• 한국운동역학회지
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• 제15권1호
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• pp.29-44
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• 2005

The purpose of this study is to reveal the effects of two different kicks, the drop kick and the punt kick, into the kicking motion, through the kinetic comparative analysis of the kicking motion, which is conducted when one kicks a soccer goal. To grasp kinetic changing factors, which is performed by individual's each body segment, I connected kicking motions, which were analyzed by a two dimension co-ordination, into the personal computer to concrete the digits of it and smoothed by 10Hz. Using the smoothed data, I found a needed kinematical data by inputting an analytical program into the computer. The result of comparative analysis of two kicking motions can be summarized as below. 1. There was not a big difference between the time of the loading phase and the time of the swing phase, which can affect the exact impact and the angle of balls aviation direction. 2. The two kicks were not affected the timing and the velocity of the kicking leg's segment. 3. In the goal kick motion, the maximum velocity timing of the kicking leg's lower segment showed the following orders: the thigh(-0.06sec), the lower leg(-0.05sec), the foot(-0.018sec) in the drop kick, and the thigh(-0.06sec), the lower leg(-0.05sec), the foot(-0.015sec) in the punt kick. It showed that whipping motion increases the velocity of the foot at the time of impact. 4. At the time of impact, there was not a significant difference in the supporting leg's knee and ankle. When one does the punt kick, the subject spreads out his hip joint more at the time of impact. 5. When the impact performed, kicking leg's every segment was similar. Because the height of the ball is higher in the punt kick than in the drop kick, the subject has to stretch the knees more when he kicks a ball, so there is a significant affect on the angle and the distance of the ball's flying. 6. When one performs the drop kick, the stride is 0.02m shorter than the punt kick, and the ratio of height of the drop kick is 0.05 smaller than the punt kick. This difference greatly affects the center of the ball, the supporting leg's location, and the location of the center of gravity with the center of the ball at the time of impact. 7. Right before the moment of the impact, the center of gravity was located from the center of the ball, the height of the drop kick was 0.67m ratio of height was 0.37, and the height of the punt kick was 0.65m ratio of height was 0.36. The drop kick was located more to the back 0.21m ratio of height was 0.12, the punt kick was located more to the back 0.28m ratio of height was 0.16. 8. There was not a significant difference in the absolute angle of incidence and the maximum distance, but the absolute velocity of incidence showed a significant difference. This difference is caused from that whether players have the time to perform of not; the drop kick is used when the players have time to perform, and punt kick is used when the players launch a shifting attack. 9. The surface reaction force of the supporting leg had some relation with the approaching angle. Vertical reaction force (Fz) showed some differences in the two movements(p<0.05). The maximum force of the right and left surface reaction force (Fx) didn't have much differences (p<0.05), but it showed the tendency that the maximum force occurs before the peak force of the front and back surface (Fy) occurs.

• 항공우주기술
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• 제8권2호
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• pp.98-104
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• 2009

소형 위성 발사체 KSLV-I은 2단의 추진기관으로 고체 킥 모터(Kick Motor)를 사용한다. 킥 모터의 연소 중에는 진동 및 충격이 발생하게 된다. 킥 모터는 2단 전자 탑재물 베이의 하단에 연결되어 있고 연소 중 발생하는 진동 및 충격이 킥 모터의 동체를 통해 전자탑재 베이로 전달 될 수 있다. 전자 탑재물로 전달되는 진동 및 충격의 크기가 큰 경우 전자탑재물의 오작동을 유발할 수 있다. 따라서 킥 모터의 연소 중 발생하는 진동, 충격의 사전검증이 필요하다. 본 연구는 킥모터의 지상 연소 시험을 통해 연소 중 발생하는 진동을 계측하고 이를 바탕으로 랜덤 진동 및 충격 응답 스펙트럼을 분석하였다.

• 한국운동역학회지
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• 제22권3호
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• pp.285-293
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• 2012

The aim of this study is to identify the appropriate movement for maintaining postural balance during Front Kick and Turning Side Kick motions. To do so, ten Taekwondo athletes: five skilled players(S, body mass: $65.0{\pm}5.8kg$, height: $172.3{\pm}3.7cm$, age: $20.0{\pm}1.2yrs$, career: $9.0{\pm}1.9yrs$) and five less-skilled players(LS, body mass: $67.1{\pm}5.5kg$, height: $173.2{\pm}5.1cm$, age: $19.4{\pm}1.7yrs$, career: $9.6{\pm}1.7yrs$) participated in this study. A three-dimensional motion analysis was performed on the participants using eight infrared cameras and two force plate(sampling frequency of 200 Hz and 2000 Hz for S and LS players, respectively). The participants' motions were divided into: a front-kick phase(P1) and a turning-side-kick phase(P2). For P2(p<.05), the range and root mean square(RMS) of the ground reaction torque and the M-L mean velocity of COP were greater for LS than for S; similarly, for P2(p<.05), the M-L range, A-P range, and velocity of the COP were greater for LS than for S. Further, the M-L range and maximum velocity of the COP was greater for failure than for success(p<.05). The femoral biceps muscle for bending the knee joint was significantly stronger in S than in LS(p<.05). It is expected that these results will be useful in developing a training program for improving the balance and stability of Taekwondo poomsae athletes and improve their front-kick and turning-side-kick motions.

