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ABSTRACT Cognitive radio is a technology that allows the unlicensed users to access the licensed spectrum based on sensing information perceived by the users. Cognitive radio user generally attempts to access the unutilized band of licensed user. However, the emergence/reappearance of primary users during ongoing cognitive user's transmission creates the interference at the primary receiver and data loss at cognitive receiver. In this context, the spectrum monitoring is a vital process of the cognitive radio network during data transmission to continuously monitor the primary user's presence or absence on a licensed channel. In this manuscript, we have utilized the spectrum monitoring technique on earlier existing MAC protocol for CR network to detect the emergence/reappearance of primary users throughout the data transmission period of cognitive users. The spectrum monitoring is employed to reduce the interference at primary receiver, which is measured in terms of interference power (IP) and data loss at CU receiver. The closed form expressions of data loss and IP for the monitoring and without monitoring scenarios are provided. In addition, the probability of monitoring error's (which causes misinterpretation of channel's status by the cognitive users) impact on these performance parameters is also provided and simulated. Further, earlier MAC protocol has significant amount of bandwidth wastage in case primary user disappears or reappears during cognitive user's data transmission, which is shown mathematically and simulated as well. However, incorporation of the monitoring phenomenon even with significant amount of monitoring error has reduced bandwidth wastage, which is measured in bps. In addition, the throughput calculation of the proposed system and the effect of monitoring error on the throughput of the proposed system are also seen. As per the results, the maximum data loss and IP occurred at licensed channel's busy probability value of 0.5, which is 23.22 bps and 3.487 W, respectively, at maximum monitoring error value. However, minimum data loss and IP are achieved at licensed busy channel's probability values of zero and one. In addition, the resource wastage at licensed channel's busy probability value of 0.5 is varying from 2.322 to 23.22 bps for varying the monitoring error value from 0.1 to 1, respectively, giving highest resource wastage at maximum monitoring error value. [ABSTRACT FROM AUTHOR]

Objectives. To investigate the hypothetical benefits of the IV2TM flow medical device. Background. Intravenous fluid administration is a standard hospital procedure with assumed inadequacies. The IV-Event Study [Fraser N, Nel G, Snyman J & Wessels F (2004) IV-EVENT Study: Intravenous Infusion Therapy – Management and Adverse Events. Data on File: Varori International (Pty) Ltd., Centurion, South Africa] quantified these inadequacies; The ‘Stargait’ intervention trial investigated the effectiveness and possible cost-benefit of the IV2TM flow. The IV2TM flow is intended for routine use with gravitational intravenous infusion sets. The IV2TM flow should reduce the incidence rate of adverse events and maintain a set flow rate. Method. Nursing staff assisted by study assessors captured relevant data. Consented patients were enrolled for the period of their prescribed infusions. Intervention. The Stargait Trial compared the treatment group (standard gravitational sets with the IV2TM flow) with the control group (standard gravitational infusion sets without IV2TM flow). The difference in observed events and the cost benefit derived from this were measured. Results. A total of 2387 drip hours were observed in 52 patients. The adverse event rates were: Control group (without IV2TM flow) 33·8%. The treatment group (IV2TM flow) 15·4%. This 55% reduction is statistically significant ( p = 0·0069). Adverse event related monetary wastage (labour and consumables) is reduced by 76% for infusion bags in the intervention group (with IV2TM flow). There was a significant difference between the treatment group and control group as far as deviation in flow rate was concerned ( p = 0·00818). The mean deviation of the IV2TM flow group was just more than 5 ml per hour. The standard line group had a mean deviation of more than 30 ml per hour. Conclusion. Gravitational intravenous therapy compromises quality of patient care. The Stargait Trial has proven the care-effectiveness and cost-effectiveness of the IV2TM flow. Relevance to clinical practice. The IV2TM flow improves quality of patient care and reduces associated wastage. [ABSTRACT FROM AUTHOR]