태권도 540도 뒤후려차기 동작의 운동역학적 분석

강동권 ( Dong Kwon Kang ),강서정 ( Suh Jung Kang ),유연주 ( Yeon Joo Yu ) 한국운동역학회 2013 한국운동역학회지 Vol.23 No.1

본 연구의 첫 번째 목적은 540° 뒤후려차기 동작의 운동역학적 변인들을 정량화 하는 것이고, 두 번째 목적은 지상동작이 공중동작에 미치는 영향을 밝혀내는 것이다. 지상회전 구간에서의 수직지면반력(GRF)을 분석한 결과 지상에서 180° 회전하면서 나타나는 수직지면반력(GRF)이 체중보다 낮아지는 것을 발견할 수 있었다. 이러한 결과는 반동(counter movement)을 사용하여 높게 점프하려는 전략으로 반동 동작시 발생하는 신장성수축으로 인한 근육과 건에 저장된 탄성에너지를 사용하여 높게 점프하는 SSC(stretch shortening cycle)시스템(Komi, 2003)을 사용하는 것이다. 이렇게 반동을 사용하는 것이 반동을 사용하지 않았을 때보다 높게 점프할 수 있다(Bobbert, Gerritsen, Litjens & Soest, 1996). 즉, 지상에서 회전하는 동안에는 반동 동작을 수행하지 않는 것으로 보이지만 실제로는 반동 동작을 하는 것으로 나타났다. 540° 뒤후려차기에서 각 구간에서 중요하다고 판단되어 정의한 8개의 변인들을 분석한 결과 8개의 변인에서 비슷한 패턴과 적은 표준편차를 나타냈다. 이러한 결과는 11명의 엘리트 시범단원들이 540° 뒤후려차기를 수행하는데 있어서 모두 비슷한 전략을 가지고 있는 것으로 해석할 수 있으며, 이러한 결과는 추후 540° 뒤후려차기를 연구하는 데 유용한 기초자료로 활용 될 수 있을 것이다. 540° 뒤후려차기는 돌개차기와 뒤후려차기가 결합된 복합 기술이다. 즉, 540° 뒤후려차기는 돌개차기로 점프하여 뒤후려차기로 차기기술을 수행한다. Kang과 Kim(1996)은 엘리트 선수의 돌개차기 동작을 연구하였는데, 엘리트 겨루기 선수들의 돌개차기 동작 수행시 지상회전 구간의 소요시간은 0.59±0.06 sec로 나타나 본연구의 지상회전 구간의 소요시간인 0.4±0.04 sec보다 길게 나타났다. 이는 득점을 위하여 빠르게 동작을 수행하는 엘리트 겨루기 선수들보다 540° 뒤후려차기를 전문적으로 수행하는 엘리트 시범단원들이 지상회전 구간에서 더 빠른 지상회전 동작을 수행하는 것으로 사료된다. 540° 뒤후려차기는 차기 구간에서 뒤후려차기를 동작을 수행한다. 이러한 뒤후려차기는 공을 던지는 듯 한 동작의 돌려차기(Throw-like motion)와 미는 형태의 옆차기(Pushlike motion)의 특징이 혼합된 복합운동(Kim, Jin & Shin, 1995; Choi, Lee, Kim & Kim, 2007)으로 복잡한 메커니즘을 가지고 있고, 돌려차기에 비해 뒤후려차기의 발끝 속도는 느리다(Kim, Y. K. & Kim, Y. H., 2010). Ha와 Kim(2009)은 엘리트 시범단원 3명을 대상으로 뒤후려차기의 발끝 속도를 분석한 결과 14.43±2.00 m/sec로 본 연구의 8.78±0.76 m/ses 보다 빠르게 나타났다. 하지만 선행연구는 한발을 지면에 딛고 기술을 수행한 것이고, 본 연구의 뒤 후려차기는 공중에서 수행 했다는 차이점을 가지고 있다. 본 연구의 두 번째 목적인 지상동작이 공중동작에 미치는 영향을 알아보기 위하여 각 구간별 변인들로 상관분석을 실시한 결과 예상하지 못한 결과가 나타났다. 기본적으로 체공시간(FT)과 충격량(impulse)으로 수직점프높이를 추정 할 수 있다(Richter, Rapple, Kurz & Schwameder, 2012; Yuktasir & Kaya, 2009). 따라서 두 변인간의 상관은 높게 나타나는데 본 연구의 결과에서는 체공시간(FT)과 충격량(impulse)에서 상관이 유의하게 나타나지 않았다. 또한 수직신체무게중심(COG)과 충격량(impulse)도 상관관계가 높을 것으로 예상하였으나, 본 연구의 결과 유의한 상관이 나타나지 않았다. 이는 점프동작 이외에 회전동작의 개입으로 인한 결과(Lee & Kim, 1996)로 판단된다. 또한 차기동작인 뒤후려차기를 수행하기 위하여 상체를 숙이는 것에 기인하여 수직신체무게중심(COG)과 충격량(impulse)의 상관이 나타나지 않은 것으로 사료된다. The aim of the study was a quantitative analysis of elite athlete`s 540o Dwihuryeochagi and effects of ground movements to the jumping height and kicking velocity. Eleven elite players(Taekwondo demonstration team) participated in this study. In order to get the kinetic and kinematic variables, ten Vicon cameras and a force plate were used. Foot segment velocity(FSV), vertical ground reaction force(GRF), impulse, ground time(GT) in phase 1, trunk angular velocity(TAV), vertical center of gravity(COG), flight time(FT) in phase 2 and kicking leg segment velocity(KSV) in phase 3 were measured and analyzed. Results indicated that there were similar patterns of variables among phases between subjects. Non-significant correlation(r=.145) between flight time(FT) and impulse was found. Also non-significant correlation(r=.119) between center of gravity(COG) and impulse was found. In conclusions, there were similar strategies in phase 1, phase 2, and phase 3 between subjects.

