Performance evaluation of nanofluid-based photovoltaic thermal (PVT) system with regression analysis

The recent global energy crisis has shocked Bangladesh's power sectors, and experts recommend using alternative energy sources to conserve natural gas, fossil fuels, and electricity. Numerous investigations on the photovoltaic thermal (PVT) system have been carried out to get the source efficiently. As a result, a parametric evaluation of the PVT system's efficiency in Dhaka, Bangladesh, is investigated numerically using CNT nanofluid as a coolant. The numerical simulation is performed using the Galerkin weighted residual based finite element method. For accurate computations, the meteorological data for Dhaka, Bangladesh, is taken from open sources of Renewables.ninja. The effect of regulating parameters Reynolds number (200 ≤ Re ≤ 1000), solar irradiation (200 W/m2 ≤ G ≤ 1000 W/m2), and the monthly influence on performance such as cell temperature, fluid domain exit temperature, efficiencies, and energy are discussed. In addition, regression analyses of electrical efficiency and thermal efficiency are discussed for the input variables Reynolds number and solar irradiation. After postprocessing, empirical results are compiled and presented as 3D surface graphs, tables, and line diagrams. As the Reynolds number increased, the cell temperature and discharge temperature decreased, resulting in increased efficiency. However, the opposite situation is found for solar irradiation. Month-to-month variation also has a considerable impact on photovoltaic thermal performance. This research will help to improve the efficacy of PVTs in Dhaka, Bangladesh, by identifying useful alternative renewable energy sources.

Computationally efficient robust adaptive filtering algorithm based on improved minimum error entropy criterion with fiducial points

Recently, there has been a strong interest in the minimum error entropy (MEE) criterion derived from information theoretic learning, which is effective in dealing with the multimodal non-Gaussian noise case. However, the kernel function is shift invariant resulting in the MEE criterion being insensitive to the error location. An existing solution is to combine the maximum correntropy (MC) with MEE criteria, leading to the MEE criterion with fiducial points (MEEF). Nevertheless, the algorithms based on the MEEF criterion usually require higher computational complexity. To remedy this problem, an improved MEEF (IMEEF) criterion is devised, aiming to avoid repetitive calculations of the aposteriori error, and an adaptive filtering algorithm based on gradient descent (GD) method is proposed, namely, GD-based IMEEF (IMEEF-GD) algorithm. In addition, we provide the convergence condition in terms of mean sense, along with an analysis of the steady-state and transient behaviors of IMEEF-GD in the mean-square sense. Its computational complexity is also analyzed. Simulation results demonstrate that the computational requirement of our algorithm does not vary significantly with the error sample number and the derived theoretical model is highly consistent with the learning curve. Ultimately, we employ the IMEEF-GD algorithm in tasks such as system identification, wind signal magnitude prediction, temperature prediction, and acoustic echo cancellation (AEC) to validate the effectiveness of the IMEEF-GD algorithm.

Bibliometric review of telematics-based automobile insurance: Mapping the landscape of research and knowledge

Telematics technology and its implementation in auto insurance have received great interest due to their potential to transform the insurance sector and promote safer driving practices. By implementing telematics technology, insurers may tailor insurance premiums to individual drivers, taking into account their real driving habits and performance, ultimately leading to improved road safety, cost savings, and an empowered driving community. The current study, through bibliometric analysis, carefully identifies and evaluates the existing body of scholarly literature on this subject for the last 21 years, including journal articles, conference papers, and related publications. The analysis uncovers key research studies, influential authors, top publication outlets, top countries with collaborations, and prolific research fields, providing useful insights into the evolution and growth of telematics-based insurance research. Furthermore, thematic mapping, cluster analysis, and critical analysis of top recent studies aided in identifying key research clusters and themes, as well as potential gaps and areas for further exploration, guiding future researchers and policymakers in advancing this transformative technology.

Design and analysis of a compatible exoskeleton rehabilitation robot system based on upper limb movement mechanism

Rehabilitation robots are used to promote structural and functional recovery of the nervous system with repetitive, task-oriented training and have been gradually applied to clinical rehabilitation training. This paper proposes an upper limb exoskeleton rehabilitation robot system that could realize shoulder-elbow-wrist joint rehabilitation training. Firstly, a motion equivalent model was established based on the upper limb movement mechanism, the robot mechanism configuration was designed, and the optimization algorithm and spatial mechanism theory were used to optimize and analyze the structural parameters and human-machine compatibility of the robot, which will guide the design of the robot's model. Then, the robot kinematics were solved, and its maximum motion range, dexterity distribution, and daily motion trajectory were simulated. Finally, a system prototype was built to test the maximum range of robot-assisted human upper limb training by laser tracker, while the pressure of human-machine interaction during training was captured and analyzed by flexible sensors. The results show that the proposed rehabilitation robot could nearly completely cover the range of motion of upper limb joints and meet the needs of trajectory training, and the linear velocity dexterity and angular velocity dexterity in the motion space are maximum 0.55 and 0.89, and the human-machine interaction pressures during the training process are all less than 10 kPa. Besides, this paper also conducted a system evaluation based on the fuzzy comprehensive evaluation model, and the evaluation result was 0.39, with an excellent evaluation grade, it indirectly indicates that the robot's overall performance was good.

How to Administer the Performance Diagnostic Checklist-Human Services

The Performance Diagnostic Checklist-Human Services (PDC-HS) is a performance analysis tool used to identify barriers to performance in human-service settings. Multiple published studies have used the PDC-HS to determine effective interventions (Wilder et al. Journal of Applied Behavior Analysis 53(2), 1170-1176, 2020). However, in a recent discussion article proposing guidelines for administering the PDC-HS, Brand et al. Behavior Analysis in Practice, 1-7 (2022) noted that procedural descriptions provided for administering the PDC-HS are somewhat ambiguous in the published literature. The purpose of the current systematic review was to compare methods used to administer the PDC-HS. Fifteen articles met inclusion criteria and were coded to evaluate commonalities among PDC-HS components. Authors generally agreed on how the outcomes of the PDC-HS were depicted and discussed but varied in their descriptions of methods used to administer the PDC-HS. Results are discussed in terms of the importance of technological descriptions and directions for future research towards the development of a more standardized tool.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40617-023-00848-3.

The pump as a turbine: A review on performance prediction, performance improvement, and economic analysis

Pumps as Turbines (PATs) are known for their ability to replace conventional turbines in Pico/micro-hydropower plants. However, selecting a suitable pump and estimating its performance in reverse mode is a challenging task. The overall efficiency of PATs is also lower when compared to purpose-made turbines. Numerous attempts have been made to analyze the performance of PAT in power-generating applications, and many scholars have presented their research on performance improvement and economic analysis. In this paper, a detailed review is conducted to show the historical development and current status of PAT technology. The review also presents the findings of performance prediction, performance improvement techniques, and economic analysis. The results of the literature survey demonstrate that the choice of an appropriate pump for a specific application significantly affects the performance of the PAT system. Among the various options, the Shear Stress Transport (SST) k-ω and standard k-ε turbulence models are widely used for simulating the pump as a turbine. Blade grooving and blade tip rounding are recognized as the most promising techniques for improving efficiency, with gains of 4.91% and 4.00%, respectively. Except for impeller diameter trimming, blade modification techniques proposed by various scholars have a significant impact on the efficiency of PATs; however, further research is needed to investigate the economic advantages of impeller modification.

Optimising classification in sport: a replication study using physical and technical-tactical performance indicators to classify competitive levels in rugby league match-play

  Determining key performance indicators and classifying players accurately between competitive levels is one of the classification challenges in sports analytics. A recent study applied Random Forest algorithm to identify important variables to classify rugby league players into academy and senior levels and achieved 82.0% and 67.5% accuracy for backs and forwards. However, the classification accuracy could be improved due to limitations in the existing method. Therefore, this study aimed to introduce and implement feature selection technique to identify key performance indicators in rugby league positional groups and assess the performances of six classification algorithms. Fifteen and fourteen of 157 performance indicators for backs and forwards were identified respectively as key performance indicators by the correlation-based feature selection method, with seven common indicators between the positional groups. Classification results show that models developed using the key performance indicators had improved performance for both positional groups than models developed using all performance indicators. 5-Nearest Neighbour produced the best classification accuracy for backs and forwards (accuracy = 85% and 77%) which is higher than the previous method's accuracies. When analysing classification questions in sport science, researchers are encouraged to evaluate multiple classification algorithms and a feature selection method should be considered for identifying key variables.

