• 한국운동역학회지
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• 제14권3호
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• pp.191-202
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• 2004

The batting performance in baseball is a repetitive movement. In order to make the stabilization of posture and the efficient shift of body weight, both the range of stance and stride are important. The previous studies explained that the consistent stride which included the amount of time, stance, and direction were needed. However, the batting performance is frequently changed according to the several speed of ball. Therefore, this study was to analyze the reaction time, the range of stance, the change of stride, and the change of GRF during the batting movement in three kinds of ball speed (120km/h, 130km/h, & 140km/h). Seven elite players are participated in this study. 1. The reaction time of the stride phase was short whereas the time of the swing phase was long according to the increasing ball speed. 2. The range of the stance was wide and the mediolateral direction of the stride was decreased according to the increasing ball speed. 3. In the three kinds of ball speed, the change of body weight was transferred to the center, the rear foot, and the front foot directions. The ball speed of 130km/h showed the high frequency of the suitable batting. At this ball speed, the movement of the body weight was shifted smoothly and the value of the Ground Reaction Force was large enough.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회A
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• pp.876-881
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• 2008

When biped robots speed up to run and reduce speed to walk after running, it needs stable speed translation. This paper proposed simple speed translation using the modified LIPM (Linear Inverted Pendulum Mode). We can change stride and period time of a biped robot in some bounded sets with this propose algorithm. This method is simple and effective in simulation.

• 한국운동역학회지
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• 제25권4호
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• pp.483-488
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• 2015

Objective : The purposes of this study was to analyze the locomotive movement of forelimbs according to changes in velocities in the quadruped cadence of horses. Methods : Horses selected as subjects consisted of Jeju pony horses (heights of withers: $1.23{\pm}0.51$). Two camcorders (HDR-HC7/HDV 1080i, Sony Corp, Japan) were used to capture the movement of the horses' forelimbs at a rate of 60 frames/sec. Additionally, raw data was collected from Kwon3D XP motion analysis package ver 4.0 program (Visol, Korea) with DARTFISH (DFKREA., Korea) video software solution. The variables analyzed consisted of 1 step lengths, 1 stride lengths, stance time, swing time, 1 stride time, velocity while walking, and trot of the horses. A two-way ANOVA and paired t-test of the variables by velocity and phase were treated at .05 level of significant difference, statistically. Results : The time elapsed of walk(stance: 0.63 sec[63.86%], swing: 0.35 sec[36.14%], 1 stride time: 0.99 sec respectively) showed significant difference with more delay than that of trot(stance: 0.29 sec[45.73%], swing: 0.34 sec[54.27% ], 1 stride time: 0.63 sec respectively), and also showed significant difference at trot in interaction (stance time>tort swing>walk swing>walk stance). The 1 step lengths and stride lengths in trot showed significant difference with longer than that of walk. Velocity of Trot showed significant difference statistically with higher than that of walk Conclusion : The horses' velocity during 1 step lengths and 1 stride lengths showed a proportional relationship, but the correlation between the horses' velocity and stance time showed a negative relationship during the quadruped cadence.

• 한국운동역학회지
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• 제27권1호
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• pp.75-81
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• 2017

Objective: The purpose of this study was to compare and analyze the kinematic variables and electromyography (EMG) findings that change with varying characteristics of crouch start and feedback provision, and to provide the fundamental data for record improvement in 400 mH. Method: Four short-distance runners participated in the experiment. The analyzed variables were elapsed time per interval, stride length, and muscle activities in three lower limb muscles. These variables were analyzed by using Kwon3d XP and Noraxon Myoresearch. The participants were subjected to three conditions, including two conditions that relate to the thrusting foot on the rear block and another condition pertinent to feedback provision. Results: In terms of a one-step interval, the elapsed time in condition A was longer than that in condition B, and the one after the feedback was the longest. The stride length of a one-step interval was the longest in condition A. The stride length of a two-step interval was the shortest in condition A. The muscle activity during a one-step interval showed differences in vastus medialis and medial gastrocnemius, with condition A being the highest. Conclusion: When the non-dominant left foot was located at the back, negative results were observed in terms of elapsed time and stride length. Moreover, an imbalance in muscle activity was observed between the left and right feet when the left foot was placed at the back. As a result, significant differences in elapsed time, stride length, and muscle activity were observed depending on the foot placed on the rear block. In conclusion, we identified the characteristics of crouch start in 400 mH, and a specialized program must be suggested.

• Physical Therapy Rehabilitation Science
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• 제12권2호
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• pp.155-160
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• 2023

Objective: The purpose of this study is to confirm a comparison of bag weight and applied location change on plantar pressure and gait parameters (stride time, stride length, cadence) of the 20s students. Design: One group cross-sectional design Methods: The subjects were measured in each condition. Each condition was no carrying a bag, carrying a 3kg bag, and a 6kg bag on the right shoulder, and walked on the gait analyzer. After the location of the bag was changed, measured when a 3kg backpack and a 6kg backpack was each carried on the back while walking. Results: There was a statistically significant difference in plantar pressure according to bag weight when carried on the right shoulder (p<0.05). As a result of the post-hoc analysis, carrying a 6kg bag was a significant difference between no carrying a bag and carrying a 3kg bag (p<0.05). There was no statistically significant difference in changes in stride time, stride length, and cadence. There was no statistically significant difference in plantar pressure and gait parameters according to backpack weight. Conclusions: As a result of this study, it is thought that it will be possible to present a method for the application of the correct bag on location and weight in 20s students, and to prevent and reduce muscle musculoskeletal system diseases caused by incorrect bag wearing.

