Search Results (16)

The Australian alpaca industry is continuing to develop as an alternative fibre industry to the traditional merino or angora industries. This study aimed to investigate herd behaviour in an extensive system in south eastern Australia. Healthy adult female alpacas (Huacaya n = 32, Suri n = 32) over two years old were inducted into the trial and kept together across a 10 month period. A total of 5 animals were removed during the study due to illthrift or death unrelated to the study. GoPro cameras were set up at 5 locations in the paddock for 3 days in the middle of every season (Summer, Autumn, Winter, Spring) to record alpaca behaviour without a human observer present. Visual observations were taken at 0800, 1000, 1100, 1300, 1500 for 60 min. Behaviour observations were taken every 5 min from the videos according to a prepared ethogram. A count of animals exhibiting each behaviour was recorded at each time point within each of the designated 60-minute periods. A generalised linear mixed-effects model (GLMM) was run on binary data for each behaviour. Behaviours that returned a predicted proportion of over 0.10 for all seasons were used in an ordinal logistic regression that was then utilised to determine the effect of the season, time of day, and weather conditions on the number of animals. Season significantly impacted the number of alpacas grazing, resting, and standing (p < 0.0001). Alpacas were more likely to be grazing throughout the day in cooler seasons (autumn, winter) and resting in the warmer parts of the day in summer and spring. The time of day impacted the proportion of alpacas resting and grazing (p < 0.05) but not standing (p = 0.4432). This study highlights that alpacas spend the majority of the daylight hours grazing, with some variability across different seasons, which may impact ideal management practices to optimise production in an extensive system. Full article

Background/Objectives: The aim of this study was to analyze the nonlinear dynamics of handgrip strength (HGS) in young adults, focusing on hand dominance, by employing the Poincaré plot method to assess short- and long-term variability utilizing dynamometry and video motion capture during sustained isometric contractions. Methods: A cross-sectional exploratory study was conducted on 30 healthy subjects (mean age 21.6 ± 1.3 years, 13 males and 17 females), measuring HGS for both the dominant hand (DH) and nondominant hand (NDH) using a Saehan hydraulic dynamometer during 25-s sustained isometric contractions. A GoPro HERO11 Black camera recorded the dynamometer’s needle movements, and the video data were analyzed using Kinovea software. Angular values were converted to force using a calibration-based formula, and the Poincaré plot computed variability indices (short-term variability—SD₁, long-term variability—SD₂, ratio SD₁/SD₂, and area of the fitting ellipse) for each hand in relation to HGS and angular velocity (AV). Data analysis included descriptive and inferential statistics. Results: We demonstrated a strong correlation between mechanical and video measurements (p ≤ 0.001), confirming the reliability of the video method. The findings highlight the importance of nonlinear analysis in understanding neuromuscular function and fatigue, revealing significant correlations among HGS, AV, Poincaré indices, and fatigue levels in both hands (p ≤ 0.001). Increased maximum HGS and AV correlated with higher nonlinear variability in force production. Conclusions: This study confirms the reliability of the proposed video-based HGS assessment and demonstrates the effectiveness of Poincaré plot analysis for capturing nonlinear variability in HGS. Full article

The operational effectiveness of a railroad track robot that is designed for railcar undercarriage inspection is provided. Beyond describing the robot’s design details and onboard imaging system, the paper analyzes the recorded video images and offers design improvements to increase their clarity. The robot is designed to be deployed trackside, traverse over the rails, and then maneuver in between the rails beneath a stopped train in a siding or a railyard. The under-carriage conditions are documented by onboard video cameras for automated or manual postprocessing. The intent is to inspect the components that are not visible to the conductor or train inspector during a walk-along inspection of a stationary train. An assessment of the existing design, followed by modification and validation, is presented. The results from a prototype unit developed by the Railway Technologies Laboratory at Virginia Tech (RTL) indicate that with proper positioning of off-the-shelf imaging systems such as cameras manufactured by GoPro® in San Mateo, CA, USA and appropriate lighting, it is possible to capture videos that are sufficiently clear for manual (by a railroad engineer), semi-automated, or fully automated (using Artificial Intelligence or Machine Learning methods) inspections of rolling stock undercarriages. Additionally, improvements to the control, mobility, and reliability of the system are documented, although reliability throughout operation and the ability to consistently climb out of the track bed remain points of future investigation. Full article