Mechanical and metabolic power in accelerated running-Part II: team sports

PURPOSE

This manuscript is devoted to discuss the interplay between velocity and acceleration in setting metabolic and mechanical power in team sports.

METHODS

To this aim, an essential step is to assess the individual Acceleration-Speed Profile (ASP) by appropriately analysing training sessions or matches. This allows one to estimate maximal mechanical and metabolic power, including that for running at constant speed, and hence to determine individual thresholds thereof.

RESULTS

Several approaches are described and the results, as obtained from 38 official matches of one team (Italian Serie B, season 2020-2021), are reported and discussed. The number of events in which the external mechanical power exceeded 80% of that estimated from the subject's ASP ([Formula: see text]) was 1.61 times larger than the number of accelerations above 2.5 m s-2 ([Formula: see text]). The difference was largest for midfielders and smallest for attackers (2.30 and 1.36 times, respectively) due to (i) a higher starting velocity for midfielders and (ii) a higher external peak power for attackers in performing [Formula: see text]. From the energetic perspective, the duration and the corresponding metabolic power of high-demanding phases ([Formula: see text]) were essentially constant (6 s and 22 W  kg-1, respectively) from the beginning to the end of the match, even if their number decreased from 28 in the first to 21 in the last 15-min period, as a consequence of the increased recovery time between [Formula: see text] from 26 s in the first to 37 s in the last 15-min period.

CONCLUSION

These data underline the flaws of acceleration counting above fixed thresholds.

Does video assistant referee technology change the magnitude and direction of home advantages and referee bias? A proof-of-concept study

BACKGROUND

This study analyzed how Video Assistant Referee (VAR), introduced to improve the accuracy of referee decisions in football, changes the magnitude and direction of home advantage and referee bias in the Turkish Super League.

METHODS

We analyzed points, goals, yellow cards and red cards, fouls, penalties, and offside data from 1,838 matches played in the Turkish Super League with and without VAR. Two-sample t-tests and two one-sided tests analysis were applied to determine the differences between the home and away team data between the seasons played with and without VAR.

RESULTS

The findings revealed that the only variable that changed significantly after VAR was implemented was fouls, which decreased for both home (p <.001; d = 0.56, medium effect) and away teams (p <.001; d = 0.69, medium effect). The results also indicated that, with or without VAR, home teams had an advantage over away teams in points and goals, and away teams faced more referee bias regarding yellow cards and penalties (against).

CONCLUSIONS

Although this study shows that VAR does not significantly impact the HA and referee bias of football matches, nevertheless, teams should be more aware that bias is reduced when playing away. In addition, this study offers some practical applications that can help football players, coaches, and match officials better understand VAR technology's effects on HA and referee bias.

Training stress, neuromuscular fatigue and well-being in volleyball: a systematic review

BACKGROUND

Volleyball, with its unique calendar structure, presents distinct challenges in training and competition scheduling. Like many team sports, volleyball features an unconventional schedule with brief off-season and pre-season phases, juxtaposed against an extensive in-season phase characterized by a high density of matches and training. This compact calendar necessitates careful management of training loads and recovery periods. The effectiveness of this management is a critical factor, influencing the overall performance and success of volleyball teams. In this review, we explore the associations between training stress measures, fatigue, and well-being assessments within this context, to better inform future research and practice.

METHODS

A systematic literature search was conducted in databases including PsycINFO, MEDLINE/PubMed, SPORTDiscus, Web of Science, and Scopus. Inclusion criteria were original research papers published in peer-reviewed journals involving volleyball athletes.

RESULTS

Of the 2535 studies identified, 31 were thoroughly analysed. From these 31 articles, 22 included professional athletes, seven included collegiate-level volleyball athletes, and two included young athletes. Nine studies had female volleyball players, while the remaining 22 had male volleyball athletes.

CONCLUSIONS

Internal training load should be collected daily after training sessions and matches with the session rating of perceived exertion method. External training load should also be measured daily according to the methods based on jump height, jump count, and kinetic energy. If force platforms are available, neuromuscular fatigue can be assessed weekly using the FT:CT ratio of a countermovement jump or, in cases where force platforms are not available, the average jump height can also be used. Finally, the Hooper Index has been shown to be a measure of overall wellness, fatigue, stress, muscle soreness, mood, and sleep quality in volleyball when used daily.

Factors that affect handball execution in Australian Football

A handball is one of two technical skills used to dispose of the ball in Australian Football. Previous research has only considered handball effectiveness in the analysis of team performance and there is a need to understand whether there are other more important characteristics of handball execution that explain effectiveness (i.e., performance). 1342 handballs from Australian Football League matches were analysed. Ten characteristic variables were created that represent the context and execution of each handball included in the analysis. A mixed effects generalised linear model was used to evaluate the effect of the (ten) characteristics on handball outcome. Three out of ten characteristics were associated with handball outcome, and these related to the posture of the handballer and the type of defensive pressure applied to the handballer and the receiver of the handball. These findings explain both how to increase handball effectiveness and how to reduce the handball effectiveness of an opposition team. Given the important role of handballing in passing sequences and maintaining ball possession, the practical application of these findings could enhance overall team performance.

Do small-sided games prepare players for the worst-case scenarios of match play in elite young soccer players?

The aim of the study was to determine whether the physical performance of young soccer player during various small sided games (SSGs) underloads, replicates or overloads the requirements of the worst-case scenarios (WCS) during match play. A total of 521 SSGs' individual observations and 15 different formats of SSGs with different areas per player (ApP) (ApP100: < 100; ApP200: ranged from 101 to 200; ApP300: > 201, all in m2 · player-1) were taken into consideration. Whole (90-min average; OM) and 15-, 5- and 1-min worst-case scenarios (WCS15, WCS5 and WCS1, respectively) were analysed. Total distance covered relative (m · min-1) (TDCR), high-speed distance relative (m · min-1) (HSDR), very high-speed distance relative (m · min-1) (VHSDR) and sprint distance relative (m · min-1) (SDR), player load relative (PLR) and both total (ACCR) and high intensity relative accelerations (n · min-1) (ACCHR) were collected. All external load measures analysed were significantly higher in WCS1 compared to WCS of longer duration and SSGs with different ApP (p < 0.001). The analysis demonstrated interactions between game type and player positions (p < 0.001) for TDCR, VHSDR, PLR and ACCHR. The SSG formats did not sufficiently stimulate the WCS for locomotor demands (VHSDR and SDR). SSGs played on an ApP100 overestimated the mechanical values compared to WCS15 and WCS5. The analysed SSG formats did not sufficiently stimulate players to cope with all external load demands that occurred during WCS1. This study provides useful information for practitioners on the heightened impact of different SSG formats on external load in relation to the WCS of competitive match play.

Modelling women's team line-ups based on effectiveness and quality

Understanding how different player rotations may impact team performance allows basketball coaches to select effective line-ups for specific tactical scenarios. The study aimed to i) assess how different line-ups or player combinations impact a team's game performance; ii) explore the variations in line-up utilization among different national women's basketball teams; and iii) examine how the offensive efficiency of each line-up evolves during the game. Data from 3,387 ball possessions in 23 international women's basketball games were collected across four major competitions over six years. Offensive and defensive ratings, along with other features, were calculated. Then, a Markov chain model distinguished overperforming and underperforming line-ups of Chinese women's basketball team, determining long-term probabilities for each rating level. The results indicated that i) the most dominant offensive line-up of the Chinese women's basketball team, is PG-G-SF-PF-C, while G-G-F-PF-PF had the highest defensive rating; and ii) US and Australian women's basketball teams favour using line-ups with three guards, while the Chinese women's basketball team heavily relies on centre players. These results offer valuable insights for coaches regarding the performance of different line-ups in FIBA Female Basketball Competitions, optimizing line-up performance and aiding talent selection and recruitment at the international level.

