The Iranian chicken industry has always been encountered to high and fluctuated chicken prices. The purpose of this article is to find the best choice to prevent chicken prices from increasing more by investments. System dynamics methodology has been used to modeling, evaluating and optimizing...

Cognitive radio networks (CRNs) can provide a means for offering end-to-end Quality of Service (QoS) required by unlicensed users (secondary users. SUs). The authors consider the approach where licensed users (primary users, PUs) play the role of routers and lease spectrum with QoS guarantees...