Volleyball spiking requires defenders to possess exceptional anticipatory skills. However, most volleyball defense video eye-tracking studies have used fixed or off-court perspectives, failing to replicate real-world environments. This study explored different visual search behaviors between elite and novice volleyball players from various viewing perspectives using video eye tracking. We examined spiking anticipation in 14 competitive elite, 13 semi-elite, and 11 novice players. We captured spiking videos from three on-court perspectives using GoPro cameras mounted on the defenders’ heads, closely replicating real game scenarios. For comparison, we recorded baseline videos using a fixed camera. The present study revealed that competitive and semi-elite players demonstrated higher accuracy than novices. Competitive elite players used fewer fixations, indicating that their superior performance was related to stable visual search patterns. All participant groups, regardless of skill level, showed similar visual allocation among areas of interest (AOIs). However, notable differences in visual search patterns and AOI allocation were observed between baseline and on-court perspective videos. From the baseline perspective, the participants primarily utilized global perception and peripheral vision, focusing more on the setter zone or the spiker’s trunk. Conversely, from the on-court perspective, they employed more fixations, focusing more intensely on the spiker’s detailed movements. Full article

The aim of this study was to compare the tactical knowledge of young football players in different playing positions during a three-a-side small-sided game (SSG). Observational data was collected from 71 players (M = 12.16; SD = 1.55 years): 11 goalkeepers, 22 defenders, 15 midfielders, and 23 forwards. In total, 4 min of three-a-side SSGs (GR + 3 vs. 3 + GR) were recorded to assess tactical performance using a digital camera (GoPro Hero 6^® version 02.01). The SSGs were performed on a field with a constant area (36 × 27 m). Video analyses were performed using LongoMatch^® version 1.5.9 to record football performance; we then assessed tactical performance by using the Football Tactical Assessment System (Fut-Sat). This instrument evaluates the average of well-defined action indexes for each game in decision making principle and motor skills, specifically: (i) Decision Making Index (DMI); (ii) Motor Effectiveness Index (MEI); (iii) Effectiveness Index (I). The indexes were calculated by the ratio between the correct actions and the total. The Kruskal–Wallis test was used to evaluate differences between playing positions. The results showed that tactical performance by principles seems to be significantly different according to playing position. Differences were found between defenders and forwards (H = −11.92; p = 0.03) and defenders and midfielders (H = −16.13; p = 0.01) in contention principle. In conclusion, tactical knowledge of training based on the principles of the game can help coaches and players better understand and predict each player’s actions during the game. Full article

This paper presents in-flight measurements of the interaction of the wing wake of a stalled Slingsby T67 Firefly light aircraft with the aircraft tailplane. Tailplane data was recorded by a GoPro360 camera and analyzed using spatial correlation methods. The tailplane movement and corresponding spectra indicate that the aerodynamic wake shedding frequency closely matches the resonant frequency of the tailplane, resulting in a significant excitation of the structure during heavy stall. Large magnitude, lower frequency tailplane movement was also identified by analysis of the pitch attitude from the image data, with results consistent in post-stall behavior reported by previous modelling and measurements. Full article

Stereo-video systems (hereafter SVS) have been widely applied to study fish ecology in marine coastal ecosystems and more recently in freshwater, especially in headwater streams, due to their dependence on water clarity. Here, we assess the use of these non-destructive methods to study microhabitat use, size structure, and the abundance of endangered Spanish toothcarp (Apricaphanius iberus) and the invasive mosquitofish (Gambusia holbrooki) in coastal salt marshes. Stereo-video measurements were obtained in situ by means of static pairs of GoPro HERO7 cameras in different shallow coastal lagoons of northeastern Spain. The analysis of stereo-video recordings were processed using the open-source videogrammetry software VidSync 1.661 in order to identify the species, sex, and total length of each fish as well as their relative position in the water column. A total of ninety 17.5 min long stereo-video clips containing more than 7300 fish positions were processed for this study. Fish assemblage and population size structure gathered with this method were compared with catches at the same places using fyke nets. The accuracy and precision of fish-length estimation using SVS was also tested in the lab. SVS revealed differential water-column use, with Spanish toothcarp occurring in a lower-water column. Larger mosquitofish tended to use the upper part of the water column, whereas no clear ontogenetic shift was observed for the Spanish toothcarp. Fyke nets and SVS yielded a similar species composition and considerably correlated with abundances for two species, particularly for mosquitofish, across the six coastal ponds. The size structure varied significantly with the two techniques, with fyke nets apparently being more size-selective as the smallest mosquitofish were underrepresented in fyke nets compared with SVS. Our results suggest that SVS is a non-destructive method that does not require capturing and handling the fish, and they also suggest that it is an ideal technique for studying endangered species, with enormous potential to improve the knowledge of microhabitat use and the behavior of fish species in natural conditions. Full article

