Real-time evolution of an embedded controller for an autonomous helicopter

In this paper we evolve the parameters of a proportional, integral, and derivative (PID) controller for an unstable, complex and nonlinear system. The individuals of the applied genetic algorithm (GA) are evaluated on the actual system rather than on a simulation of it, thus avoiding the ldquoreality gaprdquo. This makes implicit a formal model identification for the implementation of a simulator. This also calls for the GA to be approached in an unusual way, where we need to consider new aspects not normally present in the usual situations using an unnaturally consistent simulator for fitness evaluation. Although elitism is used in the GAs, no monotonic increase in fitness is exhibited by the algorithm. Instead, we show that the GApsilas individuals converge towards more robust solutions

The future burden of cancer in London compared with England.

BACKGROUND: The future burden of cancer in England is predicted to increase by 33% by 2020. Those planning health services are often interested in predictions at a local level. This study aimed to estimate the future burden of cancer in London and compare this with estimates for England. METHODS: Predictions for London were based on cancer registration data (1985-2003) and population projections up until 2024. The number of future cases and age-standardized incidence rates (ASRs) were projected using an age-period-cohort model developed for the analysis of cancer trends and projections in the Nordic countries. Estimates for England were taken from an earlier publication. RESULTS: In London, ASRs for all cancers (excluding non-melanoma skin cancer) decreased for both sexes, whereas in England, ASRs decreased in males and increased slightly in females. In London, the number of cases for both sexes is predicted to increase from approximately 27,000 in 2002 to approximately 28,500 in 2022, an increase of 5%. In England, a greater increase is predicted, from approximately 224,000 in 2001 to approximately 299,000 in 2020, an increase of 33%. CONCLUSIONS: Projections of the future burden of cancer are particularly sensitive to demographic population trends. They are likely to be different for cities compared with rural areas or entire countries

Learning from difference and similarity: identities and relational reflexive learning

Within organizations there is reciprocal interplay between identity construction and learning. Processes of learning are enabled and constrained by identity practices; concomitantly, the possibilities for learning are shaped by the identity positions available to individuals. There is a dynamic between the impositions of organizations and people’s freedom to shape their identities and learning plays a crucial role in this. Our purpose in this special issue is to contribute to the understanding of the intersection of identity work and learning as a response to experiences of being different. Experiences of difference include moving into a new role, encountering a disjuncture with others while in a role or a difference in broader life which is reacted to as if it were a problem in an organizational setting. Being different produces a variety of challenges and the papers in this special issue trace how people cope with vulnerabilities, develop resilience and often collaborate in their learning. We focus on how people reflect on their own identity and learn and how, by learning together with people who have similar experiences, micro-communities can support, develop and enhance their insight and identity-positions

An alternative technique for investigating fluid flow around the hand during front crawl

This paper presents the novel application of a technique for measuring flow around the hand during a simulated swim stroke with a view to enable a better understanding of propulsion generation in swimming. The technique relies on the instantaneous, non-intrusive, volumetric measurement of 3D velocity fields using a commercially available optical measurement system. A hand and forearm model was towed through a water tank to replicate the pull phase with fluid flow data being captured at regular intervals in a fixed volume through which the model moved. The measurement system included a single body, three-sensor probe for capturing pairs of images which were then processed to determine particle velocities and to characterise the flow. The results were used to investigate changes in mean velocity for six experimental cases based on three different angles of attack and two towing speeds. The results showed that the V3V system could be used to capture velocity data around the hand and for a 45° increase in angle of attack, the velocity magnitude of the flow reduced by half, indicating the presence of lift forces. © 2013 The Authors

Influenza vaccination and risk of stroke: self-controlled case-series study

Background: Stroke may be triggered by respiratory infections, including influenza. Influenza vaccination could therefore reduce risk of stroke. Previous studies of this association have shown conflicting results.We aimed to investigate whether influenza vaccination was associated with reduced risk of stroke. Methods: We used a self-controlled case series design. The General Practice Research Database (GPRD) was used to extract records of patients aged 18 years or over recorded with stroke (fatal or non-fatal) from September 2001 to May 2009. Statistical modelling with conditional Poisson regression was employed to compute incidence rate ratios (IRR). The incidence rate of stroke in fixed time periods after influenza vaccination was compared with the incidence rate during a baseline period. Results: There were 17,853 eligible individuals who received one or more influenza vaccinations and experienced a stroke during the observation period. The incidence of stroke was significantly reduced inthe first 59 days following influenza vaccination compared with the baseline period. We found reductionsof 55% (IRR 0.45; 95% CI 0.36–0.57) in the first 1–3 days after vaccination, 36% (0.64; 0.53–0.76) at 4–7days, 30% (0.70; 0.61–0.79) at 8–14 days, 24% (0.76; 0.70–0.84) at 15–28 days and 17% (0.83; 0.77–0.89)at 29–59 days after vaccination. Early vaccination between 1 September and 15 November showed a greater reduction in IRR compared to later vaccination given after mid-November. Conclusions: Influenza vaccination is associated with a reduction in incidence of stroke. This study sup-ports previous studies which have shown a beneficial association of influenza vaccination for stroke prevention

Anti-dialogic positioning in change stories: bank robbers, saviours and peons

Stories people tell of going through change incorporate and react to others around them. Positions can be taken in stories that tend towards the monological, having a singular perspective and being somewhat sealed off from others. Alternatively, stories can tend towards the dialogical, a multiple, less certain and more interactive mode. We explore multiple stories of an organizational change and analyse a paradoxical situation that emerges. We argue that although the stories may have the appearance of being dialogical, they can be seen as co-existing but self-sealing, or anti-dialogic. We introduce an interruption to the story and discuss a possibility for challenging anti-dialogic positioning in change stories

Trends in the epidemiology of larynx and lung cancer in south-east England, 1985–2004

We analysed data on 8987 larynx and 174060 lung cancer patients diagnosed between 1985 and 2004, of which 17.3% of larynx and 35.5% of lung cancers were in females. The age-standardised rates for each cancer declined in both sexes, but since the 1990s, the rates in females over 70 years of age have been diverging