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701.
The optimal widely linear state estimation problem for quaternion systems with multiple sensors and mixed uncertainties in the observations is solved in a unified framework. For that, we devise a unified model to describe the mixed uncertainties of sensor delays, packet dropouts and uncertain observations by using three Bernoulli distributed quaternion random processes. The proposed model is valid for linear discrete-time quaternion stochastic systems measured by multiple sensors and it allows us to provide filtering, prediction and smoothing algorithms for estimating the quaternion state through a widely linear processing. Simulation results are employed to show the superior performance of such algorithms in comparison to standard widely linear methods when mixed uncertainties are present in the observations.  相似文献   
702.
703.
Purpose: The purposes of this study were to (a) investigate the effect of physical effort (cycling for 60 min at 60 ± 5% of individually computed reserve heart-rate capacity), combined with 2 different levels of cognitive demand (2-back, oddball), on intraocular pressure (IOP) and subjective judgments of perceived exertion (ratings of perceived exertion [RPE]), affect (Affective Valence subscale of the Self-Assessment Manikin [SAM]), and mental workload (National Aeronautics and Space Administration Task Load Index [NASA-TLX]); and (b) ascertain whether baseline IOP, measured before exercise, is associated with individual differences in subjective assessments of effort and affective response during exercise. Method: Seventeen participants (Mage = 23.28 ± 2.37 years) performed 2 physical/cognitive dual tasks, matched in physical demand but with different mental requirements (2-back, oddball). We assessed IOP before exercise, after 2 min of active recovery, and after 15 min of passive recovery, and we also collected RPE and SAM measures during the sessions (28 measurement points). We used NASA-TLX and cognitive performance as checks of the mental manipulation. Results: (a) Intraocular pressure increased after concomitant physical/mental effort, with the effect reaching statistical significance after the 2-back task (p = .002, = 0.35) but not after the oddball condition (p = .092, = 0.29). (b) Baseline IOP was associated with subjective sensitivity to effort and showed statistical significance for the oddball condition (= .03, ?p2 = .622) but not for the 2-back task (F < 1). Conclusions: Results suggest a relationship between IOP and physical/cognitive effort, which could have implications for the management of glaucoma. Additionally, a rapid measure of IOP could be used as a marker of individual effort sensitivity in applied settings.  相似文献   
704.
Perhaps as a consequence of increased specialism in training and support, the focus on engendering and maintaining agility as a generic quality has diminished within many contemporary sports performance programmes. Reflecting this, we outline a rationale suggesting that such a decreased focus represents an oversight which may be detrimental to maximising the potential of performers. We present an evidence-based argument that both generic and specific elements of agility performance should be consistently emphasised within long-term performance-training programmes. We contend that prematurely early specialisation in athlete development models can diminish focus on generic movement skill development with a subsequent detriment in adult performance. Especially when this is coupled with poor primary physical education and limited movement experiences. More speculatively, we propose that generic agility can play a role in operationalising movement development through facilitating skill transfer: thereby enabling the learning of new skills, reduce incidence of injury and facilitating re-learning of old skills during rehabilitation and Return-to-Play processes.  相似文献   
705.
All Fall Down!     
This article reports on a practical activity which provides a realistic context for collecting and analysing data.  相似文献   
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707.
A scheme of professional development for teachers, leading to the award of Advanced Certificate, Advanced Diploma or degree of Master of Education, has been in operation at the University of Bath School of Education for some years. Recently this modular scheme has been extended to become more accessible to teachers in international and overseas schools around the world, with modules taught in a range of locations internationally including a Summer School held annually in July at the University of Bath. The Methods of Educational Enquiry (MEE) module provides an introduction to aspects of educational research and is recommended to participants as an early module for study: between 1992 and 1993 this module has thus been taught on more occasions than any other, in a number of different locations and by a number of different tutors. This paper considers issues arising from the implementation of an instrument for the evaluation of some aspects of the taught component of the MEE module in a wide range of contexts, and describes the development of two related measures of participants' satisfaction with respect to this component. A further paper will consider a wider range of issues across a number of different modules in a range of locations.  相似文献   
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709.
Abstract

Relevant information on effectiveness of school-based drug prevention programmes is available. Despite this, there is still contradictory evidence that makes it necessary to continue to shed light on this issue. Based on a synthesis research method, the aim of this study was to determine the relevant variables that enhance the efficacy of these programmes and to determine the weight of their empirical evidence. Furthermore, several features of the evaluation designs whose variables had been proven effective were examined. A systematic review of periodical literature was conducted, which led us to extract 1,622 papers, of which 17 studies were analysed. An in-depth analysis of these publications led us to identify 29 key variables associated with the efficacy of the programme, which were ranked according to the weight of their empirical evidence. Moreover, the characteristics of the studies included in the review highlighted the need to improve the rigorousness and quality of the evaluation designs in this field.  相似文献   
710.
Se revisan y comparan aquí las características del método natural-global de Freinet y se sugiere su convergencia con las que se deducen de la psicología cognitiva para la enseñanza de la lectoescritura. A partir de ahí se propone una secuencia determinada y se dan una serie de recomendaciones para abordar con éxito la enseñanza de la lectura.  相似文献   
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