Purpose: The aims of this study were to(1) investigate the health-related physical fitness profile of untrained adolescent boys in comparison to adolescent soccer players,(2) determine the intensity and enjoyment of 6...Purpose: The aims of this study were to(1) investigate the health-related physical fitness profile of untrained adolescent boys in comparison to adolescent soccer players,(2) determine the intensity and enjoyment of 6 v 6 and 4 v 4 small-sided games, and(3) evaluate the health-related effects of a short-period of soccer training in the untrained group.Methods: Forty-one adolescent boys(untrained, n = 24: age = 15.9 ± 0.6 years; trained, n = 17: age = 15.7 ± 0.7 years) were recruited. For Purpose 1,the players(n = 17) and the untrained(n = 24) boys were tested for speed, jumping power, postural balance, flexibility, and aerobic capacity. After baseline testing, Purposes 2 and 3 were addressed by randomly assigning the untrained boys to either a soccer-training group(small-sided games,2 sessions per week for 8 weeks) or to a control group, followed by identical retesting.Results: At baseline, physical fitness was higher(p < 0.001) in trained players than in untrained for aerobic fitness, sprinting, jumping power, and postural balance. Small-sided games using 6 v 6 or 4 v 4 elicited similar heart rate(HR)(mean: ~ 85% peak heart rate, HR_(peak)), rate of perceived exertion, and enjoyment responses. Over 8 weeks, the between-group analysis revealed that soccer training had a large beneficial effect on postural balance(45%) when compared with control group with unclear effects on other fitness parameters.Conclusion: Adolescent soccer players had markedly higher physical fitness compared with untrained adolescents. Small-sided soccer games practiced by untrained adolescents elicited high exercise intensity. While 8 weeks of twice-weekly soccer training sessions induced significant improvement in postural balance, the short duration of the study was not sufficient to result in between-group differences in sprint and jump performance or aerobic fitness.展开更多
The number of scientific investigations on women's football specific to the topics of player characteristics and demands of the game has considerably increased in recent years due to the increased popularity of the w...The number of scientific investigations on women's football specific to the topics of player characteristics and demands of the game has considerably increased in recent years due to the increased popularity of the women's game worldwide, although they are not yet as numerous as in the case of men's football. To date, only two scientific publications have attempted to review the main findings of studies published in this area. However, one of them was published about 20 years ago, when women's football was still in its infancy and there were only a few studies to report on. The other review was more recent. Nonetheless, its main focus was on the game and training demands of senior elite female players. Thus, information on female footballers of lower competitive levels and younger age groups was not included. Consequently, an updated review is needed in this area. The present article therefore aims to provide an overview of a series of studies that have been published so far on the specific characteristics of female football players and the demands of match-play. Mean values reported in the literature for age (12-27 years), body height (155-174 cm), body mass (48-72 kg), percent body fat (13%-29%), maximal oxygen uptake (45.1-55.5 mL/kg/min), Yo-Yo Intermittent Recovery Test Level l (780-1379 m), maximum heart rate (189-202 bpm), 30 m sprint times (4.34-4.96 s), and counter- movement jump or vertical jump (28-50 cm) vary mostly according to the players' competitive level and positional role. There are also some special considerations that coaches and other practitioners should he aware of when working with female athletes such as the menstrual cycle, potential pregnancy and lactation, common injury risks (particularly knee and head injuries) and health concerns (e.g., female athlete triad, iron deficiency, and anemia) that may affect players' football performance, health or return to play. Reported mean values for total distance covered (4-13 km), distance covered at high-speed (0.2-1.7 km), average/peak heart rate (74%-87%/94%-99% HRmax), average/peak oxygen uptake (52%-77%/96%-98% VO2max), and blood lactate (2.2-7.3 mmol/L) during women's football match-play vary according to the players' competitive level and positional role. Methodological differences may account for the discrepancy of the reported values as well. Finally, this review also aims to identify literature gaps that require further scientific research in women's football and to derive a few practical recom-mendations. The information presented in this report provides an objective point of reference about player characteristics and game demands at various levels of women's football, which can help coaches and sport scientists to design more effective training programs and science-based strategies for the further improvement of players' football performance, health, game standards, and positive image of this sport.展开更多
A dynamic cooperation model of multi-agent is established by combining reinforcement learning with distributed artificial intelligence(DAI),in which the concept of individual optimization loses its meaning because of ...A dynamic cooperation model of multi-agent is established by combining reinforcement learning with distributed artificial intelligence(DAI),in which the concept of individual optimization loses its meaning because of the dependence of repayment on each agent itself and the choice of other agents.Utilizing the idea of DAI,the intellectual unit of each robot and the change of task and environment,each agent can make decisions independently and finish various complicated tasks by communication and reciprocation between each other.The method is superior to other reinforcement learning methods commonly used in the multi-agent system.It can improve the convergence velocity of reinforcement learning,decrease requirements of computer memory,and enhance the capability of computing and logical ratiocinating for agent.The result of a simulated robot soccer match proves that the proposed cooperative strategy is valid.展开更多
