排序方式： 共有52条查询结果，搜索用时 31 毫秒
31.
Christian Fischer Leila S. Overney Mathieu Fauve Olaf Blanke Hansueli Rhyner Michael H. Herzog 《Journal of sports sciences》2013,31(14):1567-1576
Abstract Flexural and torsional rigidity are important properties of skis. However, the flexural and torsional rigidity that lead to optimal performance remain to be established. In the present study, four pairs of slalom skis that differed in flexural and torsional rigidity were tested by advanced and expert skiers. Using a 10-item questionnaire, different aspects of the skis' performance were rated on a 9-point scale. For each pair of skis, physical measurements were compared with the ratings of the two groups of skiers. Correlations (Spearman) were then determined between (i) different mechanical properties of the skis (static and dynamic), (ii) subjective assessments of the participants, and (iii) properties of the skis and the participants' assessments. The latter showed that expert skiers rate the aspects of the skis more accurately than advanced skiers. Most importantly, expert skiers are particularly sensitive to torsion of the skis. These results suggest that such highly rated elements should be addressed in future ski designs. 相似文献
32.
Mathieu Cynober Yukio Saito Nicolas Chaillet 《Journal of The Franklin Institute》2012,349(7):2313-2322
The objective of this work is the development of an automatic and mobile X-ray robot that is becoming necessary in a changing environment (aging society, growth of the developing countries, etc.). Specifically, there are three sides to such a project. First, there is the mechanical side, i.e. the design and implementation of motors on every mobile part of an X-ray unit allowing it to move around a standing patient. Then, comes the electronic side, i.e. the use of potentiometers and limit switches as feedback combined with microcontrollers. And last, the algorithm that computes three-dimensional models from two-dimensional X-rays. 相似文献
33.
Evelyne Cauzinille-Marmèche Jacques Mathieu Lauren Resnick 《European Journal of Psychology of Education - EJPE》1987,2(1):41-56
This study analyses students integration of new knowledge in the domain of elementary algebra, which is based on arithmetics, but differs from it in a number of ways. Subjects aged between 11 and 16 years were presented with a task which consisted in evaluating equivalence of either numerical or algebraic isomorphic expressions. The results indicate that the context plays an important role in determining the choice of a strategy of comparison. In evaluating algebric expressions, students use formal rules. The observed errors derive from over-generalisation of prototypical rules and their conditions of application. In the case of numerical expressions, the dominant strategies are re-writing procedures: these may or may not be followed by quantitative evaluations of the resulting expressions. Errors are less frequent, but our analyses show that the semantics of the procedures are not always well understood. In sum, students posses a fair amount of knowledge of various kinds, but this knowledge is not well integrated or interrelated. Hence their knowledge base is not very stable and can easily become deformed. 相似文献
34.
Jonas Masdonati Geneviève Fournier Mathieu Pinault Imane Z. Lahrizi 《International Journal for Educational and Vocational Guidance》2016,16(2):189-212
Adopting a mixed method design, this paper explores the configuration and evolution of work values of 64 young adults in transition from education to employment. Qualitative analyses point out the existence of four categories of work values: interesting tasks, good relationships, self-fulfillment, and attractive work conditions. Quantitative analyses show that work values are questioned during the school-to-work transition, refined according to the experience of labor market integration, and partially different according to gender, education type, and the quality of the integration process. Consequently, career counseling should integrate a deeper understanding of what clients consider as important in their work lives. 相似文献
35.
Mathieu Menard Arnaud Decatoire Patrick Lacouture 《Sports biomechanics / International Society of Biomechanics in Sports》2016,15(4):462-472
Besides its regulation by Union Cycliste Internationale, the evidence relating saddle setback to pedalling performance remains inconclusive. This study investigates the influence of saddle setback on pedalling effectiveness through two indexes: an index of pedalling force effectiveness and an index of pedalling work effectiveness. Eleven cyclists were assessed six saddle setback conditions while pedalling at a steady power output of 200 W and cadence of 90 rpm. A force sensor was integrated within the seat post to compute the centre of pressure on the saddle. From instrumented pedals, an index of force effectiveness (ratio between the force directed perpendicular to the crank arm and the total force applied to the pedal) and an index of work effectiveness (based on the minimisation of negative crank work) were calculated. In comparison with a forward position, sitting backward significantly decreased 5% cumulative total work, increased index of work effectiveness (84.2 ± 3.7 vs. 82.0 ± 4.7%), and increased index of force effectiveness (41.7 ± 2.9 vs. 39.9 ± 3.7 and 36.9 ± 0.7%). Thus, while it was previously reported that sitting more forward favours maximal power, this study demonstrates that it also leads to a decreased effectiveness in steady-state pedalling. 相似文献
36.