Comparative combustion, emission, and performance analysis of a diesel engine using carbon nanotube (CNT) blended with three different generations of biodiesel

Nano-additives are being employed in successive generations of biodiesels to increase the performance characteristics and output of diesel engines. In this study, the impact of mixing carbon nanotubes (CNT) with three different generations of biodiesel in a diesel engine is assessed. With 100 ppm of CNT nanoparticles mixed together, pure biodiesels made from first-generation oil (soybean), second-generation oil (neem), and third-generation oil (Nannochloropsis oculata microalgae) are used for the analysis. With an engine load ranging from 0 to 100%, a one-cylinder, four-stroke, direct injection diesel engine is employed. The engine has a water-cooling system, a compression ratio of 17.5:1, and a fuel injection angle of 23° before TDC. The evaluated engines' improved performance and lower emissions serve as proof of the outcomes. The results are evidenced by the lower emissions and higher performance of the tested engines. The biodiesel containing CNT nanoparticles enhanced the cylinder pressure by 0.8-10.69%, the heat release rate (HRR) by 6.38-21.69%, and the brake thermal efficiency (BTE) by 0.32-1.62%. Subsequently, it reduced the brake-specific fuel consumption (BSFC) by 2.53-8.13%, the brake-specific energy consumption (BSEC) by 1.07-3.77%, the smoke opacity (BSN) by 6.26-12.85%, the particulate matter (PM) emissions by 11.04-18.33%, and the carbon dioxide (CO2) emissions by 2.53-8.14% at full engine load. However, an increase in 13.62-18.37% nitrogen emissions (NOx) emissions is also observed with the addition of CNT at 100% load. The investigation supports the use of CNT nano-additives in diesel engines for improved performance and reduced emissions.

Performance analysis of biofuel-ethanol blends in diesel engine and its validation with computational fluid dynamics

The engine tests aimed to produce comparable data for fuel consumption, exhaust emissions, and thermal efficiency. The computational fluid dynamics (CFD) program FLUENT was used to simulate the combustion parameters of a direct injection diesel engine. In-cylinder turbulence is controlled using the RNG k-model. The model's conclusions are validated when the projected p-curve is compared to the observed p-curve. The thermal efficiency of the 50E50B blend (50% ethanol, 50% biofuel) is higher than the other blends as well as diesel. Diesel has lower brake thermal efficiency among the other fuel blends used. The 10E90B mix (10% ethanol, 90% biofuel) has a lower brake-specific fuel consumption (BSFC) than other blends but is slightly higher than diesel. The temperature of the exhaust gas rises for all mixtures as the brake power is increased. CO emissions from 50E50B are lower than diesel at low loads but slightly greater at heavy loads. According to the emission graphs, the 50E50B blend produces less HC than diesel. NOx emission rises with increasing load in the exhaust parameter for all mixes. A 50E50B biofuel-ethanol combination achieves the highest brake thermal efficiency, 33.59%. The BSFC for diesel is 0.254 kg/kW-hr at maximum load, while the BSFC for the 10E90B mix is 0.269 kg/kW-hr, higher than diesel. In comparison to diesel, BSFC has increased by 5.90%.

Evaluating field-goal shooting effectiveness in wheelchair basketball players across a competitive season: a preliminary study

Background

Information about non-elite wheelchair basketball (WB) players across national competitive seasons are still missing. This study aimed at identifying which situational-related variables were associated with shooting effectiveness in non-elite WB players.

Methods

All the matches played by one WB team across one national competitive season were video-recorded and analysed; 333 shooting attempts from high-point players and several situational-related variables were considered.

Results

Pearson's Chi-square test showed that increased shooting effectiveness under the following conditions: playing on home ground, during won matches, while taking shots with the wheelchair in motion, and when no opposing player raised their arm in defence. Results of the multivariable logistic regression analysis showed a statistically significant influence of match location (p-value = 0.001), shot-clock remaining (p-value = 0.015) and modality of press (p-value < 0.001). The highest attack effectiveness was achieved when teams played at home (odds ratio [OR] = 2.49), while the shooting effectiveness decreased when the shot occurred during the last seconds of the action (OR = 0.36), or the opponents defended with the arm raised (OR = 0.19). These results suggest that coaches should include exercises aimed at shooting under conditions of increased pressure in their programmes in order to create specific situations during the training sessions to prepare their high-point athletes for shots under specific match constraints.

Understanding passing network characteristics and their link to match outcome in elite Netball

Player interactions in Netball are critical during attacking phases of play to ensure possession is maintained and scoring opportunities are created. This study aims to analyse the characteristics of the passing networks of elite Netball teams and their association with performance outcomes (i.e., win/loss and final margin). Five network metrics used to represent the characteristics of teamwork were calculated for all team performances (n = 112) from one season of professional Netball in Australia. A two-way ANOVA and multiple linear modelling were used to compare characteristics between teams and match outcomes and to predict score margin, respectively. Pass density (F = 65.09, df = 102, p < .001) and pass centrality (F = 7.61, df = 102, p < .01) differed (were higher) in wins/losses. They were also statistically significant contributors (p ≤ .005) to the linear model that predicted a score margin (R2 = .731). Key player centrality and mutual connectedness were different between teams but did not differ by match outcome. The results suggest that, ideally, Netball teams should maximise the number of connections between player pairings, while also relying on a subset of players to be heavily involved in passing sequences. Team cohesion (via passing) therefore appears to be an important measure of team success in elite Netball.

Research on the fire extinguishing performance of new gel foam for preventing and controlling the spontaneous combustion of coal gangue

Coal gangue, as an associated product of coal mining, can cause a large number of piles to undergo slow oxidation and spontaneous combustion, resulting in the production of toxic and harmful gases, leading to casualties, environmental damage, and economic losses. Gel foam has been extensively employed as a fire-retardant material in coal mine fire prevention. The thermal stability and rheological properties of the newly developed gel foam were investigated in this study, as well as its oxygen barrier properties and fire extinguishing effect which were evaluated through programmed temperature rise and field fire extinguishing experiments. The experiment indicated that the temperature endurance of the new gel foam was around twice that of the ordinary gel foam, and this resistance decreased with the increment of foaming times. Moreover, the temperature endurance of the new gel foam with a stabilizer concentration of 0.5% was superior to that of 0.7% and 0.3%. Temperature has a negative effect on the rheological properties of the new gel foam, while the foam stabilizer concentration has a positive effect. The oxygen barrier performance experiment results showed that the CO release rate of coal samples treated with the new gel foam rose relatively slowly with temperature, and the CO concentration of coal samples treated with the new gel foam was only 159 ppm at 100 °C, which was significantly lower than 361.1 ppm after two-phase foam treatment and 715 ppm after water treatment. Through simulating the spontaneous combustion experiment of coal gangue, it was demonstrated that the new gel foam has a much better extinguishing effect than water and traditional two-phase foam. The new gel foam cools gradually and does not re-ignite during the fire extinguishing process, while the other two materials re-ignite after being extinguished.

Preparation, characteristics, and performance of the microemulsion system in the removal of oil from beach sand

Oil deposited on shoreline substrates has serious adverse effects on the coastal environment and can persist for a long time. In this study, a green and effective microemulsion (ME) derived from vegetable oil was developed as a washing fluid to remove stranded oil from beach sand. The pseudo-ternary phase diagrams of the castor oil/water (without or without NaCl)/Triton X-100/ethanol were constructed to determine ME regions, and they also demonstrated that the phase behaviors of ME systems were almost independent of salinity. ME-A and ME-B exhibited high oil removal performance, low surfactant residues, and economic benefits, which were determined to be the W/O microstructure. Under optimal operation conditions, the oil removal efficiencies for both ME systems were 84.3 % and 86.8 %, respectively. Moreover, the reusability evaluation showed that the ME system still had over 70 % oil removal rates, even though it was used six times, implying its sustainability and reliability.

Hierarchy performance assessment of industrial solid waste utilization - tracking resource recycling and utilization centers in China

The massive production and accumulation of industrial solid waste (ISW) have led to environmental pollution and natural resource underutilization. China's efforts to build trial industrial waste resource utilization centers provide strong support for sustainable development. However, these centers and the factors driving ISW utilization have yet to be evaluated. This paper utilizes context-dependent data envelopment analysis models without explicit inputs (DEA-WEI) to evaluate the overall utilization performance of 48 industrial waste resource utilization centers in China from 2018 to 2020. It also builds a Tobit model to assess which indicators and waste types affect overall ISW utilization. The results show overall ISW utilization performance of centers in the sample has improved, with the average value falling from 1.7193 in 2018 to 1.5624 in 2020. However, there are clear regional performance gaps, with East China having the highest utilization performance (1.3113) while the Southwest had the lowest (2.2958). Finally, this paper proposes measures to improve the overall utilization of industrial waste resources based on an analysis of the factors driving solid waste utilization.

