• Title/Summary/Keyword: mass movements

검색결과 129건 처리시간 0.025초

쪼그려 앉았다 서기 동작 시 몸통의 무게 변화가 몸통 움직임과 무릎 관절 모멘트에 미치는 영향 (The Effect of Trunk Motion and Knee Joint Moment during Deep Stand to Sit and Sit to Stand According to the Trunk Weight Increase)

  • 권문석;김상규;신성휴
    • 한국운동역학회지
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    • 제17권4호
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    • pp.89-98
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    • 2007
  • The purpose of this study was to evaluate the trunk motion and knee joint moment during deep stand to sit and sit to stand according to the trunk weight increase. These experimental subjects were 9 males, who had no skeletal muscular disease. They were performed a SATS(stand to sit), STS(sit to stand) according to the trunk weight increase. Trunk weight increase were classified into 4 bearing trunk weight of 0%, 8%, 16%, 24% of the subject' weight. 1-way(4) RM ANOVA is applied to get the difference of trunk displacement movements and knee joint moments according to he trunk weight increase. significant level of each experiment is set as $\alpha$=.05. 1. Significant difference was classified into 3 bearing trunk weight of 0%, 16%, 24% in maximum forward backward displacement of trunk COM(center of mass). Significant difference was classified into 4 bearing trunk weight of 0%, 8%, 16%, 24% in maximum upward downward displacement of trunk COM during the SATS, STS. 2. Significant difference was classified into 4 bearing trunk weight of 0%, 8%, 16%, 24% in maximum extension knee joint moment. Significant difference was classified into 2 bearing trunk weight of 0%, 16% in maximum internal rotation knee joint moment during the SATS, STS. Therefore we expect that biomechanical model of this study will used to study for mechanical characteristics of obese people.

우측 반회후두신경을 침범한 갑상선 유두상암 환자의 수술 후 발생한 양측 성대 마비의 회복 1예 (A Case of Functional Recovery of the Postoperative Bilateral Vocal Cord Paralysis in Papillary Thyroid Carcinoma with Rt. Recurrent Laryngeal Nerve Invasion)

  • 문미진;왕수건;이윤세;임윤성;이진춘;강양호;손석만;김인주
    • 대한기관식도과학회지
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    • 제17권1호
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    • pp.53-56
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    • 2011
  • Vocal cord paralysis (VCP) is a common complication after thyroidectomy despite the continuity of the recurrent laryngeal nerve (RLN) is preserved. Much efforts have been made into preventing VCP, but few of them focuses on the treatment strategies and prognosis after VCP take place. In this case, patient visited the clinic for papillary thyroid cancer in Rt. thyroid gland without VCP. She underwent total thyroidectomy with central neck dissection. During dissection, Rt main mass was encircling Rt. RLN. To make matters worse, Lt. RLN was severed due to tight attachment with Berry's ligament. After that, intratumoural dissection of Rt. RLN and end to end anastomosis of Lt. RLN were performed with microscopy to preserve the functions of RLNs as much as possible, otherwise permanent bilateral VCPs were inevitable. We report this case, since both vocal cords recovered from VCPs with symmetric, synchronous movements at postoperative follow up.

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바닥판 구조물의 진동제어를 위한 준능동 TMD의 적용 (Application of Semi-active TMD for Floor Vibration Control)

  • 김기철;곽철승
    • 한국공간구조학회논문집
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    • 제7권5호
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    • pp.49-56
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    • 2007
  • 바닥판 구조물의 진동제어를 위한 제어시스템으로 제어력의 조절에 따라서 수동, 능동, 준능동 제어 시스템이 구분할 수 있다. 본 논문에서는 MR감쇠기와 수동 TMD를 조합한 준능동 TMD(MR-TMD)의 제어기법에 따른 바닥판 구조물의 진동제어성능을 알아보았다 MR-TMD의 감쇠기 모형화 방법에 따라서 Groundhook 모델과 Skyhook 모델이 있으며 주구조물인 바닥판 구조물의 진동제어에 있어서는 Skyhook 모델보다 Groundhook 모델보다 효과적인 것을 볼 수 있다. 그러나 TMD변위가 제한적인 경우에 MR-TMD의 감쇠기를 Skyhook 모델로 모형화하여 진동을 제어할 필요가 있다 그리고 Hybrid 제어기법을 적용할 경우에 바닥판 구조물과 TMD를 동시에 최적으로 제어할 수 있으므로 우수한 제어성능을 보이고 있다.

