• 제목/요약/키워드: School Sport

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남자 해머던지기 시 각 회전 별 역학적 특성과 투사 요인 분석 (Analysis of Projectile Factors and Biomechanical Characteristics of Men's Hammer Throwing during Turning Phases)

  • 김태삼;류지선;이미숙;윤석훈;박재명
    • 한국운동역학회지
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    • 제21권2호
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    • pp.141-152
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    • 2011
  • The purpose of this study was to investigate the projectile factors and biomechanical characteristics of men's hammer throwing during turning phases. Four national leveled athletes including Korea national record holder participated in this study. After full warm-up, each participant performed 6 trials of hammer throwing with their best. The best recorded trial was selected from each participant and they were analyzed for this study. Three-Dimensional motion analysis using a system of 5 video cameras at a sampling frequency 60Hz was performed for this study. As the number of turns increased, athletes revealed following characteristics. 1) The single and double support time decreased. 2) The rotation foot was closed to axis foot and it revealed greater medio-lateral displacement than that of horizontal one. 3) At the transition point from double support to single support, ball was in front of rotation foot so that not much angular velocity obtained. For the projectile factors, projectile angle did not show differences while projectile height and velocity revealed differences among the participants. It may indicated that each athlete has different fitness and skill level to resist centrifugal force which become larger as the number of turn increased.

청소년 소비자의 스포츠 음료에 대한 TV 광도 수용태도와 구매 행동 (Adolescent Consumers' Attitudes toward TV Advertisements on and Purchasing Behaviors of the Sport Beverages)

  • 김신애;조재순
    • 한국생활과학회지
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    • 제4권1호
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    • pp.51-61
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    • 1995
  • The purpose of this study was to find out the characteristics of the adolescent consumers related to the attitudes toward TV advertisements on and purchasing behaviors of the sport beverages, and to test the role of the atitudes toward TV advertisements between the consumer characteristics and the purchasing behaviors of the sport beverages. The qusetionnaire method was utilized to 549 female and male junior and senior high school students in urban and rural areas. The results showed that the attitudes toward TV advertisement on sport beverage was related to the residentiae years in school, whom to buy, level of interests in sports, and level of knowledges of the beverages; purchasing behaviors of the sport beverages, whom to buy, gender, level of knowledges of the beverages, size of the allowance, and the residentiae years in school. The attitudes toward TV advertisements seemed to the intervenning role between the consumer characteristics and the purchasing behaviors among adolescent consumers.

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알파인 스킹 시 카빙 턴과 베이직 패러렐 턴 간의 신체중심 및 하지관절의 운동학적 패턴 비교 (Comparisons of Center of Mass and Lower Extremity Kinematic Patterns between Carved and Basic Parallel Turn during Alpine Skiing)

  • 김주년;전현민;류시현;하성희;김진해;류지선;박상균;윤석훈
    • 한국운동역학회지
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    • 제24권3호
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    • pp.201-207
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    • 2014
  • This study investigated the center of mass and lower extremity kinematic patterns between carved and basic paralell turn during alpine skiing. Six experienced skiers (age: $20.67{\pm}4.72yrs$, body mass: $72.67{\pm}7.15kg$, height: $171.00{\pm}5.51cm$) participated in this study. Each skier were asked to perform carved and basic paralell turn on a $22.95^{\circ}$ groomed slope. Each turn was divided into the initiation phase, steering phase 1 and 2. The results of this study show that the carved turn spent significantly less running time than basic paralell turn at all three phases (p<.05). Also vertical displacement of the center of mass was significantly greater in carved turn at all three phases, whereas inward leaning angle of the center of mass was significantly greater in carved turn at the steering phase 1 and 2 (p<.05). Bilateral knee and hip joint angle were significantly greater in basic paralell turn at the initiation phase and the steering phase 2 (p<.05). On the other hand, left knee and hip joint angle were significantly greater in basic paralell turn at the steering phase 1 (p<.05). In order to perform successful carved turn, we suggest that skiers should coordinate bilateral knee and hip joint angles to adjust the center of mass, depending on three ski turn phases.

