• Korean Journal of Applied Biomechanics
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• v.26 no.4
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• pp.361-367
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• 2016

Objective: The aim of this study was to compare three-dimensional kinematic changes of the lower extremity between the two different braking distances during snowplow in alpine skiing. Method: Six alpine ski instructors (age: $25.3{\pm}1.5yr$, height: $169.3{\pm}2.9cm$, weight: $66.2{\pm}5.9kg$, career: $4.2{\pm}2.9yr$) participated in this study. Each skier was asked to perform snowplow on the two different braking distances (2 and 4 m). Results: Snowplow and edging angles (p = .006 and p = .005), ankle adduction and inversion (p = .033 and p = .002), knee extension (p = .003), and hip abduction and internal rotation (p = .043 and p = .006) were significantly greater in the 2 m than in the 4 m braking distance. Conclusion: Based on our results, we suggest that skiers should make greater snowplow and edging angles on the shorter braking distance. In this situation, ankle joint adduction/inversion angle and hip joint internal-rotation make greater snowplow angle, and hip joint abduction make greater edging angle. In addition, greater knee joint extension angle may lead to more posteriorly positioned center of mass.

• Journal of Sport and Applied Science
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• v.5 no.1
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• pp.17-26
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• 2021

Purpose: The purpose of this study is to suggest the policy and scope of the concept of sports welfare and to present a systematic model enhancing sport welfare of the society. Research design, data, and methodology: In order to induce idea for welfare policy and conceptual sport welfare model, this study reviewed a literature discussing the functions and mechanism of sport in enhancing a sense of life quality and thus rebuilding welfare of community. Results: The study suggests these. First, sports welfare ensures the rights of sports of all citizens and has the main purpose of providing social services, creating environments against inequality, improving the quality of life and happiness for everyone to enjoy, and the range should be continued from the right to live, environments against inequality, to the improvement of life and happiness. Second, since the integrated perspective was first suggested, sports integration development will be researched as well as the direction of the development of policies of the integrated model. Basic research of indicator development will need to be proceeded to execute and evaluate the integrated model. Third, the improvement of treatment of sports welfare instructors is urgent. Namely, compared to sports-related budget and the enhancement of facilities, the poor environment of sports welfare instructors needs to be improved. Instead of only testing physical fitness and prescription, the business needs to be continued by connecting to the participants' continuous participation in sports. Conclusions: Whether sports welfare succeeds depends on the need for an active beneficiary, identification of demand, a beneficiary that can discover potential to join offline and online into one, the establishment of sports policies to promote competency development, and a direct progression is needed.

• Korean Journal of Exercise Nutrition
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• v.25 no.3
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• pp.8-15
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• 2021

[Purpose] Excessive reactive oxygen species (ROS) induced by prolonged high-intensity exercise can cause structural and functional damage. Antioxidant polyphenol supplementation, which reduces ROS levels, may improve high-intensity exercise performance. We evaluated the effect of lychee fruit extract, which contains high levels of low-molecular-weight oligomerized polyphenols, on high-intensity exercise performance. [Methods] Ten male athletes were included in an open-label trial that consisted of control and intervention phases, with a 7-day washout period between phases. The participants were administered oligomerized lychee fruit extract for seven days, whereas no intervention was given in the control phase. High-intensity intermittent exercise and the Wingate test were performed. The power output, blood lactate levels, reactive oxygen metabolite levels, biological antioxidant potential, heart rate, and rate of perceived exertion were measured. [Results] The average power output was significantly higher in the intervention phase than in the control phase (P < 0.01), while the change in blood lactate levels was significantly lower in the intervention phase than in the control phase (P < 0.05). The average heart rate was significantly higher in the intervention phase than in the control phase (P < 0.05), without changing the rate of perceived exertion. Although there was no difference in reactive oxygen metabolite levels between the phase, the change in biological antioxidant potential was larger in the intervention phase than in the control phase (P = 0.06). The Wingate test showed no significant differences between the phase. [Conclusion] Short-term loading with oligomerized lychee fruit extract may increase performance during high-intensity intermittent exercise by improving metabolism.

