Aircraft control via variable cant-angle winglets

Copyright @ 2008 American Institute of Aeronautics and AstronauticsThis paper investigates a novel method for the control of "morphing" aircraft. The concept consists of a pair of winglets; with adjustable cant angle, independently actuated and mounted at the tips of a baseline flying wing. The general philosophy behind the concept was that for specific flight conditions such as a coordinated turn, the use of two control devices would be sufficient for adequate control. Computations with a vortex lattice model and subsequent wind-tunnel tests demonstrate the viability of the concept, with individual and/or dual winglet deflection producing multi-axis coupled control moments. Comparisons between the experimental and computational results showed reasonable to good agreement, with the major discrepancies thought to be due to wind-tunnel model aeroelastic effects.This work has been supported by a Marie Curie excellence research grant funded by the European Commission

The Impact of Training on Productivity: Evidence from a Large Panel of Firms

This paper investigates the e®ects of training on labor productiv- ity using a unique nationally representative panel of Italian ¯rms for the period 2002 to 2005. We ¯nd that training has a positive and signi¯cant e®ect on productivity. Using a variety of panel estimation techniques, we show that failing to account for unobserved heterogene- ity leads to overestimate the impact of training on productivity, while failing to account for endogeneity leads to substantially underestimate it. Training also has a positive and signi¯cant impact on wages, but this e®ect is about half the size of the e®ect on productivity. Within occupational groups, the e®ect of training on productivity is large and signi¯cant for blue-collars, but small and not signi¯cant for white collars.On-the-Job-Training; Productivity; Wages; Panel Data

Improving the Interpretability of Classification Rules Discovered by an Ant Colony Algorithm: Extended Results

The vast majority of Ant Colony Optimization (ACO) algorithms for inducing classification rules use an ACO-based procedure to create a rule in an one-at-a-time fashion. An improved search strategy has been proposed in the cAnt-MinerPB algorithm, where an ACO-based procedure is used to create a complete list of rules (ordered rules)-i.e., the ACO search is guided by the quality of a list of rules, instead of an individual rule. In this paper we propose an extension of the cAnt-MinerPB algorithm to discover a set of rules (unordered rules). The main motivations for this work are to improve the interpretation of individual rules by discovering a set of rules and to evaluate the impact on the predictive accuracy of the algorithm. We also propose a new measure to evaluate the interpretability of the discovered rules to mitigate the fact that the commonly-used model size measure ignores how the rules are used to make a class prediction. Comparisons with state-of-the-art rule induction algorithms, support vector machines and the cAnt-MinerPB producing ordered rules are also presented

Fracture healing following high energy tibial trauma: Ilizarov versus Taylor Spatial Frame

Introduction: The optimal treatment of high energy tibial fractures remains controversial and a challenging orthopaedic problem. The role of external fi xators for all these tibial fractures has been shown to be crucial. Methods: A fi ve-year consecutive series was reviewed retrospectively, identifying two treatment groups: Ilizarov and Taylor Spatial Frame (TSF; Smith & Nephew, Memphis, TN, US). Fracture healing time was the primary outcome measure. Results: A total of 112 patients (85 Ilizarov, 37 TSF) were identifi ed for the review with a mean age of 45 years. This was higher in women (57 years) than in men (41 years). There was no signifi cant difference between frame types (p=0.83). The median healing time was 163 days in both groups. There was no signifi cant difference in healing time between smokers and non-smokers (180 vs 165 days respectively, p=0.07), open or closed fractures (p=0.13) or age and healing time (Spearman's r=0.12, p=0.18). There was no incidence of non-union or re-fracture following frame removal in either group. Conclusions: Despite the assumption of the rigid construct of the TSF, the median time to union was similar to that of the Ilizarov frame and the TSF therefore can play a signifi cant role in complex tibial fractures

The art world’s response to the challenge of inequality

This paper considers the challenges which rising economic inequality poses to the art world with a special focus on museums and galleries in the UK. Based on interviews with artists, curators and managers of leading art institutions in London, we discuss how issues of economic inequality are reflected in their thinking about cultural work and how these relate to questions of spatial power, post-colonial sensibilities and diversity issues. We show how increasing economic inequality brings about deep-seated, systematic and sustained challenges which extend well beyond public funding cuts associated with austerity politics to a wider re-positioning of the arts away from its location in a distinctive public sphere and towards elite private privilege. Against this backdrop, we put forward the term ‘the artistic politics of regionalism’ and suggest that the most promising approaches to addressing contemporary inequalities lie in institutions’ reconsideration of spatial dynamics which can link concerns with decolonisation and representation to a recognition of how economic inequality takes a highly spatialised form

Medical Pluralism, mainstream marginality or subaltern therapeutics? Globalisation and the integration of ‘Asian’ medicines and biomedicine in the UK

Medical Pluralism refers to the co-existence of differing medical traditions and practices grounded in divergent epistemological positions and based on distinctive worldviews. From the 1970s, a globalised health market, underpinned by new consumer and practitioner interest, spawned the importation of ‘non-Western’ therapeutics to the UK. Since then, these various modalities have co-existed alongside, and sometimes within, biomedical clinics. Sociologists have charted the emergence of this ‘new’ medical pluralism in the UK, to establish how complementary and alternative medicines (CAM) have fared in both the private and public health sectors and to consider explanations for the attraction of these modalities. The current positioning of CAM can be described as one of ‘mainstream marginality’ (Cant 2009): popular with users, but garnering little statutory support. Much sociological analysis has explained this marginal positioning of non-orthodox medicine by recourse to theories of professionalisation and has shown how biomedicine has been able, with the support of the state, to subordinate, co-opt and limit its competitors. Whilst insightful, this work has largely neglected to situate medical pluralism in its historical, global and colonial context. By drawing on post-colonial thinking, the paper suggests how we might differently theorise and research the appropriation, alteration and reimagining of ‘Asian’ therapeutic knowledges in the UK

Hysteresis, social congestion and debt: towards a sociology of mental health disorders in undergraduates

Sociologists have done much to show that the education system, whatever its meritocratic rationale, is associated with the generation and reproduction of fundamental inequalities. This paper explores how the recent epidemic of mental illness amongst undergraduate students can be seen as part of this dynamic. Reflecting on the dearth of sociological work in this area, the paper draws together the sociologies of inequality, education, and health and illness and explores the value of Bourdieusian framework for understanding the rise of mental health disorders in the undergraduate population. The suggestion is that whilst widening participation has extended educational opportunities, it has simultaneously created a context in which a state of hysteresis (Bourdieu, 1977) can emerge which, when combined with social congestion in the workplace (Brown, 2013) and high levels of debt, serves to elevate rates of depression and anxiet

Prediction of jet engine parameters for control design using genetic programming

The simulation of a jet engine behavior is widely used in many different aspects of the engine development and maintenance. Achieving high quality jet engine control systems requires the iterative use of these simulations to virtually test the performance of the engine avoiding any possible damage on the real engine. Jet engine simulations involve the use of mathematical models which are complex and may not always be available. This paper introduces an approach based on Genetic Programming (GP) to model different parameters of a small engine for control design such as the Exhaust Gas Temperature (EGT). The GP approach has no knowledge of the characteristics of the engine. Instead, the model is found by the evolution of models based on past measurements of parameters such as the pump voltage. Once the model is obtained, it is used to predict the behaviour of the jet engine one step ahead. The proposed approach is successfully applied for the simulation of a Behotec j66 jet engine and the results are presented