Automated impact device with non-synchronous impacts: a practical solution for modal testing during operation

Previous study has shown that synchronization of phases between impacts and the cyclic load component should be avoided to improve the effectiveness of operational modal testing, i.e. impact-synchronous modal analysis in obtaining a cleaner frequency response function (FRF) estimation with fewer number of averages. However, avoiding the phase synchronization effect is rarely achievable with the current manual impact hammer because of the lack of control of the impact timing. We investigate how to improve FRF estimation in the presence of harmonic disturbances, such as those present in operating rotating machines. An auto impact device is therefore introduced to replace the manual impact hammer. This device ensures that impact intervals can be applied at non-synchronous instances with respect to the harmonic disturbance. We demonstrate that this new device is a viable option for operational modal testing. It allows significant improvement in FRF estimation and shows good correlation of modal extraction data with benchmark experimental modal analysis results.     

Young,talented and injured: Injury perceptions,experiences and consequences in adolescent elite athletes

Even though injury is common in elite sports, there is still a lack of knowledge of young athletes’ injury perception both during and after injury. The aim of this mixed-method study was, therefore, to explore, in-depth, data on injury consequences and adolescent elite athletes’ perceptions and experience of injury. Three hundred and forty adolescent elite athletes (age range 15–19), from 16 different sports, were bi-weekly monitored over 52 weeks using a valid questionnaire. Twenty athletes from the same cohort were interviewed in focus groups about injury experience and perceptions. The results show that the average bi-weekly prevalence of injury was 38.7% (95% CI 37.3–40.1), with 30.0% (n?=?102) of the athletes injured for more than half of all reporting times. An overarching theme from the focus groups highlighted the risk among young athletes of a loss of identity while injured. The findings support several suggestions that may improve the rehabilitation process and enhance rehabilitation outcomes: (a) provide clear pathways to the medical team, (b) recognize the identity loss, (c) involve the injured athletes with the rest of the teammates and (d) educate athletes about how to interpret pain signals. Future research should explore and evaluate the effectiveness and generalization of such interventions.     

Effects of wearing lower leg compression sleeves on locomotion economy

The purpose of this investigation was to assess the effect of compression sleeves on muscle activation cost during locomotion. Twenty-two recreationally active men (age: 25 ± 3 years) ran on a treadmill at four different speeds (ordered sequence of 2.8, 3.3, 2.2, and 3.9 m/s). The tests were performed without (control situation, CON) and while wearing specially designed lower leg compression sleeves (SL). Myoelectric activity of five lower leg muscles (tibialis anterior, fibularis longus, lateral and medial head of gastrocnemius, and soleus) was captured using Surface EMG. To assess muscle activation cost, the cumulative muscle activity per distance travelled (CMAPD) of the CON and SL situations was determined. Repeated measures analyses of variance were performed separately for each muscle. The analyses revealed a reduced lower leg muscle activation cost with respect to test situation for SL for all muscles (p < 0.05, η_p² > 0.18). The respective significant reductions of CMAPD values during SL ranged between 4% and 16% and were largest at 2.8 m/s. The findings presented point towards an improved muscle activation cost while wearing lower leg compression sleeves during locomotion that have potential to postpone muscle fatigue.     

Culture,indigenous knowledge systems and sustainable development: A critical view of education in an African context

The article’s focus is the relationship between culture, indigenous knowledge systems (IKS), sustainable development and education in Africa. It analyzes the concept of sustainability with particular reference to education and indigenous knowledge systems. In particular the article analyzes the documents from the World Summit in Johannesburg in 2002 as well as from the United Nations Decade of Education for Sustainable Development. Moreover, the article discusses South Africa’s Curriculum 2005 (C 2005) launched by the African National Congress (ANC) by focusing on the dilemmas of exclusively introducing Western-based scientific knowledge in a cultural context based on indigenous epistemology. The article concludes by calling for more research into the viability of indigenous knowledge systems as a potential tool in sustainable development.     