• Korean Journal of Exercise Nutrition
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• v.23 no.2
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• pp.28-33
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• 2019

[Purpose] Recent studies have shown that glucose-6-phosphate isomerase (GPI)-which is a glycolysis interconversion enzyme-reduces oxidative stress. However, these studies are limited to tumors such as fibrosarcoma, and there are no studies that have examined the effects of exercise on GPI expression in mice skeletal muscle. Furthermore, GPI acts in an autocrine manner thorough its receptor, autocrine motility factor receptor (AMFR); therefore, we investigated expression level changes of secreted GPI from skeletal muscle in in vitro study to examine the potential role of GPI on skeletal muscle. [Methods] First, we performed an in vitro study, to identify the condition that upregulates GPI levels in skeletal muscle cells; we treated C2C12 muscle cells with an exercise-mimicking chemical, AICAR. AICAR treatment upregulated GPI expression level in C2C12 cell and its secretomes. To confirm the direct effect of GPI on skeletal muscle cells, we treated C2C12 cells with GPI recombinant protein. [Results] We found that GPI improved the viability of C2C12 cells. In the in vivo study, the exercise-treated mice group showed upregulated GPI expression in skeletal muscle. Based on the in vitro study results, we speculated that expression level of GPI in skeletal muscle might be associated with muscle function. We analyzed the association between GPI expression level and the grip strength of the all mice group. The mice group's grip strengths were upregulated after 2 weeks of treadmill exercise, and GPI expression level positively correlated with the grip strength. [Conclusion] These results suggested that the exercise-induced GPI expression in skeletal muscle might have a positive effect on skeletal muscle function.

• Journal of the Korea Society of Computer and Information
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• v.29 no.1
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• pp.211-218
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• 2024

This study attempted to derive a new policy paradigm of life-span sport of disabled children. For that purpose, collecting and analyzing related preceding researches and literatures from 2008 to present (2022), this study firstly found out past life-span sport policy paradigms for disabled children and the causes of their changes, and secondly found out social problems which present policies could not deal with. Through those study process, this study suggested life-span sport in response to the demands and needs of children with disabilities which could include life-span sport centered on disabled children, life-span sport with family members, the realization of the essential value of life-span sport for the human rights of children with disabilities, and the development of new methodologies using smart technologies.

• Proceedings of the Korean Nutrition Society Conference
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• 2003.05a
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• pp.318.2-318.2
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• 2003

• Korean Journal of Applied Biomechanics
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• v.14 no.3
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• pp.301-311
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• 2004

The purpose of this study was to verify the usefulness of the Mathcad program as a tool for the studying and teaching the sport biomechanics. A projectile motion was analyzed because it is the one of the most popular motion in sports activities. A 3 dimensional CG data for the high jump bar clear phase was used to calculate the initial velocity vector of the CG. Linear regression function and other functions such as cubic spline and derivative of Mathcad were used to calculate this vector. Finally, the approach angle to the bar and peak jump height was calculated. Programming in Mathcad was relatively easy compare to traditional computer language such as Fortran and C, because of the unique documentation method of Mathcad. Additionally the 2 and 3 dimensional graph function was very easy and useful to describe the mechanical data. If the use of Mathcad program is more popular in the field of sport biomechanics, it could greatly contribute to overcome the limit of research caused by the lack of proper programming ability.

• Korean Journal of Human Ecology
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• v.4 no.1
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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.

• Journal of Fisheries and Marine Sciences Education
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• v.29 no.3
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• pp.655-664
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• 2017

The purpose of this study was to verify the relationships among sport enjoyment, leisure satisfaction, and continuous participation intention in ski class. The study conducted a research survey through purposive sampling method. 280 questionnaires distributed and 271 were selected as final valid sample by removing 9 questionnaires that have insufficient answers. Hypothesis test on collected data was conducted by using SPSS 20.0 and AMOS 18.0 programs. The results were as followings. First, sport enjoyment factors a significant effect on psychological satisfaction, environmental satisfaction. Second, sport enjoyment factors had effect on re-participation intention, word of mouth intention. Third, leisure satisfaction had effect on re-participation intention, word of mouth intention. In addition, it had effect on continuos participation intention as the partial mediation of the leisure satisfaction.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.18 no.3
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• pp.84-91
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• 2010

New aircraft category such as Light Sport Aircraft is introduced to prevent Ultralight Vehicle accidents and to promote aviation sports. Therefore, a new rule for airworthiness standard, certification, operation and maintenance of light sport aircraft is being created. The present study deals with LSA concept, development trend of LSA, airworthiness standards and certification policy. In particular, an aircraft type analysis of FAA certified LSA is conducted to establish performance requirements of Light Sport Aircraft designs.