• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.10a
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• pp.458-461
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• 1997

We have developed a human-sized BWR(biped walking robot) driven by a new actuator based on the ball screw which has high strength and high gar ratio. Each leg of the robot is composed of three pitch joints and one roll joint. In all, a 10 degree-of-freedom robot with two balancing joints was developed. For the purpose of autonomous walking and higher performance, we improved the previous developed BWR. We improved the motor drive efficiency, designed the ball screw actuator in a modular type, and simplified the electric wires. Through this modification, we achieved better performance in walking.

• Journal of Institute of Control, Robotics and Systems
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• v.8 no.6
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• pp.484-491
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• 2002

We developed a new type of human-sized BWR (biped walking robot) driven by a new actuator based on the ball screw which has high strength and high gear ratio. Each leg of the robot is composed of three pitch joints and one roll joint. In all, a 10 degree-of-freedom robot with two balancing joints was developed. A new type of actuator for the robot is proposed, which is composed of four bar link mechanism driven by the ball screw. The robot overcomes the limit of the driving torque of conventional BWRs. The BWR was designed to walk autonomously by adapting small DC motors for the robot actuators and has a space to board DC battery and controllers. In the performance test, the BWR performed sitting-up and down motion, and walking motion. Through the test, we found the possibility of a high performance biped-walking.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.267-267
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• 2000

We developed a human-sized BWR(biped walking robot) driven by a new actuator based on the ball screw which has high strength and high gear ratio. The robot overcomes the limit of the driving torque of conventional BWRs. Each leg of the robot is composed of three pitch joints and one roll joint. In all, a 10 degree-of-freedom robot with two balancing joints was developed. The BWR was developed to walk autonomously such that it is actuated by small torque motors and is boarded with DC battery and controllers. In the performance test, the BWR peformed nice motions of sitting-up and sitting-down. Through the test, we could find capability of high performance in biped-walking.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.17 no.2
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• pp.13-22
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• 2008

For the accuracy correction of the micro-positioning industrial robot, micro-manipulator has been devised. The compliant mechanisms using piezoelectric actuators is necessary geometrically and structurally to be developed by the optimization approaches. The overall geometric advantage as the mechanical efficiencies of the mechanism are considered as objective functions, which respectively art the ratio of output displacement to input force, and their constraints are the vertical notion of supporting leg and the structural strength of manipulation. In optimizing the compliant mechanical amplifier, the sequential linear programming and an optimality criteria method are used for the geometrical dimensions of compliant bridges and flexure hinges. This paper presents the integrated design process which not only can maximize the mechanism feasibilities but also can ensure the positioning accuracy and sufficient workspace. Experiment and simulation are presented for validating the design process through the comparisons of the kinematical and structural performances.

• 한국방재학회:학술대회논문집
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• 2008.02a
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• pp.283-286
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• 2008

There were two transmission tower collapses due to Typhoon 'Maemi' in 2003. The reason that a collapse was happened was excessive wind load. One was buckled in the leg part and the other was buckled in the middle bracing part. To investigate a steel transmission tower failure mechanism, 2nd order nonlinear analysis should be performed. Considering the effect of initial imperfection and theresidual stress of angle section during nonlinear analysis, this study can estimate the ultimate strength and the ultimate behavior of the transmission tower.

• Advances in biomechanics and applications
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• v.1 no.1
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• pp.57-66
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• 2014

The purpose of the study was to investigate the kinematics between the double collar-tie and double underhook Thai Boxing clinching positions. Ten amateur mixed martial arts athletes executed six knee strikes for both clinching positions with their dominant limb directed towards a target. A standard two-dimensional video motion analysis was conducted, and the results showed a statistical significant difference at the hip joint angle and the angular acceleration of the knee and ankle. Within both clinching positions, there was a statistically significant correlation between the hip and knee joint angles, hip and knee angular velocities, and hip angular acceleration. Between both clinching positions, there was a statistically significant correlation at the knee joint angle, knee angular velocity, and hip angular acceleration. This study demonstrates the importance of the hip and knee joint movements in both clinching positions, which implies the applications of strength training and flexibility at these joints for sports performance and injury prevention. It is suggested that future studies analyzing the non-dominant leg are warranted to fully understand the Thai Boxing clinch.

