J. Fahey-Gilmour, B. Dawson, P. Peeling, J. Heasman, B. Rogalski
Abstract In Australian football (AF), few studies have assessed combinations of pre- game factors and their relation to game outcomes (win/loss) in multivariable analyses. Further, previous research has mostly been confined to association-based linear approaches and post-game prediction, with limited assessment of predictive machine learning (ML) models in a pre-game setting. Therefore, our aim was to use ML techniques to predict game outcomes and produce a hierarchy of important (win/loss) variables. A total of 152 variables (79 absolute and 73 differentials) were used from the 2013–2018 Australian Football League (AFL) seasons. Various ML models were trained (cross-validation) on the 2013–2017 seasons with the–2018 season used as an independent test set. Model performance varied (66.5-73.3% test set accuracy), although the best model (glmnet – 73.3%) rivalled bookmaker predictions in the same period (70.9%). The glmnet model revealed measures of team quality (a player-based rating and a team-based) in their relative form as the most important variables for prediction. Models that contained in-built feature selection or could model non-linear relationships generally performed better. These findings show that AFL game outcomes can be predicted using ML methods and provide a hierarchy of predictors that maximize the chance of winning.
{"title":"Multifactorial analysis of factors influencing elite Australian football match outcomes: a machine learning approach","authors":"J. Fahey-Gilmour, B. Dawson, P. Peeling, J. Heasman, B. Rogalski","doi":"10.2478/ijcss-2019-0020","DOIUrl":"https://doi.org/10.2478/ijcss-2019-0020","url":null,"abstract":"Abstract In Australian football (AF), few studies have assessed combinations of pre- game factors and their relation to game outcomes (win/loss) in multivariable analyses. Further, previous research has mostly been confined to association-based linear approaches and post-game prediction, with limited assessment of predictive machine learning (ML) models in a pre-game setting. Therefore, our aim was to use ML techniques to predict game outcomes and produce a hierarchy of important (win/loss) variables. A total of 152 variables (79 absolute and 73 differentials) were used from the 2013–2018 Australian Football League (AFL) seasons. Various ML models were trained (cross-validation) on the 2013–2017 seasons with the–2018 season used as an independent test set. Model performance varied (66.5-73.3% test set accuracy), although the best model (glmnet – 73.3%) rivalled bookmaker predictions in the same period (70.9%). The glmnet model revealed measures of team quality (a player-based rating and a team-based) in their relative form as the most important variables for prediction. Models that contained in-built feature selection or could model non-linear relationships generally performed better. These findings show that AFL game outcomes can be predicted using ML methods and provide a hierarchy of predictors that maximize the chance of winning.","PeriodicalId":38466,"journal":{"name":"International Journal of Computer Science in Sport","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44791506","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract Along with advancements in science and technology, anthropometric measurements using electronic devices have become possible, and research is being actively conducted on this topic. Recently, devices using Bluetooth that are portable because of their small size have been developed to allow real-time measurements and recording. This study investigated the concurrent validity and intra-trial reliability of a recently developed Bluetooth-embedded inertial measurement unit. Thirty-seven healthy, young adult participants (age = 22.1±1.2 years, height = 166.8±1.6 cm, mass = 61.9±12.3 kg) were included in the study. The knee extension angles during active knee extension were measured for validity, using both the Bluetooth-embedded inertial measurement unit and the standard goniometer. Intra-trial reliability was tested for consistency during repeated measurements. The intra-class correlation coefficients value for the concurrent validity between the Bluetooth-embedded inertial measurement unit and standard goniometer was 0.991, and the values for the intra-trial reliability of the two devices were 0.973 and 0.963, respectively. Based on its high validity and reliability, the Bluetooth-embedded device may be useful for evaluating functional impairment and exercise performance ability by real-time measurements of joint ranges of motion in clinical rehabilitation or sports fields.
