Call admission control algorithms in OFDM-based wireless multiservice networks

Orthogonal frequency division multiplexing (OFDM) is becoming a fundamental technology in future generation wireless communications. Call admission control is an effective mechanism to guarantee resilient, efficient, and quality-of-service (QoS) services in wireless mobile networks. In this paper, we present several call admission control algorithms for OFDM-based wireless multiservice networks. Call connection requests are differentiated into narrow-band calls and wide-band calls. For either class of calls, the traffic process is characterized as batch arrival since each call may request multiple subcarriers to satisfy its QoS requirement. The batch size is a random variable following a probability mass function (PMF) with realistically maximum value. In addition, the service times for wide-band and narrow-band calls are different. Following this, we perform a tele-traffic queueing analysis for OFDM-based wireless multiservice networks. The formulae for the significant performance metrics call blocking probability and bandwidth utilization are developed. Numerical investigations are presented to demonstrate the interaction between key parameters and performance metrics. The performance tradeoff among different call admission control algorithms is discussed. Moreover, the analytical model has been validated by simulation. The methodology as well as the result provides an efficient tool for planning next-generation OFDM-based broadband wireless access systems.

Do stressful times call for team-based working? A study of psychiatric nurses in UK mental healthcase

Background: Team-based working is now an inherent part of effective health care delivery. Previous research has identified that team working is associated with positive mental health and well-being outcomes for individuals operating in an effective team environment. This is a particularly important topic in the health services context, although little empirical attention has been paid to mental-health services. Psychiatric nurses work on a day-to-day basis with a particularly stressful and demanding client group in an environment which is characterised by high demands, uncertainty, and limited resources. This paper specifically focuses on psychiatric nurses working in National Health Service (NHS) and casts some light on the ways in which effective team-based working can help to alleviate a number of occupational stressors and strains. Method: A questionnaire method (2005 NHS Staff Survey) was employed to collect data from 6655 psychiatric nurses from 64 different NHS Trusts. The hypotheses were concerned with four overall measures from the survey; effective team working, occupational stress, work pressure and social support. Hypothesis 1 stated that effective team working will have a significant negative relationship with occupational stress and work pressure. Further, Hypothesis 2 stated that social support from supervisors and co-workers will moderate this relationship. Findings: Data was treated with a series of regression analyses. For Hypothesis 1, working in a real team did have main effects on work pressure and accounted for 1.6 per cent of the variance. Using the Nagelkerke R square value, working in a real team also had main effects on occupational stress an accounted for approximately 2.8 per cent of the variance. Further, the Exp (B) value of 0.662 suggests that the odds of suffering from occupational stress are cut by 33.8 per cent when a psychiatric nurse works in a real team. Results failed to provide support for Hypothesis 2. The analysis then went on to adopt a unique approach for assessing the extent of real team-based working, distinguishing between real teams, and a number of pseudo team typologies, as well as the absence of teamwork all together. As was hypothesised, results demonstrated that psychiatric nurses working in real teams (ones with clear objectives, where-by team members work closely with one another to achieve team objectives and meet regularly to discuss team effectiveness and how it can be improved) experienced the lowest levels of stress and work pressure of the sample. However, contrary to prediction, results indicated that psychiatric nurses working in any type of pseudo team actually experienced significantly higher levels of stress and work pressure than those who did not report as working in a team at all. Discussion: These findings have serious implications for NHS Mental Health Trusts, which may not be implementing, structuring and managing their nursing teams adequately. Indeed, results suggest that poorly-structured team work may actually facilitate stress and pressure in the workplace. Conversely, well-structured real teams serve to reduce stress and work pressure, which in turn not only enhances the working lives and well-being of psychiatric nurses, but also greatly improves the service that the NHS provides to its users.

Stressful times call for team-based measures:psychiatric nursing in the UK National Health Service

