• Advances in nano research
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• v.15 no.6
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• pp.579-585
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• 2023

This research delves into the intricate dynamics of the flight response exhibited by a golf ball that incorporates nanoparticles with the goal of enhancing its overall quality. The golf ball is meticulously modeled utilizing beam elements, and the impact of nanoparticles is intricately captured through the application of the Halpin-Tsai theory. Employing a numerical solution, the study thoroughly explores the flight response of the golf ball, taking into account the nuanced effects of the embedded nanoparticles. By scrutinizing the aerodynamic characteristics through advanced simulations, this investigation aims to provide valuable insights that could potentially revolutionize the design and performance of golf equipment, offering a pathway towards superior quality and enhanced functionality in the realm of golf ball technology. Results show that increase in the volume percent of nanoparticles, improves the flight response of the golf ball.

• Korean Journal of Applied Biomechanics
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• v.33 no.4
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• pp.185-195
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• 2023

Objective: The purpose of this study is to improve TPI OnBaseU Power Test and golf performance by conducting CrossFit power training. Method: Three male golf players from University B participated in this study. They had 3 to 4 years of golf experience and participated in 8 weeks of CrossFit power training. Results: OnBaseU Power Test: There was a lot of improvement in Sit up throw (27.9%) and Chest pass (10.58%), but there was not much improvement in Baseline Toss (R5.9, L9.8%) and Vertical Jump (4.1%). Golf shot data: There was a very statistically significant difference in Club speed, Ball speed, and Total Length, which are related to speed, and there was no difference in Club path and Smash factor, which are related to accuracy and posture. Conclusion: CrossFit power training was effective in improving TPI OnBaseU Power Test and golf performance (Club speed, Ball speed, Total Length).

• The Journal of Industrial Distribution & Business
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• v.9 no.9
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• pp.63-74
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• 2018

Purpose - The current study is to compare the cognition of stakeholders on hosting a mega sports event between Korea and the United States. In particular, to understand their cognition and perceptual conflict towards hosting a mega sports event, the study employed conflict theory. Furthermore, the study reviewed the role of social capital in the process of managing the mega sports events. Research Design, Data, and Methodology - Of homogeneous sampling, purposeful sampling method and criterion-based selection approach were used to collect interview data from key stakeholders who have been involved in hosting a mega sports events in Korea and the United States. In-depth interview transcripts were reviewed multiple tiems after transcription to extract concepts and meanings that were pertinenet to the experience involving hosting a mega sports event. Further member checks was conducted to increase the credibility of the results. Results - Results can be summarized as followed: First, stakeholders of Korea have a strong desire for positive economic effects of a mega sports event, compared to those in the United States who are more concerned in enhancing the public interests and concerns. Second, in Korea, various socio-political issues emerged at the same time and conflicts among multiple stakeholders have aggravated the situations to coordinate the issues. This was because legal system supporting socio-trust has not been established. On the other hand, major stakeholders of the United States consisted of community members who have socio-trust and networks. Thereby these social resources have been found playing a key role in building social capital that assists the stakeholders to coordinate the current issues and to solve them. Conclusions - The current study analyzed the cognition and perceptual conflict of stakehoders in a mega sports event. Social capital has beend found as a key catalyst to increase a network and cooperation among stakeholders. In order to enhance social capital in managing a mega sports event hosted in Korea, legal systems that establish networks and relationships among the related stakeholders need to be developed. Furthermore, the systematic guideline needs to be developed, organizing the sub-committees according to the types of stakeholders and the categorized common needs.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.12
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• pp.357-366
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• 2019

The purpose of this study is to analyze the relationship between students' motivation for participating in leisure sports, students' physical self-concept and the life satisfaction of university students. A total of 419 students were finally analyzed using the convenience sampling method of non-random sampling method after selecting those university students participating in leisure sports at a university located in J district. The results of analysis using SPSS version 21.0 program are as follows. First, there is a positive (+) correlation between the motives of participation of university students and their physical self-concept and satisfaction with university life. Second, the influence of the motive to participate in sports has a positive (+) effect on sports competence and this is affected by health fitness and social interaction, physical activity is affected by pleasure, health fitness, and conditioning, self-esteem, muscular strength is affected by pleasure, health fitness, condition, and society, flexibility is affected by pleasure, health fitness, and society. Third, the influence of participation motive had a positive (+) effect on school satisfaction is affected by pleasure, health fitness, physical condition, external display, socialization, and fellow satisfaction is effected by pleasure and condition.