This paper has developed the argument that live radio soccer commentary (LRSC) is a representation of soccer match events at one level but a performance of dominant socio-cultural and political trends of the societi...This paper has developed the argument that live radio soccer commentary (LRSC) is a representation of soccer match events at one level but a performance of dominant socio-cultural and political trends of the societies at another level that produce and consume them. This echoes Reaser's (2003) and Ryan's (1993) perceptions of sports announcer's talk as a complex performance form based on but not limited to the "verbal imitation" of live sport events. We have understood the performativity of the LRSCs in the light of Schechner's (2006) emphasis of what he termed "restored behaviour" in understanding performance. In our context, we have treated the interpenetration of Kenyan soccer, politics, and society as the "restored behaviour" upon which the script of the LRSCs are based. The methodological apparatus of this paper is largely qualitative, consisting in the critical analysis of audio-recordings of Kenyan LRSCs. Focus is made on the Kenyan society of the 1980s, an era perceived to have been characterized by a close interaction between soccer, society, and politics. The analysis is informed by Fabian's (1997) inter-textual approach to the "reading" and interpretation of performance texts. This approach seems to echo a wider discourse of the social nature of media-text interpretation that has been proposed by Burn and Parker (1985). Conclusions drawn from the analysis reveal what Muponde and Zegeye (2011) had described as a soccer "ecosystem" involving soccer as a sport, and the socio-cultural realities of its immediate context. This paper has argued thatLRSC is one of the channels through which this ecosystem is expressed.展开更多
The research was conducted in order to determine influence of conative characteristics on the criterion variables in Special Olympics athletes and partners in football. For this purpose, 80 athletes and partners engag...The research was conducted in order to determine influence of conative characteristics on the criterion variables in Special Olympics athletes and partners in football. For this purpose, 80 athletes and partners engaged in football were tested. For the assessment of conative characteristics, the measurement instrument CON6 was selected by which the following conative regulators were evaluated: activity regulator, organ function regulator, defense reaction regulator, attack reaction regulator, system for coordination of regulatory functions, system for integration of regulatory functions, and system for excitation and inhibition. To assess success in a football game, the following variables were used: evaluation of the effectiveness of the techniques, evaluation of the performance effectiveness in the offensive phase, evaluation of the performance effectiveness in the defensive phase, evaluation of individual creativity during the game, team responsibility evaluation, engagement evaluation, behavior evaluation, general evaluation of success in the game. All the data in this research were analyzed at the Multidisciplinary Research Center, Faculty of Sport and Physical Education, University of Pristina, by the system of data processing programs DRSOFT developed by D. Popovi~ and K. Momirovi~. The algorithms and programs implemented within this thesis have been fully presented and the results of the programs have been analyzed.展开更多
In this report we analyse a case of ischi- atic tuberosity avulsion. A 15-year-old patient who came to our first aid department two days after a football match ac- cident was treated conservatively and examined at mon...In this report we analyse a case of ischi- atic tuberosity avulsion. A 15-year-old patient who came to our first aid department two days after a football match ac- cident was treated conservatively and examined at month 1- 4, 6 and 12. In order to examine patient condition, a new index was formulated: the inability score index (ISI), which is based on hip range of motion and scales for rest, walking, running pain and compared to other parameters such as oedema area, fragment diastasis evaluated by X-ray and CT accordingly. ISI defines the inability as severe, moderate and mild. It guides the rehabilitative program in the right way. In this case, the patient was able to run softly after 35 days and to go back to the full agonist activity after 4 months. At the end of treatment the patient referred to the complete pain remission, full range of motion recovery and a good fracture consolidation. After 1 year we discuss about thera- peutic strategies used and results obtained.展开更多
In soccer, the bicycle kick has provided view- ers moments of breathtaking spectacle that seem virtuosic in scope. The novelty of such moments is underscored by the rarity with which players have performed this comple...In soccer, the bicycle kick has provided view- ers moments of breathtaking spectacle that seem virtuosic in scope. The novelty of such moments is underscored by the rarity with which players have performed this complex skill during national or international tournaments. The rarity of these occurrences is both a product of perceptions that it is a high-risk, low return skill and by the fact that there is a dearth of scientific research on the biomechanics of the technique. Two genera can be discerned based on starting position: 1) back-facing the goal, and 2) side-fac- ing the goal. The current study, using 3D motion capture technology and full-body biomechanical modeling, identi- fies elements that govern entrainment of the technique by examining jumping, kicking and falling phases of the skill execution. Motor sequencing during the first two phases can be characterized by analyzing the following pa- rameters: 1) angle between the player's thighs (humerus bones) upon take-off, 2) the whip-like control of the kicking leg, 3) timing between ball motion and joint co- ordination and, for the side-facing bicycle kick, 4) rotation of the player's trunk during the jumping phase. Dispersion of energy during falling after the kick is accomplished by sharing the load using a sequence of partial landings. Collectively, this information could help entrainment of the skill. Virtuosic in appearance, more frequent use of the kick can only enhance the excitement of the game.展开更多
