• 한국체육학회지인문사회과학편
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• v.51 no.4
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• pp.419-425
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• 2012

The purpose of the study was to investigate the effects of knee brace on anterior cruciate ligament injuries risk factors during one-legged landing of female gymnasts. Eleven female gymnasts were recruited and performed randomly one-legged drop landing in height of her's knee with (3times) and without (3times) knee brace. Kinematics and ground reaction data were collected to estimate the anterior cruciate ligament injuries risk factors. Data were analyzed with paired samples t-test. Female gymnasts with knee brace showed more reduced the distance from ankle joint center to knee joint center in sagittal plane and knee maximum joint torque than without knee brace. In conclusion, Female gymnasts with knee brace reduced anterior cruciate ligament stress.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2003.05a
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• pp.309-312
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• 2003

Though a legged robot has high terrain adaptability as compared with a wheeled vehicle, its moving speed is considerably low in general. For attaining a high moving speed with a legged robot, a dynamically stable walking, such as running for a biped robot and a trot gait or a bound gait for a quadruped robot, is a promising solution. However, energy efficiency of a dynamically stable walking is generally lower than the efficiency of a stable gait such as a crawl gait. In this paper, we present an experimental study on the energy efficiency of a quadruped walking vehicle. Energy consumption of two walking patterns for a trot gait is investigated though experiments using a TITAN-VIII.

• The Journal of Korean Physical Therapy
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• v.6 no.1
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• pp.75-84
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• 1994

This study was carried out to know correlation between age and balance performance. factors to effect on balance and prepare the basic data in balance performance evaluation clinically. 180 adults without neurosurgical and orthopedic disability from 20 to 79 years of age participated in this study voluntarily. The subjects performed One Legged Stance Test in five conditions 1) eye open 2) eye close 3) eye open & ear close 4) eye & ear close 5) on sponge. The results of this study were as follows : 1. The mean balance performance time by one legged stance test was 25.97 seconds in eye open, 10.45 seconds in eye close, 23.14 seconds in eye open & ear close, 10.18 seconds in eye & ear close and 23.15 seconds in on sponge. 2. The balance performance declined according to age increasing. 3. The visual factor effected on balance performance greatly. 4. The auditory factor effected less than visual factor on balance performance 5. The compliant surface effected on balance performance in over-fifty age group greatly.

• The Journal of Korea Robotics Society
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• v.14 no.4
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• pp.270-277
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• 2019

Inspired by small insects, which perform rapid and stable locomotion based on body softness and tripod gait, various milli-scale six-legged crawling robots were developed to move rapidly in harsh environment. In particular, cockroach's leg compliance was resembled to enhance the locomotion performance of the crawling robots. In this paper, we investigated the effects of changing leg compliance for the locomotion performance of the small light weight legged crawling robot under various payload condition. First, we developed robust milli-scale six-leg crawling robot which actuated by one motor and fabricated in SCM method with light and soft material. Using this robot platform, we measured the running velocity of the robot depending on the leg stiffness and payload. In result, there was optimal range of the leg stiffness enhancing the locomotion ability at each payload condition in the experiment. It suggests that the performance of the crawling robot can be improved by adjusting stiffness of the legs in given payload condition.

• Journal of the Korean Institute of Intelligent Systems
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• v.26 no.3
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• pp.169-175
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• 2016

There are many researches to develop robots that improve its mobility and task planning to adapt in various uneven environments. In this paper, we propose the design method and task planning of quadruped robot which can have top-bottom docking structure. The proposed quadruped robot is designed to adjust leg length using linear actuators and perform top-bottom docking and undocking using octagonal cone shaped docking module. Also, to stable walking and information gathering in the various environments, a geomagnetic sensor, PSD sensor, LRF sensor and camera. We propose an obstacle avoidance method and the topbottom docking algorithm of the two quadruped robots using linear actuator. The robot can overcome obstacles using adjusting leg length and activate the top-bottom docking function. The top-bottom docking robots of two quadruped robot can walk 4 legged walking and 6 legged walking, and use 4 arms or 2 arms the upper. We verified that the docking robots can carry objects using 4 leg of the upper robot.

