On a kayak ergometer, an accurate simulation of the athlete-paddle-kayak system kinematics is essential for analysing the relationship between technique and performance. The purpose of this study
was to establish a strong relationship between performances on flatwater and performances on an ergometer by means of propulsive
force measurement and drag models. Two trials were performed by 12 kayakers in which they were first timed over 250 m of flatwater
kayaking (the reference test) and were then asked to perform a trial of the same duration on the ergometer with the same perceived
physical exertion. Three techniques for measuring propulsive force and three drag models generated nine combinations, which
were all evaluated for their ability to estimate kayak velocity. For each combination, the distance covered by the athlete
on the ergometer was simulated. A kayakers’ ergometer ranking was based on the average velocity in the ergometer trial. Both
distance and ranking were compared to the on-water results. The simulation with the best combination of force measurement
and drag model gave an accurate estimate of distance (253 ± 10.5 vs. 250 m) and ranking compared to the reference test. 相似文献
Purpose: This study discusses the process of co-constructing a prototype pedagogical model for working with youth from socially vulnerable backgrounds.
Participants and settings: This six-month activist research project was conducted in a soccer program in a socially vulnerable area of Brazil in 2013. The study included 17 youths, 4 coaches, a pedagogic coordinator and a social worker. An expert in student-centered pedagogy and inquiry-based activism assisted as a debriefer helping in the progressive data analysis and the planning of the work sessions.
Data collection/analysis: Multiple sources of data were collected, including 38 field journal/observation and audio records of: 18 youth work sessions, 16 coaches’ work sessions, 3 combined coaches and youth work sessions, and 37 meetings between the researcher and the expert.
Findings: The process of co-construction of this prototype pedagogical model was divided into three phases. The first phase involved the youth and coaches identifying barriers to sport opportunities in their community. In the second phase, the youth, coaches and researchers imagined alternative possibilities to the barriers identified. In the final phase, we worked collaboratively to create realistic opportunities for the youth to begin to negotiate some of the barriers they identified. In this phase, the coaches and youth designed an action plan to implement (involving a Leadership Program) aimed at addressing the youths’ needs in the sport program. Five critical elements of a prototype pedagogical model were co-created through the first two processes and four learning aspirations emerged in the last phase of the project.
Implications: We suggest an activist approach of co-creating a pedagogical model of sport for working with youth from socially vulnerable backgrounds is beneficial. That is, creating opportunities for youth to learn to name, critique and negotiate barriers to their engagement in sport in order to create empowering possibilities. 相似文献
Information Retrieval systems typically sort the result with respect to document retrieval status values (RSV). According to the Probability Ranking Principle, this ranking ensures optimum retrieval quality if the RSVs are monotonously increasing with the probabilities of relevance (as e.g. for probabilistic IR models). However, advanced applications like filtering or distributed retrieval require estimates of the actual probability of relevance. The relationship between the RSV of a document and its probability of relevance can be described by a normalisation function which maps the retrieval status value onto the probability of relevance (mapping functions). In this paper, we explore the use of linear and logistic mapping functions for different retrieval methods. In a series of upper-bound experiments, we compare the approximation quality of the different mapping functions. We also investigate the effect on the resulting retrieval quality in distributed retrieval (only merging, without resource selection). These experiments show that good estimates of the actual probability of relevance can be achieved, and that the logistic model outperforms the linear one. Retrieval quality for distributed retrieval is only slightly improved by using the logistic function. 相似文献
Abstract Attitude models have been widely applied to natural resource management to ensure responsible environmental behavior. For a variety of applications, the causality among selected antecedents, such as knowledge of environmental issues, locus of control, attitude, personal responsibility, and intention to act on responsible environmental behavior has not yet been tested empirically. A hypothesized causal model based on Hine's (1986) model on responsible environmental behavior was developed. The data from 523 visitors to the urban forest trail in the Kwang-Reung Arboretum, Korea, during September 1995 were used for testing the suggested causal model. Path analysis using the LISREL program tested the model fit and statistical effects of variables. In terms of the effects on intention to act, locus of control and attitude are more important than knowledge and personal responsibility. Our findings suggest that in order to enhance responsible environmental behavior, environmental education and interpretation systems need to focus on changing the internal locus of control. Several recommendations, limitations, and directions for future research are discussed. 相似文献