{"title":"Concurrent validity and intra-trial reliability of a bluetooth-embedded inertial measurement unit for real-time joint range of motion","authors":"D. Oh, W. Lim, N. Lee","doi":"10.2478/ijcss-2019-0015","DOIUrl":"https://doi.org/10.2478/ijcss-2019-0015","url":null,"abstract":"Abstract Along with advancements in science and technology, anthropometric measurements using electronic devices have become possible, and research is being actively conducted on this topic. Recently, devices using Bluetooth that are portable because of their small size have been developed to allow real-time measurements and recording. This study investigated the concurrent validity and intra-trial reliability of a recently developed Bluetooth-embedded inertial measurement unit. Thirty-seven healthy, young adult participants (age = 22.1±1.2 years, height = 166.8±1.6 cm, mass = 61.9±12.3 kg) were included in the study. The knee extension angles during active knee extension were measured for validity, using both the Bluetooth-embedded inertial measurement unit and the standard goniometer. Intra-trial reliability was tested for consistency during repeated measurements. The intra-class correlation coefficients value for the concurrent validity between the Bluetooth-embedded inertial measurement unit and standard goniometer was 0.991, and the values for the intra-trial reliability of the two devices were 0.973 and 0.963, respectively. Based on its high validity and reliability, the Bluetooth-embedded device may be useful for evaluating functional impairment and exercise performance ability by real-time measurements of joint ranges of motion in clinical rehabilitation or sports fields.","PeriodicalId":38466,"journal":{"name":"International Journal of Computer Science in Sport","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43797307","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Astrid Salte Wiig, Else Marie Håland, M. Stålhane, L. M. Hvattum
Abstract This paper investigates the use of network analysis to identify key players on teams, and patterns of passing within teams, in association football. Networks are constructed based on passes made between players, and several centrality measures are investigated in combination with three different methods for evaluating individual passes. Four seasons of data from the Norwegian top division are used to identify key players and analyze matches from a selected team. The networks examined in this work have weights based on three different aspects of the passes made: their probability of being completed, the probability that the team keeps possession after the completed pass, and the probability of the pass being part of a sequence leading to a shot. The results show that using different metrics and network weights leads to the identification of key passers in different phases of play and in different positions on the pitch.
{"title":"Analyzing passing networks in association football based on the difficulty, risk, and potential of passes","authors":"Astrid Salte Wiig, Else Marie Håland, M. Stålhane, L. M. Hvattum","doi":"10.2478/ijcss-2019-0017","DOIUrl":"https://doi.org/10.2478/ijcss-2019-0017","url":null,"abstract":"Abstract This paper investigates the use of network analysis to identify key players on teams, and patterns of passing within teams, in association football. Networks are constructed based on passes made between players, and several centrality measures are investigated in combination with three different methods for evaluating individual passes. Four seasons of data from the Norwegian top division are used to identify key players and analyze matches from a selected team. The networks examined in this work have weights based on three different aspects of the passes made: their probability of being completed, the probability that the team keeps possession after the completed pass, and the probability of the pass being part of a sequence leading to a shot. The results show that using different metrics and network weights leads to the identification of key passers in different phases of play and in different positions on the pitch.","PeriodicalId":38466,"journal":{"name":"International Journal of Computer Science in Sport","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41775831","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract Numerous mobile applications are available that aim at supporting sustainable physical activity and fitness training in sedentary or low-trained healthy people. However, the evaluation of the quality of these applications often suffers from severe shortcomings such as reduction to selective aspects, lack of theory or suboptimal methods. What is still missing, is a framework that integrates the insights of the relevant scientific disciplines. In this paper, we propose an integrative framework comprising four modules: training, behavior change techniques, sensors and technology, and evaluation of effects. This framework allows to integrate insights from training science, exercise physiology, social psychology, computer science, and civil engineering as well as methodology. Furthermore, the framework can be flexibly adapted to the specific features of the mobile applications, e.g., regarding training goals and training methods or the relevant behavior change techniques as well as formative or summative evaluation.
