• Journal of Fisheries and Marine Sciences Education
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• v.28 no.2
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• pp.356-365
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• 2016

The purpose of this study was to verify the influences of sport enjoyment factors on recreation specialization of water sports participants. The study conducted a research survey through purposive sampling method after selecting 4 water sports center in Busan. 260 questionnaires distributed and 246 were selected as final valid sample by removing 14 questionnaires that have insufficient answers. Then data were analyzed through exploratory factor analysis, reliability analysis, correlation analysis, and multiple regression analysis using SPSS Window ver. 20.0. The results were as followings. First, the enjoyment factors have a positive effect on recreation specialization. Second, escaping from daily routine and improving technical skill dimensions of enjoyment factors have an influence on centrality of life. Third, improving technical skill dimension of enjoyment factors have a positive effect on past experience. Lastly, flow and improving technical skill dimensions of enjoyment factors have an influence on economic investment.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.21 no.3
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• pp.41-45
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• 2013

In this study, we surveyed the operating status of the Runway for the Light Sport Aircraft(LSA) in Korea, and analyzed the Airfield Facilities Manual for the Air Leisure and the Standard Specification for Recreational Airpark Design. Based on the information, we presented the displacement of the threshold concept, to ensure the Runway Length and the Runway Safety Area, and operation of LSA in Korea.

• Korean Journal of Applied Biomechanics
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• v.24 no.4
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• pp.359-365
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• 2014

A study was conducted to investigate the possible effects of fatigue which was resulted from increased running time on the stability during a prolonged run. The purposes of this study were twofold: first, to determine the discrete and non-linear variability of GRF (ground reaction force) components between running times to know the body stability, and second, to determine the pattern between discrete and non-linear variability. Nineteens healthy young adult males served in this study as subjects who ran at their preferred running speed. GRF data for twenty strides were collected at 5, 65, and 125 minutes during run. Variance coefficient and Lyapunov Exponent techniques on the GRF data were used to calculate variability index for each of the running time conditions. There were no difference between discrete variabilities of three components of GRF, but non-linear variability of the Fz component of GRF was decreased by increasing running time (p<.01). No relationship was found between discrete and non-linear variability.

• Korean Journal of Applied Biomechanics
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• v.24 no.4
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• pp.455-461
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• 2014

The purposes of this study were to reveal the kinematic and kinetic difference of hard ground soccer shoe, firm ground soccer shoe and soft ground soccer shoe. Soccer players were shoes of varying stud designs with some preferring the bladed studs while others opting for the conventional studded stud. Statistics were used one way-ANOVA and Tukey's Honestly Significant Difference Method. Seven healthy college soccer players were attended a test. All parameters were recorded using the Zebris system. Spatio-temporal variables were no significant difference. Lateral symmetry was statistically significant differences (p<.05). Vertical GRF parameters were no significant difference. Medial midfoot pressure, lateral midfoot pressure and central forefoot pressure were statistically significant differences (p<.05). This study demonstrates that playing surface significantly affects difference soccer shoes during soccer game. Furthermore, epidemiological investigation is warranted to determine the effects of playing surfaces on sport specific injury mechanisms.

• Journal of International Academy of Physical Therapy Research
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• v.9 no.4
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• pp.1669-1675
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• 2018

The present study aimed to investigate rapid weight loss (RWL) and consequent physical and psychological challenges among judo athletes at the national athlete training center in 2017. The following results were obtained. Judo athletes used weight loss methods such as "gradually reduce meal portion," "skip meals," "limit water intake," "wear sweat suit for training," and "use sauna," and had physical and mental distress from such unhealthy weight management practices. Information about weight loss was obtained from "colleagues or senior athletes," "Internet," and "head coach or coach," and not experts such as nutritionists or physicians. Thus, athletes are recommended to employ healthy weight control methods based on advice from experts, such as nutritionists and physicians.

• Advances in nano research
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• v.13 no.6
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• pp.561-574
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• 2022

The stability of protein tissues and protein fibers in the human muscle is investigated in the presented paper. The protein fibers are modeled via tube structures embedded in others proteins fibers like the elastic substrate. Physical sport and physical exercise play an important role in the stability of synthesis and strength of the protein tissues. In physical exercise, the temperature of the body increases, and this temperature change impacts the stability of the protein tissues, which is the aim of the current study. The mathematical simulation of the protein tissues is done based on the mechanical sciences, and the protein fibers are modeled via wire structures according to the high-order theory beams. The thermal stress due to the conditions of the sport is applied to the nanoscale protein fibers, then the stability regarding the frequency analysis is investigated. Finally, the impact of temperature change, physical exercise, and small-scale parameters on the stability of the protein tissues are examined in detail.