• Journal of Korean Society of Transportation
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• v.19 no.6
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• pp.207-218
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• 2001

As a city and industries are developed rapidly, a traffic accident and congestion take places on the road link become serious and it can be a large problem of the society in the future. Especially, most of the traffic accidents on the signalized intersection are caused by the human factor, vehicle and environmental factor mutually. The relation of the traffic accident and volume is acting on the outbreak of the traffic accident and the mistake of driver altogether as a major cause. The purpose of this paper is to develop a model for the forecasting of the traffic accident and to use research data gained to predict many traffic accidents. The data of this study were used with real one of the 73 areas of the four-legged signalized intersection in Kwang-ju city from 1996 to 1998 for three years to develop a model for the forecasting of the traffic accident. The statistical methods used in this paper are the principal component, regression and correlation analysis. We studied accident models to find out useful data from the statistics method and applied the data to the different area of the Choun-La province for the verification of the model. So, the result of this paper showed a reasonable model for the forecasting or the traffic accident and possibility of the model for simulating on real case. Finally, This study would be made of a study continually for the safe design and plan for the four-legged signalized intersection.

• Journal of the Korea Institute of Military Science and Technology
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• v.12 no.4
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• pp.540-547
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• 2009

In the near future, military robots are likely to be substituted for military personnel in the field of battle. The power system of a legged robot is considerably more complex than the one used for a land vehicle because of the coordination and stability issues due to the large number of degree of freedom. In this paper, a servovalve-piston combination system for a straight-line motion of robot leg is modeled as three degree of freedom based on double inputs and single output transfer function. The output is the displacement of piston from neutral. The inputs are valve displacement from neutral and arbitrary load force in this system. LQR(Linear Quadratic Regulator) technique is applied in order to achieve robust stability and fast responses of the system. The Kalman filter loop, rejection of disturbance and noise, riccati equation, filter gain matrix, and frequency domain equality are analyzed and designed.

• Journal of the Korea Computer Graphics Society
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• v.4 no.2
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• pp.1-13
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• 1998

The most important goal of character animation is to efficiently control the motions of a character. Until now, many techniques have been proposed for human gait animation, and some techniques have been created to control the emotions in gaits such as "tired walking" and "brisk walking" by using parameter interpolation or motion data mapping. This paper proposes a human running model based on a one-legged hopper with a self-balancing mechanism. The proposed technique exploits genetic programming to optimize movement, and can be easily adopted to various character models. We extend the energy minimization technique to generate various motions in accordance with emotional specification.

• Asian-Australasian Journal of Animal Sciences
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• v.4 no.1
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• pp.31-40
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• 1991

Four pairs of draught oxen (two local and two Jersey crossbred) were studied when they ploughed dry land on local farms. Work done, distance traveled and body temperature of each ox were measured continuously over a 5 h working day. A different team worked each day, completing at least six days work each. Individual food intakes and digestibility of feed were measured when the animals were given rice straw and tree fodder, and housed and fed according to local husbandry practices. The Jersey crossbreds, particularly the longer legged type, had a higher rate of work than the local oxen in this study. They did significantly more work and covered a greater distance during the day. The absence of a hump in the crossbred oxen had no effect on the position of the yoke or the way the oxen pulled when ploughing. The longer legged type of Jersey crossbred tended to work more erratically than any of the other teams. A fast rate of work made the oxen more liable to heat stress. When fed according to local practices and given the same amount of feed as local oxen, Jersey crossbreds tended to do less well. During the ploughing months, the local oxen gained weight, while the crossbreds remained at the same or lost some weight. Although there were some disadvantages to keeping Jersey crossbreds for work, their favourable work output suggests that the introduction of the Jersey crossbred in the hills of Nepal is unlikely to be detrimental to the performance of the work oxen population.

• Journal of International Academy of Physical Therapy Research
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• v.9 no.3
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• pp.1521-1527
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• 2018

The original focus of this study was to investigate the immediate effects of lumbar rotational mobilization on the one-legged standing ability. Fifteen subjects (6 men and 9 women, mean age = 22.77 (SD = 1.21), mean height = 165.46cm (SD = 11.65), mean weight = 61.46kg (SD = 8.29) volunteers from healthy individuals were recruited and randomized to a lumbar rotational mobilization (LRM) group and a trunk rotational exercise (TRE) group. Mobilization (grade 3 or 4) was applied to the LRM group on the lumbar spine (L1 to L5) in a side-lying, and trunk twist exercise (left and right side) was applied the to the TRE group with lunge position. Center of pressure (COP) and the velocity of the center of pressure (VCOP) of each participant were measured as a balance ability through one leg standing position. Results are as follows. In within-group difference, the COP of the LRM group reduced during standing with the right foot, but the VCOP change of the LRM was not statistically significant. In between-groups difference, COP of TRE group was decreased compared with LRM group only during left leg standing in the eyes (p <.05). The results of this study suggest that LRM is more effective than TRE in improving balance ability.