• 대한원격탐사학회지
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• 제39권3호
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• pp.269-282
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• 2023

본 연구는 딥러닝 모델(deep learning model)을 활용하여 토지피복분류를 수행하였으며 입력 이미지의 크기, Stride 적용 등 데이터세트(dataset)의 조절을 통해 토지피복분류를 위한 최적의 딥러닝 모델 선정을 목적으로 하였다. 적용한 딥러닝 모델은 3종류로 Encoder-Decoder 구조를 가진 U-net과 DeeplabV3+, 두 가지 모델을 결합한 앙상블(Ensemble) 모델을 활용하였다. 데이터세트는 RapidEye 위성영상을 입력영상으로, 라벨(label) 이미지는 Intergovernmental Panel on Climate Change 토지이용의 6가지 범주에 따라 구축한 Raster 이미지를 참값으로 활용하였다. 딥러닝 모델의 정확도 향상을 위해 데이터세트의 질적 향상 문제에 대해 주목하였으며 딥러닝 모델(U-net, DeeplabV3+, Ensemble), 입력 이미지 크기(64 × 64 pixel, 256 × 256 pixel), Stride 적용(50%, 100%) 조합을 통해 12가지 토지피복도를 구축하였다. 라벨 이미지와 딥러닝 모델 기반의 토지피복도의 정합성 평가결과, U-net과 DeeplabV3+ 모델의 전체 정확도는 각각 최대 약 87.9%와 89.8%, kappa 계수는 모두 약 72% 이상으로 높은 정확도를 보였으며, 64 × 64 pixel 크기의 데이터세트를 활용한 U-net 모델의 정확도가 가장 높았다. 또한 딥러닝 모델에 앙상블 및 Stride를 적용한 결과, 최대 약 3% 정확도가 상승하였으며 Semantic Segmentation 기반 딥러닝 모델의 단점인 경계간의 불일치가 개선됨을 확인하였다.

• 대한통합의학회지
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• 제10권3호
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• pp.119-129
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• 2022

Purpose : The purpose of the study was to find out the effects of obstacle walking training according on gait and balance in stroke patients. Methods : Twenty-four stroke patients are randomly assigned to experimental group 1 (n=8), experimental group 2 (n=8) and control group (n=8). Experimental group 1 performed unexpected obstacle walking training, experimental group 2 performed fixed obstacle walking training and control group performed non obstacle walking training for 12 minutes per session, 5 times a week for 4 weeks. The gait analyzer G-walk were evaluated using gait cadence, gait velocity, and stride length, balance was evaluated using FES-K and BBS. Results : In within-group comparison of gait cadence, gait velocity and stride length of change, the experimental 1,2 groups showed significant improvements post intervention (p<.05) but control group showed no significant improvement. In between-groups comparison there was significant difference in the change of gait cadence, gait velocity and stride length pre and post intervention. In within-group comparison of FES-K and BBS scores, the experimental 1,2 groups showed significant improvements post intervention (p<.05) but control group showed no significant improvement. In between-groups comparison there was significant difference in the change of FES-K and BBS scores pre and post intervention (p<.05). Conclusion : Obstacle walking training can improve the gait, function and balance of stroke patients and obstacle walking training is effective for improving gait and balance compared to non-obstacle walking training.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2022년도 추계학술대회
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• pp.285-288
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• 2022

장애물보행훈련이 뇌졸중 환자의 보행 및 균형에 미치는 효과를 확인하고자 장애물보행과 평지보행훈련 후 변화를 보기 위해 보행과 균형을 평가하였다. 훈련 전후 보행과 균형에서 장애물보행훈련을 한 실험군이 유의미한 차이를 보였고 평지보행을 한 대조군은 유의미한 차이를 보이지 않았으며 두 군간에는 유의미한 차이를 보였다.

• 대한물리의학회지
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• 제10권3호
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• pp.73-79
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• 2015

PURPOSE: This study aims to examine the impact of the location of a walker-aid pocket that is attached to the walker while walking. METHODS: The research subjects included 10 male adults and 10 elderly people. The subjects used a two-wheeled walker for the walking analysis, and a firm velcro-type pocket that can be attached to the walker aid was used for weight loading. The size of the external loads was set at 2kg, which corresponds to approximately 2.5% of the mean body weight of the subjects. The pocket was attached to the left, center, and right sides of the walker aid. Stride length, stride, step width, and time were investigated according to the location change. RESULTS: No statistical differences were observed in all the walking factors among the adults and elderly people regardless of the changes in the location of the walker pocket. In cases of no weight and the 2kg walker pocket, stride length and strides were longer for the adults, while the step width was greater and walking time was longer for the elderly people. CONCLUSION: The weight of the walker pocket turn out to retard walking speed, although the location of the walker pocket is not affect walking with the walker-aid.

• PNF and Movement
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• 제7권1호
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• pp.1-8
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• 2009

Purpose : The aim of this study was to determine the effect of Proprioceptive Neuromuscular Facilitation (PNF) on gait ability in hemiplegic patients. Method : The subjects of this study were 11 hemiplegic patients. Each subject was taken PNF exercise with 3 times per week for 4 weeks. Pre- and post-intervention change in gait ability were measured using an 6m walking test, stride length, and step length. The data were analyzed using the paired t-test. Results : The results of this study showed significantly improvement in 6m walking test, stride length, and step length after intervention. Conclusion : These results suggest that the PNF coordination exercise is an effective way of improving gait ability for hemiplegic patients.