Outreach initiatives operated by universities for increasing interest in science and technology

ABSTRACT

Since the 1990s, the low number of students choosing to study science and technology in higher education has been on the societal agenda and many initiatives have been launched to promote awareness regarding career options. The initiatives particularly focus on increasing enrolment in the engineering programmes. This article describes and compares eight European initiatives that have been established and operated by universities (and in some cases through collaboration with other actors in society). Each initiative is summarised in a short essay that discusses motivation, organisation, pedagogical approach, and activities. The initiatives are characterised by comparing the driving forces behind their creation, how the initiative activities relate to the activities at the university, size based on the number of participants and cost per participant and pedagogical framework. There seem to be two main tracks for building outreach activities, one where outreach activities are based on the university's normal activities, and one where outreach activities are designed specifically for the visiting students.     

The use of scoring rubrics: Reliability, validity and educational consequences

Several benefits of using scoring rubrics in performance assessments have been proposed, such as increased consistency of scoring, the possibility to facilitate valid judgment of complex competencies, and promotion of learning. This paper investigates whether evidence for these claims can be found in the research literature. Several databases were searched for empirical research on rubrics, resulting in a total of 75 studies relevant for this review. Conclusions are that: (1) the reliable scoring of performance assessments can be enhanced by the use of rubrics, especially if they are analytic, topic-specific, and complemented with exemplars and/or rater training; (2) rubrics do not facilitate valid judgment of performance assessments per se. However, valid assessment could be facilitated by using a more comprehensive framework of validity when validating the rubric; (3) rubrics seem to have the potential of promoting learning and/or improve instruction. The main reason for this potential lies in the fact that rubrics make expectations and criteria explicit, which also facilitates feedback and self-assessment.     

Authenticity work in higher education learning environments: a double-edged sword?

Higher Education - Educational authenticity occupies a strong position in higher education research and reform, building on the assumption that correspondence between higher education learning...     

Decomposing Cross-Country Differences in Skills: Evidence from Four Nordic Countries

This paper performs multivariate analysis of skill differences in four Nordic countries as assessed by the Organisation for Economic Co-operation and Development’s Programme for the International Assessment of Adult Competencies survey of adults aged 16–65. The differences in average skills between Finland and each of the three Scandinavian countries are decomposed into a component that is due to different skill levels in subgroups of the population and a component that is due to differences in the composition of subgroups. The decompositions show that the high Finnish average skill level compared to the three Scandinavian countries can be attributed to the low share of immigrants in Finland and to high scores among Finns with high school and less than high school education. The Finnish average score is pulled substantially downwards as a consequence of the low numeracy skill level among older Finns, which is consistent with an increase in the quantity or quality of Finnish education over time, relative to the other three Nordic countries.     

Undergraduate students’ actorship in studying an educational sciences course in a Swedish context

The study aimed to investigate how students in an introductory educational sciences course experienced and understood their own actorship during the course, in relation to conditions for learning created by the teachers. The analyses were based on students’ answers to an evaluation questionnaire that produced both quantitative and qualitative data. Those students who experienced opportunities to influence the course activities also stated that they had contributed to the development of the course to a greater extent than did those who experienced no such opportunities. There was no correlation between not feeling informed about the conditions for the course and seeking complementary information. The analysis also generated five different categories based on how the students viewed their own actorship, varying from ‘no actorship since it is not meaningful’ to ‘Real actorship exists’. The results are discussed in relation to methodological reflections and as implications for increasing students’ actorship.     

“Whatever Happened to the Social Dimension?” Aspects of Learning in a Distance-based Teacher Training Programme

In this article we discuss distance-based teacher trainees' understandings of learning and education in a computerised learning environment. Educational research today often stresses the importance of a social dimension in learning and education and computerised learning environments are said to create and fulfil the social dimension in on-campus education as well as in distance education. This social dimension of learning and education is investigated, in a Swedish distance-based teacher training programme supported by ICT, through semi-structured interviews with 19 teacher trainees. The study shows that there is a complex relationship between the use of the computerised learning environment and the physical meetings in the programme. One conclusion is that, even though theories emphasise the social dimension of learning through participation, teacher trainees view participation with others as important primarily in relation to social aspects of well-being and not in relation to learning. The use of ICT for creating a community of learners through participation seems to individualise the students' learning rather than bringing them together in their learning.