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
Evaluating and selecting players to suit football clubs and decision-makers (coaches, managers, technical, and medical staff) is a difficult process from a managerial-financial and sporting perspective. Football is a ...Evaluating and selecting players to suit football clubs and decision-makers (coaches, managers, technical, and medical staff) is a difficult process from a managerial-financial and sporting perspective. Football is a highly competitive sport where sponsors and fans are attracted by success. The most successful players, based on their characteristics (criteria and sub-criteria), can influence the outcome of a football game at any given time. Consequently, the D-day of selection should employ a more appropriate approach to human resource management. To effectively address this issue, a detailed study and analysis of the available literature are needed to assist practitioners and professionals in making decisions about football player selection and hiring. Peer-reviewed journals were selected for collecting published papers between 2018 and 2023. A total of 66 relevant articles (journal articles, conference articles, book sections, and review articles) were selected for evaluation and analysis. The purpose of the study is to present a systematic literature review (SLR) on how to solve this problem and organize the published research papers that answer our four research questions.展开更多
It is well established that Nash equilibrium exists within the framework of mixed strategies in strategic-form non-cooperative games. However, finding the Nash equilibrium generally belongs to the class of problems kn...It is well established that Nash equilibrium exists within the framework of mixed strategies in strategic-form non-cooperative games. However, finding the Nash equilibrium generally belongs to the class of problems known as PPAD (Polynomial Parity Argument on Directed graphs), for which no polynomial-time solution methods are known, even for two-player games. This paper demonstrates that in fixed-sum two-player games (including zero-sum games), the Nash equilibrium forms a convex set, and has a unique expected payoff. Furthermore, these equilibria are Pareto optimal. Additionally, it is shown that the Nash equilibrium of fixed-sum two-player games can theoretically be found in polynomial time using the principal-dual interior point method, a solution method of linear programming.展开更多
目的:探讨经颅直流电刺激(transcranial direct current stimulation,tDCS)干预左背侧前运动皮质(dorsal premotor cortex,PMd)对高水平足球运动员运动疲劳后知觉预测能力的影响。方法:24名国家一级足球运动员在完成60%最大骑行功率(Pow...目的:探讨经颅直流电刺激(transcranial direct current stimulation,tDCS)干预左背侧前运动皮质(dorsal premotor cortex,PMd)对高水平足球运动员运动疲劳后知觉预测能力的影响。方法:24名国家一级足球运动员在完成60%最大骑行功率(Powermax)恒定负荷力竭骑行后,以平衡抵消法接受2 mA tDCS正极刺激左侧PMd 10 min和伪刺激,随后进行视觉搜索任务、预测足球突破过人任务和预测足球罚点球任务测试。结果:足球运动员疲劳后,进行tDCS正极刺激的视觉搜索任务反应时在3(P=0.039)和6(P=0.017)数量型与伪刺激相比显著降低,预测足球突破过人任务的准确率在240 ms条件与伪刺激相比显著增高(P<0.001)。但是视觉搜索任务准确性、预测足球突破过人任务的反应时以及预测足球罚点球任务的准确性和反应时在tDCS正极刺激条件和伪刺激条件之间没有显著差异。结论:tDCS正极干预左侧PMd 10 min能够有效改善高水平足球运动员运动疲劳后的知觉预测表现。tDCS可以作为有效工具在足球运动员运动训练和比赛中用以缓解疲劳造成的知觉预测能力下降。展开更多
