Field and laboratory measurements of softball player swing speed and bat performance

The swing speed of the bat is one of the most important factors affecting the hit-ball speed. Most field studies tend to focus on measuring ball speed, which is easier to measure and quantify than bat speed. For this reason, relatively little data exist describing bat motion in field conditions. The following describes a relatively large swing speed field study involving bats of the same model with nearly constant weight and varying inertia. The study was conducted using right-handed batters on a regulation outdoor field with a live pitcher. Swing speed was measured by tracking markers on the bat with two high-speed video cameras so that the bat markers could be traced in three-dimensional space. The ball motion was tracked using the same high-speed video cameras and a three-dimensional Doppler radar system. Bat swing speed was observed to be proportional to the batter skill level and the normalised swing speed increased with decreasing bat inertia. The bat centre of rotation during impact was close to the knob of the bat. The bats were tested under controlled laboratory conditions using a standardised performance test. The field and laboratory results showed good agreement including the hit-ball speed and the subtle effect of bat inertia on the maximum performance location. The vibrational response of the bats was considered using modal analysis. The maximum performance location was correlated with the node of the first vibrational mode.     

Supplemental Reading Instruction for Students at Risk for Reading Disabilities: Improve Reading 30 Minutes at a Time

Supplemental reading instruction provides a way to improve the reading outcomes of students at risk for reading difficulties and to meet the challenges produced by increases in student diversity in today’s classrooms. The research–based intervention described in this article includes intensive, explicit, and systematic reading instruction in five areas: fluency, phonemic awareness, instructional–level reading with an emphasis on comprehension, word analysis, and spelling. This intervention was effective in improving the reading skills of low SES, second–grade English monolingual and English–language learners.     

Student & tutor consensus: a partnership in assessment for learning

The mistakes made when attempting tasks often prove to be some of the most invaluable learning experiences. Despite this, outcome and results driven assessment formats largely penalise student performance errors or reward students who succeed by chance. The consequences of this paradigm are visible effects on student relationships with assessment. The student–tutor consensus approach to assessment was introduced to capture student learning achieved ‘from’ assessment to complement the measurement of performance outcomes. This approach parallels student and tutor judgement in a grade negotiation, affording the student an opportunity to share with their assessor what they have learned from the assessment activity. This student self-awareness was then considered alongside the conventional outcome-based score awarded by the tutor to generate a final grade for the assessed activity. Our study evaluated the perceptions of 90 undergraduate students enrolled in the bachelor of paramedic studies, who participated in this novel assessment approach as part of a final-year capstone topic. The results comprehensively indicated value for all aspects of the assessment approach, as well as a recognition that the skills will be useful in their future professional roles.     

Trainee teachers in unpaid teaching posts: volunteering,risk and vulnerability

This paper explores the experiences and perceptions of a little-known category of in-service trainee teachers in the Further Education (FE) and Skills sector in England: those who meet the practical teaching requirements of their course mainly through unpaid teaching as ‘volunteers’. The paper reports findings from mixed-methods research which used surveys, interviews and focus groups involving trainee teachers within a large FE–HE partnership. Themes relating to motivations to volunteer, the development of teacher identity within marginal roles, and the risks associated with unpaid teaching are discussed. For increasing numbers of trainees, unpaid teaching provides an opportunity for career entry. However, the quality of teaching experience gained is mixed, with some trainees receiving high levels of support, whilst others experience marginalisation and limitations on their developing teacher identities. The paper highlights the specific challenges to professionalism posed by unpaid teaching within the FE and Skills sector, and relates these challenges to a broader context of insecurity and risk. As work experience becomes an increasingly valuable commodity, this paper illustrates the pressures individuals face as they exchange payment and security for the opportunities volunteering provides.     

The UK National Arts Education Archive: Ideas and Imaginings

The National Arts Education Archive (NAEA) is housed and maintained by the Yorkshire Sculpture Park (YSP), and managed by YSP coordinators and educators with a well‐established volunteer programme. This year, 2017, as part of the celebrations of the YSP's 40th anniversary, the Archive will hold its own exhibition entitled Treasures Revealed: a collection of items selected by people who have been involved in the Archive, whether as donors, volunteers, researchers, artists, trustees or steering group members. In parallel with the exhibition, this article aims to give voice to a selection of individuals and groups associated with the Archive, discussing their interests and experiences of it, and their thoughts on its value and importance as a repository of arts education materials, ideals and practices. Our primary motivations were to consider these different voices in relation to the purpose, direction and relevance of the NAEA today. These exchanges raise fundamental questions and debates about what art education is and what it might become, and how these historical collections, and creative engagements with it, might help to shape our contemporary thinking.     

感光度详解

与光圈和快门一样，感光度也是曝光控制系统的一个重要方面。因此，我们将在这里对它作一次全面，深入的讲解。     

LOVE AND RUIN(S): ROBERT FROST ON MORAL REPAIR

This essay begins where Alasdair MacIntyre's After Virtue begins: facing a moral world in ruin. MacIntyre argues that this predicament leaves us with a choice: we can follow the path of Friedrich Nietzsche, accepting this moral destruction and attempting to create lives in a rootless, uncertain world, or the path of Aristotle, working to reclaim a world in which close‐knit communities sustain human practices that make it possible for us to flourish. Jeff Frank rejects MacIntyre's framework and in this essay attempts to create an alternative path, one of moral repair. Through a close reading of several poems from Robert Frost's North of Boston, Frank develops the notion of moral repair and describes its ethical and educational implications.