Critical intellectual resources for praxis in physical education teacher education : the limits to rationality

This study focuses on the way four student-teachers engage with critical social discourses in a year-long physical education unit. The student-teachers were encouraged to examine and (re)construct their pedagogy through their interactions with critical discourses. Drawing on their personal theories and actions, the study examines the extent to which critical intellectual resources can provide pedagogical frames of reference that are 'practical and non-ideal'. Using a critical ethnographic methodology the students' interactions with critical social discourses are diagnosed across three levels. The first level is the case study presentations of each student's engagement with the critical intellectual resources and the extent to which they were able to understand and implement them. The second level involves an interpretation of the individual cases that is informed by Brian Fay's (1987) metatheoretical reconstruction of the critical social sciences. In the third stage of diagnosis the study focuses on retheorising critical aspirations for praxis pedagogy in physical education. Critical scholars within the physical education arena argue that critical praxis represents a pedagogy based on a 'world view' of the potential for agents to engage in a rational reordering of their qualitative existence. The essence of their claim is that critical discourses have the potential to facilitate a mode of praxis through which physical education teachers might better recognise, understand, critique and transform their values and practices. However, there is broad recognition that the translation of social-critical discourses into a pedagogic context is highly problematic. Interpretation of the study is provided by Fay's (1987) 'limits to change' thesis which recognises that critical aspirations must ultimately be adopted and implemented by real people in real settings. As a diagnostic frame of reference, Fay insists that a 'complete' critical theory [of physical education] be simultaneously scientific, critical, practical and non-ideal. In seeking to temper the "e; over-rationalistic"e; tendency of the critical project he recognises the historical, embedded, embodied and traditional nature of human existence Criticisms of critical theories of education traverse a number of philosophic perspectives. Recent post-structural criticisms of truth regimes, knowledge-power differentials, rationality and agency have seriously destabilised modernist justifications of the critical agenda. Critical theories of physical education have not been absolved of such criticism. A prominent element of this study is its promotion of a dialectical relationship between agency and structure to extend critical conceptualisations of physical education pedagogy. Through the mediation of structural determinism and self-determination this research proffers a means of practically advancing a critical praxis in physical education. The conclusion of this thesis outlines some broad recommendations pertaining to the introduction of social critical discourses in physical education teacher education.

Sociocultural influences on body image concerns and body change strategies among Indigenous and Non-Indigenous Australian adolescent girls and boys

Sociocultural messages about the ideal body build have been studied predominantlyamong White adolescent girls. In the current study we examined the relationships between perceived sociocultural influences, body image concerns, and body change strategies among 47 (22 boys and 25 girls) Indigenous Australian adolescents. These relationships were compared to those from 47 non-Indigenous adolescents (predominantly from an Anglo-Saxon background), who were matched on gender, age, and school grade. Overall, the sociocultural influences were found to be associated with body image concerns and body change strategies among both cultural groups. The only exception was that the sociocultural influences were not associated with the Indigenous girls levels of body dissatisfaction or body image importance. These findings are discussed in relation to past studies of White and Black girls.

Tensile behaviour of non-uniform fibres and fibrous composites

This work investigates the tensile behaviour of non-uniform fibres and fibrous composites. Wool fibres are used as an example of non-uniform fibres because they're physical, morphological and geometrical properties vary greatly not only between fibres but also within a fibre. The focus of this work is on the effect of both between-fibre and within-fibre diameter variations on fibre tensile behaviour. In addition, fit to the Weibull distribution by the non-brittle and non-uniform visco-elastic wool fibres is examined, and the Weibull model is developed further for non-uniform fibres with diameter variation along the fibre length. A novel model fibre composite is introduced to facilitate the investigation into the tensile behaviour of fibre-reinforced composites. This work first confirms that for processed wool, its coefficient of variation in break force can be predicted from that of minimum fibre diameters, and the prediction is better for longer fibres. This implies that even for processed wool, fibre breakage is closely associated with the occurrence of thin sections along a fibre, and damage to fibres during processing is not the main cause of fibre breakage. The effect of along-fibre diameter variation on fibre tensile behaviour of scoured wool and mohair is examined next. Only wet wool samples were examined in the past. The extensions of individual segments of single non-uniform fibres are measured at different strain levels. An important finding is the maximum extension (%) (Normally at the thinnest section) equals the average fibre extension (%) plus the diameter variation (CV %) among the fibre segments. This relationship has not been reported before. During a tensile test, it is only the average fibre extension that is measured. The third part of this work is on the applicability of Weibull distribution to the strength of non-uniform visco-elastic wool fibres. Little work has been done for wool fibres in this area, even though the Weibull model has been widely applied to many brittle fibres. An improved Weibull model incorporating within-fibre diameter variations has been developed for non-uniform fibres. This model predicts the gauge length effect more accurately than the conventional Weibull model. In studies of fibre-reinforced composites, ideal composite specimens are usually prepared and used in the experiments. Sample preparation has been a tedious process. A novel fibre reinforced composite is developed and used in this work to investigate the tensile behaviour of fibre-reinforced composites. The results obtained from the novel composite specimen are consistent with that obtained from the normal specimens.

Condition monitoring of induction motors : A review and an application of an ensemble of hybrid intelligent models

In this paper, a review on condition monitoring of induction motors is first presented. Then, an ensemble of hybrid intelligent models that is useful for condition monitoring of induction motors is proposed. The review covers two parts, i.e.; (i) a total of nine commonly used condition monitoring methods of induction motors; and (ii) intelligent learning models for condition monitoring of induction motors subject to single and multiple input signals. Based on the review findings, the Motor Current Signature Analysis (MCSA) method is selected for this study owing to its online, non-invasive properties and its requirement of only single input source; therefore leading to a cost-effective condition monitoring method. A hybrid intelligent model that consists of the Fuzzy Min-Max (FMM) neural network and the Random Forest (RF) model comprising an ensemble of Classification and Regression Trees is developed. The majority voting scheme is used to combine the predictions produced by the resulting FMM-RF ensemble (or FMM-RFE) members. A benchmark problem is first deployed to evaluate the usefulness of the FMM-RFE model. Then, the model is applied to condition monitoring of induction motors using a set of real data samples. Specifically, the stator current signals of induction motors are obtained using the MCSA method. The signals are processed to produce a set of harmonic-based features for classification using the FMM-RFE model. The experimental results show good performances in both noise-free and noisy environments. More importantly, a set of explanatory rules in the form of a decision tree can be extracted from the FMM-RFE model to justify its predictions. The outcomes ascertain the effectiveness of the proposed FMM-RFE model in undertaking condition monitoring tasks, especially for induction motors, under different environments. © 2014 Elsevier Ltd. All rights reserved.