• The Journal of Korea Robotics Society
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• v.9 no.1
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• pp.20-27
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• 2014

In this paper, an exact reshaping method for the motor dynamics of a flexible-joint robot is proposed using an integral manifold approach. Obtaining the exact model for both motor-side and link-side dynamics of a flexible-joint robot is difficult due to its under-actuated nature and complex dynamics. Despite the simple structure of the motor-side dynamics, they are difficult to model accurately for a flexible-joint robot due to motor disturbances, especially when speed reducers such as harmonic drives are installed. An integral manifold feedback control (IMFC) is proposed to reshape the motor dynamics. Based on the integral manifold approach, it is theoretically proved that the IMFC reshapes motor dynamics exactly even with bounded disturbances such as motor friction. The performance of the proposed IMFC is verified experimentally using a single degree-of-freedom flexible-joint robot under gravity conditions.

• Journal of Korean Orthopaedic Sports Medicine
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• v.3 no.1
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• pp.10-14
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• 2004

There is a large number of old athletes participating golf, and the shoulder, especially the nondominant or lead arm, appears to be at greatest risk for golf-related injury during extremes of motion. To reduce and prevent the risk of injury and improve the performance of golf, golfer should understand the biomechanics of the golf swing, increase flexibility, and perform stretching and strengthening exercises regularly .

• Proceedings of the Korea Institute of Convergence Signal Processing
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• 2003.06a
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• pp.183-187
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• 2003

When a flexible arm is rotated by a motor about an axis through the arm's fixed end, transverse vibration may occur. The motor torque should be controlled in such a way that the motor rotates by a specified angle, while simultaneously stabilizing vibration of the flexible arm so that it is arrested at the end of rotation. In this paper, we propose nonlinear observer for one-link flexible am. Then based on the error dynamic equation between the plant dynamic equation and the nonlinear observer dynamic equation of the flexible one-link am, Lyapunov candidate function is applied to achieve a stable deterministic nonlinear feedback controller for the regulation of joint angle.

• The Journal of Korea Robotics Society
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• v.14 no.4
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• pp.237-244
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• 2019

This paper suggests novel types of joint mechanisms composed of elastic strings and rigid bodies. All of the human hinge joints have the articular capsule and a pair of collateral ligaments. These fibrous tissues make the joint compliant and stable. The proposed mechanism closely imitates the human hinge joint structure by using the concept of tensegrity. The resultant mechanism has several characteristics shown commonly from both the tensegrity structure and the human joint such as compliance, stability, lightweight, and non-contact between rigid bodies. In addition, the role and feature of the human hinge joints vary according to the origins of a pair of collateral ligaments. Likewise, the locations of two strings corresponding to a pair of collateral ligaments produce different function and motion of the proposed mechanism. It would be one of the advantages obtained from the proposed mechanism. How to make a joint mechanism with different features is also suggested in this paper.

• The Journal of Korea Robotics Society
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• v.19 no.1
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• pp.1-7
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• 2024

This paper presents an under-actuated robotic hand inspired by the ligamentous structure of the human hand for a prosthetic application. The joint mechanisms are based on the concept of a tensegrity structure formed by elastic strings. These rigid bodies and elastic strings in the mechanism emulate the phalanx bones and primary ligaments found in human finger joints. As a result, the proposed hand inherently possesses compliant characteristics, ensuring robust adaptability during grasping and when interacting with physical environments. For the practical implementation of the tensegrity-based joint mechanism, we detail the installation of the strings and the routing of the driving tendon, which are related to extension and flexion, respectively. Additionally, we have designed the palm structure of the proposed hand to facilitate opposition and tripod grips between the fingers and thumb, taking into account the transverse arch of the human palm. In conclusion, we tested a prototype of the proposed hand to evaluate its motion and grasping capabilities.

• Journal of Korean Orthopaedic Sports Medicine
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• v.5 no.2
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• pp.129-134
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• 2006

Purpose: In the professional soccer team, we performed pre-seasonal physical examination and analyzed the results to establish a standardization data in relation to their position. Materials and Methods: We performed physical examination to the professional soccer team, consisted 34 player's average age 24.9 years. The examination performed were questionnaire on history, musculoskeletal examination, muscle power test, physiologic test, functional test. Results: According to the relationship between player position and injury pattern,. Knee injuries are most frequent on history. Physical examination outcome was that forward were prone to flexor hallucis longus tendinitis, midfielder for chronic ankle instability, defender for achilles tendinitis. Isokinetic test was done at dominant side, Peak torque to body weight ratio was 55.1%. Physiologic test checked body fat percentage was midfielder was superior as 19.8 (SD 2.9). Functional test out-come was that back strength 125 N. sergeant jump 59.6 cm, reaction time 208.5 sec, flexibility 19.2 m/s, side step 39.9 cm. Conclusion: Pre-seasonal physical examination gave us the standardization data and preventive measurement could be advocated from this results.