• 한국체육학회지인문사회과학편
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• v.56 no.4
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• pp.575-584
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• 2017

The purpose of this study was to examine the effects of low intensity resistance training speed on body composition, muscle activity and muscle strength in obese middle-aged women. The subjects (n = 12) were randomly assigned to normal resistance training speed group (NSG, n = 6) and slow resistance training speed group (SSG, n = 6). NSG was performed the for 3 sets ${\times}$ 35 times and total 3-s per repetition (eccentric: 1-s, isometric: 1-s, concentric: 1-s), and SSG performed for 3 sets ${\times}$ 15 times and total 7-s per repetition (eccentric: 3-s, isometric: 1-s, concentric: 3-s). Both groups performed the low intensity resistance training at 30% of 1-RM for 105-s per set, rest for 1 min between sets, rest for 3 min between exercises, and 2~3 times per week, for 4 weeks. The body composition, muscle activity and muscle strength were measured before and 4 week after resistance training. WHR at NSG and body fat at SSG were significantly decreased after resistance training compared with before (P<.05). Ｍuscle activity of biceps brachii, vastus medialis and vastus lateralis at both groups were significantly decreased after resistance training compared with before (P<.05, P<.01). Muscle strength of biceps curl and leg extension at both groups were significantly increased after resistance training compared with before (P<.01). However, body composition, muscle activity and muscle strength did not show statistically significant differences between the groups. Our results suggest that body composition, muscle activity and muscle strength should closely related to the performance time of resistance training (development time of muscle contraction), rather than resistance training speed (repetition frequency).

• Journal of Korea Entertainment Industry Association
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• v.13 no.8
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• pp.435-446
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• 2019

The purpose of this study was to investigate the effect of strength exercise program(60 minutes/day, 3 times/week) on health-related fitness and the factor of metabolic syndrome in the older at senior care facilities during 12 weeks. Twenty-seven volunteers were recruited for the study and divided into two groups: 15 persons(82.6yrs) undertook a continuous 12 weeks strength exercise program(EG), and 12 persons(78.9yrs) served as a control group(CG). The data process of this study calculated as mean(M) and standard Deviation(SD) of all measured value, used repeated measure ANOVA, and paired t-test. The significant level of hypothesis verification is set-up as α=.05. After 12 weeks in EG, health-related fitness increased by an average of 15.2% for right grip strength(p<.05), 26.9% for left grip strength(p<.05), 32.7% for chair stand(p<.05), 92.5% for one leg stand(p<.05), 29.6% for sit and reach(p<.05), and 34.5% for TUG(p<.05); CG showed no difference between pre and post. In the factor of metabolic syndrome, Systolic BP(3.1mmHg) and fasting blood glucose(7.4mg/dl) decreased in the EG group(p<.05). In summary, the strength exercise program leads to a genuine increase in health-related fitness and decrease in the factor of metabolic syndrome in the older adults. The well planned strength exercise seems to be an important intervention to improve function fitness in this population.

• Asian-Australasian Journal of Animal Sciences
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• v.11 no.5
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• pp.463-469
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• 1998

Factor analysis was applied as a multivariate statistical technique to official genetic evaluations of type classification traits for 1,265,785 Holstein cows and 10,321 sires computed from data collected between August 1982 and June 1994 in Canada. Type traits included eighteen linear descriptive traits and eight major score card traits. Principal components of the factor analysis showed that only five factors explain the information of the genetic value of linear descriptive traits for both cows and sires. Factor 1 included traits related to mammary system, like texture, median suspensory, fore attachment, fore teat placement and rear attachment height and width. Factor 2 described stature, size, chest width and pin width. These two factors had a similar pattern for both cows and sires. In constrast, Factor 3 for cows involved only bone-quality, while in addition for sires, Factor 3 included foot angle, rear legs desirability and legs set. Factor 4 for cows related to foot angle, set of rear leg and leg desirability, while Factor 4 related to loin strenth and pin setting for sires. Finally, Factor 5 included loin strength and pin setting for cows and described only pin setting for sires. Two factors only were required to describe score card traits of cows and sires. Factor 1 related to final score, feet and legs, udder traits, mammary system and dairy character, while frame/capacity and rump were described by Factor 2. Communality estimates which determine the proportion of variance of a type trait that is shared with other type traits via the common factor variant were high, the highest ${\geq}$ 80% for final score, stature, size and chest width. Pin width and pin desirability had the lowest communality, 56% and 37%. Results indicated shifts in emphasis over the twelve-year period away from udder traits and dairy character, and towards size, scale and width traits. A new system that computes fmal score from type components has been initiated.

• Journal of Institute of Control, Robotics and Systems
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• v.21 no.6
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• pp.503-509
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• 2015

In this paper, we designed and tested an ankle joint mechanism for a gait rehabilitation robot. Gait rehabilitation programs are designed to improve the natural leg motion of patients who have lost their walking capabilities by accident or disease. Strengthening the muscles of the lower-limbs and stimulation of the nervous system corresponding to walking helps patients to walk again using gait assistive devices. It is an obvious requirement that the rehabilitation system's motion should be similar to and as natural as the normal gait. However, the system being used for gait rehabilitation does not pay much attention to ankle joints, which play an important role in correct walking as the motion of the ankle should reflect the movement of the center of gravity (COG) of the body. Consequently, we have designed an ankle mechanism that ensures the safety of the patient as well as efficient gait training. Also, even patients with low leg muscle strength are able to operate the ankle joint due to the direct-drive mechanism without a reducer. This safety feature prevents any possible adverse load on the human ankle. The additional degree of freedom for the roll motion achieves a gait pattern which is similar to the normal gait and with a greater degree of comfort.