Juan Antonio Lossio-Ventura Clement Jonquet Mathieu Roche Maguelonne Teisseire 《Information Retrieval》2016,19(1-2):59-99
Terminology extraction is an essential task in domain knowledge acquisition, as well as for information retrieval. It is also a mandatory first step aimed at building/enriching terminologies and ontologies. As often proposed in the literature, existing terminology extraction methods feature linguistic and statistical aspects and solve some problems related (but not completely) to term extraction, e.g. noise, silence, low frequency, large-corpora, complexity of the multi-word term extraction process. In contrast, we propose a cutting edge methodology to extract and to rank biomedical terms, covering all the mentioned problems. This methodology offers several measures based on linguistic, statistical, graphic and web aspects. These measures extract and rank candidate terms with excellent precision: we demonstrate that they outperform previously reported precision results for automatic term extraction, and work with different languages (English, French, and Spanish). We also demonstrate how the use of graphs and the web to assess the significance of a term candidate, enables us to outperform precision results. We evaluated our methodology on the biomedical GENIA and LabTestsOnline corpora and compared it with previously reported measures. 相似文献
37.
This study examined if short-duration record power outputs can be predicted with the Anaerobic Power Reserve (APR) model in professional cyclists using a field-based approach. Additionally, we evaluated if modified model parameters could improve predictive ability of the model. Twelve professional cyclists (V?O2max 75 ± 6 ml?kg?1?min?1) participated in this investigation. Using the mean power output during the last stage of an incremental field test, sprint peak power output and an exponential constant describing the decrement in power output over time, a power-duration relationship was established for each participant. Record power outputs of different durations (5 to 180 s) were collected from training and competition data and compared to the predicted power output from the APR model. The originally proposed exponent (k = 0.026) predicted performance within an average of 43 W (Standard Error of Estimate (SEE) of 32 W) and 5.9%. Modified model parameters slightly improved predictive ability to a mean of 34–39 W (SEE of 29 – 35 W) and 4.1 – 5.3%. This study shows that a single exponent model generally fits well with the decrement in power output over time in professional cyclists. Modified model parameters may contribute to improving predictability of the model. 相似文献
38.
This study aims to describe the intensity and load demands of different stage types within a cycling Grand Tour. Nine professional cyclists, whom are all part of the same World-Tour professional cycling team, participated in this investigation. Competition data were collected during the 2016 Giro d’Italia. Stages within the Grand Tour were classified into four categories: flat stages (FLAT), semi-mountainous stages (SMT), mountain stages (MT) and individual time trials (TT). Exercise intensity, measured with different heart rate and power output based variables, was highest in the TT compared to other stage types. During TT’s the main proportion of time was spent at the high-intensity zone, whilst the main proportion of time was spent at low intensity for the mass start stage types (FLAT, SMT, MT). Exercise load, quantified using Training Stress Score and Training Impulse, was highest in the mass start stage types with exercise load being highest in MT (329, 359?AU) followed by SMT (280, 311?AU) and FLAT (217, 298?AU). Substantial between-stage type differences were observed in maximal mean power outputs over different durations. FLAT and SMT were characterised by higher short-duration maximal power outputs (5–30?s for FLAT, 30 s–2?min for SMT) whilst TT and MT are characterised by high longer duration maximal power outputs (>10?min). The results of this study contribute to the growing body of evidence on the physical demands of stage types within a cycling Grand Tour. 相似文献
39.
Mathieu Lacome Julien Piscione Jean-Philippe Hager Chris Carling 《European Journal of Sport Science》2017,17(2):132-143
This study investigated end-game and transient changes in running activities and whether these were concomitantly associated with reductions in skill-related performance in senior international rugby union match-play. Altogether, 18 official matches were analysed (322 individual observations) using computerised video-based tracking and event coding (Amisco Pro®, SUP, Nice, France). In forwards and backs, trivial to small reductions (% difference: ?2.1, ±1.3 to ?10.0, ±4.0%) in total distance and that covered at high speeds (>18.0?km?h?1) occurred in the second- versus the first-half while there were trivial differences in skill-related performance measures (?2.3, ±4.5 to 7.5, ±14.0%). In both positions, small to moderate declines (?42, ±10 to ?21, ±7%) occurred in high-speed running in the final 10-min and 5-min periods versus mean values for all other 10-min and 5-min periods throughout the game while only small changes (?18, ±51 to 13, ±41%) in skill-related performance were observed. Trivial changes in running and skill-related performance (?11, ±74 to 7, ±39%) were observed in the 5-min period immediately following the most intense 5-minute periods of play compared to mean performance over the other 5-min periods. These findings suggest that international rugby union players were generally able to maintain skill-related performance over the course of match-play even when declines in running performance occurred. 相似文献
40.
Mathieu Quet 《Journal of Cultural Economy》2017,10(2):150-162
ABSTRACTThe past decade has seen an increase in anti-counterfeiting practices, especially in the pharmaceutical field. These practices aim at reducing the number of bad medicines available on the market, especially in countries where pharmaceutical regulation is still weak. But they have been accused of serving the interests of Big Pharma by reinforcing intellectual property instead of promoting better quality medicines. Based on a study of the controversies provoked by anti-counterfeiting laws and devices, this paper analyses anti-counterfeiting politics and shows: (a) the aim of this mode of government is to discriminate between medicines in order to regulate the value attached to distribution processes and (b) the tensions and contradictions which characterize anti-counterfeiting discourses and practices. As such, a central characteristic of pharmaceutical markets is the shift of value conflicts towards circulation and distribution rather than production. The securitization of pharmaceutical flows, rather than being in addition to the production of pharmaceuticals, emerges as a new disputed way of producing economic value, legality and social legitimacy for globalized technical commodities such as medicines. 相似文献