designing wireless sensor networks should meet appropriate parameters such as quality of service (qos) defined by different users. the variable physical conditions of the environment, processing and transmission power limitations and limited communication capabilities are the most important obstacles that influence qos parameters such as throughput, delay, reliability and network lifetime. the ...

Designing wireless sensor networks should meet appropriate parameters such as quality of service (QoS) defined by different users. The variable physical conditions of the environment, processing and transmission power limitations and limited communication capabilities are the most important obstacles that influence QoS parameters such as throughput, delay, reliability and network lifetime. The ...

This paper develops a method for solving the single product multi-period production-planning problem, in which the production and the inventory costs of each period arc concave and backlogging is not permitted. It is also assumed that the unit variable cost of the production evolves according to a continuous time Markov process. We prove that this production-planning problem can be Stated as a ...

In classical transport models, it is always assumed that parameters such as the distance from each supply node to each demand node or the cost of transferring goods from one node to another, as well as quantities such as supply and demand are definite and definite amounts. But in real matters, considering these assumptions is not logical. On the other hand, there may be a real problem in mathem...

centralizing and using proper transportation facilities cut down costs and traffic. hub facilities concentrate on flows to cause economic advantage of scale and multimodal transportation helps use the advantage of another transporter. a distinctive feature of this paper is proposing a new mathematical formulation for a three-stage p-hub location routing problem with simultaneous pick-ups and de...

We describe enhancements to the IEEE 802.11 DCF MAC Protocol which enable nodes to identify themselves as exposed nodes and to opportunistically schedule concurrent transmissions whenever possible, thereby improving utilization and mitigating the exposed node problem. The algorithm makes minimal changes to the IEEE 802.11 MAC protocol. It does not require the introduction of new frame types or ...

Centralizing and using proper transportation facilities cut down costs and traffic. Hub facilities concentrate on flows to cause economic advantage of scale and multimodal transportation helps use the advantage of another transporter. A distinctive feature of this paper is proposing a new mathematical formulation for a three-stage p-hub location routing problem with simultaneous pick-ups and de...

This article presents description of the simulation study of the low rate wireless personal area networks, defined by the IEEE 802.15.4 standard. The obtained results make available an evaluation of the effective transmission rate of a transmission channel, the resistance to the phenomenon of hidden station as well as sensibility to the problem of the exposed node. Index Terms – low rate wirele...