{"title":"Evaluation of mobile applications for fitness training and physical activity in healthy low-trained people - A modular interdisciplinary framework","authors":"J. Wiemeyer","doi":"10.2478/ijcss-2019-0016","DOIUrl":"https://doi.org/10.2478/ijcss-2019-0016","url":null,"abstract":"Abstract Numerous mobile applications are available that aim at supporting sustainable physical activity and fitness training in sedentary or low-trained healthy people. However, the evaluation of the quality of these applications often suffers from severe shortcomings such as reduction to selective aspects, lack of theory or suboptimal methods. What is still missing, is a framework that integrates the insights of the relevant scientific disciplines. In this paper, we propose an integrative framework comprising four modules: training, behavior change techniques, sensors and technology, and evaluation of effects. This framework allows to integrate insights from training science, exercise physiology, social psychology, computer science, and civil engineering as well as methodology. Furthermore, the framework can be flexibly adapted to the specific features of the mobile applications, e.g., regarding training goals and training methods or the relevant behavior change techniques as well as formative or summative evaluation.","PeriodicalId":38466,"journal":{"name":"International Journal of Computer Science in Sport","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48485796","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract Even several years after total hip (THR) and total knee replacement (TKR) surgery patients frequently show deficient gait patterns leading to overloads and relieving postures on the contralateral side or in the spine. Gait training is, in these cases, an essential part of rehabilitation. The aim of this study was to compare different feedback methods during gait training after THR and TKR focusing, in particular, on auditory feedback via sonification. A total of 240 patients after THR and TKR were tested in a pre-post-test design during a 3-week rehabilitation period. Even though sonification did not show, statistically, a clear advantage over other feedback methods, it was well accepted by the patients and seemed to significantly change gait pattern during training. A sudden absence of sonification during training led to a rapid relapse into previous movement patterns, which highlights its effectiveness in breaking highly automated gait patterns. A frequent use of sonification during and after rehabilitation could, hence, reduce overloading after THR and TKR. This may soon be viable, since new technologies, such as inertial measurement units, allow for wearable joint angle measurement devices. Back to normal gait with sonification seems possible.
{"title":"Gait Training in Orthopedic Rehabilitation after Joint Replacement - Back to Normal Gait with Sonification?","authors":"Juliane Pietschmann, F. Flores, T. Jöllenbeck","doi":"10.2478/ijcss-2019-0012","DOIUrl":"https://doi.org/10.2478/ijcss-2019-0012","url":null,"abstract":"Abstract Even several years after total hip (THR) and total knee replacement (TKR) surgery patients frequently show deficient gait patterns leading to overloads and relieving postures on the contralateral side or in the spine. Gait training is, in these cases, an essential part of rehabilitation. The aim of this study was to compare different feedback methods during gait training after THR and TKR focusing, in particular, on auditory feedback via sonification. A total of 240 patients after THR and TKR were tested in a pre-post-test design during a 3-week rehabilitation period. Even though sonification did not show, statistically, a clear advantage over other feedback methods, it was well accepted by the patients and seemed to significantly change gait pattern during training. A sudden absence of sonification during training led to a rapid relapse into previous movement patterns, which highlights its effectiveness in breaking highly automated gait patterns. A frequent use of sonification during and after rehabilitation could, hence, reduce overloading after THR and TKR. This may soon be viable, since new technologies, such as inertial measurement units, allow for wearable joint angle measurement devices. Back to normal gait with sonification seems possible.","PeriodicalId":38466,"journal":{"name":"International Journal of Computer Science in Sport","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47918380","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
O. Ueberschär, D. Fleckenstein, F. Warschun, Nico Walter, Jan Wüstenfeld, B. Wolfarth, M. Hoppe
Abstract Hypogravity treadmills have become a popular training tool in distance running and triathlon. Counter-intuitively, tibial acceleration load is not attenuated by hypogravity unloading during running, while, equally surprisingly, leaps become flatter instead of higher. To explain these effects from a biomechanical perspective, Polet, Schroeder, and Bertram (2017) recently developed an energetic model for hypogravity running and validated it with recreational athletes at a constant jogging speed. The present study was conducted to refine that model for competitive athletes at relevant running speeds of 12–22 km h−1 and gravity levels of 100 %, 80 % and 60 %. Based on new experimental data on 15 well-trained runners in treadmill tests until volitional exhaustion, the enhanced semi-empirical model well describes energy expenditure and the observed biomechanical effects of hypogravity running. Remarkably, anaerobic contributions led to an increase in energy cost per meter for speeds above 16–18 km h−1 (p < 0.001), irrespective of hypogravity unloading. Moreover, some converging trends were observed that might reflect general adaptations in running motor control for optimization of efficiency. In essence, the outcome of this research might help sports scientists and practitioners to design running programs for specific training stimuli, e.g. conditioning of anaerobic energy metabolism.
