1,956 research outputs found

    Eye quietness and quiet eye in expert and novice golf performance: an electrooculographic analysis

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    Quiet eye (QE) is the final ocular fixation on the target of an action (e.g., the ball in golf putting). Camerabased eye-tracking studies have consistently found longer QE durations in experts than novices; however, mechanisms underlying QE are not known. To offer a new perspective we examined the feasibility of measuring the QE using electrooculography (EOG) and developed an index to assess ocular activity across time: eye quietness (EQ). Ten expert and ten novice golfers putted 60 balls to a 2.4 m distant hole. Horizontal EOG (2ms resolution) was recorded from two electrodes placed on the outer sides of the eyes. QE duration was measured using a EOG voltage threshold and comprised the sum of the pre-movement and post-movement initiation components. EQ was computed as the standard deviation of the EOG in 0.5 s bins from –4 to +2 s, relative to backswing initiation: lower values indicate less movement of the eyes, hence greater quietness. Finally, we measured club-ball address and swing durations. T-tests showed that total QE did not differ between groups (p = .31); however, experts had marginally shorter pre-movement QE (p = .08) and longer post-movement QE (p < .001) than novices. A group × time ANOVA revealed that experts had less EQ before backswing initiation and greater EQ after backswing initiation (p = .002). QE durations were inversely correlated with EQ from –1.5 to 1 s (rs = –.48 - –.90, ps = .03 - .001). Experts had longer swing durations than novices (p = .01) and, importantly, swing durations correlated positively with post-movement QE (r = .52, p = .02) and negatively with EQ from 0.5 to 1s (r = –.63, p = .003). This study demonstrates the feasibility of measuring ocular activity using EOG and validates EQ as an index of ocular activity. Its findings challenge the dominant perspective on QE and provide new evidence that expert-novice differences in ocular activity may reflect differences in the kinematics of how experts and novices execute skills

    IDDA: a large-scale multi-domain dataset for autonomous driving

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    Semantic segmentation is key in autonomous driving. Using deep visual learning architectures is not trivial in this context, because of the challenges in creating suitable large scale annotated datasets. This issue has been traditionally circumvented through the use of synthetic datasets, that have become a popular resource in this field. They have been released with the need to develop semantic segmentation algorithms able to close the visual domain shift between the training and test data. Although exacerbated by the use of artificial data, the problem is extremely relevant in this field even when training on real data. Indeed, weather conditions, viewpoint changes and variations in the city appearances can vary considerably from car to car, and even at test time for a single, specific vehicle. How to deal with domain adaptation in semantic segmentation, and how to leverage effectively several different data distributions (source domains) are important research questions in this field. To support work in this direction, this paper contributes a new large scale, synthetic dataset for semantic segmentation with more than 100 different source visual domains. The dataset has been created to explicitly address the challenges of domain shift between training and test data in various weather and view point conditions, in seven different city types. Extensive benchmark experiments assess the dataset, showcasing open challenges for the current state of the art. The dataset will be available at: https://idda-dataset.github.io/home/ .Comment: Accepted at IROS 2020 and RA-L. Download at: https://idda-dataset.github.io/home

    Age-related reference intervals for physical performance test outcomes relevant to male youth Middle Eastern football players

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    Purpose: To develop age-specific reference intervals for physical performance test outcomes relevant to male youth Middle Eastern football players. Methods: We analyzed mixed-longitudinal data (observations range: 1751–1943 assessments) from a sample of 441 male youth outfield football players (chronological age range: 11.7–18.4 y) as part of the Qatar Football Association and Aspire Academy development program over 14 competitive seasons. Semiparametric generalized additive models for location, scale, and shape estimated age-specific reference centiles for 10-m sprinting, 40-m sprinting, countermovement jump height, and maximal aerobic speed variables. Results: The estimated reference intervals indicated that the distribution of the physical performance test scores increased monotonically and nonlinearly with advancing chronological age for sprinting and countermovement jump outcome measures, reaching a plateau after 16 years common to each of these performance variables. The maximal aerobic speed median score increased substantially until ∼14.5 years, with the nonlinear trend flattening off toward relatively older chronological ages. Conclusions: We developed age-related reference intervals for physical performance test outcomes relevant to youth Qatari football players. Country-wide age-specific reference intervals can assist in the longitudinal tracking of the individual players’ progress over time against benchmark values derived from the reference population

    Quantifying the physical, technical, and tactical qualities discriminant of development level in the Queensland Rugby League talent pathway

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    Leesa Grier (Pearce) studied the performance characteristics of Queensland Rugby League players within the talent development pathway. Significant differences were identified between the combined Under-18 / Under-20 players, and those in the open-age level. Queensland Rugby League will use this evidence to support their talent development pathway and enhance young athlete transition

    Risk evaluation in professional football

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    Risk management is composed of three major elements viz., hazard identification, risk estimation and risk evaluation. The aim of hazard identification and risk estimation is to identify the outcomes from risk, the magnitude of the associated con&quences from risk, and the estimation of the probabilities of these outcomes. Previous work focused on hazard identification and risk estimation and identified the relatively high risks associated with playing professional football. By adhering to the risk management process, the aim of this thesis was to determine the significance of these high risks to football clubs and their players. A theoretical framework was designed to evaluate the influence of player injury on the financial and playing performance of professional football clubs. This framework was also used to assess, through use of cost benefit analysis, the practicalities of investing in suitable injury prevention strategies, to reduce the risks to football clubs and their players. Former professional footballers were surveyed to investigate the long-term medical and socioeconomic consequences associated with the high risks of playing professional football. The results identified the high financial costs associated with player injury on professional football clubs. Although the high risks of player injury have a relatively minor effect on teamperformance of the Premier League clubs, this effect still has a relatively major influence on the financial performance of the club. In contrast, the influence of player injury to teamperformance was relatively major for Division I and Division 2 clubs, but this had a relatively minor effect on financial performance. The application of cost benefit analysis to the investment of specialist personnel to reduce the risks of injury demonstrated that the proposals were practicable for Premier League and Division I clubs only. In addition, it was also demonstrated that the high risks associated with playing professional football have a significant influence on the long-term well-being of foriner players. One-third of former players had been medically diagnosed osteoarthritic in a lower limb joint. The majority of players also perceived that injury had a negative influence on their present and future welfare. The results demonstrate that the consequences associated with the relatively high acute injury risk also have a significant effect on the financial and playing performance of football clubs and the future welfare of their players
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