717 research outputs found

    Signal and System Approximation from General Measurements

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    In this paper we analyze the behavior of system approximation processes for stable linear time-invariant (LTI) systems and signals in the Paley-Wiener space PW_\pi^1. We consider approximation processes, where the input signal is not directly used to generate the system output, but instead a sequence of numbers is used that is generated from the input signal by measurement functionals. We consider classical sampling which corresponds to a pointwise evaluation of the signal, as well as several more general measurement functionals. We show that a stable system approximation is not possible for pointwise sampling, because there exist signals and systems such that the approximation process diverges. This remains true even with oversampling. However, if more general measurement functionals are considered, a stable approximation is possible if oversampling is used. Further, we show that without oversampling we have divergence for a large class of practically relevant measurement procedures.Comment: This paper will be published as part of the book "New Perspectives on Approximation and Sampling Theory - Festschrift in honor of Paul Butzer's 85th birthday" in the Applied and Numerical Harmonic Analysis Series, Birkhauser (Springer-Verlag). Parts of this work have been presented at the IEEE International Conference on Acoustics, Speech, and Signal Processing 2014 (ICASSP 2014

    Preparing athletes and teams for the Olympic Games: experiences and lessons learned from the world's best sport psychologists

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    As part of an increased effort to understand the most effective ways to psychologically prepare athletes and teams for Olympic competition, a number of sport psychology consultants have offered best-practice insights into working in this context. These individual reports have typically comprised anecdotal reflections of working with particular sports or countries; therefore, a more holistic approach is needed so that developing practitioners can have access to - and utilise - a comprehensive evidence-base. The purpose of this paper is to provide a panel-type article, which offers lessons and advice for the next generation of aspiring practitioners on preparing athletes and teams for the Olympic Games from some of the world’s most recognised and experienced sport psychologists. The sample comprised 15 sport psychology practitioners who, collectively, have accumulated over 200 years of first-hand experience preparing athletes and/or teams from a range of nations for six summer and five winter Olympic Games. Interviews with the participants revealed 28 main themes and 5 categories: Olympic stressors, success and failure lessons, top tips for neophyte practitioners, differences within one’s own consulting work, and multidisciplinary consulting. It is hoped that the findings of this study can help the next generation of sport psychologists better face the realities of Olympic consultancy and plan their own professional development so that, ultimately, their aspirations to be the world’s best can become a reality

    A Pilot Study on Patterns of Skill Development of Neurotypical Children as Measured by the ABLLS-R: Implications for Educational Programming for Children With Autism

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    Many assessments used to measure the skills of children with an autism spectrum disorder (ASD) diagnosis lack data that delineates patterns of skill development by neurotypical children. In the current pilot study, we administered the Assessment of Basic Language and Learning Skills-Revised (ABLLS-R) to neurotypical children (N = 53) between the ages of six and 72 months to examine typical skill development across the major skill sets and repertoires of the ABLLS-R. We found that skills from the Basic Learner skills section emerged and developed earlier (i.e., by age five) than those from the other skills sections. By age six, children mastered their motor skills and 90% of the self-help skills. Academic skills took the longest to emerge and develop with children mastering only 51% of the related skills by age six. Implications of these findings, as they relate to skill development and identifying developmentally appropriate teaching objectives for individuals with ASD, are discussed

    Sports coaching and the law of negligence: implications for coaching practice

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    The ordinary principles of the law of negligence are applicable in the context of sport, including claims brought against volunteer and professional coaches. Adopting the perspective of the coach, this article intends to raise awareness of the emerging intersection between the law of negligence and sports coaching, by utilising an interdisciplinary analysis designed to better safeguard and reassure coaches mindful of legal liability. Detailed scrutiny of two cases concerning alleged negligent coaching, with complementary discussion of some of the ethical dilemmas facing modern coaches, reinforces the legal duty and obligation of all coaches to adopt objectively reasonable and justifiable coaching practices when interacting with athletes. Problematically, since research suggests that some coaching practice may be underpinned by ‘entrenched legitimacy’ and ‘uncritical inertia’, it is argued that coach education and training should place a greater emphasis on developing a coach’s awareness and understanding of the evolving legal context in which they discharge the duty of care incumbent upon them

    NETIMIS: Dynamic Simulation of Health Economics Outcomes Using Big Data

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    Many healthcare organizations are now making good use of electronic health record (EHR) systems to record clinical information about their patients and the details of their healthcare. Electronic data in EHRs is generated by people engaged in complex processes within complex environments, and their human input, albeit shaped by computer systems, is compromised by many human factors. These data are potentially valuable to health economists and outcomes researchers but are sufficiently large and complex enough to be considered part of the new frontier of ‘big data’. This paper describes emerging methods that draw together data mining, process modelling, activity-based costing and dynamic simulation models. Our research infrastructure includes safe links to Leeds hospital’s EHRs with 3 million secondary and tertiary care patients. We created a multidisciplinary team of health economists, clinical specialists, and data and computer scientists, and developed a dynamic simulation tool called NETIMIS (Network Tools for Intervention Modelling with Intelligent Simulation; http://www.netimis.com) suitable for visualization of both human-designed and data-mined processes which can then be used for ‘what-if’ analysis by stakeholders interested in costing, designing and evaluating healthcare interventions. We present two examples of model development to illustrate how dynamic simulation can be informed by big data from an EHR. We found the tool provided a focal point for multidisciplinary team work to help them iteratively and collaboratively ‘deep dive’ into big data

