• Journal of Digital Convergence
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• v.18 no.12
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• pp.607-614
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• 2020

The purpose of this study is to analyze the penalty types and characteristics of world judo players. Using a total of 19,889 penalties in 9,737 matches at the World Judo Grand Prix, the team draws a difference in the types and time of fouls according to gender, weight class and time. Results Both foul play and warning showed gender differences, and both men and women affected warning rates in weight class and time classification. In addition, fouls caused by non-combat behavior and camouflage attacks have a forward direction of time, and a low time of fouling by heavyweight athletes. Judo athletes and leaders expect to be used as basic data based on scientific data, such as training, skills, tactics and motivation, taking into account the characteristics of the foul type. Requires follow-up studies of scoring relationships and winning factors.

• Advances in nano research
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• v.14 no.5
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• pp.435-442
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• 2023

Sports activities, including playing tennis, are popular with many people. As this industry has become more professionalized, investors and those involved in sports are sure to pay attention to any tool that improves athletes' performance Tennis requires perfect coordination between hands, eyes, and the whole body. Consequently, to perform long-term sports, athletes must have enough muscle strength, flexibility, and endurance. Tennis rackets with new frames were manufactured because tennis players' performance depends on their rackets. These rackets are distinguished by their lighter weight. Composite rackets are available in many types, most of which are made from the latest composite materials. During physical exercise with a tennis racket, nanocomposite materials have a significant effect on reducing injuries. Materials as strong as graphite and thermoplastic can be used to produce these composites that include both fiber and filament. Polyamide is a thermoplastic typically used in composites as a matrix. In today's manufacturing process, materials are made more flexible, structurally more vital, and lighter. This paper discusses the production, testing, and structural analysis of a new polyamide/Multi-walled carbon nanotube nanocomposite. This polyamide can be a suitable substitute for other composite materials in the tennis racket frame. By compression polymerization, polyamide was synthesized. The functionalization of Multi-walled carbon nanotube (MWCNT) was achieved using sulfuric acid and nitric acid, followed by ultrasonic preparation of nanocomposite materials with weight percentages of 5, 10, and 15. Fourier transform infrared (FTIR) and Nuclear magnetic resonance (NMR) confirmed a synthesized nanocomposite structure. Nanocomposites were tested for thermal resistance using the simultaneous thermal analysis (DTA-TG) method. scanning electron microscopy (SEM) analysis was used to determine pores' size, structure, and surface area. An X-ray diffraction analysis (XRD) analysis was used to determine their amorphous nature.

• Korean Journal of Psychosomatic Medicine
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• v.25 no.1
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• pp.19-26
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• 2017

Objectives : The aim of this meta-analysis study was to examine the relationship between cognitive anxiety and performance in closed loop skill sports. Methods : A comprehensive literature search was conducted using databases including Korean Information Service System, DBpia, Research Information Sharing Service, and National Assembly Library from 1980 to 2015. Search terms included 'Golf', 'Shooting', 'Archery', 'Anxiety', and 'Performance'. Standardized mean difference and 95% CI(confidence intervals) were calculated, and the heterogeneity of the studies was estimated using Q statistic. Results : Ten studies have satisfied the inclusion criteria. The main findings indicate that cognitive anxiety was significantly reverse correlated with performance in closed loop skill sports(r=-.198). The mean effect size for men(r=-.31) was significantly greater than that for women(r=-.05). Conclusions : Our results suggest that cognitive anxiety in closed loop skill sports is correlated with performance of athletes. Future study related to psychological aspects on athletes in sports is required in order to understand the specific evidence of relationship between anxiety and performance.

• Journal of Institute of Convergence Technology
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• v.5 no.1
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• pp.19-22
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• 2015

Human powered aircraft (HPA) is an airplane that uses only human power for its propulsion. The human power as a power resource and an engine produce the available power that is very crucial to the success of the HPA. In the present paper, the human power characteristics for completing the mission profile are discussed focusing on the take-off and climbing performance. The mission profile is designed by using an athlete's power generation. It is believed that present analysis can be helpful for the mission profile design and athletes exercise program development for the HPA competitions.

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.406.2-406.2
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• 2002

Special attention has been paid to human chorionic gonadotropin (hCG) for athlete doping control because it stimulates the endogenous production of testosterone and epitestosterone without increasing the T/E ratio which is a doping indicator for the exogenous administration of testosterone. Even though the IOC banned the use of hCG. a detection method has not been decided upon since there are a variety of immunoassay kits available on the market. We evaluated three kits in terms af their performance characteristics. (omitted)

• Journal of Nutrition and Health
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• v.36 no.7
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• pp.711-719
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• 2003

The effects of taurine, carnitine or glutamine supplementation on endurance exercise performance along with related fatigue factors were evaluated in male college students in the Department of Physical Education, who's maximal oxygen consumption rates (VO$_2$max) were equivalent to those of endurance athletes. Twenty four subjects were randomly divided into 4 groups (n=6), and given placebo, taurine (4 g/day), carnitine (4 g/day), or glutamine (4 g/day) tablets for 2 weeks. Subjects could run 6.9 min or 9.0 min longer until exhausted on a treadmill at the intensity of 75% VO$_2$max following taurine or camitine supplementation for 2 weeks, respectively, compared to the value measured prior to each supplementation. Glutamine or placebo supplementation did not improve the endurance exercise performance based on the running time until exhausted on a treadmill. Serum lactate concentrations measured 1 hr after the initiation of the endurance exercise, as well as at all-out state tended to be decreased by taurine, carnitine, or glutamine supplementation, and were significantly lowered (43% decrease) by carnitine supplementation (p < 0.05). Taurine supplementation significantly reduced the serum inorganic phosphorus concentration measured at all-out state (14% decrease, p < 0.05), while carnitine supplementation significantly lowered the resting state serum inorganic phosphorus level (20% decrease, p < 0.05). Taurine (32% reduction) or carnitine (23% reduction) supplementation significantly decreased serum ammonia concentration measured at all-out state (p < 0.05). From these results, 4 g/day of taurine or carnitine supplementation appears to improve the endurance exercise performance and related human fatigue factors.