摘要:低重力跑步机已成为长跑和铁人三项运动中流行的训练工具。与直觉相反的是，跑步时的失重卸载不会减弱胫骨加速度负荷，而同样令人惊讶的是，跳跃变得更平而不是更高。为了从生物力学的角度解释这些影响，Polet, Schroeder和Bertram(2017)最近开发了一个低重力跑步的能量模型，并通过休闲运动员以恒定的慢跑速度进行验证。目前的研究是为了完善该模型，适用于比赛运动员在相关跑步速度为12-22 km h - 1，重力水平为100%，80%和60%的情况下。基于15名训练有素的跑步者在跑步机上进行的新实验数据，增强的半经验模型很好地描述了低重力跑步的能量消耗和观察到的生物力学效应。值得注意的是，当速度超过16-18 km h - 1时，厌氧的贡献导致每米能量成本的增加(p < 0.001)，而不考虑失重卸载。此外，观察到一些收敛趋势，可能反映了运行电机控制的一般适应性，以优化效率。从本质上讲，这项研究的结果可能有助于运动科学家和实践者为特定的训练刺激设计跑步计划，例如无氧能量代谢的调节。
{"title":"Energy Cost of Running Under Hypogravity in Well-Trained Runners and Triathletes: A Biomechanical Perspective","authors":"O. Ueberschär, D. Fleckenstein, F. Warschun, Nico Walter, Jan Wüstenfeld, B. Wolfarth, M. Hoppe","doi":"10.2478/ijcss-2019-0014","DOIUrl":"https://doi.org/10.2478/ijcss-2019-0014","url":null,"abstract":"Abstract Hypogravity treadmills have become a popular training tool in distance running and triathlon. Counter-intuitively, tibial acceleration load is not attenuated by hypogravity unloading during running, while, equally surprisingly, leaps become flatter instead of higher. To explain these effects from a biomechanical perspective, Polet, Schroeder, and Bertram (2017) recently developed an energetic model for hypogravity running and validated it with recreational athletes at a constant jogging speed. The present study was conducted to refine that model for competitive athletes at relevant running speeds of 12–22 km h−1 and gravity levels of 100 %, 80 % and 60 %. Based on new experimental data on 15 well-trained runners in treadmill tests until volitional exhaustion, the enhanced semi-empirical model well describes energy expenditure and the observed biomechanical effects of hypogravity running. Remarkably, anaerobic contributions led to an increase in energy cost per meter for speeds above 16–18 km h−1 (p < 0.001), irrespective of hypogravity unloading. Moreover, some converging trends were observed that might reflect general adaptations in running motor control for optimization of efficiency. In essence, the outcome of this research might help sports scientists and practitioners to design running programs for specific training stimuli, e.g. conditioning of anaerobic energy metabolism.","PeriodicalId":38466,"journal":{"name":"International Journal of Computer Science in Sport","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45878145","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract Sports coaches today have access to a growing amount of information that describes the performance of their players. Methods such as data mining have become increasingly useful tools to deal with the analytical demands of these high volumes of data. In this paper, we present a sports data mining approach using a combination of sequential association rule mining and clustering to extract useful information from a database of more than 400 high level beach volleyball games gathered at FIVB events in the years from 2013 to 2016 for both men and women. We regard each rally as a sequence of transactions including the tactical behaviours of the players. Use cases of our approach are shown by its application on the aggregated data for both genders and by analyzing the sequential patterns of a single player. Results indicate that sequential rule mining in conjunction with clustering can be a useful tool to reveal interesting patterns in beach volleyball performance data.
