In multi-hop ad hoc networks, queuing resources become unavailable under high load. When the traffic increases, the received frames are generally dropped and retransmitted later by the senders after a short timeout. This situation led to more conflicts in accessing the wireless medium and decreases the network performances. In this paper, we propose a new scheme to avoid the bad utilization of wireless medium in high load conditions. Simulations under NS2 have been conducted to study QoS parameters, especially throughput, delay and jitter. The obtained results show that the performances of our proposal are better than those of IEEE 802.11.

The competitiveness of a cement factory depends on the intellectual capital(IC) resources and knowledge management of all the company, as well as on the
ability to use them for competitiveness. But these days the use of the IC and knowledge is not optimal in Algerian enterprises because there is lack of methods
and techniques which give managers some kind of advice how to use properly their own IC/knowledge potential-obviously maximizing advantages for this
company.
It is also the lack of research concerning what each components of both the structure of IC and knowledge influence on gaining competitive advantage and
increasing value of the hole company. the intellectual capital created in the company could have higher efficiency if it is possible to identify all its components
and to know the measurement methods. Also knowledge if used properly increases the value of the company.
The aims of this work is not only to describe all aspects of IC and knowledge management but to present a practical approach to the effective use of both of
them as applied in other companies. We also focus on some determinants of IC/knowledge to give some advices, for employers and employees, about the way
they could increase the value of the company. A comprehensive model of efficiency of IC use which helps in creating values and building competitive
advantage on a large industrial scale.

Pour faire face à la croissance du nombre d’internautes à travers le monde, des liaisons à des débits de plus en plus élevés sont nécessaires; En plus, la mise en place de routeurs de plus en plus performants est primordiale pour suivre cette évolution. Une des opérations influentes sur la performance globale d’un routeur est la recherche de l’information dans la table de routage. Nous proposons dans cet article, une architecture parallèle pour la recherche de routes dans les tables IP. À la différence d’autres approches, nous proposons un mécanisme qui utilise le critère de longueur des préfixes pour regrouper les préfixes dans des sous tables de routage équilibrées, qui seront ensuite manipulées parallèlement afin d’accélérer l’opération de recherche des adresses IP par le routeur..

The risk’s cartography is a primordial step for the valuation and management of desertification phenomenon but it is a complicated spot, which necessitate a big amount of spatial and statistic’s data. The use of GIS permits to manage and use these data efficiency. The objective of our study is the realization of the sensitivity to the desertification map of south of the Aurès region by means of Geographical information system in accordance with the MEDALUS method (Mediterranean Desertification and Land Use), which use the qualitative indices to define the sensitive environment zones to the desertification. The creation of the database consist of four information layer (soil quality, vegetation quality, climate quality and the socioeconomic state) when the articulation in the space and in the time is submit to the validation on ground. Once the database has corrected it help to the elaboration of the sensitivity to the desertification map with calculation of the indices of the sensitivity to the desertification (ISD). The result is a risk’s map at a middle scale (1/200.000) which presents a big efficacy in word of synthesis of a desertification phenomenon. The maps make a tool of help to decision as far as the protection of natural resources is concerned in regions stroke by the aridity.