Validation of a videogrammetry technique for analysing American football helmet kinematics     

Ann Bailey  James Funk  David Lessley  Chris Sherwood  Jeff Crandall  William Neale 《Sports biomechanics / International Society of Biomechanics in Sports》2020,19(5):678-700

ABSTRACT

Professional American football games are recorded in digital video with multiple cameras, often at high resolution and high frame rates. The purpose of this study was to evaluate the accuracy of a videogrammetry technique to calculate translational and rotational helmet velocity before, during and after a helmet impact. In total, 10 football impacts were staged in a National Football League (NFL) stadium by propelling helmeted 50th percentile male crash test dummies into each other or the ground at speeds and orientations representative of concussive impacts for NFL players. The tests were recorded by experienced sports film crews to obtain video coverage and quality typically available for NFL games. A videogrammetry procedure was used to track the position and rotation of the helmet throughout the relevant time interval of the head impact. Compared with rigidly mounted retroreflective marker three dimensional (3-D) motion tracking that was concurrently collected in the experiments, videogrammetry accurately calculated changes in translational and rotational velocity of the helmet using high frame rate (two cameras at 240 Hz) video (7% and 15% error, respectively). Low frame rate (2 cameras at 60 Hz) video was adequate for calculating pre-impact translational velocity but not for calculating the translational or rotational velocity change of the helmet during impact.  相似文献   

Narrative and Metaphor in Education: Look Both Ways     

Ann Ang 《Pedagogies: An International Journal》2019,14(2):169-172

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Building student-teacher relationships and improving behaviour-management for classroom teachers     

Jordan Yassine  Leigh Ann Tipton-Fisler  Barbara Katic 《Support for Learning》2020,35(3):389-407

Teachers can at times view behavioural intervention procedures as time-consuming. Thus, socially-valid classroom-based interventions are a critical component to behavioural success. This study examined the effects of traditional behavioural interventions with two kindergarten students presenting with challenging behaviours, including aggression, tantrums and noncompliance. Notably, it was found that traditional behavioural procedures were not sufficient to substantially reduce the behaviours alone. Therefore, a relationship-building component was added to target positive student-teacher relationships. Student outcomes resulted in a significant reduction in challenging behaviour as well as teacher-reported behaviours showing a reduction across all measured periods. Ongoing teacher consultation, increased student-teacher relationships (STRs) and use of effective classroom management strategies are necessary for effective models of behaviour support.  相似文献   

The value of intellectual styles     

Ceri Ann Roberts 《Educational Psychology in Practice》2018,34(3)

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Oral History Interview of PCC Founding     

David Reser  Jeanne Drewes  Ann Della Porta 《Cataloging & classification quarterly》2020,58(3-4):239-247

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Professional Cultures and Collaborative Efforts: A Case Study of Technologists and Educators Working for Change     

Ann Locke Davidson  Janet Schofield  Janet Stocks 《The Information Society》2001,17(1):21-32

The need for those working in a variety of settings to interact effectively with technical experts has grown dramatically in recent years as computers have become essential to the performance of an increasing broad range of professional work. This article presents a case of this sort of interprofessional interaction, exploring the process and outcomes of collaboration between technical professionals and educators working to bring Internet access to an urban public school district. Drawing on field note and interview data, the case reported here illustrates how differences in institutional routines and professional values can generate differing agendas, contrasting assumptions, and contrasting expectations concerning project products and outcomes among collaborators from different professional worlds. In the case we describe, these differences affected such central matters as the types and usefulness of technical resources to which users had access as well as users' confidence in the technology. The case also illustrates how aspects of this interprofessional conflict were addressed through an organizational change. The kinds of issues that arose in this project are likely to occur in a variety of professional settings; therefore, examination of this case provides insight into a variety of issues and dynamics that should be considered when embarking upon or analyzing any interprofessional collaborative effort, and particularly one that involves technical professionals.  相似文献   

Government research evaluations and academic freedom: a UK and Australian comparison     

Ann Martin-Sardesai  Helen Irvine  Stuart Tooley  James Guthrie 《高等教育研究与发展》2017,36(2):372-385

Performance management systems have been an inevitable consequence of the development of government research evaluations (GREs) of university research, and have also inevitably affected the working life of academics. The aim of this paper is to track the development of GREs over the past 25 years, by critically evaluating their adoption in the UK and Australian higher education sector and their contribution to the commodification of academic labour, and to highlight the resultant tensions between GREs and academic freedom. The paper employs a literature-based analysis, relying on publicly available policy documents and academic studies over the period 1985–2010. GREs are a global phenomenon emanating from new public management reforms and while assessments of university research have been welcomed, they have attracted critique based on their design, the manner in which they have been applied, and the unintended consequences of their implementation on academic freedom in particular. Consistent with international research on the impact of GREs, Australian research assessments appear to be undoing the academic freedom that is central to successful research. Further empirical research on the impact of GREs on academics is urgently needed.  相似文献   

Are You My Grandmother?: Constructing and Maintaining Stepgrandparent Identity and Roles     

Becky L. DeGreeff  Ann Burnett 《Communication quarterly》2017,65(5):603-623

The disruption of the biological family unit due to divorce or separation followed by remarriage or re-partnering has a profound impact on every family member, including extended family members. An individual becomes a stepgrandparent through later life re-partnering, when an adult child becomes a stepparent, or when a stepchild becomes a parent. In order to gain a greater understanding of the communication influencing the development and maintenance of stepgrandparent roles and identity, a qualitative interpretive analysis method was employed as a guide for interviews with 41 adult stepfamily members across two generations of stepfamily membership: stepparents and stepgrandparents.  相似文献   

Evaluating the potential of teacher-designed technology-based tasks for meaningful learning: Identifying needs for professional development     

Ann George  Martie Sanders 《Education and Information Technologies》2017,22(6):2871-2895

With technology increasingly being introduced into classrooms worldwide, stakeholders are asking whether ICT provides educational value. It is not simply having access to technology but how teachers use it that will determine its worth to education. Thirty-three teacher-designed technology-based tasks from eight subject areas were analysed for their effective use of ICT, and their potential to involve students in constructivist learning. Few of the tasks made effective use of ICT for meaningful learning, for reasons associated with teachers’ beliefs, attitudes, and missing TPACK components or competencies. These factors provide the basis for a model of areas to target when structuring professional development courses to help teachers better utilize educational ICT to design meaningful learning tasks.  相似文献   

Apprenticeship for ‘Liquid Life’: Learning in Contingent Work Conditions for Contingent Employment     

David Guile  Ann Lahiff 《Vocations and Learning》2017,10(2):157-175

Taking the distinction between the Institution of Apprenticeship, that is, the social partnership arrangements which underpin its organisation, and Apprenticeship as a Social Model of Learning, in other words, he configuration of pedagogic and occupational etc. dimensions which constitute the model, as its starting point the paper: (i) argues the emergence of de-centred, distributed and discontinuous conditions associated with project-work present challenges for extant ideas about apprenticeship as a social model of learning; (ii) explores this claim in relation to Fuller and Unwin’s four inter-connected dimensions of apprenticeship as a social model of learning by considering a case study of apprenticeship designed to prepare apprentices to work in the above conditions; (iii) relates issues arising from the case study to research on project work from the fields of Organisational and Cultural Studies; and (iv) based on this evidence base introduces a typology of ‘Apprenticeship for Liquid Life’.  相似文献