• 한국정책학회보
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• v.21 no.2
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• pp.277-300
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• 2012

This paper empirically analyses patterns of time allocation of the elderly, examining economic participation and volunteer work or social activities under the assumption that such activities have positive effects not only on the individuals and on the local communities but also on the society as a whole. As the result of descriptive analysis on the Korean Time Use Survey 1999, 2004 and 2009, the adults aged 60 to 64 years decrease time for paid work rapidly while increase time for passive leisure comparably slowly. In terms of time for active leisure, they devote less time to volunteer work and social activities, however, more time to self-centered activities such as education, cultural events, sport and fitness, and religious work. The overall pattern of decrease in time on economic or social participation for the elderly appeared be more significant in the birth cohorts of the early 1940s than those born in the late 1930s. The analysis implies that it is necessary for the government to encourage them to participate in community activities, either economic or social, with necessary policy responses. The result of the Tobit analysis on the dependent variables of each type of the 6 leisure activities demonstrated the self-centered active leisure time has increased over the last decaseds, whose pattern appeared to be more strengthened when the proportion of the elderly with higher education has increased.

• Journal of Life Science
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• v.18 no.1
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• pp.1-8
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• 2008

The purpose of this study was to determine the possible additive effects of endurance exercise training (EXER) and selenium (SELE) on the improvements of glucose and lactate transport capacities in diabetic Goto-kakizaki rats. Animals either remained sedentary control (SED) or performed EXER or received SELE [$5{\mu}mol$ kg body wt (-1) day (-1)], or underwent both EXER and SELE (COMBI), which lasted for 6 wk. Compared with sedentary control, EXER alone or the SELE alone group, or the combined treatment group had significant reduction in glucose response measured at 90 min and 120 min during an intraperitoneal glucose tolerance test (IPGTT) and body weight after 6week treatment. EXER alone, or combined group individually had significantly higher glycogen contents in liver compared with SED or SELE groups. EXER alone increased glycogen content in soleus and plantaris compared with SED, and this parameter was increased to greatest extent in the combined treatment groups compared with SED or SELE groups. EXER alone, SELE alone or COMBI, caused significant decreases in the plasma lactates, serum glucose, insulin, total cholesterol and HOMA-IR along with a significant increase in high-density lipoprotein cholesterol compared with SED. In addition, EXER or COMBI individually had significantly lower serum triacylglycerol compared with SED or SELE. With respect to protein expression related to glucose and lactate transport capacities, EXER alone, SELE alone, or COMBI increased in MCT1 and MCT4 protein level in soleus and plantaris. Furthermore, EXER alone, SELE alone or COMBI caused significant increases in mt MCT1 protein level in soleus and plantaris. The findings of the current study suggest that endurance exercise training and selenium treatment may provide therapeutic values to type II diabetic patients with peripheral insulin resistance and hyperlactatecemia by improving glucose and lactate transport capacities, leading to improvements in plasma lactate, serum glucose, insulin and lipid profiles (TC, TG, HDL).

• Journal of Electrical Engineering and Technology
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• v.12 no.4
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• pp.1641-1648
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• 2017

Many researchers had examined the validity of using the high-to-low ratio between two fixed frequency band amplitudes (H/L-FFB) from the surface electromyography of a face and body as the first spectral index to assess muscle fatigue. Despite these studies, the disadvantage of this index is the lack of a criterion for choosing the optimal border frequency. We tested the potential of using the high-to-low ratio between two signal spectral moments (H/L-SSM), without fixed border frequencies, to evaluate muscle fatigue and predict endurance time ($T_{end}$), which was determined when the subject was exhausted and could no longer follow the fixed contraction cycle. Ten healthy participants performed five sets of voluntary isotonic contractions until they could only produce 10% and 20% of their maximum voluntary contraction (MVC). The $T_{end}$ values for all participants were $138{\pm}35s$ at 10% MVC and $69{\pm}20s$ at 20% MVC. Changes in conventional spectral indices, such as the mean power frequency (MPF), Dimitrov spectral index (DSI), H/L-FFB, and H/L-SSM, were extracted from surface EMG signals and were monitored using the initial slope computed every 10% of $T_{end}$ as a statistical indicator and compared as a predictor of $T_{end}$. Significant correlations were found between $T_{end}$ and the initial H/L-SSM slope as computed over 30% of $T_{end}$. In conclusion, initial H/L-SSM slope can be used to describe changes in the spectral content of surface EMG signals and can be employed as a good predictor of $T_{end}$ compared to that of conventional spectral indices.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.12
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• pp.170-185
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• 2016