• Advances in nano research
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• v.14 no.2
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• pp.165-177
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• 2023

Nanomotors are gaining popularity as novel drug delivery methods since they can move rapidly, penetrate deeply into tissues, and be regulated. The ability of manufactured nanomotors to swiftly transport therapeutic payloads to their intended location constitutes a revolutionary nanomedicine strategy. The nanomotors for the drug delivery purpose are released in the blood flow under the different physical conditions, so the stability investigation of these devices is essential before the production, especially in the sport and physical exercise conditions that the blood flow enhances. As a result, using dynamic analysis, this article investigates the stability of the nanomotor released in the blood flow when sport and physical activity circumstances increase blood flow. The considered nanodevice is made of a central motor, and nanotubes are used for the nanomotor blade, which is the drug capsule. Finally, the stability examination of nanomotor as the drug delivery equipment is discussed in detail, and the proposed results can present beneficial results in designing and producing small-scale intelligent devices.

• Advances in nano research
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• v.14 no.6
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• pp.527-539
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• 2023

Measuring energy burn during intensive combat sport has been a challenging concerns for a long time. In the present article, the energy consumption during combat sports is measured by use of wearable GoBe2 equipped with nanotechnology measuring devices. In this regard, 12 professional combat athletes were asked to wear GoBe2 devices during different sessions of intensive combat exercises. The curves provided by GoBe2 nano-sensor devices are further collected and analyzed for different combat durations. On the other hand, energy consumption in these athlete is calculated using other validated methods to evaluate reliability of GoBe2 wearable devices. Based on the results obtained from these experiments a multi-parameter mathematical model is presented for estimation of combat calorie consumptions. The results show that nanotechnology in these type of sensors could help in estimation of calorie consumption during combat. Moreover, the reliability of using wearable GoBe2 sensors are satisfactory except for some specific conditions. The mathematical model provides a satisfactory results based on athlete physical condition and also duration of the combat with about 8% error margin in the results.

• Earthquakes and Structures
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• v.24 no.2
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• pp.111-126
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• 2023

Highly reliable and versatile methods artificial intelligence (AI) have found multiple application in the different fields of science, engineering and health care system. In the present study, we aim to utilize AI method to investigated vibrations in the human leg bone. In this regard, the bone geometry is simplified as a thick cylindrical shell structure. The deep neural network (DNN) is selected for prediction of natural frequency and critical buckling load of the bone cylindrical model. Training of the network is conducted with results of the numerical solution of the governing equations of the bone structure. A suitable optimization algorithm is selected for minimizing the loss function of the DNN. Generalized differential quadrature method (GDQM), and Hamilton's principle are used for solving and obtaining the governing equations of the system. As well as this, in the results section, with the aid of AI some predictions for improving the behaviors of the various sport systems will be given in detail.

• Journal of Life Science
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• v.20 no.3
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• pp.444-452
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• 2010

The purpose of this study was to investigate the effects of treadmill exercise on $A{\beta}$-42, cytochrome c, SOD-1, 2 and Sirt-3 protein expressions in brain cytosol and mitochondria in mutant (N141I) presenilin-2 transgenic mice with Alzheimer's disease (AD). The mice were divided into four groups (Non-Tg-sedentary, n=5; Non-Tg treadmill exercise, n=5; Tg-sedentary, n=5; Tg treadmill exercise, n=5). To evaluate the neuroprotective effect of treadmill exercise, Non-Tg and Tg mice were subjected to exercise training on a treadmill for 12 wk, after which their brain cytosol and mitochondria were evaluated to determine whether any changes in the cognitive performance, $A{\beta}$-42 protein, cytochrome c protein, anti-oxidant enzymes (SOD-1, SOD-2) and Sirt-3 protein had occurred. The results indicated that treadmill exercise resulted in amelioration in cognitive deficits of Tg mice. In addition, the expressions of mitochondrial $A{\beta}$-42 and cytosolic cytochrome c protein were decreased in the brains of Tg mice after treadmill exercise, whereas antioxidant enzymes, SOD-l and SOD-2 were significantly increased in response to treadmill exercise. Furthermore, treadmill exercise significantly increased the expression of Sirt-3 protein in Non-Tg and Tg mice. Taken together, these results suggest that treadmill exercise is a simple behavioral intervention which can sufficiently improve cognitive performance and inhibit $A{\beta}$-induced oxidative stress in AD.