• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 추계학술대회 논문집
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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.

• 제어로봇시스템학회논문지
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• 제8권6호
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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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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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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.

• 한국공작기계학회논문집
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• 제17권2호
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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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• 한국방재학회 2008년도 정기총회 및 학술발표대회
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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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• 제1권1호
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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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• 제56권4호
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• pp.575-584
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• 2017

이 연구에서는 비만중년여성을 대상으로 저강도 저항운동의 속도 차이가 신체조성, 근활성도 및 근력에 미치는 영향을 검토하는데 그 목적이 있다. 연구대상은 비만중년여성 24명을 일반속도의 저항운동집단(normal resistance training speed group; NSG, n=12) 및 느린속도의 저항운동집단(slow speed resistance training group; SSG, n=12)으로 무작위 분류하였다. NSG는 신장성 수축 1초, 등척성 수축 1초 및 단축성 수축 1초의 총 3초간으로 구성하여 35회 3세트를 실시하였으며, SSG는 신장성 수축 3초, 등척성 수축 1초 및 단축성 수축 3초의 총 7초간으로 구성하여 15회 3세트를 실시하였다. 1RM 30%의 저강도 저항운동은 두 집단 모두 동일하게 세트 당 105초, 세트 간 1분 및 운동 간 3분의 휴식시간, 그리고 주 2~3회의 4주간에 걸쳐서 실시하였다. 신체조성, 근활성도 및 근력은 운동전과 운동 4주후에 각각 동일한 방법으로 측정하였다. 신체조성에서 NSG는 WHR에서, SSG는 체지방률에서 운동 전과 비교하여 운동 후에 각각 유의하게 감소하였다(p<.05). 근활성도에서 NSG 및 SSG는 위팔두갈래근, 안쪽넓은근 및 가쪽넓은근에서 운동 전과 비교하여 운동 후에 각각 유의하게 감소하였다(p<.01, p<.05). 근력에서 NSG 및 SSG는 biceps curl 및 leg extension에서 운동 전과 비교하여 운동 후에 각각 유의하게 증가하였다(p<.01). 하지만 신체조성, 근활성도 및 근력은 집단 간의 비교에서 통계학적으로 유의한 차이가 나타나지 않았다. 따라서 이 연구에서 신체조성, 근활성도 및 근력은 저항운동의 속도차이(반복횟수)보다는 저항운동의 수행시간(근수축 발생시간)과 밀접한 관련성이 있을 가능성이 시사되었다.

• 한국엔터테인먼트산업학회논문지
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• 제13권8호
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• pp.435-446
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• 2019

본 논문은 노인요양시설에서 생활하는 고령자를 대상으로 12주간 실시한 근력운동 프로그램(주 3회, 회당 60분)이 노인들의 건강관련 체력 및 대사증후군 요인에 미치는 영향을 살펴보기 위하여 실시되었다. 총 27명의 대상자(운동군 15명, 대조군 12명)가 참여하였으며 연구의 결과는 다음과 같다. 12주간의 근력운동 프로그램은 노인의 건강관련 체력요인을 유의하게 증가시켰으며, 특히 근력 및 평형성, 그리고 유연성의 증가가 보행능력을 크게 향상시켜 낙상을 예방하는데 도움이 될 수 있을 것으로 생각된다. 그리고 노인요양시설에서 근력운동이 노인들의 혈압과 혈당을 유의하게 감소시켜 대사증후군의 위험인자를 긍정적으로 개선시킴으로써 건강수준을 증가시키는 것으로 나타났다.

• Asian-Australasian Journal of Animal Sciences
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• 제11권5호
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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.

• 제어로봇시스템학회논문지
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• 제21권6호
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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.