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일광항의 항만개발에 따른 수질변화에 관한 연구 (A Study on Change of Sea Water Quality due to the Development Plan of Ilgwang Harbour)

  • 이중우;국승기
    • 한국항만학회지
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    • 제12권2호
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    • pp.303-312
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    • 1998
  • It is necessary to quantitatively asses the influence of tidal currents to analysis the coastal current patterns before or after constructing offshore structures like as breakwaters. This assesment can be made through the use of simulation models designed to reproduce the water movements of the area. And it is very important to predict a phenomenon of pollutant dispersion in the area. In this study, in order to predict the changes of sea water quality for the port development plan, Ilgwang harbour, located at the east coast of Pusan, the numerical computations were carried out. The flow patterns were investigated before and after the development of the harbour bay and coastal area connected on it. The computational models are an extension of earlier work on the flow which used the ADI Method (Alternating Direction Implicit Method) in appling to Osaka Bay by KANEKO et al. The transport of pollutant constituents depends upon the currental characteristics of the water-transporting medium. In the currental flow model, water velocities and water levels are computed throughout the regions of it. These value are then used in the mass-balance equation to obtain the pollutant-constituent transport. As a result of this research, the present water quality of Ilgwang harbour and the coastal areas connected on it was proved out some good condition. The changes of sea water quality due to the port development plan of the Ilgwang habour bay and the coastal area were not large compared with the present condition, but it will be likely able to get worse by increasing the semi-enclosed areas in the harbour bay. In order to improve the water quality of the area after development, the method to activate tidal exchange in the area can be needed, as a mitigation technique.

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Effects of Center of Pressure on Muscle Activations and Joint Range of Motion of Lower Extremities during Squat

  • Yoon, Woo Ram;Park, Sang Heon;Jeong, Chan Hyeok;Park, Ji Ho;Yoon, Suk-Hoon
    • 한국운동역학회지
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    • 제28권1호
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    • pp.37-43
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    • 2018
  • Objective: The aim of this study was to analyze muscle activation of the lower extremities as a function of changes of the center of pressure (CoP) of the foot during squats in order to provide quantitative information to trainers who would like to teach correct movements for developing muscles. Method: Ten men with over three years of weight training experience participated in this study (age: $26.1{\pm}0.8yrs$, height: $171.2{\pm}3.9cm$, body mass: $71.1{\pm}5.7kg$, 60%RM: $84{\pm}9kg$, career: $4.0{\pm}0.7yrs$). The participants were instructed to perform a squat in each of 3 conditions, with different CoP's (the front, middle, and rear of the foot). Results: The position of the CoP showed significant differences according to instructions in both the eccentric and concentric contraction phases (p < .05). The range of movement of the hip and ankle joints showed significant differences corresponding to changes of the CoP position (p < .05). The rectus femoris and gluteus maximus muscle showed significant differences for different CoP positions only in the concentric contraction phase, while the gastrocnemius and anterior tibialis were significantly different in both the concentric and eccentric contraction phase (p < .05). Conclusion: When the target muscle of squat training is the gastrocnemius, the CoP should be located in the front of the foot for effective muscle training. When the target muscles of squat training are the gluteus maximus and quadriceps femoris, the CoP should be located on the rear of the foot.

