Cognitive Radio Network has been widely researched to improve utilization of radio electromagnetic spectrum efficiency usage. Spectrum occupancy in Cognitive framework includes licensed and unlicensed users sharing set of channel over a coverage area. In this paper, we develop a 2D Markov Model to define transition rate and analyze call dropping probability for unlicensed users and channel util...

In [1], the authors point out an interesting open problem concerning the schedulability (with Fixed Priorities) of uniprocessor probabilistic real-time systems with variable execution times: What is the impact of dropping some jobs, in particular when they are doomed to fail? The present paper looks at this problem—i.e., assuming that the scheduling criterion depends on the satisfaction of a su...

1 2 BACKGROUND In the context of changing admissions criteria and an expanding medical school intake in the UK, we analyse the determinants of the medical school dropout probability. AIMS To analyse the determinants of the probability that a student will drop out of medical school during their first year. To compare the results of this analysis over time. there was a substantial increase both i...

In order to provide the guaranteed mobile QoS (Quality-of-service) for arriving multi-class calls, we need to minimize the dropping rate of handoff calls while at the same time controlling the blocking rate of new calls. This paper proposed a new multi-class call admission control mechanism that is based on dynamically formed reservation pool for handoff requests. The simulation results show th...

Approximately one third of U.S. high-school freshmen do not earn their high-school diploma on time. For African-American and Hispanic students, this figure nearly reaches one half. The long-term economic consequences of dropping out of school for both the student and the larger community have been well documented. It has also been argued that school dropouts put themselves at a higher risk for ...

Our aim is to show the consistency of 2κ ≥ κ+θ, for any θ < κ starting with a singular cardinal κ of cofinality ω so that ∀n < ω∃α < κ(o(α) = α). Dropping cofinalities technics are used for this purpose. 1 א1-gap and infinite drops in cofinalities Let κ be a singular cardinal of cofinality ω such that for each γ < κ and n < ω there is α, γ < α < κ, such that o(α) = α. We fix a sequence of cardi...

Modern cognitive radio systems employ dynamic spectrum access techniques and these networks allow more efficient usage of scarce spectrum. Secondary users are supposed to operate in primary users’ channels without interfering them. In this paper, we propose model and analyze a channel sub-banding scheme for an opportunistic spectrum sharing system in which two secondary users are allowed to coe...