• Korean Journal of Applied Biomechanics
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• v.23 no.4
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• pp.307-318
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• 2013

The purpose of this study was to analyze the kinematic variables of glide kip motion on the uneven bars through a two-dimensional cinematography. Three expert female gymnastics players were involved in the data gathering process. The followings were concluded according to the results. The arm, trunk and leg segments were fully extended throughout the kip movement. The whole body center of gravity showed the biggest changes during 66 to 87% of the kip motion. During the kip phase, the horizontal displacement of the leg was greater than the vertical displacement the leg. Glide kip motion should be done in orders of upward movement of leg, forward movement of leg, upward movement of trunk and forward movement of trunk segment. It was found that trunk segment and hip joint movements showed bigger changes than those of leg segment and shoulder joint in the glide kip motion. The largest angular velocity of hip joint was shown in the middle of the kip Phase. In conclusion, effective kip movement could be resulted when the trunk was displaced posterior-upward direction with fast hip joint extension after the leg segment was elevated upward and thrusted forward in advance.

• Korean Journal of Applied Biomechanics
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• v.23 no.3
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• pp.245-252
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• 2013

The purpose of this study was to analyze the effect that various loads have on the lower limb biomechanics. The following variables were measured and analyzed; performance time for each phase, lower limb moments and joint angles, and ground reaction forces. The kinematic and kinetic data was recorded by 2 force platforms and a motion capture system while 12 healthy adults in their twenties stepped down three steps under loads of 0%, 10%, 20% BW. Results are as follows. First, the different loading conditions did not seem to significantly affect the performance times and the joint angles. Second, the largest ground reaction forces were observed at the 1 step at the 10% BW condition. Finally, at the 0% BW loading condition the right hip extension moment was the smallest and the left hip flexion moment was the largest. The results show that there are not any significant changes in the biomechanics of the lower limbs under loading conditions up to 20% BW. Further investigations including more loading conditions with more weights and more additional steps analyzed are needed.

• Korean Journal of Applied Biomechanics
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• v.29 no.3
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• pp.167-172
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• 2019

Objective: The aim of this study was to investigate the effect of midsole hardness of running shoe on muscle fatigue and impact force during distance running. Method: Ten healthy college recreational runners who were performing distance running at least three times a week participated in this experiment. They were asked to run for 15 minutes in the treadmill at 10 km/h with running shoes having three different types of midsole hardness (Soft, Medium, Hard). EMG signal and insole pressure were collected during the first and last one minute for each running trials. Data were analyzed using a one-way analysis of variance (ANOVA) with repeated measures. Results: Midsole hardness did not affect the consistency of stride length. For the median frequency of the EMG signal, only VL was affected by midsole hardness; that of medium was greater than other midsoles (p<.05). The loading rate of impact forces increased by midsole hardness (p<.01). Conclusion: Although soft midsole could attenuate impact forces at heel contact, it might have a negative effect on the fatigue of muscle which could decelerate the body after heel contact. Therefore, it is necessary to select the optimum hardness of midsole carefully for both reduction impact forces and muscle fatigue.

• Journal of Sport and Applied Science
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• v.3 no.2
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• pp.11-16
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• 2019

Purpose: New sports is a modified physical activity which is developed for participants to easily learn and play. This study is to analyze distribution channels and related strategies of Korea new sports and to discuss strategies for promoting Korea new sports, especially for two-two ball. Research design, data, and methodology: The study reviewed literatures including documents of Dae-Han two-two-ball association and new sports related research articles. Results: First, Dae-Han two-two-ball association has introduced two two ball to consumers via educational organizations such as schools and youth education sectors. Second, Dae-Han two-two-ball association has introducted two two ball to school teachers by teacher training sessions. Third, Dae-Han two-two-ball association has educated future instructors and provided certificates to them. Fourth, Dae-Han two two ball association has applied governmental projects and sought to promote domestic new sports. Finally, Dae-Han two two ball association has hosted national events every year for facilitating Korea new sports across nation. Conclusions: In conclusion, Korea new sports shoud be spread out by school teachers and educational organizations. Two-two ball association needs to develop a systematic educational and managerial process for training instructors. Finally, Two-two ball association needs to make opportunities of teacher training sessions. Future directions were discussed.

• Journal of the Korea Convergence Society
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• v.11 no.9
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• pp.163-168
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• 2020

The purpose of this study is to investigate the relationship between the selection factors of sports climbing center, customer satisfaction, and re-registration. Data collection for the purpose of this study was collected through S center, B center, V center located in Seoul and K center located in Gyeonggi-do. A total of 296 valid samples were used for the analysis. To make sure the theory, it was based on analysis of frequency, factor analysis, reliability analysis and multiple regression. First of all, it was found that the factors of selecting the sports climbing center partially affected the customer satisfaction level. Second, it was found that the factors of selecting the sports climbing center partially affected the decision to re-register.

