Validation of a model and a simulator for road cycling on real tracks

In this study, methods for data acquisition, analysis, modelling, and simulation of performance parameters in road cycling on real tracks were developed and evaluated. A simulator was designed to facilitate the measurement in a laboratory environment. The simulation included real height profiles and a video playback that was synchronised with the cyclist’s current virtual position on the track, and online visualisation of course and performance parameters. Field data obtained on mountain tracks in this study were compared with the state-of-the-art mathematical model for road cycling power, established by Martin et al. (J Appl Biomech 14: 276–291, 1998), which accounts for the gradient force, air resistance, rolling resistance, frictional losses in wheel bearings and inertia. The model described the performance parameters accurately with correlation coefficients of 0.96–0.99 and signal-to-noise ratios of 19.7–23.9 dB. It was shown that the mathematical model could be implemented on an ergometer for simulating rides on real courses, providing similar quality measures when comparing field and simulator measurements.     

Examining Differences in Achievement of Physical Activity Best Practices Between Urban and Rural Child Care Facilities by Age

Early Childhood Education Journal - Go Nutrition and Physical activity Self Assessment in Child Care (NAP SACC) is an evidence based intervention developed to positively impact childhood obesity in...     

On metaphors in thinking about preparing mathematics for teaching

Educational Studies in Mathematics - This paper explores how different schools of thought in mathematics education think and speak about preparing mathematics for teaching by introducing and...     

Organizing for radical innovation — A multi-level behavioral approach

Based on Self-Determination-Theory, Group-Effectiveness-Theory, and Cognitive-Network Theory a multi-level model is developed that explains two research questions. First, how can management motivate individuals to generate novel ideas? Second, how should management organize groups in order to facilitate creativity and implement radical innovations? From Self-Determination-Theory, propositions for the design of a reward system are derived. Arguments from Group-Effectiveness-Theory lead to the conclusion that permanent work groups with low social cohesion should emphasize idea generation, while cross-functional project teams with high social cohesion are best suited for radical innovation implementation. Effective group behavior modes for each kind of group and management practices for producing these modes are described based on Cognitive-Network-Theory. Implications of the model with regard to innovation management in different cultural settings and to group composition are discussed.     

Dynamics of the support leg in soccer instep kicking

Abstract

We aimed to illustrate support leg dynamics during instep kicking to evaluate the role of the support leg action in performance. Twelve male soccer players performed maximal instep kicks. Their motions and ground reaction forces were recorded by a motion capture system and a force platform. Moments and angular velocities of the support leg and pelvis were computed using inverse dynamics. In most joints of the support leg, the moments were not associated with or counteracting the joint motions except for the knee joint. It can be interpreted that the initial knee flexion motion counteracting the extension joint moment has a role to attenuate the shock of landing and the following knee extension motion associated with the extension joint moment indirectly contributes to accelerate the swing of kicking leg. Also, appreciable horizontal rotation of the pelvis coincided with increase of the interaction moment due to the hip joint reaction force on the support leg side. It can be assumed that the interaction moment was the main factor causing the pelvis counter-clockwise rotation within the horizontal plane from the overhead view that precedes a proximal-to-distal sequence of segmental action of the swing leg.     

Interactive and non-interactive pictures in multimedia learning environments: Effects on learning outcomes and learning efficiency

New technologies enable flexible combinations of text and interactive or non-interactive pictures. The aim of the present study was to investigate (a) whether adding pictures to texts is generally beneficial for learning or whether it can also have detrimental effects, (b) how interactivity of pictures affects learning, (c) whether the visualization format of pictures affects the structure of the learner's mental model, and (d) whether the visualization format modifies the effects of interactivity. One hundred university students were randomly assigned to five groups. In four groups, a text about the different daytimes and days on the earth was combined with interactive or non-interactive pictures of different visualization formats. In the fifth group, the text was presented without pictures. According to the results, adding pictures to text was neither beneficial nor harmful for learning. In terms of learning efficiency, however, learning from text only was more successful than learning from text and pictures. Interactivity was beneficial for one learning task, but not for the other task. The visualization format affected participants’ interaction with pictures, but not the learning outcomes; however this effect was not influenced by interactivity. Implications for multimedia design and for further research are pointed out.     

Bildung Ja — Arbeit Nein Unterbeschäftigung und Arbeitslosigkeit Weiblicher Jugendlicher

Ohne Zusammenfassung     

The influence of task and gender on search and evaluation behavior using Google

To improve search engine effectiveness, we have observed an increased interest in gathering additional feedback about users’ information needs that goes beyond the queries they type in. Adaptive search engines use explicit and implicit feedback indicators to model users or search tasks. In order to create appropriate models, it is essential to understand how users interact with search engines, including the determining factors of their actions. Using eye tracking, we extend this understanding by analyzing the sequences and patterns with which users evaluate query result returned to them when using Google. We find that the query result abstracts are viewed in the order of their ranking in only about one fifth of the cases, and only an average of about three abstracts per result page are viewed at all. We also compare search behavior variability with respect to different classes of users and different classes of search tasks to reveal whether user models or task models may be greater predictors of behavior. We discover that gender and task significantly influence different kinds of search behaviors discussed here. The results are suggestive of improvements to query-based search interface designs with respect to both their use of space and workflow.     

Gerechtigkeit und Studienabbruch. Die Rolle der wahrgenommenen Fairness von Benotungsverfahren bei der Entstehung von Abbruchsintentionen

This article investigates the relationship between grading fairness and university students’ dropout intentions. Our focus is on the extent to which students assess the grading procedures as fair from a procedural justice perspective. We distinguish between control-related and validity-related aspects of procedural justice. The fairness of grading procedures is incorporated into a rational choice model on educational decision-making. We theorize that students consider questions of procedural justice in determining their chances of success. Thus, unfair grading practices lead to an increased risk of the students developing dropout intentions. Further, we investigate the relationship between students’ socioeconomic characteristics and procedural justice. Data from the first wave of the CampusPanel are used (n = 1393). Results show that dropout intentions are significantly affected by evaluations of procedural justice. Further, there is evidence that students with low parental socioeconomic status as well as students with an immigrant background are especially prone to exhibit dropout intentions when confronted with low procedural justice.     

Assessing tackle performance using a novel collision sport simulator in comparison to a “live” one-on-one tackling drill

It is necessary to study the rugby tackle as it is associated with successful performance outcomes and is responsible for the majority of contact injuries. A novel collision sport simulator was developed to study tackle performance. The main aim of this validation study was to assess tackle technique performance between two different conditions: simulator versus a standardised one-on-one tackle drill previously used to assess technique. Tackling proficiency was assessed using a list of technical criteria. Mean scores, standard deviations and Cohen’s d effect sizes were calculated. Mean overall score for dynamic i.e. running simulator tackles was 7.78 (95%CI 7.58–7.99) (out of 9) or 87% (standard deviation or SD±8.94), and mean overall score for dynamic “live” tackles was 7.85 (95%CI 7.57–8.13) (out of 9) or 87% (SD±9.60) (effect size = 0.08; trivial; p > 0.05). Mean overall score for static i.e. standing simulator tackles was 7.45 (95%CI 7.20–7.69) (out of 9) or 83% (SD±10.71), and mean overall score for static “live” tackles was 8.05 (95%CI 7.83–8.27) (out of 9) or 89% (SD±7.53) (effect size = 0.72; moderate; p < 0.001). The simulator replicates dynamic tackle technique comparable to real-life tackle drills. It may be used for research analysing various aspects of the tackle in rugby and other contact sports.