하악 제3대구치의 존재여부 및 매복양상이 하악 우각부 골절과 과두 골절의 발생에 미치는 영향

이영주(Young-Joo Lee),송윤정(Yun-Jung Song),홍순민(Soon-Min Hong),채상식(Sang-Sik Chae),강현우(Hyeon-Woo Kang),최동주(Dong-Ju Choi),박준우(Jun-Woo Park) 대한치과의사협회 2012 대한치과의사협회지 Vol.50 No.9

Purpose : This study evaluated the impact of the presence and aspect of mandibular third molars to the mandible angle fracture or condyle fractures in Korean. Materials and Methods : A retrospective study was designed for patients attending the division of Oral and Maxillofacial Surgery, Kang-dong sacred heart hospital for treatment of mandibular fracture from January 2006 to September 2010. The primary variable was the presence of mandibular third molar and the secondary variable was the aspects of third molar impaction. Mandibular third molars were classified by the impaction depth and the available space as Pell & Gregory system. Outcome variables were the presence of mandibular angle fracture or condyle fracture. Also the source of trauma, age, sex were studied. Hospital charts, radiographs were used for study. Statistic analysis was done with descriptive statistics, the X2-test, linear-bylinear association. P value under 0.05 was considered significant statistically. Results : The number of involved patients was 86. The ratio of male to female patients was about 9:1 for angle fracture and 7:3 for condyle fracture. The most common source of trauma was assault for angle fracture and fall down for condyle fracture. The presence of mandibular third molar increased frequency of angle fracture and decreased condyle fracture with larger impaction depth. But available space of mandibular third molar did not show high association with angle or condyle fractures. Conclusion : Preventive extraction of mandibular third molar is recommended for patients with high risk of angle fracture. Male patients at their third decade or martial artists, police officer could be the case. But it is not recommended for patients with low risk of angle fracture and high risk of condyle fracture relatively. Elder female patients without any symptom on their third molar could be the case.

農民離村類型의 地域差 分析

姜信寓,閔丙卓,崔東柱 충북대학교 농업과학기술연구소 1987 農業科學硏究 Vol.5 No.1

In order to find out the regional differences of rural-urban migration pattern, this study was conducted to analyze the field survey data on 18 Ri-Dongs of Chungbuk province. The results are summarized as follows. Firstly, the proportions of infant and the aged to youths and manhood are relatively higher than the national mean of them. It says that the quality of rural labour power has been decreased. Secondly, in the rate of the population migration among regions, the exurbs are higher than the suburbs. Thirdly, the migration pattern is, for the most part, the drift to the cities, and of these 80.2 percent is single migration. Fourthly, the migration rate of lower income farms is higher. The major accupations of the migrants to the cities is simple workers or the technicians. Fifthly, the major motives of the migration are lower farmhousehold income and children's education. Specially the suburbanite is greater in the former and the exurbanite in the latter.

MPP^+와 6-OHDA에 대한 한약탕제의 보호효과 연구

강봉주,홍성길,조동욱 한국한의학연구원 1999 한국한의학연구원논문집 Vol.5 No.1

The effect of herbal medicine on 1-methyl-4-phenylpyridinium ion(MPP+) and 6-hydroxydopamine(6-OHDA) mediated neurotoxicity was studied in the rat phaeochromocytoma cell line PC12. The present study was designed to test the hypothesis that herbal medicine can protect cells from neurotoxiciy caused by MPP+ and 6-OHDA. Exposure of PC12 cells to 0.2mM MPP+ and 50 μM 6-OHDA for 24h resulted in a 50% cell death with respect to the control cells. MPP+ induced cell death was reduced by Yollyounggobondan(延齡固本丹), Sagunjatang(四君子湯), Palmihwan(八味丸), and Palmultang(八物湯) (p<0.05). However, herbal medicines did not protect cells trom degeneration caused by the 6-OHDA. Yollyounggobondan, Yungmijihwangwon(六味地黃元), Palmultang, and Samultnag(四物湯) were effective in protecting against MPP+ induced ATP loss in PC12 cells (p<0.05). Yollyounggobondan and Palmultang were effect in neurite protection against 6-OHDA treatment in differentiated PC12 cells with NGF.

