Nozha Boujemaa

Bio: Nozha Boujemaa is an academic researcher. The author has contributed to research in topics: Semantics & Document retrieval. The author has an hindex of 2, co-authored 2 publications receiving 23 citations.

IJCSI Publicity Board 2010

Abstract: In this paper we examine the behavior of Ad Hoc networks through simulations, using different routing protocols and various topologies. We examine the difference in performance, using CBR application, with packets of different size through a variety of topologies, showing the impact node placement has on networks performance. We show that the choice of routing protocol plays an important role on network’s performance. We also quantify node mobility effects, by looking into both static and fully mobile configurations. Our paper presents a systematic analysis of a variety of different ad hoc network topologies in terms of node placement, node mobility and routing protocols through several simulated scenarios.

Toward retail product recognition on grocery shelves

Abstract: This paper addresses the problem of retail product recognition on grocery shelf images. We present a technique for accomplishing this task with a low time complexity. We decompose the problem into detection and recognition. The former is achieved by a generic product detection module which is trained on a specific class of products (e.g. tobacco packages). Cascade object detection framework of Viola and Jones [1] is used for this purpose. We further make use of Support Vector Machines (SVMs) to recognize the brand inside each detected region. We extract both shape and color information; and apply feature-level fusion from two separate descriptors computed with the bag of words approach. Furthermore, we introduce a dataset (available on request) that we have collected for similar research purposes. Results are presented on this dataset of more than 5,000 images consisting of 10 tobacco brands. We show that satisfactory detection and classification can be achieved on devices with cheap computational power. Potential applications of the proposed approach include planogram compliance control, inventory management and assisting visually impaired people during shopping.

A boosting approach to multiview classification with cooperation

Abstract: In many fields, such as bioinformatics or multimedia, data may be described using different sets of features (or views) which carry either global or local information. Some learning tasks make use of these several views in order to improve overall predictive power of classifiers through fusion-based methods. Usually, these approaches rely on a weighted combination of classifiers (or selected descriptions), where classifiers are learned independently. One drawback of these methods is that the classifier learned on one view does not communicate its failures within the other views. This paper deals with a novel approach to integrate multiview information. The proposed algorithm, named Mumbo, is based on boosting. Within the boosting scheme, Mumbo maintains one distribution of examples on each view, and at each round, it learns one weak classifier on each view. Within a view, the distribution of examples evolves both with the ability of the dedicated classifier to deal with examples of the corresponding features space, and with the ability of classifiers in other views to process the same examples within their own description spaces. Hence, the principle is to slightly remove the hard examples from the learning space of one view, while their weights get higher in the other views. This way, we expect that examples are urged to be processed by the most appropriate views, when possible. At the end of the iterative learning process, a final classifier is computed by a weighted combination of selected weak classifiers. This paper provides the Mumbo algorithm in a multiclass and multiview setting, based on recent theoretical advances in boosting. The boosting properties of Mumbo are proved, as well as some results on its generalization capabilities. Several experimental results are reported which point out that complementary views may actually cooperate under some assumptions.

Towards user-adaptive structuring and organization of music collections

Abstract: We present a prototype system for organization and exploration of music archives that adapts to the user’s way of structuring music collections. Initially, a growing self-organizing map is induced that clusters the music collection. The user has then the possibility to change the location of songs on the map by simple drag-and-drop actions. Each movement of a song causes a change in the underlying similarity measure based on a quadratic optimization scheme. As a result, the location of other songs is modified as well. Experiments simulating user interaction with the system show, that during this stepwise adaptation the similarity measure indeed converges to one that captures how the user compares songs. This utimately leads to an individually adapted presentation that is intuitively understandable to the user and thus eases access to the database.

Recommending Multimedia Objects in Cultural Heritage Applications

Abstract: Italy's Cultural Heritage is the world's most diverse and rich patrimony and attracts millions of visitors every year to monuments, archaeological sites and museums. The valorization of cultural heritage represents nowadays one of the most important research challenges in the Italian scenario. In this paper, we present a general multimedia recommender system able to uniformly manage heterogeneous multimedia data and to provide context-aware recommendation techniques supporting intelligent multimedia services for the users. A specific application of our system within the cultural heritage domain is proposed by means of a real case study in the mobile environment related to an outdoor scenario, together with preliminary results on user's satisfaction.