• International Journal of Internet, Broadcasting and Communication
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• v.12 no.2
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• pp.137-143
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• 2020

The purpose of this study is to analyze the structural relationship among advertising attribute, advertising attitude, product attitude and purchase intention in YouTube advertising. The survey subjects to achieve the purpose of this study were selected the group of 300 students who have been watching YouTube VOD once more and are attending in three universities that are located in Seoul, Gyeonggi and Chungnam. Data processing was done with SPSS 23 for frequency analysis, Cronbach's α analysis. Also, AMOS 18 was used for confirmatory factor analysis and structural equation model analysis. information, irrtation and individuality affect viewers' advertisement attitude, their product attitude and purchasing intent, among advertisement attributes of e-sports items perceived by viewers of YouTube's e-sports videos with the insertion of advertisements that cannot be skipped in the middle of the video.Therefore, the similarity between the video and the advertised product or brand should be taken into account when producing advertisements inserted in the YouTube video, and a more positive advertising effect can be achieved when advertisement can be carried out reflecting the characteristics of the target viewers.

• Korean Journal of Applied Biomechanics
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• v.14 no.1
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• pp.41-50
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• 2004

The objective of the study is to analyze the myoelectrical activity involved in performing the Swallow movement, a D-level technique, in order to use it as the basic research data in helping train gymnasts in how to perform strength-related techniques. To this end, four national representative athletes who participated in the 2002 Busan Asian Games were selected. The results of the comparison analysis of the individual models are summarized as follows. 1) The results of the E.M.G analysis showed that during the Swallow movement, the myoelectrical activity was detected higher in pectorialis major muscle and bicep brachii muscle than in trapezius muscle and deltoid muscle. 2) The results of the E.M.G analysis showed that during the Swallow movement, the myoelectrical activity was measured high in triceps brachii muscle and palmaris longus muscle, while the myoelectrical activity was recorded low in latissimus dorsi muscle and rectus abdominis muscle. 3) In performing the Swallow in the rings, the mean average (%) was found high in the order of erector spinae, pectorialis major muscle, palmaris longus muscle, triceps brachii muscle, deltoid muscle, latissimus dorsi muscle, and trapezius muscle. All taken together, the athletes showed a difference in the distribution of the muscles during the performance of the Swallow. The muscle that showed a constant distribution among the athletes was pectoralis major muscle, which proves that for a stable performance, it is ideal to increase the myoelectrical activity in pectoralis major muscle.

• Korean Journal of Applied Biomechanics
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• v.26 no.2
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• pp.205-211
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• 2016

Purpose: The aim of this study was to analyze biomechanical factors and PMT (premotor time) of body muscles between elite college and amateur baseball players during the baseball batting motion. Method: Kinematic and electromyographic data were obtained for 10 elite college baseball players and 10 amateur baseball players who participated in this study. All motion capture data were collected at 200 Hz using 8 VICON cameras and the PMT of muscles was recorded using a Delsys Trigno wireless system. The peak mean bat speed and the peak mean angular velocities of trunk, pelvis, and bat with PMT of 16 body muscles were computed. These kinematic and PMT data of both groups were compared by independent t-tests (p < .05). Results: The pelvis, trunk, and bat showed a sequence of angular velocity value during baseball batting. The PMTs of right tibialis anterior, left gastrocnemius, external oblique, and erector spinae were significantly different between the two groups. Conclusion: The PMT of body muscles was related to the shifting of body and rotation of the pelvis and the trunk segment, and this action can be considered the coordinated muscle activity of the lower and upper body.

• Korean Journal of Applied Biomechanics
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• v.15 no.2
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• pp.31-39
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• 2005

The Purpose of this study was to reveal the biomechanical difference of two soccer footwear(soft ground footwear and hard ground footwear). Secondly, the purpose of this study was to clarify how each type of soccer footwear effects soccer players, which will provide scientific data to coaches and players, to further prevent injuries and to improve each players capacity. The result of comparative analysis of two soccer footwear can be summarized as below. The comparison of the very first braking force at walking found distinctive factors in the statistical data(t=3.092, p<.05). Braking impulse of two difference footwear showed distinctive factors in the statistical data(t=2.542, p<.05). In comparing GRFz max(N), the result showed a statistically significant difference in the two soccer footwear at running(t=2.784, p<.05). In the maximum braking impulse(t=2.774, p<.05) and propulsive impulse for antero-posterior direction, there was a statistically significant difference between the two soccer footwear at running. In the maximum braking force(t=3.270, p<.05) and propulsive force(t=4.956, p<.05) for antero-posterior direction, there was a statistically significant difference between the two soccer footwear at running. Significant differences were not found in moment(rotational friction) with two difference soccer footwear(moment max; t=2.231, moment min; t=1.784).

• Korean Journal of Applied Biomechanics
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• v.13 no.3
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• pp.341-354
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• 2003

The purpose of this study was to develop the uniaxial force plate system which is measured by the vertical force. The VGRF(vertical ground reaction force) 1.0 was composed of 2 bath digital scales, 2 indicaters, and analyzing software. This system was newly renovated to VGRF 2,0 which are 2 industrial digital scales, 2 adjustable indicators, and enforced analyzing software. Changes of the new system were as follows. First, the height of the plate was 75% lower than before. Second, sensing ability of the load cell was changed from 90 - 0.05kg to 300 - 0.1kg. Third, the speed of data processing was changed from 17 per second to 60 per second. Fourth, analyzing software was enforced to develop and calculate the data. For the test of the system, two different types(bare foot, high-heeled shoes) gait was adopted. highly skilled female walker(23yrs, height 165cm, body mass 46.8kg) participated for the experimental study. During the dynamic performance(gait analysis), the data of each load cell were very similar to the previous studies. Specifically, bare foot walking had less vertical force than high-heeled shoes. Consequently, VGRF 2.0 can sense the general dynamic movements as well as static load conditions.