뇌출혈 동물모델에서 육미지황원의 효과 연구

강봉주,조동욱 한국한의학연구원 2001 한국한의학연구원논문집 Vol.7 No.1

Intracerebral hemorrhage(ICH) is associated with a considerable proportion of strokes and head injuries. The mechanism of brain cell injury associated with hemorrhage may be different from that due to pure ischemia. Therefore, it is essential that models of intracerebral hemorrhage be developed and well characterized in animal model. Yukmijihwangwon (YM) has been known to reinforce the vital essence and have antioxidant activities. In this study, the protective effects of YM was investigated against ICH in animal models. Adult rats had 2 microliters saline containing 0.5 and 5 unit bacterial collagenase ifused into the right caudate nucleus. It was found out that YM was effective in protecting brain against ICH.

건조감태 polyphenol성 물질의 추출조건과 정량에 관한 연구

강영주,강동섭,고경익 제주대학교 해양연구소 1990 해양자원연구소연구보고 Vol.14 No.-

퍼즐 게임 제작 사례로 본 Applet 분석

강주성, 박동원, 안성옥, 김수균 배재대학교 공학연구소 2013 공학논문집 Vol.15 No.1

Using features in the Java Applet game is played on the screen, and web production. Linked using Applet to Database, and will save the record. It also makes the stored data with Statistics screen. What is the problem with him, looking to find ways to solve. For alternative methods are discussed.

저산소상태에서 육미지황원의 뇌신경세포 보호효과에 대한 연구

강봉주,홍성길,조동욱 한국한의학연구원 2001 한국한의학연구원논문집 Vol.7 No.1

Yukmijinhwangwon(YM) has been known to reinforce the vital essence and have antioxidant activities. This study was designed to examine the inhibitory effects of YM against in vitro hypoxia/reperfusion-induced inflammatory response. We have characterized the production of prostaglandin E₂and arachidonic acid during hypoxia/reperfusion in the human neuroblastoma SK-N-MC and human monocytic macrophage U937 cells and the ingibitory effect of YM on these inflammation-related substance formation has been found out in this study. To investigate inhibition of COX expression by YM during hypoxia in vitro. This result suggested that YM used in this experiment reinforced antiinflammatory potentials and protected cells against hypoxia/reperfusion induced inflammatory response.

ZnO 투명전도막의 전기적 특성에 미치는 Al₂O₃의 도핑 농도의 효과

박강일,김병섭,이성욱,김현수,이세종,곽동주 경성대학교 공학기술연구소 2003 공학기술연구지 Vol.10 No.-

Al doped Zinc Oxide(ZnO:AI) films, which is widely used as a transparent conductor in optoelectronic devices such as solar cell, liquid crystal display, plasma display panel, thermal heater, and other sensors, were prepared by using the capacitively coupled DC magnetron sputtering method. In this paper the effect of doping amounts of Al₂0₃ on the electrical, optical and morphological properties were investigated experimentally. The results show that the structural and electrical properties of the film are highly affected by the doping. The optimum growth conditions were obtained for films doped with 2 wt% of indium which exhibit a resistivity of 8.5×10^(-4)Ω-cm associated with a transmittance of 91.7 % for 840 nm in film thickness in the wavelength range of the visible spectrum.

열역학적 관점에 근거한 구름발생 실험의 문제점 분석 및 개선방안에 대한 고찰

박동조,백성혜,강성주 한국교원대학교 과학교육연구소 2001 청람과학교육연구논총 Vol.11 No.1

이 연구에서는 5차 교육과정과 6차 교육과정의 중학교 과학 교과서에 제시된 구름발생 실험 내용을 실험 방법 및 실험 기구 등의 측면에서 비교 분석하였다. 그리고 열역학적 관점에서 문제점을 살펴보았으며 이러한 문제점을 개선하기 위한 실험을 개발하여 교과서 실험 결과와 비교함으로서 그 효과를 알아보았다. In this study, we compared the contents of cloud making experiments in middle school science textbooks of 5th and 6th science curriculum from the viewpoint of methods and apparatus. And we analyzed the problems of the experimental methods and apparatus based on the thermodynamic theories. A new experiment was developed to solve the problems, and the effects of new experiment were compared with those of the experiments in the textbooks.