Critical incidents during anesthesia: prospective audit

BACKGROUND

Critical incident reporting and analysis is one of the key components of patient safety in anesthesiology. The aim of this study was to determine the frequency and characteristics of critical incidents during anesthesia, main causes and factors involved, influence on patient outcomes, prevalence of incident reporting and further analysis.

METHODS

A multicenter prospective audit was conducted at the clinical departments of the Bogomolets National Medical University during the period from 1 to 2021 to 1 December 2021. 13 hospitals from different Ukrainian regions took part in the study. Anesthesiologists voluntarily submitted critical incident reports into a Google form as they occurred during the working shifts, reporting the details of the incident, and the incident registration routine in their hospital. The study design was approved by the Bogomolets National Medical University (NMU) ethics committee, protocol #148, 07.09.2021.

RESULTS

The incidence of critical incidents was 9.35 cases per 1000 anesthetic procedures. Most common incidents were related to the respiratory system: difficult airway (26.8%), reintubation (6.4%), oxygen desaturation (13.8%); cardiovascular system: hypotension (14.9%), tachycardia (6.4%), bradycardia (11.7%), hypertension (5.3%), collapse (3.2%); massive hemorrhage (17%). Factors associated with critical incidents were elective surgery (OR 4.8 [3.1-7.5]), age from 45 to 75 years (OR 1.67 [1.1-2.5]), ASA II (OR 38 [13-106]}, III (OR 34 [12-98]) or IV (3.7 [1.2-11]) compared to ASA I; regional anesthesia (OR 0.67 95 CI 0.5-0.9) or general anesthesia (GA) and regional anesthesia combination (OR 0.55 95 CI 0.3-0.9] decreased the risk of incidents compared to GA alone. Procedural sedation was associated with increased risk of a critical incident, compared to GA (OR 0.55 95 CI 0.3-0.9). The incidents occurred most commonly during the maintenance phase (75/113, 40%, OR compared to extubation phase 20 95 CI 8-48) or the induction phases of anesthesia (70/118, 37%, OR compared to extubation phase 18 95 CI 7-43). Among common reasons that could lead to the incident, the physicians have identified: individual patient features (47%), surgical tactics (18%), anesthesia technique (16%) and human factor (12%). The most frequent failings contributing to the incident occurrence were: insufficient preoperative assessment (44%), incorrect interpretation of the patients' state (33%), faulty manipulation technique (14%), miscommunication with a surgical team (13%) and delay in emergency care (10%). Furthermore, 48% of cases, as judged by participating physicians, were preventable and the consequences of another 18% could be minimized. The consequences of the incidents were insignificant in over a half of the cases, but in 24.5% have led to prolonged hospital stay, in 16% patients required an urgent transfer to the ICU and 3% of patients died during their hospital stay. The majority of the critical incidents (84%) were reported through the hospital reporting system, using mostly paper forms (65%), oral reports (15%) and an electronic database (4%).

CONCLUSION

Critical incidents during anesthesia occur rather often, mainly during the induction or maintenance phases of anesthesia, and could lead to prolonged hospital stay, unplanned transfer to the ICU or death. Reporting and further analysis of the incident are crucial, so we should continue to develop the web-based reporting systems on both local and national levels.

STUDY REGISTRATION

NCT05435287, clinicaltrials.gov, 23/6/2022.

Design, implementation and performance analysis of an off- grid solar powered system for a Nigerian household

Solar panel converts direct current obtained from the sun into an alternating current which is often used in various applications. Photovoltaic (PV) power generation technology is used as a stand-alone system to bridge the power demand requirement due to increasing energy consumption. This paper aimed at presenting the design, implementation, and performance analysis of an off- grid solar power system for a Nigerian household. A comprehensive design was done on Solar PV systems, parts and components, and the principle of operation. Average solar irradiance of the location was obtained from data collation center at Nigerian Meteorological Agency (NiMet). The method utilizes the development of block diagram which shows the component layout and their connections and a flowchart which shows the procedure of achieving the objectives of the research. Battery efficiency, PV current measurement, current profile display and commissioning of the installed PV system formed the results. Thereafter, Implementation and performance analysis was carried out. The load demand assessment shows that power required was 23,820 Wh per day at maximum and 11,260 Wh per day when diversity factor was applied (Table 1). Consequently, a 3500VA inverter was selected with a battery size of 800AH.The test result showed that with a load of 11,260 Wh the device supplied energy for about 24hours uninterrupted. Therefore, off grid arrangement reduces the dependency on grid and allows users to derive maximum satisfaction without having relied on public power utilities. •Obtaining annual solar radiation data from NiMet and determine the load estimation.•Set up experiment that determine; Battery efficiency, solar panel required and connection mode suitable to achieve the desired current rating, Inverter rating, Charge controller as well appropriate protective devices.•Installation of project compartments and the commissioning tests by categories of load injection.

Real time prediction of match outcomes in Australian football

This study aimed to determine whether machine learning models based on technical performance and not score margin could be used to predict end-of-match outcome of Australian football matches in real-time. If efficacious, these models could be used to generate insights about team performance and support the decision-making of coaches during matches. A database of 168 team technical performance indicators from 829 Australian Football League matches played between 2017 and 2021 was used. Two feature sets (data-driven and data-informed) were used to train and evaluate six models (generalised linear model, random forest and adaboost) on match outcome prediction (Win/Loss) over 120 epochs (a representation of normalised time during each match). All models performed well (mean classification accuracy = 73.5-75.8%) in comparison with a benchmark score-based model (mean classification accuracy = 77.4%). Data-informed feature sets performed better than data-driven in most cases. Classification accuracy was low at the start of a match (45.7-48.8%) but increased to a peak near the end of a match (87.2-92.7%). These findings suggest that any of the employed models can be used to formulate in-match decision support. The model which is best in practice will depend on factors such as time-cost trade-off, feasibility and the perceived value of its suggestions.

Tactical positioning behaviours in short-track speed skating: A static and dynamic sequence analysis

Tactical positioning is essential for success in short-track speed skating as the race format (direct, head-to-head competition over multiple laps) prioritises finishing position over finishing time. Despite this, current research into tactical positioning treats the race's laps as discrete, independent events. Accordingly, the aggregate metrics used to summarise each lap's tactical positioning behaviour do not allow us to explore the sequential nature of the data, e.g., Lap 2 occurs after Lap 1 and before Lap 3. Here, we capture the sequential relationships between laps to investigate tactical positioning behaviours in short-track speed skating. Using intermediate and final rankings from 500 m, 1,000 m, and 1,500 m elite short-track races, we analyse whole-race and sub-race race sequences of group and winner tactical positioning behaviours. This approach, combined with a large dataset of races collected over eight seasons of competition (n  = 4,135), provides the most rigorous and comprehensive description of tactical positioning behaviours in short-track speed skating to date. Our results quantify the time-evolving complexity of tactical positioning, offer new thoughts on race strategy, and can help practitioners design more representative learning tasks to enhance skill transfer.

A lung sound recognition model to diagnoses the respiratory diseases by using transfer learning

Respiratory disease is one of the leading causes of death in the world. Through advances in Artificial Intelligence, it appears possible for the days of misdiagnosis and treatment of respiratory disease symptoms rather than their root cause to move behind us. The traditional convolutional neural network cannot extract the temporal features of lung sounds. To solve the problem, a lung sounds recognition algorithm based on VGGish- stacked BiGRU is proposed which combines the VGGish network with the stacked bidirectional gated recurrent unit neural network. A lung Sound Recognition Algorithm Based on VGGish-Stacked BiGRU is used as a feature extractor which is a pre-trained model used for transfer learning. The target model is built with the same structure as the source model which is the VGGish model and parameter transfer is done from the source model to the target model. The multi-layer BiGRU stack is used to enhance the feature value and retain the model. While fine-tuning of the parameter of VGGish is frozen which successfully improves the model. The experimental results show that the proposed algorithm improves the recognition accuracy of lung sounds and the recognition accuracy of respiratory diseases.