아동의 복합운동이 착지 시 하지 손상요인에 미치는 영향 (Effects of Combined Exercise on Injury Risk Factors of Lower Extremity during Landing)

  • 하성희;류시현;김주년;길호종;류지선;윤석훈;박상균
    • 한국운동역학회지
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    • 제24권2호
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    • pp.173-180
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    • 2014
  • The purpose of this study was to investigate the effect of combined exercise on injury risk factors of lower extremity during landing. Ten sports talented athletes participated in this study. Sports talented athletes participated in a combined exercise (sports talented exercise, coordination) for 16 weeks. A three-dimensional motion analysis was performed using eight infrared cameras (sampling rate of 100 Hz), one force plate, and electromyography system (sampling rate of 1000 Hz) during landing. Kinetic, and kinematics analysis including average impulsive force, angle of lower extremity, vertical stiffness, onset of muscle activation were calculated by Matlab2009a software. Paired t-test was performed at alpha=.05. The average impulsive force in landing phase was not statistically significant (t=-.748, p=.474). The hip joint angle was more decreased in post test compared to pre test (E1: t=2.682, p=.025, E2: t=5.609, p=.000, E3: t=2.538, p=.032). The knee joint (E1: t=-.343, p=.739, E2: t=1.319, p=.220, E3: t=.589, p=.570) and ankle joint (E1: t=.081, p=.937, E2: t=.784, p=.453, E3: t=.392, p=.704) angle were tended to decrease after combined exercise. The vertical stiffness was tended to decrease after combined exercise (t=1.972, p=.080). Onset of quadriceps femoris (t=.698, p=.503) and medial gastocnemius (t=1.858, p=.096) were tended to be faster than biceps femoris (t=-.333, p=.747) after combined exercise. Although thses findings were not statistically significant except on a hip joint angle, risk factors of lower extremity such as joint angle, vertical stiffness and onset of quadriceps femoris, medial gastrocnemius were positively changed after the combined exercise but an additional training for improved onset of biceps femoris would be required in the future.

멈춤 유형에 따른 노인 보행의 생체역학적 변화 (Biomechanical Alternation of the Elderly Depending on the Type of Gait Termination)

  • 이재훈;류지선
    • 한국운동역학회지
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    • 제21권2호
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    • pp.189-196
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    • 2011
  • The purpose of this study was to verify the difference in biomechanical variation and pattern of the lower limb between planned and unexpected termination, which is related to the prevention of fatal fall in the elderly. Therefore, selected twenty subjects for each group which composed of females(age: $73.5{\pm}4.63$ year, height: $153.2{\pm}6.46$ cm, body mass: $58.98{\pm}5.82$ kg) and women(age: $23.4{\pm}2.5$ year, height: $164.65{\pm}3.9$ cm, body mass: $58.47{\pm}5.53$ kg) in their twenties. As a result, lower limb's extension moment and power were increased significantly in statistics(p<.05). Also, knee joint power showed instant changes from concentric contraction to eccentric contraction and hip joint power from eccentric contraction to concentric contraction. During unexpected termination there were dramatical increase in eccentric contraction and power(p<.05). In both planned and unexpected termination, ankle joint moment were higher in young group, but the moment of the hip joint were higher in the elderly group(p<.05). In contrast to younger group, there were no changes in knee extension moment in elderly group(p<.05). but showed relatively higher hip joint extension moment and power(p<.05).

A Study on the Leader's Super-leadership, Self-leadership, Psychological Empowerment, Sport Commitment and Performance Perceived by Taekwondo Athletes