Due to the limitation of event sensors, the spatial resolution of event data is relatively low compared to the spatial resolution of the conventional frame-based camera. However, low-spatial-resolution events recorded by event cameras are rich in temporal information which is helpful for image deblurring, while intensity images captured by frame cameras are in high resolution and have potential to promote the quality of events. Considering the complementarity between events and intensity images, an alternately performed model is proposed in this paper to deblur high-resolution images with the help of low-resolution events. This model is composed of two components: a DeblurNet and an EventSRNet. It first uses the DeblurNet to attain a preliminary sharp image aided by low-resolution events. Then, it enhances the quality of events with EventSRNet by extracting the structure information in the generated sharp image. Finally, the enhanced events are sent back into DeblurNet to attain a higher quality intensity image. Extensive evaluations on the synthetic GoPro dataset and real RGB-DAVIS dataset have shown the effectiveness of the proposed method. Full article

Physical inactivity is the fourth leading risk factor for global mortality, causing an estimated 3.3 million deaths worldwide. Characteristics of the built environment, including buildings, public spaces, pedestrian and cycling infrastructure, transportation networks, parks, trails and green spaces can facilitate or constrain physical activity. However, objective study of built environment interventions on physical activity remains challenging due to methodological limitations and research gaps. Existing methods such as direct observations or surveys are time and labour intensive, and only provide a static, cross-sectional view of physical activity at a specific point in time. The aim of this study was to develop a novel method for objectively and inexpensively assessing how built environment changes may influence physical activity. We used a novel, unobtrusive method to capture real-time, in situ data from a convenience sample of 25 adults along a newly constructed urban greenway in an area of high deprivation in Belfast, UK. Walk/bike-along interviews were conducted with participants using a body-worn or bicycle-mounted portable digital video camera (GoPro HERO 3+ camera) to record their self-determined journeys along the greenway. This is the first study to demonstrate the feasibility of using wearable sensors to capture participants’ responses to the built environment in real-time during their walking and cycling journeys. These findings contribute to our understanding of the impact of real-world environmental interventions on physical activity and the importance of precise, accurate and objective measurements of environments where the activity occurs. Full article

During children’s sports competitions, the referees play a special role. The referees are expected to be able to identify behavioral problems (of players, coaches, and fans), applying specific techniques to prevent negative behavior of players. Adapting these actions to the specifics of the group or individuals is crucial in providing a safe educational environment that promotes child development. The main objective of this research was to assess the quality of referees’ interactions with players in terms of positive behavior management and proficiency during rugby matches of children aged 6–12 years. Twenty-three rugby referees officiating matches organized by the Polish Rugby Union in Poland participated in the study. The research used the Referee–Players’ Interaction Assessment Scoring System tool. Additionally, referee–player interactions were recorded with a GoPro 8 camera along with audio from a wireless intercom. The significance of differences between the ratings for each indicator was tested by chi-squared test, while a non-parametric Wilcoxon signed-rank test was used to compare the mean ratings of positive behavior management and proficiency. The Mann–Whitney U-test was used to compare differences between assessments of experienced and inexperienced referees. The observations showed that referees were rated significantly higher in the proficiency dimension than in positive behavior management dimension. Nevertheless, both ratings represent an average level of quality of interactions with the players. The referee’s experience did not determine the quality of his or her interactions with the players in the specific dimensions. The following conclusion was drawn from the research: referees should be trained in the methods and techniques for managing player behavior and should act to prevent the occurrence of negative behavior, by presenting clear and understandable expectations to players before the match and using preventive measures. Full article

One of the key elements of effective sports programs that contribute to a child’s sense of joy and satisfaction in participating in sports is contact with an adult who builds a caring climate deliberately and intentionally. Referees play a special role in providing positive experiences for young athletes. The main aim of this study was to assess the quality of referee–player interactions in terms of building a positive climate during the game and the referee’s responsiveness to the health, emotional, social, and cognitive needs of young rugby players aged 6–12 years. The research was conducted among 23 referees refereeing children’s rugby matches in Poland. The structure observation method and The Referee–Players’ Interaction Assessment Scoring System tool were used in the study. Each referee was observed twice. The referee’s verbal and non-verbal communication was recorded using a GoPro Hero 8 camera and an Ejeas Fbim wireless intercom system. A Wilcoxon signed-rank test was used to examine differences between referees’ ratings on two dimensions. The Mann-Whitney U test was employed to test the significance of differences in the mean scores of referees between groups divided by experience. The referees, in both dimensions (building positive climate and responsiveness to the players’ needs), scored on a 7-point scale, were rated at an average level of 3.22 (SD = 1.65) and 4.39 (SD = 1.67), respectively, with the responsiveness dimension rating being statistically significantly higher than the positive climate rating. The results showed that referee experience was not a determinant of the rating of the quality of referee–players’ interactions in both dimensions. From these studies, it was concluded that there is a need to complement the existing training programs for referees with the contents from the field of pedagogy and developmental psychology. This will help them build a positive climate during the game and show how to respond to children’s health, cognitive, emotional, and social needs. Furthermore, developing a referee’s pedagogical skills can improve their relationship with players, which can ultimately translate into a greater sense of job satisfaction. The formulated practical implications can also be transposed to other team sports. Full article

