Dear Editor,This letter addresses the impulse game problem for a general scope of deterministic,multi-player,nonzero-sum differential games wherein all participants adopt impulse controls.Our objective is to formulate...Dear Editor,This letter addresses the impulse game problem for a general scope of deterministic,multi-player,nonzero-sum differential games wherein all participants adopt impulse controls.Our objective is to formulate this impulse game problem with the modified objective function including interaction costs among the players in a discontinuous fashion,and subsequently,to derive a verification theorem for identifying the feedback Nash equilibrium strategy.展开更多
Background In light of growing concern over eating disorders among young athletes amid cultural and social pressures,this study aimed to assess the prevalence of orthorexia nervosa(ON)risk and evaluate body image perc...Background In light of growing concern over eating disorders among young athletes amid cultural and social pressures,this study aimed to assess the prevalence of orthorexia nervosa(ON)risk and evaluate body image perception and its predictive factors among young football players from Poland and Türkiye.Methods The study involved 171 players aged 15–18 years,recruited from football academies in Poland and Türkiye.The Polish and Turkish versions of the Body-Esteem Scale for Adolescents and Adults(BESAA)were administered to assess body image perception,while the Düsseldorf Orthorexia Scale(DOS)was used to measure ON risk.Anthropometric measurements were taken to calculate Body Mass Index(BMI),which was then referenced to centile charts to determine nutritional status.Results Results indicated that 13%of participants exhibited characteristics of ON,with an additional 26%classified as at elevated risk.Comparative analysis revealed no significant differences in ON prevalence between Polish and Turkish players(p=0.938)and no age-related differences(p=0.694).Among Polish players,a significant positive association emerged between BMI(relative to centile charts)and overall appearance evaluation(BE-Appearance)(p=0.008,partialη^(2)=0.10).This relationship was not observed in Turkish players.Moreover,analysis of ON risk predictors—including age,nationality,nutritional status,and body image—did not identify any single variable as a definitive predictor(all p-values>0.05),with a low predictive capacity(McFadden’s R^(2)=0.03).Conclusion The study revealed a significant risk of ON among young footballers with no clear predictors.展开更多
This study examines on badminton players following anterior cruciate ligament(ACL)surgery.It analyses the risk factors in badminton that may cause re-injury to the knee joint,such as sports postures and exercise inten...This study examines on badminton players following anterior cruciate ligament(ACL)surgery.It analyses the risk factors in badminton that may cause re-injury to the knee joint,such as sports postures and exercise intensity.Scientific and reasonable sports protection measures and training plans are formulated,including correcting sports postures and reasonably controlling exercise intensity and frequency.Rehabilitation training is carried out in stages,and the training intensity and frequency are gradually adjusted according to the recovery situation.Through scientific protection and training,the risk of re-injury to athletes can be reduced,and they can be helped to restore their best sports conditions.At the same time,future research directions are prospected,covering personalized rehabilitation programs,application of new technologies,and research on psychological factors.展开更多
Objectives:Recently,the global esports industry has experienced remarkable growth,leading to an expansion in the scale and influence of professional player communities.However,despite this outward growth,systems to pr...Objectives:Recently,the global esports industry has experienced remarkable growth,leading to an expansion in the scale and influence of professional player communities.However,despite this outward growth,systems to protect players’mental health remain inadequate.Comprehensive analysis of structural risk factors,including performance pressure,public evaluation,and career instability,remains insufficient.This study,aimed to explore stressors encountered by esports athletes,coping strategies,and the role of social support systems in safeguarding mental health.Using the transactional model of stress and coping,the job demands–resources model,and social support theory,the study adopts an integrated perspective to examine challenges faced by athletes in the competitive esports environment.Methods:A qualitative case study was conducted involving in-depth interviews and nonparticipant observations with 11 esports athletes who competed at national or international levels,as well as two team managers.Thematic analysis identified recurring patterns in the data,and credibility was ensured through triangulation and cross-review among researchers.Results:Esports athletes experience multiple interacting stressors,including performance demands,emotional strain duringmatches,and continuous evaluation on socialmedia.In response,they employed coping strategies—problem-focused,emotion-focused,and avoidance-based,which provided temporary relief but often led to burnout and self-regulation failure owing to absence of support systems.Social support networks had ambivalent effects:while offering comfort,they also intensified pressure through negative feedback and high expectations from fans and online communities.Conclusion:The findings show that mental health issues among esports athletes are not only related to individual factors but are closely linked to performance-driven structures,competitive environments,and social relationships.This study integrates the transactional model of stress and coping,the JobDemands–Resourcesmodel,and social support theoryto provide comprehensive analysis.It also offers practical recommendations,including psychological counseling,emotional labor programs,and improved communication with families and fan communities.展开更多