    A critical analysis of the conceptualisation of ‘coaching philosophy’

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    The aim of this paper was to critically review existing literature relating to, and critically analyse current conceptualisations of, ‘coaching philosophy’. The review reveals a bewildering approach to definitions, terms and frameworks that have limited explanation and reveal a lack of conceptual clarity. It is argued that rather than provide clarification and understanding the existing literature conflates coaching rhetoric and ideology with coaching philosophy and serves to reproduce existing coaching discourse rather than explain coaching practice. The paper problematises the unquestioned assumptions currently underpinning ‘coaching philosophy’; namely the overemphasis of coaches’ agency and reflexivity, the downplaying of the significance of social structure on coaches’ dispositions and the acceptance that coaching practice is an entirely conscious activity. The paper argues for an alternative philosophy of coaching that uses philosophic thinking to help coaches question existing ideology, and critically evaluate the assumptions and beliefs underpinning their practice

    Executive function and intelligence in the resolution of temporary syntactic ambiguity: An individual differences investigation

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    In the current study, we examined the role of intelligence and executive functions in the resolution of temporary syntactic ambiguity using an individual differences approach. Data were collected from 174 adolescents and adults who completed a battery of cognitive tests as well as a sentence comprehension task. The critical items for the comprehension task consisted of object/subject garden paths (e.g. While Anna dressed the baby that was small and cute played in the crib.), and participants answered a comprehension question (e.g. Did Anna dress the baby?) following each one. Previous studies have shown that garden-path misinterpretations tend to persist into final interpretations. Results showed that both intelligence and processing speed interacted with ambiguity. Individuals with higher intelligence and faster processing were more likely to answer the comprehension questions correctly, and specifically, following ambiguous as opposed to unambiguous sentences. Inhibition produced a marginal effect, but the variance in inhibition was largely shared with intelligence. Conclusions focus on the role of individual differences in cognitive ability and their impact on syntactic ambiguity resolution

    An investigation of the effect of athletes’ age on the coaching behaviours of professional top-level youth soccer coaches

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    The aim of the study was to investigate the behaviours, cognitive processes and practice activities of 12 English youth professional soccer coaches across 6 different age groups. Systematic observation data were collected using a modified version of the Coach Analysis and Intervention System which provided a detailed analysis of coaching behaviours performed during practice. Interpretive interviews were then triangulated with the behavioural data to identify the cognitive processes underlying the behaviours performed. The behavioural results showed that the coaches of the younger age groups used more instruction and the coaches of the older age groups used more divergent questioning and significantly more total feedback and punitive behaviours. The coaches of the younger age groups used more training form activities than the coaches of the older age groups who used more playing form activities. However, the interviews revealed that instead of the age of athletes' directly affecting the cognitive process of coaches it was in fact the coaches underlying beliefs about coaching, their previous experiences and perceived pressures from the context that determined the behaviours performed.</p

    Vacuum-assisted decellularization: an accelerated protocol to generate tissue-engineered human tracheal scaffolds

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    Patients with large tracheal lesions unsuitable for conventional endoscopic or open operations may require a tracheal replacement but there is no present consensus of how this may be achieved. Tissue engineering using decellularized or synthetic tracheal scaffolds offers a new avenue for airway reconstruction. Decellularized human donor tracheal scaffolds have been applied in compassionate-use clinical cases but naturally derived extracellular matrix (ECM) scaffolds demand lengthy preparation times. Here, we compare a clinically applied detergent-enzymatic method (DEM) with an accelerated vacuum-assisted decellularization (VAD) protocol. We examined the histological appearance, DNA content and extracellular matrix composition of human donor tracheae decellularized using these techniques. Further, we performed scanning electron microscopy (SEM) and biomechanical testing to analyze decellularization performance. To assess the biocompatibility of scaffolds generated using VAD, we seeded scaffolds with primary human airway epithelial cells in vitro and performed in vivo chick chorioallantoic membrane (CAM) and subcutaneous implantation assays. Both DEM and VAD protocols produced well-decellularized tracheal scaffolds with no adverse mechanical effects and scaffolds retained the capacity for in vitro and in vivo cellular integration. We conclude that the substantial reduction in time required to produce scaffolds using VAD compared to DEM (approximately 9 days vs. 3–8 weeks) does not compromise the quality of human tracheal scaffold generated. These findings might inform clinical decellularization techniques as VAD offers accelerated scaffold production and reduces the associated costs
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