Background: Team-based working is now an inherent part of effective health care delivery. Previous research has identified that team working is associated with positive mental health and well-being outcomes for individuals operating in an effective team environment. This is a particularly important topic in the health services context, although little empirical attention has been paid to mental-health services. Psychiatric nurses work on a day-to-day basis with a particularly stressful and demanding client group in an environment which is characterised by high demands, uncertainty, and limited resources. This paper specifically focuses on psychiatric nurses working in National Health Service (NHS) and casts some light on the ways in which effective team-based working can help to alleviate a number of occupational stressors and strains. Method: A questionnaire method (2005 NHS Staff Survey) was employed to collect data from 6655 psychiatric nurses from 64 different NHS Trusts. The hypotheses were concerned with four overall measures from the survey; effective team working, occupational stress, work pressure and social support. Hypothesis 1 stated that effective team working will have a significant negative relationship with occupational stress and work pressure. Further, Hypothesis 2 stated that social support from supervisors and co-workers will moderate this relationship. Findings: Data was treated with a series of regression analyses. For Hypothesis 1, working in a real team did have main effects on work pressure and accounted for 1.6 per cent of the variance. Using the Nagelkerke R square value, working in a real team also had main effects on occupational stress an accounted for approximately 2.8 per cent of the variance. Further, the Exp (B) value of 0.662 suggests that the odds of suffering from occupational stress are cut by 33.8 per cent when a psychiatric nurse works in a real team. Results failed to provide support for Hypothesis 2. The analysis then went on to adopt a unique approach for assessing the extent of real team-based working, distinguishing between real teams, and a number of pseudo team typologies, as well as the absence of teamwork all together. As was hypothesised, results demonstrated that psychiatric nurses working in real teams (ones with clear objectives, where-by team members work closely with one another to achieve team objectives and meet regularly to discuss team effectiveness and how it can be improved) experienced the lowest levels of stress and work pressure of the sample. However, contrary to prediction, results indicated that psychiatric nurses working in any type of pseudo team actually experienced significantly higher levels of stress and work pressure than those who did not report as working in a team at all. Discussion: These findings have serious implications for NHS Mental Health Trusts, which may not be implementing, structuring and managing their nursing teams adequately. Indeed, results suggest that poorly-structured team work may actually facilitate stress and pressure in the workplace. Conversely, well-structured real teams serve to reduce stress and work pressure, which in turn not only enhances the working lives and well-being of psychiatric nurses, but also greatly improves the service that the NHS provides to its users.

Price synchronicity:the closing call auction and the London Stock Market

In this paper, we consider the impact of the introduction of a closing call auction on market quality of the London Stock Exchange. We employ the market model, RDD and MEC metrics of market quality. These signify substantial improvements to market quality at both the close and open for migrating stocks.We note that these improvements are larger at the open than the close. An important contribution of our paper is that we show that changes to market quality are stronger in those securities that have the lowest liquidity in the pre-call period. In contrast, market quality changes following the introduction of a closing call auction are approximately neutral for high-liquidity securities. We conclude that the implementation of a closing call auction, for high-liquidity securities may not enhance market quality.

A simulation study of the shift system at a UK police communications centre

The UK Police Force is required to operate communications centres under increased funding constraints. Staff represent the main cost in operating the facility and the key issue for the efficient deployment of staff, in this case call handler staff, is to try to ensure sufficient staff are available to make a timely response to customer calls when the timing of individual calls is difficult to predict. A discrete-event simulation study is presented of an investigation of a new shift pattern for call handler staff that aims to improve operational efficiency. The communications centre can be considered a specialised case of a call centre but an important issue for Police Force management is the particularly stressful nature of the work staff are involved with when responding to emergency calls. Thus decisions regarding changes to the shift system were made in the context of both attempting to improve efficiency by matching staff supply with customer demand, but also ensuring a reasonable workload pattern for staff over time.

Transfer of patients from health care centres to special care services:analysis of travel distances in Nordic countries

Objectives: This paper highlights the importance of analysing patient transportation in Nordic circumpolar areas. The research questions we asked are as follows: How many Finnish patients have been transferred to special care intra-country and inter-country in 2009? Does it make any difference to health care policymakers if patients are transferred inter-country? Study design: We analysed the differences in distances from health care centres to special care services within Finland, Sweden and Norway and considered the health care policy implica tions. Methods: An analysis of the time required to drive between service providers using the "Google distance meter" (http://maps.google.com/); conducting interviews with key Finnish stakeholders; and undertaking a quantitative analyses of referral data from the Lapland Hospital District. Results: Finnish patients are generally not transferred for health care services across national borders even if the distances are shorter. Conclusion: Finnish patients have limited access to health care services in circumpolar are as across the Nordic countries for 2 reasons. First, health professionals in Norway and Sweden do not speak Finnish, which presents a language problem. Second, The Social Insurance Institution of Finland does not cover the expenditures of travel or the costs of medicine. In addition, it seems that in circumpolar areas the density of Finnish service providers is greater than Swedish ones, causing many Swedish citizens to transfer to Finnish health care providers every year. However, future research is needed to determine the precise reasons for this.

Human resource alloctaion in a call centre

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Human resource allocation in a call centre

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Land use change and the planning process in historic town centres

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