{"title":"Data Mining in Elite Beach Volleyball – Detecting Tactical Patterns Using Market Basket Analysis","authors":"S. Wenninger, D. Link, M. Lames","doi":"10.2478/ijcss-2019-0010","DOIUrl":"https://doi.org/10.2478/ijcss-2019-0010","url":null,"abstract":"Abstract Sports coaches today have access to a growing amount of information that describes the performance of their players. Methods such as data mining have become increasingly useful tools to deal with the analytical demands of these high volumes of data. In this paper, we present a sports data mining approach using a combination of sequential association rule mining and clustering to extract useful information from a database of more than 400 high level beach volleyball games gathered at FIVB events in the years from 2013 to 2016 for both men and women. We regard each rally as a sequence of transactions including the tactical behaviours of the players. Use cases of our approach are shown by its application on the aggregated data for both genders and by analyzing the sequential patterns of a single player. Results indicate that sequential rule mining in conjunction with clustering can be a useful tool to reveal interesting patterns in beach volleyball performance data.","PeriodicalId":38466,"journal":{"name":"International Journal of Computer Science in Sport","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43931990","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
K. Petri, S. Masik, Marco Danneberg, Peter Emmermacher, K. Witte
Abstract We conducted a virtual reality (VR) training with ten sessions, performed by fifteen young karate athletes, who responded to attacks of a virtual opponent to improve their response behavior and their decision-making. The control groups continued with their normal training. Results of the Friedman tests with subsequent Dunn-Bonferroni post-hoc-tests and estimation of effect sizes showed that the karate specific response behavior (measured by a movement analysis) improved significantly due to the training. The parameters time for response (as the time for the attack initiation) and response quality improved with large effect sizes for the intervention groups, whereas the control groups demonstrated improvements with only small effect sizes. The unspecific response behavior (analyzed by two forms of the reaction test of the Vienna test system) did not show any significant changes. Paired t-tests revealed an improvement in attack recognition. While in the pretests, the intervention groups responded to late movement stages of the attack (execution of the main phase), they responded to early movement stages (reduction of distance and preparing steps) in the posttests. Furthermore, Friedman-tests and bivariate correlation analysis showed that the intervention groups were highly motivated to perform the VR training because of the new and safe learning conditions.
{"title":"Possibilities to Use a Virtual Opponent for Enhancements of Reactions and Perception of Young Karate Athletes","authors":"K. Petri, S. Masik, Marco Danneberg, Peter Emmermacher, K. Witte","doi":"10.2478/ijcss-2019-0011","DOIUrl":"https://doi.org/10.2478/ijcss-2019-0011","url":null,"abstract":"Abstract We conducted a virtual reality (VR) training with ten sessions, performed by fifteen young karate athletes, who responded to attacks of a virtual opponent to improve their response behavior and their decision-making. The control groups continued with their normal training. Results of the Friedman tests with subsequent Dunn-Bonferroni post-hoc-tests and estimation of effect sizes showed that the karate specific response behavior (measured by a movement analysis) improved significantly due to the training. The parameters time for response (as the time for the attack initiation) and response quality improved with large effect sizes for the intervention groups, whereas the control groups demonstrated improvements with only small effect sizes. The unspecific response behavior (analyzed by two forms of the reaction test of the Vienna test system) did not show any significant changes. Paired t-tests revealed an improvement in attack recognition. While in the pretests, the intervention groups responded to late movement stages of the attack (execution of the main phase), they responded to early movement stages (reduction of distance and preparing steps) in the posttests. Furthermore, Friedman-tests and bivariate correlation analysis showed that the intervention groups were highly motivated to perform the VR training because of the new and safe learning conditions.","PeriodicalId":38466,"journal":{"name":"International Journal of Computer Science in Sport","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46292736","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Edelmann-Nusser, A. Raschke, A. Bentz, S. Montenbruck, Jürgen Edelmann-Nusser, M. Lames
Abstract Three inertial measurement unit (IMU) based tennis sensor systems from BABOLAT (PURE DRIVE PLAY, POP) and HEAD (Tennis Sensor) and a camera-based system (PlaySight) were tested with respect to the question whether the information about the number of strokes by swing type and spin type in training exercises and/or matches and the average as well as the maximum speed of the service per session are reliable. Subsequently, the question whether the mechanical properties of the BABOLAT PURE DRIVE PLAY racket are the same as the mechanical properties of the BABOLAT PURE DRIVE racket without IMU was addressed. For swing types in standard exercises the results are acceptable for forehand groundstrokes, backhand groundstrokes and services but not for volleys. In a match environment we find inacceptably high errors (>10%) for the number of strokes for forehand and completely inacceptable levels for volley. The wrist-based IMU of BABOLAT POP has not reached an acceptable accuracy at all. For spin types the results are acceptable. The large variances in service speed assessment between devices make it doubtful whether any of them may be used for the control of training processes aiming at increasing the average service speed The mechanical properties of the BABOLAT rackets with and without IMU are quite the same.