The purpose of this study was to investigate the relationship among instructor's non-verbal communication, emotional reaction, and self-efficacy. By using convenience sampling method of non-provability sampling, 258 student athletes from S and D cities were selected for a questionnaire survey. The 184 returned surveys were analyzed with structural equation modeling through SPSS 22.0 and AMOS 22.0 statics program. The study results are summarized as follows. First, instructor's non-verbal communication has a positive influence on emotional reaction of high school student athletes. Second, high school student athletes experiencing emotional reactions by instructor have a positive influence on self-efficacy. Third, instructor's non-verbal communication does not influence self-efficacy of high school student athletes directly. Fourth, emotional reactions of high school student athletes experienced by instructor's non-verbal communication have a mediating effect on self-efficacy. Fifth, neither gender nor exercise period has a moderating effect on the relationship between non-verbal communication, emotional reactions, and self-efficacy.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.5
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• pp.318-329
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• 2017

This study examined the physical self-concept and self-efficacy of undergraduates. Using the convenience sampling method of non-provability sampling, a total of 377 undergraduates from North Kyongsang Province G city were selected. Of the 377 completed questionnairescollected, a total of 354 surveys with structural equation modeling were analyzed using theSPSS 22.0 statistics program. The self-esteem, endurance, health, and flexibility factors have positive effects on improvingthe self-control efficacy factor of self-efficacy in the order of physical self-concept factors. On the other hand,the higher university students perceive that among the physical self-concepts, the physical activity factor had more negative effects on the self-regulated efficacy. The self-esteem, health, and muscle strength have positive effects on improvingthe confidence factor of self-efficacy in the order of physical self-concept factors. The more perceptive endurance than the appearance, sports competence, body fat, health, self-esteem, flexibility, muscle strength of physical self-concept, and the more influence on self-efficacy. Overall, the higher the perception of physical activity factors among the physical self-concept factors, the more negative effects on the task difficult preference.

• Journal of Life Science
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• v.19 no.10
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• pp.1403-1409
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• 2009

The purpose of this study was to compare Obesity Age (OA) and chronological age, to calculate Obesity Age (OA), which gauges the state of obesity, and to analyze presented factors of obesity using expectant factors on middle-aged obese women. The subjects were one hundred twenty seven middle-aged obese women ($49.6\pm7.3$ yr, BMI $29.41\pm2.9$, fat $36.8\pm4.6%$) who participated in different weight loss programs three times. The body composition, physical fitness, blood pressure and blood were measured before the weight loss programs. Informed consent was obtained from all subjects before enrollment in the study. The regression equation is as follows: (1) OAS (Obesity Age Score)=$0.106*X_1+0.035*X_2+0.048*X_3+0.041*X_4+0.003*X_5-0.037*X_6-10.667$ ($X_1$: BMI, $X_2$: weight, $X_3$: %fat, $X_4$: WC, $X_5$: TG, $X_6$: $VO_{2max}$), (2) OA (Obesity Age)=7.3*OAS+49.6*(-1), (3) Z (correction factor)=(CA-49.6)(1-0.03), (4) OAc (corrected Obesity Age)=1.03*CA-7.3*OAS+1.47. The comparison of corrected Obesity Age (OAc) and chronological age did not have any differences, and the average of the OAc was close to chronological age. The correlation coefficient between the OAc and chronological age was r=0.724 (p<0.05). The equation can be utilized for middle-aged obese women, because it could evaluate the obesity-related factors by including BMI, body weight, %fat, waist circumference, triglycerides and $VO_{2max}$.