• 한국운동역학회지
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• 제12권1호
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• pp.193-204
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• 2002

The purpose of this study was to investigate the effect of martial art type and target height on the ground reaction force factors during Dollyuchagi motion. Data were collected using force plate. Five Taekwondo players and five Hapkido players were tested during Dollyuchagi motion to three different target heights(0.8, 1.2, 1.6 m). After analysis of kinetics using force plate data, maximum vertical ground reaction force was 1.62~2.44 BW, and impulse was $0.66\sim1.01 BW{\cdot}s$. Even though there was no difference for maximum ground reaction forces and impulse between Hapkido and Taekwondo, as target height was higher, impulse increased. Anterior-posterior and vertical ground reaction forces at kicking foot take-off were greater with target height, although there was no difference for medio-lateral force with target height. At impact there was significant difference for anterior-posterior ground reaction force between Hapkido and Taekwondo players. Taekwondo players' force (range, -0.23~-0.26 BW) was greater than Hapkido players's force (range, -0.08~-0.14 BW).

• 한국운동역학회지
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• 제22권2호
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• pp.151-158
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• 2012

The purpose of this study was to investigate variables of significantly difference as the structure of the spine, pelvic deviation and foot pressure between undergraduates and golf player subjects. The subjects of study were composed of 20 male golf players and 20 male undergraduates. Both groups were right handed persons. The measurement tools of this study were Formetric 4D(Diers, Germany) which is a three dimensional measure. The result are the follows: there were a significant difference between golf players and general students of trunk imbalance, pelvic tilt, pelvic torsion, pelvic rotation, surface rotation, lumbar lordotic curve, foot pressure(fore & behind foot), weight distribution(right & left foot). In conclusion, golf players might cause transform of spine and foot pressure due to golf exercise for several years. Such as imbalance affect to induce functional impairment and pain of musculoskeletal system, and appropriate evaluation and treatment were necessary for golf players.

• 국제물리치료학회지
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• 제8권2호
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• pp.1158-1162
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• 2017

The purpose of the study was to investigate the strength of sokinetic muscle by the position of a volleyball players. Analysis and comparison of shoulder dynamic stability will be conducted according to rotational movement of the shoulder during spiking and serving amongst the various positions. Fifty professional Korean female volleyball players (age: 20~30), all different positions - attacker (left and right), center, setter, and libero were The concentric peak torque, strength ration of the internal and external rotation of the shoulder girdle for both dominant and non-dominant arms. Firstly, there were significant differences found for the strength ratio between the setter and the other positions in the dominant arm. On a second note, there was a significant decrease in shoulder dynamic stabilization for both the attacker and center in the dominant arm. However, there were no significant differences for the setter or the libero. This study suggests that the isokinetic muscle strengths of the volleyball players are different from each other.

• 한국컴퓨터정보학회논문지
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• 제23권8호
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• pp.107-114
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• 2018

This study was conducted for the purpose of examining the effects of team trust element of rugby players on self-determination motive and team performance. As for the study subjects, rugby players participated in the 97th national athletic meet in 2016 were selected. As for data collection, in the total of 221 copies of samples were collected through convenience sampling method and 182 copies were used for the final analysis. Using SPSS 18.0, the collected data were analyzed through frequency analysis, exploratory factor analysis, Cronbach's ${\alpha}$ test, correlation analysis and multiple regression analysis and the following conclusions have been obtained. First, as for the effects of rugby players' team trust element on self-determination motive, it was found that team trust influenced external moderation, internal moderation, integrated moderation and identification moderation, and teammate trust influenced internal moderation, integrated moderation and identification moderation. Second, as for the effects of rugby players' team trust element on team performance, it was found that team trust and teammate trust influenced team performance. Third, as for the effects of rugby players' self-determination motive on team performance, it was found that integrated moderation and internal moderation influenced team performance.

• 기술혁신연구
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• 제12권1호
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• pp.241-269
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• 2004

Online game business has emerged as the most lucrative entertainment industry, with over 10 million players in South Korea. The popularity of online games can be attributed to the availability of broadband network and the presence of numerous PC Bangs and around the country, which have pushed online games into the mainstream entertainment culture. The age distribution of online game players is expanding and a variety of new games are under development to target certain age groups. While the interactive entertainment market continues to expand, with many new online game publishers entering the market, relatively little is known about which factors influence online game players' behavioral intentions to play continuously n this area. It appears that in this extremely attractive and growing services segment, academics, as well as practitioners, would benefit from investigating the relationships among the players' intentions to play, flow, and the impacts of several other key game-related constructs n consumer behavioral intentions. Several types of interaction in on-line games and their relationship with the flow construct are investigated, and the resulting conceptual model is proposed. Based on data collected from online questionnaire survey, the validity of the simultaneous equation model has been tested and interesting conclusions have been developed concerning the relationships between the players' behavioral intentions to play, flow, and interactions. Other interesting results concerning game development strategy are also provided.