• 한국운동역학회지
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• 제17권2호
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• pp.11-21
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• 2007

The study was undertaken to present the quantitative materials available in underwater industries, underwater rehabilitation & physical training through comparison & analysis of effects contributing to propulsion of COG by types of fin-kick in underwater activities. For this 3D cinematography was performed for the skilled subjective and conclusions obtained on the basis of analysis of kinematic variables were as follows. In temporal variable the delay in the order of flutter>side>dolphin kick in elapsed time by total & phase resulted in longer sliding phase by larger fin kick of extension & flexion of both leg and thus more contributed in propulsion of COG. than those of the otherwise. In linear variable the contribution ratio to the result of propulsion of COG in both propulsive(mean $35.39{\pm}7.93cm$ in Y axis) and sliding phases(mean $66.36{\pm}11.01cm$ in Y axis)was shown to be order of flutter>dolphin>side fin kick. the maximum velocity of COG in Y direction was showed in both propulsive and sliding phases, and the contribution ratio to the propulsion of COG was in the order of flutter$\geq$dolphin>side fin kick. In angular variable the Significant difference in angle of leg joint by types of fin kick in both leg was showed but no routine order. The Significant difference in angular velocity of leg joint by types of fin kick in both leg was showed in the order of flutter>dolphin$\geq$side fin kick in propulsive but no in sliding phase. The Fluid resistance by tilting angle of trunk in both propulsive and sliding phase was decreased in the order of flutter>dolphin$\geq$side fin kick and tilting angle of trunk of the skilled was smaller than that of the unskilled in difference of maximum mean 7.97degree and minium mean 2.06degree. In summary of the above, It will desirable fin kick type because of more contribution to COG propulsion by the velocity & displacement in Y-axis and less fluid resistance by tilting angle of trunk and larger angular velocity in the case of more delayed in elapsed time of propulsive phase than that of the otherwise.

• 시스템엔지니어링학술지
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• 제20권spc1호
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• pp.108-118
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• 2024

As shared electric kick scooters spread to cities worldwide as a result of the proliferation of personal mobility, they have emerged as a significant social issue, impacting pedestrian and user safety, as well as urban aesthetics. In this study, we propose solutions to the unique problems associated with shared electric kick scooters, such as illegal parking, charging, and redistribution. Furthermore, we present research on supplementary services utilizing electric kick scooters in urban areas to enhance citizen safety and user satisfaction through the development of an autonomous electric kick scooter system structure and operational strategies. We suggest a low-cost autonomous electric kick scooter structure and propose AI processing, sensor fusion, and system operation methods to add autonomous capabilities to affordable electric kick scooters. Additionally, we propose operational systems and related technologies for offering various supplementary services.

• 한국응용과학기술학회지
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• 제37권4호
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• pp.870-877
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• 2020

본 연구의 목적은 제자리딛기 템포와 돌려차기 유형이 응답시간에 미치는 영향을 비교 분석하는데 있다. 본 연구에는 태권도 4단이며 10년 이상 수련한 남자 15명이 참여하였다. 실험 과제는 메트로놈의 템포에 맞춰 제자리딛기를 하다가 불빛 자극이 제시되면 최대한 빠르게 돌려차기를 하는 것이다. 5가지의 제자리딛기 템포(100, 120, 140, 160, 180 bpm)와 4가지의 돌려차기 유형(앞발 몸통 돌려차기, 앞발 얼굴 돌려차기, 뒷발 몸통 돌려차기, 뒷발 얼굴 돌려차기)에서 3회씩 총 60회를 실시하였다. 통계분석은 반복 측정 이원분산분석을 실시하였으며, 주효과의 대응별 비교는 Bonferroni를 실시하였다. 제자리딛기 템포와 돌려차기 유형의 상호작용효과가 나타났으며, 제자리딛기 템포와 돌려차기 유형에 따른 주효과도 나타났다. 160 bpm의 제자리딛기 템포에서 돌려차기의 응답시간이 제일 빠른 것으로 나타났다. 하지만 140과 160 bpm의 제자리딛기 템포에서 돌려차기 응답시간은 거의 차이가 나타나지 않았다. 앞발 몸통 돌려차기의 응답시간이 빨랐다. 그리고 제자리딛기 템포와 돌려차기 유형에 따라 140 bpm의 제자리딛기 템포에서 앞발 몸통 돌려차기의 응답시간이 가장 빠른 것으로 나타났다. 결론적으로 돌려차기의 응답시간은 140과 160 bpm의 제자리딛기 템포에서 효과적이며, 뒷발보다는 앞발, 얼굴보다는 몸통 돌려차기가 효과적인 것으로 나타났다. 본 연구를 통해 도출된 결과는 수행 향상에 유용한 정보를 제공할 것이며, 태권도 경기를 위한 전략에 도움이 될 것이다.