The athletic component in football is nowadays one of the most important factor to determinate the performance. This consideration is part of our study, which aims to evaluate and quantify the difference between the w...The athletic component in football is nowadays one of the most important factor to determinate the performance. This consideration is part of our study, which aims to evaluate and quantify the difference between the workload of an amateur footballer and an elite one. All this is allowed by match analysis made by GPS evaluation method for amateur and video tracking for elite. The examined teams were playing in 7th Italian league, and we used 10 GPS to track 6 games, 5 for each team. For every team and every game were analysed a forward, a central midfielder, a wide midfielder, a central defender and a full back （Age 25.3 ＋ 4.2, Weight 74.5 Kg a： 5.3, Height 1.76 cm ＋ 5.2）. In our study, we used a 20 Hz GPS （thanks to Advanced Research Group in Sport, School of Health and Sport Science with K-Sport Universal, Italy） to detect performance data, and then we compared the outcome with matches performance data from elite players gather from scientific literature. Data analysis shows that elite players reach higher values in almost all parameters taken into account. In particular, they obtained higher value in meters per minutes, High Speed Distance （〉 16 Km/h）, High Metabolic Power Distance （〉 20 W/Kg） and in high and very high and acceleration （2 m/s, 3 m/s, 〉 3 m/s） and deceleration （-2 m/s, -3 m/s, 〉 -3 m/s）. This study can be useful to select and catalogue player performance model, in order to better understand the real value of a player, and to help coaches and teams to identify talent, at least in physical values.展开更多
针对PowerPoint在音、视频方面无法添加多个曲目和有效控制其播放的局限性,通过对PowerPoint提供的VBA和Windows Media Player控件的深入研究,利用Windows Media Player控件的特性,运用简单的编程和界面设计,给出了在PowerPoint2007中...针对PowerPoint在音、视频方面无法添加多个曲目和有效控制其播放的局限性,通过对PowerPoint提供的VBA和Windows Media Player控件的深入研究,利用Windows Media Player控件的特性,运用简单的编程和界面设计,给出了在PowerPoint2007中对音、视频实现曲目灵活播放和控制的方法。展开更多
基金supported in part by the National Natural Science Foundation of China(62173051)the Fundamental Research Funds for the Central Universities(2024CDJCGJ012,2023CDJXY-010)+1 种基金the Chongqing Technology Innovation and Application Development Special Key Project(CSTB2022TIADCUX0015,CSTB2022TIAD-KPX0162)the China Postdoctoral Science Foundation(2024M763865)
文摘Dear Editor,This letter addresses the impulse game problem for a general scope of deterministic,multi-player,nonzero-sum differential games wherein all participants adopt impulse controls.Our objective is to formulate this impulse game problem with the modified objective function including interaction costs among the players in a discontinuous fashion,and subsequently,to derive a verification theorem for identifying the feedback Nash equilibrium strategy.
文摘Background In light of growing concern over eating disorders among young athletes amid cultural and social pressures,this study aimed to assess the prevalence of orthorexia nervosa(ON)risk and evaluate body image perception and its predictive factors among young football players from Poland and Türkiye.Methods The study involved 171 players aged 15–18 years,recruited from football academies in Poland and Türkiye.The Polish and Turkish versions of the Body-Esteem Scale for Adolescents and Adults(BESAA)were administered to assess body image perception,while the Düsseldorf Orthorexia Scale(DOS)was used to measure ON risk.Anthropometric measurements were taken to calculate Body Mass Index(BMI),which was then referenced to centile charts to determine nutritional status.Results Results indicated that 13%of participants exhibited characteristics of ON,with an additional 26%classified as at elevated risk.Comparative analysis revealed no significant differences in ON prevalence between Polish and Turkish players(p=0.938)and no age-related differences(p=0.694).Among Polish players,a significant positive association emerged between BMI(relative to centile charts)and overall appearance evaluation(BE-Appearance)(p=0.008,partialη^(2)=0.10).This relationship was not observed in Turkish players.Moreover,analysis of ON risk predictors—including age,nationality,nutritional status,and body image—did not identify any single variable as a definitive predictor(all p-values>0.05),with a low predictive capacity(McFadden’s R^(2)=0.03).Conclusion The study revealed a significant risk of ON among young footballers with no clear predictors.
