Automatic measurement of key ski jumping phases and temporal events with a wearable system   总被引：1，自引：0，他引：1  

Chardonnens J  Favre J  Le Callennec B  Cuendet F  Gremion G  Aminian K 《Journal of sports sciences》2012,30(1):53-61

We propose a new method, based on inertial sensors, to automatically measure at high frequency the durations of the main phases of ski jumping (i.e. take-off release, take-off, and early flight). The kinematics of the ski jumping movement were recorded by four inertial sensors, attached to the thigh and shank of junior athletes, for 40 jumps performed during indoor conditions and 36 jumps in field conditions. An algorithm was designed to detect temporal events from the recorded signals and to estimate the duration of each phase. These durations were evaluated against a reference camera-based motion capture system and by trainers conducting video observations. The precision for the take-off release and take-off durations (indoor < 39 ms, outdoor = 27 ms) can be considered technically valid for performance assessment. The errors for early flight duration (indoor = 22 ms, outdoor = 119 ms) were comparable to the trainers' variability and should be interpreted with caution. No significant changes in the error were noted between indoor and outdoor conditions, and individual jumping technique did not influence the error of take-off release and take-off. Therefore, the proposed system can provide valuable information for performance evaluation of ski jumpers during training sessions.  相似文献   

Using Preservice Teachers to Improve Computer Skills of At-Risk Alternative High School Students     

Martin J. Ward  Donald Kester  Kamiar Kouzekanani 《Journal of Education for Students Placed at Risk》2013,18(2):189-200

This research examined the impact of preservice teachers delivering individualized instruction of basic computer skills to at-risk, ethnic minority alternative high school students in an urban school district in South Texas. The alternative high school students' achievement of computer skills, motivation to use computers, and self-efficacy as current and future students was assessed. University preservice teachers taught a keyboard/computer skills curriculum developed specifically for this collaborative teaching and learning project in 10 1-hr-long sessions 2 times a week over a 5-week period. A series of 2 by 2 repeated measures analysis of variance showed achievement gains as measured by a survey instrument within the treatment group. This small, preliminary study supports the use of preservice teachers in the delivery of an individualized, computer-based program of instruction for at-risk students.  相似文献   

The mutual impact of personality traits on seating preference and educational achievement     

Camellia Hemyari  Kamiar Zomorodian  Iman Ahrari  Samar Tavana  Mohammad Parva  Keyvan Pakshir  Peyman Jafari  Ali Sahraian 《European Journal of Psychology of Education - EJPE》2013,28(3):863-877

Several studies have investigated the association between students' seating positions and their classroom performance. However, the role of personality traits on seating preference in the classroom has not been well investigated. The aim of the study was to understand how students choose their seats according to their personality traits in a classroom context and the influence of personality characteristics and seat selection on educational achievement. The seating positions of the medical students were recorded on an architectural plan during each class session, and the means and standard deviations of the students' locations were calculated in X and Y orientations. The locations of the students in the class were analyzed based on three architectural classifications: interactional zone, distance from the board, and access to the aisles. The NEO Five-Factor Inventory was used to evaluate the five main personality characteristics of the students. Midterm and final exam scores were used to measure the students' educational achievement. Analysis of variance showed a statistical significance correlation between the interactional zones and both agreeableness and conscientiousness. Mantel–Haenszel analysis showed a statistical significance association between sex and agreeableness and openness to experiences, which was mainly caused by zone II. Among the tested characteristics, a statistically significant relationship was observed between agreeableness and final exam scores. There was a statistical significance difference in openness and extraversion between the students with a high number of absences and their classmates. A relationship between the student's locations in the class, their educational achievements, and some of their personality characteristics are addressed.  相似文献