A holistic analysis of collective behaviour and team performance in Australian Football via structural equation modelling

Despite awareness of the importance of quantifying technical, tactical, and physical characteristics of match play, few studies have examined the structural relationship of these aspects in professional sport. Accordingly, this study concurrently examined these components in relation to quarter outcome (n = 272) in Australian Football. The study followed a retrospective longitudinal case study design where one teams' cooperative passing network, skill counts, physical loads, and spatiotemporal behaviours during official Australian Football League games were collected from a period spanning four seasons (2016-2019). A principal components analysis (PCA) and structural equation modelling were used to explore the structural relationships between components and examine the influence on quarter outcome as determined by the point differential (quarter margin). Scoring opportunity and ball movement had direct associations with quarter margin, while unpredictability, uncontested behaviour and physical behaviour did not. Negative associations between uncontested behaviour and scoring opportunity suggest that elevated high-pressure success and a lack of synchrony may positively influence scoring opportunity, a determinant of quarter margin. Further, negative associations between physical behaviour and ball movement suggest that with less physical work, a team's collective ability to transfer possession between teammates is facilitated, offering an interesting dichotomy between skill and physical demands of Australian Football. While hundreds of different metrics are available, the present study was the first to concurrently examine the influence of a variety of match play components on performance outcomes in Australian Football. These results may provide direction for coaches and practitioners when contemplating practice design, tactical strategies, or the development of behaviour through specific training exercises. Game plans and training drills that focus on optimising attacking and low-pressure ball movement coupled with high levels of mutual interaction between teammates may be beneficial for performance.

Interrelationship between trade and environment: a bibliometric analysis of published articles from the last two decades

Extant literature indicates that the concepts of international trade and the environment are intertwined. There is a plethora of theoretical and empirical research studies that explore the relationship between the two concepts. However, no bibliometric attempts have been made to analyze these publications to understand the current research trends in the trade and environment regulation/protection/policy intersection. Hence, the present study conducted a bibliometric analysis of 1390 research articles collected from the Scopus database from 2000 to 2021. The study accomplished performance and science mapping analysis using Bibliometrix and VOSViewer software. The study shows an increasing publication trend. The most productive country was the USA (259 publications with 8400 citations), and the most productive institution was the University of California (33 publications). The study found that Cole MA was the most relevant author in this area by considering multiple matrices. By using keywords, conceptual structure, and bibliographic coupling analysis, the study suggests that future studies can be conducted on climate change, carbon leakage, climate policy, environmental protection, air pollution, economic growth, carbon dioxide emission, emission trading, abatement cost, environmental performance, green supply chain management, composition effect, carbon footprints, and multi-regional input-output model. The current study provides scholars and practitioners interested in trade and environmental interlinkages with a comprehensive overview of the domain by presenting readers with significant studies, authors, universities, concepts, and sources. Further, the study results will be helpful for scholars to get insights into the current research development trends and research themes in the trade and environmental regulation field.

Performance analysis of parabolic type solar water heater by using copper-dimpled tube with aluminum coating

A solar water heater has been developed to convert solar radiation into heat for use in residential and commercial settings. The collector makes up the bulk of a solar water heating system. The solar energy is captured by the collector and transferred to the tube that delivers the working fluid, water. In addition to the collector's tube, which carries the working fluid, researchers have focused on the design of the collector's tube. This paper examines the performance of a parabolic plate solar water heater that uses a copper dimpled tube with aluminum-coated tube channels. During the test, the flow rate of base fluid was in the range of 1.0 to 3.0 kg/min in steps of 0.5. The performance of the solar water heater was also evaluated and verified using CFD. The test data such as friction factor, Reynolds number, uncertainty analysis, Nusselt number, solar collector efficiency, coefficient of convective heat transfer, linear dimpled tube velocity analysis, achieving maximum energy efficiency and thermal efficiency have been used to generate parametric values for parabolic plate solar water heaters. The results suggest that the best outcomes can be achieved with a mass flow rate of 2.5 kg/min and the overall thermal efficiency was raised to 31.85%, which is 11% greater than that of the plain tube with base fluid. At mass flow rates of 2.5 kg/min, the pressure drop was found to be 6.24% higher than that of 3.0 kg/min. The experimental results were analyzed and compared with the CFD results, and the overall deviation was ± 3.24% which is in the acceptable range.

Is he or she the main player in table tennis mixed doubles?

BACKGROUND

Since mixed doubles have been set up in the table tennis competition of the 2020 Tokyo Olympic Games, coaches and players have paid increasing attention to mixed doubles matches. This study aims to compare and analyse male and female performance in the different contexts of table tennis mixed doubles as well as the impact of their performance on the probability of winning matches.

METHODS

100 matches between the top 30 mixed doubles were selected (based on the world rankings for 2019 to 2021) as samples. According to the stroke order of a mixed doubles match, the players are divided into four groups: male versus male (P_m-m), male versus female (P_m-f), female versus male (P_f-m) and female versus female (P_f-f). Then, new methods with concepts are proposed to analyse stroke performance by four groups of players in various competition contexts of mixed doubles.

RESULTS

(1) The stroke performance in the first four strokes was much better than that in the after four strokes (P < 0.05), and males performed better than female players in the first four strokes (P < 0.05). (2) The stroke performance of each group for winning matches was significantly better than that for losing matches (P < 0.01). (3) Players in each group performed better (P < 0.01) in the ahead and under control states than in the behind and lost control states. However, most stroke performance within the four groups was not significantly different in different states. (4) The impact of scoring rates by different groups on the winning probability of a mixed doubles match from high to low was P_m-f > P_f-f > P_m-m > P_f-m. (5) In the actual competition, the percentage of female players serving first in each game is 79.64%, and the percentage of the stroke group of female players serving to female players receiving (P_f-f) is 58.25%.

CONCLUSION

This study considers several competition contexts to analyse the performance of male and female players in table tennis mixed doubles. We propose that the stroke performance of male versus female players is the most important factor affecting the results of mixed doubles matches. In addition, selecting the first server or first receiver in each game reasonably and analysing the stroke orders emphatically are also very important in mixed doubles.

Methods of performance analysis in women's Australian football: a scoping review

Background

The first women's Australian football (AF) professional competition was established in 2017, resulting in advancement in performance analysis capabilities within the sport. Given the specific constraints of women's AF, it is currently unclear what match-play performance analysis methods and techniques are implemented. Therefore, the aim of this scoping review was to describe and critically appraise physical, technical, and tactical performance analysis methods that have been employed in women's and girls' AF match-play.

Methodology

A systematic search was conducted on the 27th of June 2022 through five databases. Eligibility criteria were derived from the PCC framework with the population (P) of women and girls AF players, of any level of play; concepts (C) of interest which were measures, data, and methods related to the sport's physical, technical, and tactical performance; and the context (C) of methods that analysed any match-play performance. A narrative synthesis was conducted using extracted study characteristic data such as sample size, population, time period, collection standards, evaluation metrics for results, and application of thematic categorisations of previous sports performance reviews. Critical appraisal of eligible studies' methodologies was conducted to investigate research quality and identify methodological issues.

Results

From 183 studies screened, twelve eligible studies were included, which examined match-play through physical (9/12, 75%), technical (4/12, 33%), and tactical analysis (2/12, 17%). Running demands and game actions analysis were the most researched in senior women's AF. Research into junior girls' AF match-play performance has not been investigated. No research has been conducted on non-running physical demands, contact demands, acceleration, and tactical aspects of women's AF. All studies utilised either inferential statistics or basic predictive models. Critical appraisal deemed most studies as low risk of bias (11/12, 92%), with the remaining study having satisfactory risk.

Conclusions

Future research utilising increased longitudinal and greater contextual data is needed to combat the prominent issue of data representativeness to better characterise performance within women's and girls' AF. Additionally, research involving junior and sub-elite AF players across the talent pathways is important to conduct, as it provides greater context and insight regarding development to support the evolving elite women's AF competition. Women's AF has been constrained by its resource environment. As such, suggestions are provided for better utilisation of existing data, as well as for the creation of new data for appropriate future research. Greater data generation enables the use of detailed machine learning predictions, neural networks, and network analysis to better represent the intertwined nature of match-play performance from technical, physical, and tactical data.

The influence of removing home advantage on the Chinese Football Super League

BACKGROUND

Due to the COVID-19 pandemic, the 2020 season Chinese Super League (CSL) was held in neutral venues, this study aims to analyse the impact of removing home advantage (HA) in CSL.