• Journal of the Korean Applied Science and Technology
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• v.36 no.3
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• pp.942-953
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• 2019

The objective of this study was to evaluate the effects of L-arginine supplementation on muscle damage and fatigue indices and athletic performance improvement of canoe athletes after conducting a high-intensity training program. To achieve the objective, this study applied a high-intensity training program to seven high school canoe athletes. The high-intensity training program is composed of aerobic exercise sessions (twice per week; Tuesday and Thursday), anaerobic exercise sessions (three times per week; Monday, Wednesday, and Friday), and flexibility exercise sessions (five times per week). During the 6 week high-intensity training program, drug ingestion (L-arginine or placebo) was conducted in the first two weeks, wash out (two weeks) followed it, and drug ingestion (L-arginine or placebo) was carried out again in the last two weeks. The crossover design was used for the experiment so all study subjects were assigned to either the L-arginine intake group (the treatment group) or the placebo group (the control group). Each subject ingested 3g per day. This study confirmed the significant effects of L-arginine supplementation on muscle damage indices, fatigue indices, and antioxidants using blood samples. Additionally, FMD was analyzed to evaluate vascular endothelial cell functions and canoe performance was examined using the canoe ergometer. The results of this study showed that L-arginine intake did not have direct effects on the levels of ammonia, IP, and CK. The level of LDH decreased significantly more in the ARG group than in the PLA group due to L-arginine supplementation. Moreover, L-arginine supplementation did not change total NO, d-ROMs, BAP, and FMD significantly. Lastly, the results of the 500m canoe ergometer, which was conducted to evaluate the canoe performance, revealed that L-arginine did not have direct effects on total time, stroke distance, and mean velocity. However, L-arginine supplementation significantly improved muscle damage indices, fatigue indices, antioxidants, FMD, and canoe performance. Therefore, it is believed that additional studies are needed for examining the potential effects of L-arginine supplementation athletic performance enhancement.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.3
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• pp.787-794
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• 2010

This paper aims to evaluate the effect of each material ingredient on mechanical and dynamic performance and to determine an optimal mixing condition of a rubber granule layer. To minimize the required number of tests, the test matrix was established by using the design of experiments (DOE). The tensile tests were then performed to identify the mechanical properties. Also, to evaluate the dynamic performance that the IAAF has required for athletics tracks for athletes' safety and balance, a series of impact tests were performed by using the so-called the "artificial athlete" machine. Finally, the response surface methodology was used to decide the optimal mixing conditions needed to achieve a high level of mechanical properties and dynamic performance.

• Korean Journal of Exercise Nutrition
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• v.25 no.1
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• pp.1-6
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• 2021

[Purpose] We determined the effect of partial sleep deprivation (PSD) after an exercise session on exercise performance on the following morning. [Methods] Eleven male athletes performed either a normal sleep trial (CON) or a PSD trial. On the first day (day 1), all subjects performed an exercise session consisting of 90 min of running (at 75% ${\dot{V}}O_{2max}$) followed by 100 drop jumps. Maximal strength (MVC) was evaluated before and after exercise. In the CON trial, the sleep duration was 23:00-7:00, while in the PSD trial, the sleep duration was shortened to 40% of the regular sleep duration. On the following morning (day 2), MVC, the metabolic responses during 20 min of running (at 75% ${\dot{V}}O_{2max}$), and time to exhaustion (TTE) at 85% ${\dot{V}}O_{2max}$ were evaluated. [Results] On day 2, neither the MVC nor ${\dot{V}}O_2$ during 20 min of running differed significantly between the two trials. However, the respiratory exchange ratio was significantly lower in the PSD trial than in the CON trial (p = 0.01). Moreover, the TTE was significantly shorter in the PSD trial than in the CON trial (p = 0.01). [Conclusion] A single night of PSD after an exercise session significantly decreased endurance performance without significantly changing muscle strength or cardiopulmonary response.

• Journal of Sport and Applied Science
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• v.7 no.4
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• pp.7-12
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• 2023

Purpose: The purpose of this study is to compare and analyze power and agility, which are factors that affect performance, by dividing adult fin swimmers into groups by male and female careers, and use them as basic data for improving performance during fin swimmer guidance and training. Research design, data, and methodology: Accordingly, 21 fin swimmers were selected and they were divided to four groups by gender and career to conduct experiments. Power and agility, which are factors related to performance of fin swimmers, were measured. Independent sample T-Test was conducted to verify differences between groups. Results: As a result of this study, there was no statistically significant difference in power and agility by the careers of male and female athletes. Conclusion: The results of this study can be used as basic data for organizing training programs suitable for the gen-der of fin swimmers and basic data for the guidance and training of fin swimmers. In future follow-up studies, based on the results of this study, it is expected that follow-up studies should be con-ducted to improve detailed performance according to age, fin swimming events, and gender. Further implications were discussed.