文摘Purpose: The aims of this study were to(1) investigate the health-related physical fitness profile of untrained adolescent boys in comparison to adolescent soccer players,(2) determine the intensity and enjoyment of 6 v 6 and 4 v 4 small-sided games, and(3) evaluate the health-related effects of a short-period of soccer training in the untrained group.Methods: Forty-one adolescent boys(untrained, n = 24: age = 15.9 ± 0.6 years; trained, n = 17: age = 15.7 ± 0.7 years) were recruited. For Purpose 1,the players(n = 17) and the untrained(n = 24) boys were tested for speed, jumping power, postural balance, flexibility, and aerobic capacity. After baseline testing, Purposes 2 and 3 were addressed by randomly assigning the untrained boys to either a soccer-training group(small-sided games,2 sessions per week for 8 weeks) or to a control group, followed by identical retesting.Results: At baseline, physical fitness was higher(p < 0.001) in trained players than in untrained for aerobic fitness, sprinting, jumping power, and postural balance. Small-sided games using 6 v 6 or 4 v 4 elicited similar heart rate(HR)(mean: ~ 85% peak heart rate, HR_(peak)), rate of perceived exertion, and enjoyment responses. Over 8 weeks, the between-group analysis revealed that soccer training had a large beneficial effect on postural balance(45%) when compared with control group with unclear effects on other fitness parameters.Conclusion: Adolescent soccer players had markedly higher physical fitness compared with untrained adolescents. Small-sided soccer games practiced by untrained adolescents elicited high exercise intensity. While 8 weeks of twice-weekly soccer training sessions induced significant improvement in postural balance, the short duration of the study was not sufficient to result in between-group differences in sprint and jump performance or aerobic fitness.
文摘The number of scientific investigations on women's football specific to the topics of player characteristics and demands of the game has considerably increased in recent years due to the increased popularity of the women's game worldwide, although they are not yet as numerous as in the case of men's football. To date, only two scientific publications have attempted to review the main findings of studies published in this area. However, one of them was published about 20 years ago, when women's football was still in its infancy and there were only a few studies to report on. The other review was more recent. Nonetheless, its main focus was on the game and training demands of senior elite female players. Thus, information on female footballers of lower competitive levels and younger age groups was not included. Consequently, an updated review is needed in this area. The present article therefore aims to provide an overview of a series of studies that have been published so far on the specific characteristics of female football players and the demands of match-play. Mean values reported in the literature for age (12-27 years), body height (155-174 cm), body mass (48-72 kg), percent body fat (13%-29%), maximal oxygen uptake (45.1-55.5 mL/kg/min), Yo-Yo Intermittent Recovery Test Level l (780-1379 m), maximum heart rate (189-202 bpm), 30 m sprint times (4.34-4.96 s), and counter- movement jump or vertical jump (28-50 cm) vary mostly according to the players' competitive level and positional role. There are also some special considerations that coaches and other practitioners should he aware of when working with female athletes such as the menstrual cycle, potential pregnancy and lactation, common injury risks (particularly knee and head injuries) and health concerns (e.g., female athlete triad, iron deficiency, and anemia) that may affect players' football performance, health or return to play. Reported mean values for total distance covered (4-13 km), distance covered at high-speed (0.2-1.7 km), average/peak heart rate (74%-87%/94%-99% HRmax), average/peak oxygen uptake (52%-77%/96%-98% VO2max), and blood lactate (2.2-7.3 mmol/L) during women's football match-play vary according to the players' competitive level and positional role. Methodological differences may account for the discrepancy of the reported values as well. Finally, this review also aims to identify literature gaps that require further scientific research in women's football and to derive a few practical recom-mendations. The information presented in this report provides an objective point of reference about player characteristics and game demands at various levels of women's football, which can help coaches and sport scientists to design more effective training programs and science-based strategies for the further improvement of players' football performance, health, game standards, and positive image of this sport.
文摘A dynamic cooperation model of multi-agent is established by combining reinforcement learning with distributed artificial intelligence(DAI),in which the concept of individual optimization loses its meaning because of the dependence of repayment on each agent itself and the choice of other agents.Utilizing the idea of DAI,the intellectual unit of each robot and the change of task and environment,each agent can make decisions independently and finish various complicated tasks by communication and reciprocation between each other.The method is superior to other reinforcement learning methods commonly used in the multi-agent system.It can improve the convergence velocity of reinforcement learning,decrease requirements of computer memory,and enhance the capability of computing and logical ratiocinating for agent.The result of a simulated robot soccer match proves that the proposed cooperative strategy is valid.
