. In this paper we present a query reformulation approach for searching semantic web services. We propose three methods to enrich the query by exploiting the semantic relationships given by synonymy and derivatives of the WordNet ontology. We select the semantic web services through a matching between the query and ontologies of semantic web services OWL-S using semantic and syntactic similarity measures.Item Knowledge extraction by Internet monitoring to enhance crisis management(CERIST, 2011-04) El Hamali, Samiha; Nouali, Omar; Nouali-Taboudjemat, NadiaThis paper presents our work on developing a system for Internet monitoring and knowledge extraction from different web documents which contain information about disasters. This system is based on ontology of the disasters domain for the knowledge extraction and it presents all the information extracted according to the kind of the disaster defined in the ontology. The system disseminates the information extracted (as a synthesis of the web documents) to the users after a filtering based on their profiles. The profile of a user is updated automatically by interactively taking into account his feedback.Item Deal with multiplicity and diversity of relevance factors in XML retrieval(CERIST, 2010) Bal, Kamal; Nouali, OmarIn this paper, we are interested in content oriented XML information retrieval whose aim is to retrieve not a list of relevant documents, but only fragments of document (XML element) relevant to the user information need. Retrieved XML elements must not only contain relevant information but also be at good level of granularity. The coexistence of content and structural information in XML documents makes that multiple and diverse relevance sources condition the selection and the rank of relevant XML element. It is admitted that the consideration of several relevance sources will surely improve quality of results. However, actual XML retrieval approaches consider just some relevance sources and neglect others due to relevance sources heterogeneity. In this paper, we try to identify and classify theses relevance sources and to propose a way to exploit multiple and diverse relevance sources in retrieval process.