승마 평보 시 숙련자의 등자길이 피팅에 따른 기승자세정열의 운동학적 비교분석 (Kinematic Analysis of The Rider Postural Alignments According to The Fitting of Stirrups Lengths during Horse Walk of High Level Rider)

  • 류재청;현승현
    • 한국운동역학회지
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    • 제24권4호
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    • pp.329-338
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    • 2014
  • The purpose of this study was to analyze of the rider postural alignments according to the fitting of stirrups lengths during walk of high level riders. Participants selected as subject were consisted of horse riders of high level (age: $47.66{\pm}3.51yrs$, height: $168.40{\pm}4.84cm$, body weight: $73.36{\pm}15.58kg$, low extremity length: $94.76{\pm}3.98cm$, career: $23.33{\pm}5.77yrs$) and walk with 3 types of stirrup lengths(ratio of low extremity 68.04%, 73.25%, 78.48%). The variables analyzed were consisted of the displacement of Y axis (center of mass, head, thigh, shank and foot), FR angle, LR angle, dynamic postural stability index (DPSI), coefficient of variation (CV%), and distance (X axis) of low extremity limb between right and left. The displacement of Y axis in COM, thigh, shank, foot limbs were not statistically significant, but movements of head showed greater distance of B type and C type than that of A type during 1 stride of walk. The FR and LR angle in trunk of horse rider, dynamic postural stability index and, coefficient of variation didn't show significant difference statistically according to the fitting of stirrup lengths. Also the distance (X axis) of low extremity in thigh and shank didn't show significant difference statistically in between right and left, but right and left foot showed greater distance in C type than that of B and A types during walk in horse back riding. The hip and ankle joint angle not statistically significant according to stirrups lengths, But knee joint angle showed more extended according to the increase of stirrups lengths during stance and swing phase in walk.

축구 인사이드 페널티킥 동작 시 목표변화에 따른 하지분절의 운동학적 분석 (Kinematic Analysis of Lower Limb during Inside Penalty Kick toward Different Targets in Soccer)

  • 소재무;김재정;박혜림;강성선
    • 한국운동역학회지
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    • 제23권2호
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    • pp.117-123
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    • 2013
  • The purpose of this study was to provide data to increase the success rate of penalty kicks through quantifying the shape of skilled kicks by performing a kinematic analysis on the change of movement during the kicking phase which the goalkeeper uses as a vital clue. Three high definition video cameras(GR-HD1KR, JVC, Japan) were used for the study and 18 reflective markers were attached to the body joints. Corners of the goal, difficult for goalkeepers to block, were set as aims and 1 m by 1.2 m targets were installed. Each subject had five sets of kicks at random, and the analysis was done on the movements that hit the target. Time, speed of the right lower limb's center of mass, joint angle, and angular velocity were chosen as factors and the results of the analysis showed statistical significance. The player taking a penalty kick should train to avoid leaning one's body towards the kicking direction and change the angle of the right foot right before the impact to decide the direction of the ball. The goalkeeper can increase the save success rate by studying the angle of the kicker's body and the right foot as well as the timing of the kick.

충남 공주 제민평야의 홀로세 환경연구 (A Study on the Holocene Environments of the Jemin Plain in Gongju, Chungnam Province)

  • 박지훈;이애진
    • 한국지형학회지
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    • 제24권2호
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    • pp.65-78
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    • 2017
  • In this study, stable carbon isotopic analysis (22 specimens) and magnetic susceptibility analysis (23 specimens) were conducted out on the specimens collected from two points (trench DT1, DT2) in the floodplain of Jemincheon(hereinafter the Jemin plain) to reconstruct the Holocene Environments (Period I, Period II, Period III) of the Jemin plain in Gongju, Chungnam. The results were as follows: In Period I (approximately 7,480~4,940 yrs B.P.) and especially around 7,480~7,320 yrs B.P., it was cool-dry and there were two minor climate fluctuations. This period received a continuous flow of sediments, rather than massive amounts of sediments due to abrupt flooding, and therefore, there was almost no soilization process. Period II(approximately 4,940~2,600 yrs B.P.) was also relatively cool-dry. However, in Period II b, unlike I, the minor climate fluctuations were less pronounced. In this period, flooding and desiccation repeated, inducing soilization processes especially around 3,160 yrs B.P. In Stage III (~360 yrs B.P.), it was warm and humid compared to II b. However, in III a, there was no inflow of sediments due to irregular flooding, and in fact, soilization process was more manifested than during II b due to the impact of the desiccation environment. However, there were some mass movements from Bonghwang Mt. (a.s.l. 147m) caused by heavy rains and typhoon during III b (approximately 360 yrs B.P.), thus moving a large amount of debris (i.e. gravel), which resulted in sedimentation.