The coastal areas of Finnmark have deep Sámi roots. With the Norwegian assimilation policy—Norwegianization—the transition to the Norwegian language has been extensive here, placing the region outside Sámi core areas. Nevertheless, indigenous Sea Sámi identity still exists, and language vitalization and raising awareness of culture are shown in Sámi institution building. Within these frames, kindergarten teachers with Sámi backgrounds work to strengthen their local Sámi language and culture in a Sámi department of a kindergarten outside the core Sámi areas. This article aims to shed light on how the use of their bilingual resources in pedagogical translanguaging practices can build sustainable language practices for North Sámi. With children and adults, we explored how culturally aware, situated outdoors activities, such as building a campfire and gathering berries, encouraged children’s use of North Sámi. Both children and adults recorded these activities with GoPro cameras. The material was transcribed and analyzed using Conversation Analysis and translanguaging. For this article, I chose three episodes in which kindergarten teachers used their bilingual language register to interact with children in different pedagogical practices to give children input in North Sámi. Pedagogical translanguaging with young language learners in an emergent bilingual situation could help strengthen North Sámi language and culture outside Sámi core areas. Full article

Foraging behavior of livestock in species-rich, less intensively managed grassland communities will require different methodologies from those appropriate in floristically simple environments. In this pilot study on sheep in species-rich grassland in northern Estonia, foraging behavior and the plant species of the immediate area grazed by the sheep were registered by continually-recording Go-Pro cameras. From three days of observation of five sheep (706 animal-minutes), foraging behavior was documented. Five hundred and thirty-six still images were sampled, and a plant species list was compiled for each. Each plant species was assigned a score indicating its location, in the ecophysiological sense, on the main environmental gradient. The scores of the plant species present were averaged for each image. Thus, the fine structure of foraging behavior could be studied in parallel with the vegetation of the precise area being grazed. As expected, there was considerable individual variation, and we characterized foraging behavior by quantifying the patterns of interspersion of grazing and non-grazing behaviors. This combination of behavior recording and vegetation classification could enable a numerical analysis of the responses of grazing livestock to vegetation conditions. Full article

A study to determine the visual requirements for a remote supervisor of an autonomous sprayer was conducted. Observation of a sprayer operator identified 9 distinct “look zones” that occupied his visual attention, with 39% of his time spent viewing the look zone ahead of the sprayer. While observation of the sprayer operator was being completed, additional GoPro cameras were used to record video of the sprayer in operation from 10 distinct perspectives (some look zones were visible from the operator’s seat, but other look zones were selected to display other regions of the sprayer that might be of interest to a sprayer operator). In a subsequent laboratory study, 29 experienced sprayer operators were recruited to view and comment on video clips selected from the video footage collected during the initial ride-along. Only the two views from the perspective of the operator’s seat were rated highly as providing important information even though participants were able to identify relevant information from all ten of the video clips. Generally, participants used the video clips to obtain information about the boom status, the location and movement of the sprayer within the field, the weather conditions (especially the wind), obstacles to be avoided, crop conditions, and field conditions. Sprayer operators with more than 15 years of experience provided more insightful descriptions of the video clips than their less experienced peers. Designers can influence which features the user will perceive by positioning the camera such that those specific features are prominent in the camera’s field of view. Overall, experienced sprayer operators preferred the concept of presenting visual information on an automation interface using live video rather than presenting that same information using some type of graphical display using icons or symbols. Full article

The paper investigates on the hydro-acoustic waves propagation caused by the underwater earthquake, occurred on 6 February 2012, between the Negros and Cebu islands, in the Philippines. Hydro-acoustic waves are pressure waves that propagate at the sound celerity in water. These waves can be triggered by the sudden vertical sea-bed movement, due to underwater earthquakes. The results of three dimensional numerical simulations, which solve the wave equation in a weakly compressible sea water domain are presented. The hydro-acoustic signal is compared to an underwater acoustic signal recorded during the event by a scuba diver, who was about 12 km far from the earthquake epicenter. Full article