文摘This paper has developed the argument that live radio soccer commentary (LRSC) is a representation of soccer match events at one level but a performance of dominant socio-cultural and political trends of the societies at another level that produce and consume them. This echoes Reaser's (2003) and Ryan's (1993) perceptions of sports announcer's talk as a complex performance form based on but not limited to the "verbal imitation" of live sport events. We have understood the performativity of the LRSCs in the light of Schechner's (2006) emphasis of what he termed "restored behaviour" in understanding performance. In our context, we have treated the interpenetration of Kenyan soccer, politics, and society as the "restored behaviour" upon which the script of the LRSCs are based. The methodological apparatus of this paper is largely qualitative, consisting in the critical analysis of audio-recordings of Kenyan LRSCs. Focus is made on the Kenyan society of the 1980s, an era perceived to have been characterized by a close interaction between soccer, society, and politics. The analysis is informed by Fabian's (1997) inter-textual approach to the "reading" and interpretation of performance texts. This approach seems to echo a wider discourse of the social nature of media-text interpretation that has been proposed by Burn and Parker (1985). Conclusions drawn from the analysis reveal what Muponde and Zegeye (2011) had described as a soccer "ecosystem" involving soccer as a sport, and the socio-cultural realities of its immediate context. This paper has argued thatLRSC is one of the channels through which this ecosystem is expressed.
文摘The research was conducted in order to determine influence of conative characteristics on the criterion variables in Special Olympics athletes and partners in football. For this purpose, 80 athletes and partners engaged in football were tested. For the assessment of conative characteristics, the measurement instrument CON6 was selected by which the following conative regulators were evaluated: activity regulator, organ function regulator, defense reaction regulator, attack reaction regulator, system for coordination of regulatory functions, system for integration of regulatory functions, and system for excitation and inhibition. To assess success in a football game, the following variables were used: evaluation of the effectiveness of the techniques, evaluation of the performance effectiveness in the offensive phase, evaluation of the performance effectiveness in the defensive phase, evaluation of individual creativity during the game, team responsibility evaluation, engagement evaluation, behavior evaluation, general evaluation of success in the game. All the data in this research were analyzed at the Multidisciplinary Research Center, Faculty of Sport and Physical Education, University of Pristina, by the system of data processing programs DRSOFT developed by D. Popovi~ and K. Momirovi~. The algorithms and programs implemented within this thesis have been fully presented and the results of the programs have been analyzed.
文摘In this report we analyse a case of ischi- atic tuberosity avulsion. A 15-year-old patient who came to our first aid department two days after a football match ac- cident was treated conservatively and examined at month 1- 4, 6 and 12. In order to examine patient condition, a new index was formulated: the inability score index (ISI), which is based on hip range of motion and scales for rest, walking, running pain and compared to other parameters such as oedema area, fragment diastasis evaluated by X-ray and CT accordingly. ISI defines the inability as severe, moderate and mild. It guides the rehabilitative program in the right way. In this case, the patient was able to run softly after 35 days and to go back to the full agonist activity after 4 months. At the end of treatment the patient referred to the complete pain remission, full range of motion recovery and a good fracture consolidation. After 1 year we discuss about thera- peutic strategies used and results obtained.
基金supported by National Sciences and Engineering Research Council of Canada
文摘In soccer, the bicycle kick has provided view- ers moments of breathtaking spectacle that seem virtuosic in scope. The novelty of such moments is underscored by the rarity with which players have performed this complex skill during national or international tournaments. The rarity of these occurrences is both a product of perceptions that it is a high-risk, low return skill and by the fact that there is a dearth of scientific research on the biomechanics of the technique. Two genera can be discerned based on starting position: 1) back-facing the goal, and 2) side-fac- ing the goal. The current study, using 3D motion capture technology and full-body biomechanical modeling, identi- fies elements that govern entrainment of the technique by examining jumping, kicking and falling phases of the skill execution. Motor sequencing during the first two phases can be characterized by analyzing the following pa- rameters: 1) angle between the player's thighs (humerus bones) upon take-off, 2) the whip-like control of the kicking leg, 3) timing between ball motion and joint co- ordination and, for the side-facing bicycle kick, 4) rotation of the player's trunk during the jumping phase. Dispersion of energy during falling after the kick is accomplished by sharing the load using a sequence of partial landings. Collectively, this information could help entrainment of the skill. Virtuosic in appearance, more frequent use of the kick can only enhance the excitement of the game.