보행 시 지지면 급변에 따른 연령별 운동학적 반응 형태 비교

천영진 ( Young Jin Chun ),신인식 ( In Sik Shin ) 한국운동역학회 2011 한국운동역학회지 Vol.21 No.3

The purpose of this study was to analyze the difference in reaction patterns during the support phase after perturbation in gait according to different age. A total of 12 subjects participated; 5 elderly and 7 adults(control), to investigate the differences between normal and perturbed gait. The step length didn`t change during normal and perturbed gait but was longer in the control group. There was no difference in the step width. When the right foot was perturbed, the control group`s left foot speed was faster than the elderly group`s which was to maintain stability. The elderly flexed both right and left knees more than the control group. After the perturbation, the elderly group had a larger trunk anterior flexion. With the larger flexion of both legs of the elderly group it shows that the lack of knee flexion strength is a factor, that could cause falling and so a prevention program should focus on strengthening the quadriceps. With the excessive trunk flexion after the perturbation by the elderly group observed, it is suggested that while walking everyday a good routine of walking with an upright posture should be developed.

지지면 급변에 따른 연령별 보행 변인 비교

천영진(Chun Young-Jin) 한국체육과학회 2011 한국체육과학회지 Vol.20 No.2

This study's purpose is to examine the age-related difference in variables of gait from the perturbation during gait. In order to perform this task, a trap was installed on 7 meter-long, 1.5 meter-wide path with its base-of-support rapidly changed, on which seven subjects in their twenties, forties and seventies respectively were requested to tread and go through. Subjects were n .. 'quested to perform normal gaits and confounding gaits five times respectively in random order. The gait was analyzed using 6 infrared cameras. Kinematic variables of speed, step time, step length, step width, etc. were assessed for gait analysis. Followings are the remarkable results obtained from this study. First, as aging was in progress, velocity got slower and step time got longer. In comparison of the section with perturbation with the other, there was no difference in their twenties, but longer step time in their forties and seventies. Second, as aging was in progress, step length tended to get shorter. When perturbation occurred, they shortened the step length to keep balance in their twenties, while extended the step time instead of step length in their forties and seventies. Third, there was no difference in step width depending on the ages, but a strong possibility that balance can be lost because of reduced step width when perturbation occurred in their seventies. Fourth, when detected from left knee, as aging was in progress reaction time got slower. Fifth, as aging was in progress, onset time appeared late at tibialis anterior and gastrocnemius only.

대학야구에서 알루미늄 배트와 나무 배트 사용 시 경기력 비교

천영진(Chun, Young-Jin),김규태(Kim, Kyu-Tae) 한국체육과학회 2012 한국체육과학회지 Vol.21 No.4

The purpose of this study was to compare result of game between aluminum bat and wood bats in baseball games. The data of this study were records of the aluminum bat 1999 it uses and the wood bat it uses 2000, 2001 from collegiate baseball games. The variables of this study were runs, singles, doubles, triples, home runs, slugging percentage, opponents batting average, batters faced, innings pitched per team, and time per game from, 1999, 2000, 2001 seasons. Statistical analysis of this study was one way ANOVA. The conclusions are the following: 1. The run per team of the year which is used in aluminum bat was higher than that used in wood bat. 2. Except of triple, the hits per team of the year which is used in aluminum bat were more than that used in wood bat. 3. The slugging percentage and opponents batting average per team of the year which is used in aluminum bat were higher than that used in wood bat. 4. The innings pitched and batters faced per team of the year which is used in aluminum bat were higher than that used in wood bat. 5. The time per game of the year which is used in aluminum bat was longer than that used in wood bat.

랠리포인트제에서 여자 프로배구 득점 내용 및 추이 분석

천영진(Chun Young-Jin),김규태(Kim Kyu-Tae) 한국체육과학회 2011 한국체육과학회지 Vol.20 No.2

The purpose of this study is to analyze problems of rally point scoring system and gains and losses of set according to the serve by set score ratio every game score process and change during set is arranged in female professional volleyball games. For this, it is intended for 76 games, 303 sets which were combined with 70 games of regular season and each three games of Playoff and Championship by female professional 5 teams that participated in 2008-2009 Season V-League held from Nov. 22nd, 2008 to Apr. 11th, 2009. Set score ratio and victory probability according to score margin were calculated by percentage and the chi-squared test was conducted to verify gaps between the first score of team with the serve and outcome of it. Conclusion based on these results is as follow: First, the effort to win the 1st set is required as the probability that female teams will win in the games after winning it is 70%. Second, the effort to obtain 20 points earlier is required as the probability that teams will games if they do them earlier is 88.9%. Third, the game result can be somewhat expected when there are 20 points as the ratio that teams win come-from-behind victories after them when audience watch games is 10%. Forth, the first scores of the serve teams have nothing to do with the results of the games. When the above contents are synthesized, the games are dynamic because they are fast processed in the current rally point scoring system. But there is an disadvantage that the results of the game can be somewhat expected because there are no the real charms that turns the tide in the game in the second half of the sets. Therefore, tension should not be reduced in the second half of the games by mixing the rally point scoring system with the side out system.

