In this work, the issue of joint relay selection and power allocation in Underlay MIMO Cooperative Cognitive Radio Networks (U-MIMO-CCRN) is addressed. The system consists of a number of secondary users (SUs) in the secondary network and a primary user (PU) in the primary network. We consider the communications in the link between two selected SUs, referred to as the desired link which is enhan...

Cognitive radio has attracted considerable attention as an enabling technology for addressing the problem of radio frequency shortages. In cognitive radio networks (CRNs), secondary users (SUs) are allowed to opportunistically utilize the licensed spectrum bands of primary users (PUs) when these bands are temporarily unused. Thus, SUs should monitor the licensed spectrum bands to detect any PU ...

Corticotropin-releasing factor (CRF) injected peripherally or released in response to stressful challenges to the organism reduces gastric tone and contractility, in part by vagal pathways. However, information on the changes in gastric vagal impulse activity evoked by peripheral CRF administration is entirely lacking. Using a novel "dual recording" method in urethane-anesthetized rats, vagal e...

Genetically-determined regional differences in the GABA-ergic make-up of the brain exist in two lines of Wistar rats viz apomorphine-susceptible (APO-SUS) and apomorphine-unsusceptible (APO-UNSUS) Wistar rats, Propofol is a GABA-mimetic general anesthetic. This study compared the responses to propofol in APO-SUS and APO-UNSUS rats. Propofol induced a higher incidence of involuntary muscular con...

Cognitive radio, with the capability to flexibly adapt its transmission or reception parameters, has been proposed as the means for unlicensed secondary users (SUs) to dynamically access the licensed spectrum held by primary users (PUs) in order to increase the efficiency of spectrum utilization[1]. Recently, a new paradigm termed Cooperative Cognitive Radio Networks (CCRNs) has been advocated ...

Over the past decade, the object choice task has been used extensively to test the hypothesis that the ability of dogs to understand human social cues has resulted from the coevolutionary process of domestication (Hare et al., 2002). However, numerous factors can influence performance on this task (Reid, 2009), including artificial selection for attention and cooperation in specific working bre...

• Opportunistic spectrum access (OSA) in cognitive radio networks: using efficiently the radio frequency spectrum • Traditional static spectrum allocation to licensed primary users (PUs): severe inefficiencies, measurements indicate low spectrum utilization (under 30 %) • Dramatic demand surge for spectrum access by unlicensed secondary users (SUs), due to emerging technologies • OSA: dynamical...

Based on the non-cooperative power control game theory, we propose an efficient and unbiased power control algorithm in cognitive radio network (CRN) by improving the utility function. Without causing interference to the primary users (PUs), this effective utility function balances the fairness and system throughput of secondary users (SUs) via a fair pricing function. The pricing punishment pa...

HYPOTHESIS Surgeon-performed ultrasound (SUS) and fine-needle aspiration (FNA) may guide the management of dominant thyroid nodules of the isthmus. DESIGN Retrospective review of prospectively collected data. SETTING Tertiary academic referral center. PATIENTS Of 942 patients who underwent preoperative SUS and FNA, followed by thyroidectomy, between January 1, 2002, and April 10, 2010, a ...