900 research outputs found
Verification of Brand Authentication Technology using Infrared Light and Image Processing
Statement of Confidentiality: The complete senior project report was submitted to the project advisor and sponsor. The results of this project are of a confidential nature and will not be published at this time
Relationships between lower-body muscle structure and, lower-body strength, explosiveness and eccentric leg stiffness in adolescent athletes
The purpose of the present study was to determine whether any relationships were present between lower-body muscle structure and, lower-body strength, variables measured during a counter-movement jump (CMJ) and squat jump (SJ), and eccentric leg stiffness, in adolescent athletes. Thirty junior male (n = 23) and female (n = 7) surfing athletes (14.8 ± 1.7 y; 1.63 ± 0.09 m; 54.8 ± 12.1 kg) undertook lower-body muscle structure assessment with ultrasonography and performed a; CMJ, SJ and an isomet-ric mid-thigh pull (IMTP). In addition, eccentric leg stiffness was calculated from variables of the CMJ and IMTP. Moderate to very large relationships (r = 0.46-0.73) were identified be-tween the thickness of the vastus lateralis (VL) and lateral gas-trocnemius (LG) muscles, and VL pennation angle and; peak force (PF) in the CMJ, SJ and IMTP. Additionally, moderate to large relationships (r = 0.37-0.59) were found between eccentric leg stiffness and; VL and LG thickness, VL pennation angle, and LG fascicle length, with a large relationship (r = 0.59) also present with IMTP PF. These results suggest that greater thick-ness of the VL and LG were related to improved maximal dy-namic and isometric strength, likely due to increased hypertro-phy of the extensor muscles. Furthermore, this increased thickness was related to greater eccentric leg stiffness, as the associated enhanced lower-body strength likely allowed for greater neuromuscular activation, and hence less compliance, during a stretch-shortening cycle
Feasibility assessment of low cost stereo computer vision in clay target shooting coaching
Clay target shooting is a sport that has been slow to adopt new technology to help automate and improve coaching. Currently gun mounted cameras and shooting simulators are available but these are prohibitively expensive for most shooters. This project aims to determine if a lower cost alternative can be created to provide feedback to new shooters about the distance they missed the target using low cost stereo computer vision.
Initially an investigation was undertaken into the use of web cameras and GoPro action cameras for suitability to create a stereo vision system to track the shooter aim and the target position. The focus of this assessment was the camera resolution, frame rate and ability to be synchronized. The assessment found that these consumer-grade cameras all have high resolutions but no ability to be synchronized. Of these cameras the GoPro cameras could record in high definition at much higher frame rates then the web cameras and therefore were selected for the field trials.
Field trials to test the accuracy of the low cost stereo vision system were performed in three phases; 'static', 'dynamic' and 'vs coaches'. The static trials were designed to find a baseline accuracy where the effect of frame synchronization errors could be reduced. The dynamic trials were performed to test the system on moving targets and to try and compensate for the synchronization errors. Finally the system was trialed against the judgement of three experienced human judges to test its reliability against the current coaching method.
Matlab scripts were written to process the stereo images that were recorded as part of the field trials. Using colour thresholding and a custom filter that was created as part of this project, markers on the gun and the clay target were able to be segmented from the background in the trials. Using these positions the real world coordinates were able to be calculated and the aim of the gun vs target location estimated.
The outcome of the trials showed that low cost computer vision can have good accuracy in estimation of gun aim in a static scene. When movement was introduced to the trials the synchronization errors of the cameras resulted in large positional errors. The final outcome of the project determined that low cost stereo computer vision is far less reliable and accurate than human coaches and is not at this time feasible to be used in clay target coaching
Tracking 6 Weeks of training/surfing sessions of adolescent competitive surfers: Just what are these young surfers up to?
The assessment of weekly and even monthly surf practice/training hours is vital for understanding the loads these up and coming surfers endure. Such information will help understand what kind of training these athletes are undertaking, how long they are surfing, what they consider training, and also areas that should be improved upon in terms of specific training. The purpose of this study was to establish surfers\u27 training hours in terms of strength, balance and conditioning hours, as well as surfing hours, coached hours and competition hours. The monitoring of the athletes will provide insights into the weekly surf hours compared to land-based training these athletes do.https://ro.ecu.edu.au/ecuposters/1008/thumbnail.jp
Species abundance distributions should underpin ordinal cover-abundance transformations
Questions: The cover and abundance of individual plant species have been recorded on ordinal scales for millions of plots world-wide. Ordinal cover data often need to be transformed to a quantitative form (0%-100%), especially when scrutinising summed cover of multiple species. Traditional approaches to transforming ordinal data often assume that data are symmetrically distributed. However, skewed abundance patterns are ubiquitous in plant community ecology. The questions this paper addresses are (a) how can we estimate transformation values for ordinal data that account for the underlying right-skewed distribution of plant cover; (b) do different plant groups require different transformations; and (c) how do our transformations compare to other commonly used transformations within the context of exploring the aggregate properties of vegetation?
