• Proceedings of the Korean Society of Precision Engineering Conference
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• 2008.11a
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• pp.485-486
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• 2008

• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.117.5-117
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• 2002

. Mobility analysis for overconstrained mechanisms is not clearly explained. . Aims at mobility analysis of overconstrained mechanisms . Representative screws is employed as a tool . A method to identifying the representative screw is introduced . Mobility analysis for several overconstrained parallel mechanisms and mobile robots

• Journal of the Chungcheong Mathematical Society
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• v.23 no.4
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• pp.617-623
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• 2010

Let p be a hyperbolic periodic point of f, and let ${\Lambda}(p)$ be a closed set which containing p. In this paper, we show that $C^1$-generically, if $f{\mid}_{{\Lambda}(p)}$ has the $C^1$-stably asymptotic average shadowing property, then it admits a dominated splitting.

• Journal of the Korean Society of Physical Medicine
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• v.4 no.2
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• pp.93-100
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• 2009

Purpose：The purpose of this study was to examine the effects of self-controlled knowledge of result (KR) versus the yoked KR on learning of knee joint proprioception. Methods：Forty volunteer subjects (20 men and 20 women) were randomly assigned to each four groups: 1) self-controlled KR in open kinematic chain, 2) yoked KR in open kinematic chain, 3) self controlled KR in close kinematic chain, and 4) yoked KR in close kinematic chain. The difference between the angle of position and reproduction angle was determined as a proprioception error and measured using an angle reproduction test. The subjects in self-controlled groups were provided with feedback whenever they requested it, whereas the subjects in yoked groups were not provided with feedback. The data were analyzed using a one-way ANOVA. Results：The proprioception errors in close kinematic chain groups decreased significantly compared with those in close kinematic chain groups(p<.05). The proprioception errors in the self-controlled group decreased significantly compared with those in yoked groups during acquisition and retention test(p<.05). Conclusion：Self-controlled knowledge of result during open kinematic chain movement is considered to be a good method on motor learning.

• Journal of Advanced Marine Engineering and Technology
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• v.20 no.1
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• pp.37-43
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• 1996

This paper presents a new control scheme for decoupling the dynamics of two coordinating robot manipulators. A simple full-state feedback scheme with configuration dependent gains can be devised to decouple the system dynamics such that the dynamics of each arm and that of an object held by the two arms is independent of one another. A condition for stability is shown. The advantage of the proposed scheme is that the same control scheme can be applied both for the closed kinematic chain(object-grasping) case and open kinematic chain(no object-grasping) case.

• Journal of Mechanical Science and Technology
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• v.18 no.4
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• pp.550-559
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• 2004

In this paper, a recursive formulation for generating the equations of motion of spatial mechanical systems is presented. The rigid bodies are replaced by a dynamically equivalent constrained system of particles which avoids introducing any rotational coordinates. For the open-chain system, the equations of motion are generated recursively along the serial chains using the concepts of linear and angular momenta Closed-chain systems are transformed to open-chain systems by cutting suitable kinematic joints and introducing cut-joint constraints. The formulation is used to carry out the dynamic analysis of multi-link five-point suspension. The results of the simulation demonstrate the generality and simplicity of the proposed dynamic formulation.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.08a
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• pp.56-56
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• 2010

Using first-principles density-functional theory calculations, we find dramatically different electronic states in the C chains generated on the H-terminated C(111) surface, depending on their length and parity. The infinitely long chain has $\pi$ electrons completely delocalized over the chain, yielding an equal C-C bond length. As the chain length becomes finite, such delocalized $\pi$ electrons are transformed into localized ones. As a result, even-numbered chains exhibit a strong charge-lattice coupling, leading to a bond-alternated structure, while odd-numbered chains show a ferrimagnetic spin ordering with a solitonlike structure. These geometric and electronic features of infinitely and finitely long chains are analogous to those of the closed (benzene) and open (polyacetylene) chains of hydrocarbons, respectively.

• Journal of Advanced Marine Engineering and Technology
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• v.32 no.2
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• pp.343-350
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• 2008

In this paper, a six degree-of-freedom robot arm which is very light but capable of delivering heavy loads was studied. The proposed robot arm has much higher load capacity than conventional robot arms actuated by motors with speed reducers such as the harmonic drive since a new type of robot actuator based on a closed chain mechanism driven by the ball screw was adopted. Analysis on the design scheme and on the mechanism of the joint actuator of the robot arm were made. Since the robot arm was designed very light, it has deflection in the links. To analyze this, a finite element analysis on the structure of the designed robot links was made using ANSYS software. Verifying experiments on the performance of high load capacity of the robot arm was performed by loading heavy weights on the robot arm. Through experiments. the correctness of the numerical analysis was also verified.

• Journal of Korean Orthopaedic Sports Medicine
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• v.2 no.1
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• pp.6-14
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• 2003

The goal of rehabilitation after ACL reconstruction are return the patient to a reinjury level of activity with stable joint, removing pivot shift phenomenon, preservation of meniscus, restoration of range of motion, and minimize patello-femoral complication. The ACL reconstruction should avoid immediate surgery. The preoperative phase emphasizes two important factors. (1) The patient should have a resolution of knee swelling, a return of full ROM, and a normal gait. (2) The patient should be mentally prepared for the operation and subsequent rehabilitation. The postoperative rehabilitation program emphasizes extension, closed kinetic chain function exercises. The regular follow-up is important.

• Journal of the Korean Institute of Intelligent Systems
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• v.22 no.1
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• pp.22-27
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• 2012

This paper presents a ball screw-driven robotic gripper mechanism which is possible to grasp an object and analyzes its kinematic feature for grasping by simulation. For the purpose of identifying the feature of the robot gripper, we try to confirm the kinematics relating the joint space of the driving actuator to the gripper's tip space. To be specific, the proposed robot gripper employs one actuator and a symmetrical closed-chain structure. As a result, the specified robot gripper has an advantage of robustness to external forces structurally, and it is easy to implement simple grasping operations. Also the gripper has a useful squeezing effect for power grasping.