• 한국HCI학회:학술대회논문집
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• 한국HCI학회 2008년도 학술대회 2부
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• pp.115-120
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• 2008

본 논문은 하나의 미디어아트 작품에 대한 분석과 구현된 기술을 제공한다 3차원 그래픽 기술을 이용하여 다중 동영상 플레이어를 구현하였으며, 모든 동영상은 상호 연동되어 동작한다 컴퓨터의 소프트웨어로 구현된 동영상 플레이어에 관객이 참여하여 관객 스스로 감성적 자극을 얻을 수 있도록 구상하였다. 각 플레이어에 인간의 희로애락을 표현하며 특정화면에 대한 경험의 공감을 표현한다. 시스템의 성능에 따라 N2개 플레이어가 증가될 수 있으며, 더욱 많은 동영상간의 복합적인 연계를 통해 예술적 메시지를 전달할 수 있을 것으로 생각한다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권4호
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• pp.1768-1789
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• 2016

In contemporary video streaming systems based on HTTP protocol, video players at the client side are responsible for adjusting video quality to network conditions and user expectations. However, when multiple video clips are streamed simultaneously, an intricate application logic implemented in the video players overlays the TCP mechanism which is responsible for a balanced access to a shared network link. As a result, some video players may not obtain a fair share of network throughput and may be vulnerable to an unstable video bit-rate. Therefore, we propose to simplify the algorithms implemented in the video players, which are responsible for the adjustment of video quality and constrain their functionality only to sending feedback to a server about a state of the player buffer. The main logic of the system is shifted to the server, which is now responsible for bit-rate selection and prioritisation of the video streams transmitted to multiple clients. To verify our proposition, we performed several experiments in a laboratory environment which show that when the server cooperates with the clients, the video players experience fewer quality switches and the system achieves better fairness when allocating network throughput among the video players. However, this comes at the cost of worse utilisation of network bandwidth.

• 한국멀티미디어학회논문지
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• 제25권11호
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• pp.1591-1600
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• 2022

With the prosperity of Internet, the game industry is occuping an important position in the national economic system. The study on the game industry which has been drawing eyes from researchers is of great significance. Many scholars have done researches on game motivations, but the elements of intrinsic motivation are still in the exploratory stage. This study determines the dimensions of the influencing factors of players 'intrinsic game motivation and their game experience by adopting the method of literature research. A theoretical model is established to explore the influence of intrinsic game motivation on players' game experience. Questionnaires from players of "The Honor of Kings" are collected through the Internet. SPSS 21.0 is utilized to test the model and hypotheses, and finally the results of the data are analysed. It verifies that intrinsic motivation mainly consists of four components: achievement, social interaction, immersion and escapism. By exploring the influence of the four elements on players' experience, it is concluded that the players' immersion and social interaction have a greater positive impact on their game experience. It is indicated that a better game design highlights the storyline of the game and the interaction system is of importance to enable players to gain a better game experience.

• The Journal of Korean Physical Therapy
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• 제33권5호
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• pp.217-223
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• 2021

Purpose: This study sought to identify the effects of coordinative locomotor training (CLT) using elastic bands on the flexibility and body alignment of right-handed baseball players in elementary school. Methods: The subjects were 20 instructed right-handed baseball players in elementary school. They were classified into the experimental group with 10 players (n=10) to be given coordinative locomotor training using elastic bands and the control group with 10 players (n=10). Flexibility was measured by the sit and reach exercise. Body alignment was measured using formetric 4D method to measure the trunk imbalance angle (TI), trunk torsion angle (TT), pelvic tilt angle (PTi), pelvic torsion angle (PTo), pelvic rotation angle (PR), kyphotic angle (Ky), and lordotic angle (Lo). Results: There was a significant increase in the flexibility within the experimental group (p<0.05). after the intervention. There was also a significant increase in the difference between the experimental group and the control group (p<0.05). There was a significant decrease in PR during body alignment in the experimental group after intervention (p<0.05). An analysis of the differences between groups showed a significant decrease in the PR of the experimental group compared to the control group (p<0.05). Conclusion: These findings show that coordinative locomotor training using elastic bands would be effective for enhancing the flexibility and pelvic rotation of elementary school right-handed baseball players.

• Physical Therapy Rehabilitation Science
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• 제11권4호
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• pp.579-584
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• 2022

Objective: To identify the effect of unstable surface kettlebell exercises on muscle activity and balance in middle and high school baseball players. Design: Randomized controlled trial. Methods: The participants were 29 middle and high school baseball players (Unstable surface kettlebell exercises group, USKE: 15; Stable surface kettlebell exercise group, SSKE: 14). The players in the USKE group performed kettlebell exercises for 60 mins on a stable surface thrice a week for 6 weeks, and the return rack was solidified on a stable surface in the same way as the experimental group. Before and after the experiment, the participant's muscle activity of the tibialis anterior and soleus was measured. In addition, the participant's balance was evaluated by measuring the distance moved from the foot's center of pressure (COP). The paired t-test was used to compare groups before and after the experiment. The independent t-test was conducted to assess differences in the degree of change between the two groups before and after the experiment. Results: Compared to the SSKE group, the USKE group showed significant differences in the muscle activity of the tibialis anterior and soleus and the balance with the eyes open and closed. Conclusions: The players in the USKE group showed a significant difference in muscle activity and balance than in those in the SSKE group. Thus, effectively including an unstable surface in the kettlebell exercise program will help improve physical function in athletes and people with musculoskeletal disorders.