METHOD

240 games of the CSL 2019 season (home and away double round-robin system) and 160 games of the 2020 season (in neutral venues) were analysed. 27 technical and tactical performance indicators were involved as dependent variables. A multiple linear regression model was established to analyse the influence of removing HA on the performance indicators.

RESULTS

After moving from home stadium to neutral venue in 2020 season, goal, shot, shot on target, shot from outside box, shot from inside box, shot on target from inside box, corner kick, key pass, cross, breakthrough, tackle decreased significantly (p < 0.05), while yellow card and foul increased steeply (p < 0.05). Comparing with playing away match, in neutral venue, free kicks and pass accuracy enhanced radically (p < 0.05), while tackle, clearance and block shot dropped noticeably (p < 0.05).

CONCLUSION

When removing HA and playing in the neutral venue, teams' performance dropped significantly. This study confirmed the positive impact of HA on the teams' performance and may help elite football teams make proper playing strategies regarding different match locations.

Design and simulation analysis of a bionic ostrich robot

To look for the reason why the biped animal in nature can run with such high speed and to design a bionic biped prototype which can behave the high speed running and jumping ability, this paper takes the fastest bipedal animal in nature: ostrich as the research subject. Firstly, the body structure and motion characteristics of ostrich are investigated. Secondly, a simple mechanical structure of bionic ostrich robot is designed based on the above biological investigated results. The robot is under-actuated with one actuator each leg, with a spring on the tarsometatarsus and a torsion spring on the metatarsophalangeal joint at the foot end. And then the mechanical design of leg structure is optimized. Finally, the high-speed running and jumping running gait is planned, and comparative simulations are implemented with different design requirements among pure rigid and rigid-flexible coupling scheme, which are rigid, only with spring, only with torsion spring, and with spring and torsion spring both, in detail. Simulation results show that the rigid-flexible coupling design scheme and whole body motion coordination can achieve better high speed performance. It provides an insight for the design and control of legged robots.

Tactical positioning in short-track speed skating: The utility of race-specific athlete-opponent interactions

In short-track speed skating, tactical positioning is essential for success as the race format (head-to-head) prioritises finishing position over finishing time. At present, our understanding of this phenomenon is based on measuring the similarity between athletes' intermediate and final rankings. However, as this approach groups athlete performances across races, each lap's estimate of tactical importance ignores the athlete-opponent interactions specific to each race. Here, we examine the utility of race-specific athlete-opponent interactions for investigating tactical positioning. Using intermediate and final rankings of elite 1,000 m short-track speed skating competitors collected from 2010/11 to 2017/18 (n = 6,196, races = 1,549), we compared the current method to a novel approach that accounted for race-specific athlete-opponent interactions. This approach first applied the current method to each race independently before using these values to form (1) discrete, empirical distributions of each lap's tactical importance and (2) race-specific tactical positioning sequences. Our results showed that accounting for race-specific athlete-opponent interactions provided a higher measurement granularity (i.e., level of detail) for investigating tactical positioning in short-track speed skating, which better captured the complexity of the phenomenon. We observed 61 different tactical positioning behaviours and 1,269 unique tactical positioning sequences compared to the current approach's nine-point estimates of tactical positioning importance. For this reason, we recommend that researchers and practitioners account for race-specific athlete-opponent interactions in the future as it offers a deeper understanding of tactical positioning that will enhance both strategic and tactical decisions.

Physical and technical demands of offence, defence, and contested phases of play in Australian Football

Background

This study compared the physical demands and effect of field location for different phases of play (offence, defence and contested), and examined the physical and technical demands of successful and unsuccessful phases of play during Australian Football matches.

Methods

Global positioning system (GPS) and technical performance data were collected from 32 male Australian Football players in one club over 19 games in the 2019 season. The GPS data was aligned with phases of play acquired using Champion Data. Linear mixed models were used to detect differences between phases of play and field location which were further contextualized using Cohen’s d effect size.

Results

Physical demands were greatest (p < 0.001) in defensive phases for backs (ES 0.61 to 1.42), and offensive phases for midfielders (ES 0.65 to 0.96) and forwards (ES 0.84 to 1.94). Additionally, distance and high-speed running were lowest in contested phases irrespective of playing position. Distance and high-speed running were greatest in larger field locations (e.g., full ground). No pattern was evident for accelerations or decelerations. Successful offensive plays demonstrated greater physical and technical outputs for midfielders and forwards, whereas the opposite was found for backs. Physical output was largely greater in unsuccessful defensive plays for all positions; however, the rate of tackles and marks was greater during successful defence.

Conclusion

These findings enable a greater understanding of the demands of Australian Football matches, and can be utilized to inform both representative training design, and the evaluation of player performance.

Performance indicators and functional adaptive windows in competitive cyclists: effect of one-year strength and conditioning training programme

Changes and relationships between cycling performance indicators following a one-year strength and conditioning training have not been totally clarified. The aims of this study are to investigate (i) the effect of a combined one-year strength and conditioning training programme on performance indicators and the possible relationships between these indicators, and (ii) the existence of possible endurance-functional-adaptive windows (EFAWs) linked to changes in muscular strength and body composition markers. Functional and lactate threshold power (FTP and LTP), maximal strength (1RM) and body composition (body mass index [BMI], body cell mass [BCM] and phase angle [PA]) were measured at the beginning and the end of a one-year strength and conditioning training programme of thirty cyclists. Correlations, differences, and predictive analysis were performed among parameters. Significant differences were found between pre- and post-conditioning programme results for FTP, LTP, 1RM (p < 0.0001) and BCM (p = 0.038). When expressed as power output (W), FTP and LTP were significantly correlated with 1RM (r = 0.36, p = 0.005 and r = 0.37, p = 0.004, respectively), body mass (r = 0.30 and p = 0.02), BCM (r = 0.68, p < 0.001) and PA (r = 0.42 and 0.39, respectively and p < 0.001). When expressed as W·kg-¹, these power thresholds were strongly correlated with body mass (r = -0.56 and -0.61, respectively) and BMI (r = -0.57 and -0.61 respectively) with p < 0.001. Predictive polynomial regressions revealed possible endurance and strength adaptation zones. The present findings indicated beneficial impacts of one-year strength and conditioning training on cycling performance indicators, confirmed the correlation between performance indicators, and suggested the existence of different EFAWs. Strategies aiming to improve performance should consider cyclist characteristics and performance goals to achieve EFAWs and thereby enhance cycling performance.

Identifying and analysing game styles and factors influencing a team's strategy in field hockey

Characterising a team's game style is a performance analysis approach that captures game events, and groups them into profiles using clustering techniques to identify the consistent (and winning) strategies a team implements. The aim of this study was to identify the game styles of international hockey teams. Video footage from the 2019 Pro League tournament (n = 74 female and n = 57 male matches) were analysed retrospectively using a notational analysis system in SportsCode™. Variables were arranged into six game style categories (established attack game actions, counter attack game actions, established attack success, counter attack success, set pieces, tempo) and two game style types identified per category using a k-means clustering algorithm. Decision trees were used to identify the influence of extrinsic and intrinsic match factors on the probability of a team playing a particular game style. Opposition and other reference team game style categories were shown to be more important in predicting a game style category than contextual factors. Examination of team profiles highlights how different strategies are successful for different teams such as high-intensity attack or absorbing pressure and counter attacking. This performance analysis process provides practical insights into the holistic performance of international hockey teams.

Auxiliary controller design and performance comparative analysis in closed-loop brain-machine interface system

Brain-machine interface (BMI) can realize information interaction between the brain and external devices, and yet the control accuracy is limited by the change of electroencephalogram signals. The introduction of auxiliary controller can overcome the above problems, but the performance of different auxiliary controllers is quite different. Hence, in this paper, we comprehensively compare and analyze the performance of different auxiliary controllers to provide a theoretical basis for designing BMI system. The main work includes: (1) designing four kinds of auxiliary controllers based on simultaneous perturbation stochastic approximation-function approximator (SPSA-FA), iterative feedback tuning-PID (IFT-PID), model predictive control (MPC) and model-free control (MFC); (2) based on the model of improved single-joint information transmission, constructing the closed-loop BMI systems with the decoder-based Wiener filter; and (3) comparing their performance in the constructed closed-loop BMI systems for dynamic motion restoration. The results show that the order of tracking accuracy is MPC, IFT-PID, SPSA-FA, MFC, and the order of time consumed is opposite. A good control effectiveness is achieved at the expense of time, so a suitable auxiliary controller should be selected according to the actual requirements.

