• The Journal of the Korea Contents Association
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• v.12 no.6
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• pp.438-447
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• 2012

This study was to explore the social network structure of professional volleyball players and analyze network variables and resource exchange. This study selected 127 players of Korean professional volleyball in ten team of male and female using the purposive sampling method. The research method utilized general social survey of NGQ(Name Generator Question) and interview. To analyze data, NetMiner 3.0 and SNA(social network analysis) were used. The conclusion based on above study method and the result of material analysis are here below. First, social network of professional volleyball players is scale-free network following power law. Centrality and herb of club members' network show up richer-get-richer and poor-get-poor by collecting links of back of beyond. Second, social network structure of professional volleyball players influence resource exchange.

• Journal of the Korean Data and Information Science Society
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• v.26 no.3
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• pp.619-630
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• 2015

The purpose of this study is to provide basic information to develop a game strategy plan of a team in a future by identifying the patterns of attack and pass of national men's professional volleyball teams and extracting core key words related with volleyball game performance to evaluate game performance using 'social network analysis' and 'text mining'. As for the analysis result of 'social network analysis' with the whole data, group '0' (6 players) and group '1' (11 players) were partitioned. A point of view the degree centrality and betweenness centrality in 'social network analysis' results, we can know that the group '1' more active game performance than the group '0'. The significant result for two group (win and loss) obtained by 'text mining' according to two groups ('0' and '1') obtained by 'social network analysis' showed significant difference (p-value: 0.001). As for clustering of each network, group '0' had the tendency to score points through set player D and E. In group '1', the player K had the tendency to fail if he attack through 'dig'; players C and D have a good performance through 'set' play.

• Korean Journal of Applied Biomechanics
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• v.19 no.2
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• pp.359-367
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• 2009

This study was conducted to provide useful information for the scientific training of spikes and instruction, by analyzing all kinematical variants including time, distance, velocity, angle factors in spike movements of volleyball matches. The subjects were 4 foreigner players, who participated in the V-League of 2008-2009. The conclusion from this study is as follows. Time for a jumping step was .33s, and Angelko had a bit longer takeoff time than other players. In Angelko and Anderson who were leading in attack power, the whole distance of a spike motion was relatively short, less than 4m. The moment when the center of gravity reached the lowest point was when the right foot bearing weight in the jumping step was passing the left foot, and the highest point of gravity was 2.30m, which appeared just before the impact. The horizontal speed of the center of the gravity was highest as 4.19m/s at the beginning of a jumping step, and lowest at the stance phase of the fore foot just before takeoff. The vertical speed of the center of the gravity was lowest after the right foot touched the ground, and highest after the takeoff of the fore foot. Impact was 3.22m, and the highest ball speed was 28.18m/s.

• Korean Journal of Applied Biomechanics
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• v.17 no.4
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• pp.45-55
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• 2007

We investigated the biomechanics and characteristics of shoulder rotator muscles for professional woman volleyball players. The purpose of this study was to analyze the isokinetic peak torque and range of motion for shoulder joint rotation. We measured the strength and ROM of the internal rotation(IR) and external rotation(ER) of shoulders joint for nine professional woman Volleyball players and nine University students with Biodex and Simi-motion. 1. We measured peak torques for the shoulder joint rotator at angular velocities of 60/s and 180/s. It was found that the peak torques were significantly different between the two groups and also between the hands used. 2. At angular velocity of 60/s, IR/ER ratio of the shoulder joint was significantly different depending on the groups and the hands in use. There was a significant difference for 'Dominant side' at angular velocity of 180/s, but no significant difference for 'Non-dominant side' and the controls group. 3. Regarding the ROM of rotation of the shoulder joint group, IR was significantly different between the groups and the hands in use. 4. IR/ER ratio of the shoulder joint for Dominant side was quite different between the groups.

• Korean Journal of Applied Biomechanics
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• v.19 no.4
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• pp.671-680
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• 2009

We performed a study to obtain kinematic data on the characteristics of spike serving techniques used by volleyball players, including other basic data that will be useful for in-field applications. We used three-dimensional videography to compare good tough serves and serve errors. The subjects were 3 left attackers whose spike serves were videographed (60 fileds/s). The three-dimensional coordinates were calculated using the direct linear transformation method and then analyzed using the Kwon 3D software program version 3.1. There was no difference in time elapsed. However, the vertical displacement of the center of body mass(CM) differed between the 2 types of serves: in successful serves, the CM tended to be lower, as did the maximum ball height at the time of hitting. Further, the higher the level of the hitting hand was at the moment of impact, the higher was the likelihood of scoring points. In good serves, the players tended to accelerate their CM movement just before jumping to hit the ball and descend rapidly at the moment of hitting. The hand speed along with ball velocity during the impact was proven to be higher in successful serves. Moreover, in successful serves, the shoulder angles increased to a greater extent while the elbow angles were maintained constant. This possibly resulted in faster and more precise serves. An important observation was that the angle of trunk inclination during the jump did not increase with the swing of the shoulders, muscle tendon complex.