Using Artificial Neural Networks Approach to Estimate Compressive Strength for Rubberized Concrete

Artificial neural network (ANN) is a soft computing technique that has been used to predict with accuracy compressive strength known for its high variability of values. ANN is used to develop a model that can predict compressive strength of rubberized concrete where natural aggregate such as fine and coarse aggregate are replaced by crumb rubber and tire chips. The main idea in this study is to build a model using ANN with three parameters that are: water/cement ratio, Superplasticizer, granular squeleton. Furthermore, the data used in the model has been taken from various literatures and are arranged in a format of three input parameters: water/cement ratio, superplasticizer, granular squeleton that gathers fine aggregates, coarse aggregates, crumb rubber, tire chips and output parameter which is compressive strength. The performance of the model has been judged by using correlation coefficient, mean square error, mean absolute error and adopted as the comparative measures against the experimental results obtained from literature. The results indicate that artificial neural network has the ability to predict compressive strength of rubberized concrete with an acceptable degree of accuracy using new parameters

Nomads Horizons ; perspects for a system and recompining of the territories. Case of the steppe south-oranian of western Algeria

Partant de l’exemple des steppes sud-oranaises, nous avons essayé de démontrer l’existence d’un modèle nomade de la pratique spatiale ainsi que son évolution à travers le temps, avec ses conséquences visibles et substantielles dans cette portion de l’espace algérien. Car les relations que les nomades entretiennent avec leur espace s’établissent selon un système de significations propre à cette société, dont il traduit l’histoire, le parcours, les expériences, les valeurs et les imaginations… au total une culture qui lui est propre et qui, en interférant avec les caractéristiques et les atouts du milieu naturel, donne naissance à un paysage. Or, la société nomade ainsi que son mode d’utilisation et d’adaptation à l’espace fait l’objet depuis une trentaine d’années d’une restructuration qui a provoqué des mutations du genre de vie et une recomposition des territoires ancestraux. La sédentarisation demeure un élément essentiel de ce changement qui a ses répercussions sur l’espace en général et sur celui des sédentaires en particulier. Quoiqu’il perdure, le nomadisme se transforme, prenant d’autres formes et utilisant d’autres outils. Peut-on parler d’une adaptation ou d’une résidualité conduisant à la décadence et finissant par une disparition ? L’espace perçu, vécu et représenté des nomades est-il pris en compte dans la gestion et l’aménagement de l’environnement/territoire ? Ce qui est identifié pour les groupes nomades de la steppe sud-oranaise peut servir d’illustration pour évoquer certains processus communs à plusieurs cultures, ou de point de comparaison avec d’autres sociétés, notamment de chasseurs-cueilleurs, autres nomades confrontés à une culture et un modèle allogènes et puissants.From the example of the steppes of South Oran, we tried to demonstrate a model of nomadic space practice and its evolution through time, with its own visible and substantial consequences in a portion of Algerian’s space. The relation between nomads and their space settled in a specific meaning system. Its history, career, experiences, values and imaginations… in short, a culture of its own is arise from that relation, which by interfering with the features and advantages of the natural environment rise to a landscape. However, the nomadic society and its mode of space’s use and adaptation have been restructuring since the last thirty years. This restructuration has caused several mutations in their way of life and led to the reconstruction of ancestral territories. The settlement remains an essential element of those changes which impact on space. Although nomadism continues, it turns into other form and other tools. Can we speak of an adaptation or a residuality leading to decadence and ending with a loss? The Nomad’s perceived lived and represented space, is it taken into account in the management and development environment/territory? This identified, the south Oran nomadic society can serve as an illustration to evoke some process common to many cultures, or to compare it with other societies, such as hunter-gathers, others nomads facing an alien culture and powerful models