Modelling the Influence of Task Constraints on Goal Kicking Performance in Australian Rules Football

Background

The primary aim of this study was to determine the influence of task constraints, from an ecological perspective, on goal kicking performance in Australian football. The secondary aim was to compare the applicability of three analysis techniques; logistic regression, a rule induction approach and conditional inference trees to achieve the primary aim. In this study, an ecological perspective has been applied to explore the impact of task constraints on shots on goal in the Australian Football League, such as shot type, field location and pressure. Analytical techniques can increase the understanding of competition environments and the influence of constraints on skilled events. Differing analytical techniques can produce varying outputs styles which can impact the applicability of the technique. Logistic regression, Classification Based on Associations rules and conditional inference trees were conducted to determine constraint interaction and their influence on goal kicking, with both the accuracy and applicability of each approach assessed.

Results

Each analysis technique had similar accuracy, ranging between 63.5% and 65.4%. For general play shots, the type of pressure and location particularly affected the likelihood of a shot being successful. Location was also a major influence on goal kicking performance from set shots.

Conclusions

When different analytical methods display similar performance on a given problem, those should be prioritised which show the highest interpretability and an ability to guide decision-making in a manner similar to what is currently observed in the organisation.

Effect of training volume on footstrike patterns over an exhaustive run

BACKGROUND

Although footstrike pattern (FP) may not be a factor influencing running performance, 11-75% of world-class distance runners use a non-rearfoot FP. However, little attention has been paid to describe the effect of running volume on FP changes when a runner is fatigued.

RESEARCH QUESTION

Does the training volume provide an adequate stimulus to mitigate FP changes during an exhaustive run in non-rearfoot, habitual minimalist footwear runners?

METHODS

The objective of this study was to compare FP between non-rearfoot, habitual minimalist footwear runners with a moderate training volume (MT) and a high training volume (HT) during an exhaustive run on a motorized treadmill. Based on their weekly training volume (distance), twenty-eight runners were arranged into two groups paired by height and age. At the first visit, runners underwent a VO2max test to acquire their velocity for the exhaustive run. During the second visit, biomechanical and physiological analysis of the beginning and the end phase of the exhaustive run was done.

RESULTS

The frontal plane foot angle, the sagittal plane ankle angle at the initial contact (IC), and the foot eversion ROM showed a significant interaction effect (P < 0.05). Additionally, the sagittal plane footstrike angle, the frontal plane foot angle, the sagittal plane ankle angle, knee flexion angle at IC and foot eversion ROM showed a significant effect of fatigue (P < 0.05). Finally, the frontal plane foot angle, the sagittal plane footstrike angle, the sagittal plane ankle angle, and the knee flexion angle showed significant group effects (P < 0.05).

SIGNIFICANCE

The training volume affects the footstrike pattern of non-rearfoot, habitual minimalist footwear runners when they are fatigued. The highly trained runners maintained their ankle angle throughout the exhaustive running protocol, whereas the moderately trained group changed the frontal and sagittal plane characteristics of their footstrike pattern.

Pitfalls in international benchmarking of energy intensity across wastewater treatment utilities

The collection, treatment and disposal of wastewater is estimated to consume more than 2% of the world's electrical energy, whilst some wastewater treatment plants (WWTPs) can account for over 20% of electrical consumption within municipalities. To investigate areas to improve wastewater treatment, international benchmarking on energy (electrical) intensity was conducted with the indicator kWh/m³ and a quality control of secondary treatment or better for ≥95% of treated volume. The core sample included 321 companies from 31 countries, however, to analyse regional differences, 11 countries from an external sample made up of various studies of WWTPs was also used in places. The sample displayed a weak-negative size effect with energy intensity, although Kruskal-Wallace analyses showed there was a significant difference between the size of groups (p-value of 0.015), suggesting that as companies get larger; they consume less electricity per cubic metre of wastewater treated. This relationship was not completely linear, as mid to large companies (10,001-100,000 customers) had the largest average consumption of 0.99 kWh/m³. In the regional analysis, EU states had the largest average kWh/m³ with 1.18, which appeared a result of the higher wastewater effluent standards of the region. This was supported by Denmark being the second largest average consuming country (1.35 kWh/m³), since it has some of strictest effluent standards in the world. Along with energy intensity, the associated greenhouse gas (GHG) emissions were calculated enabling the targeting of regions for improvement in response to climate change. Poland had the highest carbon footprint (0.91 kgCO₂e/m³) arising from an energy intensity of 0.89 kWh/m³; conversely, a clean electricity grid can affectively mitigate wastewater treatment inefficiencies, exemplified by Norway who emit just 0.013 kgCO₂e per cubic meter treated, despite consuming 0.60 kWh/m³. Finally, limitations to available data and the analysis were highlighted from which, it is advised that influent vs. effluent and net energy, as opposed to gross, data be used in future analyses. The large international sample size, energy data with a quality control, GHG analysis, and specific benchmarking recommendations give this study a novelty which could be of use to water industry operators, benchmarking organisations, and regulators.

Conceptualising Rugby League Performance Within an Ecological Dynamics Framework: Providing Direction for Player Preparation and Development

Across team sports, it is critically important to appropriately define, evaluate and then aptly describe individual and team performance. This is of particular significance when we consider that performance models govern the direction of player preparation (short term) and development (long term) frameworks. Within the context of rugby league, this has traditionally been undertaken through hierarchical and linear processes. Such approaches have resulted in research and performance analysis techniques which aim to support these operational outcomes. Yet, these methods may deliver limited application on how or why match-play unfolds and therefore might be sub-optimal in providing insights to truly support coaches. In this paper, we propose the conceptualisation of rugby league performance through the lens of ecological dynamics, which may offer a different view to this traditional approach. We propose that this approach eliminates the silos of disciplinary information (e.g. technical, physical and medical) that may currently exist, allowing for a holistic approach to performance, preparation and development. Specifically, we consider that through the implementation of this ecological approach, all performance coaches (technical, physical and medical) may (co-)design learning environments that more collaboratively develop players for rugby league match-play. As a result, we put forward a new rugby league performance model from which preparation and development programs can be anchored toward. We conclude the paper by offering practical examples where these concepts are contextualised within the landscape familiar to practitioners working within rugby league.

An assessment of physical and spatiotemporal behaviour during different phases of match play in professional Australian football

Despite advancements in the scale of data available for quantifying the physical and spatiotemporal characteristics of match play, there is an absence of research combining these aspects in professional sport. This study sought to differentiate between phases of play in professional Australian football using novel physical and spatiotemporal metrics. Data was obtained from Australian Football League games to provide new insight into the specific characteristics of each phase of play. A retrospective cross-sectional design was utilised with team's physical and spatiotemporal variables, measured via global navigation satellite system devices. A multinomial logistic regression was conducted to determine which physical and spatiotemporal measures were associated with each phase of play (contested play, defence, offence, set shot, goal reset, umpire stoppage). The addition of the predictors to a model that contained only the intercept significantly improved the fit between the model and data, with the logistic model correctly predicting the phase of play for 63.7% of the cases. This was the first study to concurrently examine differences in physical and spatiotemporal characteristics with respect to phase of play in an Australian football context. Differences in duration, physical and spatiotemporal properties were observed, providing new insight for coaches and subsequently providing direction for conditioning and practice design.

The balancing act between skiing and shooting - the determinants of success in biathlon pursuit and mass start events

This study aimed to investigate how skiing speed (SS), number of missed targets (MT) and range time (RT) were associated with final rank in biathlon pursuit and mass start competitions. Data were collected from the International Biathlon Union's database over 17 seasons. Biathletes were categorised into three groups (rank 1-3, G3; rank 4-10, G10; rank 11-20, G20).  Multinomial regression was used to identify odds ratios associated with group rank in both sexes. The only variable found to be consistently related to G3 in both pursuit and mass start was MT (men OR 1.206-1.729 and women OR 1.340-3.124, all p < 0.01). SS during lap four of pursuit and mass start was most strongly related to G3 for both sexes (men OR 0.231-0.094 and women OR 0.339-0.126, all p < 0.001). RT during shooting four in pursuit was most strongly related to G3 compared to G10 and G20 (men OR 1.067; 95% CI, 1.030-1.105 and women OR 1.076; 95% CI, 1.020-1.134, all p < 0.001, respectively). Accordingly, MT was most strongly related to final rank in both sexes, while SS during lap four and last RT was also significant.