  • Kyung-Won Byun;Kun-Hyung Kim
    • International Journal of Advanced Culture Technology
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    • 제11권2호
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    • pp.142-151
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    • 2023
  • The purpose of this study is to verify the research model and identify the causal relationship among leader's super leadership, self-leadership, psychological empowerment, sport commitment and performance perceived by Taekwondo athletes. The subjects of the study were middle and high school Taekwondo athletes registered in the Korea Taekwondo Association in 2020 and 2021, and data from 454 people were used as final effective samples through convenience sampling. The collected data used the SPSS 23.0 version and the Amos 21.0 version to verify the hypothesis. As a result, the following conclusions were obtained. First, we discovered that the leader's super leadership had a positive impact on the athlete's self-leadership, psychological empowerment, and sport commitment. Second, we found that the athlete's self-leadership had a positive effect on psychological empowerment, sport commitment, and performance. Third, we found that athlete's psychological empowerment had a positive effect on sport commitment and performance. Fourth, we found that the athlete's sport commitment had a negative effect on performance. Therefore, this study has reminded us about importance of psychological empowerment and sport commitment for explaining the relationship between leadership type and performance perceived by Taekwondo athletes, and might contribute to the theoretical discussion of variables related to athletes' performance.

Antioxidant Activity of NADH and Its Analogue - An In Vitro Study

  • Olek, Robert Antoni;Ziolkowski, Wieslaw;Kaczor, Jan Jacek;Greci, Lucedio;Popinigis, Jerzy;Antosiewicz, Jedrzej
    • BMB Reports
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    • 제37권4호
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    • pp.416-421
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    • 2004
  • The antioxidant activities of NADH and of its analogue, 1,4-dihydro-2,6-dimethyl-3,5-dicarbethoxy-pyridine ($PyH_2$), were evaluated in vitro. NADH was found to be oxidized by the peroxyl radical derived from 2,2-azobis-(2-amidinopropane) dihydrochloride (AAPH) decomposition, in a pH-dependent manner. Both NADH and $PyH_2$ inhibited the peroxidation of egg yolk lecithin (EYL) liposomes, although $PyH_2$ was more effective than NADH when 2,2'-azobis-4-methoxy-2,4-dimethyl-valeronitrile (methoxy-AMVN) was employed to induce EYL liposome peroxidation. The antioxidant activities of NADH and $PyH_2$ were also evaluated by measuring their influences on 1,3-diphenylisobenzofuran (DPBF) fluorescence decay in the presence of peroxyl radicals. NADH and $PyH_2$ were much more effective at inhibiting DPBF quenching in Triton X-100 micelles than in liposomes. These results indicate that NADH can inhibit lipid peroxidation despite being hydrophilic. Nevertheless, membrane penetration is an important factor and limits its antioxidant activity.

미디어에 나타난 학교체육(진흥)법 제정 관련 사회적 담론 분석 (An Analysis of Social Discourse on the Enactment of School Sport Promotion Law Produced in the Media)

  • 박재우
    • 한국콘텐츠학회논문지
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    • 제12권9호
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    • pp.434-446
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    • 2012
  • 본 연구는 학교체육(진흥)법을 사례로 본 법안이 국회통과에 이르기까지의 제정 전반의 과정 속에 어떠한 담론이 생산되고 형성되어 왔는가를 파악하고자 하였다. 특히 미디어 매체를 통해 학교체육(진흥)법 제정과 관련하여 그동안 어떠한 사회적 담론이 생산되고 형성되었는가를 과정적 맥락적인 관점에서 고찰해봄으로써 학교체육(진흥)법 제정과 관련된 정치적 사회적 맥락에 대한 논리적인 이해와 해석을 시도하였다. 이 학교체육(진흥)법 제정 관련 담론의 분석은 학교체육, 더 나아가 한국 체육 전반의 구조적 시스템 속에 존재하는 내재적 현실과 변화의 흐름을 이해하는데 기여할 것이다. 결과론적인 입장에서 본 연구는 크게 네 가지 맥락의 사회적 담론이 생산되고 형성되었음을 확인할 수 있었다. 학교체육(진흥)법 제정 관련 사회적 담론의 지형은 첫째, 학교체육 관련 법안 제정을 요구하는 사회적 '지지' 담론, 둘째, 본회의 부결 이후 대두된 '성토' 담론, 셋째, 또 다른 '시각'으로서 엘리트체육의 위축을 염려하는 '반대' 담론 그리고 넷째, 본회의 통과 이후 학교체육 도약과 활성화를 기대하는 '희망' 담론으로 구성되어 나타났음을 알 수 있었다.