• Journal of muscle and joint health
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• v.6 no.2
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• pp.197-210
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• 1999

Muscle stiffness, pain and discomfort in dally activities are cardinal symtoms on arthritis. To reduce these symtoms, a nonequivalent one-group pre & posttest experiment was carried out at a rural community health post area in Chonbuk province during eight weeks (from 25th of January to 20th of March, 1999). The subjects were sixteen rural old women(65-89yrs) with osteoarthritis. And to reduce the level of pain, discomfort in daily living and to increase that of life satisfaction, 30 minutes of flexibility exercise followed by $15{\sim}20\;minutes$ of local heat therapy were done three times a week. Pain scale from Arthritis Impact Measurement Scales developed by Meenan(1980) for pain, Jette's Daily Activity Discomfort Scales revised by Lee(1988) for discomfort and Life Satisfaction Scales developed by Youn(1982) for life satisfaction were used as research instruments. The data were collected by face-to-face interviews with Investigator and the experiments were done under demonstration and supervision of investigator in community health post. The data were analyzed in percentage and Wilcoxon sign rank sum test by SPSS/PC+ program. The result could be summarized as follows ; 1. The scores of experiment group who were applied hot bag followed by flexibility exercise were tended to be significant lower in the level of pain statistically(Z=4.949, P=0.0001). 2. The scores of experiment group who was applied hot bag followed by flexibility exercise were tended to be significant lower in the level of discomfort in daily living statistically(Z=2.7226, P=0.0279). 3. The scores of experiment group who was applied hot bag followed by flexibility exercise were tended to be higher in the level of life satisfaction, but there was no significant statistical difference(Z=-1.2087, P=0.2171). In conclusion, flexibility exercise with local heat therapy could be identified as an effective therapy to reduce pain and discomfort in daily living of the rural elderly with osteoarthritis. And as a community health practitioner, the investigator concluded that this exercise with local heat therapy could be developed as a health promotion program for the rural aged people.

• Korean Journal of Applied Biomechanics
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• v.12 no.2
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• pp.91-107
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• 2002

This research got the following conclusion as result that analyzed high clear action kinematically to 4 C girls' junior high school badminton players who are situated in Chungchong-bukdo. 1. Most of the subject didn't rotate their right shoulder and elbow joint at back swing and moved speedy to shuttle cock. And an cooperation action of joint decreases displaying only a good action on both subject`s specification joint part. 2. When the subject S1 and S2 swing slowly and largely the joint of shoulder and elbow and then the speed of right wrist and racket head is fast, the cooperation action of joint is better than other subject. 3. An angle change of right shoulder showed angle that all subjects are great being caused in softness of joint and angular velocity was exposed that load enough Impact force and increase the speed of racket head as angular velocity decreases rapidly in Impact except subject S3. 4. All subjects of right elbow angle change showed similar form and was exposed that subject S2 sees form of impact stage serious bends from back swing and do not use force effectively in angular velocity. 5. Angle of right wrist appeared that the speed of shuttle cock is decelerated because fast bends of wrist is not formed shortly after Impact because all subject do not accomplish big angle shortly after back swing. Angular velocity can assume that the subject S1 and S4 are using and move fast strong snap shot offering angular velocity value of Impact stage sound (-). 6. While size of Impact stage knee angle accomplishes angle that is big both subject, hip joint angles sees small angle and is playing swing that do on upper body and arm without using strong waist force that is composition action with knee and hip joint.

• Journal of Dental Rehabilitation and Applied Science
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• v.33 no.1
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• pp.19-24
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• 2017

Recently, flexible denture is widely used with some advantages such as esthetics, flexibility and biocompatibility. However, there is an opposite opinion about stability because of the movement of denture by the material's flexibility. As the denture moves to tissue surface during mastication, it irritates the supporting tissue. It can lead to trauma and rapid resorption of residual ridges if this irritation lasts for a long time. In this case, the patient has used flexible denture with insufficient stability, retention and support for several years and thus continuous irritation of the supporting tissue resulted in palate bone exposure. The patient discomfort and palate bone exposure underwent improvements by the new denture with stability and retention. A careful case selection for flexible denture, regular checkup and proper treatment are necessary to prevent the side effects.

• Journal of the Korean Institute of Intelligent Systems
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• v.16 no.4
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• pp.485-492
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• 2006

This paper deals with implementation of network for distributed control system of a humanoid robot ISHURO(Inha Semyung Humanoid Robot). A humanoid robot needs much degree of freedom structurally and much data for having flexible movement. To realize such a humanoid robot, distributed control method is preferred to the centralized one since it gives a compactness, modularity and flexibility for the controllers. For organizing distributed control system of a humanoid robot, a control processor on a board is needed to individually control the joint motor and communication technology between the processors is required to transmit its information within control time. The processor is DSP-based processor and includes CAN network on a chip. It shares the computational load such as monitoring the sensor information and controlling the actuator between each of modules. In this paper, the communication architecture is suggested and its message protocol are discussed including message structure, time consumption for transmission, and controller structure at the view of distributed control for a humanoid robot. All of the sequence are simulated with Matlab and then verified with real walking experiment by ISHURO.