• Child Health Nursing Research
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• 제8권4호
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• pp.381-390
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• 2002

This study examines the factors that are associated with accidents from riding on inline skates and/or kick boards among students in the elementary schools. Data were collected from 902 students in 3 elementary schools in Seoul. Data were analyzed based on descriptive statistics and chi-square test. The results were as follows: 1. Thirty-eight percent of the students investigated were found to have kick boards while sixty-one percent of the students had inline skates. 2. The age of mothers who answered the questionnaires showed a statistically significant association with injuries of their children on inline skates and/or kick boards. Children whose mothers are younger had a lower percentage of injuries on inline skates and/or kick boards. 3. Children with a lower score on K-CBCL had a higher chance of having an accident from riding on inline skates and/or kick boards. That is, children with lack of attention were more likely to be involved in an accident. First-born children were less likely to have an accident. 4. While mothers' attitudes toward the safety of inline skates and kick boards appeared not to be associated with accidents of their children, their preventive actions for the safety related to riding on inline skates and kick boards reduced the chance to be involved in an accident of their children. In conclusion, this study shows that mothers with children going to the elementary schools should be more action-oriented to prevent their children's accidents from riding on inline skates and/or kick boards than merely recognizing the safety of inline skates and/or kick boards on their own. Implication of these findings and major findings of this study were discussed.

• 소음진동
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• 제9권6호
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• pp.1210-1217
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• 1999

This paper presents schematic process of identifying the principal cause to make the vibration problem of rotating circular saws. In the tandem pencil slat saw lines, feeding of cedar blocks is often stopped because excessive motro current is required in a saw motor. These events are called "kick-offs" in technical reports. Research on saw behavior at kick-offs is required to understand are reduce the frequency and severity of kick-offs events. This research aims at finding out the principal cause of kick-offs, and evloving design improvements for high cutting performance with fewer and less severe kick-offs. Measurements of critical speed, cutting force, cutting temeprature and dynamic displacements are carried out to observe the instability mechanism and also to obtain saw design parameters for the numerical analyses. And the numerical analyses involving FEM and multiple scale method are utilized to show the possibility of the principal cause.pal cause.

• 항공우주기술
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• 제10권2호
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• pp.128-132
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• 2011

KSLV-I 상단 추진기관 시스템인 킥모터 시스템에 대한 형상 공차 기준을 설정하기 위해서는 임무 수행을 위한 초기 제어성 분석 결과를 바탕으로 각 하위 서브시스템에 대한 형상 공차를 부여하는 것이 필요하다. 본 논문에서는 킥모터 시스템의 형상 공차 기준과 지상시험용 및 비행시험용 모델에 대해 시스템 차원에서 수행된 형상 관리 결과에 대해 다룬다.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2018년도 춘계학술대회
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• pp.119-121
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• 2018

Deepwater Horizon 사고 사례 분석을 통해 Kick 제어와 Blowout 및 인적요소 사이에 서로 관련성이 있음을 확인하였다. Deepwater Horizon 사례가 다른 시추선 사고에도 적용되는지 확인하기 위해 본 논문에서는 인적요소, Kick 제어 및 Blowout 사고와의 상관 관계에 대해 분석하였다. 분석에 사용된 사고사례는 Trident V 프로그램으로 분석된 1981년부터 2015년까지의 60건이며, 인적요소가 예측 불가한 Kick 발생 및 심각한 유정폭발에 어떠한 영향을 주는지 SPSS 프로그램을 통해서 분석하였다. 분석 결과 인적요소는 Kick의 제어에 더 많은 영향을 주는 것으로 판단되었고 이 결과를 토대로 향후 선급 및 국제표준기구의 관련 규정 개정 방안에 관해 제안하였다.