평균대 한발 몸 펴 옆 공중돌기의 성패에 따른 운동학적 요인 분석 (Analysis of Kinematic Factors between Success and Failure of Free Aerial Cartwheel on the Balance Beam)

  • Jung, Choong Min;Park, Sang-Kyoon
    • 한국운동역학회지
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    • 제32권1호
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    • pp.24-30
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    • 2022
  • Objective: The purpose of this study was to determine the factors of successful and unsuccessful movements through the analysis of kinematics and muscle activity of the Free Aerial Cartwheel on the balance beam. Method: Subjects (Age: 22.8 ± 2.4 yrs., Height: 158.7 ± 5.0 cm, Body mass: 54.1 ± 6.4 kg, Career: 13 ± 2.4 yrs.) who were currently active as female gymnasts participated in the study. They had no history of surgical treatment within 3 months. Subject criteria included more than 10 years of professional experience in college and professional level of gymnastics and the ability to conduct the Free Aerial Cartwheel on the Balance Beam. Each subject performed 10 times of Free Aerial Cartwheel on the balance beam. One successful trial and one unsuccessful trial (failure) among 10 trials were selected for the comparison. Results: It was found that longer time required in case of unsuccessful trial when performing the Free Aerial Cartwheel on the balance beam compared with successful trial. It is expected to be the result of movement in the last landing section (i.e. phase 5). In addition, it was found that the center of gravity of the body descends at a high speed to perform the jump (i.e. phase 2) in order to obtain a sufficient jumping height when the movement is successful while the knee joint is rapidly extended to perform a jump when movement fails. In the single landing section after the jump (i.e. phase 4), if the ankle joint rapidly dorsiflexed after take-off and the hip joint rapidly flexed, so landing was not successful. Conversely, in a successful landing movement, muscle activity of the biceps femoris was greatly activated resulting no shaking in the last landing section (i.e. phase 5). Conclusion: In order to succeed in this movement, it is necessary to perform a strong jump after rapidly descending the center of gravity of the body using the force of the biceps femoris muscle. Further improvement of the skills on the balance beam requires the analysis of the game-like situation with continuous research on kinematic and kinematic analysis of various techniques, jumps, turns, etc.

러시아 국가 정체성의 역학관계 모델과 정치-문화 상징의 함의: 푸틴 시대의 국가 정체성 재고를 위한 시론 (National Identity in Putin's Era and the Implication of Political and Cultural Symbols)

  • 김상현
    • 국제지역연구
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    • 제12권4호
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    • pp.23-65
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    • 2009
  • 본 논문의 목적은 푸틴 시대의 국가 정체성의 문제를 정치 및 문화 상징의 분석을 통해 살펴보는 것뿐만 아니라, 러시아 국가 정체성 문제 진단을 위한 모델을 창조해 보이는 것이다. 이를 위해 본 논문은 19세기 전제 러시아 시기로부터 현대 포스트-소비에트 시기까지 러시아의 국가 및 문화 정체성이 어떠한 일관되고 반복적인 리듬 구조 속에서 전개되어 왔는지를 제시해 보이고 있다. 삼각형-사각형이란 역학관계 모델을 제시하면서 본 연구가 주목하는 것은 정치 및 문화 상징(물)이 사용되고 있는 구체적인 맥락과, 이것들이 간직하고 있는 정치, 문화적 함의는 무엇인지, 그리고 어떠한 논리 속에서 통시적으로 이러한 상징(물)이 사용되는지를 파악하기 위한 민속 및 허위민속의 배경이다.