• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.764-767
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• 1997

This paper presents the modulation of the dexterity of a parallel manipulator using joint freezing/releasing and joint unactuation/actuation. In this paper, individual limbs have redundant number of joints, and each joint can be frozen/released and unactuated/actuated, as needed. First, given a task, the restrictions on joint freezing and joint unactuation of a parallel manipulator are derived. Next, with/without joint freezing and/or joint unactuation, the kinematics of a parallel manipulator is formulated, based on which the manipulability ellipsoid is defined. The effects of joint freezing and joint unactuation on the manipulability are analyzed and compared. Finally, simulation results for a planar parallel manipulator are given. Joint mechanisms, such as joint freezing and joint unactuation, are rather simple to adopt into a parallel manipulator, but is quite effective to improve the task adaptability of the system.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.20 no.1
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• pp.51-56
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• 2007

The K-joint is one of the commonly applied element in offshore structures. Due to its structural configuration, the stress concentration occurs in the joint. Considering the important effect to the structural safety and the design optimization, a design guideline is strongly required. The main variables determining the configuration of K-joint including ${\alpha},\;{\beta},\;{\gamma},\;{\tau}$ and ${\theta}$ are closely investigated to find the individual effect to the Stress to K-joint. The maximum Stress of joint has been differed as per the variation of parameters. The parametric study has been numerically carried out and compare with the experimental data.

• International Journal of Highway Engineering
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• v.16 no.3
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• pp.9-20
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• 2014

PURPOSES : This study is to compare load transfer efficiency of key joint and dowel joint for airport concrete pavement. METHODS : As AC150/5320-6D of FAA's [Advisory Circular] was changed into AC150/5320-6E, Key joint type of rigid pavement were excluded from Construction Joints. LTE(Load Transfer Efficiency) of dowel joint and key joint were compared by times and seasons through pavement temperature measurement, ocular investigation and HWD measurement. RESULTS : For the joint performance grade of No. 2(The second) runway of airport, 12% of poor rate was observed in key joint and 2% of poor rate in dowel joint. Poor rate of key joint was increased to 17%, if only No. 3~No. 6 slabs, which are mostly loaded from the airplanes, were applied for the study. In apron area, LTE poor rate of key joint was high in winter, and LTE poor rate of dowel joint was at least above 'Fair' grade. In summer, 'Fair' for key joint, 'Acceptable' for dowel joint appeared. CONCLUSIONS : As results, dowel joint was superior than key joint for LTE. Deviations of seasons and times were smaller in dowel joint's result. And LTE in winter was lower than LTE in summer.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2006.04a
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• pp.603-611
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• 2006

The fundamental joint configuration that is often applied in offshore structures is the K-joint. The paper describes a numerical parametric study for K-joint parameters (using the finite element program) and compared with results of the experimental test. The stress effects of various parameters including $\alpha,\;\beta,\;\gamma,\;\tau\;and\;\theta$ were investigated. The paper introduces the stress distributions as per each parameter. From the study, the maximum stress of joint became different according to the variation of joint parameters.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2018.10a
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• pp.174-175
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• 2018

This paper describes a metacarpophalangeal joint flexion and interphalangeal joint flexion of the thumb as one area of healthcare. Metacarpophalangeal joint flexion refers to bending the thumb metacarpophalangeal joint, and interphalangeal joint flexion refers to bending the thumb interphalangeal joint. When bending the joints, if the angle is below a certain angle, or if you feel pain, you have an abnormality. In addition, prevention and therapy of the thumb joint were also suggested.

• The Academic Congress of Korean Shoulder and Elbow Society
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• 2007.03a
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• pp.91-92
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• 2007

• 대한관절경학회:학술대회논문집
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• 2008.04a
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• pp.14-14
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• 2008

• 대한관절경학회:학술대회논문집
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• 2008.04a
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• pp.12-13
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• 2008

• 대한관절경학회:학술대회논문집
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• 2008.04a
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• pp.123-124
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• 2008

• 대한관절경학회:학술대회논문집
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• 2008.04a
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• pp.39-40
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• 2008