文摘This study examines on badminton players following anterior cruciate ligament(ACL)surgery.It analyses the risk factors in badminton that may cause re-injury to the knee joint,such as sports postures and exercise intensity.Scientific and reasonable sports protection measures and training plans are formulated,including correcting sports postures and reasonably controlling exercise intensity and frequency.Rehabilitation training is carried out in stages,and the training intensity and frequency are gradually adjusted according to the recovery situation.Through scientific protection and training,the risk of re-injury to athletes can be reduced,and they can be helped to restore their best sports conditions.At the same time,future research directions are prospected,covering personalized rehabilitation programs,application of new technologies,and research on psychological factors.
文摘Objectives:Recently,the global esports industry has experienced remarkable growth,leading to an expansion in the scale and influence of professional player communities.However,despite this outward growth,systems to protect players’mental health remain inadequate.Comprehensive analysis of structural risk factors,including performance pressure,public evaluation,and career instability,remains insufficient.This study,aimed to explore stressors encountered by esports athletes,coping strategies,and the role of social support systems in safeguarding mental health.Using the transactional model of stress and coping,the job demands–resources model,and social support theory,the study adopts an integrated perspective to examine challenges faced by athletes in the competitive esports environment.Methods:A qualitative case study was conducted involving in-depth interviews and nonparticipant observations with 11 esports athletes who competed at national or international levels,as well as two team managers.Thematic analysis identified recurring patterns in the data,and credibility was ensured through triangulation and cross-review among researchers.Results:Esports athletes experience multiple interacting stressors,including performance demands,emotional strain duringmatches,and continuous evaluation on socialmedia.In response,they employed coping strategies—problem-focused,emotion-focused,and avoidance-based,which provided temporary relief but often led to burnout and self-regulation failure owing to absence of support systems.Social support networks had ambivalent effects:while offering comfort,they also intensified pressure through negative feedback and high expectations from fans and online communities.Conclusion:The findings show that mental health issues among esports athletes are not only related to individual factors but are closely linked to performance-driven structures,competitive environments,and social relationships.This study integrates the transactional model of stress and coping,the JobDemands–Resourcesmodel,and social support theoryto provide comprehensive analysis.It also offers practical recommendations,including psychological counseling,emotional labor programs,and improved communication with families and fan communities.
文摘The athletic component in football is nowadays one of the most important factor to determinate the performance. This consideration is part of our study, which aims to evaluate and quantify the difference between the workload of an amateur footballer and an elite one. All this is allowed by match analysis made by GPS evaluation method for amateur and video tracking for elite. The examined teams were playing in 7th Italian league, and we used 10 GPS to track 6 games, 5 for each team. For every team and every game were analysed a forward, a central midfielder, a wide midfielder, a central defender and a full back （Age 25.3 ＋ 4.2, Weight 74.5 Kg a： 5.3, Height 1.76 cm ＋ 5.2）. In our study, we used a 20 Hz GPS （thanks to Advanced Research Group in Sport, School of Health and Sport Science with K-Sport Universal, Italy） to detect performance data, and then we compared the outcome with matches performance data from elite players gather from scientific literature. Data analysis shows that elite players reach higher values in almost all parameters taken into account. In particular, they obtained higher value in meters per minutes, High Speed Distance （〉 16 Km/h）, High Metabolic Power Distance （〉 20 W/Kg） and in high and very high and acceleration （2 m/s, 3 m/s, 〉 3 m/s） and deceleration （-2 m/s, -3 m/s, 〉 -3 m/s）. This study can be useful to select and catalogue player performance model, in order to better understand the real value of a player, and to help coaches and teams to identify talent, at least in physical values.
文摘针对PowerPoint在音、视频方面无法添加多个曲目和有效控制其播放的局限性,通过对PowerPoint提供的VBA和Windows Media Player控件的深入研究,利用Windows Media Player控件的特性,运用简单的编程和界面设计,给出了在PowerPoint2007中对音、视频实现曲目灵活播放和控制的方法。