The effect of team formation on defensive performance in Australian football

OBJECTIVES

Understanding the successful characteristics of team formation during different scenarios in Australian Football matches can assist coaches in making important tactical match-day and training decisions. The aims of this study were to explore the outcomes of entries inside 50 m of the goal, in Australian Football and to determine whether there was an association between team formation and team defensive performance after a turnover.

DESIGN

Observational.

METHODS

Global Positioning System (GPS) data, technical event data and video files from 22 matches in one season were obtained from an elite Australian Football club. Of 1092 forward 50 entries, 392 possession chains that resulted in a turnover were analysed. Variables representing team formation of players at the occurrence of turnover were compared between positive and negative outcomes of the subsequent possession chain. Logistic regression and decision tree modelling were also used to explore associations and variable importance.

RESULTS

None of 18 team formation characteristics differed between positive and negative outcomes of turnovers. Multivariate modelling identified that having a team formation with greater width than length made it more likely to result in a positive outcome (Decision tree classification accuracy = 69.5%, AUROC = 0.72).

CONCLUSIONS

No single characteristic of team formation affects the outcome of a turnover possession chain, however team formation that was wider than it was long may be associated with a more desirable outcome. The lack of association between most team formation characteristics and defensive outcomes, highlight the risk of over emphasising team formation in tactical planning for some phases of play.

Arm-leg coordination during the underwater pull-out sequence in the 50, 100 and 200 m breaststroke start

OBJECTIVES

To investigate the arm-leg coordination from different perspectives of motor control during the underwater start sequence to understand whether differences exist between the three competitive breaststroke swimming events.

DESIGN

Cross-sectional study.

METHODS

Forty-one breaststroke races (with race times relative to the world record): 50-meter (n = 14, 87.6%), 100-meter (n = 14, 88.5%) and 200-meter (n = 13, 85.4%) were recorded. A race analysis system tracked the two-dimensional displacement of the head. Key points from the underwater start sequence were obtained from notational analysis in order to compute seven time-gaps and four phases to assess the arm-leg coordination and timing of the dolphin kick. A one-way ANOVA with Bonferroni post-hoc correction was used to assess differences between the time gaps and phases for the three events.

RESULTS

Differences between the three events were found for total underwater glide, and the first (T0) and second (T1) major glide phase. No differences between the events were found in relative duration and distance for the time gaps related to arm-leg coordination (T1-3, T4, T6) and timing of the dolphin kick (T4-5) during the underwater start sequence.

CONCLUSIONS

The arm-leg coordination and timing of the dolphin kick showed no difference between the events, but the total underwater glide duration was longer in both the 100- and 200-meter compared with the 50-meter start. This shows that swimmers did not change the complex inter-limb coordination between the competitive events, but only modified the least complex movement, gliding, to adapt to the swimming speed of the respective events.

Quantitative and Qualitative Approach for Shear Wave Elastography in Superficial Lymph Nodes

The diagnostic contribution of 2-D shear-wave elastography (SWE) in management of superficial lymph nodes (LNs) of any origin was evaluated in 222 patients referred for needle core biopsy. Each patient underwent conventional B-mode/Doppler ultrasound examinations (conventional ultrasound) and SWE. Quantitative SWE parameters and qualitative SWE map features were extracted. Carcinomas were found to be significantly stiffer than benign LNs (29.5 ± 32.3 kPa vs. 6.7 ± 12.3 kPa). Lymphomas exhibited intermediate stiffness (11.4 ± 5.2 kPa). Qualitative SWE analysis provided color patterns specific to histopathology (stiff rim, nodular and undetermined patterns related to malignancy and blue pattern to benignity). Adding SWE to conventional ultrasound improved the sensitivity of LN diagnosis (from 81.1% to 92.0%) but decreased its specificity (from 73.2% to 67.6%) because of the high prevalence of lymphomas compared with carcinomas. Inter-observer agreement for quantitative SWE was good (intra-class correlation coefficient = 0.82) as was inter-observer diagnostic agreement for qualitative SWE (κ = 0.65). LN location and histology type were found to influence the reported diagnostic performance of SWE.

Swimming turn performance: the distinguishing factor in 1500 m world championship freestyle races?

Objective

Turn sections represent the second largest part of total race time in 1500 m freestyle races and may substantially affect race results. Therefore, the aim of the study was to investigate individual race strategies and compare the effect of start, swim, and turn performances between short-course and long-course races. Video footages were collected from all 16 male finalists at the 2018 short and 2019 long-course World swimming championships (age 23.06 ± 2.3 years, FINA points 941 ± 42) for subsequently analysis of start, turn, and swim performance.

Results

The larger number of turns in short-course races resulted in significantly faster race times (p = 0.004), but slower mean turn times compared to long-course races (p < 0.001). Total race velocity closely correlated with swim and turn but not start section velocity in short- (r ≥ 0.80, p ≤ 0.017) and long-course races (r ≥ 0.83, p ≤ 0.011). Analysis of individual race strategies showed that turn performance affected race results in 6 (75%) and 3 (37.5%) of the 8 world-best 1500 m swimmers in short-course and long-course races, respectively. Medal standing was improved for 1st, 3rd, and 4th ranked short- as well as 1st and 2nd ranked long-course finalist. Coaches, athletes, and performance analysts may carefully consider the importance of turn performance additionally to free-swimming skills.

Pacing strategies and relationships between speed and stroke parameters for elite sprint kayakers in single boats

The study aimed to determine the pacing strategies of elite single-boat sprint kayakers, as well as the relationships between stroke parameters (stroke rate (SR) and stroke length (SL)) and kayak speed throughout the race. High-resolution split speed and stroke parameter data from men's (MK1) and women's (WK1) single-boat A- and B-finals in 2016-2017 international sprint kayak competitions were analysed. Correlation coefficients were calculated between SR-speed and SL-speed during each split for each race group. Athletes followed all-out, positive and seahorse-shaped pacing strategies for the 200 m, 500 m and 1000 m races, respectively. SL-speed had greater correlations during the first half of the MK1 200 m race, whereas SR-speed had greater correlations during the second half. SR-speed correlations were greater than SL-speed correlations throughout the final 150 m of WK1 200 m races. There were large and very large correlations between SR-speed at the end of both the WK1 500 m and MK1 1000 m race distances, respectively, despite following different pacing strategies. Single-boat pacing strategies change due to race distance during major international sprint kayak competitions, whereas the relationships between stroke parameters and speed change depending on athlete sex and the race distance.

Applicability of statistical analysis for performance and reliability evaluation of large-scale water treatment plants with direct filtration systems

Water treatment plants (WTPs) are extremely important in basic sanitation services because of their association with human health by producing safe drinking water. Thus, their proper operation is of utmost relevance and has led to the development of distinct performance evaluation methodologies. Direct filtration is a leading technology applied in WTPs. However, although it costs less than conventional treatment, it might also be less flexible and robust. To evaluate performance with data from real-scale WTPs with direct filtration systems, the use of a statistical analysis methodology for turbidity, apparent color, and pH data from raw and effluent water is proposed. Reliability analysis, a probabilistic-based methodology, was applied for turbidity alongside evaluating the compliance of the treated water with different potability standards. The parameters pH (between 6.0 and 8.0) and apparent color (< 15 HU) showed almost complete compliance (> 99%). Reliability analysis could not be applied for apparent color and pH, while apparent color did not adhere to the lognormal distribution frequency. The turbidity results show high variability in the coefficients of variation and reliability among various plants and a general difficulty in complying with stricter standards, such as the 0.1 and 0.3 NTU defined by the United States Environmental Protection Agency. All WTP studies show a 95% compliance with the World Health Organization standard of 5.0 NTU. A higher value for the coefficient of reliability and a lower value for the variation coefficient could indicate a more stable process, regardless of the treated water quality, highlighting the relevance of applying combined methods for performance evaluation, such as compliance with established standards.