A general approach to validating evacuation models with an application to EXODUS

Too often, validation of computer models is considered as a "once and forget" task. In this paper a systematic and graduated approach to evacua tion model validation is suggested.

The effect of thermal cycle profiles on solder joint damage

The relationship between the damage caused at different thermal cycles is very important. The whole of accelerated thermal cycle testing is based on the premise that damage at one cycle is representative of damage at a different cycle. In this paper, the relative damage caused by six thermal cycle profiles are predicted using Finite Element (FE) modelling and the results validated against experiments. Both creep strain and strain energy density were used as damage indicators and creep strain was found to correlate better with experiment. The validated FE model is then used to investigate the effect of altering each of the thermal profile parameters (ramp and swell times, hot and cold temperatures). The components used for testing are surface mount resistors - 1206, 0805 and 0603. The solders investigated are eutectic SnAgCu and eutectic SnAg.

Self-optimising data farming for web applications

Many Web applications walk the thin line between the need for dynamic data and the need to meet user performance expectations. In environments where funds are not available to constantly upgrade hardware inline with user demand, alternative approaches need to be considered. This paper introduces a ‘Data farming’ model whereby dynamic data, which is ‘grown’ in operational applications, is ‘harvested’ and ‘packaged’ for various consumer markets. Like any well managed agricultural operation, crops are harvested according to historical and perceived demand as inferred by a self-optimising process. This approach aims to make enhanced use of available resources through better utlilisation of system downtime - thereby improving application performance and increasing the availability of key business data.

Semi-Lagrange time integration for PDE models of asian options

Semi-Lagrange time integration is used with the finite difference method to provide accurate stable prices for Asian options, with or without early exercise. These are combined with coordinate transformations for computational efficiency and compared with published results

Verbal abuse experienced by student nurses

Aim: This paper is a report of a study to describe the nature, severity, frequency and sources of verbal abuse experienced by nursing students while gaining clinical experience. Background: Verbal abuse of healthcare workers is currently receiving considerable attention and nursing students have been identified as a group vulnerable to experiencing workplace verbal abuse. Method: Questionnaires were distributed in 2005 to a convenience sample of 156 third year nursing students from one pre-registration nursing programme in England. A total of 114 questionnaires were returned, giving a response rate of 73.0%. Findings: Experience of verbal abuse was reported by 45.1% of respondents, 34.5% had witnessed other students experiencing this and 65.5% reported that they were aware of other students experiencing verbal abuse. The incidents involved patients in 64.7% of cases, 15.7% involved visitors or relatives and 19.6% involved other healthcare workers. Students reported experiencing threats to kill them, racial abuse and sexually oriented verbal abuse, with the majority of incidents occurring in general medical, mental health and general surgical clinical areas. Conclusion: Education and healthcare providers should prepare students to manage negative verbal exchanges during nursing education, and policies and support networks relating to managing verbal abuse in clinical practice should be available to nursing students.