Predicting ground reaction forces in running using micro-sensors and neural networks

Measurement of ground reaction force (GRF) in running provides a direct indication of the loads to which the body is subjected at each foot-ground contact, and can provide an objective explanation for performance outcomes. Traditionally, the collection of three orthogonal component GRF data in running requires an athlete to complete a series of return loops along a laboratory based runway, within which a force platform is embedded, in order to collect data from a discrete footfall. The major disadvantages associated with this GRF data collection methodology include the inability to assess multiple consecutive foot contacts and the fact that measurements are typically confined to the laboratory. The objective of this research was to investigate the potential for wearable instrumentation to be employed, in conjunction with artificial neural network (ANN) and multiple linear regression (MLR) models, for the estimation of GRF in middle distance running. A modular wearable data acquisition system was developed to acquire in-shoe force (ISF) data. Matched data sets from wearable instrumentation (source data) and force plate (target data) records were collected from elite middle-distance runners under controlled laboratory conditions for the purposes of ANN and MLR model development (MD) and model validation (MV). In terms of statistical measures of prediction accuracy the MLR model was found to provide a superior level of accuracy for the prediction of the vertical and medio-lateral components of GRF and alternatively, the ANN model provided the most accurate predictions of the anterior-posterior component of GRF. The prediction accuracy of each component of GRF was found to be governed by the inherent signal variability, in which case the vertical and anterior-posterior components were more reliable and subsequently predicted significantly more accurately than the medio-lateral component. The emerging capability for obtaining continuous GRF records from wearable instrumentation has the potential to permit unprecedented quantification of training stress and competition demands in running.     

体育教育实习成绩评估方案的研究

目前关于体育教学实习成绩的评定，各院校做法不一，还没有定论。但就目前各校的评估量表看，普遍较复杂，计算量大，指标多，内容不具体，因而不适用。而且对体育教学大都只重视一次公开课或检查课，对平时课堂教学不大重视。因此，制定出客观、全面、简便易行的评估指标体系就具有很重要的意义。     

A survey on the use of electronic databases and electronic journals accessed through the web by the academic staff of Israeli universities

The results of an extensive survey of the senior academic staff of the Israeli universities on their use of electronic journals and databases are presented. The major findings are that the use of electronic sources is already widespread among the respondents and more than 50% found the electronic services indispensable. Disparities were found between the usage patterns in the different disciplines.     

Effects of experimenting with physical and virtual manipulatives on students' conceptual understanding in heat and temperature

This study aimed to investigate the comparative value of experimenting with physical manipulatives (PM) in a sequential combination with virtual manipulatives (VM), with the use of PM preceding the use of VM, and of experimenting with PM alone, with respect to changes in students' conceptual understanding in the domain of heat and temperature. A pre–post‐comparison study design was used which involved 62 undergraduate students that attended an introductory course in physics. The participants were randomly assigned to one experimental and one control group. Both groups used the same inquiry‐oriented curriculum materials. Participants in the control group used PM to conduct the experiments, whereas, participants in the experimental group used first PM and then VM. VM differed from PM in that it could provide the possibility of faster manipulation, whereas, it retained any other features and interactions of the study's subject domain identical to the PM condition. Conceptual tests were administered to assess students' understanding before, during, and after the study's treatments. Results indicated that experimenting with the combination of PM and VM enhanced students' conceptual understanding more than experimenting with PM alone. The use of VM was identified as the cause of this differentiation. © 2008 Wiley Periodicals, Inc. J Res Sci Teach 45: 1021–1035, 2008     

“I May Be Crackin’, But Um Fackin’”: Racial Humor in The Watsons Go To Birmingham—1963

This article examines the utilization of racial humor in Christopher Paul Curtis’ novel, The Watsons Go To Birmingham—1963. The theoretical perspectives that inform the analysis include critical race theory and humor theory. The results of the analysis reveal that the use of humor in this book is influenced to a significant degree by race and racism.     

The effect of illustrations in arithmetic problem-solving: Effects of increased cognitive load

Arithmetic word problems are often presented accompanied by illustrations. The present study examined how different types of illustrations influence the speed and accuracy of performance of both good (n = 67) and poor arithmeticians (n = 63). Twenty-four arithmetic word problems were presented with four types of illustrations with increasing information value. The results show that illustrations can have a detrimental effect on performance on arithmetic word problems, produced by irrelevant, redundant or interacting sources of information. Principles from cognitive load theory are used to explain the results, in particular in relation to (poor) working memory ability.