15주 야구 수업을 통한 던지기 동작의 운동학적 변인 변화 분석

천영진 ( Young Jin Chun ),신인식 ( In Sik Shin ) 한국운동역학회 2012 한국운동역학회지 Vol.22 No.1

The purpose of this study was to investigate the pattern change of throwing in baseball after 15 weeks of participation in baseball class, by examining ball speed, trunk and upper body angles. The comparison was with 6 university students that haven`t had any experience in baseball. 8 infra red cameras and 2 force platforms were used to collect the data. First, there was an increase in the speed of the ball after the class. Second, there was no significant difference in the allocated phases during the throw before and after class. Third, the release point was lower and more in front. Forth, there was an increase in the knee flexion at the left foot landing and release point. Finally, there was an increase in the maximum shoulder external rotation and pelvis angle. It is recommended that the coordination between the segments should be investigated to improve our understanding of the learning of throwing in future research.

여자 프로 배구 경기의 팀별 연속 득점 유형 분석

천영진(Chun, Young-Jin),김규태(Kim, Kyu-Tae) 한국체육과학회 2014 한국체육과학회지 Vol.23 No.5

This research of female professional volleyball team was aimed to look at the analysis of the frequency, types and the time of occurrence of continuous scoring and their relation to gaining and losing of points, each team’s characteristics and the rankings. In order to gain the analysis, out of 100 games, 5 sets were put aside and total of 317 remaining sets were targeted from the 6 professional teams participating in the V-League of the 2013-2014 regular season. From the gatherings, the following conclusion was made. Firstly, after performing the logistic regression analysis on various types of continuous scoring with its effect on the gain and the loss of points, every variable had a power of explanation. Secondly, when it comes to the frequency, continuous scoring was the most frequent at team’s dig and mistakes; based on the result, the team needs to focus on reducing mistakes and strengthening of defense. Lastly, in regards to the time of occurrence, each team had distinctive results in the second half of the game; concentration is very essential on top of anything else until the end of the game. After putting all the above information together, acquiring points through a serve ace is ideal, however, inducement of a simple offense by making the opponent’s receive more difficult is the best method; reducing mistakes and scoring by digging is necessary.

여자 프로 배구 경기 중 듀스 후 세트포인트에서의 공격 형태 분석

천영진(Young Jin Chun) 한국자료분석학회 2020 Journal of the Korean Data Analysis Society Vol.22 No.4

본 연구는 여자 프로 배구 경기에서 듀스 후 세트포인트가 되었을 때 승리팀과 패배팀의 공격 형태를 분석하여 승패 요인을 찾는 데에 목적이 있다. 이를 위하여 여자 프로 배구 V-리그 2013시즌부터 7시즌동안 총 1,314경기 중 듀스가 만들어진 236경기, 271세트를 대상으로 분석하였다. 분석 내용으로는 패배팀의 리시브 시도 선수, 리시브 정확도, 공격 시도 선수, 공격 형태와 승리팀의 득점 형태, 공격 시도 선수 및 공격 형태 등의 결과를 빈도분석을 통한 카이제곱 검정과 관계강도를 알아보기 위하여 Cramér’s V 계수를 구하였다. 그 결과 패배팀은 리시브가 정확할 때 오픈공격, 후위공격, 퀵오픈공격 등 다양한 공격형태를 보였으나, 리시브가 부정확할 때는 오픈공격을 위주로 하였다. 외국인 선수에게 기회를 50% 가까이 주었으며, 후위공격과 오픈공격을 위주로 하였고 국내 선수는 오픈공격을 위주로 하였다. 승리팀 또한 외국인 선수에게 50%가 넘는 기회를 주었으며, 오픈공격과 후위공격을 주로 구사하였다. 따라서 승리를 하기 위해서는 상대의 리시브를 부정확하게 하여 외국인 선수가 주로 구사하는 후위공격과 오픈공격을 유효블로킹이나 디그로 방어를 한 후, 득점 확률이 가장 높은 선수에게 공격 기회를 준다면 승리할 수 있다. The purpose of this study is to find out the factors of winning and losing by analyzing the attack patterns of the winning and losing teams when they become set points after a deuce in a women s professional volleyball game. To this end, women s professional volleyball V-League was analyzed for 236 matches and 271 sets of Deuce made out of a total of 1,314 games from 2013 to 2019 seasons. As the analysis, the results of the loss team s receive attempt, receive accuracy, attack attempt, attack form, winning team s scoring type, attack attempt player and attack type are analyzed using the frequency analysis for chi-square test and relationship strength. For this, Cramér s V coefficient was obtained. As a result, the defeated team showed various attack types such as open attack, back attack, and quick open attack when the receive is correct, but when the receive was incorrect, the losing team focused on open attack and gave foreign players a chance of 50%. Foreign players mainly focused on back attack and open attack, and domestic players mainly on open attack. Therefore, in order to win, if the opponent s receive is inaccurate and the back attack and open attack commonly used by foreign players are defended with effective blocking or digging, then the player with the highest probability of scoring can win.