Location: Global.
Methods: We assigned Braun-Blanquet cover-abundance ordinal values to continuous cover observations. We fitted a Bayesian hierarchical beta regression to estimate the predicted mean (PM) cover of each of six plant growth forms within six ordinal classes. We illustrate our method using a case study (2,809 plots containing 95,812 observations), compare the model-derived estimates to other commonly used transformations and validate our model using an independent dataset (2,227 plots containing 51,497 observations) accessed through the VegBank database.
Results: Our model found that PM estimates differed by growth form and that previous methods overestimated cover, especially of smaller growth forms such as forbs and grasses. Our approach reduced the cumulative compounding of errors and was robust when validated against an independent dataset.
Conclusions: By accounting for the right-skewed distribution of cover data, our alternate approach for estimating transformation values can be extended to other ordinal scales. A more robust approach to transforming floristic data and aggregating cover estimates can strengthen ecological analyses to support biodiversity conservation and management
Comparison of Drop Jump and Tuck Jump Knee Joint Kinematics in Elite Male Youth Soccer Players: Implications for Injury Risk Screening
Context:
Despite the popularity of jump-landing tasks being used to identify injury risk factors, minimal data currently exist examining differences in knee kinematics during commonly used bilateral jumping tasks. This is especially the case for rebounding-based protocols involving young athletes.
Objective:
The purpose of this study was to compare the frontal plane projection angle (FPPA) during the drop vertical jump (DVJ) and tuck jump assessment (TJA) in a cohort of elite male youth soccer players of varying maturity status.
Methods:
A total of 57 male youth soccer players from an English championship soccer club participated in the study. Participants performed three trials of the DVJ and TJA, during which movement was recorded with two-dimensional video cameras. FPPA for both right (FPPA-r) and left (FPPA-l) legs, with values <180º indicative of medial knee displacement.
Results:
On a whole-group level, FPPA-r (172.7 ± 7.4 º versus 177.2 ± 11.7 º; p < 0.05; ES = 0.46) and FPPA-l (173.4 ± 7.3 º versus 179.2 ± 11.0 º; p < 0.05; ES = 0.62) was significantly greater for both limbs in the TJA compared to the DVJ; however, these differences were less consistent when grouped by maturity status. FPPA-r during the TJA was significantly and moderately greater in the circa-PHV group compared to the post-PHV cohorts (169.4 ± 6.4 º versus 175.3 ± 7.8 º; p < 0.05; ES = 0.49). Whole group data showed moderate relationships for FPPA-r and FPPA-l between the TJA and DVJ; however, stronger relationships were shown in circa and post-PHV players compared to the pre-PHV cohort.
Conclusions:
Considering that the TJA exposed players to a larger FPPA and was sensitive to between-group differences in FPPA-r, the TJA could be viewed as a more suitable screen for identifying FPPA in young male soccer players
The validity and inter-unit reliability of custom-made SurfTraX GPS units and use during surfing
The purposes of the study were to: i) gain further understanding of the movement patterns during surfing using custom made GPS units which are designed for surfing (SurfTraX, Gold Coast, Australia), and ii) determine the validity and inter-unit reliability of these units.https://ro.ecu.edu.au/ecuposters/1009/thumbnail.jp
Comparison of the 400 metre timed endurance surf paddle between elite competitive surfers, competitive surfers and recreational surfers
Surf competitions demand the ability to out paddle opposition to gain an optimal position for wave take offs. Those who can out paddle a heat opponent and catch waves at the most critical point when breaking are likely to maximize their scoring potential. Currently appropriate and valid testing protocols evaluating the physiological fitness of surfing athletes are not well established. The purpose of this study was to determine whether the testing procedure of a pool based, 400 endurance time trial is more appropriate (compared to geometry testing) given the nature of the sport, and pride a test that is a better discriminator of performance.https://ro.ecu.edu.au/ecuposters/1010/thumbnail.jp
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