Performance evaluation of the register insertion protocol for voice-data integration

The performance of the register insertion protocol for mixed voice-data traffic is investigated by simulation. The simulation model incorporates a common insertion buffer for station and ring packets. Bandwidth allocation is achieved by imposing a queue limit at each node. A simple priority scheme is introduced by allowing the queue limit to vary from node to node. This enables voice traffic to be given priority over data. The effect on performance of various operational and design parameters such as ratio of voice to data traffic, queue limit and voice packet size is investigated. Comparisons are made where possible with related work on other protocols proposed for voice-data integration. The main conclusions are: (a) there is a general degradation of performance as the ratio of voice traffic to data traffic increases, (b) substantial improvement in performance can be achieved by restricting the queue length at data nodes and (c) for a given ring utilisation, smaller voice packets result in lower delays for both voice and data traffic.

Evaluation of loadsharing algorithms for heterogeneous distributed systems

The performance of loadsharing algorithms for heterogeneous distributed systems is investigated by simulation. The systems considered are networks of workstations (nodes) which differ in processing power. Two parameters are proposed for characterising system heterogeneity, namely the variance and skew of the distribution of processing power among the network nodes. A variety of networks are investigated, with the same number of nodes and total processing power, but with the processing power distributed differently among the nodes. Two loadsharing algorithms are evaluated, at overall system loadings of 50% and 90%, using job response time as the performance metric. Comparison is made with the ideal situation of ‘perfect sharing’, where it is assumed that the communication delays are zero and that complete knowledge is available about job lengths and the loading at the different nodes, so that an arriving job can be sent to the node where it will be completed in the shortest time. The algorithms studied are based on those already in use for homogeneous networks, but were adapted to take account of system heterogeneity. Both algorithms take into account the differences in the processing powers of the nodes in their location policies, but differ in the extent to which they ‘discriminate’ against the slower nodes. It is seen that the relative performance of the two is strongly influenced by the system utilisation and the distribution of processing power among the nodes.

Foundations for paramedic practice: a theoretical perspective

Written by leading paramedics and academic subject experts, with a foreword by Paul Bates, this is the first foundation level text to introduce the main theoretical subjects studied on the new higher education paramedic science programmes. It underpins practice and links ways of working to the crucial theory base. The numerous examples and case studies focus specifically on pre-hospital and emergency care. Key topics covered include: * NHS and ambulance service history * Ethics and law for the paramedic * Communication and reflective practice * Professional issues, including evidence-based practice, anti-discriminatory practice, clinical governance and clinical audit * Psychological perspectives on health and ill health * Safeguarding children * Sociological perspectives on health and ill health and social policy * Managing change and leadership theory * Continuing professional development The text prompts you to stop and think about what you have just read and relate this to your role. Throughout the book, the author carefully considers how the theory being discussed relates to the role of the ambulance clinician. Foundations for Paramedic Practice: A Theoretical Perspective is a core text for students of paramedic science and will also provide a valuable resource for students of allied health professions. This text provides a stepping stone to further reading and investigation. - Taken from the back cover of: Amanda Blaber - Foundations for paramedic practice: a theoretical perspective