摘要对BABOLAT（PURE DRIVE PLAY，POP）和HEAD（tennis sensor）的三个基于惯性测量单元（IMU）的网球传感器系统以及一个基于相机的系统（PlaySight）进行了测试，以确定训练练习和/或比赛中按挥杆类型和旋转类型的击球次数信息会话是可靠的。随后，解决了BABOLAT PURE DRIVE PLAY球拍的机械性能是否与没有IMU的BABOLAT PURE DRIVE球拍的机械特性相同的问题。对于标准练习中的挥杆类型，正手滚地球、反手滚地球和发球的结果是可以接受的，但截击则不可以。在比赛环境中，我们发现正手击球次数的错误率高得令人无法接受（>10%），而凌空抽射的错误率则完全无法接受。BABOLAT POP基于手腕的IMU根本没有达到可接受的精度。对于自旋类型，结果是可以接受的。设备之间的服务速度评估差异很大，这使得人们怀疑它们中的任何一个是否可以用于控制旨在提高平均服务速度的训练过程。有IMU和没有IMU的BABOLAT球拍的机械性能完全相同。
{"title":"Validation of Sensor-Based Game Analysis Tools in Tennis","authors":"A. Edelmann-Nusser, A. Raschke, A. Bentz, S. Montenbruck, Jürgen Edelmann-Nusser, M. Lames","doi":"10.2478/ijcss-2019-0013","DOIUrl":"https://doi.org/10.2478/ijcss-2019-0013","url":null,"abstract":"Abstract Three inertial measurement unit (IMU) based tennis sensor systems from BABOLAT (PURE DRIVE PLAY, POP) and HEAD (Tennis Sensor) and a camera-based system (PlaySight) were tested with respect to the question whether the information about the number of strokes by swing type and spin type in training exercises and/or matches and the average as well as the maximum speed of the service per session are reliable. Subsequently, the question whether the mechanical properties of the BABOLAT PURE DRIVE PLAY racket are the same as the mechanical properties of the BABOLAT PURE DRIVE racket without IMU was addressed. For swing types in standard exercises the results are acceptable for forehand groundstrokes, backhand groundstrokes and services but not for volleys. In a match environment we find inacceptably high errors (>10%) for the number of strokes for forehand and completely inacceptable levels for volley. The wrist-based IMU of BABOLAT POP has not reached an acceptable accuracy at all. For spin types the results are acceptable. The large variances in service speed assessment between devices make it doubtful whether any of them may be used for the control of training processes aiming at increasing the average service speed The mechanical properties of the BABOLAT rackets with and without IMU are quite the same.","PeriodicalId":38466,"journal":{"name":"International Journal of Computer Science in Sport","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46153820","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract The purpose of this study was to examine, within a sports broadcasting setting, the relationship between social viewing users’ motivation, satisfaction, and loyalty and to determine if social viewing could be used as a marketing strategy in the sport industry. For this study, data were collected by using an online survey targeting social media users. A total of 379 survey responses were used for the data analysis. The study’s hypothesized model constructs were evaluated using Structural Equation Modeling (SEM) and the data analysis revealed several key findings. The results revealed that the sharing of social viewing experiences in sports broadcasting had a positive impact on user satisfaction. User satisfaction was also positively impacted by both information searching and the excitement found in social sports viewing. Lastly, users’ satisfaction positively influenced loyalty.
{"title":"The Relationship between Motivation of Social Viewing Experiences, Satisfaction, and Loyalty in Sports Broadcasting","authors":"Y. Suh, Taewook Chung, Jong Min Kim","doi":"10.2478/ijcss-2019-0009","DOIUrl":"https://doi.org/10.2478/ijcss-2019-0009","url":null,"abstract":"Abstract The purpose of this study was to examine, within a sports broadcasting setting, the relationship between social viewing users’ motivation, satisfaction, and loyalty and to determine if social viewing could be used as a marketing strategy in the sport industry. For this study, data were collected by using an online survey targeting social media users. A total of 379 survey responses were used for the data analysis. The study’s hypothesized model constructs were evaluated using Structural Equation Modeling (SEM) and the data analysis revealed several key findings. The results revealed that the sharing of social viewing experiences in sports broadcasting had a positive impact on user satisfaction. User satisfaction was also positively impacted by both information searching and the excitement found in social sports viewing. Lastly, users’ satisfaction positively influenced loyalty.","PeriodicalId":38466,"journal":{"name":"International Journal of Computer Science in Sport","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47451914","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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