Media access control plays a critical role in cognitive radio networks (CRNs). In our previous work, we have proposed a fairnessoriented media access control (FMAC) protocol to achieve fair and efficient coexistence of infrastructure-based CRNs. In this paper, we enhance FMAC to be used for coexisting ad hoc CRNs, where no centralized base stations exist, and secondary users (SUs) access channe...

Hot ring rolling is a highly nonlinear, unsteady-state and asymmetry process which is affected by many parameters. The friction coefficient between the ring ,the driver roll and the idle roll is one of the problems, which has significant effect on the quality of final product. In this study, the effect of these two parameters on hot ring rolling was investigated based on a 3D coupled-thermo mec...

in this paper the real time operation of an automatic teller machine (atm) is analyzed using atimed petri net (tpn) model. in the modeling, the probability of arrivals, the speed andattentiveness of customers (clients) are taken to account. different parameters are based onthe statistical data. the model is simulated for 24 hours. the diagrams of number ofsucceeded customers, failed references ...

Flow shop scheduling problem has a wide application in the manufacturing and has attracted much attention in academic fields. From other point, on time delivery of products and services is a major necessity of companies’ todays; early and tardy delivery times will result additional cost such as holding or penalty costs.  In this paper, just-in-time (JIT) flow shop scheduling problem with preemp...

The Non-Dedicated Distributed Environment (NDDE) aims to muster the idle processing power of interactive computers (workstations or PCs) into a virtual resource for parallel applications and grid computing. NDDE is novel in the sense that it allows for safe and continuous use of idle cycles. Differently from existing solutions, NDDE applications run inside a virtual machine rather than on the u...

Office and home environments are increasingly crowded with personal computers. Even though these computers see little use in the course of the day, they often remain powered, even when idle. Leaving idle PCs running is not only wasteful, but with rising energy costs it is increasingly more expensive. We propose partial migration of idle desktop sessions into the cloud to achieve energyproportio...

The paper is designated to the analysis of queueing systems, arising in the network theory and communications theory (called multiphase queueing systems, tandem queues or series of queueing systems). Also we note that multiphase queueing systems can be useful for modelling practical multi-stage service systems in a variety of disciplines, especially on manufacturing (assembly lines), computer n...

Though existing systems for sharing distributed resources in clusters of workstations are generally e ective at recruiting idle resources, these systems often have a disruptive e ect on desktop workstation users. Even when recruiting computing cycles from strictly idle workstations, a by-product of running foreign jobs is that the virtual memory pages of the original user's idle processes are u...