• Journal of the Korean Society for Precision Engineering
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• v.12 no.5
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• pp.117-125
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• 1995

An improved robust control law is proposed for uncertain rigid robots. The uncertainty is nonlinear and (possibly fast) time-varying. Therefore, the uncertain factors such as imperfect modeling, friction, payload change, and external disturbances are all addressed. Based on the possible bound of the uncertainty, the controller is constructed. For uncertain flexible-joint robots, some feedback control terms are then added to the proposed robust control law in order to stabilize the elastic vibrations at the joints. To show that the proposed control laws are indeed applicable, the stability study based on Lyapunov function, a singular perturbation approach, and simulation results are presented.

• Journal of the Korean Arthroscopy Society
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• v.5 no.2
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• pp.120-123
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• 2001

Purpose : We used transparent flexible tube which had provided the good visual field of median nerve when it was used in endoscopic release of transverse carpal ligament and evaluated the safety of that technique. Materials and Methods : We evaluated the 12 patients(20cases) who had been diagnosed as carpal tunnel syndrome and performed by endoscopic carpal tunnel release between Mar. 1997 and Mar. 2000. We used two portal technique and released the transverse carpal ligament with direct supervision of median nerve. Results : 14 cases$(70\%)$ were revealed excellent or good results and 6 cases$(30\%)$ were fair. No serious complications were shown such as nerve injury. Conclusion : We could avoid the complications of endoscopic carpal tunnel release using the transparent flexible tube which had provided tire good circumferential vision around the median nerve and it is unnecessary to maintain the wrist Joint hyperextension state during operation. Also that tube was easily obtainable in hospital so we need not to purchase the expensive operation apparatus.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.6
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• pp.1203-1211
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• 2017

This paper proposes a robust controller for flexible joint robots to achieve tracking performance and to improve robustness against both matched and mismatched disturbances. The proposed controller consists of a disturbance observer(DOB), passivity-based controller, and integral sliding mode controller(ISMC) in a backstepping manner. The DOB compensates the mismatched disturbance in the link-side and formulates the reference input for the motor-side controller. Interconnection and damping assignment passivity-based controller (IDA-PBC) performs tracking control of motor-side, and it is integrated to nominal control of ISMC to guarantee the over-all stability of the nominal system, while, matched disturbances are decoupled by the discontinuous control of ISMC. In the design of the link-side controller, PD type impedance controller is designed with DOB and this leads the continuous control input which is suitable to the reference input for the motor-side.

• Proceedings of the Korea Contents Association Conference
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• 2017.05a
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• pp.343-344
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• 2017

본 연구의 목적은 종아리 근육에 마사지를 적용하여 발목의 유연성과 균형에 미치는 영향을 알아보고자 실시하였다. 연구대상자는 건강한 대학생 32명으로 마사지 적용방법에 따라 세 그룹으로 나누어 한쪽 종아리에 각 5분간, 총 10분 동안 마사지를 적용하였다. 마사지 적용 전, 후로 발목의 유연성을 측정하기 위하여 Star excursion balance test를 실시하였다. 종아리 근육 마사지 중재 후에 두 그룹 모두 기능적 뻗기 검사와 변형된 한발 서기 검사에서 마사지전보다 유의하게 증가한 것으로 나타났다. 그러나 마사지 종류에 따른 차이는 나타나지 않았다. 마사지 종류에 관계없이 종아리 근육 마사지는 발목관절의 유연성과 균형능력에 효과가 나타났다. 따라서 종아리 마사지의 적용은 균형능력을 향상시키는 방법으로 보인다.

• Physical Therapy Korea
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• v.7 no.4
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• pp.8-15
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• 2000

이 연구의 목적은 노인들 중, 넘어지는 사람들(fallers)과 안 넘어지는 사람들(nonfallers)의 경부, 체간, 하지의 관절가동범위를 측정하여 비교하는 것이다. 본 연구대상은 남자 6명, 여자 22명, 나이 65세에서 88세의 노인으로 독립적으로 활동할 수 있는 사람들을 두 개의 집단으로 한 사람씩 면접을 통해 분류하였다. 대상자 선정 이전 일년 동안 한번 이상 넘어진 경험이 있는 사람들을 넘어진 사람들로 규정, 그리고 넘어진 경험이 없는 사람들을 안 넘어진 사람들로 정의하였다. 관절가동범위는 각도기로 측정하였고 미국 정형외과 학회(American Academy of Orthopaedic Surgeons)의 표준화된 가동 범위 측정방법을 사용하였다. 넘어진 사람들과 안 넘어진 사람들의 연구 결과의 차이를 알아보기 위하여 양측 독립성 t-검정을 사용했다. 연구결과, 넘어진 사람들과 안 넘어진 사람들간의 관절가동범위 중 흉요부의 굴곡, 신전, 우측굴곡, 좌측굴곡, 그리고 우측회전과 좌측회전, 고관절부의 신전, 내전, 외측회전과 내측회전, 그리고 족관절의 배굴에서 유의한 차이가 있었다. 이와 같은 결과는 체간, 고관절부 그리고 발목의 유연성이 노인들의 균형을 유지하는데 영향을 준다고 말할 수 있다.