여자 프로 배구 V-리그의 시즌 승률 모형 구축

천영진(Young Jin Chun) 한국자료분석학회 2020 Journal of the Korean Data Analysis Society Vol.22 No.3

본 연구는 다중회귀분석을 이용하여 여자 배구 경기에서 승률에 미치는 경기 기록 변인을 알아보고자 하였다. 한국배구연맹이 주최하는 여자 프로 배구 V-리그를 대상으로 2005-2006 시즌부터 2019-2020 시즌까지 총 15 시즌의 경기 결과를 분석하였다. 승률을 반응변수로 하고, 12개의 설명변수로 오픈공격 성공률, 시간차공격 성공률, 이동공격 성공률, 후위공격 성공률, 속공공격 성공률, 퀵오픈공격 성공률, 리시브 성공률, 디그 성공률, 세트 성공률, 세트당 서브 에이스, 세트당 블로킹 횟수, 세트당 범실 횟수 등의 경기 기록 변인으로 설정하여 다중회귀분석 중 단계별 선택방법을 사용하여 분석하였다. 승률에 영향을 미치는 변인으로 세트 성공률, 디그 성공률, 블로킹, 퀵오픈공격 성공률 순으로 나타났으며 69.2%의 설명력을 나타내었다. 이에 승률을 높이기 위해서는 세터의 정확한 토스 능력뿐만 아니라 코트 전체를 볼 수 있는 넓은 시야가 필요하고, 디그를 하더라도 세터에게 전달하여 역공의 기회를 가져야 한다. 마지막으로 중앙 공격수는 상대의 블로킹을 속일 수 있도록 움직여야 함과 동시에 상대의 중앙 블로커가 따라오지 못하도록 좌우로 빠른 퀵오픈공격을 구사해야 한다. The purpose of this study was to analyze the record variables affecting the win rate by using multiple regression analysis in the female professional volleyball V-League. To this end, the results of the 15 seasons from 2005-2006 to 2019-2020 were targeted. A total of 12 game record variables were set as explanatory variables and the winning percentage was set as response variables. During multiple regression analysis, analysis was performed using a step-by-step selection method. As a result, the most influential factors for the win rate were set success rate, dig success rate, blocking, and quick open attack success rate, followed by an explanatory power of 69.2%. Therefore, in order to increase the win rate, not only the setter s accurate toss ability, but also a wide field of view to see the entire court is required, and even if player digs, you need to give it to the setter to have a chance of counterattack. Finally, the center attacker must move to cheat the opponent s blocking, and at the same time use a quick open attack from side to side to prevent the opponent s center blocker from following.

남자 프로 배구 경기에서 팀별 연속 득점 유형 분석

천영진(Chun, Young-Jin) 한국체육과학회 2014 한국체육과학회지 Vol.23 No.3

This research of men`s professional volleyball term was aimed to look at the analysis of the frequency, types and the time of occurrence of continuous scoring and their relation to gaining and losing of points, each team`s characteristics and the rankings. In order to gain the analysis, out of 105 games, 5 sets were put aside and total of 379 remaining sets were targeted from the 7 professional teams participating in the V-League of the 2013-2014 regular season. From the gatherings, the following conclusion was made. Firstly, after performing the logistic regression analysis on various types of continuous scoring with its effect on the gain and the loss of points, every variable had a power of explanation. Secondly, when it comes to the frequency, continuous scoring was the most frequent at team`s mistakes and blocking; based on the result, the team needs to focus on reducing mistakes and strengthening of blocking. Lastly, in regards to the time of occurrence, each team had distinctive results in the second half of the game; concentration is very essential on top of anything else until the end of the game. After putting all the above information together, acquiring points through a serve ace is ideal, however, inducement of a simple offense by making the opponent`s receive more difficult is the best method; reducing mistakes and strengthening of blocking which can lead to blocking score or valid blocking then scoring by digging is necessary.

야구 던지기 동작에서 공 속도 차이에 따른 지면반력 비교 분석

천영진(Chun, Young-Jin) 한국체육과학회 2011 한국체육과학회지 Vol.20 No.5

The purpose of this study was to investigate the difference in ground reaction forces according to different ball speeds during baseball pitching. Five unexperienced baseball players before participating before and after baseball class were selected as subjects for this study and the ground reaction forces were measured separately for the right and left foot. First, the higher the ball speed, the higher the left foot’s vertical ground reaction force. This shows how the subjects push off with their left foot to increase ball speed. Second, the higher the ball speed, the higher the antereoposterior ground reaction force showing the transfer of the push off from the right foot. Third, the higher the ball speed the later the tendency for the subject to release it after the push off. Future research should consider the subject"s center of gravity, center of pressure range of movement and the analysis should include the follow through phase after the release.