在“30*60”目标背景下,低碳政策和低碳技术成为能源系统节能与减排新的出发点和落脚点,电转气(power to gas,P2G)作为一种新型能源转换方式为消纳新能源和降低碳排放提供了新的途径。文中首先将电转气精细化为电解制氢和氢气制甲烷两...在“30*60”目标背景下,低碳政策和低碳技术成为能源系统节能与减排新的出发点和落脚点,电转气(power to gas,P2G)作为一种新型能源转换方式为消纳新能源和降低碳排放提供了新的途径。文中首先将电转气精细化为电解制氢和氢气制甲烷两个阶段,构建两阶段P2G、碳捕集、微型燃气轮机掺氢、燃气锅炉掺氢相互协同的运行框架。其次考虑P2G反应热的利用,以及能源运营商和能源用户两主体阶梯碳交易机制对系统碳排放的约束。最后建立考虑两阶段P2G和燃气掺氢的综合能源系统日前双层优化调度模型,上层模型以能源商运营收益最大为目标,下层模型以能源用户的用能效用与购能成本之差最大为目标。通过不同场景下的仿真,验证了所提模型的有效性,并分析了掺氢比和碳交易基价对综合能源系统低碳经济的影响。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Evaluating and selecting players to suit football clubs and decision-makers (coaches, managers, technical, and medical staff) is a difficult process from a managerial-financial and sporting perspective. Football is a highly competitive sport where sponsors and fans are attracted by success. The most successful players, based on their characteristics (criteria and sub-criteria), can influence the outcome of a football game at any given time. Consequently, the D-day of selection should employ a more appropriate approach to human resource management. To effectively address this issue, a detailed study and analysis of the available literature are needed to assist practitioners and professionals in making decisions about football player selection and hiring. Peer-reviewed journals were selected for collecting published papers between 2018 and 2023. A total of 66 relevant articles (journal articles, conference articles, book sections, and review articles) were selected for evaluation and analysis. The purpose of the study is to present a systematic literature review (SLR) on how to solve this problem and organize the published research papers that answer our four research questions.
文摘It is well established that Nash equilibrium exists within the framework of mixed strategies in strategic-form non-cooperative games. However, finding the Nash equilibrium generally belongs to the class of problems known as PPAD (Polynomial Parity Argument on Directed graphs), for which no polynomial-time solution methods are known, even for two-player games. This paper demonstrates that in fixed-sum two-player games (including zero-sum games), the Nash equilibrium forms a convex set, and has a unique expected payoff. Furthermore, these equilibria are Pareto optimal. Additionally, it is shown that the Nash equilibrium of fixed-sum two-player games can theoretically be found in polynomial time using the principal-dual interior point method, a solution method of linear programming.
文摘目的:探讨经颅直流电刺激(transcranial direct current stimulation,tDCS)干预左背侧前运动皮质(dorsal premotor cortex,PMd)对高水平足球运动员运动疲劳后知觉预测能力的影响。方法:24名国家一级足球运动员在完成60%最大骑行功率(Powermax)恒定负荷力竭骑行后,以平衡抵消法接受2 mA tDCS正极刺激左侧PMd 10 min和伪刺激,随后进行视觉搜索任务、预测足球突破过人任务和预测足球罚点球任务测试。结果:足球运动员疲劳后,进行tDCS正极刺激的视觉搜索任务反应时在3(P=0.039)和6(P=0.017)数量型与伪刺激相比显著降低,预测足球突破过人任务的准确率在240 ms条件与伪刺激相比显著增高(P<0.001)。但是视觉搜索任务准确性、预测足球突破过人任务的反应时以及预测足球罚点球任务的准确性和反应时在tDCS正极刺激条件和伪刺激条件之间没有显著差异。结论:tDCS正极干预左侧PMd 10 min能够有效改善高水平足球运动员运动疲劳后的知觉预测表现。tDCS可以作为有效工具在足球运动员运动训练和比赛中用以缓解疲劳造成的知觉预测能力下降。
文摘在“30*60”目标背景下,低碳政策和低碳技术成为能源系统节能与减排新的出发点和落脚点,电转气(power to gas,P2G)作为一种新型能源转换方式为消纳新能源和降低碳排放提供了新的途径。文中首先将电转气精细化为电解制氢和氢气制甲烷两个阶段,构建两阶段P2G、碳捕集、微型燃气轮机掺氢、燃气锅炉掺氢相互协同的运行框架。其次考虑P2G反应热的利用,以及能源运营商和能源用户两主体阶梯碳交易机制对系统碳排放的约束。最后建立考虑两阶段P2G和燃气掺氢的综合能源系统日前双层优化调度模型,上层模型以能源商运营收益最大为目标,下层模型以能源用户的用能效用与购能成本之差最大为目标。通过不同场景下的仿真,验证了所提模型的有效性,并分析了掺氢比和碳交易基价对综合能源系统低碳经济的影响。