• Journal of Korean Orthopaedic Sports Medicine
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• v.6 no.2
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• pp.77-82
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• 2007

The thrower's shoulders require a delicate balance between mobility and functional stability. First step to successful nonoperative management is an accurate diagnostic approach. Rehabilitation program follows a well-organized, multiphase approach with focus on controlling painful inflammation, restoring muscle balance, obtaining joint flexibility, improving proprioception and neuromuscular control, and effectively returning to competitive pitching. In this article, the typical musculoskeletal profile of the overhead thrower and various rehabilitation programs for specific injuries are discussed.

• Journal of the Korean Applied Science and Technology
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• v.38 no.5
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• pp.1345-1353
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• 2021

The purpose of this study was to investigate the effects of 6 weeks hip joint strengthen on muscle strength, dynamic posture control and low extremity injury criterion. Twenty athletics were divided into two groups, the exercise group was conducted for three times a week, 60 minutes, and six weeks. The dependent variables of this study were flexibility, muscular strength, dynamic posture control, and lower body injury criterion. The results of this study showed that the flexibility was not significant, but muscle strength was significant difference. The dynamic posture control was significantly effective in the left posterolateral and posteromedial. In addition, total score was significantly exercise effect, and there was no difference between left and right leg length. In conclusion, hip joint strengthen increased muscle strength and dynamic posture control, and decreased the concern of low extremity injury criterion.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.11
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• pp.3066-3074
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• 1994

This paper addresses the residual vibration problem of robots due to joint flexibility excited by fast accelerations, which has not been easily solved with conventional closed loop controllers. In this paper, an open loop input shaping technique, proposed by singer, has been applied to a 3 DOF robot with joint flexibility. In conjunction to the technique, a closed loop controller based on time-delay controller was also used. The results of simulations and experiments showed that the technique is quite effective for suppressing the residual vibration.

• Journal of the Korean Arthroscopy Society
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• v.12 no.1
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• pp.18-23
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• 2008

Purpose: The purpose of this study is to evaluate the clinical results of the function and stability of ACL reconstruction using the flexible reamer. Materials and Methods: We reviewed 98 patients who taken ACL reconstruction using the flexible reamer from March, 1999 to May, 2004. And the follow-up period was more than 12 months in all cases. We used the subjective tests including Lysholm knee score and 2000 International Knee Documentation Committee(IKDC) subjective knee score, and the objective tests such as anterior drawer test, Lachman test, pivot shift test, and KT-2000 arthrometer to evaluate the clinical results. Results: In the range of motion of the affected knee, the extension deficit more than 5 degree was 8 cases preoperatively and 1 case postoperatively. The flexion deficit more than 5 degree was 12 cases preoperatively and 2 cases postoperatively. The mean Lysholm knee score was 61.3 point(${\pm}3.5$ SD) preoperatively and 87.7 point(${\pm}2.0$ SD) postoperatively. The mean 2000 International Knee Documentation Committee(IKDC) subjective knee score was 49 point(${\pm}3.3$ SD) preoperatively and 84 point (${\pm}2.2$ SD) postoperatively. 93 cases were more than grade II in Lachman test preoperatively and 5 cases postoperatively. 71 cases were more than grade II in pivot shift test preoperatively but 89 cases were negative postoperatively. The mean maximal manual difference by KT-2000 arthrometer was 6.8 mm(${\pm}1.9$ SD) preoperatively and 1.8 mm(${\pm}0.8$ SD) postoperatively. Conclusion: ACL reconstruction using the flexible reamer achieved the ideal isometric point of femur and anatomic graft placement, so we could obtain good results, especially in rotational stability.

• Journal of Convergence for Information Technology
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• v.11 no.12
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• pp.265-274
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• 2021

The purpose of this study is to provide basic data for confirming the convergence relationship between flexibility exercise on quality of life, oral condition, and oral health-related behavior. Data from the 2012 KNHNES were used, and complex sample linear regression analysis and logistic regression analysis were performed to confirm the effects of flexibility exercise on quality of life and oral health. As a result, those who controlled for demographic characteristics and did not exercise flexibility had .027 times worse exercise ability among the subcategories of quality of life, and .152 times higher number of carious permanent teeth. Among the symptoms of temporomandibular joint disorder, pain symptoms were 1.633 times higher in those who exercised flexibility (p<.05). Therefore, it is considered that flexibility exercise has value in that it has suggested a relationship not only with general health but also with oral health.